Sheet for forming resin film

Abstract

The present invention provides a resin film-forming film which can be used even in a harsh storage environment or use environment of the resin film-forming film. The present invention relates to a sheet for forming a resin film, a composite sheet for forming a resin film, and a release film, and a method for manufacturing a singulated workpiece such as a semiconductor chip using the same, wherein the sheet for forming a resin film, the composite sheet for forming a resin film, and the release film are capable of suppressing the generation of foreign matter that causes the appearance of the resin film or a poor appearance of the resin film. The solution of the present invention is a resin film-forming sheet having a resin film-forming film and a first release film, in which the resin film-forming film and the first release film are laminated such that one main surface of the resin film-forming film is in contact with a release surface of the first release film, and when ethanol is dropped onto the release surface, the first release film and the resin film-forming film are separated from each other. When the long diameter of the ethanol droplet 2 seconds after the start of the dropping is A and the long diameter of the ethanol droplet 5 minutes after the start of the dropping is B, the rate of change in the long diameter as shown below is 30% or less. Rate of change of major diameter = {(A-B) / A} * 100 (%).

Description

Technical Field

[0001] The present invention relates to a sheet for forming a resin film, a composite sheet for forming a resin film, a release film, and a method for manufacturing a single workpiece. In particular, it relates to a sheet for forming a resin film, a composite sheet for forming a resin film, a release film, and a method for manufacturing a single workpiece such as a semiconductor chip using the same, which can suppress the generation of foreign matters that cause defects in the appearance of the resin film-forming film or the resin film. Background Art

[0002] In recent years, a method of manufacturing a semiconductor device using a mounting method called flip chip bonding has been implemented. In this mounting method, when mounting a semiconductor chip having a circuit surface formed with convex electrodes such as bumps, the circuit surface side of the semiconductor chip is inverted (facing downward) and bonded to the chip mounting portion. Therefore, a structure is formed in which the back side of the semiconductor chip where no circuit is formed is exposed.

[0003] Therefore, in order to protect the semiconductor chip from impacts during transportation or the like, a hard resin film made of an organic material is usually formed on the back side of the semiconductor chip. Such a resin film is called a protective film. For example, the protective film, which is an example of a resin film-forming film, is attached to the back side of the semiconductor wafer and then cured, or formed in a non-cured state.

[0004] In addition, the semiconductor chip may be bonded to the circuit formation surface of the substrate through a resin film attached to its back side. Such a resin film-forming film for forming and bonding a resin film is called a die bonding film. Through die bonding, the semiconductor chip is disposed on the substrate through the die bonding film. Then, if necessary, one or more other semiconductor chips are further stacked on the semiconductor chip, and after wire bonding, the whole is resin-sealed to manufacture a semiconductor package.

[0005] Patent Document 1 discloses a long strip-shaped adhesive sheet in which a first release layer provided on a first sheet and a second release layer provided on a second sheet are disposed on both sides of an adhesive layer. In addition, Patent Document 1 discloses that the adhesive layer is used as a film-shaped adhesive, a bottom filling sheet, a diced die bonding film, a back protective film for a semiconductor wafer, etc. used in a die bonding process.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: International Publication No. 2017 / 145735 Summary of the Invention

[0009] (I) Technical Problems to be Solved

[0010] A film for forming a resin film (resin film-forming film) is usually stored in a state of contact with a release film or the like until use. When the storage environment is severe, or when the environment during use is severe, foreign matter may be generated on the surface of the resin film-forming film or the resin film. Such foreign matter will cause poor appearance of the resin film-forming film or the resin film, for example, there are problems such as a decrease in the yield of semiconductor chips.

[0011] Regarding such problems, the inventors of the present application found that when a coating agent containing a liquid resin film-forming film composition is coated on a release film and dried, after the liquid component of the resin film-forming film composition volatilizes, a part of the solid component contained in the resin film-forming film composition exists on the release film, and due to the severe environment during storage or use, these solid components sometimes aggregate and become foreign matter visible to the naked eye.

[0012] The present invention has been completed in view of such actual situations, and its object is to provide a resin film-forming sheet, a resin film-forming composite sheet, a release film, and a method for manufacturing a single workpiece such as a semiconductor chip using them, which can suppress the generation of foreign matter that causes poor appearance of the resin film-forming film or the resin film even when the storage environment or use environment of the resin film-forming film is severe.

[0013] (II) Technical solutions

[0014] The solution of the present invention is as follows.

[0015] [1] A resin film-forming sheet, which is a resin film-forming sheet having a resin film-forming film and a first release film,

[0016] The resin film-forming film and the first release film are laminated in such a manner that one main surface of the resin film-forming film is in contact with the release surface of the first release film,

[0017] When dropping ethanol on the release surface, when the major axis of the ethanol droplet 2 seconds after the start of dropping is set as A and the major axis of the ethanol droplet 5 minutes after the start of dropping is set as B, the major axis change rate as follows is 30% or less.

[0018] Major axis change rate ={(A - B) / A}×100(%)

[0019] [2] The resin film-forming sheet according to [1], wherein the resin film-forming film contains a latent curing agent.

[0020] [3] A resin film-forming composite sheet, which has the resin film-forming sheet according to [1] or [2], and a support sheet disposed on the other main surface of the resin film-forming film.

[0021] [4] A release film, which is a release film having a release surface,

[0022] When dropping ethanol onto the peeling surface, when the major axis of the ethanol droplet 2 seconds after the start of dropping is defined as A and the major axis of the ethanol droplet 5 minutes after the start of dropping is defined as B, the major axis change rate as shown below is 30% or less.

[0023] Major axis change rate = {(A - B) / A} × 100 (%)

[0024] [5] A method for manufacturing a single-piece workpiece, comprising the steps of:

[0025] A step of attaching the resin film forming film provided in the resin film forming sheet described in [1] or [2], or the resin film forming film provided in the resin film forming composite sheet described in [3] to the back surface of the workpiece;

[0026] A step of forming the attached resin film forming film into a resin film; and

[0027] A step of singulating the workpiece with the resin film or resin forming film attached thereto to obtain a plurality of single-piece workpieces with a resin film or a single-piece workpiece with a resin forming film.

[0028] (III) Advantageous Effects

[0029] According to the present invention, there is provided a resin film forming sheet, a resin film forming composite sheet, a release film, and a method for manufacturing a single-piece workpiece such as a semiconductor chip using the same, which can suppress the generation of foreign matters that cause poor appearance of the resin film forming film or the resin film even in a harsh storage environment or use environment of the resin film forming film. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1A It is a schematic cross-sectional view of an example of the resin film forming sheet of the present embodiment. Figure 1B [[ID= 31]]It is a schematic cross-sectional view of another example of the resin film forming sheet of the present embodiment.

[0031] Figure 2 It is a schematic cross-sectional view showing that the first release film has a substrate and a first release agent layer.

[0032] Figure 3A It is a schematic cross-sectional view of an example of the resin film forming composite sheet of the present embodiment.

[0033] Figure 3B It is a schematic cross-sectional view of another example of the resin film forming composite sheet of the present embodiment.

[0034] Figure 4A It is a schematic cross-sectional view for explaining the step of attaching the protective film forming sheet of the present embodiment to a wafer.

[0035] Figure 4B It is a cross-sectional schematic view for explaining the process of attaching the composite sheet for forming a protective film of this embodiment to a wafer.

[0036] Figure 5 It is a cross-sectional schematic view for explaining the process of singulating a wafer with a protective film. Detailed implementation manners

[0037] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings based on specific embodiments.

[0038] First, the main terms used in this specification will be explained.

[0039] The workpiece refers to a plate-like body that is singulated after attaching the resin film-forming film provided on the resin film-forming sheet or the composite sheet for forming a resin film of this embodiment. The resin-forming film is attached to the back surface of the workpiece. As the workpiece, a circular (including the case having an orientation plane) wafer, a square panel-level package, and a strip (rectangular substrate) with a molded resin package can be cited. Among them, from the perspective of easily obtaining the effects of the present invention, a wafer is preferred. As the wafer, for example, a semiconductor wafer such as a silicon wafer, a gallium arsenide wafer, a silicon carbide wafer, a gallium nitride wafer, an indium phosphide wafer; an insulator wafer such as a glass wafer, a lithium tantalate wafer, a lithium niobate wafer, etc. In addition, it can also be a reconstituted wafer formed of resin and semiconductor used in the production of fan-out packages and the like. From the perspective of easily obtaining the effects of the present invention, as the wafer, a semiconductor wafer or an insulator wafer is preferred, and a semiconductor wafer is more preferred.

[0040] The singulation of the workpiece means dividing the workpiece according to the circuit to obtain a singulated workpiece. For example, when the workpiece is a semiconductor wafer, the singulated workpiece is a semiconductor chip, and when the workpiece is a panel-level package or a strip (rectangular substrate) with a molded resin package, the singulated workpiece is a semiconductor package.

[0041] The "front surface" of the workpiece refers to the surface on which circuits, electrodes, etc. are formed, and the "back surface" of the workpiece refers to the surface on which no circuits, etc. are formed. As the electrode, a convex electrode such as a bump can be used.

[0042] "(Meth)acrylate" is a term representing both "acrylate" and "methacrylate", and the same applies to other similar terms.

[0043] "Energy ray" refers to ultraviolet rays, electron rays, etc., and ultraviolet rays are preferred.

[0044] Unless otherwise specified, the "weight-average molecular weight" refers to the polystyrene conversion value determined by gel permeation chromatography (GPC). The measurement by this method is carried out, for example, using a device in which "TSK guard column HXL-H", "TSK Gel GMHXL", "TSK Gel G2000 HXL" (all of the above are manufactured by TOSOH CORPORATION) are connected in this order to the high-performance GPC device "HLC-8120GPC" manufactured by TOSOH CORPORATION, under the conditions of a column temperature of 40 °C and a liquid feed rate of 1.0 mL / minute, with a differential refractometer as the detector.

