JPH11293201A - Re-releasable pressure-sensitive adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a re-releasable pressure-sensitive adhesive which shows a lowered pressure-sensitive adhesiveness after being cured with ultraviolet rays or a radiation, can be re-released without leaving any adhesive, can be diced without scattering chips, can be expanded without sheet break or chip separation, and exhibits an excellent pick-up efficiency. SOLUTION: There is provided a re-releasable pressure-sensitive adhesive comprising (a) an acrylic pressure-sensitive adhesive having at least one type of functional groups selected among carboxyl groups, hydroxyl groups, amide groups, glycidyl groups, amino groups, and sulfo groups in the molecule and having a weight-average molecular weight of at least 200,000 and a glass transition temperature of -60 to -30 deg.C, (b) a urethane acrylate compound, (c) a photopolymerization initiator, and (d) a crosslinking agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a re-peelable type used for a temporary surface protection of a metal plate, a plastic plate or the like and a semiconductor fixing adhesive sheet (hereinafter abbreviated as an adhesive sheet) in a dicing process of a semiconductor wafer or the like. Related to adhesives.

[0002]

2. Description of the Related Art In recent years, a protective sheet has been temporarily adhered to a surface of a metal plate, a plastic plate, or the like in order to prevent the generation of rust, dirt or damage, or a temporary adhesion in a dicing process of a semiconductor wafer. Adhesive sheets are often used for applications. The pressure-sensitive adhesive used for this pressure-sensitive adhesive sheet has sufficient adhesive strength when applied to an adherend, and when peeled,
It is required that the adhesiveness be sufficiently low and the surface of the adherend be free of contamination. JP-A-62-153376 discloses a pressure-sensitive adhesive for a pressure-sensitive adhesive sheet, which comprises a pressure-sensitive adhesive and a radiation-polymerizable compound which is a urethane acrylate oligomer having a molecular weight of 3,000 to 10,000 on a substrate surface. An adhesive sheet formed by applying an adhesive layer is disclosed. When the sheet is peeled off, the sheet is irradiated with ultraviolet rays, whereby the adhesive force with the adherend is rapidly reduced. Also, JP-A-9-32866.
No. 3 discloses a pressure-sensitive adhesive in which a specific amount of an elastomer, a tackifier, a curing agent, a UV-crosslinkable oligomer and / or monomer, and a polymerization initiator as a main component are laminated on a UV-permeable sheet as a base material. An adhesive sheet whose main part is formed by a sheet is disclosed.

[0003]

However, in the technique disclosed in Japanese Patent Application Laid-Open No. Sho 62-153376, although the adhesive strength after curing of the removable pressure-sensitive adhesive decreases, the pressure-sensitive adhesive remains when removed again. There is a problem that chips are scattered at the time of dicing, and chips are detached and dropped at the time of expansion, which has not been satisfactory yet. Further, the technique disclosed in Japanese Patent Application Laid-Open No. 9-328663 has a drawback that the chip is damaged when the force applied to the pickup is large and the chip is thin, and has not been satisfactory yet.

[0004]

The inventors of the present invention have conducted intensive studies on a removable pressure-sensitive adhesive in order to solve such a problem. As a result, (a) a carboxyl group,
An acrylic pressure-sensitive adhesive having at least one functional group of a hydroxyl group, an amide group, a glycidyl group, an amino group, and a sulfonic acid group, having a weight average molecular weight of 200,000 or more and a glass transition temperature of -60 to -30 ° C; The present inventors have found that a re-peelable pressure-sensitive adhesive comprising (b) a urethane acrylate compound, (c) a photopolymerization initiator, and (d) a crosslinking agent solves the above-mentioned problems, and completed the present invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The acrylic pressure-sensitive adhesive (a) used in the present invention includes:
It is necessary that the molecule has at least one functional group of a carboxyl group, a hydroxyl group, an amide group, a glycidyl group, an amino group, and a sulfonic acid group. Specifically, an acrylic acid alkyl ester or a methacrylic acid alkyl ester It is a copolymer of the main monomer of the system and a functional group-containing monomer. As the main monomer, one or two or more alkyl acrylates or alkyl methacrylates having an alkyl group having about 1 to 12 carbon atoms are used. Among them, the alkyl group has about 4 to 12 carbon atoms. Of these, alkyl acrylates and alkyl methacrylates are preferably used. Examples of the alkyl acrylate having an alkyl group having about 4 to 12 carbon atoms include n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-propyl acrylate, n-hexyl acrylate, and acrylic acid. 2-ethylhexyl, n-octyl acrylate, lauryl acrylate, and the like. Examples of the alkyl methacrylate having about 4 to 12 carbon atoms include n-butyl methacrylate, iso-butyl methacrylate, and butyl methacrylate.
rt-butyl acrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-hexyl methacrylate,
Examples include n-octyl methacrylate and lauryl methacrylate.

