WO2013105582A1

WO2013105582A1 - Adhesive composition, adhesive tape, and method for processing wafer

Info

Publication number: WO2013105582A1
Application number: PCT/JP2013/050237
Authority: WO
Inventors: 亨利根川; 隆浩麻生
Original assignee: 積水化学工業株式会社
Priority date: 2012-01-12
Filing date: 2013-01-09
Publication date: 2013-07-18
Also published as: JPWO2013105582A1; TW201339260A

Abstract

The purpose of the present invention is to provide: an adhesive composition having excellent heat resistance, which has high adhesive power and can still be easily released; an adhesive tape which uses the adhesive composition; and a method for processing a wafer, wherein the adhesive tape is used. The present invention is an adhesive composition which contains a photocurable adhesive component, a photopolymerization initiator, and a gas generator that generates a gas when irradiated with light. The gas generator is dispersed in the adhesive composition with a dispersion diameter of 0.05-37 μm.

Description

Adhesive composition, adhesive tape, and wafer processing method

The present invention relates to a pressure-sensitive adhesive composition that has high adhesive strength but can be easily peeled off and is excellent in heat resistance, a pressure-sensitive adhesive tape using the pressure-sensitive adhesive composition, and a wafer processing method using the pressure-sensitive adhesive tape About.

Adhesive compositions containing an adhesive component are widely used for adhesives such as adhesives, sealing agents, paints and coating agents, adhesives such as adhesive tapes and self-supporting tapes, and the like.
The performance required for these pressure-sensitive adhesive compositions varies depending on the application, but depending on the application, it may exhibit adhesiveness only for the required period, but may be required to be easily removed thereafter.

For example, in a semiconductor chip manufacturing process, a thick film wafer cut from a high-purity silicon single crystal or the like is polished to a predetermined thickness to form a thin film wafer, and the thick film wafer is bonded to a support plate. It has been proposed to work efficiently by reinforcing. An adhesive tape called a dicing tape is also used when dicing a thin film wafer ground to a predetermined thickness into individual semiconductor chips. The pressure-sensitive adhesive composition used in such a semiconductor manufacturing process can be firmly bonded during the process, and can be peeled without damaging the thin film wafer or semiconductor chip obtained after the process is finished (hereinafter, It is also called “high adhesion easy peeling”).

As a next-generation technology, a three-dimensional stacking technology using a TSV (Through Si via) that has been dramatically improved in performance by stacking a plurality of semiconductor chips has attracted attention. TSV can increase the density of semiconductor mounting, has an extremely fast access speed, and is excellent in releasing heat generated during use.
In manufacturing such a TSV, it is necessary to perform a high-temperature processing process of 200 ° C. or higher, such as bumping a thin film wafer obtained by grinding, bump formation on the back surface, or reflow during three-dimensional lamination. It becomes. Therefore, the pressure-sensitive adhesive composition used in the TSV manufacturing process is required to have heat resistance capable of maintaining adhesion even at a high temperature of about 250 ° C. in addition to high adhesion easy peeling.

As a pressure-sensitive adhesive composition that achieves high adhesion and easy peeling, PTL 1 discloses a pressure-sensitive adhesive tape that uses a photo-curable pressure-sensitive adhesive that is cured by irradiation with light such as ultraviolet rays to reduce its adhesive strength. . It is said that such an adhesive tape can reliably fix the semiconductor during the processing step and can be easily peeled off by irradiating ultraviolet rays or the like. However, the pressure-sensitive adhesive tape described in Patent Document 1 has insufficient reduction in adhesive strength after irradiation with ultraviolet rays and the like, and it has been difficult to peel the film without damaging the thin film wafer, the semiconductor chip, or the like.

Patent Document 2 discloses a heat-peelable pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing thermally expandable microspheres. When the heat-peelable pressure-sensitive adhesive sheet of Patent Document 2 is heated to a certain temperature or more, the thermally expandable microspheres expand, the entire pressure-sensitive adhesive layer is foamed and irregularities are formed on the surface, and the adhesion area with the adherend is reduced. Therefore, the adherend can be easily peeled off. However, in the heat-peelable pressure-sensitive adhesive sheet described in Patent Document 2, the heat-expandable microspheres are expanded by heating, and fine irregularities are generated on the pressure-sensitive adhesive surface. The surface that adheres to the adherend due to this shape change develops stress that peels off the adhesive layer from the adherend during the expansion process, and the peeling progresses, but the fine irregularities become point adherence to the adherend. Since the adhesive force remains, it is difficult to peel the thin film wafer or the semiconductor chip without damaging them. In addition, there is also a problem that glue remains on the surface of the peeled adherend. Furthermore, even when heat-expandable microspheres having relatively high heat resistance are used, they have only heat resistance of about 130 ° C. and are difficult to use in the TSV manufacturing process.

Patent Document 3 describes a double-sided pressure-sensitive adhesive tape having an adhesive layer containing a gas generating agent that generates a gas by stimulation with an azo compound or the like. When the double-sided pressure-sensitive adhesive tape of Patent Document 3 is stimulated, gas generated from the gas generating agent is released to the interface between the surface of the tape and the adherend, and at least a part of the adherend is peeled off by the pressure. If the double-sided adhesive tape of patent document 3 is used, it can peel, without damaging a thin film wafer, a semiconductor chip, etc., and without the adhesive residue. However, the double-sided pressure-sensitive adhesive tape of Patent Document 3 also has a problem in terms of heat resistance, and it has been difficult to use it in the TSV manufacturing process.

At present, the TSV manufacturing process uses a pressure-sensitive adhesive containing light absorber fine particles such as carbon black, and uses laser-induced heat to decompose and separate the pressure-sensitive adhesive ( Non-patent document 1). However, in order to use the technique of Non-Patent Document 1, there is a problem of equipment that a laser irradiation device is required, and in addition, the fine particle powder is scattered by the decomposition of the adhesive by laser irradiation, and the cleanliness of the manufacturing environment There was a problem of lowering.

JP-A-5-32946 JP-A-11-166164 JP 2003-231872 A

The present invention relates to a pressure-sensitive adhesive composition that has high adhesive strength but can be easily peeled off and is excellent in heat resistance, a pressure-sensitive adhesive tape using the pressure-sensitive adhesive composition, and a wafer processing method using the pressure-sensitive adhesive tape The purpose is to provide.

The present invention is a pressure-sensitive adhesive composition comprising a photocurable pressure-sensitive adhesive component, a photopolymerization initiator, and a gas generating agent that generates gas when irradiated with light, wherein the gas generating agent is a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition is dispersed in the adhesive composition with a dispersion diameter of 0.05 to 37 μm.
The present invention is described in detail below.

