JP2012007009A - Adhesive sheet for fixing electronic component - Google Patents

Abstract

[PROBLEMS] To provide a pressure-sensitive adhesive layer which has no adhesive protrusion at room temperature and normal pressure, has sufficient initial adhesive force by drying and crosslinking, is easily cured by light irradiation or heat, and has high peeling resistance. To provide an adhesive sheet for fixing an electronic component that can be formed.
An adhesive composition comprising a (meth) acrylic polymer, a graft polymer obtained by graft polymerization of a chain containing a cyclic ether group-containing monomer, and a photocationic polymerization initiator or a thermosetting catalyst. A pressure-sensitive adhesive sheet for fixing an electronic component comprising a pressure-sensitive adhesive layer formed from a product or having such a pressure-sensitive adhesive layer on both sides of a support is prepared.
[Selection figure] None

Description

  The present invention relates to an adhesive sheet for fixing electronic components. More specifically, the present invention relates to an adhesive sheet for fixing electronic components used in electrical and electronic equipment and semiconductor assembly processes.

  In recent years, adhesive sheets having an acrylic adhesive having excellent heat resistance are widely used as adhesive sheets for fixing integrated and miniaturized electronic components.

  However, acrylic adhesives cannot exhibit high heat resistance and peeling resistance like adhesives. Therefore, various devices have been studied. Attempts have been made to increase the adhesiveness of acrylic adhesive and the heat resistance and peeling resistance by curing epoxy resin by blending an acrylic polymer with an epoxy resin and a curing agent for epoxy resin curing. Has been made.

For example, a curable thermoadhesive sheet including an acrylic polymer, a resin having an epoxy group, a photoinitiator, and a tackifying resin has been proposed (Patent Document 1).

A thermosetting adhesive agent comprising an acidic polymer, an epoxy resin, and an amine-containing compound has also been proposed (Patent Document 2). However, since it contains a low molecular weight epoxy resin or the like, it is difficult to prevent the paste from protruding during temporary attachment.

Further, for example, a thermosetting type that is cured by heat treatment has been proposed. Such a thermosetting adhesive is excellent in adhesive strength and heat resistance, but is not tacky at room temperature bonding and is difficult to temporarily bond. In addition, before curing, there is a problem of glue sticking out at the time of bonding because of the low molecular weight component contained in the adhesive component.

Japanese Patent Laid-Open No. 10-140095 Special table 2003-518153 gazette

The present invention provides a pressure-sensitive adhesive sheet for fixing electronic parts that exhibits moderate tackiness as a pressure-sensitive adhesive at the initial stage of adhesion to an adherend, and exhibits high adhesion and high heat resistance equivalent to those of an adhesive after bonding. The purpose is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found the following adhesive component fixing sheet for electronic parts and have completed the present invention.

  That is, the present invention relates to an adhesive comprising a (meth) acrylic polymer, a graft polymer obtained by graft polymerization of a chain containing a cyclic ether group-containing monomer, and a photocationic polymerization initiator or a thermosetting catalyst. The present invention relates to an adhesive sheet for fixing an electronic component having an adhesive layer formed from a composition.

In the adhesive sheet for fixing electronic parts, the adhesive composition contains the cyclic ether group-containing monomer and other monomers, and the weight ratio of the cyclic ether group-containing monomer: other monomer. , 90:10 to 10:90.

  In the adhesive sheet for fixing an electronic component, the adhesive composition may further contain a crosslinking agent.

  In the adhesive sheet for fixing electronic parts, the adhesive composition may further contain 5 to 100 parts by weight of an epoxy resin and / or an oxetane resin with respect to 100 parts by weight of the graft polymer.

  In the adhesive sheet for fixing an electronic component, the cyclic ether group-containing monomer may be any one or both of an epoxy group-containing monomer and an oxetane group-containing monomer.

In the electronic component fixing adhesive sheet, the glass transition temperature of the (meth) acrylic polymer may be 250K or less.

  In the adhesive sheet for fixing an electronic component, the (meth) acrylic polymer may contain 0.2 to 10% by weight of a hydroxyl group-containing monomer as a monomer unit with respect to the total amount of the (meth) acrylic polymer.

The graft polymer is composed of 2 to 50 parts by weight of the cyclic ether group-containing monomer and 5 to 50 parts by weight of the other monomer to 100 parts by weight of the (meth) acrylic polymer, and 0.02 to 5 parts by weight of peroxide. It can be obtained by graft polymerization in the presence.

  The thermosetting catalyst may be at least one selected from the group consisting of an imidazole compound, an acid anhydride, a phenol resin, a Lewis acid complex, an amino resin, a polyamine, and a melamine resin.

  The photocationic polymerization initiator may be at least one selected from the group consisting of allylsulfonium hexafluorophosphate salt, sulfonium hexafluorophosphate salt, and bis (alkylphenyl) iodonium hexafluorophosphate. .

  In the above-mentioned adhesive sheet for fixing electronic parts, the adhesive layer may be prepared such that the gel fraction after photocuring or thermosetting is 70 to 98%.

The electronic component fixing adhesive sheet may be formed of only an adhesive layer.

  The electronic component fixing adhesive sheet may have a structure in which an adhesive layer is formed on both sides of the support.

The present invention is also a method for fixing an electronic component using any one of the above-described adhesive components for fixing an electronic component, wherein the adhesive composition includes a photocationic polymerization initiator,
The present invention relates to a method for fixing an electronic component, which includes a step of curing the sheet by applying light to the electronic component after the electronic component fixing adhesive sheet is bonded to the electronic component.

The present invention is also a method for fixing an electronic component using any one of the above-described adhesive sheets for fixing an electronic component, wherein the adhesive composition includes a thermosetting catalyst,
The present invention relates to a method for fixing an electronic component, which includes a step of bonding the adhesive sheet for fixing an electronic component to the electronic component and then curing the sheet by heating.

  The adhesive sheet for fixing an electronic component of the present invention has no adhesive protrusion at room temperature and normal pressure, has sufficient initial adhesive force by drying and crosslinking, and is easily cured by photocuring or thermosetting, and It has an adhesive layer with high peel resistance. The adhesive sheet for fixing an electronic component of the present invention can be applied to an application in which curing is completed by light irradiation or heating after being attached to an adherend before curing.

Furthermore, the adhesive sheet for fixing an electronic component of the present invention has a small deformation of the adhesive even when used at a high temperature, and is excellent in heat resistance.

The adhesive sheet for fixing electronic parts of the present invention comprises a (meth) acrylic polymer, a graft polymer obtained by graft polymerization of a chain containing a cyclic ether group-containing monomer, a photocationic polymerization initiator or a thermosetting catalyst. It has the adhesive layer formed from the adhesive composition formed.

