JP7724069B2 - Support sheet, composite sheet for forming protective film, and method for manufacturing the device - Google Patents

Description

The present invention relates to a support sheet, a composite sheet for forming a protective film, and a method for manufacturing a device. In particular, it relates to a support sheet used to secure a workpiece such as a semiconductor wafer during processing, a composite sheet for forming a protective film having the support sheet and a protective film-forming film that is suitable for protecting a workpiece such as a semiconductor wafer or a processed product such as a semiconductor chip obtained by processing the workpiece, and a method for manufacturing a device such as a semiconductor chip.

In recent years, semiconductor devices have been manufactured using a mounting method known as the face-down method. In the face-down method, a semiconductor chip with electrodes such as bumps on its circuit surface is used, and the electrodes are bonded to a substrate. As a result, the back surface of the semiconductor chip, opposite the circuit surface, may be exposed.

A resin film made of an organic material is formed as a protective film on the backside of this exposed semiconductor chip, and such semiconductor chips with a protective film are sometimes incorporated into semiconductor devices. The protective film is used to prevent chipping, such as cracking or chipping, in the semiconductor chip during processes after the dicing process.

To form such a protective film, a composite sheet for forming a protective film is used, which comprises a protective film-forming film (protective film-forming layer) on a support sheet. For example, a laminated sheet in which an adhesive layer or the like is laminated on a resin substrate is used as the support sheet. Furthermore, the support sheet alone can function as a dicing sheet for semiconductor wafers, etc. Since the protective film-forming film has protective film-forming ability and the support sheet can function as a dicing sheet, the composite sheet for forming a protective film can be said to be a sheet in which the protective film-forming film and dicing sheet are integrated.

The surface of the substrate used in the support sheet that comes into contact with other members typically has an uneven shape. This is because, if the surface does not have such an uneven shape, the substrate and the release film formed on the adhesive layer will stick together and cause blocking when the support sheet is unwound from the roll, making it difficult to unwind the support sheet from the roll. Therefore, if the surface of the substrate that comes into contact with other members has an uneven shape, the area of the contact surface is reduced, thereby suppressing blocking.

The same applies to a composite sheet for forming a protective film, in which a protective film-forming film is formed on the adhesive layer of a support sheet. That is, when the composite sheet for forming a protective film is unwound from the roll on which it is wound, the substrate and the release film formed on the protective film-forming film stick together and cause blocking, so the surface of the substrate that comes into contact with the release film has an uneven shape.

On the other hand, in order to identify the semiconductor wafer or semiconductor chip, marks, letters, etc. are marked on the surface of the semiconductor wafer or protective film-forming film, for example, by laser marking. Such laser marking is performed by irradiating laser light from the side of the substrate of the support sheet on which the adhesive layer is not formed. Therefore, if the side on which the adhesive layer is not formed has an uneven shape, the laser light will be scattered or diffused on that surface, which may result in an unclear marking.

Patent Document 1 describes a support sheet comprising a substrate and an adhesive layer laminated on the substrate, or a composite sheet for forming a protective film comprising a protective film-forming film on the adhesive layer of the support sheet, in which the surface on the side on which the adhesive layer is formed has a surface roughness (Ra) of 0.4 μm or less, and the surface roughness (Ra) of the substrate surface opposite the side on which the adhesive layer is formed is greater than the surface roughness on the side on which the adhesive layer is formed, and is 0.053 to 0.48 μm. It also describes that this support sheet or composite sheet for forming a protective film can suppress blocking while improving the recognizability of laser marking.

International Publication No. 2017/163971

However, even with the support sheet or composite sheet for forming a protective film described in Patent Document 1, there was a problem in that it was difficult to reliably achieve both poor sheet feeding caused by blocking and the visibility of the laser marking when viewed through the substrate.

The present invention was made in consideration of these circumstances, and aims to provide a support sheet that can eliminate sheet feeding problems while ensuring that laser markings are easily visible when viewed through the substrate, a composite sheet for forming a protective film that includes the support sheet and a protective film-forming film, and a method for manufacturing devices such as semiconductor devices.

The aspects of the present invention are as follows.
[1] A film having a substrate and a pressure-sensitive adhesive layer formed on one main surface of the substrate,
In the substrate, the arithmetic mean height Sa1 of a 4.91 mm × 4.90 mm square region on the main surface on which the pressure-sensitive adhesive layer is not formed is greater than 0.50 μm,
The support sheet has a gloss value of 20 or more at an incident angle of 60° on the main surface on which the pressure-sensitive adhesive layer is not formed.
[2] A 4.91 mm × 4.90 mm square region on the main surface on which the pressure-sensitive adhesive layer is not formed is a wide region obtained by combining 300 narrow regions, each of which is a 0.36 mm × 0.27 mm square region,
The support sheet according to [1], wherein Sa2 is 0.43 μm or less when the average of the 20 smallest arithmetic mean heights of the narrow regions is Sa2.
[3] The support sheet according to [1] or [2], wherein the ratio of Sa1 to Sa2, Sa1/Sa2, is 1.40 or more.
[4] The support sheet according to any one of [1] to [3], wherein no other layer is formed on the main surface on which the pressure-sensitive adhesive layer is not formed.
[5] A composite sheet for forming a protective film, comprising the support sheet according to any one of [1] to [4] and a protective film-forming film formed on the pressure-sensitive adhesive layer of the support sheet.
[6] A kit comprising the support sheet according to any one of [1] to [4] and a protective film-forming film to be attached to the surface of the adhesive layer of the support sheet.
[7] A step of unwinding and unrolling the support sheet according to any one of [1] to [4] wound in a roll;
A step of attaching the unwound support sheet to a workpiece;
A step of laser marking a workpiece;
and a step of processing the workpiece to obtain a processed product of the workpiece.
[8] A step of unwinding and unwinding the composite sheet for forming a protective film according to [5] wound in a roll;
A step of attaching the protective film-forming film of the unwound protective film-forming composite sheet to the back surface of the workpiece;
A step of converting the attached protective film-forming film into a protective film;
A step of laser marking the protective film or the protective film-forming film;
The method for manufacturing the device includes a step of dividing a workpiece having a protective film or a protective film-forming film on its back surface into individual pieces to obtain a plurality of workpieces having a protective film or a protective film-forming film.

The present invention provides a support sheet that can eliminate sheet feeding problems while ensuring that laser markings are easily visible when viewed through the substrate, a composite sheet for forming a protective film that includes the support sheet and a protective film-forming film, and a method for manufacturing devices such as semiconductor devices.

FIG. 1 is a schematic cross-sectional view of an example of a support sheet according to this embodiment. FIG. 2 is a schematic cross-sectional view of an example of the composite sheet for forming a protective film according to this embodiment. FIG. 3 is a schematic diagram illustrating the surface properties of the main surface of the substrate of the support sheet according to this embodiment on which the pressure-sensitive adhesive layer is not formed. FIG. 4 is an enlarged schematic view of part IV in FIG. FIG. 5 is a schematic cross-sectional view of an example of a chip having a protective film obtained by forming a protective film from a protective film-forming film. FIG. 6 is a schematic cross-sectional view illustrating a step of attaching the composite sheet for forming a protective film according to this embodiment to a wafer. FIG. 7 is a cross-sectional schematic view of another example of the composite sheet for forming a protective film according to this embodiment.

The present invention will now be described in detail based on specific embodiments and with reference to the accompanying drawings. First, the main terms used in this specification will be explained.

The workpiece is a plate-like body to which the support sheet or composite sheet for forming a protective film according to this embodiment is attached and processed. Examples of the workpiece include wafers and panels. Specifically, examples include semiconductor wafers and semiconductor panels. Examples of processed workpieces include chips obtained by dicing a wafer. Specifically, examples include semiconductor chips obtained by dicing a semiconductor wafer. In this case, the protective film is formed on the backside of the wafer and chip.

The "front surface" of a workpiece such as a wafer refers to the surface on which circuits, bumps, and other convex electrodes are formed, while the "back surface" refers to the surface on which circuits, electrodes (for example, bumps and other convex electrodes) are not formed.

Wafer singulation refers to dividing the wafer into individual circuits to obtain chips.

In this specification, for example, "(meth)acrylate" is used to refer to both "acrylate" and "methacrylate," and the same applies to other similar terms.

"Energy rays" refers to ultraviolet rays, electron beams, etc., with ultraviolet rays being preferred.

A release film is a film that supports the adhesive layer or protective film-forming film in a releasable manner. The term "film" is not limited to a specific thickness and is used to refer to sheets as well.

The mass ratios in descriptions of compositions such as protective film-forming compositions are based on the active ingredient (solid content), and do not include the solvent unless otherwise specified.

(1. Support Sheet)
The support sheet according to this embodiment is used to fix a workpiece when processing the workpiece. For example, such a sheet is used to attach to a workpiece when cutting the workpiece to obtain multiple processed workpieces. Therefore, the support sheet according to this embodiment can be used as a dicing sheet. Furthermore, like the composite sheet for forming a protective film described below, a functional layer that imparts predetermined performance to the workpiece or a processed product of the workpiece may be formed on the support sheet.

