JP2013110084A - Conductive paste composition and conductive adhesive agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive paste composition that is excellent in the mechanical strength, the heat resistance, the humidity resistance, the flexibility, the thermal cycle resistance, the solder reflow resistance, the dimension stability and the like after hardening, and that shows a high adhesion reliability and a high conduction reliability if used as a conduction material.SOLUTION: A conductive paste composition contains (A) epoxy resin, (B) polyvinyl acetal resin, (C) rosin derivative, (D) epoxy resin hardener, and (E) metal fine particles having a center particle diameter of 10 nm to 30 μm.

Description

The present invention relates to a conductive paste composition and a conductive adhesive.

In recent years, with the miniaturization of various electronic devices, various conductive pastes for electronic materials have been developed. These conductive pastes for electronic materials are required to have a high degree of reliability, and in order to ensure this, there is little curing shrinkage, high adhesion and adhesion to the substrate, and excellent printability. In addition, polyester resins and epoxy resins that are abundant in type and easy to design are often used.

As an epoxy resin, general-purpose epoxy resins such as bisphenol A diglycidyl ether type epoxy resin, bisphenol F type epoxy resin, urethane-modified epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin are used because of excellent workability. ing. However, conductive pastes for electronic materials using these general-purpose epoxy resins cannot meet the current requirements for extremely high reliability.

Currently, the required performance for the reliability of the conductive paste for electronic materials includes, for example, heat resistance, moisture resistance, cold cycle resistance, solder reflow resistance, and the like. Above all, regarding moisture resistance and solder reflow resistance when designing a conductive paste as a conductive adhesive, it is necessary that the water absorption of the cured adhesive is low and the water absorption is small. This is because if the water absorption rate of the cured adhesive is high, water easily enters the bonding interface, and the adhesive force at the interface may be reduced.

On the other hand, in order to improve the thermal cycle resistance, a method of using a large amount of an inorganic filler for reducing the linear expansion coefficient (linear expansion coefficient) is generally mentioned. This is because the inorganic filler has a much smaller linear expansion coefficient than the organic filler. However, when a large amount of inorganic filler is used, the coefficient of linear expansion is reduced, but the elastic modulus of the adhesive is increased, so that there is a problem that it is difficult for the cured adhesive to relieve stress.

In addition, with respect to the improvement of the thermal cycle resistance, a rubber polymer such as acrylic rubber is generally added in order to reduce the generated stress.

However, the addition of the rubber polymer improves the thermal cycle resistance, but at the cost of lowering the thermal resistance, it achieves stress relaxation, so it has high thermal and humidity resistance and high thermal cycle resistance. It is difficult to achieve both.

In order to relieve the stress, generally, epoxy resins are modified with carboxylic acid or glycidyl-modified polyolefins such as diene rubber polymers having functional groups such as CTBN and ATBN, nitrile rubbers, and silicones having terminal functional groups. In addition, a method of mixing so that flexibility imparting components such as acrylic rubber and styrene elastomer are compatible or phase-separated is also used. However, when these flexibility-imparting components are compatible with the epoxy resin serving as the matrix resin, the heat resistance is greatly reduced, and a high heat-resistant adhesive force at high temperatures cannot be expressed. Further, even if these flexibility-imparting components have a phase separation structure, the heat resistance tends to decrease due to the slight compatibility of the interface between the flexibility-imparting component and the epoxy resin. In addition, the phase separation structure is not necessarily stable with respect to temperature change, and may become compatible with temperature change.

Conventionally, epoxy resin-based curable compositions often use an acid anhydride or the like as a curing agent, but unreacted materials may remain in the cured product after curing. This unreacted material reacts due to moisture absorption and becomes acidic or alkaline, so that there is a problem that an acidic substance or alkaline substance flows out on and near the surface of the cured product and causes corrosion of electrode metals such as aluminum and copper. is there.

On the other hand, in the manufacturing process of electronic products such as liquid crystal displays, personal computers, portable communication devices, etc., when small parts such as semiconductor elements are electrically connected to a substrate, it is necessary to connect fine electrodes facing each other. is there.

