JP2012062477A - Circuit connecting component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit connecting component that enables connection in seconds to hours at 100-130°C and can prevent an expansion of a substrate due to heat.SOLUTION: The circuit connecting component includes: an adhesive composition containing an oxetane compound and an epoxy resin; and conductive particles, wherein the oxetane compound has two to four oxetane ring in its molecule. The circuit connecting component is formed between electrodes facing each other, which are respectively provided on two circuit substrates, and is a film used for obtaining the electrical connection of both electrodes and the adhesion of the two circuit substrates through heating and pressing.

Description

  The present invention relates to a circuit connecting member.

  Adhesives that bond two circuit boards and provide electrical continuity between these electrodes are known to be thermoplastic materials such as styrene and polyester, and thermosetting materials such as epoxy and silicone. It has been. In this case, conductive particles are blended in the adhesive, and electrical connection is obtained in the thickness direction of the adhesive by pressurization (for example, JP-A-55-104007), and connection without using conductive particles is performed. In some cases, electrical connection is obtained by contact of fine irregularities on the electrode surface by pressurizing (for example, JP-A-60-262430).

  In the past, these bonds have been performed by pressing at a relatively high temperature (140 ° C. to 200 ° C.) for a short time. However, if the connection temperature is lowered, for example, when connection is possible at 100 ° C. or 120 ° C., the displacement of the connection region due to the difference in the thermal expansion coefficient of the connection body is reduced, and the material to be connected is made cheaper. Since it can be switched to one having low heat resistance, it is industrially desirable. Conventionally used thermosetting adhesives are usually connected at a high temperature of 170 ° C. or higher in order to carry out the curing reaction more reliably, but the materials of the two types of substrates generally connected are different. Therefore, the respective thermal expansion coefficients are different, and it is difficult to form a connection body with a narrow pitch.

  The inventions according to claims 1 to 4 provide a circuit connection member that can be connected at 100 to 130 ° C. for several tens of seconds to several hours and can suppress expansion of the substrate due to heating. In addition to the effects of the inventions of claims 1 to 4, the inventions of claims 5 to 7 further provide a circuit connecting member having excellent electrical characteristics during circuit connection. In addition to the effects of the inventions of the first to seventh aspects, the invention described in the eighth to ninth aspects provides a circuit connection member having higher connection reliability.

  The present invention relates to an adhesive composition containing an oxetane compound and a circuit connection member containing conductive particles. The present invention also relates to an adhesive composition containing (1) an oxetane compound, (2) a film-forming polymer, and (3) a curing catalyst as essential components, and a circuit connection member comprising conductive particles. The present invention also relates to the circuit connection member, wherein the curing catalyst is an onium salt.

  Moreover, this invention relates to the said connection member for circuits whose film property provision polymer is a phenoxy resin. Moreover, this invention relates to the said member for circuit connection whose film property provision polymer is a vinyl copolymer. Moreover, this invention relates to the said member for circuit connection whose film property provision polymer is a vinyl copolymer containing methyl methacrylate as a copolymerization monomer. The present invention also relates to the circuit connecting member, wherein the film-imparting polymer is a vinyl copolymer containing styrene as a copolymerization monomer.

  The present invention also relates to the circuit connecting member, wherein the molecular weight of the oxetane compound is in the range of 102 to 5000. The present invention also relates to the circuit connecting member, wherein the oxetane compound is an oxetane compound having 1 to 4 oxetane rings in the molecule.

  The connection member for a circuit according to claims 1 to 11 can be connected at 100 to 130 ° C. for several tens of seconds to several hours, and can suppress expansion of the substrate due to heating.

  The adhesive composition in the present invention will be described. The oxetane compound, which is an essential component in the adhesive composition used in the present invention, is not particularly limited as long as it has an oxetane ring in the molecule, and any compound can be used. Among these, a circuit connecting member using an oxetane compound having 1 to 4 oxetane rings in the molecule is preferable from the viewpoint that cracking hardly occurs after curing.

  Examples of the compound having one oxetane ring include compounds represented by the following general formula (1).