The functional group-containing monomers include acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, and acrylamide N-
Carboxyl group-containing unsaturated compounds such as glycolic acid and cinnamic acid or 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, methacrylic acid 2 -Hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, tetrahydrofurfuryl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, diethylene glycol acrylate, polyethylene glycol acrylate, N-methylol acrylamide, N-methylol methacryl Hydroxy group-containing unsaturated compounds such as amides, glycidyl group-containing unsaturated compounds such as glycidyl methacrylate and allyl glycidyl methacrylate, acrylamide, methacrylamide, N- (n-butene) Shiarukiru) acrylamide, N
Amide group-containing unsaturated compounds such as-(n-butoxyalkyl) methacrylamide; amino group-containing unsaturated compounds such as acrylamido-3-methylbutylmethylamine, dimethylaminoalkylacrylamide and dimethylaminoalkylmethacrylamide; ethylenesulfonic acid; An sulfonic acid group-containing unsaturated compound such as olefinsulfonic acid such as allylsulfonic acid and methallylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid or a salt thereof is used. Unsaturated compounds other than the above, such as 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate, 3-methoxyethyl acrylate, and the like, in the copolymer without departing from the spirit of the present invention.
Alkyl vinyl ethers such as 3-methoxyethyl methacrylate, methoxydiethylene glycol acrylate, methoxydiethylene glycol methacrylate, N-acrylamidomethyltrimethylammonium chloride,
Allyl trimethyl ammonium chloride, dimethyl allyl vinyl ketone, N-vinyl pyrrolidone, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, vinyl acetate, styrene and the like are used.

The polymerization ratio (weight ratio) of the main monomer and the functional group-containing monomer is preferably 99.9 / 0.1 to 70/30. If the polymerization ratio is out of the above range, the removable adhesive remains on the chip. May be undesirable.

The method for producing the (a) acrylic pressure-sensitive adhesive used in the present invention is not particularly limited, but a main monomer, a functional group-containing monomer, and a polymerization initiator are mixed or dropped into an organic solvent, and the mixture is refluxed or mixed. 4 at 50-90 ° C
A method of polymerizing for 20 to 20 hours is preferably employed.

(A) The glass transition temperature of the acrylic pressure-sensitive adhesive must be -60 to -30.degree. C., preferably -55 to -30.degree. Glass transition temperature of -60
If the temperature is lower than 0 ° C, the compatibility with the urethane acrylate compound (b) is inferior, and the adhesive strength does not sufficiently decrease when irradiated with ultraviolet rays or radiation, and the adhesive remains on the wafer surface. The adhesive force when attaching the wafer is weak and inappropriate.

(A) The weight average molecular weight of the acrylic pressure-sensitive adhesive must be 200,000 or more, preferably 2
It is between 10,000 and 1.5 million, and further between 400,000 and 1,000,000. If the weight-average molecular weight is less than 200,000, the pressure-sensitive adhesive is unsuitable because it has a disadvantage that it remains on the chip when peeled off.

The (b) urethane acrylate compound used in the present invention is an acrylate compound having a urethane bond in the molecule, and can be produced by reacting a hydroxyl group-containing acrylic compound with a polyvalent isocyanate compound.

The acrylic compound includes hydroxypropylated trimethylolpropane triacrylate,
Hydroxyl-containing acrylic compounds having three or more acryloyl groups in the molecule, such as pentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetraacrylate, and tetramethylolmethane triacrylate, are preferably used.

As the polyvalent isocyanate compound,
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, tetramethyl xylylene diisocyanate, 1,5-naphthalene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, tolylene diisocyanate adduct of trimethylolpropane, xylylene diisocyanate adduct of trimethylolpropane, triphenylmethane triisocyanate, methylene bis (4- Phenylmethane) triisocyanate and the like,
Preferably 2,4-tolylene diisocyanate, 2,6
-Tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate,
Examples include diisocyanate compounds such as diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and tetramethylxylylene diisocyanate.

The method for producing the above-mentioned urethane acrylate compound (b) is not particularly limited, but a hydroxyl group-containing acrylic compound and a polyvalent isocyanate compound are mixed in an inert gas atmosphere, and the mixture is mixed at 30 to 80 ° C. for 2 to 10 hours. Let react. In the reaction, it is preferable to use a urethanization catalyst such as duz octenoate, di-n-butyltin dilaurate, lead octylate, potassium octylate, potassium acetate, stannas octoate, and triethylenediamine.

