Film for forming protective film and composite sheet for forming protective film

Abstract

The present invention provides a film for forming a protective film and a composite sheet for forming a protective film which are capable of preventing the occurrence of poor curing even in the presence of oxygen gas, such a film for forming a protective film is an energy ray-curable film for forming a protective film, a photo-radical initiator having an absorption coefficient of 4.0 * 101 ml / (g.cm) or more at a wavelength of 365 nm is blended in the resin composition. The photoradical initiator is preferably a hydrogen abstracting type photoradical initiator having three or more aromatic rings in one molecule, and is preferably a photoradical initiator having two or more photodecomposable groups in one molecule.

Description

[0001] The present invention is a divisional application of Chinese patent application with application number 201780023956.5, application date April 25, 2017, and invention name “Film for forming a protective film and composite sheet for forming a protective film”. This application claims the priority of Japanese patent application No. 2016-092011 filed in Japan on April 28, 2016. Technical Field

[0002] The present invention relates to a film for forming a protective film and a composite sheet for forming a protective film.

[0003] This application claims priority based on Japanese Patent Application No. 2016-092011 filed in Japan on April 28, 2016, the contents of which are incorporated herein by reference. Background Art

[0004] In recent years, semiconductor devices are being manufactured using a so-called face-down mounting method. In the face-down mounting method, a semiconductor chip having electrodes such as bumps on a circuit surface is used, and the electrodes are bonded to a substrate. Therefore, the back side of the semiconductor chip opposite to the circuit surface is sometimes exposed.

[0005] A resin film made of an organic material is formed as a protective film on the back of the exposed semiconductor chip, and the semiconductor chip is sometimes incorporated into a semiconductor device as a semiconductor chip with a protective film. The protective film is used to prevent cracks from occurring on the semiconductor chip during a dicing process or after packaging.

[0006] In order to form such a protective film, for example, a composite sheet for forming a protective film is used, which has a protective film forming film on a support sheet for forming a protective film. In the composite sheet for forming a protective film, the protective film forming film can be formed into a protective film by curing. In addition, the support sheet can be used as a cutting sheet, and a composite sheet for forming a protective film can be made in which the protective film forming film and the cutting sheet are integrated.

[0007] As such a composite sheet for forming a protective film, for example, a composite sheet for forming a protective film having a thermosetting protective film forming film that is cured by heating to form a protective film has been mainly used so far. In this case, for example, the composite sheet for forming a protective film is attached to the back side (the side opposite to the electrode forming side) of the semiconductor wafer using a thermosetting protective film forming film. Then, the protective film forming film is cured by heating to form a protective film, and the semiconductor wafer and the protective film are divided together by cutting to form a semiconductor chip. Sometimes, the curing and cutting of the protective film forming film are performed in the opposite order to the above.

[0008] However, the heat curing of the thermosetting protective film forming film usually requires a long time of about several hours, so it is expected to shorten the curing time. In this regard, research is being conducted on using a protective film forming film that can be cured by irradiation with energy rays such as ultraviolet rays for the formation of a protective film. For example, an energy ray-curable protective film formed on a peeling film (see Patent Document 1) and an energy ray-curable chip protective film that can form a protective film with high hardness and excellent adhesion to a semiconductor chip (see Patent Document 2) have been disclosed.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent No. 5144433

[0012] Patent Document 2: Japanese Patent Application Publication No. 2010-031183

[0013] Figure 7 (a)~ Figure 7 (c) is a cross-sectional view schematically showing the conventional process from cutting a semiconductor wafer to curing it and picking it up. There are two types of semiconductor wafers 18: a type in which a protective film forming composite sheet 10 is attached to the back thereof, and the protective film forming film 13' is cured after a cutting process; and a type in which a protective film forming composite sheet 10 is attached to the back thereof and then cut after curing. Among them, in the type in which the semiconductor wafer 18 is cured after cutting, the semiconductor wafer 18 is cut into a plurality of semiconductor chips 181, 181 by a cutting blade 20 through cutting. ( Figure 7 (a) At this time, the side surface of the cut semiconductor chip 181 is exposed, and the protective film forming film 13 attached to the back surface of the semiconductor chip 181 is also cut to expose its cross section. Summary of the invention

[0014] 1. Technical issues to be resolved

[0015] Thus, the cross section of the protective film forming film 13 is exposed to oxygen, which has the property of inhibiting curing. Figure 7 (b)), there is a case where the protective film forming film is not sufficiently cured by the irradiation of energy rays, resulting in poor curing. In this case, if it is provided to the following pick-up step ( Figure 7 (c)) There is a problem that the semiconductor chip 181 may be cracked or damaged during pickup, resulting in poor pickup, which leads to a decrease in the yield of products.

[0016] in addition, Figure 7In the drawings, reference numerals 11, 12, 16, 17, 19 and 21 respectively denote a substrate, an adhesive layer, a jig adhesive layer, a ring frame, divided silicon wafers and an energy ray irradiation device.

[0017] The present invention is made to solve the above-mentioned problems. That is, an object of the present invention is to provide an energy-ray-curable protective film-forming film and a protective film-forming composite sheet that do not cause poor curing and poor pickup even when cured in the presence of oxygen.

[0018] (II) Technical solution

[0019] The inventors of the present application have conducted intensive research to solve the above technical problems. As a result, they have found that by adding a light having an extinction coefficient of 4.0×10 1 The photo-radical initiator with a concentration of ml / (g·cm) or more can solve the above-mentioned technical problems, thereby completing the present invention.

[0020] That is, the present invention is a protective film-forming film, which is an energy ray-curable protective film-forming film, wherein the protective film-forming film contains an extinction coefficient of 4.0×10 1 ml / (g·cm) or more photo-radical initiator.

[0021] In the protective film-forming film of the present invention, it is preferred that the photoradical initiator is a hydrogen abstraction type photoradical initiator having three or more aromatic rings in one molecule.

[0022] Furthermore, in the protective film-forming film of the present invention, it is preferred that the photoradical initiator be a photoradical initiator having two or more photodegradable groups in one molecule.

[0023] Furthermore, the present invention may be a composite sheet for forming a protective film, which includes the above-described film for forming a protective film provided on a supporting sheet.

[0024] (III) Beneficial effects

[0025] According to the present invention, it is possible to provide an energy-ray-curable protective film forming film and a protective film forming composite sheet which do not cause poor curing and poor pickup even when cured in the presence of oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a cross-sectional view schematically showing one embodiment of the composite sheet for forming a protective film of the present invention.

[0027] Figure 2This is a cross-sectional view schematically showing another embodiment of the composite sheet for forming a protective film of the present invention.

[0028] Figure 3 This is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.

[0029] Figure 4 This is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.

[0030] Figure 5 This is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.

[0031] Figure 6 This is a cross-sectional view schematically showing one embodiment of the protective film forming sheet of the present invention.

[0032] Figure 7 The figure is a cross-sectional view schematically showing the conventional process from dicing a semiconductor wafer to solidifying it and picking it up.

[0033] Description of Reference Numerals

[0034] 1A, 1B, 1C, 1D, 1E: composite sheet for forming a protective film; 1F: sheet for forming a protective film; 10: support sheet; 10a: surface of the support sheet; 11: substrate; 11a: surface of the substrate; 12: adhesive layer; 12a: surface of the adhesive layer; 13, 23: film for forming a protective film; 13a, 23a: surface of the film for forming a protective film; 15: peeling film; 16: adhesive layer for a clamp; 16a: adhesive layer for a clamp. DETAILED DESCRIPTION

[0035] ◇Film for protective film formation

[0036] The protective film forming film of the present invention is an energy ray-curable protective film forming film, wherein the protective film forming film contains an extinction coefficient of 4.0×10 1 ml / (g·cm) or more photo-radical initiator.

[0037] The photoradical initiator of the present invention may be a hydrogen abstraction type photoradical initiator having three or more aromatic rings in one molecule.

[0038] The photoradical initiator of the present invention may be a photoradical initiator having two or more photodegradable groups in one molecule.

[0039] The extinction coefficient of the photoradical initiator of the present invention at a wavelength of 365 nm is preferably 1.0×10 4ml / (g·cm) or less.

[0040] When the extinction coefficient of the photoradical initiator at a wavelength of 365 nm is equal to or less than the above value, unintended reactions can be suppressed when the composite sheet is used under a fluorescent lamp or natural light, thereby achieving an effect of enabling stable use of the composite sheet.

[0041] The protective film-forming film of the present invention may have a first release film on at least one surface, and may further have a second release film on the other surface. The protective film-forming film of the present invention may be provided as a long film wound in a roll. Figure 6 FIG. 2 is a cross-sectional view schematically showing one embodiment of the protective film-forming film of the present invention. Figure 6 In the embodiment, the first release film 15b, the protective film forming film 13 (23), and the second release film 15a are stacked in this order.

[0042] ◇Composite sheet for protective film formation

[0043] The composite sheet for forming a protective film of the present invention comprises a protective film for forming a film having energy ray curability on a support sheet, wherein the protective film for forming a film is mixed with an extinction coefficient of 4.0×10 1 ml / (g·cm) or more photo-radical initiator.

[0044] In addition, in this specification, "film for protective film formation" means a film before curing, and "protective film" means a film formed by curing the film for protective film formation.

[0045] The protective film forming film is cured by irradiation with energy rays to form a protective film. The protective film is used to protect the back side (the side opposite to the electrode forming side) of a semiconductor wafer or a semiconductor chip. The protective film forming film is soft and can be easily attached to an attached object.

[0046] Furthermore, by setting the surface resistivity of the protective film forming film to 10 12 The composite sheet for forming a protective film of the present invention has antistatic properties when the surface roughness is less than Ω·cm. For example, even after the dicing process, the semiconductor chip can be prevented from being charged. Therefore, when the semiconductor chip is sealed in a reel and sent out, and when the cover tape is peeled off in the next process, the semiconductor chip can be prevented from being attached to the cover tape.

[0047] Furthermore, since the semiconductor chip itself is prevented from being charged, dust or dirt can be prevented from being attached to the semiconductor chip due to static electricity.

[0048] In the present invention, "energy rays" refer to rays having energy particles among electromagnetic waves or charged particle beams, and examples thereof include ultraviolet rays, radiation, and electron beams.

[0049] Ultraviolet rays can be irradiated by using, for example, a high pressure mercury lamp, a fusion H lamp, a xenon lamp, a black light lamp, or an LED lamp as an ultraviolet light source. Electron beams can be irradiated using electron beams generated by an electron beam accelerator or the like.

[0050] In the present invention, “energy ray-curable” means a property of being cured by irradiation with energy rays, and “non-energy ray-curable” means a property of not being cured even by irradiation with energy rays.

[0051] The thickness of the semiconductor wafer or semiconductor chip to which the composite sheet for forming a protective film of the present invention is applied is not particularly limited, but is preferably 30 to 1000 μm, more preferably 100 to 300 μm, because the effects of the present invention can be more significantly obtained.

[0052] Hereinafter, the configuration of the present invention will be described in detail.

[0053] ◎Support sheet

[0054] The support sheet may be composed of one layer (single layer) or more than two layers. When the support sheet is composed of multiple layers, the constituent materials and thicknesses of these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effect of the present invention is not impaired.

[0055] In addition, in this specification, not limited to the case of a supporting sheet, "multiple layers may be the same as or different from each other" means "all the layers may be the same, all the layers may be different, or only some of the layers may be the same", and "multiple layers may be different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0056] Preferred supporting sheets include, for example, a supporting sheet in which an adhesive layer is directly in contact with and laminated on a substrate, a supporting sheet in which an adhesive layer is laminated on a substrate via an intermediate layer, and a supporting sheet consisting only of a substrate.

[0057] Below, while referring to the attached Figure 1 The examples of the composite sheet for forming the protective film of the present invention are described according to the types of such support sheets. In addition, in order to make it easier to understand the features of the present invention, for convenience, important parts of the figures used in the following description are sometimes enlarged, and the size ratios of the components are not necessarily the same as the actual ones.

[0058] Figure 11 is a cross-sectional view schematically showing an embodiment of a composite sheet for forming a protective film of the present invention. The composite sheet for forming a protective film 1A shown here has an adhesive layer 12 on a substrate 11, and a protective film forming film 13 on the adhesive layer 12. The support sheet 10 is a laminate of the substrate 11 and the adhesive layer 12. In other words, the composite sheet for forming a protective film 1A has a structure in which the protective film forming film 13 is laminated on the surface 10a of one side of the support sheet 10. In addition, the composite sheet for forming a protective film 1A further has a release film 15 on the protective film forming film 13.

[0059] In the composite sheet 1A for forming a protective film, an adhesive layer 12 is laminated on the surface 11a of one side of the substrate 11. A protective film-forming film 13 is laminated on the entire surface 12a of the adhesive layer 12. A jig adhesive layer 16 is laminated on a portion of the surface 13a of the protective film-forming film 13, that is, on a region near the peripheral portion. A release film 15 is laminated on the surface of the surface 13a of the protective film-forming film 13 where the jig adhesive layer 16 is not laminated and on the surface 16a (upper surface and side surface) of the jig adhesive layer 16.

[0060] In the protective film forming composite sheet 1A, the protective film forming film 13 has an extinction coefficient of 4.0×10 1 ml / (g·cm) or more photo-radical initiator.

[0061] Furthermore, it is preferable that the adhesive force between the protective film-forming film 13 (ie, the protective film) and the support sheet 10 after curing, in other words, the adhesive force between the protective film and the adhesive layer 12 is 50 to 1500 mN / 25 mm.

[0062] The jig adhesive layer 16 may have, for example, a single-layer structure containing an adhesive component, or a multilayer structure in which layers containing an adhesive component are laminated on both surfaces of a sheet material serving as a core material.

[0063] Figure 1 The composite sheet 1A for forming a protective film shown is used in the following manner: with the release film 15 removed, the back side of a semiconductor wafer (not shown) is adhered to the surface 13a of the protective film forming film 13, and the upper surface 16a of the surface 16a of the clamp adhesive layer 16 is further adhered to a clamp such as a ring frame.

[0064] Figure 2 FIG. 2 is a cross-sectional view schematically showing another embodiment of the composite sheet for forming a protective film of the present invention. Figure 2 In the subsequent drawings, the same components as those shown in the drawings that have already been described are denoted by the same reference numerals as those in the drawings that have already been described, and detailed description thereof will be omitted.

[0065] The protective film forming composite sheet 1B shown here is similar to the composite sheet 1B except that it does not include the jig adhesive layer 16. Figure 1 That is, in the composite sheet 1B for forming a protective film, an adhesive layer 12 is laminated on a surface 11a on one side of the substrate 11. A protective film forming film 13 is laminated on the entire surface 12a of the adhesive layer 12, and a release film 15 is laminated on the entire surface 13a of the protective film forming film 13.

