JPH0345842B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to an anisotropically conductive electrode composition that can be used in the same way as a connector for connecting between circuits of a printed circuit, a detection section of a printed circuit, a circuit and a control section, etc. It is. (Prior art) Recently, as connectors used to connect parts related to printed circuits have become smaller and the number of terminals has increased, it has become impossible to use soldering or caulking to remove the terminals, and silicone rubber connectors with gold-plated stainless steel wire embedded in them, elastomer connectors made up of multiple layers of conductors and insulating plates, connectors with many parallel printed conductors rolled into a pipe shape, anisotropically conductive pressure-sensitive rubber sheets, etc. A connector is used.
Among these, anisotropically conductive pressure-sensitive rubber sheets are rubber sheets containing a certain amount of conductive fine particles, and are used to connect two circuits with parallel conductors, such as printed circuits. Therefore, it is attracting attention as a connector that is conductive in the direction of thickness and insulating in the direction perpendicular to the thickness. However, conventional connectors like this have a certain particle size (about 1 μm) in the plastic.
It is made by mixing metal powders and roll-forming them into a sheet, which is interposed between two electrodes and pressed together, and the conductivity depends on the thickness of the sheet that can be rolled and the amount of metal powder mixed in. Due to physical limitations, it was not possible to create a coating that was less than a certain thickness, and the emergence of an extremely thin paint format was eagerly awaited. This type of paint was first published in 1983.
No. 2179 etc. are known. However, the technology disclosed in this specification uses conductive fine particles having a normal shape, and maintains effective conductive anisotropy even when a composition containing these particles is interposed between electrical members by applying pressure. I can't. As a result of intensive research to solve these problems, the present inventor used two types of conductive particles with many protrusions and different sizes, and used hot melt resin (thermoplastic resin) as a binder. He filed a patent application for a conductive composition that exhibits extremely effective anisotropy when applied as a paint by using a printing solvent and a printing solvent (Japanese Patent Application No. 1983-
No. 227057). (Purpose of the Invention) However, since the above-mentioned anisotropically conductive composition according to the inventor's earlier application uses hot melt resin as a binder, there are problems with heat resistance, adhesive strength, and solvent resistance, which limits its use. It had been. The purpose of the present invention is to provide a composition that has excellent anisotropic conductivity and improved each of the above characteristics by using two types of conductive particles, large and small, and selecting the type of resin that serves as a binder, as in the previous application. It's about doing. (Structure of the Invention) The present inventor solved the problems of the anisotropically conductive composition according to the prior application by using a thermosetting resin in whole or in part instead of a hot melt resin as a binder. succeeded in. Specifically, the present invention includes 0.2 to 20% by weight of conductive particles having a particle size of 0.5 μm or less, 10 to 75% by weight of conductive particles having a large number of protrusions having a particle size of 1.0 μm or more, and a thermosetting resin soluble in a printing solvent. composition 30-80% by weight,
It is an anisotropically conductive composition consisting of 0 to 70% by weight of a powder resin insoluble in a printing solvent, and a solid component and an appropriate amount of a printing solvent blended so that the total amount is 100% by weight. Carbon black and graphite are generally used as conductive particles with a particle size of 0.5 μm or less, but colloidal gold, platinum, rhodium, ruthenium, palladium, and iridium, which can be produced by chemical reduction or pyrolysis vapor deposition, are also used. Metal powders such as, colloidal titanium, etc. are also used. Also particle size
Conductive particles having a large number of protrusions of 1.0 μm or more include metal particles such as nickel, cobalt, iron, etc. made by the carbonyl method, or metals such as alloys of these made by the atomy method or stamp method. Oxides, nitrides, carbides, borides as particles and abrasives such as Al ₂ O ₃ ,
Pigment particles such as SiO ₂ , SiC, WC, TaC, and Si ₃ N ₄ are plated with highly conductive metals such as nickel, copper, silver, gold, platinum, rhodium, ruthenium, osmium, and palladium. Can be mentioned. Furthermore, abrasive conductive particles of metal carbide, nitride, or boride may be used. For example, metal carbides such as tungsten carbide (WC), silicon carbide (SiC), titanium carbide (TiC), tantalum carbide (TaC), silicon nitride (Si ₃ N ₄ ), titanium nitride (TiN), vanadium nitride (VN), metal nitrides such as zirconium nitride (ZrN), and metal borides such as tantalum boride (TaB), zirconium boride (ZrB), and titanium boride (TiB). Conductive particles with a particle size of 0.5 μm or less are as described above.