The weight average molecular weight of the urethane acrylate compound (b) is preferably from 1,000 to 4.0,
00, more preferably 1,000 to 3,500, especially 1,2
00 to 3,000. Weight average molecular weight of 1,000
If it is less than 3, the adhesive is likely to remain on the chip when peeled, and
If it exceeds 00, the adhesive strength will not be sufficiently reduced upon irradiation with ultraviolet rays or radiation, and the viscosity will be too high, and the handleability will be poor, which is not preferable. Further, it is preferable to select the urethane acrylate compound (b) having a curing shrinkage of 4 to 10%, and more preferably 5 to 9%. If the curing shrinkage is less than 4%, the adhesive strength after irradiation with ultraviolet rays or radiation is insufficiently reduced, and if it exceeds 10%,
Chips tend to scatter during expansion, which is not preferable. The cure shrinkage is measured by the following method. First, 100 g of the urethane acrylate compound was added to α-
4 g of hydroxyisobutylphenone is added and mixed, bubbles are removed, and the specific gravity of the liquid is measured by a specific gravity cup method according to JIS K 5400 to obtain a specific gravity d (g / cm ³ ) before curing. Next, a part of the liquid was cylindrically shaped (diameter 5.0 cm, height 1.0 c).
m, an inner volume of 19.6 cm ³ ), poured into a polyethylene mold, irradiated with ultraviolet rays at 500 mJ / cm ² , cured, removed from the mold, and placed in the above specific gravity cup (internal volume 100 cm ³ ). Further, the weight of the entire specific gravity cup is measured by filling with water, and the specific gravity (s) after curing is calculated by the following equation (1).
The cure shrinkage is determined by the following equation (2). s = a × b / (100a + bc) (1) Curing shrinkage = [(sd) / s)] × 100 (%) (2) [where a: specific gravity of water (G / cm ³ ), b: weight after curing (g), c: weight of water in specific gravity cup + weight after curing (g), d: specific gravity before curing (g / cm ³ ), s: Specific gravity after curing (g / cm ³ )]

The photopolymerization initiator (c) used in the present invention includes benzoin, isopropylbenzoin ether, isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, acetophenone diethylketal, benzyl Dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc., and benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl -1-Phenylpropan-1-one is preferred.

As the crosslinking agent (d) used in the present invention, bisphenol A / epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6- Hexanediol diglycidyl ether,
Epoxy-based compounds such as trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl ether, tetramethylol methane-tri-β-aziridinyl propionate, Trimethylolpropane-tri-β-aziridinylpropionate, N, N′-diphenylmethane-4,4′-bis (1
-Aziridinecarboxamide), aziridine compounds such as N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide), hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexaptoxy Methyl melamine,
Melamine-based compounds such as hexapentyloxymethylmelamine and hexahexyloxymethylmelamine;
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, tetramethyl xylylene diisocyanate, 1,5-naphthalene diisocyanate, trimethylol Tolylene diisocyanate adduct of propane, xylylene diisocyanate adduct of trimethylolpropane, triphenylmethane triisocyanate, methylene bis (4-phenylmethane)
Although an isocyanate compound such as triisocyanate is optionally used, a tolylene diisocyanate adduct of trimethylolpropane is preferred.

Component (a) in the removable pressure-sensitive adhesive of the present invention,
The blending amount of the component (b) is not particularly limited, but the blending amount of the component (b) is 5 with respect to the total amount of the component (a) and the component (b).
The content is preferably from about 75 to 75% by weight, and more preferably from 10 to 70% by weight. If the amount is less than 5% by weight, the adhesive strength after irradiation with ultraviolet rays or radiation is insufficiently reduced. If the chip is thin when picking up, it may be damaged. The force for fixing the wafer is insufficient, and the wafer may be peeled off during dicing, which is not preferable.

The compounding amount of (c) in the removable pressure-sensitive adhesive of the present invention is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the components (a) and (b). Furthermore, 1.0
５5.0 parts by weight. If the amount is less than 0.1 part by weight, the decrease in adhesive strength after irradiation with ultraviolet rays or radiation is not sufficiently reduced. If the amount exceeds 10 parts by weight, (c) the photopolymerization initiator remains on the chip. It is not preferable because it causes contamination.

