JP2010153882A - Circuit connecting material, connection structure of circuit member and method of connecting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit connecting material with which sufficient adhesive strength can be obtained, when connecting a circuit member having a substrate made of polyester terephthalate, polyimide resin, polyester sulfone, acrylic resin or glass, or a circuit member, wherein a layer made of silicone resin, polyimide resin, acrylic resin, etc. is formed on its surface. <P>SOLUTION: The circuit connecting material 1 contains an adhesive composition which is cured by light or heat, and an organic compound having an urethane group and an ester group and is used to connect circuit members with each other. The organic compound has a weight-average molecular weight of 5,000 to 100,000. The circuit connecting material 1 is used to connect circuit members with each other, that are provided with a substrate and a circuit electrode formed on its main surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circuit connecting material for connecting circuit members having circuit electrodes, a circuit member connecting structure, and a circuit member connecting method.

  In recent years, the density of circuits has been increasing in the field of precision electronic equipment, and the electrode width and the electrode interval have become extremely narrow. In order to solve this problem, circuit connection materials for electric and electronic use that have excellent low-temperature fast-curing properties and have a sufficiently long pot life have been developed (for example, Patent Documents 1 and 2).

International Publication No. 98/44067 Pamphlet International publication 01/015505 pamphlet

  However, the conventional circuit connection member has a problem that the adhesive strength is not always sufficient depending on the type of material constituting the circuit member to be connected. In particular, when the substrate supporting the circuit electrode is a substrate formed of polyester terephthalate, polyimide resin, polyethersulfone, acrylic resin or glass, or the surface of the circuit member is made of silicone resin, polyimide resin, acrylic resin, or the like. When the layer is formed, there is a problem that the adhesive strength is remarkably lowered.

  Therefore, in the present invention, a circuit member having a substrate formed of polyester terephthalate, polyimide resin, polyethersulfone, acrylic resin or glass, or a layer made of silicone resin, polyimide resin, acrylic resin or the like is formed on the surface. It is an object of the present invention to provide a circuit connecting material that can provide a sufficient adhesive strength when connected circuit members are connected.

  In order to solve the above problems, the circuit connection material of the present invention contains an adhesive composition that is cured by light or heat, and an organic compound having a urethane group and an ester group, and the weight average molecular weight of the organic compound is 5000. It is a circuit connection material for connecting circuit members having circuit electrodes formed on the main surface of the substrate.

  The circuit connection material of the present invention is a substrate formed of polyester terephthalate, polyimide resin, polyethersulfone, acrylic resin or glass by using an adhesive composition and an organic compound having a urethane group and an ester group. Adequate adhesive strength can be obtained when connecting a circuit member having a surface or a circuit member having a surface formed of a layer made of silicone resin, polyimide resin, acrylic resin, or the like.

  The adhesive composition preferably contains a radical polymerizable compound and a radical initiator that generates radicals by heating or light. In this case, it is more preferable that the radical polymerizable compound contains a phosphate ester compound having an acrylate group or a methacrylate group, from the viewpoint that the adhesive strength with the surface of an inorganic substance such as a metal can be further improved.

  The glass transition temperature of the organic compound is preferably 50 ° C. or higher. When the organic compound has both a urethane group and an ester group and has a glass transition temperature of 50 ° C. or higher, the adhesive strength particularly after the high-temperature and high-humidity test can be further increased. When the organic compound has only one of a urethane group and an ester group, when the glass transition temperature is 50 ° C. or higher, a decrease in the adhesive strength in a high-temperature and high-humidity environment can be suppressed, but the initial adhesive strength is Not enough.

  The organic compound preferably has an aromatic group and / or a cyclic aliphatic group. The weight average molecular weight of the organic compound is preferably 5000 to 60000, and more preferably 27000 to 60000.

  The circuit connection material of the present invention preferably contains conductive particles. Thereby, the circuit members can be more stably electrically connected while maintaining the insulation state between the circuit electrodes on the same substrate.

  The circuit member connection structure according to the present invention includes a first circuit member having a first substrate and a first circuit electrode formed on the main surface thereof, and a second substrate and the main surface thereof. The second circuit member having the second circuit electrode formed is made of a cured product of the circuit connection material of the present invention, and is provided by the circuit connection member provided between the first and second circuit members. The circuit electrode and the second circuit electrode face each other and are connected so as to be electrically connected.

  The circuit member connection method of the present invention includes a first circuit member having a first substrate and a first circuit electrode formed on the main surface of the first substrate, and a layer comprising the circuit connection material of the present invention. And the second circuit member having the second circuit electrode formed on the second substrate and the main surface of the second substrate in this order so that the first circuit electrode and the second circuit electrode face each other. By heating and pressurizing the laminated body, the first circuit member and the second circuit member are connected so that the first circuit electrode and the second circuit electrode are electrically connected. is there.

  In the circuit member connection structure of the present invention, the circuit members are connected to each other by the circuit connection material of the present invention, so that the adhesive strength between the circuit members is high and the durability under high temperature and high humidity is also excellent. Further, according to the circuit member connection method of the present invention, the circuit members are connected by the circuit connection material of the present invention, so that the adhesive strength between the circuit members is high and the durability under high temperature and high humidity is also excellent. A circuit member connection structure is obtained.

  In the circuit member connection structure and the circuit member connection method, at least one of the first and second circuit electrodes has a surface made of gold, silver, tin, a platinum group metal, and indium-tin oxide. It is preferably made of a material containing at least one selected from the group.

