JPH0641506A - Energy beam curing type adhesive - Google Patents

Abstract

PURPOSE:To obtain an energy beam curing type adhesive excellent in curing rate and thick film-curing properties and having good reliability in uses of electronic parts by blending a polymer containing glycidyl (meth)acrylate with a specific light proton generating agent. CONSTITUTION:The energy beam curing type adhesive excellent in storage stability, curing rate and thick film curing properties is obtained by blending (A) 100 pts.wt. polymer having 5000-50000 weight-average molecular weight and consisting of A1: 5-100wt.%, preferably 30-100wt.% glycidyl (meth)acrylate and A2: a monomer (e.g. styrene) arbitrarily copolymerizable with the component A1 with (B) 0.01-20 pts.wt., preferably 1-5 pts.wt. light proton generating agent containing an atom selected from among boron, phosphorus, sulfur, chlorine and oxygen (e.g. triphenylsulfoniumtetrafluoroborate or 2,6-dinitrobenzyl tosylate) and (C), if necessary, 0-70 pts. reactive diluent (e.g. phenylglycidyl ether).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy ray curable adhesive which is excellent in curing speed and thick film curability and is useful for electronic parts related applications.

[0002]

2. Description of the Related Art In recent years, in order to meet the demands for resource saving, energy saving, automatic speeding of lines, and low pollution, curing is performed in seconds by irradiation with energy rays such as ultraviolet rays and electron beams. Demand for energy-ray curable adhesives having various physical properties such as flexibility, adhesion, chemical resistance, and electrical characteristics is expanding in various applications.

Most of the energy ray curable adhesives currently on the market are radical polymerization type adhesives composed of an unsaturated polyester or acrylic resin and a photoradical polymerization initiator such as benzoin. However, when curing these radical-polymerization types in air, the polymerization is suppressed by oxygen, and the curing rate is insufficient. Even after the above procedure, a part of the adhesive may be in an uncured state.

Therefore, as a means for solving the fundamental problem of radical polymerization in which curing is suppressed by oxygen,
Adhesives that cure an epoxy resin using an onium salt that generates a proton or a Lewis acid upon irradiation with energy rays are disclosed in JP-A-61-60720 and JP-A-61-1927.
No. 24 publication.

[0005]

However, the above-mentioned conventional energy ray-curable adhesives have insufficient curing speed,
Further, there is a problem that it is not suitable for thick film adhesion, that is, if a thick film is used, it is difficult to cure the inside sufficiently. Furthermore, these adhesives use triphenylsulfonium hexafluoroantimonate as an onium salt, but since this salt contains antimony metal, this adhesive is used to bond electronic components. If used for, there is a risk of corrosive disconnection of semiconductor wiring after long-term storage,
There is also a problem that the reliability of electronic components is reduced.

In view of the above-mentioned conventional circumstances, the present invention provides an energy ray curable adhesive which has an excellent curing speed and thick film curability and has improved reliability when used in electronic parts. Has an aim.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that a composition obtained by adding a specific photoproton generator to a specific polymer has a curing rate. The inventors have found that an energy-ray curable adhesive having excellent thick film curability and improved reliability when used in electronic parts can be obtained, and completed the present invention.

That is, the present invention provides the following components a to c: a) 100 parts by weight of a polymer using at least glycidyl acrylate or glycidyl methacrylate as a monomer b) boron in the counterion of the generated proton, 0.01 to 20 parts by weight of a photoproton generating agent containing an atom selected from phosphorus, sulfur, chlorine and oxygen c) An energy ray curable adhesive containing 0 to 70 parts by weight of a reactive diluent It is a thing.

[0009]

The polymer as the component a used in the present invention is prepared by using at least glycidyl acrylate or glycidyl methacrylate [hereinafter, both are collectively referred to as glycidyl (meth) acrylate] as a monomer. Thus, this polymer includes a homopolymer of glycidyl (meth) acrylate and a copolymer of glycidyl (meth) acrylate and a monomer copolymerizable therewith. The use of such polymers has been successful in improving the cure rate, thick film curability and adhesion of adhesives.

