Adhesive composition, adhesive sheet, and method for manufacturing electronic component device

Abstract

Provided is an adhesive composition comprising: a compound that generates an acid by at least one of heating or irradiation with an active energy ray; and a protected compound that has, in the molecule, a hydrophilic group protected by a protective group, said hydrophilic group being deprotected by the acid.

Description

Pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, and method for manufacturing electronic component device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from Japanese Patent Application No. 2023-173900, which is incorporated herein by reference.

[0002] The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet used for producing electronic component devices such as semiconductor integrated circuits, etc. The present invention also relates to a method for producing an electronic component device using the pressure-sensitive adhesive composition or the pressure-sensitive adhesive sheet.

[0003] Conventionally, there have been known manufacturing methods for electronic component devices, such as semiconductor integrated circuits. In this type of manufacturing method for electronic component devices, a substrate, such as a silicon wafer, is divided into small pieces to produce a large number of chips. During this process, when the substrate is divided into small pieces, a small portion of the substrate may become tiny pieces, resulting in minute foreign matter. When circuit components, such as circuit wiring or electrodes, are arranged on one side of the substrate, minute foreign matter may adhere to the circuit wiring or electrodes. Furthermore, foreign matter may also adhere to the other side, where circuit components, such as circuit wiring or electrodes, are not arranged. When a large amount of foreign matter adheres to the surface of the substrate, the reliability of the manufactured electronic component device may be reduced, regardless of whether circuit components are arranged on the side with the foreign matter attached.

[0004] In response to this, there is known a method for manufacturing an electronic component device in which a protective adhesive tape is attached to at least one surface of the substrate before the above-described processing is carried out (for example, see Patent Document 1).

[0005] The method for manufacturing an electronic component device described in Patent Document 1 uses a semiconductor protective adhesive tape having a substrate and a photocurable adhesive layer (adhesive layer) superimposed on one side of the substrate. The substrate has a specific thickness and is designed to have a specific heat shrinkage rate after heating at 150°C for 30 minutes. The photocurable adhesive layer (adhesive layer) is formed from a composition with a predetermined formulation, has a predetermined thickness, and is designed to have a relatively small predetermined adhesive strength after light irradiation. More specifically, the method for manufacturing an electronic component device described in Patent Document 1 first superimposes the photocurable adhesive layer (adhesive layer) of the protective adhesive tape on the circuit surface of a substrate (hereinafter referred to as a semiconductor package) on which a circuit is formed, and then divides the protective adhesive tape and the semiconductor package in this superimposed state into small pieces. Next, the small semiconductor packages and the protective adhesive tape are attached to the temporary fixing tape so that the circuit surface of the small semiconductor packages faces the temporary fixing tape and so that the temporary fixing tape contacts the substrate of the protective adhesive tape. Next, a metal film is formed on a part of the surface of the semiconductor package in a temporarily fixed state. Finally, the circuit surface of the semiconductor package is peeled off from the photo-curable adhesive layer, and the semiconductor package is picked up.

[0006] According to the method for manufacturing an electronic component device described in Patent Document 1, when the semiconductor package and protective adhesive tape are processed into small pieces, the circuit surface of the semiconductor package can be protected by covering it with the protective adhesive tape. The protective adhesive tape can then be removed by peeling the circuit surface of the semiconductor package from the photocurable adhesive layer of the protective adhesive tape fixed to the temporary fixing tape. The peel force required to remove the photocurable adhesive layer (adhesive layer) of the protective adhesive tape is weakened by curing the photocurable adhesive layer through light irradiation. Furthermore, heat generated when forming a metal film on a portion of the surface of the semiconductor package generates shrinkage stress (residual strain) within the substrate, which can easily deform the substrate, making the peeling more likely to occur.

[0007] Japanese Patent Application Publication No. 2021-147579

[0008] However, in the manufacturing method of an electronic component device described in Patent Document 1, for example, the peeling speed must be adjusted to prevent the circuit surface from being damaged by the peeling force when peeling between the circuit surface of the semiconductor package and the photocurable adhesive layer (adhesive layer), and the process of removing the adhesive layer is not necessarily simple. Furthermore, the use of temporary fixing tape for the above-mentioned peeling can make the process of removing the adhesive layer complicated. Furthermore, after peeling, a portion of the photocurable adhesive layer (adhesive layer) may remain on the circuit surface, making it difficult to remove the photocurable adhesive layer (adhesive layer). Even if the photocurable adhesive layer (adhesive layer) overlapping the non-circuit surface where no circuit surface is formed is removed, the above-mentioned problems can occur.

[0009] Therefore, there is a demand for a pressure-sensitive adhesive composition that can not only protect at least one surface to be protected (surface to be protected) of a substrate or the like during processing by covering the surface to be protected, but also form an adhesive layer that can be relatively easily removed from the surface to be protected after processing, etc. In particular, there is a demand for a pressure-sensitive adhesive composition that can form an adhesive layer that can be relatively easily removed when it comes into contact with a solvent such as water.

[0010] However, it cannot be said that sufficient research has been conducted yet on adhesive compositions for forming adhesive layers that can not only cover and protect the surface to be protected, but also be relatively easily removed by contact with a liquid containing water after protection.

[0011] Therefore, an object of the present invention is to provide a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer that can be relatively easily removed upon contact with a liquid containing water after protecting a surface to be protected. Another object of the present invention is to provide a pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. Another object of the present invention is to provide a method for manufacturing an electronic component device using the pressure-sensitive adhesive layer.

[0012] In order to solve the above-mentioned problems, the pressure-sensitive adhesive composition according to the present invention includes: a compound that generates an acid upon at least one of heating and irradiation with active energy rays; and a protected compound having, in the molecule, a hydrophilic group that is protected by a protecting group and that can be deprotected by the acid.

[0013] The pressure-sensitive adhesive sheet according to the present invention comprises a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

[0014] The method for manufacturing an electronic component device according to the present invention includes the steps of: protecting at least one of the surfaces to be protected of both surfaces of a substrate by overlaying an adhesive layer formed from an adhesive composition on the surface to be protected; and removing the adhesive layer overlaid on the surface to be protected, wherein the adhesive composition includes a compound that generates an acid upon at least one of heating or irradiation with active energy rays, and a protected compound having in its molecule a hydrophilic group that is protected by a protecting group and is deprotected by the acid; and in the removing step, the acid is generated from the compound that generates an acid upon at least one of heating or irradiation with active energy rays, thereby increasing the hydrophilicity of the adhesive layer, and the adhesive layer is removed by contacting it with a liquid containing water.

[0015] 1 is a schematic cross-sectional view of an example of a pressure-sensitive adhesive sheet according to the present embodiment, cut in the thickness direction; FIG. 2 is a schematic cross-sectional view of an example of a protection step in the manufacturing method for an electronic component device according to the present embodiment; FIG. 3 is a schematic cross-sectional view of an example of a protection step in the manufacturing method for an electronic component device according to the present embodiment; FIG. 4 is a schematic cross-sectional view of an example of a state before a substrate is cleaved in the manufacturing method for an electronic component device according to the present embodiment; FIG. 5 is a schematic cross-sectional view of an example of a state after a substrate is cleaved in the manufacturing method for an electronic component device according to the present embodiment; FIG. 6 is a schematic cross-sectional view of an example of a removal step in the manufacturing method for an electronic component device according to the present embodiment; FIG. 7 is a schematic cross-sectional view of an example of a removal step in the manufacturing method for an electronic component device according to the present embodiment; FIG. 8 is a schematic cross-sectional view of an example of a dicing tape cut in the thickness direction; FIG. 9 is a cross-sectional view of an example of a dicing die bond film cut in the thickness direction; FIG. 10 is a cross-sectional view of an example of a mounting step and a protection step according to the present embodiment; FIG. 11 is a cross-sectional view of an example of a blade dicing step during the blade dicing step according to the present embodiment; 1 is a cross-sectional view schematically showing a state of a removal step in this embodiment; a cross-sectional view schematically showing a state of a removal step in this embodiment; a cross-sectional view schematically showing a state of a pick-up step in this embodiment; a cross-sectional view schematically showing a state of a bonding step in this embodiment; a cross-sectional view schematically showing a state of half-cut processing of a semiconductor wafer in another example of this embodiment; a cross-sectional view schematically showing a state of half-cut processing of a semiconductor wafer in another example of this embodiment; a cross-sectional view schematically showing a state of half-cut processing of a semiconductor wafer in another example of this embodiment; a cross-sectional view schematically showing a state of a mounting step in another example of this embodiment.

[0016] Hereinafter, embodiments of the pressure-sensitive adhesive composition, the pressure-sensitive adhesive sheet, and the method for producing an electronic component device according to the present invention will be described in order with reference to the drawings.

