JP4572960B2 - Anisotropic conductive adhesive film for circuit connection, circuit terminal connection method and circuit terminal connection structure using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to an anisotropic conductive adhesive film for circuit connection, a method of connecting a circuit terminal using the same, and a connection structure thereof, and in particular, CHIP ON GLASS mounting (hereinafter referred to as COG mounting) or CHIP ON FILM (hereinafter referred to as COF). The present invention relates to a circuit terminal connection method and a circuit terminal connection structure.

The liquid crystal driving IC is mounted on the glass panel for liquid crystal display by a COG mounting method in which the liquid crystal driving IC is directly bonded to the glass panel with a circuit connecting member, or the liquid crystal driving IC is bonded to a flexible tape having metal wiring. A COF mounting method in which the glass glass panel and the circuit connecting member are joined is used. Along with the high definition of the liquid crystal display, the gold bumps, which are electrodes of the liquid crystal driving IC, are becoming narrower in pitch and area. As a result, the conductive particles in the bonding material flow out between adjacent electrodes, causing a short circuit, and the number of conductive particles in the bonding material captured on the bumps is reduced. As a result, the connection resistance between the circuits is reduced. There is a problem of rising and causing poor connection. In order to solve these problems, an insulating adhesive layer is formed on at least one surface of the bonding material to prevent deterioration in bonding quality in COG mounting and COF mounting (for example, Patent Document 1), A method (for example, Patent Document 2) in which the surface of the particle is coated with an electrically insulating film has been proposed.
JP-A-8-279371 Japanese Patent No. 2779409

However, in the method of forming an insulating adhesive layer on one side, when the bump area is less than 3000 μm ² , if the particle filling amount is increased in order to obtain a stable connection resistance value, a short circuit occurs between adjacent circuits. There was a problem that the rate increased and insulation failure occurred. Further, the method of coating the surface of the conductive particles with an electrically insulating film has a problem that the connection resistance value increases and a stable electric resistance cannot be obtained. The present invention provides an anisotropic conductive adhesive film for electrical / electronic circuit connection, which has low resistance electrical connection to COG mounting and COF mounting, and does not cause a short circuit between adjacent electrodes. A circuit terminal connection method and a circuit terminal connection structure are provided.

The anisotropic conductive adhesive film for circuit connection of the present invention is an adhesive composition that is interposed between circuit electrodes facing each other, heats and presses opposite circuit electrodes, and electrically connects the electrodes in the pressing direction. an adhesive film having an adhesive layer made of an object, [1] (1) a curing agent that generates free radicals upon heating, (2) first and second radically polymerizable substance, (3) film formation A material, (4) a first adhesive layer comprising an adhesive composition containing, as an essential component, conductive particles whose surfaces are coated with an organic polymer compound containing a water-soluble polymer , (1) a curing agent, (2) The first and second radical polymerizable substances, and (3) a two-layer structure comprising a second adhesive layer made of an adhesive composition k containing a film forming material and not containing conductive particles. . Then, measured at 23 ° C. using water and diiodomethane, polar component surface tension at the surface of the first adhesive layer (γsv, p) is Ru 3.0~4.0dyne / cm der. If the polar component (γsv, p) of the surface tension of the adhesive composition surface is less than 1, the adhesive may be poorly excluded from between the electrode and the conductive particles, and good electrical connection may not be obtained. If it exceeds 6, the adhesive is not peeled off from the coated substrate (separator) such as PET (polyethylene terephthalate), and the productivity is lowered, which is not preferable. The conductive particles used in the present invention have a surface composed of at least one selected from gold, silver, and platinum group metals, and the metal surface is coated with an organic polymer compound. It is preferable that the organic polymer compound is water-soluble because the coating workability is good. The adhesive film of the present invention, conductive particles may be a multi-layer structure separated into a layer and other layers containing, this time, the thickness of the first adhesive layer containing the conductive particles, conductive particles The particle size is preferably less than 3 times, more preferably less than 2 times. If the thickness of the first adhesive layer containing the conductive particles is more than 3 times, the amount of the conductive particles flow out between adjacent electrodes increases, the insulating property is lowered undesirably.