  In the circuit member connection structure and the circuit member connection method, at least one of the first and second substrates is made of polyester terephthalate, polyethersulfone, epoxy resin, acrylic resin, polyimide resin, and glass. A substrate made of a material containing at least one selected from the group is preferred. Alternatively, a layer containing at least one selected from the group consisting of a silicone resin, an acrylic resin, and a polyimide resin is preferably formed between at least one of the first and second circuit members and the circuit connection member. . When the circuit connection material of the present invention is cured to form a circuit connection member, the circuit connection material exhibits high adhesive strength with a layer composed of these specific materials.

  According to the present invention, a circuit member having a substrate formed of polyester terephthalate, polyimide resin, polyethersulfone, acrylic resin or glass, or a layer made of silicone resin, polyimide resin, acrylic resin or the like is formed on the surface. Provided is a circuit connecting material capable of obtaining sufficient adhesive strength when connecting existing circuit members. Further, according to the present invention, it is easy to achieve both adhesive strength and other required characteristics (connection resistance, insulation, etc.). Further, according to the present invention, the range of material composition selection for obtaining the above effects is relatively wide.

It is sectional drawing which shows one Embodiment of the film-form circuit connection material by this invention. It is sectional drawing which shows one Embodiment of the connection structure of the circuit member by this invention. It is sectional drawing which shows other embodiment of the connection structure of the circuit member by this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

  The circuit connection material of the present invention contains an adhesive composition that is cured by light or heat. This adhesive composition preferably contains a radical polymerizable compound and a radical initiator that generates radicals by heating or light.

  The radical polymerizable compound has a functional group that is polymerized by an active radical, and for example, an acrylate compound, a methacrylate compound, and a maleimide compound are preferably used. The radical photopolymerizable compound may be either a polymerizable monomer or a polymerizable oligomer. Since the polymerizable oligomer generally has a high viscosity, when the polymerizable oligomer is used, it is preferable to adjust the viscosity by using a polymerizable monomer such as a polymerizable polyfunctional acrylate monomer having a low viscosity.

  As the acrylic acid ester compound or methacrylic acid ester compound, polymerizable oligomers such as epoxy acrylate oligomers, urethane acrylate oligomers, polyether acrylate oligomers, and polyester acrylate oligomers, and polymerizable monomers such as acrylic acid esters and methacrylic acid esters are used. .

  Examples of acrylic esters include trimethylolpropane triacrylate, polyethylene glycol diacrylate, polyalkylene glycol diacrylate, pentaerythritol acrylate, 2-cyanoethyl acrylate, cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 2- (2-ethoxyethoxy) ethyl acrylate, 2-ethoxyethyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, isobornyl acrylate, isodecyl acrylate, isooctyl acrylate, n- Lauryl acrylate, 2-methoxyethyl acrylate, 2-phenoxye Le acrylate, tetrahydrofurfuryl acrylate, neopentyl glycol diacrylate, dipentaerythritol hexaacrylate, and allyl acrylate, acrylate monomer monofunctional or polyfunctional the like.

  As the methacrylic acid ester, compounds similar to the above acrylic acid ester, t-butylaminoethyl methacrylate, cyclohexyl methacrylate, dicyclopentenyloxyethyl methacrylate, 2-hydroxyethyl methacrylate, isobornyl methacrylate, isodecyl methacrylate, Examples thereof include monofunctional or polyfunctional methacrylate monomers such as n-lauryl acrylate, stearyl methacrylate, tridecyl methacrylate, glycidyl methacrylate, and allyl methacrylate.

  As the acrylic ester or methacrylic ester, in addition to the above, a phosphoric ester compound having an acrylate group or a methacrylate group is preferably used. As this phosphate compound, for example, a compound represented by the following general formula (1) is preferable. In formula (1), n represents an integer of 1 to 3, and R represents a hydrogen atom or a methyl group. Specific examples of the compound represented by the formula (1) include mono (2-methacryloyloxyethyl) acid phosphate and di (2-methacryloyloxyethyl) acid phosphate. This phosphate ester compound is synthesized, for example, by a reaction between phosphoric anhydride and 2-hydroxyethyl acrylate.

  As the maleimide compound, those having at least two maleimide groups are preferable. Examples of maleimide compounds having two or more maleimide groups include 1-methyl-2,4-bismaleimidebenzene, N, N′-m-phenylenebismaleimide, N, N′-p-phenylenebismaleimide, N, N'-m-toluylene bismaleimide, N, N'-4,4-biphenylene bismaleimide, N, N'-4,4- (3,3'-dimethyl-biphenylene) bismaleimide, N, N'- 4,4- (3,3′-dimethyldiphenylmethane) bismaleimide, N, N′-4,4- (3,3′-diethyldiphenylmethane) bismaleimide, N, N′-4,4-diphenylmethane bismaleimide, N, N′-4,4-diphenylpropane bismaleimide, N, N′-4,4-diphenyl ether bismaleimide, N, N′-3,3′-diphe Rusulfone bismaleimide, 2,2-bis (4- (4-maleimidophenoxy) phenyl) propane, 2,2-bis (3-s-butyl-4-8 (4-maleimidophenoxy) phenyl) propane, 1, 1-bis (4- (4-maleimidophenoxy) phenyl) decane, 4,4′-cyclohexylidene-bis (1- (4maleimidophenoxy) -2-cyclohexylbenzene, 2,2-bis (4- (4 -Maleimidophenoxy) phenyl) hexafluoropropane, etc. These may be used alone or in combination.