[0066] Figure 2 The composite sheet 1B for forming a protective film shown is used in the following manner: with the release film 15 removed, the back side of a semiconductor wafer (not shown) is attached to a portion of the central side of the surface 13a of the protective film forming film 13. Furthermore, the area near the peripheral edge of the protective film forming film 13 is attached to a jig such as a ring frame.

[0067] Figure 3 This is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.

[0068] The protective film forming composite sheet 1C shown here is similar to the composite sheet 1C except that it does not include the adhesive layer 12. Figure 1 The composite sheet 1A for forming a protective film is the same as that shown in FIG. That is, in the composite sheet 1C for forming a protective film, the support sheet 10 is composed only of the substrate 11. Moreover, a protective film forming film 13 is laminated on the surface 11a on one side of the substrate 11 (the surface 10a on one side of the support sheet 10). Next, a clamp adhesive layer 16 is laminated on a part of the surface 13a of the protective film forming film 13, that is, on the area near the peripheral portion. A release film 15 is laminated on the surface of the surface 13a of the protective film forming film 13 where the clamp adhesive layer 16 is not laminated and on the surface 16a (upper surface and side surface) of the clamp adhesive layer 16.

[0069] In the protective film forming composite sheet 1C, the protective film forming film 13 contains a light having an extinction coefficient of 4.0×10 1 ml / (g·cm) or more photo-radical initiator.

[0070] Furthermore, it is preferable that the adhesive force between the protective film-forming film 13 (ie, the protective film) and the support sheet 10 after curing, in other words, the adhesive force between the protective film and the substrate 11 is 50 to 1500 mN / 25 mm.

[0071] and Figure 1 The protective film forming composite sheet 1A shown is the same as that shown in FIG. Figure 3The protective film forming composite sheet 1C shown is used in the following manner: the back side of a semiconductor wafer (not shown) is attached to the surface 13a of the protective film forming film 13 with the release film 15 removed. Furthermore, the upper surface of the surface 16a of the clamp adhesive layer 16 is attached to a clamp such as a ring frame.

[0072] Figure 4 This is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.

[0073] The protective film forming composite sheet 1D shown here is similar to the composite sheet 1D except that it does not include the jig adhesive layer 16. Figure 3 That is, in the composite sheet 1D for forming a protective film, a protective film-forming film 13 is laminated on one surface 11a of the substrate 11. Furthermore, a release film 15 is laminated on the entire surface 13a of the protective film-forming film 13.

[0074] and Figure 2 The same as the composite sheet 1B for forming a protective film shown, Figure 4 The composite sheet 1D for forming a protective film shown is used in the following manner: with the release film 15 removed, the back side of a semiconductor wafer (not shown) is attached to a portion of the central side of the surface 13a of the protective film forming film 13. Furthermore, the area near the peripheral edge of the protective film forming film 13 is attached to a fixture such as a ring frame.

[0075] Figure 5 This is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.

[0076] The protective film-forming composite sheet 1E shown here is similar to the composite sheet 1E except that the shape of the protective film-forming film is different. Figure 1 The composite sheet 1E for forming a protective film is the same as the composite sheet 1A for forming a protective film shown. That is, the composite sheet 1E for forming a protective film has an adhesive layer 12 on the substrate 11, and a protective film forming film 23 on the adhesive layer 12. The support sheet 10 is a laminate of the substrate 11 and the adhesive layer 12. In other words, the composite sheet 1E for forming a protective film has a structure in which the protective film forming film 23 is laminated on the surface 10a of one side of the support sheet 10. In addition, the composite sheet 1E for forming a protective film further has a release film 15 on the protective film forming film 23.

[0077] In the composite sheet 1E for forming a protective film, an adhesive layer 12 is laminated on the surface 11a of one side of the substrate 11, and a protective film forming film 23 is laminated on a part of the surface 12a of the adhesive layer 12, that is, on the central area. In addition, a release film 15 is laminated on the surface of the surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated and on the surface 23a (upper surface and side surface) of the protective film forming film 23.

[0078] When the protective-film-forming composite sheet 1E is viewed from above, the surface area of ​​the protective-film-forming film 23 is smaller than that of the adhesive layer 12 , and has a circular shape, for example.

[0079] In the composite sheet 1E for forming a protective film, the film 23 for forming a protective film has an extinction coefficient of 4.0×10 1 ml / (g·cm) or more photo-radical initiator.

[0080] Furthermore, it is preferable that the adhesive force between the protective film-forming film 23 (ie, the protective film) and the support sheet 10 after curing, in other words, the adhesive force between the protective film and the adhesive layer 12 is 50 to 1500 mN / 25 mm.

[0081] Figure 5 The composite sheet 1E for forming a protective film shown is used in the following manner: the back side of a semiconductor wafer (not shown) is attached to the surface 23a of the protective film forming film 23 with the release film 15 removed. Furthermore, the surface of the surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated is attached to a fixture such as a ring frame.

[0082] In addition, Figure 5 In the composite sheet 1E for forming a protective film shown in FIG. Figure 1 and Figure 3 In the same manner as shown, a jig adhesive layer (not shown) is laminated on the surface of the surface 12a of the adhesive layer 12 where the protective film forming film 13 is not laminated. Figure 1 and Figure 3 Similar to the composite sheet for forming a protective film shown in the figure, the composite sheet for forming a protective film 1E having such a jig adhesive layer is used in such a manner that the surface of the jig adhesive layer is attached to a jig such as a ring frame.

[0083] As described above, the composite sheet for forming a protective film of the present invention may include a jig adhesive layer regardless of the form of the support sheet and the protective film forming film. Figure 1 and Figure 3 As shown, the composite sheet for forming a protective film of the present invention having an adhesive layer for a jig preferably has an adhesive layer for a jig on a film for forming a protective film.

[0084] The composite sheet for forming a protective film of the present invention is not limited to Figures 1 to 5 The composite sheet shown in the figure can be changed or deleted without damaging the effect of the present invention. Figures 1 to 5 The composite sheet shown may be a composite sheet composed of a part of the composite sheet for forming a protective film, or may be a composite sheet in which another structure is added to the composite sheet for forming a protective film described above.

[0085] For example, in Figure 3 and Figure 4 In the composite sheet for forming a protective film shown, an intermediate layer may be provided between the substrate 11 and the protective film-forming film 13. As the intermediate layer, any intermediate layer may be selected according to the purpose.

[0086] In addition, Figure 1 , Figure 2 and Figure 5 In the composite sheet for forming a protective film shown in FIG. 1 , an intermediate layer may be provided between the substrate 11 and the adhesive layer 12. That is, in the composite sheet for forming a protective film of the present invention, the support sheet may be formed by sequentially stacking the substrate, the intermediate layer, and the adhesive layer. Here, the intermediate layer refers to the intermediate layer that can be provided between the substrate 11 and the adhesive layer 12. Figure 3 and Figure 4 The intermediate layers provided in the composite sheets for forming a protective film shown are the same intermediate layers.

[0087] also, Figures 1 to 5 The protective film-forming composite sheet shown above may include layers other than the intermediate layer at arbitrary positions.

[0088] Furthermore, in the composite sheet for forming a protective film of the present invention, a partial gap may be generated between the release film and the layer in direct contact with the release film.

[0089] Furthermore, in the composite sheet for forming a protective film of the present invention, the size and shape of each layer can be arbitrarily adjusted according to the purpose.

[0090] In the composite sheet for forming a protective film of the present invention, as described below, the layer of the support sheet directly in contact with the protective film forming film, such as the adhesive layer, is preferably non-energy ray-curable. Such a composite sheet for forming a protective film can more easily pick up a semiconductor chip having a protective film on the back side.

[0091] The support sheet can be transparent, opaque, or colored according to the purpose.

[0092] Among them, in the present invention in which the protective film forming film has energy ray curability, it is preferred that the support sheet transmits energy rays.

[0093] For example, in the support sheet, the transmittance of light with a wavelength of 375 nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. By making the transmittance of the light in such a range, when the protective film forming film is irradiated with energy rays (ultraviolet rays) through the support sheet, the curing degree of the protective film forming film is further improved.

[0094] On the other hand, in the support sheet, the upper limit of the transmittance of light having a wavelength of 375 nm is not particularly limited, and can be set to 95%, for example.

[0095] In addition, in the support sheet, the transmittance of light having a wavelength of 532 nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more.

[0096] By setting the light transmittance in such a range, when printing is performed by irradiating the protective film-forming film or the protective film with laser light through the support sheet, the printing can be performed more clearly.

[0097] On the other hand, in the support sheet, the upper limit of the transmittance of light having a wavelength of 532 nm is not particularly limited, and can be set to 95%, for example.

[0098] In addition, in the support sheet, the transmittance of light with a wavelength of 1064 nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. By setting the transmittance of the light to such a range, when the protective film forming film or the protective film is irradiated with laser through the support sheet to print on it, it is possible to print more clearly.

[0099] On the other hand, in the support sheet, the upper limit of the transmittance of light having a wavelength of 1064 nm is not particularly limited, and can be set to 95%, for example.

[0100] Next, each layer constituting the support sheet will be described in further detail.

[0101] ○Base material

[0102] The substrate is in a sheet or film shape, and examples of its constituent material include various resins.

[0103] Examples of the resin include the following: polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resins; ethylene copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylate copolymers, and ethylene-norbornene copolymers; vinyl chloride resins (copolymers obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymers; Polyesters include polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene 2,6-naphthalate, and fully aromatic polyesters in which all structural units have aromatic cyclic groups; copolymers of two or more of the above polyesters; poly(meth)acrylates; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene ethers; polyphenylene sulfides; polysulfones; polyether ketones, and the like.

[0104] In addition, examples of the resin include polymer alloys such as a mixture of the polyester and other resins. The amount of the resin other than polyester in the polymer alloy of the polyester and other resins is preferably relatively small.

[0105] Examples of the resin include crosslinked resins obtained by crosslinking one or more of the resins listed above; and modified resins such as ionomers using one or more of the resins listed above.

[0106] In addition, in this specification, "(meth)acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid.

[0107] The resin constituting the substrate may be one type or two or more types. When two or more types are used, the combination and ratio of the resins may be arbitrarily selected.

[0108] The substrate may consist of one layer (single layer) or two or more layers. When the substrate consists of multiple layers, the multiple layers may be the same as or different from each other, and the combination of the multiple layers is not particularly limited.

[0109] The thickness of the substrate is preferably 50 to 300 μm, more preferably 60 to 100 μm. When the thickness of the substrate is within such a range, the flexibility of the composite sheet for forming a protective film and the adhesion to a semiconductor wafer or a semiconductor chip are further improved.

[0110] Here, the “thickness of the substrate” refers to the thickness of the entire substrate. For example, the thickness of a substrate composed of a plurality of layers refers to the total thickness of all the layers constituting the substrate.

[0111] The substrate is preferably a substrate with high thickness accuracy, that is, a substrate in which the thickness deviation is suppressed at any position. Among the above-mentioned constituent materials, the following materials can be cited as materials that can be used to constitute such a substrate with high thickness accuracy. For example, polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, ethylene-vinyl acetate copolymer, etc.

[0112] The base material may contain various known additives such as a filler, a colorant, an antistatic agent, an antioxidant, an organic lubricant, a catalyst, and a softener (plasticizer), in addition to the above-mentioned main constituent materials such as the resin.

[0113] The optical properties of the substrate only need to satisfy the optical properties of the support sheet described above. That is, the substrate may be transparent or opaque, may be colored according to the purpose, or may have other layers deposited thereon.

[0114] Furthermore, in the present invention in which the protective film forming film has energy ray curability, it is preferred that the substrate transmits energy rays.

[0115] In order to improve the adhesion with other layers such as the adhesive layer arranged thereon, the substrate may be a substrate that has been subjected to surface embossing treatment based on sandblasting, solvent treatment, etc., corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment, and other oxidation treatments.

[0116] In addition, the substrate may also be a substrate whose surface is treated with a primer.

[0117] Furthermore, when the composite sheets for forming an antistatic coating or protective film are stacked and stored, the substrate may have a layer for preventing adhesion between the substrate and other sheets or between the substrate and the suction table.

[0118] Among them, from the viewpoint of suppressing the generation of fragments of the substrate due to friction of a blade during cutting, it is particularly preferred that the substrate be a substrate whose surface has been subjected to electron beam irradiation treatment.

[0119] The substrate can be produced by a known method. For example, a substrate containing a resin can be produced by molding a resin composition containing the resin.

[0120] ○Adhesive layer

[0121] The adhesive layer is in a sheet or film shape and contains an adhesive.

[0122] Examples of the adhesive include the following: For example, adhesive resins such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, and ester resins, and acrylic resins are preferred.

[0123] In addition, in the present invention, "adhesive resin" is a concept including both resins having adhesiveness and resins having adhesion. For example, it includes not only resins having adhesiveness itself, but also resins showing adhesiveness by using other components such as additives, or resins showing adhesiveness by the presence of triggers such as heat or water.

[0124] The adhesive layer may be composed of one layer (single layer) or may be composed of two or more layers. When composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0125] The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 1 to 60 μm, and particularly preferably 1 to 30 μm.

[0126] Here, “the thickness of the adhesive layer” refers to the thickness of the entire adhesive layer. For example, the thickness of an adhesive layer composed of a plurality of layers refers to the total thickness of all the layers constituting the adhesive layer.

[0127] The optical properties of the adhesive layer only need to satisfy the optical properties of the support sheet described above. That is, the adhesive layer may be transparent or opaque, and may be colored according to the purpose.

[0128] Furthermore, in the present invention in which the protective film forming film has energy ray curability, it is preferred that the pressure-sensitive adhesive layer transmits energy rays.

[0129] The adhesive layer may be formed using an energy-ray-curable adhesive or a non-energy-ray-curable adhesive. The adhesive layer formed using an energy-ray-curable adhesive can easily adjust the physical properties before and after curing.

[0130] <<Adhesive composition>>

[0131] An adhesive layer can be formed using an adhesive composition containing an adhesive. For example, by applying the adhesive composition on the surface of the object to be formed on the adhesive layer and drying it as needed, an adhesive layer can be formed on the target site. A more specific method for forming the adhesive layer will be described in detail later together with the method for forming other layers. The content ratio of the components in the adhesive composition that do not vaporize at room temperature is usually the same as the content ratio of the components in the adhesive layer. In addition, in this specification, "normal temperature" refers to a temperature that is not particularly cooled or heated, that is, a normal temperature. For example, a temperature of 15 to 25°C can be cited.

[0132] The adhesive composition can be applied by a known method, for example, a method using various coating machines such as an air knife coater, a blade coater, a rod coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a blade coater, a screen coater, a Meyer rod coater, and a kiss coater.

[0133] The drying conditions of the adhesive composition are not particularly limited. When the adhesive composition contains a solvent described below, it is preferably dried by heating. In this case, the drying is preferably performed at 70 to 130° C. for 10 seconds to 5 minutes, for example.

