JP2002201438A - Adhesive composition, and connection method and connection structure of circuit terminal using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide adhesive compositions for electric/electronic uses which give low-resistance electric connection in COG mounting or COF mounting without causing a short circuit; and a connection method and connection structure of circuit terminals using the same. SOLUTION: A bonding material is caused to intervene between circuit electrodes facing each other and, when the circuit electrodes facing each other are pressed, electrically connects the electrodes to each other in the pressing direction. The bonding material at least comprises an insulating adhesive layer and an adhesive layer containing conductive particles. Each layer of the bonding material is an adhesive composition containing, as essential ingredients, at least three ingredients selected from among (1) a curing agent which generates free radicals under heating, (2) a free-radical-polymerizable substance, (3) a film-forming material, and (4) conductive particles. The fluidity (B)/(A) represented by the area (A) of the bonding material comprising the adhesive layers before heating and pressing and the area (B) of the bonding material after heating and pressing is 1.3-2.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition, and a circuit terminal in a CHIP-ON-GLASS mounting (hereinafter referred to as COG mounting) or a CHIP-ON-FLEX (hereinafter referred to as COF mounting) using the same. The present invention relates to a connection method and a connection structure of circuit terminals.

[0002]

2. Description of the Related Art A liquid crystal driving IC is mounted on a liquid crystal display glass panel by a COG mounting method in which the liquid crystal driving IC is directly joined to the glass panel by a circuit connecting member, or the liquid crystal driving IC has metal wiring. A COF mounting method of bonding to a flexible tape and bonding to a glass panel and a circuit connecting member is used. As the definition of liquid crystal displays has become higher,
The gold bump, which is the electrode of C, has a narrow pitch and a narrow area. For this reason, there is a problem that the conductive particles in the bonding material flow out between the adjacent electrodes, causing a short circuit, and a problem that the number of conductive particles in the bonding material captured on the bumps is reduced, resulting in poor connection. . In order to solve these problems, a method has been developed in which an insulating adhesive layer is formed on at least one surface of a bonding material to prevent a decrease in bonding quality in COG mounting and COF mounting (for example, Japanese Patent Application Laid-Open No. H08-208,1992). -279371).

[0003]

However, when the bump area of the connection member is less than 3000 μm ² , the number of conductive particles in the bonding material captured on the bump is reduced, and a stable connection resistance value is obtained. However, there is a problem that when the filling amount of the particles is increased to increase the short-circuiting rate and the insulation failure occurs, the connection resistance value is lowered. The present invention provides an electric / electronic adhesive composition that provides low-resistance electrical connection to COG mounting and COF mounting and does not cause short circuit, a method for connecting circuit terminals using the same, and a method for connecting circuit terminals. Provides structure.

[0004]