  As a radically polymerizable compound, said compound is used individually or in mixture of multiple types as needed. In particular, urethane acrylate oligomers are preferable because curing shrinkage of the circuit connecting material can be suppressed and flexibility can be imparted to the cured product, and it is more preferable to use the urethane acrylate and one or more polymerizable monomers in combination.

  Examples of radical initiators that generate radicals by heating or light include compounds that generate active radicals by treatment of at least one of heating and light irradiation, such as organic peroxides, azo compounds, and photoinitiators. Used.

  Organic peroxides and azo compounds generate active radicals mainly by heating. When these compounds are used as radical initiators, one or more of the organic oxides and / or azo compounds are appropriately selected depending on the intended connection temperature, connection time, pot life, and the like.

  The organic peroxide preferably has a half-life temperature of 40 ° C. or more and a half-life of 1 minute at a temperature of 180 ° C. or less in terms of both high reactivity and sufficient pot life. More preferably, the temperature for a period of 10 hours is 60 ° C. or more, and the temperature for a half-life of 1 minute is 170 or less. Further, the organic oxide preferably has a chlorine ion or organic acid content of 5000 ppm or less in order to prevent corrosion of circuit electrodes (connection terminals) of the circuit member, and further, an organic matter generated after thermal decomposition. Those with less acid are more preferred.

  Specifically, as the organic oxide, diacyl peroxide, dialkyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, hydroperoxide, silyl peroxide and the like are preferably used.

  Diacyl peroxides include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, benzoyl Examples include peroxytoluene and benzoyl peroxide.

  Dialkyl peroxides include α, α ′ bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and t-butylcumi. Examples include ruperoxide.

  Examples of peroxydicarbonate include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, (2-Ethylhexylperoxy) dicarbonate, dimethoxybutylperoxydicarbonate, di (3-methyl-3-methoxybutylperoxy) dicarbonate and the like.

  Peroxyesters include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxynoedecanoate, and t-hexyl. Peroxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di (2- Ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate Nate, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane, -Hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanonate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (m-toluoyl par Oxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, t-butylperoxyacetate, di (t-butylperoxy) hexahydroterephthalate Etc.

  Peroxyketals include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t- Butyl peroxy) -3,3,5-trimethylcyclohexane, 1,1- (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) decane and the like.

  Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

  Examples of silyl peroxides include t-butyltrimethylsilyl peroxide, bis (t-butyl) dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis (t-butyl) divinylsilyl peroxide, and tris (t-butyl). Examples thereof include vinylsilyl peroxide, t-butyltriallylsilyl peroxide, bis (t-butyl) diallylsilyl peroxide, and tris (t-butyl) allylsilyl peroxide.

  These organic oxides and azo compounds can be used alone or as a mixture of two or more. Moreover, you may use a decomposition accelerator, an inhibitor, etc. together. Further, those obtained by coating these compounds with a polyurethane-based or polyester-based polymer compound or the like and microencapsulated are preferable because a long pot life can be obtained.

  Examples of the photoinitiator include benzoin ethers such as benzoin ethyl ether and isopropyl benzoin ether, benzyl ketals such as benzyl and hydroxycyclohexyl phenyl ketone, ketones such as benzophenone and acetophenone and derivatives thereof, thioxanthones, and bisimidazoles. Preferably used.

  When a photoinitiator is used, an optimal photoinitiator is selected according to the wavelength of the light source used, desired curing characteristics, and the like. Moreover, a photoinitiator may use together sensitizers, such as amines, a sulfur compound, and a phosphorus compound, in arbitrary ratios as needed.

  Sensitizers include aliphatic amines, aromatic amines, cyclic amines such as piperidine having a nitrogen-containing cyclic structure, o-tolylthiourea, sodium diethyldithiophosphate, soluble sulfinic acid salts, N, N′-dimethyl -P-aminobenzonitrile, N, N'-diethyl-p-aminobenzonitrile, N, N'-di (β-cyanoethyl) -p-aminobenzonitrile, N, N'-di (β-chloroethyl)- P-aminobenzonitrile, tri-n-butylphosphine and the like are preferable.

  Alternatively, propiophenone, acetophenone, xanthone, 4-methylacetophenone, benzophenone, fluorene, triphenylene, biphenyl, thioxanthone, anthraquinone, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, Phenanthrene, naphthalene, 4-phenylacetophenone, 4-phenylbenzophenone, 1-iodonaphthalene, 2-iodonaphthalene, acenaphthene, 2-naphthonitrile, 1-naphthonitrile, chrysene, benzyl, fluoranthene, pyrene, 1,2-benzoanthracene , Non-dye sensitizers such as acridine, anthracene, perylene, tetracene, 2-methoxynaphthalene, thionine, methylene blue, lumiflavin, riboflavin, ru Chromium, coumarin, psoralen, 8-methoxypsoralen, 6-methylcoumarin, 5-methoxypsoralen, 5-hydroxypsoralen, coumarylpyrone, acridine orange, acriflavine, proflavine, fluorescein, eosin Y, eosin B, erythrosine, rose bengal, etc. The following dye-based sensitizers can be used.

  As a radical initiator, you may use together the above photoinitiators and the compound which generate | occur | produces a radical by heat, such as an organic oxide and an azo compound.

The adhesive composition may contain an epoxy resin and a curing agent thereof. As the epoxy resin, various epoxy compounds having two or more glycidyl groups in one molecule may be used alone or in admixture of two or more. Specifically, bisphenol-type epoxy resins derived from epichlorohydrin and bisphenol A, F, AD, etc., epoxy novolac resins derived from epichlorohydrin and phenol novolac or cresol novolac, and naphthalene-based epoxy resins having a skeleton containing a naphthalene ring Glycidylamine type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin and the like. The epoxy resin is preferably a high-purity product in which impurity ions (Na ⁺ , Cl ^−, etc.), hydrolyzable chlorine, etc. are reduced to 300 ppm or less in order to prevent electron migration.

