Adhesive composition and adhesive sheet

Abstract

The objective is to provide an adhesive composition for forming an adhesive layer that can be relatively easily removed when it comes into contact with a liquid containing water after protecting the surface to be protected. [Solution] An adhesive composition comprising a compound that generates acid upon heating or irradiation with active energy rays, and a protected compound having a hydrophilic group in its molecule that is protected by a protecting group and deprotected by the acid, wherein, on the surface of a molded product of the adhesive composition, the contact angle of water before heating or irradiation with active energy rays is 2500 mJ / cm using a high-pressure mercury lamp. 2 The present invention provides an adhesive composition, etc., in which the contact angle of water after being irradiated by at least one of the following is 10° or less smaller.

Description

[Technical Field]

[0001] [Cross-reference of related applications] This application claims priority to Japanese Patent Application No. 2023-173900, which is incorporated into the description of this application by reference. [Technical field] The present invention relates to an adhesive composition and an adhesive sheet used, for example, in the manufacture of electronic component devices such as semiconductor integrated circuits. The present invention also relates to a method for manufacturing electronic component devices using the above-mentioned adhesive composition or adhesive sheet. [Background technology]

[0002] Conventionally, there are known methods for manufacturing electronic components, such as semiconductor integrated circuits. In this type of electronic component manufacturing method, for example, a substrate such as a silicon wafer is divided into smaller pieces to produce a large number of chips. During this type of processing, when the substrate is divided into smaller pieces, a small portion of the substrate may become a minute fragment, resulting in the generation of minute foreign matter. If circuit components such as circuit wiring or electrodes are located 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 no circuit components such as circuit wiring or electrodes are located. If 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 or not circuit components are located on the side where the foreign matter is attached.

[0003] In contrast, a method for manufacturing electronic component devices is known in which protective adhesive tape is attached to at least one side of the substrate before performing the above-described processing (for example, Patent Document 1).

[0004] In the method for manufacturing an electronic component device described in Patent Document 1, a semiconductor protective adhesive tape is used as the protective adhesive tape, which has a base material and a photocurable adhesive layer (adhesive layer) superimposed on one side of the base material. The base material is designed to have a specific thickness and a specific heat shrinkage rate after being heated at 150°C for 30 minutes. The photocurable adhesive layer (adhesive layer) is formed from a composition with a predetermined compound composition, has a predetermined thickness, and is designed to have a relatively small predetermined adhesive strength after light irradiation. More specifically, in the method for manufacturing an electronic component device described in Patent Document 1, first, a photocurable adhesive layer (adhesive layer) of protective adhesive tape is placed on the circuit surface of a substrate on which a circuit is formed (hereinafter referred to as a semiconductor package), and the protective adhesive tape and the semiconductor package are divided into smaller pieces while they are stacked together. Next, the small pieces of semiconductor package and protective adhesive tape are attached to a temporary fixing tape so that the circuit surface of the small pieces of semiconductor package faces the temporary fixing tape, and the temporary fixing tape and the base material of the protective adhesive tape are in contact. Subsequently, a metal film is formed on a part of the surface of the semiconductor package while it is temporarily fixed. Finally, the semiconductor package is picked up by peeling it apart from the circuit surface of the semiconductor package and the photocurable adhesive layer.

[0005] According to the method for manufacturing electronic components described in Patent Document 1, when processing semiconductor packages and protective adhesive tapes into smaller pieces, the circuit surface of the semiconductor package can be protected by covering it with the protective adhesive tape. Subsequently, the protective adhesive tape can be removed by peeling it off from the circuit surface of the semiconductor package and the photocurable adhesive layer of the protective adhesive tape fixed to the temporary fixing tape. The peeling force when removing the photocurable adhesive layer (adhesive layer) of the protective adhesive tape is weakened by the hardening of the photocurable adhesive layer by light irradiation. In addition, the heat generated when forming a metal film on a part of the surface of the semiconductor package creates shrinkage stress (residual strain) inside the substrate, and because the substrate becomes more easily deformed by the shrinkage stress (residual strain), the above-mentioned peeling is more likely to occur. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-147579 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in the method for manufacturing electronic component devices described in Patent Document 1, it is necessary to adjust, for example, the peeling speed, etc., so that the circuit surface is not damaged by the peeling force when peeling the circuit surface of the semiconductor package from the photocurable adhesive layer (adhesive layer), and the process of removing the adhesive layer is not necessarily simple. Furthermore, the process of removing the adhesive layer can become complicated because temporary fixing tape is used for the peeling as described above. In addition, after peeling, a part of the photocurable adhesive layer (adhesive layer) may remain on the circuit surface, and it is not always possible to remove the photocurable adhesive layer (adhesive layer) simply. Even when removing a photocurable adhesive layer (adhesive layer) that overlaps a non-circuit surface where a circuit surface has not been formed, the above-mentioned problems may occur.

[0008] Therefore, there is a need for an adhesive composition that can not only protect a surface to be protected (a surface to be protected) by covering it with at least one surface of a substrate or the like during processing, but also form an adhesive layer that can be removed relatively easily from the surface to be protected after processing is complete. In particular, there is a demand for adhesive compositions that can form an adhesive layer that can be removed relatively easily when in contact with a solvent such as water.

[0009] However, adhesive compositions for forming an adhesive layer that not only covers and protects the surface to be protected, but can also be removed relatively easily by contact with a water-containing liquid after protection, have not yet been sufficiently investigated.

[0010] Therefore, the object of the present invention is to provide an adhesive composition for forming an adhesive layer that can be removed relatively easily by contact with a liquid containing water after protecting a surface to be protected. Another object is to provide an adhesive sheet comprising an adhesive layer formed from the adhesive composition. Furthermore, another object is to provide a method for manufacturing an electronic component device using the adhesive layer. [Means for solving the problem]

[0011] In order to solve the above problems, the adhesive composition according to the present invention is A compound that produces acid upon heating or irradiation with active energy rays, The protected compound comprises a hydrophilic group protected by a protecting group and having a hydrophilic group in its molecule that is deprotected by the acid.

[0012] The adhesive sheet according to the present invention comprises an adhesive layer formed with the above-mentioned adhesive composition.

[0013] The method for manufacturing an electronic component device according to the present invention is: A step of protecting a surface to be protected by overlapping an adhesive layer formed from an adhesive composition onto at least one of the two surfaces of the substrate to be protected, The step includes removing the adhesive layer that overlaps the surface to be protected, The aforementioned adhesive composition is The compound comprises a compound that produces an acid upon heating or irradiation with active energy rays, and a protected compound having a hydrophilic group in its molecule that is protected by a protecting group and deprotected by the acid, In the removal step, the acid is generated from the acid-producing compound by heating or irradiation with active energy rays to increase the hydrophilicity of the adhesive layer, and the adhesive layer is removed by bringing it into contact with a liquid containing water. [Effects of the Invention]

[0014] The adhesive composition according to the present invention can form an adhesive layer that can be relatively easily removed when it comes into contact with a liquid containing water after covering the surface to be protected. The adhesive sheet according to the present invention includes the above-mentioned adhesive layer. The method for manufacturing an electronic component device according to the present invention can suppress the adhesion of foreign substances to the surface to be protected by the above-mentioned adhesive layer, and moreover, thereafter, a liquid containing water can be brought into contact with the above-mentioned adhesive layer to relatively easily remove the above-mentioned adhesive layer.