The content is adjusted to 0.2 to 20% by weight, preferably 1 to 15% by weight, but if it is less than this range, the conductivity will be insufficient, and if it exceeds this range, the insulation in the required direction will decrease, and the adhesive strength will deteriorate. As the seal resistance decreases, the seal resistance increases and the resistance varies. Examples of such conductive fine particles having a particle size of 0.5 μm or less and the resistance values when mixed with resin are as follows.

[Table] Also, conductive substances with a particle size of 1.0 μm or more and many protrusions on the surface are coarse particles commonly called abrasive particles. If the amount exceeds 75% by weight, the adhesive strength will be weak and it will be difficult to obtain a practical coating film. The characteristics etc. of examples of conductive particles having a particle diameter of 1.0 μm or more are as follows.

[Table] In this case, if the particle size is increased, printability deteriorates, but it is possible to create a material with low bonding resistance between electrodes and little change over time. In addition, when using conductive particles with a particle diameter of 1.0 μm or more,
The specific selection of particles depends on the characteristics such as the gap between circuits, the thickness of the anisotropic conductive composition film, the adhesive strength, the resistance value between opposing electrodes and between adjacent electrodes, the method of forming the conductive film, This is determined by taking into consideration the thermocompression bonding method, etc. The thermosetting resin as a binder used in the present invention has a melting point of 50 to 150°C and a gelation time of 1 at 170°C.
It is appropriate to use the resin for 5 seconds to 30 minutes, preferably 5 seconds to 2 minutes, such as epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, thermosetting acrylic resin, diallyl phthalate resin, urethane resin, or Modified resins may be used alone or in mixtures. Additionally, reactive monomers, curing agents, catalysts, curing accelerators, and the like are used to cure the thermosetting resin. Other additives include tackifying agents such as rosin derivatives, terpene resins, and petroleum resins, solvents that can be dried to the touch at temperatures below the curing temperature of the resin, such as cyclohexane, ethyl cellosolve, benzyl alcohol, diacetone alcohol, and terpineol, and flexible A property imparting agent, a flame resistance imparting agent, a flame resistance aid, etc. are used as necessary. The above epoxy resins include bisphenol type A and type F.
type, hydrogenated bisphenol type A, tetrabromo bisphenol type A, phenol novolak type, brominated phenol novolak type, cresol novolak type, glycidylamine type, hydantoin type, triglycidyl isocyanurate type, alicyclic type, etc. can be mentioned. As a curing agent, aliphatic amines such as diethylenetriamine, metaxylylene diamine, polyamide resin, cycloaliphatic amines such as para-menthanediamine, 2-ethyl-4-methylimidazole, metaphenylene diamine, 4-4'-diaminodiph Aromatic amines such as enylmethane, acid anhydrides such as phthalic anhydride and nadic anhydride, tertiary amines, boron trifluoride-monoethylamine, dicyandiamide, molecular sieve hardening agents, microcapsule hardening agents, etc. latent curing agents are used. A cationic polymerization type Lewis acid catalyst can also be used. The unsaturated polyester resin includes one or more unsaturated dibasic acids such as maleic anhydride, fumaric acid, itaconic acid, citraconic acid, glutamic acid, and mesaconic acid, and the saturated dibasic acids include succinic acid, glutaric acid, Aliphatic dicarboxylic acids such as adipic acid, sebacic acid, dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, tetrahydrophthalic acid, and hexahydrophthalic acid.