In general formula (1), R ¹ is a hydrogen atom, a methyl group, an ethyl group, a propyl group or a butyl group, such as an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, or an allyl group. An aryl group, a furyl group or a thienyl group. R ² is an alkyl group having 1 to 6 carbon atoms such as methyl group, ethyl group, propyl group or butyl group, 1-propenyl group, 2-propenyl group, 2-methyl-1-propenyl group, 2-methyl- Such as 2-propenyl group, 1-butenyl group, 2-butenyl group or 3-butenyl group, alkenyl group having 2 to 6 carbon atoms, phenyl group, benzyl group, fluorobenzyl group, methoxybenzyl group, phenoxyethyl group, etc. A group having an aromatic ring, an alkylcarbonyl group having 2 to 6 carbon atoms such as an ethylcarbonyl group, a propylcarbonyl group or a butylcarbonyl group, an alkylcarbonyl group having 2 to 6 carbon atoms such as an ethoxycarbonyl group, a propoxycarbonyl group or a butoxycarbonyl group; Alkoxycarbonyl group, ethylcarbamoyl group, propylcarbamoyl group, butylcarbamoyl group or Etc. pentylcarbamoyl group having a carbon number of 2-6 of a N- alkylcarbamoyl group.

  Next, examples of the compound having two oxetane rings include a compound represented by the following general formula (2).

In the general formula (2), R ¹ is the same group as that in the general formula (1). R ³ is, for example, a linear or branched alkylene group such as an ethylene group, a propylene group or a butylene group, or a linear or branched poly (alkyleneoxy) such as a poly (ethyleneoxy) group or a poly (propyleneoxy) group. ) Group, propenylene group, methylpropenylene group or butenylene group or other linear or branched unsaturated hydrocarbon group, carbonyl group, alkylene group containing carbonyl group, alkylene group containing carboxyl group or alkylene group containing carbamoyl group Etc.

R ³ is also a polyvalent group selected from the groups represented by the following general formulas (3) to (14).

In the general formula (3), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, a methoxy group, an ethoxy group, a propoxy group or a butoxy group. An alkoxy group having 1 to 4 carbon atoms, a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group.

である。 In the general formula (4), R ⁵ represents an oxygen atom, a sulfur atom, a methylene group,

It is.

In the general formula (5), R ⁶ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, a methoxy group, an ethoxy group, a propoxy group or a butoxy group. An alkoxy group having 1 to 4 carbon atoms, a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group.

である。 In the general formula (6), R ⁵ represents an oxygen atom, a sulfur atom, a methylene group,

It is.

In the general formula (7) and the general formula (8), R ⁸ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, a methoxy group, an ethoxy group, or a propoxy group. Or a C 1-4 alkoxy group such as a butoxy group, a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group or a carbamoyl group. Further, R ⁸ may be substituted on 2 to 4 naphthalene rings.

Among the compounds having two oxetane rings, preferred examples other than the above-described compounds include compounds represented by the following general formula (15). In general formula (151), R ¹ is the same group as in general formula (1).

  Examples of the compound having 3 to 4 oxetane rings include compounds represented by the following general formula (16).

In General Formula (16), R ¹ is the same group as in General Formula (1), and m is 3 or 4. R ⁹ is, for example, a branched alkylene group having 1 to 12 carbon atoms such as groups represented by the following general formula (17), formula (18) and formula (19), a group represented by the following general formula (20), etc. And a branched poly (alkyleneoxy) group.

〔一般式（１７）において、Ｒ¹⁰はメチル基、エチル基又はプロピル基等の低級アルキル基である〕

[In the general formula (17), R ¹⁰ is a lower alkyl group such as a methyl group, an ethyl group or a propyl group]

〔一般式（２０）において、ｎは１〜１０の整数である〕

[In General Formula (20), n is an integer of 1 to 10]

  Preferable specific examples of the oxetane compound used in the present invention include the following compounds.

  In addition to these, compounds having 1 to 4 oxetane rings having a relatively high molecular weight of about 1,000 to 5,000 are also included. Furthermore, as a polymer containing oxetane, a polymer having an oxetane ring in a side chain (see, for example, K. Sato, A. Kameyama and T. Nishikubo, Macromolecules, 25, 1198 (1992)) can be used in the same manner. In the present invention, two or more kinds of oxetane compounds can be used in combination.