According to the present invention, there is provided a bonding material which is interposed between opposing circuit electrodes, presses the opposing circuit electrodes, and electrically connects the electrodes in the pressing direction. A bonding material comprising at least an insulating bonding layer and a bonding layer containing conductive particles, each bonding layer comprising: (1) a curing agent that generates free radicals by heating; (2) a radical polymerizable substance; and (3) a film. An adhesive composition containing, as an essential component, at least three of the forming material and (4) conductive particles. The area (A) of the bonding material composed of each adhesive layer before heating and pressing and the area after heating and pressing are Is an adhesive composition having a flowability (B) / (A) value of 1.3 to 2.0 expressed using the area (B) of the adhesive composition. If the fluidity of the adhesive composition is less than 1.3, the fluidity is poor and a good connection may not be obtained,
If it exceeds 2.0, the number of conductive particles captured on the bumps is small, so that the electrical resistance of the connection portion increases, which is not preferable. [2] An insulating adhesive layer containing (1) a curing agent that generates free radicals upon heating, (2) a radical polymerizable substance, and (3) a film-forming material as essential components; A curing agent that generates free radicals when heated,
(2) radical polymerizable substance, (3) film forming material,
(4) The adhesive composition according to the above [1], comprising two layers of an adhesive layer containing conductive particles containing conductive particles as an essential component. [3] The adhesive composition according to the above [1] or [2], wherein the surface of the conductive particles is covered with an organic polymer compound. The surface of the conductive particles used in the present invention is gold, silver,
It is preferable to use one composed of at least one selected from white metal, and it is more preferable to coat the metal surface with an organic polymer compound. [4] The adhesive composition according to any one of [1] to [3], wherein the thickness of the adhesive layer containing the conductive particles is less than three times the particle size of the conductive particles. The adhesive composition of the present invention can be formed into a multilayer structure composed of a layer containing conductive particles and another layer. At this time, the thickness of the adhesive layer containing the conductive particles is preferably less than three times the particle size of the conductive particles, and more preferably less than two times. When the thickness of the adhesive layer containing the conductive particles is three times or more, the amount of the conductive particles flowing out between the adjacent electrodes increases, and the insulating property decreases, which is not preferable. In addition, the present invention relates to [5] a first circuit member having a first connection terminal, and a second circuit member having a second connection terminal, the first connection member and the second connection terminal. The adhesive composition according to any one of the above [1] to [4] is interposed between the first connection terminal and the second connection terminal which are arranged to face each other, and heated and pressed. And a circuit terminal for electrically connecting the first connection terminal and the second connection terminal arranged opposite to each other. [6] The circuit member having at least one connection terminal is I
The method for connecting circuit terminals according to the above [5], which is a C chip. [7] The surface of at least one of the connection terminals is gold, silver, tin,
The circuit terminal connection method according to the above [5] or [6], comprising at least one selected from a platinum group metal and indium-tin oxide (ITO). [8] at least one circuit member surface is silicon nitride,
The method of connecting a circuit terminal according to any one of the above [5] to [7], wherein the circuit terminal is coated or adhered with at least one selected from a silicone compound and a polyimide resin. Further, the present invention provides

[9] A circuit terminal connection structure obtained by the circuit terminal connection method according to any one of [5] to [8].

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bonding material interposed between opposed circuit electrodes for heating and pressing the opposed circuit electrodes and electrically connecting the electrodes in the pressing direction. And a bonding material containing conductive particles. Each adhesive layer contains, as essential components, at least three of (1) a curing agent that generates free radicals upon heating, (2) a radical polymerizable substance, (3) a film forming material, and (4) conductive particles. Agent composition.
The bonding material is composed of an insulating adhesive layer (Z) and an adhesive layer (D) containing conductive particles.
-D, in three layers, ZDZ, DZD, and the like,
Similarly, a configuration having four or more layers can be employed. Then, the value of the fluidity (B) / (A) expressed by using the area (A) before the heating and pressurizing and the area (B) after the heating and pressurizing of the bonding material composed of each adhesive layer is 1 .3 to 2.0. If the fluidity is less than 1.3, the fluidity is poor and good connection may not be obtained. If the fluidity is more than 2.0, the connection terminals, for example, the number of conductive particles captured on the bumps is small. The electric resistance value of the part increases. The fluidity was measured by using a glass having a thickness of 0.7 mm and a size of 15 mm × 15 mm, sandwiching an adhesive composition having a thickness of 35 μm and a size of 5 mm × 5 mm between the two glasses, and setting the temperature to 200 ° C. and 2 MPa.
a) Heating and pressing were performed for 10 seconds, and the value of (B) / (A) was determined from the initial area (A) and the area (B) after heating and pressing.
This area can also be measured using an image processing device or the like. When the thickness of each adhesive layer was different, the thickness of the bonding material was 35 μm in proportion to the thickness.

[0006] The insulating adhesive layer constituting the bonding material is
(1) a curing agent that generates free radicals when heated,
It is preferable that (2) a radical polymerizable substance and (3) a film-forming material be contained as an essential component, and the adhesive layer containing conductive particles comprises (1) a curing agent that generates free radicals upon heating; ) A radical polymerizable substance, (3) a film forming material, and (4) conductive particles are preferably contained as essential components. It is preferable that the conductive particles have the surface of the conductive particles covered with an organic polymer compound,
For coating with the organic polymer compound, a method usually used for a microcapsule technique can be adopted. For example, spraying, immersion drying, and the like of a polymer compound on conductive particles are used. The coating thickness may be an insulating property, and may be an extremely thin thickness. The thickness of the adhesive layer containing conductive particles is preferably less than three times the particle size of the conductive particles. When the thickness of the adhesive layer containing the conductive particles is three times or more, the amount of the conductive particles flowing out between the adjacent electrodes increases, and the insulating property tends to decrease. Since the number is reduced, connection resistance is increased and connection reliability is deteriorated.