Species or two or more types, glycol components include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, neopentyl glycol, hexylene glycol, octylene One or more of glycol, bisphenol A, hydrogenated bisphenol A, crosslinking monomers such as styrene, divinylbenzene, diallyl phthalate, triallyl cyanurate, (meth)acrylic acid and its alkyl ester, acrylonitrile , vinyl acetate, acrylamide, etc. or two.
More than one species is used. As curing catalysts, common organic peroxides such as benzoyl poroxide,
Methyl ethyl ketone peroxide, tertiary butyl perbenzoate, etc. are used. Other accelerators such as cobalt naphthenate and cobalt octylate, and polymerization inhibitors such as hydroquinone may be added as necessary. As the phenol resin, a resol resin obtained by reacting phenol and formalin in the presence of an alkali catalyst or a novolak resin obtained in the presence of an acid catalyst are used. As the melamine resin, a liquid or powder resin obtained by heating and reacting melamine and formalin at a pH of 7 or higher is used. Examples of the diallyl phthalate resin include prepolymers produced from diallyl orthophthalate, diallyl isophthalate, diallyl terephthalate, etc. alone or in mixtures, or copolymerized prepolymers with vinyl monomers, allyl monomers, etc. that can be copolymerized with the diallyl phthalates. Polymers are used. The molecular weight urethane resin is obtained by reacting polyisocyanate with polyglycol or polyester polyol containing hydroxyl groups at both ends.
2,000 to 4,000 prepolymers with isocyanate groups at both ends or two or more, use polyethylene glycol as a crosslinking agent, or compounds with two or more active hydrogens such as polyesters, polyamines, and polycarboxylic acids that have hydroxyl groups at both ends. It is used by adding it. Examples of polyisocyanates include tolylene diisocyanate, 3,3'-tolylene-4,4' diisocyanate, diphenylmethane 4,4'-diisocyanate, triphenylmethane pp'p''-triisocyanate, 2,4-tolylene dimer, and naphthalene-diisocyanate. 1,5-diisocyanate, tris(4-phenyl isocyanate) thiophosphate, tolylene diisocyanate trimer, dicyclohexamethane 4,4'-diisocyanate, metaxylene diisocyanate, hexahydrometaxylene diisocyanate, hexamethylene diisocyanate,
Trimethylpropane-1-methyl-2-isocyano-4-carbamate, polymethylene polyphenyl isocyanate, 3,3'-dimethoxy 4,4'-
Examples include diphenyl diisocyanate, and polyisocyanate may be added to polyester polyols, polyether polyols, and the like having hydroxyl groups at both ends of the molecule. Examples of thermosetting acrylic resins include those in which two or more carboxylic acid groups or their anhydrides, epoxy groups, amino groups, and other polymerizable functional groups have been introduced into the acrylic resin. What is necessary is to add a curing agent and heat curing. For flexible terminal connections, adhesive strength cannot be satisfied with the above resins alone, but in order to further improve the impact resistance, flexibility, and initial adhesive strength of thermosetting resins, we use composite thermosetting resins blended with thermoplastic resins and elastomer resins. Polymer resins may also be used. Examples of such resins include phenol polyvinyl acetal resin, phenol synthetic rubber, and epoxy resin.
Examples include nylon, epoxy-nitrile rubber, and epoxy polybutadiene. In addition, in the present invention, 0 to 70% by weight of a powder resin insoluble in the printing solvent is used, and blending a specified amount of this resin is important from the viewpoint of printability of the anisotropic conductive ink for the reasons described later. A certain amount of pigment is required, but if that much pigment is mixed in, the adhesion strength will decrease, and conductive pigments will decrease the insulation, so solvent-insoluble powder resin can be used without reducing the adhesive strength. It can be used as a pigment substitute. The particle size is 70 μm or less, which is the size that can pass through the screen, and preferably in the range of 2 to 10 μm, and is soluble in the solvent.
