Member processing method

Abstract

To provide a member processing method which can prevent damage etc. of a processed body (member etc.) while including peeling of a hard substrate from the processed body.SOLUTION: A member processing method of the invention includes: a lamination step in which a hard substrate, an ultraviolet absorption layer, and a processed body are laminated in a written order; a processing step in which the processed body is processed after the lamination step, and a peeling step in which ultraviolet light is radiated to the ultraviolet absorption layer to peel the hard substrate from the processed body after the processing step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for processing a component. [Background technology]

[0002] In the processing of electronic components (members), in consideration of ease of handling between processes, the member may be sandwiched between a pair of substrates and processed (see, for example, Patent Document 1). For example, in a process of thermocompression bonding a member to a terminal on a wiring circuit board, the member is temporarily placed on the terminal on the wiring circuit board, and a steel plate is placed on top of the member via a double-sided pressure-sensitive adhesive sheet, and the member is held in place while pressure is applied, followed by heat treatment to fix the terminal. After heat treatment, the pressure is released, the steel plate is peeled off from the member, and the member is fixed to the terminal on the wiring circuit board. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6691184 Summary of the Invention [Problem to be solved by the invention]

[0004] In a process in which a component is sandwiched between a pair of substrates (a first substrate and a second substrate) and then one of the substrates (the second substrate) is peeled off from the component, such as in the process of thermocompression bonding a component on a wired circuit board, if the second substrate to be peeled off is hard, the second substrate (the hard substrate) is difficult to bend, and therefore the second substrate (the hard substrate) must be separated in the vertical direction. This places a load on the component, causing problems such as damage to the component or unwanted detachment of the component from the first substrate.

[0005] The present invention has been made to solve the above-mentioned conventional problems, and its object is to provide a component processing method that includes peeling a hard substrate from a workpiece (component, etc.), while preventing damage to the workpiece, etc. [Means for solving the problem]

[0006] The component processing method of the present invention includes a lamination step of laminating a hard substrate, an ultraviolet absorbing layer, and a workpiece in this order, a processing step of subsequently processing the workpiece, and a peeling step of subsequently irradiating the ultraviolet absorbing layer with ultraviolet light and peeling the hard substrate from the workpiece. In one embodiment, the workpiece includes another rigid substrate and a member disposed on at least one side of the rigid substrate. In one embodiment, the workpiece is a semiconductor wafer. In one embodiment, the rigid substrate is optically transparent. In one embodiment, the ultraviolet absorbing layer has adhesive properties. In one embodiment, the ultraviolet absorbing layer contains an active energy ray-curable pressure-sensitive adhesive. In one embodiment, the ultraviolet absorbing layer contains an ultraviolet absorber. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a member processing method that includes peeling off a hard substrate from a workpiece (such as a member), while preventing damage to the workpiece. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating a method for processing a member according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. Overview of component processing methods 1 is a schematic diagram illustrating a component processing method according to one embodiment of the present invention. The component processing method of the present invention includes: (i) a step of stacking a hard substrate 10, an ultraviolet absorbing layer 20, and a workpiece 30 in this order (hereinafter also referred to as a stacking step), (ii) a step of subsequently processing the workpiece 30 (a processing step), and (iii) a step of subsequently irradiating the ultraviolet absorbing layer 20 with ultraviolet light to peel the hard substrate 10 from the workpiece 30 (a peeling step).

[0010] B.Lamination process As described above, the lamination step is a step of laminating the hard substrate 10, the ultraviolet absorbing layer 20, and the workpiece 30 in this order. In one embodiment, the ultraviolet absorbing layer has adhesive properties. The workpiece 30 in the illustrated example includes another hard substrate 31 and a member 32 arranged on one side of the other hard substrate 31.

[0011] In one embodiment, a substrate 21 and a pressure-sensitive adhesive layer 22 may be further disposed between the ultraviolet absorbing layer 20 and the workpiece 30. The ultraviolet absorbing layer 20, the substrate 21, and the pressure-sensitive adhesive layer 22 may be disposed in this order. In one embodiment, a laminate composed of the ultraviolet absorbing layer 20, the substrate 21, and the pressure-sensitive adhesive layer 22 may be a double-sided pressure-sensitive adhesive sheet A.

[0012] In another embodiment, the rigid substrate and the workpiece may be disposed with an ultraviolet absorbing layer interposed therebetween. More specifically, the rigid substrate is disposed directly on one side of the ultraviolet absorbing layer, and the workpiece is disposed directly on the other side of the ultraviolet absorbing layer.

[0013] B-1. Hard substrate The hard substrate is a plate-shaped molded product having a flexural modulus of 1 GPa or more. The flexural modulus can be measured by a four-point bending test in accordance with JIS K7171 or JIS R1602, depending on the material constituting the hard substrate.

[0014] Any appropriate material can be used as the material for the hard substrate, such as a glass substrate, a metal substrate, a silicon substrate, a sapphire substrate, or a plastic substrate.

[0015] Preferably, the hard substrate has optical transparency. The transmittance of the hard substrate to ultraviolet light (wavelength 360 nm) is preferably 70% or more, more preferably 80% to 99.9%. If the hard substrate has optical transparency, peeling can be preferably performed in the peeling step.