The (3) film-forming material used in the present invention includes phenoxy resin, polyvinyl formal resin,
Polystyrene resin, polyvinyl butyral resin, polyester resin, polyamide resin, xylene resin, polyurethane resin and the like can be mentioned. Film forming material, when the liquid material is solidified and the constituent composition is in the form of a film,
The film is easy to handle and imparts mechanical properties and the like that are not easily torn, cracked or sticky, and can be handled as a film in a normal state. Phenoxy resins are preferred among the film-forming materials because of their excellent 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 bifunctional phenols with 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 be. In addition, from the viewpoint of the mechanical and thermal properties of the resin, in particular, the blending equivalent ratio of the bifunctional epoxy resin and the bifunctional phenol is set such that epoxy group / phenol hydroxyl group = 1.
/0.9 to 1 / 1.1, amides, ethers, ketones having a boiling point of 120 ° C. or more in the presence of a catalyst such as an alkali metal compound, an organic phosphorus compound, or a cyclic amine compound;
Those obtained by heating at 50 to 200 ° C. in a lactone-based or alcohol-based organic solvent at a reaction solid content of 50 parts by weight or less and performing a polyaddition reaction are preferred. Examples of the bifunctional epoxy resin include a bisphenol A epoxy resin, a bisphenol F epoxy resin, a bisphenol AD epoxy resin, and a bisphenol S epoxy resin. Bifunctional phenols have two phenolic hydroxyl groups and include, for example, hydroquinones, bisphenols such as bisphenol A, bisphenol F, bisphenol AD, and bisphenol S. The phenoxy resin may be modified with a radically polymerizable functional group. The phenoxy resins may be used alone or as a mixture of two or more.

The curing agent used in the present invention which generates free radicals upon heating is a compound which decomposes upon heating a peroxide compound or an azo compound to generate free radicals. The temperature, the connection time, the pot life and the like are appropriately selected. From the viewpoint of high reactivity and pot life, the temperature at the half-life of 10 hours is 40 ° C. or more,
In addition, an organic peroxide having a half-life of 1 minute at a temperature of 180 ° C. or less is preferable, and 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. preferable. When the connection time is set to 10 seconds or less, the amount of the curing agent is based on the total of 100 parts by weight of the radical polymerizable substance and the film forming material in order to obtain a sufficient reaction rate.
It is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight. If the amount of the curing agent is less than 0.1 part by weight, a sufficient reaction rate cannot be obtained, and good adhesive strength and small connection resistance tend to be hardly obtained. If the amount exceeds 30 parts by weight, the fluidity of the adhesive composition tends to decrease, the connection resistance increases, and the pot life of the adhesive composition tends to be short.

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 the corrosion of the connection terminal of the circuit member, chlorine ions and organic acids contained in the curing agent are 500%.
The content is preferably 0 ppm or less, and more preferably, an organic acid generated after thermal decomposition is small. Specifically, it is selected from peroxyesters, dialkyl peroxides, hydroperoxides, and silyl peroxides, and is more preferably selected from peroxyesters having high reactivity. The above-mentioned curing agents can be appropriately mixed and used.

Examples of the diacyl peroxide include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinyl peroxide, and succinyl peroxide. Nickel peroxide, benzoylperoxytoluene, benzoyl peroxide and the like can be mentioned.

As peroxydicarbonate, di-
n-propylperoxydicarbonate, diisopropylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, di (2-ethylhexylperoxy) Dicarbonate, dimethoxybutylperoxydicarbonate, di (3-methyl-3-methoxybutylperoxy) dicarbonate and the like can be mentioned.

