JP2000345131A - Re-release type adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in tackiness to various adherends, and having excellent re-releasability and stain resistance after cured with ultraviolet rays, or the like, and usuful for temporary adhesion as that in e.g. a process of dicing semiconductor wafers, by including a hydrophilic acrylic adhesive, an active energy ray-curable compound, and the like. SOLUTION: This composition is obtained by including (A) a hydrophilic acrylic adhesive, (B) an active energy ray-curable compound comprising pref. a hydrophilic urethane acrylate oligomer, (C) a photopolymerization initiator such as a 1-hydroxycyclohexyl phenyl ketone, and (D) a crosslinking agent pref. so that the weight ratio of the component A to the component B is (95:5) to (30:70), and the components C and D are at 0.5 to 5.0 pts.wt. and 0.01 to 4 pts.wt., respectively, each based on the total of 100 pts.wt. of the components A and B. the component A is pref. a neutralized product of a copolymer made from an unsaturated monomer containing a carboxyl group, or the like (e.g. acrylic acid) and a monomer copolymerizable therewith such as butyl acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive sheet for temporarily protecting a surface of a semiconductor wafer, a metal plate, a glass plate, a plastic plate or the like, and an adhesive sheet for temporarily fixing a semiconductor wafer or the like in a dicing process. The present invention relates to a removable pressure-sensitive adhesive composition used as a pressure-sensitive adhesive.

[0002]

2. Description of the Related Art In recent years, an adhesive sheet has been used temporarily as a protective sheet on the surface to prevent dirt or damage on a metal plate, a glass plate, a plastic plate, etc. Pressure-sensitive adhesive sheets have been used for applications such as temporary adhesion. The pressure-sensitive adhesive used for these pressure-sensitive adhesive sheets has sufficient tackiness when attached to an adherend, and when peeled after being cured by ultraviolet irradiation or the like, the tackiness is sufficiently reduced. It is required to have removability and contamination resistance with no adhesive remaining on the adherend surface.

[0003] Japanese Patent Application Laid-Open No.
No. 153376 discloses a pressure-sensitive adhesive containing a radiation-polymerizable compound composed of a urethane acrylate oligomer having a molecular weight of 3,000 to 10,000,
At the time of peeling, the adhesive force with the adherend is intended to be sharply reduced by irradiating ultraviolet rays. Also,
Japanese Patent Application Laid-Open No. 9-328663 similarly discloses a pressure-sensitive adhesive containing an elastomer, a tackifier, a curing agent, an ultraviolet-crosslinkable oligomer and / or monomer, and a polymerization initiator as main components. Japanese Patent Application Laid-Open No. 63-153814 discloses an adhesive sheet that is adhered to the wafer surface when the back surface of the wafer having a pattern formed on the surface is polished (back-ground). Discloses a pressure-sensitive adhesive sheet coated with a water-swellable pressure-sensitive adhesive as a pressure-sensitive adhesive layer. Further, JP-A-64-64772 discloses a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive and a radiation-polymerizable compound on the front and back surfaces of a substrate.

[0004]

However, as a result of examining the above disclosed technology, the pressure-sensitive adhesive disclosed in Japanese Patent Application Laid-Open No. 62-153376 shows that the pressure-sensitive adhesive strength at the time of re-peeling (after curing) of the pressure-sensitive adhesive does not decrease. Although it is recognized, the adhesive may remain on the adhered surface after re-peeling, and when used for the temporary bonding in the dicing process of the semiconductor wafer, chips are scattered during dicing or expanded. There is a problem that the chip sometimes peels off. Also, in the technology disclosed in Japanese Patent Application Laid-Open No. 9-328663, when used for similar applications, the force applied to the pickup is large, and the chip may be damaged particularly when the chip is thin. There was found. Further, JP-A-63-
In the pressure-sensitive adhesive sheet disclosed in 153814, the pressure-sensitive adhesive force at the time of peeling (corresponding to re-peeling) is high, and when the wafer is thin,
It was found that there was a tendency to break, and that if the adhesive strength was designed to be low, the fixing force during back grinding was insufficient. Further, in the pressure-sensitive adhesive sheet disclosed in JP-A-64-64772, the pressure-sensitive adhesive may remain on the adhered surface after re-peeling after irradiation, and a water-washing step for completely removing the pressure-sensitive adhesive is performed. However, there is a disadvantage that the pressure-sensitive adhesive cannot be completely removed because the radiation polymerizable compound is not water-soluble. In recent years, there has been a demand for a pressure-sensitive adhesive which can be applied to various uses such as a device having a large surface unevenness and protection of a thin and large silicon wafer. In this case, the initial pressure is 1000 g / 25 mm. Or more (preferably 1
500g / 25mm or more), the adhesive strength when re-peeling is 1
It is required that the weight is not more than 00 g / 25 mm (preferably not more than 50 g / 25 mm). However, in any of the above disclosed techniques, there is a drawback that the circuit which should have been protected because of too high adhesive force (before and after curing) or particles (a part of the adhesive) is increased, Particles formed once hardened were difficult to remove by washing with water.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve such a problem.
The removable pressure-sensitive adhesive composition comprising (a) a water-affinity acrylic pressure-sensitive adhesive, (b) an active energy ray-curable compound, (c) a photopolymerization initiator, and (d) a cross-linking agent is high in temporary bonding. Adhesiveness, re-peelability, which is an adhesive force that can be peeled off with a slight force during curing peeling, and stain resistance, etc. with very little particle adhesion etc. on the substrate after peeling, are all kept in a well-balanced manner. Good, it can be completely removed from the substrate surface by curing with active energy rays and then washing with water, so it can be used for back bonding of semiconductor wafers and temporary bonding in dicing. The present invention was found to be excellent in grinding suitability, dicing suitability, expandability, pickup efficiency, etc. and was very useful, and completed the present invention.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The (a) water-affinity acrylic pressure-sensitive adhesive used in the present invention is not particularly limited as long as it is an acrylic pressure-sensitive adhesive having an affinity for water. Specifically, water-soluble, water-swellable, and water-dispersible water-soluble adhesives are used. This is a big difference from a general acrylic pressure-sensitive adhesive conventionally used for a pressure-sensitive adhesive tape, which shows a property that does not change at all even in the presence of water.