As a method for connecting these electrodes, a method is generally used in which bumps are connected using solder, conductive connection paste, or the like, or the opposing bumps are directly pressure-bonded. Moreover, in order to protect the electrode after connection, the method of sealing the electrode after connection using resin is used.

However, since a fine electrode has a short connection distance, it is difficult to uniformly inject and seal a resin within a short time. Moreover, when connecting the glass surface and the electrode surface of a conduction circuit, there exists a problem that a connection part becomes high temperature by the connection by soldering.

In view of the present situation and problems, the present invention is excellent in mechanical strength, heat resistance, moisture resistance, flexibility, cold cycle resistance, solder reflow resistance, dimensional stability, etc. after curing, and has high adhesion reliability. Another object is to provide a conductive paste composition that exhibits high conduction reliability when used as a conductive material.

  As a result of intensive studies, the present inventors have found that these problems can be solved by using a conductive paste composition comprising a combination of specific components, and have completed the present invention.

That is, the present invention provides a conductive material comprising (A) an epoxy resin, (B) a polyvinyl acetal resin, (C) a rosin derivative, (D) an epoxy resin curing agent, and (E) a metal fine particle having a center particle size of 10 nm to 30 μm. The present invention relates to a paste composition.

According to the conductive paste composition of the present invention, when used in various printing methods such as screen printing and gravure printing, it is easy to adjust an appropriate viscosity with a solvent, and after curing, mechanical strength, heat resistance, It is excellent in moisture resistance, flexibility, thermal cycle resistance, solder reflow resistance, dimensional stability, etc., and can exhibit high adhesion reliability and high conduction reliability when used as a conduction material. Moreover, the electrically conductive paste composition of this invention can be used also as an electrically conductive adhesive.

The conductive paste of the present invention comprises (A) an epoxy resin (hereinafter referred to as component (A)), (B) a polyvinyl acetal resin (hereinafter referred to as component (B)), (C) a rosin derivative (hereinafter referred to as (C). Component), (D) an epoxy resin curing agent (hereinafter referred to as (D) component), and (E) metal fine particles having a central particle size of 10 nm to 30 μm (hereinafter referred to as (E) component). To do.

As (A) component, if it is a polyfunctional epoxy compound which is a compound which has an epoxy group, it will not specifically limit, A well-known thing can be used. Specifically, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolak type epoxy resin, naphthalene Skeleton-containing epoxy resin, aralkylene skeleton-containing epoxy resin, phenol biphenyl aralkyl type epoxy resin, phenol salicylaldehyde novolak type epoxy resin, lower alkyl group-substituted phenol salicylaldehyde novolak type epoxy resin, dicyclopentadiene skeleton containing epoxy resin, polyfunctional glycidylamine Type epoxy resin and polyfunctional alicyclic epoxy resin can be exemplified, and one or more of these can be used.

(A) A commercial item can also be used as a component. As the commercially available product (A), for example, NC-3000H and NC-3000S (trade name) manufactured by Nippon Kayaku Co., Ltd. are used as a biphenyl aralkyl type epoxy resin, and Nippon Steel Chemical (as a phosphorus-containing epoxy resin) ZX-1548 (trade name) manufactured by Co., Ltd., EPICLON N-660 (trade name) manufactured by DIC Corporation as the cresol novolac type epoxy resin, and JER- manufactured by Mitsubishi Chemical Corporation as the bisphenol A type epoxy resin. 828 (trade name).

In these, it is preferable that a novolak-type epoxy resin is included, and it is especially preferable that it is a novolak-type epoxy resin which has a biphenyl structure.

As the component (A), a rubber-modified epoxy resin can also be used. The rubber-modified epoxy resin is not particularly limited as long as it is a product that is commercially available for adhesives or paints, and known ones can be used. Commercially available rubber-modified epoxy resins include EPICLON TSR-960 (trade name) manufactured by DIC Corporation, EPOTOHTO YR-102 (trade name) manufactured by Nippon Steel Chemical Co., Ltd., and Sumitomo Chemical Co., Ltd. Sumiepoxy ESC-500 (trade name) manufactured by the company and the like are listed. By using the rubber-modified epoxy resin in combination with another epoxy resin, the elongation at the time of curing is increased and the adhesion to the copper foil surface is improved. The content of the rubber-modified epoxy resin when used in combination with another epoxy resin is preferably 10 to 80% by mass of the total epoxy resin. More preferably, it is 30-70 mass%. Two or more kinds of rubber-modified epoxy resins may be used, but the total amount is preferably within the above-mentioned range.