As shown in FIG. 1, the support sheet 1 according to this embodiment has a substrate 2 and an adhesive layer 3 formed on one main surface 2a of the substrate. In this embodiment, it is preferable that no other layer be formed on the main surface 2b of the substrate 2 on which the adhesive layer is not formed. In other words, it is preferable that the main surface 2b of the substrate 2 on which the adhesive layer is not formed is an exposed surface that is exposed to the outside.

The support sheet according to this embodiment may be in the form of a long sheet whose longitudinal length is significantly longer than its lateral length. It may also be in the form of a sheet roll in which such a long sheet is wound up.

When the support sheet is rolled up, it is preferable that a release film be formed on the surface 3a of the adhesive layer 3. By forming a release film on the surface of the adhesive layer, even when the support sheet is rolled up into a sheet roll, it is possible to prevent the substrate, the surface 3a of the adhesive layer, and the main surface 2b of the substrate on which the adhesive layer is not formed from sticking together.

(2. Composite sheet for forming protective film)
The composite sheet for forming a protective film according to this embodiment is used to protect the workpiece or a processed product of the workpiece by attaching the protective film-forming film to the workpiece and turning the protective film-forming film into a protective film.

As shown in FIG. 2, the composite sheet 10 for forming a protective film according to this embodiment comprises a protective film-forming film 4, a support sheet 1 that supports the protective film-forming film 4, and a jig adhesive layer 5 for adhering the composite sheet 10 for forming a protective film to a jig such as a ring frame. The support sheet 1 is the same as the support sheet described in (1), and comprises a substrate 2 and an adhesive layer 3 formed on one main surface 2a of the substrate 2. The protective film-forming film 4 is formed on the surface 3a of the adhesive layer 3. The jig adhesive layer 5 is formed on the peripheral portion of the main surface 4a of the protective film-forming film 4.

Similar to (1), in this embodiment, it is preferable that no other layers are formed on the main surface 2b of the substrate 2 on which the adhesive layer is not formed. In other words, it is preferable that the main surface 2b of the substrate 2 on which the adhesive layer is not formed is an exposed surface that is exposed to the outside.

Furthermore, as with (1), the composite sheet for forming a protective film according to this embodiment may be in the form of a long sheet in which the length in the longitudinal direction is very long relative to the length in the lateral direction. It may also be in the form of a sheet roll in which such a long sheet is wound up.

When the composite sheet for forming a protective film is wound up, it is preferable that a release film be formed on the surface 4a of the protective film-forming film 4 and the surface of the jig adhesive layer 5. By forming a release film on the surface of the adhesive layer, even when the composite sheet for forming a protective film is wound into a sheet roll, it is possible to prevent the surface 4a of the protective film-forming film 4 and the surface of the jig adhesive layer 5 from sticking to the main surface 2b of the substrate on which the adhesive layer is not formed.

However, when a roll of a composite sheet for forming a protective film with a release film is unwound and unwound to be applied to a workpiece, the composite sheet for forming a protective film located directly radially below the release film may stick to the release film formed on the surface of the protective film-forming film, making it impossible to unwind the composite sheet for forming a protective film. Similarly, when a roll of a support sheet with a release film is unwound and unwound to be applied to a workpiece, the support sheet located directly radially below the release film may stick to the release film formed on the surface of the adhesive layer, making it impossible to unwind the support sheet.

To prevent such unwinding problems, it is preferable that the main surface 2b of the substrate of the support sheet and the composite sheet for forming a protective film, where the adhesive layer is not formed, be slightly uneven. The formation of such unevenness reduces the contact area between the main surface 2b of the substrate and the release film, reducing adhesion of the support sheet or composite sheet for forming a protective film to the release film.

By the way, to improve identification, markings are sometimes applied to wafers or chips cut into individual wafers as workpieces. In this case, the markings may be applied directly to the wafer or chip, or to a protective film attached to the wafer or chip. In either case, the markings are usually applied by irradiating them with laser light (laser marking).

When laser marking is performed, the wafer or chip is positioned on the surface 3a of the adhesive layer shown in Figure 1 or on the main surface 4a of the protective film-forming film shown in Figure 2, so the laser light enters from the main surface 2b of the substrate, passes through the support sheet 1, and reaches the wafer or chip. If the main surface 2b of the substrate is uneven, the laser light may be scattered or diffused, resulting in unclear marking.

In addition, to check the markings applied to the wafer or chip, the markings can be observed either after peeling off the support sheet or through the support sheet. When observing the markings through the support sheet, the markings are observed using a microscope or the like from the main surface 2b side of the substrate, so if the observation light is scattered or diffusely reflected, the markings may not be clearly discernible.

Therefore, the surface condition of the side of the support sheet substrate on which the adhesive layer is not formed affects the payout ability of the support sheet or composite sheet for forming a protective film and the recognizability of the laser marking, which are contradictory properties. In other words, it is very difficult to achieve both.

In this embodiment, therefore, the surface properties of the support sheet substrate are controlled as follows to achieve both payout ease and laser marking visibility. The components of the support sheet and the composite sheet for forming a protective film according to this embodiment are described in detail below.

(3. Base material)
The substrate of the support sheet supports the workpiece via the adhesive layer during processing of the workpiece. The substrate may be made of a single-layer film made of one resin film, or may be made of a multi-layer film in which multiple resin films are laminated.

However, it is preferable that no other layers be formed on the main surface of the substrate opposite the main surface on which the adhesive layer is formed (the main surface on which the adhesive layer is not formed). Therefore, it is preferable that the main surface of the substrate on which the adhesive layer is not formed is an exposed surface that is exposed to the outside.

The formation of such other layers is costly. There is also the risk that components contained in the other layers will migrate and adhere to the surface that the other layers are in contact with. In particular, when the support sheet or composite sheet for forming a protective film is in the form of a sheet roll, the other layers will come into contact with the back surface of the release film, making the above risks highly likely to become apparent.

The thickness of the substrate is not particularly limited, as long as it can function properly in each process in which the composite sheet for forming a protective film is used. It is preferably in the range of 20 to 200 μm, more preferably 40 to 170 μm, and especially preferably 50 to 140 μm.

(3.1 Gloss of the substrate)
In this embodiment, the gloss value at an incident angle of 60° on the main surface of the substrate opposite to the main surface on which the pressure-sensitive adhesive layer is formed (main surface 2b in Figs. 1 and 2) is 20 or more.

By keeping the gloss value at an incident angle of 60° within the above range, scattering or diffuse reflection of the observation light is suppressed, allowing the marking to be clearly recognized even when observed through the support sheet.

The gloss value at an incident angle of 60° is preferably 25 or greater, more preferably 35 or greater, and even more preferably 45 or greater. On the other hand, there is no particular upper limit to the gloss value, but it is preferably 140 or less, more preferably 110 or less, and even more preferably 80 or less.

The gloss value at an incident angle of 60° is measured in accordance with JIS Z 8741. That is, it is measured in the same manner as the measurement method specified in JIS Z 8741, but the measurement conditions may be different. The specific measurement method is explained in the examples.

(3.2 Surface properties of substrate)
In this embodiment, the surface properties of the main surface (main surface on which the adhesive layer is not formed: main surface 2b in Figures 1 and 2) opposite to the main surface (one main surface) on which the adhesive layer of the substrate is formed are controlled to a predetermined shape.

Specifically, if the arithmetic mean height of a 4.91 mm x 4.90 mm square region on the main surface of the substrate where the adhesive layer is not formed is defined as Sa1, Sa1 is greater than 0.50 μm. Arithmetic mean height of the surface is one of the surface roughness parameters defined in ISO 25178, and is the average of the absolute values of the peak heights and valley depths on the measured surface. Sa1 indicates the average surface roughness over the entire measured surface, with the effects of localized irregularities minimized.

By ensuring that Sa1 is within the above range, the surface roughness of the main surface of the substrate on which the adhesive layer is not formed is relatively rough when viewed as a whole. As a result, the contact area with the release film can be reduced, thereby suppressing unwinding problems.

Sa1 is preferably 0.55 μm or more, more preferably 0.60 μm or more, and even more preferably 0.65 μm or more. On the other hand, the upper limit of Sa1 is not limited as long as the gloss value is within the above-mentioned range, but it is preferably 1.2 μm or less.

Sa1 is the surface roughness obtained by measuring a rectangular area of 4.91 mm x 4.90 mm.

In addition to the above Sa1, in this embodiment, it is preferable to control the surface roughness in a smaller area obtained by subdividing the area where the above Sa1 is measured.

Specifically, first, a 4.91 mm x 4.90 mm square area on the main surface where the adhesive layer is not formed is defined as the area obtained by combining 0.36 mm x 0.27 mm square areas. Therefore, the 4.91 mm x 4.90 mm square area is a wide area, and the 0.36 mm x 0.27 mm square area is a narrow area.