[0134] When the adhesive layer is energy-ray-curable, the following substances can be listed as adhesive compositions containing energy-ray-curable adhesives, i.e., energy-ray-curable adhesive compositions. For example, adhesive compositions (I-1) containing non-energy-ray-curable adhesive resins (I-1a) (hereinafter, sometimes abbreviated as "adhesive resin (I-1a)") and energy-ray-curable compounds; adhesive compositions (I-2) containing energy-ray-curable adhesive resins (I-2a) (hereinafter, sometimes abbreviated as "adhesive resin (I-2a)") having unsaturated groups introduced into the side chains of non-energy-ray-curable adhesive resins (I-1a); adhesive compositions (I-3) containing the adhesive resins (I-2a) and energy-ray-curable compounds, etc. can be listed.

[0135] <Adhesive composition (I-1)>

[0136] As described above, the adhesive composition (I-1) contains the non-energy ray-curable adhesive resin (I-1a) and the energy ray-curable compound.

[0137] [Adhesive resin (I-1a)]

[0138] The adhesive resin (I-1a) is preferably an acrylic resin.

[0139] Examples of the acrylic resin include acrylic polymers having at least a structural unit derived from an alkyl (meth)acrylate.

[0140] The acrylic resin may have only one type of structural unit or two or more types of structural units. When there are two or more types of structural units, the combination and ratio of these structural units may be arbitrarily selected.

[0141] Examples of the alkyl (meth)acrylate include alkyl (meth)acrylates in which the alkyl group constituting the alkyl ester has a carbon number of 1 to 20. The alkyl group is preferably linear or branched.

[0142] More specifically, the alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isooctyl (meth)acrylate, and isobutyl (meth)acrylate. Nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearate (meth)acrylate), nonadecyl (meth)acrylate, eicosyl (meth)acrylate, and the like.

[0143] From the viewpoint of improving the adhesive force of the adhesive layer, the acrylic polymer preferably has a structural unit derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 4 or more. Furthermore, from the viewpoint of further improving the adhesive force of the adhesive layer, the alkyl group preferably has 4 to 12 carbon atoms, more preferably 4 to 8 carbon atoms. Furthermore, the alkyl (meth)acrylate having an alkyl group with a carbon number of 4 or more is preferably an alkyl acrylate.

[0144] The acrylic polymer preferably further has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the (meth)acrylic acid alkyl ester.

[0145] Examples of the functional group-containing monomer include monomers that can generate a crosslinking starting point by reacting the functional group with a crosslinking agent described below, or can introduce an unsaturated group into a side chain of an acrylic polymer by reacting the functional group with an unsaturated group in an unsaturated group-containing compound described below.

[0146] Examples of the functional group in the functional group-containing monomer include a hydroxyl group, a carboxyl group, an amino group, and an epoxy group.

[0147] That is, examples of the functional group-containing monomer include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, and an epoxy group-containing monomer.

[0148] The hydroxyl-containing monomers include the following: for example, hydroxyalkyl (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and non-(meth)acrylic unsaturated alcohols (unsaturated alcohols without a (meth)acryloyl skeleton) such as vinyl alcohol and allyl alcohol.

[0149] The carboxyl group-containing monomers include the following substances, for example, ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having ethylenically unsaturated bonds) such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having ethylenically unsaturated bonds) such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; anhydrides of the ethylenically unsaturated dicarboxylic acids; (meth)acrylic acid carboxylalkyl esters such as 2-carboxyethyl methacrylate, and the like.

[0150] The functional group-containing monomer is preferably a hydroxyl group-containing monomer or a carboxyl group-containing monomer, and more preferably a hydroxyl group-containing monomer.

[0151] The functional group-containing monomer constituting the acrylic polymer may be one type or two or more types. When two or more types are used, the combination and ratio of the monomers may be arbitrarily selected.

[0152] In the acrylic polymer, the content of the structural unit derived from the functional group-containing monomer is preferably 1 to 35% by mass, more preferably 2 to 32% by mass, and particularly preferably 3 to 30% by mass, based on the total mass of the structural units.

[0153] The acrylic polymer may further have a structural unit derived from other monomers in addition to the structural unit derived from the (meth)acrylic acid alkyl ester and the structural unit derived from the functional group-containing monomer.

[0154] The other monomers are not particularly limited as long as they are copolymerizable with the (meth)acrylic acid alkyl ester and the like.

[0155] Examples of the other monomers include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

[0156] The other monomers constituting the acrylic polymer may be one type or two or more types. When two or more types are used, the combination and ratio of the other monomers may be arbitrarily selected.

[0157] The acrylic polymer can be used as the non-energy ray-curable adhesive resin (I-1a).

[0158] On the other hand, a compound containing an unsaturated group having an energy-ray-polymerizable unsaturated group (energy-ray-polymerizable group) and a functional group in the acrylic polymer react with each other can be used as the energy-ray-curable adhesive resin (I-2a).

[0159] The adhesive resin (I-1a) contained in the adhesive composition (I-1) may be one type or two or more types. When two or more types are used, the combination and ratio of these types may be arbitrarily selected.

[0160] In the adhesive composition (I-1), the content of the adhesive resin (I-1a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass.

[0161] [Energy beam curable compound]

[0162] Examples of the energy-ray-curable compound contained in the adhesive composition (I-1) include monomers or oligomers that have an energy-ray-polymerizable unsaturated group and are curable by irradiation with energy rays.

[0163] The following substances can be cited as monomers in the energy-ray curable compound, for example, poly (meth)acrylates such as trimethylolpropane tri (meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra (meth)acrylate, dipentaerythritol hexa (meth)acrylate, 1,4-butanediol di (meth)acrylate, and 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; epoxy (meth)acrylate, etc.

[0164] Examples of the oligomer in the energy-ray curable compound include oligomers obtained by polymerizing the monomers exemplified above.

[0165] The energy beam curable compound is preferably a urethane (meth)acrylate or a urethane (meth)acrylate oligomer because the molecular weight is relatively large and the storage elastic modulus of the pressure-sensitive adhesive layer is less likely to decrease.

[0166] The energy-curable compound contained in the adhesive composition (I-1) may be one kind or two or more kinds. When two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

[0167] In the adhesive composition (I-1), the content of the energy ray-curable compound is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and particularly preferably 10 to 85% by mass.

[0168] [Crosslinking agent]

[0169] When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth)acrylate is used as the adhesive resin (I-1a), the adhesive composition (I-1) preferably further contains a crosslinking agent.

[0170] The cross-linking agent cross-links the adhesive resins (I-1a) by, for example, reacting with the functional groups.

[0171] As the crosslinking agent, the following substances can be listed. For example, isocyanate crosslinking agents (crosslinking agents having an isocyanate group) such as toluene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether; triazine crosslinking agents (crosslinking agents having an aziridine group) such as hexa[1-(2-methyl)-aziridinyl]triphosphatriazine; metal chelate crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelate; isocyanurate crosslinking agents (crosslinking agents having an isocyanuric acid skeleton), etc. can be listed.

[0172] From the viewpoint of increasing the cohesive force of the adhesive to thereby increase the adhesive force of the adhesive layer and from the viewpoint of easy availability, the crosslinking agent is preferably an isocyanate crosslinking agent.

[0173] The crosslinking agent contained in the adhesive composition (I-1) may be one type or two or more types. When two or more types are used, the combination and ratio of these types may be arbitrarily selected.

[0174] In the adhesive composition (I-1), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass, based on 100 parts by mass of the adhesive resin (I-1a).

[0175] [Photopolymerization initiator]

[0176] The adhesive composition (I-1) may further contain a photopolymerization initiator. Even when the adhesive composition (I-1) containing a photopolymerization initiator is irradiated with relatively low energy rays such as ultraviolet rays, the curing reaction proceeds sufficiently.

[0177] As the photopolymerization initiator, the following substances can be listed. For example, benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin benzoic acid methyl ester, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, and 2,2-dimethoxy-1,2-diphenylethane-1-one; acylphosphine oxides such as phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide can be listed. sulfur compounds such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; α-keto alcohol compounds such as 1-hydroxycyclohexyl phenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzil; dibenzil; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone; 2-chloroanthraquinone, etc.

[0178] Furthermore, as the photopolymerization initiator, for example, quinone compounds such as 1-chloroanthraquinone, photosensitizers such as amines, and the like can be used.

[0179] The photopolymerization initiator contained in the adhesive composition (I-1) may be one kind or two or more kinds. When two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

[0180] In the adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the energy ray-curable compound.

[0181] [Other additives]

[0182] The adhesive composition (I-1) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.

[0183] Examples of the other additives include known additives such as antistatic agents, antioxidants, softeners (plasticizers), fillers (fillers), rust inhibitors, colorants (pigments, dyes), sensitizers, thickeners, reaction retarders, and crosslinking accelerators (catalysts).

[0184] In addition, the reaction retarder refers to an additive that suppresses the unintended crosslinking reaction in the adhesive composition (I-1) during storage, for example, by the action of a catalyst mixed in the adhesive composition (I-1). As a reaction retarder, for example, a reaction retarder that forms a chelate complex using a chelate corresponding to the catalyst can be listed. More specifically, a reaction retarder having two or more carbonyl groups (-C(=O)-) in one molecule can be listed.

[0185] The adhesive composition (I-1) may contain only one type of other additives or two or more types of other additives. When there are two or more types of other additives, the combination and ratio thereof may be arbitrarily selected.

[0186] In the adhesive composition (I-1), the content of other additives is not particularly limited and may be appropriately selected depending on the type of the additive.

[0187] [Solvent]

[0188] The adhesive composition (I-1) may contain a solvent. The adhesive composition (I-1) contains a solvent to improve the coating suitability on the surface of the coating object.

[0189] The solvent is preferably an organic solvent. Examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; esters (carboxylates) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

[0190] As the solvent, for example, the solvent used in the manufacture of the adhesive resin (I-1a) can be used directly in the adhesive composition (I-1) without removing it from the adhesive resin (I-1a). In addition, a solvent of the same type or a different type as the solvent used in the manufacture of the adhesive resin (I-1a) can be added when preparing the adhesive composition (I-1).

[0191] The solvent contained in the adhesive composition (I-1) may be only one kind or two or more kinds. When two or more kinds are used, the combination and ratio of these solvents may be arbitrarily selected.

[0192] In the adhesive composition (I-1), the content of the solvent is not particularly limited and can be appropriately adjusted.

[0193] <Adhesive composition (I-2)>

[0194] As described above, the adhesive composition (I-2) contains an energy-ray-curable adhesive resin (I-2a) in which an unsaturated group is introduced into the side chain of a non-energy-ray-curable adhesive resin (I-1a).

[0195] [Adhesive resin (I-2a)]

[0196] For example, the adhesive resin (I-2a) can be obtained by reacting an unsaturated group-containing compound having an energy ray-polymerizable unsaturated group with a functional group in the adhesive resin (I-1a).

[0197] The unsaturated group-containing compound is a compound having, in addition to the energy-ray-polymerizable unsaturated group, a group capable of bonding to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a).

[0198] Examples of the energy beam polymerizable unsaturated group include a (meth)acryloyl group, a vinyl (ethylene) group, an allyl (2-propenyl) group, and the like, and a (meth)acryloyl group is preferred.

[0199] Examples of the group that can be bonded to the functional group in the adhesive resin (I-1a) include an isocyanate group and a glycidyl group that can be bonded to a hydroxyl group or an amino group, and a hydroxyl group and an amino group that can be bonded to a carboxyl group or an epoxy group.

[0200] Examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

[0201] The adhesive resin (I-2a) contained in the adhesive composition (I-2) may be one type or two or more types. When two or more types are used, the combination and ratio of these types may be arbitrarily selected.

[0202] In the adhesive composition (I-2), the content of the adhesive resin (I-2a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 10 to 90% by mass.

[0203] [Crosslinking agent]

[0204] For example, when the acrylic polymer having a structural unit derived from a functional group-containing monomer similar to that in the adhesive resin (I-1a) is used as the adhesive resin (I-2a), the adhesive composition (I-2) preferably further contains a crosslinking agent.

[0205] Examples of the cross-linking agent in the adhesive composition (I-2) include the same cross-linking agents as those in the adhesive composition (I-1).

[0206] The crosslinking agent contained in the adhesive composition (I-2) may be one type or two or more types. When two or more types are used, the combination and ratio of the crosslinking agents may be arbitrarily selected.

[0207] In the adhesive composition (I-2), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass, based on 100 parts by mass of the adhesive resin (I-2a).

[0208] [Photopolymerization initiator]

[0209] The adhesive composition (I-2) may further contain a photopolymerization initiator. Even when the adhesive composition (I-2) containing a photopolymerization initiator is irradiated with relatively low energy rays such as ultraviolet rays, the curing reaction proceeds sufficiently.

[0210] Examples of the photopolymerization initiator in the adhesive composition (I-2) include the same photopolymerization initiators as those in the adhesive composition (I-1).

[0211] The photopolymerization initiator contained in the adhesive composition (I-2) may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of these can be arbitrarily selected.

[0212] In the adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the adhesive resin (I-2a).

[0213] [Other additives]

[0214] The adhesive composition (I-2) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.

[0215] Examples of the other additives in the adhesive composition (I-2) include the same additives as those in the adhesive composition (I-1).

[0216] The adhesive composition (I-2) may contain only one type of other additives or two or more types of other additives. When there are two or more types of other additives, the combination and ratio thereof may be arbitrarily selected.

[0217] In the adhesive composition (I-2), the content of other additives is not particularly limited and may be appropriately selected depending on the type of the additive.

[0218] [Solvent]

[0219] The adhesive composition (I-2) may contain a solvent for the same purpose as in the case of the adhesive composition (I-1).

[0220] Examples of the solvent in the adhesive composition (I-2) include the same solvents as those in the adhesive composition (I-1).

[0221] The solvent contained in the adhesive composition (I-2) may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of these solvents may be arbitrarily selected.

[0222] In the adhesive composition (I-2), the content of the solvent is not particularly limited and can be appropriately adjusted.

[0223] <Adhesive composition (I-3)>

[0224] As described above, the adhesive composition (I-3) contains the adhesive resin (I-2a) and an energy-ray-curable compound.

[0225] In the adhesive composition (I-3), the content of the adhesive resin (I-2a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass.

[0226] [Energy beam curable compound]

[0227] As the energy-ray curable compound contained in the adhesive composition (I-3), a monomer or oligomer having an energy-ray polymerizable unsaturated group and curable by irradiation with energy rays can be listed. In addition, the same energy-ray curable compound as the energy-ray curable compound contained in the adhesive composition (I-1) can be listed.

[0228] The energy-ray curable compound contained in the adhesive composition (I-3) may be one kind or two or more kinds. When two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

[0229] In the adhesive composition (I-3), the content of the energy ray-curable compound is preferably 0.01 to 300 parts by mass, more preferably 0.03 to 200 parts by mass, and particularly preferably 0.05 to 100 parts by mass, relative to 100 parts by mass of the adhesive resin (I-2a).