The (a) water-philic acrylic pressure-sensitive adhesive of the present invention is an acrylic copolymer comprising an unsaturated monomer having a carboxyl group or a sulfonic acid group and a monomer copolymerizable with the unsaturated monomer. And a neutralized product of an acrylic copolymer obtained by preferably using (meth) acrylate having an ether bond as one component.

The unsaturated monomer containing a carboxyl group or a sulfonic group includes acrylic acid, methacrylic acid,
Maleic acid, maleic anhydride, fumaric acid, itaconic acid,
Carboxyl group-containing unsaturated monomers such as crotonic acid, aconitic acid, cinnamic acid, monoalkyl malate, monoalkyl fumarate, monoalkyl itaconate, ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamide- Examples thereof include sulfonic acid group-containing unsaturated monomers such as 2-methylpropanesulfonic acid and styrenesulfonic acid, which are used alone or in combination of two or more, and are preferably acrylic acid and methacrylic acid.

Other monomers copolymerizable with the unsaturated monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n -Hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, n
-Propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-
Hexyl methacrylate, 2-ethylhexyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, alkyl acrylates such as lauryl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2 -Hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, 2
-Hydroxy-3-phenoxypropyl acrylate,
Hydroxy group-containing unsaturated monomers such as N-methylol acrylamide and N-methylol methacrylamide, glycidyl group-containing unsaturated monomers such as glycidyl methacrylate and allyl glycidyl methacrylate, acrylamide, methacrylamide, N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride Dimethyl allyl vinyl ketone, N-vinylpyrrolidone, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, vinyl acetate, styrene and the like are used by one or more selected from among them, preferably n-butyl acrylate , 2-ethylhexyl acrylate and methyl methacrylate.

In the present invention, when a (meth) acrylate having an ether bond is used as a component other than those exemplified above, the affinity for water is improved, and the adhesive strength after curing with active energy rays is sufficiently reduced. The effect is obtained. As the (meth) acrylate, 2-
Ethoxyethyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, ethyl carbitol acrylate, 2-butoxyethyl acrylate, polyethylene glycol (meth) acrylate, etc., which are used alone or in combination of two or more. . Particularly, 2-ethoxyethyl acrylate, 2-methoxyethyl acrylate and the like are preferably used.

In the (a) water-affinity acrylic pressure-sensitive adhesive, the copolymerization ratio (weight ratio) with and is:
It is preferably from 1/99 to 40/60, more preferably from 5/95 to 3
0/70. When the copolymerization ratio is less than 1/99,
When the ratio exceeds 40/60, the pressure-sensitive adhesive becomes too hard, resulting in poor tackiness, low adhesive strength, and poor sticking workability. When (meth) acrylate having an ether bond is contained as another monomer copolymerizable with the unsaturated monomer, unsaturated monomer having a carboxyl group or a sulfonic acid group / (meth) acrylate having an ether bond
The copolymerization ratio of acrylate / other monomer (% by weight) is preferably from 1 to 40/5 to 99/0 to 55, and more preferably from 2 to 20/68 to 98/0 to 30. One of the properties and the removability is undesirably reduced.

The (a) water-affinity acrylic pressure-sensitive adhesive is
It is produced by radically copolymerizing the above-mentioned components in an organic solvent. Examples of the organic solvent used in the polymerization include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, and aliphatic alcohols such as methanol, ethanol, n-propyl alcohol and iso-propyl alcohol. And ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

The polymerization catalysts used for radical polymerization include azobisisobutyronitrile, azobisdimethylvaleronitrile, azobis-2-methylbutyronitrile, benzoyl peroxide, di-t, which are conventional radical polymerization catalysts. -Butyl peroxide, cumene hydroperoxide and the like are specific examples.

The polymerization method is not particularly limited, and the polymerization may be effected by a general method such as a method in which the monomers are charged in a polymerization solvent all at once and then a polymerization catalyst is charged and polymerization is carried out. Polymerization temperature is 60-150 ° C,
The polymerization time is about 5 to 10 hours.

After completion of the polymerization, the carboxyl group or the sulfonic group during the copolymerization is neutralized with an alkali. Examples of the alkali include sodium hydroxide, potassium hydroxide, ammonia, various primary, secondary, and tertiary amines such as ethylamine, ethanolamine, diethylamine, diethanolamine, triethylamine, and triethanolamine. Can be The neutralization may be carried out by partially or completely neutralizing the carboxyl group or sulfonic acid group, and the degree of neutralization is preferably 0.1 equivalent or more based on the carboxyl group or sulfonic acid group. The corresponding amount is 0.1
When the amount is less than the equivalent, water swelling is poor upon washing with water after peeling.

The water-affinic acrylic pressure-sensitive adhesive (a) thus obtained has a weight average molecular weight of 2 to 1,000,000 (preferably 200,000 to 800,000). If the molecular weight is less than 20,000, the cohesive strength is reduced, and adhesive residue is generated at the time of re-peeling. If it exceeds 1,000,000, the coating workability is poor. Further, the glass transition temperature of the pressure-sensitive adhesive is preferably -70 to -15 ° C, more preferably -60 to-
20 ° C. If the temperature is lower than -70 ° C, the cohesive strength is reduced and glue remains, and if it is higher than -15 ° C, tackiness and adhesive strength are insufficient, which is not preferable.

The active energy ray-curable compound (b) used in the present invention is not particularly limited as long as it is a compound which undergoes a curing reaction with an active energy ray (ultraviolet ray, electron beam, radiation, etc.). A water-soluble active energy ray-curable compound having good compatibility with the hydrophilic acrylic pressure-sensitive adhesive is preferably used, for example, a water-compatible urethane acrylate oligomer, polyethylene glycol diacrylate,
Examples include polyethylene glycol dimethacrylate, ethylene oxide-modified trimethylolpropane triacrylate, ethylene oxide-modified trimethylolpropane trimethacrylate, and ethoxylated bisphenol A dimethacrylate. Preferred is a water-affinity urethane acrylate oligomer, which will be described in detail below.

The above-mentioned urethane acrylate oligomer having water affinity is not particularly limited, but preferably (a) a polyol having a carboxyl group or a sulfonic acid group, and / or (b) a polyol having an ester bond or an ether bond. And a reaction product of an isocyanate and a hydroxyl group-containing acrylic compound, and may be neutralized with an alkali if necessary.

