JP7541503B2 - Thermosetting resin film and first protective film forming sheet - Google Patents

Description

The present invention relates to a thermosetting resin film and a sheet for forming a first protective film.
This application claims priority based on Japanese Patent Application No. 2019-032829, filed in Japan on February 26, 2019, the contents of which are incorporated herein by reference.

Traditionally, when mounting a multi-pin LSI package used in an MPU, gate array, etc., on a printed wiring board, a flip-chip mounting method has been used in which a workpiece (e.g., a semiconductor wafer, etc.) with protruding electrodes (e.g., bumps, pillars, etc.) is used, and the protruding electrodes in the workpiece (e.g., a semiconductor chip which is a divided part of a semiconductor wafer, etc.) are brought face-to-face and into contact with corresponding terminal parts on the board using the so-called face-down method, and melt/diffusion bonding is performed.

When this mounting method is adopted, in order to protect the circuit surface of the workpiece and the protruding electrode, a curable resin film may be attached to the surface of the protruding electrode and the circuit surface of the workpiece, and this film may be cured to form a protective film on these surfaces.
In this specification, the surface of the protruding electrode and the circuit surface of the workpiece or the processed workpiece may be referred to as the "protruding electrode forming surface."

The curable resin film is usually attached to the protruding electrode formation surface of the workpiece in a state softened by heating. By doing so, the upper part including the top of the protruding electrode penetrates the curable resin film and protrudes from the curable resin film. Meanwhile, the curable resin film spreads between the protruding electrodes of the workpiece so as to cover them, adheres to the circuit surface, and covers the surfaces of the protruding electrodes, especially the surfaces in the vicinity of the circuit surface, embedding the protruding electrodes. After this, the curable resin film is further cured to cover the circuit surface of the workpiece and the surfaces in the vicinity of the circuit surface of the protruding electrodes, becoming a protective film that protects these areas.

When a semiconductor wafer is used, the semiconductor chip used in this mounting method can be obtained, for example, by grinding or dicing the surface opposite to the circuit surface of a semiconductor wafer having protruding electrodes formed on the circuit surface to divide the wafer.
In the process of obtaining such semiconductor chips, a curable resin film is usually attached to the surface on which the protruding electrodes are formed in order to protect the circuit surface and protruding electrodes of the semiconductor wafer, and this film is cured to form a protective film on the surface on which the protruding electrodes are formed.
Furthermore, the semiconductor wafer is divided into semiconductor chips, and finally the semiconductor chips are provided with a protective film on the surface on which the protruding electrodes are formed (sometimes referred to in this specification as "semiconductor chips with protective film") (see Patent Document 1).

Such a workpiece having a protective film on the protruding electrode forming surface (sometimes referred to in this specification as a "workpiece with protective film") is further mounted on a substrate to form a package, and the desired device is constructed using this package. When a semiconductor chip with a protective film is mounted on a substrate, the desired semiconductor device is constructed using the semiconductor package obtained thereby.

Japanese Patent No. 5515811

When conventional curable resin films, such as that disclosed in Patent Document 1, are used, the division of the work (e.g., the division of a semiconductor wafer into semiconductor chips) is usually performed by blade dicing using a dicing blade. However, although this method is the most widely used, it is not suitable for manufacturing workpieces that are small in size or thin in thickness, for example. This is because such workpieces are prone to cracking and chipping.

Therefore, the present invention aims to provide a resin film capable of forming a protective film for protecting the protruding electrode formation surface of a workpiece or a workpiece processed product, which makes it possible to apply a new method for dividing a workpiece by using this resin film.

The present invention provides a thermosetting resin film for forming a first protective film on a surface having a protruding electrode of a workpiece by attaching the film to the surface and thermally curing the film, the thermosetting resin film being a single layer having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm and being constituted by laminating two or more layers of the thermosetting resin film, each layer having a thickness of less than 200 μm, the transmittance of light having a wavelength of 1342 nm being 50% or more.
The thermosetting resin film of the present invention may contain a thermosetting component other than an acrylic resin having an epoxy group, and the ratio of the content of the thermosetting component in the thermosetting resin film to the total mass of the thermosetting resin film may be 40 mass% or more.
The present invention also provides a first protective film-forming sheet comprising a first support sheet and the thermosetting resin film on one surface of the first support sheet.

According to the present invention, a resin film is provided that can form a protective film for protecting the protruding electrode formation surface of a workpiece or a workpiece processed product, and by using this resin film, a new method for dividing the workpiece can be applied.

1 is a cross-sectional view showing an example of a state in which a first protective film is formed on a surface on which projecting electrodes are formed by using a curable resin film according to one embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view illustrating an example of a first protective film-forming sheet according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a schematic diagram of another example of the first protective film-forming sheet according to one embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a schematic diagram of still another example of a first protective film-forming sheet according to an embodiment of the present invention. 1 is an enlarged cross-sectional view for illustrating a method for manufacturing a workpiece with a first protective film when a sheet for forming a first protective film according to one embodiment of the present invention is used. FIG. 1 is an enlarged cross-sectional view for illustrating a method for manufacturing a workpiece with a first protective film when a sheet for forming a first protective film according to one embodiment of the present invention is used. FIG. 1 is an enlarged cross-sectional view for illustrating a method for manufacturing a workpiece with a first protective film when a sheet for forming a first protective film according to one embodiment of the present invention is used. FIG. 1 is an enlarged cross-sectional view for illustrating a method for manufacturing a workpiece with a first protective film when a sheet for forming a first protective film according to one embodiment of the present invention is used. FIG. 1 is an enlarged cross-sectional view for illustrating a method for manufacturing a workpiece with a first protective film when a sheet for forming a first protective film according to one embodiment of the present invention is used. FIG. 1 is an enlarged cross-sectional view for illustrating a method for manufacturing a workpiece with a first protective film when a sheet for forming a first protective film according to one embodiment of the present invention is used. FIG.

◇Thermosetting resin film, sheet for forming first protective film The thermosetting resin film of one embodiment of the present invention is a thermosetting resin film for forming a first protective film on a surface having a protruding electrode of a workpiece (sometimes referred to in this specification as the "protruding electrode forming surface") by being attached to the surface and thermally cured, and the transmittance of light with a wavelength of 1342 nm of the thermosetting resin film in one layer having a thickness of 200 μm, or the laminated film having a total thickness of 200 μm and constituted by stacking two or more layers of the thermosetting resin film, each less than 200 μm in thickness, is 50% or more.

In addition, the first protective film forming sheet according to one embodiment of the present invention comprises a first support sheet, and the thermosetting resin film is provided on one surface of the first support sheet. In the first protective film forming sheet, the "thermosetting resin film" is sometimes referred to as a "thermosetting resin layer."

In this embodiment, the workpiece may be, for example, a semiconductor wafer.
An example of the workpiece is a semiconductor chip which is a divided part of a semiconductor wafer.
The processing of the workpiece includes, for example, division.
Examples of the protruding electrodes include bumps, pillars, etc. The protruding electrodes are provided on the connection pads of the workpiece and are made of eutectic solder, high-temperature solder, gold, copper, or the like.

The first protective film forming sheet is used by being attached to the protruding electrode forming surface of the work (i.e., the surface of the protruding electrodes and the circuit surface of the work) via the thermosetting resin film (thermosetting resin layer). The thermosetting resin film after attachment increases in fluidity when heated, spreads between the protruding electrodes so as to cover the protruding electrodes, and adheres to the circuit surface, while covering the surface of the protruding electrodes, particularly the surface of the area near the circuit surface, and embeds the protruding electrodes. The thermosetting resin film in this state is further hardened by heating, and finally forms the first protective film, which protects the circuit surface and the protruding electrodes in a state of adherence to them.

Furthermore, when the thermosetting resin film is applied to the surface of the workpiece on which the protruding electrodes are formed, the upper portion of the protruding electrodes, including the top portion, may be able to penetrate the thermosetting resin film and protrude from the thermosetting resin film. In such a case, the workpiece is immediately ready for flip-chip connection to the circuit surface of the substrate. As will be described later, the upper portion of the protruding electrodes must be exposed at the final stage of the workpiece.
On the other hand, if the upper part of the protruding electrode including the top part does not protrude from the thermosetting resin film when the thermosetting resin film is applied to the protruding electrode forming surface of the work, the upper part of the protruding electrode is exposed by separately removing the thermosetting resin film remaining on the upper part of the protruding electrode or the first protective film formed by the hardening of the thermosetting resin film, whereby the workpiece becomes ready for flip chip connection to the circuit surface of the substrate.

In this way, by using the thermosetting resin film of this embodiment, the circuit surface of the workpiece and the portion of the protruding electrode near the circuit surface, i.e., the base, are adequately protected by the first protective film.

After the first protective film forming sheet is attached, the workpiece is ground on the surface opposite to the circuit surface as necessary, the first support sheet is removed, and then the thermosetting resin film is heated to embed the protruding electrodes and form the first protective film. The workpiece is then divided (i.e., divided into individual workpieces) and the first protective film is cut, and the resulting workpiece (sometimes referred to in this specification as "workpiece with first protective film") having the first protective film on the protruding electrode forming surface after cutting is used to manufacture the desired substrate device, such as a semiconductor device. These steps will be described in detail later.

In this specification, unless otherwise specified, the mere description "curable resin film" means "curable resin film before curing", and the mere description "curable resin layer" means "curable resin layer before curing". For example, "thermosetting resin film" means "thermosetting resin film before curing", and "first protective film" means the cured product of the thermosetting resin film.

The thermosetting resin film of the present embodiment is suitable for applying a method different from the conventional method for dividing a workpiece into workpieces (in other words, for individualization). Here, examples of the "method different from the conventional method" include the following methods.
That is, a workpiece having a first protective film formed from the thermosetting resin film on the protruding electrode forming surface is irradiated with laser light to form a modified layer inside the workpiece. Next, a force is applied to the workpiece after the modified layer is formed. More specifically, in this embodiment, the workpiece is expanded in a direction parallel to its circuit surface. As a result, the workpiece is divided at the site of the modified layer. At this time, there are cases where the first protective film can also be cut at the same time by applying a force to the first protective film, more specifically, by expanding the first protective film in a direction parallel to the attachment surface to the workpiece. At this time, the first protective film is cut along the dividing portion of the workpiece. In that case, a workpiece with a first protective film is immediately obtained, which includes a workpiece processed product and the first protective film formed on the protruding electrode forming surface of the workpiece after cutting. On the other hand, if the first protective film cannot be cut at the same time when the workpiece is divided, the first protective film is further cut after the workpiece is divided. As a result, a workpiece with a first protective film similar to the above is obtained.

This method of dividing a workpiece that involves the formation of a modified layer is called Stealth Dicing (registered trademark), and is fundamentally different from laser dicing, in which the workpiece is cut from its surface by irradiating it with laser light, removing the irradiated area of the workpiece.

<<Light transmittance of thermosetting resin film>>
As described above, the transmittance of one layer of the thermosetting resin film having a thickness of 200 μm is 50% or more for light having a wavelength of 1,342 nm.
Furthermore, as described above, the transmittance of light with a wavelength of 1,342 nm of a laminate film having a total thickness of 200 μm, which is formed by laminating two or more of the thermosetting resin films each having a thickness of less than 200 μm, is 50% or more.

When applying the method of forming a modified layer inside the workpiece by dividing the workpiece as described above, the modified layer can be formed by irradiating the workpiece with a laser beam having a wavelength of 1342 nm. At this time, the laser beam may be irradiated from the circuit side of the workpiece or from the back side of the workpiece. However, when the laser beam is irradiated from the circuit side of the workpiece, the laser beam is irradiated through the first protective film formed on the circuit side.
On the other hand, the transmittance of light of the same wavelength is almost or completely the same between the thermosetting resin film and its cured product (for example, the first protective film). Therefore, when the transmittance of light of wavelength 1342 nm of one layer of thermosetting resin film having a thickness of 200 μm is 50% or more, the transmittance of light of wavelength 1342 nm of the cured product is also 50% or more. Similarly, when the transmittance of light of wavelength 1342 nm of the laminated film is 50% or more, the transmittance of light of wavelength 1342 nm of the cured product is also 50% or more. That is, the first protective film formed using a thermosetting resin film of the same composition as that which satisfies such a condition of light transmittance transmits laser light of wavelength 1342 nm well. Therefore, a workpiece having such a first protective film on its circuit surface is suitable for forming a modified layer inside the workpiece by irradiating laser light from the circuit surface side.

In order to make the above-mentioned effects more pronounced, the transmittance of light with a wavelength of 1342 nm of a single layer of thermosetting resin film having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm, may be, for example, any of 60% or more, 70% or more, 80% or more, and 85% or more.

The upper limit of the transmittance of light with a wavelength of 1342 nm for a single layer of thermosetting resin film with a thickness of 200 μm or a laminated film with a total thickness of 200 μm is not particularly limited, and the higher the transmittance, the better. For example, in terms of the relative ease of manufacturing the thermosetting resin film, it is preferable that the transmittance of the light is 95% or less.

The light transmittance can be adjusted as appropriate within a range that is set by any combination of the above-mentioned lower and upper limits. In one embodiment, the light transmittance may be, for example, any of 50 to 95%, 60 to 95%, 70 to 95%, 80 to 95%, and 85 to 95%.

If the components contained in a single layer of thermosetting resin film having a thickness of 200 μm and the laminated film having a total thickness of 200 μm are the same, the light transmittance of these (the single layer of thermosetting resin film and the laminated film) will be the same regardless of whether the wavelength of light is 1342 nm.

The number of layers of the thermosetting resin film having a thickness of less than 200 μm that constitutes the laminated film is not particularly limited, but is preferably 2 to 6. With such a number of layers, the laminated film can be more easily produced.

The thicknesses of the thermosetting resin films constituting the laminate film and each of which has a thickness of less than 200 μm may all be the same, all be different, or only some of them may be the same.

In this embodiment, the reason why the thickness of one layer of the thermosetting resin film or laminate film, which is the target for specifying the light transmittance, is specified to 200 μm is that by using a thermosetting resin film or laminate film of such a thickness, the light transmittance can be measured more accurately and easily.
In this embodiment, the thickness of either the single-layer thermosetting resin film or the multiple-layer thermosetting resin film consisting of two or more layers is not limited to 200 μm, as will be described later.

The light transmittance can be adjusted, for example, by adjusting the type and content of the components contained in the thermosetting resin film, such as the colorant (I) and filler (D) described below, as well as the surface condition of the thermosetting resin film.

