Adhesive composition and protective sheet

Abstract

Provided is an adhesive composition and the like, the adhesive composition being for forming an adhesive protective layer that protects a to-be-protected surface of a substrate when manufacturing an electronic component device, the adhesive composition containing: a compound that generates an acid by irradiation with an active energy ray; and a polymer having, in a molecule, an ester group that is hydrolyzed by the acid to generate a hydrophilic group.

Description

Cross-reference of related applications

[0001] This application claims priority to Japanese Patent Application No. 2024-111958, which is incorporated into the description of this application by reference. [Technical Field]

[0002] The present invention relates to an adhesive composition and a protective sheet used, for example, in the manufacture of electronic components such as semiconductor integrated circuits. [Background technology]

[0003] 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.

[0004] In contrast, a surface protection sheet is known that has a protective layer that is attached to at least one surface of a substrate and removed after protecting the substrate (for example, Patent Document 1). The protective layer of the surface protection sheet described in Patent Document 1 is formed of a surface protection composition that includes a polymer such as polyvinyl alcohol and a compound that produces an acid or base upon irradiation with active energy rays or the like.

[0005] The protective layer of the surface protection sheet described in Patent Document 1 is attached to the surface to be protected, such as a substrate, and protects the surface to be protected when the substrate is processed. After the surface to be protected is protected, the protective layer is removed and used. Specifically, the protective layer contains a compound that generates the acid or base described above, and the acid or base is generated by the active energy rays irradiated after the substrate is processed, thereby increasing the hydrophilicity of the protective layer. Therefore, the protective layer is removed with water or the like after the surface to be protected has been protected. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2023 / 195445 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the protective layer formed from the surface protection composition described in Patent Document 1 does not always adhere sufficiently to the substrate or other object to be protected, and the protective layer may unintentionally peel off from the protected surface due to the force applied when processing the substrate or other object. On the other hand, if the hydrophilicity of the protective layer is reduced in order to increase its adhesion, for example, the protective layer may not be easily removed by water or the like. Even when irradiated with active energy rays, the hydrophilicity of the protective layer only increases to the extent that an acid or base is generated, making it difficult to achieve both sufficient adhesion of the protective layer and sufficient improvement of the hydrophilicity of the protective layer after irradiation with active energy rays.

[0008] Therefore, there is a need for a protective layer that can adhere relatively strongly to a surface to be protected, such as a substrate during processing, and that can be removed relatively easily from the surface by water or other means after processing is complete through irradiation with active energy rays. Furthermore, there is a need for an adhesive composition that can form such a protective layer.

[0009] However, adhesive compositions that can form a protective layer that adheres relatively strongly to the surface to be protected, and that can be removed relatively easily with a water-containing liquid by irradiation with active energy rays, have not yet been sufficiently investigated.

[0010] Therefore, the object of the present invention is to provide an adhesive composition that can form a protective layer that adheres relatively strongly to a surface to be protected, and which can be removed relatively easily with a liquid containing water by irradiation with active energy rays. Another objective is to provide a protective sheet comprising a protective layer formed from the adhesive composition. [Means for solving the problem]

[0011] In order to solve the above problems, the adhesive composition according to the present invention is An adhesive composition for forming an adhesive protective layer to protect the protective surface of a substrate when manufacturing electronic component devices, Compounds that produce acid upon irradiation with active energy rays, The present invention comprises a polymer having an ester group in its molecule that is hydrolyzed by the aforementioned acid to produce a hydrophilic group.

[0012] The protective sheet according to the present invention comprises a protective layer formed of the above-mentioned adhesive composition. [Brief explanation of the drawing]

[0013] [Figure 1] A schematic cross-sectional view of an example of the protective sheet of this embodiment, cut in the thickness direction. [Figure 2A] A schematic cross-sectional view showing an example of the protection process in the manufacturing method of the electronic component device according to this embodiment. [Figure 2B] A schematic cross-sectional view showing an example of the protection process in the manufacturing method of the electronic component device according to this embodiment. [Figure 2C] A schematic cross-sectional view showing an example of the state of the substrate before it is cut in the manufacturing method of the electronic component device of this embodiment. [Figure 2D] A schematic cross-sectional view showing an example of the state after cutting the substrate in the method for manufacturing an electronic component device of the present embodiment. [Figure 2E] A schematic cross-sectional view showing an example of the state in the removal step in the method for manufacturing an electronic component device of the present embodiment. [Figure 2F] A schematic cross-sectional view showing an example of the state in the removal step in the method for manufacturing an electronic component device of the present embodiment. [Figure 3A] A cross-sectional view of an example of a dicing tape cut in the thickness direction. [Figure 3B] A cross-sectional view of an example of a dicing die bond film cut in the thickness direction. [Figure 4A] A cross-sectional view schematically showing the state after performing the mounting step and the protection step in a specific example of the method for manufacturing an electronic component device. [[ID=十九]] [Figure 4B] A cross-sectional view schematically showing the state during the blade dicing process in a specific example of the method for manufacturing an electronic component device. [Figure 4C] A cross-sectional view schematically showing the state after performing the blade dicing process in a specific example of the method for manufacturing an electronic component device. [Figure 4D] A cross-sectional view schematically showing the state in the removal step in a specific example of the method for manufacturing an electronic component device. [Figure 4E] A cross-sectional view schematically showing the state in the removal step in a specific example of the method for manufacturing an electronic component device. [Figure 4F] A cross-sectional view schematically showing the state in the pickup step in a specific example of the method for manufacturing an electronic component device. [Figure 4G] A cross-sectional view schematically showing the state in the bonding step in a specific example of the method for manufacturing an electronic component device. [Figure 4H] A cross-sectional view schematically showing the state of half-cut processing of a semiconductor wafer in another specific example of the method for manufacturing an electronic component device. [Figure 4I] A cross-sectional view schematically showing the state of half-cut processing of a semiconductor wafer in another specific example of the method for manufacturing an electronic component device. [Figure 4J]A schematic cross-sectional diagram illustrating the half-cutting process of a semiconductor wafer in another specific example of an electronic component manufacturing method. [Figure 4K] A schematic cross-sectional view illustrating the mounting process in another specific example of a manufacturing method for electronic components. [Modes for carrying out the invention]

[0014] The following describes in detail each embodiment of the adhesive composition and protective sheet according to the present invention.