The above-mentioned (a) polyol having a carboxyl group or a sulfonic acid group includes 2,2-dimethylolpropionic acid, a caprolactone adduct of 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, dimethylol Heptanoic acid and the like can be mentioned, and tartaric acid can also be used in view of its structure. The polyol having a sulfonic acid group is obtained by substituting the above carboxyl group with a sulfonic acid group.

The above-mentioned (b) polyol having an ester bond or an ether bond includes polyether polyols (polymerized polyether polyols of ethylene oxide or propylene oxide, block-polymerized or random-polymerized polyether polyols of ethylene oxide and propylene oxide). ) And polyester polyols (ethylene glycol, 1,2- or 1,3-
Propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 1,3- or 1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, hydrogenated bisphenol A, neopentyl glycol, 2-methylpentanediol, cyclohexanedimetal, polybutadiene polyol, trimethylolpropane, polytrimethylolpropane, pentaerythritol, polypentaerythritol, sorbitol, mannitol, glycerin , Polyalcohols such as polyglycerin, and maleic anhydride,
Maleic acid, fumaric acid, itaconic anhydride, itaconic acid,
Reaction products with polybasic acids such as adipic acid and isophthalic acid), and bifunctional ones are particularly preferably used.

Examples of the polyisocyanate include aromatic, aliphatic, cycloaliphatic and alicyclic isocyanates and mixtures thereof. Among them, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate Tolylene diisocyanate (TDI) such as isocyanate and mixtures thereof, hydrogenated TDI, 4,4′-diphenylmethane diisocyanate (MDI), hydrogenated MDI, crude M
DI, modified MDI, xylylene diisocyanate (XD
I), hydrogenated XDI, tetraxylylene diisocyanate (TMXDI), isophorone diisocyanate (IPD
I), norbornene diisocyanate (NBDI), dimer of tolylene diisocyanate (TT), hexamethylene diisocyanate (HMDI), trimethylhexamethylene diisocyanate (TMHMDI), o-tolidine diisocyanate (TODI), naphthalene diisocyanate (NDI), diphenyl ether diisocyanate ( PEDI), dianisidine diisocyanate (DADI), p-phenylene diisocyanate (PP
DI), polyisocyanates such as isopropylidenebis-4-cyclohexyl diisocyanate (IPCI), lysine diisocyanate methyl ester (LDI), trimethylhexamethylene diisocyanate (TMDI) and dimer acid diisocyanate (DDI). 4-Tolylene diisocyanate, isophorone diisocyanate (IPDI) and norpollenenedisocyanate (NBDI) are preferably used.

Examples of the hydroxyl-containing acrylic compound include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
Hydroxyethyl acryloyl phosphate, 4-hydroxybutyl acrylate, caprolactone-modified 2-
Hydroxyethyl acrylate, 3-chloro-3-hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, polyethylene glycol acrylate, glycerin dirotaacrylate, 2-hydroxy-3
-Acryloyloxypropyl methacrylate, glycidol dimethacrylate, 2-acryloyloxyethyl acid phosphate, bismethacryloyloxyacid phosphate, hydroxypropylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Tetraacrylate, tetramethylol methane triacrylate and the like are used, preferably 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate and pentaerythritol triacrylate.

As a method for producing a urethane acrylate oligomer, for example, a polyol having an ester bond or an ether bond is reacted with a polyisocyanate, and then a polyol having a carboxyl group or a sulfonic acid group is reacted, and the isocyanate remaining in the molecule is reacted. A method in which a hydroxyl group-containing acrylic compound is further reacted with the group. The number average molecular weight of the urethane acrylate oligomer is preferably about 500 to 10,000.

The carboxyl group or sulfonic acid group in the obtained urethane acrylate oligomer is then neutralized with ammonia, sodium hydroxide, potassium hydroxide or an amine compound to make it hydrophilic. The amine compound is not particularly limited and includes, for example, triethylamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylguanidine, triethylenediamine,
Examples include dimethylaminoethanol and bis (2-dimethylaminoethyl) ether. The neutralization may be carried out by partially or completely neutralizing the carboxyl group or sulfonic acid group, and the degree of neutralization is preferably 0.1 equivalent or more based on the carboxyl group or sulfonic acid group. The corresponding amount is 0.1
If the amount is less than the equivalent, water swelling is poor upon washing with water after re-peeling.

The photopolymerization initiator (c) of the present invention includes α-hydroxyisobutylphenone benzoin, isopropyl benzoin ether, isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, acetophenone Examples include diethyl ketal, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and the initiator is selected in consideration of the absorption characteristics of the light irradiation device. However, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one are preferred.

The crosslinking agent (d) is not particularly limited as long as it has a function of inducing crosslinking by heat and thermally crosslinks (a) and (b). Melamine compounds, azilysine compounds, melamine compounds, isocyanate compounds, chelate compounds and the like. Specific examples include bisphenol A / epichlorohydrin type epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and glycerin diglycidyl ether. Glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether,
Epoxy compounds such as polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl ether, tetramethylolmethane-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpro Pionate, N, N'-diphenylmethane-
4,4'-bis (1-aziridinecarboxamide),
Aziridine compounds such as N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide), hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexaptoxymethylmelamine, hexapentyloxymethyl Melamine compounds such as melamine and hexahexyloxymethylmelamine, 2,4-tolylene diisocyanate, 2,6-
Tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4
-Xylylene diisocyanate, diphenylmethane-
4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5
-Naphthalene diisocyanate, tolylene diisocyanate adduct of trimethylolpropane, xylylene diisocyanate adduct of trimethylolpropane, triphenylmethane triisocyanate, methylene bis (4-
Examples of the chelating compound include dipropoxy-bis (acetylacetonato) titanium, dibutoxytitanium-bis (octylene glycolate), and dipropoxytitanium-bis (ethylacetoacetate). , Dipropoxytitanium-bis (lactate), dipropoxytitanium-bis (triethanolaminate), di-n-butoxytitanium-bis (triethanolaminate), tri-n-butoxytitanium monostearate, butyl titanate dimer , Titanium chelate compounds such as poly (titanium acetylacetonate), aluminum diisopropoxide monoethyl acetate, aluminum di-n-butoxide monomethyl acetoacetate, aluminum di-
n-butoxide monoethyl acetoacetate, di-i-
Aluminum chelates such as butoxide monomethyl acetoacetate, aluminum di-sec-butoxide monoethyl acetoacetate, aluminum tris (acetylacetonate), aluminum tris (ethyl acetoacetonate), and aluminum mono-acetylacetonate bis (ethyl acetoacetonate) And zirconium chelate compounds such as zirconium tetraacetylacetonate. Of these, epoxy compounds and metal chelate compounds are preferred.