Examples of peroxy esters include cumyl peroxy neodecanoate, 1,1,3,3-tetramethylbutyl peroxy neodecanoate, 1-cyclohexyl-1-methylethyl peroxynodecanoate. Ethate, t-hexylperoxy neodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanonate, 2,5-dimethyl-
2,5-di (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-
2-ethylhexanonate, t-hexylperoxy-2
-Ethylhexanonate, t-butylperoxy-2-ethylhexanonate, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane, t-hexylperoxyisopropylmono Carbonate, t-butylperoxy-3,5,5-trimethylhexanonate, t-butylperoxylaurate, 2,5
-Dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, t
-Butyl peroxyacetate and the like.

The peroxyketal includes 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, , 1-bis (t-butylperoxy)-
Examples include 3,3,5-trimethylcyclohexane, 1,1- (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) decane, and the like.

As the dialkyl peroxide, α,
α'-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-
Examples thereof include 2,5-di (t-butylperoxy) hexane and t-butylcumyl peroxide.

Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

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

These curing agents which generate free radicals by heating can be used alone or in combination, and may be used in combination with a decomposition accelerator, an inhibitor and the like. A microcapsule obtained by coating these curing agents with a polyurethane-based or polyester-based polymer substance or the like is preferable because the pot life is extended.

The radically polymerizable substance (2) used in the present invention is a substance having a functional group capable of polymerizing by radicals, such as acrylate, methacrylate, and maleimide compounds. The radical polymerizable substance can be used in any state of a monomer and an oligomer, and the monomer and the oligomer can be used in combination. Specific examples of acrylates (methacrylates) include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylol methane tetraacrylate, and 2-
Hydroxy-1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, dicyclopentynyl Acrylate,
Examples include tricyclodecanyl acrylate, tris (acryloyloxyethyl) isocyanurate, urethane acrylate, and methacrylate corresponding to these acrylates. These can be used alone or in combination. If necessary, a polymerization inhibitor such as hadroquinone or methyl ether hydroquinone may be used as appropriate.
Further, it is preferable to have a dicyclopentynyl group and / or a tricyclodecanyl group and / or a triazine ring because heat resistance is improved.

The maleimide compound is a compound containing at least two maleimide groups in the molecule, for example, 1-methyl-2,4-bismaleimidebenzene, N,
N'-m-phenylenebismaleimide, N, N'-p-phenylenebismaleimide, N, N'-m-toluylenebismaleimide, N, N'-4,4-biphenylenebismaleimide, 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-diphenylmethanebismaleimide,
N, N'-4,4-diphenylpropanebismaleimide,
N, N′-3,3′-diphenylsulfonebismaleimide,
N, N'-4,4-diphenylether 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 and the like. These can be used alone or in combination.

The adhesive composition of the present invention contains acrylic acid,
A copolymer or a copolymer containing at least one of acrylic acid ester, methacrylic acid ester and acrylonitrile as a monomer component can be used, and a copolymer acrylic rubber containing glycidyl acrylate or glycidyl methacrylate containing a glycidyl ether group can be used. The use of a combination of these is preferred because of excellent 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 of the present invention further comprises a filler, a softener, an accelerator, an antioxidant, a flame retardant, a pigment, a thixotropic agent, a coupling agent, a phenol resin, a melamine resin, and an isocyanate. And the like. When a filler is contained, it is preferable because an improvement in connection reliability and the like can be obtained. It can be used as long as the maximum diameter of the filler is smaller than the particle diameter of the conductive particles, and a range of 5 to 60 parts by volume (based on 100 parts by volume of the adhesive resin component) is preferable. If it exceeds 60 parts by volume, the effect of improving 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, a vinyl group, an acryl group, an amino group, an epoxy group and an isocyanate group-containing material are preferred from the viewpoint of improving the adhesiveness. Specifically, as a silane coupling agent having an amino group, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane Ethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane and the like can be mentioned. Examples of the silane coupling agent having a ketimine include those obtained by reacting a silane coupling agent having an amino group with a ketone compound such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