[0016] B-2. UV absorbing layer The ultraviolet absorbing layer may be a layer that initially has adhesiveness (i.e., before ultraviolet irradiation) and exhibits peelability due to reduced adhesiveness after ultraviolet irradiation. In one embodiment, the ultraviolet absorbing layer may be a layer whose adhesiveness is partially reduced by partial ultraviolet irradiation (e.g., UV laser light irradiation).

[0017] In one embodiment, the ultraviolet absorbing layer includes an ultraviolet absorber. Preferably, the ultraviolet absorbing layer further includes an adhesive. Examples of the adhesive include a pressure-sensitive adhesive and an active energy ray-curable adhesive.

[0018] The inclusion of an ultraviolet absorber in the ultraviolet absorbing layer enables peeling of the adherend by irradiation with UV laser light. More specifically, when the ultraviolet absorbing layer is irradiated with UV laser light, the ultraviolet absorber decomposes to generate gas, and / or the ultraviolet absorbing layer decomposes due to heat generated by the ultraviolet absorber, generating gas, which causes deformation of the ultraviolet absorbing layer, resulting in the development of peelability in the area irradiated with UV laser light.

[0019] Furthermore, if the ultraviolet absorbing layer contains an active energy ray-curable adhesive, the adhesive strength of the entire ultraviolet absorbing layer can be reduced by irradiating it with active energy rays. In one embodiment, the entire ultraviolet absorbing layer is irradiated with active energy rays to reduce the adhesive strength, and then laser light is irradiated as described above. This significantly prevents adhesive residue after peeling and re-adhesion to the hard substrate, which is advantageous from the perspective of preventing contamination, even compared to conventional methods using varnish, for example. Examples of active energy rays include gamma rays, ultraviolet rays, visible light, infrared rays (heat rays), radio waves, alpha rays, beta rays, electron beams, plasma flow, ionizing rays, and particle beams. Ultraviolet rays are preferred.

[0020] The light transmittance of the ultraviolet absorbing layer at a wavelength of 360 nm is preferably 50% or less. By reducing this light transmittance, the laser output required for peeling can be reduced. The light transmittance of the ultraviolet absorbing layer at a wavelength of 355 nm is preferably 30% or less. Within this range, the above-mentioned effects become more pronounced. Furthermore, the light transmittance of the ultraviolet absorbing layer at a wavelength of 380 nm is preferably 30% or more, more preferably 50% or more.

[0021] The initial adhesive strength at 23°C when the ultraviolet absorbing layer is attached to a stainless steel plate is preferably 0.1 N / 20 mm to 20 N / 20 mm, more preferably 0.5 N / 20 mm to 15 N / 20 mm. This range allows for the formation of an ultraviolet absorbing layer that can effectively hold a workpiece. The adhesive strength is measured in accordance with JIS Z 0237:2000. Specifically, the ultraviolet absorbing layer is attached to a stainless steel plate (arithmetic mean surface roughness Ra: 50±25 nm) using a 2 kg roller in one stroke, left at 23°C for 30 minutes, and then peeled off at a peel angle of 180° and a peel rate (pulling speed) of 300 mm / min. The adhesive strength of the ultraviolet absorbing layer changes upon irradiation with active energy rays and laser light. In this specification, "initial adhesive strength" refers to the adhesive strength before irradiation with active energy rays and laser light.

[0022] In one embodiment, the ultraviolet absorbing layer is attached to a stainless steel plate, and the ultraviolet absorbing layer is 460 mJ / cm 2 The adhesive strength at 23°C after irradiation with ultraviolet rays is preferably 0.01 N / 20 mm to 2 N / 20 mm, more preferably 0.02 N / 20 mm to 1 N / 20 mm. If the adhesive strength is within such a range, a peelable ultraviolet absorbing layer can be formed with little adhesive residue. The ultraviolet irradiation can be carried out, for example, by using an ultraviolet irradiation device (manufactured by Nitto Seiki Co., Ltd., product name "UM-810") and irradiating the adhesive with ultraviolet rays from a high-pressure mercury lamp (characteristic wavelength: 365 nm, cumulative light amount: 460 mJ / cm). 2 , Irradiation energy: 70W / cm 2 The ultraviolet absorbing layer is irradiated with light (irradiation time: 6.6 seconds).

[0023] The thickness of the ultraviolet absorbing layer is preferably 50 μm or less. Within this range, it is possible to further reduce the laser output during peeling. The thickness of the ultraviolet absorbing layer is more preferably 40 μm or less, even more preferably 30 μm or less, and even more preferably 1 μm to 30 μm. Within this range, the above-mentioned effects become more pronounced.

[0024] UV absorber: Any appropriate ultraviolet absorber can be used as the ultraviolet absorber, as long as it is a compound that absorbs ultraviolet light (for example, a wavelength of 355 nm). Examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. Among these, triazine-based ultraviolet absorbers or benzotriazole-based ultraviolet absorbers are preferred, and triazine-based ultraviolet absorbers are particularly preferred. In particular, when an acrylic adhesive is used as the adhesive A, triazine-based ultraviolet absorbers can be preferably used because of their high compatibility with the base polymer of the acrylic adhesive. The triazine-based ultraviolet absorber is more preferably composed of a compound having a hydroxyl group, and is particularly preferably an ultraviolet absorber composed of a hydroxyphenyltriazine-based compound (hydroxyphenyltriazine-based ultraviolet absorber).

