JP7814871B2 - PROTECTIVE FILM FORMING FILM, COMPOSITE SHEET FOR PROTECTIVE FILM FORMING, AND METHOD FOR MANUFACTURING WORK PRODUCED BY PROTECTIVE FILM - Google Patents

Description

The present invention relates to a protective film-forming film, a composite sheet for forming a protective film, and a method for manufacturing a workpiece with a protective film.

Some wafers, such as semiconductor wafers and insulator wafers, have circuits formed on one surface (circuit surface) and also have protruding electrodes such as bumps on that surface (circuit surface). Such wafers are divided into chips, and the protruding electrodes are connected to connection pads on a circuit board, thereby mounting the chips on the circuit board.
In such wafers and chips, the surface opposite the circuit surface (back surface) may be protected with a protective film to prevent damage such as cracks (see Patent Document 1).
Furthermore, in the manufacturing process of a semiconductor device, a semiconductor device panel, which will be described later, is used as a workpiece, and in order to prevent warping or cracks from occurring in this panel, some part of the panel may be protected with a protective film.

In such cases, a protective film-forming film for forming a protective film is applied to the desired location on the workpiece, such as the backside of a wafer. The workpiece is then processed to produce a workpiece. The protective film-forming film is cured as needed, and the protective film-forming film or protective film is cut to produce a protective film-equipped workpiece comprising the workpiece and a protective film provided somewhere on the workpiece. One example of a protective film-equipped workpiece is a semiconductor chip with a protective film, which comprises a semiconductor chip and a protective film provided on its backside.

International Publication No. 2014/148642

In light-emitting devices equipped with a workpiece with a protective film, the protective film in the workpiece with a protective film can absorb light. In such cases, the amount of light output from the light-emitting device decreases, and the protective film can appear dark and shadowy in the light-emitting device, resulting in problems. However, the protective film disclosed in Patent Document 1 does not solve these problems.

The present invention aims to provide a protective film-forming film for forming a protective film in a workpiece having a workpiece and a protective film provided at some location on the workpiece, the protective film being capable of suppressing light absorption as the protective film and capable of forming a film that is easily visible under normal conditions, and a protective film-forming composite sheet including the protective film-forming film.

The present invention provides a protective film-forming film for forming a protective film anywhere on a workpiece obtained by processing a workpiece. When the protective film-forming film is curable, the cured product of the protective film-forming film has a reflectance of 20% or more for light in the entire wavelength range of 400 to 700 nm. When the protective film-forming film is non-curable, the protective film-forming film has a reflectance of 20% or more for light in the entire wavelength range of 400 to 700 nm.

When the protective film-forming film of the present invention is curable, the arithmetic mean height Sa of one or both sides of the cured product of the protective film-forming film may be 100 nm or less, and when the protective film-forming film of the present invention is non-curable, the arithmetic mean height Sa of one or both sides of the protective film-forming film may be 100 nm or less.
The protective film-forming film of the present invention may contain a white pigment.
When the protective film-forming film of the present invention is curable, the x value in the Yxy color system, calculated from the reflectance of light in a wavelength range of 380 to 780 nm, of a cured product of the protective film-forming film may be 0.26 to 0.34, and the y value in the Yxy color system may be 0.26 to 0.34. When the protective film-forming film of the present invention is non-curable, the x value in the Yxy color system, calculated from the reflectance of light in a wavelength range of 380 to 780 nm, of the protective film-forming film may be 0.26 to 0.34, and the y value in the Yxy color system may be 0.26 to 0.34.

When the protective film-forming film of the present invention is curable, the Y value in the Yxy color system calculated from the reflectance of light in a wavelength range of 380 to 780 nm of a cured product of the protective film-forming film may be 20 or more, and when the protective film-forming film of the present invention is non-curable, the Y value in the Yxy color system calculated from the reflectance of light in a wavelength range of 380 to 780 nm of the protective film-forming film may be 20 or more.
When the protective film-forming film of the present invention is curable, the maximum reflectance of the cured product of the protective film-forming film for light in the wavelength range of 400 to 700 nm may be 25% or more, and when the protective film-forming film of the present invention is non-curable, the maximum reflectance of the protective film-forming film for light in the wavelength range of 400 to 700 nm may be 25% or more.
In the protective film-forming film of the present invention, the workpiece may be a chip in a light-emitting device.

The present invention provides a composite sheet for forming a protective film, comprising a support sheet and a protective film-forming film provided on one side of the support sheet, wherein the protective film-forming film is the protective film-forming film of the present invention described above.

The present invention is a method for manufacturing a workpiece with a protective film, the workpiece with a protective film comprising a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, the protective film being formed from a protective film-forming film in the composite sheet for forming a protective film of the present invention described above, and when the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film after being attached to any location on the workpiece is the protective film, and the manufacturing method is The method for manufacturing a workpiece with a protective film includes: an attachment step of attaching the protective film-forming film in a forming composite sheet to a desired location on the workpiece to produce a first laminate in which the protective film-forming composite sheet is provided on the workpiece; a processing step of processing the workpiece to produce the workpiece after the attachment step; and a cutting step of cutting the protective film-forming film or protective film after the attachment step. If the protective film-forming film is curable, the method further includes a curing step of curing the protective film-forming film after the attachment step to form the protective film.

The present invention is a method for manufacturing a workpiece with a protective film, the workpiece with a protective film comprising a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, the protective film being formed from the protective film-forming film of the present invention described above, and when the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film after being attached to any location on the workpiece is the protective film, and the manufacturing method is The method for manufacturing a workpiece with a protective film includes: an attachment step of attaching a protective film-forming film to a desired location on the workpiece to create a second laminate in which the workpiece is provided with the protective film-forming film or protective film; a processing step of processing the workpiece to create the workpiece after the attachment step; and a cutting step of cutting the protective film-forming film or protective film after the attachment step. If the protective film-forming film is curable, the method further includes a curing step of curing the protective film-forming film to form the protective film after the attachment step.

The present invention provides a protective film-forming film for forming a protective film in a workpiece having a workpiece and a protective film provided at some location on the workpiece, the protective film being capable of suppressing light absorption and forming a film that is easily visible under normal conditions, and a protective film-forming composite sheet including the protective film-forming film.

1 is a cross-sectional view schematically illustrating an example of a protective film-forming film according to an embodiment of the present invention. 1 is a cross-sectional view schematically illustrating an example of a composite sheet for forming a protective film according to an embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing another example of a composite sheet for forming a protective film according to one embodiment of the present invention. FIG. 10 is a cross-sectional view schematically showing yet another example of a composite sheet for forming a protective film according to one embodiment of the present invention. FIG. 10 is a cross-sectional view schematically showing yet another example of a composite sheet for forming a protective film according to one embodiment of the present invention. 1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a workpiece with a protective film according to an embodiment of the present invention. 10A to 10C are cross-sectional views for schematically explaining another example of a method for manufacturing a workpiece with a protective film according to an embodiment of the present invention.

◇Protective film-forming film A protective film-forming film according to one embodiment of the present invention is a protective film-forming film for forming a protective film at any location on a workpiece obtained by processing a workpiece, and when the protective film-forming film is curable, the cured product of the protective film-forming film has a reflectance of 20% or more for light in the entire wavelength range of 400 to 700 nm, and when the protective film-forming film is non-curable, the protective film-forming film has a reflectance of 20% or more for light in the entire wavelength range of 400 to 700 nm.
The protective film-forming film of this embodiment can be laminated with a support sheet to form a composite sheet for forming a protective film, as will be described later, for example.

The protective film-forming film of this embodiment is a film used to provide a protective film at any location on a workpiece to protect the workpiece.
The protective film-forming film is soft and can be attached to a workpiece before it is processed into the processed product.

In this embodiment, examples of the workpiece include a semiconductor wafer, a semiconductor device panel, etc. A semiconductor device panel is handled in the manufacturing process of a semiconductor device, and a specific example thereof is a semiconductor device in which one or more electronic components are sealed with a sealing resin, and a plurality of such semiconductor devices are arranged in a plane within a circular, rectangular, or other shaped area.
In this specification, a processed workpiece is referred to as a “workpiece artifact.” For example, if the workpiece is a semiconductor wafer, an example of the workpiece artifact is a semiconductor chip.

The following description of this embodiment will take a wafer as an example of a workpiece and a chip as an example of a workpiece.

The protective film-forming film of the present embodiment may be curable or non-curable. That is, the protective film-forming film may function as a protective film by being cured, or may function as a protective film in an uncured state.
The curable protective film-forming film may be either thermosetting or energy ray-curable, or may have both thermosetting and energy ray-curable properties.

In this specification, "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum. Examples of energy rays include ultraviolet rays, radioactive rays, and electron beams. Ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet light source. Electron beams can be irradiated using those generated by an electron beam accelerator or the like.
In this specification, "energy ray curable" means a property of being cured by irradiation with energy rays, and "non-energy ray curable" means a property of not being cured even when irradiated with energy rays.
In this specification, "non-curable" means a property of not being cured by any means such as heating, irradiation with energy rays, etc. A non-curable protective film-forming film can be considered to be a protective film after being provided (formed) on a target object.

In this specification, the term "wafer" refers to a semiconductor wafer made of an elemental semiconductor such as silicon, germanium, or selenium, or a compound semiconductor such as GaAs, GaP, InP, CdTe, ZnSe, or SiC; or an insulating wafer made of an insulating material such as sapphire or glass.
A circuit is formed on one surface of each of these wafers, and in this specification, the surface of the wafer on which the circuit is formed is referred to as the "circuit side," and the surface of the wafer opposite the circuit side is referred to as the "back side."
The wafer is divided into chips by dicing or other means. In this specification, as with the wafer, the surface of the chip on which the circuit is formed is referred to as the "circuit side," and the surface of the chip opposite the circuit side is referred to as the "back side."
Both the circuit surface of the wafer and the circuit surface of the chip are provided with protruding electrodes such as bumps, pillars, etc. The protruding electrodes are preferably made of solder.

By using the protective film-forming film of this embodiment or a composite sheet for forming a protective film comprising the same, a chip with a protective film can be manufactured that comprises a chip and a protective film provided on the back surface of the chip.
Then, prior to manufacturing the chip with the protective film, the protective film-forming film can be used to manufacture a wafer with the protective film-forming film, which comprises a wafer and a protective film-forming film provided on the back surface of the wafer.

Furthermore, by using the chip with the protective film, a substrate device can be manufactured.
In this specification, the term "substrate device" refers to a device in which a chip with a protective film is flip-chip connected to connection pads on a circuit board at protruding electrodes on the circuit surface of the chip. For example, if a semiconductor wafer is used as the wafer, the substrate device may be a semiconductor device.

In the case where the protective film-forming film of the present embodiment is curable, when the reflectance of light in the entire wavelength range of 400 to 700 nm is measured for the cured product of the protective film-forming film, the reflectance of these lights is 20% or more. In other words, the minimum value of the reflectance of light in the wavelength range of 400 to 700 nm for the cured product of the protective film-forming film is 20% or more.
When the protective film-forming film of the present embodiment is non-curable, when the reflectance of the protective film-forming film is measured for light in the entire wavelength range of 400 to 700 nm, the reflectance of these lights is 20% or more. In other words, the minimum value of the reflectance of the protective film-forming film for light in the wavelength range of 400 to 700 nm is 20% or more.
In a protective film obtained using a protective film-forming film having such properties, absorption of visible light is suppressed. Therefore, for example, when a light-emitting device includes a workpiece with a protective film obtained using the protective film-forming film, a decrease in the amount of light output from the light-emitting device is suppressed, and the protective film is also suppressed from appearing dark like a shadow in the light-emitting device. Furthermore, a protective film obtained using a protective film-forming film having such properties is easily visible under normal conditions.

In other words, in this embodiment, the workpiece is preferably a chip in a light-emitting device, and may also be a semiconductor chip in a light-emitting device.

The light-emitting device may be any device equipped with a light-emitting element such as an LED (Light Emitting Diode), and its type is not particularly limited. Examples of the light-emitting device include a substrate device having a surface-mounted LED package equipped with a light-emitting element, a substrate device equipped with a mini LED element, and a substrate device equipped with a micro LED element.

In this specification, unless otherwise specified, the term "cured product of the protective film-forming film" refers to a cured product with a sufficiently high degree of curing, and is synonymous with the term "protective film."

Hereinafter, in this specification, the reflectance of light in the entire wavelength range of 400 to 700 nm of the cured product of the protective film-forming film when the protective film-forming film is curable, and the reflectance of light in the entire wavelength range of 400 to 700 nm of the protective film-forming film when the protective film-forming film is non-curable, may be collectively referred to simply as "reflectance of light (400 to 700 nm)."

The reflectance of light (400 to 700 nm) can be measured by the following method.
That is, for each of the protective film-forming film or a cured product thereof and a barium sulfate reference plate, the angle of incidence of incident light on these measurement objects is set to 8°, and an integrating sphere is used to measure the amount of total reflected light, which is a combination of specular reflected light (specular reflected light) and diffuse reflected light, in the wavelength range of 400 to 700 nm by the SCI (Specular Component Include) method. Then, the ratio of the measured value for the protective film-forming film or a cured product thereof to the measured value for the reference plate ([measured amount of total reflected light for the cured product of the protective film-forming film] / [measured amount of total reflected light for the reference plate] × 100, or [measured amount of total reflected light for the protective film-forming film] / [measured amount of total reflected light for the reference plate] × 100), i.e., the relative total light reflectance of the protective film-forming film or a cured product thereof, is determined, and this can be used as the reflectance of light (400 to 700 nm). The maximum and minimum values among these can be used as the maximum and minimum values of the reflectance of light (400 to 700 nm) described below.

The reflectance of light (400 to 700 nm) may be 20% or more, and may be, for example, 22% or more, 24% or more, or 26% or more.
The upper limit of the reflectance of light (400 to 700 nm) is not particularly limited. For example, a protective film-forming film having a reflectance of light (400 to 700 nm) of 55% or less can be more easily produced, and the reflectance of light (400 to 700 nm) may be, for example, 45% or less.
The reflectance of light (400 to 700 nm) may be, for example, any one of 20 to 55%, 22 to 55%, 24 to 55%, and 26 to 55%, or any one of 20 to 45%, 22 to 45%, 24 to 45%, and 26 to 45%.

When the protective film-forming film of the present embodiment is curable, the maximum reflectance of the cured product of the protective film-forming film for light in the wavelength range of 400 to 700 nm is preferably 25% or more.
When the protective film-forming film of the present embodiment is non-curable, the maximum value of the reflectance of the protective film for light in the wavelength range of 400 to 700 nm is preferably 25% or more.
In the protective film obtained using the protective film-forming film having such properties, the absorption of visible light is further suppressed. Therefore, for example, when a light-emitting device includes a workpiece with a protective film obtained using the protective film-forming film, the reduction in the amount of light output from the light-emitting device is further suppressed, the protective film is further suppressed from appearing dark like a shadow in the light-emitting device, and the protective film is more easily visible under normal conditions.

The maximum reflectance of light (400 to 700 nm) may be, for example, any one of 28% or more, 32% or more, and 36% or more.
The upper limit of the maximum reflectance of light (400 to 700 nm) is not particularly limited. For example, a protective film-forming film having a maximum reflectance of light (400 to 700 nm) of 60% or less can be more easily produced, and the maximum value may be, for example, 50% or less.
The maximum reflectance of light (400 to 700 nm) may be, for example, any one of 25 to 60%, 28 to 60%, 32 to 60%, and 36 to 60%, or any one of 25 to 50%, 28 to 50%, 32 to 50%, and 36 to 50%.

In the protective film-forming film, the reflectance and its maximum value of light (400 to 700 nm) can be adjusted, for example, by the components contained in the protective film-forming composition described below, particularly the type and content of the colorant (colorant (J) in the thermosetting protective film-forming composition (III), and the colorant in the energy ray-curable protective film-forming composition (IV) and the non-curable protective film-forming composition (V)). If the colorant is a pigment, it can also be adjusted by its particle size. For example, by using a colorant with high whiteness and increasing its content, the reflectance of light (400 to 700 nm) can be increased. For example, when the protective film-forming film contains a white pigment, such a protective film is suitable because its reflectance of light (400 to 700 nm) or its maximum value of light (400 to 700 nm) satisfies the above-mentioned conditions.

When the protective film-forming film of this embodiment is curable, it is preferable that the arithmetic mean height Sa of one or both surfaces of the cured product of the protective film-forming film is 100 nm or less, and it is particularly preferable that the arithmetic mean height Sa of the surface opposite to the surface to be attached to the workpiece (e.g., the surface on which laser printing is performed) is 100 nm or less.
When the protective film-forming film of this embodiment is non-curable, it is preferable that the arithmetic mean height Sa of one or both surfaces of the protective film-forming film is 100 nm or less, and it is particularly preferable that the arithmetic mean height Sa of the surface opposite to the surface to be attached to the workpiece (for example, the surface on which laser printing is performed) is 100 nm or less.
When the cured product of the curable protective film-forming film of this embodiment or the exposed surface of the non-curable protective film-forming film has such roughness characteristics, when laser printing is performed on the exposed surface of the cured product or the non-curable protective film-forming film (i.e., the protective film), the printing can be more easily visually recognized. The above Sa does not usually affect the reflectance of light (400 to 700 nm).

In this specification, the arithmetic mean height Sa of the surface may be simply referred to as "Sa".
In this specification, the arithmetic mean height Sa of the surface means a value measured in accordance with ISO 25178.

In order to further enhance the above-mentioned effects, the arithmetic mean height Sa of one surface or both surfaces of the cured product or non-curable protective film-forming film is preferably 85 nm or less, more preferably 70 nm or less, and even more preferably 65 nm or less.
There is no particular limitation on the lower limit of Sa. For example, a protective film-forming film having Sa of 30 nm or more can be more easily produced.
The Sa may be, for example, any one of 30 to 100 nm, 30 to 85 nm, 30 to 70 nm, and 30 to 65 nm.