[0045] The release film is a film that supports the resin film to form a film in a peelable manner. The film, without being limited to thickness, is used in the concept including sheets.

[0046] In the description of compositions such as the resin film-forming composition, the mass ratio is calculated based on the active ingredient (solid component), and unless otherwise specified, the solvent is not included in the calculation.

[0047] (1. Sheet for forming resin film)

[0048] As Figure 1A shown, the sheet 1 for forming a resin film (more specifically, the sheet 1 for forming a protective film) of the present embodiment has a configuration in which a first release film 20 that supports the resin film-forming film 10 is disposed on one main surface 10a of the resin film-forming film 10 (more specifically, the protective film-forming film 10), and a second release film 30 is disposed on the other main surface 10b.

[0049] As Figure 1A shown, when release films are formed on both main surfaces of the resin film-forming film 10, it is preferable that the peeling force of one release film is large and it is used as a heavy-release type release film, and the peeling force of the other release film is small and it is used as a light-release type film. In the present embodiment, the first release film 20 is a heavy-release type film, and the second release film 30 is a light-release type film.

[0050] The sheet 1 for forming a resin film is preferably a long sheet capable of forming a plurality of resin film-forming films 10 attached to a workpiece. In addition, the sheet 1 for forming a resin film is also preferably a sheet roll formed by winding the long sheet. In addition, the sheet 1 for forming a resin film may also be a single sheet obtained by cutting a long strip-shaped sheet for forming a resin film and capable of forming one resin film-forming film 10 attached to a workpiece.

[0051] The sheet 1 for forming a resin film in this embodiment is not limited to Figure 1A the configuration shown. For example, the sheet for forming a resin film may also have a configuration without a second release film. Figure 1B Fig. 1 shows a sheet 1 for forming a resin film having a configuration in which a first release film 20 is disposed on one main surface 10a of a resin film forming film 10.

[0052] Hereinafter, a sheet for forming a resin film having the configuration shown in Figure 1A Fig. 2 will be used for description. However, the following description also applies to the configuration shown in Figure 1B Fig. 3.

[0053] In this embodiment, the sheet for forming a resin film is used to attach a resin film forming film to a workpiece to form a resin film. After attaching the resin film forming film to the workpiece, the release film ( Figure 1A and Figure 1B the first release film 20 in Fig. 2) is peeled off from the resin film forming film or the resin film. Examples of the resin film include a protective film for protecting a workpiece or a single object of the workpiece, and an adhesive film for bonding a single object of the workpiece to a substrate or the like.

[0054] Generally, a sheet for forming a resin film is manufactured by applying a liquid composition (a coating agent containing a composition for a resin film forming film) for forming a resin film forming film onto a release film, and then drying the composition to form a resin film forming film.

[0055] In order to uniformly mix the components constituting the resin film forming film, the coating agent containing the composition for the resin film forming film usually contains a solvent that can dissolve the components. However, in order to impart desired properties to the resin film forming film, it sometimes contains components that are insoluble in the solvent. When the coating agent containing the composition for the resin film forming film is applied onto the release film, the components insoluble in the solvent are present on the release film.

[0056] The sheet for forming a resin film manufactured by applying a coating agent containing such a composition for a resin film forming film containing components insoluble in a solvent is usually stored in a predetermined environment until use.

[0057] The inventors of the present application have found that when the sheet for forming a resin film is attached to a workpiece and then the release film is peeled off from the sheet for forming a resin film, in the case where the normal storage environment is not maintained, the storage environment is a harsh environment, or the environment at the time of using the sheet for forming a resin film is a harsh environment, due to the harsh environment, the components insoluble in the solvent become clearly visible, and these components move from the release film to the resin film forming film or the resin film, and thus adhere in a visually visible manner.

[0058] Since the components adhering to the resin film-forming film or the resin film are visually visible, they may become foreign matters causing poor appearance.

[0059] As a mechanism for such a problem, for example, the following mechanism is considered. When a coating agent containing a resin film-forming film composition is coated on a release film, components insoluble in the solvent are uniformly dispersed in the coating agent containing the resin film-forming film composition. After the solvent is volatilized by drying, the components insoluble in the solvent exist on the release film in a state where they are separated from each other at a predetermined distance.

[0060] However, in the case where the solvent of the coating agent containing the resin film-forming film composition easily penetrates into the release film (in the case where the solvent is easily absorbed by the release film), before the solvent is volatilized by drying, the distance between the components insoluble in the solvent in the coating agent containing the resin film-forming film composition near the surface of the release film becomes smaller corresponding to the amount of the solvent penetrating from the surface of the release film (that is, the density of the components insoluble in the solvent in the coating agent containing the resin film-forming film composition near the surface of the release film increases). As a result, it is considered that after the solvent is volatilized, the components insoluble in the solvent exist on the release film in a state where their distances from each other are closer compared to the case where the solvent hardly penetrates into the release film. Through such a state, a sheet for forming a resin film is manufactured.

[0061] It is considered that when the sheet for forming a resin film is exposed to a harsh environment with the components insoluble in the solvent being in a state where their distances from each other are relatively close, the components insoluble in the solvent easily aggregate and grow to a visually visible level. As a result, when using the sheet for forming a resin film exposed to a harsh environment, the components insoluble in the solvent adhere to the resin film-forming film or the resin film and are recognized as foreign matters.

[0062] Therefore, in the present embodiment, the characteristics of the release surface of the release film coated with the coating agent containing the resin film-forming film composition are controlled in the following manner so that the solvent hardly penetrates into the release film, thereby suppressing the generation of foreign matters causing poor appearance of the resin film-forming film or the resin film due to the components insoluble in the solvent.

[0063] Hereinafter, the case where the resin film is a protective film, the resin film-forming film is a protective film-forming film, and the resin film-forming film composition is a protective film-forming film composition will be described.

[0064] (2. First Release Film)

[0065] In the present embodiment, Figure 1A and 1B the first release film 20 shown is a release film whose release surface characteristics are controlled. The release surface is the surface coated with the coating agent containing the resin film-forming film composition and in contact with the protective film-forming film.

[0066] (2.1. Rate of change in major axis of ethanol droplet on release surface)

[0067] In the present embodiment, when ethanol is dropped onto the release surface of the first release film, if the major axis of the ethanol droplet 2 seconds after the start of dropping is designated as A and the major axis of the ethanol droplet 5 minutes after the start of dropping is designated as B, the rate of change in major axis shown below is 30% or less.

[0068] Rate of change in major axis = {(A - B) / A} × 100 (%)

[0069] When the ethanol droplet dropped onto the release surface penetrates into the release film, the volume of the ethanol droplet decreases and the major axis becomes smaller. Therefore, the smaller the above rate of change in major axis, the more the ethanol droplet remains on the release surface without penetrating into the release film. That is, the smaller the rate of change in major axis, the easier it is to maintain the distance between the components insoluble in the solvent in the coating agent for forming a protective film by coating a coating agent containing a resin film-forming composition and drying it. Therefore, by making the rate of change in major axis within the above range, the components insoluble in the solvent do not grow to a visually recognizable level and tend not to be recognized as foreign matters causing poor appearance of the protective film-forming film or the protective film.

[0070] The above rate of change in major axis is simulated using ethanol as a solvent. As the solvent contained in the coating agent for forming a protective film, solvents other than ethanol can also be used, but the inventors of the present application confirmed that even when solvents other than ethanol are used, the characteristics of the release surface can be evaluated by the above rate of change in major axis. Therefore, from the viewpoints of the versatility of the solvent and the stability of the evaluation operation due to its low volatility, it is preferable to use ethanol as the solvent.

[0071] The rate of change in major axis is preferably 25% or less, more preferably 18% or less, still more preferably 10% or less, and particularly preferably 5% or less. On the other hand, the lower limit value of the rate of change in major axis is preferably 0%. The method for measuring the rate of change in major axis will be described in detail in the examples described later.

[0072] As long as the rate of change in major axis of the ethanol droplet on the release surface is within the above range, the first release film can have any structure. For example, the first release film can be composed of one layer (single layer) or two or more layers of base materials, and from the viewpoint of controlling the rate of change in major axis, the surface of the base material can also be subjected to a release treatment. That is, the surface of the base material can be modified, or a material not derived from the base material can be formed on the surface of the base material.

[0073] In this embodiment, it is preferred that the release surface of the first release film is dense. Since the release surface is dense, the solvent contained in the film-forming composition for the protective film is difficult to penetrate into the release surface. Such a release surface is preferably relatively hard. For example, the surface elastic modulus of the release surface is preferably relatively high.

[0074] In this embodiment, as Figure 2 shown, it is preferred that the first release film 20 has a substrate 21 and a first release agent layer 22, and the release surface 20a is the surface 22a of the first release agent layer. By having the first release agent layer 22, it is easy to control the properties of the release surface 20a of the first release film 20.

[0075] In addition, in the first release film, it is preferred that the first release agent layer is directly formed on the surface of the substrate. By directly forming the first release agent layer on the surface of the substrate, the production of the first release film can be made easier, thus achieving cost reduction.

[0076] The thickness of the first release film is not particularly limited, and is preferably 30 μm or more and 100 μm or less. In addition, the thickness of the first release film is more preferably 40 μm or more, and further preferably 45 μm or more. In addition, the thickness of the first release film is more preferably 80 μm or less, and further preferably 70 μm or less.