  Further, the adhesive composition in the present invention may contain a curing catalyst and a film imparting polymer in addition to the oxetane compound. Hereinafter, these components that can be added will be described.

  Examples of the curing catalyst used in the present invention include onium salts, tertiary amines, quaternary ammonium salts, imidazole compounds, boron compounds and phosphorus compounds.

〔式中、カチオンはオニウムであり、ＺはＳ、Ｓｅ、Ｔｅ、Ｐ、Ａｓ、Ｓｂ、Ｂｉ、Ｏ、Ｉ、Ｂｒ、ＣｌまたはＮ≡Ｎであり、Ｒ¹¹、Ｒ¹²、Ｒ¹³及びＲ¹⁴は同一または異なる有機基であり、ａ、ｂ、ｃ、ｄは、それぞれ０〜３の整数であって（ａ＋ｂ＋ｃ＋ｄ）は、Ｚの価数に等しく、Ｍは、ハロゲン化物錯体の中心原子を構成する金属またはメタロイドであり、例えばＢ、Ｐ、Ａｓ、Ｓｂ、Ｆｅ、Ｓｎ、Ｂｉ、Ａｌ、Ｃａ、Ｉｎ、Ｔｉ、Ｚｎ、Ｓｃ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏなどであり、Ｘはハロゲン原子であり、ｐはハロゲン化物錯体イオンの正味の電荷であり、ｑはハロゲン化物錯体イオン中の原子の数である〕 Examples of onium salts include compounds represented by the following general formula (27).

[Wherein the cation is onium, Z is S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl or N≡N, and R ¹¹ , R ¹² , R ¹³ and R ¹⁴ is the same or different organic group, a, b, c and d are each an integer of 0 to 3, (a + b + c + d) is equal to the valence of Z, and M is the central atom of the halide complex. A constituent metal or metalloid, for example, B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc., X is a halogen atom Where p is the net charge of the halide complex ion and q is the number of atoms in the halide complex ion.

Specific examples of the anion (MX _{q + p} ) in the general formula (27) include tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), Examples include hexafluoroarsenate (AsF ₆ ⁻ ) and hexachloroantimonate (SbCl ₆ ⁻ ).

In addition, an onium salt having an anion represented by the general formula [MX _q (OH) ⁻ ] in the general formula (27) can be used, and further, a perchlorate ion (ClO ₄ ⁻ ), Oniums with other anions such as trifluoromethanesulfonate ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, trinitrobenzenesulfonate anion, trinitrotoluenesulfonate anion A salt can also be used. These onium salts can be used alone or in combination of two or more. Among such onium salts, particularly effective onium salts are aromatic onium salts.

（式中、Ｒ¹⁵〜Ｒ¹⁷はアルキル基、アリール基であり、同一であっても良く、Ｍはハロゲン化合物錯体の中心原子である金属又は半金属であり、Ｂ、Ｐ、Ａｓ、Ｆｅ、Ｓｎ、Ｂｉ、Ａｌ、Ｃａ、Ｉｎ、Ｔｉ、Ｚｎ、Ｓｅ、Ｖ、Ｃｒ、Ｍｎ、Ｃｏなどであり、Ｘはハロゲンであり、ｒはＭとＸの種類によって決まる６までの自然数である） Of these, onium salt compounds represented by the following general formula (28) are preferred.

(Wherein R ^{15 to} R ¹⁷ are an alkyl group and an aryl group, and may be the same, M is a metal or a semimetal which is a central atom of a halogen compound complex, and B, P, As, Fe, (Sn, Bi, Al, Ca, In, Ti, Zn, Se, V, Cr, Mn, Co, etc., X is a halogen, and r is a natural number up to 6 determined by the types of M and X)

Furthermore, an anion of the general formula (MX _r (OH) ⁻ ) can be used in place of the anion (MX _r ⁻ ). In addition, other anions (MX _r ⁻ ) can be replaced by perchlorate ion (ClO ₄ ⁻ ), trifluoromethyl sulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ). And so on. Among these, those having the structure of the following general formula (29) are commercially available and useful.