The compounding amount of (d) in the removable pressure-sensitive adhesive of the present invention is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the components (a) and (b). And 0.5
~ 5% by weight. If the amount is less than 0.1% by weight, the removable pressure-sensitive adhesive remains on the chip, causing contamination. If the amount exceeds 5% by weight, the removable pressure-sensitive adhesive is not irradiated with ultraviolet rays or radiation. It is not preferable because it may become stiff.

In the preparation method of the removable pressure-sensitive adhesive of the present invention, the mixing order of the above (a), (b), (c) and (d) is not particularly limited, but (a) and (b) Is mixed in a solvent, and then (c) or (d) is directly blended.

Examples of the solvent used at this time include esters such as methyl acetate, ethyl acetate, methyl acetoacetate and ethyl acetoacetate; ketones such as acetone and methyl isobutyl ketone; and aromatic compounds such as toluene and xylene. However, ethyl acetate and toluene are preferably used from the viewpoints of solubility, drying property and cost.

Thus, the removable pressure-sensitive adhesive of the present invention can be obtained. However, as long as the effects of the present invention are not impaired, a pressure-sensitive adhesive other than the above (a), a urethane resin, rosin,
Known additives such as rosin ester, hydrogenated rosin ester, phenol resin, aromatic modified terpene resin, aliphatic petroleum resin, alicyclic petroleum resin, styrene resin and xylene resin can be added.

The removable pressure-sensitive adhesive of the present invention is usually applied to a substrate sheet or the like and is often used for a pressure-sensitive adhesive sheet or the like. To manufacture such a pressure-sensitive adhesive tape, first, the removable pressure-sensitive adhesive of the present invention is used. The pressure-sensitive adhesive is adjusted as it is or with an appropriate organic solvent, and is coated on a silicon-treated release film or directly on a substrate, for example, at 80 to 105 ° C. for 30 seconds to 1 hour.
It is dried by a heat treatment or the like for 0 minutes.

The substrate is not particularly limited as long as it is a transparent film that transmits ultraviolet light and has good stretchability at the time of expansion, but specific examples thereof include polyvinyl chloride, polybutene, polybutadiene, polyurethane, and ethylene-acetic acid. Examples include vinyl copolymer, polyethylene terephthalate, polyethylene, and polypropylene. Films such as ethylene-propylene copolymer, polyurethane, polymethylpentene, and polybutylene terephthalate are used.

Since the removable pressure-sensitive adhesive of the present invention is preferably used for a pressure-sensitive adhesive sheet (for a wafer dicing step), its use will be described below.

In this application, after the semiconductor wafer is attached to the adhesive sheet and fixed, the semiconductor wafer is cut into chips by a rotary round blade. After that, the adhesive sheet is cured by irradiating ultraviolet rays or radiation from the substrate side. As a light source for performing 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, or the like is used. In the case of a high-pressure mercury lamp, it is performed under the conditions of 50 to 3000 mJ / cm ² , preferably 250 to 1000 mJ / cm ² . The irradiation time depends on the type of light source, the distance between the light source and the coating surface, the coating thickness,
Although it depends on other conditions, it is usually several seconds, and in some cases, a fraction of a second. In the case of electron beam irradiation,
For example, it is preferable to use an electron beam having an energy in the range of 50 to 1000 Kev and to set the irradiation amount to 2 to 50 Mrad.

The adhesive strength before and after the curing varies depending on the type of the base material and the type of the wafer.
180 ° C peel adhesive strength of 150 to 600 g / 37
The adhesive strength after irradiation is preferably about 5 to 50 g / 25 mm. Next, the adhesive sheet is expanded (stretched) using a wafer expanding device to expand the chip interval to a predetermined interval. Then, the chips are pushed up with a needle or the like, and are picked up by a method of adsorbing with air tweezers or the like.
The chip is adhered to the base, and the electrodes are connected by gold wires to produce a semiconductor chip as a product. Although the removable pressure-sensitive adhesive used for the semiconductor fixing pressure-sensitive adhesive sheet in the semiconductor dicing step has been described above, the removable pressure-sensitive adhesive of the present invention is not limited thereto, and may be a metal plate, a plastic plate, or a glass plate. Is a very useful removable adhesive which is also used as a temporary surface protective agent for silicon wafers and the like.