Anisotropically conductive adhesive film for circuit connection of the invention, that the second radical-polymerizable substance having a phosphoric ester structure Yusuke free. In the anisotropic conductive adhesive film for circuit connection of the present invention, the film forming material contains a phenoxy resin . Moreover, this invention is an anisotropic conductive adhesive film for circuit connection as described in said [ 1 ] in which a [ 2 ] phenoxy resin has the molecular structure resulting from a polycyclic aromatic compound in a molecule | numerator. Moreover, this invention is an anisotropic conductive adhesive film for circuit connection as described in said [ 2 ] whose molecular structure resulting from a [ 3 ] polycyclic aromatic compound is a fluorene ring.

The present invention provides [ 4 ] a first circuit member having a first connection terminal and a second circuit member having a second connection terminal, the first connection terminal and the second connection terminal being opposed to each other. The anisotropic conductive adhesive film for circuit connection according to any one of the above [1] to [ 3] is interposed between the first connection terminal and the second connection terminal that are arranged opposite to each other. A method of connecting circuit terminals in which the first connection terminal and the second connection terminal which are arranged to face each other by heating and pressing are electrically connected. The present invention also provides a circuit connection structure obtained by the circuit terminal connection method described in [ 5 ] above [ 4 ], wherein the insulation resistance between adjacent electrodes is 10 ⁹ when a DC voltage of 50 V is applied to the circuit terminal. The circuit connection structure is Ω or more. Moreover, this invention is a circuit connection structure as described in said [ 5 ] whose circuit member which has [ 6 ] at least one connection terminal is an IC chip. [ 7 ] The circuit connection according to [ 5 ] or [ 6 ], wherein the connection resistance between the connection terminal of the [ 7 ] IC chip and the connection terminal on the second circuit member is 1Ω or less. It is a structure. The present invention also provides [ 8 ] above [ 5 ] or [ 5 ], wherein the surface of at least one of the connection terminals is composed of at least one selected from gold, silver, tin, platinum group metals, and indium-tin oxide (ITO). The circuit connection structure according to any one of [ 7 ] above. Further, the present invention is claimed in any one of [9] At least one of the circuit member surface silicon nitride, a silicone compound, at least one coated or deposited by which the selected polyimide resin [5] to [8] above This is a circuit connection structure.

According to the present invention, even in a driving IC with a short distance between bumps in COG mounting or COF mounting, an electrical connection with low resistance and high insulation can be obtained between adjacent electrodes. An electronic adhesive film can be provided.

  According to the Journal of the Adhesion Society of Japan (Vol. 26, No. 1 (1990) p39-48, Satoshi Imoto) “About dividing surface tension into components”, the Young-Dupre equation represented by the numbers (1) and (2) is is there.

When γsv of number (1) is put into number (2) and rearranged, number (3) is obtained. According to Fowkes, there is a number (4) for a material having a polar group, and substituting this into the number (2) yields the number (5). The number (6) is obtained from the number (5) and the number (3). Here, for example, two kinds of liquids such as water (H ₂ O) and dimethyliodomethane are prepared, and each surface tension γLV, dispersion component (γLV, d), and polar component (γLV, p) (number (7)) , (8)) is substituted into the number (6), the numbers (9) and (10) are obtained, the simultaneous equations are solved, and the polar component (γsv, p) of the solid (film) is calculated. In the present invention, the polar component (γsv, p) of the surface tension is set to 3.0 to 4.0 dyne / cm. As described above, when the polar component (γsv, p) of the surface tension of the adhesive composition surface is less than 1, the adhesive is poorly excluded from between the electrode and the conductive particles, and good electrical connection is obtained. If it exceeds 6, the adhesive does not peel off from the coated substrate (separator) such as PET (polyethylene terephthalate), and the productivity is lowered, which is not preferable.

  Examples of the film forming material used in the present invention include phenoxy resin, polyvinyl formal resin, polystyrene resin, polyvinyl butyral resin, polyester resin, polyamide resin, xylene resin, polyurethane resin and the like. A film-forming material is a material that solidifies a liquid material and forms a constituent composition into a film shape, so that the film is easy to handle and imparts mechanical properties that are not easily torn, cracked, or sticky. It can be handled as a film in a normal state. Among the film forming materials, a phenoxy resin is preferable because it is excellent in adhesiveness, compatibility, heat resistance, and mechanical strength. The phenoxy resin is a resin obtained by reacting a bifunctional phenol and epihalohydrin to a high molecular weight or by polyaddition of a bifunctional epoxy resin and a bifunctional phenol. Specifically, it is obtained by reacting 1 mol of a bifunctional phenol and epihalohydrin 0.985 to 1.015 in a non-reactive solvent at a temperature of 40 to 120 ° C. in the presence of an alkali metal hydroxide. Can do. Further, from the viewpoint of the mechanical properties and thermal properties of the resin, the blending equivalence ratio of the bifunctional epoxy resin and the bifunctional phenols is particularly determined as epoxy group / phenol hydroxyl group = 1 / 0.9 to 1/1. 1 in the presence of a catalyst such as an alkali metal compound, organic phosphorus compound, cyclic amine compound, etc. in an amide, ether, ketone, lactone, alcohol or other organic solvent having a boiling point of 120 ° C. or higher. What is obtained by heating to 50 to 200 ° C. and subjecting it to a polyaddition reaction with a content of 50 parts by weight or less is preferred. Examples of the bifunctional epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, and bisphenol S type epoxy resin. Bifunctional phenols have two phenolic hydroxyl groups, and examples include hydroquinones, bisphenols such as bisphenol A, bisphenol F, bisphenol AD, and bisphenol S. The phenoxy resin may be modified with a radical polymerizable functional group. The phenoxy resin used in the present invention preferably has a molecular structure resulting from a polycyclic aromatic compound in the molecule. Examples thereof include dihydroxy compounds such as naphthalene, biphenyl, acenaphthene, fluorene, dibenzofuran, anthracene and phenanthrene, and 9,9'-bis (4-hydroxyphenyl) fluorene is particularly preferable. This phenoxy resin may also be modified with a radical polymerizable functional group, and the phenoxy resin may be used alone or in combination of two or more.

  Curing agents that generate free radicals upon heating used in the present invention are those that decompose upon heating of peroxide compounds, azo compounds, etc. to generate free radicals, and the intended connection temperature, connection time, pot Although it is appropriately selected depending on the life and the like, from the viewpoint of high reactivity and pot life, an organic peroxide having a half life of 10 hours at a temperature of 40 ° C. or more and a half life of 1 minute at a temperature of 180 ° C. or less is preferable, An organic peroxide having a half-life of 10 hours at a temperature of 60 ° C. or more and a half-life of 1 minute at a temperature of 170 ° C. or less is more preferable. When the connection time is 10 seconds or less, the blending amount of the curing agent is 0.1 to 30 parts by weight with respect to a total of 100 parts by weight of the radical polymerizable substance and the film forming material in order to obtain a sufficient reaction rate. 1 to 20 parts by weight is more preferable. When the blending amount of the curing agent is less than 0.1 parts by weight, a sufficient reaction rate cannot be obtained, and good adhesive strength and small connection resistance tend to be difficult to obtain. When the blending amount exceeds 30 parts by weight, the fluidity of the adhesive composition is lowered, the connection resistance is increased, or the pot life of the adhesive composition tends to be shortened.

  The curing agent can be selected from diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, silyl peroxide, and the like. Further, in order to suppress corrosion of the connection terminals of the circuit member, the chlorine ions and organic acids contained in the curing agent are preferably 5000 ppm or less, and more preferably less organic acids generated after the thermal decomposition. . Specifically, it is more preferably selected from peroxyesters, dialkyl peroxides, hydroperoxides, silyl peroxides, and peroxyesters that provide high reactivity. The said hardening | curing agent can be mixed suitably and used.