(A) in the removable pressure-sensitive adhesive composition of the present invention
The amount (solid content ratio) of each of (a) to (d) is not particularly limited, but the weight ratio of (a) / (b) is 95/5 to 30/7.
It is preferably set to 0. When the compounding ratio exceeds 95/5, the adhesive strength after irradiation with active energy rays is insufficiently reduced and the removability is poor, and particularly when the compound is used for temporary bonding in a dicing process of a semiconductor wafer. May be damaged if the chip is thin during pickup,
Conversely, if the ratio is less than 30/70, the adhesive strength is insufficient, and in particular, when used for the above-mentioned applications, the fixing force of various dicing is too weak to cause miscut, thickness unevenness, and the like, and tend to be easily contaminated. Not preferred.

The amount of the photopolymerization initiator (c) is not particularly limited, but is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the total of (a) and (b). Further, the amount is preferably 0.5 to 5.0 parts by weight. If the amount is less than 0.1 part by weight, the adhesive strength after irradiation with active energy rays is insufficient and the removability is poor, and is particularly used for temporary bonding in a back grinding process and a dicing process of a semiconductor wafer. In some cases, if the wafer is thin at the time of peeling, the wafer may be damaged. Conversely, if it exceeds 10 parts by weight, the photopolymerization initiator remains on the surface to be adhered and causes contamination. If the initiator is used for temporary bonding in the back grinding process and the dicing process, the initiator may remain on the chip, which is not preferable.

Further, the amount of (d) is not particularly limited, but the total amount of (a) and (b) is 100 parts by weight.
It is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 4% by weight. When the amount is 0.0
When the content is less than 01% by weight, the pressure-sensitive adhesive composition tends to remain on the surface to be adhered when fine adjustment of the bonding operation before the irradiation with the active energy ray or reattachment is performed. Before the irradiation, the curing proceeds, and the decrease in the adhesive strength after the irradiation may not be sufficient, which is not preferable.

As a method for preparing the removable pressure-sensitive adhesive composition of the present invention, the above-mentioned (a) to (d) may be blended (mixed), and the blending order and the like are not particularly limited. ,
It is preferable to mix (b) in a solvent and then blend (c) and (d).

The solvents used at this time include (a)
There is no particular limitation as long as it dissolves (d),
Methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, methoxyethyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol diacetate,
Esters such as methyl acetoacetate and ethyl acetoacetate,
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ether solvents such as diethyl ether, ethylene glycol dimethyl ether and dioxane; aromatic compounds such as toluene and xylene; aliphatic compounds such as pentane and hexane; methylene chloride and chlorobenzene And halogen compounds such as chloroform, aliphatic alcohols such as n-propyl alcohol, iso-propyl alcohol, methanol and ethanol, etc., which are selected and used from the viewpoint of solubility, drying property, price and the like. Of course, it may be a mixed solvent.

The removable pressure-sensitive adhesive composition of the present invention is usually applied to a substrate sheet or the like and is often put to practical use as a pressure-sensitive adhesive sheet or a pressure-sensitive adhesive tape. First, the concentration of the removable pressure-sensitive adhesive composition of the present invention as it is or by adjusting the concentration with an appropriate organic solvent is applied to the treated surface of the substrate subjected to silicon treatment or the like, or directly to the substrate. For example, 80-105
It is dried by heat treatment or the like at 30 ° C. for 30 seconds to 10 minutes to form an adhesive layer.

As such a substrate, a film through which active energy rays penetrate is preferable. For example, polyvinyl chloride, polybutene, polybutadiene, polyurethane, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polyethylene, polypropylene, ethylene-propylene copolymer are preferable. Polymers, polymethylpentene, transparent films such as polybutylene terephthalate, and the like.Especially, when used for the surface protection application of the uneven surface in the back grinding process of a semiconductor wafer, or in the application requiring expansion in the dicing process. A transparent or active energy ray-permeable colored film of polyvinyl chloride, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer or the like having excellent flexibility and stretchability is preferably used.

The removable pressure-sensitive adhesive composition of the present invention can be widely used as a protective sheet on the surface of a metal plate, a glass plate, a plastic plate or the like or a pressure-sensitive adhesive sheet as a temporary fixing sheet. Particularly, it is useful for a temporary bonding application in a back grinding process and a dicing process of a semiconductor wafer, and such an application will be specifically described.

In the back grinding process,
An adhesive sheet or an adhesive tape or the like coated with a substrate of the removable pressure-sensitive adhesive composition of the present invention is adhered to the pattern side of a semiconductor wafer (silicon wafer) to protect the surface, and then the back surface of the wafer is polished by a grinder. . The grinder (grinding stone) grinds the wafer at a high speed (about 3000 revolutions / minute) while usually cooling with water. At this time, the pieces of the adhesive tape and shavings (Si dust) are protected by the adhesive sheet. Then, the substrate is cured by irradiating an active energy ray such as an ultraviolet ray or an electron beam from a substrate side such as an adhesive sheet or an adhesive tape. As the light source for performing the ultraviolet irradiation, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light, and the like are used. In the case of a high-pressure mercury lamp, 5 to 3000 mJ / cm ² , preferably 10 to 500 m
It is performed under the condition of J / cm ² . The irradiation time varies depending on the type of light source, the distance between the light source and the coated surface, the coating thickness, and other conditions, but is usually several seconds, and in some cases, a fraction of a second.
It can be seconds. In the case of electron beam irradiation, for example, 50 to 1
Using an electron beam having an energy in the range of 000 Kev,
The irradiation amount is preferably 2 to 50 Mrad.

Adhesion before and after curing (JIS Z 0237)
180 degree peel strength) varies depending on the type of the base material and the type of the wafer (thickness of the adhesive layer, amount of the crosslinking agent, etc.), but has a high adhesive strength of 1000 g / 25 mm or more before curing. At the time of re-peeling after irradiation with active energy rays, 10
The adhesive strength is preferably as low as 0 g / 25 mm or less, particularly preferably 1500 g / 25 mm or more before curing and 50 g / 25 mm or less at the time of re-peeling after curing. After curing, the adhesive tape is peeled off by a remover. still,
The same applies to the case of use for temporary surface protection of metal plates, glass plates, plastic plates, etc. other than wafers.