As shown in Figure 3, the 4.91 mm x 4.90 mm rectangular region 50 is obtained by combining 300 0.36 mm x 0.27 mm rectangular regions 60, arranged in 15 columns in the X-axis direction and 20 rows in the Y-axis direction. Therefore, the wide region 50 is made up of 300 narrow regions 60.

In this embodiment, the arithmetic mean height is calculated for each 0.36 mm x 0.27 mm rectangular region 60. That is, the arithmetic mean height is measured for each narrow region 60, and 300 arithmetic mean heights are obtained. Of the 300 arithmetic mean heights, the 20 smallest arithmetic mean height is selected. That is, of the 300 narrow regions 60 obtained by subdividing the wide region 50, 20 smooth narrow regions (with low surface roughness) are selected. The arithmetic mean heights of the selected 20 narrow regions are averaged to obtain Sa2. In this embodiment, Sa2 is 0.43 μm or less.

As mentioned above, Sa1 is the surface roughness obtained by measuring the entire wide area 50, while Sa2 is the surface roughness of locally smooth areas in the wide area 50. Normally, surface irregularities are present almost uniformly, and when the narrow areas are the above-mentioned size, the irregularities are present almost uniformly in each narrow area. As a result, there is not much difference in the surface roughness of each narrow area, and it is close to the surface roughness of the wide area, which is the area obtained by combining the narrow areas.

Therefore, if the surface irregularities are approximately uniform, even if 20 narrow areas with low surface roughness are selected from 300 narrow areas 60, the average surface roughness Sa2 will be close to the wide-area surface roughness Sa1.

In contrast, in this embodiment, although Sa1 is greater than 0.50 μm, Sa2 is 0.43 μm or less. Therefore, the fact that Sa1 and Sa2 are both within the above ranges indicates that, on the main surface on which the adhesive layer is not formed, there are large irregularities such that the surface roughness of the entire wide area 50 falls within the above range, but there are also many areas with low surface roughness. In other words, on the main surface on which the adhesive layer is not formed, relatively large irregularities are sparsely distributed on a relatively smooth surface.

Therefore, the relatively large irregularities reduce the contact area with the release film, while the smooth areas suppress scattering or diffuse reflection of laser light, resulting in clearer markings (i.e., improved laser marking properties), and it also makes it easier to increase the gloss value. In other words, the main surface on which the adhesive layer is not formed has a different surface texture from the surface on which the irregularities are almost uniformly distributed, making it possible to achieve both payout ability and laser marking ability, which are contradictory properties.

Sa2 is preferably 0.35 μm or less, and more preferably 0.30 μm or less. On the other hand, the lower limit of Sa2 is not limited as long as the gloss value is within the above-mentioned range, but it is preferably 0.10 μm or more.

In addition, in this embodiment, it is preferable that the ratio of Sa1 to Sa2 (Sa1/Sa2) be 1.40 or greater. By having Sa1/Sa2 within the above range, it is possible to achieve high levels of both payout performance and laser marking performance.

Sa1/Sa2 is more preferably 1.70 or greater, even more preferably 2.0 or greater, and particularly preferably 2.3 or greater.

The surface texture of the main surface of the substrate on which the adhesive layer is not formed can be measured as follows. If the main surface on which the adhesive layer is not formed is represented as an XY plane using mutually perpendicular X and Y axes, the surface texture of the main surface on which the adhesive layer is not formed can be represented as a displacement in the Z axis direction, which is perpendicular to the XY plane. In other words, the surface roughness of the main surface on which the adhesive layer is not formed is represented as a three-dimensional (X, Y, Z) shape.

Therefore, the arithmetic mean height, which is a surface roughness parameter, is calculated from the measurement results of the displacement in the Z-axis direction in the measurement area. In this embodiment, it is preferable to use a non-contact white light interference microscope to measure the surface texture.

In a white light interference microscope, the optical path of light emitted from a white light source is split into two, one directed onto a reference mirror and the other onto the sample surface, and the light reflected from both is imaged on a camera. In the resulting image, the interference fringes generated by the difference in optical path due to the unevenness of the sample surface are converted into height information, thereby obtaining the three-dimensional shape of the sample surface.

The measurement results of the surface texture of a measurement surface, obtained as three-dimensional shape data, mainly include factors caused by the shape of the measurement surface, factors caused by the surface roughness of the measurement surface, and factors caused by the waviness of the measurement surface. Therefore, the measurement results of the surface texture of a measurement surface are a contour curved surface obtained by combining these factors. These factors are distinguished by the length of their period (wavelength), with factors caused by surface roughness having a short period (short wavelength), factors caused by shape having a long period (long wavelength), and factors caused by waviness having a period intermediate between these.

From the measurement results obtained, factors due to shape and factors due to waviness are removed to obtain a surface roughness surface composed of factors due to surface roughness. Based on the obtained surface roughness surface, the arithmetic mean height is calculated in accordance with the method specified in ISO 25178. In other words, measurement can be performed using a method similar to that specified in ISO 25178, but measurement can also be performed under conditions different from those specified in ISO 25178.

The surface roughness curve can be obtained from the measurement results using known filtering, flattening, etc. For example, analysis software included with the white light interference microscope or commercially available analysis software can be used.

When measuring the surface properties of the main surface, the magnification of the white light interference microscope should preferably be 20 to 110 times, with 50 times being more preferable.

The wide area 50 is obtained by combining 300 narrow areas 60, and as shown in Figure 4, the narrow areas are combined with their peripheral edges overlapping. That is, when focusing on one of the narrow areas (60a) that make up the wide area 50, the peripheral edge of narrow area 60a overlaps with the peripheral edges of each of the narrow areas 60b to 60i that are adjacent to narrow area 60a. By providing such overlapping areas OA, it is possible to ensure continuity of surface roughness at the boundaries between adjacent narrow areas. If the narrow areas 60 were combined without providing overlapping areas OA, irregularities that do not exist in the actual surface texture may be included as noise.

(3.3 Substrate material)
The material of the substrate is not particularly limited as long as it can support the workpiece via the adhesive layer during processing and is a material that easily transmits the laser light used for laser marking. Typically, the substrate is made of a film mainly made of a resin-based material (hereinafter referred to as a "resin film"). The wavelength of the laser light used for laser marking is preferably 1064 nm, 532 nm, 355 nm, or 266 nm, and 532 nm is more preferred from the viewpoints of marking clarity and versatility.

Specific examples of resin films include polyethylene films such as low-density polyethylene (LDPE) film, linear low-density polyethylene (LLDPE) film, and high-density polyethylene (HDPE) film; polyolefin films such as polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, and norbornene resin film; ethylene copolymer films such as ethylene-vinyl acetate copolymer film, ethylene-(meth)acrylic acid copolymer film, and ethylene-(meth)acrylic acid ester copolymer film; polyvinyl chloride films such as polyvinyl chloride film and vinyl chloride copolymer film; polyester films such as polyethylene terephthalate film and polybutylene terephthalate film; polyurethane film; polyimide film; polystyrene film; polycarbonate film; and fluororesin films. Modified films such as crosslinked films and ionomer films can also be used. The substrate may be a film made of one of these materials, or a laminate film combining two or more of these materials.

Of the above, polyethylene film, polypropylene film, ethylene-vinyl acetate copolymer film, ethylene-(meth)acrylic acid ester copolymer film, polyvinyl chloride film, and polybutylene terephthalate film are preferred from the viewpoints of the ease of obtaining the payout effect of the present invention and ease of use in dicing processes, etc., and among these, polypropylene film, which has excellent heat resistance, is particularly preferred.

(4. Pressure-sensitive adhesive layer)
The adhesive layer of the support sheet may be made of a non-energy ray curable adhesive or an energy ray curable adhesive, but is preferably made of a material that easily transmits the laser light used for laser marking.

Preferably, the non-energy ray-curable adhesive has the desired adhesive strength and removability. For example, acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, etc. can be used.

Among these, acrylic adhesives are preferred because they have high adhesion to the protective film-forming film and can effectively prevent the workpiece or processed product from falling off during dicing processes, etc. Acrylic adhesives are also preferred from the perspective of making it easier to control the pick-up suitability of the processed product of the workpiece with the protective film.

The non-energy ray curable adhesive preferably contains a crosslinking agent such as an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent to crosslink the main component (e.g., acrylic polymer).

On the other hand, the adhesive strength of energy ray-curable adhesives decreases when irradiated with energy rays, so when it is desired to separate the workpiece or processed workpiece from the support sheet, they can be easily separated by irradiating them with energy rays.

The energy ray-curable adhesive constituting the adhesive layer may be primarily composed of an energy ray-curable polymer, or may be primarily composed of a mixture of a non-energy ray-curable polymer and an energy ray-curable monomer and/or oligomer.

Examples of energy ray-curable polymers include (meth)acrylic acid ester (co)polymers into which energy ray-curable groups have been introduced. Examples of energy ray-curable monomers and/or oligomers include esters of polyhydric alcohols and (meth)acrylic acid. Furthermore, energy ray-curable adhesives may contain additives such as photopolymerization initiators and crosslinking agents in addition to the energy ray-curable components.