(B) It does not specifically limit as a component, A well-known polyvinyl acetal resin can be used. The degree of polymerization is not particularly limited, but usually 600 to 2500 is preferable. Within this range, the effect of improving the solder heat resistance is remarkably high, and the viscosity and handleability of the varnish can be extremely excellent. The number average degree of polymerization of the polyvinyl acetal resin can be determined from the number average molecular weight of polyvinyl acetate as a raw material (measured using a standard polystyrene calibration curve by gel permeation chromatography). In addition, as (B) component, what changed the polyvinyl acetal resin to carboxylic acid can also be used.

As the component (B), a commercially available product can be used as it is. Examples of commercially available products include SLECK BX-1, BX-2, BX-5, BX-55, BX-7, BH-3, BH-S, KS-3Z, and KS- manufactured by Sekisui Chemical Co., Ltd. 5, KS-5Z, KS-8, KS-23Z (all trade names), electrified butyral 3000-1, 4000-2, 5000A, 6000C, 6000EP (all trade names) manufactured by Denki Kagaku Kogyo Co., Ltd. Can be used. These resins can be used alone or in admixture of two or more.

Although the usage-amount of (B) component is not specifically limited, Usually, it is preferable that (B) component is about 0.5-40 mass parts with respect to 100 mass parts of (A) component. In particular, when the crosslinked rubber particles are used in an amount of 1 part by mass or more, it is particularly preferable that the blending amount of the polyvinyl acetal resin is 1 part by mass or more because the peel strength to the metal substrate and the film substrate is improved. .

The component (C) is not particularly limited as long as it is a compound derived from rosin, and known compounds can be used. Specific examples include rosin esters, rosin aldehyde, rosin dicarboxylic acid derivatives, acrylated rosin, maleated rosin, and rosin-modified phenolic resin.

  Examples of rosin esters include esters of rosins and alcohols. As rosins, for example, natural rosins such as wood rosin, tall oil rosin, gum rosin, etc., hydrogenated rosin obtained by hydrogenating natural rosins, disproportionated rosin obtained by disproportionating natural rosins, (Anhydrous) α, β-unsaturated carboxylic acid modified rosin modified with α, β-unsaturated carboxylic acid such as maleic acid, fumaric acid, (meth) acrylic acid, etc., and natural rosin modified with phenol resin Rosin-modified phenol resin, rosin phenol resin obtained by modifying natural rosins with phenol, polymerized rosin obtained by polymerizing natural rosins, and the like. In addition, as the rosins, those obtained by combining operations such as modification, polymerization, disproportionation, and hydrogenation can also be used. Specific examples include hydrogenated polymerized rosin obtained by hydrogenating polymerized rosin and hydrogenated α, β-unsaturated carboxylic acid modified rosin obtained by hydrogenating α, β-unsaturated carboxylic acid-modified rosin.

  In addition, as rosins, you may use the resin acid which comprises rosins individually or in mixture. Examples of the resin acid include dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, and maleopimaric acid.

  Alcohols used for producing the rosin ester are not particularly limited. For example, monohydric alcohols such as methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, propylene glycol, neopentyl glycol, Divalent alcohols such as methylene glycol, tetramethylene glycol, 1,3-butanediol, 1,6-hexanediol, trivalent alcohols such as glycerin, trimethylolpropane, trimethylolethane, triethylolethane, pentaerythritol, di Examples include tetravalent alcohols such as glycerin and pentavalent alcohols such as dipentaerythritol.

  As the component (C), rosin aldehyde obtained by reducing the rosins can also be used. In particular, rosin aldehyde is preferable because it can directly react with a polyvinyl acetal resin by a ketalization reaction or a ketal exchange reaction.