Since the removable pressure-sensitive adhesive composition of the present invention has such characteristics, it can have both strong surface protection and easy removability. The pressure-sensitive adhesive composition of the present invention is practical only by re-peeling after irradiation with energy rays, but has a characteristic that even if the pressure-sensitive adhesive composition remains on a wafer, it can be removed with water. Next, the application of the dicing process will be described. The pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape or the like obtained by coating the substrate with the removable pressure-sensitive adhesive composition of the present invention is attached as a dicing tape to the back-ground surface of the wafer. After attaching and fixing the wafer (silicon wafer), the opposite side of the tape (pattern side)
Then, the semiconductor wafer is cut into chips by a rotating round blade. Thereafter, the substrate is cured by irradiating an active energy ray from a substrate side such as an adhesive sheet or an adhesive tape. The conditions for performing the ultraviolet irradiation are almost the same as those for the back grinding described above.

Adhesion before and after curing (JIS Z 0237)
180 degrees peel strength before curing is 1000 g /
25 mm or more, 100 g / 25 after irradiation (at the time of re-peeling)
mm or less, especially 1500 g / 25 m before curing.
m or more and 50 g / 25 mm or less after irradiation.
The same applies to the case of using for temporary surface protection of metal plates, glass plates, plastic plates, etc. other than wafers.

Next, after expanding (stretching) the pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape or the like using a wafer expanding device to widen the chip interval, the chips are pushed up with a needle or the like, and are suctioned with air tweezers or the like. Then, the chip is adhered to the base, the electrodes are connected by gold wires, and molded with an insulating resin to obtain a semiconductor chip as a product. The presence or absence of the expansion is determined by the blade width and the like at the time of dicing. However, if the force required for the expansion is too large, or if the chip breaks during the expansion, it is not preferable in terms of productivity.

However, the removable pressure-sensitive adhesive composition of the present invention, when irradiated with an active energy ray as described above,
(B) reacts and further shrinks, so that it has appropriate elongation and elasticity during the above-mentioned expansion, but its adhesive strength is reduced, adhesive residue is small, and water is removed after re-peeling. By cleaning with, the adhesive residue is completely removed and the reliability is high. The removable pressure-sensitive adhesive composition of the present invention has a high adhesive strength before curing with active energy rays, the adhesive strength is sufficiently reduced after curing, and even though it can be washed with water, it does not break the protection circuit. , (A)-
This is considered to be due to the fact that the compatibility of the component (d) is good and unevenness in curing is extremely small.

Although the above description has been given of the use of the temporary surface protection in the back grinding process of the semiconductor wafer and the use of the temporary fixing in the dicing process, the removable pressure-sensitive adhesive composition of the present invention is not limited thereto. Metal plate, glass plate,
It is a very useful removable pressure-sensitive adhesive composition that can be used for temporary surface protection of plastic plates, silicon wafers, etc., as well as for fixing pressure-sensitive adhesive sheets.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below.
In the following description, “%” and “parts” are based on weight unless otherwise specified.

Example 1 <(a) Water-affinity acrylic pressure-sensitive adhesive> 5 parts of acrylic acid,
2-methoxyethyl acrylate 65 parts, butyl acrylate 20 parts, vinyl acetate 10 parts, ethyl acetate 60 parts,
20 parts of methanol, azobisisobutyronitrile 0.1
The part was charged into a flask equipped with a condenser, a stirrer and a thermometer, and heated to 90 ° C. for polymerization. During the polymerization, polymerization was carried out for 7 hours while sequentially adding a polymerization catalyst solution in which 0.1 part of azobisisobutyronitrile was dissolved in 10 parts of ethyl acetate. After the polymerization is completed, the concentration is adjusted by adding ethyl acetate,
500,000 weight average molecular weight, glass transition temperature (Tg) -40
° C copolymer solution [resin content 50%, solvent content 50%
(Ethyl acetate / methanol = 8/2 weight ratio)]. The weight composition ratio of the copolymer was acrylic acid / 2-methoxyethyl acrylate / butyl acrylate / vinyl acetate = 5 /
65/20/10. A methanol solution of ethanolamine was added to neutralize the carboxyl groups in the copolymer by 0.9 equivalent to obtain a water-affinity acrylic pressure-sensitive adhesive solution having a resin content of 40%.

<(B) Active energy ray-curable compound>
A four-necked round-bottomed flask was equipped with a reflux condenser, a stirrer, an air drying inlet and a thermometer. 0.4 mol (88.9 parts) of isophorone diisocyanate (IPDI) and a block type polyol of ethylene oxide and propylene oxide were added. (Number average molecular weight 500) 0.2 mol (100
Parts), and further, ethyl acetate (112 parts) was charged, and the mixture was reacted at about 80 ° C. for 4 hours with stirring to obtain a urethane-containing polyol having isocyanate groups at both terminals. Thereafter, 0.1 mol (13.4 parts) of 2,2′-dimethylolpropionic acid was added to the polyol, and a further 8
The reaction was continued at 0 ° C. for 7 hours to react only one isocyanate group. Thereafter, the mixture was cooled to about 60 ° C., and pentaerythritol triacrylate containing 0.01% of monomethyl ether hydroquinone (total system) dissolved therein was added.
After the addition of 2 mol (60.2 parts), the mixture was further stirred at about 60 ° C. for about 6 hours, and then 0.02 parts of di-n-butyltin dilaurate was added as a catalyst, and the reaction was continued for another 6 hours. Is reacted with the isocyanate group until the acrylate becomes 0.1%, and the carboxyl group-containing urethane acrylate oligomer (number average molecular weight 260
0) was obtained. Separately, an ethanolamine solution dissolved in methanol was prepared, and the carboxyl group in the urethane oligomer was neutralized by 0.9 equivalent to obtain an active energy ray-curable compound (b) having a resin content of 40%.

<Preparation of Removable Adhesive Composition> In a 250 ml polyethylene container in a state where ultraviolet rays are blocked,
The (a) solution of the water-affinity acrylic pressure-sensitive adhesive (resin content 4
0%) and 50 parts of the above (b) methanol solution of the active energy ray-curable compound (resin content: 40%), (c) 1
1 part of hydroxycyclohexyl phenyl ketone ("Irgacure 184", manufactured by Ciba-Geigy Japan), (d)
As a crosslinking agent, 2 parts of an epoxy compound (1% ethyl acetate solution of "Epolite 80MF" manufactured by Kyoeisha Chemical Co., Ltd.) was added and stirred to obtain a solution of a removable adhesive composition.