[0077] By setting the lower limit value of the thickness of the first release film to the above value, there is an advantage that the adhesion operability of the protective film-forming sheet to the workpiece is better. In addition, by setting the upper limit value of the thickness of the first release film to the above value, there is an advantage that the release operability of the first release film from the protective film-forming film is better.

[0078] In addition, the thickness of the first release film refers to the thickness of the entire first release film. For example, the thickness of the first release film composed of multiple layers refers to the total thickness of all the layers constituting the first release film.

[0079] Hereinafter, the case where the first release film has a substrate and a first release agent layer will be described.

[0080] (2.2 Substrate)

[0081] The substrate of the first release film is not particularly limited as long as it is a material that can support the protective film-forming film until the protective film-forming film is attached to the workpiece, and is usually composed of a film having a resin-based material as the main material (hereinafter referred to as "resin film").

[0082] As specific examples of the resin film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, a polyurethane film, an ethylene-vinyl acetate copolymer film, an ionomer resin film, an ethylene-(meth)acrylic acid copolymer film, an ethylene-(meth)acrylate copolymer film, a polystyrene film, a polycarbonate film, a polyimide film, a fluororesin film, etc. can be used. In addition, a crosslinked film of these films can also be used. Further, a laminated film of these films can also be used. In the present embodiment, from the viewpoints of environmental safety, cost, etc., a polyethylene terephthalate film is preferred.

[0083] In the above resin film, the base material may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, a filler, etc.

[0084] As long as it can function properly in each process of using the sheet for forming a protective film and is within the range of the thickness of the first release film described above, the thickness of the base material is not particularly limited. The thickness of the base material is preferably 30 μm or more and 100 μm or less. Further, the thickness of the base material is more preferably 40 μm or more, and still more preferably 45 μm or more. In addition, the thickness of the base material is more preferably less than 80 μm, and still more preferably less than 70 μm.

[0085] (2.3 First release agent layer)

[0086] The first release agent layer imparts releasability and denseness to the release surface of the first release film for peeling from the protective film forming film. In the present embodiment, by forming a thin composition for the first release agent layer on the base material and curing it, the first release agent layer can be obtained. As a method for curing the composition for the first release agent layer, it can be a method of curing it by heating, and in the case where the composition for the first release agent layer contains an energy ray curable compound, it can also be a method of curing it by irradiating energy rays.

[0087] The thickness of the first release agent layer is not particularly limited, and is preferably 30 nm or more and 200 nm or less. Further, the thickness of the first release agent layer is more preferably 50 nm or more, and still more preferably 80 nm or more. In addition, the thickness of the first release agent layer is more preferably less than 180 nm.

[0088] By making the thickness of the first release film within the above range, stable release performance can be exhibited when the protective film forming film is attached to the workpiece.

[0089] (2.4 Composition for first release agent layer)

[0090] In this embodiment, examples of the composition for the first release agent layer include compositions containing alkyd-based release agents, silicone-based release agents, fluorine-based release agents, unsaturated polyester-based release agents, polyolefin-based release agents, and wax-based release agents. Among them, a silicone-based release agent is preferred. When the composition for the first release agent layer contains a silicone-based release agent, it preferably contains a silicone-based release agent and a heavy release additive.

[0091] (2.4.1 Silicone-based release agent)

[0092] As the silicone-based release agent, a silicone-based release agent blended with silicone having a dimethylpolysiloxane as a basic skeleton can be used.

[0093] This silicone can be any of energy ray curable types such as addition reaction type, condensation reaction type, ultraviolet curable type, and electron beam curable type, and an addition reaction type silicone is preferred. The addition reaction type silicone has high reactivity and excellent productivity, and compared with the condensation reaction type silicone, it has advantages such as less change in the release force after manufacturing and no curing shrinkage.

[0094] Specific examples of the addition reaction type silicone include organopolysiloxanes having two or more alkenyl groups with 2 to 10 carbon atoms such as vinyl, allyl, propenyl, and hexenyl at the ends and / or side chains of the molecule. In addition, from the perspective of making the surface of the release surface dense, it is preferred that the number of alkenyl groups in the addition reaction type silicone is relatively large.

[0095] When the total weight of the composition for the first release agent layer (excluding the catalyst described later) is set to 100 parts by mass, the content of the silicone formed from dimethylpolysiloxane is preferably less than 100 parts by mass, less than 90 parts by mass, less than 80 parts by mass, less than 70 parts by mass.

[0096] When using an addition reaction type silicone, it is preferred to use a crosslinking agent simultaneously as one material constituting the silicone-based release agent. In addition, it is preferred to use a catalyst simultaneously.

[0097] As the crosslinking agent, for example, organopolysiloxanes having at least 2 hydrogen atoms bonded to silicon atoms in one molecule can be cited.

[0098] Specific examples of the crosslinking agent include dimethylsiloxane-methylhydrogensiloxane copolymer capped with dimethylhydrogensilanyloxy, dimethylsiloxane-methylhydrogensiloxane copolymer capped with trimethylsilanyloxy, methylhydrogenpolysiloxane capped with trimethylsilanyloxy, poly(hydrosilsesquioxane), etc.

[0099] In addition, from the perspective of making the surface of the release surface dense, it is preferable that the content of the crosslinking agent in the composition for the first release agent layer is relatively large. Specifically, when the total weight of the composition for the first release agent layer (excluding the catalyst described later) is set to 100 parts by mass, the content of the crosslinking agent is preferably 3 parts by mass or more and 55 parts by mass or less, more preferably 7 parts by mass or more and 45 parts by mass or less, and still more preferably 10 parts by mass or more and 40 parts by mass or less.

[0100] Examples of the catalyst include particulate platinum, particulate platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, an olefin complex of chloroplatinic acid, and platinum group metal compounds such as palladium and rhodium.

[0101] From the perspective of making the surface of the release surface dense, it is preferable that the amount of the catalyst used in the composition for the first release agent layer is relatively large. Specifically, relative to 100 parts by mass of the composition for the first release agent layer, the amount of the catalyst used is preferably 2 to 20 parts by mass, more preferably 6 to 15 parts by mass.

[0102] By using such a catalyst, the curing reaction of the composition for the first release agent layer can be further effectively carried out.

[0103] From the perspective of making the surface of the release surface dense, when the total weight of the composition for the first release agent layer (excluding the catalyst) is set to 100 parts by mass, the total content of the above-mentioned silicone and the above-mentioned crosslinking agent is preferably 30 to 100 parts by mass, 50 to 100 parts by mass, or 63 to 100 parts by mass.

[0104] (2.4.2 Double Release Additive)

[0105] The double release additive is used to increase the release force of the first release film from the protective film forming film. That is, the first release film can be appropriately used as a double release type release film. Examples of the double release additive include silicone resins and organosilanes such as silane coupling agents, and among them, silicone resins are preferably used.

[0106] As the silicone resin, for example, an MQ resin containing an M unit as a monofunctional siloxane unit [R3SiO 1 / 2 and a Q unit as a tetrafunctional siloxane unit [SiO 4 / 2 is preferably used. In addition, each of the three Rs in the M unit independently represents a hydrogen atom, a hydroxyl group, or an organic group. From the perspective of easily suppressing silicone migration, one or more of the three Rs in the M unit are preferably a hydroxyl group or a vinyl group, and more preferably a vinyl group.

[0107] From the perspective of densifying the surface of the release surface and increasing the release force, it is preferable that the content of the silicone resin (especially MQ resin) in the composition for the first release agent layer is relatively large. Specifically, when the total weight of the composition for the first release agent layer (excluding the catalyst) is set to 100 parts by mass, the content of the heavy release additive is preferably 20 to 60 parts by mass, 25 to 55 parts by mass, or 30 to 55 parts by mass.

[0108] Within the range that does not impair the effects of the present invention, the composition for the first release agent layer may contain other additives commonly used in the release agent layer (specifically, additives other than the above-mentioned silicone, crosslinking agent, catalyst, and heavy release additive). Examples of such additives include dyes and dispersants. When the total weight of the composition for the first release agent layer (excluding the catalyst) is set to 100 parts by mass, the content of the above-mentioned other additives is preferably less than 5 parts by mass, less than 2 parts by mass, or less than 1 part by mass.

[0109] (3. Protective film forming film)

[0110] As described above, the protective film forming film is a form of the resin film forming film. After being attached to the workpiece, the protective film forming film is converted into a protective film to form a protective film for protecting the workpiece or the individual particles of the workpiece.

[0111] The so-called "conversion into a protective film" means making the protective film forming film into a state having properties sufficient to protect the workpiece or the individual particles of the workpiece. Specifically, when the protective film forming film is curable, the so-called "conversion into a protective film" means converting the uncured protective film forming film into a cured product. In other words, the protective film forming film after conversion into a protective film is a cured product of the protective film forming film and is different from the protective film forming film. Similarly, when the resin film forming film is curable, the so-called "forming a resin film" means converting the uncured resin film forming film into a cured product.

[0112] After overlapping the workpiece on the curable protective film forming film, curing the protective film forming film can firmly bond the protective film to the workpiece and form a protective film with durability.

[0113] On the other hand, in the case where the protective film forming film does not contain curable components and is used in an uncured state, at the time point when the protective film forming film is attached to the workpiece, the protective film forming film is converted into a protective film. In other words, the protective film forming film after conversion into a protective film is the same as the protective film forming film. Similarly, in the case where the resin film forming film does not contain curable components and is used in an uncured state, at the time point when the resin film forming film is attached to the workpiece, the resin film forming film is formed into a resin film.

[0114] In the case where high protective performance is not required, since it is not necessary to cure the film for forming the protective film, the use of the film for forming the protective film is easy.