Use a thermoplastic resin or thermosetting resin that does not swell. Incorporation of these powder resins improves printability, eliminates air bubbles during printing, increases adhesive strength, and reduces seal resistance. For example, nylon 12 (product name T40P-1, Daicel Chemical Industries, Ltd.)
is used as such a resin, and other resins include saturated polyester (product name: Byron GM-900, Toyobo Co., Ltd.), epoxy resin (product name: TEPIC, Nissan Chemical Co., Ltd.), polyurethane resin (product name: Europolymer)
200, Nomura Office), etc. Examples of applying the composition according to the present invention between conductors of printed circuits and the like are shown in FIGS. 1 and 2. First, when there are a plurality of parallel conductors A ₁ , B ₁ , C ₁ on the surface of the insulating film F, when the composition of the present invention is screen printed on this, conductive particles E ₁ of 1.0 μm or more are separated by 0.5 μm or less. Conductive particles E ₂ are mixed therein, and the thermosetting resin composition H is applied as a binder to these particles. When a similar substrate, that is, a substrate having a plurality of parallel conductors A ₂ , B ₂ , C ₂ on an insulating film F is placed so as to face the parallel conductors A ₁ , B ₁ , C _{1 ,} A ₁ , Conductive between A ₂ , B ₁ , B ₂ , and C ₁ , C ₂ , and insulating between A ₁ , A ₂ and B ₁ , B ₂ , B ₁ , B ₂ and C ₁ , C ₂ It exhibits anisotropic conductivity. In the present invention, by using two types of large and small conductive particles in combination, the conductivity in the thickness direction and the insulation in the surface direction can be made constant without variation during coating film formation. The reason is that in order for a paint film to exhibit conductivity, conductive particles must be in contact with each other.
When using only small conductive particles of 0.5 μm or less and mixing a large amount of conductive particles as in the past, the content range that satisfies insulation between adjacent circuits and conductivity between opposing circuits is narrow; If only one conductive particle with a large size is insulated from each other, an anisotropic conductive adhesive with a large variation in resistance value will be obtained. However, when two types of conductive particles, large and small, are combined as in the present invention, In this case, small conductive particles are inserted between large conductive particles, and each particle can be electrically connected, resulting in stable electrical properties. In this case, since a thermosetting resin is used, in the process of curing the resin during thermocompression bonding, conductive particles with a particle size of 0.5 μm or less and conductive particles with a particle size of 1.0 μm or more are heat-sealed between opposing electrodes. When pressurized, the conductive particles are insulated in the planar direction by the resin in the curing process, and between the upper and lower opposing electrodes, the conductive particles can electrically conduct between the conductors. In other words, in this case, large-diameter conductive particles, such as abrasive grains, have many irregularities on their surfaces, so A ₁ , A ₂ in FIG.
It is difficult to move between the electrodes B ₁ , B ₂ , C ₁ , and C ₂ , and the resin content is mainly pushed out and flows into the G part, which has a larger gap, so the resin content in this part increases and A ₁ ,
It acts conductively between A ₂ , between B ₁ and B ₂ , and between C ₁ and C ₂ ,
A ₁ , A ₂ and B ₁ , B ₂ , B ₁ , B ₂ and C ₁ , C ₂ act insulatively and exhibit anisotropic conductivity. Pigments with abrasive grains work to prevent misalignment when the resin melts and exhibits fluidity during heat sealing. FIG. 3 is a graph showing the relationship between the content of conductive particles and the resistance value, and the solid line indicates the area between the opposing conductors (between the seals) in FIG. 2. And, when only carbon black with a particle size of 0.5 μm or less is mixed, and when only conductive particles with a particle size of 1 μm or more are mixed, then: =
An example of the present invention with a ratio of 5:95 is shown. Figure 3
Q _A , Q _B , Q _C points have a content that does not show conductivity due to Hall effect or contact resistance before thermocompression bonding, and during thermocompression bonding, adjacent conductors A, B, C... are insulated in the direction, and in the thickness direction Only A ₁ , A ₂ , B ₁ , B ₂ , C ₁ , C _{2 .} . . have contents P _A , P _B , P _C that exhibit conductivity. In the case of Figure 3, in order to increase the resistance value between A, B, C... and make them insulating, move point Q _A or point Q _B to the left (that is, reduce the content of each particle). , it is not possible to maintain point P _A or point P _B in the charged region during thermocompression bonding. On the other hand, if the Q _A point or Q _B point is moved to the right (that is, if the content of each particle is increased), A, B,
The insulation between C... cannot be made sufficient. In other words, since the range that satisfies both is narrow, slight differences in manufacturing conditions can cause defects. Therefore, the conductive particles shown in Fig. 3 were combined to form the structure shown in Fig. 3. The conductive particles constituting the graph in Figure 3 do not need to be carbon black, but may be particles that exhibit colloidal conductivity, and the content in the anisotropically conductive composition is composition Q, which alone provides insulation between adjacent conductors. Choose point _A. Next, the conductive particles that make up the graph in Figure 3 are conductive particles with a rough surface that is suitable as abrasive grains, such as nickel powder produced by the carbonyl method, nickel alloy powder produced by the stamping method, nickel alloy powder produced by the attomy method, or fine particles. (SiC, Al ₂ O ₃ , WC, Si ₃ N ₄ , TaC), etc., plated with nickel, gold, platinum group metal, etc. are used. This is also due to the conductive particles, and the content of conductive particles that alone serve as insulation between adjacent conductors.
