TW200804557A - Conductive adhesive agent - Google Patents

Abstract

The present invention provides a conductive adhesive agent that has no problem of conductive metal migration while applying electric voltage, and shows low electric resistance. One feature of this invention is related to the conductive adhesive agent comprising the conductive filler and the resin, wherein the conductive filler is characterized by the alloy powder of Ag and Sn. The conductive adhesive agent further comprises at least one of chelating agent, anti-oxidation agent and metal surface active agent as additive. As the additive, the chelating agent can be selected from hydroxylquinolines, salicylideneaminothiophenol or phenolanthroline. The antioxidant can be selected from hydroquinones or phenyltriazoles. The metal surface active agent can be selected from organic acids oracid anhydrides or organic acid salts.

Description

200804557 (1) VENTION DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a conductive adhesive, and more particularly to an electronic component package such as a semiconductor component for electrically connecting an electronic component to a substrate Adhesive. [Prior Art] In the packaging of a conventional electronic component, the connection between the electrode on the surface of the substrate and the electronic component can be performed by flip chip bonding of solder or the like. However, the dance material used in the electronic equipment in which the solder is a lead-tin alloy is dissolved by acidic rain and dissolved in the groundwater, and the environmental impact is worrying. Therefore, in terms of error-free packaging technology, it is proposed to use a conductive adhesive instead of a conventional solder in connection with a substrate electrode and an electronic component. Further, when solder is used to connect the substrate electrode and the electronic component, if stress is applied repeatedly, damage due to metal fatigue may occur, and cracks may occur in the connection portion. In the case where the substrate electrode and the electronic component are connected by using a conductive adhesive, the connecting portion is bonded by a resin, and has an advantage of being soft to the deformation. The packaging of electronic components using conductive adhesives in this way is not only an aspect of environmental problems, but also contributes to the reliability of the connection, and has recently attracted particular attention. The conductive adhesive is generally a matrix resin such as an epoxy resin, an acrylate resin, a polyester resin or a phenol resin, and the conductive metal particles such as silver, copper or nickel which are conductive conductive materials are dispersed therein. In recent years, in the field of electronic packaging, conductive adhesives have been used to print -5 - (2) 200804557 on the circuit portion of the substrate by screen printing, and the electronic components are adhered to a predetermined position. Agents can also be used for this purpose. However, in recent years, with the development of the miniaturization of electronic devices, the printing of conductive adhesives using screen printing requires extremely fine screen printing. Silver is generally used as the conductive material, but there is a problem of metal migration when a voltage is applied, and in particular, the problem of printing a conductive adhesive on a substrate by screen printing becomes a very large problem. Therefore, the proposal φ uses an alloy powder of silver and tin as a conductive material (Patent Document 1). When the alloy powder of silver and tin is used, the problem of metal migration is solved, and the electric resistance is high, and the degree of application of the electronic component of the substrate electrode cannot be achieved. In order to solve the problem of high resistance 値, it is proposed to add a low melting point alloy such as tin-bismuth alloy powder to silver-tin bismuth, but the effect of reducing the contact resistance is not good, and in the case of adding tin-bismuth alloy powder. When the adhesive is hardened, a high temperature of about 180 ° C is required. [Patent Document 1] Japanese Laid-Open Patent Publication No. 2002-2 65920 (Patent Document 2) U.S. Patent No. 6,341,451, No. 5, Patent Document 3, US Patent No. 65 8 3 20 1 , and the contents of the invention. DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION The present invention has been made to solve the above problems, and to provide a problem of no metal migration when a voltage is applied and a conductive adhesive exhibiting a low resistance. [Means for Solving the Problem] (3) 200804557 Means for Solving the above Objects] An aspect of the present invention relates to a conductive adhesive containing a conductive coating and a resin, characterized in that the conductive coating contains silver and An alloy powder of tin, the conductive adhesive further comprising an additive of at least one of a chelating agent, an oxidation preventing agent, and a metal surfactant. The conductive adhesive of the present invention is characterized in that at least one of a resin (matrix-resin) and a silver-tin-dye material is added to at least one of a chelating agent, an oxidation inhibitor, and a gold genus surfactant. Additive for contact resistance. [Embodiment] In the present invention, an additive which is used as an additive for reducing contact resistance can be added, for example, as a chelating agent, hydroxyquinoline, salicyllidene aminothiophenol or phenanthroline ( Phenanthroline) class. Specifically, for example, a quinoline derivative such as 8-hydroxyquinoline (8·HQL), 6-hydroxyquinoline or 2-hydroxyquinoline of the following formula 1, a salicylic acid of the following formula 2 -thiophenol, 1,10-phenanthroline of the following formula 3, and the like. 【化1】