（式中、Ｒ¹⁸〜Ｒ²⁰はアリール基又はアルキル基を示す）市販品の具体例としては、サンエイドＳＩシリーズ（三新化学）などを挙げることができる。

(Wherein R ^{18 to} R ^{20 each} represent an aryl group or an alkyl group) Specific examples of commercially available products include Sun Aid SI Series (Sanshin Chemical).

  Tertiary amines include triethanolamine, tetramethylhexanediamine, triethylenediamine, dimethylaniline, dimethylaminoethanol, diethylaminoethanol, 2,4,6-tris (dimethylaminomethyl) phenol, N, N'-dimethylpiperazine, pyridine, picoline, 1,8-diaza-bicyclo (5,4,0) undecene-7, benzyldimethylamine and 2- (dimethylamino) methylphenol. Quaternary ammonium salts include dodecyltrimethylammonium chloride, cetyltrimethylammonium chloride, benzyldimethyltetradecylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide and stearyltrimethylammonium chloride.

  Examples of imidazoles include 2-methyl imidazole, 2-undecyl imidazole, 2-ethyl imidazole, 1-benzyl-2-methyl imidazole and 1-cyanoethyl-2-undecyl imidazole. There are. Examples of the boron compound include tetraphenyl boron salts such as triethyleneamine tetraphenyl borate and N-methylmorpholine tetraphenyl borate. Examples of phosphorus compounds include triphenylphosphine, tris-2,6dimethoxyphenylphosphine, tri-ptolylphosphine, triphenyl phosphite, tetra-n-butylphosphonium-o, o-diethyl phosphorodithioate. And tetra-n-butylphosphonium bromide.

  Among these curing catalysts, onium salts are preferable because they can achieve both stability during storage and high reactivity when used as an adhesive composition or a circuit connecting material. Although the addition amount of a curing catalyst is not specifically limited, Usually, it is 0.01-20 weight part with respect to 100 weight part of oxetane compounds.

  The film property-imparting polymer in the present invention is not particularly limited as long as it has an ability to form a film, and examples thereof include phenoxy resin, vinyl copolymer, polyamide, polyimide, polyether, and polysulfone. Examples of the phenoxy resin include bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol A, and F copolymer type phenoxy resin.

  Examples of the vinyl monomer used in the vinyl copolymer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, and acrylic acid n. -Propyl, n-propyl methacrylate, iso-propyl acrylate, iso-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, sec- Butyl, sec-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, heptyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate Octyl acrylate, octyl methacrylate, nonyl acrylate, nonyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, tetradecyl methacrylate, hexadecyl acrylate, hexadecyl methacrylate, acrylic acid Octadecyl, octadecyl methacrylate, eicosyl acrylate, eicosyl methacrylate, docosyl acrylate, docosyl methacrylate, cyclopentyl acrylate, cyclopentyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, cycloheptyl acrylate, cycloheptyl methacrylate, acrylic acid Benzyl, benzyl methacrylate, phenyl acrylate, phenyl methacrylate, methoxyethyl acrylate , Methoxyethyl methacrylate, methoxydiethylene glycol acrylate, methoxydiethylene glycol methacrylate, methoxydipropylene glycol acrylate, methoxydipropylene glycol methacrylate, methoxytriethylene glycol acrylate, methoxytriethylene glycol methacrylate, 2-hydroxyacrylate Ethyl, 2-hydroxyethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, 2-chloroethyl acrylate, methacrylic acid 2-chloroethyl acid, 2-fluoroethyl acrylate, 2-fluoromethacrylic acid Chill, 2-cyanoethyl acrylate, 2-cyanoethyl methacrylate, ethylene, styrene, α-methylstyrene, vinyl toluene, vinyl chloride, vinyl acetate, N-vinyl pyrrolidone, butadiene, isoprene, chloroprene, acrylamide, methacrylamide, acrylonitrile, Examples include methacrylonitrile. These may be used alone or in combination of two or more.