In the pressure-sensitive adhesive containing a gas generating agent that generates a gas by stimulation of an azo compound or the like described in Patent Document 3 or the like, it is essential that the gas generating agent is dissolved in the pressure-sensitive adhesive. . This is because if the gas generating agent is not dissolved in the adhesive, when the gas is generated from the gas generating agent at the time of peeling, the gas generating agent itself becomes the core and the entire adhesive is foamed. This is because the properties of the adhesive may be reduced or adhesive residue may be caused.
However, when the inventor selects an incompatible gas generator as the pressure-sensitive adhesive component and disperses the solid gas-generating agent in the pressure-sensitive adhesive composition, the inventor generates gas in the pressure-sensitive adhesive composition. It has been found that the heat resistance is clearly improved as compared with the case where the agent is dissolved. In particular, when a compound having a relatively high thermal decomposition temperature, such as a bistetrazole compound or a salt thereof described later, high heat resistance that does not decompose even at a high temperature of about 250 ° C. can be exhibited. This is presumably because the material state is more stable when the gas generating agent is dispersed in a solid state than when the gas generating agent is dissolved.
And even when an incompatible gas generating agent is used for such an adhesive component, the present inventor makes the adhesive component a photo-curing type and has sufficient adhesion to the adherend after irradiation with light. It was found that the pressure-sensitive adhesive can be easily peeled without foaming, and the present invention has been completed.

The pressure-sensitive adhesive composition of the present invention contains a photocurable pressure-sensitive adhesive component.
The photocurable pressure-sensitive adhesive component (hereinafter also simply referred to as “pressure-sensitive adhesive component”) is not particularly limited, and a conventionally known one can be used. Specific examples include a photocurable pressure-sensitive adhesive containing a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule.
Such a photocurable pressure-sensitive adhesive is uniformly and quickly polymerized and cross-linked by light irradiation, so that the elastic modulus is remarkably increased due to polymerization and curing, and the adhesive strength is greatly reduced.

The polymerizable polymer is prepared by, for example, previously synthesizing a (meth) acrylic polymer having a functional group in the molecule (hereinafter referred to as a functional group-containing (meth) acrylic polymer) It can be obtained by reacting with a compound having a reactive functional group and a radical polymerizable unsaturated bond (hereinafter referred to as a functional group-containing unsaturated compound).

The functional group-containing (meth) acrylic polymer is an acrylic polymer having an alkyl group usually in the range of 2 to 18 as a polymer having adhesiveness at room temperature, as in the case of general (meth) acrylic polymers. By copolymerizing an acid alkyl ester and / or methacrylic acid alkyl ester as a main monomer, a functional group-containing monomer, and, if necessary, another modifying monomer copolymerizable therewith by a conventional method It is obtained. The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000.

Examples of the functional group-containing monomer include a carboxyl group-containing monomer such as acrylic acid and methacrylic acid; a hydroxyl group-containing monomer such as hydroxyethyl acrylate and hydroxyethyl methacrylate; and an epoxy group containing glycidyl acrylate and glycidyl methacrylate. Monomers; Isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate; and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate.
Examples of other modifying monomers that can be copolymerized include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

The functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer is the same as the functional group-containing monomer described above according to the functional group of the functional group-containing (meth) acrylic polymer. it can. For example, when the functional group of the functional group-containing (meth) acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used, and when the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used, and when the functional group is an amino group, an epoxy group-containing monomer is used.

The (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule may be used in combination with a polyfunctional oligomer or monomer.
The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5, so that the three-dimensional network of the pressure-sensitive adhesive layer can be efficiently formed by heating or light irradiation. 000 or less and the number of radically polymerizable unsaturated bonds in the molecule is 2 to 20. As such more preferred polyfunctional oligomers or monomers, for example, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate Or the above-mentioned methacrylates etc. are mentioned. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and methacrylates similar to those described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The pressure-sensitive adhesive composition of the present invention contains a photopolymerization initiator.
Examples of the photopolymerization initiator include those activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such a photopolymerization initiator include acetophenone derivative compounds such as methoxyacetophenone. Benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether; ketal derivative compounds such as benzyldimethyl ketal and acetophenone diethyl ketal; phosphine oxide derivative compounds; bis (η5-cyclopentadienyl) titanocene derivative compounds, benzophenone, Michler's ketone , Chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenyl pro Examples thereof include photo radical polymerization initiators such as bread. These photoinitiators may be used independently and 2 or more types may be used together.

The pressure-sensitive adhesive composition of the present invention contains a gas generating agent that generates gas when irradiated with light.
The gas generating agent is incompatible with the photocurable pressure-sensitive adhesive component and is dispersed in a solid state in the pressure-sensitive adhesive composition. When the gas generating agent is dispersed in a solid state, the pressure-sensitive adhesive composition of the present invention can exhibit higher heat resistance than when the gas generating agent is dissolved.
In the present specification, being incompatible means that particles of 0.005 μm or more can be observed when an adhesive composition is prepared, cured at 40 ° C. for 2 days, and then observed with an electron microscope or the like. means.

The gas generating agent is not particularly limited as long as it is incompatible with the photocurable pressure-sensitive adhesive component. When the photocurable pressure-sensitive adhesive component is a photocurable pressure-sensitive adhesive containing a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule, Examples include tetrazole compounds or salts thereof, triazole compounds or salts thereof, azo compounds, azide compounds, xanthone acetic acid, and carbonates. These gas generating agents may be used independently and may use 2 or more types together. Of these, a tetrazole compound or a salt thereof, or a triazole compound or a salt thereof is preferable. A bistetrazole compound or a salt thereof, which is a kind of a tetrazole compound or a salt thereof, is particularly preferable since it has a high heat resistance and can exhibit a high heat resistance that does not decompose even at a high temperature of about 250 ° C.

Examples of the tetrazole compound include tetrazole compounds represented by the following general formulas (1) to (3).
Examples of the salt of the tetrazole compound include tetrazole compounds represented by the following general formulas (1) to (3) and basic compounds such as amines, hydrazine compounds, quaternary ammonium hydroxide salts, and phosphine compounds. Examples thereof include salts represented by the following general formulas (1 ′) to (3 ′) prepared by mixing in a container.