[0025] Examples of hydroxyphenyltriazine-based ultraviolet absorbers include a reaction product of 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenyl with [(C10-C16 (mainly C12-C13) alkyloxy)methyl]oxirane (trade name "TINUVIN 400", manufactured by BASF), 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-[3-(dodecyloxy)-2-hydroxypropoxy]phenol), a reaction product of 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine with (2-ethylhexyl)-glycidic acid ester (trade name "TINUVIN 405, manufactured by BASF), 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (trade name "TINUVIN 460", manufactured by BASF), 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol (trade name "TINUVIN 1577", manufactured by BASF), 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]-phenol (trade name "ADEKA STAB LA-46", manufactured by ADEKA Corporation), 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (trade name "TINUVIN BASF's trade name "TINUVIN 477" and the like.

[0026] Examples of benzotriazole-based ultraviolet absorbers (benzotriazole-based compounds) include 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (trade name "TINUVIN PS", manufactured by BASF), an ester compound of benzenepropanoic acid and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy (C7-9 side chain and linear alkyl) (trade name "TINUVIN 384-2", manufactured by BASF), a mixture of octyl 3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate and 2-ethylhexyl-3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate (trade name "TINUVIN 109, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (trade name "TINUVIN 900", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (trade name "TINUVIN 928", manufactured by BASF), reaction products of methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate / polyethylene glycol 300 (trade name "TINUVIN 1130", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-p-cresol (trade name "TINUVIN P", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (trade name "TINUVIN 234", manufactured by BASF), 2-[5-chloro-2H-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (trade name "TINUVIN 326", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (trade name "TINUVIN 328", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (trade name "TINUVIN 329", manufactured by BASF), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol] (trade name "TINUVIN 360", manufactured by BASF), reaction products of methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate with polyethylene glycol 300 (trade name "TINUVIN 213", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (trade name "TINUVIN 571", manufactured by BASF), 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimido-methyl)-5-methylphenyl]benzotriazole (trade name "Sumisorb 250" manufactured by Sumitomo Chemical Co., Ltd.), 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole (trade name "SEESORB 703" manufactured by Shipro Chemical Co., Ltd.), 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidylmethyl)phenol (trade name "SEESORB 706" manufactured by Shipro Chemical Co., Ltd.), 2-(4-benzoyloxy-2-hydroxyphenyl)-5-chloro-2H-benzotriazole (trade name "SEESORB 7012BA" manufactured by Shipro Chemical Co., Ltd.), 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (trade name "KEMISORB 73" manufactured by Chemipro Chemical Co., Ltd.), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (trade name "ADK STAB LA-31" manufactured by ADEKA Corporation), 2-(2H-benzotriazol-2-yl)-p-cellulose (trade name "ADK STAB LA-32" manufactured by ADEKA Corporation), 2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol (trade name "ADK STAB LA-36" manufactured by ADEKA Corporation), etc.

[0027] The ultraviolet absorber may be a dye or a pigment. Examples of pigments include azo-based, phthalocyanine-based, anthraquinone-based, lake-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxandine-based, isoindolinone-based, and quinophthalone-based pigments. Examples of dyes include azo-based, phthalocyanine-based, anthraquinone-based, carbonyl-based, indigo-based, quinoneimine-based, methine-based, quinoline-based, and nitro-based dyes.

[0028] The molecular weight of the compound constituting the ultraviolet absorber is preferably 100 to 1500, more preferably 200 to 1200, and even more preferably 200 to 1000. Within such a range, an ultraviolet absorbing layer capable of forming a better deformed portion by laser light irradiation can be formed.

[0029] The maximum absorption wavelength of the ultraviolet absorber is preferably 300 nm to 450 nm, more preferably 320 nm to 400 nm, and even more preferably 330 nm to 380 nm. The difference between the maximum absorption wavelength of the ultraviolet absorber and the maximum absorption wavelength of the photopolymerization initiator is preferably 10 nm or more, more preferably 25 nm or more.

[0030] The 5% weight loss temperature of the ultraviolet absorber is preferably 350°C or lower, more preferably 330°C or lower. The lower limit of the 5% weight loss temperature of the ultraviolet absorber is, for example, 100°C. Within this range, an ultraviolet absorbing layer capable of forming a better deformed portion by laser light irradiation can be formed. The 5% weight loss temperature of the ultraviolet absorber refers to the temperature at which the weight of the ultraviolet absorber, when heated, decreases by 5% by weight relative to the weight before heating. The 5% weight loss temperature is measured using a differential thermal analyzer under measurement conditions of a heating rate of 10°C / min, an air atmosphere, and a flow rate of 25 ml / min.

[0031] The content of the ultraviolet absorber is preferably 1 to 50 parts by weight, more preferably 5 to 20 parts by weight, relative to 100 parts by weight of the base polymer in the ultraviolet absorbing layer. Within this range, when the adhesive strength of the entire ultraviolet absorbing layer is satisfactorily reduced by irradiation with active energy rays, the ultraviolet absorbing layer is cured satisfactorily, and an ultraviolet absorbing layer that exhibits good releasability by irradiation with laser light can be formed.