[0230] [Photopolymerization initiator]

[0231] The adhesive composition (I-3) may further contain a photopolymerization initiator. Even when the adhesive composition (I-3) containing a photopolymerization initiator is irradiated with relatively low energy rays such as ultraviolet rays, the curing reaction proceeds sufficiently.

[0232] Examples of the photopolymerization initiator in the adhesive composition (I-3) include the same photopolymerization initiators as those in the adhesive composition (I-1).

[0233] The photopolymerization initiator contained in the adhesive composition (I-3) may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of these can be arbitrarily selected.

[0234] In the adhesive composition (I-3), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the total content of the adhesive resin (I-2a) and the energy ray-curable compound.

[0235] [Other additives]

[0236] The adhesive composition (I-3) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.

[0237] Examples of the other additives include the same additives as those in the adhesive composition (I-1).

[0238] The adhesive composition (I-3) may contain only one type of other additives or two or more types of other additives. When there are two or more types of other additives, the combination and ratio thereof may be arbitrarily selected.

[0239] In the adhesive composition (I-3), the content of other additives is not particularly limited and may be appropriately selected depending on the type of the additive.

[0240] [Solvent]

[0241] The adhesive composition (I-3) may contain a solvent for the same purpose as in the case of the adhesive composition (I-1).

[0242] Examples of the solvent in the adhesive composition (I-3) include the same solvents as those in the adhesive composition (I-1).

[0243] The solvent contained in the adhesive composition (I-3) may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of these can be arbitrarily selected.

[0244] In the adhesive composition (I-3), the content of the solvent is not particularly limited and can be appropriately adjusted.

[0245] <Adhesive compositions other than adhesive compositions (I-1) to (I-3)>

[0246] So far, adhesive composition (I-1), adhesive composition (I-2) and adhesive composition (I-3) have been mainly described. However, the substances described as their contained components can also be used in all adhesive compositions other than these three adhesive compositions (referred to as "adhesive compositions other than adhesive compositions (I-1) to (I-3)" in this specification).

[0247] As adhesive compositions other than the adhesive compositions (I-1) to (I-3), in addition to energy-ray-curable adhesive compositions, non-energy-ray-curable adhesive compositions can be mentioned.

[0248] As non-energy ray-curable adhesive compositions, the following substances can be listed. For example, adhesive compositions (I-4) containing non-energy ray-curable adhesive resins (I-1a) such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, and ester resins can be listed. Among them, non-energy ray-curable adhesive compositions containing acrylic resins are preferred.

[0249] It is preferred that the adhesive compositions other than the adhesive compositions (I-1) to (I-3) contain one or more crosslinking agents, and the content thereof can be set to be the same as in the case of the above-mentioned adhesive composition (I-1) and the like.

[0250] <Adhesive composition (I-4)>

[0251] As a preferable adhesive composition (I-4), an adhesive composition containing the said adhesive resin (I-1a) and a crosslinking agent is mentioned, for example.

[0252] [Adhesive resin (I-1a)]

[0253] Examples of the adhesive resin (I-1a) in the adhesive composition (I-4) include the same adhesive resins (I-1a) as those in the adhesive composition (I-1).

[0254] The adhesive resin (I-1a) contained in the adhesive composition (I-4) may be one type or two or more types. When two or more types are used, the combination and ratio of these types may be arbitrarily selected.

[0255] In the adhesive composition (I-4), the content of the adhesive resin (I-1a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass.

[0256] [Crosslinking agent]

[0257] When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth)acrylate is used as the adhesive resin (I-1a), the adhesive composition (I-4) preferably further contains a crosslinking agent.

[0258] Examples of the cross-linking agent in the adhesive composition (I-4) include the same cross-linking agents as those in the adhesive composition (I-1).

[0259] The crosslinking agent contained in the adhesive composition (I-4) may be one type or two or more types. When two or more types are used, the combination and ratio of the crosslinking agents may be arbitrarily selected.

[0260] In the adhesive composition (I-4), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass, based on 100 parts by mass of the adhesive resin (I-1a).

[0261] [Other additives]

[0262] The adhesive composition (I-4) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.

[0263] Examples of the other additives include the same additives as those in the adhesive composition (I-1).

[0264] The adhesive composition (I-4) may contain other additives of one kind or of two or more kinds. When there are two or more kinds, the combination and ratio of these additives may be arbitrarily selected.

[0265] In the adhesive composition (I-4), the content of other additives is not particularly limited and may be appropriately selected depending on the type of the additive.

[0266] [Solvent]

[0267] The adhesive composition (I-4) may contain a solvent for the same purpose as in the case of the adhesive composition (I-1).

[0268] Examples of the solvent in the adhesive composition (I-4) include the same solvents as those in the adhesive composition (I-1).

[0269] The adhesive composition (I-4) may contain only one type of solvent or two or more types of solvent. When there are two or more types of solvent, the combination and ratio of these solvents may be arbitrarily selected.

[0270] In the adhesive composition (I-4), the content of the solvent is not particularly limited and can be appropriately adjusted.

[0271] In the composite sheet for forming a protective film of the present invention, it is preferred that the adhesive layer is non-energy ray curable. This is because, if the adhesive layer is energy ray curable, when the protective film forming film is cured by irradiation with energy rays, the simultaneous curing of the adhesive layer cannot be suppressed. If the adhesive layer and the protective film forming film are cured at the same time, the cured protective film forming film and the adhesive layer will be attached to the extent that they cannot be peeled off at their interface. At this time, it is difficult to peel off a semiconductor chip having a cured protective film forming film, i.e., a protective film on the back (sometimes referred to as a "semiconductor chip with a protective film" in this specification) from a support sheet having a cured adhesive layer. As a result, the semiconductor chip with a protective film cannot be picked up normally. For the support sheet of the present invention, by making the adhesive layer non-energy ray curable, such an undesirable condition can be accurately avoided, and the semiconductor chip with a protective film can be picked up more easily.

[0272] Here, the effect when the adhesive layer is non-energy ray curable is described. However, even if the layer of the support sheet directly contacting the protective film forming film is a layer other than the adhesive layer, the same effect can be exerted as long as the layer is non-energy ray curable.

[0273] <<Method for preparing adhesive composition>>

[0274] By blending the adhesive and, if necessary, components other than the adhesive, etc., which are used to constitute the adhesive composition, an adhesive composition other than the adhesive compositions (I-1) to (I-3) such as the adhesive composition (I-4) can be obtained.

[0275] The order of adding the components when blending them is not particularly limited, and two or more components may be added simultaneously.

[0276] When a solvent is used, the solvent may be mixed with any blending component other than the solvent to pre-dilute the blending component before use. Alternatively, the solvent may be mixed with the blending component without pre-diluting any blending component other than the solvent.

[0277] The method for mixing the components during blending is not particularly limited, and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer or a stirring blade, a method of mixing by using a blender, a method of mixing by applying ultrasonic waves, and the like.

[0278] The temperature and time for adding and mixing the components are not particularly limited as long as the components do not deteriorate, and may be appropriately adjusted. The temperature is preferably 15 to 30°C.

[0279] ◎Film for protective film formation

[0280] In the present invention, the adhesion between the protective film obtained by curing the protective film forming film and the support sheet is preferably 50~1500mN / 25mm, more preferably 52~1450mN / 25mm, and further preferably 53~1430mN / 25mm. By making the adhesion above the lower limit, when picking up a semiconductor chip with a protective film, the picking up of a non-target semiconductor chip with a protective film can be suppressed. As a result, the semiconductor chip with a protective film as the target can be picked up with high selectivity. In addition, by making the adhesion below the upper limit, when picking up a semiconductor chip with a protective film, the cracking and defect of the semiconductor chip can be suppressed. In this way, by making the adhesion within a specific range, the composite sheet for protective film formation has good pickup suitability.

[0281] In the present invention, even after the protective film forming film is cured, as long as the stacked structure of the support sheet and the cured product of the protective film forming film (in other words, the support sheet and the protective film) is maintained, the stacked structure is referred to as a "composite sheet for protective film formation".

[0282] The adhesive force between the protective film and the support sheet was measured by the following method.

[0283] That is, a composite sheet for forming a protective film having a width of 25 mm and an arbitrary length is attached to an adherend via the protective film forming film.

[0284] Next, the protective film is cured by irradiating energy rays to form a protective film. Then, the support sheet is peeled off from the protective film attached to the adherend at a peeling speed of 300 mm / min. The peeling at this time is set to the so-called 180° peeling, that is, the support sheet is peeled off along its length direction (the length direction of the composite sheet for forming the protective film) in such a way that the surfaces where the protective film and the support sheet are in contact with each other are at an angle of 180° to each other. Then, the load (peeling force) during the 180° peeling is measured, and the measured value is used as the adhesion (mN / 25mm).

[0285] The length of the composite sheet for forming a protective film to be measured is not particularly limited as long as it is within the range in which the adhesive force can be stably detected, and is preferably 100 to 300 mm. In addition, during the measurement, it is preferred that the composite sheet for forming a protective film is attached to the adherend and the attached state of the composite sheet for forming a protective film is stabilized.

[0286] In the present invention, the adhesion between the protective film forming film and the support sheet is not particularly limited. For example, it can be 80mN / 25mm or more, preferably 100mN / 25mm or more. More preferably, it is 150mN / 25mm or more, and particularly preferably 200mN / 25mm or more. By making the adhesion force 100mN / 25mm or more, the peeling of the protective film forming film and the support sheet can be suppressed during cutting. As a result, for example, a semiconductor chip having a protective film forming film on the back side can be suppressed from flying off the support sheet.

[0287] On the other hand, the upper limit of the adhesive force between the protective film forming film and the support sheet is not particularly limited. For example, it can be set to any one of 4000mN / 25mm, 3500mN / 25mm, 3000mN / 25mm, etc. However, these are only examples.

[0288] The adhesion between the protective film forming film and the supporting sheet can be measured by the same method as the above-mentioned adhesion between the protective film and the supporting sheet, except that the protective film forming film to be measured is not cured by irradiation with energy rays.

[0289] The adhesion between the protective film and the support sheet, and the adhesion between the protective film forming film and the support sheet can be appropriately adjusted. For example, it can be appropriately adjusted by adjusting the type and amount of components contained in the protective film forming film, the constituent material of the layer on the support sheet where the protective film forming film is provided, and the surface state of the layer.

[0290] For example, the type and amount of the components of the protective film-forming film can be adjusted by the type and amount of the components of the protective film-forming composition described later. In addition, by adjusting the type and content of the polymer (b) having no energy ray curable group, the content of the filler (d), or the content of the crosslinking agent (f) in the components of the protective film-forming composition, it is possible to more easily adjust the adhesion between the protective film or the protective film-forming film and the support sheet.

[0291] In addition, for example, when the layer provided with the protective film forming film in the support sheet is an adhesive layer, the constituent material thereof can be appropriately adjusted by adjusting the type and amount of the components contained in the adhesive layer. Furthermore, the type and amount of the components contained in the adhesive layer can be adjusted by the type and amount of the components contained in the above-mentioned adhesive composition.

[0292] On the other hand, when the layer provided with the protective film forming film in the support sheet is a substrate, the adhesion between the protective film or the protective film forming film and the support sheet can be adjusted by the surface state of the substrate in addition to being adjusted by the constituent material of the substrate. Moreover, the surface state of the substrate can be adjusted by, for example, implementing the following treatments. For example, the surface treatment listed above as a surface treatment to improve the adhesion between the substrate and other layers, that is, a convexo-convex treatment based on sandblasting, solvent treatment, etc.; an oxidation treatment such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment; any one of primer treatment, etc.

[0293] The protective film forming film has energy ray curability. For example, the protective film forming film includes an energy ray curable component (a) and a photoradical initiator (c′).

[0294] The energy ray-curable component (a) is preferably uncured, preferably has adhesiveness, and more preferably is uncured and has adhesiveness.

[0295] The protective film-forming film may be a single layer (monolayer) or a plurality of layers of two or more. In the case of a plurality of layers, the plurality of layers may be the same as or different from each other, and the combination of the plurality of layers is not particularly limited.

[0296] The thickness of the protective film forming film is preferably 1 to 100 μm, more preferably 5 to 75 μm, and particularly preferably 5 to 50 μm. By making the thickness of the protective film forming film above the lower limit, a protective film with higher protective ability can be formed. In addition, by making the thickness of the protective film forming film below the upper limit, the thickness can be suppressed from becoming excessive.

[0297] Here, the “thickness of the protective film forming film” refers to the thickness of the entire protective film forming film. For example, the thickness of a protective film forming film composed of a plurality of layers refers to the total thickness of all the layers constituting the protective film forming film.

[0298] The curing conditions when the protective film is cured to form the protective film are not particularly limited as long as the protective film has a degree of curing to a degree that allows the protective film to fully exhibit its function, and may be appropriately selected depending on the type of the protective film.

[0299] For example, the illuminance of the energy ray when curing the protective film-forming film is preferably 4 to 280 mW / cm 2 The amount of energy ray during curing is preferably 3 to 1000 mJ / cm 2 .

[0300] <<Protective film forming composition>>

[0301] The protective film-forming film can be formed using a protective film-forming composition containing its constituent materials. For example, by applying the protective film-forming composition on the surface of the protective film-forming film to be formed and drying as needed, the protective film-forming film can be formed at the target site. The content ratio of the components in the protective film-forming composition that do not vaporize at room temperature is usually the same as the content ratio of the components in the protective film-forming film. Here, "room temperature" is the same as described above.

[0302] The protective film-forming composition may be applied by a known method, for example, a method using various coaters such as an air knife coater, a blade coater, a rod coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, a Meyer rod coater, and a kiss coater.

[0303] The drying conditions of the protective film forming composition are not particularly limited. However, when the protective film forming composition contains a solvent described below, it is preferably dried by heating. In this case, the drying is preferably performed at 70 to 130° C. for 10 seconds to 5 minutes, for example.

[0304] <Protective film forming composition (IV-1)>

[0305] Examples of the protective film-forming composition include a protective film-forming composition (IV-1) containing the energy ray-curable component (a) and a photoradical initiator (c′).

[0306] [Energy beam curable component (a)]

[0307] The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and is also a component for imparting film-forming properties, flexibility, and the like to the film for forming a protective film.

[0308] Examples of the energy-ray curable component (a) include a polymer (a1) having an energy-ray curable group and having a weight average molecular weight of 80,000 to 2,000,000, and a compound (a2) having an energy-ray curable group and having a molecular weight of 100 to 80,000. The polymer (a1) may be at least partially cross-linked with a cross-linking agent (f) described below, or may be uncross-linked.

[0309] In addition, in this specification, unless otherwise specified, the weight average molecular weight means a polystyrene conversion value measured by gel permeation chromatography (GPC) method.