[0015] The adhesive composition of this embodiment comprises a compound that generates acid upon irradiation with active energy rays, The adhesive composition of this embodiment is used, for example, to form a protective layer that protects the surface of a substrate constituting an electronic component device.

[0016] By overlapping the protective layer formed with the above adhesive composition onto the surface to be protected, the protective layer adheres strongly to the substrate surface (the surface to be protected) until the protective layer is removed. Therefore, it is possible to prevent foreign matter from adhering to the surface to be protected. For example, even when processing is performed to break down the substrate and the protective layer into smaller pieces while the protective layer formed with the adhesive composition and the substrate are overlapping, the above-mentioned adhesion force prevents the protective layer from peeling off the substrate as a result of the breaking down. In addition, since it is possible to prevent foreign matter such as fragments that may be generated by the processing from adhering to the surface to be protected, the surface to be protected can be protected. Furthermore, by irradiating the protective layer with active energy rays, acid is generated from the acid-producing compound. This causes hydrolysis of the ester groups in the polymer molecules, increasing the number of hydrophilic groups in the polymer and significantly increasing the hydrophilicity of the protective layer formed by the adhesive composition. The protective layer, with its significantly increased hydrophilicity, can be peeled off relatively easily from the protected surface by contact with a liquid containing water. Therefore, the protective layer can be easily removed from the protected surface. Thus, the protective layer formed with the above adhesive composition can not only adhere sufficiently to the protected 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 irradiation with active energy rays.

[0017] In this embodiment, the acid-producing compound is, for example, an acid generator that produces acid upon irradiation with active energy rays. A photoacid generator that produces acid upon irradiation with active energy rays (particularly ultraviolet light) is preferred as the acid-producing compound.

[0018] Because the above adhesive composition contains a compound that produces the above acid, the acid produced by irradiation with active energy rays such as ultraviolet light hydrolyzes the ester groups of the polymer, increasing the number of hydrophilic groups in the polymer, and thus increasing the hydrophilicity of the above adhesive composition. The above adhesive composition only needs to have a predetermined level of hydrophilicity after the ester groups of the polymer have been hydrolyzed. Therefore, in the state before the ester groups of the polymer are hydrolyzed, the hydrophilicity of the above adhesive composition may be less than or greater than the predetermined level. If the above adhesive composition has a predetermined level of hydrophilicity, at least a portion of the protective layer formed with the above adhesive composition may dissolve in a liquid containing water.

[0019] The polymer described above has ester groups in its molecule that are hydrolyzed by the acid produced (hereinafter also simply referred to as "easily hydrolyzable ester groups"). In other words, the polymer described above is a polymer compound that generates hydrophilic groups when the easily hydrolyzable ester groups in its molecule are hydrolyzed by the acid produced.

[0020] Examples of hydrophilic groups that can be formed from the above-mentioned easily hydrolyzable ester group (-C(O)O-) by the above-mentioned acid include carboxyl groups (-COOH) and hydroxyl groups (-OH). In other words, a carboxyl group or a hydroxyl group can be formed from the above-mentioned easily hydrolyzable ester group.

[0021] From another perspective, the polymer described above is a macromolecule that has hydrophilic groups (such as carboxyl groups) in its molecule that are protected by protecting groups but deprotected by the acid described above. The protecting groups exist in the polymer in a state where they are chemically bonded to the hydrophilic groups.

[0022] Examples of protective groups that can protect the hydrophilic groups mentioned above include the following: Examples of protecting groups that can protect a carboxyl group include tert-butyl groups, alkoxyalkyl groups, or cyclic acetal groups (groups containing a dioxolane structure). Examples of alkoxyalkyl groups include methoxymethyl groups, ethoxyethyl groups, or butoxyethyl groups. In an alkoxyalkyl group, the number of consecutively bonded carbon atoms may be between 2 and 4. Examples of protecting groups that can protect a hydroxyl group include trityl groups, alkoxymethyl groups, tetrahydropyranyl groups, cyclic acetal groups (groups containing dioxolane structures), tert-butyldimethylsilyl groups, or tert-butoxycarbonyl groups.

[0023] It should be noted that the above notation for protecting groups 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 cases, the protecting group is still described as a tert-butyl group. Furthermore, the protected hydrophilic group is also described using its name before protection.

[0024] When the easily hydrolyzable ester groups in the above polymer are hydrolyzed by the above acid, new hydrophilic groups are formed in the polymer. In other words, when the protecting group is removed from the above hydrophilic group (deprotected), the protecting group portion is removed from the hydrophilic group portion. The compound separated from the above polymer by hydrolysis, i.e., the compound removed from the protecting group, may or may not be volatile.

[0025] The above polymer may have ester groups (easily hydrolyzable ester groups) of the constituent units of (meth)acrylic acid ester type monomers in its molecule. In other words, the above polymer may be a polymer (hereinafter simply referred to as acrylic polymer) obtained by polymerizing (meth)acrylic acid ester type monomers containing at least easily hydrolyzable ester groups. In this specification, the term "(meth)acrylic acid" encompasses both acrylic acid and methacrylic acid. The same applies to "(meth)acrylate."