The arithmetic mean height Sa of one or both surfaces of the cured product can be adjusted by adjusting the arithmetic mean height Sa of the corresponding surface of the curable protective film-forming film.
Regardless of whether the protective film is curable or non-curable, the arithmetic mean height Sa of one or both surfaces of the protective film-forming film can be adjusted by applying a protective film-forming composition described below to the surface to be formed of the protective film-forming film and drying it as necessary to adjust the surface condition of the surface to be formed of the protective film-forming film. Furthermore, when pressing the surface of a means for transferring the surface condition (hereinafter sometimes referred to as a "transfer means") against one or both surfaces of the formed protective film-forming film, Sa can also be adjusted by using a means with an adjusted surface condition as the transfer means or by adjusting the pressure with which the surface of the transfer means is pressed. Examples of the transfer means include the first release film described below. Sa can also be adjusted by adjusting the particle size of solid components such as fillers in the protective film-forming composition described below.

When the protective film-forming film of the present embodiment is curable, the x value in the Yxy color system calculated from the reflectance of light in the wavelength range of 380 to 780 nm of the cured product of the protective film-forming film is preferably 0.26 to 0.34, more preferably 0.28 to 0.33.
When the protective film-forming film of this embodiment is non-curable, the x value in the Yxy color system calculated from the reflectance of the protective film-forming film in the wavelength range of 380 to 780 nm is preferably 0.26 to 0.34, more preferably 0.28 to 0.33.
When the x value is in this range, the protective film obtained using the protective film-forming film further suppresses absorption of visible light. Therefore, for example, when a light-emitting device includes a workpiece with a protective film obtained using the protective film-forming film, a decrease in the amount of light output from the light-emitting device is further suppressed, and the protective film is also further suppressed from appearing dark like a shadow in the light-emitting device.
In this embodiment, the x value can be calculated using a standard light source, C light source (2° field of view).

When the protective film-forming film of the present embodiment is curable, the y value in the Yxy color system calculated from the reflectance of light in the wavelength range of 380 to 780 nm of the cured product of the protective film-forming film is preferably 0.26 to 0.34, more preferably 0.28 to 0.34.
When the protective film-forming film of this embodiment is non-curable, the y value in the Yxy color system calculated from the reflectance of the protective film-forming film in the wavelength range of 380 to 780 nm is preferably 0.26 to 0.34, more preferably 0.28 to 0.34.
The protective film-forming film of this embodiment, when the y value is in this range, exhibits the same effects as when the x value is limited as described above.
In this embodiment, the y value can be calculated using a standard light source, C light source (2° field of view).

When the protective film-forming film of this embodiment is curable, it is preferable that the cured product of the protective film-forming film satisfies both the above-mentioned conditions of the x value and the y value, and when the protective film-forming film of this embodiment is non-curable, it is preferable that the protective film-forming film satisfies both the above-mentioned conditions of the x value and the y value. In such a case, in the protective film obtained using the protective film-forming film of this embodiment, the absorption of visible light is suppressed, and for example, when a light-emitting device is provided with a workpiece with a protective film, the reduction in the amount of light output from the light-emitting device is suppressed, and the protective film is prevented from appearing dark like a shadow in the light-emitting device, which is a more excellent effect.
Examples of protective film-forming films that can achieve such superior effects include, when the protective film-forming film is curable, a film in which the x value in the Yxy color system, calculated from the reflectance of light in a wavelength range of 380 to 780 nm, of the cured product of the protective film-forming film is 0.26 to 0.34, and a y value in the Yxy color system is 0.26 to 0.34; and, when the protective film-forming film is non-curable, a film in which the x value in the Yxy color system, calculated from the reflectance of light in a wavelength range of 380 to 780 nm, of the protective film-forming film is 0.26 to 0.34, and a y value in the Yxy color system is 0.26 to 0.34. However, this is just one example of a protective film-forming film that can achieve the above-mentioned superior effects.

When the protective film-forming film of this embodiment is curable, the Y value in the Yxy color system calculated from the reflectance of light in the wavelength range of 380 to 780 nm of the cured product of the protective film-forming film is preferably 20 or more.
When the protective film-forming film of this embodiment is non-curable, it is preferable that the Y value in the Yxy color system calculated from the reflectance of the protective film-forming film in the wavelength range of 380 to 780 nm is 20 or more.
When the Y value is in this range, the protective film obtained using the protective film-forming film further suppresses the absorption of visible light. Therefore, for example, when a light-emitting device includes a workpiece with a protective film obtained using the protective film-forming film, the reduction in the amount of light output from the light-emitting device is further suppressed, and the protective film is also further suppressed from appearing dark like a shadow in the light-emitting device.
In this embodiment, the Y value can be calculated using a C light source (2° field of view), which is a standard light source.

Whether the protective film-forming film of the present embodiment is curable or non-curable, the Y value may be, for example, any one of 25 or more, 30 or more, and 35 or more.
Whether the protective film-forming film of the present embodiment is curable or non-curable, the upper limit of the Y value is not particularly limited. For example, a protective film-forming film having a Y value of 60 or less can be more easily produced, and the Y value may be, for example, 50 or less.
The Y value may be, for example, any one of 20 to 60, 25 to 60, 30 to 60, and 35 to 60, or any one of 20 to 50, 25 to 50, 30 to 50, and 35 to 50.

When the protective film-forming film of this embodiment is curable, it is more preferable that the cured product of the protective film-forming film satisfies all of the conditions of the above-mentioned x value, y value, and Y value, and when the protective film-forming film of this embodiment is non-curable, it is more preferable that the protective film-forming film satisfies all of the conditions of the above-mentioned x value, y value, and Y value. In such a case, the protective film obtained using the protective film-forming film suppresses absorption of visible light, and, for example, when a light-emitting device is provided with a workpiece with a protective film, a decrease in the amount of light output from the light-emitting device is suppressed, and a particularly excellent effect is achieved in that the protective film is prevented from appearing dark like a shadow in the light-emitting device.
Examples of protective film-forming films that can achieve such particularly excellent effects include, when the protective film-forming film is curable, a cured product of the protective film-forming film having an x value of 0.26 to 0.34 in the Yxy color system, calculated from the reflectance of light in a wavelength range of 380 to 780 nm, and a y value of 0.26 to 0.34 in the Yxy color system, and a Y value of 20 or more; and when the protective film-forming film is non-curable, a protective film-forming film having an x value of 0.26 to 0.34 in the Yxy color system, calculated from the reflectance of light in a wavelength range of 380 to 780 nm, and a y value of 0.26 to 0.34 in the Yxy color system, and a Y value of 20 or more. However, this is just one example of a protective film-forming film that can achieve the above-mentioned particularly excellent effects.

In the protective film-forming film, the x, y, and Y values in the Yxy color system can be adjusted, for example, by the components contained in the protective film-forming composition described below, particularly the type and content of the colorant (colorant (J) in the thermosetting protective film-forming composition (III), and the colorant in the energy ray-curable protective film-forming composition (IV) and the non-curable protective film-forming composition (V)). When the colorant is a pigment, they can also be adjusted by its particle size. For example, the Y value can be increased by using a colorant with high whiteness and increasing its content.

It is preferable that the color tone of at least both surfaces of the protective film-forming film of this embodiment is uniform, and the color tone of the entire protective film-forming film may be uniform. Such a protective film-forming film is advantageous in that the printing can be clearly confirmed visually in the final state of the protective film after laser printing. In addition, such a protective film-forming film is advantageous in that it is easy to manufacture and that the color tones of all protective film-coated chips produced from a single protective film-coated wafer are uniform.
Both surfaces of the protective film-forming film are, for example, the same as the first surface and second surface described below.

The phrase "both surfaces of the protective film-forming film have a single color tone" means that both surfaces of the protective film-forming film have a single color tone (the same color tone) throughout their entire area.
Furthermore, the phrase "the entire color tone of the protective film-forming film is uniform" means that not only the entire area on both sides of the protective film-forming film, but also the entire interior area has a single color tone (the color is the same).

The color tone of the protective film-forming film can be adjusted, for example, by the components contained in the protective film-forming composition described below, particularly the type and content of the colorant (colorant (J) in the thermosetting protective film-forming composition (III), and the colorant in the energy ray-curable protective film-forming composition (IV) and the non-curable protective film-forming composition (V)).

When the protective film-forming film is thermosetting, the cured product of the protective film-forming film, which defines the reflectance of the light (400 to 700 nm) and its maximum value, the Sa, the x value, the y value, and the Y value, is a thermosetting product, and is the protective film, which is a cured product obtained by heating the protective film-forming film at 140°C for 2 hours.
When the protective film-forming film is energy ray-curable, the cured product of the protective film-forming film, which defines the reflectance of the light (400 to 700 nm) and its maximum value, the Sa, the x value, the y value, and the Y value, is an energy ray-cured product, and is the protective film, which is a cured product obtained by irradiating the protective film-forming film with energy rays under conditions of an illuminance of 220 mW/cm ² and an energy ray light amount of 600 mJ/cm ² .

When a protective film is formed by thermally curing a protective film-forming film, unlike when the protective film is cured by irradiation with energy rays, the protective film-forming film is sufficiently cured by heating even if its thickness is large, so that a protective film with high protective ability can be formed. Furthermore, by using a conventional heating means such as a heating oven, a large number of protective film-forming films can be heated and thermally cured all at once.
When the protective film-forming film is cured by irradiation with energy rays to form a protective film, unlike when it is cured by heat, the composite sheet for forming a protective film described below does not need to have heat resistance, and a wide range of composite sheets for forming a protective film can be constructed. In addition, the composite sheet can be cured in a short time by irradiation with energy rays.
When the protective film-forming film is used as the protective film without being cured, the curing step can be omitted, and therefore a chip with a protective film can be manufactured by a simplified process.

The protective film-forming film is preferably thermosetting or energy ray-curable. A thermosetting or energy ray-curable protective film-forming film is not only well suited for application to wafers, but also forms a protective film with higher protective capabilities upon curing.

The protective film-forming film may consist of one layer (single layer), or may consist of two or more layers. When the protective film-forming film consists of multiple layers, these multiple layers may be the same or different, and there are no particular limitations on the combination of these multiple layers.

In this specification, not only in the case of a protective film-forming film, "multiple layers may be the same or different" means "all layers may be the same, all layers may be different, or only some layers may be the same," and further, "multiple layers are different" means "at least one of the constituent materials and thicknesses of each layer is different from each other."

If the protective film-forming film consists of two or more layers, there is a possibility that problems such as poor adhesion between the layers or warping of the protective film due to differences in the ease of stretching of the layers, causing the protective film to peel off from the back surface of the chip, etc., can occur. In order to prevent such problems, it is preferable that the protective film-forming film consists of one layer.
Furthermore, a protective film-forming film consisting of one layer is preferable in that it can be easily produced with high thickness uniformity and has a high degree of freedom in design.

The thickness of the protective film-forming film is preferably 1 to 100 μm, more preferably 3 to 80 μm, and particularly preferably 5 to 60 μm, and may be, for example, any one of 10 to 50 μm, 15 to 40 μm, 17 to 38 μm, and 20 to 30 μm. When the thickness of the protective film-forming film is equal to or greater than the lower limit, a protective film with higher protective ability can be formed. When the thickness of the protective film-forming film is equal to or less than the upper limit, excessive thickness of the protective film-coated chip can be avoided.
Here, "thickness of the protective film-forming film" means the thickness of the entire protective film-forming film, and for example, the thickness of a protective film-forming film consisting of multiple layers means the total thickness of all layers that make up the protective film-forming film.

<<Composition for forming a protective film>>
The protective film-forming film can be formed using a protective film-forming composition containing its constituent materials. For example, the protective film-forming film can be formed by applying the protective film-forming composition to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at room temperature in the protective film-forming composition is usually the same as the ratio of the contents of the components in the protective film-forming film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, i.e., an ordinary temperature, and examples thereof include a temperature of 18 to 28°C.

In the protective film-forming film, the ratio of the total content of one or more components contained in the protective film, which will be described later, to the total mass of the protective film-forming film is 100 mass % or less.
Similarly, in the composition for forming a protective film, the ratio of the total content of one or more components contained in the composition for forming a protective film, as described below, to the total mass of the composition for forming a protective film is 100 mass % or less.

A thermosetting protective film-forming film can be formed using a thermosetting protective film-forming composition, an energy ray-curable protective film-forming film can be formed using an energy ray-curable protective film-forming composition, and a non-curable protective film-forming film can be formed using a non-curable protective film-forming composition. In this specification, when a protective film-forming film has both thermosetting and energy ray-curable properties, and the contribution of the heat curing of the protective film to the formation of the protective film is greater than the contribution of the energy ray curing, the protective film-forming film is treated as being thermosetting. Conversely, when the contribution of the energy ray curing of the protective film to the formation of the protective film is greater than the contribution of the heat curing, the protective film-forming film is treated as being energy ray-curable.

The protective film-forming composition may be applied by any known method, including methods using various coaters such as an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Meyer bar coater, and kiss coater.

The drying conditions for the protective film-forming composition are not particularly limited. However, if the protective film-forming composition contains a solvent, as described below, it is preferable to heat-dry it. A protective film-forming composition containing a solvent is preferably heat-dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, a thermosetting protective film-forming composition is preferably heat-dried so as not to thermally cure the composition itself or the thermosetting protective film-forming film formed from this composition.

The following describes the thermosetting protective film-forming film, energy ray-curable protective film-forming film, and non-curable protective film-forming film in that order.

Thermosetting Protective Film-Forming Film The curing conditions when the thermosetting protective film-forming film is thermally cured to form a protective film are not particularly limited, as long as the degree of curing is such that the protective film can fully exhibit its functions, and may be selected appropriately depending on the type of thermosetting protective film-forming film.
For example, the heating temperature during thermal curing of the thermosetting protective film-forming film is preferably 100 to 200° C., more preferably 110 to 170° C., and particularly preferably 120 to 150° C. The heating time during thermal curing is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 3 hours.
The protective film formed by thermal curing is preferably cooled slowly to room temperature. The method of cooling is not particularly limited, and the protective film may be cooled naturally.

A protective film-forming film at room temperature is heated to a temperature above room temperature and then cooled to room temperature to produce a heated and cooled protective film-forming film.When the hardness of the heated and cooled protective film is compared with the hardness of the unheated protective film at the same temperature, if the heated and cooled protective film is harder, then the protective film-forming film is thermosetting.

A preferred thermosetting protective film-forming film is, for example, one containing a polymer component (A), a thermosetting component (B), and a colorant (J).
The polymer component (A) is a component that can be considered to be formed by a polymerization reaction of a polymerizable compound.
The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction when triggered by heat. In this specification, the term "polymerization reaction" also includes polycondensation reaction.

<Thermosetting protective film forming composition (III)>
A preferred example of a thermosetting protective film-forming composition is a thermosetting protective film-forming composition (III) (sometimes abbreviated herein as "composition (III)") containing the polymer component (A), the thermosetting component (B), and the colorant (J).

[Polymer component (A)]
The polymer component (A) is a component that imparts film-forming properties, flexibility, toughness, ductility, etc. to the thermosetting protective film-forming film, and that imparts flexibility, toughness, ductility, etc. to the protective film.
The polymer component (A) contained in the composition (III) and the thermosetting protective film-forming film may be one type only or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Examples of polymer component (A) include acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, etc., with acrylic resin being preferred. In this specification, the acrylic resin used as polymer component (A) may be referred to as "acrylic resin (A1)."

The weight average molecular weight (Mw) of the acrylic resin (A1) is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000. When the weight average molecular weight of the acrylic resin (A1) is at least the lower limit, the shape stability (stability over time during storage) of the thermosetting protective film-forming film is improved. When the weight average molecular weight of the acrylic resin (A1) is at most the upper limit, the thermosetting protective film-forming film can more easily conform to the uneven surface of the adherend, further suppressing the occurrence of voids, etc., between the adherend and the thermosetting protective film-forming film.

In this specification, unless otherwise specified, "weight average molecular weight" refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

The glass transition temperature (Tg) of the acrylic resin (A1) is preferably -60 to 70°C, more preferably -50 to 50°C, even more preferably -45 to 40°C, still more preferably -40 to 30°C, still more preferably -35 to 20°C, and particularly preferably -35 to 10°C. When the Tg of the acrylic resin (A1) is at least the lower limit, the adhesion between the cured product of the protective film-forming film and the support sheet is suppressed, and peelability is appropriately improved. When the Tg of the acrylic resin (A1) is at most the upper limit, the adhesive strength of the thermosetting protective film-forming film to the adherend and the adhesive strength of the protective film to the adherend are improved.

When acrylic resin (A1) has m types of structural units (m is an integer of 2 or greater), and the m types of monomers from which these structural units are derived are each assigned a unique number from 1 to m, successively designated "monomer m," the glass transition temperature (Tg) of acrylic resin (A1) can be calculated using the Fox formula shown below.

(In the formula, Tg is the glass transition temperature of the acrylic resin (A1); m is an integer of 2 or greater; _Tgk is the glass transition temperature of a homopolymer of monomer m; and _Wk is the mass fraction of structural unit m derived from monomer m in the acrylic resin (A1), with the proviso that _Wk satisfies the following formula.)

(In the formula, m and _Wk are the same as above.)

The Tg _k can be a value listed in the Polymer Data Handbook, Adhesive Handbook, Polymer Handbook, etc. For example, the Tg _k of a homopolymer of methyl acrylate is 10°C, the Tg _k of a homopolymer of methyl methacrylate is 105°C, the Tg k of a homopolymer of 2-hydroxyethyl acrylate is -15°C, the Tg _k of a homopolymer of n-butyl acrylate is -54°C, and the Tg _k of a homopolymer of glycidyl _methacrylate is 41°C.

Examples of the acrylic resin (A1) include polymers of one or more (meth)acrylic acid esters; copolymers of one or more (meth)acrylic acid esters with one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, etc.