OH 200804557

Further, in the case of the oxidation preventive agent, a hydroquinone or a benzotriazole is used as an additive for reducing the contact resistance of the conductive adhesive by using the conductive adhesive of the present invention. Specifically, as the hydroquinone, for example, 1,4-dihydroxybenzene, (HQ) (the following formula 4), 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, and benzotriazole can be used. , benzotriazole of the following formula 5, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl) can be used. Benzotriazole, 2-(3,5-di-p-pentyl-2-hydroxyphenyl)benzotriazole, and the like. [Chemical 2]

8 - (5) 200804557

Further, as the metal surfactant, an organic acid, an acid anhydride or an organic acid salt can be used. Specifically, an organic acid such as neodecanoic acid, lactic acid, citric acid, oleic acid, glutaric acid, benzoic acid, oxalic acid, rosin acid, adipic acid, stearic acid or the like, methyl group of the following formula 6 can be used. Tetrahydrophthalic anhydride (Me-THPA), methyl hexahydrophthalic anhydride (MHHpA), methyl_intra-methylenetetrahydrophthalic anhydride (NMA), norbornene dicarboxylic anhydride (5 -norbornene-2,3-dicarboxylic anhydride; himic acid), anhydrides such as acetal anhydride, trimellitic anhydride, pyromellitic anhydride, etc., 1,8-mono-heterobicyclo ring of the following formula 7 (5,4,0) ~f - s/hexanoic acid 2-ethyl ester (wherein R represents -C(= 0)CH(C2H5)CH2CH2CH2CH3), 2-(benzotriazol-1-ylindenyl)-4 of the following formula 8 -Tri-n-butyldodecylphosphonium 2-(benzotriazol-l-ylcaronyl-4-methylcyclohexane-l-carboxyate) (PX-412MCH), etc. Organic acid salts.

[化3]

(6)