In the above general formulas (1) to (3), R ¹ and R ² represent hydrogen, a hydroxyl group, an amino group, or an alkyl group having 1 to 7 carbon atoms, an alkene group, a phenyl group, or a mercapto group. The alkyl group having 1 to 7 carbon atoms, alkene group, phenyl group or mercapto group may be substituted. In the case where the alkyl group or the like is substituted, examples of the substituent include an amino group, an alkyl group, an alkene group, a phenyl group, and a mercapto group.

Examples of the salts represented by the general formulas (1 ') to (3') include metal salts such as sodium salts, potassium salts, zinc salts, copper salts, iron salts, ammonium salts, guanidine salts, and the like.

Among the tetrazole compounds represented by the general formulas (1) to (3) and the general formulas (1 ′) to (3 ′) or salts thereof, the maximum value of the molar extinction coefficient at a wavelength of 250 to 400 nm (hereinafter, “Ε _max (250-400)”) is 100 or more, and the weight residual ratio when heated from 100 ° C. to 200 ° C. measured using a thermobalance (hereinafter simply referred to as “weight residual ratio”). When the tetrazole compound or salt thereof is 80% or more, the heat resistance is extremely excellent, and even when light is irradiated using a light source having a relatively small output such as ultraviolet light or white light. Gas (nitrogen gas) can be easily generated. In particular, a tetrazole compound or a salt thereof having a maximum molar extinction coefficient at a wavelength of 270 to 400 nm (hereinafter also referred to as “ε _max (270-400)”) of 100 or more is preferable.

Among the tetrazole compounds represented by the general formulas (1) to (3) and the general formulas (1 ′) to (3 ′) or salts thereof, εmax (250-400) is 100 or more, and εmax (270- 400) is 100 or more and the weight residual ratio is 80% or more, for example, 5-phenyl-1H-tetrazole (401 is εmax (250-400), 401 is εmax (270-400) 401 , Weight residual ratio is 98%), 4,5 ditetrazolyl- [1,2,3] triazole (εmax (250-400) is 629, εmax (270-400) is 605, weight residual ratio is 85%), 1 -(P-Ethoxyphenyl) -5-mercaptotetrazole (εmax (250-400) is 718, εmax (270-400) is 718, weight residual rate is 83 %), 1- (4-benzamide) -5-mercaptotetrazole (εmax (250-400) is 713, εmax (270-400) is 713, weight residual rate is 82%), 5-tolyltetrazole (εmax (250 -400) is 368, εmax (270-400) is 368, weight residual ratio is 99%), 2- (5-tetrazoyl) aniline (εmax (250-400) is 372, εmax (270-400) is 372, Residual weight is 99%), 5- (m-aminophenyl) tetrazole (εmax (250-400) is 301, εmax (270-400) is 301, residual weight is 100%), 5-acetamidotetrazole (Εmax (250-400) is 262, εmax (270-400) is 258, weight residual rate is 100%), N- (1H tet Zol-5-yl) -n-octaneamide (εmax (250-400) is 562, εmax (270-400) is 428, weight residual rate is 98%), 1-cyclohexyl-5-chlorobutyltetrazole (εmax ( 250-400) is 304, εmax (270-400) is 262, and the weight residual ratio is 82%).

Among the tetrazole compounds represented by the general formulas (1) to (3) and the general formulas (1 ′) to (3 ′) or salts thereof, εmax (270-400) is less than 100. The tetrazole compound or salt thereof in which (250-400) is 100 or more and the weight residual ratio is 80% or more is, for example, a bistetrazole piperazine salt (εmax (250-400) is 606, weight residual ratio is 98%) Bistetrazole ammonium salt (εmax (250-400) is 473, weight residual rate is 99%), bistetrazole disodium salt (εmax (250-400) is 320, weight residual rate is 100%), bistetrazole monohydride Rate (εmax (250-400) is 402, weight residual rate is 98%), bistetrazole monoammonium (εmax 250-400) 506, weight residual rate 97%), 5-aminotetrazole monohydrate (εmax (250-400) 299, weight residual rate 83%), 5-aminomethyl-1H-tetrazole (εmax (250-400) is 282, weight residual rate is 82%), 1-methyl-5-mercaptotetrazole (εmax (250-400) is 364, εmax (270-400) is 364, weight residual rate is 80%) Etc.

In this specification, the molar extinction coefficient means that 10 mg of tetrazole compound or a salt thereof is weighed and dissolved in a mixed solvent of 5 mL of methyl alcohol and 5 mL of 1N sodium hydroxide aqueous solution, and a spectrophotometer (for example, Hitachi It means a value obtained by measuring an absorption spectrum in a wavelength range of 200 to 600 nm according to the following formula using U-3000) manufactured by Seisakusho and using the absorbance in the obtained absorption spectrum to calculate by the following formula.
ε = A / c × d
(In the formula, ε represents the molar extinction coefficient, A represents the absorbance, c represents the molar concentration, and d represents the cell thickness.)
In the present specification, the maximum value of the molar extinction coefficient at a wavelength of 250 to 400 nm is 100 or more as long as the molar extinction coefficient at any wavelength between the wavelengths of 250 nm and 400 nm is 100 or more. It is not necessary that a peak of the molar extinction coefficient exists between wavelengths of 250 nm to 400 nm.

The weight residual rate is determined by, for example, weighing 5 to 10 mg of a tetrazole compound or a salt thereof in an aluminum pan of a thermobalance (eg, TG / DTA6200 manufactured by SII), and heating in an air atmosphere (flow rate 200 mL / min). It can be obtained by measuring the weight loss rate when the temperature is raised from room temperature (30 ° C.) to 400 ° C. under the condition of 5 ° C./min.
Here, “from 100 ° C.” is used to eliminate the influence of water adsorbed on the tetrazole compound or a salt thereof.

The gas generating agent is dispersed in the pressure-sensitive adhesive composition with a dispersion diameter of 0.05 to 37 μm. If the dispersion diameter of the gas generating agent is less than 0.05 μm, the effect of improving the heat resistance to the extent that it can withstand a heat treatment step of about 250 ° C. cannot be obtained. When the dispersion diameter of the gas generating agent exceeds 37 μm, the generation of gas when irradiated with light is non-uniform, and there is a possibility that poor peeling occurs. Moreover, the adhesive force of an adhesive composition may be impaired. In particular, when the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of the present invention is formed on at least one surface of the substrate as described later, when the dispersion diameter of the gas generating agent is larger than the thickness of the pressure-sensitive adhesive layer, The adhesive strength is significantly reduced. The preferable lower limit of the dispersion diameter of the gas generating agent is 0.1 μm, the preferable upper limit is 10.0 μm, and the more preferable upper limit is 5.0 μm.

