Composite conductive adhesive film and manufacturing method thereof

Abstract

The invention discloses a composite conductive adhesive film, which comprises an upper adhesive layer, a strengthening layer, a conductive adhesive layer and a lower adhesive layer, wherein the conductive adhesive layer comprises a conductive particle of which a substrate is an ABS (acrylonitrile butadiene styrene) particle, the surface of the ABS particle is coated with an alloy layer and the alloy layer is coated with a monometallic layer; the particle size of the ABS particle is 10 to 50 mu m; the thickness of the alloy layer is 3 to 10 mu m; the thickness of the monometallic layer is 4 to8 mu m; the conductive particle is a waxberry-shaped particle distributed with flaky bulges on the surface, a waxberry-shaped particle distributed with needlelike bulges on the surface or a waxberry-shaped particle distributed with rod-shaped bulges on the surface; the strengthening layer is a metal mesh woven from micron-sized metal wires. The composite conductive adhesive film has the propertiesof high electric property, strong bonding strength, high solderability, high reliability, high flame resistance and the like; by the conductive particle, the shortcomings of a material, such as a carbon fiber, a solder and nickel powder, used as the conductive particle can be overcome.

Description

technical field [0001] The invention belongs to the technical field of conductive cloth for printed circuit boards, in particular to a composite conductive adhesive film. Background technique [0002] With the development of the electronics industry, electronic assembly is becoming more and more miniaturized and high-density. Many conductive connections no longer rely on traditional methods such as welding or plugging, but are realized through conductive adhesive films. [0003] Homotropic conductive adhesive film is a compound formed by dispersing conductive particles in adhesive insulating resin, which is used for bonding components and cured under heat and pressure, so as to realize the functions of electricity and bonding. The same sex conductive adhesive film is mainly composed of resin, curing agent and silver powder, and the resin is generally solid resin and liquid resin. The solid resin is mainly used for pre-curing to form a film, and the liquid resin has the main...

AI Technical Summary

Problems solved by technology

[0005] However, the above-cited conventional techniques using organic or inorganic particles and insulating fibrous fillers have the disadvantage that the amount of conductive particles is limited, and it causes many problems during the production of the anisotropic conductive film and may also be damaged after connection. Will reduce the long-term reliability of the electrical connection

The electrical conductivity of carbon fiber is not high. In order to obtain a large enough electrical conductivity, it must be filled with 5% to 25% particles by weight, so that the transparency of ACF is very low.

Solder particles are easy to form intermetallic compounds (IMC) during the soldering process. IMC is relatively brittle and has a large difference in thermal expansion coefficient and other properties from the base material (electrodes, components or substrates during packaging, etc.). If it grows too large It is easy to crack and cause reliability problems

Someone proposed to use instant melting technology to avoid the formation of IMC, but this process adds tin-lead plating on the bumps, which increases the complexity of the process

In the fine-pitch interconnection, the solder particles must be very small, but the time required for the diffusion of small solder particles to generate IMC is shorter, and the reliability problem is more serious, so in the ultra-fine-pitch ACF, solder particles are rarely used

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