Examples of the (meth)acrylic acid ester constituting the acrylic resin (A1) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure and has 1 to 18 carbon atoms, such as isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate);
(meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate;
(Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate;
(Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester;
(Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester;
(Meth)acrylic acid imide;
glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate;
hydroxyl group-containing (meth)acrylic acid esters such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate;
Examples include substituted amino group-containing (meth)acrylic acid esters such as N-methylaminoethyl (meth)acrylate. Here, the term "substituted amino group" refers to a group in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

The acrylic resin (A1) may contain only one type of monomer, or two or more types. If two or more types are used, the combination and ratio of these monomers can be selected arbitrarily.

The acrylic resin (A1) may have a functional group capable of bonding to other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxy group, or an isocyanate group. The functional group of the acrylic resin (A1) may bond to other compounds via the crosslinking agent (G) described below, or may bond directly to other compounds without the crosslinking agent (G). Bonding the acrylic resin (A1) to other compounds via the functional group tends to improve the adhesion reliability of the protective film to the adherend.

In the present invention, a thermoplastic resin other than the acrylic resin (A1) (hereinafter sometimes simply referred to as "thermoplastic resin") may be used as the polymer component (A) either alone without the acrylic resin (A1) or in combination with the acrylic resin (A1). The use of such a thermoplastic resin may improve the peelability of the protective film from the support sheet, or may make it easier for the thermosetting protective film-forming film to conform to the uneven surface of the adherend, thereby further suppressing the occurrence of voids, etc., between the adherend and the thermosetting protective film-forming film.

The weight-average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, and more preferably 3,000 to 80,000.

The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150°C, and more preferably -20 to 120°C.

Examples of the thermoplastic resin include urethane resin, phenoxy resin, silicone resin, saturated polyester resin, etc.

In composition (III), the ratio of the content of polymer component (A) to the total content of all components other than the solvent is preferably 5 to 80 mass%, more preferably 10 to 65 mass%, and may be, for example, any one of 15 to 50 mass% and 15 to 35 mass%, regardless of the type of polymer component (A).
This is equivalent to saying that the content ratio of the polymer component (A) in the thermosetting protective film-forming film relative to the total mass of the thermosetting protective film-forming film is preferably 5 to 80 mass%, more preferably 10 to 65 mass%, regardless of the type of polymer component (A), and may be, for example, either 15 to 50 mass% or 15 to 35 mass%.
This is based on the fact that in the process of removing the solvent from a solvent-containing resin composition to form a resin film, the amount of components other than the solvent usually does not change, and the content ratio of the components other than the solvent is the same between the resin composition and the resin film. Therefore, in this specification, not only in the case of the thermosetting protective film-forming film, but also in the case of the content of the components other than the solvent, only the content in the resin film obtained by removing the solvent from the resin composition will be described.

Polymer component (A) may also be considered a thermosetting component (B). In the present invention, when composition (III) contains components that fall under both polymer component (A) and thermosetting component (B), composition (III) is considered to contain polymer component (A) and thermosetting component (B).

[Thermosetting component (B)]
The thermosetting component (B) has thermosetting properties and is a component for curing the thermosetting protective film-forming film.
The thermosetting component (B) contained in the composition (III) and the thermosetting protective film-forming film may be one type only or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

Examples of the thermosetting component (B) include epoxy resins, thermosetting polyimide resins, and unsaturated polyester resins, with epoxy resins being preferred.
In this specification, the epoxy resin as the thermosetting component (B) may be referred to as "epoxy resin (B1)."
The thermosetting polyimide resin is a general term for a polyimide precursor and a thermosetting polyimide, which form a polyimide resin by thermal curing.

Epoxy resin (B1)
Examples of the epoxy resin (B1) include known epoxy resins, such as bifunctional or higher functional epoxy compounds, including polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxy resins, biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and phenylene skeleton-type epoxy resins.

The epoxy resin (B1) may be an epoxy resin having an unsaturated hydrocarbon group.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of the curability of the thermosetting protective film-forming film and the strength and heat resistance of the protective film that is the cured product thereof, it is preferably 300 to 30,000, more preferably 300 to 10,000, and particularly preferably 300 to 3,000.
The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1000 g/eq, more preferably 150 to 950 g/eq.

Epoxy resin (B1) may be used alone or in combination of two or more types. When two or more types are used in combination, the combination and ratio thereof can be selected arbitrarily.

[Thermal curing agent (C)]
When the thermosetting component (B) is an epoxy resin (B1), the composition (III) and the thermosetting protective film-forming film preferably contain a thermosetting agent (C).
The thermosetting agent (C) may be, for example, a compound having two or more functional groups capable of reacting with an epoxy group in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an anhydride group of an acid group. A phenolic hydroxyl group, an amino group, or an anhydride group of an acid group is preferred, and a phenolic hydroxyl group or an amino group is more preferred.

Among the heat curing agents (C), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins.
Among the heat curing agents (C), examples of amine-based curing agents having an amino group include dicyandiamide.

Thermal curing agent (C) may have an unsaturated hydrocarbon group.

Of the thermosetting agents (C), for example, the number average molecular weight of resin components such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000.
Of the thermosetting agent (C), the molecular weight of the non-resin component such as biphenol or dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

Thermal curing agents (C) may be used singly or in combination of two or more types. When two or more types are used in combination, the combination and ratio of these can be selected arbitrarily.

The content of the thermosetting agent (C) in the thermosetting protective film-forming film is preferably 0.1 to 500 parts by mass, more preferably 0.1 to 200 parts by mass, even more preferably 0.1 to 100 parts by mass, and particularly preferably 0.5 to 50 parts by mass, per 100 parts by mass of the thermosetting component (B). For example, it may be any of 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, and 0.5 to 5 parts by mass. When the content of the thermosetting agent (C) is at least the lower limit, curing of the thermosetting protective film-forming film proceeds more easily. When the content of the thermosetting agent (C) is at most the upper limit, the moisture absorption rate of the thermosetting protective film-forming film is reduced, further improving the adhesive reliability of the protective film to the adherend.

In the thermosetting protective film-forming film, the ratio of the total content of the thermosetting component (B) and the thermosetting agent (C) to the total mass of the thermosetting protective film-forming film is preferably 3 to 50 mass%, more preferably 5 to 35 mass%, even more preferably 7 to 25 mass%, and particularly preferably 9 to 20 mass%. When the ratio is within this range, the protective film's ability to protect chips and the like is further improved. Furthermore, the adhesive reliability of the protective film to the adherend is further improved. Furthermore, the adhesion force between the cured product of the protective film-forming film and the support sheet is suppressed, thereby appropriately improving peelability.

[Colorant (J)]
The colorant (J) is a component for adjusting the light reflectance of the thermosetting protective film-forming film and the protective film. A protective film containing the colorant (J) is more easily visible under normal conditions, and a protective film provided at any location on a workpiece is also more easily visible under normal conditions.

Examples of colorants (J) include organic dyes and inorganic pigments.

Examples of the organic dyes include diimonium dyes, aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squarium dyes, azulenium dyes, polymethine dyes, naphthoquinone dyes, pyrylium dyes, phthalocyanine dyes, naphthalocyanine dyes, naphtholactam dyes, azo dyes, condensed azo dyes, indigo dyes, perinone dyes, perylene dyes, dioxazine dyes, quinacridone dyes, isoindolinone dyes, quinophthalone dyes, pyrrole dyes, thioindigo dyes, metal complex dyes (metal complex dyes), dithiol metal complex dyes, indolephenol dyes, triarylmethane dyes, anthraquinone dyes, naphthol dyes, azomethine dyes, benzimidazolone dyes, spiron dyes, pyranthrone dyes, and threne dyes.

Examples of the inorganic pigment include carbon materials such as carbon black; lanthanum-based materials; tin-based materials; antimony-based materials; tungsten-based materials; and titanium-based materials. Here, lanthanum-based materials, tin-based materials, antimony-based materials, tungsten-based materials, and titanium-based materials refer to materials containing lanthanum, tin, antimony, tungsten, and titanium, respectively.

The colorant (J) contained in the composition (III) and the thermosetting protective film-forming film may be one type only, or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.
For example, the composition (III) and the thermosetting protective film-forming film may contain, as the colorant (J), one or more organic dyes alone, one or more inorganic pigments alone, or one or more organic dyes and one or more inorganic pigments together.

It is preferable that the colorant (J) is a white pigment, i.e., the thermosetting protective film-forming film contains a white pigment. A protective film obtained using such a thermosetting protective film-forming film (a protective film containing a white pigment) has a higher reflectance of light (400 to 700 nm), and this value can be easily adjusted to 20% or more. It is also easy to adjust the maximum reflectance of light (400 to 700 nm) to 25% or more. Furthermore, because a protective film containing a white pigment has such a higher reflectance of light (400 to 700 nm), when a light-emitting device is equipped with a workpiece with a protective film, it is highly effective in suppressing a decrease in the amount of light output from the light-emitting device, and is also highly effective in suppressing the protective film from appearing dark like a shadow in the light-emitting device. Furthermore, it also has a high effect of making the protective film easily visible under normal conditions.
Preferred examples of the white pigment include titanium oxide pigments (pigments containing titanium oxide).

The content of colorant (J) in composition (III) can be adjusted appropriately depending on, for example, the type of colorant (J).

For example, when the colorant (J) is a white pigment, the content ratio of the colorant (J) in the thermosetting protective film-forming film relative to the total mass of the thermosetting protective film-forming film is preferably 0.1 to 15 mass%, more preferably 0.3 to 12 mass%, and even more preferably 0.4 to 9 mass%, and may be, for example, 0.5 to 6 mass%. When the ratio is equal to or greater than the lower limit, the effect of using the colorant (J), i.e., the effect of suppressing light absorption in the protective film obtained using the protective film-forming film, is enhanced. When the ratio is equal to or less than the upper limit, excessive use of the colorant (J) is suppressed.

For example, when the colorant (J) is a component other than a white pigment, the content ratio of the colorant (J) in the thermosetting protective film-forming film relative to the total mass of the thermosetting protective film-forming film may be, for example, 0.1 to 15 mass%. When this ratio is equal to or greater than the lower limit, the effect of using the colorant (J) is more pronounced. When the ratio is equal to or less than the upper limit, excessive use of the colorant (J) is suppressed.

[Curing accelerator (D)]
The composition (III) and the thermosetting protective film-forming film may contain a curing accelerator (D). The curing accelerator (D) is a component for adjusting the curing rate of the composition (III).
Preferred curing accelerators (D) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines (phosphines in which one or more hydrogen atoms are substituted with organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

The curing accelerator (D) contained in the composition (III) and the thermosetting protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

When a curing accelerator (D) is used, the content of the curing accelerator (D) in the thermosetting protective film-forming film is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 7 parts by mass, per 100 parts by mass of the total content of the thermosetting component (B) and the thermosetting agent (C). When the content of the curing accelerator (D) is at or above the lower limit, the effects of using the curing accelerator (D) are more pronounced. When the content of the curing accelerator (D) is at or below the upper limit, for example, the highly polar curing accelerator (D) is more effectively inhibited from migrating and segregating to the adhesive interface with the adherend under high temperature and high humidity conditions in the thermosetting protective film-forming film. As a result, the adhesive reliability of the protective film to the adherend is further improved.

[Filler (E)]
The composition (III) and the thermosetting protective film-forming film may contain a filler (E). When the thermosetting protective film-forming film contains the filler (E), the thermal expansion coefficient of the thermosetting protective film-forming film and its cured product (i.e., the protective film) can be easily adjusted, and by optimizing this thermal expansion coefficient for the object on which the protective film is formed, the adhesive reliability of the protective film to the adherend can be further improved. Furthermore, when the thermosetting protective film-forming film contains the filler (E), the moisture absorption rate of the protective film can be reduced and the heat dissipation properties can be improved.

The filler (E) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler.
Preferred inorganic fillers include, for example, powders of silica, stainless steel, alumina, etc.; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers.
Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

The average particle size of the filler (E) is not particularly limited, but is preferably 10 to 4000 nm, more preferably 30 to 3500 nm, even more preferably 40 to 1000 nm, and particularly preferably 50 to 600 nm. When the average particle size of the filler (E) is in this range, the effect of using the filler (E) is more pronounced, and it becomes easier to adjust Sa within the above range.
In this specification, unless otherwise specified, the term "average particle size" refers to the particle size (D ₅₀ ) at an integrated value of 50% in a particle size distribution curve determined by a laser diffraction scattering method.

The filler (E) contained in the composition (III) and the thermosetting protective film-forming film may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

When filler (E) is used, the content of filler (E) in the thermosetting protective film-forming film relative to the total mass of the thermosetting protective film-forming film is preferably 20 to 75 mass%, more preferably 30 to 70 mass%, and may be, for example, either 40 to 67.5 mass% or 50 to 65 mass%. Having the ratio within this range makes it easier to adjust the thermal expansion coefficients of the thermosetting protective film-forming film and the protective film, and also makes it easier to adjust Sa within the above-mentioned range.

[Coupling agent (F)]
The composition (III) and the thermosetting protective film-forming film may contain a coupling agent (F). By using a coupling agent (F) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesive reliability of the protective film to the adherend can be improved.

The coupling agent (F) is preferably a compound having a functional group capable of reacting with the functional group of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.
Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples thereof include bis(3-(aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane.

Preferred examples of the silane coupling agent include oligomeric silane coupling agents having multiple alkoxysilyl groups in one molecule. The oligomeric silane coupling agent is preferred in that it is less likely to volatilize and has multiple alkoxysilyl groups in one molecule, which is effective in improving the durability of the protective film.
Examples of the oligomeric silane coupling agent include epoxy group-containing oligomeric silane coupling agents "X-41-1053,""X-41-1059A,""X-41-1056," and "X-40-2651" (all manufactured by Shin-Etsu Chemical Co., Ltd.); and mercapto group-containing oligomeric silane coupling agents "X-41-1818,""X-41-1810," and "X-41-1805" (all manufactured by Shin-Etsu Chemical Co., Ltd.).

The coupling agent (F) contained in composition (III) and the thermosetting protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

When a coupling agent (F) is used, the content of the coupling agent (F) in the thermosetting protective film-forming film is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass, per 100 parts by mass of the total content of the polymer component (A), the thermosetting component (B), and the thermosetting agent (C). When the content of the coupling agent (F) is at or above the lower limit, the effects of using the coupling agent (F), such as improved dispersibility of the filler (E) in the resin and improved adhesion reliability of the protective film to the adherend, are more significantly achieved. Furthermore, when the content of the coupling agent (F) is at or below the upper limit, outgassing is further suppressed.

[Crosslinking agent (G)]
When the polymer component (A) is one having a functional group such as a vinyl group, (meth)acryloyl group, amino group, hydroxyl group, carboxy group, or isocyanate group that can bond with other compounds, such as the above-mentioned acrylic resin (A1), the composition (III) and the thermosetting protective film-forming film may contain a crosslinking agent (G). The crosslinking agent (G) is a component that bonds the functional group in the polymer component (A) with other compounds to form a crosslink, and by crosslinking in this manner, the adhesiveness and cohesive strength of the thermosetting protective film-forming film when it is attached to an adherend can be adjusted.

Examples of the crosslinking agent (G) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

The crosslinking agent (G) contained in composition (III) and the thermosetting protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

When crosslinking agent (G) is used, the content of crosslinking agent (G) in composition (III) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of polymer component (A). When the content of crosslinking agent (G) is at least the lower limit, the effects of using crosslinking agent (G) are more pronounced. When the content of crosslinking agent (G) is at most the upper limit, excessive use of crosslinking agent (G) is suppressed.

[Energy ray curable resin (H)]
The composition (III) and the thermosetting protective film-forming film may contain an energy ray-curable resin (H). By containing the energy ray-curable resin (H), the thermosetting protective film-forming film can change its properties by irradiation with energy rays.

The energy ray curable resin (H) is obtained by polymerizing (curing) an energy ray curable compound.
Examples of the energy ray-curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

Examples of the acrylate-based compound include the compounds described in paragraph 0203 of JP 2019-062107 A.

The weight-average molecular weight of the energy ray-curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

The energy ray-curable compound used in the polymerization may be one type only, or two or more types. If two or more types are used, the combination and ratio of these compounds can be selected arbitrarily.

The energy ray-curable resin (H) contained in the composition (III) and the thermosetting protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

When an energy ray-curable resin (H) is used, the content of the energy ray-curable resin (H) in the thermosetting protective film-forming film relative to the total mass of the thermosetting protective film-forming film is preferably 1 to 30 mass%, more preferably 5 to 25 mass%, and even more preferably 10 to 20 mass%.

[Photopolymerization initiator (I)]
When the composition (III) and the thermosetting protective film-forming film contain the energy ray-curable resin (H), they may contain a photopolymerization initiator (I) in order to efficiently proceed with the polymerization reaction of the energy ray-curable resin (H).

Examples of the photopolymerization initiator (I) in the composition (III) include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one; bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2,4,6-trimethylbenzoylphenylphosphine oxide; acylphosphine oxide compounds such as benzoyldiphenylphosphine oxide; sulfide compounds such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexyl phenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; and quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone.
As the photopolymerization initiator (I), for example, a photosensitizer such as an amine can also be used.

The photopolymerization initiator (I) contained in composition (III) and the thermosetting protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

When photopolymerization initiator (I) is used, the content of photopolymerization initiator (I) in composition (III) is preferably 0.1 to 20 parts by mass per 100 parts by mass of energy ray-curable resin (H).

[General-purpose additives (K)]
The composition (III) and the thermosetting protective film-forming film may contain a general-purpose additive (K) within the range that does not impair the effects of the present invention.
The general-purpose additive (K) may be a known one and can be arbitrarily selected depending on the purpose, and is not particularly limited. Preferred examples thereof include plasticizers, antistatic agents, antioxidants, gettering agents, ultraviolet absorbers, and tackifiers.

The general-purpose additive (K) contained in the composition (III) and the thermosetting protective film-forming film may be one type only, or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.
The content of the composition (III) and the general-purpose additive (K) in the thermosetting protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose.

[solvent]
Composition (III) preferably further contains a solvent, since composition (III) containing a solvent has good handleability.
The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.
The composition (III) may contain only one type of solvent, or two or more types of solvents. When two or more types of solvents are contained, the combination and ratio thereof can be selected arbitrarily.