[0026] The above-mentioned acrylic polymer has, for example, a main chain and a plurality of side chains in its molecule. The main chain is a covalent chain formed, for example, by a radical polymerization reaction. Preferably, at least a portion of the main chain is a covalent chain formed by a polymerization reaction of (meth)acrylic acid ester type monomers containing easily hydrolyzable ester groups. The side chains have readily hydrolyzable ester groups, for example, formed by the dehydration condensation of a carboxyl group acting as a hydrophilic group. From another perspective, in the side chains of acrylic polymers, the carboxyl group acting as a hydrophilic group, which is generated by the above-mentioned acid, is protected by a protecting group to become a readily hydrolyzable ester group.

[0027] The above acrylic polymer may be a homopolymer of (meth)acrylic acid ester type monomers containing easily hydrolyzable ester groups, or it may be a copolymer of a (meth)acrylic acid ester type monomer containing easily hydrolyzable ester groups and a monomer other than such monomer. The average molecular weight of the above acrylic polymer may be between 50,000 and 900,000.

[0028] Examples of constituent units of the (meth)acrylic acid ester type monomer (containing an easily hydrolyzable ester group) that the above-mentioned acrylic polymer has in its molecule include the constituent units of the following monomers. • tert-butyl (meth)acrylate [(meth)acrylate t-butyl ester] • Alkoxyalkyl (meth)acrylate [(meth)acrylate alkoxyalkyl ester] (represented by the following general formula (I)) [ka]

[0029] Examples of alkoxyalkyl (meth)acrylates represented by the above general formula (I) include n-propoxyethyl acrylate [(meth)acrylate propoxyethyl ester], n-butoxyethyl (meth)acrylate [(meth)acrylate 1-butoxyethyl ester], or cyclohexoxyethyl acrylate [(meth)acrylate cycloalkoxyethyl ester].

[0030] When the above-mentioned acrylic polymer contains readily hydrolyzable ester groups in its molecule, the hydrophilicity of the protective layer formed by the adhesive composition is low. Therefore, even when in contact with a solvent containing water, the protective layer is not removed from the surface to be protected and continues to protect the surface. Moreover, because the polymer molecule contains many polar ester groups, the protective layer can adhere relatively strongly to the object to be protected. On the other hand, after the protective layer is irradiated with active energy rays, the easily hydrolyzable ester groups are hydrolyzed by the acid produced by such irradiation, generating carboxyl groups and the like. In other words, the protected carboxyl groups and the like are deprotected. As a result, the hydrophilicity of the protective layer formed with the above adhesive composition is increased, and the protective layer can be removed relatively easily from the protected surface with a liquid containing water.

[0031] The constituent units of the above (meth)acrylic acid ester type monomer contain an easily hydrolyzable ester group, and after hydrolysis, they yield constituent units of either acrylic acid monomer or methacrylic acid monomer. In other words, the constituent units of the above (meth)acrylic acid ester type monomer have a molecular structure in which the carboxyl group in each constituent unit of the acrylic acid monomer or methacrylic acid monomer is protected by a protecting group.

[0032] The above acrylic polymer preferably contains 50% by mass or more of the above (meth)acrylic acid ester type monomer constituent units (containing easily hydrolyzable ester groups) in its molecule, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The above acrylic polymer may also contain 95% by mass or more of the above (meth)acrylic acid ester type monomer constituent units (containing easily hydrolyzable ester groups). The more the above-mentioned acrylic polymer contains the above-mentioned (meth)acrylic acid ester type monomer constituent units, the stronger the protective layer formed with the above-mentioned adhesive composition adheres to the surface to be protected. On the other hand, the protective layer that has been treated with active energy ray irradiation in the removal process (described in detail later) can be removed more easily with a liquid containing water.

[0033] Examples of monomers that can copolymerize with the above-mentioned (meth)acrylic acid ester type monomers 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, N-(hydroxyalkyl)(meth)acrylamide, and (meth)acrylate having a polyethylene glycol chain. In other words, the above-mentioned acrylic polymer may have, in addition to the constituent units of the above-mentioned (meth)acrylic acid ester type monomer, each of the constituent units of the monomers listed above in its molecule.

[0034] As the acrylic polymer described above, an acrylic copolymer having at least one of a (meth)acrylic acid ester type monomer (containing an easily hydrolyzable ester group) and a hydroxyalkyl (meth)acrylate or N-(hydroxyalkyl)(meth)acrylamide in its molecule is preferred.

[0035] In this embodiment, the compound that generates the above-mentioned acid is a compound that generates a new acid by irradiation with active energy rays. The irradiation treatment using active energy rays will be described in detail later.

[0036] Examples of compounds that produce the above-mentioned acid include photoacid generators. When the above-mentioned acid-producing compound generates acid upon light irradiation, at least some of the easily hydrolyzable ester groups in the polymer contained in the protective layer are hydrolyzed, and hydrophilic groups such as carboxyl groups are exposed. This increases the hydrophilicity of the protective layer. Therefore, the protective layer can be easily removed from the surface to be protected by contact between the protective layer and a liquid containing water.

[0037] Photoacid generators, used as acid generators, are, for example, photocationic polymerization initiators commonly used for cationic polymerization. Commercially available products can be used as the photoacid generator mentioned above.

[0038] 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.