In this specification, the dispersion diameter of the gas generating agent in the pressure-sensitive adhesive composition is the D50 particle diameter measured by the following method (when the gas generating agent particles are divided into two from a certain particle diameter, the larger side). And the smaller side means an equivalent particle diameter, generally also referred to as “median diameter”).
That is, the pressure-sensitive adhesive composition was placed in a solvent capable of dissolving the photocurable pressure-sensitive adhesive component, stirred for 24 hours to dissolve the pressure-sensitive adhesive component, and then dispersed for 1 hour using an ultrasonic irradiator. The solution is filtered through a 50 μm mesh to separate the gas generant particles. The separated gas generating agent is measured using a laser diffraction / scattering particle size distribution analyzer (for example, LA-950, manufactured by HORIBA), and the D50 particle size is calculated.

The content of the gas generating agent is such that a preferable lower limit with respect to 100 parts by weight of the pressure-sensitive adhesive component is 5 parts by weight, and a preferable upper limit is 50 parts by weight. If the content of the gas generating agent is less than 5 parts by weight, gas generation due to light irradiation may be reduced and sufficient peeling may not be performed. If the content exceeds 50 parts by weight, the adhesive strength is reduced. It may end up. The minimum with more preferable content of the said gas generating agent is 10 weight part, and a more preferable upper limit is 30 weight part.

The pressure-sensitive adhesive composition of the present invention may contain a photosensitizer.
Since the photosensitizer has an effect of amplifying stimulation by light on the gas generating agent, gas can be released by irradiation with less light. In addition, gas can be emitted by light in a wider wavelength region.

The photosensitizer is not particularly limited as long as it has excellent heat resistance.
Examples of the photosensitizer excellent in heat resistance include polycyclic aromatic compounds having at least one alkoxy group. Among these, a substituted alkoxy polycyclic aromatic compound having an alkoxy group partially substituted with a glycidyl group or a hydroxyl group is preferable. These photosensitizers have high resistance to sublimation and can be used at high temperatures.

The polycyclic aromatic compound is preferably an anthracene derivative. The alkoxy group preferably has 1 to 18 carbon atoms, and more preferably has 1 to 8 carbon atoms.

Examples of the polycyclic aromatic compound having at least one alkoxy group include 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 2-tbutyl-9,10-dimethoxyanthracene, 2, 3-dimethyl-9,10-dimethoxyanthracene, 9-methoxy-10-methylanthracene, 9,10-diethoxyanthracene, 2-ethyl-9,10-diethoxyanthracene, 2-tbutyl-9,10-di Ethoxyanthracene, 2,3-dimethyl-9,10-diethoxyanthracene, 9-ethoxy-10-methylanthracene, 9,10-dipropoxyanthracene, 2-ethyl-9,10-dipropoxyanthracene, 2-tbutyl -9,10-dipropoxyanthracene, 2,3-dimethyl-9, 0-dipropoxyanthracene, 9-isopropoxy-10-methylanthracene, 9,10-dibutoxyanthracene, 9,10-dibenzyloxyanthracene, 2-ethyl-9,10-dibenzyloxyanthracene, 2-tbutyl -9,10-dibenzyloxyanthracene, 2,3-dimethyl-9,10-dibenzyloxyanthracene, 9-benzyloxy-10-methylanthracene, 9,10-di-α-methylbenzyloxyanthracene, 2- Ethyl-9,10-di-α-methylbenzyloxyanthracene, 2-tbutyl-9,10-di-α-methylbenzyloxyanthracene, 2,3-dimethyl-9,10-di-α-methylbenzyloxy Anthracene, 9- (α-methylbenzyloxy) -10-methylanthracase , 9,10-di (2-hydroxyethoxy) anthracene, and the like anthracene derivative such as 2-ethyl-9,10-di (2-carboxyethoxy) anthracene.

The substituted alkoxy polycyclic aromatic compound having an alkoxy group partially substituted with a glycidyl group or a hydroxyl group includes, for example, 9,10-di (glycidyloxy) anthracene, 2-ethyl-9,10-di (glycidyloxy) ) Anthracene, 2-tbutyl-9,10-di (glycidyloxy) anthracene, 2,3-dimethyl-9,10-di (glycidyloxy) anthracene, 9- (glycidyloxy) -10-methylanthracene, 9, 10-di (2-vinyloxyethoxy) anthracene, 2-ethyl-9,10-di (2-vinyloxyethoxy) anthracene, 2-tbutyl-9,10-di (2-vinyloxyethoxy) anthracene, 2 , 3-Dimethyl-9,10-di (2-vinyloxyethoxy) anthracene, 9- (2-vinyloxy) Ethoxy) -10-methylanthracene, 9,10-di (3-methyl-3-oxetanylmethoxy) anthracene, 2-ethyl-9,10-di (3-methyl-3-oxetanylmemethoxy) anthracene, 2-t Butyl-9,10-di (3-methyl-3-oxetanylmemethoxy) anthracene, 2,3-dimethyl-9,10-di (3-methyl-3-oxetanylmemethoxy) anthracene, 9- (3-methyl -3-Oxetanylmemethoxy) -10-methylanthracene, 9,10-di (p-epoxyphenylmethoxy) anthracene, 2-ethyl-9,10-di (p-epoxyphenylmethoxy) anthracene, 2-tbutyl- 9,10-di (p-epoxyphenylmethoxy) anthracene, 2,3-dimethyl-9,10-di (p-ethylene) Xylphenylmethoxy) anthracene, 9- (p-epoxyphenylmethoxy) -10-methylanthracene, 9,10-di (p-vinylphenylmethoxy) anthracene, 2-ethyl-9,10-di (p-vinylphenylmethoxy) ) Anthracene, 2-tbutyl-9,1-di (p-vinylphenylmethoxy) anthracene, 2,3-dimethyl-9,10-di (p-vinylphenylmethoxy) anthracene, 9- (p-vinylphenylmethoxy) ) -10-methylanthracene, 9,10-di (2-hydroxyethoxy) anthracene, 9,10-di (2-hydroxypropoxy) anthracene, 9,10-di (2-hydroxybutoxy) anthracene, 9,10- Di (2-hydroxy-3-butoxypropoxy) anthracene, 9,10-di (2-hydroxy-3- (2-ethylhexyloxy) propoxy) anthracene, 9,10-di (2-hydroxy-3-allyloxypropoxy) anthracene, 9,10-di (2-hydroxy-3-phenoxypropoxy) Anthracene, 9,10-di (2,3-dihydroxypropoxy) anthracene and the like can be mentioned.