  As the curing agent for the epoxy resin, a latent curing agent is preferable in order to obtain a sufficiently long pot life. Imidazole-based, hydrazide-based, boron trifluoride-amine complex, sulfonium salt, amine imide, polyamine salt, dicyandiamide, and these hardeners coated with polyurethane-based or polyester-based polymeric substances, etc. Can be mentioned. These can be used alone or in combination, and a decomposition accelerator, an inhibitor, and the like may be used in combination.

  The circuit connecting material of the present invention is a combination of the above adhesive composition and an organic compound having a urethane group and an ester group (hereinafter sometimes referred to as “ester urethane compound”). The ester urethane compound preferably has a urethane group and an ester group in its main chain.

  This ester urethane compound is obtained, for example, by a reaction between a polyester polyol and a diisocyanate. The ester urethane compound obtained by this reaction may be generally referred to as a polyester urethane resin.

  Diisocyanates include 2,4-tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and aromatic and alicyclic rings. An aliphatic or aliphatic diisocyanate is preferably used.

  The polyester polyol is obtained, for example, by a reaction between a dicarboxylic acid and a diol. As the dicarboxylic acid, aromatic or aliphatic dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, and sebacic acid are preferable. As the diol, glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, hexanediol, neopentyl glycol, diethylene glycol, and triethylene glycol are preferable.

  The glass transition temperature of the ester urethane compound is preferably 50 ° C. or higher. The ester urethane compound can have a glass transition temperature of 50 ° C. or higher by appropriately adjusting the type, molecular weight, and the like of polyester polyol and diisocyanate.

  The ester urethane compound preferably has an anionic property. Thereby, adhesive strength further improves. The ester urethane compound having an anionic property can be obtained by copolymerizing a diol or diamine having a sulfonic acid group or a carboxyl group in the side chain in the reaction of the polyester polyol and the diisocyanate.

  The ester urethane compound preferably has an aromatic group containing a benzene ring or the like, or a cyclic aliphatic group containing a cyclohexane ring or the like.

  Two or more types of ester urethane compounds can be mixed and used. For example, what is obtained by reaction of an aromatic polyester polyol and aliphatic diisocyanate and what is obtained by reaction of an aliphatic polyester polyol and aromatic diisocyanate can be combined.

  The ester urethane compound preferably has a weight average molecular weight of 5,000 to 100,000. If the weight average molecular weight is less than 5,000, the film formability when formed into a film tends to be reduced, and if the weight average molecular weight exceeds 200,000, the solubility in the solvent and the compatibility are reduced. It tends to be difficult to prepare a coating liquid for forming into a shape.

  The ester urethane compound preferably has an unsaturated double bond and / or an epoxy group having radical polymerizability. Thereby, when hardening a circuit connection material, it reacts with the epoxy resin and radically polymerizable compound in an adhesive composition, and the elasticity modulus and heat resistance of the hardened | cured material of a circuit connection material improve.

  The circuit connecting material may contain a hydroxyl group-containing resin in addition to the components described above. As the hydroxyl group-containing resin, resins such as polyvinyl butyral, polyvinyl formal, polyamide, polyester, phenol resin, epoxy resin, phenoxy resin, polyurethane (excluding the ester urethane compound) are used. Among these, phenoxy resin is particularly preferable. By using these hydroxyl group-containing resins, the stress relaxation property during curing is excellent, and the adhesion is further improved by the hydroxyl group.

  The weight average molecular weight of the hydroxyl group-containing resin is preferably 10,000 or more, and more preferably 10,000 to 1,000,000. When the weight average molecular weight of the hydroxyl group-containing resin exceeds 1,000,000, the miscibility with other components tends to decrease. Moreover, it is preferable that the glass transition temperature of hydroxyl-containing resin is -50 degreeC or more.

  In order to further improve the heat resistance, the hydroxyl group-containing resin preferably has a radical polymerizable functional group. However, in this case, the hydroxyl group-containing resin is used as the above-mentioned radical polymerizable compound. Further, the hydroxyl group-containing resin may be modified with a carboxyl group-containing elastomer, an epoxy group-containing elastomer, or the like.

  In order to make the circuit connection material excellent in stress relaxation, it is preferable to contain acrylic rubber. As the acrylic rubber, a polymer or copolymer obtained by polymerizing at least one acrylic monomer among acrylic acid, acrylic acid ester, methacrylic acid ester and acrylonitrile is used. The acrylic rubber may be one obtained by copolymerizing the above monomer with glycidyl acrylate or glycidyl methacrylate. The weight average molecular weight (weight average) of the acrylic rubber is preferably 200,000 or more from the viewpoint of increasing the cohesive strength of the circuit connecting material.

  The circuit connection material may contain a styrene resin. The styrene resin may be one obtained by polymerizing styrene alone, or may be a copolymer obtained by copolymerizing styrene with at least one of a maleic anhydride compound and a maleimide compound. The weight average molecular weight (weight average) of the styrene resin is preferably 100,000 or more from the viewpoint of increasing the cohesive strength of the circuit connecting material.

  The circuit connection material further contains a filler, softener, accelerator, anti-aging agent, colorant, flame retardant, thixotropic agent, coupling agent, phenol resin, melamine resin, isocyanates, and the like. Also good.