[0017] The pressure-sensitive adhesive composition of the present embodiment is a composition containing a compound that generates an acid upon at least one of heating and irradiation with active energy rays, and a protected compound having, in its molecule, a hydrophilic group that is protected by a protecting group and that can be deprotected by the acid. The pressure-sensitive adhesive composition of the present embodiment is used, for example, to form an adhesive layer that protects a surface to be protected of a substrate that constitutes an electronic component device.

[0018] By overlaying an adhesive layer formed from the above-mentioned pressure-sensitive adhesive composition on a surface to be protected, it is possible to prevent foreign matter from adhering to the surface of the substrate to be protected (the surface to be protected) until the adhesive layer overlaid on the surface is removed. For example, when the adhesive layer formed from the pressure-sensitive adhesive composition and the substrate are processed into small pieces while they are overlapped, foreign matter such as fragments that may be generated during the small pieces are prevented from adhering to the surface to be protected, thereby protecting the surface to be protected. Furthermore, by subjecting the above-mentioned pressure-sensitive adhesive layer to a heat treatment or an active energy ray irradiation treatment, an acid is generated from the above-mentioned acid-producing compound. As a result, the protecting group protecting the hydrophilic group of the protected compound is released from the hydrophilic group, thereby increasing the hydrophilicity of the adhesive layer formed from the pressure-sensitive adhesive composition. The adhesive layer with increased hydrophilicity swells upon contact with a liquid containing water and can be relatively easily peeled from the surface to be protected. Therefore, the adhesive layer is easily released from the surface to be protected. Therefore, the adhesive layer can be more easily removed from the surface to be protected than, for example, when a release tape is attached to the adhesive layer and the adhesive layer is removed together with the release tape. In this way, the adhesive layer formed from the above-mentioned pressure-sensitive adhesive composition can not only protect the surface to be protected of the substrate, which is a member of the electronic component device to be manufactured, but also, after protection, can be relatively easily removed from the surface to be protected by a liquid containing water.

[0019] In this embodiment, the compound that generates an acid is, for example, an acid generator that generates an acid upon at least one of heating and irradiation with active energy rays. Examples of the compound that generates an acid include a photoacid generator and a thermal acid generator.

[0020] The pressure-sensitive adhesive composition contains the acid-generating compound, and therefore has a physical property that allows its hydrophilicity to be increased by at least one of heating treatment and irradiation with active energy rays such as ultraviolet rays. The pressure-sensitive adhesive composition only needs to have a predetermined level of hydrophilicity or higher after the hydrophilic group of the protected compound is deprotected. Therefore, in a state in which the hydrophilic group of the protected compound is protected, the pressure-sensitive adhesive composition may have a hydrophilicity less than a predetermined level or a hydrophilicity greater than a predetermined level. When the pressure-sensitive adhesive composition has a hydrophilicity greater than a predetermined level, an adhesive layer formed from the pressure-sensitive adhesive composition may swell in a liquid containing water. The acid-generating compound is preferably a compound that generates an acid upon irradiation with active energy rays (particularly ultraviolet rays).

[0021] The compound to be protected has at least a hydrophilic group and a protecting group that protects the hydrophilic group in the molecule. In other words, the compound to be protected is a compound that contains a hydrophilic group protected by a protecting group. The compound to be protected may be a low molecular weight compound or a high molecular weight compound.

[0022] Examples of the hydrophilic group protected by a protecting group include a carboxy group (—COOH), a hydroxy group (—OH), and a sulfo group (—SO ３ H), or amino group (-NH ２ ) etc.

[0023] Examples of protecting groups capable of protecting the hydrophilic group to be protected include the following. When the hydrophilic group to be protected is a carboxy group, examples of the protecting group include a tertiary (tert-)butyl group, an alkoxyalkyl group, or a cyclic acetal (dioxolane) group. Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxyethyl group, a butoxyethyl group, or a cyclohexoxyethyl group. In an alkoxyalkyl group, the number of consecutively bonded carbon atoms may be 2 or more and 4 or less. When the hydrophilic group to be protected is a hydroxy group, examples of the protecting group include a trityl group, an alkoxymethyl group, a tetrahydropyranyl group, a cyclic acetal (dioxolane) group, a tert-butyldimethylsilyl group, or a (tert-)butoxycarbonyl group. When the hydrophilic group to be protected is an amino group, examples of the protecting group include a (tert-)butoxycarbonyl group.

[0024] The above-mentioned protecting groups are present in the compound to be protected in a state chemically bonded to a hydrophilic group. The notation of the above-mentioned protecting groups does not necessarily directly represent the state in which the hydrophilic group and the protecting group are bonded. For example, when the hydrophilic group is a carboxy group and the protecting group is a tert-butyl group, an ester bond is formed by the reaction of the carboxy group with tert-butyl alcohol. Even in such a case, the protecting group is described as a tert-butyl group. Furthermore, the hydrophilic group to be protected is also described by its name before protection.

[0025] When the protecting group is removed from the hydrophilic group (deprotection), the protecting group portion is removed from the hydrophilic group portion. The compound derived from the removed protecting group may or may not be volatile, for example.

[0026] The protected compound may have, in its molecule, a structural unit of a (meth)acrylic acid type monomer containing a hydrophilic group protected by a protecting group. In other words, the protected compound may be a polymer obtained by polymerizing a protected (meth)acrylic acid type monomer containing a hydrophilic group protected by a protecting group. The term "protected (meth)acrylic acid type monomer" encompasses both a monomer in which the carboxy group of (meth)acrylic acid is protected and a monomer in which the hydrophilic group in a (meth)acrylic acid ester is protected. Examples of the protected (meth)acrylic acid type monomer include a protected carboxy group-containing (meth)acrylic monomer in which the carboxy group is protected by a protecting group, a protected hydroxyalkyl (meth)acrylate monomer in which the hydroxy group is protected by a protecting group, and a protected 2-acrylamido-2-methylpropanesulfonic acid monomer in which the sulfo group is protected by a protecting group.

[0027] Examples of the protected compound include oligomers or polymers having structural units of protected (meth)acrylic acid monomers containing hydrophilic groups protected by protecting groups. The oligomers may be, for example, oligomers formed by polymerization of 3 to 10 protected carboxyl group-containing (meth)acrylic monomers whose carboxyl groups are protected by protecting groups. The oligomers may be, for example, oligomers formed by polymerization of 3 to 10 protected hydroxyalkyl (meth)acrylate monomers whose hydroxyl groups are protected by protecting groups. The oligomers may be, for example, oligomers formed by polymerization of 3 to 10 protected (meth)acrylamidoalkylsulfonic acid monomers whose sulfo groups are protected by protecting groups.

[0028] The polymer or oligomer as the above-mentioned protected compound has, for example, a main chain and multiple side chains in the molecule. The main chain is, for example, a covalently bonded chain formed by a radical polymerization reaction. At least a part of the main chain is preferably a covalently bonded chain formed by a polymerization reaction of a protected (meth)acrylic acid type monomer containing a carboxy group protected by a protecting group as a hydrophilic group. The side chain has, for example, a hydrophilic group. The hydrophilic group is, for example, a hydroxy group or a carboxy group. The hydrophilic group is protected by a protecting group in the side chain of the polymer or oligomer.

[0029] The oligomer may be a homopolymer of a monomer containing a hydrophilic group protected by a protecting group, or a copolymer of a monomer containing a hydrophilic group protected by a protecting group and a monomer other than the protecting group. Similarly, the polymer may be a homopolymer of a monomer containing a hydrophilic group protected by a protecting group, or a copolymer. The average molecular weight of the polymer may be 50,000 or more and 900,000 or less.

[0030] Since the above polymer or oligomer contains a hydrophilic group such as a hydroxy group or a carboxy group protected by a protecting group in the molecule, the adhesive layer formed from the adhesive composition has low hydrophilicity when the hydrophilic group is protected. Therefore, even when contacted with a solvent containing water, the adhesive layer is not removed from the surface to be protected and continues to protect the surface to be protected. On the other hand, after the adhesive layer is subjected to a treatment such as heating or irradiation with active energy rays, the protected hydrophilic group is deprotected, thereby increasing the hydrophilicity of the adhesive layer formed from the above adhesive composition. Therefore, as described above, the adhesive layer swells and can be removed from the surface to be protected relatively easily.

[0031] The above polymer or oligomer is preferably a (meth)acrylic polymer containing at least the above-mentioned structural unit of the protected carboxy group-containing (meth)acrylic monomer in the molecule. Examples of the structural unit of the protected carboxy group-containing (meth)acrylic monomer include a structural unit of a protected (meth)acrylic acid monomer in which the carboxy group is protected by a protecting group, and a structural unit of a protected carboxyalkyl (meth)acrylate monomer in which the carboxy group is protected by a protecting group. Specific examples of the structural unit of the protected (meth)acrylic acid monomer are the structural units of a protected acrylic acid monomer or a methacrylic acid monomer. Specific examples of the structural unit of the protected carboxyalkyl (meth)acrylate monomer are the structural units of a protected carboxyethyl (meth)acrylate.

