Preparation method of epoxy resin conductive adhesive

Abstract

The invention discloses a preparation method of an epoxy resin conductive adhesive. The conductive adhesive is prepared from nanometer graphite powder, epoxy resin and polybutadiene epoxy resin by weight percentage of 70-80% to 15-20 % to 5-10%. The nano graphite powder is dissolved in a supercritical carbon dioxide fluid, the supercritical carbon dioxide fluid is low in viscosity, big in diffusivity coefficient and small in diffusion boundary layer, and the dissolved nanometer graphite powder can quickly penetrate into gaps in the epoxy resin matrix, after the graphite powder completely penetrates, carbon dioxide is recycled and reused by decompression expansion, the production efficiency is high, the time period is short, the surface treatment on the nano graphite powder is not required,the nano-graphite powder can be uniformly dispersed in the epoxy resin matrix without adding a coupling agent, it is ensured that the excellent conductivity of the nano-graphite powder is not lowered, and the conductivity of the finished conductive adhesive is further improved.

Description

technical field [0001] The invention relates to a conductive adhesive, in particular to a preparation method of an epoxy resin conductive adhesive. Background technique [0002] Conductive adhesive, referred to as conductive adhesive, is an adhesive that can effectively bond various materials and has conductive properties. Conductive adhesive can be divided into two categories: structural type and filling type according to the composition of the matrix. The structural type refers to the conductive adhesive in which the polymer material itself as the matrix of the conductive adhesive has conductivity; the filled type refers to the adhesive as the matrix, adding conductivity. The filler is a conductive adhesive that makes the glue conductive. At present, the preparation of conductive polymer materials is very complicated, and there is still a long way to go from practical application, so filled conductive adhesives are widely used in the market. [0003] The matrix of filled...

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Problems solved by technology

[0004] Compared with gold surface, silver is the most suitable conductive filler because it is relatively cheap and has low resistance. However, under the conditions of high temperature and DC potential, silver will electrolytically migrate to the surface of the adhesive layer. Nickel, aluminum and copper Metals such as graphite have special oxidation problems. The oxide film formed hinders the contact between particles and particles, thereby reducing the conductivity. In contrast, graphite is cheap, but its conductivity is quite small, far inferior to gold and silver.

[0005] Nano-graphite powder is graphite that is pulverized into graphite powder particles by an ultrafine pulverizer. , the dispersibility is poor, and the phenomenon of nano-powder agglomeration is easy to occur. If it is modified, it is easy to reduce the conductivity and adhesion of nano-graphite powder