[0310] (Polymer (a1) having an energy ray curable group and a weight average molecular weight of 80,000 to 2,000,000)

[0311] The polymer (a1) having an energy-ray curable group and a weight average molecular weight of 80,000 to 2,000,000 can be exemplified by the following: For example, an acrylic resin (a1-1) obtained by polymerizing an acrylic polymer (a11) having a functional group that can react with a group possessed by another compound and an energy-ray curable compound (a12) having an energy-ray curable group such as a group that reacts with the functional group and an energy-ray curable double bond can be exemplified.

[0312] Examples of the functional group that can react with groups possessed by other compounds include hydroxyl, carboxyl, amino, substituted amino (a group in which one or two hydrogen atoms of an amino group are replaced by groups other than hydrogen atoms), epoxy, etc. Among them, from the perspective of preventing corrosion of circuits such as semiconductor wafers or semiconductor chips, it is preferred that the functional group is a group other than a carboxyl group.

[0313] Among them, it is preferred that the functional group is a hydroxyl group.

[0314] Acrylic polymer having functional groups (a11)

[0315] Examples of the acrylic polymer (a11) having a functional group include a polymer obtained by copolymerizing an acrylic monomer having the functional group and an acrylic monomer not having the functional group, and a polymer obtained by copolymerizing a monomer other than the acrylic monomer (non-acrylic monomer) in addition to these monomers.

[0316] Furthermore, the acrylic polymer (a11) may be a random copolymer or a block copolymer.

[0317] Examples of the acrylic monomer having the functional group include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, a substituted amino group-containing monomer, and an epoxy group-containing monomer.

[0318] The hydroxyl-containing monomers include the following: for example, hydroxyalkyl (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and non-(meth)acrylic unsaturated alcohols (unsaturated alcohols without a (meth)acryloyl skeleton) such as vinyl alcohol and allyl alcohol.

[0319] The carboxyl group-containing monomers include the following substances, for example, ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having ethylenically unsaturated bonds) such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having ethylenically unsaturated bonds) such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; anhydrides of the ethylenically unsaturated dicarboxylic acids; (meth)acrylic acid carboxylalkyl esters such as 2-carboxyethyl methacrylate, and the like.

[0320] The acrylic monomer having the functional group is preferably a hydroxyl group-containing monomer or a carboxyl group-containing monomer, and more preferably a hydroxyl group-containing monomer.

[0321] The acrylic monomer having the functional group constituting the acrylic polymer (a11) may be one type or two or more types. When two or more types are used, the combination and ratio of the two types may be arbitrarily selected.

[0322] Examples of acrylic monomers not having the functional group include the following. For example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, and tert-butyl (meth)acrylate. (meth)acrylate alkyl esters in which the alkyl group constituting the alkyl ester is a chain structure having 1 to 18 carbon atoms, such as undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearate (meth)acrylate), and the like.

[0323] In addition, as acrylic monomers not having the above functional groups, the following substances can be listed. For example, alkoxyalkyl-containing (meth)acrylates such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; (meth)acrylates having aromatic groups such as (meth)acrylate aryl esters such as (meth)acrylate phenyl; non-crosslinking (meth)acrylamide and its derivatives; non-crosslinking (meth)acrylates having tertiary amino groups such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate, etc. can also be listed.

[0324] The acrylic monomer having no functional group constituting the acrylic polymer (a11) may be one type or two or more types. When two or more types are used, the combination and ratio of the two types may be arbitrarily selected.

[0325] Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

[0326] The non-acrylic monomer constituting the acrylic polymer (a11) may be one type or two or more types. When two or more types are used, the combination and ratio of the non-acrylic monomers may be arbitrarily selected.

[0327] In the acrylic polymer (a11), the ratio (content) of the amount of the structural unit derived from the acrylic monomer having the functional group relative to the total amount of the structural units constituting the polymer is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and particularly preferably 3 to 30% by mass. By making the ratio within such a range, the content of the energy-ray curable group in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy-ray curable compound (a12) can easily adjust the degree of curing of the first protective film to a preferred range.

[0328] The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be one type or two or more types. When two or more types are used, the combination and ratio of the two types may be arbitrarily selected.

[0329] In the protective film-forming composition (IV-1), the content of the acrylic resin (a1-1) is preferably 1 to 40% by mass, more preferably 2 to 30% by mass, and particularly preferably 3 to 20% by mass.

[0330] Energy ray curable compound (a12)

[0331] The energy-ray curable compound (a12) preferably has one or more selected from the group consisting of an isocyanate group, an epoxy group, and a carboxyl group as a group that can react with the functional group possessed by the acrylic polymer (a11), and more preferably has an isocyanate group as the group. For example, when the energy-ray curable compound (a12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

[0332] The energy ray curable compound (a12) preferably has 1 to 5 energy ray curable groups in one molecule, and more preferably has 1 to 3 energy ray curable groups in one molecule.

[0333] Examples of the energy-ray-curable compound (a12) include the following: 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate;

[0334] Acryloyl monoisocyanate compounds obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate;

[0335] Acryloyl monoisocyanate compounds obtained by reaction of a diisocyanate compound or a polyisocyanate compound, a polyol compound, and hydroxyethyl (meth)acrylate, and the like.

[0336] Among them, it is preferred that the energy ray curable compound (a12) is 2-methacryloyloxyethyl isocyanate.

[0337] The energy-ray curable compound (a12) constituting the acrylic resin (a1-1) may be one type or two or more types. When two or more types are used, the combination and ratio of these types may be arbitrarily selected.

[0338] In the acrylic resin (a1-1), the content of the energy-ray curable group from the energy-ray curable compound (a12) relative to the content of the functional group from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. By making the ratio of the content such a range, the adhesive force of the protective film formed by curing becomes greater. In addition, when the energy-ray curable compound (a12) is a monofunctional (having 1 group in 1 molecule) compound, the upper limit of the ratio of the content is 100 mol%. However, when the energy-ray curable compound (a12) is a multifunctional (having more than 2 groups in 1 molecule) compound, the upper limit of the ratio of the content is sometimes greater than 100 mol%.

[0339] The weight average molecular weight (Mw) of the polymer (a1) is preferably 100,000 to 2,000,000, and more preferably 300,000 to 1,500,000.

[0340] When the polymer (a1) is a substance in which at least a part is crosslinked by a crosslinking agent (f), the polymer (a1) may be a polymer obtained by copolymerizing a monomer which is not any of the monomers described above as monomers constituting the acrylic polymer (a11) and has a group reactive with the crosslinking agent (f), and crosslinking at the group reactive with the crosslinking agent (f). In addition, the polymer may be a polymer obtained by crosslinking at a group reactive with the functional group derived from the energy ray curable compound (a12).

[0341] The polymer (a1) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of the polymers may be arbitrarily selected.

[0342] (Compound (a2) having an energy ray curable group and a molecular weight of 100 to 80,000)

[0343] The energy-curable group of the compound (a2) having a molecular weight of 100 to 80000 and having an energy-curable group includes a group containing an energy-curable double bond, and preferred groups include a (meth)acryloyl group and a vinyl group.

[0344] The compound (a2) is not particularly limited as long as it satisfies the above conditions, and examples thereof include low molecular weight compounds having an energy-ray curable group, epoxy resins having an energy-ray curable group, and phenol resins having an energy-ray curable group.

[0345] Examples of the low molecular weight compound having an energy ray curable group in the compound (a2) include polyfunctional monomers and oligomers, and an acrylate compound having a (meth)acryloyl group is preferred.

[0346] Examples of the acrylic acid ester compounds include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloyloxypolypropoxy)phenyl]propane, tricyclodecane dimethanol di(meth)acrylate (tricyclodecane dihydroxymethyl di(meth)acrylate), 1,10 - difunctional (meth)acrylates such as decanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and 2-hydroxy-1,3-di(meth)acryloyloxypropane;

[0347] Multifunctional (meth)acrylates such as tris(2-(meth)acryloyloxyethyl)isocyanurate, ε-caprolactone-modified tris(2-(meth)acryloyloxyethyl)isocyanurate, ethoxylated glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and dipentaerythritol hexa(meth)acrylate;

[0348] Polyfunctional (meth)acrylate oligomers such as urethane (meth)acrylate oligomers, and the like.

[0349] As the epoxy resin having an energy-ray curable group and the phenol resin having an energy-ray curable group in the compound (a2), for example, the resin described in paragraph 0043 of "Japanese Patent Publication No. 2013-194102" can be used. Such a resin is also equivalent to the resin constituting the thermosetting component (h) described later, but it is regarded as the compound (a2) in the present invention.

[0350] The weight average molecular weight of the compound (a2) is preferably 100 to 30,000, more preferably 300 to 10,000.

[0351] The compound (a2) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of the compounds may be arbitrarily selected.

[0352] [Polymer (b) Not Having an Energy-Ray Curable Group]

[0353] When the protective film-forming composition (IV-1) and the protective film-forming film contain the compound (a2) as the energy-ray-curable component (a), it is preferred that they further contain a polymer (b) having no energy-ray-curable group.

[0354] The polymer (b) may be at least partially cross-linked by a cross-linking agent (f), or may be uncross-linked.

[0355] Examples of the polymer (b) having no energy-ray-curable group include the following: for example, acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber resins, acrylic urethane resins, polyvinyl alcohol (PVA), butyral resins, polyester urethane resins, and the like.

[0356] Among them, the polymer (b) is preferably an acrylic polymer (hereinafter, sometimes abbreviated as "acrylic polymer (b-1)").

[0357] The acrylic polymer (b-1) may be a known acrylic polymer, and the following may be mentioned. For example, it may be a homopolymer of one acrylic monomer, a copolymer of two or more acrylic monomers, or a copolymer of one or more acrylic monomers and one or more monomers other than acrylic monomers (non-acrylic monomers).

[0358] The acrylic monomers constituting the acrylic polymer (b-1) include the following. For example, alkyl (meth)acrylates, (meth)acrylates having a cyclic skeleton, (meth)acrylates containing a glycidyl group, (meth)acrylates containing a hydroxyl group, (meth)acrylates containing a substituted amino group, etc. Here, the "substituted amino group" is the same as described above.

[0359] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, and tert-butyl (meth)acrylate. (meth)acrylate alkyl esters in which the alkyl group constituting the alkyl ester is a chain structure having 1 to 18 carbon atoms, such as undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearate (meth)acrylate), and the like.

[0360] Examples of the (meth)acrylate having a cyclic skeleton include the following: (meth)acrylate cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentyl (meth)acrylate;

[0361] Aralkyl (meth)acrylates such as benzyl (meth)acrylate;

[0362] Cycloalkenyl (meth)acrylates such as dicyclopentenyl (meth)acrylate;

[0363] Cycloalkenyloxyalkyl (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate and the like.

[0364] Examples of the glycidyl group-containing (meth)acrylate include glycidyl (meth)acrylate and the like.

[0365] Examples of the hydroxyl-containing (meth)acrylate include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0366] Examples of the substituted amino group-containing (meth)acrylate include N-methylaminoethyl (meth)acrylate and the like.

[0367] Examples of the non-acrylic monomer constituting the acrylic polymer (b-1) include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

[0368] Examples of the polymer (b) having no energy ray-curable group and at least partially crosslinked by the crosslinking agent (f) include a polymer obtained by reaction of a reactive functional group in the polymer (b) with the crosslinking agent (f).

[0369] The reactive functional group can be appropriately selected according to the type of crosslinking agent (f), etc., and is not particularly limited. For example, when the crosslinking agent (f) is a polyisocyanate compound, as the reactive functional group, hydroxyl, carboxyl, amino, etc. can be listed, wherein preferably a hydroxyl with high reactivity with an isocyanate group. In addition, when the crosslinking agent (f) is an epoxy compound, as the reactive functional group, carboxyl, amino, amide, etc. can be listed, wherein preferably a carboxyl with high reactivity with an epoxy group. However, in terms of preventing corrosion of the circuit of a semiconductor wafer or a semiconductor chip, it is preferred that the functional group is a group other than a carboxyl group.

[0370] As the polymer (b) having the reactive functional group and not having an energy-ray curable group, for example, a polymer obtained by polymerizing a monomer having at least the reactive functional group can be cited. In the case of an acrylic polymer (b-1), any one or both of the acrylic monomers and non-acrylic monomers listed as monomers constituting the acrylic polymer (b-1) using a monomer having the reactive functional group can be used. For example, as the polymer (b) having a hydroxyl group as a reactive functional group, for example, a polymer obtained by polymerizing a hydroxyl-containing (meth) acrylate can be cited. In addition, in addition to this, a polymer obtained by polymerizing a monomer in which one or more hydrogen atoms in the acrylic monomer or non-acrylic monomer listed above are substituted with the reactive functional group can be cited.

[0371] In the polymer (b) having a reactive functional group, the ratio (content) of the amount of the structural unit derived from the monomer having a reactive functional group to the total amount of the structural units constituting the polymer (b) is preferably 1 to 25% by mass, more preferably 2 to 20% by mass. By making the ratio within such a range, the degree of crosslinking in the polymer (b) is within a more preferred range.

[0372] The weight average molecular weight (Mw) of the polymer (b) having no energy ray curable group is preferably 10,000 to 2,000,000, more preferably 100,000 to 1,500,000, from the viewpoint of better film forming properties of the protective film forming composition (IV-1).

[0373] The polymer (b) having no energy ray curable group contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one type or two or more types. When two or more types are used, the combination and ratio thereof may be arbitrarily selected.

[0374] As the protective film forming composition (IV-1), a protective film forming composition containing any one or both of the polymer (a1) and the compound (a2) can be cited. Moreover, when containing the compound (a2), it is preferred that the protective film forming composition (IV-1) further contains a polymer (b) having no energy ray curable group. At this time, it is also preferred to further contain the (a1). In addition, the protective film forming composition (IV-1) may not contain the compound (a2) but contain the polymer (a1) and the polymer (b) having no energy ray curable group.

[0375] When the protective film forming composition (IV-1) contains the polymer (a1), the compound (a2) and the polymer (b) having no energy ray curable group, in the protective film forming composition (IV-1), the content of the compound (a2) is preferably 10 to 400 parts by mass, and more preferably 30 to 350 parts by mass, relative to 100 parts by mass of the total content of the polymer (a1) and the polymer (b) having no energy ray curable group.

[0376] In the protective film-forming composition (IV-1), the total content of the energy-ray curable component (a) and the polymer (b) having no energy-ray curable group (i.e., the total content of the energy-ray curable component (a) and the polymer (b) having no energy-ray curable group in the protective film-forming film) is preferably 5 to 90% by mass, more preferably 10 to 80% by mass, and particularly preferably 15 to 70% by mass relative to the total content of the components other than the solvent. By making the total content ratio within such a range, the energy-ray curability of the protective film-forming film becomes better.

[0377] When the protective film forming composition (IV-1) contains the energy ray curable component (a) and the polymer (b) having no energy ray curable group, in the protective film forming composition (IV-1) and the protective film forming film, the content of the polymer (b) is preferably 3 to 160 parts by mass, more preferably 6 to 130 parts by mass, relative to 100 parts by mass of the content of the energy ray curable component (a). By setting the content of the polymer (b) to such a range, the energy ray curability of the protective film forming film becomes better.