The content of the photosensitizer is preferably 0.05 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive component. When the content of the photosensitizer is less than 0.05 parts by weight, a sufficient sensitizing effect may not be obtained. When the content exceeds 10 parts by weight, the residue derived from the photosensitizer increases. , Sufficient peeling may not be performed. The minimum with more preferable content of the said photosensitizer is 0.1 weight part, and a more preferable upper limit is 5 weight part.

The pressure-sensitive adhesive composition of the present invention preferably contains a silicone compound having a functional group capable of crosslinking with the pressure-sensitive adhesive component (hereinafter also simply referred to as “silicone compound A”).
Since the silicone compound is excellent in heat resistance, the adhesive is prevented from being burnt even after a high temperature processing process of 200 ° C. or higher, and at the time of peeling, it bleeds out to the adherend interface to facilitate peeling. Thereby, it can suppress more effectively that the whole adhesive composition foams with the gas generated from the gas generating agent at the time of peeling.
In addition, since the silicone compound has a functional group capable of cross-linking with the pressure-sensitive adhesive component, it is incorporated into the pressure-sensitive adhesive component by chemically reacting with the pressure-sensitive adhesive component by light irradiation at the time of peeling. Silicone compounds do not adhere and become contaminated. In addition, when one of the adherends is a support plate made of a glass plate, by adding a silicone compound having a functional group capable of crosslinking with the above-mentioned pressure-sensitive adhesive component, the affinity for the support plate is improved. The effect of preventing adhesive residue on the skin is also exhibited.

The silicone skeleton of the silicone compound A is not particularly limited, and may be either D-form or DT-form.
The silicone compound A preferably has the functional group at the side chain or terminal of the silicone skeleton.
In particular, the use of a silicone compound having a D-form silicone skeleton and having a functional group capable of crosslinking with the above-mentioned pressure-sensitive adhesive component at the end achieves both high initial adhesive strength and peeling strength after a high-temperature processing process. It is preferable because it is easy.

As the functional group of the silicone compound A, an appropriate one is selected and used according to the pressure-sensitive adhesive component. For example, when the pressure-sensitive adhesive component is a photocurable pressure-sensitive adhesive mainly composed of a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule, (meth) A functional group capable of crosslinking with an acrylic group is selected.
The functional group capable of crosslinking with the (meth) acryl group is a functional group having an unsaturated double bond, and specific examples include a vinyl group, a (meth) acryl group, an allyl group, and a maleimide group. .

The functional group equivalent of the silicone compound A is not particularly limited, but the preferred lower limit is 1, and the preferred upper limit is 20. When the functional group equivalent is less than 1, the silicone compound A is not sufficiently taken into the pressure-sensitive adhesive component when the resulting pressure-sensitive adhesive composition is cured, and the adherend is contaminated or exhibits sufficient peelability. If it exceeds 20, sufficient adhesive strength may not be obtained. A more preferable upper limit of the functional group equivalent is 10, a more preferable lower limit is 2, and a more preferable upper limit is 6.

The molecular weight of the silicone compound A is not particularly limited, but a preferred lower limit is 300 and a preferred upper limit is 50000. If the molecular weight is less than 300, the resulting pressure-sensitive adhesive composition may have insufficient heat resistance, and if it exceeds 50,000, mixing with the pressure-sensitive adhesive component may be difficult. The more preferable lower limit of the molecular weight is 400, the more preferable upper limit is 10,000, the still more preferable lower limit is 500, and the more preferable upper limit is 5000.

The method of synthesizing the silicone compound A is not particularly limited. For example, by reacting a silicone resin having a SiH group with a vinyl compound having a functional group capable of crosslinking with the pressure-sensitive adhesive component, a hydrosilylation reaction is performed. Examples thereof include a method of introducing a functional group capable of crosslinking with the pressure-sensitive adhesive component into the silicone resin, and a method of causing a condensation reaction between the siloxane compound and a siloxane compound having a functional group capable of crosslinking with the pressure-sensitive adhesive component.

Commercially available silicone compounds A include, for example, X-22-164, X-22-164AS, X-22-164A, X-22-164B, X-22-164C manufactured by Shin-Etsu Chemical Co., Ltd. , X-22-164E and other silicone compounds having methacrylic groups at both ends, and X-22-174DX, X-22-2426, X-22-2475 manufactured by Shin-Etsu Chemical Co., Ltd. Silicone compounds having acrylic groups such as EBECRYL350 and EBECRYL1360 manufactured by Daicel-Cytec, and silicone compounds having acrylic groups such as AC-SQ TA-100 and AC-SQ SI-20 manufactured by Toagosei Co., Ltd. MAC-SQ TM-100, MAC-SQ SI-20, MAC manufactured by Toagosei Co., Ltd. Silicone compounds having a methacryl group such as SQ HDM like.

Among these, the silicone compound A has particularly high heat resistance and high polarity, so that bleeding out from the pressure-sensitive adhesive composition is easy. Therefore, the following general formula (I), general formula (II), and general formula A silicone compound represented by (III) having a (meth) acryl group in the siloxane skeleton is preferred.

In the formula, X and Y represent an integer of 0 to 1200, and R represents a functional group having an unsaturated double bond.

Of the silicone compounds having a (meth) acryl group in the siloxane skeleton represented by the above general formula (I), general formula (II), or general formula (III), commercially available products are, for example, Daicel Cytec Examples thereof include EBECRYL350, EBECRYL1360 (both of which R is an acrylic group).

Although content of the said silicone compound A is not specifically limited, A preferable minimum is 0.1 weight% and a preferable upper limit is 30 weight%. If the content of the silicone compound A is less than 0.1% by weight, it may not be peeled from the adherend, and if it exceeds 30% by weight, the initial adhesive strength may not be obtained. The more preferable lower limit of the content of the silicone compound A is 0.2% by weight, and the more preferable upper limit is 20% by weight.

The content of the silicone compound A is preferably 0.5 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive component, and 40 parts by weight with a preferred upper limit. When the content of the silicone compound A is less than 0.5 parts by weight, the adhesive strength may not be sufficiently reduced even when irradiated with light, and may not be peeled off from the adherend. May cause body contamination. The more preferable lower limit of the content of the silicone compound A is 1 part by weight, and the more preferable upper limit is 30 parts by weight.

The pressure-sensitive adhesive composition of the present invention may appropriately contain various polyfunctional compounds that are blended with general pressure-sensitive adhesives such as isocyanate compounds, melamine compounds, and epoxy compounds for the purpose of adjusting the cohesive force. In addition, known additives such as an antistatic agent, a plasticizer, a resin, a surfactant, a wax, and a fine particle filler can be added. Furthermore, you may mix | blend a heat stabilizer and antioxidant in order to improve stability of an adhesive.