The adhesive composition of the present invention can be connected by direct contact of opposing circuit electrodes at the time of connection even without conductive particles. When the adhesive composition contains conductive particles, a more stable connection can be obtained. Au, Ag, N as conductive particles
There are metal particles such as i, Cu, solder, and carbon, and the like. In order to obtain a sufficient pot life, the surface layer is preferably made of noble metals such as Au, Ag, and white metal instead of transition metals such as Ni and Cu. More preferred. Further, the surface of a transition metal such as Ni may be coated with a noble metal such as Au.
Further, the conductive layer described above may be formed on a nonconductive glass, ceramic, plastic, or the like by coating or the like, and the outermost layer may be made of a noble metal. When a conductive layer is formed on a plastic by coating, etc., or when it is deformed by fusing and heating and pressing of hot-melt metal particles, the contact area with the electrode increases during connection, and the thickness variation of the circuit terminal of the circuit member is absorbed. This is preferable because the reliability is improved. The thickness of the noble metal coating layer is preferably 100 Å or more in order to obtain good resistance. However, when a layer of a noble metal is formed on a transition metal such as Ni, free radicals are generated due to oxidation-reduction action caused by a defect of the noble metal layer or a defect of the noble metal layer generated during mixing and dispersion of conductive particles, and the storage is performed. The thickness is preferably 300 Å or more in order to cause deterioration in the property. When the thickness increases, their effects become saturated. Therefore, it is preferable to set the thickness to 1 μm at the maximum, but there is no limitation. The conductive particles are properly used in a range of 0.1 to 30 parts by volume based on 100 parts by volume of the adhesive resin component. In order to prevent a short circuit or the like in an adjacent circuit due to excessive conductive particles, the content is more preferably 0.1 to 10 parts by volume.

The adhesive composition of the present invention can be used for COG mounting or C
It can also be used as a film adhesive for bonding a flexible tape or a glass substrate to an IC chip in OF mounting. That is, a first circuit member having a first connection terminal and a second circuit member having a second connection terminal are arranged such that the first connection terminal and the second connection terminal are opposed to each other. The adhesive composition (film-like adhesive) of the present invention is interposed between the arranged first connection terminal and the second connection terminal, and heated and pressurized, and the first connection terminal and the second connection terminal arranged opposite to each other are heated and pressed. The connection terminals can be electrically connected.
These circuit members are usually provided with a large number of connection terminals (in some cases, a single terminal may be provided), and at least one set of the circuit members may be provided with at least a part of the connection terminals provided on the circuit members facing each other. Then, the adhesive of the present invention is interposed between the opposed connection terminals, and the connection terminals opposed to each other are electrically connected to each other by heating and pressing to form a circuit board. By heating and pressurizing at least one set of circuit members, the connection terminals arranged opposite to each other can be electrically connected to each other by direct contact or via conductive particles in the adhesive composition.

In the method for connecting circuit terminals of the present invention, the adhesive composition of the present invention is used, and the surfaces of the connection terminals are selected from gold, silver, tin, platinum group metals, and indium-tin oxide (ITO). After forming at least one type of connection terminal (electrode circuit), the other connection terminal (circuit electrode) can be positioned, heated and pressed, and connected. At this time, light may be emitted from one of the circuit members. In the present invention, the flexible tape is an organic insulating material such as a polyimide resin, the surface of a glass substrate is particularly good for a circuit member coated or adhered with at least one selected from silicon nitride, a silicone compound, a polyimide resin, and a silicone resin. It is possible to provide an electric / electronic adhesive composition capable of obtaining an adhesive strength, a circuit terminal connection method using the same, and a circuit terminal connection structure.

[0026]