More preferred examples of the solvent contained in composition (III) include methyl ethyl ketone, toluene, ethyl acetate, etc., as these solvents allow the components contained in composition (III) to be mixed more uniformly.

The solvent content of composition (III) is not particularly limited and may be selected appropriately depending on, for example, the types of components other than the solvent.

<Method for producing a thermosetting protective film-forming composition>
A thermosetting protective film-forming composition such as composition (III) can be obtained by blending the components that constitute the composition.
The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously.
The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blades, a method of mixing using a mixer, or a method of mixing by applying ultrasound.
The temperature and time for adding and mixing each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

Energy Ray-Curable Protective Film-Forming Film The curing conditions when the energy ray-curable protective film-forming film is cured with energy rays to form a protective film are not particularly limited as long as the degree of curing is such that the protective film can fully exhibit its functions, and may be appropriately selected depending on the type of energy ray-curable protective film-forming film.
For example, the illuminance of the energy ray during energy ray curing of the energy ray-curable protective film-forming film is preferably 60 to 320 mW/cm ^2. The amount of energy ray during the curing is preferably 100 to 1000 mJ/cm ² .

The energy ray-curable protective film-forming film may, for example, contain an energy ray-curable component (a) and a colorant.
In the energy ray-curable protective film-forming film, the energy ray-curable component (a) is preferably uncured and has adhesive properties, and more preferably uncured and has adhesive properties.

<Energy ray-curable protective film-forming composition (IV)>
A preferred example of the energy ray-curable protective film-forming composition is energy ray-curable protective film-forming composition (IV) (sometimes abbreviated herein simply as “composition (IV)”) containing the energy ray-curable component (a) and a colorant.

[Energy ray-curable component (a)]
The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and provides film-forming properties, flexibility, etc. to the energy ray-curable protective film-forming film, and is also a component for forming a hard protective film after curing.
Examples of the energy ray-curable component (a) include a polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000, and a compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000. The polymer (a1) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

(Polymer (a1) having an energy ray-curable group and a weight-average molecular weight of 80,000 to 2,000,000)
Examples of the polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000 include an acrylic resin (a1-1) having a structure obtained by reacting an acrylic polymer (a11) having a functional group capable of reacting with a group possessed by another compound with an energy ray-curable compound (a12) having a group reactive with the functional group and an energy ray-curable group such as an energy ray-curable double bond.

Examples of the functional group capable of reacting with a group possessed by another compound include a hydroxyl group, a carboxy group, an amino group, a substituted amino group (a group in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom), an epoxy group, etc. However, from the viewpoint of preventing corrosion of circuits of a wafer, a chip, etc., it is preferable that the functional group be a group other than a carboxy group.
Among these, the functional group is preferably a hydroxyl group.

Acrylic polymer (a11) having a functional group
The acrylic polymer (a11) having a functional group may be, for example, a polymer obtained by copolymerizing an acrylic monomer having the functional group with an acrylic monomer not having the functional group. In addition to these monomers, the acrylic polymer may also be a polymer obtained by copolymerizing a monomer other than the acrylic monomer (a non-acrylic monomer).
The acrylic polymer (a11) may be a random copolymer or a block copolymer, and known methods can be used for the polymerization method.

Examples of acrylic monomers having the functional group include hydroxyl group-containing monomers, carboxy group-containing monomers, amino group-containing monomers, substituted amino group-containing monomers, and epoxy group-containing monomers.

Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and non-(meth)acrylic unsaturated alcohols (unsaturated alcohols without a (meth)acryloyl skeleton) such as vinyl alcohol and allyl alcohol.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; anhydrides of the above ethylenically unsaturated dicarboxylic acids; and (meth)acrylic acid carboxyalkyl esters such as 2-carboxyethyl methacrylate.

The acrylic monomer having the functional group is preferably a hydroxyl group-containing monomer.

The acrylic monomer having the functional group that constitutes the acrylic polymer (a11) may be of one type or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

Examples of acrylic monomers not having the functional group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and isopropyl (meth)acrylate. Examples include alkyl (meth)acrylate esters in which the alkyl group constituting the alkyl ester has a chain structure containing 1 to 18 carbon atoms, such as Sononyl, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate).

Further examples of acrylic monomers that do not have the functional group include (meth)acrylic acid esters containing an alkoxyalkyl group, such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; (meth)acrylic acid esters having an aromatic group, including aryl (meth)acrylate esters such as phenyl (meth)acrylate; non-crosslinkable (meth)acrylamide and derivatives thereof; and (meth)acrylic acid esters having a non-crosslinkable tertiary amino group, such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

The acrylic monomer not having a functional group that constitutes the acrylic polymer (a11) may be of one type or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; and styrene.
The non-acrylic monomer constituting the acrylic polymer (a11) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof can be selected arbitrarily.

In the acrylic polymer (a11), the proportion (content) of the structural units derived from the acrylic monomer having the functional group relative to the total amount of structural units constituting the acrylic polymer (a11) is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and particularly preferably 3 to 30% by mass. When the proportion is within this range, the content of the energy ray-curable groups in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy ray-curable compound (a12) can adjust the degree of curing of the protective film within a preferred range.

The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be of one type or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

The content of acrylic resin (a1-1) in the energy ray-curable protective film-forming film is preferably 1 to 70 mass%, more preferably 5 to 60 mass%, and particularly preferably 10 to 50 mass%, relative to the total mass of the energy ray-curable protective film-forming film.

Energy ray-curable compound (a12)
The energy ray-curable compound (a12) preferably has one or more groups selected from the group consisting of an isocyanate group, an epoxy group, and a carboxy group as a group reactive with the functional group of the acrylic polymer (a11), and more preferably has an isocyanate group as the group. For example, when the energy ray-curable compound (a12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

The number of energy ray-curable groups that the energy ray-curable compound (a12) has in one molecule is not particularly limited and can be appropriately selected in consideration of, for example, the physical properties required for the target protective film, such as the shrinkage rate.
For example, the energy ray-curable compound (a12) preferably has 1 to 5, and more preferably 1 to 3, energy ray-curable groups in one molecule.

Examples of the energy ray-curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate;
an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate;
Examples of the isocyanate include an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate.
Among these, the energy ray-curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

The energy ray-curable compound (a12) constituting the acrylic resin (a1-1) may be one type or two or more types. When two or more types are used, the combination and ratio thereof can be selected arbitrarily.

In the acrylic resin (a1-1), the ratio of the content of the energy ray-curable groups derived from the energy ray-curable compound (a12) to the content of the functional groups derived from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. Having this content ratio within this range increases the adhesive strength of the cured product of the energy ray-curable protective film-forming film. Note that when the energy ray-curable compound (a12) is a monofunctional compound (having one such group per molecule), the upper limit of the content ratio is 100 mol%. However, when the energy ray-curable compound (a12) is a polyfunctional compound (having two or more such groups per molecule), the upper limit of the content ratio may exceed 100 mol%.

The weight average molecular weight (Mw) of the polymer (a1) is preferably 100,000 to 2,000,000, and more preferably 300,000 to 1,500,000.

The polymer (a1) contained in composition (IV) and the energy ray-curable protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

(Compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000)
[0047] Examples of the energy ray-curable group in the compound (a2) having an energy ray-curable group and having a molecular weight of 100 to 80,000 include groups containing an energy ray-curable double bond, and preferred examples thereof include a (meth)acryloyl group and a vinyl group.

The compound (a2) is not particularly limited as long as it satisfies the above conditions, but examples include low-molecular-weight compounds having energy ray-curable groups, epoxy resins having energy ray-curable groups, and phenolic resins having energy ray-curable groups.

Among the compounds (a2), examples of the low molecular weight compound having an energy ray-curable group include polyfunctional monomers or oligomers, and acrylate compounds having a (meth)acryloyl group are preferred.
Examples of the acrylate-based compound include compounds described in paragraph 0195 of International Publication No. 2017-188197.

Of the compounds (a2), examples of epoxy resins having energy ray-curable groups and phenolic resins having energy ray-curable groups that can be used include those described in paragraph 0043 of JP 2013-194102 A. Such resins also fall under the category of resins that constitute the thermosetting component described below, but are treated as compound (a2) in composition (IV).

The weight-average molecular weight of the compound (a2) is preferably 100 to 30,000, and more preferably 300 to 10,000.

The compound (a2) contained in composition (IV) and the energy ray-curable protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[Polymer (b) having no energy ray-curable group]
When the composition (IV) and the energy ray-curable protective film-forming film contain the compound (a2) as the energy ray-curable component (a), they preferably further contain a polymer (b) having no energy ray-curable group.
The polymer (b) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

Examples of the polymer (b) having no energy ray-curable group include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins.
Among these, the polymer (b) is preferably an acrylic resin (hereinafter sometimes abbreviated as "acrylic resin (b-1)").

Examples of the acrylic resin (b-1) include those similar to the acrylic resin (A1) described above.

The polymer (b) not having an energy ray-curable group contained in composition (IV) and the energy ray-curable protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

Examples of composition (IV) include compositions containing either or both of the polymer (a1) and the compound (a2). When composition (IV) contains compound (a2), it preferably also contains polymer (b) that does not have an energy ray-curable group. Alternatively, composition (IV) may contain both polymer (a1) and polymer (b) that does not have an energy ray-curable group without containing compound (a2).

In the energy ray-curable protective film-forming film, the combined content of the energy ray-curable component (a) and the polymer (b) not having an energy ray-curable group relative to the total mass of the energy ray-curable protective film-forming film is preferably 5 to 90 mass%. Having this ratio within this range makes it easier to obtain a uniformly formed protective film-forming film.

[Colorant]
The colorant is a component for adjusting the light reflectance of the energy ray-curable protective film-forming film and the protective film. A protective film containing the colorant is more easily visible under normal conditions, and a protective film provided at any location on a workpiece is also more easily visible under normal conditions.

The colorant contained in composition (IV) and the energy ray-curable protective film-forming film is the same as the colorant (J) contained in composition (III) and the thermosetting protective film-forming film described above.

The inclusion of the colorant in composition (IV) and the energy ray-curable protective film-forming film may be the same as the inclusion of colorant (J) in composition (III) and the thermosetting protective film-forming film.

For example, the colorant contained in the composition (IV) and the energy ray-curable protective film-forming film may be one type only, or may be two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.
For example, the composition (IV) and the energy ray-curable protective film-forming film may contain, as the colorant, one or more organic dyes alone, one or more inorganic pigments alone, or one or more organic dyes and one or more inorganic pigments together.

It is preferable that the colorant be a white pigment, i.e., that the energy ray-curable protective film-forming film contains a white pigment. A protective film obtained using such an energy ray-curable protective film-forming film has a higher reflectance of light (400 to 700 nm), and this value can be easily adjusted to 20% or more. It is also easy to adjust the maximum reflectance of light (400 to 700 nm) to 25% or more. Furthermore, because a protective film containing a white pigment has such a higher reflectance of light (400 to 700 nm), when a light-emitting device is equipped with a workpiece with a protective film, it is highly effective in suppressing a decrease in the amount of light output from the light-emitting device, and is also highly effective in suppressing the protective film from appearing dark like a shadow in the light-emitting device. Furthermore, it is also highly effective in making the protective film easily visible under normal conditions.
Preferred examples of the white pigment include titanium oxide pigments (pigments containing titanium oxide).

The colorants contained in the composition (IV) can be classified according to their types, and the content thereof can be adjusted appropriately.
For example, the colorant can be classified into two types: a case where the colorant is a white pigment, and a case where the colorant is a component other than a white pigment, and the content of the colorant in composition (IV) can be adjusted in the same manner as the content of colorant (J) in composition (III) described above.
The effect obtained by adjusting the content of the colorant in composition (IV) is the same as the effect obtained by adjusting the content of colorant (J) in composition (III).

Depending on the purpose, composition (IV) and the energy ray-curable protective film-forming film may contain one or more components selected from the group consisting of thermosetting components, thermosetting agents, fillers, coupling agents, crosslinking agents, photopolymerization initiators, and general-purpose additives that do not fall under any of the energy ray-curable component (a), the polymer (b), and the colorant.

The thermosetting component, thermosetting agent, filler, coupling agent, crosslinking agent, photopolymerization initiator, and general-purpose additive in composition (IV) may be the same as the thermosetting component (B), thermosetting agent (C), filler (E), coupling agent (F), crosslinking agent (G), photopolymerization initiator (I), and general-purpose additive (K) in composition (III), respectively.

For example, when composition (IV) contains a thermosetting component, the energy ray-curable protective film-forming film formed using such composition (IV) has improved adhesive strength to the adherend upon heating, and the strength of the protective film formed from this energy ray-curable protective film-forming film is also improved.

In composition (IV), the thermosetting component, thermosetting agent, filler, coupling agent, crosslinking agent, photopolymerization initiator, and general-purpose additive may each be used alone or in combination of two or more types. When two or more types are used in combination, the combination and ratio of these may be selected arbitrarily.

The contents of the thermosetting component, thermosetting agent, filler, coupling agent, crosslinking agent, photopolymerization initiator, and general-purpose additives in composition (IV) can be adjusted appropriately depending on the purpose and are not particularly limited.

Composition (IV) preferably further contains a solvent, since dilution improves its handling properties.
Examples of the solvent contained in composition (IV) include the same solvents as those in composition (III).
The composition (IV) may contain only one type of solvent, or two or more types of solvents.
The content of the solvent in the composition (IV) is not particularly limited and may be appropriately selected depending on, for example, the types of components other than the solvent.

<Method of producing energy ray-curable protective film-forming composition>
The energy ray-curable protective film-forming composition such as composition (IV) can be obtained by blending the components constituting the composition.
The energy ray-curable composition for forming a protective film can be produced in the same manner as the heat-curable composition for forming a protective film described above, except that the types of ingredients used are different.

Non-curable protective film-forming film Preferred non-curable protective film-forming films include those containing a polymer component and a colorant.

<Non-curable protective film forming composition (V)>
A preferred example of a non-curable protective film-forming composition is a non-curable protective film-forming composition (V) (sometimes abbreviated herein simply as "composition (V)") containing the polymer component and a colorant.

[Polymer component]
The polymer component is not particularly limited.
More specifically, examples of the polymer component include those similar to the non-curable resins such as the polymer component (A) listed as a component contained in the composition (III) above.

The polymer component contained in composition (V) and the non-curable protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

In the non-curable protective film-forming film, the content of the polymer component relative to the total mass of the non-curable protective film-forming film is preferably 25 to 75 mass%.

[Colorant]
The colorant is a component for adjusting the light reflectance of the non-curable protective film-forming film and the protective film. A protective film containing the colorant is more easily visible under normal conditions, and a protective film provided at any location on a workpiece is also more easily visible under normal conditions.

In this embodiment, the non-curing protective film-forming film is considered to be a protective film after it is attached to any location on the workpiece (e.g., the backside of a wafer, etc.), i.e., the intended location on the object to be protected.

The colorant contained in composition (V) and the non-curable protective film-forming film is the same as the colorant (J) contained in composition (III) and the thermosetting protective film-forming film described above.

The inclusion of the colorant in composition (V) and the non-curable protective film-forming film may be the same as the inclusion of colorant (J) in composition (III) and the thermosetting protective film-forming film.

For example, the colorant contained in the composition (V) and the non-curable protective film-forming film may be one type only, or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.
For example, the composition (V) and the non-curable protective film-forming film may contain, as the colorant, one or more organic dyes alone, one or more inorganic pigments alone, or one or more organic dyes and one or more inorganic pigments together.

It is preferable that the colorant be a white pigment, i.e., that the non-curable protective film-forming film contains a white pigment. A protective film obtained using such a non-curable protective film-forming film has a higher reflectance of light (400 to 700 nm), and this value can be easily adjusted to 20% or more. It is also easy to adjust the maximum reflectance of light (400 to 700 nm) to 25% or more. Furthermore, because a protective film containing a white pigment has such a higher reflectance of light (400 to 700 nm), when a light-emitting device is equipped with a workpiece with a protective film, it is highly effective in suppressing a decrease in the amount of light output from the light-emitting device, and is also highly effective in suppressing the protective film from appearing dark like a shadow in the light-emitting device. Furthermore, it also has a high effect of making the protective film easily visible under normal conditions.
Preferred examples of the white pigment include titanium oxide pigments (pigments containing titanium oxide).

The colorants contained in the composition (V) can be classified according to their types, and the content thereof can be adjusted appropriately.
For example, the colorant can be classified into two cases: a case where the colorant is a white pigment, and a case where the colorant is a component other than a white pigment, and the content of the colorant in composition (V) can be adjusted in the same manner as the content of colorant (J) in composition (III) described above.
The effect obtained by adjusting the content of the colorant in the composition (V) is the same as the effect obtained by adjusting the content of the colorant (J) in the composition (III).

Depending on the purpose, the composition (V) may contain other components that do not fall into either the polymer component or the colorant.
The other components are not particularly limited and can be selected arbitrarily depending on the purpose.

Examples of the other components in the composition (V) include a filler, a coupling agent, a crosslinking agent, and general-purpose additives.
The filler, coupling agent, crosslinking agent, and general-purpose additive in composition (V) may be the same as the filler (E), coupling agent (F), crosslinking agent (G), and general-purpose additive (K) in composition (III), respectively.

The other components contained in composition (V) and the non-curable protective film-forming film may be one type only, or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

The content of the other components in composition (V) is not particularly limited and can be adjusted appropriately depending on the purpose.

Composition (V) preferably further contains a solvent, since dilution improves its handling properties.
Examples of the solvent contained in the composition (V) include the same solvents as those in the above-mentioned composition (III).
The composition (V) may contain only one type of solvent, or two or more types of solvents.
The content of the solvent in the composition (V) is not particularly limited and may be appropriately selected depending on, for example, the types of components other than the solvent.

<Method for producing a composition for forming a non-curable protective film>
A non-curable protective film-forming composition such as composition (V) can be obtained by blending the components that constitute the composition.
The non-curable protective film-forming composition can be produced in the same manner as the thermosetting protective film-forming composition described above, except that the types of ingredients used are different.