[0039] Examples of onium salt compounds include iodonium salt compounds, sulfonium salt compounds, oxime sulfonate compounds, and diazonium salt compounds. Among these, iodonium salt compounds or sulfonium salt compounds are preferred, and sulfonium salt compounds are more preferred, because they produce a stronger acid (stronger acid) and can generate hydrophilic groups from the polar groups of the polymer even with a small amount of use.

[0040] Examples of iodonium salt compounds include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfate, diphenyliodonium nonafluoron-butanesulfonate, diphenyliodonium perfluoron-octanesulfonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, diphenyliodonium camphor sulfonate, bis(4-tert-butylphenyl)iodonium camphor sulfonate, 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.

[0041] 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, 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 (for instance, "CPI-310FG" manufactured by Sunapro).

[0042] 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.

[0043] Examples of diazonium salt compounds include 4-nitrobenzenediazonium tetrafluoroborate.

[0044] 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 IGM Resin), 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.).

[0045] 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 4-methylphenylsulfonyloxy)diphenylmaleimide.

[0046] 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.

[0047] Other examples of photoacid generators include 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)vinyl]-1,3,5-triazine.

[0048] The photoacid generator preferably has good compatibility with the polymers contained in the adhesive composition. An ionic photoacid generator is preferred as the photoacid generator.

[0049] In the above adhesive composition, the amount of the acid-producing compound per 100 parts by mass of the polymer is preferably 0.2 parts by mass or more, and more preferably 1.0 part by mass or more. As a result, the protective layer formed with the adhesive composition can have higher hydrophilicity after irradiation with active energy rays, and therefore the protective layer is more easily removed by a liquid containing water. The amount of the acid-producing compound per 100 parts by mass of the polymer is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less. This makes it possible to more effectively suppress the residue of the acid-producing compound in the adhesive composition.

[0050] 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.

[0051] 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 easily hydrolyzable ester groups in the polymer may chemically react with the photopolymerization initiator and the thermal polymerization initiator. When this reaction occurs, hydrophilic groups that would normally be formed after hydrolysis may not be formed. Therefore, the protective layer formed from the adhesive composition may have difficulty retaining its hydrophilicity even after being subjected to irradiation with active energy rays. Consequently, it may be difficult to remove the protective layer with a liquid containing water.

[0052] 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.

[0053] 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.

[0054] The adhesive composition of this embodiment can be used, for example, to produce a protective sheet, which will be described later.

[0055] Next, the protective sheet of this embodiment will be described with reference to the drawings.

[0056] The protective sheet 10 of this embodiment comprises at least a protective layer 11, as shown in Figure 1. The protective sheet 10 of this embodiment may further comprise a release liner 15 that overlaps at least one side of the protective layer 11. The release liner 15 may overlap one or both sides of the protective layer 11. Please note that each figure in the drawings is a schematic representation and does not necessarily reflect the aspect ratio of the actual object. The same applies to the other drawings.

[0057] In this embodiment, the protective layer 11 of the protective sheet 10 is formed in sheet form from the adhesive composition described above. When the protective sheet 10 is used, for example, the release liner 15 is peeled off from the protective layer 11 and the protective layer 11 is attached to at least one surface (surface to be protected) of the substrate (object to be protected).

[0058] The protective layer 11 described above has flexibility that allows it to be deformed with relatively weak force. Furthermore, the protective 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 protective 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.

[0059] The total mass of the polymer described above and the acid-producing compound described above is preferably 98% by mass or more, and more preferably 99% by mass or more, of the total mass of the protective layer 11 (total mass of the adhesive composition described above). Preferably, the protective layer 11 (the adhesive composition described above) does not contain a compound having an isocyanate group in its molecule.

[0060] The protective layer 11 is irradiated with active energy rays from a high-pressure mercury lamp at a rate of 1 J / cm². 2 Preferably, after irradiation, the glass transition temperature is 30°C or more higher than that before irradiation. In other words, it is preferable that the glass transition temperature of the protective layer 11 after irradiation (after irradiation treatment) is 30°C or more higher than the glass transition temperature of the protective layer 11 before irradiation with active energy rays (before irradiation treatment). The above change in glass transition temperature is more preferably 40°C or more, and even more preferably 50°C or more. A larger change in the glass transition temperature allows for a better balance between the adhesion of the protective layer 11 to the object to be protected before the irradiation treatment and the ease of removal of the protective layer 11 by water or the like after the treatment. The above-mentioned change in the glass transition temperature may be, for example, below 200°C.

[0061] The protective layer 11 may have a glass transition temperature of -30°C to 40°C before being irradiated with active energy rays. Such a glass transition temperature is preferably -25°C or higher, more preferably -10°C or higher. Such a glass transition temperature is preferably 30°C or lower, more preferably 20°C or lower. Having a glass transition temperature of -30°C or higher can suppress excessive tackiness, making it easier to peel off the release liner, for example, and potentially improving handling during use. On the other hand, having a glass transition temperature of 40°C or lower can potentially improve adhesion between the protective layer 11 and the adherend.

[0062] The protective layer 11 is irradiated with active energy rays (1 J / cm² from a high-pressure mercury lamp). 2 After irradiation, it preferably has a glass transition temperature of 30°C to 150°C. A higher glass transition temperature can improve the removal of the protective layer 11 with water or the like.