<Production of pressure-sensitive adhesive sheet> In a state where ultraviolet rays are blocked, the re-peelable pressure-sensitive adhesive composition is dried on a polyethylene film (thickness: 80 μm) as a substrate to a thickness of 1 μm.
Coating was performed so as to have a thickness of 0 μm, and heating and drying were performed at 80 ° C. for 2 minutes. Thereafter, the resultant was transferred onto a silicone release-treated polyester film having a thickness of 38 μm, and aged at 40 ° C. for 3 days to prepare a pressure-sensitive adhesive sheet. Using the obtained pressure-sensitive adhesive sheet, evaluate the adhesive force, removability, contamination, dicing suitability when used for temporary bonding in the dicing process of semiconductor wafers, expandability, and pickup efficiency in the following manner. went.

(Adhesive force) In a state where ultraviolet rays are blocked, a 180-degree peel strength (g / 25 m
m) was measured according to JISZ0237.

(Removability) A silicon wafer, SUS, and a glass plate were adhered as adherends, left at 20 ° C. for 24 hours, and then 180 mJ / cm using a high-pressure mercury lamp.
Irradiation with ultraviolet light was performed under the conditions of ² , and the 180-degree peel strength (g / 25 mm) after 30 minutes was measured according to JIS Z 0237.

(Contamination) i) No water washing A 4-inch square silicon wafer with no foreign matter attached, S
The above-mentioned pressure-sensitive adhesive sheet was stuck on the surface of each of US and a glass plate, left for 1 hour in a room adjusted to 23 ° C. and 65% RH, and irradiated with ultraviolet light from a high-pressure mercury lamp under the condition of 180 mJ / cm ² . Thereafter, the pressure-sensitive adhesive sheet was peeled off from the surface of each adherend, and for each adherend after peeling, the number of foreign matters of 0.15 μm or more remaining on the surface was measured using a laser surface inspection device, and as follows. evaluated. ○ −−− 9 or less △ −−− 10 to 30 × −−− 31 or more

Ii) After Rinsing Each of the separated adherends obtained above was further immersed in water at 30 ° C. for 10 minutes, and the number of remaining 0.15 μm or larger foreign substances was measured in the same manner. The evaluation was as follows. ◎ −−− 0 pieces ○ −−− 1 to 9 pieces △ −−− 10 to 30 pieces × −−− 31 pieces or more

(Appropriate dicing) The above-mentioned pressure-sensitive adhesive sheet was adhered to a semiconductor wafer having a diameter of 5 inches, and then diced into 10 mm square chips, and the condition of the chips was evaluated as follows. ○ −−− No chip damage is observed △ −−− Only chips formed on the edge of the wafer are scattered × −−− Chip damage is observed on the whole

(Suitability for Expanding) After the above dicing, ultraviolet irradiation was performed under the same conditions as described above, and the wafer was expanded using a wafer expanding apparatus.
The retention of the chip at the time of was observed and evaluated as follows. ○ −−− No chips are scattered × −−− Chips are scattered

(Pickup Efficiency) When there was no breakage of the adhesive sheet and no peeling (scattering) of the chip after the expansion, when picking up with a die bonder, the number picked up out of 10,000 pieces was measured. The evaluation was as follows. ○ −−− 10000 pieces △ −−− 9995 to 9999 pieces × −−− 9994 pieces or less

Example 2 A re-peelable pressure-sensitive adhesive of the present invention was prepared in the same manner as in Example 1, except that (a) the production of the water-affinity acrylic pressure-sensitive adhesive was changed as follows. Obtained and evaluated similarly. <(A) Water affinity acrylic pressure-sensitive adhesive> acrylic acid 10
Parts, 80 parts of butyl acrylate, 10 parts of vinyl acetate, 80 parts of ethyl acetate, 20 parts of methanol, and 0.1 part of azobisisobutyronitrile were charged into a flask equipped with a condenser, a stirrer and a thermometer, and heated to 90 ° C. And polymerize,
During the polymerization, polymerization was carried out for 7 hours while sequentially adding a polymerization catalyst solution in which 0.1 part of azobisisobutyronitrile was dissolved in 10 parts of ethyl acetate. The concentration was adjusted by adding ethyl acetate, and the weight average molecular weight was adjusted. 520,000, glass transition temperature (Tg)
A copolymer solution of 30 ° C. was obtained [resin content 50%, solvent content 5
0% (ethyl acetate / methanol = 8/2 weight ratio)]. The weight composition of the copolymer was acrylic acid / butyl acrylate / vinyl acetate = 10/1080/10. A methanol solution of ethanolamine was added to neutralize 0.9 equivalent of the carboxylic acid in the copolymer, and the resin content was 4%.
A 0% aqueous affinity acrylic pressure-sensitive adhesive solution was obtained.

Example 3 In Example 1, the block polymerization type polyol of ethylene oxide and propylene oxide used in the production of (b) was replaced with a polyol having a hydroxyl group at both terminals consisting of ethylene glycol and adipic acid (number average molecular weight). 50
Except having changed to 0), it carried out similarly to Example 1 and obtained the removable pressure-sensitive adhesive composition, and evaluated similarly.

Example 4 A re-peelable pressure-sensitive adhesive composition of the present invention was prepared in the same manner as in Example 1 except that (b) the production of the active energy ray-curable compound was changed as follows. And evaluated similarly. <(B) Active energy ray-curable compound> A reflux condenser, a stirrer, an air drying inlet and a thermometer were attached to a four-necked round bottom flask, and isophorone diisocyanate (I
(PDI) 0.2 mol (44.4 parts) and 0.1 mol (13.4 parts) of 2,2'-dimethylolpropionic acid were charged, and ethyl acetate (50.3 parts) was further charged and stirred. The reaction was carried out at 80 ° C. for 4 hours to obtain a carboxyl group-containing terminal isocyanate urethane oligomer. After cooling to 60 ° C., 0.2 mol (60.2 parts) of pentaerythritol triacrylate in which 0.01% of monomethyl ether hydroquinone (total system) is dissolved is added, and the mixture is further stirred at 60 ° C. for 4 hours. After that, 0.02 parts of di-n-butyltin dilaurate was added as a catalyst, and the reaction was continued for another hour. When the residual isocyanate group became 0.1%, the reaction was terminated, and the carboxyl group-containing urethane acrylate oligomer was obtained. (Number average molecular weight 1200) was obtained. Separately, 0.9 equivalent of the carboxyl group in the above-mentioned carboxyl group-containing urethane acrylate oligomer is neutralized with an ethanolamine solution dissolved in methanol and diluted with methanol to obtain an active energy ray-curable compound having a resin content of 40%. A solution was obtained.