First, as the monomer unit contained in the (meth) acrylic polymer, any (meth) acrylate can be used and is not particularly limited. Here, preferably, for example, an alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms is contained in an amount of 50% by weight or more of the entire (meth) acrylic polymer.

  In the present specification, the term “alkyl (meth) acrylate” simply refers to a (meth) acrylate having a linear or branched alkyl group. The alkyl group has 4 or more carbon atoms, preferably 4 to 9 carbon atoms. (Meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning.

  Specific examples of the alkyl (meth) acrylate include n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, and isopentyl. (Meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl ( (Meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, isomyristyl (meth) acrylate, n-tridecyl (meth) acrylate Rate, n- tetradecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate. Especially, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. can be illustrated and these can be used individually or in combination.

  In this invention, the said alkyl (meth) acrylate is 50 weight% or more with respect to all the monomer components of a (meth) acrylic-type polymer, Preferably it is 80 weight% or more, More preferably, it is 90 weight% or more. Further, all the monomers may be alkyl (meth) acrylates, but are preferably 99% by weight or less, and may be 98% by weight or less or 97% by weight or less.

  In addition to this, it is preferable that the (meth) acrylic polymer of the present invention contains a hydroxyl group-containing monomer containing at least one hydroxyl group in the alkyl group. That is, this monomer is a monomer containing one or more hydroxyalkyl groups. Here, the hydroxyl group is preferably present at the terminal of the alkyl group. Carbon number of an alkyl group becomes like this. Preferably it is 4-12, More preferably, it is 4-8, More preferably, it is 4-6. By including such a hydroxyl group-containing monomer, there is a positive effect on the position at which hydrogen abstraction occurs during graft polymerization and the compatibility between the graft polymer and the homopolymer of the cyclic ether group-containing monomer generated during graft polymerization. It is considered useful for preparing a graft polymer having good heat resistance.

As such a monomer, those having a polymerizable functional group having an unsaturated double bond of a (meth) acryloyl group and having a hydroxyl group can be used without particular limitation. For example, 2-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxy Hydroxyalkyl (meth) acrylates such as octyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, etc .; 4-hydroxymethylcyclohexyl (meth) acrylate, 4-hydroxybutyl vinyl ether Etc. Of these, hydroxyalkyl (meth) acrylate is preferably used.

The hydroxyl group-containing monomer is preferably 0.2% by weight or more, more preferably 0.5% by weight or more, and preferably 10% by weight or less based on the total amount of monomer components forming the (meth) acrylic polymer. More preferably, it is 3% by weight or less. Most preferably, it is 0.5 to 3% by weight.

  As a monomer component for forming the (meth) acrylic polymer, an unsaturated carboxylic acid-containing monomer can be used in addition to the monomer.

  As the unsaturated carboxylic acid-containing monomer, a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a carboxyl group can be used without any particular limitation. . Examples of the unsaturated carboxylic acid-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. These can be used alone or in combination. Among these, it is preferable to use (meth) acrylic acid, particularly acrylic acid.

  The unsaturated carboxylic acid-containing monomer is preferably used in a proportion of 0.01 to 2% by weight, more preferably 0.05 to 2% by weight, based on the total amount of monomer components forming the (meth) acrylic polymer. %, More preferably 0.05 to 1.5% by weight, particularly preferably 0.1 to 1% by weight.

  As the monomer component for forming the (meth) acrylic polymer, other copolymerization monomers may be used alone or in combination as long as the object of the present invention is not impaired. Other comonomer includes, for example, a polymerizable functional group having an unsaturated double bond such as a (meth) acrylate having a C 4 alkyl group, a (meth) acryloyl group, or a vinyl group. And an aromatic ring-containing monomer having an aromatic ring. Specific examples of the (meth) acrylate having an alkyl group having less than 4 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and the like, and specific examples of the aromatic ring-containing monomer. Are phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenol ethylene oxide modified (meth) acrylate, 2-naphthoethyl (meth) acrylate, 2- (4-methoxy-1-naphthoxy) ethyl (meth) acrylate, phenoxy Examples thereof include propyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, and polystyryl (meth) acrylate.

  In addition, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; styrene sulfonic acid and allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) Sulfonic acid group-containing monomers such as acrylamide propanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; methoxyethyl (meth) acrylate, ( And (meth) acrylic acid alkoxyalkyl monomers such as ethoxyethyl (meth) acrylate.

  In addition, vinyl monomers such as vinyl acetate, vinyl propionate, styrene, α-methylstyrene, N-vinylcaprolactam; glycidyl (meth) acrylate, methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) Epoxy group-containing monomers such as acrylate; glycol-based acrylic ester monomers such as (meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol, (meth) acrylic acid methoxypolypropylene glycol; Acrylic ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate; Bromide group-containing monomers, amino group-containing monomers, imide group-containing monomer, N- acryloyl morpholine, may be used, such as vinyl ether monomers.

  The weight average molecular weight of the (meth) acrylic polymer of the present invention is preferably 600,000 or more, more preferably 700,000 to 3,000,000. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

Such a (meth) acrylic polymer can be produced by appropriately selecting a known production method such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. Further, the (meth) acrylic polymer obtained may be either a random copolymer or a block copolymer.

  In solution polymerization, for example, ethyl acetate, toluene or the like is used as a polymerization solvent. As a specific example of solution polymerization, the reaction is performed under an inert gas stream such as nitrogen, and a polymerization initiator is added, and the reaction is usually performed at about 50 to 70 ° C. under reaction conditions of about 5 to 30 hours.

  The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (5-methyl-2). -Imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), 2,2 '-Azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, VA-057) and other azo initiators, and persulfates such as potassium persulfate and ammonium persulfate , Di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butyl -Oxydicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3 , 3-tetramethylbutylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) ) Peroxides such as cyclohexane, t-butyl hydroperoxide, hydrogen peroxide, peroxides and sodium bisulfite, peroxides and sodium ascorbate Redox initiators combined with Not intended to be.

  The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 part by weight with respect to 100 parts by weight of the monomer. Is preferably about 0.02 to 0.5 parts by weight.

  In order to produce the (meth) acrylic polymer having the weight average molecular weight using, for example, 2,2′-azobisisobutyronitrile as the polymerization initiator, the amount of the polymerization initiator used is a monomer. The total amount of the components is preferably about 0.06 to 0.3 parts by weight, more preferably about 0.08 to 0.2 parts by weight.

  Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight with respect to 100 parts by weight of the total amount of monomer components. Less than or equal to

  Examples of the emulsifier used in emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxy Nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer are listed. These emulsifiers may be used alone or in combination of two or more.