[0378] In addition to containing an energy-ray curable component (a) and a polymer (b) without an energy-ray curable group, the protective film-forming composition (IV-1) may also contain one or more selected from the group consisting of a photopolymerization initiator (c), a filler (d), a coupling agent (e), a cross-linking agent (f), a colorant (g), a thermosetting component (h), and a general additive (z) according to the purpose. For example, by using a protective film-forming composition (IV-1) containing the energy-ray curable component (a) and the thermosetting component (h), the adhesion of the formed protective film-forming film to the adherend is increased by heating. Furthermore, the strength of the protective film formed by the protective film-forming film is also improved.

[0379] [Photoradical initiator (c')]

[0380] The extinction coefficient of the photoradical initiator used in the protective film forming composition of the present invention at a wavelength of 365 nm is 4.0×10 1 ml / (g·cm) or more (in this specification, sometimes referred to as "photoradical initiator (c')".

[0381] As a photoradical initiator (c'), as long as the absorption coefficient of the wavelength 365nm is 4.0×10 1 The content is not particularly limited as long as it is ml / (g·cm) or more.

[0382] Examples of the photoradical initiator (c') include the following. For example, acetophenone, propiophenone, benzophenone, xanthenol, fluorene, benzaldehyde, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-methylacetophenone, 3-pentylacetophenone, 2,2-diethoxyacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, p-diacetophenone, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4 '-Dimethoxybenzophenone, 4-chloro-4'-benzylbenzophenone, 3-chloroxanthenone, 3,9-dichloroxanthenone, 3-chloro-8-nonylxanthenone, benzoin, benzoin methyl ether, benzoin butyl ether, bis(4-dimethylaminophenyl)ketone, benzylmethoxyketal, 2-chlorothioxanthenone, 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name IRGACURE 651, manufactured by BASF JAPAN LTD.), 1-hydroxy-cyclohexyl-phenyl-ketone (trade name IRGACURE 184, manufactured by BASF JAPAN LTD.), 2-hydroxy-2-methyl-1-phenyl-propane-1-one (trade name DAROCUR 1173, manufactured by BASF JAPAN LTD.), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (trade name IRGACURE 2959, manufactured by BASF JAPAN LTD.), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one (trade name IRGACURE 907, manufactured by BASF JAPAN LTD.), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (trade name IRGACURE 369), 2-morpholinopropane-1-one (trade name IRGACURE 907, manufactured by BASF JAPAN LTD.), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (trade name IRGACURE 369, manufactured by BASF JAPAN LTD.), 2-(4-methylbenzyl)-dimethylamino-1-(4-morpholin-4-yl-phenyl)-butane-1-one (trade name IRGACURE 379, manufactured by BASF JAPAN LTD.), dibenzoyl, etc.

[0383] Among them, α-hydroxyketone compounds (for example, benzoin, benzoin methyl ether, benzoin butyl ether, 1-hydroxy-cyclohexyl-phenyl-ketone, etc.), phenyl ketone derivatives (for example, acetophenone, propiophenone, benzophenone, 3-methylacetophenone, 4-methylacetophenone, 3-pentylacetophenone, 2,2-diethoxyacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, 4-allylacetophenone, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4-chloro-4'-benzylbenzophenone, bis(4-dimethylaminophenyl)ketone, etc.) are preferred.

[0384] The photoradical initiator (c') preferably has two or more photodegradable groups in one molecule.

[0385] Examples of the photoradical initiator (c') having two or more photodegradable groups in one molecule include the following. For example, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl-2-methyl-propane-1-one (trade name: 369IRGACURE 127, manufactured by BASF JAPAN LTD.), 1-[4-(4-benzyloxyphenylaminobenzenesulfonyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propane-1-one (trade name: ESURE 1001M), methylbenzoylformate (trade name: SPEEDCURE MBF, manufactured by LAMBSON), O-ethoxyimino-1-phenylpropane-1-one (trade name: SPEEDCURE PDO, manufactured by LAMBSON), oligo[2-hydroxy-2-methyl-[4-(1-methylvinyl)phenyl]propanone (trade name: ESCURE KIPI50, manufactured by LAMBERTI), etc. can be mentioned.

[0386] Furthermore, the photoradical initiator (c′) is preferably a hydrogen abstraction type photoradical initiator having three or more aromatic rings in one molecule.

[0387] Examples of hydrogen abstraction type photoradical initiators having three or more aromatic rings in one molecule include the following: 1-[4-(phenylthio)-2-(O-benzoyloxime)]1,2-octanedione (trade name IRGACUREOXE01, manufactured by BASF JAPAN LTD.), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) (trade name IRGACUREOXE 02, manufactured by BASF JAPAN LTD.), 4-benzoyl-4'-methyldiphenyl sulfide, 4-phenylbenzophenone, 4,4',4''-(hexamethyltriamino)triphenylmethane, and the like. In addition, acylphosphine oxide-based photoradical initiators such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (trade name DAROCUR TPO, manufactured by BASF JAPAN LTD.), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (trade name IRGACURE 819, manufactured by BASF JAPAN LTD.), and bis(2,6-dimethylbenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, which are characterized by improved deep curing properties, can be cited.

[0388] From the viewpoint of balancing the curability and storage stability of the protective film-forming composition (IV-1), the photoradical initiator (c′) is more preferably 1-hydroxy-cyclohexyl-phenyl-ketone (trade name IRGACURE 184, manufactured by BASF JAPAN LTD.), 2-hydroxy-2-methyl-1-phenyl-propane-1-one (trade name DAROCUR 1173, manufactured by BASF JAPAN LTD.), bis(4-dimethylaminophenyl)ketone, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl]-2-methyl-propane-1-one (trade name IRGACURE 127, manufactured by BASF JAPAN LTD.), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (trade name IRGACURE 369, manufactured by BASF JAPAN LTD.). LTD.), 2-(4-methylbenzyl)-2-dimethylamino-1-(4-morphin-4-yl-phenyl)-butan-1-one (trade name IRGACURE379, manufactured by BASF JAPAN LTD.), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (trade name DAROCURTPO, manufactured by BASF JAPAN LTD.), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (trade name IRGACURE819, manufactured by BASF JAPAN LTD.), bis(2,6-dimethylbenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, etc.

[0389] The extinction coefficient of the photoradical initiator (c') at a wavelength of 365 nm is preferably 4.0×10 1 ml / (g·

[0390] cm) or more, more preferably 1.0×10 2 ml / (g·cm) or more, more preferably 1.0×10 3 ml / (g·cm) or more.

[0391] The upper limit of the extinction coefficient of the photoradical initiator (c') at a wavelength of 365 nm is not particularly limited. For example, it can be set to 1.0×10 4 ml / (g·cm).

[0392] The photoradical initiator (c') contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one type or two or more types. When two or more types are used, the combination and ratio of these types may be arbitrarily selected.

[0393] The photoradical initiator (c') may also be used in combination with other compounds.

[0394] As the combination with other compounds, specifically, the following combinations can be listed. Combinations with amines such as 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, methyldiethanolamine, dimethylethanolamine, triethanolamine, ethyl 4-dimethylaminobenzoate, and 2-ethylhexyl-4-dimethylaminobenzoate can be listed, and combinations formed by combining these with iodonium salts such as diphenyliodonium chloride, and combinations formed by combining with pigments such as methylene blue and amines can also be listed.

[0395] The photoradical initiator (c') may be used together with a photopolymerization initiator other than the photoradical initiator (c') such as hydroquinone, hydroquinone monomethyl ether, benzoquinone, p-tert-butylcatechol, 2,2,6,6-tetramethylpiperidin-1-oxyl radical, N,N-diethylhydroxylamine, N,N-distearoylhydroxylamine, N,N-dialkylhydroxylamine, etc., as required.

[0396] The photopolymerization initiator contained in the protective film-forming composition (IV-1) may be one kind or two or more kinds. When two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

[0397] In the protective film forming composition (IV-1), the content of the photoradical initiator (c′) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the energy ray curable compound (a).

[0398] By setting the content of the photoradical initiator (c′) to be equal to or less than the above upper limit, unintended reactions can be suppressed when the composite sheet is used under a fluorescent lamp or natural light, thereby achieving an effect of enabling stable use of the composite sheet.

[0399] By setting the content of the photoradical initiator (c′) to be not less than the above lower limit, an effect of suppressing insufficient reaction can be obtained.

[0400] [Filling material (d)]

[0401] By making the protective film forming film contain the filler (d), it is easy to adjust the thermal expansion coefficient of the protective film obtained by curing the protective film forming film. In addition, by optimizing the thermal expansion coefficient with respect to the object of forming the protective film, the reliability of the package obtained using the composite sheet for forming the protective film is further improved. In addition, by making the protective film forming film contain the filler (d), the moisture absorption rate of the protective film can be reduced, or the heat dissipation can also be improved.

[0402] Examples of the filler (d) include fillers made of a thermally conductive material.

[0403] The filler (d) may be any of an organic filler and an inorganic filler, and is preferably an inorganic filler.

[0404] Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium dioxide, red iron, silicon carbide, boron nitride, etc.; beads obtained by sphericalizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, etc.

[0405] Among them, the inorganic filler is preferably silicon dioxide or aluminum oxide.

[0406] The average particle size of the filler (d) is not particularly limited, but is preferably 0.01 to 20 μm, more preferably 0.1 to 15 μm, and particularly preferably 0.3 to 10 μm. By setting the average particle size of the filler (d) to such a range, the adhesion of the protective film to the object to be formed can be maintained while suppressing the decrease in the light transmittance of the protective film.

[0407] In addition, unless otherwise specified, the "average particle size" in this specification 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.

[0408] The filler (d) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one type or two or more types. When two or more types are used, the combination and ratio of these types may be arbitrarily selected.

[0409] When the filler (d) is used, the content of the filler (d) (i.e., the content of the filler (d) in the protective film-forming film) in the protective film-forming composition (IV-1) is preferably 5 to 83% by mass, more preferably 7 to 78% by mass, relative to the total content of all components other than the solvent. By setting the content of the filler (d) to be within such a range, the above-mentioned thermal expansion coefficient can be more easily adjusted.

[0410] [Coupling agent (e)]

[0411] By using a substance having a functional group that can react with an inorganic compound or an organic compound as a coupling agent (e), the adhesion and closeness of the protective film-forming film to the adherend can be improved. In addition, by using a coupling agent (e), the water resistance of the protective film obtained by curing the protective film-forming film is improved without impairing the heat resistance.

[0412] The coupling agent (e) is preferably a compound having a functional group reactive with a functional group possessed by the energy-ray curable component (a) or the polymer (b) having no energy-ray curable group, and more preferably a silane coupling agent.

[0413] As the preferred silane coupling agent, the following substances can be listed. For example, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl diethoxysilane, 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxymethyl diethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, 3-(2-aminoethylamino)propyl trimethoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureapropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane, etc.

[0414] The coupling agent (e) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one type or two or more types. When two or more types are used, the combination and ratio of these may be arbitrarily selected.

[0415] When a coupling agent (e) is used, in the protective film forming composition (IV-1) and the protective film forming film, the content of the coupling agent (e) is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total content of the energy ray curable component (a) and the polymer (b) not having an energy ray curable group. By making the content of the coupling agent (e) above the lower limit, the improvement of the dispersibility of the filler (d) in the resin, the improvement of the adhesion between the protective film forming film and the adherend, etc., and the effect produced by using the coupling agent (e) can be more significantly obtained. In addition, by making the content of the coupling agent (e) below the upper limit, the generation of degassing can be further suppressed.

[0416] [Crosslinking agent (f)]

[0417] By crosslinking the energy-ray curable component (a) or the polymer (b) having no energy-ray curable group using the crosslinking agent (f), the initial adhesive force and cohesive force of the protective film-forming film can be adjusted.

[0418] Examples of the crosslinking agent (f) include organic polyisocyanate compounds, organic polyimide compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridine group).

[0419] As the organic polyisocyanate compound, the following substances can be listed. For example, aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds and alicyclic polyisocyanate compounds (hereinafter, these compounds are sometimes collectively referred to as "aromatic polyisocyanate compounds, etc."); trimers, isocyanurates and adducts of the aromatic polyisocyanate compounds, etc.; terminal isocyanate urethane prepolymers obtained by reacting the aromatic polyisocyanate compounds, etc. with polyol compounds, etc. The "adduct" refers to the reaction product of the aromatic polyisocyanate compound, aliphatic polyisocyanate compound or alicyclic polyisocyanate compound with a low molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil. As an example thereof, the xylene diisocyanate adduct of trimethylolpropane, etc., as described later, can be listed. Furthermore, the "isocyanate-terminated urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at the terminal portion of the molecule.

[0420] More specifically, the organic polyisocyanate compound includes, for example, 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; a compound in which any one or two or more of toluene diisocyanate, hexamethylene diisocyanate and xylylene diisocyanate are added to all or part of the hydroxyl groups of a polyol such as trimethylolpropane; lysine diisocyanate, etc.

[0421] Examples of the organic polyimide compound include N,N′-diphenylmethane-4,4′-bis(1-aziridinecarboxamide), trimethylolpropane-tris-β-aziridine propionate, tetramethylolmethane-tris-β-aziridine propionate, and N,N′-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine.

[0422] When an organic polyisocyanate compound is used as the crosslinking agent (f), a hydroxyl-containing polymer is preferably used as the energy-ray curable component (a) or the polymer (b) not having an energy-ray curable group. When the crosslinking agent (f) has an isocyanate group and the energy-ray curable component (a) or the polymer (b) not having an energy-ray curable group has a hydroxyl group, a crosslinking structure can be easily introduced into the protective film-forming film by the reaction of the crosslinking agent (f) with the energy-ray curable component (a) or the polymer (b) not having an energy-ray curable group.

[0423] The crosslinking agent (f) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of these can be arbitrarily selected.

[0424] When a crosslinking agent (f) is used, in the protective film forming composition (IV-1), the content of the crosslinking agent (f) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass relative to the total content of the energy ray curable component (a) and the polymer (b) not having an energy ray curable group of 100 parts by mass. By making the content of the crosslinking agent (f) above the lower limit, the effect produced by using the crosslinking agent (f) can be more significantly obtained. In addition, by making the content of the crosslinking agent (f) below the upper limit, the excessive use of the crosslinking agent (f) can be suppressed.

[0425] [Colorant (g)]

[0426] Examples of the colorant (g) include known colorants such as inorganic pigments, organic pigments, and organic dyes.

[0427] Examples of the organic pigments and organic dyes include the following. For example, amine pigments, cyanine pigments, merocyanine pigments, croconium pigments, squarylium pigments, azulenium pigments, polymethine pigments, naphthoquinone pigments, pyrylium pigments, phthalocyanine pigments, naphthalocyanine pigments, naphtholactam pigments, azo pigments, condensed azo pigments, indigo pigments, Pigments include oxadiazole pigments, thiocyanate pigments, isoindolinone pigments, quinophthalone pigments, pyrrole pigments, thioindigo pigments, metal complex pigments (metal complex salt dyes), dithiol metal complex pigments, indoxyl pigments, triallylmethane pigments, anthraquinone pigments, naphthol pigments, azomethine pigments, benzimidazolone pigments, pyranthrone pigments, and threne pigments.