Since Q _B is different, the appropriate value is determined by experiment. The Q _C point is estimated by combining the above Q _A and Q _B. The cross-sectional state of the anisotropically conductive composition as a connector at the Q _C point is as shown in Figure 1, with sufficient insulation between the adjacent connectors, and when the two connectors are aligned and thermocompressed as shown in Figure 2, the third As shown in the graph of the figure, the Q _C point is the content of conductive particles and A ₁ , since the resin flows out to part G in Figure 2 during thermocompression bonding.
The resistance value between A ₂ , B ₁ , B ₂ , C ₁ , C ₂ . . . moves to point P _C , and that region is definitely a conductive region. Therefore, the adjacent directions A, B, C, ... maintain sufficient insulation of 10 ¹⁰ Ω or more, and the junction resistance is A ₁ , A ₂ , B ₁ , B ₂ , C ₁ , C ₂
…It becomes 0.5 to 1.5Ω/0.1× ^4mm2 . In addition, when considering adhesiveness and anisotropic conductivity characteristics, the compositional balance of conductive particles, resin, and solvent as an ink may be inappropriate depending on how the resin is selected. In general, if the amount of conductive particles is reduced to improve adhesion, the resulting ink lacks thixotropy and tends to generate viscous bubbles, resulting in a film that is prone to pinholes. Therefore, it is preferable to use a thermosetting or thermoplastic powder resin that does not dissolve in solvents as a substitute for the conductive particles. This powder resin does not dissolve in solvents and acts as a pigment when the printed film is dry to the touch, so that the surface does not become sticky, and it melts during thermocompression bonding to improve adhesion. To explain the embodiments below, the anisotropically conductive composition of the present invention is a two-component type in which a curing agent and a catalyst are added immediately before use depending on the purpose, and a one-component type in which a latent curing agent is added.
Liquid type is used. The thermosetting resin may be completely cured in the thermocompression bonding process, or may be temporarily bonded (semi-cured) in the thermocompression bonding process and then heated in a thermostatic chamber or the like to be post-cured. In addition, if the component is not a heat-resistant component that can be placed in a thermostatic chamber, an anisotropically conductive composition is prepared in which the main component of the thermosetting resin and the curing agent catalyst are mixed separately, and the two layers are coated or each layer is placed facing each other. It is also possible to apply it separately to the circuit terminals, bring both adhered surfaces into close contact, and cure in a short time. (Effect of the invention) The anisotropically conductive composition according to the invention has a small diameter of 0.5 μm.
A combination of two types of conductive particles with a large diameter of 1.0 μm or more and a large number of protrusions, and the use of two types: a solvent-soluble or liquid thermosetting resin and a solvent-insoluble thermosetting or thermoplastic resin; By appropriately blending these combinations, it is possible to obtain an anisotropically conductive film that is sufficiently insulated in the adjacent direction of the conductor and conductive in the opposite direction during thermocompression bonding. It is also possible to print on one board that is easy to print on, dry to the touch, and make a connector.It is also possible to print not only on the circuit connector to be joined, but also on passive elements of electronic components (capacitors, etc.).