  The inclusion of a filler is preferable because improvement in connection reliability and the like can be obtained. The maximum diameter of the filler is preferably less than the particle diameter of the conductive particles, and the amount is preferably in the range of 5 to 60 parts by volume (with respect to 100 parts by volume of the adhesive composition). If it exceeds 60 parts by volume, the effect of improving the reliability may be saturated, and if it is less than 5 parts by volume, the effect of addition is small. As a coupling agent, a vinyl group, an acrylic group, an amino group, an epoxy group, and an isocyanate group-containing material are preferable from the viewpoint of improving adhesiveness.

  The circuit connection material preferably contains conductive particles. Even if the conductive particles are not contained, it is possible to connect the circuit members by direct contact between the circuit electrodes, but the inclusion of the conductive particles makes it possible to connect more stably.

  Examples of the conductive particles include metal particles such as Au, Ag, Ni, Cu, and solder, and carbon particles. In order to make the pot life sufficiently long, the conductive particles preferably contain Au, Ag, or a white metal, and more preferably contain Au.

  The conductive particles may be particles in which transition metal such as Ni or non-conductive glass, ceramic, plastic or the like is used as a core and the surface is coated with a coating layer made of a noble metal such as Au. preferable. The conductive particles having such a noble metal coating layer are deformed when the circuit connecting material is heated and pressurized, thereby increasing the contact area with the circuit electrode and further improving the reliability. The thickness of the noble metal coating layer is preferably 100 angstroms or more in order to obtain good connection resistance. Furthermore, when the core is particles of a transition metal such as Ni, the thickness of the coating layer is more preferably 300 angstroms or more. When the thickness of the coating layer is less than 300 angstroms, when a part of the coating layer is lost when the conductive particles are dispersed in the resin, free radicals are generated due to the redox action, and the circuit connection material Storage stability tends to decrease.

  It is preferable that the quantity of electroconductive particle is 0.1-30 volume parts with respect to 100 volume parts of adhesive compositions. In order to prevent an adjacent circuit from being short-circuited by excessive conductive particles, the amount is more preferably 0.1 to 10 parts by volume.

  FIG. 1 is a cross-sectional view showing an embodiment of a film-like circuit connecting material according to the present invention. The film-like circuit connection material 1 is obtained by forming a circuit connection material in which a plurality of conductive particles 5 are dispersed in a resin composition layer 3 containing an adhesive composition, an ester urethane compound, and the like into a film shape. is there. The film-like circuit connection material 1 can be produced, for example, by coating the circuit connection material with a predetermined thickness on a support film. As the support film, a PET film or the like surface-treated so as to have releasability is preferably used.

  When the film-like circuit connecting material 1 is heated and pressed in a state sandwiched between a pair of opposing circuit members, the circuit electrodes melted and flowed to electrically connect each other, Hardens and develops adhesive strength. Therefore, the fluidity of the film-like circuit connecting material 1 is important. Specifically, a film-like circuit connecting material 1 (thickness 35 μm, 5 mm × 5 mm) is sandwiched between two glass plates (thickness 0.7 mm, 15 mm × 15 mm), 150 ° C., 2 MPa, When heating and pressurizing for 10 seconds, the fluidity index (B) / () expressed using the initial area (A) of the circuit connecting material 1 and the area (B) after heating and pressurizing. The value of A) is preferably 1.3 to 3.0, and more preferably 1.5 to 2.5. If the value of (B) / (A) is less than 1.3, there is a tendency that fluidity is insufficient and good connection cannot be obtained, and if it exceeds 3.0, bubbles are generated and reliability tends to be lowered. It is in.

  Although the film-like circuit connection material 1 has only one layer, the circuit connection material of the present invention may be used in a state of being formed into a film having a plurality of layers having different compositions instead. In particular, when the circuit connection material contains conductive particles and the adhesive composition in the circuit connection material contains a radical initiator that generates radicals by heating or light, the circuit connection material is heated or irradiated by light. It is preferable to form a multilayer film having a layer containing a radical initiator that generates radicals and a layer containing conductive particles separately. Thereby, a longer pot life is obtained.

  The film-like circuit connecting material 1 is used for connecting chip components such as a semiconductor chip, a resistor chip, and a capacitor chip, and circuit members such as a printed board.

  FIG. 2 is a cross-sectional view showing an embodiment of a circuit member connection structure according to the present invention. A circuit member connection structure 101 shown in FIG. 2 includes a first circuit member 10 having a first substrate 11 and a first circuit electrode 13 formed on the main surface of the first substrate 11 via an adhesive layer 12; The second circuit member 20 having the second circuit electrode 21 and the second circuit electrode 23 formed on the main surface of the second substrate 21 is made of a cured product obtained by curing the circuit connection material described above. The circuit members 10 and 20 are connected by a circuit connecting member 1a formed between them. In the circuit member connection structure 101, the first circuit electrode 13 and the second circuit electrode 23 face each other and are electrically connected.

  The circuit connection member 1a is composed of a cured product 3a of a resin composition containing an adhesive composition, an ester urethane compound, and the like, and conductive particles 5 dispersed therein. The first circuit electrode 13 and the second circuit electrode 23 are electrically connected via the conductive particles 5. The elastic modulus at 40 ° C. of the circuit connecting member 1a is preferably 100 to 3000 MPa, and more preferably 500 to 2000 MPa.

  The first substrate 11 is a resin film containing at least one resin selected from the group consisting of polyester terephthalate, polyethersulfone, epoxy resin, acrylic resin, and polyimide resin.