The method for producing the pressure-sensitive adhesive composition of the present invention is not particularly limited. For example, the pressure-sensitive adhesive component, the photopolymerization initiator, the gas generating agent, and the silicone compound to be blended as necessary are mixed with a bead mill, an ultrasonic wave. Examples of the method include mixing using a dispersion, a homogenizer, a high output disper, a roll mill, and the like.
The method of dispersing the gas generating agent in the pressure-sensitive adhesive composition with a dispersion diameter of 0.05 to 37 μm is not particularly limited, but the gas generating agent is finely pulverized in advance and classified by a sieve of each mesh size. Examples thereof include a method of adjusting the particle diameter to 0.05 to 37 μm and then mixing with the above-mentioned pressure-sensitive adhesive component. In particular, the dispersion method is also important for fine dispersion so that the dispersion diameter is 30 μm or less. For example, when kneading using a bead mill, the dispersion diameter of the gas generating agent can be reduced by increasing the rotation speed of the bead mill, increasing the dispersion time, or reducing the particle diameter of the beads. Can be adjusted.

While the pressure-sensitive adhesive composition of the present invention has a high initial adhesive strength, it can be easily peeled off by irradiation with light such as ultraviolet rays. Since the pressure-sensitive adhesive composition of the present invention is particularly excellent in heat resistance, the wafer is fixed to the support plate in the TSV manufacturing process, the wafer or chip is temporarily fixed to the support plate when passing through a reflow furnace, etc. It can also be used in applications where high-temperature treatment at 220 to 270 ° C., preferably 230 to 260 ° C.

The pressure-sensitive adhesive composition of the present invention can be used for various adhesive products.
The adhesive product is, for example, an adhesive, a pressure-sensitive adhesive, a paint, a coating agent, a sealing agent or the like using the pressure-sensitive adhesive composition of the present invention as a binder resin, or the pressure-sensitive adhesive composition of the present invention as a pressure-sensitive adhesive. Examples thereof include adhesive tapes such as single-sided adhesive tape, double-sided adhesive tape, and non-support tape (self-supporting tape). Among them, a support plate fixing tape at high temperature processing, a fixing tape for both high temperature processing and back grinding, a fixing tape for high temperature processing and dicing, and used for further high temperature processing of individual semiconductor chips. It is suitable for a semiconductor chip temporary fixing tape or the like.

An adhesive tape having an adhesive layer made of the adhesive composition of the present invention on at least one surface of the substrate is also one aspect of the present invention.
The base material is, for example, a sheet made of a transparent resin such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, polyimide, or a network structure. And a sheet having a hole and the like.

The method for producing the pressure-sensitive adhesive tape of the present invention is not particularly limited. For example, a conventionally known method such as coating the above-mentioned pressure-sensitive adhesive or the like on a base material using a doctor knife, a spin coater or the like can be used. .

The pressure-sensitive adhesive composition of the present invention is intended to facilitate handling of a wafer and prevent damage during processing of a wafer including a high-temperature processing process of about 250 ° C., more specifically, 220 to 270 ° C. It is suitable as an adhesive for fixing the wafer to the support plate.
A support plate fixing step of fixing the wafer to the support plate via the pressure-sensitive adhesive composition of the present invention, a wafer processing step of subjecting the surface of the wafer fixed to the support plate to a treatment involving heating at 220 to 270 ° C., A wafer processing method is also included in the present invention, which includes a support plate peeling step of irradiating the treated wafer with light to cure the pressure-sensitive adhesive composition and peeling the support plate from the wafer.

The said support plate is not specifically limited, For example, a glass plate, a quartz glass plate, a stainless steel plate etc. are mentioned.
A process involving heating at about 250 ° C. on the surface of the wafer fixed to the support plate is not particularly limited, and examples thereof include chemical vapor deposition (CVD), reflow, reactive ion etching (RIE), and the like.

ADVANTAGE OF THE INVENTION According to this invention, while having high adhesive force, it can peel easily and is excellent in heat resistance, the adhesive tape using this adhesive composition, and the wafer using this adhesive tape A processing method can be provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared. In this reactor, 94 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of acrylic acid, 5 parts by weight of 2-hydroxyethyl acrylate, 0.01% lauryl mercaptan After adding parts by weight and 80 parts by weight of ethyl acetate, the reactor was heated to start refluxing. Subsequently, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added as a polymerization initiator in the reactor, and polymerization was started under reflux. It was. Next, after 1 hour and 2 hours from the start of polymerization, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added, and the polymerization was started. 4 hours later, 0.05 part by weight of t-hexylperoxypivalate was added to continue the polymerization reaction. And 8 hours after the start of polymerization, an acrylic copolymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained.

3.5 parts by weight of 2-isocyanatoethyl methacrylate was added to and reacted with 100 parts by weight of the resin solid content of the resulting ethyl acetate solution containing the acrylic copolymer. Furthermore, with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution after the reaction, 1 part by weight of a photopolymerization initiator (Esacure One, manufactured by Nippon Shibel Hegner), 5 parts by weight of a silicone compound (EBECRYL 350, manufactured by Daicel Cytec), 20 parts by weight of bistetrazole sodium salt and 0.5 parts by weight of a polyisocyanate crosslinking agent (Coronate L45, manufactured by Nippon Polyurethane Co., Ltd.) were added to prepare an ethyl acetate solution of the pressure-sensitive adhesive composition.
The bistetrazole sodium salt was finely pulverized in advance and then classified with a sieve having a mesh size of 100 μm, and added to ethyl acetate. Using a bead mill (produced by AIMEX, RMB-08), the rotational speed was 1000 rpm, 12 What was disperse | distributed on condition of time was used.

A doctor knife so that the ethyl acetate solution of the obtained pressure-sensitive adhesive composition has a dry film thickness of 30 μm on the corona-treated surface of a transparent polyethylene naphthalate film having a thickness of 50 μm that has been corona-treated on one side. The coating solution was dried by heating at 110 ° C. for 5 minutes. Thereafter, static curing was performed at 40 ° C. for 3 days to obtain an adhesive tape.

The obtained adhesive tape was cut finely. 1 g of the cut adhesive tape is placed in 5 mL of a solvent capable of dissolving the acrylic copolymer, and stirred for 24 hours to dissolve the adhesive component, and then an ultrasonic irradiator (manufactured by ASONE, VS-100III) is used. Then, the solution dispersed for 1 hour was filtered through a 50 μm mesh to separate particles of bistetrazole sodium salt. When the separated bistetrazole sodium salt was measured using a laser diffraction / scattering particle size distribution analyzer (HORIBA, LA-950), the dispersion diameter of bistetrazole sodium salt (D50 particle size) was 0.7 μm. Met.

(Example 2)
An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that bistetrazole ammonium salt was blended instead of bistetrazole sodium salt.
The bistetrazole ammonium salt was finely pulverized in advance and classified with a sieve having a mesh size of 100 μm, and the mixture was added to ethyl acetate. Using a bead mill (produced by AIMEX, RMB-08), the rotational speed was 1000 rpm, 12 What was disperse | distributed on condition of time was used.
When the dispersion diameter (D50 particle diameter) of the bistetrazole ammonium salt was calculated | required by the method similar to Example 1 about the obtained adhesive tape, it was 0.7 micrometer.

(Example 3)
An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that a bistetrazole piperazine salt was added instead of the bistetrazole sodium salt.
The bistetrazole piperazine salt was finely pulverized in advance and classified with a sieve having a mesh size of 100 μm, and the mixture was added to ethyl acetate. Using a bead mill (produced by AIMEX, RMB-08), the rotational speed was 1000 rpm, 12 What was disperse | distributed on condition of time was used.
When the dispersion diameter (D50 particle diameter) of the bistetrazole piperazine salt was determined for the obtained adhesive tape by the same method as in Example 1, it was 0.7 μm.

(Example 4)
As bistetrazole sodium salt, finely pulverized in advance and classified with a sieve having a mesh size of 100 μm was added to ethyl acetate, and a bead mill (produced by AIMEX, RMB-08) was used at a rotational speed of 1000 rpm for 24 hours. An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that those dispersed under conditions were used.
When the dispersion diameter (D50 particle diameter) of the bistetrazole sodium salt was calculated | required by the method similar to Example 1 about the obtained adhesive tape, it was 0.4 micrometer.

(Example 5)
As bistetrazole sodium salt, finely pulverized in advance and classified with a sieve having a mesh size of 100 μm was added to ethyl acetate, and a bead mill (manufactured by AIMEX, RMB-08) was rotated at 1500 rpm for 30 hours. An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that those dispersed under conditions were used.
With respect to the obtained pressure-sensitive adhesive tape, the dispersion diameter (D50 particle diameter) of bistetrazole sodium salt was determined in the same manner as in Example 1. As a result, it was 0.1 μm.

(Example 6)
As bistetrazole sodium salt, finely pulverized in advance and classified with a sieve having a mesh size of 100 μm was added to ethyl acetate, and the mixture was rotated at 3000 rpm for 48 hours using a bead mill (RIM-08 manufactured by AIMEX). An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that those dispersed under conditions were used.
With respect to the obtained pressure-sensitive adhesive tape, the dispersion diameter (D50 particle diameter) of bistetrazole sodium salt was determined in the same manner as in Example 1. As a result, it was 0.05 μm.

(Example 7)
As bistetrazole sodium salt, finely pulverized in advance and classified with a sieve having a mesh size of 100 μm was added to ethyl acetate, and a bead mill (manufactured by AIMEX, RMB-08) was used at a rotational speed of 1000 rpm for 30 minutes. An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that those dispersed under conditions were used.
About the obtained adhesive tape, when the dispersion diameter (D50 particle diameter) of the bistetrazole sodium salt was calculated | required by the method similar to Example 1, it was 5 micrometers.

(Example 8)
Bistetrazole sodium salt, which was finely pulverized in advance and classified with a sieve having a mesh size of 100 μm, was added to ethyl acetate, and a bead mill (manufactured by AIMEX, RMB-08) was used for 15 minutes at a rotation speed of 1000 rpm. An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that those dispersed under conditions were used.
When the dispersion diameter (D50 particle diameter) of the bistetrazole sodium salt was calculated | required by the method similar to Example 1 about the obtained adhesive tape, it was 10 micrometers.

Example 9
An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that the bistetrazole sodium salt was finely pulverized in advance and then classified with a sieve having a mesh size of 40 μm.
With respect to the obtained pressure-sensitive adhesive tape, the dispersion diameter (D50 particle diameter) of bistetrazole sodium salt was determined in the same manner as in Example 1. As a result, it was 37 μm.

(Example 10)
An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that 5- (m-aminophenyl) tetrazole was added instead of bistetrazole sodium salt.
The 5- (m-aminophenyl) tetrazole used was finely pulverized in advance and classified with a sieve having a mesh size of 100 μm.
With respect to the obtained adhesive tape, the dispersion diameter (D50 particle diameter) of 5- (m-aminophenyl) tetrazole was determined in the same manner as in Example 1. As a result, it was 9 μm.

(Comparative Example 1)
An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that bistetrazole sodium salt was not blended.

(Comparative Example 2)
A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared. In this reactor, 85 parts by weight of 2-ethylhexyl acrylate, 2.5 parts by weight of acrylic acid, 2.5 parts by weight of 2-hydroxyethyl acrylate, dimethyl After 10 parts by weight of aminoethyl acrylate, 0.01 parts by weight of lauryl mercapcaptan and 180 parts by weight of ethyl acetate were added, the reactor was heated to start refluxing. Subsequently, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added as a polymerization initiator in the reactor, and polymerization was started under reflux. It was. Next, after 1 hour and 2 hours from the start of polymerization, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added, and the polymerization was started. 4 hours later, 0.05 part by weight of t-hexylperoxypivalate was added to continue the polymerization reaction. And 8 hours after the start of polymerization, an acrylic copolymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained.

The resin solid content of 100 parts by weight of the ethyl acetate solution containing the acrylic copolymer thus obtained is reacted by adding 3.5 parts by weight of 2-isocyanatoethyl methacrylate, and further the resin of the ethyl acetate solution after the reaction. 1 part by weight of a photopolymerization initiator (Esacure One, manufactured by Nippon Siebel Hegner), 5 parts by weight of a silicone compound (EBECRYL 350, manufactured by Daicel Cytec), and 5- (m-aminophenyl) tetrazole 20 with respect to 100 parts by weight of solid content Part by weight and 0.5 part by weight of a polyisocyanate-based crosslinking agent (Coronate L45, manufactured by Nippon Polyurethane Co., Ltd.) were mixed to prepare an ethyl acetate solution of the pressure-sensitive adhesive composition.

A doctor knife so that the ethyl acetate solution of the obtained pressure-sensitive adhesive composition has a dry film thickness of 30 μm on the corona-treated surface of a transparent polyethylene naphthalate film having a thickness of 50 μm that has been corona-treated on one side. The coating solution was dried by heating at 110 ° C. for 5 minutes. Thereafter, static curing was performed at 40 ° C. for 3 days to obtain an adhesive tape.
As a result of microscopic observation, 5- (m-aminophenyl) tetrazole was dissolved in the pressure-sensitive adhesive layer, and no particles were observed.

(Comparative Example 3)
Instead of 20 parts by weight of bistetrazole sodium salt, 20 parts by weight of 2,2′-azobis- (N-butyl-2-methylpropionamide) is used instead of 1 part by weight of 9,10-diglycidyloxyanthracene. An adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that 3 parts by weight were blended.
As a result of microscopic observation, 2,2′-azobis- (N-butyl-2-methylpropionamide) was dissolved in the pressure-sensitive adhesive layer, and no particles were observed.

(Comparative Example 4)
Bistetrazole sodium salt 20 parts by weight, polyisocyanate-based crosslinking agent for 100 parts by weight of resin solid content of acrylic resin SK Dyne 1495C (manufactured by Soken Kagaku Co., Ltd.), which is a non-photo-curing pressure-sensitive adhesive. (Coronate L45, manufactured by Nippon Polyurethane Co., Ltd.) A pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that 0.5 part by weight was mixed to prepare an ethyl acetate solution of the pressure-sensitive adhesive composition.
The bistetrazole ammonium salt was finely pulverized in advance and classified with a sieve having a mesh size of 100 μm, and the mixture was added to ethyl acetate. Using a bead mill (produced by AIMEX, RMB-08), the rotational speed was 1000 rpm, 12 What was disperse | distributed on condition of time was used.
When the dispersion diameter (D50 particle diameter) of the bistetrazole ammonium salt was calculated | required by the method similar to Example 1 about the obtained adhesive tape, it was 0.7 micrometer.

(Evaluation)
About the adhesive composition and adhesive tape obtained by the Example and the comparative example, it evaluated by the following method.
The results are shown in Table 1.

(1) Adhesive evaluation before heat treatment of adhesive tape, peelability evaluation An adhesive tape cut into a circle having a diameter of 20 cm was attached to a silicon wafer having a diameter of 20 cm and a thickness of about 750 μm. Tempax glass having a diameter of 20 cm and a thickness of 0.7 mm was attached to the surface opposite to the surface attached to the silicon wafer.
As an adhesive evaluation, after placing the silicon wafer on the suction table so that the glass was on the top surface, the glass edge was pulled with a suction cup, and the glass could not be peeled at all. The case was evaluated as “△”, and the case where the film could be peeled almost without resistance was evaluated as “x”.

Next, using an ultrahigh pressure mercury lamp from the glass plate side, ultraviolet rays were irradiated for 2 minutes while adjusting the illuminance so that the irradiation intensity on the glass plate surface was 100 mW / cm ^{2 in} terms of 254 nm. As the evaluation of peelability after light irradiation, after placing the silicon wafer on the suction table so that the glass is on the top surface, the glass edge was pulled with a suction cup, and the case where it was possible to peel off without any resistance was "Good". The case where the product could be peeled was evaluated as “Δ”, and the case where the material was not peeled off was evaluated as “x”.

(2) Adhesive evaluation after heat treatment of adhesive tape, evaluation of peelability An adhesive tape cut into a circle having a diameter of 20 cm was attached to a silicon wafer having a diameter of 20 cm and a thickness of about 750 μm. Tempax glass having a diameter of 20 cm and a thickness of 0.7 mm was attached to the surface opposite to the surface attached to the silicon wafer. The laminate was heated at 250 ° C. for 20 minutes and then returned to room temperature.
For adhesion evaluation, visually observe the heated surface, place the silicon wafer on the suction table so that the glass is on the top surface, and then pull the glass edge with a suction cup to observe the entire surface. "◎" when it was not peeled and could not be peeled at all even when pulled, and "○" when the float was 3% or less of the total area and could not be peeled even when pulled, Although it was 3% or more and 10% or less of the area, it was evaluated as “Δ” when it could not be peeled even when pulled, and “x” when it could be easily peeled off.

Next, using an ultrahigh pressure mercury lamp from the glass plate side, ultraviolet rays were irradiated for 2 minutes while adjusting the illuminance so that the irradiation intensity on the glass plate surface was 100 mW / cm ^{2 in} terms of 254 nm. For evaluation of peelability after light irradiation, after placing the silicon wafer on the suction table so that the glass is on the top surface, when the glass edge is pulled with a suction cup, it peels from the interface between the wafer and the adhesive layer and adheres to the wafer. “◎” when no residue of the adhesive was found, and peeling from the interface between the wafer and the adhesive layer, but a slight stain was found on the wafer side (however, the stain could be removed by washing). “◯” indicates that the film was peeled off but the wafer side was soiled (however, the dirt was removed by washing).
The same evaluation was performed for a case where heat treatment was performed at 260 ° C. for 10 minutes.

Claims

A pressure-sensitive adhesive composition, a photopolymerization initiator, and a pressure-sensitive adhesive composition containing a gas generating agent that generates gas when irradiated with light,
The pressure-sensitive adhesive composition, wherein the gas generating agent is dispersed in the pressure-sensitive adhesive composition with a dispersion diameter of 0.05 to 37 μm.
The pressure-sensitive adhesive composition according to claim 1, wherein the gas generating agent is a tetrazole compound or a salt thereof, or a triazole compound or a salt thereof.
The pressure-sensitive adhesive composition according to claim 1, wherein the gas generating agent is a bistetrazole compound or a salt thereof.
4. The pressure-sensitive adhesive according to claim 1, 2, or 3, wherein the pressure-sensitive adhesive component is a photocurable pressure-sensitive adhesive containing a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond. Agent composition.
The pressure-sensitive adhesive composition according to claim 1, 2, 3, or 4, further comprising a photocurable pressure-sensitive adhesive component and a silicone compound having a crosslinkable functional group.
A pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to claim 1, 2, 3, 4, or 5 on at least one surface of a substrate.
6. A support plate fixing step for fixing a wafer to a support plate via the pressure-sensitive adhesive composition according to claim 1, and heating at 220 to 270 ° C. on the surface of the wafer fixed to the support plate. And a support plate peeling step of irradiating the processed wafer with light, curing the pressure-sensitive adhesive composition, and peeling the support plate from the wafer. Wafer processing method.