It can be used to connect terminals of active elements (ICs, diodes, transistors). Furthermore, a tape-shaped passive element or an active element whose terminal portions are coated with ink or varnish of an anisotropically conductive composition can be bonded to the printed circuit board side. In order to electrically and physically join two objects, one of the two substrates described above is used as a hot plate, and an anisotropically conductive composition is sandwiched between the two substrates for heat sealing. In other words, a method is employed in which the weight of the component itself is used, a method in which a weight is placed on the component and the component is heat-sealed in a thermostatic oven, or a method in which the component is sealed by passing it through a heated roll. As the heat source, in addition to a hot plate kept at a constant temperature, electric heating, dielectric heating, or partial heating such as ultrasonic, hot melt bonding, microwave, or ultrasonic bonding can be used as a substitute. The application fields of connector bonding using anisotropically conductive compositions can be classified as shown in Table 3.

[Table] In particular, since the anisotropically conductive composition of the present invention uses a thermosetting resin as a binder, the circuit shown in FIG. The peel strength in the direction perpendicular to the circuit was 2 to 3 times greater, and the tensile shear strength, heat resistance, moisture resistance, and solvent resistance were also significantly improved. Examples will be described below. In addition, % and parts in the examples represent weight % and parts by weight unless otherwise specified. Example 1 10 to 20% of conductive particles having the composition shown in Table 5 were mixed into the thermosetting resin composition shown in Table 4 to prepare an anisotropically conductive composition. Flexible copper clad board with polyester film base material (polyester 50μm, electrolytic copper foil)
35μm) with a conductor circuit width of 0.5 using the usual etching method.
A wiring pattern consisting of 22 circuits with a distance of 1.0 mm between adjacent circuits and a circuit length of 50 mm was created, and the terminals were made of the above anisotropic conductive composition with a width of 5 mm and a thickness of 5 mm.
It was printed at 30 μm and dried by heating at 120° C. for 10 minutes. Next, the above wiring pattern was formed on a glass cloth base material with a thickness of 0.8 mm and an epoxy resin single-sided copper clad plate, and then a flexible printed wiring board on which the above anisotropically conductive composition was printed was placed on a printed wiring board prepared by the same etching method. Heat compression bonding was carried out at 200°C and 10 kg/cm ² for 20 seconds. Table 6 shows the characteristics of this product. Table 19 shows the performance when the content of conductive particles is 15%.
Note that 16% of the conductive particles had a particle size of 0.5 μm. Table 4 Resin composition Unsaturated polyester resin (Yupica 8524, Japan Upica Co., Ltd.) 25 parts Soft unsaturated polyester resin (KC-970, Dainippon Ink Co., Ltd.) 25〃 Diallyl terephthalate monomer 10〃 Nylon 12 40〃 Dichromyl peroxide 3〃 Carbinol acetate 70〃 Table 5 Conductive particle carbon black (Ketsutin Black EC, Lion Agno Co., Ltd.) Hereinafter simply referred to as EC Two-part carbon black (Acetylene Black AB, Denki Kagaku Kogyo Co., Ltd.) Hereinafter simply referred to as AB 4〃 Colloidal Nickel (300A, Mitsubishi Metals) 10〃 Nickel (#255 Nickel, Inco) 84〃

[Table] Example 2 The conductive particles shown in Table 8 were mixed into the epoxy resin composition shown in Table 7 in an amount of 40 to 60% in terms of solid content to prepare an anisotropically conductive composition. The particle size of the conductive particles is 0.5 μm.
The following particles are 4%. Table 7 Resin composition Epoxy resin (Epotote YD-128, Toto Kasei Co., Ltd.) 70 parts Polyamide resin (curing agent) 30〃 Nylon 12 (T-450P-1, Daicel Chemical Industries, Ltd.) 100〃 Ethyl cellosolve 50〃 Cyclohexanone 50〃 Table 8 Conductive particle carbon black (EC) 1 part carbon black (AB) 3 Nickel (#287 Nickel, Inco Co., Ltd.) 36 Nickel alloy (Fukurodai FR401, Fukuda Kinzoku Co., Ltd.)