-9 - (8) (6) 200804557

Θ (C12H24)(n-C4H9)3P

In the case of using an electroconductive adhesive using silver bismuth, tin, tin-lead is used as an electrode, and when an electronic component is packaged, it is proposed to use corrosion as a tendency to suppress a slow rise in contact resistance under a moisture resistance test. Inhibitor (refer to Patent Documents 2 and 3 above). However, these compounds are examples of the use of an additive for reducing the contact resistance 初期 (initial resistance 値) for a conductive adhesive using silver enamel, and have not been known by the inventors until now. In the conductive adhesive of the present invention, the conductive material is an alloy powder containing silver and tin, and specifically, 40% by weight or more of the conductive material is a silver-tin alloy powder. As the constituent component of the conductive paste other than the silver-tin alloy powder, silver powder, tin powder, tantalum powder, indium powder, or two or more alloy powders of these metals and/or a mixed powder can be used. In the case of using these components, it is preferable that the fef silver-tin alloy powder is used in an amount of 25% by weight or less. Further, when the conductive crucible is substantially composed of a silver-tin alloy powder and an alloy powder having a melting point lower than that of silver-tantalum, indium-tin alloy powder, etc., the contact resistance 値 of the conductive adhesive is further reduced. Big. Therefore, it is preferable to use a combination of a silver-tin alloy powder and an alloy powder having a melting point lower than a curing temperature, in particular, in that it is required to greatly reduce the contact resistance 导电 of the conductive adhesive. However, when an alloy powder having a melting point lower than the curing temperature is added as a component of the conductive material, the contact resistance 导电 of the conductive adhesive is largely lowered, but the mechanical strength of the conductive adhesive is lowered. Therefore, in particular, it is required to maintain the high mechanical strength of the conductive adhesive in -10-(7) (7)200804557. The composition of the conductive coating is composed of silver-tin alloy powder, and does not contain melting point ratio hardening. A low temperature alloy powder is preferred. Further, when the tin-bismuth alloy powder of the alloy powder having a melting point lower than the curing temperature is used as the component of the conductive material, the curing of the conductive adhesive must be performed at a temperature of 180 ° C which is also high in the melting point of the tin-bismuth alloy. Insufficient conductivity is not obtained. In the present invention, a silver-tin alloy powder which can be used as a conductive material, for example, silver and tin are mixed and melted at a desired molar ratio, and then the molten material is sprayed in an inert gas atmosphere to form an alloy powder (atomization method). It is obtained by taking it below the desired particle size. Further, the powder formed by the above atomization method is vaporized by a plasma furnace, and then solidified by cooling to obtain an alloy powder. Further, silver-tin alloy powder can also be obtained by heating and alloying the powder of the silver powder and the tin powder by any method. Tin-bismuth alloy powder can also be obtained in the same manner. The shape of the alloy powder which can be used in the present invention is not particularly limited, and examples thereof include a spherical shape, a scaly shape, a needle shape, and a dendritic shape. Further, the size of the alloy powder, the particle diameter (average particle diameter), is, for example, 0.1 to 30 μm, or for example, 1 to 20 μm. In the conductive adhesive of the present invention, the amount of the conductive material is preferably 60 to 98% by weight based on the total amount of the resin component and the conductive material, and more preferably 70 to 95% by weight. In the conductive adhesive of the present invention, any of a thermoplastic resin and a thermosetting resin can be used as the resin component (matrix resin). Examples of the thermoplastic resin include acrylate resin, ethyl cellulose, polyester, poly pulverized resin, phenoxy resin, polyimide resin, and the like, and as a thermosetting resin, Example-11 _ (8) (8) 200804557 For example, amine resin such as urea resin, melamine resin, guanamine resin, bisphenol a, bisphenol ρ, phenol novolac resin, alicyclic epoxy resin, oxetane resin, phenol resin, hydrazine A polydecane modified resin such as a ketone epoxy resin or an anthrone polyester resin. Further, these resins may be used in combination of two or more kinds. Further, the above-described additive for lowering the contact resistance of the conductive adhesive may be mixed with a resin, a conductive paste, and other components, or may be previously surface-treated with an additive, and then mixed with a resin and other components. . In this case, the conductive paste can be added as an additive by a method of adding an additive when the conductive material is processed into a sheet shape, a method of dissolving the additive in an organic solvent, impregnating the conductive material therein, and then gasifying and removing the organic solvent. Surface treatment. When the epoxy resin is used as the matrix resin in the conductive adhesive of the present invention, even if a self-curing epoxy resin is used, a curing agent such as an amine, an imidazole, an acid anhydride or a key salt, or a hardening accelerator can be used. The amine resin and the phenol resin can also be formulated as a hardener for the epoxy resin. In the conductive adhesive of the present invention, the amount of the resin to be added is preferably 2 to 40% by weight based on the total amount of the resin and the conductive material, and more preferably 5 to 30% by weight. Regarding the conductive adhesive of the present invention, a diluent can be formulated as needed. The diluent can be an organic solvent, and particularly in the case where the resin is an epoxy resin, a reactive diluent can be used. The organic solvent is selected according to the kind of the resin, and is an organic solvent such as toluene, xylene, mesitylene, tetrahydronaphthalene (-12-200804557 Ο) aromatic hydrocarbons; for example, ethers of tetrahydrofuran; - pyrrolidone, 1-methyl-2-pyrrolidone, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol Monoethyl ether, diethylene glycol monobutyl ether, ether alcohols corresponding to these propylene glycol derivatives, such as esters corresponding to these acetates; and dicarboxylic acids of malonic acid, succinic acid, etc. Diesters of esters and ethyl esters. The amount of the organic solvent to be used may be arbitrarily selected as the ratio of the amount of the conductive paste to be used and the type of the resin (matrix resin) to φ and the method of printing or coating the conductive adhesive. In the conductive adhesive of the present invention, it is diluted by any pattern formed by printing or coating, in order to fill the fine portion, to impart appropriate fluidity, or to prevent shrinkage due to volatilization of the solvent and deterioration of the operating environment. It is preferred to use a reactive diluent for some or all of the agents. As a diluent, for example, polyethylene glycol diepoxypropyl ether, poly(2-hydroxypropanediol) diepoxypropyl ether, polypropylene glycol diepoxypropyl ether, butanediol diepoxypropyl ether, new Pentyl glycol diepoxypropyl ether, diepoxypropyl aniline, 1,4-cyclohexanol dimethanol diepoxypropyl ether, 1,3-bis(3-diglycidoxypropyl) Di-epoxypropyl compound of 1,1,3,3-tetramethyldicyclohexane; and trisepoxide of trimethylolpropane triepoxypropyl ether and glycerol triepoxypropyl ether a propyl compound, if necessary, a reactive diluent such as n-butyl epoxypropyl ether, allyl-p-propyl epoxide or propylene glycol methacrylate When only a reactive diluent is used without using an organic solvent as a diluent, the solvent may be removed and the polymerized and cured under appropriate conditions to be placed in the conductive layer. The conductive adhesive of the present invention, In addition to the above, according to the need -13- (10) (10)200804557 ' as a dispersing agent can be adjusted with diisopropoxy (ethyl ethyl acetonitrile) aluminum aluminum pliers Titanate of isopropyl triisostearate titanate; aliphatic polyvalent carboxylate; unsaturated fatty acid amine salt; surfactant such as sorbitan monooleate; or polyester An amine salt, a polymer compound of polyamine, etc. Further, an inorganic and organic pigment, a decane coupling agent, a homogenizer, a thixotropic agent, an antifoaming agent, etc. may be added. About the conductive adhesive of the present invention The agent can be prepared by uniformly mixing by means of a mixing means such as a grinder, a propeller mixer, a kneader, a drum, a ball mill, etc. The preparation temperature is not particularly limited, and can be prepared, for example, at room temperature. Regarding the conductive adhesive of the present invention, Printing or coating can be carried out by any method such as stencil printing, screen printing, gravure printing, dispersion, etc. The conductive adhesive of the present invention can be used for adhesion even by fine stencil printing. The agent is applied to the pattern on the substrate. Thus, the conductive adhesive of the present invention is used, and the electronic component such as a semiconductor element, a wafer part, a discrete part, or a combination thereof is used. The electrode 'bonded to the circuit board' can form an electronic circuit on the surface of the substrate. [Examples] The present invention will be more specifically described by the following examples. However, the present invention is not limited to the following description. Examples 1 to 11 and Comparative Examples 1~3