1 is a cross-sectional view schematically illustrating an example of a protective film-forming film according to one embodiment of the present invention. Note that the drawings used in the following description may show essential parts enlarged for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality.

The protective film-forming film 13 shown here has a first release film 151 on one of its surfaces (sometimes referred to as the "first surface" in this specification) 13a, and a second release film 152 on the other surface (sometimes referred to as the "second surface" in this specification) 13b opposite the first surface 13a.
Such a protective film-forming film 13 is suitable for storage in a roll form, for example.

When the protective film-forming film 13 is curable, the reflectance of the cured product of the protective film-forming film 13 to light in the entire wavelength range of 400 to 700 nm is 20% or more, and when the protective film-forming film 13 is non-curable, the reflectance of the protective film-forming film 13 to light in the entire wavelength range of 400 to 700 nm is 20% or more.
The protective film-forming film 13 can be formed using the above-mentioned protective film-forming composition.

The first release film 151 and the second release film 152 may both be of known types.
The first release film 151 and the second release film 152 may be the same as each other, or may be different from each other, for example, by requiring different peeling forces when peeling them from the protective film-forming film 13.

When either the first release film 151 or the second release film 152 is removed from the protective film-forming film 13 shown in FIG. 1, the resulting exposed surface becomes the surface to be attached to any location on the workpiece. Then, when the other remaining first release film 151 or second release film 152 is removed, the resulting exposed surface becomes the surface to be attached to the support sheet or dicing sheet described below.

Figure 1 shows an example in which a release film is provided on both sides (first side 13a, second side 13b) of the protective film-forming film 13, but the release film may be provided on only one side of the protective film-forming film 13, i.e., only the first side 13a or only the second side 13b.

The protective film-forming film of this embodiment can be attached to any location on the workpiece (to the back surface of the semiconductor wafer if the workpiece is a semiconductor wafer) without being used in combination with a support sheet, which will be described later. In this case, a release film may be provided on the surface of the protective film opposite the surface attached to the workpiece, and this release film can be removed at the appropriate time.

On the other hand, the protective film-forming film of this embodiment can be used in combination with a support sheet, described below, to form a composite sheet for forming a protective film, which can perform both protective film formation and dicing. Such a composite sheet for forming a protective film will be described below.

◇Composite sheet for forming a protective film A composite sheet for forming a protective film according to one embodiment of the present invention comprises a support sheet and a protective film-forming film provided on one side of the support sheet, and the protective film-forming film is the protective film-forming film according to one embodiment of the present invention described above.

In this specification, as long as the laminated structure of the support sheet and the cured product of the protective film-forming film is maintained even after the protective film-forming film has cured, this laminated structure will be referred to as a "composite sheet for forming a protective film."

The following describes in detail each layer that makes up the composite sheet for forming a protective film.

The support sheet may be one layer (single layer) or two or more layers. When the support sheet is made up of multiple layers, the constituent materials and thicknesses of these multiple layers may be the same or different, and the combination of these multiple layers is not particularly limited as long as it does not impair the effects of the present invention.

The support sheet may be transparent or opaque, and may be colored depending on the purpose.
For example, when the protective film-forming film has energy ray curability, the support sheet is preferably one that transmits energy rays.

Examples of support sheets include those comprising a substrate and an adhesive layer provided on one side of the substrate; and those consisting of only the substrate. When the support sheet comprises an adhesive layer, the adhesive layer is disposed between the substrate and the protective film-forming film in the composite sheet for forming a protective film.

When a support sheet having a substrate and a pressure-sensitive adhesive layer is used, the adhesion and peelability between the support sheet and the protective film-forming film in the composite sheet for forming a protective film can be easily adjusted.
When a support sheet consisting of only a substrate is used, a composite sheet for forming a protective film can be produced at low cost.

Examples of composite sheets for forming protective films according to this embodiment will be described below with reference to the drawings for each type of support sheet.

Example of Composite Sheet for Forming a Protective Film FIG. 2 is a cross-sectional view schematically showing an example of a composite sheet for forming a protective film according to one embodiment of the present invention.
In FIG. 2 and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

The composite sheet 101 for forming a protective film shown here is composed of a support sheet 10 and a protective film forming film 13 provided on one surface 10a of the support sheet 10 (sometimes referred to as the "first surface" in this specification).
The support sheet 10 is configured to include a substrate 11 and an adhesive layer 12 provided on one surface (first surface) 11a of the substrate 11. In the composite sheet 101 for forming a protective film, the adhesive layer 12 is disposed between the substrate 11 and the protective film-forming film 13.
That is, the composite sheet 101 for forming a protective film is constructed by laminating a substrate 11, a pressure-sensitive adhesive layer 12, and a protective film-forming film 13 in this order in the thickness direction.
The first surface 10a of the support sheet 10 is the same as the surface 12a of the pressure-sensitive adhesive layer 12 opposite to the substrate 11 side (sometimes referred to as the "first surface" in this specification).

The composite sheet for forming a protective film 101 further includes a jig adhesive layer 16 and a release film 15 on the protective film-forming film 13 .
In the composite sheet 101 for forming a protective film, a protective film-forming film 13 is laminated over the entire or almost entire first surface 12a of the pressure-sensitive adhesive layer 12, and a jig adhesive layer 16 is laminated over a portion of the surface 13a of the protective film-forming film 13 opposite the pressure-sensitive adhesive layer 12 side (sometimes referred to as the "first surface" in this specification), i.e., the area near the periphery. Furthermore, a release film 15 is laminated over the area of the first surface 13a of the protective film-forming film 13 where the jig adhesive layer 16 is not laminated, and over the surface 16a of the jig adhesive layer 16 opposite the protective film-forming film 13 side (sometimes referred to as the "first surface" in this specification).

Not only in the case of the composite sheet for forming a protective film 101, but also in the composite sheet for forming a protective film of this embodiment, the release film (for example, the release film 15 shown in Figures 3 to 5 described below) is an optional configuration, and the composite sheet for forming a protective film of this embodiment may or may not include a release film.

The jig adhesive layer 16 is used to fix the composite sheet for forming a protective film 101 to a jig such as a ring frame.
The jig adhesive layer 16 may have, for example, a single-layer structure containing an adhesive component, or a multi-layer structure in which layers containing adhesive components are laminated on both sides of a core sheet.

The protective film-forming film 13 acts as a protective film, suppressing light absorption and forming a film that is easily visible under normal conditions.

When the protective film-forming composite sheet 101 is used, with the release film 15 removed, any location on the workpiece is attached to the first surface 13a of the protective film-forming film 13, and the first surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame. When the workpiece is a semiconductor wafer, the back surface of the semiconductor wafer is attached to the first surface 13a of the protective film-forming film 13.

FIG. 3 is a cross-sectional view schematically showing another example of the composite sheet for forming a protective film according to one embodiment of the present invention.
The composite sheet 102 for forming a protective film shown here is the same as the composite sheet 101 for forming a protective film shown in Figure 1, except that the shape and size of the protective film-forming film are different and the jig adhesive layer is laminated on the first surface of the pressure-sensitive adhesive layer rather than the first surface of the protective film-forming film.

More specifically, in the composite sheet 102 for forming a protective film, the protective film-forming film 23 is laminated in a partial region of the first surface 12a of the pressure-sensitive adhesive layer 12, i.e., in a region on the central side in the width direction (left-right direction in FIG. 3 ) of the pressure-sensitive adhesive layer 12. Furthermore, the jig adhesive layer 16 is laminated in a region of the first surface 12a of the pressure-sensitive adhesive layer 12 where the protective film-forming film 23 is not laminated, i.e., in a region near the periphery. Then, a release film 15 is laminated on the surface 23a of the protective film-forming film 23 opposite the pressure-sensitive adhesive layer 12 side (one surface, sometimes referred to as the "first surface" in this specification) and the first surface 16a of the jig adhesive layer 16.
The symbol 23b indicates the surface (the other surface, sometimes referred to as the "second surface" in this specification) opposite the first surface 23a of the protective film-forming film 23 (in other words, the adhesive layer 12 side).

FIG. 4 is a cross-sectional view schematically showing still another example of the composite sheet for forming a protective film according to one embodiment of the present invention.
The composite sheet 103 for forming a protective film shown here is the same as the composite sheet 102 for forming a protective film shown in FIG. 3 except that it does not include the jig adhesive layer 16 .

FIG. 5 is a cross-sectional view schematically showing still another example of the composite sheet for forming a protective film according to one embodiment of the present invention.
The composite sheet 104 for forming a protective film shown here is the same as the composite sheet 101 for forming a protective film shown in FIG. 2, except that it is configured to include a support sheet 20 instead of the support sheet 10 .
The support sheet 20 is made of only the substrate 11 .
That is, the protective film-forming composite sheet 104 is configured by laminating the substrate 11 and the protective film-forming film 13 in the thickness direction.
The surface (first surface, one surface) 20 a of the support sheet 20 on the protective film-forming film 13 side is the same as the first surface 11 a of the substrate 11 .
The substrate 11 has adhesiveness at least on its first surface 11a.

The composite sheet for forming a protective film of this embodiment is not limited to the one shown in Figures 2 to 5, and may have some of the components shown in Figures 2 to 5 modified or removed, or may have other components added to those described above, as long as the effects of the present invention are not impaired.

Next, we will explain each layer that makes up the support sheet in more detail.

Substrate The substrate is in the form of a sheet or film, and examples of the constituent material thereof include various resins.
Examples of the resin include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer; and vinyl chloride-based resins (copolymers obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymer. Examples of the polyester include polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all structural units have aromatic cyclic groups; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; and polyether ketones.
Further, examples of the resin include polymer alloys such as mixtures of the polyester and other resins. The polymer alloys of the polyester and other resins preferably contain a relatively small amount of resin other than polyester.
Examples of the resin include crosslinked resins in which one or more of the resins exemplified above are crosslinked; and modified resins such as ionomers using one or more of the resins exemplified above.

The resin constituting the substrate may be one type only, or two or more types. If two or more types are used, the combination and ratio of these can be selected arbitrarily.

The substrate may consist of one layer (single layer), or two or more layers. If it consists of multiple layers, these layers may be the same or different, and there are no particular limitations on the combination of these layers.

The thickness of the substrate is preferably 50 to 300 μm, more preferably 60 to 100 μm. When the thickness of the substrate is in this range, the flexibility of the composite sheet for forming a protective film and the suitability for attachment to a wafer are further improved.
Here, the "thickness of the substrate" means the thickness of the entire substrate, and for example, the thickness of a substrate consisting of multiple layers means the total thickness of all layers that make up the substrate.

In addition to the main constituent materials such as the resin, the substrate may contain various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

The substrate may be transparent or opaque, may be colored according to the purpose, or may have other layers vapor-deposited thereon.
For example, when the protective film-forming film has energy ray curability, the substrate is preferably one that transmits energy rays.

In order to adjust the adhesion to a layer (e.g., a pressure-sensitive adhesive layer, a protective film-forming film, or any of the other layers) disposed thereon, the surface of the substrate may be subjected to a roughening treatment such as sandblasting or solvent treatment; an oxidation treatment such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone/ultraviolet irradiation treatment, flame treatment, chromic acid treatment, or hot air treatment; an oleophilic treatment; a hydrophilic treatment; or the like. The surface of the substrate may also be treated with a primer.

The substrate may contain a specific range of components (e.g., resin, etc.) to provide adhesiveness on at least one surface.

The substrate can be manufactured by a known method. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the resin.

Adhesive Layer The adhesive layer is in the form of a sheet or film and contains an adhesive.
Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber-based resins, silicone resins, epoxy-based resins, polyvinyl ethers, polycarbonates, and ester-based resins.

The adhesive layer may consist of one layer (single layer), or two or more layers. If it consists of multiple layers, these layers may be the same or different, and there are no particular restrictions on the combination of these layers.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 1 to 60 μm, and particularly preferably 1 to 30 μm.
Here, "thickness of the adhesive layer" means the thickness of the entire adhesive layer, for example, the thickness of an adhesive layer consisting of multiple layers means the total thickness of all layers that make up the adhesive layer.

The adhesive layer may be either energy ray-curable or non-energy ray-curable. An energy ray-curable adhesive layer can adjust its physical properties before and after curing.

The adhesive layer can be formed using an adhesive composition containing an adhesive. For example, the adhesive composition can be applied to the surface on which the adhesive layer is to be formed, and then dried as necessary to form the adhesive layer in the desired location. The ratio of the contents of the components in the adhesive composition that do not vaporize at room temperature is usually the same as the ratio of the contents of the components in the adhesive layer.

In the pressure-sensitive adhesive layer, the proportion of the total content of one or more components contained in the pressure-sensitive adhesive layer, which will be described later, relative to the total mass of the pressure-sensitive adhesive layer is 100 mass % or less.
Similarly, in the pressure-sensitive adhesive composition, the ratio of the total content of one or more components contained in the pressure-sensitive adhesive composition, which will be described later, to the total mass of the pressure-sensitive adhesive composition is 100 mass % or less.

The adhesive composition can be applied and dried, for example, using the same method as for applying and drying the protective film-forming composition described above.

When providing a pressure-sensitive adhesive layer on a substrate, for example, the pressure-sensitive adhesive composition may be applied to the substrate and dried as necessary. Alternatively, for example, the pressure-sensitive adhesive composition may be applied to a release film and dried as necessary to form a pressure-sensitive adhesive layer on the release film, and the exposed surface of this pressure-sensitive adhesive layer may be attached to one surface of the substrate, thereby laminating the pressure-sensitive adhesive layer on the substrate. In this case, the release film may be removed at any time during the manufacturing process or use of the composite sheet for forming a protective film.

When the pressure-sensitive adhesive layer is energy ray-curable, examples of the energy ray-curable pressure-sensitive adhesive composition include pressure-sensitive adhesive composition (I-1) containing a non-energy ray-curable pressure-sensitive adhesive resin (I-1a) (hereinafter sometimes abbreviated as "pressure-sensitive adhesive resin (I-1a)") and an energy ray-curable compound; pressure-sensitive adhesive composition (I-2) containing an energy ray-curable pressure-sensitive adhesive resin (I-2a) (hereinafter sometimes abbreviated as "pressure-sensitive adhesive resin (I-2a)") in which an unsaturated group has been introduced into the side chain of the non-energy ray-curable pressure-sensitive adhesive resin (I-1a); and pressure-sensitive adhesive composition (I-3) containing the pressure-sensitive adhesive resin (I-2a) and an energy ray-curable compound.

When the pressure-sensitive adhesive layer is non-energy ray-curable, examples of the non-energy ray-curable pressure-sensitive adhesive composition include pressure-sensitive adhesive composition (I-4) containing the non-energy ray-curable pressure-sensitive adhesive resin (I-1a).

[Non-energy ray curable adhesive resin (I-1a)]
The adhesive resin (I-1a) is preferably an acrylic resin.

Examples of the acrylic resin include acrylic polymers having at least a structural unit derived from an alkyl (meth)acrylate ester.
The (meth)acrylic acid alkyl ester may be, for example, an alkyl ester in which the alkyl group has 1 to 20 carbon atoms, and the alkyl group is preferably linear or branched.

The acrylic polymer preferably further contains a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the alkyl (meth)acrylate ester.
Examples of the functional group-containing monomer include those whose functional group reacts with a crosslinking agent described below to become a starting point for crosslinking, and those whose functional group reacts with an unsaturated group in an unsaturated group-containing compound described below to enable the introduction of an unsaturated group into a side chain of an acrylic polymer.

Examples of the functional group-containing monomer include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, and epoxy group-containing monomers.

The acrylic polymer may further contain structural units derived from other monomers in addition to the structural units derived from the alkyl (meth)acrylate ester and the structural units derived from the functional group-containing monomer.
The other monomer is not particularly limited as long as it is copolymerizable with the (meth)acrylic acid alkyl ester and the like.
Examples of the other monomers include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

In the pressure-sensitive adhesive compositions (I-1), (I-2), (I-3), and (I-4) (hereinafter, these pressure-sensitive adhesive compositions will be collectively referred to as "pressure-sensitive adhesive compositions (I-1) to (I-4)"), the structural units contained in the acrylic resin such as the acrylic polymer may be of one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

In the acrylic polymer, the content of structural units derived from functional group-containing monomers is preferably 1 to 35% by mass based on the total amount of structural units.

The adhesive resin (I-1a) contained in the adhesive composition (I-1) or (I-4) may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

In a pressure-sensitive adhesive layer formed from pressure-sensitive adhesive composition (I-1) or pressure-sensitive adhesive composition (I-4), the content of adhesive resin (I-1a) relative to the total mass of the pressure-sensitive adhesive layer is preferably 5 to 99 mass%.

[Energy ray-curable adhesive resin (I-2a)]
The adhesive resin (I-2a) can be obtained, for example, by reacting a functional group in the adhesive resin (I-1a) with an unsaturated group-containing compound having an energy ray-polymerizable unsaturated group.

The unsaturated group-containing compound is a compound that has, in addition to the energy ray-polymerizable unsaturated group, a group that can bond to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a).
Examples of the energy ray-polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), and an allyl group (2-propenyl group), with a (meth)acryloyl group being preferred.
Examples of groups capable of bonding to functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups capable of bonding to hydroxyl groups or amino groups, and hydroxyl groups and amino groups capable of bonding to carboxyl groups or epoxy groups.

Examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

The adhesive resin (I-2a) contained in the adhesive composition (I-2) or (I-3) may be one type or two or more types, and if two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

In a pressure-sensitive adhesive layer formed from pressure-sensitive adhesive composition (I-2) or (I-3), the content of adhesive resin (I-2a) relative to the total mass of the pressure-sensitive adhesive layer is preferably 5 to 99 mass%.

[Energy ray curable compound]
The energy ray-curable compound in the pressure-sensitive adhesive compositions (I-1) and (I-3) includes a monomer or oligomer having an energy ray-polymerizable unsaturated group and capable of being cured by irradiation with energy rays.