  Peroxyesters include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxynoedecanoate, and t-hexyl. Peroxyneodecanodate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanate, 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-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate and the like.

  Dialkyl peroxides include α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and t-butyl. Cumyl peroxide and the like.

  Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

  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.

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

  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 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 curing agents that generate free radicals upon heating can be used alone or in combination, and a decomposition accelerator, an inhibitor, and the like may be used in combination. In addition, those encapsulating these curing agents with polyurethane-based or polyester-based polymeric substances and the like and microencapsulated are preferable because the pot life is extended.

  The radically polymerizable substance used in the present invention is a substance having a functional group that is polymerized by radicals, and examples thereof include acrylates, methacrylates, and maleimide compounds. The radical polymerizable substance can be used in either a monomer or oligomer state, and the monomer and oligomer can be used in combination. Specific examples of the acrylate (methacrylate) include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, 2-hydroxy-1,3. -Diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclodecanyl Examples include acrylate, tris (acryloyloxyethyl) isocyanurate, urethane acrylate, and the like. These can be used alone or in combination. If necessary, a polymerization inhibitor such as hydroquinone or methyl ether hydroquinone may be used as appropriate. Moreover, when it has a dicyclopentenyl group and / or a tricyclodecanyl group and / or a triazine ring, since heat resistance improves, it is preferable.

  The maleimide compound contains at least two maleimide groups in the molecule. For example, 1-methyl-2,4-bismaleimidebenzene, N, N′-m-phenylenebismaleimide, N, N′— p-phenylene bismaleimide, 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′-3,3′-diphenylsulfone bismaleimide N, N′-4,4-diphenyl ether 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- (4-maleimidophenoxy) -2-cyclohexylbenzene 2,2-bis (4- (4-maleimidophenoxy) phenyl) hexafluoropropane, etc. These can be used alone or in combination, and the above radical polymerizable substance is represented by Formula 1. It is preferable to use a radically polymerizable substance having a phosphate ester structure in combination because the adhesive strength on the surface of an inorganic substance such as a metal is improved. A radical polymerizable substance having an acid ester structure is obtained as a reaction product of phosphoric anhydride and 2-hydroxyethyl (meth) acrylate, specifically, mono (2-methacryloyloxyethyl) acid phosphate, di ( 2-methacryloyloxyethyl) acid phosphate, etc. These can be used alone or in combination.

  The blending amount of the radical polymerizable substance having a phosphate ester structure is preferably 0.01 to 50 parts by weight, and 0.5 to 5 parts by weight with respect to 100 parts by weight of the total of the film-forming material and the radical polymerizable substance. Is more preferable. If it is less than 0.01 part by weight, it is difficult to improve the adhesion strength with the surface of an inorganic material such as a metal, and if it exceeds 50 parts by weight, the expected curing characteristics cannot be obtained. Allyl (meth) acrylate can be added to the adhesive composition of the present invention. The blending amount is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total of the film forming material and the radical polymerizable substance. If the amount is less than 0.1 parts by weight, the adhesive strength becomes inferior. If the amount exceeds 10 parts by weight, the radical polymerization reactivity is low, resulting in insufficient reaction, making it difficult to obtain good adhesive strength.

The adhesive composition for the anisotropic conductive adhesive film for circuit connection of the present invention comprises a polymer or copolymer containing at least one of acrylic acid, acrylic ester, methacrylic ester or acrylonitrile as a monomer component. It is preferable to use a copolymer acrylic rubber containing glycidyl acrylate or glycidyl methacrylate containing a glycidyl ether group because it is excellent in stress relaxation. The molecular weight (weight average) of these acrylic rubbers is preferably 200,000 or more from the viewpoint of increasing the cohesive strength of the adhesive.