<<Thermosetting component content>>
The thermosetting resin film contains a thermosetting component other than an acrylic resin having an epoxy group, and the ratio of the content of the thermosetting component in the thermosetting resin film to the total mass of the thermosetting resin film ([content of thermosetting component in thermosetting resin film (parts by mass)]/[total mass of thermosetting resin film (parts by mass)]×100) is preferably 40% by mass or more. When the thermosetting resin film contains two or more types of thermosetting components, the content of the thermosetting component (parts by mass) mentioned above means the total content (parts by mass) of all types of the thermosetting components of these two or more types.

By satisfying the above-mentioned content ratio condition, the thermosetting resin film can suppress the upper part, including the top part, of the protruding electrode from remaining when the thermosetting resin film is attached to the protruding electrode-forming surface of the workpiece. In this way, the upper part of the protruding electrode protrudes through the attached thermosetting resin film, so that the final workpiece can be sufficiently electrically coupled to the substrate by the protruding electrode when flip-chip mounted.
If no thermosetting resin film remains on the top of the protruding electrode when the electrode is attached to the protruding electrode forming surface of the workpiece, then there is no need to separately remove such remaining thermosetting resin film or the first protective film formed by its hardening, thereby simplifying the process.

In the thermosetting resin film, the "thermosetting component" that specifies the above-mentioned content ratio is a component that exhibits a curing reaction by heating. However, acrylic resins having epoxy groups are not included in this thermosetting component. Examples of the thermosetting component include the thermosetting component (B) described below.
Examples of the thermosetting component (B) include epoxy-based thermosetting resins, polyimide resins, unsaturated polyester resins, etc. The epoxy-based thermosetting resins consist of an epoxy resin (B1) and a thermosetting agent (B2), and both of these two components are subject to the above-mentioned content ratio.
On the other hand, examples of acrylic resins having an epoxy group that are not included in the thermosetting component include those having an epoxy group among the acrylic resins in the polymer component (A) described below. For example, an acrylic resin having a glycidyl group is included in the acrylic resin having an epoxy group.

The thermosetting resin film may contain only one type of thermosetting component or two or more types, and if there are two or more types, the combination and ratio of these can be selected arbitrarily.

In order to obtain the above-mentioned advantageous effects more significantly, the ratio of the content of the thermosetting component in the thermosetting resin film to the total mass of the thermosetting resin film may be, for example, any one of 50 mass% or more, 60 mass% or more, 70 mass% or more, and 80 mass% or more.

The upper limit of the content ratio is not particularly limited. For example, in order to improve the film-forming properties of the thermosetting resin film, it is preferable that the total content ratio is 90 mass% or less.

The content ratio can be appropriately adjusted within a range set by any combination of the above-mentioned lower limit value and upper limit value. For example, in one embodiment, the content ratio may be any of 40 to 90 mass%, 50 to 90 mass%, 60 to 90 mass%, 70 to 90 mass%, and 80 to 90 mass%.

<<Total of X values>>
In the case where the thermosetting resin film contains two or more kinds of the thermosetting components other than the acrylic resin having an epoxy group, the thermosetting resin film is preferably formed by mixing the two or more kinds of the thermosetting components contained in the thermosetting resin film with each other, and the two or more kinds of the thermosetting components may be formed by mixing the two or more kinds of the thermosetting components with each other, and the two or more kinds of the thermosetting components may be formed by mixing the two or more kinds of the thermosetting resin films with each other.
X = [equivalent weight (g/eq) of functional group involved in the thermosetting reaction of the thermosetting component] x [content (parts by mass) of the thermosetting component in the thermosetting resin film] / [total content (parts by mass) of all types of thermosetting components in the thermosetting resin film]
and calculating a total value of the X values for all types of the thermosetting components contained in the thermosetting resin film, the total value may be, for example, 400 g/eq or less.

If the thermosetting resin film satisfies these conditions, when the workpiece with the first protective film described above is manufactured, the first protective film can be cut at the same time as the workpiece is divided at the site of the modified layer. Therefore, there is no need to provide a separate process for cutting the first protective film, and the workpiece with the first protective film can be manufactured with high efficiency.

The X value is calculated by the above formula for one type of thermosetting component contained in the thermosetting resin film.
The "thermosetting component" that is the subject of calculation of the X value is the same as the "thermosetting component" that defines the above-mentioned content ratio in the thermosetting resin film.

The "functional group involved in the thermosetting reaction of the thermosetting component" for calculating the X value is, for example, an epoxy group in the case of the epoxy resin (B1) described below, and a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, an anhydride group of an acid group, etc. in the case of the thermosetting agent (B2) described below. However, these are just examples of the functional group.

Consider a case where the thermosetting resin film contains p types of thermosetting components (p is an integer of 2 or more). These thermosetting components are denoted by M ₁ and M _p , respectively. The equivalent of the functional group of the thermosetting component M ₁ is denoted by m ₁ (g/eq), the equivalent of the functional group of the thermosetting component M _p is denoted by _mp (g/eq), the content of the thermosetting component M ₁ in the thermosetting resin film is denoted by C ₁ (parts by mass), and the content of the thermosetting component M _p in the thermosetting resin film is denoted by C _p (parts by mass).
In this case, for the thermosetting component _M1 , the X value (hereinafter referred to as " _X1 value") is calculated by the following formula.

Similarly, for the thermosetting component _Mp , the X value (hereinafter referred to as " _Xp value") is calculated by the following formula.

The total value of the X values (X ₁ , . . . , Xp) in all types of thermosetting components (M ₁ , . . . , M _P ) contained in the thermosetting resin film is as follows.

When the equivalent weight (m1 _{, mp} (g/eq)) of the functional group of the thermosetting component is not specified as a fixed value but as a numerical range with a certain width, the average value calculated from the lower limit value and the upper limit value of the numerical range may be adopted as the equivalent weight of the functional group.

In order to obtain the above-mentioned advantageous effects more significantly, the total value of the X values in the thermosetting resin film may be, for example, 375 g/eq or less, 350 g/eq or less, or 325 g/eq or less.

The lower limit of the total value of the X values is not particularly limited. For example, in order to suppress a decrease in flexibility due to an excessive crosslinking reaction in the thermosetting resin film, it is preferable that the total value of the X values is 100 g/eq or more.

The total value of the X values can be appropriately adjusted within a range set by any combination of the above-mentioned lower limit value and upper limit value. For example, in one embodiment, the total value of the X values may be any of 100 to 400 g/eq, 100 to 375 g/eq, 100 to 350 g/eq, and 100 to 325 g/eq.

Preferred examples of the thermosetting resin film include those that satisfy all of the above-mentioned conditions of light transmittance, the content ratio of the thermosetting component, and the total value of the X value.
For example, the thermosetting resin film contains two or more types of thermosetting components other than an acrylic resin having an epoxy group, and the ratio of the total content of all types of the thermosetting components to the total mass of the thermosetting resin film in the thermosetting resin film is 40 mass% or more;
a single layer of the thermosetting resin film having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm, which is formed by laminating two or more layers of the thermosetting resin film having a thickness of less than 200 μm, has a transmittance of 50% or more for light having a wavelength of 1342 nm;
Regarding the thermosetting component contained in the thermosetting resin film, the following formula is used for each type:
X = [equivalent weight (g/eq) of functional group involved in the thermosetting reaction of the thermosetting component] x [content (parts by mass) of the thermosetting component in the thermosetting resin film] / [total content (parts by mass) of all types of thermosetting components in the thermosetting resin film]
and calculating the total value of the X values for all the types of thermosetting components contained in the thermosetting resin film, the total value is preferably 400 g/eq or less.

<<Breaking strength of first protective film>>
The first protective film having a size of 20 mm×130 mm and a thickness of 40 μm may have a breaking strength of, for example, 55 MPa or less, measured by the following method. A first protective film having the same composition as a first protective film having the breaking strength of the upper limit or less is easier to cut by expanding, which will be described later.
The breaking strength of the first protective film can be the maximum stress measured when the first protective film is pulled in a direction parallel to its surface by the gripping tools with a distance between the gripping tools of 80 mm and a pulling speed of 200 mm/min.
The first protective film, which is the object of measurement of the maximum stress, can be obtained by heating a thermosetting resin film at 130° C. for two hours and thermally curing the film.

In order to make the above-mentioned effect more pronounced, the breaking strength of the first protective film may be, for example, any one of 52.5 MPa or less, 50 MPa or less, and 47.5 MPa or less.

The lower limit of the breaking strength of the first protective film is not particularly limited. In order to enhance the protective ability of the first protective film, it is preferable that the breaking strength of the first protective film is 0.1 MPa or more.

The breaking strength of the first protective film can be adjusted as appropriate within a range set by any combination of the above-mentioned lower limit and upper limit. In one embodiment, the breaking strength of the first protective film may be, for example, any of 0.1 to 55 MPa, 0.1 to 52.5 MPa, 0.1 to 50 MPa, and 0.1 to 47.5 MPa.

The breaking strength of the first protective film can be adjusted, for example, by adjusting the components contained in the composition for forming the thermosetting resin layer described below, particularly the type and content of the polymer component (A), coupling agent (E), filler (D), etc., as well as the thickness of the first protective film (in other words, the thickness of the thermosetting resin film).

In a workpiece or workpiece having a protruding electrode on a circuit surface, the surface opposite to the circuit surface (back surface) may be exposed. Therefore, a protective film containing an organic material (sometimes referred to as a "second protective film" in this specification to distinguish it from the first protective film) may be formed on this back surface. The second protective film is used to prevent cracks from occurring in the workpiece after the workpiece is divided or packaged. Such a workpiece having the second protective film on its back surface is finally incorporated into a target substrate device such as a semiconductor device.
On the other hand, the second protective film may be required to have a function of allowing information about the workpiece to be marked with a laser, or to hide the back surface of the workpiece. To satisfy such requirements, a curable resin film with adjusted light transmission characteristics that can form the second protective film by curing is known.
However, the second protective film for protecting the back surface of the workpiece and the first protective film for protecting the protruding electrode forming surface of the workpiece are formed at different positions on the workpiece, and therefore the required characteristics are different from each other, so it is usually difficult to immediately use a thermosetting resin film capable of forming the second protective film for forming the first protective film.

Figure 1 is a cross-sectional view showing an example of a state in which a first protective film is formed on a protruding electrode formation surface using the thermosetting resin film of this embodiment. Note that the figures used in the following description may show important 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.

A circuit surface 90a of the workpiece 90 shown here is provided with a plurality of protruding electrodes 91. In Fig. 1, reference numeral 90b denotes the surface (back surface) of the workpiece 90 opposite to the circuit surface 90a.
The protruding electrode 91 has a shape in which a part of a sphere is cut away by a flat surface, and the flat surface corresponding to the cut-away exposed portion is in contact with the circuit surface 90 a of the workpiece 90 .
The projecting electrode 91 is substantially spherical in shape.

The first protective film 12' is formed using the thermosetting resin film of this embodiment, and covers the circuit surface 90a of the workpiece 90, and further covers the area of the surface 91a of the protruding electrode 91 other than the top 910 of the protruding electrode 91 and its vicinity. In this way, the first protective film 12' adheres closely to the surface 91a other than the top 910 of the protruding electrode 91 and its vicinity, and also adheres closely to the circuit surface 90a of the workpiece 90, embedding the protruding electrode 91.
The above-mentioned substantially spherical shape of the protruding electrode 91 is particularly advantageous for forming the first protective film using the hardening resin film.

The height H ₉₁ of the protruding electrode 91 is not particularly limited, but is preferably 50 to 500 μm. When the height H ₉₁ of the protruding electrode 91 is equal to or greater than the lower limit, the function of the protruding electrode 91 can be further improved. When the height H ₉₁ of the protruding electrode 91 is equal to or less than the upper limit, the effect of suppressing the thermosetting resin film remaining on the upper part including the top part 910 of the protruding electrode 91 when the thermosetting resin film is attached to the protruding electrode forming surface of the workpiece 90 (i.e., the surface 91a of the protruding electrode 91 and the circuit surface 90a of the workpiece 90) is enhanced, and as a result, the effect of suppressing the formation of the first protective film 12′ on the upper part of the protruding electrode 91 is enhanced.
In this specification, the "height of the projecting electrode" refers to the height of the part of the projecting electrode that is located highest from the circuit surface of the workpiece or the workpiece (i.e., the top part).

The width W ₉₁ of the protruding electrode 91 is not particularly limited, but is preferably 50 to 600 μm. When the width W ₉₁ of the protruding electrode 91 is equal to or greater than the lower limit, the function of the protruding electrode 91 can be further improved. When the width W ₉₁ of the protruding electrode 91 is equal to or less than the upper limit, the effect of suppressing the thermosetting resin film remaining on the upper part including the top part 910 of the protruding electrode 91 when the thermosetting resin film is attached to the protruding electrode forming surface of the workpiece 90 (i.e., the surface 91a of the protruding electrode 91 and the circuit surface 90a of the workpiece 90) is enhanced, and as a result, the effect of suppressing the formation of the first protective film 12′ on the upper part of the protruding electrode 91 is enhanced.
In this specification, the "width of the protruding electrode" means the maximum value of the line segment obtained by drawing a straight line between two different points on the surface of the protruding electrode when the protruding electrode is viewed in a planar view looking down on the protruding electrode from a direction perpendicular to the circuit surface of the workpiece or workpiece.

The distance D ₉₁ between adjacent projecting electrodes 91 is not particularly limited, but is preferably 100 to 800 μm. When the distance D ₉₁ between the projecting electrodes 91 is equal to or greater than the lower limit, the effect of suppressing the thermosetting resin film remaining on the upper part including the top part 910 of the projecting electrode 91 when the thermosetting resin film is attached to the projecting electrode forming surface of the workpiece 90 (i.e., the surface 91a of the projecting electrode 91 and the circuit surface 90a of the workpiece 90) is enhanced, and as a result, the effect of suppressing the formation of the first protective film 12' on the upper part of the projecting electrode 91 is enhanced. When the distance D ₉₁ between the projecting electrodes 91 is equal to or less than the upper limit, the degree of freedom in the arrangement of the projecting electrodes 91 is increased.
In this specification, the "distance between adjacent projecting electrodes" means the minimum distance between the surfaces of adjacent projecting electrodes.