Example 5 Using (b) the urethane acrylate containing a carboxyl group (number-average molecular weight: 2600, non-neutralized product) of Example 1, a removable pressure-sensitive adhesive composition was prepared as follows and evaluated. <Preparation of Removable Adhesive Composition> In a room where ultraviolet rays were blocked, the above (a) was placed in a 250 ml polyethylene container.
Water-affinity acrylic adhesive solution (resin content 40%) 80
20 parts of the above (b) methanol solution of the active energy ray-curable compound (adjusted to a resin content of 40%), and (c) 1-
1 part of hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Geigy Japan) and (d) 2 parts of an epoxy compound (1% ethyl acetate solution of "Epolite 80MF", manufactured by Kyoeisha Chemical Co., Ltd.) as a cross-linking agent are added, followed by stirring and re-stripping. A pressure-sensitive adhesive composition solution was obtained.

Example 6 Example 1 was carried out except that (b) of Example 1 was changed as follows.
In the same manner as in the above, a removable pressure-sensitive adhesive composition was obtained and evaluated. <(B) Active energy ray-curable compound> A reflux condenser, a stirrer, an air drying inlet and a thermometer were attached to a four-necked round bottom flask, and isophorone diisocyanate (I
PDI) 0.2 mol (44.4 parts) and 0.1 mol (2) of a polyol having a hydroxyl group at both terminals composed of ethylene oxide and propylene oxide (number average molecular weight 2000)
00 parts), and further, ethyl acetate (112.2 parts) was charged, and the mixture was reacted at about 80 ° C. for 4 hours with stirring.
A urethane oligomer having an isocyanate group at a terminal was obtained. Thereafter, the mixture was cooled to about 60 ° C., and 0.2 mol of pentaerythritol triacrylate (6%) in which 0.01% of monomethyl ether hydroquinone (total system) was dissolved.
After stirring at about 60 ° C. for about 6 hours, di-n-butyltin dilaurate was added as a catalyst in an amount of 0.02 parts.
The reaction was continued for another 6 hours and the remaining isocyanate groups were reacted with the isocyanate groups until the residual isocyanate groups reached 0.1%, and the urethane acrylate oligomer (number average molecular weight 3
300) and diluted with methanol to obtain (b) an active energy ray-curable compound having a resin content of 40%.

Example 7 Example 1 was carried out except that (b) of Example 1 was changed as follows.
In the same manner as in the above, a removable pressure-sensitive adhesive composition was obtained and evaluated. <(B) Active energy ray-curable compound> A reflux condenser, a stirrer, an air drying inlet and a thermometer were attached to a four-necked round bottom flask, and isophorone diisocyanate (I
PDI) 0.4 mole (88.9 parts) and 0.2 mole (100 parts) of 2,2′-dimethylolpropanesulfonic acid were further charged, and ethyl acetate (112.2 parts) was further charged.
The mixture was reacted at about 80 ° C. for about 4 hours with stirring to obtain a sulfonic acid group-containing isocyanate urethane oligomer.
Thereafter, the mixture was cooled to about 60 ° C. to dissolve 0.01% (total system) of monomethyl ether hydroquinone 2-
0.4 mol of hydroxyethyl acrylate (46.4
After stirring for about 6 hours at about 60 ° C., 0.02 part of di-n-butyltin dilaurate was added as a catalyst, and the reaction was continued for further 6 hours to reduce residual isocyanate groups to 0.1 part.
At 1%, the reaction was terminated and the sulfonic acid group-containing urethane acrylate oligomer (number average molecular weight 86
0) was obtained. Separately, 0.9 equivalent of sulfonic acid in the sulfonic acid group-containing urethane acrylate oligomer was neutralized using an ethanolamine solution dissolved in methanol, and diluted with methanol to obtain a resin component having an active energy ray curability of 40%. A compound solution was obtained.

Example 8 In Example 1, (c) 1-hydroxycyclohexyl phenyl ketone (Nippon Ciba-Geigy Co., Ltd., "Irgacure 184") was replaced with 1.4 parts of benzyl methyl ketal (Nippon Ciba-Geigy Co., Ltd., Irgacure 651). 1.
A removable pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that 4 parts were used, and was evaluated in the same manner.

Comparative Example 1 A removable pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that (a) was changed to the following acrylic pressure-sensitive adhesive. When (a) to (d) were mixed, a precipitate was formed without forming a homogeneous solution, but the same evaluation was performed. <Acrylic adhesive> A reflux condenser, a stirrer, a dropping funnel and a thermometer were attached to a four-necked round bottom flask, and 80 parts of n-butyl acrylate and methyl methacrylate 13 were added.
, 7 parts of 2-hydroxyethyl methacrylate, 80 parts of ethyl acetate, and 0.1 part of azobisisobutyronitrile were charged into a flask equipped with a condenser, a stirrer and a thermometer, and heated to 90 ° C for polymerization. During the polymerization, polymerization was carried out for 7 hours while sequentially adding a polymerization catalyst solution in which 0.1 part of azobisisobutyronitrile was dissolved in 10 parts of ethyl acetate. After completion of the polymerization, the concentration was adjusted by adding ethyl acetate, the weight average molecular weight was 470,000, and the glass transition temperature (Tg) was −35 ° C.
(Resin content 40%, solvent content 60%)
(Ethyl acetate)〕. The weight composition of the copolymer was n-butyl acrylate / methyl methacrylate / 2-hydroxyethyl methacrylate = 80/13/7. This copolymer did not have water affinity. Tables 1, 2 and 3 show the evaluation results of the examples and comparative examples.