The adhesive composition for the anisotropic conductive adhesive film for circuit connection of the present invention further includes a filler, a softener, an accelerator, an anti-aging agent, a colorant, a flame retardant, a thixotropic agent, and a coupling. An agent, a phenol resin, a melamine resin, isocyanates and the like can also be contained. The inclusion of a filler is preferable because improvement in connection reliability and the like can be obtained. If the maximum diameter of a filler is less than the particle size of an electroconductive particle, it can be used, and the range of 5-60 volume parts (with respect to 100 volume parts of adhesive resin components) is preferable. 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 the coupling agent, ketimine, vinyl group, acrylic group, amino group, epoxy group and isocyanate group-containing material are preferable from the viewpoint of improving adhesiveness. Specifically, as the silane coupling agent having an amino group, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane. Examples include ethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and the like. Examples of the silane coupling agent having ketimine include those obtained by reacting the above silane coupling agent having an amino group with a ketone compound such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

The adhesive composition in the first adhesive layer of the anisotropic conductive adhesive film for circuit connection of the present invention essentially uses conductive particles coated with an organic polymer compound, and circuit electrodes facing each other at the time of connection are used. A stable connection can be obtained by electrical connection through conductive particles. The conductive particles before coating with the organic polymer compound are metal particles such as Au, Ag, Ni, Cu, and solder, carbon, and the like, and in order to obtain a sufficient pot life, the surface layer is made of Ni, Cu, or the like. Au, Ag, and white metal noble metals are preferred, and Au is more preferred, rather than transition metals. Further, the surface of a transition metal such as Ni may be coated with a noble metal such as Au. In addition, when the conductive layer is formed on a non-conductive glass, ceramic, plastic, etc. by coating or the like and the outermost layer is made of noble metals, or in the case of hot-melt metal particles, it is deformable by heating and pressurization. It is preferable because it absorbs the height variation and increases the contact area with the electrode at the time of connection to improve the reliability. The thickness of the noble metal coating layer is preferably 100 angstroms or more in order to obtain good resistance. However, when a noble metal layer is formed on a transition metal such as Ni, free radicals are generated and preserved due to redox action caused by the loss of the noble metal layer or the loss of the noble metal layer generated when the conductive particles are mixed and dispersed. In order to cause deterioration of the properties, 300 angstroms or more is preferable. When the thickness is increased, these effects are saturated, so that the maximum thickness is preferably 1 μm, but is not limited. The surface of these conductive particles is coated with an organic polymer compound. It is preferable that the organic polymer compound is water-soluble because the coating workability is good. As water-soluble polymers, polysaccharides such as alginic acid, pectic acid, carboxymethylcellulose, agar, curdlan and pullulan; polyaspartic acid, polyglutamic acid, polylysine, polymalic acid, polymethacrylic acid, polymethacrylic acid ammonium salt, polymethacrylic acid Sodium salt, polyamic acid, polymaleic acid, polyitaconic acid, polyfumaric acid, poly (p-styrene carboxylic acid), polyacrylic acid, polyacrylamide, polymethyl acrylate, ethyl polyacrylate, ammonium polyacrylate, polyacrylic acid Polycarboxylic acids such as sodium salt, polyamic acid, polyamic acid ammonium salt, polyamic acid sodium salt and polyglyoxylic acid, polycarboxylic acid esters and salts thereof; polyvinyl alcohol, polyvinyl pyrrole These vinyl-based monomers such as emissions and polyacrolein the like may be used a single compound may be used in combination of two or more compounds. The thickness of the coating is preferably 1 μm or less. Since the conductive particles electrically connect the connection terminal and the connection terminal by excluding this coating, the coating of the portion that contacts the connection terminal during heating and pressurization is excluded. is required. The conductive particles are properly used in the range of 0.1 to 30 parts by volume with respect to 100 parts by volume of the adhesive resin component. In order to prevent a short circuit of an adjacent circuit due to excessive conductive particles, the amount is more preferably 0.1 to 10 parts by volume.