[0032] The (meth)acrylic polymer preferably contains 50% by mass or more, more preferably 80% by mass or more, of the structural units of the protected carboxy group-containing (meth)acrylic monomer in the molecule. The (meth)acrylic polymer may contain 95% by mass or more of the structural units of the protected carboxy group-containing (meth)acrylic monomer. When the (meth)acrylic polymer contains a larger amount of the structural units of the protected carboxy group-containing (meth)acrylic monomer, the adhesive layer formed from the adhesive composition has higher water resistance, while the adhesive layer subjected to heat treatment or active energy ray irradiation treatment in the removal step (described in detail later) can be more easily removed with a liquid containing water.

[0033] Examples of monomers copolymerizable with the above-mentioned protected (meth)acrylic acid type monomers include vinyl acetate (vinyl acetate), alkyl (meth)acrylates [(meth)acrylic acid alkyl esters], hydroxyalkyl (meth)acrylates [(meth)acrylic acid hydroxyalkyl esters], carboxyalkyl (meth)acrylates [(meth)acrylic acid carboxyalkyl esters], (meth)acrylic acid, and (meth)acrylates having a polyethylene glycol chain. In other words, the above-mentioned (meth)acrylic polymer may contain, in addition to the structural units of the above-mentioned protected carboxy group-containing (meth)acrylic monomer, the structural units of the above-listed monomers in the molecule. In the above-mentioned (meth)acrylic polymer, the content of the structural unit of alkyl (meth)acrylate [(meth)acrylic acid alkyl ester] may be less than 5% by mass (including 0% by mass). In this specification, the term "(meth)acrylic" encompasses both "acrylic" and "methacrylic." The same applies to "(meth)acrylate."

[0034] The alkyl (meth)acrylate is preferably an alkyl (meth)acrylate having 6 to 22 carbon atoms in the alkyl moiety. Examples of preferred alkyl (meth)acrylates include hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, arachidyl (meth)acrylate, and behenyl (meth)acrylate. When the alkyl (meth)acrylate has 6 to 22 carbon atoms in the alkyl moiety, the glass transition point (Tg) of the (meth)acrylic polymer becomes relatively low, making the (meth)acrylic polymer easier to handle. The hydrocarbon moiety may be linear or branched. The hydrocarbon moiety is preferably composed solely of saturated hydrocarbons.

[0035] The (meth)acrylic polymer is preferably a (meth)acrylic copolymer having at least in the molecule a structural unit of a (meth)acrylic monomer containing a protected carboxy group and a structural unit of the alkyl (meth)acrylate.

[0036] In this embodiment, the acid-generating compound is a compound that newly generates an acid by at least one of a heat treatment and an active energy ray irradiation treatment. The heat treatment and the active energy ray irradiation treatment will be described in detail later.

[0037] Examples of the acid-generating compound include photoacid generators and thermal acid generators, with photoacid generators being preferred because they can more reliably deprotect the protecting groups. A single compound may have both the functions of a photoacid generator and a thermal acid generator. In other words, for example, a specific acid generator may generate an acid by both heat treatment and active energy ray irradiation. When the acid-generating compound generates an acid by light irradiation or heat treatment, the protecting group in the protected compound contained in the adhesive layer is deprotected, revealing a hydrophilic group. This increases the hydrophilicity of the adhesive layer. Therefore, the adhesive layer can be more easily removed from the surface to be protected by contacting the adhesive layer with a liquid containing water.

[0038] The photoacid generator as the acid generator is, for example, a photocationic polymerization initiator generally used for cationic polymerization, and the thermal acid generator as the acid generator is, for example, a thermal cationic polymerization initiator generally used for cationic polymerization. Commercially available products can be used as the photoacid generator or the thermal acid generator.

[0039] Photoacid generators include ionic and nonionic types. Ionic photoacid generators have a cationic structure and an anionic structure. Examples of ionic photoacid generators, depending on the type of cationic structure, include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

[0040] Examples of the onium salt compound include onium salt compounds such as iodonium salt compounds, sulfonium salt compounds, oxime sulfonate compounds, and diazonium salt compounds. Of these, iodonium salt compounds or sulfonium salt compounds are preferred, and sulfonium salt compounds are more preferred.

[0041] Examples of iodonium salt compounds include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, bis(4-t-butylphenyl)iodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-fluorophenyl)iodonium triflate, diphenyliodonium hexafluorophosphate, etc. Other examples include the iodonium salt compounds used in the following examples.

[0042] Examples of sulfonium salt compounds include diphenyl[4-(phenylsulfanyl)phenyl]sulfonium=trifluorotris(pentafluoroethyl)-λ ５-phosphanide, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, triphenylsulfonium trifluoromethanesulfonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, triphenylsulfonium adamantanecarboxylate trifluoroethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium methanesulfonate, triphenylsulfonium phenolsulfonate, triphenylsulfonium nitrate, triphenylsulfonium maleate, bis(triphenylsulfonium)maleate, triphenylsulfonium hydrochloride (triphenylsulfonium chloride), triphenylsulfonium acetate, triphenylsulfonium trifluoroacetate, triphenylsulfonium salicylate, triphenylsulfonium benzoate, triphenylsulfonium hydroxide, and the like. Other examples include the sulfonium salt compounds used in the following examples.

[0043] Examples of the oxime sulfonate compound include (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (5-octylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (camphorsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (5-p-toluenesulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, and (5-octylsulfonyloxyimino)-(4-methoxyphenyl)acetonitrile.

[0044] The diazonium salt compound may, for example, be 4-nitrobenzenediazonium tetrafluoroborate.

[0045] Examples of commercially available onium salt compounds include OPTOMER SP-150, OPTOMER SP-170, and OPTOMER SP-171 (all manufactured by ADEKA Corporation), UVE-1014 (manufactured by General Electronics Corporation), OMNICAT250 and OMNICAT270 (both manufactured by IGM Resin), IRGACURE290 (manufactured by BASF Corporation), SAN-AID SI-60L, SAN-AID SI-80L, and SAN-AID SI-100L (all manufactured by Sanshin Chemical Industry Co., Ltd.), CPI-100B, CPI-100P, CPI-101A, and CPI-200K (all manufactured by San-Apro Ltd.).

[0046] Examples of the sulfonimide compound as a photoacid generator include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, N-(trifluoromethanesulfonyloxy)naphthalimide, N-(camphorsulfonyloxy)succinimide, N-(4-methylphenylsulfonyloxy)succinimide, N-(2-trifluoromethylphenylsulfonyloxy)succinimide, N-(4-fluorophenylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(camphorsulfonyloxy)phthalimide, N-(2-trifluoromethylphenylsulfonyloxy)phthalimide, N-(2-fluorophenylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(camphorsulfonyloxy)diphenylmaleimide, and N-(4-methylphenylsulfonyloxy)diphenylmaleimide.

[0047] Examples of disulfonyldiazomethane compounds as photoacid generators include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0048] Other examples of photoacid generators include 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)vinyl]-1,3,5-triazine.

[0049] Examples of the thermal acid generator include sulfonium salts such as aryl diazonium salts, diaryliodonium salts, triaryl sulfonium salts, and diaryl monoalkyl sulfonium salts, triaryl sulfoxonium salts, pyridinium salts, quinolinium salts, isoquinolinium salts, sulfonate esters, iron arene complexes, etc. Examples of the anion constituting the sulfonium salt include trifluorotris(perfluoroethyl)phosphate and hexafluorophosphate.

[0050] The acid generator, such as a photoacid generator or a thermal acid generator, preferably has good compatibility with the polymer contained in the pressure-sensitive adhesive composition. As the acid generator, an ionic acid generator is preferred, and an ionic photoacid generator is more preferred.

[0051] In the pressure-sensitive adhesive composition, the amount of the acid-generating compound relative to 100 parts by mass of the compound to be protected is preferably 0.2 parts by mass or more, more preferably 1.0 part by mass or more. This allows the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition to have higher hydrophilicity after heat treatment or active energy ray irradiation treatment, and therefore to be more likely to swell in a liquid containing water. The amount of the acid-generating compound relative to 100 parts by mass of the compound to be protected is preferably 10 parts by mass or less. This more sufficiently prevents the acid-generating compound from remaining in the pressure-sensitive adhesive composition.

[0052] The pressure-sensitive adhesive composition of the present embodiment may further contain, in addition to the above-mentioned components, for example, a solvent, a surfactant, etc. Examples of the solvent include water or an organic solvent. As the organic solvent, a relatively volatile organic solvent is preferable. Examples of such organic solvents include ethanol and methanol.