  The circuit electrode 13 is formed of a material having a degree of conductivity that can function as an electrode (preferably at least one selected from the group consisting of gold, silver, tin, platinum group metals, and indium-tin oxide). . A plurality of circuit electrodes 13 are bonded onto the main surface of the first substrate 11 via the adhesive layer 12. The adhesive layer 12 is formed of an adhesive or the like normally used for circuit members.

  The second substrate 21 is a glass substrate, and a plurality of second circuit electrodes 23 are formed on the main surface of the second substrate 21.

  The circuit member connection structure 101 includes, for example, a first circuit member 10, the above-described film-like circuit connection material 1, and a second circuit member 20, and a first circuit electrode 13 and a second circuit electrode. The first circuit member 10 is electrically connected to the first circuit electrode 13 and the second circuit electrode 23 by heating and pressurizing the laminate laminated in this order so as to face each other. And the second circuit member 20 are obtained.

  In this method, first, the circuit-connecting material 1 formed on the support film is temporarily bonded to the second circuit member 20 by heating and pressurizing the circuit-connecting material 1 while being bonded together, After peeling off the support film, the first circuit member 10 can be placed while aligning the circuit electrodes to prepare a laminate.

  Conditions for heating and pressurizing the laminate are appropriately adjusted so that the circuit connecting material is cured and sufficient adhesive strength is obtained in accordance with the curability of the adhesive composition in the circuit connecting material.

  FIG. 3 is a sectional view showing another embodiment of the circuit member connection structure according to the present invention. The circuit member connection structure 102 shown in FIG. 3 is the same as the circuit member connection structure except that the first circuit electrode 13 is directly formed on the main surface of the first substrate 11 in the first circuit member 10. 101.

  When the circuit connection member 1a is in direct contact with a substrate formed of a material such as polyester terephthalate, polyethersulfone, epoxy resin, acrylic resin, polyimide resin, or glass, as in the circuit member connection structure 102 It has been difficult to obtain sufficient adhesive strength with conventional circuit connection materials. On the other hand, in the circuit member connection structure 102, the circuit connection member 1a is a cured product of the circuit connection material of the present invention, so that sufficient adhesive strength can be maintained even in a high temperature and high humidity environment. Such an effect is also obtained when a layer containing polyimide resin, acrylic resin, silicone resin, or the like is formed between the circuit connecting member and the circuit member.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples.

(Preparation method of polyester urethane resin)
A solution obtained by dissolving polyester polyol obtained by the reaction of dicarboxylic acid and diol in methyl ethyl ketone was charged into a stainless steel autoclave equipped with a heater equipped with a stirrer, thermometer, condenser, vacuum generator and nitrogen gas inlet tube. Next, a predetermined amount of isocyanate was added, and dibutyltin laurate was added as a catalyst in an amount of 0.02 parts by weight with respect to 100 parts by weight of polyester polyol, reacted at 75 ° C. for 10 hours, and then cooled to 40 ° C. Further, piperazine was added and reacted for 30 minutes to extend the chain, and then neutralized with triethylamine.

  When the solution after the reaction was dropped into pure water, the solvent and the catalyst were dissolved in water, and a polyester urethane resin as an ester urethane compound was precipitated. The precipitated polyester urethane resin was dried with a vacuum dryer to obtain a polyester urethane resin.

Example 1
(Synthesis of polyester urethane resin A)
Terephthalic acid as digalbonic acid, propylene glycol as diol, 4,4'-diphenylmethane diisocyanate as isocyanate, and a molar ratio of terephthalic acid / propylene glycol / 4,4'-diphenylmethane diisocyanate to 1.0 / 1.3 Polyester urethane resin A was obtained according to the procedure described above using an amount of /0.25. It was 27000 when the weight molecular weight of the polyester urethane resin A was measured by the gel permeation chromatography.

  A methyl ethyl ketone solution obtained by dissolving polyester urethane resin A in methyl ethyl ketone so as to be 20% by weight is applied to a PET film (thickness 80 μm) having one surface treated using a coating apparatus, and dried by hot air at 70 ° C. for 10 minutes. A film having a thickness of 35 μm was formed. About this film, the temperature dependence of the elastic modulus was measured on condition of tensile load 5gf and frequency 10Hz using the wide range dynamic viscoelasticity measuring apparatus. In the obtained elastic modulus-temperature curve, a straight line equidistant in the vertical axis direction from a straight line extending the base line before and after the glass transition region intersects with the curve of the stepped change portion of the glass transition region. It was 105 degreeC when temperature (midpoint glass transition temperature) was calculated | required as a glass transition temperature of the polyester urethane resin A. FIG.

(Circuit connection material)
400 parts by weight of polycaprolactone diol having a weight average molecular weight of 800, 131 parts by weight of 2-hydroxypropyl acrylate, 0.5 parts by weight of dibutyltin dilaurate as a catalyst and 1.0 part by weight of hydroquinone monomethyl ether as a polymerization inhibitor The mixture was stirred while heating. Next, 222 parts by weight of isophorone diisocyanate was added dropwise, and the temperature was raised to 80 ° C. while stirring to advance the urethanization reaction. After confirming that the reaction rate of the isocyanate group was 99% or more, the temperature was lowered to obtain urethane acrylate as a radical polymerizable compound.

  A nickel layer having a thickness of 0.2 μm and a gold layer having a thickness of 0.04 μm were formed in this order on the surface of particles having polystyrene as a core to produce conductive particles having an average particle diameter of 10 μm.