[0032] Active energy ray curable adhesive: In one embodiment, an active energy ray-curable adhesive (A1) is used as the active energy ray-curable adhesive, which comprises a base polymer as a matrix and an active energy ray-reactive compound (monomer or oligomer) capable of bonding to the base polymer. In another embodiment, an active energy ray-curable adhesive (A2) is used, which comprises an active energy ray-reactive polymer as the base polymer. Preferably, the base polymer has a functional group capable of reacting with a photopolymerization initiator. Examples of such functional groups include a hydroxyl group and a carboxyl group.

[0033] Examples of base polymers used in the PSA (A1) include rubber-based polymers such as natural rubber, polyisobutylene rubber, styrene-butadiene rubber, styrene-isoprene-styrene block copolymer rubber, reclaimed rubber, butyl rubber, polyisobutylene rubber, and nitrile rubber (NBR); silicone-based polymers; and acrylic-based polymers. These polymers may be used alone or in combination of two or more. Among these, acrylic polymers are preferred.

[0034] Examples of acrylic polymers include homopolymers or copolymers of hydrocarbon group-containing (meth)acrylic acid esters, such as (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters; and copolymers of such hydrocarbon group-containing (meth)acrylic acid esters with other copolymerizable monomers. Examples of (meth)acrylic acid alkyl esters include the methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester (i.e., lauryl ester), tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, and eicosyl ester of (meth)acrylic acid. Examples of (meth)acrylic acid cycloalkyl esters include the cyclopentyl ester and cyclohexyl ester of (meth)acrylic acid. Examples of (meth)acrylic acid aryl esters include phenyl (meth)acrylate and benzyl (meth)acrylate. The content of the structural unit derived from the hydrocarbon group-containing (meth)acrylic acid ester is preferably 40 parts by weight or more, more preferably 60 parts by weight or more, per 100 parts by weight of the base polymer.

[0035] Examples of the other copolymerizable monomers include functional group-containing monomers such as carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphate group-containing monomers, acrylamide, and acrylonitrile. Examples of the carboxyl group-containing monomers include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acid anhydride monomers include maleic anhydride and itaconic anhydride. Examples of the hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. Examples of glycidyl group-containing monomers include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate. Examples of sulfonic acid group-containing monomers include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid. Examples of phosphate group-containing monomers include 2-hydroxyethyl acryloyl phosphate. Examples of acrylamides include N-acryloylmorpholine. These may be used alone or in combination of two or more. The content of the structural units derived from the copolymerizable monomers is preferably 60 parts by weight or less, more preferably 40 parts by weight or less, per 100 parts by weight of the base polymer.

[0036] The acrylic polymer may contain structural units derived from polyfunctional monomers to form crosslinked structures in the polymer backbone. Examples of polyfunctional monomers include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy (meth)acrylate (i.e., polyglycidyl (meth)acrylate), polyester (meth)acrylate, and urethane (meth)acrylate. These may be used alone or in combination of two or more. The content of the structural units derived from the polyfunctional monomer is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, per 100 parts by weight of the base polymer.

[0037] The weight-average molecular weight of the acrylic polymer is preferably 100,000 to 3,000,000, and more preferably 200,000 to 2,000,000. The weight-average molecular weight can be measured by GPC (solvent: THF).

[0038] Examples of the active energy ray reactive compound that can be used in the pressure-sensitive adhesive (A1) include photoreactive monomers or oligomers having a functional group with a polymerizable carbon-carbon multiple bond, such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, or an acetylene group. Specific examples of the photoreactive monomer include esters of (meth)acrylic acid and polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and polyethylene glycol di(meth)acrylate; polyfunctional urethane (meth)acrylate; epoxy (meth)acrylate; oligoester (meth)acrylate; etc. Also usable are monomers such as methacryloisocyanate, 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), and m-isopropenyl-α,α-dimethylbenzyl isocyanate. Specific examples of the photoreactive oligomer include dimers to pentamers of the above-mentioned monomers. The molecular weight of the photoreactive oligomer is preferably 100 to 3,000.

[0039] Furthermore, as the active energy ray reactive compound, a monomer such as epoxidized butadiene, glycidyl methacrylate, acrylamide, vinyl siloxane, or the like, or an oligomer composed of such a monomer may be used.

[0040] Furthermore, the active energy ray-reactive compound may be a mixture of an organic salt such as an onium salt and a compound having multiple heterocycles in the molecule. When the mixture is irradiated with active energy rays (e.g., ultraviolet light or an electron beam), the organic salt is cleaved to generate ions, which act as initiating species to cause a ring-opening reaction of the heterocycles, forming a three-dimensional network structure. Examples of the organic salt include iodonium salts, phosphonium salts, antimonium salts, sulfonium salts, and borate salts. Examples of the heterocycle in the compound having multiple heterocycles in the molecule include oxirane, oxetane, oxolane, thiirane, and aziridine.

[0041] In the pressure-sensitive adhesive (A1), the content of the active energy ray-reactive compound is preferably 0.1 to 500 parts by weight, more preferably 5 to 300 parts by weight, and even more preferably 40 to 150 parts by weight, relative to 100 parts by weight of the base polymer.