[0053] The pressure-sensitive adhesive composition of this embodiment preferably does not contain either a photopolymerization initiator or a thermal polymerization initiator. If the pressure-sensitive adhesive composition of this embodiment contains a photopolymerization initiator or a thermal polymerization initiator, the protected hydrophilic group in the above-mentioned protected compound may chemically react with the photopolymerization initiator or the thermal polymerization initiator. When this reaction occurs, the hydrophilic group may disappear and change into an organic group that does not have hydrophilicity. Therefore, it may be difficult for the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition to retain hydrophilicity even after heat treatment or active energy ray irradiation treatment. Therefore, it may be difficult to remove the pressure-sensitive adhesive layer using a liquid containing water.

[0054] The PSA composition of the present embodiment may be a solid having no fluidity, or may have fluidity. When the PSA composition contains a solvent, it may have fluidity.

[0055] The pressure-sensitive adhesive composition of the present embodiment can be produced by mixing the above-mentioned polymer, the above-mentioned acid-generating compound such as the photoacid generator, and, if necessary, a solvent, etc., by a general method. Alternatively, the pressure-sensitive adhesive composition of the present embodiment may be produced by volatilizing the solvent after the above-mentioned mixing.

[0056] The pressure-sensitive adhesive composition of the present embodiment is used, for example, to produce a pressure-sensitive adhesive sheet, which will be described later.

[0057] Next, the pressure-sensitive adhesive sheet 10 of this embodiment will be described.

[0058] As shown in Fig. 1, the pressure-sensitive adhesive sheet 10 of this embodiment includes at least a pressure-sensitive adhesive layer 11. The pressure-sensitive adhesive sheet 10 of this embodiment may further include a release liner 15 that overlaps at least one surface of the pressure-sensitive adhesive layer 11. The release liner 15 may be overlapped on one or both surfaces of the pressure-sensitive adhesive layer 11. Note that each figure in the drawings is a schematic view, and the aspect ratio is not necessarily the same as that of the actual product. The same applies to the other figures.

[0059] In this embodiment, the adhesive layer 11 of the adhesive sheet 10 is formed into a sheet shape from the above-mentioned adhesive composition. When the above-mentioned adhesive sheet 10 is used, for example, the release liner 15 is peeled off from the adhesive layer 11, and the adhesive layer 11 is attached to at least one surface (surface to be protected) of a substrate.

[0060] The adhesive layer 11 has flexibility that allows it to be deformed by a relatively weak force. The adhesive layer 11 also has adhesiveness that allows it to adhere to the surface of a substrate to be protected. In other words, the adhesive layer 11 can be used as a pressure-sensitive sheet adhesive that can be adhered to the surface to be protected by being pressed against the surface to be protected.

[0061] In the present embodiment, the water contact angle of the pressure-sensitive adhesive layer 11 that has not been subjected to heating or irradiation with active energy rays may be 70° or more and less than 120°. ２ The contact angle of water of the adhesive layer 11 after being subjected to at least one of the irradiations (irradiation with water or irradiation with water) is preferably 100° or less.

[0062] The contact angle is measured as follows. Specifically, the contact angle of water on one surface of the pressure-sensitive adhesive layer 11 (the surface to be attached to the surface to be protected) is measured using a general contact angle meter. More specifically, in accordance with JIS R3257, the contact angle with 0.15 μL of water is measured at 25° C. using a fully automatic contact angle measuring device (for example, product name: DM-500 manufactured by Kyowa Interface Science Co., Ltd.). The average value of five measurements is used. The contact angle is measured 30 seconds after water is dropped onto the smooth surface of a molded product (for example, pressure-sensitive adhesive layer 11) molded from the pressure-sensitive adhesive composition. When the pressure-sensitive adhesive composition contains an organic solvent, the contact angle is measured on a molded product (for example, pressure-sensitive adhesive layer 11) from which the organic solvent has been removed.

[0063] In this embodiment, the water contact angle of the adhesive layer 11 after being subjected to at least one of heating (heat treatment) and irradiation (irradiation treatment) (hereinafter sometimes simply referred to as "after treatment") is preferably 3° or more smaller, more preferably 10° or more smaller, than the water contact angle of the adhesive layer 11 (before treatment) that has not been subjected to either heating (heat treatment) or irradiation (irradiation treatment) with active energy rays. A larger change in the contact angle can more fully achieve both the water resistance of the adhesive layer 11 before the treatment and the water swelling property of the adhesive layer 11 after the treatment (good water penetration into the adhesive layer 11). The change in the contact angle may be 50° or less.

[0064] The contact angle of the adhesive layer 11 after the above-mentioned treatment is a value measured after the above-mentioned treatment is carried out under the following conditions: (When the adhesive layer contains a photoacid generator) Active energy ray irradiation treatment: 2500 mJ / cm using a high-pressure mercury lamp ２ After the irradiation, further heat treatment: 100°C for 30 seconds, then left for 30 minutes (if the adhesive layer contains a thermal acid generator) Heat treatment: 100°C for 1 hour, then left for 30 minutes

[0065] The pressure-sensitive adhesive layer 11 may be formed, for example, by applying the solvent-containing pressure-sensitive adhesive composition to one surface of a substrate and then volatilizing the solvent. Alternatively, the pressure-sensitive adhesive layer 11 may be formed by applying the solvent-containing pressure-sensitive adhesive composition to one surface of a release liner 15 and then volatilizing the solvent. The formed pressure-sensitive adhesive layer 11 preferably does not contain a solvent blended to impart fluidity to the pressure-sensitive adhesive composition. The pressure-sensitive adhesive layer 11 may be formed, for example, from the solvent-free pressure-sensitive adhesive composition by a general molding method.

[0066] In the above-mentioned pressure-sensitive adhesive sheet, the thickness of the pressure-sensitive adhesive layer 11 is not particularly limited, but is, for example, 1 μm or more and 100 μm or less. Such a thickness may be 3 μm or more, or 5 μm or more. Also, such a thickness may be 40 μm or less. Note that when the pressure-sensitive adhesive layer 11 is a laminate, the above thickness is the total thickness of the laminate.

[0067] The adhesive layer 11 may have physical properties that allow it to be broken into small pieces by being stretched in the planar direction. Adhesive layer 11 having such physical properties is preferably used when manufacturing electronic component devices through a stealth processing step using a stealth dicing device, which will be described later. Similarly, it is preferably used when manufacturing electronic component devices through a DBG process (described in detail later). Note that the adhesive layer 11 may also be preferably used when manufacturing electronic component devices through a blade dicing processing step (described in detail later), and therefore does not need to have such physical properties.

[0068] The protective sheet 1 of this embodiment is used, for example, during the process of manufacturing an electronic component device. Specifically, the protective sheet 1 of this embodiment is used for purposes such as temporarily protecting the surface to be protected (the surface to be protected) of an electronic component (a type of substrate). More specifically, the protective sheet 1 of this embodiment is used, for example, by being attached to the surface to be protected of the electronic component (a type of substrate). Examples of the electronic component include substrates such as semiconductor wafers, semiconductor chips, and wired circuit boards, connected wired circuit boards formed by connecting multiple wired circuit boards, and pseudo wafers.

[0069] The semiconductor chip typically includes a semiconductor chip body and electrode portions disposed on one or both sides of the semiconductor chip body and electrically connected to electrode portions of another component. Examples of such other components include a wiring circuit board or another semiconductor chip. The semiconductor chip may have a circuit surface on at least one side thereof, on which a circuit is formed. Specifically, the semiconductor chip may be a TSV (Through Silicon Via) type semiconductor chip having paired electrode portions disposed on both sides of the semiconductor chip body and a conductive portion penetrating the semiconductor chip body in the thickness direction to electrically connect one electrode portion to the other. A TSV type semiconductor chip may have a circuit surface formed on only one side, or may have a circuit surface formed on both sides. The circuit of the semiconductor chip may also include a sensor element (e.g., a light-receiving element or a vibration element) as an element. An example of such a semiconductor chip is a sensor chip. Examples of sensor chips include a CMOS (Complementary Metal-Oxide Semiconductor) chip and a MEMS (Micro Electro Mechanical Systems) chip.

[0070] The pseudo wafer includes, for example, a support substrate and a package body in which a plurality of semiconductor chips arranged on the support substrate are collectively sealed with resin. The pseudo wafer may be the package body removed from the support substrate. A rewiring layer may be formed on at least a portion of the surface of the pseudo wafer. The protective sheet 1 may be used to cover the rewiring layer. Note that the divided bodies obtained by dividing the pseudo wafer into constituent units each including at least one semiconductor chip may be electronic components.

[0071] As described above, there are various types of electronic components that have surfaces to be protected, and various electronic components can serve as the substrate.

[0072] Next, a method for manufacturing the electronic component device of this embodiment will be described.