  Each component was mixed so that the weight of solid content was 50 g of polyester urethane resin A, 49 g of urethane acrylate resin, 1 g of phosphate ester acrylate, and 5 g of t-hexylperoxy 2-ethylhexanate as a radical initiator, Further, the conductive particles were added in an amount of 3% by volume of the whole and dispersed uniformly to obtain a dispersion for coating. At the time of preparing the dispersion, the polyester urethane resin A is in a solution in a concentration of 20% by mass in methyl ethyl ketone, and t-hexylperoxy 2-ethylhexanonate is a 50% by weight DOP solution (manufactured by NOF Corporation). , Trade name "Percure HO") and mixed with other ingredients. The obtained dispersion is applied to a PET film (thickness 80 μm) with one surface treated using a coating apparatus and dried with hot air at 70 ° C. for 10 minutes to obtain a film-like circuit connection material having a thickness of 20 μm. It was.

(Example 2)
Isophthalic acid, terephthalic acid and adipic acid, diphthalic acid, isophthalic acid, terephthalic acid and adipic acid, ethylene glycol, neopentyl glycol and 1,6-hexanediol as diol, 4,4'-diphenylmethane diisocyanate as diisocyanate / Ethylene glycol / neopentyl glycol / 1,6-hexanediol / 4,4′-diphenylmethane diisocyanate molar ratio is 0.21 / 0.21 / 0.58 / 0.19 / 0.55 / 0.46 / Polyester urethane resin B was synthesized according to the above procedure using an amount such that the amount was 0.3. It was 60000 when the weight molecular weight of the polyester urethane resin B was measured by the gel permeation chromatography. Moreover, when the glass transition temperature of the polyester urethane resin B was measured like Example 1, it was -3 degreeC.

  A film-like circuit connecting material was produced in the same manner as in Example 1 except that the polyester urethane resin B was used in place of the polyester urethane resin A.

(Example 3)
A film-like circuit connecting material was produced in the same manner as in Example 2 except that 20 g of 50 g of polyester urethane resin B was replaced with phenoxy resin (trade name “PKHC”, weight average molecular weight 45000, manufactured by Union Carbide Co., Ltd.). .

(Comparative Example 1)
A film-like circuit connection material is produced in the same manner as in Example 1 except that the polyester polyol (glass transition temperature: 85 ° C.) used in the synthesis of the polyester urethane resin A is used instead of the polyester urethane resin A. did.

(Comparative Example 2)
Instead of the polyester urethane resin B, a film-like circuit connecting material was prepared in the same manner as in Example 2 except that the polyester polyol (glass transition temperature: −5 ° C.) used in the synthesis of the polyester urethane resin B was used. Produced.

(Comparative Example 3)
In place of the polyester urethane resin B, a film-like circuit connecting material was prepared in the same manner as in Example 3 except that the polyester polyol (glass transition temperature: −5 ° C.) used in the synthesis of the polyester urethane resin B was used. Produced.

(Comparative Example 4)
Example 1 except that instead of the polyester urethane resin A, a polyurethane resin having no ester group (DIC Bayer Polymer Co., Ltd., trade name “Pandex T-8175”) (glass transition temperature: −30 ° C.) was used. In the same manner as above, a film-like circuit connecting material was produced.

(Production of circuit member connection structure)
A circuit member was prepared in which 500 chrome circuits (line width 50 μm, pitch 100 μm, thickness 0.4 μm) as circuit electrodes were formed on a glass substrate (trade name “# 1737” manufactured by Corning). On this circuit member, the film-like circuit connection material produced in Example 1 was affixed, and this was temporarily bonded by heating and pressing at 70 ° C. and 0.5 MPa for 5 seconds.

  Subsequently, the PET film was peeled off, and 500 copper circuits (line width 50 μm, pitch 100 μm, thickness 18 μm) were placed on the polyimide film (Ube Industries, trade name “Upilex”, thickness 75 μm) through the adhesive layer. The flexible circuit member (FPC1) having a three-layer structure bonded to each other was placed on a film-like circuit connection material, and heated and pressurized at 160 ° C. and 3 MPa for 10 seconds. Thereby, the circuit member which has a glass substrate, and FPC1 were connected over 2 mm in width.

  Further, instead of FPC1, a two-layer structure in which 500 copper circuits having a line width of 50 μm, a pitch of 100 μm, and a thickness of 8 μm are directly formed on a polyimide film (manufactured by Ube Industries, Ltd., trade name “Upilex 25S”, thickness of 25 μm). Using the flexible circuit board (FPC2), the circuit member having the glass substrate and the FPC2 were connected over a width of 2 mm in the same manner as described above.

  Using the film-like circuit connection materials produced in Examples 2-3 and Comparative Examples 1-4, FPC1 and FPC2 were each connected to a circuit member having a glass substrate in the same manner as described above.

(Connection resistance)
About the connection structure of the produced circuit member, the resistance value (connection resistance) between the circuit electrodes which oppose was measured using the multimeter. The measurement was performed at the initial stage and after the high-temperature and high-humidity treatment held in a high-temperature and high-humidity tank at 85 ° C. and 85% RH for 500 hours. Table 1 shows the average value (x + 3σ) of 150 resistance values as the connection resistance.

(Adhesive strength)
About the connection structure of the produced circuit member, the adhesive strength when peeling at 90 ° was measured at a peeling speed of 50 mm / min. The measurement was performed at the initial stage and after the high temperature and high humidity treatment similar to the above.