  Further, as reactive emulsifiers, as emulsifiers into which radical polymerizable functional groups such as propenyl groups and allyl ether groups are introduced, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05 BC-10, BC-20 (all of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Soap SE10N (manufactured by ADEKA), and the like. Reactive emulsifiers are preferable because they are incorporated into the polymer chain after polymerization and thus have improved water resistance. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight and 0.5 to 1 part by weight from the viewpoint of polymerization stability and mechanical stability with respect to 100 parts by weight of the total amount of monomer components.

The glass transition temperature (Tg) of the (meth) acrylic polymer is 250K or less, preferably 240K or less. The glass transition temperature is also preferably 200K or higher. If the glass transition temperature is 250K or less, an adhesive composition excellent in initial adhesiveness is obtained. Such a (meth) acrylic polymer can be adjusted by appropriately changing the monomer component and composition ratio to be used. Such glass transition temperature is, for example, by solution polymerization, using 0.06 to 0.2 part of a polymerization initiator such as azobisisobityronitrile or benzoyl peroxide, and using a polymerization solvent such as ethyl acetate. And it is obtained by making it react at 50 to 70 degreeC under nitrogen stream for 8 to 30 hours. Here, the glass transition temperature (Tg) is calculated from the following Fox equation.
1 / Tg = W1 / Tg1 + W2 / Tg2 + W3 / Tg3 +
The above-mentioned Tg1, Tg2, Tg3 and the like represent the glass transition temperatures of the individual copolymer components 1, 2, 3, etc. in absolute temperature, and W1, W2, W3 and the like represent the respective copolymer components. The weight fraction. In addition, the glass transition temperature (Tg) of the single polymer was obtained from Polymer Handbook (4th edition, John Wiley & Sons. Inc.).

  Next, a solution obtained by diluting the (meth) acrylic polymer thus obtained as it is or by adding a diluent is subjected to graft polymerization.

Although it does not specifically limit as a diluent, Ethyl acetate or toluene is illustrated.

Graft polymerization is carried out by reacting a (meth) acrylic polymer with a cyclic ether group-containing monomer and optionally a cyclic ether group-containing monomer and other monomers.

Here, the cyclic ether group-containing monomer is not particularly limited, but is preferably an epoxy group-containing monomer, an oxetane group-containing monomer, or a combination of both.

Examples of the epoxy group-containing monomer include glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, or 4-hydroxybutyl acrylate glycidyl ether. These may be used alone or in combination. Can be used.

Examples of the oxetane group-containing monomer include 3-oxetanylmethyl (meth) acrylate, 3-methyl-3-oxetanylmethyl (meth) acrylate, 3-ethyl-3-oxetanylmethyl (meth) acrylate, and 3-butyl-3-oxetanylmethyl. (Meth) acrylate or 3-hexyl-3-oxetanylmethyl (meth) acrylate is exemplified, and these can be used alone or in combination.

The amount of the cyclic ether group-containing monomer is preferably 2 parts by weight or more, more preferably 3 parts by weight or more with respect to 100 parts by weight of the (meth) acrylic polymer. The upper limit is not particularly limited, but is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, and even more preferably 30 parts by weight or less. When the amount of the cyclic ether group-containing monomer is 2 parts by weight or more, the function of the composition as a pressure-sensitive adhesive is sufficiently exhibited. On the other hand, when the amount is 100 parts by weight or more, tackiness is reduced and initial adhesion is difficult. There is.

  It is also possible to use other monomers that co-graft with the cyclic ether group-containing monomer during the graft polymerization. Such a monomer is not particularly limited as long as it does not contain a cyclic ether group, and examples thereof include alkyl (meth) acrylates having 1 to 9 carbon atoms. Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl acrylate and the like. Moreover, alicyclic (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate can also be used. These can be used alone or in combination.

The use of other monomers that are co-grafted at the time of grafting can facilitate the curing of the adhesive. For example, in the case of photocuring, the amount of light irradiation can be reduced. The amount of curing catalyst can be reduced. This is presumably because the mobility of the graft chain is increased, or because the compatibility between the graft chain and the by-product ungrafted chain and the backbone polymer is improved.

Such other monomers are also preferably selected from the same monomers as the main chain (trunk), that is, the components of the (meth) acrylic polymer.

When the amount of the monomer other than the cyclic ether group-containing monomer is blended, the weight ratio of the cyclic ether group-containing monomer to the cyclic ether group-containing monomer: other monomer, preferably 90:10 to 10:90. More preferably, it is 80:20 to 20:80. If the content of other monomers is small, the effect of reducing the amount of photocuring or heat curing for curing may not be sufficient, and if it is large, the peel resistance after photocuring or heat curing may increase.

Graft polymerization conditions are not particularly limited, and can be carried out by methods known to those skilled in the art. In the polymerization, it is preferable to use a peroxide as a polymerization initiator.
The amount of such a polymerization initiator is 0.02 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer. When the amount of this polymerization initiator is small, it takes too much time for the graft polymerization reaction, and when it is large, many homopolymers of cyclic ether group-containing monomers are formed, which is not preferable.

In graft polymerization, for example, in solution polymerization, a cyclic ether group-containing monomer and a viscosity-adjustable solvent are added to a solution of a (meth) acrylic polymer, followed by nitrogen substitution, and then a polymer such as dibenzoyl peroxide. Although it can carry out by adding 0.02-5 weight part of oxide type polymerization initiators and heating at 50 to 80 degreeC for 4 to 15 hours, it is not limited to this.

The state of the obtained graft polymer (molecular weight, branch polymer branch size, etc.) can be appropriately selected depending on the reaction conditions.

  The adhesive composition for forming the adhesive sheet for fixing an electronic component of the present invention contains the graft polymer thus obtained and a thermosetting catalyst of a cyclic ether group or a photocationic polymerization initiator.

  As the cyclic ether group thermosetting catalyst, any cyclic ether group thermosetting catalyst known to those skilled in the art can be preferably used. More specifically, at least one selected from the group consisting of imidazole compounds, acid anhydrides, phenol resins, Lewis acid complexes, amino resins, polyamines, and melamine resins can be used. Among these, an imidazole compound is particularly preferable, and the imidazole compound is not limited, but 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4- Methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2- Undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazoli Such Mutorimeriteito are exemplified. These compounds are selected in consideration of the curing start temperature and compatibility with the adhesive.

  For example, when the adhesive polymer is a water-dispersed emulsion, 1,2-dimethylimidazole is selected, and 1-cyanoethyl is selected for the purpose of preserving storage or for thermosetting at a relatively high temperature. If 2-undecylimidazole is selected and the purpose is to cure at relatively low temperatures, 2-phenylimidazole can be selected.