[0073] The method for manufacturing an electronic component device of this embodiment includes: a step of protecting at least one of the surfaces to be protected of both surfaces of a substrate by overlaying an adhesive layer 11 formed from an adhesive composition on the surface to be protected (protection step); and a step of removing the adhesive layer 11 overlaid on the surface to be protected (removal step), wherein the adhesive composition includes a compound that generates an acid when heated or irradiated with active energy rays, and a protected compound having, in its molecule, a hydrophilic group that is protected by a protecting group and is deprotected by the acid, and in the removing step, the acid is generated from the compound that generates an acid when heated or irradiated with active energy rays, thereby increasing the hydrophilicity of the adhesive layer 11, and the adhesive layer 11 is removed by contacting it with a liquid containing water.

[0074] In the above protection step, as shown in Fig. 2A, the surface to be protected of the substrate S may be protected using a pressure-sensitive adhesive sheet 10 having a release liner 15 on one side of the pressure-sensitive adhesive layer 11. For example, after the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 10 is superimposed on the surface to be protected of the substrate S, the release liner 15 may be peeled off from the pressure-sensitive adhesive layer 11 (see Fig. 2B).

[0075] 2C and 2D , the method for manufacturing an electronic component device of this embodiment may further include a step of dividing the stacked laminate of substrates S and adhesive layers 11 into small pieces at intervals in the surface direction, thereby producing a plurality of stacked small pieces of chips S′ formed by dividing the substrate into small pieces and adhesive layer small pieces 11′. Note that, before being divided, the substrate S may have weakened portions or the like formed inside for the purpose of dividing into small pieces.

[0076] In the removal step, as shown in Figure 2E, the adhesive layer pieces 11' are subjected to, for example, a heat treatment or irradiation with active energy rays such as ultraviolet light, thereby generating new acid from the acid-producing compounds contained in each piece 11' and increasing the hydrophilicity of each piece 11'. Then, in the removal step, as shown in Figure 2F, each adhesive layer piece 11' overlapping the circuit surface of the chip S' is removed using a liquid containing water. The manufacturing method for an electronic component device of this embodiment may further include a step of placing the circuit surface of the chip S' facing the adherend and bonding the chip S' to the adherend.

[0077] The electronic component device manufactured by the manufacturing method of this embodiment includes at least one of the various electronic components described above. Examples of the electronic component device include a semiconductor device such as a semiconductor integrated circuit including a semiconductor chip, a device including a system LSI having a complementary metal oxide semiconductor (CMOS), or a device including a microelectromechanical system (MEMS) in which mechanical elements, sensors, actuators, or electronic circuits are integrated on a single silicon substrate, glass substrate, or organic material substrate using microfabrication technology. The manufactured electronic component device may also include a device including a wiring circuit board.

[0078] In the method for manufacturing an electronic component device according to this embodiment, at least one surface of the substrate is protected by an adhesive layer. The surface to be protected (hereinafter simply referred to as the surface to be protected) may be either one surface or both surfaces of the substrate. Circuit components (described in detail below) may or may not be disposed on the surface to be protected.

[0079] The substrate may be made of any material, as long as it is plate-shaped. Examples of the substrate material include glass, silicon, stainless steel (SUS), plastic, and ceramic. Examples of the substrate include a semiconductor wafer, a sensor wafer such as a CMOS or MEMS, a pseudo wafer, and a wiring circuit board.

[0080] In the above-mentioned protection step, an adhesive layer 11 may be overlaid on the surface of the substrate on which at least one of the circuit wiring, sensor unit, and electrode unit is arranged as a circuit component. For example, the adhesive layer 11 may be overlaid on one side (circuit surface) of the substrate on which the circuit wiring is arranged, the adhesive layer 11 may be overlaid on one side of the substrate on which the sensor unit is arranged, or the adhesive layer 11 may be overlaid on one side of the substrate on which the electrode unit is arranged. In the above-mentioned protection step, it is preferable to overlay the adhesive layer 11 on at least one side of the substrate so as to cover the circuit wiring, sensor unit, or electrode unit with the adhesive layer 11. Examples of circuit components include circuit wiring, electrode units, or elements such as transistors, diodes, or sensor units (such as light-receiving sensors or vibration sensors).

[0081] The following will describe in detail the case where a semiconductor integrated circuit (semiconductor device) is manufactured as an electronic component device.

[0082] Generally, a method for manufacturing a semiconductor device includes a front-end process in which a circuit surface is formed on one side of a wafer using highly integrated electronic circuits, and a back-end process in which chips are cut out from the wafer with the circuit surface formed and assembled.

[0083] In a post-process, for example, a fragile portion is formed on the wafer (semiconductor wafer) as a substrate on which a circuit surface is formed, for dicing into small semiconductor chips (dies), and an adhesive fixing layer of dicing tape is attached to the surface opposite the circuit surface. Then, while the semiconductor wafer is attached to the adhesive fixing layer of the dicing tape, the dicing tape is stretched in the planar direction, dicing the semiconductor wafer into semiconductor chips along the fragile portion. The diced semiconductor chips are then peeled off from the adhesive fixing layer of the dicing tape.

[0084] The above-mentioned post-processing includes, for example, a stealth processing step in which fragile portions for dicing the wafer into small chips (dies) are formed in the wafer using laser light or the like, a mounting step in which the surface of the semiconductor wafer opposite the circuit surface is attached to a dicing tape to fix the semiconductor wafer, an expanding step in which the semiconductor wafer is diced into semiconductor chips (dies) by stretching the dicing tape in the surface direction, a pick-up step in which the semiconductor chips are peeled off from the adhesive fixing layer and removed, and a bonding step in which the removed semiconductor chips are bonded to an adherend. A semiconductor integrated circuit (semiconductor device) is manufactured through, for example, these steps.

[0085] In the manufacturing method of a semiconductor device (electronic component device) of this embodiment, for example, semiconductor chips are cut out from a semiconductor wafer on which a circuit surface is formed, and a semiconductor device having the cut-out semiconductor chips is assembled. In the manufacturing method of a semiconductor device of this embodiment, a semiconductor device is manufactured as follows using at least the adhesive layer 11 of the adhesive sheet 10 and a dicing tape 20 (see FIG. 3A). These sheets and tapes are used as auxiliary tools for manufacturing a semiconductor device. It is also possible to use a dicing die bond film in which a die bond sheet 30 is superimposed on the adhesive fixing layer 22 of the dicing tape 20 (see FIG. 3B). Commercially available products can be used as the dicing tape 20 and the dicing die bond film.

[0086] An embodiment of the method for manufacturing a semiconductor device will be described in detail below.

[0087] The method for manufacturing a semiconductor device according to this embodiment includes an assembly process in which semiconductor chips X are cut out from a semiconductor wafer W (substrate) on which a circuit surface is formed, and a semiconductor device having such semiconductor chips X is assembled. Such an assembly process includes a step (protection step) of protecting the circuit surface (surface to be protected) by overlaying an adhesive layer 11 for protecting the circuit components on at least one surface of the semiconductor wafer W, which is a circuit surface on which any of the circuit components is formed; a step (dividing and fragmenting the laminate of the overlapping semiconductor wafer W and adhesive layer 11 at intervals in the surface direction to produce a plurality of small pieces of a laminate in which the semiconductor chips X obtained by fragmenting the semiconductor wafer W and the adhesive layer small pieces 11' are overlapped; a step (removal step) of subjecting each of the adhesive layer small pieces 11' overlapping the circuit surface of the semiconductor chip X to a heat treatment or active energy ray irradiation treatment or the like to generate an acid from the acid-producing compound in each of the small pieces 11' to increase the hydrophilicity of each of the small pieces 11', and then removing each of the adhesive layer small pieces 11' with a liquid containing water; and a step (bonding step) of bonding the semiconductor chip X to the adherend.

[0088] The assembly process of this embodiment includes, for example, the following steps. Specifically, the assembly process of this embodiment includes a mounting process in which a semiconductor wafer W having circuit components formed on one side thereof is attached to a dicing die bond film (a die bond sheet 30 superimposed on a dicing tape 20) and the semiconductor wafer W is fixed to the dicing die bond film; a protection process in which an adhesive layer 11 is attached to the circuit surface of the semiconductor wafer W to protect the circuit surface; a blade dicing process (a process for producing a plurality of small pieces of the laminate) in which the semiconductor wafer W to which the die bond sheet 30 and the adhesive layer 11 are attached is diced with a dicing blade T or the like to produce semiconductor chips (dies) obtained by dicing the semiconductor wafer W; a removal process (the above-mentioned removing process) in which a plurality of small pieces 11' of the adhesive layer attached to the semiconductor chip X are removed after the above-mentioned heat treatment or active energy ray irradiation treatment; and a pick-up process in which the small pieces 30' of the die bond sheet are peeled away from the dicing tape 20 to take out the semiconductor chip X with the small pieces 30' of the die bond sheet attached. and a bonding step (the above-mentioned bonding step) of bonding the extracted semiconductor chip X to an adherend via the small piece 30' of the die bond sheet. When these steps are carried out, the above-mentioned adhesive layer 11 and the dicing die bond film having the dicing tape 20 are used as manufacturing aids.

[0089] The semiconductor wafer W is configured to obtain a plurality of semiconductor chips X. Specifically, the semiconductor wafer W is configured to be divided into small pieces at intervals in a plurality of directions along the surface (for example, directions along the surface that are perpendicular to each other), so that a plurality of semiconductor chips X can be fabricated. Furthermore, the semiconductor wafer W has a circuit surface on at least one surface on which at least one type of circuit component is arranged. For example, the semiconductor wafer W used in this embodiment has a circuit surface formed on one of its surfaces.

[0090] In recent years, with the further advancement of integration technology in the semiconductor industry, thinner semiconductor chips (e.g., thicknesses of 20 μm to 50 μm) are desired. When viewed from one side in the thickness direction, the semiconductor chip has, for example, a rectangular shape, with a side length of, for example, 5 mm to 20 mm.

[0091] In the mounting step, as shown in FIG. 4A, a dicing ring R is attached to the adhesive fixing layer 22 of the dicing tape 20, and a semiconductor wafer W is attached and fixed to a die bond sheet 30 superimposed on the dicing tape 20.

[0092] In the protection step, as shown in FIG. 4A , an adhesive layer 11 is superimposed on one of the circuit surfaces of the semiconductor wafer W. In the protection step, the adhesive layer 11 may be superimposed on the circuit surface by, for example, directly pressing the adhesive layer 11 against the circuit surface to adhere it. Alternatively, an adhesive composition containing solid components constituting the adhesive layer 11 and a solvent that dissolves the solid components may be prepared, and the prepared adhesive composition may be applied to the circuit surface, followed by volatilizing the solvent to form an adhesive layer 11 that contacts the circuit surface, thereby superimposing the adhesive layer 11 on the circuit surface. By superimposing the adhesive layer 11 on the circuit surface of the semiconductor wafer W, the circuit surface can be protected by the adhesive layer 11 until the adhesive layer 11 is removed. Therefore, the adhesion of dust and the like to the circuit surface of the semiconductor wafer W covered with the adhesive layer 11 can be prevented. The protection step may be performed after the mounting step, or the mounting step may be performed after the protection step.

[0093] In the blade dicing process, the semiconductor wafer W is diced, as shown in FIGS. 4B and 4C . Specifically, the semiconductor wafer W is cut to a predetermined size together with the die bond sheet 30 to form semiconductor chips with the die bond sheet 30. The blade dicing process is performed using, for example, a dicing blade T in a conventional manner. For example, a cutting method called a full cut, in which the cut is made up to the die bond sheet 30, can be employed in the blade dicing process. The dicing device used in the blade dicing process is not particularly limited, and any conventionally known device can be used. In the blade dicing process, foreign matter such as debris may be generated when the semiconductor wafer W is cut. Since the surface of the semiconductor wafer W to be protected is protected by the adhesive layer 11, adhesion of foreign matter to the surface to be protected can be suppressed. Prior to the blade dicing process, a dicing ring R may be attached to the adhesive fixing layer 22 of the dicing tape 20, and then the dicing ring R may be fixed to the holder H of the expanding device.

[0094] In the removal step, as shown in Fig. 4D, the adhesive layer pieces 11' are subjected to a treatment to generate an acid from the acid-generating compound. As such a treatment, at least one of a heat treatment and an active energy ray irradiation treatment is adopted. The heat treatment is carried out, for example, by exposing the adhesive layer pieces 11' to an environment of 90°C or higher and 250°C or lower for 10 minutes or longer and 300 minutes or shorter. The active energy ray irradiation treatment is carried out, for example, by exposing the adhesive layer pieces 11' to an environment of 90°C or higher and 250°C or lower for 10 minutes or longer and 300 minutes or shorter. ２ More than 300mW / cm ２ The ultraviolet rays with the following intensity are used as active energy rays, and the cumulative light amount is 50 mJ / cm ２ More than 5000mJ / cm ２The adhesive layer fragments 11' are irradiated with ultraviolet light as follows: In the removal process, the adhesive layer fragments 11' are subjected to the above-described treatment, whereby an acid is generated from the acid-generating compound contained in the fragments 11'. The newly generated acid causes protecting groups to be released from the protected compounds contained in the adhesive layer fragments 11', generating unprotected hydrophilic groups. This increases the hydrophilicity of the adhesive layer fragments 11'. As a result, when the fragments 11' later come into contact with a liquid containing water, the fragments 11' swell and are relatively easily removed from the surface of the semiconductor chip X.

[0095] In the removal step, as shown in Figure 4E, the adhesive layer pieces 11' are brought into contact with a liquid containing water, and the adhesive layer pieces 11' are swelled by the liquid, thereby removing the adhesive layer pieces 11' from the surface (surface to be protected) of the semiconductor chip X. By removing the adhesive layer pieces 11' in this manner, all of the adhesive layer pieces 11' can be removed relatively easily, and the liquid can also relatively easily reduce the number of foreign substances attached to the semiconductor chip surface. In addition, the surface (surface to be protected) of each semiconductor chip X on which the adhesive layer pieces 11' overlap can also be washed with the liquid.

[0096] In the removal step, the small pieces of adhesive layer (multiple small pieces 11' of the adhesive layer) swell due to the liquid. As a result, the adhesive force of the small pieces 11' of the adhesive layer to the semiconductor chip X weakens, making them easier to peel off from the semiconductor chip X. This allows the multiple small pieces 11' of the adhesive layer to be removed relatively easily. Furthermore, although the multiple small pieces 11' of the adhesive layer peeled off from the semiconductor chip X swell due to the liquid, they do not all dissolve in the liquid in a short period of time. Therefore, the multiple small pieces 11' of the adhesive layer can be recovered relatively easily. This reduces the load on the equipment used in the removal step and also reduces the environmental load when disposing of the liquid.

[0097] The water-containing liquid is not particularly limited as long as it is a liquid substance containing water. Such a liquid may contain 30% by mass or more of water, 50% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more of water. The liquid may contain a component that dissolves in water in addition to water. Examples of such a component include water-soluble organic solvents. Examples of such water-soluble organic solvents include monohydric alcohols having 4 or less carbon atoms, such as methanol, ethanol, propanols such as isopropyl alcohol, and butanols such as t-butanol.

[0098] In the removal step of this embodiment, the adhesive layer pieces 11' may be immersed in the stirred liquid to bring the liquid into contact with the adhesive layer pieces 11'. Alternatively, liquid sprayed from a nozzle or the like may be brought into contact with the adhesive layer pieces 11'. The temperature of the liquid is not particularly limited and may be set to, for example, 10°C or higher and 90°C or lower.

[0099] For example, in the removal step, the liquid is sprayed toward the semiconductor chips X that are respectively attached to the small pieces 30' of the die bond sheet while rotating a disk-shaped stage that supports the dicing tape 20 from below in the circumferential direction. This makes it possible to remove the multiple small pieces 11' of the adhesive layer that are respectively overlapping the semiconductor chips X. The rotation speed of the stage may be, for example, 500 rpm or more and 4000 rpm or less, the amount of liquid sprayed may be, for example, 0.05 L / min or more and 5.0 L / min or less, and the spraying time may be, for example, 5 seconds or more and 300 seconds or less.

[0100] According to the semiconductor device manufacturing method of this embodiment, the adhesive layer 11 is superimposed on the surface (circuit surface) of the semiconductor wafer W on which the circuit components are formed, thereby protecting the circuit surface until the adhesive layer 11 is removed. Specifically, the semiconductor wafer W is diced into small pieces while the semiconductor wafer W and the adhesive layer 11 are superimposed, thereby producing the semiconductor chips X. This prevents foreign matter, such as fragments that may be generated when the semiconductor wafer W is cleaved, from adhering to the circuit surface of the semiconductor chips X. Even if foreign matter is adhering to the circuit surface of the semiconductor chips X before the adhesive layer 11 is superimposed, the foreign matter can be removed when the small pieces 11' of the adhesive layer superimposed on the circuit surface of the semiconductor chips X are removed. This prevents foreign matter from adhering to the circuit surface of the semiconductor chips X to be manufactured.

[0101] 4F, in the pick-up process, the semiconductor chip X is peeled off from the adhesive fixing layer 22 of the dicing tape 20. More specifically, the pin members P are raised to push up the semiconductor chip X to be picked up through the dicing tape 20. The pushed-up semiconductor chip X is held by the suction jig J.

[0102] During the pickup process, the die bond sheet fragments 30' attached to the semiconductor chips X must be easily peeled from the adhesive fixing layer 22 of the dicing tape 20. Furthermore, during the expanding process, the dicing tape 20 must be stretched to effectively separate the die bond sheet 30, the semiconductor wafer W, and the adhesive layer 11 into small pieces, as needed. The dicing tape 20 described above is designed to effectively achieve this performance. For example, the dicing tape 20 is configured so that the adhesive fixing layer 22 hardens and the adhesive strength of the adhesive fixing layer 22 decreases when irradiated with active energy rays (e.g., ultraviolet rays). The adhesive strength of the adhesive fixing layer 22 is reduced by the hardening of the adhesive fixing layer 22 after irradiation, allowing the semiconductor chips X and the die bond sheet fragments 30' to be relatively easily peeled from the adhesive fixing layer 22 after irradiation. Dicing tapes 20 configured in this manner are commercially available.

[0103] In the bonding process, the semiconductor chip X with the die bond sheet piece 30' attached thereto is bonded to the adherend Z. In other words, the semiconductor chip X is bonded to the adherend Z via the die bond sheet piece 30'. Note that, in the bonding process, as shown in FIG. 4G, the semiconductor chips X with the die bond sheet piece 30' attached thereto may be stacked multiple times. In this embodiment, the semiconductor chip X is bonded to the adherend, such as a substrate or semiconductor chip X, via the die bond sheet piece 30'. When stacking multiple semiconductor chips X as described above in the bonding process, the stacked semiconductor chips X are prevented from having foreign matter attached to their circuit surfaces, thereby reducing the number of foreign matter that gets between one stacked semiconductor chip X and the other stacked semiconductor chip X. Note that the adherend Z may be, for example, an interposer, a wired circuit board, or a small piece of a substrate (when small pieces of a substrate are stacked and laminated).

[0104] In this embodiment, in order to protect the semiconductor chip X after the bonding step, a resin sealing step may be performed in which the semiconductor chip X is sealed (covered) with a thermosetting resin or the like.

[0105] In the above description of this embodiment, an example of dividing the semiconductor wafer W into small pieces using a blade dicing process has been given. However, the semiconductor wafer W may also be divided into small pieces through a so-called DBG process, in which the thickness of the semiconductor wafer W is reduced after the semiconductor wafer W is half-cut. In the half-cut process, for example, grooves are formed in the semiconductor wafer W to process the semiconductor wafer W into chips (dies) by a fracturing process, and the semiconductor wafer W is then ground to reduce its thickness. In the half-cut process, as shown in FIGS. 4H to 4K, for example, a wafer processing tape E is applied to the surface of the semiconductor wafer W opposite the circuit surface. With the wafer processing tape E applied, a dividing groove is formed. A backgrinding tape B is applied to the surface with the grooves formed, while the initially applied wafer processing tape E is peeled off. With the backgrinding tape B applied, the semiconductor wafer W is ground until it reaches a predetermined thickness. Then, a mounting process is performed, and then a semiconductor device is manufactured in the same manner as described above.

[0106] The semiconductor wafer W (substrate) before being diced into semiconductor chips X may be ground to a desired thickness by back-grinding, for example. Specifically, in the back-grinding, the semiconductor wafer W having a back-grinding tape B attached to its circuit surface may be ground to reduce the thickness of the semiconductor wafer W to the thickness of the semiconductor chips X to be fabricated later.

[0107] Processes other than those shown in the above specific examples may also be performed. For example, in processes such as plasma dicing and stealth dicing, the adhesive layer 11 may be superimposed on the circuit surface of the semiconductor wafer W, and after various processing steps are performed, the adhesive layer 11 may be removed. Alternatively, with the adhesive layer 11 disposed between the backgrind tape B and the semiconductor wafer W as described above, the grinding process may be performed as described above, and then the mounting process may be performed.

[0108] The methods for producing the pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, and electronic component device according to the embodiments of the present invention are as exemplified above, but the present invention is not limited to the methods for producing the pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, and electronic component device exemplified above. In other words, various forms used in general methods for producing pressure-sensitive adhesive compositions, pressure-sensitive adhesive sheets, and electronic component devices can be adopted within the scope that does not impair the effects of the present invention.

[0109] For example, as described above, the semiconductor wafer used in the manufacturing method of the present invention may be a semiconductor wafer having circuit surfaces formed on both sides, or, as described in other embodiments, a semiconductor wafer having a circuit surface formed on only one side. In other words, the semiconductor chip produced by the manufacturing method of the present invention may have circuit components arranged on only one side of the two sides, or may have circuit components arranged on both sides.

[0110] The present specification discloses the following: (1) A pressure-sensitive adhesive composition comprising: a compound that generates an acid upon at least one of heating or irradiation with active energy rays; and a protected compound having, in its molecule, a hydrophilic group protected by a protecting group that is deprotected by the acid. Such a pressure-sensitive adhesive composition can form, for example, an adhesive layer that is relatively easily removed upon contact with a liquid containing water after covering at least one surface of a substrate in an electronic component to be manufactured. (2) The pressure-sensitive adhesive composition according to (1) above, wherein the protected compound has, in its molecule, a structural unit of a protected carboxy group-containing (meth)acrylic monomer that contains, in its molecule, a carboxy group protected by the protecting group. (3) A pressure-sensitive adhesive composition according to (1) or (2) above, wherein the surface of a molded product of the pressure-sensitive adhesive composition according to (1) or (2) above has a contact angle of 70° or more and less than 120° before being heated or irradiated with active energy rays, and the heating or irradiating with active energy rays is performed using a high-pressure mercury lamp at a dose of 2500 mJ / cm. ２ (4) A pressure-sensitive adhesive composition, wherein the contact angle of water on the surface of a molded product of the pressure-sensitive adhesive composition according to any one of (1) to (3) above is 100° C. or less after the heating or the irradiation of the active energy ray is 2500 mJ / cm from a high-pressure mercury lamp, compared to the contact angle of water before the heating or the irradiation of the active energy ray. ２(5) A pressure-sensitive adhesive composition, having a water contact angle that is smaller by 3° or more after being exposed to at least one of irradiation with heat or active energy rays. (6) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of (1) to (4) above. (7) A pressure-sensitive adhesive sheet according to (5), further comprising a release liner overlaid on at least one surface of the pressure-sensitive adhesive layer. (8) A method for manufacturing an electronic component device, comprising the steps of: protecting at least one of the surfaces to be protected of both surfaces of a substrate by overlaying a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition on the surface to be protected; and removing the pressure-sensitive adhesive layer overlaid on the surface to be protected, wherein the pressure-sensitive adhesive composition comprises a compound that generates an acid when exposed to at least one of heating or active energy ray irradiation, and a protected compound having, in its molecule, a hydrophilic group that is protected by a protecting group and can be deprotected by the acid, and wherein the removing step generates the acid from the compound that generates an acid when exposed to at least one of heating or active energy ray irradiation to increase the hydrophilicity of the pressure-sensitive adhesive layer, and then removing the pressure-sensitive adhesive layer by contacting the pressure-sensitive adhesive layer with a liquid containing water. According to the method for manufacturing an electronic component device, the adhesive layer can prevent foreign matter from adhering to the surface to be protected, and further, the adhesive layer can be subsequently removed relatively easily by bringing a liquid containing water into contact with the adhesive layer. (8) The method for manufacturing an electronic component device according to (7) above, wherein a circuit component is disposed on the surface to be protected of the substrate.

[0111] The present invention will now be described in more detail with reference to experimental examples, but the present invention is not limited to these examples.

[0112] Each pressure-sensitive adhesive composition (adhesive layer) of the Examples and Comparative Examples was prepared, and each pressure-sensitive adhesive sheet including the adhesive layer was manufactured as follows. Details of each pressure-sensitive adhesive composition (adhesive layer) in each manufacturing method and evaluation results are shown in Tables 1 and 2.

[0113] [Examples 1 to 10, Comparative Examples 1 and 2] (Preparation of Protected Compounds) A (meth)acrylic polymer was prepared as a protected compound using each of the compositions shown in Tables 1 and 2. Specifically, the monomers shown in Tables 1 and 2, a polymerization initiator (azobisisobutyronitrile AIBN), and a reaction solvent (ethyl acetate) were mixed so that the solid content was 23% by mass. A solution polymerization reaction was carried out at a temperature of 65°C to 69°C to synthesize the polymer. Details of the monomers are as follows. <Protected (meth)acrylic acid type monomers (monomers containing a protected hydrophilic group)> - [Protected Monomer 1] t-butyl acrylate (tBA) Purchased product [Protected Monomer 2] n-Butoxyethyl acrylate (BEA) Purchased [Protected Monomer 3] n-Butoxyethyl methacrylate (BEMA) Purchased [Protected Monomer 4] Cyclohexoxyethyl acrylate (CHEA) Purchased [Protected Monomer 5] n-Propoxyethyl acrylate (PEA) Purchased <Other monomers> ・[BA] n-butyl acrylate (monomer without a protecting group) purchased product ・[BMA] n-butyl methacrylate (monomer without a protecting group) purchased product ・[4HBA] 4-hydroxybutyl acrylate (monomer without a protecting group) purchased product

[0114] (Preparation of Pressure-Sensitive Adhesive Sheets) An acid-generating compound (photoacid generator) was added to and mixed with the polymer solutions containing each polymer prepared as described above in the amounts shown in Tables 1 and 2 relative to the polymer solids. Each polymer solution was applied to a release liner a (PET film, 50 μm thick). Each release liner a had a surface that had been treated with a silicone release agent, and the polymer solution was applied to this surface using an applicator. This was then dried at 130°C for 2 minutes to form a 5 μm thick adhesive layer superimposed on one side of the release liner a. Release liner b (PET film, 25 μm thick) was then superimposed on the exposed surface of each adhesive layer. Each release liner b had a surface that had been treated with a silicone release agent, and this surface was attached to the adhesive layer. In this manner, pressure-sensitive adhesive sheets comprising an adhesive layer (adhesive composition) sandwiched between two release liners were prepared.