[0042] Examples of the active energy ray-reactive polymer (base polymer) contained in the pressure-sensitive adhesive (A2) include polymers having functional groups with carbon-carbon multiple bonds such as acryloyl groups, methacryloyl groups, vinyl groups, allyl groups, acetylene groups, etc. Specific examples of the active energy ray-reactive polymer include polymers composed of multifunctional (meth)acrylates, photocationic polymerizable polymers, cinnamoyl group-containing polymers such as polyvinyl cinnamate, diazotized amino novolac resins, polyacrylamides, etc.

[0043] In one embodiment, an active energy ray-reactive polymer is used, which is constructed by introducing an active energy ray-polymerizable carbon-carbon multiple bond into the side chain, main chain, and / or main chain terminal of the acrylic polymer. A method for introducing a radiation-polymerizable carbon-carbon double bond into an acrylic polymer includes, for example, copolymerizing raw material monomers including a monomer having a predetermined functional group (first functional group) to obtain an acrylic polymer, and then subjecting a compound having a radiation-polymerizable carbon-carbon double bond and a predetermined functional group (second functional group) capable of reacting with and bonding to the first functional group to a condensation reaction or addition reaction with the acrylic polymer while maintaining the radiation polymerizability of the carbon-carbon double bond.

[0044] Examples of combinations of the first functional group and the second functional group include a carboxyl group and an epoxy group, an epoxy group and a carboxyl group, a carboxyl group and an aziridyl group, an aziridyl group and a carboxyl group, a hydroxyl group and an isocyanate group, and an isocyanate group and a hydroxyl group. Among these combinations, a hydroxyl group and an isocyanate group, or an isocyanate group and a hydroxyl group, is preferred from the viewpoint of ease of reaction tracking. Furthermore, while producing a polymer having a highly reactive isocyanate group is technically difficult, from the viewpoint of ease of production or availability of the acrylic polymer, it is more preferred that the first functional group on the acrylic polymer be a hydroxyl group and the second functional group be an isocyanate group. In this case, examples of isocyanate compounds having both a radiation-polymerizable carbon-carbon double bond and an isocyanate group as the second functional group include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate. Furthermore, the acrylic polymer having a first functional group is preferably one that contains a structural unit derived from the above-mentioned hydroxy group-containing monomer, and is also preferably one that contains a structural unit derived from an ether compound such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, or diethylene glycol monovinyl ether.

[0045] The pressure-sensitive adhesive (A2) may further contain the active energy ray-reactive compound (monomer or oligomer).

[0046] The active energy ray-curable pressure-sensitive adhesive may contain a photopolymerization initiator.

[0047] Any suitable initiator can be used as the photopolymerization initiator. Examples of the photopolymerization initiator include α-ketol compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenyl ketone; acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; and ketal compounds such as benzyl dimethyl ketal. Examples of suitable photopolymerization initiators include aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride, photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime, benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone, camphorquinone, halogenated ketones, acylphosphinoxides, and acylphosphonates. The amount of the photopolymerization initiator used can be set to any appropriate amount.

[0048] In one embodiment, a photopolymerization initiator having a maximum absorption wavelength in the range of 400 nm or less (preferably 380 nm or less, more preferably 340 nm or less) is used. By using such a photopolymerization initiator, when the adhesive strength of the entire ultraviolet absorbing layer is reduced by irradiation with active energy rays, a curing reaction of the adhesive preferably occurs, and an ultraviolet absorbing layer with particularly little adhesive residue can be formed.

[0049] The photopolymerization initiator may be a commercially available product. For example, examples of photopolymerization initiators having a maximum absorption wavelength in the range of 400 nm or less include those under the trade names "Irgacure 127," "Irgacure 369," "Irgacure 369E," "Irgacure 379," "Irgacure 379EG," "Irgacure 819," "Irgacure TOP," "Irgacure 784," and "Irgacure OXE01," manufactured by BASF.

[0050] In one embodiment, the active energy ray-curable pressure-sensitive adhesive may contain a photosensitizer.

[0051] In one embodiment, the photosensitizer can be used in combination with the photopolymerization initiator. The photosensitizer can transfer the energy it obtains by absorbing light to the photopolymerization initiator, thereby generating radicals from the photopolymerization initiator. This allows polymerization to proceed with light on the long wavelength side, where the photopolymerization initiator itself does not have an absorption peak. Therefore, by incorporating a photosensitizer, it is possible to increase the difference between the absorption wavelength of the UV absorber and the wavelength at which radicals can be generated from the photopolymerization initiator. As a result, photopolymerization of the UV absorbing layer and peeling by the UV absorber can be performed without affecting each other. In one embodiment, 2,2-dimethoxy-1,2-diphenylethan-1-one (e.g., BASF, trade name "Irgacure 651") as a photopolymerization initiator and a photosensitizer are used in combination. Examples of such photosensitizers include "UVS-581" (trade name, manufactured by Kawasaki Chemical Industries, Ltd.), and 9,10-diethoxyanthracene (for example, "UVS1101" (trade name, manufactured by Kawasaki Chemical Industries, Ltd.)).