Among the energy ray-curable compounds, examples of the monomer include polyhydric (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; and epoxy (meth)acrylate.
Among the energy ray-curable compounds, examples of oligomers include oligomers obtained by polymerizing the above-exemplified monomers.

The pressure-sensitive adhesive composition (I-1) or (I-3) may contain only one type of energy ray-curable compound, or two or more types. If two or more types are contained, the combination and ratio of these compounds can be selected arbitrarily.

In a pressure-sensitive adhesive layer formed from pressure-sensitive adhesive composition (I-1) or (I-3), the content of the energy ray-curable compound relative to the total mass of the pressure-sensitive adhesive layer is preferably 1 to 95 mass%.

[Crosslinking agent]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from a (meth)acrylic acid alkyl ester is used as the pressure-sensitive adhesive resin (I-1a), it is preferable that the pressure-sensitive adhesive composition (I-1) or (I-4) further contains a crosslinking agent.
Furthermore, when the adhesive resin (I-2a) is, for example, the acrylic polymer having a structural unit derived from a functional group-containing monomer similar to that in the adhesive resin (I-1a), the adhesive composition (I-2) or (I-3) may further contain a crosslinking agent.

The crosslinking agent reacts with the functional group to crosslink the adhesive resins (I-1a) together or the adhesive resins (I-2a) together, for example.
Examples of the crosslinking agent include isocyanate-based crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether; aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group) such as hexa[1-(2-methyl)-aziridinyl]triphosphatriazine; metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelate; and isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton).

The crosslinking agents contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be one type or two or more types. If two or more types are contained, the combination and ratio of these may be selected arbitrarily.

In the pressure-sensitive adhesive composition (I-1) or (I-4), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass per 100 parts by mass of the pressure-sensitive adhesive resin (I-1a).
In the pressure-sensitive adhesive composition (I-2) or (I-3), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass per 100 parts by mass of the pressure-sensitive adhesive resin (I-2a).

[Photopolymerization initiator]
The pressure-sensitive adhesive compositions (I-1), (I-2), and (I-3) (hereinafter, these pressure-sensitive adhesive compositions are collectively referred to as "pressure-sensitive adhesive compositions (I-1) to (I-3)") may further contain a photopolymerization initiator. The pressure-sensitive adhesive compositions (I-1) to (I-3) containing a photopolymerization initiator undergo a sufficient curing reaction even when irradiated with relatively low-energy energy rays such as ultraviolet light.

Examples of the photopolymerization initiator include those similar to the photopolymerization initiator (I) described above.

The photopolymerization initiators contained in the pressure-sensitive adhesive compositions (I-1) to (I-3) may be one type or two or more types, and if two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

In the pressure-sensitive adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the content of the energy ray-curable compound.
In the pressure-sensitive adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the pressure-sensitive adhesive resin (I-2a).
In the pressure-sensitive adhesive composition (I-3), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total content of the pressure-sensitive adhesive resin (I-2a) and the energy ray-curable compound.

[Other additives]
The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain other additives that do not fall under any of the above-mentioned components, as long as the effects of the present invention are not impaired.
Examples of the other additives include known additives such as antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retarders, and crosslinking accelerators (catalysts).
The reaction retarder is, for example, a component that suppresses the progress of an unintended crosslinking reaction in the PSA compositions (I-1) to (I-4) during storage due to the action of a catalyst mixed in the PSA compositions (I-1) to (I-4). Examples of the reaction retarder include those that form a chelate complex by chelating with the catalyst, and more specifically, those that have two or more carbonyl groups (—C(═O)—) in one molecule.

The other additives contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be one type only, or two or more types. If there are two or more types, the combination and ratio of these can be selected arbitrarily.

The content of other additives in the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited and may be selected appropriately depending on the type of additive.

[solvent]
The PSA compositions (I-1) to (I-4) may contain a solvent, which improves the suitability of the PSA compositions (I-1) to (I-4) for application to a surface to be coated.

The solvent is preferably an organic solvent, and examples of such organic solvents include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain only one type of solvent, or two or more types. If two or more types are contained, the combination and ratio of these solvents can be selected arbitrarily.

The solvent content of the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited and may be adjusted as appropriate.

Method for producing pressure-sensitive adhesive composition Pressure-sensitive adhesive compositions such as pressure-sensitive adhesive compositions (I-1) to (I-4) can be obtained by blending the pressure-sensitive adhesive and, as necessary, components for constituting the pressure-sensitive adhesive composition, such as components other than the pressure-sensitive adhesive.
The pressure-sensitive adhesive composition can be produced by the same method as the thermosetting protective film-forming composition described above, except that the types of ingredients used are different.

Manufacturing Method of Composite Sheet for Forming a Protective Film The composite sheet for forming a protective film can be manufactured by laminating the above-mentioned layers so that they are in a corresponding positional relationship, and adjusting the shapes of some or all of the layers as necessary. The method for forming each layer is as described above.

For example, when a support sheet is produced by laminating a pressure-sensitive adhesive layer on a substrate, the pressure-sensitive adhesive composition may be applied to the substrate and dried as necessary.
Alternatively, a pressure-sensitive adhesive layer can be laminated on a substrate by coating a release film with a pressure-sensitive adhesive composition and optionally drying the composition to form a pressure-sensitive adhesive layer on the release film, and then laminating the exposed surface of the pressure-sensitive adhesive layer to one surface of the substrate. In this case, the pressure-sensitive adhesive composition is preferably coated on the release-treated surface of the release film.
Up to this point, the case where a pressure-sensitive adhesive layer is laminated on a substrate has been taken as an example, but the above-mentioned method can also be applied to the case where an intermediate layer or the other layer is laminated on a substrate, for example.

On the other hand, for example, when a protective film-forming film is further laminated on a pressure-sensitive adhesive layer already laminated on a substrate, it is possible to coat a protective film-forming composition on the pressure-sensitive adhesive layer to directly form a protective film-forming film. Layers other than the protective film-forming film can also be laminated on the pressure-sensitive adhesive layer in a similar manner using a composition for forming this layer. In this way, when a new layer (hereinafter abbreviated as "second layer") is formed on any layer (hereinafter abbreviated as "first layer") already laminated on the substrate to form a continuous two-layer laminate structure (in other words, a laminate structure of the first layer and the second layer), a method can be applied in which a composition for forming the second layer is coated on the first layer and dried as necessary.
However, it is preferable that the second layer be formed in advance on a release film using a composition for forming the second layer, and the exposed surface of the second layer opposite the side in contact with the release film be bonded to the exposed surface of the first layer to form a continuous two-layer laminate structure. In this case, it is preferable that the composition be applied to the release-treated surface of the release film. The release film can be removed as needed after the laminate structure is formed.
Here, we have given an example of laminating a protective film-forming film on an adhesive layer, but the target laminate structure can be selected arbitrarily, for example, when laminating an intermediate layer or other layer on an adhesive layer.

In this way, all layers other than the substrate that make up the composite sheet for forming a protective film can be formed in advance on a release film and then laminated by laminating it to the surface of the desired layer. Therefore, the composite sheet for forming a protective film can be manufactured by appropriately selecting the layers that will undergo this process as needed.

The composite sheet for forming a protective film is typically stored with a release film attached to the surface of the outermost layer (e.g., the protective film-forming film) opposite the support sheet. Therefore, a composition for forming the layer that constitutes the outermost layer, such as a protective film-forming composition, is applied to this release film (preferably its release-treated surface) and dried as necessary to form the layer that constitutes the outermost layer on the release film. The remaining layers are then laminated by one of the methods described above onto the exposed surface opposite the side that is in contact with the release film, and the composite sheet for forming a protective film with a release film is obtained by leaving the laminated state without removing the release film.

◇Manufacturing method for workpieces with protective film (method of using composite sheet for forming protective film)
The composite sheet for forming a protective film can be used to manufacture a workpiece with a protective film.
An example of a method for manufacturing a workpiece with a protective film includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, wherein the protective film is formed from a protective film-forming film in a composite sheet for forming a protective film according to one embodiment of the present invention described above, and when the protective film-forming film is curable, a cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film after being attached to any location on the workpiece is the protective film, and the manufacturing method includes: Examples of methods for manufacturing a workpiece with a protective film include an attachment step of attaching the protective film-forming film in the film-forming composite sheet to a desired location on the workpiece to create a first laminate in which the protective film-forming composite sheet is provided (laminated) on the workpiece, a processing step of processing the workpiece after the attachment step to create the workpiece, and a cutting step of cutting the protective film-forming film or protective film after the attachment step, and if the protective film-forming film is curable, further including a curing step of hardening the protective film-forming film after the attachment step to form the protective film.

Whether the protective film-forming film or the protective film is handled in each step after the attachment step is determined by the timing of forming the protective film. If the protective film-forming film is non-curable, it is the protective film that is handled in each step after the attachment step. If the protective film-forming film is curable, it is the protective film-forming film that is handled before the curing step, and the protective film that is handled after the curing step.

An example of a method for manufacturing a workpiece with a protective film, i.e., a semiconductor chip with a protective film, when the workpiece is a semiconductor wafer is a method for manufacturing a semiconductor chip with a protective film, which includes a semiconductor chip and a protective film provided on the back surface of the semiconductor chip, wherein the protective film is formed from a protective film-forming film in a composite sheet for forming a protective film according to one embodiment of the present invention described above, and when the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film after being attached to the back surface of the semiconductor wafer is the protective film, and the manufacturing method includes: Examples of methods for manufacturing semiconductor chips with protective films include a bonding step of bonding the protective film-forming film in the film-forming composite sheet to the back surface of the semiconductor wafer to produce a first laminate in which the protective film-forming composite sheet is provided (laminated) on the back surface of the semiconductor wafer, a dividing step of dividing the semiconductor wafer after the bonding step to produce semiconductor chips, and a cutting step of cutting the protective film-forming film or protective film after the bonding step.If the protective film-forming film is curable, the method further includes a curing step of curing the protective film-forming film after the bonding step to form the protective film.

This manufacturing method allows for the production of a workpiece with a protective film that suppresses light absorption and is easily visible under normal conditions.

The production method is divided into a production method that includes the curing step (sometimes referred to as "production method (1)" in this specification) and a production method that does not include the curing step (sometimes referred to as "production method (2)" in this specification).
These manufacturing methods will be explained below in order.

<<Manufacturing method (1)>>
The manufacturing method (1) is a method for manufacturing a workpiece with a protective film, which includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, and the protective film is formed from the protective film-forming film in the composite sheet for forming a protective film according to one embodiment of the present invention described above. Since the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film. The manufacturing method includes an attachment step of attaching the protective film-forming film in the composite sheet for forming a protective film to a desired location on the workpiece to produce a first laminate in which the composite sheet for forming a protective film is provided (laminated) on the workpiece; a processing step of processing the workpiece after the attachment step to produce the workpiece; a cutting step of cutting the protective film-forming film or protective film after the attachment step; and a curing step of curing the protective film-forming film to form the protective film after the attachment step.

When the workpiece is a semiconductor wafer, the manufacturing method (1) may be a method for manufacturing a semiconductor chip with a protective film, the semiconductor chip having a semiconductor chip and a protective film provided on the back surface of the semiconductor chip, the protective film being formed from the protective film-forming film in the protective film-forming composite sheet. Because the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film. The manufacturing method includes a bonding step of bonding the protective film-forming film in the protective film-forming composite sheet to the back surface of the semiconductor wafer to produce a first laminate in which the protective film-forming composite sheet is provided (laminated) on the semiconductor wafer; a dividing step of dividing the semiconductor wafer after the bonding step to produce the semiconductor chip; a cutting step of cutting the protective film-forming film or protective film after the bonding step; and a curing step of curing the protective film-forming film to form the protective film after the bonding step.

When the workpiece is a semiconductor wafer, the order in which the dividing step and the cutting step are performed can be selected arbitrarily depending on the purpose. The dividing step may be performed first, then the cutting step, or the dividing step and the cutting step may be performed simultaneously, or the cutting step may be performed first, then the dividing step.
In this embodiment, if the dividing of the semiconductor wafer and the cutting of the protective film-forming film or protective film are performed continuously by the same operation without interruption, regardless of the order, the dividing process and the cutting process are considered to be performed simultaneously.

The dividing and cutting steps can be performed using known methods, depending on the order in which they are performed.

When the cutting step is performed after the dividing step, the semiconductor wafer can be divided (in other words, diced into individual pieces) by, for example, stealth dicing (registered trademark) or laser dicing.
Stealth Dicing (registered trademark) is a method as follows. First, a planned dividing point is set within a semiconductor wafer, and a laser beam is irradiated so as to converge at this point, forming a modified layer within the semiconductor wafer. Unlike other parts of the semiconductor wafer, the modified layer of the semiconductor wafer has been altered by the irradiation of the laser beam, and its strength has been weakened. Therefore, when a force is applied to the semiconductor wafer, cracks extending in the direction of both sides of the semiconductor wafer are generated in the modified layer within the semiconductor wafer, which become the starting point for dividing (cutting) the semiconductor wafer. Next, a force is applied to the semiconductor wafer to divide the semiconductor wafer at the site of the modified layer, thereby producing semiconductor chips.

When the cutting step is performed after the dividing step, the protective film-forming film or protective film can be cut by, for example, expanding the protective film-forming film or protective film, which is pulled in a direction parallel to the surface attached to the semiconductor chip. The expanded protective film-forming film or protective film is cut along the periphery of the semiconductor chip. Such cutting by expanding is preferably performed at a low temperature, such as -20 to 5°C.

When the dividing step and the cutting step are performed simultaneously, the dividing of the semiconductor wafer and the cutting of the protective film-forming film or the protective film can be performed simultaneously by dicing such as blade dicing using a blade, laser dicing by irradiating a laser, or water dicing by spraying water containing an abrasive.
In addition, by expanding a semiconductor wafer on which a modified layer has been formed by Stealth Dicing (registered trademark) and which has not been divided, together with the protective film-forming film or protective film, in the same manner as described above, it is possible to simultaneously divide the semiconductor wafer and cut the protective film-forming film or protective film.

If the dividing step is performed after the cutting step, the protective film-forming film or protective film can be cut without dividing the semiconductor wafer using the same dicing techniques as described above, and the semiconductor wafer can then be divided by breaking.

Figure 6 is a cross-sectional view for schematically explaining an example of the manufacturing method (1) when the workpiece is a semiconductor wafer. Here, we will explain the manufacturing method when using the composite sheet 101 for forming a protective film shown in Figure 2.

<Attachment process>
In the bonding step, the protective film-forming composite sheet 101 from which the release film 15 has been removed is used, and as shown in Fig. 6(a), the protective film-forming film 13 in the protective film-forming composite sheet 101 is bonded to the back surface 9b of the workpiece, that is, the semiconductor wafer 9. In this way, a first laminate 901 is produced that includes the semiconductor wafer 9 and the protective film-forming composite sheet 101 provided on the back surface 9b thereof.

In the attaching step, the protective film-forming film 13 may be softened by heating and then attached to the semiconductor wafer 9 .
Here, bumps and the like on the circuit surface 9a of the semiconductor wafer 9 are omitted from the illustration, as is the case in the subsequent drawings.

The back surface of the semiconductor wafer 9 may be ground to achieve the desired thickness. In other words, the back surface 9b of the semiconductor wafer 9 may be a ground surface.

<Curing process>
After the attaching step, in the curing step, the protective film-forming film 13 is cured to form a protective film 13', as shown in FIG. 6(b).
In this embodiment, the cured product obtained by curing the protective film-forming film 13 after it has been attached to the semiconductor wafer 9 is used as the protective film, regardless of whether it has been cut or not.

By carrying out the curing process, the composite sheet 101 for forming a protective film becomes a composite sheet 1011 for forming a protective film in which the protective film forming film 13 has become a protective film 13', and a cured first laminate 9011 is obtained which is composed of the semiconductor wafer 9 and the composite sheet 1011 for forming a protective film provided on its back surface 9b.
Symbol 13a' indicates the first surface of the protective film 13' corresponding to the first surface 13a of the protective film-forming film 13, and symbol 13b' indicates the second surface of the protective film 13' corresponding to the second surface 13b of the protective film-forming film 13.

In the curing process, if the protective film-forming film 13 is thermosetting, the protective film 13' is formed by heating the protective film-forming film 13. If the protective film-forming film 13 is energy ray-curable, the protective film 13' is formed by irradiating the protective film-forming film 13 with energy rays through the support sheet 10.

In the curing process, the curing conditions for the protective film-forming film 13, i.e., the heating temperature and heating time during thermal curing, and the illuminance and light amount of the energy rays during energy ray curing, are as described above.

<Dividing process, cutting process>
In this embodiment, after the bonding step, a dividing step of dividing the semiconductor wafer 9 to produce semiconductor chips and a cutting step of cutting the protective film 13' are performed.
As explained above, the order in which the dividing step and the cutting step are performed is not limited.
The methods for carrying out the dividing step and cutting step are as described above.
By performing the dividing step and the cutting step, as shown in Figure 6(c), a plurality of semiconductor chips 91 with protective films are obtained, each of which includes a semiconductor chip 90, which is a workpiece, and a protective film 130' formed on the back surface 90b of the semiconductor chip 90 after cutting. The semiconductor chips 91 with protective films are workpieces with protective films. All of these plurality of semiconductor chips 91 with protective films are aligned on a single support sheet 10, and these semiconductor chips 91 with protective films and the support sheet 10 constitute a group of semiconductor chips with protective films 910.

Symbol 130a' indicates the first surface of the protective film 130' after cutting, which corresponds to the first surface 13a' of the protective film 13', and symbol 130b' indicates the second surface of the protective film 130' after cutting, which corresponds to the second surface 13b' of the protective film 13'.
Reference numeral 90 a denotes a circuit surface of the semiconductor chip 90 that corresponds to the circuit surface 9 a of the semiconductor wafer 9 .

<Pickup process>
After the dividing and cutting processes, as shown in Figure 6 (d), a pick-up process is performed in which the semiconductor chip 91 with a protective film (semiconductor chip 90 with the protective film 130' after cutting) is pulled away from the support sheet 10 and picked up, thereby allowing the semiconductor chip 91 with a protective film to be removed from the group of semiconductor chips with a protective film 910.
Here, the pickup direction is indicated by an arrow P.