[0428] Examples of the inorganic pigments include carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, ruthenium pigments, platinum pigments, ITO (indium tin oxide) pigments, and ATO (antimony tin oxide) pigments.

[0429] The colorant (g) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of the colorants may be arbitrarily selected.

[0430] When using colorant (g), the content of the colorant (g) of the protective film forming film is appropriately adjusted according to the purpose. For example, the protective film is sometimes printed by laser irradiation, and the content of the colorant (g) of the protective film forming film is adjusted and the light transmittance of the protective film is adjusted, so that the visibility of the printing can be adjusted. At this time, in the protective film forming composition (IV-1), the content of the colorant (g) (i.e., the content of the colorant (g) of the protective film forming film) is preferably 0.1~10 mass %, more preferably 0.4~7.5 mass %, and particularly preferably 0.8~5 mass %. By making the content of the colorant (g) more than the lower limit, the effect produced by using the colorant (g) can be more significantly obtained. In addition, by making the content of the colorant (g) less than the upper limit, the excessive use of the colorant (g) can be suppressed.

[0431] [Thermosetting component (h)]

[0432] The thermosetting component (h) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.

[0433] Examples of the thermosetting component (h) include epoxy-based thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, and silicone resins, and epoxy-based thermosetting resins are preferred.

[0434] (Epoxy thermosetting resin)

[0435] The epoxy thermosetting resin is composed of an epoxy resin (h1) and a thermosetting agent (h2). The epoxy thermosetting resin contained in the protective film-forming composition (IV-1) and the protective film-forming film may be only one type or two or more types. When there are two or more types, their combination and ratio may be arbitrarily selected.

[0436] Epoxy resin (h1)

[0437] As the epoxy resin (h1), known epoxy resins can be listed, for example, epoxy compounds having two or more functions such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydride, o-cresol novolac epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenylene skeleton type epoxy resin can be listed.

[0438] As the epoxy resin (h1), an epoxy resin having an unsaturated hydrocarbon group can be used. Compared with an epoxy resin without an unsaturated hydrocarbon group, an epoxy resin having an unsaturated hydrocarbon group has high compatibility with an acrylic resin. Therefore, by using an epoxy resin having an unsaturated hydrocarbon group, the reliability of the package obtained by using a composite sheet for forming a protective film is improved.

[0439] Examples of epoxy resins having an unsaturated hydrocarbon group include compounds in which a portion of epoxy groups of a polyfunctional epoxy resin is converted into groups having an unsaturated hydrocarbon group. Such compounds can be obtained, for example, by subjecting (meth)acrylic acid or a derivative thereof to an epoxy group by an addition reaction.

[0440] In addition, as the epoxy resin having an unsaturated hydrocarbon group, for example, a compound having a group having an unsaturated hydrocarbon group directly bonded to an aromatic ring constituting the epoxy resin can be cited. The unsaturated hydrocarbon group is an unsaturated group having polymerizability. As specific examples thereof, ethylene (vinyl), 2-propylene (allyl), (meth) acryloyl, (meth) acrylamide, etc. can be cited, preferably acryloyl.

[0441] The number average molecular weight of the epoxy resin (h1) is not particularly limited, but is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000 from the viewpoint of the curability of the protective film-forming film and the strength and heat resistance of the protective film.

[0442] The epoxy equivalent of the epoxy resin (h1) is preferably 100 to 1000 g / eq, more preferably 150 to 800 g / eq.

[0443] The epoxy resin (h1) may be used alone or in combination of two or more. When two or more kinds are used in combination, the combination and ratio thereof may be arbitrarily selected.

[0444] Heat curing agent (h2)

[0445] The thermosetting agent (h2) functions as a curing agent for the epoxy resin (h1).

[0446] As the thermosetting agent (h2), for example, a compound having two or more functional groups that can react with an epoxy group in one molecule can be cited. As the functional group, for example, a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, a group formed by acid anhydride of an acid group, etc. are cited. A phenolic hydroxyl group, an amino group, or a group formed by acid anhydride of an acid group is preferred, and a phenolic hydroxyl group or an amino group is more preferred.

[0447] Examples of the phenolic curing agent having a phenolic hydroxyl group in the thermosetting agent (h2) include polyfunctional phenol resins, biphenol, novolac-type phenol resins, dicyclopentadiene-based phenol resins, and aralkylphenol resins.

[0448] Examples of the amine curing agent having an amino group in the heat curing agent (h2) include dicyandiamide (hereinafter, sometimes abbreviated as "DICY") and the like.

[0449] The heat curing agent (h2) may have an unsaturated hydrocarbon group.

[0450] Examples of the thermosetting agent (h2) having an unsaturated hydrocarbon group include compounds in which a portion of the hydroxyl groups of a phenol resin are substituted with a group having an unsaturated hydrocarbon group, and compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenol resin.

[0451] The unsaturated hydrocarbon group in the thermosetting agent (h2) is the same as the unsaturated hydrocarbon group in the above-mentioned epoxy resin having an unsaturated hydrocarbon group.

[0452] When a phenolic curing agent is used as the thermosetting agent (h2), the thermosetting agent (h2) is preferably a thermosetting agent having a high softening point or glass transition temperature from the viewpoint of improving the releasability of the protective film from the support sheet.

[0453] The thermosetting agent (h2) includes the following: For example, the number average molecular weight of the resin component such as polyfunctional phenol resin, novolac phenol resin, dicyclopentadiene phenol resin, aralkylphenol resin is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000.

[0454] The molecular weight of non-resin components such as biphenol and dicyandiamide in the thermosetting agent (h2) is not particularly limited, but is preferably 60 to 500, for example.

[0455] The thermosetting agent (h2) may be used alone or in combination of two or more. When two or more are used in combination, their combination and ratio may be arbitrarily selected.

[0456] When the thermosetting component (h) is used, the content of the thermosetting agent (h2) is preferably 0.01 to 20 parts by mass based on 100 parts by mass of the epoxy resin (h1) in the protective film-forming composition (IV-1) and the protective film-forming film.

[0457] When a thermosetting component (h) is used, in the protective film-forming composition (IV-1) and the protective film-forming film, the content of the thermosetting component (h) (for example, the total content of the epoxy resin (h1) and the thermosetting agent (h2)) is preferably 1 to 500 parts by mass relative to 100 parts by mass of the polymer (b) not having an energy ray-curable group.

[0458] [General additives (z)]

[0459] The general-purpose additive (z) may be a known additive, and may be arbitrarily selected according to the purpose, without particular limitation. Preferred additives include, for example, plasticizers, antistatic agents, antioxidants, gettering agents, and the like.

[0460] The general-purpose additive (z) contained in the protective film-forming composition (IV-1) and the protective film-forming film may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of these additives may be arbitrarily selected.

[0461] When the general-purpose additive (z) is used, the content of the general-purpose additive (z) in the protective film-forming composition (IV-1) and the protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose.

[0462] [Solvent]

[0463] The protective film forming composition (IV-1) preferably further contains a solvent. The protective film forming composition (IV-1) containing a solvent has good handling properties.

[0464] The solvent is not particularly limited, but the following solvents can be cited as preferred solvents. For example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone, etc. can be cited.

[0465] The solvent contained in the protective film-forming composition (IV-1) may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of these solvents may be arbitrarily selected.

[0466] The solvent contained in the protective film forming composition (IV-1) is preferably methyl ethyl ketone, toluene, ethyl acetate, or the like, from the viewpoint of being able to more uniformly mix the components contained in the protective film forming composition (IV-1).

[0467] <<Method for preparing protective film-forming composition>>

[0468] A protective film-forming composition such as the protective film-forming composition (IV-1) can be obtained by blending the respective components constituting the protective film.

[0469] The order of adding the components when blending them is not particularly limited, and two or more components may be added simultaneously.

[0470] When a solvent is used, the solvent may be mixed with any blending component other than the solvent to pre-dilute the blending component before use. Alternatively, the solvent may be mixed with the blending component without pre-diluting any blending component other than the solvent.

[0471] The method for mixing the components during blending is not particularly limited, and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer or a stirring blade, a method of mixing by using a blender, a method of mixing by applying ultrasonic waves, and the like.

[0472] The temperature and time for adding and mixing the components are not particularly limited as long as the components do not deteriorate. They may be adjusted appropriately, but the temperature is preferably 15 to 30°C.

[0473] As a composite sheet similar to the protective film forming composite sheet of the present invention, which is attached to the back surface opposite to the circuit surface of a semiconductor wafer or a semiconductor chip and has an adhesive layer on a support sheet, there is a dicing die bonding sheet.

[0474] However, after the adhesive layer possessed by the cutting chip bonding sheet is picked up from the support sheet together with the semiconductor chip, the adhesive layer acts as an adhesive when the semiconductor chip is attached to a substrate, a lead frame, or other semiconductor chips. On the other hand, in terms of picking it up from the support sheet together with the semiconductor chip, the protective film forming film in the protective film forming composite sheet of the present invention is the same as the adhesive layer, but it eventually becomes a protective film by curing, and has the effect of protecting the back of the attached semiconductor chip. In this way, the protective film forming film of the present invention is different from the adhesive layer in the cutting chip bonding sheet, and the performance sought is of course different. Moreover, generally, compared with the adhesive layer in the cutting chip bonding sheet, the protective film forming film has a tendency to be hard and difficult to pick up, which also reflects the difference in the above-mentioned uses. Therefore, it is generally difficult to directly transfer the adhesive layer in the cutting chip bonding sheet to the protective film forming film in the protective film forming composite sheet. The composite sheet for forming a protective film of the present invention is a composite sheet for forming a protective film having an energy-ray-curable film for forming a protective film, which is unprecedented and has extremely excellent pick-up suitability for semiconductor chips with a protective film.

[0475] ◇Method for producing composite sheet for forming protective film

[0476] The protective film-forming composite sheet of the present invention can be produced by sequentially laminating the above-mentioned layers so that the above-mentioned layers are in a corresponding positional relationship. The method for forming each layer is the same as described above.

[0477] For example, when manufacturing a support sheet, when laminating an adhesive layer on a substrate, the above-mentioned adhesive composition may be applied on the substrate and dried as necessary.

[0478] On the other hand, for example, when a protective film forming film is further laminated on an adhesive layer laminated on a substrate, a protective film forming composition can be applied to the adhesive layer and directly form a protective film forming film. For layers other than protective film forming film, the same method can also be used to laminate the layer on the adhesive layer using a composition for forming the layer. Like this, when using any composition to form a continuous two-layer laminated structure, a composition can be further applied to the layer formed by the composition to form a new layer. Among them, it is preferred to use the composition to pre-form the layer of the above-mentioned two layers on other release films, and by bonding the exposed surface of the formed layer on the opposite side to the exposed surface of the other layer that has been formed with the side in contact with the release film, thereby forming a continuous two-layer laminated structure. At this time, it is preferred that the composition is applied on the peeling treatment surface of the release film. After forming the laminated structure, the release film can be removed as needed.

[0479] For example, when manufacturing a composite sheet for forming a protective film obtained by laminating an adhesive layer on a substrate and laminating a protective film forming film on the adhesive layer (a composite sheet for forming a protective film in which the supporting sheet is a laminate of a substrate and an adhesive layer), an adhesive layer is laminated on the substrate by applying an adhesive composition to the substrate and drying as needed, and then a protective film forming film is formed on the release film by applying a protective film forming composition to a release film and drying as needed. Then, by laminating the exposed surface of the protective film forming film to the exposed surface of the adhesive layer laminated on the substrate, and laminating the protective film forming film on the adhesive layer, a composite sheet for forming a protective film can be obtained.

[0480] In addition, when stacking an adhesive layer on a substrate, the adhesive composition may be applied on a release film as described above and dried as needed to form an adhesive layer on the release film, and the exposed surface of the layer may be bonded to the surface of one side of the substrate to stack the adhesive layer on the substrate, thereby replacing the method of coating the adhesive composition on the substrate.

[0481] In any method, the release film may be removed at any timing after the target layered structure is formed.

[0482] As described above, the layers other than the substrate constituting the composite sheet for forming a protective film can be pre-formed on a release film and laminated by laminating on the surface of the target layer. Therefore, the composite sheet for forming a protective film can be manufactured by appropriately selecting the layers using such a process as needed.

[0483] In addition, the composite sheet for forming a protective film is usually stored in a state where a release film is attached to the surface of the outermost layer (e.g., a protective film forming film) on the opposite side of the support sheet. Therefore, even if a composition for forming a layer constituting the outermost layer, such as a protective film forming composition, is applied to the release film (preferably its release-treated surface) and dried as needed, thereby forming a layer constituting the outermost layer on the release film, and other layers are stacked on the exposed surface of the layer opposite to the side in contact with the release film by any of the above methods, and the release film is not removed and attached, a composite sheet for forming a protective film can be obtained.

[0484] ◇How to use the composite sheet for protective film formation

[0485] The protective film-forming composite sheet of the present invention can be used, for example, by the method described below.

[0486] That is, the composite sheet for forming a protective film is attached to the back side (the side opposite to the electrode forming side) of the semiconductor wafer through its protective film forming film. Then, by cutting, the semiconductor wafer and the protective film forming film are divided together to form a semiconductor chip with a protective film forming film. Next, the protective film forming film of the semiconductor chip with a protective film forming film is irradiated with energy rays to solidify the protective film forming film to form a protective film. Then, the semiconductor chip is separated from the support sheet in a state where the protective film is attached (i.e., as a semiconductor chip with a protective film) and picked up.

[0487] Then, the obtained semiconductor chip with a protective film is flip-chip connected to the circuit surface of the substrate by the same method as in the prior art to form a semiconductor package. Then, the target semiconductor device can be manufactured using the semiconductor package.

[0488] ◇Sheet for forming protective film

[0489] Figure 6 This is a cross-sectional view schematically showing a protective film-forming film which is one embodiment of the protective film-forming sheet of the present invention.

[0490] like Figure 6 As shown, the protective film forming sheet 1F of the present embodiment is preferably formed into a "roll shape". The protective film forming sheet 1F has the following structure: a protective film forming composition is applied in a layered structure in such a manner that a protective film forming film 13 is arranged between a release film 15a (hereinafter, sometimes referred to as a "first release film") and a release film 15b (hereinafter, sometimes referred to as a "second release film").

[0491] The protective film-forming composition used for the protective film-forming sheet 1F is based on the above-mentioned protective film-forming composition.

[0492] The protective film forming sheet 1F can be formed, for example, by applying a protective film forming composition on the release surface of a first release film 15a and drying it to form a protective film forming film 13, and then attaching the release surface of a second release film 15b to the exposed surface. The application method of the protective film forming composition is based on the above-mentioned application method of the protective film forming composition.