Examples of the monomer copolymerizable with glycidyl (meth) acrylate include the following (1) to (14)
Among these monomers, dry edging resistance, heat resistance, solvent resistance, water resistance, adhesion,
Depending on the performance required for the adhesive, such as adhesiveness, flexibility, and tackiness, one kind thereof can be used alone or two or more kinds can be used in combination.

(1) Carbon number 1 to 1 such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octadecyl acrylate, docosyl acrylate, etc.
Acrylic ester having 22 alkyl groups, or methacrylic acid ester having the same alkyl group as above (2) Polyethylene glycol acrylate, polyethylene glycol methacrylate, polypropylene glycol acrylate, polypropylene glycol methacrylate -Acrylates or methacrylates having polyalkylene glycol groups such as

(3) Unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid (4) Unsaturated dicarboxylic acids such as fumaric acid and itaconic acid or acid anhydrides thereof (5) Dimethyl fumarate, diethyl fumarate , Dibutyl fumarate, dimethyl itaconate, dibutyl itaconate,
Dicarboxylic acid esters such as methyl ethyl fumarate, methyl butyl fumarate and methyl ethyl itaconate (6) Styrene derivatives such as styrene, α-methyl styrene and chlorostyrene (7) Vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride And vinylidene halides such as (8) unsaturated ketones such as methyl vinyl ketone and butyl vinyl ketone

(9) Vinyl esters such as vinyl acetate and vinyl butyrate (10) Vinyl ethers such as methyl vinyl ether and butyl vinyl ether (11) Vinyl cyanide such as acrylonitrile, methacrylonitrile and vinylidene cyanide (12) Acrylamide and its alkyl-substituted amides (13) Unsaturated sulfonic acids such as vinylsulfonic acid, allylsulfonic acid, methacrylsulfonic acid (14) N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide

In the polymer of the component a, the amount of glycidyl (meth) acrylate used is preferably 5 to 100% by weight, more preferably 30 to 100% by weight, based on the total amount of the monomers. Good results cannot be obtained in improving the curing speed, thick film curability and adhesiveness of the adhesive. The polymer can be produced by a known radical polymerization method such as a solution polymerization method. The molecular weight of the polymer is not particularly limited, but it is usually 5,000 to 500,000 in terms of weight average molecular weight.
It should be in the range of.

The photo-proton generating agent as the component b used in the present invention is boron in the counter ion of the generated proton.
It contains an atom selected from phosphorus, sulfur, chlorine, and oxygen, and specifically includes the following a to i, and among these, one kind alone or two kinds. The above can be mixed and used. In addition, in the following exemplary compounds, the description in the parentheses at the end of the compound indicates an atom contained in the counterion of the generated proton.

A) Ants such as phenyldiazonium tetrafluoroborate (boron), 4-methoxyphenyldiazonium hexafluorophosphate (phosphorus), 4-methylphenyldiazonium perchlorate (chlorine), etc. -Rudiazonium salt b) Diphenyl iodonium tetrafluoroborate (boron), phenyl-4-methoxyphenyl iodonium tetrafluoroborate (boron), di (4-methylphenyl) iodonium hexa Diaryl iodonium salts such as fluorophosphate (phosphorus) and di (4-butylphenyl) iodonium hexafluorophosphate (phosphorus)

C) Triphenylsulfonium hexafluorophosphate (phosphorus), triphenylsulfonium tetrafluoroborate (boron), tris (4-methoxyphenyl) sulfonium hexafluorophosphate
Triary of phosphorus (tris), tris (3.5-dimethyl-4-hydroxyphenyl) sulfonium tetrafluoroborate (boron), diphenyl-2,5-dimethylphenylsulfonium tetrafluoroborate (boron), etc. -Disulfonium salt d) Dimethylphenacylsulfonium hexafluorophosphite (phosphorus), phenacyltetramethylenesulfonium tetrafluoroborate (boron), phenacyltetramethylenesulfonium hexafluorophosphite
Dialkyl phenacyl sulfonium salts such as phosphorus