[0115] In the present embodiment, it is preferable that the film for forming the protective film is curable. Therefore, it is preferable that the protective film is a cured product. As the cured product, for example, a thermoset and a radiation-cured product can be exemplified. In the present embodiment, it is more preferable that the protective film is a thermoset.

[0116] In addition, it is preferable that the film for forming the protective film has adhesiveness at room temperature (23°C) or exhibits adhesiveness by heating. Thereby, when the workpiece is overlapped on the film for forming the protective film, the two can be adhered. Therefore, positioning can be surely performed before the film for forming the protective film is cured.

[0117] The film for forming the protective film may be formed of one layer (single layer) or may be formed of two or more layers (multilayer). When the film for forming the protective film has multiple layers, these multiple layers may be the same or different from each other, and there is no particular limitation on the combination of the layers constituting these multiple layers.

[0118] In the present embodiment, the film for forming the protective film is preferably one layer (single layer). Since a single-layer film for forming the protective film can achieve high precision in terms of thickness, it is easy to produce. In addition, when the film for forming the protective film is formed of multiple layers, it is necessary to consider the adhesion between layers and the stretchability of each layer, and there is a risk of peeling from the adherend due to these factors. In the case where the film for forming the protective film is one layer, the above risks can be reduced, and the degree of freedom in design is also higher.

[0119] The thickness of the film for forming the protective film is not particularly limited, and is preferably less than 100 μm, 70 μm or less, 45 μm or less, 40 μm or less. By setting the upper limit value of the thickness of the film for forming the protective film to the above values, it becomes easy to cut the film for forming the protective film from the sheet for forming the protective film.

[0120] [[ID=ID=18]]In addition, the thickness of the film for forming the protective film is preferably 5 μm or more, 10 μm or more, 15 μm or more. By setting the lower limit value of the thickness of the film for forming the protective film to the above values, the performance of protecting the workpiece can be easily obtained as the protective film.

[0121] In addition, the thickness of the film for forming the protective film refers to the overall thickness of the film for forming the protective film. For example, the thickness of the film for forming the protective film composed of multiple layers refers to the total thickness of all the layers constituting the film for forming the protective film.

[0122] (3.1 Composition for Film for Forming Protective Film)

[0123] In this embodiment, the protective film forming film is formed using a composition constituting the protective film forming film (composition for protective film forming film). As long as the protective film forming film can exhibit the above-described properties, the composition of the composition for protective film forming film can be arbitrarily set. In this embodiment, it is preferable that the composition for protective film forming film is 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 regarded as a polymerizable compound and is formed by a polymerization reaction. In addition, the curable component is a component that can undergo a curing (polymerization) reaction. In the present invention, the polymerization reaction may also include a polycondensation reaction.

[0124] In addition, the components contained in the polymer component may sometimes correspond to the curable component. In this embodiment, when the composition for protective film forming film contains such components corresponding to both the polymer component and the curable component, it is regarded that the composition for protective film forming film contains both the polymer component and the curable component.

[0125] (3.1.1 Polymer component)

[0126] The polymer component (A) enables the protective film forming film to have film-forming property (film-forming ability), and at the same time imparts appropriate adhesiveness to ensure uniform adhesion 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. If the weight average molecular weight is too low, there is a concern that the peel force of the release film may increase excessively. On the other hand, if the weight average molecular weight is too high, the compatibility with other components deteriorates, and as a result, it becomes difficult to form a uniform film. As such a polymer component, for example, an acrylic resin, a urethane resin, a phenoxy resin, a silicone resin, a saturated polyester resin, etc. can be used, and an acrylic resin is particularly preferably used.

[0127] As the acrylic resin, for example, an (meth)acrylate copolymer composed of (meth)acrylate monomers and structural units derived from (meth)acrylic acid derivatives can be cited. Here, as the (meth)acrylate monomer, (meth)acrylic acid alkyl esters having 1 to 18 carbon atoms in the alkyl group can be preferably cited, and specifically, (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid propyl ester, (meth)acrylic acid butyl ester, etc. can be cited. In addition, as the (meth)acrylic acid derivative, for example, (meth)acrylic acid, (meth)acrylic acid glycidyl ester, (meth)acrylic acid hydroxyethyl ester, etc. can be cited.

[0128] In this embodiment, it is preferable to introduce a glycidyl group into the acrylic resin using glycidyl methacrylate or the like. The compatibility of the acrylic resin into which the glycidyl group has been introduced with the epoxy resin as a thermosetting component described later is improved, and a uniform film is easily formed. Therefore, there is a tendency to easily obtain a protective film-forming film with stable properties. In addition, in this embodiment, in order to control the adhesiveness and tackiness to the workpiece, it is preferable to introduce a hydroxyl group into the acrylic resin using 2-hydroxyethyl acrylate or the like.

[0129] The glass transition temperature of the acrylic resin is preferably -70 to 40 °C, -35 to 35 °C, -20 to 30 °C, -10 to 25 °C, or -5 to 20 °C. By setting the glass transition temperature of the acrylic resin within the above range, it is easy to adjust the peel force of the release film laminated on the protective film-forming film to a desired value. In addition, by setting the upper limit value of the glass transition temperature of the acrylic resin to the above value, the tackiness of the protective film-forming film is moderately increased, and at the same time, the adhesive force of the protective film-forming film to the workpiece is increased, so that the adhesive force between the protective film and the workpiece is moderately increased.

[0130] In the case where the acrylic resin has m kinds (m is an integer of 2 or more) of structural units, the glass transition temperature of the acrylic resin can be calculated as follows. That is, any non-repeating number from 1 to m is assigned to each of the m kinds of monomers that are the structural units in the acrylic resin and named "monomer m". In this case, the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula shown below.

[0131] [Mathematical formula 1][[ID=IO]]

[0132]

[0133] (In the formula, Tg is the glass transition temperature of the acrylic resin, m is an integer of 2 or more, Tgk is the glass transition temperature of the homopolymer of monomer m, and Wk is the mass fraction of the structural unit m derived from monomer m in the acrylic resin. Among them, Wk satisfies the following mathematical formula.)

[0134] [Mathematical formula 2]

[0135]

[0136] (In the formula, m and Wk are the same as above.)

[0137] As the Tgk, the values described in a polymer data handbook (Polymer Data Handbook), an adhesion handbook (Adhesion 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 2-hydroxyethyl acrylate is -15 °C, and the Tgk of a homopolymer of glycidyl methacrylate is 41 °C.

[0138] When the total weight of the composition for forming the protective film is set to 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, 15 to 45 parts by mass. By setting the content of the polymer component within the above range, the peel force of the release film laminated on the protective film-forming film can be more easily adjusted to a desired value.

[0139] (3.1.2 Thermosetting component)

[0140] 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 of these components can be used. In the case of curing by irradiation with energy rays, since the protective film-forming film contains a filler and a colorant described later, the light transmittance decreases. Therefore, for example, when the thickness of the protective film-forming film becomes thick, the energy ray curing tends to be insufficient.

[0141] On the other hand, the thermosetting protective film-forming film can be sufficiently cured by heating even if its thickness becomes thick, so that a protective film with high protective performance can be formed. In addition, by using a usual heating means such as a heating oven, a plurality of protective film-forming films can be heated at once to be thermally cured.

[0142] Therefore, in this embodiment, it is preferable that the curable component is thermosetting. That is, the protective film-forming film is preferably thermosetting.

[0143] Whether the protective film-forming film is thermosetting can be judged as follows. First, the protective film-forming film at room temperature (23 °C) is heated to a temperature higher than room temperature and then cooled to room temperature, thereby making it the heated / cooled protective film-forming film. Next, the hardness of the heated / cooled protective film-forming film is compared with the hardness of the protective film-forming film before heating at the same temperature. If the heated / cooled protective film-forming film is harder, it is judged that the protective film-forming film is thermosetting.

[0144] As the thermosetting component, for example, an epoxy resin, a thermosetting polyimide resin, an unsaturated polyester resin, or a mixture of these components can be preferably used. In addition, the so-called thermosetting polyimide resin is a general term for low molecular weight and low viscosity monomers or precursor polymers that form a polyimide resin through thermal curing. Non-limiting specific examples of the thermosetting polyimide resin are described, for example, in the Journal of the Fiber Society "Fibers and Industry", Vol. 50, No. 3 (1994), P106 - P118.

[0145] The epoxy resin as the thermosetting component has the property of forming a three-dimensional network structure and a firm coating film when heated. As such an epoxy resin, various known epoxy resins can be used. In the present 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, 300 or more and less than 3,000. In addition, the epoxy equivalent of the epoxy resin is preferably 50 - 5,000 g / eq, more preferably 100 - 2,000 g / eq, and further preferably 150 - 1,000 g / eq.

[0146] Specifically, as such an epoxy resin, glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac can be cited; 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 group type or alkyl glycidyl group type epoxy resins obtained by substituting the active hydrogen bonded to the nitrogen atom of aniline isocyanurate, etc. with a glycidyl group; so-called alicyclic epoxides such as vinylcyclohexane dioxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, etc., which are obtained by oxidizing, for example, the carbon-carbon double bond in the molecule to introduce an epoxy group. In addition, epoxy resins having a biphenyl skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton, etc. can also be used.

[0147] When using the thermosetting component as the curable component (B), it is preferable to use a curing agent (C) as an auxiliary agent at the same time. As the curing agent, a phenolic resin having a phenolic hydroxyl group and good compatibility with the epoxy resin can be used, but a latent curing agent is more preferable. A latent curing agent is a curing agent that is not easily reactive at normal temperature (23°C), but causes a curing reaction by external stimuli such as heat, light, moisture, and pressure.