[0052] Other examples of the photosensitizer include 9,10-dibutoxyanthracene (e.g., Kawasaki Chemical Industries, Ltd., trade name "UVS-1331"), 2-isopropylthioxanthone, benzophenone, thioxanthone derivatives, 4,4'-bis(dimethylamino)benzophenone, etc. Examples of thioxanthone derivatives include ethoxycarbonylthioxanthone, isopropylthioxanthone, etc.

[0053] The content of the photosensitizer is preferably 0.01 to 2 parts by weight, and more preferably 0.5 to 2 parts by weight, relative to 100 parts by weight of the base polymer.

[0054] Preferably, the active energy ray-curable pressure-sensitive adhesive contains a crosslinking agent, such as an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an oxazoline-based crosslinking agent, an aziridine-based crosslinking agent, a melamine-based crosslinking agent, a peroxide-based crosslinking agent, a urea-based crosslinking agent, a metal alkoxide-based crosslinking agent, a metal chelate-based crosslinking agent, a metal salt-based crosslinking agent, a carbodiimide-based crosslinking agent, or an amine-based crosslinking agent.

[0055] The content of the crosslinking agent is preferably 0.5 to 10 parts by weight, and more preferably 1 to 8 parts by weight, relative to 100 parts by weight of the base polymer of the pressure-sensitive adhesive.

[0056] In one embodiment, an isocyanate-based crosslinking agent is preferably used, which is preferred because it can react with a variety of functional groups. Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and xylylene diisocyanate; and isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL"), and isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HX"). Preferably, a crosslinking agent having three or more isocyanate groups is used.

[0057] The active energy ray-curable pressure-sensitive adhesive may further contain any appropriate additives as necessary, such as an active energy ray polymerization accelerator, a radical scavenger, a tackifier, a plasticizer (e.g., a trimellitic acid ester-based plasticizer, a pyromellitic acid ester-based plasticizer, etc.), a pigment, a dye, a filler, an antioxidant, a conductive material, an antistatic agent, an ultraviolet absorber, a light stabilizer, a release adjuster, a softener, a surfactant, a flame retardant, and an antioxidant.

[0058] Pressure-sensitive adhesive: Examples of pressure-sensitive adhesives include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, and styrene-diene block copolymer adhesives. Among these, acrylic adhesives or rubber adhesives are preferred, and acrylic adhesives are more preferred. The above adhesives may be used alone or in combination of two or more.

[0059] Examples of the acrylic adhesive include an acrylic adhesive having as a base polymer an acrylic polymer (homopolymer or copolymer) using one or more (meth)acrylic acid alkyl esters as a monomer component. Specific examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, and methyl (meth)acrylate. Examples of (meth)acrylic acid C1-20 alkyl esters include nonyl acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate. Among these, (meth)acrylic acid alkyl esters having a linear or branched alkyl group having 4 to 18 carbon atoms can be preferably used.

[0060] The acrylic polymer may contain, as necessary, units corresponding to other monomer components copolymerizable with the alkyl (meth)acrylate, for the purpose of modifying properties such as cohesive strength, heat resistance, and crosslinkability. Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and itanoic anhydride; hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl methacrylate; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid; (N-substituted) amide monomers such as methylol (meth) acrylamide, N,N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, and N-methylol propane (meth) acrylamide; aminoalkyl (meth) acrylate monomers such as aminoethyl (meth) acrylate, N,N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate; alkoxyalkyl (meth) acrylate monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; maleimide monomers such as N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide, and N-phenyl maleimide; itaconimide monomers such as N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexyl itaconimide, and N-lauryl itaconimide;succinimide-based monomers such as N-(meth)acryloyloxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, and N-(meth)acryloyl-8-oxyoctamethylene succinimide; vinyl-based monomers such as vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholine, N-vinylcarboxylic acid amides, styrene, α-methylstyrene, and N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate; polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and (meth)acrylate. Examples of suitable monomers include glycol-based acrylic ester monomers such as methoxypolypropylene glycol acrylate; acrylic ester monomers having heterocycles, halogen atoms, silicon atoms, etc., such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, and silicone (meth)acrylate; polyfunctional monomers such as hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate; olefin-based monomers such as isoprene, butadiene, and isobutylene; and vinyl ether-based monomers such as vinyl ether. These monomer components may be used alone or in combination of two or more.

[0061] Examples of the rubber-based pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives whose base polymer is natural rubber; polyisoprene rubber, styrene-butadiene (SB) rubber, styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene-styrene block copolymer (SBS) rubber, styrene-ethylene-butylene-styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) rubber, reclaimed rubber, butyl rubber, polyisobutylene, and synthetic rubbers such as modified versions of these.

[0062] The pressure-sensitive adhesive may contain any suitable additives as needed, such as crosslinkers, tackifiers (e.g., rosin-based tackifiers, terpene-based tackifiers, hydrocarbon-based tackifiers, etc.), plasticizers (e.g., trimellitic ester-based plasticizers, pyromellitic ester-based plasticizers), pigments, dyes, antioxidants, conductive materials, antistatic agents, light stabilizers, release modifiers, softeners, surfactants, flame retardants, antioxidants, etc.

[0063] B-3. ​​Workpiece The workpiece may be any suitable workpiece, and in one embodiment, an electronic component is used as the workpiece.