As the component (C), commercially available products can be used. Commercially available products include, for example, ester gum AAG, ester gum AAL, ester gum A, ester gum AAV, ester gum 105, ester gum AT, ester gum H, ester gum P, Pencel A, Pencel AZ, Pencel C, Pencel D -125, Pencel D-135, Pencel D-160, Pencel KK, Superester L, Superester A-18, Superester A-75, Superester A-100, Superester A-115, Superester A-125, Superester T-125, Pine Crystal KR-85, Pine Crystal KR-612, Pine Crystal KR-614, Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE 604, Pine Crystal D-6011, Pine Crystal KE-615-3, Pine Crystal KM-1500, Pine Crystal KR-50M, Tamanoru 135, Tamanoru 340, Tamanoru 350, Tamanoru 352, Tamanoru 354, Tamanoru 361, Tamanoru 366, Tamanoru 380, Tamanoru 386, Tamanoru 392, Tamanoru 396, Tamanoru 406, Tamanoru 409, Tamanoru 410, Tamanoru 412, Tamanoru 414, Tamanoru 417, Tamanoru 418, Tamanoru 420, all of which are manufactured by Arakawa Chemical Co., Ltd. Can be mentioned.

  Although it does not specifically limit as the usage-amount of (C) component, It is preferable that (C) component is about 1-70 mass parts with respect to 100 mass parts of (A) component.

(D) A well-known thing can be used for a component, if it is a compound used for hardening of an epoxy resin. A phenol resin curing agent, a polyamine curing agent, a polycarboxylic acid curing agent and the like can be used. Specifically, examples of the phenol resin-based curing agent include aminotriazine-modified novolak resin, biphenyl novolac resin, phenol novolac resin, cresol novolac resin, bisphenol novolac resin, poly p-vinylphenol, and the like. Is diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dicyandiamide, polyamidoamine (polyamide resin), ketimine compound, isophoronediamine, m-xylenediamine, m-phenylenediamine, 1,3-bis (aminomethyl) cyclohexane, N- Aminoethylpiperazine, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, diaminodiphenylsulfone, etc. Recarboxylic acid curing agents include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, hexachloroendomethylenetetrahydrophthalic anhydride, methyl-3,6-endo And methylenetetrahydrophthalic anhydride and methylhexahydrophthalic anhydride. Of these, phenol resin curing agents are preferred. In particular, a novolac type phenol resin is preferable, and a triazine ring-containing novolac type phenol resin is more preferable because the peel strength to a metal substrate and a film substrate is improved. The triazine ring-containing novolak type phenol resin means a novolac type phenol resin containing a triazine ring in the main chain of the novolak type phenol resin, and may be a cresol novolac type phenol resin containing a triazine ring. The nitrogen content is preferably 10 to 25% by mass, more preferably 12 to 19% by mass in the triazine ring-containing novolac type phenol resin. When the nitrogen content in the molecule is within this range, the dielectric loss does not become too large, and when the adhesive is used as a varnish, the solubility in the solvent is appropriate and the remaining amount of undissolved material can be suppressed. . As the triazine ring-containing novolac type phenol resin, one having a number average molecular weight of 500 to 600 can be used. These may be used alone or in combination of two or more.

A commercially available product may be used as it is as the phenol resin-based curing agent. Commercially available phenolic resin-based curing agents include aminotriazine-modified novolak resins such as Phenolite LA-1356 and Phenolite LA-3018 manufactured by DIC Corporation, and MEH-7851 manufactured by Meiwa Kasei Co., Ltd. as a biphenyl novolak resin. Is mentioned.

As the component (E), gold, silver, copper, nickel, tin, palladium, aluminum, or a metal thereof having a center particle size (measured by a laser diffraction scattering particle size distribution measurement method) of 10 nm to 30 μm. There is no particular limitation as long as it is a fine particle of this alloy, and known ones can be used. Among these, it is preferable to use fine particles having a granular or scale-like shape of gold, silver, copper, because high conductivity is obtained.

The amount of component (E) used is preferably about 80 to 95% by mass, more preferably 85 to 92% by mass, based on the total mass of components (A) to (D). In order to disperse the metal fine particles in the compositions of the components (A) to (D), a known kneading method such as a kneader, a ball mill, a bead mill, or a three roll can be used.

  In addition, (F) silane coupling agent (henceforth (F) component) can be used for the electrically conductive paste composition of this invention as needed. (F) It does not specifically limit as a component, A well-known thing can be used. Specifically, for example, 3-glycidoxypropyltrimethoxysilane, epoxy-functional silane such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2- Amino-functional silanes such as (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, vinyltrimethoxysilane, vinylphenyltrimethoxysilane, vinyltris (2-methoxy) Olefin-functional silanes such as ethoxy) silane, acrylic-functional silanes such as 3-acryloxypropyltrimethoxysilane, methacryl-functional silanes such as 3-methacryloxypropyltrimethoxysilane, mercapto such as 3-mercaptopropyltrimethoxysilane Official Such as sexual silane. In consideration of compatibility with an adhesion aid to be applied later, those having an epoxy group or amino group in the molecule are preferred. These may be used alone or in combination. Although it does not specifically limit as the usage-amount of (F) component, Usually, it is preferable that (F) component shall be about 1-20 mass% with respect to 100 mass parts of (A) component.

In addition, you may use a (G) hardening accelerator (henceforth (G) component) as needed for the electrically conductive paste composition of this invention. (G) As the component can be in particular using any known not limited, it is preferable to use imidazoles and BF ₃ amine complexes, in particular 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate is preferred.

Although the usage-amount in the case of using a hardening accelerator is not specifically limited, Usually, it is preferable to set it as about 0.1-5 mass parts with respect to 100 mass parts of (A) component, and 0.3-1 It is more preferable to set it as a mass part. As a result, sufficient solder heat resistance and good storage stability can be obtained, and the handleability when using the B stage is improved.

In order to mix these components (A) to (F) at a ratio corresponding to the purpose and adjust the viscosity to the optimum printing method, a solvent or a reactive diluent can be used as necessary.

  Solvents include ketones such as acetone, methyl ethyl ketone, cyclohexanone, aromatic hydrocarbons such as benzene, xylene, and toluene, alcohols such as ethylene glycol monoethyl ether, esters such as ethyl ethoxypropionate, N, N -Amides such as dimethylformamide and N, N-dimethylacetamide. These solvents may be used alone or in combination of two or more. It is not specifically limited, It can be set as the quantity conventionally used.

Examples of the reactive diluent include glycidyl orthotoluidine, ethylene glycol diglycidyl ether, 2-ethylhexyl glycidyl ether, glycidyl methacrylate, cyclohexane dimethanol diglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, Examples thereof include phenyl glycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. These reactive diluents may be used alone or in combination of two or more.

  The amount used when using the solvent or reactive diluent may be appropriately adjusted so as to obtain an optimum viscosity for printing, but it is usually preferably about 1 to 40% by mass of the conductive paste composition. .

  The method of dispersing the components (A) to (F) in the solvent or the reactive diluent and, if necessary, the curing accelerator is not particularly limited, and a known method can be adopted. For example, a kneader, a star mill, A 3-roll mill, a bead mill or the like can be used. Dispersibility in the metal powder can be improved by the dispersion treatment, and problems such as gelation and phase separation can be prevented.

The present invention will be described in more detail below with reference to production examples and examples, but the present invention is not limited to these examples.

Production Example 1
(Production of dehydroabietic acid ethyl ester)
Under stirring conditions, 100 g (0.33 mol) of dehydroabietic acid was dissolved in 1000 ml of ethanol and heated to 100 ° C. under reflux. Next, 45 g (0,38 mol) of thionyl chloride was gradually added dropwise and reacted for 5 hours. After the reaction, excess etal was removed under reduced pressure to obtain 101 g of dehydroabietic acid ethyl ester.

Production Example 2
(Production of dehydroabietic acid aldehyde)
50 g (0.15 mol) of dehydroabietic acid ethyl ester was dissolved in 500 ml of tetrahydrofuran (THF) with stirring and cooled to 0 ° C. Next, a THF solution containing 25 g (0.17 mol) of diisobutylaluminum hydride (DIBAL) was added dropwise while keeping the solution at 0 ° C. After reacting for 3 hours, THF was distilled off and 500 ml of toluene was added to dissolve again. After the toluene solution was washed with water, toluene was distilled off to obtain 45 g of dehydroabietic acid aldehyde.