[0148] By using a latent curing agent, the storage stability at normal temperature can be improved, and the curing reaction can be made to proceed at a desired timing. Therefore, it is preferable to include a latent curing agent as the curing agent.

[0149] On the other hand, latent curing agents usually exist in the form of solid components at room temperature and are in a dispersed state in a coating agent for forming a protective film by solvent dilution (i.e., a coating agent containing a composition for forming a protective film). That is, the latent curing agent is a component insoluble in the solvent. In addition, the inventors of the present application have also confirmed that aggregates caused by the latent curing agent are likely to grow under severe environments and are easily recognized as foreign matters that cause poor appearance of the protective film-forming film or the protective film.

[0150] Therefore, when using a latent curing agent as a curing agent, there are the above-mentioned advantages and disadvantages. However, in the present embodiment, since the physical properties of the release surface of the release film are controlled as described above, the disadvantages can be suppressed and the advantages can be enjoyed.

[0151] In the present embodiment, when the curable component is thermosetting, as the latent curing agent, a heat-activated latent curing agent is preferably used. The heat-activated latent curing agent is a curing agent that does not easily react at room temperature but is activated by heating to a certain temperature or higher and reacts with the curable component.

[0152] When using an epoxy resin as the thermosetting component, as the latent curing agent, a heat-activated latent epoxy resin curing agent is preferably used. Regarding the activation method of the heat-activated latent epoxy resin curing agent, there are the following methods: a method of generating active species (anions, cations) through a chemical reaction caused by heating; a method of being stably dispersed in the epoxy resin at a temperature close to room temperature, being compatible / dissolved with the epoxy resin at a high temperature, and initiating a curing reaction; a method of using a molecular sieve-encapsulated curing agent that dissolves at a high temperature to initiate a curing reaction; using microcapsules, etc.

[0153] Among the exemplified methods, a method of being stably dispersed in the epoxy resin at a temperature close to room temperature, being compatible / dissolved with the epoxy resin at a high temperature, and initiating a curing reaction is preferably used.

[0154] Specific examples of the heat-activated latent epoxy resin curing agent include various onium salts, diacid dihydrazide compounds, dicyandiamide, amine adduct curing agents, high-melting-point active hydrogen compounds such as imidazole compounds, etc. These heat-activated latent epoxy resin curing agents can be used alone or in combination of two or more. In the present embodiment, dicyandiamide is particularly preferred.

[0155] With respect to 100 parts by mass of the curable component (B), the content of the 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, 0.3 to 10 parts by mass, 0.5 to 5 parts by mass. By making the content of the curing agent (C) within the above range, the effects of the present invention can be more easily obtained, and as a protective film, the performance of protecting the workpiece can be easily obtained.

[0156] When dicyandiamide is used as the curing agent (C), it is preferable to further use a curing accelerator (D) simultaneously. As the curing accelerator, for example, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxyimidazole (imidazoles in which one or more hydrogen atoms are replaced by groups other than hydrogen atoms) are preferred. Among them, 2-phenyl-4,5-dihydroxymethylimidazole is preferred.

[0157] With respect to 100 parts by mass of the epoxy resin, 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. By setting the content of the curing accelerator (D) within the above range, it is easy to obtain the performance of protecting the workpiece as a protective film.

[0158] When the total weight of the protective film-forming composition is set to 100 parts by mass, the total content of the thermosetting component and the 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. If the thermosetting component and the curing agent are blended in such proportions, it is easy to obtain the performance of protecting the workpiece as a protective film.

[0159] (3.1.3 Energy ray curable component)

[0160] When the curable component (B) is an energy ray curable component, the energy ray curable component is preferably uncured, preferably has adhesiveness, and more preferably is uncured and has adhesiveness.

[0161] The energy ray curable component is a component that is cured by irradiation with energy rays and is also a component that imparts film-forming properties, flexibility, etc. to the protective film-forming film.

[0162] As the energy ray curable component, for example, compounds having an energy ray curable group are preferred. As such compounds, known compounds can be cited.

[0163] (3.1.4 Filler)

[0164] By making the protective film-forming film contain the filler (E), it becomes easy to adjust the thermal expansion coefficient of the protective film obtained by protecting the protective film-forming film, and the thermal expansion coefficient can be made close to that of the workpiece, further improving the adhesion reliability with the workpiece. In addition, by making the protective film-forming film contain the filler (E), a hard protective film can be obtained, and it is easy to obtain the performance of protecting the workpiece. In addition, the moisture absorption rate of the protective film can be reduced.

[0165] The filler (E) can be either an organic filler or an inorganic filler. However, from the perspective of shape stability at high temperatures, an inorganic filler is preferred.

[0166] As preferred inorganic fillers, for example, powders such as silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, boron nitride, etc. can be cited; beads formed by spheroidizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystalline fibers of these inorganic fillers; glass fibers, etc. Among them, silica and surface-modified silica are preferred. The surface-modified silica is preferably surface-modified using a coupling agent, and more preferably surface-modified using a silane coupling agent.

[0167] The average particle size of the filler is preferably 0.02 - 10 μm, 0.05 - 5 μm, 0.10 - 3 μm.

[0168] By making the average particle size range of the filler within the above range, the workability of the composition for forming the protective film becomes good. As a result, the quality of the composition for forming the protective film and the protective film is easily stabilized.

[0169] In addition, in this specification, unless otherwise specified, the so-called "average particle size" refers to the value of the particle size (D50) at the cumulative value of 50% in the particle size distribution curve obtained by the laser diffraction scattering method.

[0170] When the total weight of the composition for forming the protective film is set to 100 parts by mass, the content of the filler is preferably 15 - 80 parts by mass, 30 - 75 parts by mass, 40 - 70 parts by mass, 45 - 65 parts by mass.

[0171] By making the lower limit value of the content of the filler the above value, it is easier to obtain the effects brought by the above filler. In addition, by making the upper limit of the content of the filler the above value, the adhesion between the protective film and the workpiece is improved, and the adhesion between the protective film and the workpiece is moderately improved.

[0172] (3.1.5 Coupling Agent)

[0173] The protective film preferably contains a coupling agent (F). By containing the coupling agent, after the protective 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 (humidity resistance) can be improved. As the coupling agent, from the perspective of its versatility and cost advantage, a silane coupling agent is preferred.

[0174] As silane coupling agents, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloyloxypropyl)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)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, etc. can be cited. These silane coupling agents can be used alone or in combination of two or more.

[0175] As exemplary examples of preferred silane coupling agents, oligomer-type silane coupling agents having multiple alkoxysilyl groups in one molecule can be cited. Since the above oligomer-type silane coupling agents are not easily volatile and have multiple alkoxysilyl groups in one molecule, they are very effective in improving durability and are thus preferred. As the above oligomer-type silane coupling agents, for example, "X-41-1053", "X-41-1059A", "X-41-1056" and "X-40-2651" (all manufactured by Shin-Etsu Chemical Co., Ltd.), which are epoxy group-containing oligomer-type silane coupling agents; "X-41-1818", "X-41-1810", "X-41-1805" (all manufactured by Shin-Etsu Chemical Co., Ltd.), which are mercapto group-containing oligomer-type silane coupling agents, etc. can be cited.

[0176] When the total weight of the composition for forming the protective film is set to 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, 0.3 to 3 parts by mass.

[0177] (3.1.6 Colorant)

[0178] The protective film-forming film preferably contains a colorant (G). Thus, since the back surface of a single workpiece such as a chip can be shielded, various electromagnetic waves generated inside the electronic device can be blocked, and failures of the single workpiece can be reduced.

[0179] As the colorant (G), for example, known colorants such as inorganic pigments, organic pigments, and organic dyes can be used. In the present embodiment, inorganic pigments are preferred.

[0180] As inorganic pigments, for example, 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, ATO (antimony tin oxide)-based pigments, etc. can be cited. Among them, carbon black is particularly preferably used. If it is carbon black, electromagnetic waves in a relatively wide wavelength range can be blocked.

[0181] The blending amount of the colorant (especially carbon black) in the protective film forming film also varies depending on the thickness of the protective film forming film. For example, in the case where the thickness of the protective film forming film is 25 μm, when the total weight of the protective film forming film composition is set to 100 parts by mass, the content of the colorant is preferably 0.01 to 10 parts by mass, 0.03 to 7 parts by mass, 0.05 to 4 parts by mass.

[0182] The average particle diameter of the colorant (especially carbon black) is preferably 1 to 500 nm, particularly preferably 3 to 100 nm, and further preferably 5 to 50 nm. If the average particle diameter of the colorant is within the above range, it is easy to control the light transmittance within the desired range.

[0183] (3.1.7 Other Additives)

[0184] Within the range that does not impair the effects of the present invention, the protective film forming film composition can contain, for example, a photoinitiator, a crosslinking agent, a plasticizer, an antistatic agent, an antioxidant, a gettering agent, a tackifier, a release agent, etc. as other additives. When the total weight of the protective film forming film composition is set to 100 parts by mass, the content of other additives is preferably less than 5 parts by mass, less than 2 parts by mass, less than 1 part by mass.

[0185] (4. Second Release Film)

[0186] The second release film is a film that can support the protective film forming film in a peelable manner. As described above, it is preferable that the second release film is a light release type release film. In the case where the second release film is a light release type release film, when the protective film forming sheet is attached to the workpiece, the second release film is peeled off from the protective film forming sheet, and then the exposed protective film forming film is attached to the workpiece.

[0187] The second release film can be composed of one layer (single layer) or two or more layers of substrates. From the perspective of controlling the peelability, the surface of the substrate can also be subjected to a release treatment. That is, the surface of the substrate can be modified, or a material not derived from the substrate can be formed on the surface of the substrate.