[0115] Details of the acid generating compound are as follows. All of the following raw materials are 50% by mass propylene carbonate solutions. [Photoacid generator] Sulfonium salt type Product name: "CPI-200K" manufactured by San-Apro Co., Ltd. Chemical name: diphenyl[4-(phenylsulfanyl)phenyl]sulfonium=trifluorotris(pentafluoroethyl)-λ ５ -Phosphanoid [Also known as: Diphenyl[4-(phenylthio)phenyl]sulfonium, trifluorotris(1,1,2,2,2-pentafluoroethyl)phosphate(1-) (1:1)] - Sulfonium salt type Product name: CPI-101A, manufactured by San-Apro Chemical name: Diphenyl[p-(phenylthio)phenyl]sulfonium hexafluoroantimonate - Sulfonium salt type Product name: CPI-310FG, manufactured by San-Apro [Thermal acid generator] - Sulfonium salt type Product name: TA-100FG, manufactured by San-Apro

[0116] (Pseudo-protection step) The release liner b was peeled off and removed from the prepared pressure-sensitive adhesive sheet to expose one side of the pressure-sensitive adhesive layer. This exposed surface was bonded to a bare silicon wafer (substrate) on a dicing tape using a laminator heated to 90°C. The bare silicon wafer was used instead of a semiconductor wafer. A commercially available dicing tape (product name "V-12SR" manufactured by Nitto Denko Corporation) was used.

[0117] Thereafter, a blade dicing process was carried out by a conventional method.

[0118] (Removal step) The adhesive layer is irradiated with 2,500 mJ / cm 2 by a high-pressure mercury lamp. ２ The adhesive layer was then subjected to an irradiation treatment (light irradiation treatment including ultraviolet light) to enhance the hydrophilicity of the adhesive layer. To remove the adhesive layer, a cleaning unit (product name: DFD6361) manufactured by DISCO Corporation was used to perform the removal process as follows. While rotating a circular stage supporting the dicing tape from below in the circumferential direction, water at 25°C was sprayed onto the small pieces of adhesive layer on the silicon chip. The stage rotation speed was 1000 rpm, and the water spraying time was 90 seconds.

[0119]

[0120]

[0121] <Physical Properties: Change in Contact Angle on the Surface of the Adhesive Layer (Before and After UV Irradiation / Heat Treatment)> A pressure-sensitive adhesive composition (adhesive layer) attached to a bare wafer was exposed to 2,500 mJ / cm ２An irradiation treatment was performed in which light containing ultraviolet light was irradiated so that the integrated light intensity was 100°C. Furthermore, a heat treatment was performed at 100°C for 30 seconds. The amount of water dropped was 0.15 μL, and the contact angle was measured before the above treatments (irradiation treatment and heat treatment) and 30 minutes after the end of the treatments. The contact angle 30 seconds after the water drop was measured at 25°C. Note that only Example 10 (containing a thermal acid generator) was subjected to the above treatment, which consisted of only a 1-hour heat treatment at 100°C, and then the contact angle was measured in the same manner as above. Evaluation was performed according to the following method. Specifically, when the contact angle before treatment was defined as a degree and the contact angle after irradiation treatment and heat treatment was defined as b degrees, a-b<3 was considered poor (×), a-b≧3 was considered good (◯), and of the above "good" results, a-b≧10 was considered excellent (◎). The results of the change in contact angle are shown in Tables 1 and 2.

[0122] <Evaluation: Removability / Swelling Peelability of Adhesive Layer (After UV Irradiation)> With the adhesive layer attached to the substrate (bare silicon wafer) (undiced), an irradiation treatment was carried out in the same manner as in the removal process described above. Furthermore, a heat treatment at 100°C for 30 seconds was carried out. Next, a water spray treatment was carried out in the same manner as in the removal process described above. Then, it was evaluated whether the adhesive layer formed from the adhesive composition swelled and peeled off from the substrate (bare silicon wafer). The following evaluation criteria were followed: (Excellent) ⊚: The adhesive layer swelled and peeled off, resulting in complete removal. (Good) ○: The adhesive layer swelled, but some remained without peeling. (Poor) ×: The adhesive layer swelled and did not peel off, resulting in most remaining. Note that the adhesion to the substrate (bare silicon wafer) before UV irradiation was good for all adhesive layers.

[0123] <Evaluation: Ease of Removal of Adhesive Layer (After UV Irradiation)> A bare wafer substrate with an adhesive layer formed from each adhesive composition attached thereto was diced (cut into small pieces) into 1 cm square pieces. The small test samples (small adhesive layer and chips) were irradiated with UV light at the same intensity as above. Thereafter, the test samples were placed in a beaker containing 100 mL of water, and the water was stirred with a stirrer for 3 minutes. After 3 minutes, the test samples were diced into 1 cm square pieces. ２It was visually confirmed whether the adhesive layer (adhesive composition) peeled from the chip of 100 mm area remained in almost the same shape. The evaluation criteria for ease of removing the adhesive layer are as follows: (Good) ○ The adhesive layer peeled off and the shape of the peeled adhesive layer could be confirmed (the adhesive layer was removed all at once in a relatively short time) (Poor) × The adhesive layer did not peel off

[0124] As can be seen from the above evaluation results, by manufacturing a semiconductor device using the semiconductor device manufacturing method of the embodiment, the surface to be protected can be protected. Furthermore, in the removal process, the multiple pieces of adhesive layer could be removed relatively easily with water. Therefore, semiconductor devices can be manufactured efficiently.

[0125] By carrying out the method for manufacturing a semiconductor device according to the embodiment as described above, it is possible to efficiently manufacture a semiconductor device in which a plurality of semiconductor chips are stacked together, with almost no foreign matter adhering thereto.

[0126] The method for manufacturing an electronic component device of the present invention is suitably used for manufacturing a semiconductor device having, for example, a semiconductor integrated circuit.

[0127] 10: Adhesive sheet, 11: Adhesive layer, 11': Small piece of adhesive layer, 15: Release liner, 20: Dicing tape, 21: Base material layer, 22: Adhesive fixing layer, 30: Die bond sheet, G: Glass carrier, W: Semiconductor wafer, X: Semiconductor chip, V: Through via, D: Electrode portion, B: Backgrinding tape.

Claims

1. A pressure-sensitive adhesive composition comprising: a compound that generates an acid upon at least one of heating or irradiation with active energy rays; and a protected compound having, in the molecule, a hydrophilic group that is protected by a protecting group and can be deprotected by the acid.

2. The pressure-sensitive adhesive composition according to claim 1, wherein the compound to be protected has a structural unit of a protected carboxy group-containing (meth)acrylic monomer that contains a carboxy group protected by the protecting group in the molecule.

3. In the surface of a molded product of the pressure-sensitive adhesive composition according to claim 1 or 2, the contact angle of water before the heating or the irradiation of the active energy rays is 2500 mJ / cm by a high-pressure mercury lamp. ２ The pressure-sensitive adhesive composition has a water contact angle smaller by 3° or more after being exposed to at least one of the above irradiation.

4. An adhesive sheet comprising an adhesive layer formed from the adhesive composition according to claim 1 or 2.

5. A method for manufacturing an electronic component device, comprising: a step of protecting at least one of the surfaces to be protected of both surfaces of a substrate by overlaying an adhesive layer formed from an adhesive composition on the surface to be protected; and a step of removing the adhesive layer overlaid on the surface to be protected, wherein the adhesive composition comprises a compound that generates an acid when subjected to at least one of heating or irradiation with active energy rays, and a protected compound having in its molecule a hydrophilic group that is protected by a protecting group and is deprotected by the acid, and in the removing step, the acid is generated from the compound that generates the acid when subjected to at least one of heating or irradiation with active energy rays, thereby increasing the hydrophilicity of the adhesive layer, and the adhesive layer is removed by contacting it with a liquid containing water.

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