[0064] In one embodiment, as shown in FIG. 1 , a workpiece 30 includes another hard substrate 31 and a member 32 disposed on at least one side of the other hard substrate 31. The hard substrate described in Section B-1 may be used as the other hard substrate. Alternatively, a rigid wiring circuit board or the like may be used as the other hard substrate. Examples of such members include electronic components such as semiconductor elements and optical semiconductor elements. Specific examples of the workpiece include a rigid wiring circuit board on which multiple semiconductor elements are arranged and mounted to connect to terminals of the board, and a glass carrier on which semiconductor elements are mounted via a double-sided adhesive sheet.

[0065] In another embodiment, the workpiece is a semiconductor wafer, which may be, for example, an optical semiconductor wafer such as an LED or a light receiving element.

[0066] The workpiece may be disposed in plural or in single piece.

[0067] When multiple workpieces are arranged, the intervals between them are, for example, 2 μm to 10 mm.

[0068] B-4. Base material As described above, in one embodiment, a substrate 21 and a pressure-sensitive adhesive layer 22 may be further disposed between the ultraviolet absorbing layer 20 and the workpiece 30. In one embodiment, a laminate composed of the ultraviolet absorbing layer 20, the substrate 21, and the pressure-sensitive adhesive layer 22 may be a double-sided pressure-sensitive adhesive sheet A. This configuration makes it possible to peel off the double-sided pressure-sensitive adhesive sheet A in a subsequent process, thereby reducing adhesive residue due to cohesive failure. Because adhesive residue can be significantly reduced, the burden of the cleaning process required to remove burnt residue, which is a problem with existing varnish methods, can be reduced. Furthermore, by providing a substrate, the substrate functions as a protective material and can prevent damage to the workpiece.

[0069] The substrate may be made of any suitable resin. Examples of such resins include polyolefin resins such as polyethylene resins, polypropylene resins, polybutene resins, and polymethylpentene resins, polyurethane resins, polyester resins, polyimide resins, polyether ketone resins, polystyrene resins, polyvinyl chloride resins, polyvinylidene chloride resins, fluorine-containing resins, silicone resins, cellulose resins, and ionomer resins. Polyimide resins are particularly preferred. Using a substrate made of a polyimide resin significantly enhances the above-described effects, effectively prevents damage to the workpiece (device) caused by laser light incident from the glass substrate side, and enables selective peeling only from the glass substrate side.

[0070] The thickness of the substrate is preferably 1 μm to 300 μm, more preferably 1 μm to 100 μm, and even more preferably 1 μm to 50 μm.

[0071] The substrate preferably has a light transmittance of 90% or less at a wavelength of 355 nm, more preferably 85% or less, even more preferably 50% or less, and particularly preferably 15% or less. A low light transmittance is preferable in that damage to the adherend can be reduced. The lower limit of the substrate's light transmittance at a wavelength of 355 nm is, for example, 0%, and in one embodiment, 10%.

[0072] B-5.Adhesive layer The adhesive layer may include any suitable adhesive, such as the pressure-sensitive adhesives described above.

[0073] In one embodiment, a heat-resistant adhesive is used as the adhesive contained in the adhesive layer. By providing an adhesive layer composed of a heat-resistant adhesive, it is possible to prevent burning (adhesive residue) on the workpiece (device) when irradiated with laser light. In this specification, a heat-resistant adhesive means an adhesive that has a predetermined adhesive strength in an environment of 260°C. It is preferable that the heat-resistant adhesive can be used in an environment of 260°C without leaving any adhesive residue. Preferably, the heat-resistant adhesive contains an acrylic resin, a silicone resin, or the like as a base polymer.

[0074] C. Processing process In the processing step, the workpiece placed on the hard substrate is processed as described above. The processing in this step can be any appropriate processing. Examples include a heating step, a back-grinding step, a dicing step, a mounting (reflow) step, and a circuit formation (RDL) step. In FIG. 1, a press equipped with an upper plate 100 and a lower plate 200 processes (heats) the laminate formed in the lamination step while pressing (or after pressing).

[0075] In one embodiment, when the ultraviolet absorbing layer contains an active energy ray-curable adhesive, the ultraviolet absorbing layer may be irradiated with active energy rays (e.g., ultraviolet rays) before the processing to increase the adhesive strength of the ultraviolet absorbing layer.

[0076] D. Peeling process In the peeling step, the ultraviolet absorbing layer is irradiated with ultraviolet light to peel the hard substrate from the workpiece.

[0077] 1, the hard substrate 10 is peeled off from the ultraviolet absorbing layer 20, and then the ultraviolet absorbing layer 20 is peeled off. When the double-sided pressure-sensitive adhesive sheet A is composed of the ultraviolet absorbing layer 20, the base material 21, and the pressure-sensitive adhesive layer 22, the double-sided pressure-sensitive adhesive sheet A is peeled off after the ultraviolet absorbing layer 20 is peeled off.

[0078] In another embodiment, the hard substrate and the ultraviolet absorbing layer are peeled off together.