  The connection structure of the circuit members connected using the circuit connection materials of Examples 1 to 3 has a sufficiently low initial connection resistance, and almost no increase in connection resistance after high-temperature and high-humidity treatment, and high durability. Showed sex. In particular, the durability was particularly excellent in Example 1 using a polyester urethane resin having a glass transition temperature of 50 ° C. or higher. In the case of Example 2 using a polyester urethane resin having a glass transition temperature of less than 50 ° C., the connection becomes somewhat loose after the high-temperature and high-humidity treatment, and the increase in connection resistance is relatively larger than that in Example 1. However, it was practically acceptable. Further, in Example 3 in which the polyester urethane resin and the phenoxy resin having a glass transition temperature of 50 ° C. or higher were used in combination, the increase in connection resistance due to the high-temperature and high-humidity treatment was suppressed to substantially the same level as in Example 1.

  In Examples 1 to 3, in both cases of FPC1 and FPC2, 6 N / cm or more was maintained after the initial and high-temperature and high-humidity treatment. In the case of this test, it is generally considered practically sufficient if the adhesive strength is 6 N / cm or more. In comparison between Example 2 and Example 3, Example 2 with a higher content of polyester urethane resin was superior in adhesive strength after high-temperature and high-humidity treatment to Example 3.

  In contrast, Comparative Example 4 using a polyurethane resin having no ester bond and having a low glass transition temperature of −30 ° C. greatly increased the connection resistance after the high temperature and high humidity treatment. Moreover, although the comparative example 4 showed the comparatively favorable adhesive strength in the connection structure using FPC1, in the connection structure using FPC2, the adhesive strength decreased significantly after the high temperature and high humidity treatment. Comparative Examples 1 to 3 had an adhesive strength of 6 N / cm or more, and did not exhibit practically sufficient characteristics at least in terms of adhesive strength.

  DESCRIPTION OF SYMBOLS 1 ... Film-like circuit connection material, 1a ... Circuit connection member, 5 ... Conductive particle, 10 ... First circuit member, 11 ... First substrate, 12 ... Adhesive layer, 13 ... First circuit electrode, DESCRIPTION OF SYMBOLS 20 ... 2nd circuit member, 21 ... 2nd board | substrate, 23 ... 2nd circuit electrode, 101 ... Connection structure of a circuit member, 102 ... Connection structure of a circuit member.

Claims (16)

An adhesive composition that is cured by light or heat;
An organic compound having a urethane group and an ester group,
The organic compound has a weight average molecular weight of 5,000 to 100,000,
A circuit connecting material for connecting circuit members having circuit electrodes formed on a substrate and a main surface thereof.   The circuit connection material according to claim 1, wherein the adhesive composition contains a radical polymerizable compound and a radical initiator that generates radicals by heating or light.   The circuit connection material according to claim 2, wherein the radical polymerizable compound includes a phosphate ester compound having an acrylate group or a methacrylate group.   The circuit connection material as described in any one of Claims 1-3 whose glass transition temperature of the said organic compound is 50 degreeC or more.   The circuit connection material according to any one of claims 1 to 4, wherein the organic compound has an aromatic group and / or a cyclic aliphatic group.   The circuit connection material as described in any one of Claims 1-5 whose weight average molecular weights of the said organic compound are 5000-60000.   The circuit connection material according to any one of claims 1 to 6, wherein the organic compound has a weight average molecular weight of 27000 to 60000.   The circuit connection material according to any one of claims 1 to 7, comprising conductive particles. A first circuit member having a first substrate and a first circuit electrode formed on a main surface of the first substrate;
A second circuit member and a second circuit member having a second circuit electrode formed on the main surface of the second substrate;
A circuit connection member made of a cured product of the circuit connection material according to any one of claims 1 to 8 and provided between the first and second circuit members, and the first circuit electrode and the first circuit electrode. The connection structure of the circuit member connected so that two circuit electrodes may be opposed and electrically connected.   At least one of the first and second circuit electrodes is made of a material containing at least one selected from the group consisting of gold, silver, tin, platinum group metals, and indium-tin oxide. The circuit member connection structure according to 9.   At least one of the first and second substrates is a substrate made of a material containing at least one selected from the group consisting of polyester terephthalate, polyethersulfone, epoxy resin, acrylic resin, polyimide resin, and glass, Item 9. The circuit member connection structure according to Item 9 or 10.   A layer containing at least one selected from the group consisting of a silicone resin, an acrylic resin, and a polyimide resin is formed between at least one of the first and second circuit members and the circuit connection member. The connection structure of the circuit member of 9 or 10. A first circuit member having a first substrate and a first circuit electrode formed on a main surface of the first substrate;
A layer made of the circuit connection material according to any one of claims 1 to 8,
A second circuit member having a second substrate electrode and a second circuit electrode formed on the main surface of the second substrate;
The first circuit electrode and the second circuit electrode are electrically connected to each other by heating and pressurizing the laminate laminated in this order so that the first circuit electrode and the second circuit electrode are opposed to each other. A circuit member connection method, wherein the first circuit member and the second circuit member are connected so as to be connected to each other.   At least one of the first and second circuit electrodes is made of a material containing at least one selected from the group consisting of gold, silver, tin, platinum group metals, and indium-tin oxide. 14. A method for connecting circuit members according to 13.   At least one of the first and second substrates is a substrate formed of a material containing at least one selected from the group consisting of polyester terephthalate, polyethersulfone, epoxy resin, acrylic resin, polyimide resin, and glass. The method for connecting circuit members according to claim 13 or 14.   A layer containing at least one selected from the group consisting of a silicone resin, an acrylic resin and a polyimide resin is formed between at least one of the first and second circuit members and the layer made of the circuit connection material. The method for connecting circuit members according to claim 13 or 14.

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