In the present invention , when the adhesive composition is formed into a film, the adhesive composition is divided into two or more layers, and divided into a layer containing a curing agent that generates free radicals upon heating and a layer containing conductive particles. , Pot life can be improved. The anisotropic conductive adhesive film for circuit connection of the present invention can also be used as a film adhesive for adhesion between an IC chip and a chip mounting substrate or between electric circuits. That is, the first circuit member having the first connection terminal and the second circuit member having the second connection terminal are arranged so that the first connection terminal and the second connection terminal are opposed to each other, and the opposing An anisotropic conductive adhesive film for circuit connection of the present invention (film adhesive) is interposed between the first connecting terminal and the second connecting terminal, and the first and second facing terminals are arranged by heating and pressing. The connection terminal and the second connection terminal can be electrically connected. As such a circuit member, a chip component such as a semiconductor chip, a resistor chip or a capacitor chip, a substrate such as a printed circuit board, or the like is used. These circuit members are usually provided with a large number of connection terminals (or a single connection terminal in some cases), and at least one set of the circuit members is arranged so that at least a part of the connection terminals provided on the circuit members are opposed to each other. Then, the anisotropic conductive adhesive film for circuit connection of the present invention is interposed between the connection terminals arranged opposite to each other, and the connection terminals arranged opposite to each other by heating and pressing are electrically connected to form a circuit connection body. By heating and pressurizing at least one set of circuit members, the connection terminals arranged to face each other can be electrically connected via the conductive particles in the adhesive composition. The adhesive film of the present invention can be used as a film-like adhesive for bonding a flexible tape or glass substrate to an IC chip in COG mounting or COF mounting. The first circuit member having the first connection terminal and the second circuit member having the second connection terminal are arranged so that the first connection terminal and the second connection terminal are opposed to each other, and the opposite arrangement is made. An anisotropic conductive adhesive film for circuit connection of the present invention (film adhesive) is interposed between the first connection terminal and the second connection terminal, and heated and pressurized to place the first connection facing each other. The terminal and the second connection terminal can be electrically connected. In the circuit terminal connection method of the present invention, the surface of the connection terminal is selected from gold, silver, tin, a platinum group metal, and indium-tin oxide (ITO). After forming at least one kind of connection terminal (electrode circuit), the other connection terminal (circuit electrode) can be aligned, heated and pressurized to be connected.

In the present invention, the substrate supporting the connection terminal is an organic insulating material such as polyimide resin, at least one circuit member selected from glass, and the surface is at least one selected from silicon nitride, silicone compound, polyimide resin, and silicone resin. It is possible to provide an anisotropic conductive adhesive film for circuit connection for electric and electronic use that can obtain particularly good adhesion strength to a coated or adhered circuit member.

Example 1
A phenoxy resin having a glass transition temperature of 80 ° C. was synthesized from bisphenol A type epoxy resin and 9,9′-bis (4-hydroxyphenyl) fluorene. 50 g of this resin was dissolved in a mixed solvent of toluene / ethyl acetate = 50/50 by weight to obtain a solution having a solid content of 40% by weight. The solid weight ratio is 60 g of phenoxy resin, 39 g of dicyclopentenyl dialcohol diacrylate, 1 g of phosphate ester acrylate, 5 g of t-hexylperoxy-2-ethylhexanate, and the surface is an organic polymer compound. Conductive particles coated with 0.01 to 0.2 μm (using polyvinyl alcohol) (on the surface of particles having polystyrene as a core, a 0.2 μm thick nickel layer is provided on the outside of the nickel layer, Using a coating device, a PET (polyethylene terephthalate) film whose surface is treated by dispersing 5% by volume of a gold layer with a thickness of 0.04μm and using conductive particles with an average particle diameter of 5μm is mixed and dispersed by 5% by volume. Then, by drying with hot air at 70 ° C. for 10 minutes, a film adhesive composition having an adhesive layer thickness of 10 μm was obtained. Moreover, it mix | blends so that it may become 60g of phenoxy resin by solid weight ratio, 39g of dicyclopentenyl dialcohol diacrylate, 1g of phosphate ester type acrylates, and 5g of t-hexylperoxy-2-ethylhexanoate, and the single side | surface of thickness 80 micrometers Was applied to a PET (polyethylene terephthalate) film surface-treated with a coating apparatus, and dried with hot air at 70 ° C. for 10 minutes to obtain a film adhesive composition having an adhesive layer thickness of 10 μm. These adhesive compositions were bonded using a laminator to obtain an adhesive film having a two-layer structure.