[0493] ◇How to use the protective film forming film

[0494] The protective film forming film of the present invention can be used, for example, by the method described below.

[0495] That is, the protective film forming film is attached to the back side of the semiconductor wafer (the side opposite to the electrode forming side). Then, by dicing, the semiconductor wafer and the protective film forming film are divided together to form a semiconductor chip with a protective film forming film. Next, the protective film forming film of the semiconductor chip with a protective film forming film is irradiated with energy rays to solidify the protective film forming film to form a protective film. Then, the semiconductor chip is separated from the support sheet and picked up in a state where the protective film is attached (i.e., as a semiconductor chip with a protective film).

[0496] Then, the obtained semiconductor chip with a protective film is flip-chip connected to the circuit surface of the substrate by the same method as in the prior art to form a semiconductor package. Then, the target semiconductor device can be manufactured using the semiconductor package.

[0497] Example

[0498] Hereinafter, the present invention will be described in more detail based on specific examples. However, the present invention is not limited to the following examples.

[0499] The components used for preparing the protective film-forming composition are shown below.

[0500] Energy ray curable ingredients

[0501] (a2)-1: tricyclodecane dimethylol diacrylate ("KAYARAD R-684" manufactured by Nippon Kayaku Co., Ltd., a bifunctional ultraviolet curable compound, molecular weight 304)

[0502] ·Polymers without energy-ray curable groups

[0503] (b)-1: an acrylic resin (weight average molecular weight 300,000, glass transition temperature -1°C) prepared by copolymerizing butyl acrylate (hereinafter, abbreviated as "BA") (10 parts by mass), methyl acrylate (hereinafter, abbreviated as "MA") (70 parts by mass), glycidyl methacrylate (hereinafter, abbreviated as "GMA") (5 parts by mass) and 2-hydroxyethyl acrylate (hereinafter, abbreviated as "HEA") (15 parts by mass)

[0504] Photo radical initiator

[0505] (c')-1: 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone ("Irgacure (registered trademark) 369" manufactured by BASF, absorption coefficient at a wavelength of 365 nm: 7.9 × 10 3 )

[0506] (c')-2: 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyl oxime) ("Irgacure (registered trademark) OXE02" manufactured by BASF, absorption coefficient at a wavelength of 365 nm: 7.7 × 10 3 )

[0507] (c')-3: 1-[4-(phenylthio)-, 2-(O-benzoyloxime)] 1,2-octanedione) ("Irgacure (registered trademark) OXE01" manufactured by BASF, absorption coefficient at a wavelength of 365 nm: 7.0 × 10 3 )

[0508] (c')-4: 2-Hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1-one ("Irgacure (registered trademark) 127" manufactured by BASF, absorption coefficient at a wavelength of 365 nm: 1.1 × 10 2 )

[0509] (c)-1: methyl phenylglyoxylate ("Irgacure (registered trademark) MBF manufactured by BASF), absorption coefficient at a wavelength of 365 nm: 3.8 × 10 1 )

[0510] Filling material

[0511] (d)-1: Silica filler (molten quartz filler, average particle size 8 μm)

[0512] ·Coupling agent

[0513] (e)-1: 3-methacryloxypropyltrimethoxysilane ("KBM-503" manufactured by Shin-Etsu Chemical Co., Ltd., silane coupling agent)

[0514] Colorants

[0515] (g)-1: A pigment obtained by mixing 32 parts by mass of a phthalocyanine blue pigment (Pigment Blue 15:3), 18 parts by mass of an isoindolinone yellow pigment (Pigment Yellow 139), and 50 parts by mass of an anthraquinone red pigment (Pigment Red 177) and pigmenting them so that the total amount of the three pigments / the amount of styrene acrylic resin=1 / 3 (mass ratio)

[0516] [Example 1]

[0517] <Manufacturing of composite sheet for forming protective film>

[0518] (Preparation of protective film-forming composition (IV-1))

[0519] Energy ray curable component (a2)-1, polymer (b)-1, photo radical initiator (c')-1, photo radical initiator (c')-2, filler (d)-1, coupling agent (e)-1, and colorant (g)-1 were dissolved or dispersed in methyl ethyl ketone so that the contents (solid content, parts by mass) were the values ​​shown in Table 1, and stirred at 23° C., thereby preparing a protective film forming composition (IV-1) having a solid content concentration of 50% by mass. In addition, the description of "-" in the column of the contained component in Table 1 means that the protective film forming composition (IV-1) does not contain the component.

[0520] (Preparation of Adhesive Composition (I-4))

[0521] A non-energy ray-curable adhesive composition (I-4) containing an acrylic polymer (100 parts by mass, solid content) and a trifunctional xylylene diisocyanate crosslinking agent ("TAKENATE D110N" manufactured by Mitsui Takeda Chemical Co., Ltd.) (10.7 parts by mass, solid content) and further containing methyl ethyl ketone as a solvent and having a solid content concentration of 30% by mass was prepared. The acrylic polymer is an acrylic polymer having a weight average molecular weight of 600,000 obtained by copolymerizing 2-ethylhexyl acrylate (hereinafter, abbreviated as "2EHA") (36 parts by mass), BA (59 parts by mass), and HEA (5 parts by mass).

[0522] (Manufacturing of Support Sheet)

[0523] The adhesive composition (I-4) obtained above was applied on the release-treated surface of a release film ("SP-PET381031" manufactured by Lintec Corporation, 38 μm thick, hereinafter sometimes referred to as "P1") made of polyethylene terephthalate and subjected to release treatment on one side by silicone treatment, and heated and dried at 120°C for 2 minutes to form a non-energy ray-curable adhesive layer with a thickness of 10 μm.

[0524] Next, a polypropylene film (Young's modulus 400 MPa, thickness 80 μm, hereinafter sometimes referred to as "S1") as a substrate is bonded to the exposed surface of the adhesive layer, thereby obtaining a support sheet (10)-1 having the adhesive layer on the surface of one side of the substrate.

[0525] (Manufacture of composite sheet for forming protective film)

[0526] The protective film-forming composition (IV-1) obtained above was applied onto the release-treated surface of a release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm, P1) obtained by silicone treatment on one side of a polyethylene terephthalate film using a doctor blade coater, and dried at 100° C. for 2 minutes to prepare an energy-ray-curable protective film-forming film (13)-1 having a thickness of 25 μm.

[0527] Next, the release film was removed from the adhesive layer of the support sheet (10)-1 obtained above, and the exposed surface of the protective film forming film (13)-1 obtained above was attached to the exposed surface of the adhesive layer to prepare a composite sheet for forming a protective film in which the substrate, the adhesive layer, the protective film forming film (13)-1 and the release film were sequentially stacked in their thickness direction. The structure of the composite sheet for forming a protective film is shown in Table 2.

[0528] (Evaluation of cutting suitability)

[0529] The protective film-forming composite sheet obtained above was attached to the #2000 polished surface of a 6-inch silicon wafer (350 μm thick) via the protective film-forming film (13)-1, and the sheet was further fixed to a ring frame.

[0530] Next, the silicon wafer and the protective film-forming film (13)-1 were sliced ​​together using a dicing blade to obtain silicon chips of 5 mm×5 mm.

[0531] (Evaluation of Pickup Suitability)

[0532] Next, an ultraviolet irradiation device (manufactured by Lintec Corporation, “RAD2000m / 8”) was used at an illuminance of 195 mW / cm 2 , light intensity 170mJ / cm 2 Under the conditions of, ultraviolet rays are irradiated from the support sheet (10)-1 side to the protective film forming film (13)-1, thereby curing the protective film forming film (13)-1 to form a protective film.

[0533] Then, using a die bonder (manufactured by Canon Machinery Inc., "BESTEM-D02"), 15 silicon chips with protective films were pushed up and picked up with a push pin. At this time, the presence or absence of cracks and defects in the silicon chips was visually confirmed, and the case of no cracks and defects was judged as "A", and the case of only slight cracks or defects was judged as "B", and the pick-up suitability was evaluated. The results are shown in Table 2. The records in the "Suppression of chip cracking and defects" column in Table 2 are the corresponding results.

[0534] <Production and evaluation of composite sheet for forming protective film>

[0535] [Example 2]

[0536] A protective film-forming film (13)-2 was prepared in the same manner as in Example 1 except that (c')-1 was used as a photoradical initiator and the added amount was 0.6 parts by mass. A protective film-forming composite sheet was prepared using the composite sheet and its properties were evaluated. The results are shown in Table 2.

[0537] <Production and evaluation of composite sheet for forming protective film>

[0538] [Example 3]

[0539] A protective film-forming film (13)-3 was prepared in the same manner as in Example 1 except that (c')-2 was used as a photoradical initiator and the added amount was 0.6 parts by mass. A protective film-forming composite sheet was prepared using the composite sheet and its properties were evaluated. The results are shown in Table 2.

[0540] <Production and evaluation of composite sheet for forming protective film>

[0541] [Example 4]

[0542] A protective film-forming film (13)-4 was prepared in the same manner as in Example 1 except that (c')-3 was used as a photoradical initiator and the added amount was 0.6 parts by mass. A protective film-forming composite sheet was prepared using the composite sheet and its properties were evaluated. The results are shown in Table 2.

[0543] <Production and evaluation of composite sheet for forming protective film>

[0544] [Example 5]

[0545] A protective film-forming film (13)-5 was prepared in the same manner as in Example 1 except that (c')-4 was used as a photoradical initiator and the added amount was 0.6 parts by mass. A protective film-forming composite sheet was prepared using the composite sheet and its properties were evaluated. The results are shown in Table 2.

[0546] <Production and evaluation of composite sheet for forming protective film>

[0547] [Comparative Example 1]

[0548] A protective film-forming film (13)-6 was prepared in the same manner as in Example 1 except that (c)-1 was used as a photoradical initiator and the added amount was 0.6 parts by mass. A protective film-forming composite sheet was prepared using the composite sheet and its properties were evaluated. The results are shown in Table 2.

[0549] [Table 1]

[0550]

[0551] [Table 2]

[0552]

[0553] Note: 1) is the absorption coefficient of (c')-1; 2) is the absorption coefficient of (c')-2

[0554] From the above results, it can be seen that when the protective film-forming films (13)-1 to (13)-5 of Examples 1 to 4 were used, no cracking or chipping was observed during pickup. On the other hand, when the protective film-forming film (13)-6 of Comparative Example 1 was used, cracking or chipping was observed during pickup.

[0555] Based on the above results, it is believed that when the photo radical initiators (c')-1 to (c')-4 were used, the curing failure of the protective film forming film due to oxygen hindrance did not occur, and when the photopolymerization initiator (c)-1 was used, the curing failure of the protective film forming film due to oxygen hindrance occurred. Therefore, it is believed that the use of a photo radical initiator having an absorption coefficient of 4×101 ml / (g·cm) or more at a wavelength of 365 nm is effective.

[0556] Industrial Applicability

[0557] The present invention can be used in the manufacture of semiconductor devices.

Claims

1. A composite sheet for forming a protective film, which is a composite sheet for forming a protective film having an energy ray-curable protective film formed on a support sheet, wherein: The support sheet is a support sheet formed by directly contacting and laminating the adhesive layer and the substrate. The adhesive layer side is directly laminated on the protective film forming film, The adhesion between the protective film and the adhesive layer after the protective film-forming film is cured by irradiating ultraviolet rays is 50 to 1500 mN / 25 mm, The protective film-forming film contains: The absorption coefficient at a wavelength of 365 nm is 4.0×10 1 ml / (g·cm) or more 1.0×10 4 Photo radical initiators below ml / (g·cm); An acrylate compound having a (meth)acryloyl group as the energy-ray-curable component (a); The polymer (b) having no energy ray-curable group is an acrylic copolymer having at least a structural unit derived from an alkyl (meth)acrylate and a structural unit derived from a hydroxyl group-containing (meth)acrylate and having a weight average molecular weight of 100,000 to 1,500,000.

2. The composite sheet for forming a protective film according to claim 1, wherein The adhesive layer contains: an acrylic polymer having a structural unit derived from an alkyl (meth)acrylate and a structural unit derived from a hydroxyl-containing monomer, and an isocyanate crosslinking agent, The hydroxyl group of the structural unit derived from the hydroxyl group-containing monomer reacts with the isocyanate-based crosslinking agent and crosslinks.

3. The composite sheet for forming a protective film according to claim 1, wherein: The protective film-forming film further includes a filler (d) and a coupling agent (e).

4. The composite sheet for forming a protective film according to claim 1, wherein The protective film-forming film further comprises a filler (d) and a coupling agent (e), The adhesive layer contains an acrylic polymer having a structural unit derived from an alkyl (meth)acrylate and a structural unit derived from a hydroxyl group-containing monomer, and an isocyanate crosslinking agent, and the hydroxyl group of the structural unit derived from the hydroxyl group-containing monomer reacts with the isocyanate crosslinking agent to form a crosslink.

5. Use of a laminated body comprising an energy-ray-curable protective film-forming film on a supporting sheet for manufacturing a composite sheet for protective film-forming, wherein: The support sheet is a support sheet formed by directly contacting and laminating the adhesive layer and the substrate. The adhesive layer side is directly laminated on the protective film forming film, The adhesion between the protective film and the adhesive layer after the protective film-forming film is cured by irradiating ultraviolet rays is 50 to 1500 mN / 25 mm, The protective film-forming film contains: The absorption coefficient at a wavelength of 365 nm is 4.0×10 1 ml / (g·cm) or more 1.0×10 4 Photo radical initiators below ml / (g·cm); An acrylate compound having a (meth)acryloyl group as the energy-ray-curable component (a); The polymer (b) having no energy ray-curable group is an acrylic copolymer having at least a structural unit derived from an alkyl (meth)acrylate and a structural unit derived from a hydroxyl group-containing (meth)acrylate and having a weight average molecular weight of 100,000 to 1,500,000.

6. Use of an energy-ray-curable protective film-forming film in manufacturing a composite sheet for protective film-forming, wherein the composite sheet comprises the protective film-forming film on a supporting sheet, wherein: The support sheet is a support sheet formed by directly contacting and laminating the adhesive layer and the substrate. The adhesive layer side is directly laminated on the protective film forming film, The adhesion between the protective film and the adhesive layer after the protective film-forming film is cured by irradiating ultraviolet rays is 50 to 1500 mN / 25 mm, The protective film-forming film contains: The absorption coefficient at a wavelength of 365 nm is 4.0×10 1 ml / (g·cm) or more 1.0×10 4 Photo radical initiators below ml / (g·cm); An acrylate compound having a (meth)acryloyl group as the energy-ray-curable component (a); The polymer (b) having no energy ray-curable group is an acrylic copolymer having at least a structural unit derived from an alkyl (meth)acrylate and a structural unit derived from a hydroxyl group-containing (meth)acrylate and having a weight average molecular weight of 100,000 to 1,500,000.

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