  Such a cyclic ether group thermosetting catalyst may be used alone or as a mixture of two or more, but the total content is 100 parts by weight of the graft polymer. And 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight.

  As the photocationic polymerization initiator, any photocationic polymerization initiator known to those skilled in the art can be preferably used. More specifically, at least one selected from the group consisting of allylsulfonium hexafluorophosphate salt, sulfonium hexafluorophosphate salt, and bis (alkylphenyl) iodonium hexafluorophosphate can be used. .

  Such a cationic photopolymerization initiator may be used alone or in combination of two or more, but the total content is based on 100 parts by weight of the graft polymer. 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight.

  A crosslinking agent is added to the adhesive composition for forming the adhesive sheet for fixing electronic parts of the present invention, if necessary. Although it does not specifically limit as a crosslinking agent, Isocyanate which is a compound which has two or more isocyanate groups (including the isocyanate reproduction | regeneration functional group which protected the isocyanate group temporarily by the blocking agent or quantification etc.) in 1 molecule. A system crosslinking agent is illustrated.

  Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

  More specifically, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, 2,4-tolylene diisocyanate, Aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenyl isocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.), tri Methylolpropane / hexamethylene diisocyanate trimer adduct (product name: Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diiso Isocyanurate of anate (product name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) And polyisocyanates polyfunctionalized with allophanate bonds. Of these, it is preferable to use an aliphatic isocyanate because of its high reaction rate.

The above isocyanate-based crosslinking agents may be used alone or as a mixture of two or more, but the total content is based on 100 parts by weight of the graft polymer. It is preferable to contain 0.01 to 2 parts by weight of the compound crosslinking agent, more preferably 0.02 to 2 parts by weight, and 0.05 to 1.5 parts by weight. Further preferred. It can be appropriately contained in consideration of cohesive force and prevention of peeling in a durability test.

Such an isocyanate-based crosslinking agent is preferably used because it can contribute to the curing reaction of the cyclic ether group in the graft chain together with the crosslinking of the main chain of the adhesive polymer.

  Moreover, you may use together an organic type crosslinking agent and a polyfunctional metal chelate as a crosslinking agent. Examples of the organic crosslinking agent include epoxy crosslinking agents (referring to compounds having two or more epoxy groups in one molecule). Examples of the epoxy-based crosslinking agent include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, terephthalic acid diglycidyl ester acrylate, spiroglycol diglycidyl ether, and the like. These may be used alone or in combination of two or more.

  A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. can give. Examples of the atom in the organic compound that is covalently or coordinately bonded include an oxygen atom, and the organic compound includes an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, a ketone compound, and the like.

  In the present invention, it is also possible to add an oxazoline-based crosslinking agent or peroxide as a crosslinking agent.

  As the oxazoline-based crosslinking agent, those having an oxazoline group in the molecule can be used without particular limitation. The oxazoline group may be any of a 2-oxazoline group, a 3-oxazoline group, and a 4-oxazoline group. As the oxazoline-based cross-linking agent, a polymer obtained by copolymerizing an unsaturated monomer with an addition-polymerizable oxazoline is preferable, and a compound using 2-isopropenyl-2-oxazoline as the addition-polymerizable oxazoline is particularly preferable. As an example, trade name “Epocross WS-500” manufactured by Nippon Shokubai Co., Ltd. can be cited.

The peroxide can be used as appropriate as long as it generates radical active species by heating and proceeds with crosslinking of the base polymer of the adhesive composition, but in consideration of workability and stability, It is preferable to use a peroxide having a one-minute half-life temperature of 80 ° C. to 160 ° C., and more preferable to use a peroxide having a 90 ° C. to 140 ° C.

  Examples of peroxides that can be used include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.), di (4-t-butylcyclohexyl) peroxydicarbonate (1 Minute half-life temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103 0.5 ° C), t-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C), dilauroyl peroxide ( 1 minute half-life temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutyl Oxy-2-ethylhexanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (half-minute for 1 minute) Period temperature: 130.0 ° C.), t-butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.). Especially, since the crosslinking reaction efficiency is excellent, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), dilauroyl peroxide (1 minute half-life temperature: 116. 4 ° C), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C) and the like are preferably used.

  The peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer catalog, for example, “Organic peroxide catalog 9th edition by Nippon Oil & Fats Co., Ltd.” (May 2003) ".

  The peroxide may be used alone or as a mixture of two or more thereof, but the total content of the peroxide is 100 parts by weight of the graft polymer. 0.01 to 2 parts by weight, preferably 0.04 to 1.5 parts by weight, more preferably 0.05 to 1 part by weight. In order to adjust processability, reworkability, cross-linking stability, peelability, and the like, it is appropriately selected within this range.

  In addition, as a measuring method of the peroxide decomposition amount which remained after the reaction process, it can measure by HPLC (high performance liquid chromatography), for example.

More specifically, for example, after about 0.2 g of the adhesive composition after reaction treatment is taken out, immersed in 10 ml of ethyl acetate, and extracted by shaking at 25 ° C. and 120 rpm for 3 hours with a shaker. Let stand at room temperature for 3 days. Next, 10 ml of acetonitrile was added, shaken at 120 rpm at 25 ° C. for 30 minutes, and about 10 μl of the extract obtained by filtration through a membrane filter (0.45 μm) was injected into the HPLC for analysis. The amount of peroxide can be set.

  Although the adhesive layer is formed by the crosslinking agent, in the formation of the adhesive layer, the addition amount of the entire crosslinking agent is adjusted, and the influence of the crosslinking treatment temperature and the crosslinking treatment time is sufficiently considered. There is a need.

  The adhesive composition for forming the adhesive sheet for fixing electronic parts of the present invention may further contain an epoxy resin or an oxetane resin in order to further improve the adhesive strength and heat resistance.

Examples of the epoxy resin include bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, cresol novolac type. Examples thereof include bifunctional epoxy resins such as trishydroxyphenylmethane type and tetraphenylolethane type and polyfunctional epoxy resins, and glycidylamine types such as hydantoin type and trisglycidyl isocyanurate type. These epoxy resins can be used alone or in combination of two or more.

  These epoxy resins are not limited, but commercially available epoxy resins can be used. Examples of such commercially available epoxy resins include, but are not limited to, for example, bisphenol type epoxy resins such as Japan Epoxy Resin Co., Ltd. jER828, jER806, etc .; alicyclic epoxy resins such as Japan Epoxy Resin Co., Ltd. YX8000, YX8034, etc. ADEKA Co., Ltd. EP4000, EP4005, etc .; polyglycidyl ethers of polyalcohols include known epoxy resins such as Nagase ChemteX Corporation Denacol EX-313, EX-512, EX-614B, EX-810, etc. .