(Example 2)
An adhesive film was obtained in the same manner as in Example 1 except that 50 g of phenoxy resin and 49 g of dicyclopentenyl dialcohol diacrylate were mixed at a solid weight ratio.

(Comparative Example 1)
An adhesive film was obtained in the same manner as in Example 1 except that conductive particles whose surfaces were not coated with an organic polymer compound were used.

(Comparative Example 2)
An adhesive film was obtained in the same manner as in Example 1 except that 40 g of phenoxy resin and 60 g of a liquid epoxy resin (epoxy equivalent 185) containing a microcapsule-type latent curing agent were blended in a solid weight ratio.

(Circuit connection)
An ITO substrate (surface resistance <20Ω / □) was sandwiched between quartz glass and a pressure head using the above adhesive composition, and connected by heating and pressing at 200 ° C. and 100 MPa (in terms of gold bump area) for 10 seconds. At this time, the film-like adhesive composition is applied on the ITO substrate in advance by heating and pressurizing the adhesive surface with the conductive particles of the adhesive composition at 70 ° C. and 0.5 MPa for 5 seconds, and then the PET film is peeled off. And connected to the IC chip.

(Measurement of polar component of surface tension (γsv, p))
Water and diiodomethane are dropped onto the surface of an anisotropic conductive adhesive film for circuit connection comprising a 5 mm × 5 mm circuit connection resin composition (23 ° C.), and the contact angle is measured to measure the surface tension in the adhesive film . The plant of polar components was sought.

(Measurement of contact resistance)
After the circuit was connected, the electrical resistance value of the connecting part was measured with a multimeter using a two-terminal measurement method after maintaining 500 cycles in the temperature cycle bath at −40 ° C./30 min and 100/30 min.

(Measurement of insulation resistance between adjacent electrodes)
After connection of the circuit, a direct current (DC) voltage of 50 V was applied to the connection part for 1 minute, and the insulation resistance after application was measured with a multimeter using a two-terminal measurement method. The results are summarized in Table 1.

As shown in Table 1, the polar component (γsv, p) of the surface tension of the adhesive film surface shown in Examples 1 and 2 of the present invention is 3.0 to 4.0 dyne / cm, By using an adhesive composition containing conductive particles whose surfaces are coated with an organic polymer compound, the connection resistance immediately after the connection of the COG connection and the connection resistance after the temperature cycle are small and good. Moreover, the insulation resistance between adjacent electrodes is high and shows favorable connectivity. On the other hand, as in Comparative Example 1, even when the polar component (γsv, p) of the surface tension of the adhesive film surface is 3.0 to 4.0 dyne / cm, the surface of the conductive particles is an organic polymer compound. When an adhesive composition containing conductive particles not coated with is used, the connection resistance is small and good, but the insulation resistance between adjacent electrodes is too small to show good connectivity. Further, as in Comparative Example 2, the polar component (γsv, p) of the surface tension of the adhesive film surface is outside the range of 3.0 to 4.0 dyne / cm, and the surface of the conductive particles is an organic polymer compound. When the adhesive composition containing the conductive particles coated with is used, the insulation resistance between adjacent electrodes is high and good, but the connection resistance after temperature cycling becomes very high and does not show good connectivity. By covering the surface of the conductive particles with an organic polymer compound, the conduction due to contact between adjacent conductive particles in the surface direction of the adhesive (perpendicular to the thickness direction) is insulated and the insulation resistance is increased. By setting the polar component of the surface tension of the composition within an appropriate range, the thickness of the adhesive gradually decreases during heating and pressurization, and the distance between the conductive particles existing between the electrodes to be electrically connected is further increased. As a result of good exclusion when the adhesive is removed from the gap between the electrode and the conductive particles in the process where the conductive particles are deformed by pressure, it seems that the connection resistance is small and good connectivity is exhibited. . On the other hand, if the rejection is poor, the contact between the electrodes is maintained immediately after connection as in Comparative Example 2, and the connection resistance is small, but the adhesive is relaxed by the stress applied to the adhesive due to the temperature cycle. It is presumed that the conductive particles moved slightly due to the deformation at the time, and the contact could not be maintained.