[0063] The glass transition temperature is measured as follows. Specifically, differential scanning calorimetry (DSC) is performed on the protective layer, and the glass transition temperature (Tg) is determined from the measurement chart. When determining the glass transition temperature (Tg) from the measurement chart, the "intermediate glass transition temperature (Tmg)" described in JIS K7121 (1987) "Method for Measuring Transition Temperatures of Plastics" is adopted as the glass transition temperature (Tg). <Measurement conditions> • Measurement temperature: -60℃ to 100℃ • Sample quantity to measure: Weigh out 5-10 mg. The glass transition point of the protective layer 11 after irradiation with active energy rays, as described above, is a measurement taken after performing irradiation under the following conditions. Activated energy ray irradiation treatment: 1 J / cm using a high-pressure mercury lamp. 2 irradiation

[0064] The protective layer 11 has a peeling force of 4 N / 10 mm or more against the silicon wafer, and the active energy irradiation is 1 J / cm using a high-pressure mercury lamp.2 It is preferable that the material has a peeling force of 1 N / 10 mm or less relative to the silicon wafer after irradiation. The greater peeling force before irradiation with the active energy rays results in improved adhesion of the protective layer 11 to the surface to be protected. The smaller peeling force after irradiation with the active energy rays allows the protective layer 11 to be removed more easily after protecting the surface of the adherend. The peeling force before irradiation as described above may be, for example, 20 N / 10 mm or less. The peeling force after irradiation as described above may be, for example, 0.001 N / 10 mm or more.

[0065] The above-mentioned peeling force measurement is carried out as follows. First, the protective layer is cut to a width of 30 mm and bonded to the surface of a silicon bare wafer at 70°C, and then a backing tape is bonded to the protective layer. Cuts are made at both ends in the width direction so that the protective layer and backing tape are 10 mm wide, and the excess is peeled off to prepare a test sample that is 10 mm wide. Using a tensile testing machine, one end of the sheet-like test sample in the longitudinal direction is gripped with a chuck, and a 180-degree peel test (peel test) is performed at room temperature (23°C) by peeling the test sample at a speed of 300 mm / min. The delamination force after irradiation with active energy rays will be measured by the following method: A protective layer is bonded to a silicon bare wafer, and ultraviolet light is irradiated from the protective layer side (1 J / cm²). 2 ) and let stand for 15 minutes. Then, attach backing tape to the protective layer and prepare a 10 mm wide test sample in the same manner as above. Using a tensile testing machine, measure the peel force after irradiation with active energy rays in the same manner as above.

[0066] The peeling force described above can be increased, for example, by reducing the proportion of the acid-producing compound contained in the protective layer 11. On the other hand, the peeling force described above can be decreased, for example, by increasing the proportion of the acid-producing compound contained in the protective layer 11.

[0067] The protective layer 11 may be formed, for example, by applying the adhesive composition containing the solvent to the surface to be protected of the adherend, and then volatilizing the solvent. Alternatively, the protective layer 11 may be formed by applying the adhesive composition containing the solvent to one side of the release liner 15, and then volatilizing the solvent. Preferably, the formed protective layer 11 does not contain the solvent that is added to the adhesive composition to impart fluidity. The protective layer 11 may, for example, be formed from the above-mentioned adhesive composition that does not contain a solvent by a general molding method.

[0068] In the protective sheet described above, the thickness of the protective 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. Such a thickness may also be 40 μm or less, 30 μm or less, or 20 μm or less. If the protective layer 11 is a laminate, the above thickness is the total thickness of the laminate.

[0069] The protective layer 11 described above may have the property of being stretched in the planar direction and broken into smaller pieces before being irradiated with active energy rays. A protective layer 11 having such properties is preferably used when manufacturing electronic components and devices via a DBG process. Similarly, it is preferably used when manufacturing electronic components and devices via a stealth processing process using a stealth dicing apparatus. Furthermore, since the protective layer 11 described above can also be suitably used when manufacturing electronic component devices through a blade dicing process, it does not necessarily have to possess the physical properties described above.

[0070] The protective sheet 10 of this embodiment is used, for example, in the process of manufacturing electronic component devices. Specifically, the protective sheet 10 of this embodiment is used for purposes such as temporarily protecting the protected surface (surface to be protected) of an electronic component (a type of substrate). More specifically, the protective layer 11 of the protective sheet 10 of this embodiment is used by being attached to the protected surface of an electronic component (a type of substrate), for example. 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.

[0071] 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 Systems) chips.

[0072] 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 10 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.

[0073] 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.

[0074] Next, an embodiment of a method for manufacturing electronic component devices will be described.

[0075] The manufacturing method of the above-mentioned electronic component device is: A step of protecting the surface to be protected by overlapping a protective layer 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 protective layer that overlaps the surface to be protected (removal step), The aforementioned adhesive composition is The present invention comprises a compound that generates an acid upon irradiation with active energy rays, and the above-mentioned polymer having an ester group in its molecule that is hydrolyzed by the acid to produce a hydrophilic group, In the removal step, the acid is generated from the acid-producing compound by irradiation with active energy rays, thereby hydrolyzing the ester group (easily hydrolyzable ester group) to increase the hydrophilicity of the protective layer, and the protective layer is removed by bringing the protective layer into contact with a liquid containing water.

[0076] In the above protection process, as shown in Figure 2A, a protective sheet 10 having a release liner 15 on one side of the protective layer 11 may be used to protect the surface of the substrate S to be protected. For example, after placing the protective layer 11 of the protective sheet 10 on the surface of the substrate S to be protected, the release liner 15 may be peeled off from the protective layer 11 (see Figure 2B).

[0077] 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 protective 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 chips S' and small pieces of protective layer 11' overlap. Note that before division, the substrate S may have weakened areas or other structures formed inside to facilitate fragmentation.

[0078] In the removal process described above, as shown in Figure 2E, by irradiating multiple small pieces 11' of the protective layer with active energy rays such as ultraviolet light, new acid is generated from the acid-producing compound contained in each small piece 11', and the easily hydrolyzable ester group is hydrolyzed by the newly generated acid, thereby 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 protective 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.

[0079] 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.

[0080] In the method for manufacturing an electronic component device according to this embodiment, at least one surface of the substrate is protected by a protective 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.

[0081] 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.

[0082] In the above protection step, the protective 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 protective 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 protective layer 11 on at least one side of the substrate so as to cover the circuit wiring, sensor part, or electrode part with the protective 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).

[0083] The following provides a detailed explanation of the process of manufacturing semiconductor integrated circuits (semiconductor devices) as electronic components.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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 protective layer 11 of the protective sheet 10 and the dicing tape 20 (see Figure 3A) are used at least to manufacture the semiconductor device as follows. These sheets and tapes are used as auxiliary tools for manufacturing the semiconductor device. Note that 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.

[0088] The following provides a detailed explanation of a specific example of a semiconductor device manufacturing method.

[0089] The semiconductor device manufacturing method in this specific example 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 a protective 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 wafer W and protective layer 11 are stacked and overlapped by dividing the stacked semiconductor wafer W and protective layer 11 into small pieces with spacing in the planar direction, and The process involves irradiating each small piece 11' of the protective layer overlapping the circuit surface of the semiconductor chip X with an active energy ray to generate acid from the acid-producing compound in each small piece 11', hydrolyzing the easily hydrolyzable ester group with this acid, thereby increasing the hydrophilic groups in the polymer molecule and enhancing the hydrophilicity of each small piece 11', and then removing each small piece 11' of the protective layer with a water-containing liquid (removal step), The process includes a step of joining a semiconductor chip X to an adherend.

[0090] The assembly process of this specific example includes, for example, the following steps: Specifically, the assembly process in this example is: 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 to protect the circuit surface of a semiconductor wafer W by attaching a protective layer 11 to the circuit surface, A blade dicing process (a process for producing multiple small pieces of the above-mentioned laminate) involves dividing a semiconductor wafer W, to which a die bond sheet 30 and a protective 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 irradiation treatment with active energy rays as described above, a removal step (the removal step described above) is performed to remove multiple small pieces 11' of the protective 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 protective layer 11 and the dicing tape 20 described above is used as a manufacturing aid.

[0091] A 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 its surface (for example, directions along the surface that are mutually orthogonal), thereby enabling the fabrication of multiple semiconductor chips X. Furthermore, the semiconductor wafer W 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 specific example has a circuit surface formed on one of its surfaces.

[0092] 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.

[0093] 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.

[0094] In the protection process, for example, as shown in Figure 4A, the protective layer 11 is superimposed on one of the circuit surfaces of the semiconductor wafer W. In the protection process, for example, the protective layer 11 may be superimposed on the circuit surface by directly pressing and attaching it to the circuit surface. Alternatively, an adhesive composition containing a solid component constituting the protective 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 a protective layer 11 that is in contact with the circuit surface, thereby superimposing the protective layer 11 on the circuit surface. Typically, the protective layer 11 is superimposed on the circuit surface while heating at a temperature higher than room temperature. By overlaying a protective layer 11 onto the circuit surface of a semiconductor wafer W, the circuit surface can be protected by the protective layer 11 until the protective 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 protective layer 11. Furthermore, the protection process may be performed after the mounting process, or the mounting process may be performed after the protection process.

[0095] 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 layer 11 protects the surface of the semiconductor wafer W, 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.

[0096] In the removal step, as shown in FIG. 4D, a treatment for generating an acid from the compound that generates the acid is performed on a plurality of small pieces 11' of the protective layer. As such a treatment, an irradiation treatment with active energy rays is employed. In the irradiation treatment with active energy rays, for example, ultraviolet rays with an intensity of 10 mW / cm 2 or more and 300 mW / cm 2 or less are employed as the active energy rays, and the plurality of small pieces 11' of the protective layer are irradiated with ultraviolet rays so that the integrated light quantity is 50 mJ / cm 2 or more and 5000 mJ / cm 2 or less. In the removal step, by performing the above-described treatment on a plurality of small pieces 11' of the protective layer, an acid is generated from the compound that generates the acid contained in the small pieces 11'. The newly generated acid hydrolyzes the easily hydrolyzable ester group in the polymer contained in the small pieces 11' of the protective layer, and a hydrophilic group such as a carboxy group is newly generated. Thus, the hydrophilicity of the small pieces 11' of the protective layer is enhanced. Thereby, when the small pieces 11' and the liquid containing water come into contact later, at least a part of the small pieces 11' dissolves, and the small pieces 11' are relatively easily removed from the surface of the semiconductor chip X.

[0097] In the removal step, as shown in FIG. 4E, a liquid containing water is brought into contact with a plurality of small pieces 11' of the protective layer, and at least a part of each small piece 11' is dissolved with the above liquid, whereby each small piece 11' of the protective layer is removed from the surface (protected surface) of the semiconductor chip X. By removing the small pieces 11' of the protective layer in this manner, all of the plurality of small pieces 11' of the protective layer can be removed relatively easily, and the number of foreign substances adhering to the surface of the semiconductor chip can be reduced relatively easily by the above liquid. Also, the surface (protected surface) of each semiconductor chip X where the small pieces 11' of the protective layer overlapped can be washed with the liquid.

[0098] In the removal process, at least a portion of the fragmented protective layer (multiple small pieces 11' of the protective layer) is dissolved by the liquid. As a result, the adhesion of the small pieces 11' of the protective 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 protective layer to be removed relatively easily.

[0099] 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 tert-butanol.

[0100] In the removal step in this specific example, the protective layer pieces 11' may be immersed in the stirred liquid to bring the liquid into contact with the protective layer pieces 11'. Alternatively, the liquid sprayed from a nozzle or the like may be brought into contact with the protective 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.