[0079] The conditions for ultraviolet irradiation can be any appropriate conditions depending on the structure of the ultraviolet absorbing layer, as long as they can impart peelability to the ultraviolet absorbing layer. In one embodiment, the ultraviolet absorbing layer is irradiated with UV laser light (e.g., wavelength: 200 nm to 380 nm). By irradiating the ultraviolet absorbing layer with UV laser light at any appropriate output (e.g., 0.01 W to 6 W, preferably 0.05 W to 5 W), gas generated by decomposition of the ultraviolet absorber and / or gas generated by decomposition of the pressure-sensitive adhesive layer due to heat generated by the ultraviolet absorber causes deformation of the ultraviolet absorbing layer, resulting in peelability in the area irradiated with the laser light. The wavelength of the UV laser light is preferably 360 nm or less. When a hard substrate is placed directly on one side of the ultraviolet absorbing layer and a workpiece is placed directly on the other side of the ultraviolet absorbing layer, peeling is preferably performed by irradiation with UV laser light.

[0080] When the ultraviolet absorbing layer contains an active energy ray-curable adhesive, the adhesive strength of the ultraviolet absorbing layer may be reduced by irradiating the entire ultraviolet absorbing layer with active energy rays. In one embodiment, the adhesive strength of the ultraviolet absorbing layer may be reduced by irradiating the entire ultraviolet absorbing layer with active energy rays after irradiating with UV laser light. Examples of active energy rays include gamma rays, ultraviolet rays, visible light, infrared rays (heat rays), radio waves, alpha rays, beta rays, electron beams, plasma flow, ionizing rays, and particle beams. Ultraviolet rays are preferred. The wavelength of the ultraviolet rays is preferably 300 nm to 400 nm. The irradiation dose is, for example, an integrated light dose of 300 mJ / cm. 2 ~1500mJ / cm 2 In this way, if active energy rays are irradiated before laser light irradiation, re-adhesion can be prevented and the hard substrate can be peeled off.

[0081] In the present invention, the hard substrate can be peeled off by irradiating the ultraviolet absorbing layer with ultraviolet light, and since the peeling force is low, the load on the workpiece can be reduced, and as a result, damage to the workpiece can be prevented. [Example]

[0082] (Lamination process) A semiconductor element 32 (member 32) was placed on a terminal on a rigid wiring circuit board 31 (another hard board 31), and a workpiece 30 was prepared. The glass substrate 10 (hard substrate 10) was placed on top of the semiconductor element 32 and fixed using a double-sided adhesive sheet including the ultraviolet absorbing layer 20. The double-sided adhesive sheet used was one in which an ultraviolet absorbing layer 20 containing an ultraviolet curable adhesive was formed on one side of a PI substrate 21, and an adhesive layer 22 was formed on the other side. (Processing process) The laminate obtained in the lamination step was sandwiched between a press machine so that the semiconductor element 32 was embedded in the adhesive layer 22 and held. The upper plate of the press was removed, and ultraviolet light (wavelength: 355 nm to 365 nm, cumulative light intensity: 1380 mJ / cm ) was applied through the glass substrate 10 (hard substrate 10). 2 ) was irradiated onto the ultraviolet absorbing layer 20 to harden the ultraviolet absorbing layer, thereby reducing the adhesive strength of the ultraviolet absorbing layer to the glass substrate 10 (hard substrate 10). The semiconductor element 32 (member 32) was fixed to the terminals on the rigid wiring circuit board 31 (another hard board 31) by heating while being pressed with a press. As a fixing means, metal bonding such as solder, ACF (anisotropic conductive film), ACP (anisotropic conductive paste), etc. can be used. (peeling process) The upper plate of the press was removed, and ultraviolet laser light (wavelength: 355 nm, irradiation energy: 10 J / cm) was applied through the glass substrate 10 (hard substrate 10). 2 ) was irradiated onto the ultraviolet absorbing layer, and the glass substrate 10 (hard substrate 10) was peeled off. Next, the double-sided pressure-sensitive adhesive sheet was peeled off. There was no damage to the semiconductor element 32 (member 32). Furthermore, the semiconductor element 32 (member 32) did not detach from the rigid wired circuit board 31 (another hard substrate 31). [Explanation of symbols]

[0083] 10 Hard substrate 20 UV absorbing layer 30 Workpiece

Claims

1. a lamination step of laminating a hard substrate, an ultraviolet absorbing layer, and a workpiece in this order; and thereafter, a processing step of processing the workpiece, and thereafter, a step of peeling the hard substrate from the workpiece, the peeling step including irradiating the ultraviolet absorbing layer with UV laser light and irradiating the entire ultraviolet absorbing layer with active energy rays to reduce adhesive strength of the ultraviolet absorbing layer; the ultraviolet absorbing layer contains an ultraviolet absorber, the ultraviolet absorber is a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a triazine-based ultraviolet absorber, a salicylate-based ultraviolet absorber, or a cyanoacrylate-based ultraviolet absorber; the workpiece includes another rigid substrate and a member disposed on at least one side of the other rigid substrate; The member is an electronic component. Component processing method.

2. The member processing method according to claim 1 , wherein the hard substrate is optically transparent.

3. The member processing method according to claim 1 or 2, wherein the ultraviolet absorbing layer has adhesive properties.

4. The member processing method according to claim 1 , wherein the ultraviolet absorbing layer contains an active energy ray-curable adhesive.

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