The thickness of the adhesive layer is not particularly limited, as long as it functions properly in each process in which the composite sheet for forming a protective film is used. Specifically, the thickness of the adhesive layer is preferably 1 to 50 μm, 2 to 30 μm, 2 to 20 μm, 3 to 10 μm, or 3 to 8 μm.

(5. Protective Film-Forming Film)
The protective film-forming film of the composite sheet for forming a protective film is attached to a workpiece to form a protective film for protecting the workpiece or a processed product of the workpiece.

"Protecting" refers to making the protective film-forming film into a state in which it has sufficient properties to protect the workpiece or a processed product of the workpiece. Specifically, when the protective film-forming film is curable, "protecting" refers to turning the uncured protective film-forming film into a cured product. In other words, a protective film-forming film that has been protective film-formed is a cured product of the protective film-forming film, and is different from the original protective film-forming film.

After placing the workpiece on the curable protective film-forming film, the protective film can be firmly adhered to the workpiece by curing the protective film-forming film, forming a durable protective film.

On the other hand, if the protective film-forming film does not contain a curable component and is used in an uncured state, the protective film-forming film becomes a protective film when it is attached to the workpiece. In other words, the protective film-forming film that has become a protective film is the same as the protective film-forming film.

When high protective performance is not required, the protective film-forming film does not need to be cured, making it easy to use.

In this embodiment, the protective film-forming film is preferably curable. Therefore, it is preferable that the protective film is a cured product. Examples of cured products include thermosetting products and energy ray-cured products. In this embodiment, it is more preferable that the protective film is a thermosetting product.

It is also preferable that the protective film-forming film be adhesive at room temperature (23°C) or become adhesive when heated. This allows the workpiece to be laminated to the protective film-forming film when it is placed on top of it. This allows for reliable positioning before the protective film-forming film is cured.

The protective film-forming film may be composed of one layer (single layer), or may be composed of two or more layers. When the protective film-forming film has multiple layers, these multiple layers may be the same or different, and there are no particular restrictions on the combination of layers that make up these multiple layers.

In this embodiment, the protective film-forming film is preferably one layer (single layer). A single-layer protective film-forming film is easy to produce because it can achieve high precision in terms of thickness. Furthermore, if the protective film-forming film is composed of multiple layers, it is necessary to consider the adhesion between the layers and the elasticity of each layer, which can lead to the risk of peeling from the adherend. If the protective film-forming film is one layer, the above risks can be reduced and design freedom is increased. Furthermore, the risk of peeling between layers due to differences in thermal elasticity between layers can be reduced in processes where temperature changes occur (during reflow processing or when using the equipment).

The thickness of the protective film-forming film is not particularly limited, but is preferably 100 μm or less, 70 μm or less, 45 μm or less, or 30 μm or less. Furthermore, the thickness of the protective film-forming film is preferably 5 μm or more, 10 μm or more, or 15 μm or more. When the thickness of the protective film-forming film is within the above range, the protective performance of the resulting protective film will be good.

The thickness of the protective film-forming film refers to the thickness of the entire protective film-forming film. For example, the thickness of a protective film-forming film composed of multiple layers refers to the total thickness of all layers that make up the protective film-forming film.

The following describes the protective film formed on the tip, which is the workpiece. Specifically, we will use the protective film-equipped tip 70 shown in Figure 5 to describe the protective film formed by converting the protective film-forming film into a protective film.

As shown in Figure 5, the chip 70 with a protective film has a protective film 40 formed on the back side (upper side in Figure 5) of the chip 6a, and a convex electrode 6b formed on the front side (lower side in Figure 5) of the chip 6a.

A circuit is formed on the surface side of the chip 6a, and the convex electrode 6b is formed to be electrically connected to the circuit. Examples of the convex electrode 6b include a bump and a pillar electrode.

In this embodiment, the protective film-coated chip 70 is placed on the chip-mounting substrate so that the surface on which the convex electrode 6b is formed faces the chip-mounting substrate. A predetermined heating process (e.g., reflow process) electrically and mechanically bonds the convex electrode 6b to the substrate, and the protective film-coated chip 70 is mounted on the substrate.

(5.1 Protective Film-Forming Film Composition)
As long as the protective film has the above-mentioned physical properties, the composition of the protective film-forming film is not particularly limited. In this embodiment, the composition constituting the protective film-forming film (composition for protective film-forming film) is preferably a resin composition containing at least a polymer component (A), a curable component (B), and a filler (E). The polymer component is a component that can be considered to be formed by a polymerization reaction of a polymerizable compound. Furthermore, the curable component is a component that can undergo a curing (polymerization) reaction. In the present invention, the polymerization reaction also includes a polycondensation reaction.

Furthermore, components contained in the polymer component may also fall under the category of curable components. In this embodiment, when the composition for the protective film-forming film contains components that fall under both the polymer component and the curable component, the composition for the protective film-forming film is considered to contain both the polymer component and the curable component.

5.1.1 Polymer Component
The polymer component (A) provides the protective film-forming film with film-forming properties (film-forming properties) while imparting appropriate tack, ensuring uniform application of the protective film-forming film to the workpiece. The weight-average molecular weight of the polymer component is usually in the range of 50,000 to 2,000,000, preferably 100,000 to 1,500,000, and particularly preferably 200,000 to 1,000,000. Examples of such polymer components include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins, with acrylic resins being particularly preferred.

In this specification, unless otherwise specified, the "weight average molecular weight" refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC). Measurements by this method are carried out, for example, using a high-speed GPC apparatus "HLC-8120GPC" manufactured by Tosoh Corporation, connected in this order to high-speed columns "TSK guard column H _XL -H,""TSK Gel GMH _XL ," and "TSK Gel G2000 H _XL " (all manufactured by Tosoh Corporation), under conditions of a column temperature of 40°C, a liquid flow rate of 1.0 mL/min, and a differential refractometer as a detector.

Examples of acrylic resins include (meth)acrylic acid ester copolymers composed of structural units derived from (meth)acrylic acid ester monomers and (meth)acrylic acid derivatives. The (meth)acrylic acid ester monomers are preferably (meth)acrylic acid alkyl esters in which the alkyl group has 1 to 18 carbon atoms, and specific examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate. Furthermore, examples of (meth)acrylic acid derivatives include (meth)acrylic acid, glycidyl (meth)acrylate, and hydroxyethyl (meth)acrylate.

In this embodiment, it is preferable to introduce glycidyl groups into the acrylic resin using glycidyl methacrylate or the like. This improves the compatibility of the acrylic resin into which glycidyl groups have been introduced with the epoxy resin serving as the thermosetting component described below, making it easier to obtain a protective film-forming film with stable performance. In addition, in this embodiment, it is preferable to introduce hydroxyl groups into the acrylic resin using hydroxyethyl acrylate or the like in order to control the adhesion to the workpiece and adhesive properties.

The glass transition temperature of the acrylic resin is preferably -70°C to 40°C, -35°C to 35°C, -20°C to 30°C, -10°C to 25°C, or -5°C to 20°C. By setting the glass transition temperature of the acrylic resin within the above range, the tack of the protective film-forming film is appropriately increased, the adhesive strength of the protective film-forming film to the workpiece is improved, and the adhesive strength of the protective film to the workpiece is appropriately improved.

When an acrylic resin has m types of structural units (m is an integer of 2 or more), the glass transition temperature of the acrylic resin can be calculated as follows: That is, when m types of monomers from which structural units in the acrylic resin are derived are each sequentially assigned a unique number from 1 to m and named "monomer m," the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula shown below.

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

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

For Tgk, values listed in the Polymer Data Handbook, Adhesive Handbook, or Polymer Handbook can be used. For example, the Tgk of a homopolymer of methyl acrylate is 10°C, the Tgk of a homopolymer of n-butyl acrylate is -54°C, the Tgk of a homopolymer of methyl methacrylate is 105°C, the Tgk of a homopolymer of 2-hydroxyethyl acrylate is -15°C, the Tgk of a homopolymer of glycidyl methacrylate is 41°C, and the Tgk of 2-ethylhexyl acrylate is -70°C.

When the total weight of the composition for the protective film-forming film is taken as 100 parts by mass, the content of the polymer component is preferably 5 to 80 parts by mass, 8 to 70 parts by mass, 10 to 60 parts by mass, 12 to 55 parts by mass, 14 to 50 parts by mass, or 15 to 45 parts by mass. By keeping the content of the polymer component within the above range, it becomes easier to control the tack of the protective film-forming film.

(5.1.2 Thermosetting component)
The curable component (B) cures the protective film-forming film to form a hard protective film. As the curable component, a thermosetting component, an energy ray-curable component, or a mixture thereof can be used. When cured by irradiation with energy rays, the protective film-forming film according to this embodiment contains a filler and a colorant, etc., which will be described later, and therefore the light transmittance is reduced. Therefore, for example, when the thickness of the protective film-forming film is increased, the energy ray curing is likely to be insufficient.