An epoxy resin (manufactured by Tosho Kasei Co., Ltd., trade name: zxl〇59) and a latent curing agent (Ajinomoto FINE -14- (11) (11) 200804557 TECHNO Co., Ltd.: PN- H), imidazole (trade name: 2P4MHZ), a decane coupling agent (manufactured by TORAY Dow Corning Corporation, trade name: SH6040) manufactured by Shikoku Chemical Industry Co., Ltd. as a hardening accelerator was blended in the ratios shown in Tables 1 and 2. Butyl carbitol acetate (BC a A) as a diluent; various compounds shown in Tables 1 and 2 as additives for reducing contact resistance; silver-tin alloy powder (silver: tin = 65) : 3 5 , particle size of 15 μιη), or adding 5% by weight of tin-bismuth alloy powder to the silver-tin alloy powder material (tin: 铋 = 42 : 5 8 , granules) The diameter was 1 5 μχη); the components were added and mixed in the amounts shown in Tables 1 and 2, respectively, and the adhesive composition was prepared, which was hardened by heating at 15 (TC for 10 minutes). However, in Comparative Example 3 It was not able to obtain sufficient conductivity by heating at 150 ° C for 1 minute, and it was cured by heating at 18 ° C for 30 minutes. The contact resistance 値 and the bonding strength of each thermosetting adhesive composition were measured. Further, in Table 1, the blending ratio of each component is represented by a weight portion. The contact resistance of the cured adhesive composition was measured by using the test piece shown in Fig. 1. On the FR4 substrate 1 The electrode portion 3 of the FR4 circuit substrate in which the daisy chain pattern 2 is formed by copper plating (coated with a copper pad OSP (organic solder) For the protective film, a conductive mask having the thickness of 70 μm is used, and the conductive adhesive composition prepared as described above is applied by hollow plate printing. In the printed portion, a tin outer portion is provided in a size of 2 0 1 2 The 0 Ω chip resistance 4 of the electrode was prepared by curing in the oven under the above conditions, and the test piece was prepared. The contact resistance between the terminals of the electrode pad 5 adjacent to the measurement electrode of the FR4 circuit thus obtained was measured by a 4-point probe method. The resistance 所示 shown in 1 and 2 indicates the resistance 每 per one contact (that is, -15- (12) 200804557 resistance 20 of one-twentieth of one continuous resistance). Moreover, as the adhesion strength The above-prepared conductive adhesive composition was applied to the FR4 substrate by hollow plate printing, and the same 0 Ω chip resistance as described above was placed thereon, and the test piece was prepared by curing in the oven under the above conditions, and the tensile test was performed. (tensile) strength.