60〃 Next, in the same manner as in Example 1, using the above anisotropic conductive composition, printed wiring boards were heated at 200°C for 10
After heat-pressing for 20 seconds at Kg/ ^cm2 , 150
Post-curing was carried out at .degree. C. for 2 hours. Table 9 shows the characteristics of this product.

[Table] Table 19 shows the performance when the content of conductive particles is 45%. Example 3 Printed wiring boards were bonded together at 250°C and 5 kg/cm ² in the same manner as in Example 1, except that the phenolic resin composition shown in Table 10 and the conductive particles shown in Table 11 were used.
After heat-pressing for 10 seconds, post-curing was performed at 150°C for 30 minutes in a constant temperature oven. The particle size of the conductive particles is 0.5 μm.
The following particles are 16%. Table 10 Resin composition Phenol resin (Mirex RN, Mitsui Toatsu Chemical Co., Ltd.) 60 parts Hexamethylenetetramine 3 Epoxy resin (TEPIC, Nissan Chemical Co., Ltd.) 37 Ethyl cellosolve 30 Cyclohexane 30 Table 11 Conductive particles gold metal Nickel (30 % Gold plated Ni#287, Inco Co., Ltd.) 84 parts Colloidal Nickel (300A, Mitsubishi Metals Co., Ltd.) 10〃 Carbon black (EC) 2〃 Carbon black (AB) 4〃

[Table] From Table 12, the most preferable value for the content of conductive particles can be determined between 40 and 50%. Table 19 shows the performance with a conductive substance content of 45%. Example 4 Using the polyurethane resin composition shown in Table 13 as a binder, an anisotropically conductive composition was prepared by mixing 48% of the conductive particles shown in Table 14 in terms of resin solid content. In addition, particles with a particle size of 0.5 μm or less in the conductive particles are
It is 13%. Table 13 Resin composition Polyester polyol (Desmorphen 670,
Sumitomo Bayer) 60 parts aliphatic polyisocyanate (Sumidyur N75,
Sumitomo Bayer) 40〃 Ethyl cellosolve 20〃 Cyclohexane 20〃 Table 14 Other conductive particles Nickel (Ni#287, Inco) 78 parts Silica (Aerosil R-972, Nippon Aerosil)
10〃 Colloidal titanium (black titanium, Mitsubishi Metals)
10〃 Carbon black (EC) 2〃 This anisotropic conductive composition was printed on a printed circuit board with a width of 40 mm using a metal mask screen (thickness 75 μm), dried to the touch at 80℃ for 10 minutes, and then heated to 3Kg at 150℃. /cm ² for 20 seconds. The printed circuit board used here is a polyester film (thickness 75 μm) with a silver resin film printed on it with a circuit width of 0.1 mm, a circuit gap of 0.1 mm, a circuit length of 60 mm, and 30 circuits.The resistance of the silver resin film is R0 = 0.05Ω, the resistance between opposing electrodes after thermocompression bonding is 10 to 15Ω, and the resistance between adjacent electrodes is
It was over 10 ¹² . The voltage resistance was 100V without any abnormality. The characteristics of this product are shown in Table 19. Example 5 An anisotropically conductive composition was prepared by mixing 48% of the conductive particles shown in Table 15 into the main agent and primer of a commercially available modified acrylic adhesive (Bond Koniset AG-1, Konishi Co., Ltd.). . Note that the content of particles with a particle size of 0.5 μm or less in the conductive particles was 6%. Apply this adhesive to the terminals of the printed wiring board of Example 1 with a width of 5 mm.