On the other hand, thermosetting protective film-forming films can be sufficiently cured by heating, even when they are thick, allowing for the formation of protective films with high protective performance. Furthermore, by using conventional heating means such as a heating oven, multiple protective film-forming films can be heated and thermally cured all at once.

Therefore, in this embodiment, it is desirable that the curable component be thermosetting. In other words, it is preferable that the protective film-forming film in this embodiment be thermosetting.

Whether a protective film-forming film is thermosetting can be determined as follows. First, a protective film-forming film at room temperature (23°C) is heated to a temperature above room temperature, and then cooled to room temperature to obtain a protective film-forming film after heating and cooling. Next, when the hardness of the protective film-forming film after heating and cooling is compared with the hardness of the protective film-forming film before heating at the same temperature, if the protective film-forming film after heating and cooling is harder, the protective film-forming film is determined to be thermosetting.

Preferably used thermosetting components include, for example, epoxy resins, thermosetting polyimide resins, unsaturated polyester resins, and mixtures thereof. Thermosetting polyimide resin is a general term for low-molecular-weight, low-viscosity monomers or precursor polymers that form polyimide resins upon thermal curing. Non-limiting examples of thermosetting polyimide resins are described, for example, in the Sen'i Gakkaishi Journal, "Sen'i to Kogyo," Vol. 50, No. 3 (1994), pp. 106-118.

Epoxy resins, which are thermosetting components, have the property of forming a three-dimensional network structure and a strong coating when heated. Various known epoxy resins can be used as such epoxy resins. In this embodiment, the molecular weight (formula weight) of the epoxy resin is preferably 300 or more and less than 50,000, 300 or more and less than 10,000, 300 or more and less than 5,000, or 300 or more and less than 3,000. The epoxy equivalent of the epoxy resin is preferably 50 to 5,000 g/eq, more preferably 100 to 2,000 g/eq, and even more preferably 150 to 1,000 g/eq.

Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidyl or alkylglycidyl epoxy resins in which the active hydrogen bonded to the nitrogen atom is substituted with a glycidyl group, such as aniline isocyanurate; and so-called alicyclic epoxides in which epoxy groups are introduced by, for example, oxidizing the carbon-carbon double bonds within the molecule, such as vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane. Other epoxy resins that can be used include those with a biphenyl skeleton, dicyclohexadiene skeleton, or naphthalene skeleton.

When a thermosetting component is used as the curing component (B), it is preferable to use a curing agent (C) in combination as an auxiliary. A heat-activated latent epoxy resin curing agent is preferred as a curing agent for epoxy resins. A "heat-activated latent epoxy resin curing agent" is a type of curing agent that does not react well with epoxy resins at room temperature (23°C) but becomes activated and reacts with epoxy resins when heated above a certain temperature. Methods for activating heat-activated latent epoxy resin curing agents include generating active species (anions, cations) through a chemical reaction caused by heating; stably dispersing the curing agent in the epoxy resin at room temperature and becoming compatible and dissolved with the epoxy resin at high temperatures to initiate the curing reaction; using a molecular sieve-encapsulated curing agent that dissolves at high temperatures to initiate the curing reaction; and using microcapsules.

Of the methods listed above, the preferred method is one in which the compound is stably dispersed in the epoxy resin at room temperature, and becomes compatible and soluble with the epoxy resin at high temperatures, initiating the curing reaction.

Specific examples of heat-activated latent epoxy resin curing agents include various onium salts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and high-melting point active hydrogen compounds such as imidazole compounds. These heat-activated latent epoxy resin curing agents can be used alone or in combination of two or more. In this embodiment, dicyandiamide is particularly preferred.

Phenolic resins are also preferred as curing agents for epoxy resins. Phenolic resins include, without limitation, condensates of phenols such as alkylphenols, polyphenols, and naphthol with aldehydes. Specific examples include phenol novolac resin, o-cresol novolac resin, p-cresol novolac resin, t-butylphenol novolac resin, dicyclopentadiene cresol resin, polyparavinylphenol resin, bisphenol A novolac resin, and modified versions of these.

The phenolic hydroxyl groups contained in these phenolic resins easily undergo addition reaction with the epoxy groups of the above-mentioned epoxy resins when heated, forming a cured product with high impact resistance.

The content of curing agent (C) is preferably 0.01 to 30 parts by mass, 0.1 to 20 parts by mass, 0.2 to 15 parts by mass, or 0.3 to 10 parts by mass per 100 parts by mass of epoxy resin. By keeping the content of curing agent (C) within the above range, the network structure of the protective film becomes denser, making it easier for the protective film to provide protection for the workpiece.

When dicyandiamide is used as the curing agent (C), it is preferable to use a curing accelerator (D) in addition. Preferred curing accelerators include imidazoles (imidazoles in which one or more hydrogen atoms have been replaced with groups other than hydrogen atoms), such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Of these, 2-phenyl-4,5-dihydroxymethylimidazole is particularly preferred.

The content of the curing accelerator is preferably 0.01 to 30 parts by mass, 0.1 to 20 parts by mass, 0.2 to 15 parts by mass, or 0.3 to 10 parts by mass per 100 parts by mass of the epoxy resin. By keeping the content of the curing accelerator (D) within the above range, the network structure of the protective film becomes denser, making it easier for the protective film to provide protection for the workpiece.

When the total weight of the composition for protective film-forming films is taken as 100 parts by mass, the total content of the thermosetting component and curing agent is preferably 3 to 80 parts by mass, 5 to 60 parts by mass, 7 to 50 parts by mass, 9 to 40 parts by mass, or 10 to 30 parts by mass. Blending the thermosetting component and curing agent in these proportions results in a moderate amount of tack before curing, allowing for stable application. Furthermore, after curing, the composition is more likely to function as a protective film, protecting the workpiece.

(5.1.3 Energy ray-curable component)
When the curable component (B) is an energy ray-curable component, the energy ray-curable component is preferably uncured and has adhesive properties, and more preferably uncured and has adhesive properties.

The energy ray-curable component is a component that hardens when irradiated with energy rays, and is also a component that imparts film-forming properties, flexibility, etc. to the protective film-forming film.

As the energy ray-curable component, for example, a compound having an energy ray-curable group is preferred. Examples of such compounds include known compounds.

(5.1.4 Filler)
By containing the filler (E) in the protective film-forming film, the protective film obtained by converting the protective film-forming film into a protective film can easily adjust the thermal expansion coefficient, and by making this thermal expansion coefficient closer to the thermal expansion coefficient of the workpiece, the adhesive reliability of the protective film-equipped chip obtained using the protective film-forming film is further improved. Also, by containing the filler (E) in the protective film-forming film, a hard protective film can be obtained, and the moisture absorption rate of the protective film can be reduced, further improving the adhesive reliability of the protective film-equipped chip.

The filler (E) may be either an organic filler or an inorganic filler, but from the standpoint of shape stability at high temperatures, an inorganic filler is preferred.

Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, boron nitride, etc.; beads made by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Of these, silica and surface-modified silica are preferred. Surface-modified silica is preferably surface-modified with a coupling agent, and more preferably surface-modified with a silane coupling agent.

The average particle size of the filler is preferably 0.02 to 10 μm, 0.05 to 5 μm, or 0.10 to 3 μm.

By setting the average particle size of the filler within the above range, the composition for a protective film-forming film is easier to handle. As a result, the quality of the composition for a protective film-forming film and the protective film-forming film tends to be more stable.

In this specification, unless otherwise specified, "average particle size" refers to the particle size (D50) at 50% of the integrated value on the particle size distribution curve obtained by laser diffraction scattering.

When the total weight of the composition for the protective film-forming film is taken as 100 parts by mass, the content of the filler is preferably 15 to 80 parts by mass, 30 to 75 parts by mass, 40 to 70 parts by mass, or 45 to 65 parts by mass.

By setting the lower limit of the filler content to the above value, the adhesive reliability of the protective film-equipped chip obtained using the protective film-forming film is further improved. Furthermore, by setting the upper limit of the filler content to the above value, the adhesive strength of the protective film-forming film to the workpiece is improved, and the adhesive strength of the protective film to the workpiece is appropriately improved.

5.1.5 Coupling Agents
The protective film-forming film preferably contains a coupling agent (F). By containing the coupling agent, after the protective film-forming film is cured, the adhesion between the protective film and the workpiece can be improved without impairing the heat resistance of the protective film, and the water resistance (moist heat resistance) can be improved. As the coupling agent, a silane coupling agent is preferred from the viewpoint of its versatility and cost benefits.

Examples of silane coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. These may be used alone or in combination.

When the total weight of the composition for the protective film-forming film is taken as 100 parts by mass, the content of the coupling agent is preferably 0.01 to 20 parts by mass, 0.1 to 10 parts by mass, 0.2 to 5 parts by mass, or 0.3 to 3 parts by mass.

5.1.6 Colorants
The protective film-forming film preferably contains a colorant (G). This conceals the back surface of the workpiece, such as a chip, thereby blocking various electromagnetic waves generated in electronic devices and reducing malfunction of the workpiece, such as a chip. In addition, the recognizability of laser marking is further improved.