According to the present invention, by adding an additive for lowering a predetermined contact resistance and using a silver-tin alloy powder as a conductive adhesive for a conductive material, the contact resistance can be greatly reduced, and the conductive adhesive for electronic parts can be put to practical use. . Table 1 : Test results of Examples 1 to 7 Example 1 2 3 4 5 6 7 Thermosetting resin composition epoxy resin 11.88 11.88 11.88 11.88 11.88 11.88 11.88 Potential hardener 1.8 1.8 1.8 1.8 1.8 1.8 1.8 Hardening accelerator 1.2 1.2 1.2 1.2 1.2 1.2 1.2 decane coupling agent 0.12 0.12 0.12 0.12 0.12 0.12 0.12 mmm BCaA 1 1 3 Additive 8-HQL 3 5 0.1 Salicylic acid 2-aminophenol-2 thiophenol 3 1,1 〇-phenanthroline 3 HQ — 3 benzotriazole — 3 New dodecyl acid Me-THPH DBU//2-ethyl hexanoate j PX-412MCH Ag AgSn 塡 85 85 85 85 85 85 85 AgSn/SnBi Hardening condition 150 °C x lOmin Contact resistance (ιβΩ/contact) 12 11 8015 2480 5996 335 968 Bonding strength kgF wafer 3.13 2.99 5.56 6.22 4.51 6.71 8 -16- (13) 200804557 Table 2: Examples 8 to 1 1 and Comparative Example 1 ~3 _Na test results Example Comparative Example 8 9 10 11 1 2 3 Thermosetting resin composition epoxy resin 11.88 11.88 11.88 11.88 11.88 11.88 11.88 Potential hardener 1.8 1.8 1.8 1.8 1.8 1.8 1.8 Promoter 1.2 1.2 1·2 12 1.2 1.2 1.2 decane coupling agent 0.12 0.12 0.12 0.12 0.12 0.12 0.12 Thinner BCAA 3 3 Additive 8-HQL Salicylic acid, 2-thiophenol 1,1 thiophene Porphyrin HQ benzotriazole neododecyl acid 3 Me-THPH 3 DBU//2-ethyl hexanoate 3 PX-412MCH 3 Ag AgSn 塡 85 85 85 85 85 AgSn/SnBi 85 h 85 Hardening condition 150 °Cxl〇min 180°CX 30min Contact resistance_/contact) 172 8965 437 1770 18535 71000 15335 Bonding strength kgf/wafer 5.81 5.9 6.87 5.51 5.12 4.31 4.41

Examples 12 to 20 and Comparative Example 4 In the present embodiment/comparative example, a conductive paste having an additive for reducing contact resistance was blended, and a mixture of silver tin/tin-lanthanum of the above Comparative Examples 2 and 3 was used. In the case of powder, the adhesion strength was investigated. The thermosetting resin composition (epoxy resin + latent curing agent + hardening accelerator + decane coupling agent) was prepared in the same weight ratio as in Example 1 by adding the various additives shown in Tables 3 and 4 in the weight portion; The silver-tin alloy powder of the tin-bismuth alloy powder was placed in the same manner as in the first embodiment, and the adhesive composition was mixed and prepared in the same manner as in Example 1, and the contact resistance was measured. And bonding strength. The results are shown in Tables 3 and 4. -17- (14) 200804557 According to the present invention, a conductive adhesive which is added with an additive for reducing contact resistance is used as a conductive material by using a tin-bismuth alloy powder formulated with tin-bismuth alloy powder, even if conductive conductive material The content is low, and the contact resistance can be maintained at a practical level, and the bonding strength can be increased. In particular, when a combination of 8-HQL or 8-HQL and a new dodecyl acid or Me-THPA is used, the contact resistance can be kept at an extremely low enthalpy, and the bonding strength can be increased. In this way, the contact resistance 値 can be greatly reduced, and the conductive adhesive for electronic parts can be put to practical use.