E) Dialkyl such as 3,5-dimethyl-4-hydroxyphenylsulfonium tetrafluoroborate (boron) and 3,5-dibutyl-4-hydroxyphenylsulfonium hexafluorophosphate (phosphorus) -4-Hydroxyphenyl sulfonium salt f) α-hydroxymethyl benzoin sulfonate (sulfur), N-hydroxyimide sulfonate (sulfur), α-sulfonyloxy ketone (sulfur), β-sulfonyloxy ketone (Sulfur), sulfonic acid ester such as 2,6-dinitrobenzyl tosylate (sulfur), p-nitrobenzyl-9,10-diethoxyanthracene-2-sulfoneate (sulfur)) 2- (4- Triazine compounds such as methoxyphenyl) -4,6-di (trichloromethyl) triazine (chlorine) Ortho-diazonaphthoquinone-4-sulfonic acid ester (oxygen), ortho-diazonaphthoquinone-5-sulfonic acid ester (oxygen) diazonaphthoquinone compound, such as

The amount of the photo-proton generator as the component b is a
The amount is 0.01 to 20 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the component polymer. If it is less than 0.01 part by weight, the energy ray curability will be poor. If it exceeds 20 parts by weight, the tackiness and the adhesiveness are deteriorated, and the storage stability of the adhesive is deteriorated.

The reactive diluent as the component c in the present invention is for adjusting the viscosity at which the adhesive can be applied, usually at a viscosity of 15,000 centipoise or less, and the viscosity at which the polymer of the component a can be applied. If it has, the use thereof may be omitted. Such reactive diluents include I)
There are epoxy compounds, II) glycidyl compounds, III) mixtures of radically polymerizable monomers and photopolymerization initiators,
Of these, one kind can be used alone, or two or more kinds can be mixed and used.

The epoxy compound of the above-mentioned I is an epoxy resin or a phenol obtained by reacting a polyvalent alcohol such as bisphenol A or bisphenol F or an alkylene oxide adduct thereof with epichlorohydrin.
Aromatic epoxy resins represented by novolak type epoxy resins such as lunovolac type and cresol novolak type, and epoxy resins obtained by the reaction of hydrogenated bisphenol A or its alkylene oxide adduct with epichlorohydrin Cycloaliphatic epoxy resin having alicyclic structure such as cyclohexene oxide group, tricyclodecene oxide group, cyclopentene oxide group, etc. Aliphatic polyhydric alcohol such as 1,4-butanediol, 1,6-hexanediol Examples thereof include polyglycidyl ethers obtained by the reaction of chlorophenol and its alkylene oxide adducts with epichlorohydrin, and aliphatic epoxy resins represented by diglycidyl esters of aliphatic long-chain dibasic acids.

As the glycidyl compound of the above II, methyl glycidyl ether, butyl glycidyl ether, 2
-Ethylhexyl glycidyl ether, phenyl glycidyl ether, sec-butyl phenyl glycidyl ether
Ter, allyl glycidyl ether and other glycidyl ethers
Ter, phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, diglycidyl p-oxybenzoic acid, dimer acid glycidyl ester, glycidyl acrylate, glycidyl methacrylate glycidyl ester, N. Examples thereof include glycidyl amines such as N-diglycidyl aniline, tetraglycidyl diaminophenyl methane, and triglycidyl p-aminophenol.

Examples of the radically polymerizable monomer of the above III include the same as the monomers (1) to (14) exemplified as the copolymerizable monomer in the polymer of the component a. . As a photopolymerization initiator used by mixing with this monomer, acetophenone derivatives such as 4-phenoxydichloroacetophenone and 2-hydroxy-2-methyl-1-phenylpropan-1-one Examples thereof include benzophenone derivatives such as benzoin and benzoin isopropyl ether, and thioxanthone derivatives such as thioxanthone and isopropylthioxanthone.

The amount of the reactive diluent of the component c used is 0 to 70 parts by weight, more preferably 0 to 60 parts by weight, based on 100 parts by weight of the polymer of the component a. If it exceeds 70 parts by weight, the curing rate will be reduced and thick film curing will be difficult.

The energy ray curable adhesive of the present invention contains the above-mentioned two components a, b or three components a to c as essential components, but this adhesive impairs the effect of the present invention. Unless otherwise specified, antioxidants, dyes, fillers, pigments, thixotropy imparting agents, plasticizers, surfactants and the like can be included. In addition to thermosetting resins such as phenol resin and melamine resin and thermosetting catalysts, thermoplastic resins such as polyolefin resin, polystyrene resin, nylon, polyethylene terephthalate, polycarbonate, polyimide, etc. Resin may be added. Furthermore, it can be used in a mixed system with an anaerobic adhesive, a thermosetting adhesive, a moisture-curing adhesive, or the like.