The primer was printed to a thickness of 5 μm and the base material was printed to a thickness of 100 μm using a metal mask screen, and immediately pressed at 50° C. and 2 kg/cm ² for 20 seconds. The characteristics of this product are shown in Table 19. Table 15 Conductive particles Nickel (#287 Nickel, Inco) 74 parts silicon carbide (#8000SiC, Showa Denko) 20 Carbon black (EC) 2 Carbon black (AB) 4 Example 6 Cations shown in Table 16 Polymerization catalyst (Lewis acid type)
Using an epoxy resin composition containing as a binder, the conductive particles shown in Table 17 were added to
% of the anisotropically conductive composition was prepared. Note that 20% of the conductive particles had a particle size of 0.5 μm. Apply this adhesive to the printed wiring board of Example 1 using 200 meshes and a 120 μm thick screen to a width of 5 mm.
printed on. After drying this to the touch for 8 minutes at 90℃,
Thermocompression bonding was carried out at 220° C. and 8 kg/cm ² for 10 seconds. The variation in resistance value of the counter electrode was 0.1% or less, which was good. Table 19 shows the performance of this product. Table 16 Resin composition Alicyclic epoxy resin (CY-179, Asahi Denka)
100 parts catalyst (700C, Asahi Denka Co., Ltd.) 1 Ethyl Cellosolve 20 Table 17 Conductive particles and other Nickel (#287 Nickel, Inco Co., Ltd.) 72 parts Silica (Aerosil R-972, Nippon Aerosil Co., Ltd.)
10〃 Carbon black (EC) 2〃 Carbon black (AB) 6〃 Colloidal titanium (Black titanium, Mitsubishi Metals)
10 Comparative Example 1 The conductive particles of Example 2 were mixed at 40% in terms of solid content into the thermoplastic resin composition shown in Table 18 to prepare an anisotropically conductive composition. Table 18 Resin composition Thermoplastic polyester (Vylon 300, Toyobo Co., Ltd.) 15 parts Thermoplastic polyester (Stafix LC, Fujifilm Co., Ltd.) 15〃 Nylon 12 (T-450P-1, Daicel Chemical Industries, Ltd.) 70〃 Carbitol acetate 70〃 Next, using the above anisotropically conductive composition in the same manner as in Example 1, Example 1 was applied at 100°C and 3 Kg/cm ² for 10 seconds.
The printed wiring boards were bonded together by thermocompression. The characteristics of this product are shown in Table 19.

[Table] As shown in the above table, this comparative example has good insulation between adjacent electrodes and good conductivity between opposing electrodes, but is inferior in adhesive strength and heat resistance compared to each of the examples. Comparative Example 2 A nickel alloy (Fukudaloy FR-401, manufactured by Fukuda Kinzoku Co., Ltd.) was mixed into the binder of Example 1 in the composition shown in Table 20, and printed wiring boards were bonded together by thermocompression in the same manner as in Example 1. This product cannot be used as a connector when the resistance value between adjacent electrodes is 10 ¹⁰ Ω or more because the resistance value between opposing electrodes is large and uneven.

【table】 [Brief explanation of drawings]

Figure 1 is a cross-sectional view of a substrate having three parallel conductors (circuits) coated with the composition of the present invention;
The figure is a cross-sectional view of a state in which the composition of the present invention is applied between two similar substrates, FIG. 3 is a graph showing the relationship between the content of conductive particles and the resistance value, and FIG. is a schematic diagram of the test piece used for the tensile shear strength and peel strength (circuit direction) shown in Table 19. In FIGS. 1 and 2, F is a substrate film,
A ₁ , B ₁ , C ₁ , A ₂ , B ₂ , C ₂ are conductors, E is large-diameter conductive particles, E ₂ is small-diameter conductive particles, H is thermosetting resin, and G is resin content. Indicates a large number of bands. The arrow in FIG. 4 indicates the direction of tension.

Claims (1)

[Claims] 1 0.2 to 20% by weight of conductive particles with a particle size of 0.5 μm or less, 10 to 75% by weight of conductive particles having a large number of protrusions with a particle size of 1.0 μm or more, 30 to 30% by weight of a thermosetting resin composition soluble in a printing solvent 80% by weight, 0-70% by weight of powder resin insoluble in printing solvents, totaling 100% by weight.
An anisotropically conductive composition comprising a solid component and an appropriate amount of a printing solvent, which are blended in weight percentages.