The thickness T ₉₀ of the workpiece 90 excluding the protruding electrode 91 may be appropriately selected depending on the intended use of the workpiece 90 and is not particularly limited.
For example, the thickness _T90 of the workpiece 90 after grinding the back surface 90b is preferably 50 to 500 μm. When the thickness _T90 of the workpiece 90 after grinding the back surface 90b is equal to or greater than the lower limit, the effect of suppressing damage to the workpiece when dividing the workpiece 90 (in other words, dividing into individual workpieces) is increased. When the thickness _T90 of the workpiece 90 after grinding the back surface 90b is equal to or less than the upper limit, a thin workpiece can be obtained.
The thickness T ₉₀ before the rear surface 90 b of the workpiece 90 is ground is preferably 250 to 1500 μm.

The workpiece for which the thermosetting resin film of this embodiment is used is not limited to that shown in Figure 1, and some of the configuration may be modified, deleted, or added within the scope that does not impair the effects of the present invention.

For example, in Fig. 1, the protruding electrode has an approximately spherical shape (a part of a sphere cut by a plane) as described above, but a protruding electrode having a shape obtained by stretching such an approximately spherical shape in the height direction (in Fig. 1, a direction perpendicular to the circuit surface 90a of the work 90), i.e., an approximately oblate spheroid shape (in other words, a shape in which a portion including one end of an oblate spheroid in the long axis direction is cut by a plane), or a protruding electrode having a shape obtained by squashing such an approximately spherical shape in the height direction, i.e., an approximately oblate spheroid shape (in other words, a shape in which a portion including one end of an oblate spheroid in the short axis direction is cut by a plane) can also be cited as a preferred shape of the protruding electrode. Like the approximately spherical protruding electrode described above, such an approximately spheroid-shaped protruding electrode is particularly advantageous for forming a first protective film using the thermosetting resin film of this embodiment.
In addition to these, examples of the protruding electrodes include those that are cylindrical, elliptical cylindrical, rectangular prism, elliptical cone-shaped, pyramidal, truncated cone-shaped, elliptical truncated cone-shaped, or truncated pyramidal; and those that have a shape that combines a cylinder, an elliptical cylinder, a rectangular prism, a truncated cone, an elliptical truncated cone, or a truncated pyramid with the above-mentioned approximately sphere or approximately spheroid.
The shapes of the projecting electrodes described above are merely examples of preferred shapes when applying the thermosetting resin film of this embodiment, and the shape of the projecting electrodes in the present invention is not limited to these.
The configuration of the present invention will be described in detail below.

The first support sheet may be one layer (single layer) or two or more layers. When the support sheet is made 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.
In this specification, not only in the case of the first support sheet, "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".

Preferred first support sheets include, for example, those comprising a first substrate and a first adhesive layer provided on the first substrate (in other words, those in which the first substrate and the first adhesive layer are laminated in their thickness direction), those comprising a first substrate, a first intermediate layer provided on the first substrate and a first adhesive layer provided on the first intermediate layer (in other words, those in which the first substrate, the first intermediate layer and the first adhesive layer are laminated in this order in their thickness direction), those consisting only of the first substrate, etc.

Examples of sheets for forming the first protective film in this embodiment are described below with reference to the drawings for each type of first support sheet.

FIG. 2 is a cross-sectional view that illustrates an example of the first protective film-forming sheet of the present embodiment.
The first protective film-forming sheet 1 shown here uses a first support sheet formed by laminating a first substrate and a first adhesive layer in the thickness direction thereof. That is, the first protective film-forming sheet 1 is configured to include a first substrate 11, a first adhesive layer 13 provided on one surface of the first substrate 11, and a thermosetting resin layer (thermosetting resin film) 12 provided on a surface 13a of the first adhesive layer 13 opposite to the first substrate 11 side.
The first support sheet 101 is a laminate of a first base material 11 and a first adhesive layer 13. The first protective film-forming sheet 1 can be said to include the first support sheet 101 and a thermosetting resin layer 12 provided on one surface 101a of the first support sheet 101, in other words, on one surface 13a of the first adhesive layer 13.

In the first protective film forming sheet 1, the transmittance of one thermosetting resin layer 12 having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm, which is composed of two or more thermosetting resin layers 12 each having a thickness of less than 200 μm, is 50% or more for light having a wavelength of 1342 nm. In addition, in the thermosetting resin layer 12 in the first protective film forming sheet 1, the content ratio of the above-mentioned thermosetting component may be 40% by mass or more.

FIG. 3 is a cross-sectional view that illustrates another example of the first protective film-forming sheet of the present embodiment.
In FIG. 3 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 first protective film forming sheet 2 shown here uses a first support sheet formed by laminating a first substrate, a first intermediate layer, and a first adhesive layer in this order in the thickness direction. That is, the first protective film forming sheet 2 is configured to include a first substrate 11, a first intermediate layer 14 provided on one side of the first substrate 11, a first adhesive layer 13 provided on the side of the first intermediate layer 14 opposite to the first substrate 11 side, and a thermosetting resin layer (thermosetting resin film) 12 provided on the side 13a of the first adhesive layer 13 opposite to the first intermediate layer 14 side.
The first support sheet 102 is a laminate of the first base material 11, the first intermediate layer 14, and the first adhesive layer 13. The first protective film-forming sheet 2 includes the first support sheet 102, and the thermosetting resin layer 12 on one surface 102a of the first support sheet 102, in other words, on one surface 13a of the first adhesive layer 13.

In other words, the first protective film forming sheet 2 is the first protective film forming sheet 1 shown in Figure 2, which further comprises a first intermediate layer 14 between the first substrate 11 and the first adhesive layer 13.

In the first protective film forming sheet 2, the transmittance of one thermosetting resin layer 12 having a thickness of 200 μm, or the laminated film having a total thickness of 200 μm, which is composed of two or more thermosetting resin layers 12 each having a thickness of less than 200 μm, is 50% or more for light having a wavelength of 1342 nm. In addition, in the thermosetting resin layer 12 in the first protective film forming sheet 2, the content ratio of the above-mentioned thermosetting component may be 40% by mass or more.

FIG. 4 is a cross-sectional view that illustrates still another example of the first protective film-forming sheet of the present embodiment.
The first protective film-forming sheet 3 shown here uses a first support sheet made only of a first substrate. That is, the first protective film-forming sheet 3 includes a first substrate 11 and a thermosetting resin layer (thermosetting resin film) 12 provided on the first substrate 11.
The first support sheet 103 is composed only of the first base material 11. The first protective film-forming sheet 3 includes the first support sheet 103, and includes a thermosetting resin layer 12 on one surface 103a of the first support sheet 103, in other words, on one surface 11a of the first base material 11.

In other words, the first protective film forming sheet 3 is the first protective film forming sheet 1 shown in Figure 2 with the first adhesive layer 13 omitted.

In the first protective film forming sheet 3, the transmittance of one thermosetting resin layer 12 having a thickness of 200 μm, or the laminated film having a total thickness of 200 μm, which is composed of two or more thermosetting resin layers 12 each having a thickness of less than 200 μm, is 50% or more for light having a wavelength of 1342 nm. In addition, in the thermosetting resin layer 12 in the first protective film forming sheet 3, the content ratio of the above-mentioned thermosetting component may be 40% by mass or more.

Next, the configuration of the first support sheet will be described.
In this embodiment, a known first support sheet may be used, and the first support sheet can be appropriately selected depending on the purpose.

First Substrate The first substrate is in the form of a sheet or film, and examples of the constituent material thereof include various resins.

The resin constituting the first substrate may be of only one type, or of two or more types; if there are two or more types, the combination and ratio of these may be selected arbitrarily.

The first substrate may be a single layer (monolayer) or may be a multilayer structure of two or more layers. If the first substrate is a multilayer structure, the multiple layers may be the same or different from each other, and the combination of the multiple layers is not particularly limited.

The thickness of the first substrate is preferably 50 to 200 μm.
Here, "the thickness of the first substrate" means the thickness of the entire first substrate. For example, the thickness of a first substrate consisting of multiple layers means the total thickness of all layers constituting the first substrate.

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

The first substrate may be transparent or opaque, may be colored according to the purpose, and may have other layers vapor-deposited thereon.
When the first pressure-sensitive adhesive layer or the thermosetting resin layer described below has energy ray curing properties, the first base material is preferably one that transmits energy rays.

The first substrate may be, for example, a release film in which one side of a resin film has been subjected to a release treatment such as silicone treatment, as described later in the examples.

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

First Pressure-Sensitive Adhesive Layer The first pressure-sensitive adhesive layer is in the form of a sheet or film, and contains a pressure-sensitive adhesive.
Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber-based resins, silicone resins, epoxy-based resins, polyvinyl ethers, and polycarbonates, with acrylic resins being preferred.

In the present invention, the term "adhesive resin" is a concept that includes both resins that have adhesive properties and resins that have adhesive properties, and includes, for example, not only resins that are adhesive in themselves, but also resins that exhibit adhesive properties when used in combination with other components such as additives, and resins that exhibit adhesive properties in the presence of a trigger such as heat or water.

The first adhesive layer may be only one layer (single layer) or may be two or more layers. If it is multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

The thickness of the first pressure-sensitive adhesive layer is preferably 3 to 40 μm.
Here, "the thickness of the first adhesive layer" means the thickness of the entire first adhesive layer, and for example, the thickness of a first adhesive layer consisting of multiple layers means the total thickness of all layers that make up the first adhesive layer.

The first pressure-sensitive adhesive layer may be formed using an energy ray-curable pressure-sensitive adhesive or a non-energy ray-curable pressure-sensitive adhesive. The first pressure-sensitive adhesive layer formed using an energy ray-curable pressure-sensitive adhesive can easily adjust the physical properties before and after curing.
In this specification, the term "energy ray" refers to electromagnetic waves or charged particle beams that have an energy quantum, and examples of such beams include ultraviolet rays, radioactive rays, and electron beams.
The ultraviolet light can be irradiated by using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, an LED lamp, etc. as an ultraviolet light source. The electron beam can be generated by an electron beam accelerator or the like.
In the present invention, "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.

<First Pressure-Sensitive Adhesive Composition>
The first pressure-sensitive adhesive layer can be formed using a first pressure-sensitive adhesive composition containing a pressure-sensitive adhesive. For example, the first pressure-sensitive adhesive composition can be applied to the surface on which the first pressure-sensitive adhesive layer is to be formed, and then dried as necessary to form the first pressure-sensitive adhesive layer at the desired site. A more specific method for forming the first pressure-sensitive adhesive layer will be described in detail later, together with methods for forming other layers.

The first adhesive composition may be applied by any known method, such as a method 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, Mayer bar coater, or kiss coater.

The drying conditions for the first adhesive composition are not particularly limited, but if the first adhesive composition contains a solvent, it is preferable to heat-dry it. The first adhesive composition containing a solvent may be dried, for example, at 70 to 130°C for 10 seconds to 5 minutes.

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

<First Pressure-Sensitive Adhesive Composition Other Than First Pressure-Sensitive Adhesive Compositions (I-1) to (I-3)>
The components contained in the first pressure-sensitive adhesive composition (I-1), the first pressure-sensitive adhesive composition (I-2) or the first pressure-sensitive adhesive composition (I-3) can be similarly used in general first pressure-sensitive adhesive compositions other than these three types of first pressure-sensitive adhesive compositions (referred to in this specification as "first pressure-sensitive adhesive compositions other than the first pressure-sensitive adhesive compositions (I-1) to (I-3)").

Examples of the first pressure-sensitive adhesive composition other than the first pressure-sensitive adhesive compositions (I-1) to (I-3) include not only energy ray-curable pressure-sensitive adhesive compositions but also non-energy ray-curable pressure-sensitive adhesive compositions.
An example of the non-energy ray-curable first pressure-sensitive adhesive composition is the first pressure-sensitive adhesive composition (I-4) containing the pressure-sensitive adhesive resin (I-1a).
The first pressure-sensitive adhesive composition (I-4) preferably contains an acrylic resin as the pressure-sensitive adhesive resin (I-1a), and more preferably further contains one or more crosslinking agents.

<Method for producing first pressure-sensitive adhesive composition>
The first pressure-sensitive adhesive compositions, such as the first pressure-sensitive adhesive compositions (I-1) to (I-4), can be obtained by blending the pressure-sensitive adhesive and, as necessary, each component for constituting the first pressure-sensitive adhesive composition, such as a component other than the pressure-sensitive adhesive.
The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, the solvent may be used by mixing it with any of the other ingredients to pre-dilute the ingredients, or the solvent may be used by mixing it with any of the other ingredients without pre-diluting the ingredients.
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 blade, a method of mixing using a mixer, a method of mixing by applying ultrasound, etc.
The temperature and time during addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. The temperature is preferably 15 to 30°C.

First Intermediate Layer The first intermediate layer is in the form of a sheet or film, and the material constituting the first intermediate layer may be appropriately selected depending on the purpose, and is not particularly limited.
For example, in the case where the purpose is to prevent deformation of the first protective film provided on the protruding electrode forming surface by reflecting the shape of the protruding electrodes present on the circuit surface, a preferred constituent material of the first intermediate layer includes urethane (meth)acrylate, etc., which further improves the adhesion of the first intermediate layer.

The first intermediate layer may be only one layer (single layer) or may be two or more layers. If it is multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

The thickness of the first intermediate layer can be appropriately adjusted according to the height of the protruding electrodes present on the surface of the workpiece or workpiece to be protected. For example, the thickness of the first intermediate layer is preferably 50 to 600 μm so that the effect of a relatively tall protruding electrode can be easily absorbed.
Here, "the thickness of the first intermediate layer" means the thickness of the entire first intermediate layer; for example, the thickness of a first intermediate layer consisting of multiple layers means the total thickness of all layers that make up the first intermediate layer.

<<Composition for forming first intermediate layer>>
The first intermediate layer can be formed using a composition for forming a first intermediate layer containing its constituent materials. For example, the composition for forming a first intermediate layer is applied to a surface on which the first intermediate layer is to be formed, If necessary, the mixture is dried or cured by irradiation with energy rays, whereby the first intermediate layer can be formed in the desired location. Also, this will be explained in detail later.

The composition for forming the first intermediate layer can be applied, for example, in the same manner as the first adhesive composition.

The drying conditions for the first intermediate layer forming composition are not particularly limited, and may be, for example, the same as the drying conditions for the first pressure-sensitive adhesive composition.
When the composition for forming the first intermediate layer is energy ray curable, it may be further cured by irradiation with energy rays after drying.

<Method for producing the composition for forming the first intermediate layer>
The first intermediate layer forming composition can be produced, for example, by the same method as that for the first pressure-sensitive adhesive composition, except that the blending components are different.

Thermosetting resin film (thermosetting resin layer)
The thermosetting resin film (thermosetting resin layer) is a film (layer) for protecting the circuit surface of the workpiece and the workpiece product, as well as the protruding electrodes provided on this circuit surface.
The thermosetting resin film forms a first protective film by thermal curing.

In this specification, even after the thermosetting resin film has hardened (in other words, after the first protective film has been formed), as long as the laminated structure of the first support sheet and the cured product of the thermosetting resin film (in other words, the first support sheet and the first protective film) is maintained, this laminated structure is referred to as a "sheet for forming the first protective film."

The thermosetting resin film may or may not have energy ray curing properties in addition to the thermosetting properties.
However, when the thermosetting resin film has energy ray curing properties, the contribution of the thermal curing of the thermosetting resin film to the formation of the first protective film from the thermosetting resin film is greater than the contribution of the energy ray curing.

The thermosetting resin film may be one layer (single layer) or two or more layers, regardless of whether it is energy ray curable or not. When the thermosetting resin film is made up of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

The thickness of the thermosetting resin film is preferably 1 to 100 μm, more preferably 3 to 80 μm, and particularly preferably 5 to 60 μm, regardless of whether it is energy ray curable or not. When the thickness of the thermosetting resin film is equal to or greater than the lower limit, a first protective film with higher protective ability can be formed. When the thickness of the thermosetting resin film is equal to or less than the upper limit, the effect of suppressing the thermosetting resin film from remaining on the upper part of the protruding electrode when the thermosetting resin film is attached to the protruding electrode forming surface of the workpiece is enhanced. Furthermore, when the thickness of the thermosetting resin film is equal to or less than the upper limit, the first protective film can be cut more satisfactorily when the workpiece is divided.
Here, the "thickness of the thermosetting resin film" means the thickness of the entire thermosetting resin film. For example, the thickness of a thermosetting resin film consisting of multiple layers means the total thickness of all layers constituting the thermosetting resin film.

<<Composition for forming thermosetting resin layer>>
The thermosetting resin film can be formed by using a composition for forming a thermosetting resin layer containing the constituent materials thereof. For example, the thermosetting resin film can be formed by applying a composition for forming a thermosetting resin layer to a surface to be formed. The ratio of the contents of the components that do not vaporize at room temperature in the composition for forming a thermosetting resin layer is usually the same as that in the thermosetting resin film. The ratio is the same as the content ratio between the above components.

The composition for forming the thermosetting resin layer may be applied by a known method, such as a method 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, Mayer bar coater, or kiss coater.

The drying conditions for the thermosetting resin layer forming composition are not particularly limited, regardless of whether the thermosetting resin film is energy ray curable or not. However, when the thermosetting resin layer forming composition contains a solvent described below, it is preferable to heat-dry it. The thermosetting resin layer forming composition containing a solvent may be dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, it is preferable to heat-dry the thermosetting resin layer forming composition so that the composition itself and the thermosetting resin film formed from this composition are not thermally cured.

The curing conditions when the thermosetting resin film is thermally cured to form the first protective film are not particularly limited, so long as the first protective film is cured to a degree that allows it to fully perform its function, and may be appropriately selected depending on the type of thermosetting resin film.
For example, the heating temperature during thermal curing of the thermosetting resin film is preferably 100 to 200° C., more preferably 110 to 180° C., and particularly preferably 120 to 170° 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.

A preferred example of a thermosetting resin film is one that contains a polymer component (A) and a thermosetting component (B). The polymer component (A) is a component that can be considered to have been formed by a polymerization reaction of a polymerizable compound. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction using heat as a reaction trigger. In this specification, the polymerization reaction also includes a polycondensation reaction.

<Thermosetting resin layer forming composition (III-1)>
A preferred thermosetting resin layer-forming composition is, for example, a thermosetting resin layer-forming composition (III-1) (referred to in the present specification) containing the polymer component (A) and the thermosetting component (B). In the text, this may be abbreviated simply as "composition (III-1)."

[Polymer component (A)]
The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility, etc. to the thermosetting resin film. The polymer component (A) has thermoplastic properties and does not have thermosetting properties.
The polymer component (A) contained in the composition (III-1) and the thermosetting resin film may be one type or two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

Examples of the polymer component (A) include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins.
Of these, the polymer component (A) is preferably a polyvinyl acetal or an acrylic resin.

The polyvinyl acetal in the polymer component (A) may be any of the known polyvinyl acetals.
Among them, preferred polyvinyl acetals include, for example, polyvinyl formal and polyvinyl butyral, with polyvinyl butyral being more preferred.
Examples of polyvinyl butyral include those having structural units represented by the following formulas (i)-1, (i)-2 and (i)-3.

（式中、ｌ、ｍ及びｎは、それぞれ独立に１以上の整数である。）

(In the formula, l, m, and n are each independently an integer of 1 or more.)

The weight-average molecular weight (Mw) of the polyvinyl acetal is preferably 5,000 to 200,000, and more preferably 8,000 to 100,000. When the weight-average molecular weight of the polyvinyl acetal is in this range, the effect of suppressing the thermosetting resin film from remaining on the upper part of the protruding electrode is enhanced when the thermosetting resin film is attached to the protruding electrode formation surface.

The glass transition temperature (Tg) of the polyvinyl acetal is preferably 40 to 80° C., and more preferably 50 to 70° C. When the Tg of the polyvinyl acetal is in this range, the effect of suppressing the thermosetting resin film from remaining on the upper part of the protruding electrode is enhanced when the thermosetting resin film is attached to the protruding electrode formation surface.

The ratio of the three or more monomers that make up the polyvinyl acetal can be selected arbitrarily.

The acrylic resin in the polymer component (A) means a resin having a structural unit derived from (meth)acrylic acid or a derivative thereof.
In this specification, the term "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid". The same applies to terms similar to (meth)acrylic acid. For example, the term "(meth)acryloyl group" is a concept that includes both "acryloyl group" and "methacryloyl group", and the term "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate".
In addition, in this specification, a "derivative" of a certain compound means a compound having a structure in which one or more hydrogen atoms of the compound are replaced with a group (substituent) other than a hydrogen atom. For example, a (meth)acrylic acid ester is a derivative of (meth)acrylic acid.

The acrylic resin in the polymer component (A) may be any known acrylic polymer.
The weight average molecular weight (Mw) of the acrylic resin 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 is equal to or greater than the lower limit, the shape stability (stability over time during storage) of the thermosetting resin film is improved. When the weight average molecular weight of the acrylic resin is equal to or less than the upper limit, the thermosetting resin film is more likely to conform to the uneven surface of the adherend, and the occurrence of voids between the adherend and the thermosetting resin film is more suppressed.
In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70°C, and more preferably -30 to 50°C. When the Tg of the acrylic resin is equal to or greater than the lower limit, for example, the adhesive strength between the cured product of the thermosetting resin film and the support sheet is suppressed, and the peelability of the support sheet is appropriately improved. When the Tg of the acrylic resin is equal to or less than the upper limit, the adhesive strength between the thermosetting resin film and its cured product and the adherend is improved.

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

Examples of the (meth)acrylic acid ester constituting the acrylic resin 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 ) (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms, such as isononyl 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 of such esters include (meth)acrylic acid esters containing a substituted amino group, 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 may be, for example, a copolymer of one or more monomers selected from the (meth)acrylic acid ester, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, etc.

The monomers constituting the acrylic resin may be of only one type or of two or more types, and if there are two or more types, the combination and ratio of these can be selected arbitrarily.

The acrylic resin may have a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group. The functional group of the acrylic resin may bond with other compounds via a crosslinking agent (F) described below, or may bond directly with other compounds without the crosslinking agent (F). The acrylic resin bonds with other compounds via the functional group, which tends to improve the reliability of the package obtained using the first protective film-forming sheet.

In the present invention, for example, a thermoplastic resin other than polyvinyl acetal and acrylic resin (hereinafter, sometimes simply abbreviated as "thermoplastic resin") may be used as the polymer component (A) alone without using polyvinyl acetal and acrylic resin, or may be used in combination with polyvinyl acetal or acrylic resin. By using the thermoplastic resin, the peelability of the first protective film from the first support sheet is improved, the thermosetting resin film is easily conformed to the uneven surface of the adherend, and the occurrence of voids between the adherend and the thermosetting resin film may be further suppressed.

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 polyester resin, polyurethane resin, phenoxy resin, polybutene, polybutadiene, polystyrene, etc.

The thermoplastic resin contained in composition (III-1) and the thermosetting resin film may be only 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 composition (III-1), the ratio of the content of polymer component (A) to the total content of all components other than the solvent (i.e., in the thermosetting resin film, the ratio of the content of polymer component (A) to the total mass of the thermosetting resin film) may be, for example, any of 5 to 60 mass%, 5 to 45 mass%, 5 to 30 mass%, and 5 to 15 mass%, regardless of the type of polymer component (A).

The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III-1) contains a component that corresponds to both the polymer component (A) and the thermosetting component (B), the composition (III-1) is deemed to contain the polymer component (A) and the thermosetting component (B).

[Thermosetting component (B)]
The thermosetting component (B) has thermosetting properties and is a component for forming a hard first protective film by thermally curing the thermosetting resin film.
In addition, in the thermosetting resin film, both the "thermosetting component" that specifies the above-mentioned content ratio and the "thermosetting component" that is the subject of the calculation of the X value are thermosetting components. (B) is applicable.

The thermosetting component (B) contained in the composition (III-1) and the thermosetting resin film may be of only one type or of 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-based thermosetting resins, polyimide resins, and unsaturated polyester resins.
Among these, the thermosetting component (B) is preferably an epoxy-based thermosetting resin.

(Epoxy thermosetting resin)
The epoxy thermosetting resin comprises an epoxy resin (B1) and a thermosetting agent (B2).
In the thermosetting resin film, both the epoxy resin (B1) and the thermosetting agent (B2) fall under both the "thermosetting component" that specifies the above-mentioned content ratio and the "thermosetting component" that is the subject of calculation of the X value.

The epoxy-based thermosetting resin contained in composition (III-1) and the thermosetting resin 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.

Epoxy resin (B1)
The epoxy resin (B1) may be any known epoxy resin, such as a polyfunctional epoxy resin, a biphenyl compound, bisphenol A diglycidyl ether and its hydrogenated product, orthocresol novolac epoxy resin, a dicyclopentadiene type epoxy resin, a biphenyl type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a phenylene skeleton type epoxy resin.

As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group may be used. An epoxy resin having an unsaturated hydrocarbon group has a higher compatibility with acrylic resin than an epoxy resin not having an unsaturated hydrocarbon group. Therefore, by using an epoxy resin having an unsaturated hydrocarbon group, the reliability of the workpiece with the first protective film obtained using the sheet for forming the first protective film is improved.

Examples of epoxy resins having an unsaturated hydrocarbon group include compounds obtained by converting a part of the epoxy groups of a polyfunctional epoxy resin into a group having an unsaturated hydrocarbon group. Such compounds can be obtained, for example, by subjecting the epoxy groups to an addition reaction with (meth)acrylic acid or a derivative thereof.
Furthermore, examples of epoxy resins having an unsaturated hydrocarbon group include compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like constituting the epoxy resin.
The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethenyl group (vinyl group), a 2-propenyl group (allyl group), a (meth)acryloyl group, and a (meth)acrylamide group, with an acryloyl group being preferred.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the standpoint of the curability of the thermosetting resin film and the strength and heat resistance of the resin film after curing, 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, and more preferably 150 to 970 g/eq.

The 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 of the resins may be selected arbitrarily.

Heat curing agent (B2)
The heat curing agent (B2) functions as a curing agent for the epoxy resin (B1).
The heat curing agent (B2) 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, and the like. The phenolic hydroxyl group, the amino group, or an anhydride group of an acid group is preferable, and the phenolic hydroxyl group or the amino group is more preferable.

Among the heat curing agents (B2), 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 (B2), examples of amine-based curing agents having an amino group include dicyandiamide.

The heat curing agent (B2) may have an unsaturated hydrocarbon group.
Examples of the heat curing agent (B2) having an unsaturated hydrocarbon group include a compound in which some of the hydroxyl groups of a phenol resin are substituted with a group having an unsaturated hydrocarbon group, and a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenol resin.
The unsaturated hydrocarbon group in the heat curing agent (B2) is the same as the unsaturated hydrocarbon group in the above-mentioned epoxy resin having an unsaturated hydrocarbon group.

When a phenol-based curing agent is used as the heat curing agent (B2), it is preferable that the heat curing agent (B2) has a high softening point or glass transition temperature, since this improves the peelability of the first protective film from the first support sheet.

Of the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resins, novolac type phenol resins, dicyclopentadiene type phenol resins, and aralkyl type phenol resins is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000.
Of the thermosetting agent (B2), the molecular weight of the non-resin components, such as biphenol and dicyandiamide, is not particularly limited, but is preferably, for example, 60 to 500.

The thermosetting agent (B2) 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 of the two or more types can be selected arbitrarily.

In the composition (III-1) and the thermosetting resin film, the content of the thermosetting agent (B2) may be, for example, 0.1 to 500 parts by mass, 1 to 250 parts by mass, 1 to 150 parts by mass, 1 to 100 parts by mass, 1 to 75 parts by mass, or 1 to 50 parts by mass, relative to 100 parts by mass of the epoxy resin (B1). When the content of the thermosetting agent (B2) is equal to or greater than the lower limit, the curing of the thermosetting resin film proceeds more easily. When the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the thermosetting resin film is reduced, and the reliability of the package obtained using the first protective film-forming sheet is further improved.

In the composition (III-1) and the thermosetting resin film, the content of the thermosetting component (B) (e.g., the total content of the epoxy resin (B1) and the thermosetting agent (B2)) may be, for example, any of 300 to 1400 parts by mass, 400 to 1300 parts by mass, 500 to 1100 parts by mass, 600 to 1000 parts by mass, and 700 to 900 parts by mass per 100 parts by mass of the polymer component (A). When the content of the thermosetting component (B) is in such a range, for example, the adhesive strength between the first protective film and the first support sheet is suppressed, and the peelability of the first support sheet is improved.

[Curing Accelerator (C)]
The composition (III-1) and the thermosetting resin film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing speed of the composition (III-1).
Preferred examples of the curing accelerator (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

The curing accelerator (C) contained in the composition (III-1) and the thermosetting resin 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 the curing accelerator (C) is used, the content of the curing accelerator (C) in the composition (III-1) and the thermosetting resin film may be, for example, 0.01 to 10 parts by mass or 0.1 to 7 parts by mass relative to 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is equal to or greater than the lower limit, the effect of using the curing accelerator (C) is more pronounced. When the content of the curing accelerator (C) is equal to or less than the upper limit, for example, the effect of suppressing the highly polar curing accelerator (C) from migrating to the adhesive interface with the adherend and segregating in the thermosetting resin film under high temperature and high humidity conditions is enhanced. As a result, the reliability of the workpiece with the first protective film obtained using the sheet for forming the first protective film is further improved.

[Filler (D)]
The composition (III-1) and the thermosetting resin film may contain a filler (D). When the thermosetting resin film contains the filler (D), the first protective film obtained by curing the thermosetting resin film can easily adjust the thermal expansion coefficient. Then, by optimizing this thermal expansion coefficient for the object on which the first protective film is formed, the reliability of the workpiece with the first protective film obtained using the sheet for forming the first protective film is further improved. In addition, when the thermosetting resin film contains the filler (D), the moisture absorption rate of the first protective film can be reduced and the heat dissipation can be improved.

The filler (D) 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, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, and the like; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, and the like.
Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

The average particle size of the filler (D) may be appropriately selected depending on the purpose, and is not particularly limited, and may be, for example, 0.02 to 2 μm.
In this specification, unless otherwise specified, the term "average particle size" refers to the particle size (D ₅₀ ) value at an integrated value of 50% in a particle size distribution curve determined by a laser diffraction scattering method.

The filler (D) contained in the composition (III-1) and the thermosetting resin film may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

In composition (III-1), the ratio of the content of filler (D) to the total content of all components other than the solvent (i.e., the ratio of the content of filler (D) in the thermosetting resin film to the total mass of the thermosetting resin film) may be, for example, any of 3 to 60 mass%, 4 to 40 mass%, 5 to 30 mass%, 5 to 20 mass%, and 5 to 15 mass%. When the ratio is in such a range, it becomes easier to adjust the thermal expansion coefficient of the first protective film as described above.

[Coupling Agent (E)]
The composition (III-1) and the thermosetting resin film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness and adhesion of the thermosetting resin film to an adherend can be improved. In addition, by using the coupling agent (E), the water resistance of the cured product of the thermosetting resin film is improved without impairing the heat resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional groups 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 of the silane 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.

The coupling agent (E) contained in the composition (III-1) and the thermosetting resin film may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

When a coupling agent (E) is used, the content of the coupling agent (E) in the composition (III-1) and the thermosetting resin film may be, for example, 0.03 to 20 parts by mass, 0.05 to 10 parts by mass, or 0.1 to 5 parts by mass, relative to 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). When the content of the coupling agent (E) is equal to or greater than the lower limit, the effects of using the coupling agent (E), such as improved dispersibility of the filler (D) in the resin and improved adhesion of the thermosetting resin film to the adherend, are more significantly obtained. When the content of the coupling agent (E) is equal to or less than the upper limit, the generation of outgassing is further suppressed.

[Crosslinking agent (F)]
When the polymer component (A) is one having a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group, such as the above-mentioned acrylic resin, the composition (III-1) and the thermosetting resin film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for bonding the functional group in the polymer component (A) with other compounds to cause crosslinking, and by crosslinking in this manner, the initial adhesive strength and cohesive strength of the thermosetting resin film can be adjusted.

Examples of the crosslinking agent (F) include organic polyisocyanate compounds, organic polyimine compounds, metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure), aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group), etc.

Examples of the organic polyisocyanate compound include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, and alicyclic polyisocyanate compounds (hereinafter, these compounds may be collectively referred to as "aromatic polyisocyanate compounds, etc."); trimers, isocyanurates, and adducts of the aromatic polyisocyanate compounds; and terminal isocyanate urethane prepolymers obtained by reacting the aromatic polyisocyanate compounds, etc. with polyol compounds. The "adduct" refers to a reaction product of the aromatic polyisocyanate compound, aliphatic polyisocyanate compound, or alicyclic polyisocyanate compound with a low molecular weight active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, or castor oil. Examples of the adduct include a xylylene diisocyanate adduct of trimethylolpropane, as described below. Moreover, the term "isocyanate-terminated urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at the terminal of the molecule.

More specifically, examples of the organic polyisocyanate compound include 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; a compound in which one or more of tolylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are added to all or some of the hydroxyl groups of a polyol such as trimethylolpropane; lysine diisocyanate, and the like.

Examples of the organic polyvalent imine compounds include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-β-aziridinyl propionate, N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine, etc.

When an organic polyisocyanate compound is used as the crosslinking agent (F), it is preferable to use a hydroxyl group-containing polymer as the polymer component (A). When the crosslinking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, a crosslinked structure can be easily introduced into the thermosetting resin film by the reaction between the crosslinking agent (F) and the polymer component (A).

The crosslinking agent (F) contained in the composition (III-1) and the thermosetting resin film may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

When a crosslinking agent (F) is used, the content of the crosslinking agent (F) in the composition (III-1) may be, for example, any of 0.01 to 20 parts by mass, 0.1 to 10 parts by mass, and 0.5 to 5 parts by mass per 100 parts by mass of the content of the polymer component (A). When the content of the crosslinking agent (F) is equal to or greater than the lower limit, the effect of using the crosslinking agent (F) is more pronounced. When the content of the crosslinking agent (F) is equal to or less than the upper limit, excessive use of the crosslinking agent (F) is suppressed.

[Energy ray curable resin (G)]
The composition (III-1) and the thermosetting resin film may contain an energy ray curable resin (G). By containing the energy ray curable resin (G), the thermosetting resin film can change its properties by irradiation with energy rays.

The energy ray curable resin (G) is obtained by polymerizing (curing) an energy ray curable compound.
The energy ray-curable compound includes, for example, a compound having at least one polymerizable double bond in the molecule, and is preferably an acrylate-based compound having a (meth)acryloyl group.

Examples of the acrylate-based compounds include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. cyclic aliphatic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the above-mentioned polyalkylene glycol (meth)acrylates; and itaconic acid oligomers.

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, and if two or more types are used, the combination and ratio thereof may be selected arbitrarily.

The energy ray-curable resin (G) contained in the composition (III-1) and the thermosetting resin 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 an energy ray curable resin (G) is used, in composition (III-1), the content ratio of the energy ray curable resin (G) relative to the total mass of composition (III-1) may be, for example, any one of 1 to 95 mass%, 5 to 90 mass%, and 10 to 85 mass%.

[Photopolymerization initiator (H)]
When the composition (III-1) and the thermosetting resin film contain an energy ray curable resin (G), they may contain a photopolymerization initiator (H) in order to efficiently proceed with the polymerization reaction of the energy ray curable resin (G).

Examples of the photopolymerization initiator (H) in the composition (III-1) 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, and 2,2-dimethoxy-1,2-diphenylethane-1-one; bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the like. acylphosphine oxide compounds such as thiophene; 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; 2-chloroanthraquinone, and the like.
Examples of the photopolymerization initiator include quinone compounds such as 1-chloroanthraquinone; and photosensitizers such as amines.

The photopolymerization initiator (H) contained in the composition (III-1) and the thermosetting resin film may be of only one type or of two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

When a photopolymerization initiator (H) is used, the content of the photopolymerization initiator (H) in the composition (III-1) may be, for example, 0.1 to 20 parts by mass, 1 to 10 parts by mass, or 2 to 5 parts by mass per 100 parts by mass of the energy ray-curable resin (G).

[Colorant (I)]
The composition (III-1) and the thermosetting resin film may contain a colorant (I).
Examples of the colorant (I) include known colorants such as inorganic pigments, organic pigments, and organic dyes.

Examples of the organic pigments and organic dyes include aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squalium 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, pyranthrone dyes, and threne dyes.

Examples of inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (indium tin oxide)-based pigments, and ATO (antimony tin oxide)-based pigments.

The colorant (I) contained in the composition (III-1) and the thermosetting resin 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 the colorant (I) is used, the content of the colorant (I) in the thermosetting resin film may be adjusted appropriately depending on the purpose. For example, in the composition (III-1), the ratio of the content of the colorant (I) to the total content of all components other than the solvent (i.e., the ratio of the content of the colorant (I) in the thermosetting resin film to the total mass of the thermosetting resin film) may be 0.1 to 5 mass%. When the ratio is equal to or greater than the lower limit, the effect of using the colorant (I) is more pronounced. When the ratio is equal to or less than the upper limit, excessive decrease in the light transmittance of the thermosetting resin film is suppressed.

[General-purpose additives (J)]
The composition (III-1) and the thermosetting resin film may contain a general-purpose additive (J) within the range not impairing the effects of the present invention.
The general-purpose additive (J) may be a known one and may be arbitrarily selected depending on the purpose, and is not particularly limited. Preferred examples thereof include plasticizers, antistatic agents, antioxidants, gettering agents, and the like.

The general-purpose additive (J) contained in the composition (III-1) and the thermosetting resin film may be one type or two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.
The content of the composition (III-1) and the general-purpose additive (J) in the thermosetting resin film is not particularly limited and may be appropriately selected depending on the purpose.

[solvent]
The composition (III-1) preferably further contains a solvent, since the composition (III-1) containing a solvent has good handleability.
The solvent is not particularly limited, but preferred examples thereof 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-1) may contain only one type of solvent, or two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

The solvent contained in composition (III-1) is preferably methyl ethyl ketone or the like, since this allows the components contained in composition (III-1) to be mixed more uniformly.

The solvent content of composition (III-1) is not particularly limited and may be selected appropriately depending on, for example, the types of components other than the solvent.

An example of a preferred thermosetting resin film of the present embodiment is a thermosetting resin film for forming a first protective film on a surface having a protruding electrode of a workpiece by attaching the film to the surface and thermally curing the film,
a single layer of the thermosetting resin film having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm, which is formed by laminating two or more layers of the thermosetting resin film having a thickness of less than 200 μm, has a transmittance of 50% or more for light having a wavelength of 1342 nm;
The thermosetting resin film contains a polymer component (A), an epoxy resin (B1) other than an acrylic resin having an epoxy group, a heat curing agent (B2), and a filler (D),
a ratio of a total content of the epoxy resin (B1) and the heat curing agent (B2) to a total mass of the thermosetting resin film in the thermosetting resin film is 40 mass% or more;
The content ratio of the polymer component (A) in the thermosetting resin film relative to the total mass of the thermosetting resin film is 5 to 30 mass%,
In the thermosetting resin film, the content of the filler (D) relative to the total mass of the thermosetting resin film is 5 to 20 mass %.

Another example of a preferred thermosetting resin film of the present embodiment is a thermosetting resin film for forming a first protective film on a surface having a protruding electrode of a workpiece by attaching the surface to the workpiece and thermally curing the surface,
a single layer of the thermosetting resin film having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm, which is formed by laminating two or more layers of the thermosetting resin film having a thickness of less than 200 μm, has a transmittance of 50% or more for light having a wavelength of 1342 nm;
The thermosetting resin film contains a polymer component (A), two or more thermosetting components other than an acrylic resin having an epoxy group, and a filler (D),
the thermosetting component comprises an epoxy resin (B1) and a thermosetting agent (B2);
the ratio of the total content of all types of the thermosetting components in the thermosetting resin film (in other words, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) to the total mass of the thermosetting resin film is 40 mass% or more;
The content ratio of the polymer component (A) in the thermosetting resin film relative to the total mass of the thermosetting resin film is 5 to 30 mass%,
The content ratio of the filler (D) in the thermosetting resin film relative to the total mass of the thermosetting resin film is 5 to 20 mass%,
Regarding the thermosetting component contained in the thermosetting resin film, the following formula is used for each type:
X = [equivalent weight (g/eq) of functional group involved in the thermosetting reaction of the thermosetting component] x [content (parts by mass) of the thermosetting component in the thermosetting resin film] / [total content (parts by mass) of all types of thermosetting components in the thermosetting resin film]
and calculating a total value of the X values of all the types of the thermosetting components contained in the thermosetting resin film, the total value is 400 g/eq or less.

Another example of a preferred thermosetting resin film of the present embodiment is a thermosetting resin film for forming a first protective film on a surface having a protruding electrode of a workpiece by attaching the surface to the workpiece and thermally curing the surface,
a single layer of the thermosetting resin film having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm, which is formed by laminating two or more layers of the thermosetting resin film having a thickness of less than 200 μm, has a transmittance of 50% or more for light having a wavelength of 1342 nm;
The thermosetting resin film contains a polymer component (A), two or more thermosetting components other than an acrylic resin having an epoxy group, and a filler (D),
the thermosetting component comprises an epoxy resin (B1) and a thermosetting agent (B2);
the ratio of the total content of all types of the thermosetting components in the thermosetting resin film (in other words, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) to the total mass of the thermosetting resin film is 40 mass% or more;
The content ratio of the polymer component (A) in the thermosetting resin film relative to the total mass of the thermosetting resin film is 5 to 30 mass%,
The content ratio of the filler (D) in the thermosetting resin film relative to the total mass of the thermosetting resin film is 5 to 20 mass%,
Regarding the thermosetting component contained in the thermosetting resin film, the following formula is used for each type:
X = [equivalent weight (g/eq) of functional group involved in the thermosetting reaction of the thermosetting component] x [content (parts by mass) of the thermosetting component in the thermosetting resin film] / [total content (parts by mass) of all types of thermosetting components in the thermosetting resin film]
and calculating a total value of the X values of all the thermosetting components contained in the thermosetting resin film, the total value is 400 g/eq or less,
The thermosetting resin film is heated at 130°C for 2 hours to heat it, and a first protective film having a size of 20 mm x 130 mm and a thickness of 40 µm is used, and the first protective film is obtained by thermally curing the thermosetting resin film. When the first protective film is pulled by the gripping tools in a direction parallel to its surface with a distance between the gripping tools of 80 mm and a pulling speed of 200 mm/min, the breaking strength of the first protective film is 55 MPa or less.

<<Method for producing composition for forming thermosetting resin layer>>
The thermosetting resin layer-forming composition such as composition (III-1) can be obtained by blending the respective components constituting the composition.
The order of addition of the components is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, the solvent may be used by mixing it with any of the other ingredients to pre-dilute the ingredients, or the solvent may be used by mixing it with any of the other ingredients without pre-diluting the ingredients.
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 blade, a method of mixing using a mixer, a method of mixing by applying ultrasound, etc.
The temperature and time during addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. The temperature is preferably 15 to 30°C.

Manufacturing Method of the Sheet for Forming the First Protective Film The sheet for forming the first protective film can be manufactured by laminating the above-mentioned layers in order so as to have a corresponding positional relationship. The method for forming each layer is as described above.
For example, when manufacturing a first support sheet, if a first adhesive layer or a first intermediate layer is laminated on a first substrate, the above-mentioned first adhesive composition or composition for forming a first intermediate layer can be applied to the first substrate, and then dried or irradiated with energy rays as necessary to laminate the first adhesive layer or the first intermediate layer.

On the other hand, for example, when a thermosetting resin layer (thermosetting resin film) is laminated on the first adhesive layer already laminated on the first substrate, it is possible to directly form the thermosetting resin layer by applying a composition for forming a thermosetting resin layer on the first adhesive layer. Similarly, when a first adhesive layer is laminated on the first intermediate layer already laminated on the first substrate, it is possible to directly form the first adhesive layer by applying the first adhesive composition on the first intermediate layer. In this way, when forming a continuous two-layer laminate structure using any of the compositions, it is possible to form a new layer by applying another composition on the layer formed from the composition. However, it is preferable that the layer to be laminated later of these two layers is formed in advance using the composition on another release film, and the exposed surface of the formed layer opposite to the side in contact with the release film is bonded to the exposed surface of the remaining layer already formed to form a continuous two-layer laminate structure. At this time, it is preferable that the composition is applied to the release-treated surface of the release film. The release film may be removed as necessary after the laminate structure is formed.

For example, when manufacturing a first protective film-forming sheet (a first support sheet which is a laminate of a first substrate and a first adhesive layer) in which a first adhesive layer is laminated on a first substrate and a thermosetting resin layer is laminated on the first adhesive layer, a first adhesive composition is applied to the first substrate and dried as necessary to laminate the first adhesive layer on the first substrate, a thermosetting resin layer-forming composition is separately applied to a release film and dried as necessary to form a thermosetting resin layer on the release film, and the exposed surface of this thermosetting resin layer is bonded to the exposed surface of the first adhesive layer already laminated on the first substrate, and the thermosetting resin layer is laminated on the first adhesive layer to obtain a first protective film-forming sheet.
In addition, for example, when manufacturing a first support sheet in which a first intermediate layer is laminated on a first substrate and a first adhesive layer is laminated on the first intermediate layer, a composition for forming a first intermediate layer is applied to the first substrate, and dried as necessary or irradiated with energy rays to laminate the first intermediate layer on the first substrate, and a first adhesive composition is applied to a release film separately and dried as necessary to form a first adhesive layer on the release film, and the exposed surface of the first adhesive layer is bonded to the exposed surface of the first intermediate layer already laminated on the first substrate, and the first adhesive layer is laminated on the first intermediate layer to obtain a first support sheet. In this case, for example, a composition for forming a thermosetting resin layer is further applied to a release film separately and dried as necessary to form a curable resin layer on the release film, and the exposed surface of the curable resin layer is bonded to the exposed surface of the first adhesive layer already laminated on the first intermediate layer, and the thermosetting resin layer is laminated on the first adhesive layer to obtain a first protective film-forming sheet.

In addition, when laminating a first adhesive layer or a first intermediate layer on a first substrate, instead of the method of applying the first adhesive composition or the composition for forming a first intermediate layer onto the first substrate as described above, the first adhesive composition or the composition for forming a first intermediate layer may be applied onto a release film, and if necessary, dried or irradiated with energy rays to form a first adhesive layer or a first intermediate layer on the release film, and the exposed surfaces of these layers may be bonded to one surface of the first substrate to laminate the first adhesive layer or the first intermediate layer onto the first substrate.
In either method, the release film may be removed at any time after the desired laminate structure is formed.

In this way, all layers other than the first substrate constituting the sheet for forming the first protective film can be formed in advance on a release film and laminated by bonding it to the surface of the desired layer, so the sheet for forming the first protective film can be manufactured by appropriately selecting the layers for which such a process is to be adopted as necessary.

The first protective film-forming sheet is usually stored with a release film attached to the surface of the outermost layer (e.g., thermosetting resin layer) opposite the first support sheet. Therefore, a composition for forming a layer constituting the outermost layer, such as a thermosetting resin layer-forming composition, is applied to this release film (preferably its release-treated surface) and dried as necessary to form a layer constituting the outermost layer on the release film, and the remaining layers are laminated by any of the methods described above on the exposed surface opposite the side in contact with the release film of this layer, and the first protective film-forming sheet can also be obtained by leaving the layers attached without removing the release film.

A commercially available product may be used as the first support sheet.

◇Manufacturing method of workpiece with first protective film When using a thermosetting resin film or a sheet for forming a first protective film according to one embodiment of the present invention, a manufacturing method of a workpiece with a first protective film includes a step of attaching a thermosetting resin film to a surface of the workpiece having a protruding electrode (i.e., the protruding electrode forming surface) (sometimes abbreviated herein as an "attaching step"), a step of thermally curing the thermosetting resin film after attachment to form a first protective film (sometimes abbreviated herein as a "first protective film forming step"), a step of forming a modified layer inside the workpiece by irradiating laser light through the first protective film onto the workpiece from the side having the first protective film (sometimes abbreviated herein as a "modified layer forming step"), and a step of expanding the workpiece after the modified layer has been formed together with the first protective film in a direction parallel to its circuit surface to divide the workpiece at the site of the modified layer, thereby obtaining a workpiece (sometimes abbreviated herein as a "dividing step").
The manufacturing method will now be described in detail with reference to the drawings.

5A to 5C and 6A to 6C are enlarged cross-sectional views for explaining the manufacturing method of the workpiece. Here, the manufacturing method will be explained when using the first protective film forming sheet 1 shown in FIG.

<<Attachment process>>
In the attachment step, as shown in Fig. 5A, the thermosetting resin film 12 is attached to the protruding electrode formation surface of the workpiece 90 (i.e., the surface 91a of the protruding electrode 91 and the circuit surface 90a of the workpiece 90). By carrying out this step, the thermosetting resin film 12 spreads between the numerous protruding electrodes 91 and adheres closely to the protruding electrode formation surface, and covers the surface 91a of the protruding electrodes 91, particularly the surface 91a in the vicinity of the circuit surface 90a of the workpiece 90, embedding the protruding electrodes 91, and covering these regions. Furthermore, when the content ratio of the thermosetting component described above in the thermosetting resin film 12 is adjusted, by carrying out this step, the upper portion including the top portion 910 of the protruding electrode 91 penetrates the thermosetting resin film 12 and protrudes from the thermosetting resin film 12.

In the attachment process, for example, the thermosetting resin film 12 may be used alone, but as shown here, it is preferable to use a first protective film forming sheet 1 that is configured with a first support sheet 101 and a thermosetting resin film 12 provided on the first support sheet 101. As described later, when grinding the back surface 90b of the workpiece 90, a surface protection tape for back grinding can be used as the first support sheet 101.

In the attachment process, when a first protective film forming sheet 1 as shown here is used, the thermosetting resin film 12 in the first protective film forming sheet 1 is attached to the protruding electrode forming surface of the workpiece 90, and the first protective film forming sheet 1 itself is attached to the protruding electrode forming surface of the workpiece 90.

In this specification, the structure in which the first protective film forming sheet is attached to the protruding electrode forming surface of the workpiece as shown here may be referred to as the "first laminated structure." Figure 5A shows the first laminated structure 201 in which the first protective film forming sheet 1 is attached to the protruding electrode forming surface of the workpiece 90.

In the attachment process, the exposed surface (sometimes referred to as the "first surface" in this specification) 12a of the thermosetting resin film 12 facing the workpiece 90 is pressed against the protruding electrode forming surface of the workpiece 90 (i.e., the surface 91a of the protruding electrode 91 and the circuit surface 90a of the workpiece 90), thereby attaching the thermosetting resin film 12 to the protruding electrode forming surface.

In the attachment process, it is preferable to attach the thermosetting resin film 12 to the protruding electrode formation surface while heating it. In this way, the occurrence of voids can be further suppressed both between the thermosetting resin film 12 and the protruding electrode formation surface, i.e., between the thermosetting resin film 12 and the circuit surface 90a of the work 90, and between the thermosetting resin film 12 and the surface 91a of the protruding electrode 91. In addition, the remaining of the thermosetting resin film 12 can be further suppressed in the upper part including the top part 910 of the protruding electrode 91, and finally, the remaining of the first protective film can be further suppressed in this upper part.

The heating temperature of the thermosetting resin film 12 during application should not be excessively high, and is preferably, for example, 60 to 100° C. Here, "excessively high temperature" means a temperature at which the thermosetting resin film 12 exhibits unintended effects, such as the progress of thermal curing of the thermosetting resin film 12.

When the thermosetting resin film 12 is attached to the protruding electrode forming surface, it is preferable that the pressure applied to the thermosetting resin film 12 (sometimes referred to in this specification as "application pressure") is 0.3 to 1 MPa.

After the first laminated structure 201 is formed by the attachment process, the first laminated structure 201 may be used as is in the next process, but if necessary, the thickness of the workpiece 90 may be adjusted by grinding the back surface 90b of the workpiece 90. The first laminated structure 201 after grinding the back surface 90b of the workpiece 90 is also in the state shown in FIG. 5A, except that the thickness of the workpiece 90 is different.

Grinding of the back surface 90b of the workpiece 90 can be performed by known methods, such as using a grinder.

The thickness of the workpiece 90 excluding the protruding electrode 91 before and after grinding the back surface 90b of the workpiece 90 is as described above.

After the first laminated structure 201 is formed by the bonding step, the first support sheet 101 is removed from the thermosetting resin film 12 in the first laminated structure 201. When the back surface 90b of the workpiece 90 is ground, it is preferable to remove the first support sheet 101 after this grinding.
By carrying out such a process, as shown in FIG. 5B, a second laminated structure (in other words, a workpiece with a thermosetting resin film) 202 is obtained, which has a thermosetting resin film 12 on the protruding electrode forming surface of the workpiece 90 and is configured without having a first support sheet 101.
In the second laminated structure 202, the upper portion including the top portion 910 of the projecting electrode 91 penetrates the thermosetting resin film 12, protrudes, and is exposed.

When the first adhesive layer 13 is energy ray curable, it is preferable to cure the first adhesive layer 13 by irradiating it with energy rays to reduce the adhesiveness of the first adhesive layer 13, and then remove the first support sheet 101 from the thermosetting resin film 12.

<<First protective film forming step>>
In the first protective film forming step, the applied thermosetting resin film 12 is thermally cured to form a first protective film 12' as shown in FIG. 5C.
When the first laminate structure 201 is formed, the first protective film forming step can be performed after the first support sheet 101 is removed.
Furthermore, in the case where the rear surface 90b of the workpiece 90 is ground, the first protective film forming step can be performed after the rear surface 90b is ground.
By carrying out this step, a third laminated structure (in other words, a work with a first protective film) 203 is obtained, which is configured by providing a first protective film 12′ on the projecting electrode forming surface of the work 90. 5C, reference numeral 12a' denotes a surface of the first protective film 12' that comes into contact with the workpiece 90 (sometimes referred to as a "first surface" in this specification).

The curing conditions for the thermosetting resin film 12 are not particularly limited as long as the first protective film 12 ′ is cured to a degree that allows it to fully perform its functions.
For example, the heating temperature and heating time during thermal curing of the thermosetting resin film 12 are as described above.
When the thermosetting resin film 12 is thermally cured, the thermosetting resin film 12 may be pressurized. In this case, the pressure applied is preferably 0.3 to 1 MPa.

In the second laminated structure (workpiece with thermosetting resin film) 202 shown in FIG. 5B, the remaining thermosetting resin film 12 is suppressed in the upper portion including the top portion 910 of the protruding electrode 91. Therefore, after completion of this process, the remaining first protective film 12' is also suppressed in the upper portion of the protruding electrode 91.

<<Modified layer forming process>>
In the modified layer formation process, as shown in FIG. 6A, a modified layer 900 is formed inside the workpiece 90 by irradiating laser light R through the first protective film 12' onto the workpiece 90 from the side having the first protective film 12'.
After the modified layer formation process, the workpiece 90 is divided (i.e., diced) as described below, so the modified layer formation process is preferably performed after attaching a dicing sheet or a sheet for forming a second protective film to the back surface 90b of the workpiece 90 in the third laminate structure (workpiece with first protective film) 203.

In this specification, a structure having a first protective film on the protruding electrode forming surface of the workpiece and a dicing sheet or a sheet for forming a second protective film on the back surface of the workpiece may be referred to as a "fourth laminate structure."
Furthermore, a structure in which a modified layer is formed inside the workpiece in the fourth laminated structure may be referred to as a "fifth laminated structure."
Figure 6A shows a fifth laminated structure 205 having a first protective film 12' on the protruding electrode forming surface of the workpiece 90, a second protective film forming sheet 8 on the back surface 90b of the workpiece 90, and a modified layer 900 formed inside the workpiece 90.

The second protective film forming sheet 8 shown here is composed of a second substrate 81, a second adhesive layer 83 provided on the second substrate 81, and a resin layer (resin film) 82 provided on the second adhesive layer 83.
The laminate of the second substrate 81 and the second pressure-sensitive adhesive layer 83 is the second support sheet 801 .
Therefore, the second protective film forming sheet 8 can be said to comprise a second support sheet 801 and a resin layer (resin film) 82 provided on one surface 801a of the second support sheet 801, in other words, on one surface 83a of the second adhesive layer 83.

The resin layer (resin film) 82 is for forming a second protective film on the back surface 90b of the workpiece 90. The second protective film covers and protects the back surface 90b of the workpiece 90. More specifically, the second protective film prevents cracks from occurring in the workpiece when the workpiece is divided and during the time when the workpiece obtained by dividing the workpiece is packaged to manufacture the desired substrate device.

The resin layer 82 may have only one of the properties of thermosetting and energy ray curing, or may have both properties, or may not have both properties. If the resin layer 82 is curable (i.e., has at least one of the properties of thermosetting and energy ray curing), the cured product is the second protective film. If the resin layer 82 is non-curable (i.e., does not have the properties of both thermosetting and energy ray curing), the second protective film is considered to be provided at the stage when the resin layer 82 is attached to the back surface 90b of the workpiece 90.

The second adhesive layer 83 may be either energy ray curable or non-energy ray curable, similar to the first adhesive layer 13. The second adhesive layer 83, which is energy ray curable, can easily adjust its physical properties before and after curing.

The second substrate 81 may be, for example, similar to the first substrate in the first protective film forming sheet described above (for example, the first substrate 11 in the first protective film forming sheet 1).

In the above-described manufacturing method, a sheet other than the sheet 8 for forming a second protective film may be used as the sheet for forming a second protective film.
In the above-mentioned manufacturing method, the second protective film-forming sheet is not limited to the sheet 8, and any known sheet can be used as the second protective film-forming sheet.
Similarly, in the above-mentioned manufacturing method, a known dicing sheet can be used.

In the modified layer formation process, a focal point is set on a specific area inside the workpiece 90 where the workpiece 90 will be divided, and laser light R is irradiated so as to converge on this focal point. By irradiating the laser light R, a modified layer 900 is formed in the irradiated area.

The thermosetting resin film 12 and the first protective film 12' are transparent to light with a wavelength of 1342 nm, and preferably, when the transmittance of the thermosetting resin film 12 and the first protective film 12' to light with a wavelength of 1342 nm is high as described above, the laser light with a wavelength of 1342 nm is transmitted well through the first protective film 12'. Therefore, even if the laser light R is irradiated through the first protective film 12' from the side of the workpiece 90 that has the first protective film 12', the modified layer 900 can be well formed inside the workpiece 90.

<<Dividing process>>
In the dividing process, the workpiece 90 after the formation of the modified layer 900 is divided at the site of the modified layer 900 by expanding the workpiece 90 together with the first protective film 12', in other words the fifth laminated structure 205, in a direction parallel to its circuit surface 90a (the direction of arrow E in Figure 6A), thereby obtaining the workpiece 9.
By performing this process, for example, as shown in Figure 6B, a fifth intermediate laminate structure 205' is obtained in which a plurality (a large number) of workpieces 9 having an uncut first protective film 12' on the protruding electrode forming surface are aligned on the second support sheet 801.

Alternatively, in the dividing step, it may be possible to divide the workpiece 90 at the site of the modified layer 900 and cut the first protective film 12' by expanding as described above. In that case, as shown in Fig. 6C instead of Fig. 6B, a workpiece 990 with a first protective film is immediately obtained, which includes the workpiece 9 and the first protective film (first protective film 120' after cutting) formed on the protruding electrode forming surface of the workpiece 9 (i.e., the surface 91a of the protruding electrode 91 and the circuit surface 9a of the workpiece 9) (in this case, this step may be referred to as a "dividing/cutting step").
That is, the manufacturing method may be such that, in the dividing step (in other words, the step of obtaining a workpiece), the workpiece is divided at the location of the modified layer and the first protective film is cut.
In this case, by carrying out this step, a sixth laminated structure 206 is obtained in which a plurality (a large number) of workpieces 9 having the first protective film 120' after cutting on the protruding electrode forming surface (i.e., workpiece 990 with the first protective film) are aligned on the second support sheet 801. In Fig. 6C, reference numeral 120a' denotes a contact surface (sometimes referred to as the "first surface" in this specification) of the first protective film 120' after cutting with the workpiece 9, and reference numeral 9b denotes a back surface of the workpiece 9.

In the dividing and cutting process, the first protective film 12' is cut along the dividing points of the workpiece 90, and is ultimately cut along the outer periphery of the workpiece 9.

In this process, whether or not the first protective film 12' is cut at the same time as the workpiece 90 is divided is determined by the composition of the first protective film 12', in other words the thermosetting resin film 12, and the expansion conditions.

For example, if the first protective film 12' is formed from a thermosetting resin film 12 that satisfies the condition of the total value of the X values, the first protective film 12' can be easily cut in the dividing process (dividing and cutting process). As a result, the workpiece 9 having the first protective film 120' after cutting on the protruding electrode forming surface can be manufactured with high efficiency. In this process, the first protective film 12' is cut along the outer periphery of the workpiece 9.

On the other hand, if the first protective film 12' is formed from a thermosetting resin film 12 that does not satisfy the condition for the total value of the X values, it is difficult to cut the first protective film 12' in the dividing step.
In this case, after dividing the workpiece 90 (i.e., after the dividing step), the first protective film 12′ is cut (this step may be referred to as the “cutting step” in this specification). As a result, a workpiece 990 with the first protective film similar to the above is obtained.
The cutting step can be performed simultaneously with, for example, a step of picking up the workpiece 9 (more specifically, the workpiece having the uncut first protective film) by separating it from the second support sheet 801. In this way, when a cutting step of the first protective film 12' is performed separately after dividing the workpiece 9, the workpiece 9 does not necessarily have the second protective film forming sheet 8 in its original state in the cutting step, as shown in FIG.

In the dividing process (or dividing and cutting process), the expanding is preferably performed under a temperature condition of -15 to 5°C. By keeping the temperature during expanding below the upper limit, it becomes easier to cut the first protective film 12'. By keeping the temperature during expanding above the lower limit, excessive cooling can be avoided.

Here, the case where the resin layer 82 in the second protective film forming sheet 8 is also cut by carrying out the dividing step (or dividing and cutting step) is shown, but the cutting of the resin layer 82 may be carried out separately by a known method after the dividing step (or dividing and cutting step). In Figures 6B to 6C, the resin layer 82 after cutting is given the reference numeral 820. Also, here, the case where the resin layer 82 is cut is shown, but rather than cutting at the resin layer 82 stage, the second protective film obtained by hardening the resin layer may be cut.

In the above-described manufacturing method, the resin layer 82 or the second protective film is cut along the division portions of the workpiece 90 in the same manner as in the case of the first protective film 12'.
In this specification, even after the resin layer is cut, as long as the laminated structure of the second support sheet and the resin layer (in other words, the second support sheet and the resin layer after cutting) is maintained, this laminated structure is referred to as a "sheet for forming a second protective film."

In the pasting step, if the upper part including the top part 910 of the protruding electrode 91 does not penetrate the thermosetting resin film 12 and does not protrude from the thermosetting resin film 12, a thermosetting resin film removing step or a first protective film removing step is separately performed at any stage after the pasting step, in which the thermosetting resin film remaining on the upper part of the protruding electrode or the first protective film which is the cured product thereof is removed to expose the upper part of the protruding electrode. The thermosetting resin film removing step is performed after the pasting step and before the first protective film forming step, and the first protective film removing step is performed after the first protective film forming step. As a result, a sixth laminated structure 206 shown in FIG. 6C is finally obtained.
The remaining thermosetting resin film or first protective film can be removed, for example, by irradiating the thermosetting resin film or the first protective film with plasma.

◇Method of manufacturing a substrate device After obtaining a workpiece with a first protective film (in other words, a sixth laminated structure) by the above-mentioned manufacturing method, this workpiece with the first protective film is flip-chip connected to the circuit surface of a substrate by a known method, and then packaged, and the desired substrate device can be manufactured by using this package (not shown). When a semiconductor chip with a first protective film is used, a semiconductor package is produced, and then the semiconductor package is used to manufacture the desired semiconductor device. Also, when a semiconductor chip having a first protective film and a second protective film is used, these semiconductor chips with protective films are flip-chip connected to manufacture the desired semiconductor device.

The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the following examples.
For convenience, the products produced in the comparative examples shown below are given the same names as the products produced in the examples.

The components used in the production of the composition for forming the thermosetting resin layer are shown below.
[Polymer component (A)]
(A)-1: Polyvinyl butyral ("S-LEC SV-10" manufactured by Sekisui Chemical Co., Ltd., weight average molecular weight 65,000, glass transition temperature 66°C)
(A)-2: Polyvinyl butyral ("S-LEC BL-10" manufactured by Sekisui Chemical Co., Ltd., weight average molecular weight 25,000, glass transition temperature 59°C)
(A)-3: An acrylic resin (weight average molecular weight 800,000, glass transition temperature -28°C) obtained by copolymerizing n-butyl acrylate (55 parts by mass), methyl acrylate (10 parts by mass), glycidyl methacrylate (20 parts by mass), and 2-hydroxyethyl acrylate (15 parts by mass).
[Thermosetting component (B)]
Epoxy resin (B1)
(B1)-1: Bisphenol A type epoxy resin ("EXA-4810-1000" manufactured by DIC Corporation, epoxy equivalent: 404 to 412 g/eq)
(B1)-2: Dicyclopentadiene type epoxy resin (DIC Corporation, "EPICLON HP-7200", epoxy equivalent 265 g/eq)
(B1)-3: Liquid modified epoxy resin ("YX7110" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 962 g/eq)
(B1)-4: A mixture of liquid bisphenol A type epoxy resin and acrylic rubber fine particles ("BPA328" manufactured by Nippon Shokubai Co., Ltd., epoxy equivalent 235 g/eq)
(B1)-5: Solid bisphenol A type epoxy resin ("Epikote 1055" manufactured by Mitsubishi Chemical Corporation, molecular weight 1600, softening point 93°C, epoxy equivalent 800 to 900 g/eq)
(B1)-6: Dicyclopentadiene type epoxy resin ("XD-1000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 248 g/eq)
Heat curing agent (B2)
(B2)-1: Novolak type phenolic resin ("Shounol BRG-556" manufactured by Showa Denko K.K., hydroxyl group equivalent: 104 g/eq)
(B2)-2: Dicyandiamide ("ADEKA Hardener EH-3636AS" manufactured by ADEKA Corporation, solid dispersion type latent hardener, active hydrogen amount 21 g/eq)
[Curing Accelerator (C)]
(C)-1: 2-phenyl-4,5-dihydroxymethylimidazole ("Curesol 2PHZ" manufactured by Shikoku Chemical Industries, Ltd.)
[Filler (D)]
(D)-1: Silica filler ("YA050C-MKK" manufactured by Admatechs Co., Ltd., average particle size 0.05 μm)
(D)-2: Silica filler ("SC2050MA" manufactured by Admatechs Co., Ltd., silica filler surface-modified with an epoxy compound, average particle size 500 nm)
(D)-3: Silica filler ("SV-10" manufactured by Tatsumori Co., Ltd., average particle size 8 μm)
[Coupling Agent (E)]
(E)-1: Silane coupling agent ("MKC Silicate MSEP2" manufactured by Mitsubishi Chemical Corporation, a silicate compound to which γ-glycidoxypropyltrimethoxysilane is added)
[Colorant (I)]
(I)-1: Carbon black ("MA-600B" manufactured by Mitsubishi Chemical Corporation)

[Example 1]
<<Production of Thermosetting Resin Film and Sheet for Forming First Protective Film>>
<Production of Thermosetting Resin Layer-Forming Composition>
Polymer component (A)-1 (9.9 parts by mass), epoxy resin (B1)-1 (37.8 parts by mass), epoxy resin (B1)-2 (25.0 parts by mass), heat curing agent (B2)-1 (18.1 parts by mass), curing accelerator (C)-1 (0.2 parts by mass) and filler (D)-1 (9.0 parts by mass) were mixed, further diluted with methyl ethyl ketone and stirred at 23 ° C. to prepare a thermosetting resin layer forming composition (III-1) having a total concentration of 55 mass % of the six components other than the above-mentioned methyl ethyl ketone. These components and their contents are shown in Table 1. In addition, the description of "-" in the column of the contained components in Table 1 means that the thermosetting resin layer forming composition does not contain that component. In addition, "proportion of the content of the thermosetting component (mass %)" in Table 1 means "proportion of the content of the thermosetting component in the thermosetting resin film with respect to the total mass of the thermosetting resin film".

<Production of Thermosetting Resin Film>
A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate film, one side of which was subjected to a release treatment by silicone treatment, was used. The composition for forming a thermosetting resin layer (III-1) obtained above was applied to the release-treated surface, and the resulting composition was dried at 100° C. for 2 minutes to produce a thermosetting resin film having a thickness of 30 μm.

<Production of Sheet for Forming First Protective Film>
Next, one side of a surface protection tape for back grinding ("Adwill E-8180HR" manufactured by Lintec Corporation) was attached to the exposed surface of the obtained thermosetting resin film (in other words, the surface opposite to the side provided with the release film) to prepare a first protective film-forming sheet. The surface protection tape corresponds to the first support sheet.

<<Manufacture of Semiconductor Chip with First Protective Film>>
The release film was removed from the thermosetting resin film in the first protective film forming sheet obtained above, and the exposed surface of the thermosetting resin film (in other words, the surface opposite to the surface protective tape) was pressed against the bump formation surface of the semiconductor wafer to attach the first protective film forming sheet to the bump formation surface of the semiconductor wafer. At this time, the first protective film forming sheet was attached to the bump formation surface of the semiconductor wafer by using an attachment device (roller type laminator, Lintec Corporation's "RAD-3510 F/12") while heating the thermosetting resin film under the conditions of a table temperature of 90°C, an attachment speed of 2 mm/sec, and an attachment pressure of 0.5 MPa. The semiconductor wafer used had a bump height of 210 μm, a bump width of 250 μm, a distance between adjacent bumps of 400 μm, and a thickness of 750 μm excluding the bumps.
In this manner, a first laminate structure was obtained in which the first protective film forming sheet was attached to the bump formation surface of the semiconductor wafer.

Next, a grinder (DISCO Corporation's "DGP8760") was used to grind the surface (back surface) of the semiconductor wafer in the first laminated structure obtained, opposite the surface on which the bumps were formed. At this time, the back surface was ground until the thickness of the semiconductor wafer excluding the bumps was 250 μm.

Next, the surface protection tape (in other words, the first support sheet) was removed from the thermosetting resin film in the first laminated structure.
In this manner, a second laminate structure (semiconductor wafer with a thermosetting resin film) was obtained, which was configured by providing a thermosetting resin film on the bump-forming surface of the semiconductor wafer.

Next, using a heat curing device ("RAD-9100 m/12" manufactured by Lintec Corporation), the thermosetting resin film in the second laminate structure obtained above was heat cured by heating and pressurizing under conditions of a treatment temperature of 130°C, a treatment pressure of 0.5 MPa, and a treatment time of 2 hours, thereby forming a first protective film.
In this manner, a third laminate structure (in other words, a semiconductor wafer with a first protective film) was obtained, which was configured by providing the first protective film on the bump formation surface of the semiconductor wafer.

Next, a dicing tape ("Adwill D-841" manufactured by Lintec Corporation) was applied to the back surface (in other words, the ground surface) of the semiconductor wafer in the obtained third laminate structure, thereby obtaining a fourth laminate structure having a first protective film on the bump-forming surface of the semiconductor wafer and a dicing tape on the back surface. The dicing tape corresponds to the second support sheet.

Next, using a dicing device (DISCO Corporation's "DFL7361"), the semiconductor wafer in the fourth stack structure was irradiated with laser light from the side having the first protective film through the first protective film so as to be focused on a focal point set inside the semiconductor wafer, thereby forming a modified layer inside the semiconductor wafer. At this time, the wavelength of the laser light was 1342 nm, the output was 0.7 W, and the frequency was 90 kHz.
In this manner, a fifth laminated structure was obtained, in which a modified layer was formed inside the semiconductor wafer in the fourth laminated structure.

Next, in an environment of 0° C., the semiconductor wafer after the formation of the modified layer (in other words, the fifth laminated structure) was expanded together with the first protective film in a direction parallel to the circuit surface, thereby dividing the semiconductor wafer at the site of the modified layer, and cutting the first protective film along the dividing portion of the semiconductor wafer. At this time, a die separator (Disco Corporation's "DDS2300") was used, and the second support sheet in the fifth laminated structure was placed on the table in the die separator, and the peripheral portion of the fifth laminated structure was fixed. In this state, the table was pushed up under the conditions of a push-up speed of 50 mm/sec and a push-up amount of 20 mm, thereby expanding the semiconductor wafer and the first protective film. The size of the obtained semiconductor chip was 2 mm×2 mm.
As a result of the above, a sixth laminated structure was obtained in which a plurality (a large number) of semiconductor chips having the first protective film after cutting on the bump forming surface (i.e., semiconductor chips with the first protective film) were aligned on the second support sheet (in other words, the dicing tape).

<<Evaluation of Thermosetting Resin Film>>
<Confirmation of suppression of remaining thermosetting resin film on the top of bumps>
During the manufacture of the semiconductor chip with the first protective film described above, the first laminated structure was observed from the bump-formed surface side of the semiconductor wafer using a scanning electron microscope ("VE-9800" manufactured by Keyence Corporation) at an acceleration voltage of 5 keV. The suppression of the remaining thermosetting resin film on the upper part of the bump in the first laminated structure was evaluated according to the following evaluation criteria. The results are shown in Table 1.
(Evaluation Criteria)
A: The boundary between the bump and the thermosetting resin film can be confirmed, and it can be confirmed that no thermosetting resin film remains on the top of the bump.
B: The boundary between the bump and the thermosetting resin film cannot be confirmed, and it is confirmed that the thermosetting resin film remains on the top of the bump.

<Measurement of light transmittance of thermosetting resin film>
Five test thermosetting resin films (thickness 40 μm) were produced in the same manner as in the production of the above-mentioned thermosetting resin film, except that the coating amount of the thermosetting resin layer-forming composition (III-1) was changed.
Next, these five test thermosetting resin films were laminated in their thickness direction to obtain a laminated film (thickness: 200 μm).
Next, the transmittance of light with a wavelength of 1,342 nm was measured for this laminated film using a spectrophotometer (Shimadzu Corporation's "UV-VIS-NIR SPECTROPHOTOMETER UV-3600") The results are shown in Table 1.

<<Evaluation of First Protective Film>>
<Evaluation of Semiconductor Wafer Separability>
The sixth laminated structure obtained above was observed from the first protective film side using a digital microscope (Keyence Corporation "VH-Z100"). At this time, a total of five observation regions were selected, including a first region corresponding to the center of the alignment surface of the second support sheet for the semiconductor chips with the first protective film, and a second region, a third region, a fourth region, and a fifth region that are located at the peripheral side that is point-symmetrical with respect to the first region and are at the same distance from the first region. All of these five regions were selected to include 25 semiconductor chips with the first protective film in 5 rows and 5 columns, assuming that the semiconductor wafer was normally divided. In addition, these five regions were selected so that the first region was located approximately at the center of the first line segment connecting the second region and the third region, the first region was located approximately at the center of the second line segment connecting the fourth region and the fifth region, and the second region, the fourth region, the third region, and the fifth region were located in this order in a clockwise direction. The first line segment and the second line segment are perpendicular to each other. These five regions were then observed, and the divisibility of the semiconductor wafer was evaluated according to the following evaluation criteria. The results are shown in Table 1.
(Evaluation Criteria)
A: The semiconductor wafer is properly divided in all five regions (all of the first to fifth regions).
B: In at least one region (at least one of the first region to the fifth region), there is a portion where the semiconductor wafer is not properly divided.

<Evaluation of Cuttability of First Protective Film When Dividing Semiconductor Wafer>
When the above-mentioned semiconductor wafer separation property was evaluated, the cuttability of the first protective film was also evaluated according to the following evaluation criteria. The results are shown in Table 1.
(Evaluation Criteria)
A: The first protective film was normally cut in all five regions (all of the first to fifth regions).
B: In at least one region (at least one of the first region to the fifth region), there is a portion where the first protective film is not cut normally.

<Measurement of Breaking Strength of First Protective Film>
A test thermosetting resin film (thickness 40 μm) was produced in the same manner as in the production of the above-mentioned thermosetting resin film, except that the coating amount of the thermosetting resin layer-forming composition (III-1) was changed.
The test thermosetting resin film was then heat cured by heating at 130° C. for 2 hours.
Next, a piece measuring 20 mm×130 mm was cut out from this cured product (i.e., the first protective film) and used as a test piece.
Using a universal tensile tester (Shimadzu Corporation, "Autograph AG-IS"), the test piece was pulled by the gripping tools in a direction parallel to its surface at a gripping distance of 80 mm and a pulling speed of 200 mm/min, and the maximum stress of the test piece at this time was measured and used as the breaking strength of the first protective film. The results are shown in Table 1.

[Example 2]
<<Production of Thermosetting Resin Film and Sheet for Forming First Protective Film>>
<Production of Thermosetting Resin Layer-Forming Composition>
Polymer component (A)-2 (10.0 parts by mass), epoxy resin (B1)-2 (30.0 parts by mass), epoxy resin (B1)-3 (33.0 parts by mass), heat curing agent (B2)-1 (16.0 parts by mass), curing accelerator (C)-1 (0.2 parts by mass) and filler (D)-1 (11.0 parts by mass) were mixed, further diluted with methyl ethyl ketone and stirred at 23 ° C. to prepare a resin layer forming composition having a total concentration of 55 mass % of the six components other than the above-mentioned methyl ethyl ketone. These components and their contents are shown in Table 1.

<Production of Thermosetting Resin Film and Sheet for Forming First Protective Film>
A thermosetting resin film and a sheet for forming a first protective film were produced in the same manner as in Example 1, except that the composition for forming a resin layer obtained above was used.

<<Manufacture of Semiconductor Chip with First Protective Film>>
An attempt was made to manufacture a semiconductor chip with a first protective film (in other words, a sixth laminated structure) in the same manner as in Example 1, except that the sheet for forming the first protective film obtained above was used.

<<Evaluation of Thermosetting Resin Film and First Protective Film>>
The thermosetting resin film and the first protective film produced in this example were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
<<Production of Thermosetting Resin Film and Sheet for Forming First Protective Film>>
<Production of Thermosetting Resin Layer-Forming Composition>
Polymer component (A)-3 (21.0 parts by mass), epoxy resin (B1)-4 (10.0 parts by mass), epoxy resin (B1)-5 (2.0 parts by mass), epoxy resin (B1)-6 (5.6 parts by mass), heat curing agent (B2)-2 (0.5 parts by mass), curing accelerator (C)-1 (0.5 parts by mass), filler (D)-2 (6.0 parts by mass), filler (D)-3 (54.0 parts by mass), coupling agent (E)-1 (0.4 parts by mass) and colorant (I)-1 (1.9 parts by mass) were mixed, further diluted with methyl ethyl ketone, and stirred at 23 ° C. to prepare a resin layer forming composition having a total concentration of 55% by mass of the 10 components other than the above-mentioned methyl ethyl ketone. These components and their contents are shown in Table 1.

<Production of Thermosetting Resin Film and Sheet for Forming First Protective Film>
A thermosetting resin film and a sheet for forming a first protective film were produced in the same manner as in Example 1, except that the composition for forming a resin layer obtained above was used.

<<Manufacture of Semiconductor Chip with First Protective Film>>
An attempt was made to manufacture a semiconductor chip with a first protective film (in other words, a sixth laminate structure) in the same manner as in Example 1, except that the sheet for forming the first protective film obtained above was used.

<<Evaluation of Thermosetting Resin Film and First Protective Film>>
The thermosetting resin film and the first protective film produced in this comparative example were evaluated in the same manner as in Example 1. The results are shown in Table 1.

As is clear from the above results, in Example 1, the divisibility of the semiconductor wafer was good.
The thermosetting resin film of Example 1 had a high transmittance of light with a wavelength of 1,342 nm, and as a result, the first protective film formed from this film also had a similarly high transmittance of light. When laser light was irradiated onto the semiconductor wafer through the first protective film, a modified layer was successfully formed inside the semiconductor wafer.

Furthermore, the thermosetting resin film of Example 1 had favorable properties in that it was possible to prevent the film from remaining on the upper parts of the bumps when the film was applied to the bump-formed surface of a semiconductor wafer.
In the thermosetting resin film of Example 1, the ratio of the content of the thermosetting component to the total mass of the thermosetting resin film was 80.9 mass %.

In Example 1, the first protective film also had good cuttability when dividing the semiconductor wafer.
In Example 1, the total X value was 296 (={408×37.8/(37.8+25.0+18.1)}+{265×25.0/(37.8+25.0+18.1)}+{104×18.1/(37.8+25.0+18.1)}) g/eq, and the breaking strength of the first protective film was 45 MPa.

In Example 2 as well, the divisibility of the semiconductor wafer was good.
The thermosetting resin film of Example 2 had a high transmittance of light with a wavelength of 1,342 nm, and as a result, the first protective film formed from this film also had a similarly high transmittance of light. When laser light was irradiated onto the semiconductor wafer through the first protective film, a modified layer was successfully formed inside the semiconductor wafer.

The thermosetting resin film of Example 2 also had favorable properties, in that it was possible to prevent the film from remaining on the upper parts of the bumps when the film was applied to the bump-formed surface of a semiconductor wafer.
In the thermosetting resin film of Example 2, the ratio of the content of the thermosetting component to the total mass of the thermosetting resin film was 78.8 mass %.

In Example 2, the cuttability of the first protective film was poor when dividing the semiconductor wafer, but this first protective film could be cut in a subsequent process, and semiconductor chips with the first protective film could be manufactured.
In Example 2, the total X value was 524 (={265×30.0/(30.0+33.0+16.0)}+{962×33.0/(30.0+33.0+16.0)}+{104×16.0/(30.0+33.0+16.0)}) g/eq, and the breaking strength of the first protective film was 60 MPa.

In contrast, in Comparative Example 1, the divisibility of the semiconductor wafer was poor.
The thermosetting resin film of Comparative Example 1 had a low transmittance of light with a wavelength of 1342 nm, and as a result, the first protective film formed from this film also had a low transmittance of light, and when the semiconductor wafer was irradiated with laser light through the first protective film, a modified layer could not be properly formed inside the semiconductor wafer, and as a result, the semiconductor wafer could not be divided normally.

In addition, the thermosetting resin film of Comparative Example 1 could not prevent the film from remaining on the upper parts of the bumps when applied to the bump-formed surface of the semiconductor wafer, and had inferior properties to the thermosetting resin films of Examples 1 and 2.
In the thermosetting resin film of Comparative Example 1, the ratio of the content of the thermosetting component to the total mass of the thermosetting resin film was 17.8 mass %.

In Comparative Example 1, the first protective film could not be cut when the semiconductor wafer was divided, but it was not possible to determine the extent to which the characteristics of the first protective film itself had an influence on this result, and the cuttability of the first protective film when the semiconductor wafer was divided could not be evaluated. However, since the breaking strength of the first protective film was small at 25 MPa, it was speculated that the reason the first protective film could not be cut was mainly due to the poor divisibility of the semiconductor wafer.

The present invention can be used to manufacture workpieces having protruding electrodes on the connection pads used in flip chip mounting methods.

1, 2, 3: Sheet for forming first protective film, 11: First substrate, 11a: One side of first substrate, 12: Thermosetting resin layer (thermosetting resin film), 12': First protective film, 120': First protective film after cutting, 13: First adhesive layer, 13a: One side of first adhesive layer, 14: First intermediate layer, 101, 102, 103: First support sheet, 101a, 102a, 103a: Surface of first support sheet, 206: Sixth laminated structure, 90: Work, 90a: Circuit surface of work, 91: Projecting electrode, 91a: Surface of projecting electrode, 900: Modified layer, 990: Workpiece with first protective film, R: Laser light

Claims (3)

A thermosetting resin film for forming a first protective film on a surface of a workpiece having a protruding electrode by being attached to the surface and being thermally cured,
a single layer of the thermosetting resin film having a thickness of 200 μm, or a laminated film having a total thickness of 200 μm, which is formed by laminating two or more layers of the thermosetting resin film having a thickness of less than 200 μm, has a transmittance of 50% or more for light having a wavelength of 1342 nm;
A thermosetting resin film, in which a first protective film having a size of 20 mm x 130 mm and a thickness of 40 μm is used, the first protective film being obtained by thermally curing the thermosetting resin film by heating it at 130° C. for 2 hours, and when the first protective film is pulled in a direction parallel to its surface by the gripping tools with a distance between the gripping tools of 80 mm and a pulling speed of 200 mm/min, the breaking strength of the first protective film is 55 MPa or less . The thermosetting resin film contains a thermosetting component other than an acrylic resin having an epoxy group,
The thermosetting resin film according to claim 1 , wherein a content of the thermosetting component in the thermosetting resin film is 40% by mass or more relative to a total mass of the thermosetting resin film. A first protective film forming sheet comprising a first support sheet and a thermosetting resin film according to claim 1 or 2 on one side of the first support sheet.

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