  These film property-imparting polymers can be used alone or in admixture of two or more. The blending amount of the film property-imparting polymer is preferably 3 to 10,000 parts by weight and more preferably 5 to 5,000 parts by weight with respect to 100 parts by weight of the oxetane compound. If the blending amount is less than 3 parts by weight, the formability of the film tends to decrease, and if it exceeds 10,000 parts by weight, the adhesive strength tends to decrease.

  Moreover, the adhesive composition in the present invention may contain a curing agent in addition to the above components. The curing agent is not particularly limited as long as it cures in the presence of an oxetane compound and a curing catalyst, such as an amine-based, acid anhydride-based, or phenol-based curing agent.

  Examples of amine curing agents include aliphatic polyamines, polyamide polyamines, alicyclic polyamines, aromatic polyamines and others, and examples of aliphatic polyamines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and diethylaminopropylamine. The polyamide polyamine includes polyamide polyamine, and the alicyclic polyamine includes mensendiamine, isophoronediamine, N-aminoethylpiperazine, 3,9-bis (3-aminopropyl) -2,4. , 8,10-tetraoxaspiro (5,5) undecane adduct, bis (4-amino-3-methylcyclohexyl) methane, bis (4-aminocyclohexyl) methane, and the like. Min, diaminodiphenylmethane, diaminodiphenyl sulfone and m- phenylenediamine. Examples of the other, include dicyandiamide and adipic acid Jihirashido.

  Examples of the acid anhydride curing agent include hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Examples of phenolic curing agents are those having 2 or more, preferably 3 or more phenolic hydroxyl groups in the molecule. Specifically, phenol or substituted phenol such as o-cresol, p-cresol, t-butylphenol, cumylphenol, phenylphenol and formaldehyde are reacted with acid or alkali. The thing which was done is mentioned. Instead of formaldehyde, other aldehydes such as benzaldehyde, crotonaldehyde, salicylaldehyde, hydroxybenzaldehyde, glyoxal and terephthalaldehyde can be used. A reaction product of resorcin and aldehyde and polyvinyl phenol can also be used as the curing agent of the present invention. The blending ratio when these curing agents are added is preferably in the range of 10 to 100 parts by weight with respect to 100 parts by weight of the oxetane compound.

  In addition to the above components, the adhesive composition according to the present invention can also contain a reactive diluent, a coupling agent, and a commonly used epoxy resin.

  Specific epoxy resins include phenol ether type epoxy resins [for example, bispheninol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, halogenated bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol. Nopolac type epoxy resin, halogenated phenol novolac type epoxy resin, etc.]: Ether type epoxy resin [eg, condensate of polyol, polyether polyol, etc. and epichlorohydrin]; ester epoxy resin [eg, glycidyl (meta ) Copolymer of acrylate and ethylenically unsaturated monomer (acrylonitrile, etc.)]: (A-4) Glycidylamine epoxy resin [for example, aniline, diaminodiphenylmethane, aminophenol Condensates of amines such as xylylenediamine, halogenated aniline, bisaminomethylcyclohexane and epichlorohydrin, etc.]; non-glycidyl type epoxy resins [for example, aliphatic and cycloaliphatic epoxy resins, etc.]; monofunctional epoxy compounds [ Styrene oxide, cresyl glycidyl ether, phenyl glycidyl luter, 2-ethylhexyl glycidyl ether, etc.], polyfunctional epoxy compounds [diglycidyl ether, polypropylene glycol diglycidyl ether, butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, di Glycidyl aniline, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, etc.], vinyl bond-containing epoxy compound [allyl glycidyl ether, Rishijiru (meth) acrylate, vinyl cyclohexene monoepoxide, etc.] or the like. These epoxy resins may be used alone or in combination of two or more.

  When these epoxy resins are used, the mixing amount is preferably 0.01 to 500 parts by weight, more preferably 0.1 to 400 parts by weight, and most preferably 0.5 to 300 parts by weight with respect to 100 parts by weight of the oxetane compound. preferable. When the mixing amount of the epoxy resin is less than 0.01 parts by weight, there is a tendency that a substantial addition effect cannot be obtained, while when it exceeds 500 parts by weight, the effect speed tends to be slow.