Examples of the oxetane resin include xylylene oxetane such as 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene, 3-ethyl-3-{[3-ethyloxetane-3-yl] methoxy. } Methyl} oxetane, 3-ethylhexyloxetane, 3-ethyl-3-hydroxyoxetane, 3-ethyl-3-hydroxymethyloxetane, and other known oxetane resins can be used. These oxetane resins can be used singly or in combination of two or more.

The oxetane resin is not limited, but a commercially available resin can be used. Examples of such commercially available oxetane resins include Aron Oxetane OXT-121, OXT221, OXT101, and OXT212 manufactured by Toa Gosei Co., Ltd., but are not limited thereto.

Such an epoxy resin and an oxetane resin can be used in an adhesive composition for forming an adhesive sheet for fixing an electronic component of the present invention by combining either one or both.

In the present invention, when the epoxy resin and / or oxetane resin is contained with respect to 100 parts by weight of the graft polymer, the total amount thereof is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably Is 100 parts by weight or less, more preferably 70 parts by weight or less. When the total amount is 5 parts by weight or more, a remarkable effect is recognized in improving the adhesive strength and heat resistance. When the total amount exceeds 100 parts by weight, it may not be sufficiently cured.

In the present invention, when an epoxy resin is added to a graft polymer obtained by grafting a cyclic ether group-containing monomer to an acrylic polymer, a composition capable of producing a good adhesive layer in which no glue sticking out occurs before curing. Can be prepared. This is presumably because the grafted cyclic ether group is compatible with the low molecular weight epoxy resin to form a strong adhesive layer structure.

  In addition, a tackifier and a softening agent can be blended in the adhesive composition for forming the adhesive sheet for fixing an electronic component of the present invention. A total of 10-100 weight part of tackifiers may be used with respect to 100 weight part of graft polymers, Preferably, 20-80 weight part may be used.

The adhesive composition for forming the adhesive sheet for fixing electronic parts of the present invention may contain other known additives, such as powders such as colorants and pigments, dyes, Surfactant, plasticizer, tackifier, surface lubricant, leveling agent, softener, antioxidant, anti-aging agent, light stabilizer, UV absorber, polymerization inhibitor, inorganic or organic filler, metal It can be added as appropriate according to the application in which powder, particles, foil, etc. are used. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.

  The adhesive layer contained in the adhesive sheet for fixing electronic parts of the present invention is obtained by applying the adhesive composition on both sides of a supporting substrate, drying and removing the polymerization solvent, and crosslinking treatment. Can be formed. Alternatively, the separator can be used as the supporting substrate, and the substrate can be formed without using the substrate in practical use. The adhesive sheet for fixing an electronic component of the present invention includes all forms such as a sheet and a vertically long tape.

As a support substrate in the adhesive sheet for fixing electronic components, for example, a porous substrate made of paper, cloth, nonwoven fabric, etc., plastic film or sheet such as polyethylene, polypropylene, polyethylene terephthalate, polyester film, net, foam, Appropriate thin leaves such as metal foils and laminates thereof can be used. These support base materials are appropriately selected according to the use for which the adhesive sheet is used. The thickness of the supporting substrate is not particularly limited, and is appropriately determined depending on the application.

  More specifically, for example, the adhesive layer is formed by applying the adhesive composition to a release-treated separator or the like, drying and removing the polymerization solvent, etc., and then crosslinking the adhesive composition. A method of forming a layer, or a method of applying the adhesive composition to a support substrate, drying and removing the polymerization solvent, etc., and photocuring or thermosetting to form an adhesive layer on the support substrate It is produced by. In applying the adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

A silicone release liner is preferably used as the release-treated separator. Examples of the constituent material of the release liner include polyethylene, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, ethylene / vinyl acetate copolymer film, polybutylene terephthalate film, polyurethane film, Examples thereof include plastic films such as polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and suitable thin leaves such as laminates thereof. A plastic film is preferably used from the viewpoint of excellent surface smoothness. Or suitable thin leaf bodies, such as a sheet | seat, a net | network, a foam, metal foil, and these laminated bodies, etc. are mention | raise | lifted.

In the step of applying the adhesive composition for forming the adhesive sheet for fixing electronic parts of the present invention on such a liner and drying it to form the adhesive layer, the adhesive is dried. As a method, an appropriate method can be appropriately adopted depending on the purpose. Preferably, a method of heating and drying the coating film is used. The heat drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By setting the heating temperature within the above range, an adhesive having excellent adhesive properties can be obtained.

As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

  Moreover, an adhesive layer can be formed after forming an anchor layer on the surface of a support body or performing various easy-adhesion treatments such as corona treatment and plasma treatment. Moreover, you may perform an easily bonding process on the surface of an adhesive agent layer.

  Various methods are used as a method for forming the adhesive layer. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.

  The thickness of the adhesive layer is not particularly limited and is, for example, about 1 to 100 μm. Preferably, it is 2-50 micrometers, More preferably, it is 2-40 micrometers, More preferably, it is 5-35 micrometers.

  When the adhesive layer is exposed, the adhesive layer may be protected with a sheet (separator) that has been subjected to a release treatment until practical use.

  As a constituent material of such a protective separator, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and these Although an appropriate thin leaf body such as a laminate can be mentioned, a plastic film is preferably used from the viewpoint of excellent surface smoothness.

  The plastic film is not particularly limited as long as it can protect the adhesive layer, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, chloride film. Examples thereof include a vinyl copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

  The thickness of the release liner for coating or protection and the separator is usually 5 to 200 μm, preferably about 5 to 100 μm. For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, when the surface of the separator is appropriately subjected to a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, the peelability from the adhesive layer can be further enhanced.

  In addition, the said sheet | seat which carried out the peeling process can be used as a separator of an adhesive agent sheet as it is, and can simplify in the surface of a process.

  When the adhesive composition that forms the adhesive sheet for fixing electronic parts of the present invention contains a thermosetting catalyst, curing occurs by heating. Therefore, the adhesive sheet for fixing an electronic component of the present invention can be easily cured by further heating after being bonded to the adherend. Moreover, for example, it is preferably used in a form such as a double-sided pressure-sensitive adhesive tape, and can be cured by applying heat at any time after bonding. By such a curing reaction, adhesion to the electronic component or adhesion between the adherend and the member is ensured.

  Conditions such as the temperature of thermosetting are not particularly limited, but are preferably up to about 170 ° C. in consideration of the heat resistance of the support.

  When the curing start temperature of the cyclic ether group thermosetting catalyst used in the present invention is low, in the heat drying step, together with the drying of the solvent and the reaction of the main chain polymer of the adhesive composition, A curing reaction may also occur. In this case, it is preferable that the curing reaction is not completed and the cyclic ether group remains.

  On the other hand, when the curing start time of the thermosetting catalyst of the cyclic ether group used is high, only the drying of the solvent and the reaction of the main chain polymer of the adhesive composition proceed in this drying step, and the cyclic ether The group remains.

  Moreover, when the adhesive composition which forms the adhesive sheet for electronic component fixation of this invention contains a photocationic polymerization initiator, hardening will occur by irradiating specific light. Therefore, the pressure-sensitive adhesive sheet for fixing an electronic component of the present invention can be easily cured by irradiating light immediately before or after bonding to an adherend that is an electronic component. Further, for example, it is preferably used in a form such as a double-sided pressure-sensitive adhesive tape, and can be cured by irradiating light any time after bonding. By such a curing reaction, adhesiveness to electronic parts or adhesiveness between electronic parts is ensured.

Although the light for irradiation is not specifically limited, Preferably, it is active energy rays, such as an ultraviolet-ray, visible light, and an electron beam. The crosslinking treatment by ultraviolet irradiation can be performed using an appropriate ultraviolet source such as a high-pressure mercury lamp, a low-pressure mercury lamp, an excimer laser, or a metal halide lamp. In this case, the irradiation amount of the ultraviolet ray can be appropriately selected according to the required degree of crosslinking, but it is usually preferable to select the ultraviolet ray within the range of 0.2 to 10 J / cm ^2. . Although the temperature at the time of irradiation is not specifically limited, Considering the heat resistance of a support body, about 140 degreeC is preferable.

The gel fraction after the thermosetting or photocuring reaction of the cyclic ether group of the adhesive layer of the present invention is 70 to 98%, preferably 80 to 98%, and has a very high cohesive force. It is preferable to become an adhesive layer. The storage elastic modulus at 23 ° C. is preferably 10,000 to 1,000,000 Pa, and still has tackiness, so that an adhesive composition and a pressure-sensitive adhesive sheet excellent in heat resistance are obtained.
Here, the dynamic viscoelasticity measuring method is a value measured as follows.
Apparatus: ARES manufactured by TA Instruments
Deformation mode: Torsion measurement frequency: 1Hz constant frequency
Temperature increase rate: 5 ° C / min Measurement temperature: Measured from near the glass transition temperature of the adhesive to 160 ° C Shape: Parallel plate 8.0mmφ
Sample thickness: 0.5-2mm (initial stage)
Reading storage elastic modulus (G ') at 23 ° C

Here, “after the thermosetting reaction” means a state that can be achieved by performing a heat treatment at least 150 ° C. for 60 minutes including a drying step. “After photocuring reaction” refers to a state in which 0.2 J / cm ² or more (in the case of ultraviolet rays) is irradiated.

  The adhesive sheet for fixing an electronic component of the present invention is used for an application for bonding a semiconductor element or an electronic component to an organic substrate or a lead frame.

  More specifically, in the method of sticking an electronic component of the present invention, first, an adhesive sheet for fixing an electronic component of the present invention formed on a separator, for example, is attached to the back surface of a silicon wafer at room temperature. Adhere further dicing tape. This is fixed on a dicing machine, and the above-mentioned silicon wafer with tape is cut into individual pieces by using a cutting means such as a dicing saw, thereby obtaining a semiconductor chip as a single die.

  In the case of photocuring, subsequently, the dicing tape is peeled off from the semiconductor chip obtained as described above, and the light-transmitting base material surface of the adhesive sheet for fixing electronic components of the present invention attached to the semiconductor chip is applied. , Can be irradiated with ultraviolet rays. Next, only the separator is peeled off while the adhesive sheet for fixing an electronic component of the present invention remains adhered to the back side of the semiconductor chip. Thus, the semiconductor chip to which the adhesive sheet for fixing an electronic component of the present invention is fixed can be bonded to the metal lead frame or substrate as it is by pressing and heating through the adhesive layer. . As heating conditions after pressure bonding, heating at 50 to 150 ° C. is preferable. In the case of thermosetting, it is desirable to further age at 50 to 80 ° C. for 2 to 3 days.

  As described above, the adhesive sheet for fixing an electronic component of the present invention is particularly preferably used as a die bond film of a semiconductor element.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight. Unless otherwise specified, the room temperature standing conditions are all 23 ° C. and 65% RH (1 hour or 1 week). In the examples, the evaluation of adhesiveness was performed by evaluating the shear adhesive strength between SUS-BA plates. This model is suitable for evaluating the state of electronic component fixation.

<Measurement of weight average molecular weight>
The weight average molecular weight of the obtained (meth) acrylic polymer was measured by GPC (gel permeation chromatography). The sample was prepared by dissolving the sample in dimethylformamide to give a 0.1% by weight solution, which was allowed to stand overnight and then filtered through a 0.45 μm membrane filter.
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
Column: manufactured by Tosoh Corporation, G7000H _XL + GMH _XL + GMH _XL
・ Column size: 7.8mmφ × 30cm each 90cm in total
・ Eluent: Tetrahydrofuran (concentration 0.1% by weight)
・ Flow rate: 0.8ml / min
・ Detector: Differential refractometer (RI)
-Column temperature: 40 ° C
・ Injection volume: 100 μl
・ Standard sample: Polystyrene

<Measurement of gel fraction>
The dried and crosslinked adhesive (initial weight W1) was immersed in an ethyl acetate solution and allowed to stand at room temperature for 1 week, then the insoluble matter was taken out and the dried weight (W2) was measured. I asked for it.
Gel fraction = (W2 / W1) × 100

<Heat resistance>
With respect to the adhesive sheet for fixing electronic parts obtained in Examples and Comparative Examples, TMA (Thermo-mechanical analyzer) measurement is performed under the following conditions to measure the heat resistance level. Thermophysical properties are TMA / SS6100 manufactured by SII Nanotechnology Co., Ltd., with a cross-sectional area of 0.6 mm ² , a sample length of 10 mm, and a heating rate of 10 ° C./min at a load of 19.6 mN, and a softening point at 20 ° C. to 300 ° C. Was measured.

<Measurement method of shear adhesive strength>
The adhesive sheet for fixing electronic parts obtained in Examples and Comparative Examples is attached to a SUS plate with a 1 cm square, heated or irradiated with light, and another SUS plate is immediately attached from above. The adhesive pressure-sensitive adhesive film after the dark reaction at 60 ° C. for 2 days and heat-curing or photo-curing was subjected to shear adhesion measurement under the following conditions using an autograph.
Temperature 23 ° C, pulling speed: 10mm / min

Example 1
(Preparation of acrylic polymer)
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 97 parts by weight of n-butyl acrylate, 3 parts by weight of 4-hydroxybutyl acrylate, and 2,2′-azobis as a polymerization initiator After charging 0.1 parts by weight of isobutyronitrile together with 140 parts by weight of ethyl acetate and 60 parts by weight of toluene, nitrogen gas was introduced with gentle stirring and the atmosphere was purged with nitrogen for 1 hour. Then, a polymerization reaction was carried out for 10 hours to prepare an acrylic polymer solution having a weight average molecular weight of 900,000.

(Preparation of graft polymer)
The obtained acrylic polymer solution was diluted with ethyl acetate so that the solid content was 25% to prepare a diluted solution (I). In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 20 parts by weight of 4-hydroxybutyl acrylate glycidyl ether and 20 parts of isobornyl acrylate are used with respect to 400 parts by weight of the diluted solution (I). Part by weight and 0.1 part by weight of benzoyl peroxide were added, nitrogen gas was introduced with gentle stirring, and the atmosphere was purged with nitrogen for 1 hour. Then, the liquid temperature in the flask was kept around 60 ° C. for 4 hours, and then 70 ° C. A polymerization reaction was carried out for 4 hours to obtain a graft polymer solution.

(Formation of adhesive layer) Adhesive strength measurement sample: 1A
Next, with respect to 100 parts by weight of the solid content of the graft polymer solution thus obtained, Yasuhara Chemical trade name YS resin CP 10 parts by weight, hexamethylene diisocyanate trimethylolpropane adduct (manufactured by Nippon Polyurethane Co., Ltd., Coronate HL) An adhesive solution was prepared by blending 0.3 part by weight and 1 part by weight of allylsulfonium hexafluorophosphate (manufactured by LANBERTI, ESACURE1064).

On the one side of a 38 μm PET separator (MRF-38, manufactured by Mitsubishi Plastics Co., Ltd.), the above adhesive solution is subjected to silicone treatment so that the thickness of the adhesive layer after drying is 20 μm. The sample was applied and dried at 120 ° C. for 3 minutes to prepare a test sample, which was then bonded to a 38 μm PET separator (MRF-38, manufactured by Mitsubishi Plastics, Inc.) subjected to silicone treatment.

(Formation of adhesive layer) Sample for gel fraction measurement: 1A
Further, the gel fraction is measured without irradiating light to the test sample 1A thus obtained, and this is set as the gel fraction when no light is irradiated.

(Light not irradiated) 1B
Next, a 10 mm × 10 mm sample piece was cut out from the test sample 1A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). Remove the other separator and place the same BA plate together. The shearing adhesive force (peeling speed 10 mm / min) at this time is measured and set as the adhesive force when no light is irradiated.

(Light irradiation) 1C
In addition, a sample of an appropriate size is cut out from the sample 1A, irradiated with 1 J / cm ² light with a meta-harara UV lamp, and then subjected to a dark reaction treatment (50 ° C. × 48 hours). The gel fraction is measured with this sample to obtain the gel fraction at the time of light irradiation.

(Light irradiation) 1D
A 10 mm × 10 mm sample piece was cut out from the test sample 1A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). This test sample is irradiated with 1 J / cm ² light with a meta-harass UV lamp, and then bonded to the other BA plate and subjected to a dark reaction treatment (50 ° C. × 48 hours). The shearing adhesive force (peeling speed 10 mm / min) at this time is measured and set as the adhesive force at the time of light irradiation.

Example 2
(Preparation of acrylic polymer)
The acrylic polymer solution obtained in the same manner as in Example 1 was diluted with ethyl acetate so that the solid content was 25% to prepare a diluted solution (I). In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser, 20 parts of 4-hydroxybutyl acrylate glycidyl ether and 20 parts of 2-ethylhexyl acrylate with respect to 400 parts by weight of the diluted solution (I) And 0.1 part of benzoyl peroxide were added, nitrogen gas was introduced with gentle stirring, and the atmosphere was purged with nitrogen for 1 hour. Then, the liquid temperature in the flask was kept at around 60 ° C. for 4 hours, and then at 70 ° C. for 4 hours. A time polymerization reaction was performed to obtain a graft polymer solution.

(Formation of adhesive layer) Sample for measuring adhesive strength: 2A
Subsequently, 0.3 parts by weight of trimethylolpropane adduct of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., Coronate HL) with respect to 100 parts by weight of the solid content of the graft polymer solution thus obtained, 2 phenylimidazole 4 An adhesive solution was prepared by blending parts by weight.

  On the one side of a 38 μm PET separator (MRF-38, manufactured by Mitsubishi Plastics Co., Ltd.), the above adhesive solution is subjected to silicone treatment so that the thickness of the adhesive layer after drying is 20 μm. The sample was applied and dried at 160 ° C. for 3 minutes to produce a test sample, which was then bonded to a 38 μm PET separator (MRF-38, manufactured by Mitsubishi Plastics, Inc.).

(Formation of adhesive layer) Sample for gel fraction measurement: 2A
Moreover, the gel fraction is measured without heating the test sample 2A thus obtained, and this is used as the gel fraction when not heated.

(Unheated) 2B
Next, a 10 mm × 10 mm sample piece was cut out from the test sample 2A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). Remove the other separator and place the same BA plate together. The shearing adhesive strength (peeling speed 10 mm / min) at this time is measured and set as the adhesive strength when not heated.

(Heating) 2C
Heat treatment (50 ° C. × 72 hours) is performed on the test sample 2A. The gel fraction is measured with this sample to obtain the gel fraction upon heating.

(Heating) 2D
A 10 mm × 10 mm sample piece was cut out from the test sample 2A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). This test sample is subjected to heat treatment (50 ° C. × 72 hours) and then bonded to the other BA plate and subjected to dark reaction treatment (50 ° C. × 48 hours). The shearing adhesive force (peeling speed 10 mm / min) at this time is measured and set as the adhesive force during heating.

Comparative Example 1
(Formation of adhesive layer)
To 100 parts by weight of the solid content of the graft polymer solution obtained in the same manner as in Example 1, 0.3 part by weight of trimethylolpropane adduct of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., Coronate HL) was blended. An adhesive solution was prepared.

  On the one side of a 38 μm PET separator (MRF-38, manufactured by Mitsubishi Plastics Co., Ltd.), the above adhesive agent solution was subjected to silicone treatment so that the thickness of the adhesive layer after drying was 20 μm. The sample was applied and dried at 120 ° C. for 3 minutes to prepare a test sample, which was then bonded to a 38 μm PET separator (MRF-38, manufactured by Mitsubishi Plastics, Inc.) subjected to silicone treatment.