EXAMPLES (Example 1) A phenoxy resin having a glass transition temperature of 80 ° C was synthesized from bisphenol A type epoxy resin and bisphenol A. 50 g of this resin was mixed with toluene (boiling point 110.6 ° C.) / Ethyl acetate (boiling point 77.
1 ° C.) = 50/50 mixed solvent to give a solid content of 40
% Solution. 60 g of phenoxy resin (solid weight ratio) as a film-forming material and dicyclopentenyl dialcohol diacrylate as a radical polymerizable substance
39 g, phosphoric acid ester type acrylate (P2M; trade name, manufactured by Kyoeisha Yushi Co., Ltd.) 1 g, t-hexylperoxy-2 as a curing agent that generates free radicals when heated
-Ethylhexanonate was added in an amount of 5 g.
A 2 μm nickel layer and a 0.04 μm thick gold layer provided on the outside of the nickel layer have an average particle size of 5 μm,
5% by volume) and dispersed to a thickness of
A 0 μm single-sided surface-treated PET (polyethylene terephthalate) film was applied using a coating device,
The thickness of the adhesive layer is 10μ
m was obtained. A phenoxy resin 60 g, a dicyclopentenyl dialcohol diacrylate 39 g, a phosphoric acid ester type acrylate 1 g, and a t-hexylperoxy-2-ethylhexanonate 5 g were blended in a solid weight ratio, and the thickness was 80 μm.
Is coated on a PET (polyethylene terephthalate) film having one surface treated with
By hot-air drying for 0 minutes, a film-like adhesive composition having an adhesive layer thickness of 10 μm was obtained. These adhesive compositions were bonded together using a laminator to obtain a two-layered film adhesive composition.

Example 2 A two-layered film adhesive composition was prepared in the same manner as in Example 1 except that the phenoxy resin and the dicyclopentynyl dialcohol diacrylate were mixed in a solid weight ratio of 50 g and 49 g, respectively. I got

Comparative Example 1 A two-layer film adhesive composition was obtained in the same manner as in Example 1 except that the phenoxy resin was 40 g and the dicyclopentenyl dialcohol diacrylate was 59 g in terms of solid weight ratio.

(Circuit connection) Bump area 50 μm × 50
An IC chip on which gold bumps having a pitch of 100 μm and a height of 20 μm are arranged, and an indium tin oxide (ITO) formed on a 1.1 mm thick glass by vapor deposition.
An O substrate (surface resistance, <20Ω / □) was sandwiched between quartz glass and a pressure head using the above-mentioned adhesive composition.
The connection was performed by heating and pressing at 100 ° C. and 100 MPa (bump area conversion) for 10 seconds. At this time, the film-shaped adhesive composition was previously coated on the ITO substrate with an adhesive surface of 70%.
The film was bonded by heating and pressing at 0.5 ° C. and a pressure of 0.5 MPa (in terms of bump area) for 5 seconds, and then the PET film was peeled off and connected to an IC chip. (Measurement of fluidity) Thickness 0.7 mm, 15 mm x 15 mm
A circuit connecting material made of a resin composition for circuit connecting having a thickness of 35 μm and 5 mm × 5 mm was sandwiched between the glasses, and heated and pressed at 200 ° C., 2 MPa, and 10 seconds to obtain an initial area (A ) And the area (B) after heating and pressing, the value of (B) / (A) was determined. (Measurement of Number of Trapped Particles on Bump) After connection of the circuit, the bumps were observed from the glass side with a metallographic microscope (magnification: 200 times), and the number of conductive particles on the bumps was counted to obtain an average value. (Measurement of connection resistance) After the circuit was connected, the electric resistance value of the connection portion was initially kept at 500 cycles in a temperature cycle bath of −40 ° C./30 minutes and 100 ° C./30 minutes, and then a two-terminal measurement method was used. It was measured with a multimeter. Table 1 shows the measurement results.

[0030]

[Table 1]

When the amount of the phenoxy resin used as the film forming material is small and the amount of the radical polymerizable substance is large, the fluidity increases. As the fluidity increases, the number of conductive particles on the bump decreases. When the number of particles decreases, the connection resistance for evaluating the connection reliability after the temperature cycle test greatly increases, and reaches as high as 20Ω or more. When the fluidity of the bonding material of the present invention is in the range of 1.3 to 2.0, both the initial and the connection resistance after the reliability test are low, and good results are shown. On the other hand, when the fluidity of Comparative Example 1 is 2.7, the initial value of the connection resistance is low and good, but the connection resistance after the reliability test is extremely large, which is not suitable as a bonding material for circuit members. In addition, as a result of various experiments, if the thickness of the adhesive layer containing the conductive particles is less than three times the particle size of the conductive particles, the number of the conductive particles captured on the bumps increases and the connection resistance decreases. Could be maintained. Further, when the fluidity is less than 1.3, the fluidity is poor and bubbles are involved, so that a good connection cannot be obtained. When the conductive particles are covered with the organic polymer, there is no significant effect on the fluidity, but there is no short circuit between adjacent connection terminals and the insulation failure is eliminated. In addition, the filling amount of the conductive particles was increased, and a reliable connection could be secured.