[0101] 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 protective 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.

[0102] In the semiconductor device manufacturing method of this specific example, a protective layer 11 is superimposed on the surface (circuit surface) of the semiconductor wafer W on which circuit components are formed, thus protecting the circuit surface until the protective 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 protective 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 protective layer 11 is superimposed, that foreign matter can be removed when the small piece 11' of the protective 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. Furthermore, even if water comes into contact with the protective layer 11 while the protective layer 11 is protecting the circuit surface, the protective layer 11 will not be removed by liquids containing water because the hydrophilicity of the protective layer 11 is low before irradiation with active energy rays.

[0103] 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.

[0104] 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 protective 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.

[0105] 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 semiconductor chips X with small pieces 30' of the die bond sheet attached may be stacked. In this specific example, 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).

[0106] In this specific example, 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.

[0107] In the above explanation of this specific example, 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.

[0108] 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.

[0109] Other processes besides those shown in the specific examples above may be performed. For example, in processes such as plasma dicing or stealth dicing, a protective layer 11 may be superimposed on the circuit surface of the semiconductor wafer W, and after various processing steps are performed, the protective layer 11 may be removed. Alternatively, with the protective layer 11 placed between the backgrind tape B and the semiconductor wafer W as described above, grinding may be performed as described above, and then the mounting process may be performed.

[0110] The adhesive composition and protective sheet of the embodiments of the present invention are as illustrated above, but the present invention is not limited to the examples above. In other words, various forms of general adhesive compositions and protective sheets used in such materials can be employed, as long as they do not impair the effects of the present invention.

[0111] 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 explained in the specific example above, a semiconductor wafer with circuit surfaces formed on only one side. In other words, of the semiconductor chip manufactured by the manufacturing method described above, circuit components may be arranged on only one side, or circuit components may be arranged on both sides.

[0112] The matters disclosed herein include the following: (1) An adhesive composition for forming an adhesive protective layer to protect the protective surface of a substrate when manufacturing electronic component devices, Compounds that produce acid upon irradiation with active energy rays, An adhesive composition comprising a polymer having an ester group in its molecule that is hydrolyzed by the aforementioned acid to produce a hydrophilic group. According to the adhesive composition described above, a protective layer can be formed that adheres relatively strongly to the surface to be protected and can be removed relatively easily with a liquid containing water by irradiation with active energy rays. (2) The protective layer formed with the adhesive composition is The aforementioned activation energy beam irradiation was performed using a high-pressure mercury lamp at a rate of 1 J / cm². 2 The adhesive composition according to (1) above, which has a glass transition temperature that is 30°C or higher than that before irradiation after being irradiated. (3) The adhesive composition according to (1) or (2) above, wherein the polymer has constituent units of a (meth)acrylic acid ester monomer in its molecule, the carboxyl group being formed as the hydrophilic group by the acid. (4) A protective sheet comprising a protective layer formed of the adhesive composition described in any of (1) to (3) above. (5) The protective layer has a peel force of 4 N / 10 mm or more against the silicon wafer, and the irradiation of the active energy ray is 1 J / cm using a high-pressure mercury lamp. 2A protective sheet as described in (4) above, which has a peeling force of 1 N / 10 mm or less from the silicon wafer after being irradiated. [Examples]

[0113] The present invention will be further explained with experimental examples, but the present invention is not limited to these.

[0114] The adhesive compositions (protective layers) for the examples and comparative examples were prepared as follows, and protective sheets equipped with these protective layers were manufactured. Details of each adhesive composition (protective layer) in each manufacturing method and the evaluation results are shown in Table 1.

[0115] <Monomer raw materials (containing easily hydrolyzable ester groups in the molecule)> Details of the monomers used for polymer polymerization are as follows: • [BEA] n-butoxyethyl acrylate (see formula (A) below; purchased item) [ka] • [PEA] n-propoxyethyl acrylate (see formula (B) below; purchased item) [ka] • [CHEA] Cyclohexoxyethyl acrylate (See formula (C) below; purchased item) [ka] • [BEMA] n-butoxyethyl methacrylate (see formula (D) below; purchased item) [ka] • [t-BA] tert-butyl acrylate (see formula (E) below; purchased item) [ka] <Other monomers> • [4HBA] 4-hydroxybutyl acrylate (purchased item) • [HEAA] N-(2-hydroxyethyl)acrylamide (Purchased item)

[0116] [Example 1~ 3. Reference Example 4, Example of Implementation 5. Comparative Example 2] (Preparation of polymers) Acrylic polymers were prepared according to the compositions shown in Table 1. Specifically, the monomers shown in Table 1, polymerization initiator (azobisisobutyronitrile AIBN), and reaction solvent (ethyl acetate) were mixed so that the solid content was approximately 25% by mass. Solution polymerization was carried out at a temperature of 65°C to 70°C to synthesize acrylic polymers.

[0117] [Comparative Examples 1 and 3] The details of the polyvinyl alcohol (PVA) used in Comparative Examples 1 and 3 are as follows. • [PVA] Polyvinyl alcohol Saponification degree: 35 (mol%), Average degree of polymerization: 200

[0118] (Making protective sheets) To the polymer solutions containing each acrylic polymer prepared as described above, an acid-generating compound (photoacid generator) was added and mixed in an amount shown in Table 1 relative to the polymer solids (except for Comparative Example 2). Each acrylic 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 a protective layer with a thickness of 5 μm overlapping one side of each release liner a. Then, release liner b (PET film, 38 μm thick) was placed on the exposed surface of each protective layer. Each release liner b had a surface treated with silicone release agent, and this side was attached to the protective layer. In this way, protective sheets comprising a protective layer (adhesive composition) sandwiched between two release liners were prepared.

[0119] Details of the acid-generating compounds (photoacid generators) are as follows. Note that all of the raw materials listed below were used in the form of a 50% by mass solution in an organic solvent. • Sulfonium salt type. Product name: "CPI-310FG". Manufactured by Sunapro Co., Ltd. Solid content: 100% by mass (to be used after preparing a 50% by mass MEK solution). • Sulfonium salt type Product name "CPI-410B" Manufactured by Sunapro Co., Ltd. 50% by mass solution of propylene carbonate Chemical name:(9-Oxo-9H-thioxanthen-2-yl)[4-[(9-oxo-9H-thioxanthen-2-yl)thio]phenyl](phenyl)sulfonium • Sulfonium salt type. Product name: "CPI-200K". Manufactured by Sunapro Co., Ltd. 50% by mass solution of propylene carbonate. 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)]

[0120] [Table 1]

[0121] <Physical properties: Glass transition temperature (Tg) of the protective layer (before and after UV irradiation treatment)> The glass transition temperature (Tg) of each adhesive composition (protective layer) was measured by differential scanning calorimetry (DSC) according to the glass transition temperature measurement method described above. The glass transition temperature (Tg) was measured before and after irradiation with active energy rays. The irradiation treatment using active energy rays is 1 J / cm² relative to the adhesive composition (protective layer). 2 This was carried out by irradiating with light containing ultraviolet rays to achieve the cumulative light intensity. Table 1 shows the results of the glass transition temperature (Tg) measurements.

[0122] <Evaluation: Adhesion of the protective layer to the silicon wafer (measurement of peel force)> The peel force of each adhesive composition (protective layer) from the silicon wafer was measured as follows, and its adhesion to the silicon wafer was evaluated. First, each adhesive composition (protective layer) was cut to a width of 30 mm and bonded to the surface of a silicon bare wafer at 70°C. Then, a backing tape was bonded to each protective layer. Cuts were made at both ends in the width direction so that the laminated sheet of protective layer and backing tape would be 10 mm wide, and the excess material was peeled off to prepare a test sample with a width of 10 mm. Using a tensile testing machine, a 180-degree peel test was performed at room temperature (23°C) by gripping one end of the sheet-like test sample in the longitudinal direction with a chuck and peeling the test sample at a speed of 300 mm / min. The delamination force after irradiation with active energy rays was measured using the following method. In the same manner as described above, each protective layer was bonded to a silicon bare wafer. Then, ultraviolet light was irradiated from the protective layer side (1 J / cm²). 2 The samples were then left to stand for 15 minutes. After that, backing tape was attached to each protective layer, and 10 mm wide test samples were prepared in the same manner as above. Using a tensile testing machine, the peel force after irradiation with active energy rays was measured in the same manner as above.

[0123] <Evaluation: Removability of protective layer (water solubility) (after UV irradiation)> Each protective layer was bonded to a 6-inch diameter silicon bare wafer at 70°C, and then the silicon bare wafer was bonded to a dicing tape. The test sample prepared in this way was then bonded to a dicing ring. For the protective layer, apply 0.5 or 1.0 [J / cm²] of high-pressure mercury lamp. 2 The protective layer was treated with a light irradiation process (including ultraviolet light) to enhance its hydrophilicity. Subsequently, to remove the protective layer, a cleaning unit manufactured by DISCO (product name DFD6361) was used to spray 25°C water onto the silicon bare wafer while rotating a disc-shaped stage that supported the dicing tape from below in the circumferential direction. The stage rotation speed was set to 1500 rpm, and the water spraying time was set to 180 seconds. Then, we evaluated whether the protective layer formed with the adhesive composition had peeled off and been removed from the substrate (silicon bare wafer). The following evaluation criteria were followed. (Excellent) ○: The protective layer has been completely removed. (Good)△: Most of the protective layer was removed, but some remained (remaining was confirmed in less than 10% of the total area). (Defective) ×: The protective layer was not removed at all, or most of it remained (remaining was confirmed in an area exceeding 10% of the total area).

[0124] As can be seen from the evaluation results above, the protective layer in each embodiment was able to adhere relatively strongly to the protected surface of the silicon wafer, which is the object to be protected. Furthermore, after irradiating the fragmented protective layer with active energy rays (such as ultraviolet light), the fragmented protective layer could be removed relatively easily with water.

[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: Protective sheet, 11: Protective layer, 11': Small piece of protective 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. An adhesive composition for forming an adhesive protective layer to protect the surface of a substrate when manufacturing electronic component devices, A photoacid generator that produces acid upon irradiation with active energy rays, The acrylic polymer comprises an ester group in its molecule that is hydrolyzed by the aforementioned acid to produce a hydrophilic group, The acrylic polymer is an adhesive composition having a constituent unit of a (meth)acrylic acid ester type monomer represented by the following general formula (I) in its molecule.

2. The protective layer formed with the adhesive composition is The aforementioned activation energy beam irradiation was performed using a high-pressure mercury lamp at a rate of 1 J / cm². ２ The adhesive composition according to claim 1, which has a glass transition temperature that is 30°C or higher than that before irradiation after being irradiated.

3. A protective sheet comprising a protective layer formed of the adhesive composition described in claim 1 or 2.

4. The protective layer has a peel force of 4 N / 10 mm or more against the silicon wafer, and the irradiation of the active energy ray is 1 J / cm using a high-pressure mercury lamp. ２ The protective sheet according to claim 3, which, after being irradiated, has a peel force of 1 N / 10 mm or less relative to the silicon wafer.

Images