Table 3: Test results of Examples 12 to 16 Example 12 13 14 15 16 Thermosetting sapphire composition 23 23 23 23 23 Additive 8-HQL 3 HQ 3 Benzotriazole 3 Neodecyl acid 3 Me -THPH 3 DBU//2-ethyl hexanoate PX-412MCH Ag AgSn/SnBi 77 77 77 77 77 Contact resistance ιηΩ / Contact 17 14900 3300 5800 4400 Bond strength kgf wafer 3.55 4.63 5.2 3.43 4.43 -18- (15 200804557 Table 4: Test Results of Examples 17 to 20 and Comparative Example 4 Comparative Example __ 17 ] 18 19 20 4 Thermosetting Resin Composition 23 23 23 23 23 ^ Additive 8-HQL 2 2 HO Benzene Triazole neodecanoic acid 1 Me-THPH 1 DBU//2-ethyl hexanoate 3 PX-412MCH 3 Ag AgSn/SnBi 77 77 77 77 77 Contact resistance ιηΩ/contact 1500 1000 18 12 30700 Adhesive strength Kg·tablet 5.3 4.8 3.7 2.7 3.32 Example 2 1 and Comparative Example 5 The weight of the silver-tin alloy powder used in Example 1 was immersed in a solution of the weight of 8-HQL2 and dissolved in 30 parts by weight of acetone. Stirring, removing acetone by gasification Silver - tin alloy material powder Tian treated to be surface-8-HQL. In the same weight ratio as in Example 1, 23 parts by weight of the thermosetting resin composition (epoxy resin + latent curing agent + hardening accelerator + decane coupling agent) was prepared by using the above-mentioned 8-HQL with 77 parts by weight. The surface-treated silver-tin alloy powder or the silver-tin alloy powder without surface treatment is mixed to prepare a conductive adhesive composition. The film was cured in the same manner as in Example 1, and the electric resistance and the bonding strength of the cured electric adhesive were measured. The results are not shown in Table 5. According to the present invention, the adhesive composition is prepared by adding a silver-tin alloy powder and a silver-tin alloy powder to reduce the surface treatment of the additive for contact resistance in a resin or the like, and exhibits a good low. Contact resistance 値 and high adhesion strength. -19- (16) 200804557 Table 5: Test Results of Example 21 and Comparative Example 5 Example 21 Comparative Example 5 Thermosetting Resin Composition 23 23 AgSn Tantalum 8-HQL Surface Treatment 77 No Surface Treatment 77 Contact Resistance πιΩ / Contact 8180 30660 Adhesive strength kgf / wafer 3.4 3.3 [Industrial use possibility] According to the present invention, a resin-based conductive adhesive 'uses a silver-tin alloy as a conductive material, and then reduces conductivity by blending At least one of an additive for an electric resistance of a contact adhesive, a chelating agent, an oxidation preventing agent, and a metal surfactant, and there is no problem of migration of a conductive metal when a voltage is applied, and further, the contact resistance can be greatly reduced when hardened. A conductive adhesive for electronic components can be used as a practical conductive adhesive. [Brief Description] FIG. 1 shows a measurement of the contact resistance used in the examples. [Description of main component symbols] 1 ·· FR4 substrate 2 : Daisy chain pattern 3 : Electrode part of FR4 electric circuit substrate 4 : 0Ω chip resistance -20- 200804557

Claims (1)

200804557 (1) X. Patent application scope 1 'A conductive adhesive, which is a conductive adhesive containing conductive conductive material and resin', characterized in that the conductive conductive material is an alloy powder containing silver and tin. The adhesive further includes an additive of at least one of a chelating agent, an oxidation preventing agent, and a metal surfactant. - 2 · The conductive adhesive of claim 1 wherein the v-agent is hydroxyquinoline, salicylidene aminothiophenol or phenanthr〇line The oxidation inhibitor is hydroquinone or benzotriazole, and the metal surfactant is an organic acid, an acid anhydride or an organic acid salt. 3. The conductive adhesive according to claim 1 or 2, wherein the conductive binder is one of conductive conductive materials, and further comprises tin-bismuth alloy powder. 4. An electronic circuit characterized by using the conductive adhesive according to any one of claims 1 to 3 to bond the electronic component to the electrode of the circuit board. •twenty two·