[0029]

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) Production of acrylic pressure-sensitive adhesive> A 4-neck round bottom flask was equipped with a reflux condenser, a stirrer, a dropping funnel and a thermometer, and 74 parts of n-butyl acrylate, 10 parts of methyl methacrylate, After charging 1 part of acrylic acid, 15 parts of 2-hydroxyethyl acrylate and 80 parts of ethyl acetate and starting heating under reflux, 0.07 part of azobisisobutyronitrile was added as a polymerization initiator, and the mixture was heated at the reflux temperature of ethyl acetate for 3 hours. After the reaction, a solution prepared by dissolving 0.07 part of azobisisobutyronitrile in 5 parts of toluene was added, and the mixture was further reacted at reflux temperature for 4 hours.
%, A weight average molecular weight of 710,000, and an acrylic pressure-sensitive adhesive having a glass transition temperature of -39 ° C. The weight average molecular weight was determined by gel permeation chromatography, and the glass transition temperature was determined by a differential scanning calorimeter (DSC). <(B) Production of urethane acrylate compound> A 4-neck round bottom flask was equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, and 17.5 parts of isophorone diisocyanate, dipentaerythritol pentaacrylate 82. 5 parts, di-n-butyltin dilaurate
02 parts and 0.03 part of hydroquinone monoethyl ether were charged and reacted at 50 ° C. for 7 hours.
300 (b) urethane acrylate compounds were obtained.
The curing shrinkage of the urethane acrylate compound is 8.5.
%Met.

<Production of Removable Adhesive> In a room shielded from ultraviolet rays, 30 parts of toluene and 30 parts of the above urethane acrylate compound (b) were placed in a 250 ml polyethylene container.
After adding 0 parts and dissolving at 40 ° C., 50 parts of the above-mentioned (a) toluene solution of the acrylic pressure-sensitive adhesive (resin content: 40%),
(C) 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Nippon Ciba Geigy) 1.4
, (D) 0.5 part of a 55% ethyl acetate solution of tolylene diisocyanate adduct of trimethylolpropane (manufactured by Nippon Polyurethane Co., Ltd., Coronate L-55E), followed by stirring and uniform solution (removable adhesive) I got <Production of pressure-sensitive adhesive sheet> A polyester film having a thickness of 38 μm obtained by subjecting the solution to silicone release treatment has a thickness of 1 after drying.
Coating was performed so as to be 0 μm, and the resultant was heated and dried for 2 minutes at 100 ° C. Thereafter, the resultant was transferred onto an 80 μm polyethylene film as a base material, and aged at 40 ° C. for 3 days to produce a pressure-sensitive adhesive sheet.

<Evaluation of pressure-sensitive adhesive sheet> The obtained pressure-sensitive adhesive sheet was evaluated for removability, adhesive strength, particle amount, dicing suitability, expandability, and pickup efficiency.
The ultraviolet irradiation employed in these evaluations was performed with a high-pressure mercury lamp at 500 mJ / cm ² . (A) Adhesive Force A 180 ° C. peel adhesive force (g / 25 mm) at a peeling rate of 300 mm / min before and after ultraviolet irradiation was measured according to JIS Z 0237 using a silicon wafer as an adherend. (B) Particle amount The above-mentioned pressure-sensitive adhesive sheet was stuck on the surface of a 4-inch silicon wafer to which no foreign matter was adhered, left in a room adjusted to 23 ° C. and 65% RH for 1 hour, and irradiated with ultraviolet rays. The pressure-sensitive adhesive sheet was peeled off from the surface, and the number of foreign particles having a size of 0.3 μm or more remaining on the surface of the wafer after peeling was measured using a laser surface inspection apparatus, and evaluated as follows. ○: Less than 10 △: Less than 10 to 30 ×: More than 30 (c) Suitability for dicing After sticking the above adhesive sheet to a semiconductor wafer having a diameter of 5 inches, dicing into a 10 mm square chip shape Was done.
The condition of the chip at that time was evaluated as follows.・ ・ ・: No chips were scattered. Δ: Only chips formed at the edge of the wafer were scattered. ×: Scattered as a whole.

(D) Suitability for Expanding After the above dicing, ultraviolet irradiation was performed, and the wafer was expanded at an air pressure of 2.0 kg / cm ² using a wafer expanding device, and the chip retention when the chip gap was 100 μm was observed. And evaluated as follows. ○ ・ ・ ・ No chips are scattered × ・ ・ ・ No chips are scattered (e) Pickup Efficiency When the adhesive sheet is not broken or chips are not peeled off after the above expansion, when picking up with a die bonder, The number picked up out of 10,000 pieces was measured and evaluated as follows.・ ・ ・: 10000 pieces Δ: 9995 to 9999 pieces ×: 9994 pieces or less Table 1 shows the above evaluation results.

Example 2 The same experiment as in Example 1 was carried out except that the production of the acrylic pressure-sensitive adhesive was changed as follows. <(A) Production of Acrylic Adhesive> A four-necked round bottom flask was equipped with a reflux condenser, a stirrer, a dropping funnel and a thermometer, and 85 parts of n-butyl acrylate, 10 parts of methyl methacrylate, and acrylic acid After charging 2 parts, 3 parts of 2-hydroxyethyl acrylate and 80 parts of ethyl acetate, starting heating under reflux, adding 0.07 parts of azobisisobutyronitrile as a polymerization initiator, and reacting at the reflux temperature of ethyl acetate for 7 hours. By diluting with toluene, an acrylic pressure-sensitive adhesive having a resin content of 40%, a weight average molecular weight of 810,000 and a glass transition temperature of -43 ° C was obtained. A re-peelable pressure-sensitive adhesive was produced using the pressure-sensitive adhesive in the same manner as in Example 1, and a pressure-sensitive adhesive sheet was produced using the pressure-sensitive adhesive. The results are shown in Table 1.

Example 3 The same experiment as in Example 1 was carried out except that the production of the urethane acrylate compound (b) was changed as follows. <(B) Production of urethane acrylate compound> A four-necked round-bottomed flask was equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, and 10 parts of tolylene diisocyanate, 30 parts of pentaerythritol triacrylate, and 60 parts of pentaerythritol pentaacrylate,
0.02 parts of stannas octoate and 0.03 parts of hydroquinone monoethyl ether were charged and reacted at 50 ° C. for 7 hours to obtain a urethane acrylate compound having a weight average molecular weight of 1,200. The curing shrinkage of the urethane acrylate compound was 9.3%. Using the compound,
A re-peelable pressure-sensitive adhesive was produced in the same manner as in Example 1, and a pressure-sensitive adhesive sheet was produced using the pressure-sensitive adhesive, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4 In Example 1, in the production of the removable pressure-sensitive adhesive,
(A) The compounding amount of the acrylic compound was changed from 50 parts to 65 parts, and the compounding amount of the (b) urethane acrylate compound was changed to 20 parts.
The pressure-sensitive adhesive was manufactured in the same manner as in Example 1 except that the part was changed to 14 parts, and a pressure-sensitive adhesive sheet was further manufactured. The evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

Example 5 In Example 1, (c) 1.4 parts of 1-hydroxycyclohexyl phenyl ketone (Nippon Ciba-Geigy, Irgacure 184) was replaced with 1.4 parts of benzyl methyl ketal (Nippon Ciba-Geigy, Irgacure 651). A re-peelable pressure-sensitive adhesive was produced in the same manner as in Example 1 except for using a part, and a pressure-sensitive adhesive sheet was produced using the pressure-sensitive adhesive, and was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 6 In Example 1, (d) a 55% ethyl acetate solution of tolylene diisocyanate adduct of trimethylolpropane (Coronate L-55E, manufactured by Nippon Polyurethane Industries, Ltd.)
A re-peelable pressure-sensitive adhesive was produced in the same manner as in Example 1 except that the amount of 5 parts was changed to 1.0 part, and a pressure-sensitive adhesive sheet was produced using the pressure-sensitive adhesive, and was similarly evaluated. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 The same experiment as in Example 1 was carried out except that the production of the acrylic pressure-sensitive adhesive was changed as follows. <(A) Production of acrylic pressure-sensitive adhesive> A four-necked round bottom flask was equipped with a reflux condenser, a stirrer, a dropping funnel and a thermometer, 64 parts of n-butyl acrylate, 30 parts of methyl methacrylate, and 1 part of acrylic acid , 5 parts of 2-hydroxyethyl methacrylate and 60 parts of ethyl acetate were charged and polymerized in the same manner as in Example 1; the resin content was 40%; the weight average molecular weight was 830,000;
An acrylic pressure-sensitive adhesive having a glass transition temperature of -17 ° C was obtained. A re-peelable pressure-sensitive adhesive was produced using the pressure-sensitive adhesive in the same manner as in Example 1, and a pressure-sensitive adhesive sheet was produced using the pressure-sensitive adhesive. The results are shown in Table 1. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 The same experiment as in Example 1 was carried out except that the production of the acrylic pressure-sensitive adhesive was changed as follows. <(A) Production of acrylic pressure-sensitive adhesive> A 4-neck round bottom flask was equipped with a reflux condenser, a stirrer, a dropping funnel and a thermometer, and 80 parts of 2-ethylhexyl acrylate, 10 parts of methyl methacrylate, and 2 parts of acrylic acid -Hydroxyethyl 10
And 60 parts of ethyl acetate, and after heating to reflux, adding 0.07 parts of azobisisobutyronitrile as a polymerization initiator, reacting at the reflux temperature of ethyl acetate for 7 hours, and diluting with toluene. An acrylic pressure-sensitive adhesive having 40%, a weight average molecular weight of 260,000 and a glass transition temperature of -66 ° C was obtained. A re-peelable pressure-sensitive adhesive was produced using the pressure-sensitive adhesive in the same manner as in Example 1, and a pressure-sensitive adhesive sheet was produced using the pressure-sensitive adhesive. The results are shown in Table 1. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 The same experiment as in Example 1 was performed except that the production of the acrylic pressure-sensitive adhesive was changed as follows. <(A) Production of acrylic pressure-sensitive adhesive> A 4-neck round bottom flask was equipped with a reflux condenser, a stirrer, a dropping funnel and a thermometer, and 74 parts of n-butyl acrylate and 10 parts of methacrylic acid were added.
Parts, 1 part of acrylic acid, 15 parts of 2-hydroxyethyl acrylate and 80 parts of toluene, and after heating and refluxing,
After adding 0.3 parts of azobisisobutyronitrile as a polymerization initiator and reacting at the reflux temperature of toluene for 7 hours, the mixture was diluted with toluene to give a resin content of 40% and a weight average molecular weight of 1
An acrylic pressure-sensitive adhesive having a glass transition temperature of -39 ° C was obtained. A re-peelable pressure-sensitive adhesive was produced using the pressure-sensitive adhesive in the same manner as in Example 1, and a pressure-sensitive adhesive sheet was produced using the pressure-sensitive adhesive. The results are shown in Table 1.
Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 4 In the production of the removable pressure-sensitive adhesive of Example 1, (a) the addition of 50 parts of a toluene solution of an acrylic pressure-sensitive adhesive was carried out in the same manner as described above, and the results are shown in Table 1.

Comparative Example 5 In the production of the removable pressure-sensitive adhesive of Example 1, (b) the addition of 20 parts of the urethane acrylate compound was omitted, and the same procedure was carried out to obtain a removable pressure-sensitive adhesive. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[0043]

[Table 1] (a) (b) (c) (d) (e) Before irradiation After irradiation (g / 25mm) (g / 25mm) Example 1 500 10 ○ ○ ○ ○ Example 2 430 11 ○ ○ ○ ○ Example 3 480 9 ○ ○ ○ ○ Example 4 550 15 ○ ○ ○ ○ Example 5 490 11 ○ ○ ○ ○ Example 6 240 12 ○ ○ ○ ○ Comparative Example 1 20 15 ○ × * 1 * 1 Comparative Example 2 510 170 × ○ ○ × Comparative Example 3 530 35 × × × ○ Comparative Example 40 0 * 2 * 2 * 2 * 2 * 2 Comparative Example 5 480 470 ○ ○ ○ × * 1: Initial adhesion is weak, No evaluation was performed because the chips were scattered. * 2: No evaluation was performed because no adhesion was exhibited.

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[Procedure amendment]

[Submission date] February 24, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The acrylic pressure-sensitive adhesive (a) used in the present invention includes:
It is necessary that the molecule has at least one functional group of a carboxyl group, a hydroxyl group, an amide group, a glycidyl group, an amino group, and a sulfonic acid group. Specifically, an acrylic acid alkyl ester or a methacrylic acid alkyl ester It is a copolymer of the main monomer of the system and a functional group-containing monomer. As the main monomer, one or two or more alkyl acrylates or alkyl methacrylates having an alkyl group having about 1 to 12 carbon atoms are used. Among them, the alkyl group has about 4 to 12 carbon atoms. Of these, alkyl acrylates and alkyl methacrylates are preferably used. Examples of the alkyl acrylate having an alkyl group having about 4 to 12 carbon atoms include n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-propyl acrylate, n-hexyl acrylate, and acrylic acid. 2-ethylhexyl, n-octyl acrylate, lauryl acrylate, and the like. Examples of the alkyl methacrylate having about 4 to 12 carbon atoms include n -butyl methacrylate,
Methacrylic acid iso - butyl, methacrylic acid tert -
Butyl , n-octyl methacrylate, lauryl methacrylate and the like.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

<Manufacture of Removable Adhesive> In a room protected from ultraviolet rays, 30 parts of toluene and 30 parts of the above urethane acrylate compound (b) were placed in a 250 ml polyethylene container.
After adding 0 parts and dissolving at 40 ° C., 50 parts of the above-mentioned (a) solution of an acrylic pressure-sensitive adhesive (resin content: 40%) and (c) 1-hydroxycyclohexylphenyl ketone (Irgacure 184, manufactured by Ciba-Geigy Japan) 1.4 parts and (d) 0.5 part of a 55% ethyl acetate solution of tolylene diisocyanate adduct of trimethylolpropane (manufactured by Nippon Polyurethane Co., Coronate L-55E) were added and stirred to obtain a uniform solution (removable type). Pressure-sensitive adhesive). <Production of pressure-sensitive adhesive sheet> A polyester film having a thickness of 38 μm obtained by subjecting the solution to silicone release treatment has a thickness of 1 after drying.
Coating was performed so as to be 0 μm, and the resultant was heated and dried at 100 ° C. for 2 minutes. Thereafter, the resultant was transferred onto an 80 μm polyethylene film as a base material, and aged at 40 ° C. for 3 days to produce a pressure-sensitive adhesive sheet.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

<Evaluation of pressure-sensitive adhesive sheet> Obtained pressure-sensitive adhesive sheet
The adhesive strength , particle amount, suitability for dicing, suitability for expandability, and pick-up efficiency were evaluated. The ultraviolet irradiation used in these evaluations was performed with a high-pressure mercury lamp for 5 hours.
The test was performed at 00 mJ / cm ² . (A) Adhesive Force A 180 ° C. peel adhesive force (g / 25 mm) at a peeling rate of 300 mm / min before and after ultraviolet irradiation was measured according to JIS Z 0237 using a silicon wafer as an adherend. (B) Particle amount The above-mentioned pressure-sensitive adhesive sheet was stuck on the surface of a 4-inch silicon wafer to which no foreign matter was adhered, left in a room adjusted to 23 ° C. and 65% RH for 1 hour, and irradiated with ultraviolet rays. The pressure-sensitive adhesive sheet was peeled off from the surface, and the number of foreign particles having a size of 0.3 μm or more remaining on the surface of the wafer after peeling was measured using a laser surface inspection apparatus, and evaluated as follows. ○: Less than 10 △: Less than 10 to 30 ×: More than 30 (c) Suitability for dicing After sticking the above adhesive sheet to a semiconductor wafer having a diameter of 5 inches, dicing into a 10 mm square chip shape Was done.
The condition of the chip at that time was evaluated as follows.・ ・ ・: No chips were scattered. Δ: Only chips formed at the edge of the wafer were scattered. ×: Scattered as a whole.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

(D) Suitability for Expanding After the above dicing, ultraviolet irradiation was performed, and the wafer was expanded at an air pressure of 2.0 kg / cm ² using a wafer expanding device, and the chip retention when the chip interval was 100 μm was observed. And evaluated as follows. ○: No chip scattering ×: Chip scattering is observed (e) Pickup efficiency After the above-mentioned expansion, pick-up is carried out by a die bonder device for the case where there is no breakage of the adhesive sheet or peeling of the chip. At this time, the number picked up out of 10,000 pieces was measured and evaluated as follows.・ ・ ・: 10000 pieces Δ: 9995 to 9999 pieces ×: 9994 pieces or less Table 1 shows the above evaluation results.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction contents]

Comparative Example 4 In the production of the removable pressure-sensitive adhesive of Example 1, the same procedure was carried out except that the addition of (a) 50 parts of the solution of the acrylic pressure-sensitive adhesive was omitted, and the results are shown in Table 1.

Claims (5)

[Claims] (A) a molecule having at least one kind of functional group of a carboxyl group, a hydroxyl group, an amide group, a glycidyl group, an amino group and a sulfonic acid group in a molecule, having a weight average molecular weight of 200,000 or more, and a glass transition temperature; A removable pressure-sensitive adhesive comprising: an acrylic pressure-sensitive adhesive having a temperature of -60 to -30 ° C; (b) a urethane acrylate-based compound; (c) a photopolymerization initiator; and (d) a crosslinking agent. 2. The removable pressure-sensitive adhesive according to claim 1, wherein the amount of component (b) is 5 to 75% by weight based on the total amount of component (a) and component (b). . 3. The compounding amount of the component (d) is 0.1 to 10 based on 100 parts by weight of the total amount of the components (a) and (b).
3. The removable pressure-sensitive adhesive according to claim 1, wherein the adhesive is in parts by weight. 4. The (b) urethane acrylate compound is a reaction product of a hydroxyl group-containing acrylic compound having three or more acryloyl groups in a molecule and a diisocyanate compound, and has a weight average molecular weight of 1,000 to 4,000. The removable pressure-sensitive adhesive according to any one of claims 1 to 3, wherein 5. The removable adhesive according to claim 1, which is used for an adhesive sheet for fixing a semiconductor in a dicing step of a semiconductor wafer.