  As the conductive particles in the present invention, there are metal particles such as Au, Ag, Ni, Cu, and solder, carbon, etc., and the above-described conductive layer is formed by coating or the like on non-conductive glass, ceramic, plastic, or the like. What you did is fine. In the case of using plastic as a core or hot-melt metal particles, it is preferable because it has deformability by heating and pressurization, so that the contact area with the electrode is increased at the time of connection and reliability is improved. The conductive particles are properly used in a wide range of 0.1 to 30% by volume with respect to 100 volumes of adhesive components (resin components such as oxetane compounds, curing catalysts, and film-forming polymers). In order to prevent a short circuit of the circuit due to excessive conductive particles, 0.1 to 10% by volume is more preferable.

  The electrode connection using the circuit connection member of the present invention will be described. This method is an electrode connection method in which a circuit connecting member is formed between opposing electrodes on a substrate, and contact between both electrodes and adhesion between the substrates are obtained by heating and pressing. As the substrate for forming the electrodes, semiconductors, inorganic substances such as glass and ceramics, organic substances such as polyimide and polycarbonate, and combinations of these composites such as glass / epoxy can be applied.

  Hereinafter, the present invention will be described with reference to examples.

  Example 1 As a film-imparting polymer, 50 g of bisphenol A type phenoxy resin (trade name PKHC, number average molecular weight 45,000, manufactured by Union Carbide Co., Ltd.) was used and dissolved in ethyl acetate to obtain a solid content of 40% by weight. It was set as the solution. To this solution, 50 g of xylylene bisoxetane (Ube Industries, oxetane equivalent 167) and 1 g of onium salt (trade name Sun Aid SI-100, manufactured by Sanshin Chemical Co., Ltd.) were mixed and stirred until uniform. Thus, a resin solution (a) was obtained. This resin solution (a) was applied to a fluororesin film having a thickness of 80 μm by using a coating apparatus, and a circuit connecting member having a thickness of 25 μm was obtained by hot air drying at 60 ° C. for 10 minutes. The obtained circuit connecting member had sufficient flexibility at room temperature, and even when it was left at 5 ° C. for 30 days, there was almost no change in the properties of the film, and it showed good storage stability.

  Example 2 Conductive particles (in which a nickel layer having a thickness of 0.2 μm is provided on the surface of particles having polystyrene as a core, and a gold layer having a thickness of 0.02 μm is provided outside the nickel layer) are mixed with a resin solution ( A) 3% by volume of resin solid content of 100% by volume is dispersed and applied to a fluororesin film having a thickness of 80 μm using a coating apparatus, and the thickness of the adhesive layer is reduced by hot air drying at 60 ° C. for 10 minutes. A circuit connection member of 25 μm was obtained. The obtained circuit connecting member had sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there was almost no change in the properties of the circuit connecting member and showed good storage stability. .

  Comparative Example 1 As in Example 1 except that bisphenol type liquid epoxy resin (bisphenol A type epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., trade name Epicoat 828, epoxy equivalent 184) was used instead of xylylene bisoxetane. Thus, a circuit connection member was obtained.

  Comparative Example 2 Similar to Example 2 except that bisphenol type liquid epoxy resin (bisphenol A type epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., trade name Epicoat 828, epoxy equivalent 184) was used instead of xylylene bisoxetane. Thus, a circuit connection member was obtained.

  (Circuit connection) Flexible circuit board having 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm using the circuit connection members obtained in Example 1, Example 2, Comparative Example 1 and Comparative Example 2. (FPC) were heated and pressurized at 120 ° C. and 2 MPa for 20 seconds to be connected over a width of 2 mm. At this time, after pasting the adhesive surface of the circuit connection member on one FPC in advance, it is temporarily connected by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds, and then the fluororesin film is peeled off. Connected to one FPC.