[0188] The thickness of the second release film is not particularly limited, preferably 10 μm or more and 75 μm or less. In addition, the thickness of the second release film is more preferably 18 μm or more, and further preferably 24 μm or more. In addition, the thickness of the second release film is more preferably 60 μm or less, and further preferably 45 μm or less. From the perspective of making the second release film a light-release type release film, the thickness of the second release film is preferably equal to or less than the thickness of the first release film, and more preferably less than the thickness of the first release film.

[0189] In addition, the thickness of the second release film refers to the overall thickness of the second release film. For example, in the case of a second release film composed of multiple layers, the thickness refers to the total thickness of all the layers constituting the second release film.

[0190] (4.1 Substrate)

[0191] In the case where the second release film has a substrate and a second release agent layer, the substrate of the second release film can be appropriately selected from the materials exemplified as the substrate of the first release film.

[0192] (4.2 Second release agent layer)

[0193] In the case where the second release film has a substrate and a second release agent layer, the second release agent layer is not particularly limited as long as it is composed of a material capable of imparting releasability. For example, the second release agent layer can be obtained by curing a second release agent layer composition containing a silicone-based release agent in the same manner as the first release agent layer.

[0194] As long as the second release film is made into a light-release type release film, the composition for the second release agent layer can be selected from the materials exemplified in the composition for the first release agent layer. However, it is preferable that the content of the materials exemplified as the heavy release additive is less than that in the composition for the first release agent layer, or such materials are not contained.

[0195] (5. Composite sheet for resin film formation)

[0196] The above-mentioned sheet for resin film formation has a resin film forming film and a release film supporting the resin film forming film, while the composite sheet for resin film formation in this embodiment has a resin film forming film and a support sheet supporting the resin film forming film. The support sheet only needs to have a structure capable of supporting the resin film forming film other than the release film. In this embodiment, it is preferable that the support sheet is an adhesive sheet having a substrate and an adhesive layer. In addition, a first release film is provided on the resin film forming film exposed by peeling.

[0197] Hereinafter, the case where the composite sheet for resin film formation is a composite sheet for protective film formation will be described.

[0198] Figure 3AThe composite sheet 61 for forming a protective film shown has a structure including an adhesive sheet 4 formed by laminating an adhesive layer 42 on one surface of a base material 41, a protective film forming film 10 laminated on the adhesive layer 42 side of the adhesive sheet 4, and a jig adhesive layer 5 laminated on the peripheral portion of the protective film forming film 10 opposite to the adhesive sheet 4. Further, the jig adhesive layer 5 is a layer for bonding the composite sheet 61 for forming a protective film to a jig such as an annular frame. The first release film 20 is disposed above the protective film forming film 10 and the jig adhesive layer 5 (on the upper part in Figure 3A the upper part).

[0199] In addition, Figure 3B the composite sheet 62 for forming a protective film shown has a structure including an adhesive sheet 4 formed by laminating an adhesive layer 42 on one surface of a base material 41, and a protective film forming film 10 laminated on the adhesive layer 42 side of the adhesive sheet 4. The first release film 20 is disposed above the protective film forming film 10 and the exposed adhesive layer 42 (on the upper part in Figure 3B the upper part).

[0200] When processing a workpiece, the composite sheet for forming a protective film in this embodiment is attached to the workpiece to hold the workpiece, and the protective film forming film is protected to form a protective film on the workpiece or a single particle of the workpiece.

[0201] Specifically, the composite sheet for forming a protective film is used to hold a wafer as a workpiece during dicing, and to form a protective film on a chip as a single particle of the workpiece obtained by dicing, but is not limited thereto.

[0202] (5.1 Adhesive sheet)

[0203] The adhesive sheet 4 of the composite sheet for forming a protective film in this embodiment includes a base material 41 and an adhesive layer 42 laminated on one surface of the base material 41.

[0204] (5.1.1. Base material)

[0205] The base material of the adhesive sheet is not particularly limited as long as it is suitable for processing of a workpiece, such as dicing and expanding of a wafer, and is generally formed of a film mainly made of a resin-based material (hereinafter referred to as "resin film").

[0206] As specific examples of the resin film, polyethylene films such as polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, and high density polyethylene (HDPE) film can be cited; polyolefin-based films such as polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, and norbornene resin film; ethylene-based copolymer films such as ethylene-vinyl acetate copolymer film, ethylene-(meth)acrylic acid copolymer film, and ethylene-(meth)acrylate copolymer film; polyvinyl chloride-based films such as polyvinyl chloride film and vinyl chloride copolymer film; polyester-based films such as polyethylene terephthalate film and polybutylene terephthalate film; polyurethane film; polyimide film; polystyrene film; polycarbonate film; fluororesin film, etc. In addition, modified films such as crosslinked films and ionomer films of these films can also be used. The above-mentioned base material 41 can be a film composed of one of these films, or can be a laminated film formed by combining two or more of these films. In the present embodiment, from the viewpoint of heat resistance during the heating process of the composite sheet for forming the protective film, a polypropylene film and a polybutylene terephthalate film are preferred.

[0207] In order to improve the adhesion with the adhesive layer laminated on the surface of the above resin film, the above resin film can be surface-treated on one or both sides as needed by an oxidation method, an unevenness method, etc., or a primer treatment can be performed. As the above oxidation method, for example, corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, etc. can be cited, and as the unevenness method, for example, sandblasting method, thermal spraying treatment method, etc. can be cited.

[0208] The above resin film can contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, fillers, etc.

[0209] As long as it can function properly in each process of using the sheet for forming the protective film, the thickness of the base material is not particularly limited. It is preferably in the range of 20 to 200 μm, more preferably in the range of 40 to 170 μm, and particularly preferably in the range of 50 to 140 μm.

[0210] (5.1.2. Adhesive layer)

[0211] The adhesive layer of the pressure-sensitive adhesive sheet of the composite sheet for forming a protective film according to this embodiment may be composed of a non-energy-ray-curable pressure-sensitive adhesive or an energy-ray-curable pressure-sensitive adhesive. As the non-energy-ray-curable pressure-sensitive adhesive, a pressure-sensitive adhesive having a desired adhesive force and peelability is preferred. For example, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a polyvinyl ether-based pressure-sensitive adhesive, etc. may be used. Among them, from the perspective of having a high adhesion to the protective film-forming film and being able to effectively suppress the detachment of the workpiece or single workpiece particles during the cutting process, etc., an acrylic pressure-sensitive adhesive is preferred. In addition, from the perspective of easily controlling the pick-up suitability of the single workpiece particles with the protective film, an acrylic pressure-sensitive adhesive is preferred.

[0212] On the other hand, since the adhesive force of the energy-ray-curable pressure-sensitive adhesive decreases upon irradiation with energy rays, when it is necessary to separate the workpiece or single workpiece particles from the pressure-sensitive adhesive sheet 4, it can be easily separated by irradiation with energy rays.

[0213] The energy-ray-curable pressure-sensitive adhesive constituting the adhesive layer may have a polymer having energy-ray curability as the main component, or may have a mixture of a polymer not having energy-ray curability and an energy-ray-curable monomer and / or oligomer as the main component.

[0214] Examples of the polymer having energy-ray curability include (meth)acrylate (co)polymers into which an energy-ray curable group has been introduced. Examples of the energy-ray curable monomer and / or oligomer include esters of polyhydric alcohols and (meth)acrylic acid. In addition, in addition to the components having energy-ray curability, the energy-ray-curable pressure-sensitive adhesive may also contain additives such as a photoinitiator and a crosslinking agent.

[0215] As long as it can function properly in each process of using the composite sheet for forming a protective film, the thickness of the adhesive layer is not particularly limited. 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, 3 to 8 μm.

[0216] As the adhesive constituting the adhesive layer for the jig, a pressure-sensitive adhesive having a desired adhesive force and peelability is preferred. For example, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a polyvinyl ether-based pressure-sensitive adhesive, etc. may be used. Among them, from the perspective of having a high adhesion to a jig such as an annular frame and being able to effectively suppress the peeling of the composite sheet for forming a protective film from the annular frame during the cutting process, etc., an acrylic pressure-sensitive adhesive is preferred. In addition, a base material as a core material may be interposed in the middle of the thickness direction of the adhesive layer for the jig.

[0217] From the perspective of the adhesiveness to fixtures such as an annular frame, the thickness of the adhesive layer for the fixture is preferably 5 to 200 μm, and particularly preferably 10 to 100 μm.

[0218] (6. Method for manufacturing a sheet for forming a resin film)

[0219] The method for manufacturing the sheet for forming a resin film in the present embodiment is not particularly limited, and a known method can be adopted. For example, first, a composition for forming a release agent layer for forming the first release film and the second release film (the composition for the first release agent layer and the composition for the second release agent layer) is prepared. In the present embodiment, from the perspective of adjusting the viscosity to improve the coatability on the substrate, it is preferable to coat a coating agent (that is, a coating agent containing the composition for the first release agent layer and the composition for the second release agent layer) formed by diluting the composition for the release agent layer containing the above components with a dilution solvent on the substrate.

[0220] Examples of the dilution solvent include organic solvents such as aromatic hydrocarbons such as toluene, fatty acid esters such as ethyl acetate, ketones such as methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and heptane. These dilution solvents can be used alone or in combination of two or more.

[0221] The solid content concentration of the coating agent containing the composition for the first release agent layer is preferably 0.3 to 10% by mass, more preferably 0.5 to 5% by mass, and further preferably 0.5 to 3% by mass. The solid content concentration of the coating agent containing the composition for the second release agent layer is the same as that of the coating agent containing the composition for the first release agent layer.

