JP2008311667A5 - - Google Patents

Description

The anisotropic conductive adhesive composition for circuit connection of the present invention is an adhesive that is interposed between facing circuit electrodes, heats and presses opposite circuit electrodes, and electrically connects the electrodes in the pressing direction. a composition, [1] the polar component of the surface tension of adhesives compositions surfaces (γsv, p) is a 3.0 ~ 4.0 dyne / cm, ( 1) generating free radicals by heating (2) Radical polymerizable substance, (3) Film forming material, (4) Circuit connection containing conductive particles coated with an organic polymer compound containing a water-soluble polymer as an essential component An anisotropic conductive adhesive composition . Contact Chakuzai composition surface tension polar component (γsv, p) in less than 1, the adhesive electrodes and the poor immunity from between the conductive particles, may not be obtained a good electrical connection If it exceeds 6, the adhesive is not peeled off from the coated substrate (separator) such as PET (polyethylene terephthalate), and the productivity is lowered, which is not preferable. Conductive particles used in the present invention, the surface of gold, silver, composed of at least one member selected from platinum group metals, that is further coated with the metal surface with an organic polymeric compound. It is preferable that the organic polymer compound is water-soluble because the coating workability is good. The adhesive composition of the present invention can have a multilayer structure separated into a layer containing conductive particles and another layer. At this time, the thickness of the adhesive layer containing conductive particles is determined by the particle size of the conductive particles. Is preferably less than 3 times, more preferably less than 2 times. When the thickness of the adhesive layer containing the conductive particles is three times or more, the amount of the conductive particles flowing out between the adjacent electrodes is increased, which is not preferable.

The present invention also provides: [2] An anisotropic conductive adhesive for circuit connection according to the above [1], wherein the anisotropic conductive adhesive composition for circuit connection further contains a radical polymerizable substance having a phosphate ester structure. Adhesive composition. Moreover, this invention is [3] The anisotropic conductive adhesive composition for circuit connection as described in said [2] whose film formation material is a phenoxy resin. The present invention is also the anisotropic conductive adhesive composition for circuit connection according to the above [3], wherein the [4] phenoxy resin has a molecular structure derived from a polycyclic aromatic compound in the molecule. [5] The anisotropic conductive adhesive composition for circuit connection according to the above [4], wherein the molecular structure resulting from the [5] polycyclic aromatic compound is a fluorene ring.

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

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

Claims (14)

Polar component of the surface tension of adhesives compositions surfaces (γsv, p) is 3.0 to 4.0 dyne / cm,
(1) Curing agent that generates free radicals upon heating, (2) Radical polymerizable material, (3) Film-forming material, (4) Conductive particles whose surface is coated with an organic polymer compound containing a water-soluble polymer As an essential component ,
The anisotropic conductive adhesive composition for film-like circuit connection , wherein the radical polymerizable substance (2) contains an acrylate or methacrylate having at least one selected from a dicyclopentenyl group, a tricyclodecanyl group and a triazine ring . object. The anisotropic conductive adhesive composition for circuit connection according to claim 1, further comprising a radical polymerizable substance having a phosphate ester structure. The anisotropic conductive adhesive composition for circuit connection according to claim 1 or 2, wherein the film forming material is a phenoxy resin.   The anisotropic conductive adhesive composition for circuit connection according to claim 3, wherein the phenoxy resin has a molecular structure resulting from a polycyclic aromatic compound in the molecule.   The anisotropic conductive adhesive composition for circuit connection according to claim 4, wherein the molecular structure resulting from the polycyclic aromatic compound is a fluorene ring. The circuit connection according to any one of claims 1 to 5, wherein the water-soluble polymer includes at least one selected from polycarboxylic acid, polycarboxylic acid ester, polycarboxylic acid ester salt, and vinyl monomer. An anisotropic conductive adhesive composition. The anisotropic conductive adhesive composition for circuit connection according to any one of claims 1 to 6, which is used for COG mounting, COF mounting, or driving IC connection. Bump area 3000μm ² The anisotropic conductive adhesive composition for circuit connection according to any one of claims 1 to 6, which is for circuit connection of less than. A first circuit member having a first connection terminal and a second circuit member having a second connection terminal are disposed so that the first connection terminal and the second connection terminal are opposed to each other, and the opposed arrangement is performed. claim 1-8 or by interposing a circuit connecting anisotropically conductive adhesive composition according to one of the opposed heating pressurized between the first connecting terminal and the a second connection terminal A circuit terminal connection method for electrically connecting the first connection terminal and the second connection terminal. A circuit connection structure obtained by the circuit terminal connection method according to claim 9 , wherein an insulation resistance between adjacent electrodes is 10 ⁹ Ω or more when a direct current of 50 V is applied to the circuit terminal. The circuit connection structure according to claim 10 , wherein the circuit member having at least one connection terminal is an IC chip. The circuit connection structure according to claim 10 or 11 , wherein a connection resistance between the connection terminal of the IC chip and the connection terminal on the second circuit member is 1Ω or less. The circuit according to any one of claims 10 to 12 , wherein the surface of at least one of the connection terminals is composed of at least one selected from gold, silver, tin, a platinum group metal, and indium-tin oxide (ITO). Connection structure. The circuit connection structure according to any one of claims 10 to 13 , wherein at least one of the circuit member surfaces is coated or adhered with at least one selected from silicon nitride, silicone compound, and polyimide resin.