[0062]

[Table 1] Adhesive strength (g / 25mm) Removability (g / 25mm) Silicon wafer SUS glass plate Silicon wafer SUS glass plate Example 1 1650 1600 1650 19 20 23 〃2 2000 1900 2000 28 27 29 ３3 1750 1550 1600 30 30 30 ４ 4 1750 1600 1600 17 19 19 〃 5 2500 2600 2550 65 70 68 〃 6 1600 1550 1550 28 29 29 ７ 7 1700 1700 1650 31 33 32 〃 8 1650 1600 1650 19 20 22 Comparative Example 1 125 130 125 125 125 125

[0063]

[Table 2] Silicon wafer SUS glass before and after contaminated water washing SUS glass Silicon wafer SUS glass Example 1 ○ ○ ○ ◎ ◎ ◎ 〃 2 ○ ○ ○ ◎ ◎ ◎ 〃 3 ○ ○ ○ ◎ ◎ ◎ 〃 4 ○ ○ ○ ◎ ◎ ◎ ◎ ５ 5 ○ ○ ○ ◎ ◎ ◎ 〃 6 ○ ○ ○ ○ ◎ ◎ ◎ 〃 7 ○ ○ ○ ◎ ◎ ◎ 〃 8 ○ ○ ○ ◎ ◎ ◎ Comparative Example 1 × × × × × × ×

[0064]

[Table 3] Dicing suitability Expandability Pickup efficiency Example 1 ○ ○ ○ 〃2 ○ ○ ○ 〃3 ○ ○ ○ 〃4 ○ ○ ○ 〃5 ○ ○ ○ ○ 6 ○ ○ ○ 〃7 ○ ○ ○ ○ 8 ○ ○ ○ Comparative Example 1 × × ×

[0065]

EFFECT OF THE INVENTION The removable pressure-sensitive adhesive composition of the present invention comprises:
(A) a water-affinity acrylic pressure-sensitive adhesive, (b) an active energy ray-curable compound, (c) a photopolymerization initiator, and (d) a crosslinking agent; Excellent re-peelability afterwards, excellent in stain resistance, especially excellent in stain resistance, especially excellent in dicing suitability, expandability, pickup efficiency, etc. when used for temporary bonding in the dicing process of a semiconductor wafer. It is very useful for applications, background applications in the production of semiconductor wafers, and dicing applications.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 24, 2000 (2005.2.
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

Examples of the polyisocyanate include aromatic, aliphatic, cycloaliphatic and alicyclic isocyanates and mixtures thereof. Among them, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate Tolylene diisocyanate (TDI) such as isocyanate and mixtures thereof, hydrogenated TDI, 4,4′-diphenylmethane diisocyanate (MDI), hydrogenated MDI, crude M
DI, modified MDI, xylylene diisocyanate (XD
I), hydrogenated XDI, tetraxylylene diisocyanate (TMXDI), isophorone diisocyanate (IPD
I), norbornene diisocyanate (NBDI), dimer of tolylene diisocyanate (TT), hexamethylene diisocyanate (HMDI), trimethylhexamethylene diisocyanate (TMHMDI), o-tolidine diisocyanate (TODI), naphthalene diisocyanate (NDI), diphenyl ether diisocyanate ( PEDI), dianisidine diisocyanate (DADI), p-phenylene diisocyanate (PP
DI), polyisocyanates such as isopropylidenebis-4-cyclohexyl diisocyanate (IPCI), lysine diisocyanate methyl ester (LDI), trimethylhexamethylene diisocyanate (TMDI) and dimer acid diisocyanate (DDI). 4-tolylene diisocyanate, isophorone diisocyanate (IPDI), Noruporunenji Lee Seo <br/> cyanate (NBDI) is preferably used.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

Examples of the hydroxyl-containing acrylic compound include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
Hydroxyethyl acryloyl phosphate, 4-hydroxybutyl acrylate, caprolactone-modified 2-
Hydroxyethyl acrylate, 3-chloro-3-hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, polyethylene glycol acrylate, glycerin di main methacrylate, 2-hydroxy-3
-Acryloyloxypropyl methacrylate, glycidol dimethacrylate, 2-acryloyloxyethyl acid phosphate, bismethacryloyloxyacid phosphate, hydroxypropylated trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Tetraacrylate, tetramethylol methane triacrylate and the like are used, preferably 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate and pentaerythritol triacrylate.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J040 DF041 DF042 DF051 DF052 EC002 EF181 FA161 FA162 FA281 FA282 FA291 FA292 GA07 GA08 GA25 HB13 HB19 HC16 HC22 HC25 HD19 HD41 JA09 JB07 JB09 KA13 KA16 MA02 MA05 MA10 NA20

Claims (8)

[Claims] (1) a water-friendly acrylic pressure-sensitive adhesive,
A removable pressure-sensitive adhesive composition comprising (b) an active energy ray-curable compound, (c) a photopolymerization initiator, and (d) a crosslinking agent. 2. The removable pressure-sensitive adhesive composition according to claim 1, wherein (b) the active energy ray-curable compound has an affinity for water. (A) a water-affinity acrylic pressure-sensitive adhesive,
(B) the weight ratio of the active energy ray-curable compound is
3. The removable pressure-sensitive adhesive composition according to claim 1, wherein (a) / (b) = 95/5 to 30/70. 4. The method according to claim 1, wherein (a) the water-affinity acrylic pressure-sensitive adhesive is
An unsaturated monomer containing a carboxyl group or a sulfonic acid group, and a neutralized product of a copolymer consisting of a monomer copolymerizable with the unsaturated monomer, according to any one of claims 1 to 3, wherein Removable adhesive composition. 5. The removable pressure-sensitive adhesive composition according to claim 4, wherein the monomer copolymerizable with the unsaturated monomer contains an unsaturated monomer having an ether bond. 6. The removable pressure-sensitive adhesive composition according to claim 1, wherein (b) the active energy ray-curable compound is a water-affinity urethane acrylate oligomer. 7. The urethane acrylate oligomer,
A hydroxyl group-containing acrylic compound capable of reacting with an isocyanate group is reacted with (a) a polyol having a carboxyl group or a sulfonic acid group and / or (b) a polyol having an ester bond or an ether bond and a polyisocyanate. 7. The removable pressure-sensitive adhesive composition according to claim 6, wherein 8. The removable pressure-sensitive adhesive composition according to claim 1, which is used for a pressure-sensitive adhesive sheet for temporary fixing in a back grinding step or a dicing step of a semiconductor wafer.