  Example 3 50 g of bisphenol A type phenoxy resin (trade name PKHC, average molecular weight 45,000, manufactured by Union Carbide Co., Ltd.) was used as a film-imparting polymer, and this was dissolved in ethyl acetate to obtain a solution having a solid content of 40%. did. In this solution, 50 g of catechol bisoxetane (1,2-bis [(3-methyl-3-oxetanyl) methyl] benzene, oxetane equivalent 139) and onium salt (Sun-Aid SI-100 (manufactured by Sanshin Chemical Co., Ltd.)) 1 g was mixed and stirred until uniform to obtain a resin solution (b). Conductive particles (with a nickel layer having a thickness of 0.2 μm provided on the surface of a particle having polystyrene as a core and a gold layer having a thickness of 0.02 μm provided on the outside of the nickel layer) were added to the resin solution (b). 3% by volume of resin solid content of 100% by volume is dispersed and coated on a fluororesin film with a thickness of 80 μm using a coating device, and dried with hot air at 60 ° C. for 10 minutes and a circuit with an adhesive layer thickness of 25 μm A connecting member was obtained. The obtained circuit connecting member had sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there was almost no change in the properties of the circuit connecting member and showed good storage stability. .

  Example 4 Example 3 except that 50 g of resorcinol bisoxetane (1,3-bis [(3-methyl-3-oxetanyl) methyl] benzene, oxetane equivalent 139) was used instead of catechol bisoxetane in Example 3. The circuit connection member having a thickness of 25 μm was obtained in the same manner as described above. The obtained circuit connecting member had sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there was almost no change in the properties of the circuit connecting member and showed good storage stability. .

  Example 5 Vinyl copolymer A (methyl methacrylate: methacrylic acid: ethyl acrylate = 52.8: 17.5: 29.8 (mol%), average molecular weight 70,000) was used as a film-imparting polymer. Otherwise, the same operation as in Example 3 was performed to obtain a circuit connecting member having an adhesive layer thickness of 25 μm. The obtained circuit connecting member has sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there is almost no change in the properties of the circuit connecting member, and it shows good storage stability. It was.

  Example 6 Similar to Example 3 except that vinyl copolymer B (methyl methacrylate: styrene: ethyl acrylate = 40: 30: 30 (mol%), average molecular weight 50,000) was used as the film-imparting polymer. To obtain a circuit connecting member having an adhesive layer thickness of 25 μm. The obtained circuit connecting member has sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there is almost no change in the properties of the circuit connecting member, and it shows good storage stability. It was.

  Example 7 Vinyl copolymer A (methyl methacrylate: methacrylic acid: ethyl acrylate = 52.8: 17.5: 29.8 (mol%), average molecular weight 70,000) was used as a film-imparting polymer. Except for the above, the same operation as in Example 4 was performed to obtain a circuit connecting member having an adhesive layer thickness of 25 μm. The obtained circuit connecting member has sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there is almost no change in the properties of the circuit connecting member, and it shows good storage stability. It was.

  Example 8 Similar to Example 4 except that vinyl copolymer B (methyl methacrylate: styrene: ethyl acrylate = 40: 30: 30 (mol%), average molecular weight 50,000) was used as the film-imparting polymer. To obtain a circuit connecting member having an adhesive layer thickness of 25 μm. The obtained circuit connecting member has sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there is almost no change in the properties of the circuit connecting member, and it shows good storage stability. It was.

  Example 9 Instead of 50 g of catechol bisoxetane, a mixture of 45 g of catechol bisoxetane and 5 g of bisphenol type liquid epoxy resin (Bisphenol A type epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., trade name Epicoat 828, epoxy equivalent 184) was used. Otherwise, the same operation as in Example 3 was performed to obtain a circuit connecting member having an adhesive layer thickness of 25 μm. The obtained circuit connecting member has sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there is almost no change in the properties of the circuit connecting member, and it shows good storage stability. It was.

  Example 10 Instead of 50 g of catechol bisoxetane, a mixture of 45 g of catechol bisoxetane and 5 g of bisphenol type liquid epoxy resin (bisphenol A type epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., trade name Epicoat 828, epoxy equivalent 184) was used. Otherwise, the same operation as in Example 5 was performed to obtain a circuit connection member having an adhesive layer thickness of 25 μm. The obtained circuit connecting member has sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there is almost no change in the properties of the circuit connecting member, and it shows good storage stability. It was.