[0222] In the present embodiment, by coating a coating agent containing the composition for the first release agent layer on one surface of the substrate and then drying and curing the coating film, the first release agent layer is formed. Thus, the first release film can be obtained. The second release film can also be manufactured in the same manner.

[0223] Next, a composition for forming a resin film forming film for forming the resin film is prepared. Similar to the composition for the release agent layer, in the present embodiment, it is preferable to coat a coating agent (that is, a coating agent containing the composition for the resin film forming film) formed by diluting the composition for the resin film forming film with a dilution solvent on the release film. The type of the dilution solvent can be the same as that of the dilution solvent for the composition for the release agent layer.

[0224] On the other hand, the solid content concentration of the coating agent containing the composition for the resin film forming film is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass.

[0225] In the present embodiment, a coating agent containing a resin film-forming composition is coated on the first release agent layer of the first release film by a known method, and then heated and dried to form a coating film. Next, the second release agent layer of the second release film is laminated on the coating film to produce a sheet for forming a resin film.

[0226] As coating methods for the coating agent containing each composition, for example, spin coating, spray coating method, bar coating method, knife coating method, roll coating method, knife-over-roll coating method, blade coating method, die coating method, gravure coating method, etc. can be exemplified.

[0227] (7. Method for manufacturing a composite sheet for forming a resin film)

[0228] The method for manufacturing the sheet for forming a resin film of the present embodiment is not particularly limited, and a known method can be adopted. For example, it can be manufactured by separately producing a first laminate including a resin film-forming film and a second laminate including an adhesive sheet as a support sheet, and then using the first laminate and the second laminate to laminate the resin film-forming film and the adhesive sheet.

[0229] The first laminate can be manufactured by the same method as the above-mentioned sheet for forming a resin film. That is, a resin film-forming film is formed on the release surface of the first release film, and the release surface of the second release film is laminated on the exposed surface of the resin film-forming film.

[0230] On the other hand, in order to manufacture the second laminate, first, an adhesive composition constituting the adhesive layer is prepared, or a composition formed by diluting the adhesive composition with a solvent (the above two compositions are referred to as "coating agents") is prepared. Subsequently, the coating agent is coated on the release surface of the third release film, and dried as needed to form an adhesive layer on the third release film. Then, a substrate is laminated on the exposed surface of the adhesive layer to obtain a laminate (second laminate) composed of an adhesive sheet and the third release film, where the adhesive sheet is composed of the substrate and the adhesive layer.

[0231] Here, when the adhesive layer is composed of an energy ray-curable adhesive, the adhesive layer can be irradiated with energy rays at this stage to cure the adhesive layer, or the adhesive layer can be cured after being laminated with the resin film-forming film. In addition, when the adhesive layer is cured after being laminated with the resin film-forming film, the adhesive layer can be cured before the cutting process or after the cutting process.

[0232] As the energy rays, ultraviolet rays, electron rays, etc. are usually used. The irradiation amount of the energy rays varies depending on the type of energy rays. For example, in the case of ultraviolet rays, it is preferably 50 to 1000 mJ / cm 2 , particularly preferably 100 to 500 mJ / cm 2In addition, in the case of electron rays, it is preferably about 10 to 1000 krad.

[0233] When the first laminate and the second laminate are obtained as described above, the second release film in the first laminate is peeled off, and the third release film in the second laminate is peeled off, and the resin film forming film exposed in the first laminate is bonded to the adhesive layer of the adhesive sheet exposed in the second laminate.

[0234] In this way, an adhesive sheet formed by laminating an adhesive layer on a substrate, a resin film forming film laminated on the adhesive layer side of the adhesive sheet, and a resin film forming composite sheet formed by a first release film laminated on the side opposite to the adhesive sheet of the resin film forming film can be obtained. If necessary, the resin film forming film can be cut into a shape close to the planar shape of the workpiece, or a jig adhesive layer can be formed on the peripheral portion of the exposed resin film forming film or adhesive layer after peeling off the first release film.

[0235] (8. Method for manufacturing individual workpieces)

[0236] The method for manufacturing individual workpieces according to this embodiment at least includes the following steps 1 to 3.

[0237] Step 1: A step of bonding the resin film forming film included in the resin film forming sheet or the resin film forming film included in the resin film forming composite sheet to the back surface of the workpiece;

[0238] Step 2: A step of forming the attached resin film forming film into a resin film

[0239] Step 3: A step of singulating the workpiece with the resin film or the resin film forming film attached thereto to obtain a plurality of individual workpieces with a resin film or individual workpieces with a resin forming film

[0240] In addition, from the above, it can be understood that Step 2 can be performed before Step 3 or after Step 3.

[0241] Use Figure 4A 、 Figure 4B And Figure 5 The method for manufacturing individual workpieces having Steps 1 to 3 described above will be described.

[0242] Hereinafter, as an example of the method for manufacturing individual workpieces using the resin film forming sheet or the resin film forming composite sheet of this embodiment, the method for manufacturing a chip with a protective film obtained by processing a wafer with a protective film forming film attached thereto will be described.

[0243] As Figure 4AAs shown, the protective film forming film 10 of the protective film forming sheet 1 is attached to the back surface of the wafer 6 (Step 1). If necessary, the second release film 30 can be peeled off. In addition, after Step 1, if necessary, the first release film 20 can be peeled off.

[0244] In addition, as Figure 4B shown, the protective film forming film 10 of the protective film forming composite sheet 61 is attached to the wafer 6 (Step 1). At this time, the outer peripheral portion of the protective film forming film 10 can be fixed by the annular frame 7. In the present embodiment, as Figure 3A shown, since the adhesive layer 5 for jig is provided on the outer periphery of the protective film forming film 10, the adhesive layer 5 for jig is attached to the annular frame 7. The wafer 6 is attached to the surface of the protective film forming film 10 on the side opposite to the attachment surface of the adhesive layer 42. When the protective film forming film 10 is attached to the wafer 6, if necessary, the protective film forming film 10 can be heated to make it adhesive.

[0245] Then, the attached protective film forming film 10 is made into a protective film to form a protective film (Step 2), and a wafer 6 with a protective film is obtained. In the case where the protective film forming film 10 is thermosetting, the protective film forming film 10 can be heated at a predetermined temperature for an appropriate time. In addition, in the case where the protective film forming film 10 is energy ray curable, energy rays can be irradiated from the adhesive sheet 4 side or the release film side.

[0246] In addition, the formation of the protective film of the protective film forming film 10 can be performed after the dicing process, or the chip with the protective film forming film can be picked up from the adhesive sheet, and then the protective film forming film can be made into a protective film.

[0247] Next, if necessary, the Figure 4A wafer 6 with the protective film forming film 10 obtained by making the protective film forming film 10 into a protective film as shown and the annular frame 7 are attached to a known dicing sheet 80, and the wafer 6 with a protective film is diced to obtain Figure 5 the chip with the protective film 11 as shown (the chip 70 with a protective film). Or, the Figure 4A wafer 6 with the protective film forming film 10 and the annular frame 7 as shown are attached to a known dicing sheet 80, and the wafer 6 with the protective film forming film is diced to obtain a chip with the protective film forming film 10 (the chip with a protective film) (Step 3).

[0248] In addition, by a known method, the wafer 6 with the protective film forming film 10 obtained by making the protective film forming film 10 into a protective film as shown is diced to obtain Figure 4B the chip with the protective film 11 as shown (the chip 70 with a protective film). Or, dice Figure 5 the wafer 6 with the protective film forming film 10 as shown to obtain Figure 4BThe wafer 6 with the protective film forming film 10 shown is obtained to get a chip with a protective film forming film (chip with a protective film) (Process 3).

[0249] Pick up and mount the obtained chip with a protective film or a protective film forming film on a substrate or the like.

[0250] (9. Modification example)

[0251] In the above, the case where the resin film forming film is a protective film forming film has been described. However, as described above, the resin film forming film can also be a chip bonding film. The chip bonding film is composed of a film-like adhesive. The film-like adhesive can have a composition similar to the above-described protective film forming film composition. For example, a composition containing the above polymer component (A), curable component (B), and filler (E) is preferably used, and a composition containing polymer component (A), curable component (B), curing agent (C), and filler (E) is more preferably used.

[0252] In addition, the composite sheet for resin film formation can also be a dicing chip bonding sheet obtained by laminating and integrating a chip bonding film and a support sheet (dicing sheet) used for fixing a semiconductor wafer during dicing. As the dicing sheet, a known dicing sheet can be used.

[0253] In the above, embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0254] Examples

[0255] Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

[0256] (Production of the first release film)

[0257] Mix the following respective components according to the blending ratios A to H (in terms of solid content) shown in Table 1 so that the solid content concentration becomes 2% by mass, and prepare a coating agent containing a composition for the first release agent layer (Formulations A to H) using a mixed solvent of toluene and methyl ethyl ketone (toluene / methyl ethyl ketone = 1 / 1 (mass ratio)).

[0258] (α) Silicone-based release agent

[0259] (α-1) Polydimethylsiloxane having vinyl in the side chain (manufactured by AZmax Corporation, product name "VDT-163", weight average molecular weight: 430,000, vinyl (vinyl) ratio: 6 mol%)

[0260] (α-2) Dimethylpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., product name: X-62-1387, weight-average molecular weight: 2000)

[0261] (β) Silicone resin

[0262] MQ resin with vinyl groups (manufactured by Dow Corning Toray Co., Ltd., SD-7292, solid content 71% by mass)

[0263] (γ) Catalyst

[0264] Platinum (Pt) catalyst (manufactured by Dow Corning Toray Co., Ltd., SRX-212, solid content 100% by mass)

[0265] The coating agent containing each composition for forming the first release agent layer prepared was coated on a PET film (manufactured by Mitsubishi Chemical Corporation, product name: DIAFOIL (registered trademark) T-100, thickness: 50 μm) as a substrate, and the first release agent layers A to H were formed on the PET film so that the film thickness after heating and drying was 0.15 μm, and each first release film was produced.