When the energy ray curable adhesive of the present invention is used, it is applied to an adherend such as a semiconductor substrate by transfer or a dispenser. Alternatively, it may be applied on a release paper, a film or the like and used as a sheet-like adhesive. After applying it to the adherend or applying a sheet adhesive to the adherend and irradiating it with energy rays,
Even when the layer thickness of the adhesive is quite large, the adhesive can be cured rapidly to the inside, whereby a desired adhesive strength can be obtained. As the energy rays, for example, ultraviolet rays, electron rays, X rays, γ rays and the like are used.

[0027]

As described above, the energy ray curable adhesive of the present invention is excellent in curing speed and thick film curability, and does not contain heavy metal atoms such as antimony. Even when it is used for electronic component-related applications such as temporary adhesion of chip components, the semiconductor wiring can be used without corrosive disconnection and without impairing the reliability of electronic components.

[0028]

EXAMPLES Next, the present invention will be explained by examples. Hereinafter, parts and% in the examples are parts by weight and% by weight, unless otherwise specified.

Example 1 Glycidyl acrylate homopolymer (weight average molecular weight 2
50,000) 100 parts, triphenylsulfonium tetrafluoroborate 2 parts, and phenylglycidyl ether
50 parts of tel was mixed to obtain an energy ray-curable adhesive.

Comparative Example 1 An energy ray curable adhesive was obtained in the same manner as in Example 1 except that the number of parts of triphenylsulfonium tetrafluoroborate was changed to 0.005 part.

Comparative Example 2 The procedure of Example 1 was repeated except that the number of parts of triphenylsulfonium tetrafluoroborate was changed to 21 parts.
An energy ray curable adhesive was obtained.

Comparative Example 3 An energy ray-curable adhesive was obtained in the same manner as in Example 1 except that the number of parts of phenylglycidyl ether was changed to 100 parts.

Comparative Example 4 Energy-ray curable type was prepared in the same manner as in Example 1 except that 2 parts of triphenylsulfonium hexafluoroantimonate was used in place of 2 parts of triphenylsulfonium tetrafluoroborate. An adhesive was obtained.

Example 2 A copolymer of glycidyl methacrylate and 2-ethylhexyl acrylate in a weight ratio of 1: 1 (weight average molecular weight 40,
000) 100 parts, phenyl-4-methoxyphenyl iodonium tetrafluoroborate 2 parts, 2-ethylhexyl acrylate 50 parts, and benzophenone 1 part are mixed to obtain an energy-ray curable adhesive. Obtained.

Example 3 Weight ratio of glycidyl methacrylate to vinyl acetate 1: 4
100 parts of the copolymer (weight average molecular weight 5,000) of
2 parts of phenyl-4-methoxyphenyl iodonium tetrafluoroborate and butyl glycidyl ether 50
And the parts were mixed to obtain an energy ray-curable adhesive.

Example 4 100 parts of a copolymer of glycidyl methacrylate, styrene and N-phenylmaleimide in a weight ratio of 3: 1: 1 (weight average molecular weight 15,000) was added to triphenylsulfonium tetrafluoroborate. 2 parts and butyl acrylate 5
Mixing 0 parts and 1 part of benzophenone, the energy
A line-curable adhesive was obtained.

Example 5 Copolymer of glycidyl methacrylate and methyl methacrylate in a weight ratio of 1: 1 (weight average molecular weight 10,000) 1
3 parts of triphenylsulfonium tetrafluoroborate and 40 parts of phenylglycidyl ether were mixed with 00 parts to obtain an energy ray-curable adhesive.

Example 6 To 100 parts of a copolymer of glycidyl methacrylate and styrene in a weight ratio of 7: 3 (weight average molecular weight 80,000),
0.1 part of phenacyl tetramethylene sulfonium tetrafluoroborate and phenyl glycidyl ether 70
And the parts were mixed to obtain an energy ray-curable adhesive.

Example 7 To 100 parts of a copolymer of glycidyl methacrylate and styrene in a weight ratio of 1: 1 (weight average molecular weight 10,000),
An energy ray-curable adhesive was obtained by mixing 3 parts of phenacyl tetramethylene sulfonium tetrafluoroborate and 40 parts of butylglycidyl ether.