  Example 11 Instead of 50 g of catechol bisoxetane, a mixture of 45 g of catechol bisoxetane and 5 g of bisphenol type liquid epoxy resin (bisphenol A type epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd., trade name Epicoat 828, epoxy equivalent 184) was used. Otherwise, the same operation as in Example 6 was performed to obtain a circuit connecting member having an adhesive layer thickness of 25 μm. The obtained circuit connecting member has sufficient flexibility at room temperature, and even when left at 5 ° C. for 30 days, there is almost no change in the properties of the circuit connecting member, and it shows good storage stability. It was.

  (Circuit connection) Using the circuit connection members obtained in Example 3 and Example 4, flexible circuit boards (FPC) having 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 18 μm were combined at 130 ° C. It was heated and pressurized at 40 MPa for 20 seconds and connected over a width of 2 mm. At this time, after pasting the adhesive surface of the circuit connection member on one FPC in advance, it is temporarily connected by heating and pressing at 70 ° C. and 1 MPa for 5 seconds, and then the fluororesin film is peeled off to the other FPC. Connected to FPC.

(Measurement of tensile shear adhesive strength) High temperature and high humidity treatment (85 ° C., 85%) for connection bodies connected using the circuit connection members obtained in Examples 1 to 11, Comparative Example 1 and Comparative Example 2 Tensile shear adhesion strength (JIS, K-6850, where bonding area is 3 × 1 mm ² , average of 5 pieces) before and after was kept in a high-temperature and high-humidity bath of RH for 500 hours. The results are shown in Tables 1 and 2.

  (Measurement of connection resistance) After connection of the circuit, the resistance value between adjacent circuits of the FPC including the connection portion is initially maintained with a multimeter after being held in a high-temperature and high-humidity tank at 85 ° C. and 85% RH for 500 hours. It was measured. The resistance value is shown as an average (x + 3σ) of 150 resistances between adjacent circuits. The results are shown in Tables 1 and 2.

  As shown in Tables 1 and 2, the circuit connection members obtained in Examples 1 to 11 exhibited good adhesion and connectivity. In addition, the initial connection resistance was low, and the increase in resistance after the high-temperature and high-humidity test was slight, indicating high durability. On the other hand, in Comparative Examples 1 and 2 using an epoxy compound instead of the oxetane compound, sufficient adhesive strength was not obtained.

Claims (10)

An adhesive composition containing an oxetane compound and an epoxy resin and conductive particles;
The oxetane compound comprises an oxetane compound having 2 to 4 oxetane rings in its molecule;
A circuit connection member, which is a film formed between two opposing electrodes on a circuit board and used to obtain electrical connection between the electrodes and adhesion between the two circuit boards by heating and pressing.   The circuit connection member according to claim 1, wherein the adhesive composition contains the oxetane compound, the epoxy resin, a film-imparting polymer, and a curing catalyst as essential components.   The circuit connection member according to claim 2, wherein the curing catalyst is an onium salt.   The circuit connection member according to claim 2, wherein the film property-imparting polymer is a phenoxy resin.   The circuit connection member according to claim 2 or 3, wherein the film property-imparting polymer is a vinyl copolymer.   The circuit connecting member according to claim 2 or 3, wherein the film property-imparting polymer is a vinyl copolymer containing methyl methacrylate as a copolymerization monomer.   The circuit connection member according to claim 2 or 3, wherein the film property-imparting polymer is a vinyl copolymer containing styrene as a copolymerization monomer.   The circuit connection member according to claim 1, wherein each of the two circuit boards has a different coefficient of thermal expansion.   The circuit connection member according to claim 1, wherein the conductive particles are contained in an amount of 0.1 to 30% by volume with respect to 100% by volume of the adhesive composition.   The circuit connection member according to any one of claims 1 to 9, wherein the molecular weight of the oxetane compound is in a range of 102 to 5000.