Picking up the semiconductor chips 91 with protective films can be performed using known methods. For example, a vacuum collet or the like can be used as the separation means 7 for separating the semiconductor chips 91 with protective films from the support sheet 10.

<Other processes>
The manufacturing method (1) may include a step other than the adhering step, the curing step, the dividing step, the cutting step, and the picking up step.
The types of other steps and the timing of performing them can be selected arbitrarily depending on the purpose, and are not particularly limited.

An example of such another process is a printing process (not shown) in which laser light is applied to the second surface of the protective film-forming film or protective film (for example, the second surface 13b of the protective film-forming film 13 or the second surface 13b' of the protective film 13' in FIG. 6 ) to print on the protective film-forming film or protective film. The printing is performed on the second surface of the protective film-forming film or protective film.

In the printing process, laser light can be irradiated from the outside of the support sheet side of the composite sheet for forming a protective film, through the support sheet, onto the second surface of the protective film-forming film or protective film.

The printing process can be carried out using known methods.

In this embodiment, the printing process can be performed after the adhering process, and is preferably performed between the curing process and the dividing process, or between the curing process and the cutting process.

<Timing of curing process>
Up to this point, the case where the curing step is performed between the adhering step and the dividing step, and between the adhering step and the cutting step has been described, but the timing of performing the curing step in manufacturing method (1) is not limited to this. For example, in manufacturing method (1), the curing step may be performed between the printing step and the dividing step, between the printing step and the cutting step, between the dividing step and the cutting step, between the dividing step and the pick-up step, between the cutting step and the pick-up step, or after the pick-up step.

<<Manufacturing method (2)>>
The manufacturing method (2) is a method for manufacturing a protective film-attached workpiece, which includes a workpiece obtained by processing a workpiece and a protective film provided at a location on the workpiece, the protective film being formed from the protective film-forming film in the composite sheet for forming a protective film according to one embodiment of the present invention. Because the protective film-forming film is non-hardening, the protective film after being attached to a location on the workpiece constitutes the protective film. The manufacturing method includes an attaching step of attaching the protective film-forming film in the composite sheet for forming a protective film to a desired location on the workpiece to form a first laminate in which the composite sheet for forming a protective film is provided (laminated) on the workpiece, a processing step of processing the workpiece after the attaching step, and a cutting step of cutting the protective film after the attaching step. In the manufacturing method (2), the protective film-forming film after being attached to the workpiece in the attaching step constitutes the protective film.
Manufacturing method (2) is the same as manufacturing method (1) except that it does not include the curing step and the protective film-forming film after being attached to the workpiece is used as the protective film, regardless of the type of workpiece.

When the workpiece is a semiconductor wafer, the manufacturing method (2) may be a method for manufacturing a semiconductor chip with a protective film, which includes a semiconductor chip and a protective film provided on the back surface of the semiconductor chip. The protective film is formed from the protective film-forming film in the composite sheet for forming a protective film. Because the protective film-forming film is non-curing, the protective film-forming film after being attached to the back surface of the semiconductor wafer to obtain the semiconductor chip is the protective film. The manufacturing method includes an attachment step of attaching the protective film-forming film in the composite sheet for forming a protective film to the back surface of the semiconductor wafer to produce a first laminate in which the composite sheet for forming a protective film is provided (laminated) on the semiconductor wafer; a dividing step of dividing the semiconductor wafer after the attachment step to produce the semiconductor chip; and a cutting step of cutting the protective film after the attachment step.

Up to this point, we have mainly described a method for manufacturing a workpiece with a protective film when using the composite sheet 101 for forming a protective film shown in Figure 2, but the method for manufacturing a workpiece with a protective film in this embodiment is not limited to this.
For example, even if a composite sheet for forming a protective film other than the composite sheet for forming a protective film 101 shown in Figure 2, such as the composite sheets for forming a protective film shown in Figures 3 to 5, is used, a workpiece with a protective film can be manufactured in the same way using the above-mentioned manufacturing method.

◇Manufacturing method for workpieces with protective film (How to use protective film forming film)
A protective film-forming film that does not constitute the protective film-forming composite sheet can also be used to manufacture the protective film-coated workpiece.
Another example of the method for manufacturing the workpiece with a protective film is a method for manufacturing a workpiece with a protective film, which includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, wherein the protective film is formed from the protective film-forming film according to one embodiment of the present invention, which does not constitute the composite sheet for forming a protective film, and when the protective film-forming film is curable, a cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film-forming film after being attached to any location on the workpiece is the protective film, and The manufacturing method includes an attachment step of attaching the protective film-forming film to a desired location on the workpiece to create a second laminate in which the protective film-forming film or protective film is provided (laminated) on the workpiece, a processing step of processing the workpiece after the attachment step to create the workpiece, and a cutting step of cutting the protective film-forming film or protective film after the attachment step, and if the protective film-forming film is curable, the manufacturing method can further include a curing step of forming the protective film by curing the protective film-forming film after the attachment step.

Whether the protective film-forming film or the protective film is handled in each step after the attachment step is determined by the timing of forming the protective film. If the protective film-forming film is non-curable, it is the protective film that is handled in each step after the attachment step. If the protective film-forming film is curable, it is the protective film-forming film that is handled before the curing step, and the protective film that is handled after the curing step.

Another example of a method for manufacturing a workpiece with a protective film, i.e., a semiconductor chip with a protective film, when the workpiece is a semiconductor wafer is a method for manufacturing a semiconductor chip with a protective film, which includes a semiconductor chip and a protective film provided on the back surface of the semiconductor chip, wherein the protective film is formed from a protective film-forming film according to one embodiment of the present invention described above, which does not constitute the composite sheet for forming a protective film; if the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film; if the protective film-forming film is non-curable, the protective film after being attached to the back surface of the semiconductor wafer is the protective film; The manufacturing method includes a bonding step of bonding the protective film-forming film to the back surface of the semiconductor wafer to produce a second laminate in which the protective film-forming film or protective film is provided (laminated) on the back surface of the semiconductor wafer; a dividing step of dividing the semiconductor wafer after the bonding step to produce the semiconductor chips; and a cutting step of cutting the protective film-forming film or protective film after the bonding step. If the protective film-forming film is curable, the manufacturing method can further include a curing step of curing the protective film-forming film after the bonding step to form the protective film.

This manufacturing method allows for the production of a workpiece with a protective film that suppresses light absorption and is easily visible under normal conditions.

The method for manufacturing a workpiece with a protective film when using a protective film-forming film that does not constitute a composite sheet for forming a protective film is the same as the method for manufacturing a workpiece with a protective film when using the composite sheet for forming a protective film described above, except that such a protective film-forming film is used instead of the composite sheet for forming a protective film. If necessary, other steps different from those when using a composite sheet for forming a protective film may be added.

For example, when a protective film-forming film that does not constitute a composite sheet for forming a protective film is used, the manufacturing method can be divided into a manufacturing method that includes the curing step (sometimes referred to in this specification as "manufacturing method (3)") and a manufacturing method that does not include the curing step (sometimes referred to in this specification as "manufacturing method (4)").
These manufacturing methods will be explained below in order.

<<Manufacturing method (3)>>
The manufacturing method (3) is a method for manufacturing a workpiece with a protective film, which includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, and the protective film is formed from a protective film-forming film according to one embodiment of the present invention described above, which does not constitute the composite sheet for forming a protective film.Since the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film.The manufacturing method includes an attachment step of attaching the protective film-forming film to a desired location on the workpiece to produce a second laminate in which the protective film-forming film is provided (laminated) on the workpiece, a processing step of processing the workpiece after the attachment step to produce the workpiece, a cutting step of cutting the protective film-forming film or protective film after the attachment step, and a curing step of hardening the protective film-forming film to form the protective film after the attachment step.

When the workpiece is a semiconductor wafer, the manufacturing method (3) may be a method for manufacturing a semiconductor chip with a protective film, the semiconductor chip having a semiconductor chip and a protective film provided on the back surface of the semiconductor chip, wherein the protective film is formed from the protective film-forming film that is not part of the protective film-forming composite sheet, and since the protective film-forming film is curable, a cured product of the protective film-forming film is the protective film. The manufacturing method may include a bonding step of bonding the protective film-forming film to the back surface of the semiconductor wafer to produce a second laminate in which the protective film-forming film is provided (laminated) on the semiconductor wafer, a dividing step of dividing the semiconductor wafer after the bonding step to produce the semiconductor chip, a cutting step of cutting the protective film-forming film or protective film after the bonding step, and a curing step of curing the protective film-forming film to form the protective film after the bonding step.

Figure 7 is a cross-sectional view for schematically explaining an example of the manufacturing method (3) when the workpiece is a semiconductor wafer. Here, we will explain the manufacturing method when using the protective film-forming film 13 shown in Figure 1.

<Attachment process>
In the bonding step of manufacturing method (3), the protective film-forming film 13 from which the first release film 151 has been removed is used, and as shown in Fig. 7(a), the protective film-forming film 13 is bonded to the back surface 9b of the semiconductor wafer 9. In this way, a second laminate 902 is produced that includes the semiconductor wafer 9 and the protective film-forming film 13 provided on the back surface 9b. The protective film-forming film 13 in the second laminate 902 further includes a second release film 152 on its second surface 13b.

In the attachment step of manufacturing method (3), the protective film-forming film 13 may be softened by heating and then attached to the semiconductor wafer 9.

<Lamination process>
After the bonding process, as shown in Figure 7(b), the second release film 152 is removed from the protective film-forming film 13, and a lamination process can be performed in which a dicing sheet 80 is attached and laminated to the newly exposed surface, in other words, the second surface 13b of the protective film-forming film 13.

The dicing sheet 80 is composed of a substrate 81 and an adhesive layer 82 provided on one surface 81a of the substrate 81. In this process, the surface 82a of the adhesive layer 82 opposite the substrate 81 (sometimes referred to as the "first surface" in this specification) is attached to the second surface 13b of the protective film-forming film 13. The first surface 82a of the adhesive layer 82 is the same as the first surface 80a of the dicing sheet 80.

The dicing sheet 80 may have the same configuration as the support sheet in the composite sheet for forming a protective film.
Here, the case where a dicing sheet 80 having an adhesive layer 82 is used is shown, but in manufacturing method (3), a known dicing sheet other than the dicing sheet 80, such as a dicing sheet consisting of only a base material, may also be used.

The dicing sheet 80 can be attached to the protective film-forming film 13 using a known method, for example, the same method as used to attach the protective film-forming composite sheet 101 to the semiconductor wafer 9 in the attachment step of manufacturing method (1).

<Curing process>
After the attaching step of the manufacturing method (3), in the curing step, the protective film-forming film 13 is cured to form a protective film 13', as shown in FIG. 7(c).
In this embodiment, the cured product obtained by curing the protective film-forming film 13 after it has been attached to the semiconductor wafer 9 is used as the protective film, regardless of whether it has been cut or not.

By performing the curing process, a cured second laminate 9021 is obtained, which is composed of the semiconductor wafer 9 and the protective film 13' (cured protective film-forming film 13) provided on its back surface 9b.

<Dividing process, cutting process>
In this embodiment, after the bonding step, a dividing step of dividing the semiconductor wafer 9 to produce semiconductor chips and a cutting step of cutting the protective film 13' are carried out.
7(d), a plurality of semiconductor chips 91 with protective films are obtained, each of which includes a semiconductor chip 90 and a post-cut protective film 130′ provided on the back surface 90b of the semiconductor chip 90. All of these plurality of semiconductor chips 91 with protective films are aligned on one dicing sheet 80, and these semiconductor chips 91 with protective films and the dicing sheet 80 constitute a group of semiconductor chips 920 with protective films.
The semiconductor chip 91 with a protective film obtained by the manufacturing method (3) is the same as the semiconductor chip 91 with a protective film obtained by the manufacturing method (1).

<Pickup process>
After the dividing and cutting processes, as shown in Figure 7 (e), a pick-up process is performed in which the semiconductor chip 91 with a protective film (semiconductor chip 90 with the protective film 130' after cutting) is pulled away from the dicing sheet 80 and picked up, thereby allowing the semiconductor chip 91 with a protective film to be removed from the group of semiconductor chips with a protective film 920.
The pick-up step in the manufacturing method (3) can be carried out in the same manner as the pick-up step in the manufacturing method (1).

<Other processes>
The manufacturing method (3) may include a step other than the adhering step, laminating step, curing step, dividing step, cutting step, and picking up step.
The types of other steps and the timing of performing them can be selected arbitrarily depending on the purpose, and are not particularly limited.

The other process may be, for example, a printing process similar to that in manufacturing method (1) (not shown). In the printing process, laser light can be irradiated onto the second surface of the protective film-forming film or protective film through the dicing sheet from the side of the dicing sheet opposite the protective film-forming film side or from the outside opposite the protective film side.

In this embodiment, the printing process can be performed after the adhering process, and is preferably performed between the curing process and the dividing process, or between the curing process and the cutting process.

<Timing of curing process>
Up to this point, the case where the curing step is performed between the laminating step and the dividing step, and between the laminating step and the cutting step in the manufacturing method (3) has been described, but the timing of performing the curing step in the manufacturing method (3) is not limited to this. For example, in the manufacturing method (3), the curing step may be performed between the adhering step and the laminating step, between the printing step and the dividing step, between the printing step and the cutting step, between the dividing step and the cutting step, between the dividing step and the pick-up step, between the cutting step and the pick-up step, or after the pick-up step.

<<Manufacturing method (4)>>
The manufacturing method (4) is a method for manufacturing a protective film-attached workpiece comprising a workpiece obtained by processing a workpiece and a protective film provided at a location on the workpiece, the protective film being formed from a protective film-forming film according to one embodiment of the present invention, which is not part of the composite sheet for forming a protective film. Because the protective film-forming film is non-hardening, the protective film-forming film after being attached to a location on the workpiece constitutes the protective film. The manufacturing method includes an attaching step of attaching the protective film-forming film to a desired location on the workpiece to create a second laminate in which the protective film is provided (laminated) on the workpiece, a processing step of processing the workpiece after the attaching step, and a cutting step of cutting the protective film after the attaching step. In manufacturing method (4), the protective film-forming film after being attached to the workpiece in the attaching step constitutes the protective film.
Manufacturing method (4) is the same as manufacturing method (3) except that it does not include the curing step and the protective film-forming film after being attached to the workpiece is used as the protective film, regardless of the type of workpiece.

When the workpiece is a semiconductor wafer, manufacturing method (4) may be a method for manufacturing a semiconductor chip with a protective film, the semiconductor chip having a semiconductor chip and a protective film provided on the back surface of the semiconductor chip, wherein the protective film is formed from a protective film-forming film that is not part of the protective film-forming composite sheet, and since the protective film-forming film is non-curing, the protective film is the protective film after being attached to the back surface of the semiconductor wafer to obtain the semiconductor chip. The manufacturing method may include a bonding step of bonding the protective film-forming film to the back surface of the semiconductor wafer to produce a second laminate in which the protective film-forming film is provided (laminated) on the semiconductor wafer, a dividing step of dividing the semiconductor wafer after the bonding step to produce the semiconductor chip, and a cutting step of cutting the protective film after the bonding step.

The present invention will be described in more detail below using specific examples. However, the present invention is not limited to the examples shown below.

<Raw materials for resin production>
The full names of the raw materials for producing the resins, which are abbreviated in the examples and comparative examples, are shown below.
BA: n-butyl acrylate MA: methyl acrylate GMA: glycidyl methacrylate HEA: 2-hydroxyethyl acrylate

<Materials for producing the protective film-forming composition>
The raw materials used in the production of the protective film-forming composition are shown below.
[Polymer component (A)]
(A)-1: Acrylic resin ("Teisan Resin SG-P3" manufactured by Nagase ChemteX Corporation)
(A)-2: Acrylic resin (weight average molecular weight 500,000, glass transition temperature −2° C.) obtained by copolymerizing BA (12 parts by mass), MA (65 parts by mass), GMA (7 parts by mass), and HEA (16 parts by mass).
(A)-3: Acrylic resin (weight average molecular weight 450,000, glass transition temperature 6°C) obtained by copolymerizing MA (87 parts by mass) and HEA (13 parts by mass).
(A)-4: Acrylic resin (weight average molecular weight 500,000, glass transition temperature −31° C.) obtained by copolymerizing BA (60 parts by mass), MA (10 parts by mass), GMA (17 parts by mass), and HEA (13 parts by mass).
[Thermosetting component (B)]
(B)-1: Bisphenol A epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 184 to 194 g/eq)
(B)-2: Dicyclopentadiene-type epoxy resin (DIC Corporation, "Epicron HP-7200", epoxy equivalent: 254 to 264 g/eq)
[Thermal curing agent (C)]
(C)-1: Dicyandiamide ("DICY7" manufactured by Mitsubishi Chemical Corporation)
[Curing accelerator (D)]
(D)-1: 2-phenyl-4,5-dihydroxymethylimidazole ("Curesol 2PHZ" manufactured by Shikoku Chemicals Corporation)
[Filler (E)]
(E)-1: Silica filler ("SC2050MA" manufactured by Admatechs Co., Ltd., silica filler surface-modified with an epoxy compound, average particle diameter 0.5 μm)
[Coupling agent (F)]
(F)-1: Oligomeric silane coupling agent having an epoxy group, a methyl group, and a methoxy group ("X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent: 280 g/eq)
[Crosslinking agent (G)]
(G)-1: Tolylene diisocyanate-based trifunctional crosslinking agent ("Coronate L" manufactured by Tosoh Corporation)
[Colorant (J)]
(J)-1: Titanium oxide-based white pigment ("NX-501 White" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.)
(J)-2: Organic black pigment ("6377 Black" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.)