Claims (13)

Curing agent that generates free radicals by applying heat, a dicyclopentenyl group, the first radical-polymerizable substances containing an acrylate or methacrylate having at least one selected from a tricyclodecanyl group and a triazine ring, phosphoric acid ester structure An adhesive composition containing, as an essential component , a second radical-polymerizable substance having a phenoxy resin, a film-forming material containing a phenoxy resin , and conductive particles whose surfaces are coated with an organic polymer compound containing a water-soluble polymer A first adhesive layer comprising:
A second adhesive layer comprising an adhesive composition containing the curing agent, the first radical polymerizable substance, the second radical polymerizable substance, and the film forming material, and not containing the conductive particles; Having a two-layer structure consisting of
Anisotropy for circuit connection , wherein the polar component (γsv, p) of surface tension on the surface of the first adhesive layer is 3.0 to 4.0 dyne / cm, measured at 23 ° C. using water and diiodomethane Conductive adhesive film. The anisotropic conductive adhesive film for circuit connection according to claim 1, wherein the second radical polymerizable substance is represented by the formula (1).

The anisotropic conductive adhesive film for circuit connection according to claim 1 or 2 , wherein the phenoxy resin has a molecular structure derived from a polycyclic aromatic compound in the molecule. The anisotropic conductive adhesive film for circuit connection according to claim 3 , wherein the molecular structure resulting from the polycyclic aromatic compound is a fluorene ring. The circuit connection according to any one of claims 1 to 4 , wherein the water-soluble polymer includes at least one selected from polycarboxylic acid, polycarboxylic acid ester, salt of polycarboxylic acid ester, and vinyl monomer. Anisotropic conductive adhesive film . The anisotropic conductive adhesive film for circuit connection according to any one of claims 1 to 5 , which is for COG mounting, for COF mounting, or for driving IC connection. The anisotropic conductive adhesive film for circuit connection according to any one of claims 1 to 5 , which is for circuit connection having a bump area of less than 3000 µm ² . A first circuit member having a first connection terminal and a second circuit member having a second connection terminal are disposed so that the first connection terminal and the second connection terminal are opposed to each other, and the opposed arrangement is performed. The anisotropic conductive adhesive film for circuit connection according to any one of claims 1 to 7 is interposed between the first connection terminal and the second connection terminal, and the opposing connection is performed by heating and pressing. A circuit terminal connection method for electrically connecting a first connection terminal and a second connection terminal. A circuit connection structure obtained by the circuit terminal connection method according to claim 8 , wherein an insulation resistance between adjacent electrodes is 10 ⁹ Ω or more when a direct current of 50 V is applied to the circuit terminal. The circuit connection structure according to claim 9 , wherein the circuit member having at least one connection terminal is an IC chip. The circuit connection structure according to claim 9 or 10 , wherein a connection resistance between the connection terminal of the IC chip and the connection terminal on the second circuit member is 1Ω or less. The circuit according to any one of claims 9 to 11 , wherein the surface of at least one of the connection terminals is composed of at least one selected from gold, silver, tin, a platinum group metal, and indium-tin oxide (ITO). Connection structure. The circuit connection structure according to any one of claims 9 to 12 , wherein the surface of at least one circuit member is coated or adhered with at least one selected from silicon nitride, a silicone compound, and a polyimide resin.