[0266] [Table 1]

[0267]

[0268] (Production of the second release film)

[0269] As the second release film, a film obtained by subjecting a PET film to a release treatment (manufactured by LINTEC Corporation, "SP-PET381130", thickness 38 μm) was used.

[0270] (Production of the protective film forming film)

[0271] The following respective components were mixed according to the blending ratios A and B (in terms of solid content) shown in Table 2, and diluted with methyl ethyl ketone so that the solid content concentration became 50% by mass, to prepare a coating agent containing a composition for forming a protective film (formulation A) and a coating agent containing a composition for forming a protective film (formulation B).

[0272] (A) Polymer component

[0273] (A-1) A (meth)acrylate copolymer obtained by copolymerizing 12 parts by mass of n-butyl acrylate, 65 parts by mass of methyl acrylate, 7 parts by mass of glycidyl methacrylate, and 16 parts by mass of 2-hydroxyethyl acrylate (weight average molecular weight: 500,000, glass transition temperature: -2°C)

[0274] (A-2) A (meth)acrylate copolymer obtained by copolymerizing 87 parts by mass of methyl acrylate and 13 parts by mass of 2-hydroxyethyl acrylate (weight average molecular weight: 450,000, glass transition temperature: 6°C)

[0275] (B) Curing component (thermosetting component)

[0276] (B-1) Bisphenol A liquid epoxy resin (manufactured by NIPPON SHOKUBAI CO., LTD., BPA328, epoxy equivalent: 230 - 240 g / eq)

[0277] (B-2) Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828, epoxy equivalent: 184 - 194 g / eq)

[0278] (B-3) Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER1055, epoxy equivalent: 800 - 900 g / eq)

[0279] (B-4) Dicyclopentadiene type epoxy resin (manufactured by DIC CORPORATION, EPICLON HP-7200HH, epoxy equivalent: 274 - 286 g / eq)

[0280] (B-5) Dicyclopentadiene type epoxy resin (manufactured by DIC CORPORATION, EPICLON HP-7200, epoxy equivalent: 254 - 264 g / eq)

[0281] (C) Curing agent: Dicyandiamide (manufactured by Mitsubishi Chemical Corporation, DICY7)

[0282] (D) Curing accelerator: 2-Phenyl-4,5-dihydroxymethylimidazole (manufactured by SHIKOKU CHEMICALS CORPORATION, Curezol 2PHZ)

[0283] (E) Filler: Epoxy group-modified spherical silica filler (manufactured by Admatechs Corporation, SC2050MA, average particle size: 0.5 μm)

[0284] (F) Coupling agent: Epoxy group-containing oligomer type silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., X-41-1056, epoxy equivalent 280 g / eq)

[0285] (G) Colorant

[0286] (G-1) Carbon black (manufactured by Mitsubishi Chemical Corporation, MA600B, average particle size 28 nm)

[0287] (G-2) Organic black pigment (manufactured by Dainichiseika Color&Chemicals Mfg.Co.,Ltd., 6377 Black)

[0288] [Table 2]

[0289]

[0290] The coating agent containing each protective film-forming film composition prepared was coated on the release surface (the surface formed with the first release agent layer) of the first release film produced, and dried at 100 °C for 2 minutes to form protective film-forming films A and B with a thickness of 35 μm. Subsequently, the surface of the second release film that had undergone the release treatment was attached to the protective film-forming film to obtain a protective film-forming sheet with release films formed on both sides of the protective film-forming film. The attachment conditions were a temperature of 60 °C, a pressure of 0.4 MPa, and a speed of 1 m / minute. The combinations of the types of protective film-forming films and the types of the first release agent layers in the protective film-forming sheets of each example and comparative example are shown in Table 3.

[0291] Subsequently, the following measurements and evaluations were carried out.

[0292] (Long diameter change rate of ethanol droplet)

[0293] The first release film was peeled off from the produced protective film-forming sheet to obtain a sample for measurement. Subsequently, an ethanol solution for the dropping test (ethanol 99.5%, Deer 1 grade) was prepared. In order to make the liquid droplet easily visible, a very small amount of colorant (manufactured by Orient Chemical Industries Co., Ltd., OIL BLACK 860) was added to the ethanol solution to color the ethanol (concentration of OILBLACK 860 = 0.1 wt%).

[0294] In an environment of 23°C (±1°C) and relative humidity of 50% (±5%), a drop (15 ± 2 mg) of the above-mentioned colored ethanol solution is dropped from a height of 50 mm onto the release surface of the first release film. The major axis of the ethanol droplet 2 seconds after the start of dropping is measured and designated as A (mm). Thereafter, the major axis of the ethanol droplet 5 minutes after the start of dropping is measured and designated as B (mm). From the measured A and B, the major axis change rate (%) of the ethanol droplet is calculated using the following mathematical formula. The results are shown in Table 3.

[0295] Major axis change rate = {(A - B) / A} × 100 (%)

[0296] (Appearance evaluation of the protective film forming film)

[0297] Each protective film forming sheet produced is stored under the following conditions. The operation of storing the protective film forming sheet at 30°C for 24 hours and then at -5°C for 24 hours is defined as 1 cycle, and 15 cycles are carried out.

[0298] The second release film is peeled off from each of the stored protective film forming sheets, and using a laminating device at an attachment temperature of 60°C (the temperature of the laminating roller is 60°C and the temperature of the silicon mirror wafer is 60°C), with the attachment speed set at 300 mm / min and the attachment pressure set at 0.3 MPa, the exposed protective film forming sheet is attached to the mirror surface of the silicon wafer. After attachment, the first release film is manually peeled off to obtain a silicon wafer with a protective film forming film.

[0299] The surface of the protective film forming film of the obtained silicon wafer with a protective film forming film (the surface in contact with the first release film) is visually observed and observed using an optical microscope to evaluate whether foreign matter is generated.

[0300] When visually observing the appearance, 3 observers evaluate the appearance of the surface of the protective film forming film according to the following criteria. The results are shown in Table 3.

[0301] A: All 3 people judge that there are no appearance defects that hinder use

[0302] B: 1 person out of 3 judges that there is an appearance defect that hinders use, and 2 people judge that there are no appearance defects that hinder use

[0303] C: 2 or more people out of 3 judge that there are appearance defects that hinder use

[0304] In the visual inspection using an optical microscope, an optical microscope (manufactured by KEYENCE CORPORATION, VHX-7000) was used to observe a region measuring 1.9 mm in length and 2.6 mm in width on the surface of the protective film forming film at an observation magnification of 100 times, and an image was obtained. For the obtained image, binarization was performed in such a way as to distinguish foreign matter from the other regions. For the binarized image, the area (%) of the region corresponding to the foreign matter with respect to the area of the entire image was calculated, and evaluation was performed according to the following criteria. The results are shown in Table 3.

[0305] A: The area of the region corresponding to the foreign matter with respect to the area of the entire image is less than 10%.

[0306] B: The area of the region corresponding to the foreign matter with respect to the area of the entire image is 10% or more and less than 20%.

[0307] C: The area of the region corresponding to the foreign matter with respect to the area of the entire image is 20% or more and less than 30%.

[0308] D: The area of the region corresponding to the foreign matter with respect to the area of the entire image is 30% or more.

[0309] [Table 3]

[0310]

[0311] It can be confirmed from Table 3 that if the major axis change rate of the ethanol droplet is within the above range, the generation of foreign matter can be suppressed, and the appearance defect of the protective film forming film can be suppressed.

[0312] Explanation of Reference Numerals

[0313] 1: Sheet for resin film formation; 10: Resin film forming film; 20: First release film; 21: Substrate; 22: First release agent layer; 30: Second release film.

Claims

1. A sheet for forming a resin film, which is a sheet for forming a resin film having a resin film-forming layer and a first release film, The resin film-forming layer and the first release film are laminated in such a manner that one main surface of the resin film-forming layer contacts the release surface of the first release film. When ethanol is dropped onto the release surface, when the major axis of the ethanol droplet 2 seconds after the start of dropping is designated as A and the major axis of the ethanol droplet 5 minutes after the start of dropping is designated as B, the major axis change rate shown below is 30% or less. Major axis change rate = {(A - B) / A} × 100 (%).

2. The sheet for forming a resin film according to claim 1, wherein, The resin film-forming layer contains a latent curing agent.

3. A composite sheet for forming a resin film, which has the sheet for forming a resin film according to claim 1 or 2, and a support sheet disposed on the other main surface of the resin film-forming layer.

4. A release film, which is a release film having a release surface. When ethanol is dropped onto the release surface, when the major axis of the ethanol droplet 2 seconds after the start of dropping is designated as A and the major axis of the ethanol droplet 5 minutes after the start of dropping is designated as B, the major axis change rate shown below is 30% or less. Major axis change rate = {(A - B) / A} × 100 (%).

5. A method for manufacturing a singulated workpiece, which includes: A step of attaching the resin film-forming layer included in the sheet for forming a resin film according to claim 1 or 2, or the resin film-forming layer included in the composite sheet for forming a resin film according to claim 3, to the back surface of a workpiece; A step of forming the attached resin film-forming layer into a resin film; and A step of singulating the workpiece to which the resin film or the resin-forming layer is attached, thereby obtaining a plurality of singulated workpieces with resin films or a plurality of singulated workpieces with resin-forming layers.

Images