Production Example 3
(Modification of polyvinyl acetal with dehydroabietic acid)
In a reactor equipped with a Dean-Stark apparatus, 100 g of Denkabutyral 3000-1 (manufactured by Denki Kagaku Kogyo Co., Ltd.) was dispersed in 500 ml of a mixed solvent of ethanol / toluene, then 20 g of dehydroabietic acid aldehyde was added, and the mixture was stirred with heating under reflux. . After the reaction for 8 hours, the solvent was completely distilled off to obtain 119 g of resin modified with dehydroabietic acid aldehyde.

Production Example 4
(Modification of polyvinyl butyral by dehydroabietic acid)
In a reactor equipped with a Dean-Stark apparatus, 100 g of Denkabutyral 3000-1 was dispersed in 500 ml of a mixed solvent of ethanol / toluene, then 15 g of dehydroabietic acid was added, and the mixture was stirred while distilling off toluene under heating and reflux. The reaction was carried out for 8 hours while keeping the amount of the solution constant while adding the same amount of toluene as the distilled toluene. After the reaction, the solvent was completely distilled off to obtain 110 g of resin modified with dehydroabietic acid.

Example 1
(Preparation of conductive paste composition)
35 parts by mass of novolak-type epoxy resin NC3000S-H (manufactured by Nippon Kayaku Co., Ltd.) having a biphenyl structure, 5 parts by mass of dehydroabietic acid aldehyde-modified polyvinyl acetal obtained in Production Example 3, and 3-glycidoxypropyltrimethoxy 5 parts by mass of silane, 1-cyanoethyl-2-phenylimidazolium trimellitate 2PZ-CNS (manufactured by Shikoku Kasei Kogyo Co., Ltd.) 0.3 parts by mass is added to an appropriate amount of diethylene glycol monoethyl ether acetate and mixed to form a conductive paste composition I got a thing.

Practical example 1
(Preparation of conductive adhesive)
10 parts by mass (solid conversion) of the resin composition obtained in Example 1 and 90 parts by mass of silver fine particles (average particle size: 3 μm) were added to an appropriate amount of diethylene glycol monoethyl ether acetate, and mixed and dispersed with three rolls. Paste composition was obtained.

Practical example 2
(Preparation of conductive paste composition)
40 parts by mass of bisphenol A type epoxy resin EPICLON 860 (manufactured by DIC Corporation), 2 parts by mass of surfactant BYK361N (manufactured by Big Chemie Japan), dehydroabietic acid-modified polyvinyl butyral resin curing agent obtained in Production Example 4 2 parts by mass of 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2 parts by mass of 2-phenylimidazole, 10 parts by mass of Pine Crystal KE-614 (Arakawa Chemical Industries, Ltd.), 3-glycidoxypropyl 5 parts by mass of trimethoxysilane was added to an appropriate amount of diethylene glycol monoethyl ether acetate and mixed.

(Preparation of conductive adhesive)
10 parts by mass (solid conversion) of the resin composition obtained in Example 2 and 90 parts by mass of silver powder (average particle size: 3 μm) were added to an appropriate amount of diethylene glycol monoethyl ether acetate and mixed and dispersed with three rolls to form a conductive paste composition. I got a thing.

The conductive pastes obtained in the above examples satisfied the adhesive strength and specific resistance.

Claims (6)

An electrically conductive paste composition containing (A) an epoxy resin, (B) a polyvinyl acetal resin, (C) a rosin derivative, (D) an epoxy resin curing agent, and (E) metal fine particles having a center particle diameter of 10 nm to 30 μm. The conductive material according to claim 1, wherein the rosin derivative is at least one selected from the group consisting of rosin esters, rosin aldehyde, a dicarboxylic acid derivative of rosin, an acrylated rosin, a maleated rosin, and a rosin-modified phenol resin. Paste composition. 3. The conductive paste composition according to claim 1, wherein the metal fine particles are at least one selected from the group consisting of gold, silver, copper, nickel, tin, palladium, aluminum, and alloys of these metals. Furthermore, (F) The electrically conductive paste composition in any one of Claims 1-3 containing a silane coupling agent. Furthermore, (G) The electrically conductive paste composition in any one of Claims 1-4 containing a hardening accelerator. The electroconductive adhesive agent containing the electroconductive paste composition in any one of Claims 1-5.