As the colorant (G), known agents such as organic pigments, organic dyes, and inorganic pigments can be used. In this embodiment, inorganic pigments are preferred.

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. Of these, carbon black is particularly preferred. Carbon black can block electromagnetic waves over a wide wavelength range.

The amount of colorant (especially carbon black) in the protective film-forming film varies depending on the thickness of the protective film-forming film. For example, if the thickness of the protective film-forming film is 20 μm, the content of the colorant is preferably 0.01 to 10 parts by mass, 0.03 to 7 parts by mass, or 0.05 to 4 parts by mass when the total weight of the protective film-forming composition is 100 parts by mass.

The average particle size of the colorant (especially carbon black) is preferably 1 to 500 nm, 3 to 100 nm, or 5 to 50 nm. If the average particle size of the colorant is within the above range, it is easy to control the light transmittance within the desired range.

(5.1.7 Other Additives)
The composition for the protective film-forming film may contain other additives, such as a photopolymerization initiator, a crosslinking agent, a plasticizer, an antistatic agent, an antioxidant, a gettering agent, a tackifier, a release agent, etc., within the range that does not impair the effects of the present invention.

(6. Pressure-sensitive adhesive layer for jig)
The adhesive constituting the jig adhesive layer is preferably one having the desired adhesive strength and removability, and examples thereof include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, and polyvinyl ether adhesives. Among these, acrylic adhesives are preferred because they have high adhesion to jigs such as ring frames and can effectively prevent the composite sheet for forming a protective film from peeling from the ring frame during dicing processes, etc. A substrate serving as a core material may be interposed in the thickness direction of the jig adhesive layer.

From the viewpoint of adhesion to jigs such as ring frames, the thickness of the adhesive layer for jigs is preferably 5 to 200 μm, and more preferably 10 to 100 μm.

(7. Release Film)
The release film is preferably disposed on the surface of the pressure-sensitive adhesive layer of the support sheet and on the surface of the protective film-forming film of the composite sheet for forming a protective film. The release film may be composed of one layer (single layer) or two or more layers of substrate, and the surface of the substrate may be subjected to a release treatment from the viewpoint of controlling releasability. That is, the surface of the substrate may be modified, or a material (release agent layer) not derived from the substrate may be formed on the surface of the substrate.

The substrate is not particularly limited as long as it is a material that can support the protective film-forming film until it is attached to the workpiece, and is usually composed of a film primarily made of a resin-based material. In this embodiment, polyethylene terephthalate film is preferred from the standpoints of environmental safety, cost, etc. The substrate may also contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers.

The release agent layer is obtained by applying a coating agent containing a release agent layer composition to one surface of the substrate, and then drying and curing the coating. The release agent layer composition is not particularly limited as long as it is a material that can impart releasability to the substrate from the protective film-forming film. In this embodiment, the release agent layer composition is preferably, for example, an alkyd-based release agent, a silicone-based release agent, a fluorine-based release agent, an unsaturated polyester-based release agent, a polyolefin-based release agent, or a wax-based release agent, with silicone-based release agents being particularly preferred.

The thickness of the release film is not particularly limited, but is preferably 15 to 100 μm, more preferably 25 to 80 μm, and even more preferably 35 to 60 μm.

(8. Method for producing a composite sheet for forming a support sheet and a protective film)
The support sheet is manufactured, for example, as follows. First, a substrate for the support sheet is prepared. The substrate may be obtained by melt-kneading a raw material composition and extruding the sheet-like substrate using an extruder, and then contacting the substrate in a soft state with a roll that has been treated with a predetermined unevenness, such as a grained finish, to form the surface texture described above. Alternatively, the raw material substrate may be passed between a roll that has been treated with a predetermined unevenness, such as a grained finish, and a roll that has not been treated with an unevenness, and the unevenness formed on the roll is transferred to the substrate to obtain a substrate with the surface texture described above.

Examples of specified unevenness treatments include grinding with abrasive stones, wet blasting such as liquid honing, and dry blasting such as sand blasting. Grinding with abrasive stones is a process that grinds the surface of the roll and typically smooths the surface of the roll. Wet blasting and dry blasting are processes that spray an abrasive material onto the surface of the roll to change the surface condition of the roll and typically form unevenness on the roll surface. The size of the unevenness can be controlled by changing the material and particle size of the abrasive material.

Therefore, by combining the surface smoothing process with the process of forming irregularities, it is possible to obtain a roll with a surface that has been treated to have the desired irregularities.

Next, a pressure-sensitive adhesive composition that will form the pressure-sensitive adhesive layer, or a composition obtained by diluting the pressure-sensitive adhesive composition with a solvent (these two compositions are collectively referred to as "coating agent"), is prepared. The resulting coating agent is applied to the release surface of the first release film using a coating machine such as a roll coater, knife coater, roll knife coater, air knife coater, die coater, bar coater, gravure coater, or curtain coater, and then dried as necessary to form a pressure-sensitive adhesive layer on the first release film. Next, the exposed surface of the pressure-sensitive adhesive layer is bonded to the main surface of the substrate prepared above that does not have the above-mentioned surface texture, to produce a support sheet having the first release film on the surface of the pressure-sensitive adhesive layer.

Here, if the adhesive layer is made of an energy ray-curable adhesive, the adhesive layer may be cured by irradiating it with energy rays at this stage, or the adhesive layer may be cured after laminating it with the protective film-forming film. Furthermore, if the adhesive layer is cured after laminating it with the protective film-forming film, the adhesive layer may be cured before the dicing step, or the adhesive layer may be cured after the dicing step.

As the energy beam, ultraviolet rays, electron beams, etc. are usually used. The irradiation dose of the energy beam varies depending on the type of energy beam, but for example, in the case of ultraviolet rays, the light dose is preferably 50 to 1000 mJ/ ^cm2 , and particularly preferably 100 to 500 mJ/ ^cm2 . In addition, in the case of electron beams, the dose is preferably about 10 to 1000 krad.

The composite sheet for forming a protective film can be produced, for example, by separately preparing the support sheet prepared above and a laminate including the protective film-forming film, and then laminating the protective film-forming film and support sheet using the support sheet and laminate.

First, the above-described composition for a protective film-forming film, or a composition obtained by diluting the composition for a protective film-forming film with a solvent (these two compositions are referred to as "coating agents"), is prepared. Next, the coating agent is applied to the release surface of a second release film and dried as necessary to form a protective film-forming film on the second release film. Next, the release surface of a third release film is bonded to the exposed surface of the protective film-forming film to obtain a laminate.

Once the support sheet and laminate are obtained in this manner, the first release film on the support sheet is peeled off, and the third release film on the laminate is peeled off, and the exposed adhesive layer of the support sheet is bonded to the exposed protective film-forming film. If necessary, after peeling off the second release film, a jig adhesive layer formed on a fourth release film is bonded to the peripheral edge of the exposed protective film-forming film or adhesive layer. In this way, the composite sheet for forming a protective film shown in Figure 2 is obtained.

The resulting support sheet and composite sheet for forming a protective film are cut on both sides of the width to fit the size of the workpiece to be attached, and then wound up into a sheet roll by a winding device while applying a predetermined tension.

(9. Device Manufacturing Method)
As an example of a method for manufacturing a device using the support sheet and protective film-forming composite sheet of this embodiment, a method for manufacturing a chip with a protective film obtained by processing a wafer to which a protective film-forming film is attached will be described.

The method for manufacturing the device according to this embodiment includes at least the following steps 1 to 5.
Step 1: A step of unwinding and unwinding a rolled composite sheet for forming a protective film. Step 2: A step of attaching the protective film-forming film of the unwound composite sheet for forming a protective film to the back surface of a wafer. Step 3: A step of converting the attached protective film-forming film into a protective film. Step 4: A step of laser marking the protective film or protective film-forming film. Step 5: A step of singulating a wafer having a protective film or protective film-forming film on the back surface to obtain a plurality of chips with the protective film or protective film-forming film.

As is clear from the above, step 3 may be performed before or after step 5.

The manufacturing method for the device, which includes steps 1 to 5 above, is explained using Figure 6.

First, the rolled composite sheet for forming a protective film is unwound and the composite sheet for forming a protective film is unwound (Step 1). At this time, because the surface properties of the main surface of the base material of the support sheet on which the adhesive layer is not formed are controlled as described above, there is no blocking between the base material and the release film formed on the protective film-forming film. As a result, poor unwinding of the composite sheet for forming a protective film can be suppressed.

Next, as shown in FIG. 6, the protective film-forming film 4 of the unwound composite sheet 10 for forming a protective film is attached to the back surface of the wafer 6 (step 2). At this time, the outer periphery of the protective film-forming film 4 may be fixed by a ring frame 7. In this embodiment, as shown in FIG. 6, a jig adhesive layer 5 is provided on the outer periphery of the protective film-forming film 4, so the jig adhesive layer 5 is attached to the ring frame 7. The wafer 6 is attached to the surface of the protective film-forming film 4 opposite the surface attached to the adhesive layer 3. When attaching the protective film-forming film 4 to the wafer 6, the protective film-forming film 4 may be heated, if desired, to exhibit adhesive properties.

Then, the attached protective film-forming film 4 is made into a protective film to form a protective film (step 3), thereby obtaining a wafer 6 with a protective film. If the protective film-forming film 4 is thermosetting, the protective film-forming film 4 can be heated at a predetermined temperature for an appropriate period of time. If the protective film-forming film 4 is energy ray-curable, energy rays can be applied through the support sheet 1.

The protective film-forming film 4 may be cured after the dicing process, or the chip with the protective film-forming film may be picked up from the adhesive sheet and then the protective film-forming film may be cured.

Next, laser marking is performed on the protective film (Step 4). Note that Step 4 is preferably performed after Step 3, and in this embodiment, Step 4 is more preferably performed before Step 5.

Laser marking may be performed by scraping off the surface of the protective film-forming film or protective film with laser irradiation, or by increasing the volume of the protective film-forming film or protective film with laser irradiation to form convex portions. Laser marking may be performed using a known laser marking device.

Because the gloss value and surface properties of the main surface of the support sheet substrate on which the adhesive layer is not formed are controlled as described above, clear markings can be made and the markings can be clearly recognized when observed.

Then, the protective film-coated wafer 6 is diced using a known method to obtain chips (protective film-coated chips 70) having the protective film 40 shown in Figure 5 (Step 5). In other words, the support sheet of the composite sheet for forming a protective film can function as a dicing sheet.

(10. Modifications)
In the above embodiment, a composite sheet for forming a protective film in which a support sheet and a protective film-forming film are integrated has been described, but the support sheet and the protective film-forming film do not have to be integrated. That is, a kit composed of the above support sheet and a protective film-forming film to be attached to the surface of the adhesive layer of the support sheet is also included in the present invention. This kit can be used by first attaching the protective film-forming film to a workpiece, and then attaching the adhesive layer of the support sheet and the protective film-forming film.

The composite sheet for forming a protective film may have the configuration shown in Figure 7. The composite sheet for forming a protective film 11 shown in Figure 7 is composed of a support sheet 1 formed by laminating an adhesive layer 3 on one side of a substrate 2, and a protective film-forming film 4 laminated on the adhesive layer 3 side of the support sheet 1. The protective film-forming film 4 is formed to be approximately the same size as the workpiece or slightly larger than the workpiece in a plan view, and smaller than the support sheet 1. The adhesive layer 3 in the portion not laminated with the protective film-forming film 4 can be attached to a jig such as a ring frame.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and may be modified in various ways within the scope of the present invention.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

Example 1
(Preparation of support sheet)
First, the substrate constituting the support sheet was prepared as follows.

The base material was a polypropylene film (tensile modulus 320 MPa in the machine direction/290 MPa in the cross direction, melting point 156°C) that was melt-kneaded in a kneader to obtain the extrusion raw material.

The resulting extrusion raw material was extruded at 220°C using a small T-die extruder (manufactured by Toyo Seiki Seisaku-sho, product name "Labo Plastomill (registered trademark)"), and the extrusion-molded sheet immediately after molding was cooled on a metal roll (40°C) that had been textured (grinding with a grindstone, wet blasting (liquid honing), and dry blasting (sandblasting)). This produced an 80μm-thick substrate with an adjusted surface roughness on the surface that came into contact with the metal roll.

Next, the adhesive layer that constitutes the support sheet was prepared as follows.

A coating agent containing a pressure-sensitive adhesive layer composition was prepared by adding 15 parts by mass of a trifunctional xylylene diisocyanate crosslinking agent (manufactured by Mitsui Takeda Chemicals, Inc., trade name "Takenate 110N") to 100 parts by mass (solids content equivalent) of an acrylic copolymer (weight average molecular weight: 800,000) obtained by copolymerizing 80 parts by mass of 2-ethylhexyl acrylate (2EHA) and 20 parts by mass of 2-hydroxyethyl acrylate (HEA), and diluting with methyl ethyl ketone to a solids concentration of 25% by mass.

The above-mentioned adhesive layer composition coating agent was applied to the release-treated surface of a release film (manufactured by Lintec Corporation, product name "SP-PET381031", a polyethylene terephthalate (PET) film with a silicone release treatment, thickness: 38 μm) and dried to produce a release film with an adhesive layer having a thickness of 5 μm.

A support sheet was produced by bonding the surface of the adhesive layer of the release film with the adhesive layer to the side of the substrate whose surface roughness was not adjusted (the side not in contact with the metal roll). This support sheet was long and was wound up into a sheet roll.

(1) Preparation of a first laminate including a protective film-forming film The following components (a) to (g) were mixed and diluted with methyl ethyl ketone to a solid content of 50% by mass to prepare a coating agent for a protective film-forming film.
(a) Binder polymer: 150 parts by mass (solids equivalent, the same applies hereinafter) of (meth)acrylic acid ester copolymer (an acrylic copolymer obtained by copolymerizing 10 parts by mass of n-butyl acrylate, 70 parts by mass of methyl acrylate, 5 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate, having a weight average molecular weight of 800,000 and a glass transition temperature of −1° C.)
(b-1) Thermosetting component: 60 parts by mass of bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "jER828", epoxy equivalent 184 to 194 g/eq) (b-2) Thermosetting component: 10 parts by mass of bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "jER1055", epoxy equivalent 800 to 900 g/eq) (b-3) Thermosetting component: 30 parts by mass of dicyclopentadiene type epoxy resin (manufactured by Dainippon Ink and Chemicals, Inc., product name "Epicron HP-7200HH", epoxy equivalent 255 to 260 g/eq)
(c) Heat-activated latent epoxy resin curing agent: dicyandiamide (manufactured by ADEKA Corporation: ADEKA HARDNER EH3636AS, active hydrogen content 21 g/eq) 2 parts by mass (d) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd., product name "Curesol 2PHZ") 2 parts by mass (e) Filler: Silica filler (manufactured by Admatechs Co., Ltd., product name "SC2050MA", average particle size: 0.5 μm) 320 parts by mass (f) Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, product name "#MA650", average particle size: 28 nm) 1.2 parts by mass (g) Silane coupling agent: (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-403") 2 parts by mass

A first release film (manufactured by Lintec Corporation, product name "SP-PET381031") was prepared, consisting of a 38 μm-thick polyethylene terephthalate (PET) film with a silicone-based release agent layer formed on one side, and a second release film (manufactured by Lintec Corporation, product name "SP-PET381130") was prepared, consisting of a 38 μm-thick PET film with a silicone-based release agent layer formed on one side.

First, the above-mentioned protective film-forming film coating agent was applied to the release surface of the first release film using a knife coater and dried to form a protective film-forming film with a thickness of 25 μm. The release surface of the second release film was then placed on top of the protective film-forming film and the two were bonded together to obtain a first laminate consisting of the first release film, the protective film-forming film (thickness: 25 μm), and the second release film. This laminate was long and was wound up into a sheet roll.

(2) Preparation of a second laminate including a pressure-sensitive adhesive layer for a jig The following components (j) and (k) were mixed and diluted with toluene to a solids concentration of 15% by mass to prepare a coating agent for a pressure-sensitive adhesive layer for a jig.
(j) Adhesive base: 100 parts by mass of (meth)acrylic acid ester copolymer (a copolymer obtained by copolymerizing 69.5 parts by mass of butyl acrylate, 30 parts by mass of methyl acrylate, and 0.5 parts by mass of 2-hydroxyethyl acrylate, weight average molecular weight: 500,000) (k) Crosslinking agent: 5 parts by mass of tolylene diisocyanate crosslinking agent (manufactured by Toyochem Co., Ltd., product name "BHS8515")

The first and second release films (manufactured by Lintec Corporation, product name "SP-PET381031") were made of a 38 μm-thick PET film with a silicone-based release agent layer formed on one side, and a polyvinyl chloride film (manufactured by Okamoto Corporation, thickness: 50 μm) was used as the core material.

First, the adhesive layer coating agent was applied to the release surface of the first release film using a knife coater and dried to form a 5 μm-thick first adhesive layer. The core material was then laminated to the first adhesive layer, yielding laminate A consisting of the core material, first adhesive layer, and first release film. This laminate A was long and was wound up into a sheet roll.

Next, the adhesive layer coating agent was applied to the release surface of the second release film using a knife coater and dried to form a 5 μm-thick second adhesive layer. The exposed surface of the core material in the laminate A was then bonded to the second adhesive layer, yielding a second laminate consisting of first release film/first adhesive layer/core material/second adhesive layer/second release film. This laminate was long and was wound up into a sheet roll.

(3) Preparation of a third laminate The second release film was peeled off from the first laminate obtained in (1) above to expose the protective film-forming film. Meanwhile, the release film was peeled off from the support sheet obtained above to expose the pressure-sensitive adhesive layer. The first laminate and the support sheet were bonded together so that the protective film-forming film was in contact with the pressure-sensitive adhesive layer, thereby obtaining a third laminate in which the support sheet consisting of the substrate and the pressure-sensitive adhesive layer, the protective film-forming film, and the first release film were laminated.

(4) Preparation of a composite sheet for forming a protective film: The second release film was peeled off from the second laminate obtained in (2) above, leaving the first release film, and the inner peripheral edge of the pressure-sensitive adhesive layer for the jig was half-cut to remove the inner circular portion, so that the diameter of the inner peripheral edge of the pressure-sensitive adhesive layer for the jig was 220 mm.

The first release film was peeled off from the third laminate obtained in (3) above, and the exposed protective film-forming film was superimposed on the exposed jig adhesive layer in the second laminate and pressed together. Then, leaving the first release film in the second laminate, the outer edge of the composite sheet for forming a protective film was half-cut to remove the outer portion. At this time, the diameter of the outer edge of the composite sheet for forming a protective film was 270 mm.

In this way, a composite sheet for forming a protective film was obtained, consisting of a support sheet in which an adhesive layer (thickness: 5 μm) was laminated on a substrate, a protective film-forming film laminated on the adhesive layer side of the support sheet, a ring-shaped jig adhesive layer laminated on the peripheral portion of the protective film-forming film on the side opposite the support sheet, and a release film laminated on the jig adhesive layer on the side opposite the protective film-forming film. This composite sheet for forming a protective film was long and was wound up into a sheet roll.

(Examples 2 to 4 and Comparative Examples 1 to 3)
A composite sheet for forming a protective film was produced by the same method as in Example 1, except that the metal roll used to produce the substrate in Example 1 was changed to a metal roll with a predetermined grain shape by combining grinding wheel grinding, wet blasting, and dry blasting to change the state of existence of relatively large irregularities and a smooth surface, thereby changing the surface roughness of the surface in contact with the metal roll.

The following measurements and evaluations were carried out using the support sheets or composite sheets for forming protective films obtained in Examples 1 to 4 and Comparative Examples 1 to 3.

(Glossiness of exposed surface of substrate)
The release film was peeled from the support sheet of each Example and Comparative Example and attached to a colorless, transparent soda-lime glass to prepare a measurement sample. A gloss meter (Nippon Denshoku Corporation's gloss meter "VG 2000") was used to measure the 60° specular gloss of the surface (exposed surface) of the substrate on which the adhesive layer was not formed, in accordance with JIS Z 8741, by irradiating the measurement sample from the side on which the adhesive layer was not formed. The measured value was used as the gloss value of the substrate surface. The results are shown in Table 1.

(Surface roughness Sa1 and Sa2 of exposed surface of substrate)
The exposed surface of the substrate of the support sheet of each example and comparative example was observed using a scanning white light interference microscope VS-1550 manufactured by Hitachi High-Tech Science Corporation, and Sa1 and Sa2 were calculated as follows.

The observation magnification was 50x, and observation was performed in multi-field mode. An area measuring 0.36 mm in the X-axis direction and 0.27 mm in the Y-axis direction was set in the observation field, and 15 columns in the X-axis direction and 20 rows in the Y-axis direction were observed, for a total of 300 cells.

Images from 300 cells were combined to create a single image measuring 4.91 mm x 4.90 mm. Sa was measured for the entire combined image, and this was taken as Sa1. The results are shown in Table 1.

Next, Sa was measured for each of the 300 cells without combining the images, obtaining 300 Sa data points. Of the 300 Sa data points, the 20 smallest Sa data points were extracted. The average of the 20 extracted Sa data points was taken as Sa2. The results are shown in Table 1.

(Laser marking recognition)
The release film was removed from the composite sheet for forming a protective film of each example and comparative example, and the composite sheet for forming a protective film and a ring frame were attached to a silicon wafer having a thickness of 350 μm and an outer diameter of 8 inches at a temperature of 70°C using an attachment device ("RAD-2700F/12" manufactured by Lintec). The protective film-forming film was then heat-cured at 130°C for 2 hours to form a protective film. Next, a printing device (manufactured by EO, CSM300M, wavelength 532 nm) was used to irradiate the protective film with a laser through the support sheet, thereby marking the following two patterns (pattern 1 and pattern 2).
Pattern 1: Character size 0.5mm x 0.5mm, character spacing 0.05mm, number of characters 20 Pattern 2: Character size 0.15mm x 0.25mm, character spacing: 0.05mm, number of characters 20

The characters formed on the protective film by the above laser marking were observed both through the support sheet and without the support sheet (after removing the support sheet) and evaluated according to the following criteria. The results are shown in Table 1.
A: I was able to read all the characters in patterns 1 and 2 without any problems.
B: There are some unclear parts in pattern 2, but all the characters can be read without any problems in pattern 1.
C: Both patterns 1 and 2 had unclear areas.

(Mount payout property of composite sheet for forming protective film)
The composite sheet for forming a protective film of each example and comparative example was wound into a sheet roll. The sheet roll was stored at room temperature (23°C) for 3 days. After storage, the composite sheet for forming a protective film was unwound from the sheet roll, the release film was peeled off, and the unwound composite sheet for forming a protective film was attached to a silicon wafer (thickness 350 μm, outer diameter 8 inches) and a ring frame using an attachment device (RAD-2700, manufactured by Lintec Corporation). The operability regarding unwinding failures during attachment was evaluated using the following three-point scale. Unwinding failures were defined as when partial peeling occurred between the adhesive layer and the film for forming a protective film when unwinding the composite sheet for forming a protective film, resulting in the support sheet being transferred to the release film, or when the composite sheet for forming a protective film could not be unwound at all. The results are shown in Table 1.
A: 50 sheets were attached, and there was one or less sheet with a feeding defect. B: 50 sheets were attached, and there were two to five sheet with a feeding defect. C: 50 sheets were attached, and there were six or more sheet with a feeding defect.

Table 1 confirms that when the gloss value and surface texture of the main surface of the support sheet substrate on which the adhesive layer is not formed are controlled as described above, it is possible to achieve both payout performance and laser marking visibility.

DESCRIPTION OF SYMBOLS 1... Support sheet 2... Base material 3... Adhesive layer 10... Composite sheet for forming protective film 4... Protective film-forming film 5... Adhesive layer for jig 70... Chip with protective film 40... Protective film

Claims (7)

A substrate and a pressure-sensitive adhesive layer formed on one main surface of the substrate,
In the base material, the arithmetic mean height Sa1 of a 4.91 mm × 4.90 mm square region on the main surface on which the pressure-sensitive adhesive layer is not formed is greater than 0.50 μm,
the 4.91 mm × 4.90 mm square region on the main surface on which the pressure-sensitive adhesive layer is not formed is a wide region obtained by combining 300 narrow regions, each of which is a 0.36 mm × 0.27 mm square region;
When the average of the arithmetic mean heights of the 20 smallest of the arithmetic mean heights of each narrow region is defined as Sa2, Sa2 is 0.43 μm or less,
A support sheet having a gloss value of 20 or more at an incident angle of 60° on the main surface on which the pressure-sensitive adhesive layer is not formed. A substrate and a pressure-sensitive adhesive layer formed on one main surface of the substrate,
In the base material, the arithmetic mean height Sa1 of a 4.91 mm × 4.90 mm square region on the main surface on which the pressure-sensitive adhesive layer is not formed is greater than 0.50 μm,
the 4.91 mm × 4.90 mm square region on the main surface on which the pressure-sensitive adhesive layer is not formed is a wide region obtained by combining 300 narrow regions, each of which is a 0.36 mm × 0.27 mm square region;
When the average of the 20 smallest arithmetic mean heights of the respective narrow regions is defined as Sa2, the ratio of Sa1 to Sa2, Sa1/Sa2, is 1.40 or more,
A support sheet having a gloss value of 20 or more at an incident angle of 60° on the main surface on which the pressure-sensitive adhesive layer is not formed. The support sheet according to claim 1 or 2 , wherein no other layer is formed on the main surface on which the pressure-sensitive adhesive layer is not formed. A composite sheet for forming a protective film, comprising: the support sheet according to claim 1 ; and a protective film-forming film formed on the pressure-sensitive adhesive layer of the support sheet. A kit comprising the support sheet according to any one of claims 1 to 3 and a protective film-forming film to be attached to the surface of the adhesive layer of the support sheet. a step of unwinding and unwinding the support sheet according to any one of claims 1 to 3 wound in a roll;
A step of attaching the unwound support sheet to a workpiece;
A step of laser marking the workpiece;
and processing the workpiece to obtain a processed product of the workpiece. a step of unwinding and unwinding the composite sheet for forming a protective film according to claim 4 wound in a roll;
A step of attaching the protective film-forming film of the unwound protective film-forming composite sheet to the back surface of the workpiece;
A step of converting the attached protective film-forming film into a protective film;
A step of performing laser marking on the protective film or the protective film-forming film;
A method for manufacturing an apparatus, comprising: a step of dividing the workpiece having a protective film or protective film-forming film on the back surface into individual pieces to obtain a plurality of workpieces with protective films or protective film-forming films.