Brief Description of the Drawings

[0015] [Figure 1] Schematic cross-sectional view of an example of the adhesive sheet of the present embodiment cut in the thickness direction. [Figure 2A] Schematic cross-sectional view showing an example of the state of the protection step in the method for manufacturing an electronic component device of the present embodiment. [Figure 2B] Schematic cross-sectional view showing an example of the state of the protection step in the method for manufacturing an electronic component device of the present embodiment. [Figure 2C] Schematic cross-sectional view showing an example of the state before dicing the substrate in the method for manufacturing an electronic component device of the present embodiment. [Figure 2D] Schematic cross-sectional view showing an example of the state after dicing the substrate in the method for manufacturing an electronic component device of the present embodiment. [Figure 2E] Schematic cross-sectional view showing an example of the state of the removal step in the method for manufacturing an electronic component device of the present embodiment. <G [Figure 2F] Schematic cross-sectional view showing an example of the state of the removal step in the method for manufacturing an electronic component device of the present embodiment. [Figure 3A] Cross-sectional view of an example of a dicing tape cut in the thickness direction. [Figure 3B] Cross-sectional view of an example of a dicing die bond film cut in the thickness direction. [Figure 4A] Cross-sectional view schematically showing the state after performing the mounting step and the protection step in the present embodiment. [Figure 4B] Cross-sectional view schematically showing the state during the blade dicing process in the present embodiment. [Figure 4C]A schematic cross-sectional view showing the state after the blade dicing process in this embodiment has been carried out. [Figure 4D] A schematic cross-sectional view illustrating the removal process in this embodiment. [Figure 4E] A schematic cross-sectional view illustrating the removal process in this embodiment. [Figure 4F] A schematic cross-sectional view illustrating the pickup process in this embodiment. [Figure 4G] A schematic cross-sectional view illustrating the joining process in this embodiment. [Figure 4H] A schematic cross-sectional view showing the half-cutting process of a semiconductor wafer in another example of this embodiment. [Figure 4I] A schematic cross-sectional view showing the half-cutting process of a semiconductor wafer in another example of this embodiment. [Figure 4J] A schematic cross-sectional view showing the half-cutting process of a semiconductor wafer in another example of this embodiment. [Figure 4K] A schematic cross-sectional view illustrating the mounting process in another example of this embodiment. [Modes for carrying out the invention]

[0016] Hereinafter, embodiments of the adhesive composition, adhesive sheet, and method for manufacturing electronic component devices according to the present invention will be described in order with reference to the drawings.

[0017] The adhesive composition of this embodiment comprises a compound that generates an acid upon heating or irradiation with active energy rays, and a protected compound having a hydrophilic group in its molecule that is protected by a protecting group and deprotected by the acid. The adhesive composition of this embodiment is used, for example, to form an adhesive layer that protects the surface to be protected of a substrate constituting an electronic component device.

[0018] By overlapping an adhesive layer formed with the above-described adhesive composition onto the surface to be protected, it is possible to prevent foreign matter from adhering to the substrate surface (the surface to be protected) until the adhesive layer overlapping the surface is removed. For example, when processing to break down the substrate and the adhesive layer into smaller pieces while the substrate and the adhesive layer formed with the adhesive composition are overlapping, it is possible to prevent foreign matter such as fragments that may be generated as a result of the breaking down from adhering to the surface to be protected, thereby protecting the surface to be protected. Furthermore, by applying heat treatment or irradiation with active energy rays to the adhesive layer, acid is generated from the acid-producing compound. As a result, the protective groups that were protecting the hydrophilic groups of the compound to be protected detach from the hydrophilic groups, increasing the hydrophilicity of the adhesive layer formed by the adhesive composition. The adhesive layer with increased hydrophilicity swells upon contact with a liquid containing water and can be peeled off relatively easily from the surface to be protected. Therefore, the adhesive layer can be easily removed from the surface to be protected. Consequently, compared to, for example, applying a release tape to the adhesive layer and removing the adhesive layer together with the release tape, the adhesive layer can be easily removed from the surface to be protected. Thus, the adhesive layer formed with the above adhesive composition can not only protect the surface of the substrate, which is a component of the manufactured electronic device, but can also be removed relatively easily from the protected surface with a water-containing liquid after protection.

[0019] In this embodiment, the acid-producing compound is, for example, an acid generator that produces acid by heating or irradiation with active energy rays, at least one of the two. Examples of the acid-producing compound include photoacid generators and thermal acid generators.

[0020] The above adhesive composition contains a compound that produces the above acid, and therefore has the property of becoming more hydrophilic upon at least one of heat treatment or irradiation with active energy rays such as ultraviolet light. The above adhesive composition only needs to have a predetermined level of hydrophilicity after the hydrophilic groups of the compound to be protected are deprotected. Therefore, in a state where the hydrophilic groups of the compound to be protected are protected, the above adhesive composition may have a hydrophilicity of less than the predetermined level or a hydrophilicity of the predetermined level. If the above adhesive composition has a hydrophilicity of a predetermined level or higher, the adhesive layer formed with the above adhesive composition may swell in a liquid containing water. As for the compounds that produce the above-mentioned acids, compounds that produce acids upon irradiation with active energy rays (particularly ultraviolet light) are preferred.

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

[0022] Examples of hydrophilic groups protected by protecting groups include carboxyl groups (-COOH), hydroxyl groups (-OH), sulfol groups (-SO3H), and amino groups (-NH2).

[0023] Examples of protective groups that can protect hydrophilic groups include the following: When the hydrophilic group to be protected is a carboxyl group, examples of protecting groups include tert-butyl groups, alkoxyalkyl groups, or cyclic acetal (dioxolane) groups. Examples of alkoxyalkyl groups include methoxymethyl groups, ethoxyethyl groups, propoxyethyl groups, butoxyethyl groups, or cyclohexoxyethyl groups. In alkoxyalkyl groups, the number of consecutively bonded carbon atoms may be between 2 and 4. When the hydrophilic group to be protected is a hydroxyl group, examples of protecting groups include trityl group, alkoxymethyl group, tetrahydropyranyl group, cyclic acetal (dioxolane) group, tert-butyldimethylsilyl group, or (tert-)butoxycarbonyl group. When the hydrophilic group to be protected is an amino group, examples of protecting groups include the (tert-)butoxycarbonyl group.

[0024] The protecting group described above exists in the protected compound in a state where it is chemically bonded to the hydrophilic group. The notation for the protecting group described above does not necessarily directly represent the state in which the hydrophilic group and the protecting group are bonded. For example, if the hydrophilic group is a carboxyl group and the protecting group is a tert-butyl group, an ester bond exists formed by the reaction of the carboxyl group with tert-butyl alcohol, but even in such a case, the protecting group is still described as a tert-butyl group. Furthermore, the protected hydrophilic groups are also listed under their names before they were protected.

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

[0026] The above protected compound may have constituent units of a (meth)acrylic acid type monomer containing a hydrophilic group protected by a protecting group in its molecule. In other words, the above protected compound may be a polymer obtained by polymerizing protected (meth)acrylic acid type monomers containing a hydrophilic group protected by a protecting group. Note that the notation "protected (meth)acrylic acid type monomer" includes both monomers in which the carboxyl group of (meth)acrylic acid is protected, and monomers in which the hydrophilic group in (meth)acrylic acid ester is protected. Examples of the protected (meth)acrylic acid type monomers mentioned above include protected carboxyl group-containing (meth)acrylic monomers in which the carboxyl group is protected by a protecting group, protected hydroxyalkyl (meth)acrylate monomers in which the hydroxyl group is protected by a protecting group, or protected 2-acrylamido-2-methylpropanesulfonic acid monomers in which the sulfo group is protected by a protecting group.

[0027] Examples of the protected compounds mentioned above include oligomers or polymers having constituent units of a protected (meth)acrylic acid type monomer containing a hydrophilic group protected by a protecting group. The above oligomer may be, for example, an oligomer in which 3 to 10 protected carboxyl group-containing (meth)acrylic monomers, whose carboxyl groups are protected by a protecting group, are linked together by a polymerization reaction. The above oligomer may be, for example, an oligomer in which 3 to 10 protected hydroxyalkyl (meth)acrylate monomers, whose hydroxyl groups are protected by a protecting group, are linked together by a polymerization reaction. The above oligomer may be, for example, an oligomer in which 3 to 10 protected (meth)acrylamide alkylsulfonic acid monomers, whose sulfo groups are protected by protecting groups, are linked together by a polymerization reaction.

[0028] The polymer or oligomer used as the protected compound described above has, for example, a main chain and a plurality of side chains in its molecule. The main chain is, for example, a covalent chain formed by a radical polymerization reaction. Preferably, at least a portion of the main chain is a covalent chain formed by a polymerization reaction of a protected (meth)acrylic acid type monomer containing a carboxyl group protected by a protecting group as a hydrophilic group. The side chains may have, for example, hydrophilic groups. These hydrophilic groups may be, for example, hydroxyl or carboxyl groups. The hydrophilic groups are protected by protecting groups in the side chains of the polymer or oligomer.

[0029] The above oligomer may be a homopolymer of monomers containing hydrophilic groups protected by a protecting group, or it may be a copolymer of a monomer containing hydrophilic groups protected by a protecting group and a monomer other than such monomer. Similarly, the polymer described above may be a homopolymer or copolymer of monomers containing hydrophilic groups protected by a protecting group. The average molecular weight of the polymer described above may be between 50,000 and 900,000.

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

[0031] As the polymer or oligomer mentioned above, a (meth)acrylic polymer is preferred, which contains at least one constituent unit of the above-mentioned protected carboxyl group-containing (meth)acrylic monomer in its molecule. Examples of constituent units of protected carboxyl group-containing (meth)acrylic monomers include constituent units of protected (meth)acrylic acid monomers in which the carboxyl group is protected by a protecting group, or constituent units of protected carboxyalkyl (meth)acrylate monomers in which the carboxyl group is protected by a protecting group. Specific examples of the constituent units of protected (meth)acrylic acid monomers are the constituent units of protected acrylic acid monomers or methacrylic acid monomers. Specific examples of the constituent units of protected carboxyalkyl (meth)acrylate monomers are the constituent units of protected carboxyethyl (meth)acrylate.

[0032] The above (meth)acrylic polymer preferably contains 50% by mass or more of the above-mentioned protected carboxyl group-containing (meth)acrylic monomer constituent units in its molecule, more preferably 80% by mass or more. The above (meth)acrylic polymer may also contain 95% by mass or more of the above-mentioned protected carboxyl group-containing (meth)acrylic monomer constituent units. The (meth)acrylic polymer described above contains a greater proportion of the constituent units of the protected carboxyl group-containing (meth)acrylic monomer, resulting in a more water-resistant adhesive layer formed from the adhesive composition described above. On the other hand, the adhesive layer subjected to heat treatment or active energy ray irradiation in the removal process (described in detail later) can be more easily removed with a water-containing liquid.

[0033] Examples of monomers that can copolymerize with the above-mentioned protected (meth)acrylic acid type monomer include vinyl acetate, alkyl (meth)acrylate [(meth)acrylate alkyl ester], hydroxyalkyl (meth)acrylate [(meth)acrylate hydroxyalkyl ester], carboxyalkyl (meth)acrylate [(meth)acrylate carboxyalkyl ester], (meth)acrylic acid, and (meth)acrylate having a polyethylene glycol chain. In other words, the above-mentioned (meth)acrylic polymer may have, in addition to the constituent units of the above-mentioned protected carboxyl group-containing (meth)acrylic monomer, each of the constituent units of the monomers listed above in its molecule. In the above-mentioned (meth)acrylic polymer, the content of the constituent units of alkyl (meth)acrylate [(meth)acrylate alkyl ester] may be less than 5% by mass (including 0% by mass). In this specification, the term "(meth)acrylic" includes both "acrylic" and "methacrylic." The same applies to "(meth)acrylate."

[0034] The alkyl (meth)acrylates mentioned above are preferably alkyl (meth)acrylates in which the alkyl portion has 6 to 22 carbon atoms. 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, or behenyl (meth)acrylate. By using alkyl (meth)acrylates in which the alkyl portion has 6 to 22 carbon atoms, the glass transition temperature (Tg) of the (meth)acrylic polymer becomes relatively low, which can make the (meth)acrylic polymer easier to handle. The hydrocarbon portion may be linear or branched. Preferably, the hydrocarbon portion consists only of saturated hydrocarbons.

[0035] As the above (meth)acrylic polymer, a (meth)acrylic copolymer having at least one constituent unit of a protected carboxyl group-containing (meth)acrylic monomer and one constituent unit of the above alkyl (meth)acrylate in its molecule is preferred.

[0036] In this embodiment, the compound that generates the above-mentioned acid is a compound that generates a new acid by at least one of heat treatment and irradiation treatment with active energy rays. Heat treatment and irradiation with active energy rays will be described in detail later.

[0037] Examples of compounds that produce the above-mentioned acid include photoacid generators and thermal acid generators, with photoacid generators being preferred because they can more reliably deprotect the protecting group. It should be noted that a single compound may possess the functions of both a photoacid generator and a thermal acid generator. In other words, for example, a particular acid generator may produce acid through both heat treatment and irradiation with active energy rays. When the acid-producing compound generates acid through light irradiation or heat treatment, the protective groups in the protected compound contained in the adhesive layer are deprotected, and hydrophilic groups are exposed. This increases the hydrophilicity of the adhesive layer. Therefore, the adhesive layer can be more easily removed from the protected surface by contact with a liquid containing water.

[0038] Photoacid generators, as acid generators, are photocationic polymerization initiators commonly used for cationic polymerization, for example, while thermal acid generators, as acid generators, are thermal cationic polymerization initiators commonly used for cationic polymerization, for example. Commercially available products can be used as the photoacid generator or thermal acid generator mentioned above.

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

[0040] Examples of onium salt compounds include iodonium salt compounds, sulfonium salt compounds, oximesulfonate compounds, and diazonium salt compounds. Among 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 trifluoromethanesulfate, diphenyliodonium nonafluoron-butanesulfonate, diphenyliodonium perfluoron-octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-fluorophenyl)iodonium triflate, and diphenyliodonium hexafluorophosphate. 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 5Examples include phosphanoids, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoron-butanesulfonate, triphenylsulfonium camphorsulfonate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, triphenylsulfonium trifluoromethanesulfonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, triphenylsulfonium adamantane carboxylate 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, and triphenylsulfonium hydroxide. Other examples include the sulfonium salt compounds used in the following examples.

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

[0044] Examples of diazonium salt compounds include 4-nitrobenzenediazonium tetrafluoroborate.

[0045] Examples of commercially available onium salt compounds include, for example, Optomer SP-150, Optomer SP-170, Optomer SP-171 (all manufactured by ADEKA), UVE-1014 (manufactured by General Electronics), OMNICAT250, OMNICAT270 (both manufactured by IGMresin), IRGACURE290 (manufactured by BASF), SunAid SI-60L, SunAid SI-80L, SunAid SI-100L (all manufactured by Sanshin Chemical Industry Co., Ltd.), CPI-100B, CPI-100P, CPI-101A, CPI-200K (all manufactured by SunApro Co., Ltd.).

[0046] Examples of sulfonimide compounds used as photoacid generators include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)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 disulfonyl diazomethane compounds used 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 thermal acid generators include sulfonium salts such as aryldiazonium salts, diaryliodonium salts, triarylsulfonium salts, or diarylmonoalkylsulfonium salts, triarylsulfoxonium salts, pyridinium salts, quinolinium salts, isoquinolinium salts, sulfonic acid esters, and iron arene complexes. Examples of anions constituting the above sulfonium salts include trifluorotris(perfluoroethyl) phosphate or hexafluorophosphate.

[0050] Acid generators, such as photoacid generators or thermal acid generators, preferably have good compatibility with the polymers contained in the adhesive composition. Ionic acid generators are preferred as acid generators, and ionic photoacid generators are more preferred.

[0051] In the above adhesive composition, the amount of the acid-producing compound relative to 100 parts by mass of the protected compound is preferably 0.2 parts by mass or more, and more preferably 1.0 part by mass or more. As a result, the adhesive layer formed with the adhesive composition can have higher hydrophilicity after heat treatment or irradiation with active energy rays, and therefore becomes more easily swollen in liquids containing water. The amount of the acid-producing compound relative to 100 parts by mass of the protected compound is preferably 10 parts by mass or less. This makes it possible to more effectively suppress the residue of the acid-producing compound in the adhesive composition.

[0052] The adhesive composition of this embodiment may further contain, in addition to the above-mentioned components, a solvent, a surfactant, and the like. Examples of solvents include water or an organic solvent. As the organic solvent, a relatively volatile organic solvent is preferred. Examples of such organic solvents include ethanol and methanol.

[0053] The adhesive composition of this embodiment preferably does not contain either a photopolymerization initiator or a thermal polymerization initiator. If the adhesive composition of this embodiment contains a photopolymerization initiator or a thermal polymerization initiator, the protected hydrophilic groups in the protected compound may chemically react with the photopolymerization initiator and the thermal polymerization initiator. When this reaction occurs, the hydrophilic groups may disappear and change into non-hydrophilic organic groups. Therefore, the adhesive layer formed from the adhesive composition may have difficulty retaining its hydrophilicity even after heat treatment or irradiation with active energy rays. Consequently, it may be difficult to remove the adhesive layer with a liquid containing water.

[0054] The adhesive composition of this embodiment may be a solid that does not flow, or it may be fluid. If the adhesive composition contains a solvent, it may be fluid.

[0055] The adhesive composition of this embodiment can be manufactured by mixing the above-mentioned polymer, an acid-generating compound such as the above-mentioned photoacid generator, and a solvent as needed, using a general method. Alternatively, the adhesive composition of this embodiment may be manufactured by volatilizing the solvent after the above mixing.

[0056] The adhesive composition of this embodiment can be used, for example, to produce an adhesive sheet, as described later.

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

[0058] The adhesive sheet 10 of this embodiment comprises at least an adhesive layer 11, as shown in Figure 1. The adhesive sheet 10 of this embodiment may further comprise a release liner 15 that overlaps at least one side of the adhesive layer 11. The release liner 15 may overlap one or both sides of the adhesive layer 11. Please note that each figure in the drawings is a schematic representation and does not necessarily reflect the actual aspect ratio of the object. The same applies to the other drawings.

[0059] In this embodiment, the adhesive layer 11 of the adhesive sheet 10 is formed in sheet form from the adhesive composition described above. When the 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 the substrate.

[0060] The adhesive layer 11 described above has flexibility that allows it to be deformed with relatively weak force. Furthermore, the adhesive layer 11 has adhesive properties that allow it to adhere to, for example, the surface of a substrate to be protected. In other words, the adhesive layer 11 can be used as a pressure-sensitive sheet-type adhesive that adheres to the surface to be protected by being pressed against it.

[0061] In this embodiment, the water contact angle of the 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°. On the other hand, heating and irradiation with active energy rays (2500 mJ / cm² using a high-pressure mercury lamp) 2 The water contact angle of the adhesive layer 11 after being subjected to at least one of the irradiations is preferably 100° or less.

[0062] The above contact angle is measured as follows. Specifically, the contact angle of water on one side of the adhesive layer 11 (the side that is 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 respect to 0.15 μL of water is measured at 25°C using a fully automatic contact angle measuring device (for example, Kyowa Interface Science Co., Ltd., product name: DM-500). The average value of five measurements is adopted. The above contact angle is measured 30 seconds after water is dropped onto a smooth surface of a molded product (e.g., adhesive layer 11) molded from the adhesive composition. If the adhesive composition contains an organic solvent, the above contact angle is measured on the molded product (e.g., adhesive layer 11) after 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 / or irradiation (irradiation treatment) (hereinafter sometimes simply referred to as "after treatment") is preferably 3° or more smaller than the water contact angle of the adhesive layer 11 before being subjected to heating (heat treatment) or irradiation (irradiation treatment) (before treatment). A larger change in the contact angle allows for a better balance between the water resistance of the adhesive layer 11 before the treatment and the water swelling properties of the adhesive layer 11 after the treatment (good water penetration into the adhesive layer 11). Furthermore, the above change in contact angle may be 50° or less.

[0064] The contact angle of the adhesive layer 11 after the above-described treatment is a measurement taken after the above-described treatment is carried out under the following conditions. (If the adhesive layer contains a photoacid generator) • Activated energy ray irradiation treatment: 2500 mJ / cm using a high-pressure mercury lamp. 2 After irradiation, Heat treatment: 100°C for 30 seconds, then leave for 30 minutes. (If the adhesive layer contains a heat-induced acid generator) • Heat treatment: 100°C for 1 hour, then let stand for 30 minutes.

[0065] The adhesive layer 11 may be formed, for example, by applying the adhesive composition containing the solvent to one side of a substrate and then volatilizing the solvent. Alternatively, the adhesive layer 11 may be formed by applying the adhesive composition containing the solvent to one side of a release liner 15 and then volatilizing the solvent. Preferably, the formed adhesive layer 11 does not contain the solvent that is added to the adhesive composition to impart fluidity. The adhesive layer 11 may be formed, for example, from the above-mentioned adhesive composition that does not contain a solvent by a general molding method.

[0066] In the adhesive sheet described above, the thickness of the 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. Such a thickness may also be 40 μm or less. If the adhesive layer 11 is a laminate, the above thickness is the total thickness of the laminate.

[0067] The adhesive layer 11 described above may have the property of being broken into small pieces when stretched in the planar direction. An adhesive layer 11 having such properties is preferably used when manufacturing electronic component devices via a stealth processing process using a stealth dicing apparatus described later. Similarly, it is preferably used when manufacturing electronic component devices via a DBG process (described in detail later). Furthermore, since the adhesive layer 11 described above can also be suitably used when manufacturing electronic component devices through a blade dicing process (described in detail later), it does not necessarily have to possess the physical properties described above.

[0068] The protective sheet 1 of this embodiment is used, for example, in the process of manufacturing electronic component devices. 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 by being attached to the surface to be protected of an electronic component (a type of substrate). Examples of the electronic components mentioned above include semiconductor wafers, semiconductor chips, substrates such as wiring circuit boards, interconnected wiring circuit boards formed by connecting multiple wiring circuit boards, or pseudo-wafers.

[0069] The semiconductor chip described above typically comprises a semiconductor chip body and electrode portions arranged on one or both sides of the semiconductor chip body and electrically connected to electrode portions of other components. Examples of other components include a wiring circuit board or other semiconductor chips. The semiconductor chip has, for example, a circuit surface on at least one side where a circuit is formed. Specifically, the semiconductor chip described above may be a TSV (Through Silicon Via) type semiconductor chip comprising a pair of electrode portions arranged on both sides of the semiconductor chip body, and a conductive portion that penetrates the semiconductor chip body in the thickness direction so as to conduct electricity between one of the electrode portions and the other. In a TSV type semiconductor chip, the circuit surface may be formed on only one side, or the circuit surface may be formed on both sides. Furthermore, the semiconductor chip circuit may be equipped with sensor elements (for example, light-receiving elements or vibration elements). An example of this type of semiconductor chip is a sensor chip. Examples of sensor chips include CMOS (Complementary Metal-Oxide Semiconductor) chips and MEMS (Micro Electro Mechanical Systems) chips.

[0070] The pseudo-wafer described above comprises, for example, a support substrate and a package in which a plurality of semiconductor chips arranged on the support substrate are collectively sealed in resin. The pseudo-wafer may also be the package removed from the support substrate. A redistribution 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 such redistribution layer. Note that the divided pseudo-wafer, each containing at least one semiconductor chip, may be an electronic component.

[0071] As mentioned above, there are various types of electronic components that have a surface to be protected, and various electronic components can serve as substrates.

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

[0073] The method for manufacturing the electronic component device of this embodiment is: A step of protecting the surface to be protected by overlapping an adhesive layer 11 formed from an adhesive composition onto at least one of the two surfaces of the substrate to be protected (protection step), The process includes removing the adhesive layer 11 that overlaps the surface to be protected (removal step), The aforementioned adhesive composition is The compound comprises a compound that produces an acid upon heating or irradiation with active energy rays, and a protected compound having a hydrophilic group in its molecule that is protected by a protecting group and deprotected by the acid, In the removal step, the acid is generated from the acid-producing compound by heating or irradiation with active energy rays to increase the hydrophilicity of the adhesive layer 11, and the adhesive layer 11 is removed by bringing it into contact with a liquid containing water.

[0074] In the above protection process, as shown in Figure 2A, an adhesive sheet 10 having a release liner 15 on one side of the adhesive layer 11 may be used to protect the surface of the substrate S to be protected. For example, after placing the adhesive layer 11 of the adhesive sheet 10 on the surface of the substrate S to be protected, the release liner 15 may be peeled off from the adhesive layer 11 (see Figure 2B).

[0075] The manufacturing method of the electronic component device of this embodiment is further as shown in Figures 2C and 2D, The process may include a step of dividing the stacked substrate S and adhesive layer 11 into smaller pieces with spacing in the planar direction, thereby producing multiple small pieces of the stacked material in which the small pieces of substrate chip S' and the small pieces of adhesive layer 11' overlap. Note that before division, the substrate S may have weak areas or other structures formed inside to facilitate fragmentation.

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

[0077] The electronic component device manufactured by the manufacturing method of this embodiment comprises at least one of the various electronic components described above. Examples of electronic component devices include semiconductor devices such as semiconductor integrated circuits equipped with semiconductor chips, devices equipped with system LSIs having complementary MOS (CMOS), or devices equipped with MEMS (Micro Electro Mechanical Systems) in which mechanical components, sensors, actuators, or electronic circuits are integrated on a single silicon substrate, glass substrate, or organic material substrate by microfabrication technology. The manufactured electronic component device may also be a device equipped with 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 protected surface (hereinafter also simply referred to as the protected surface) may be only one side of the substrate or both sides. Circuit components (described in detail later) may or may not be arranged on the protected surface.

[0079] The substrate is not particularly limited in material as long as it is in the form of a plate. Examples of substrate materials include glass, silicon, stainless steel (SUS), plastic, or ceramic. Examples of substrates include semiconductor wafers, sensor wafers such as CMOS or MEMS, pseudo-wafers, or wiring circuit boards.

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

[0081] The following provides a detailed explanation of the process of manufacturing semiconductor integrated circuits (semiconductor devices) as electronic components.

[0082] Generally, a semiconductor device manufacturing method comprises 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 on it and assembled.

[0083] In the subsequent process, for example, a weak area is formed on the wafer (semiconductor wafer) that has a circuit surface formed on it, in order to break it into smaller semiconductor chips (dies), and the adhesive fixing layer of dicing tape is attached to the side opposite to 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, thereby breaking the semiconductor wafer into smaller semiconductor chips using the weak area as the boundary. After that, the small semiconductor chips are peeled off from the adhesive fixing layer of the dicing tape.

[0084] The subsequent processes described above include, for example, a stealth processing step in which a fragile area is formed on the wafer using laser light or the like to break down the wafer into smaller chips (dies); a mounting step in which the semiconductor wafer is fixed by attaching the side of the semiconductor wafer opposite to the circuit side to a dicing tape; an expanding step in which the semiconductor wafer is broken down into semiconductor chips (dies) by stretching the dicing tape in the planar direction; a pick-up step in which the semiconductor chip is peeled off and removed from the adhesive fixing layer; and a bonding step in which the removed semiconductor chip is bonded to a substrate. Semiconductor integrated circuits (semiconductor devices) are manufactured, for example, through these processes.

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

[0086] The following describes in detail one embodiment of a method for manufacturing a semiconductor device.

[0087] The semiconductor device manufacturing method of this embodiment includes an assembly step of cutting out a semiconductor chip X from a semiconductor wafer W (substrate) on which a circuit surface is formed, and assembling a semiconductor device having the semiconductor chip X. Such an assembly process includes a step of protecting the circuit surface (surface to be protected) by superimposing an adhesive layer 11 for protecting the circuit components onto at least one surface of the semiconductor wafer W, which is the circuit surface on which any of the circuit components are formed, (protection step), A process to produce multiple small pieces of a laminate in which the semiconductor chips X and adhesive layer pieces 11' are superimposed, by dividing the stack of overlapping semiconductor wafers W and adhesive layer pieces 11 into small pieces with spacing in the planar direction, The process involves applying heat treatment or irradiation with active energy rays to each small piece 11' of the adhesive layer overlapping the circuit surface of the semiconductor chip X to generate acid from the acid-producing compound in each small piece 11', thereby increasing the hydrophilicity of each small piece 11', and then removing each small piece 11' of the adhesive layer with a water-containing liquid (removal process), The process includes a step of joining a semiconductor chip X to an adherend.

[0088] The assembly process of this embodiment includes, for example, the following steps: Specifically, the assembly process of this embodiment is as follows: A mounting process involves attaching a semiconductor wafer W, on which circuit components are formed on one side, to a dicing die bond film (a die bond sheet 30 superimposed on a dicing tape 20) to fix the semiconductor wafer W to the dicing die bond film. A protection step in which an adhesive layer 11 is attached to the circuit surface of a semiconductor wafer W to protect the circuit surface, A blade dicing process (a process for producing multiple small pieces of the above-mentioned laminate) is performed by dividing the semiconductor wafer W, to which the die bond sheet 30 and the adhesive layer 11 are attached, into small pieces using a dicing blade T or the like to create semiconductor chips (dies) from the semiconductor wafer W. After undergoing the above-mentioned heat treatment or irradiation treatment with active energy rays, a removal step (the above-mentioned removal step) is performed to remove multiple small pieces 11' of the adhesive layer attached to the semiconductor chip X, A pickup process involves peeling off the small piece 30' of the die bond sheet from the dicing tape 20 to remove the semiconductor chip X with the small piece 30' of the die bond sheet still attached, The process includes a bonding step (the bonding step described above) in which the extracted semiconductor chip X is bonded to the adherend via a small piece 30' of the die bond sheet. When these steps are carried out, the dicing die bond film having the adhesive layer 11 and the dicing tape 20 described above is used as a manufacturing aid.

[0089] The semiconductor wafer W is configured to produce multiple semiconductor chips X. More specifically, the semiconductor wafer W is divided into smaller pieces with spacing in multiple directions along the surface (for example, directions along the surface that are mutually orthogonal), thereby enabling the fabrication of multiple semiconductor chips X. The semiconductor wafer W also has a circuit surface on at least one of its surfaces 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 the semiconductor industry in recent years, with the further advancement of integration technology, there is a demand for thinner semiconductor chips (for example, with a thickness of 20 μm to 50 μm). The shape of a semiconductor chip when viewed from one side in the thickness direction is, for example, rectangular, and the length of one side is a predetermined length, for example, 5 mm to 20 mm.

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

[0092] In the protection step, for example, as shown in Figure 4A, the 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 and attaching the adhesive layer 11 to the circuit surface. Alternatively, an adhesive composition containing a solid component constituting the adhesive layer 11 and a solvent that dissolves the solid component may be prepared, and after applying the prepared adhesive composition to the circuit surface, the solvent is evaporated to form an adhesive layer 11 that is in contact with the circuit surface, thereby superimposing the adhesive layer 11 on the circuit surface. By overlapping the adhesive layer 11 onto 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, it is possible to prevent dust and other debris from adhering to the circuit surface of the semiconductor wafer W covered with the adhesive layer 11. Furthermore, the protection process may be performed after the mounting process, or the mounting process may be performed after the protection process.

[0093] In the blade dicing process, the semiconductor wafer W is diced, for example, as shown in Figures 4B and 4C. More specifically, the semiconductor wafer W is cut to a predetermined size together with the die bond sheet 30 to form a semiconductor chip with the die bond sheet 30. The blade dicing process is carried out according to a conventional method, for example, using a dicing blade T. In the blade dicing process, a cutting method called full cut, which cuts all the way to the die bond sheet 30, can be employed. The dicing apparatus used in the blade dicing process is not particularly limited, and conventionally known apparatus can be used. In the blade dicing process, foreign matter such as fragments may be generated when the semiconductor wafer W is cut. However, since the protective surface of the semiconductor wafer W is protected by the adhesive layer 11, the adhesion of foreign matter to the protected surface can be suppressed. Alternatively, before the blade dicing process, the dicing ring R may be attached to the adhesive fixing layer 22 of the dicing tape 20, and then fixed to the holder H of the expander.

[0094] In the removal process, as shown in Figure 4D, multiple small pieces 11' of the adhesive layer are subjected to a treatment that generates acid from the acid-producing compound. Such a treatment may be at least one of heat treatment or irradiation with active energy rays. The heat treatment is carried out, for example, by exposing multiple small pieces 11' of the adhesive layer to an environment of 90°C to 250°C for a period of 10 minutes to 300 minutes. In irradiation treatment with active energy rays, for example, 10 mW / cm² 2 More than 300mW / cm 2 The following intensity of ultraviolet light was adopted as the active energy ray, with an integrated light intensity of 50 mJ / cm². 2 More than 5000mJ / cm 2 The following is achieved by irradiating multiple small pieces 11' of the adhesive layer with ultraviolet light. In the removal process, by performing the above-described treatment on multiple small pieces 11' of the adhesive layer, acid is generated from the acid-producing compound contained in the small pieces 11'. The newly generated acid causes the protective group to detach from the protected compound contained in the small pieces 11' of the adhesive layer, resulting in unprotected hydrophilic groups. As a result, the hydrophilicity of the small pieces 11' of the adhesive layer increases. Consequently, when the small pieces 11' later come into contact with a liquid containing water, the small pieces 11' swell and can be removed relatively easily from the surface of the semiconductor chip X.

[0095] In the removal process, as shown in Figure 4E, a liquid containing water is brought into contact with multiple small pieces 11' of the adhesive layer, and each small piece 11' is swollen by the liquid, thereby removing each small piece 11' of the adhesive layer from the surface (protected surface) of the semiconductor chip X. By removing the small pieces 11' of the adhesive layer in this way, all of the multiple small pieces 11' of the adhesive layer can be removed relatively easily, and the number of foreign objects adhering to the semiconductor chip surface can be reduced relatively easily by the above-mentioned liquid. In addition, the surface (protected surface) of each semiconductor chip X where the small pieces 11' of the adhesive layer were overlapping can also be cleaned with the liquid.

[0096] During the removal process, the fragmented adhesive layer (multiple small pieces 11' of the adhesive layer) swells due to the liquid. As a result, the adhesion 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 for relatively easy removal of the multiple small pieces 11' of the adhesive layer. Furthermore, although the multiple small pieces 11' of the adhesive layer peeled off from the semiconductor chip X swell with the liquid, they do not all dissolve in the liquid in a short time. Therefore, the multiple small pieces 11' of the adhesive layer can be recovered relatively easily. Thus, the load on the equipment used in the removal process can be reduced, and the environmental burden when disposing of the liquid can also be reduced.

[0097] The liquid containing water 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. The above liquid may contain components that dissolve in water in addition to water. Examples of such components include water-soluble organic solvents. Examples of such water-soluble organic solvents include monohydric alcohols with 4 or fewer carbon atoms, such as methanol, ethanol, propanols such as isopropyl alcohol, or butanols such as t-butanol.

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

[0099] For example, in the removal process, a disc-shaped stage supporting the dicing tape 20 from below is rotated circumferentially, and the liquid is sprayed onto the semiconductor chips X attached to each of the small pieces 30' of the die bond sheet. This removes multiple small pieces 11' of the adhesive layer that are superimposed on the semiconductor chips X. The rotation speed of the stage may be, for example, 500 rpm to 4000 rpm, the amount of liquid sprayed may be, for example, 0.05 L / min to 5.0 L / min, and the spraying time may be, for example, 5 seconds to 300 seconds.

[0100] In 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, thus protecting the circuit surface until the adhesive layer 11 is removed. Specifically, since the semiconductor wafer W is cut into small pieces to produce a semiconductor chip X while the semiconductor wafer W and the adhesive layer 11 are superimposed, it is possible to prevent foreign matter such as fragments that may be generated due to the cleavage of the semiconductor wafer W from adhering to the circuit surface of the semiconductor chip X. Even if foreign matter is adhering to the circuit surface of the semiconductor chip X before the adhesive layer 11 is superimposed, that foreign matter can also be removed when the small piece 11' of the adhesive layer superimposed on the circuit surface of the semiconductor chip X is removed. Therefore, it is possible to suppress the adhesion of foreign matter to the circuit surface of the manufactured semiconductor chip X.

[0101] In the pickup process, as shown in Figure 4F, the semiconductor chip X is peeled from the adhesive fixing layer 22 of the dicing tape 20. Specifically, the pin member P is raised to push up the semiconductor chip X to be picked up via the dicing tape 20. The pushed-up semiconductor chip X is held by the suction jig J.

[0102] When performing the pickup process in this manner, it is necessary that the small pieces 30' of the die bond sheet attached to the semiconductor chip X be easily peeled off from the adhesive fixing layer 22 of the dicing tape 20. Furthermore, when performing the expansion process described above, it is necessary to stretch the dicing tape 20 to effectively break down 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 perform these functions. For example, the dicing tape 20 is configured such that when irradiated with active energy rays (e.g., ultraviolet light), the adhesive fixing layer 22 hardens, reducing the adhesive strength of the adhesive fixing layer 22. Because the adhesive strength of the adhesive fixing layer 22 can be reduced by hardening after irradiation, the semiconductor chip X and the small pieces 30' of the die bond sheet can be peeled off from the adhesive fixing layer 22 relatively easily after irradiation. Dicing tapes 20 with such a configuration are commercially available.

[0103] In the bonding process, the semiconductor chip X, with small pieces 30' of the die bond sheet attached, is bonded to the substrate Z. In other words, the semiconductor chip X is bonded to the substrate Z via the small pieces 30' of the die bond sheet. In the bonding process, as shown in Figure 4G, multiple stacks of semiconductor chip X with small pieces 30' of the die bond sheet attached may be made. In this embodiment, the semiconductor chip X is bonded to the substrate or other substrate via the small pieces 30' of the die bond sheet. When stacking multiple semiconductor chips X as described above during the bonding process, the number of foreign objects that can get between one semiconductor chip X and the other is reduced because the stacking of multiple semiconductor chips X is such that the adhesion of foreign objects to the circuit surface is suppressed. Examples of the adherend Z include an interposer, a wiring circuit board, or a small piece of a substrate (when small pieces of substrate are stacked and laminated).

[0104] In this embodiment, a resin encapsulation step may be performed to encapsulate (cover) the semiconductor chip X with a thermosetting resin or the like in order to protect the semiconductor chip X after the bonding process.

[0105] In the above description of this embodiment, an example was given in which the semiconductor wafer W is cut into smaller pieces by a blade dicing process. However, the semiconductor wafer W may also be cut into smaller pieces by a so-called DBG process, which involves half-cutting the semiconductor wafer W and then thinning the thickness of the semiconductor wafer W. In half-cut processing, for example, grooves are formed in the semiconductor wafer W to process it into chips (dies) by a cutting process, and then the semiconductor wafer W is ground down to reduce its thickness. In the half-cut process, for example, as shown in Figures 4H to 4K, wafer processing tape E is attached to the side of the semiconductor wafer W opposite to the circuit side. With the wafer processing tape E attached, grooves for division are formed. Backgrind tape B is attached to the grooved side, while the wafer processing tape E that was initially attached is peeled off. With the backgrind tape B attached, the semiconductor wafer W is ground down until it reaches a predetermined thickness. Then, a mounting process is carried out, and after that, a semiconductor device is manufactured in the same manner as described above.

[0106] The semiconductor wafer W (substrate) before being cut into smaller pieces for semiconductor chips X may, for example, be ground to a desired thickness by backgrinding. Specifically, in backgrinding, a semiconductor wafer W with a backgrind tape B attached to the circuit surface may be ground to reduce the thickness of the semiconductor wafer W until it reaches the thickness of the semiconductor chip X to be manufactured later.

[0107] Other processes besides those shown in the specific examples above may be performed. For example, in processes such as plasma dicing or stealth dicing, the adhesive layer 11 may be placed on the circuit surface of the semiconductor wafer W, and after various processing steps are performed, the adhesive layer 11 may be removed. Alternatively, the adhesive layer 11 may be placed 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] While the methods for manufacturing the adhesive composition, adhesive sheet, and electronic component device according to embodiments of the present invention are as illustrated above, the present invention is not limited to the methods for manufacturing the adhesive composition, adhesive sheet, and electronic component device as illustrated above. In other words, various forms used in general adhesive compositions, adhesive sheets, and manufacturing methods of electronic component devices can be adopted as long as they do 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 with circuit surfaces formed on both sides, or, as described in other embodiments, a semiconductor wafer with circuit surfaces formed on only one side. In other words, circuit components may be arranged on only one of the two sides of the semiconductor chip produced by the manufacturing method of the present invention, or circuit components may be arranged on both sides.

[0110] The matters disclosed herein include the following: (1) A compound that produces acid upon heating or irradiation with active energy rays, An adhesive composition comprising a protected compound having a hydrophilic group protected by a protecting group and a hydrophilic group in its molecule that is deprotected by the acid. Such adhesive compositions can, for example, form an adhesive layer that can be relatively easily removed by contacting a water-containing liquid after covering at least one side of a substrate in an electronic component being manufactured. (2) The adhesive composition according to (1) above, wherein the protected compound has a structural unit of a protected carboxy group-containing (meth)acrylic monomer containing a carboxy group protected by the protecting group in the molecule. (3) On the surface of the molded product of the adhesive composition according to (1) or (2) above, the contact angle before being heated or irradiated with the active energy rays is 70° or more and less than 120°, and the contact angle after being subjected to at least one of heating or irradiation with the active energy rays by a high-pressure mercury lamp at 2500 mJ / cm 2 is 100° or less, an adhesive composition. (4) On the surface of the molded product of the adhesive composition according to any one of (1) to (3) above, with respect to the contact angle of water before being subjected to either heating or irradiation with the active energy rays, the contact angle of water after being subjected to at least one of heating or irradiation with the active energy rays by a high-pressure mercury lamp at 2500 mJ / cm 2 is 3° or more smaller, an adhesive composition. (5) An adhesive sheet comprising an adhesive layer formed of the adhesive composition according to any one of (1) to (4) above. (6) The adhesive sheet according to (5) above, further comprising a release liner overlapping at least one surface of the adhesive layer. (7) A step of protecting a surface to be protected by overlapping an adhesive layer formed from an adhesive composition on at least one surface to be protected of both surfaces of a substrate, and a step of removing the adhesive layer overlapping the surface to be protected, and the adhesive composition includes a compound that generates an acid by at least one of heating or irradiation with active energy rays, and a protected compound having a hydrophilic group protected by a protecting group and having the hydrophilic group deprotected by the acid in the molecule. A method for manufacturing an electronic component device, wherein in the removal step, the acid is generated from a compound that generates the acid by heating or irradiation with active energy rays to increase the hydrophilicity of the adhesive layer, and the adhesive layer is removed by bringing it into contact with a liquid containing water. According to this method for manufacturing electronic components, the adhesive layer can prevent foreign matter from adhering to the protected surface, and the adhesive layer can then be removed relatively easily by bringing a liquid containing water into contact with the adhesive layer. (8) A method for manufacturing an electronic component device according to (7) above, wherein a circuit component is arranged on the protected surface of the substrate. [Examples]

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

[0112] The adhesive compositions (adhesive layers) for the examples and comparative examples were prepared as follows, and adhesive sheets equipped with these adhesive layers were manufactured. Details of each adhesive composition (adhesive layer) in each manufacturing method, and the evaluation results are shown in Tables 1 and 2.

[0113] [Examples 4, 6-10, Reference Examples 1-3, 5, Comparative Examples 1, 2] (Preparation of protected compounds) (Meth)acrylic polymers were prepared as the protected compounds according to 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 to obtain a solid content of 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 monomer (monomer containing a protected hydrophilic group)> • [Protected Monomer 1] t-Butyl Acrylate (tBA) - Purchased item [ka] • [Protected Monomer 2] n-Butoxyethyl Acrylate (BEA) - Purchased item [ka] • [Protected Monomer 3] n-Butoxyethyl Methacrylate (BEMA) - Purchased item [ka] • [Protected Monomer 4] Cyclohexoxyethyl acrylate (CHEA) - Purchased item [ka] • [Protected Monomer 5] n-Propoxyethyl Acrylate (PEA) - Purchased item [ka] <Other monomers> • [BA] n-butyl acrylate (monomer without protecting group) purchased item • [BMA] n-butyl methacrylate (protecting group-free monomer) purchased item • [4HBA] 4-hydroxybutyl acrylate (monomer without protecting group) - purchased item

[0114] (Making adhesive sheets) To the polymer solutions containing each polymer prepared as described above, an acid-generating compound (photoacid generator) was added and mixed in the amount 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 treated with silicone release agent, and the polymer solution was applied to this surface using an applicator. Furthermore, a drying treatment was performed at 130°C for 2 minutes to form an adhesive layer with a thickness of 5 μm overlapping one side of each release liner a. Then, release liner b (PET film, 25 μm thick) was placed on the exposed surface of each adhesive layer. Each release liner b also had a surface treated with silicone release agent, and this side was attached to the adhesive layer. In this way, adhesive sheets comprising an adhesive layer (adhesive composition) sandwiched between two release liners were prepared.

[0115] Details of the acid-generating compounds are as follows. Note that all of the raw materials listed below are 50% by mass propylene carbonate solutions. [Photoacid Generator] • Sulfonium salt type, product name "CPI-200K", manufactured by Sunapro 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 Sunapro Co., Ltd. Chemical name: Diphenyl[p-(phenylthio)phenyl]sulfonium hexafluoroantimonate • Sulfonium salt type. Product name: "CPI-310FG". Manufactured by Sunapro Co., Ltd. [Thermal acid generator] • Sulfonium salt type, Product name "TA-100FG", Manufactured by Sunapro Co., Ltd.

[0116] (A pseudo-protection process) The release liner b was peeled off and removed from the fabricated adhesive sheet, exposing one side of the adhesive layer. This exposed side was then bonded to a silicon bare wafer (substrate) on dicing tape using a laminator heated to 90°C. The silicon bare wafer was used in place of a semiconductor wafer. A commercially available product (product name "V-12SR," manufactured by Nitto Denko Corporation) was used as the dicing tape.

[0117] Subsequently, the blade dicing process was carried out using a standard method.

[0118] (Removal process) The adhesive layer was subjected to a high-pressure mercury lamp at a rate of 2,500 mJ / cm². 2 The hydrophilicity of the adhesive layer was increased by irradiation treatment (light irradiation treatment including ultraviolet light). Subsequently, to remove the adhesive layer, the removal process was carried out using a cleaning unit manufactured by DISCO (product name DFD6361) as follows: While rotating a disc-shaped stage that supports the dicing tape from below in the circumferential direction, 25°C water was sprayed onto small pieces of the adhesive layer on the silicon chip. The rotation speed of the stage was set to 1000 rpm, and the water spraying time was set to 90 seconds.

[0119] [Table 1]

[0120] [Table 2]

[0121] <Physical properties: Change in contact angle on the surface of the adhesive layer> (Before UV irradiation / heat treatment, and after UV irradiation / heat treatment) The adhesive composition (adhesive layer) attached to the bare wafer contains 2,500 mJ / cm² 2An irradiation treatment was performed using light including ultraviolet light to achieve the specified cumulative light intensity. Furthermore, a heat treatment was performed at 100°C for 30 seconds. The contact angle was measured before the above treatment (irradiation treatment and heat treatment) and 30 minutes after the completion of the above treatment, using 0.15 μL of water as the amount of water added. The contact angle 30 seconds after adding water was measured at 25°C. In addition, for Example 10 (including the hot acid generator), only the above treatment was performed as a heat treatment at 100°C for 1 hour, and then the contact angle was measured in the same manner as above. The evaluation was performed according to the following method. Specifically, when the contact angle before treatment is denoted as a degree, and the contact angles after irradiation and heat treatment are denoted as b degrees, ab<3 Bad(×) ab≧3 Good (〇) Of the above "Good" ratings, those with ab≧10 were judged as Excellent (◎). The results of the contact angle change are shown in Tables 1 and 2.

[0122] <Evaluation: Removability of adhesive layer / Swelling and peelability (after UV irradiation)> With the adhesive layer attached to the substrate (silicon bare wafer) (without dicing), irradiation treatment was performed in the same manner as the removal process described above. Furthermore, a heat treatment at 100°C for 30 seconds was performed. Next, a water spray treatment was performed in the same manner as the removal process described above. Then, we evaluated whether the adhesive layer formed by the adhesive composition swelled and peeled off and was removed from the substrate (silicon bare 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 parts remained without peeling off. (Defective) × The adhesive layer swelled and did not peel off, and most of it remained. Furthermore, the adhesion to the substrate (silicon bare wafer) before UV irradiation was good for all adhesive layers.

[0123] <Evaluation: Ease of removing the adhesive layer (after UV irradiation)> Bare wafer substrates with adhesive layers formed from each adhesive composition were diced (cut into 1 cm squares). The diced test samples (diced adhesive layers and chips) were irradiated with ultraviolet light at the same intensity as above. Then, 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, 1 cm 2 We visually inspected whether the adhesive layer (adhesive composition) peeled off from the chips remained in almost the same shape. The evaluation criteria related to the ease of removing the adhesive layer are as follows: (Good) ○ The adhesive layer peels off, and the shape of the peeled-off adhesive layer can be confirmed (the adhesive layer is removed all at once in a relatively short time). (Defective) × The adhesive layer does not peel off.

[0124] As can be seen from the evaluation results above, the semiconductor device can be protected by manufacturing it using the semiconductor device manufacturing method of the example. Furthermore, in the removal process, the multiple fragmented adhesive layers could be removed relatively easily with water. Therefore, semiconductor devices can be manufactured efficiently.

[0125] By implementing the semiconductor device manufacturing method described in the above embodiment, it is possible to efficiently manufacture semiconductor devices in which multiple semiconductor chips with virtually no foreign matter attached are stacked. [Industrial applicability]

[0126] The method for manufacturing electronic component devices of the present invention is suitably used, for example, to manufacture semiconductor devices having semiconductor integrated circuits. [Explanation of Symbols]

[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: Diebond sheet, G: Glass carrier, W: Semiconductor wafer, X: Semiconductor chip, V: Through-hole via, D: Electrode section B: Backgrind tape.

Claims

1. A compound that produces acid upon heating or irradiation with active energy rays, A protective compound comprising a hydrophilic group protected by a protecting group and having a hydrophilic group in its molecule that is deprotected by the acid, On the surface of the molded product of the adhesive composition, With respect to the contact angle of water before it is heated or irradiated with the active energy rays, The aforementioned heating or irradiation with the aforementioned active energy rays is performed using a high-pressure mercury lamp at a rate of 2500 mJ / cm². ２ The contact angle of water after being exposed to at least one of the irradiations is 10° or less. Adhesive composition.

2. The adhesive composition according to claim 1, wherein the protected compound has a constituent unit of a protected carboxyl group-containing (meth)acrylic monomer containing a carboxyl group protected by the protecting group in the molecule.

3. The protected compound has constituent units of a (meth)acrylic acid type monomer having a hydrophilic group protected by the protecting group in its molecule. The adhesive composition according to claim 1, wherein the constituent units of the (meth)acrylic acid type monomer have an alkoxyalkyl group or a cyclic acetal group as the protecting group.

4. An adhesive sheet comprising an adhesive layer formed of the adhesive composition described in claim 1 or 2.

5. The adhesive sheet according to claim 4, wherein the adhesive layer is used by being attached to the surface to be protected in order to temporarily protect the surface of an electronic component, and the adhesive layer is configured to swell with a liquid containing water and be removed by the liquid.

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