Example 8 To 100 parts of a copolymer of glycidyl methacrylate and styrene in a weight ratio of 3: 7 (weight average molecular weight 10,000),
5 parts of 2.6-dinitrobenzyl tosylate and an epoxy resin (ERL4206 manufactured by Union Carbide Co.) 60
And the parts were mixed to obtain an energy ray-curable adhesive.

Example 9 To 100 parts of a copolymer of glycidyl methacrylate and styrene in a weight ratio of 1: 1 (weight average molecular weight 10,000),
An energy ray curable adhesive was obtained by mixing 1 part of 4-methoxyphenyldiazonium hexafluorophosphate and 30 parts of phenylglycidyl ether.

Example 10 100 Copolymer (weight average molecular weight 5,000) of glycidyl methacrylate and butyl acrylate in a weight ratio of 3: 7
2 parts of 3.5-dibutyl-4-hydroxyphenylsulfonium hexafluorophosphate were mixed with 2 parts,
An energy ray curable adhesive was obtained.

Example 11 To 100 parts of a copolymer of glycidyl methacrylate and styrene in a weight ratio of 1: 1 (weight average molecular weight 10,000),
2- (4-methoxyphenyl) -4,6-di (trichloromethyl) triazine (2 parts) and phenylglycidyl ether
30 parts of tell was mixed to obtain an energy ray curable adhesive.

Example 12 To 100 parts of a copolymer of glycidyl methacrylate and styrene in a weight ratio of 1: 1 (weight average molecular weight 10,000),
Orthodiazonaphthoquinone-4-sulfonic acid ester 3
Parts and 50 parts of butylglycidyl ether are mixed,
An energy ray curable adhesive was obtained.

The above Examples 1 to 12 and Comparative Examples 1 to 4
For each of the energy ray-curable adhesives, the storage stability, curing time, thick film curability, and moisture resistance (corrosion) were examined in the following manner. The results are shown in Table 1 below.

<Storage stability> The adhesive was stored in a constant temperature bath at 60 ° C. for 8 weeks, and the deterioration such as viscosity increase or gelation of the adhesive was observed. did.

<Curing Time> On the test circuit [Eiichita's Organic Materials for Electronics, published by CMC, Inc. (1982), page 74, circuit having the same shape as FIG. 2.28], After applying the adhesive to a thickness of 40 μm, 4
Using a KW high-pressure mercury lamp, ultraviolet rays were irradiated at an irradiation distance of 8 cm, and the time (seconds) until the surface was cured was measured.

<Thick film curability> After applying an adhesive to a test circuit similar to the above with a thickness of 1 cm, ultraviolet rays are radiated in the same manner as above to cure the whole in the thickness direction. The time until was determined from the side surface of the adhesive layer by finger pressure.

<Moisture resistance (corrosion)> After applying an adhesive to a thickness of 40 μm on a test circuit similar to the above,
100 chips were prepared by irradiating UV rays for 15 seconds and cured in the same manner as above, and using these, a pre-cooker tester (conditions: 121 ° C., 2 atm ×
1,000 hours) to determine the defective rate of aluminum wiring (breakage failure and insulation failure) in the circuit by Masahide Nakagawa, "Practical printed wiring board mounting design", Nikkan Kogyo Shimbun (1989).
According to the method described on page 118, a bare board test (40V) was performed to obtain the value.

[0050]

[Table 1]

As is clear from Table 1 above, the energy ray-curable adhesive of the present invention has good storage stability, excellent curing rate and thick-film curability, and is a Since it does not contain an antimony heavy metal as in Comparative Example 4, it does not corrode or break the wiring of the semiconductor when used for electronic parts applications, and can be used very suitably in terms of reliability. Recognize.

Claims (1)

[Claims] 1. The following components a to c: a) 100 parts by weight of a polymer using at least glycidyl acrylate or glycidyl methacrylate as a monomer b) Boron, phosphorus, sulfur in the counterion of the generated proton, 0.01 to 20 parts by weight of a photoproton generator containing an atom selected from chlorine and oxygen c) An energy ray curable adhesive containing 0 to 70 parts by weight of a reactive diluent.