[Example 1]
<<Production of protective film-forming film>>
<Production of protective film-forming composition (III)>
Polymer component (A)-1 (125 parts by mass), thermosetting component (B)-1 (60 parts by mass), thermosetting component (B)-2 (30 parts by mass), thermosetting agent (C)-1 (2 parts by mass), curing accelerator (D)-1 (2 parts by mass), filler (E)-1 (360 parts by mass), coupling agent (F)-1 (2 parts by mass), crosslinking agent (G)-1 (2 parts by mass), and colorant (J)-1 (2.3 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain a thermosetting protective film-forming composition (III) having a total concentration of all components other than the solvent of 45% by mass. Note that the blending amounts of all components other than the solvent shown here are the blending amounts of the target product excluding the solvent.

<Production of Protective Film-Forming Film>
A release film (second release film, "SP-PET50 1031" manufactured by Lintec Corporation, thickness 50 μm) made of polyethylene terephthalate film, one side of which had been subjected to a silicone treatment for release, was used, and the protective film-forming composition (III) obtained above was applied to the release-treated surface, followed by drying at 100°C for 2 minutes, thereby producing a thermosetting protective film-forming film having a thickness of 25 μm.

Furthermore, the release-treated surface of a release film (first release film, "SP-PET38 1031" manufactured by Lintec Corporation, thickness 38 μm) was attached using a laminating roll to the exposed surface of the obtained protective film-forming film that was not provided with the second release film. The temperature of the laminating roll was 60°C, the application pressure was 0.4 MPa, and the application speed was 1 m/min. As a result, a laminated film was obtained that was composed of the protective film-forming film, the first release film provided on one side of the protective film-forming film, and the second release film provided on the other side of the protective film-forming film.

<<Manufacturing chips with protective film>>
The first release film was removed from the laminated film obtained above, and the exposed surface of the resulting protective film-forming film was attached to the entire surface of a mirror-polished surface corresponding to the back surface of an 8-inch silicon wafer (thickness 300 μm) that did not have bumps (projecting electrodes). The attachment was performed using a laminating roll, with the laminating roll temperature set to 23 ° C., the attachment pressure set to 0.3 MPa, and the attachment speed set to 50 mm / s. Furthermore, the second release film was removed from the protective film-forming film after this attachment, and the second laminate composed of the protective film-forming film and the silicon wafer was obtained (attaching process).
Next, this laminate was heat-treated at 140° C. for 2 hours using an oven manufactured by Espec Corporation to thermally cure the protective film-forming film and form a protective film (curing step).
Next, after the heat-cured second laminate was slowly cooled, a dicing sheet ("Adwill G-562" manufactured by Lintec Corporation) was attached to the exposed surface of the protective film (i.e., the surface opposite to the side on which the silicon wafer was provided) to obtain a laminate (the cured second laminate) composed of the dicing sheet, protective film, and silicon wafer stacked in this order in the thickness direction (lamination process). Then, using a dicing blade, the silicon wafer was divided (diced) into 2 mm x 2 mm pieces to produce silicon chips, and the protective film was also cut to the same size. This resulted in the production of a group of protective film-coated silicon chips, each comprising the silicon chip and the protective film after cutting provided on the back surface of the silicon chip, held in a large number in an aligned state on the dicing sheet (division process, cutting process).
Next, the silicon chips with protective films in the group of silicon chips with protective films were picked up by being separated from the dicing sheet (pick-up step).

<<Evaluation of protective film-forming films>>
<Measurement of reflectance of cured product to light (400 to 700 nm)>
The first release film was removed from the laminate film obtained above, which included the first release film, protective film-forming film, and second release film. The protective film-forming film was then heat-cured by heating at 140°C for 2 hours to obtain a cured product (i.e., a protective film). The exposed surface of the obtained cured product (the surface opposite to the side provided with the second release film) was measured for the amount of total reflected light, which combined specular reflected light (specular reflected light) and diffuse reflected light, in the wavelength range of 380 to 780 nm using the SCI method at 1 nm intervals. Furthermore, the amount of total reflected light was also measured using a barium sulfate reference plate in the same manner as above. In both cases, the amount of total reflected light was measured using a UV-Vis spectrophotometer (Shimadzu Corporation's "UV-VIS-NIR SPECTROPHOTOMETER UV-3600"). Furthermore, a Shimadzu Corporation "Large Sample Chamber MPC-3100" was used as the sample folder, and a Shimadzu Corporation "Integrating Sphere Accessory ISR-3100" was used as the integrating sphere, with the angle of incidence of light incident on the measurement object being 8°. Then, the ratio of the measured value for the cured product to the measured value for the reference plate ([measured light amount of total light reflected by the cured product of the protective film-forming film] / [measured light amount of total light reflected by the reference plate] × 100), i.e., the relative total light reflectance of the cured product of the protective film-forming film, was determined, and this was adopted as the reflectance of light (400 to 700 nm). The results are shown in Table 1.

<Calculation of Y value, x value, and y value in Yxy color system of cured product>
Using the measured value of the reflectance of the above light (400 to 700 nm), the Y value, x value, and y value in the Yxy color system of the cured product of the protective film-forming film (i.e., the protective film) were calculated under the conditions of C light source (2° field of view). The results are shown in Table 1.

<Measurement of Sa on the surface of the cured product>
The first release film was removed from the laminated film obtained above, and the resulting exposed surface (the surface opposite to the side with the second release film) was attached to the entire mirror-polished surface of an 8-inch silicon wafer (thickness 300 μm) using a laminating roll. At this time, the temperature of the laminating roll was 23 ° C., the attachment pressure was 0.3 MPa, and the attachment speed was 50 mm / s. Next, the second release film was removed from the protective film-forming film, and the resulting silicon wafer with the protective film-forming film (a laminate of the protective film-forming film and the silicon wafer) was heated at 140 ° C. for 2 hours to thermally cure the protective film-forming film. The arithmetic mean height Sa of the exposed surface (the surface opposite to the side attached to the silicon wafer) of the cured product of the obtained protective film-forming film (i.e., the protective film) was measured in accordance with ISO 25178. More specific measurement of Sa is as follows.
That is, using a scanning white light interference microscope ("VS-1550" manufactured by Hitachi High-Tech Science Corporation), the surface of the cured protective film-forming film to be measured was observed at a magnification of 50 times in a multiple field of view mode. At this time, in the observation field of view, an area with a length of 0.36 mm in the X-axis direction and a length of 0.27 mm in the Y-axis direction was set, and three columns in the X-axis direction and four rows in the Y-axis direction were observed, thereby observing a total of 12 cells. Then, the images of the 12 cells were combined to form a single image of 1.0 mm x 1.0 mm, and Sa was measured for the entire area of this single combined image. The results are shown in Table 1.

<Evaluation of laser marking visibility of cured product>
The laminate (i.e., the silicon wafer with the protective film) of the cured product of the protective film-forming film for which the Sa measurement was performed above was placed in a laser marking device (EO Technics Corporation, "CSM300M"). Then, the surface (i.e., the exposed surface) of the cured product (i.e., the protective film) opposite the silicon wafer side was directly irradiated with laser light, thereby performing laser marking on the surface. At this time, the laser wavelength was set to 532 nm, the scan speed was set to 300 mm/s, and the character string "ABCDEF" was printed. The character size was 400 μm vertically and 300 μm horizontally per character, and the character spacing was set to 50 μm. Next, three evaluators visually observed the laser-printed characters, and the laser marking visibility of the cured product was evaluated according to the following criteria. The results are shown in Table 1.
[Evaluation criteria]
A: All three evaluators were able to see all the letters.
B: Only one of the three evaluators was unable to see at least one letter.
C: Two or more of the three evaluators were unable to see at least one letter.

<Evaluation of visibility suppression of chips with protective film in light-emitting devices>
Using the silicon chip with the protective film and measuring 2 mm x 2 mm obtained above, a pseudo-evaluation structure including a light-emitting device was fabricated as shown below.
Specifically, a surface-mount white LED package (size: 3.2 mm length × 2.8 mm width × 2 mm height, luminous intensity: 230 mcd (typical)) was mounted on a white substrate (size: 50 mm × 50 mm). The LED package was oriented such that its light emission direction was opposite the white substrate. One protective film-equipped silicon chip was mounted 2 mm from one widthwise end of the LED package, and another protective film-equipped silicon chip was mounted 10 mm from the other widthwise end of the LED package, resulting in a total of two protective film-equipped silicon chips mounted on the white substrate. Each of the two protective film-equipped silicon chips was mounted on the white substrate with its silicon chip facing the white substrate and its protective film facing away from the white substrate. A 15 mm high white resin housing (size: 40 mm x 40 mm) was placed at a position 20 mm away from the center of the LED package in four directions, namely the length and width directions of the LED package, and a light diffusion plate (size: 45 mm x 45 mm) with a haze of 50% was placed on top of it to prepare a pseudo-evaluation structure including a light-emitting device.
Next, the assembly was placed in a dark room, and the LED package was caused to emit light at a current value of 20 mA. The light-emitting device in this state was visually observed from a position 70 cm directly above it, and the visibility of the protective film-coated chip in the light-emitting device was evaluated according to the following criteria. The results are shown in Table 1.
[Evaluation criteria]
A: When the LED package was made to emit light, the two silicon chips with protective film were not visible.
B: When the LED package was lit, only one silicon chip with a protective film was visible.
C: When the LED package was made to emit light, two silicon chips with protective film were visible.

<Evaluation of visibility of protective film on chip with protective film>
In a room with a general fluorescent lamp on, three evaluators visually observed the silicon chip with a protective film, measuring 2 mm x 2 mm, obtained above, for 3 seconds from a position 50 cm directly above it, confirmed whether the presence of the protective film was visible, and evaluated the visibility of the protective film on the chip with the protective film according to the following criteria. The results are shown in Table 1.
[Evaluation criteria]
A: All three evaluators could see the protective film.
B: Only one of the three evaluators could not visually recognize the protective film.
C: Two or more of the three evaluators could not visually recognize the protective film.

<<Production of protective film-forming film, production of chip with protective film, and evaluation of protective film-forming film>>
[Examples 2 to 6, Comparative Examples 1 and 2]
A protective film-forming film and a chip with a protective film were produced and the protective film-forming film was evaluated in the same manner as in Example 1, except that either one or both of the types and amounts of the components blended during the production of the protective film-forming composition (III) were changed so that the types and contents of the components contained in the protective film-forming composition (III) were as shown in Tables 1 and 2. The results are shown in Tables 1 and 2.
In addition, the notation "-" in the column of the components contained in the protective film-forming composition means that the component is not blended (the component is not contained).

As is clear from the above results, in Examples 1 to 6, the visibility of the chip with the protective film in the light-emitting device was highly inhibited, light absorption by the protective film was suppressed, and further, the visibility of the protective film in the chip with the protective film under normal conditions was high.
In Examples 1 to 6, the reflectance of the cured product of the protective film-forming film for light (400 to 700 nm) was 20.5% or more, which was sufficiently high. The protective film-forming films of Examples 1 to 6 contained a white pigment (colorant (J)-1).

In Examples 1 to 6, the cured product of the protective film-forming film had a Y value of 25.1 or more, an x value of 0.29 to 0.32, and a y value of 0.30 to 0.33 in the Yxy color system. In addition, the maximum reflectance of the cured product for light (400 to 700 nm) was 26.2% or more.

Furthermore, in Examples 1 to 6, the laser marking visibility of the protective film was also high, and the protective film-forming film had excellent properties.
In Examples 1 to 6, the cured protective film-forming film had an Sa of 65.1 nm or less.

In contrast to this, in Comparative Example 1, the visibility of the chip with the protective film in the light-emitting device was low, and the light absorption by the protective film was not suppressed.
In Comparative Example 1, the reflectance of light (400 to 700 nm) of the cured product of the protective film-forming film was low, at 11.0% or less. The protective film-forming film of Comparative Example 1 did not contain a white pigment (colorant (J)-1) but contained a black pigment (colorant (J)-2).

In Comparative Example 2, the visibility of the protective film on the chip with the protective film under normal conditions was low.
In Comparative Example 2, the reflectance of light (400 to 700 nm) of the cured product of the protective film-forming film was low, at 18.1% or less. The protective film-forming film of Comparative Example 2 did not contain either the white pigment (colorant (J)-1) or the black pigment (colorant (J)-2).

This invention can be used in the manufacture of various substrate devices, including semiconductor devices.

101, 102, 103, 104, 1011...Composite sheet for forming a protective film, 10, 20...Support sheet, 10a, 20a...One side (first side) of the support sheet, 11...Substrate, 12...Adhesive layer, 13, 23...Protective film-forming film, 13a, 23a...One side (first side) of the protective film-forming film, 13b, 23b...Other side (second side) of the protective film-forming film, 13'...Protective film, 130'...Protective film after cutting, 9...Semiconductor wafer (workpiece), 90...Semiconductor chip (workpiece), 9b...Backside of semiconductor wafer, 90b...Backside of semiconductor chip, 901...First laminate, 9011...Cured first laminate, 902...Second laminate, 9021...Cured second laminate, 91...Semiconductor chip with protective film (protective film-containing workpiece)

Claims (9)

A protective film-forming film for forming a protective film on any part of a workpiece obtained by processing a workpiece,
the workpiece is a wafer or a semiconductor device panel, and the processing is division;
When the protective film-forming film is curable, the reflectance of the cured product of the protective film-forming film in the entire wavelength range of 400 to 700 nm is 20% or more,
When the protective film-forming film is non-curable, the reflectance of the protective film-forming film for light in the entire wavelength range of 400 to 700 nm is 20% or more,
When the protective film-forming film is curable, the arithmetic mean height Sa of one surface or both surfaces of the cured product of the protective film-forming film is 100 nm or less,
When the protective film-forming film is non-curable, the arithmetic mean height Sa of one surface or both surfaces of the protective film-forming film is 100 nm or less . A protective film-forming film for forming a protective film on any part of a workpiece obtained by processing a workpiece,
the workpiece is a wafer or a semiconductor device panel, and the processing is division;
When the protective film-forming film is curable, the reflectance of the cured product of the protective film-forming film in the entire wavelength range of 400 to 700 nm is 20% or more,
When the protective film-forming film is non-curable, the reflectance of the protective film-forming film for light in the entire wavelength range of 400 to 700 nm is 20% or more,
When the protective film-forming film is curable, the x value in a Yxy color system calculated from the reflectance of light in a wavelength range of 380 to 780 nm of a cured product of the protective film-forming film is 0.26 to 0.34, and the y value in the Yxy color system is 0.26 to 0.34,
When the protective film-forming film is non-curable, the x value in a Yxy color system calculated from the reflectance of the protective film in a wavelength range of 380 to 780 nm is 0.26 to 0.34, and the y value in the Yxy color system is 0.26 to 0.34 . A protective film-forming film for forming a protective film on any part of a workpiece obtained by processing a workpiece,
the workpiece is a wafer or a semiconductor device panel, and the processing is division;
When the protective film-forming film is curable, the reflectance of the cured product of the protective film-forming film in the entire wavelength range of 400 to 700 nm is 20% or more,
When the protective film-forming film is non-curable, the reflectance of the protective film-forming film for light in the entire wavelength range of 400 to 700 nm is 20% or more,
When the protective film-forming film is curable, a Y value in a Yxy color system calculated from the reflectance of light in a wavelength range of 380 to 780 nm of a cured product of the protective film-forming film is 20 or more,
When the protective film-forming film is non-curable, the protective film-forming film has a Y value in the Yxy color system calculated from the reflectance of light in a wavelength range of 380 to 780 nm of 20 or more . A protective film-forming film for forming a protective film on any part of a workpiece obtained by processing a workpiece,
the workpiece is a wafer or a semiconductor device panel, and the processing is division;
When the protective film-forming film is curable, the reflectance of the cured product of the protective film-forming film in the entire wavelength range of 400 to 700 nm is 20% or more,
When the protective film-forming film is non-curable, the reflectance of the protective film-forming film for light in the entire wavelength range of 400 to 700 nm is 20% or more,
The protective film-forming film contains a white pigment . When the protective film-forming film is curable, the maximum value of the reflectance of the cured product of the protective film-forming film in a wavelength range of 400 to 700 nm is 25% or more,
When the protective film-forming film is non-curable, the maximum reflectance of the protective film-forming film in the wavelength range of 400 to 700 nm is 25% or more. The protective film-forming film according to any one of claims 1 to 4 . The protective film-forming film according to any one of claims 1 to 5 , wherein the workpiece is a chip in a light-emitting device. A support sheet and a protective film-forming film provided on one surface of the support sheet,
A composite sheet for forming a protective film, wherein the protective film-forming film is the protective film-forming film according to any one of claims 1 to 6 . A method for manufacturing a workpiece with a protective film,
The workpiece with a protective film includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece,
the workpiece is a wafer or a semiconductor device panel, and the processing is division;
The protective film is formed from the protective film-forming film in the composite sheet for forming a protective film according to claim 7 ,
When the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film-forming film after being attached to any location on the workpiece is the protective film,
The manufacturing method includes a pasting step of pasting the protective film-forming film in the composite sheet for forming a protective film to a desired location on the workpiece, thereby producing a first laminate in which the composite sheet for forming a protective film is provided on the workpiece;
a processing step of processing the workpiece after the attaching step to produce the workpiece;
a cutting step of cutting the protective film-forming film or the protective film after the attaching step,
If the protective film-forming film is curable, the method for manufacturing a workpiece with a protective film further includes a curing process for forming the protective film by curing the protective film-forming film after the attaching process. A method for manufacturing a workpiece with a protective film,
The workpiece with a protective film includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece,
the workpiece is a wafer or a semiconductor device panel, and the processing is division;
The protective film is formed from the protective film-forming film according to any one of claims 1 to 6 ,
When the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film-forming film after being attached to any location on the workpiece is the protective film,
The manufacturing method includes a pasting step of pasting the protective film-forming film to a desired location of the workpiece to produce a second laminate in which the protective film-forming film or protective film is provided on the workpiece;
a processing step of processing the workpiece after the attaching step to produce the workpiece;
a cutting step of cutting the protective film-forming film or the protective film after the attaching step,
If the protective film-forming film is curable, the method for manufacturing a workpiece with a protective film further includes a curing process for forming the protective film by curing the protective film-forming film after the attaching process.