(Formation of adhesive layer) Gel fraction measurement sample: 3A
Moreover, the gel fraction is measured without irradiating light to the test sample 3A thus obtained, and this is used as the gel fraction when no light is irradiated.

(No light irradiation) 3B
Next, a 10 mm × 10 mm sample piece was cut out from the test sample 3A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). Remove the other separator and place the same BA plate together. The shearing adhesive strength (peeling speed 10 mm / min) at this time is measured, and is defined as the adhesive strength when not irradiated.

(Light irradiation) 3C
The test sample 3B is irradiated with 1 J / cm ² light with a meta-harahal UV lamp, and then subjected to a dark reaction treatment (50 ° C. × 48 hours). The gel fraction is measured with this sample to obtain the gel fraction at the time of light irradiation.

(Light irradiation) 3D
A 10 mm × 10 mm sample piece was cut out from the test sample 3A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). This test sample was irradiated with 1 J / cm ² light with a meta-harara UV lamp, then subjected to dark reaction treatment (50 ° C. × 48 hours), and the shear adhesive force (peeling speed 10 mm / min) at this time was measured. Adhesive strength of

Comparative Example 2
(Formation of adhesive layer) Sample for measuring adhesive strength: 4A
To 100 parts by weight of the solid content of the graft polymer solution obtained in the same manner as in Example 2, 0.3 part by weight of trimethylolpropane adduct of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., Coronate HL) was blended. An adhesive solution was prepared.

The thickness of the adhesive layer after drying is 20 μm on one side of a 38 μm polyethylene terephthalate (PET) film (Mitsubishi Resin Co., Ltd., MRF-38) that has been subjected to silicone treatment. Then, the sample was dried at 120 ° C. for 3 minutes to prepare a test sample, which was bonded to a 38 μm PET separator (MRF-38, manufactured by Mitsubishi Plastics, Inc.).

(Formation of adhesive layer) Sample for gel fraction measurement: 4A
Moreover, the gel fraction is measured without heating the test sample 4A thus obtained, and this is used as the gel fraction when not heated.

(Unheated) 4B
Next, a 10 mm × 10 mm sample piece was cut out from the test sample 4A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). Remove the other separator and place the same BA plate together. The shearing adhesive strength (peeling speed 10 mm / min) at this time is measured and set as the adhesive strength when not heated.

(Heating) 4C
The test sample 4B is subjected to a heat treatment (50 ° C. × 72 hours) and then a dark reaction treatment (50 ° C. × 48 hours). The gel fraction is measured with this sample to obtain the gel fraction upon heating.

(Heating) 4D
Next, a 10 mm × 10 mm sample piece was cut out from the test sample 4A and attached to a 0.4 mm thick BA plate (SUS430 steel plate surface-finished BA steel plate). After heat treatment (50 ° C. × 72 hours), dark reaction treatment (50 ° C. × 48 hours) is performed. The shearing adhesive force (peeling speed 10 mm / min) at this time is measured and set as the shearing adhesive force during heating.

Table 1 shows the evaluation results of the gel fraction, shear adhesive strength and heat resistance of the pressure-sensitive adhesive layer obtained for the samples obtained in the above Examples and Comparative Examples.

Claims (15)

It is formed from an adhesive composition containing a photo-cationic polymerization initiator or a thermosetting catalyst on a graft polymer obtained by graft-polymerizing a chain containing a cyclic ether group-containing monomer to a (meth) acrylic polymer. An adhesive sheet for fixing electronic components having an adhesive layer. The adhesive composition contains the cyclic ether group-containing monomer and other monomers, and the weight ratio of the cyclic ether group-containing monomer: other monomer is in the range of 90:10 to 10:90. The adhesive sheet for fixing electronic parts according to claim 1, wherein the adhesive sheet is fixed.   3. The adhesive sheet for fixing an electronic component according to claim 1, wherein the adhesive composition further contains a cross-linking agent.   The said adhesive composition contains 5-100 weight part of epoxy resins and / or oxetane resin further with respect to 100 weight part of said graft polymers, The any one of Claim 1 to 3 characterized by the above-mentioned. Adhesive sheet for fixing electronic components.   The adhesive for fixing an electronic component according to any one of claims 1 to 4, wherein the cyclic ether group-containing monomer is one or both of an epoxy group-containing monomer and an oxetane group-containing monomer. Attached sheet. The glass transition temperature of the (meth) acrylic polymer is 250 K or less, and the adhesive sheet for fixing electronic components according to any one of claims 1 to 5.   The said (meth) acrylic-type polymer contains 0.2-10 weight% of hydroxyl-containing monomers as a monomer unit with respect to this (meth) acrylic-type polymer whole quantity, The any one of Claim 1-6 characterized by the above-mentioned. 2. An adhesive sheet for fixing electronic components according to 1. The graft polymer is composed of 2 to 50 parts by weight of the cyclic ether group-containing monomer and 5 to 50 parts by weight of the other monomer to 100 parts by weight of the (meth) acrylic polymer, and 0.02 to 5 parts by weight of peroxide. The adhesive sheet for fixing an electronic component according to any one of claims 1 to 7, wherein the adhesive sheet is obtained by graft polymerization in the presence of the electronic component.   9. The thermosetting catalyst is at least one selected from the group consisting of an imidazole compound, an acid anhydride, a phenol resin, a Lewis acid complex, an amino resin, a polyamine, and a melamine resin. The adhesive sheet for electronic component fixation as described in any of the above.   The photocationic polymerization initiator is at least one selected from the group consisting of allylsulfonium hexafluorophosphate salt, sulfonium hexafluorophosphate salt, and bis (alkylphenyl) iodonium hexafluorophosphate. An adhesive sheet for fixing an electronic component according to any one of claims 1 to 9, wherein:   The pressure-sensitive adhesive sheet for fixing an electronic component according to any one of claims 1 to 10, wherein the gel fraction after photocuring or thermosetting is prepared so as to be 70 to 98%.   The pressure-sensitive adhesive sheet for fixing an electronic component according to any one of claims 1 to 11, wherein an adhesive layer is formed on both surfaces of the support. The adhesive sheet for fixing an electronic component according to any one of claims 1 to 11, wherein the adhesive sheet is formed of only an adhesive layer. An electronic component fixing method using the electronic component fixing adhesive sheet according to claim 1,
The adhesive composition contains a photocationic polymerization initiator,
A step of curing the sheet by irradiating with light after bonding the electronic component fixing adhesive sheet to the electronic component;
How to fix electronic components. An electronic component fixing method using the electronic component fixing adhesive sheet according to claim 1,
The adhesive composition comprises a thermosetting catalyst;
Including the step of curing the sheet by heating after sticking the adhesive sheet for fixing the electronic part to the electronic part,
How to fix electronic components.