[0032]

According to the present invention, there is provided an adhesive composition for electric / electronic use which can provide a low-resistance electric connection even in a driving IC having a small bump area in COG mounting or COF mounting. It is possible to provide the connection method of the used circuit terminals and the connection structure of the circuit terminals.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/29 H01R 4/04 5F0423 23/31 H05K 3/32 B H01R 4/04 H01L 23/30 R H05K 3/32 (72) Inventor Yukihisa Hirosawa 1150 Goshomiya, Shimodate, Ibaraki Pref.Hitachi Kasei Kogyo Co., Ltd. (72) Inventor Tadashi Fujii 1150 Goshomiya, Shimodate, Ibaraki Pref. F-term in the Goshonomiya Office of the Company (reference) JA09 JB10 KA02 KA03 KA07 KA16 KA32 LA09 LA11 MA01 MA02 MA10 NA20 PA32 PA33 4M109 AA02 BA05 BA07 CA22 EA20 EB 02 EB18 EC07 5E085 CC01 DD05 EE34 JJ50 5E319 AA03 AA08 AB05 AC04 AC17 BB16 CC12 CD25 5F044 KK03 KK06 LL07 LL11 RR17 RR18 RR19

Claims (9)

[Claims] 1. A bonding material interposed between opposing circuit electrodes, pressurizing the opposing circuit electrodes, and electrically connecting the electrodes in the pressing direction with at least an insulating adhesive layer and conductive particles. Each bonding layer is a bonding material comprising a bonding layer, and each bonding layer is any one of (1) a curing agent that generates free radicals upon heating, (2) a radical polymerizable substance, (3) a film forming material, and (4) a conductive particle. An adhesive composition containing at least 3 as an essential component, and is expressed using an area (A) before heating and pressing and an area (B) after heating and pressing of a bonding material formed of each adhesive layer. An adhesive composition having a fluidity (B) / (A) value of 1.3 to 2.0. 2. A bonding material comprising: (1) a curing agent that generates free radicals upon heating; (2) a radical polymerizable substance;
(3) an insulating adhesive layer containing a film forming material as an essential component, (1) a curing agent that generates free radicals by heating, (2) a radical polymerizable substance, (3) a film forming material, (4) The adhesive composition according to claim 1, comprising two layers of an adhesive layer containing conductive particles containing conductive particles as an essential component. 3. The adhesive composition according to claim 1, wherein the surface of the conductive particles is covered with an organic polymer compound. 4. The method according to claim 1, wherein the thickness of the adhesive layer containing the conductive particles is less than three times the particle diameter of the conductive particles.
The adhesive composition according to any one of the above. 5. A first circuit member having a first connection terminal and a second circuit member having a second connection terminal are arranged with the first connection terminal and the second connection terminal facing each other. The adhesive composition according to any one of claims 1 to 4, wherein the adhesive composition according to any one of claims 1 to 4 is interposed between the first connection terminal and the second connection terminal disposed opposite to each other, and heated and pressurized to form the second connection terminal. A connection method of a circuit terminal for electrically connecting one connection terminal and a second connection terminal. 6. The method according to claim 5, wherein the circuit member having at least one connection terminal is an IC chip. 7. The surface of at least one connection terminal is gold,
Silver, tin, platinum group metals, indium-tin oxide (IT
6. A structure comprising at least one selected from O).
Alternatively, the method for connecting circuit terminals according to claim 6. 8. The method according to claim 5, wherein at least one surface of the circuit member is coated or adhered with at least one selected from silicon nitride, a silicone compound, and a polyimide resin. . 9. A connection structure for circuit terminals obtained by the method for connecting circuit terminals according to claim 5. Description: