There are many kinds of conductive adhesives, which can be divided into isotropic conductive adhesives (ICAS) and anisotropic conductive adhesives (ACAS) according to the conductive direction. ICA refers to an adhesive that is conductive in all directions and can be widely used in many electronic fields. ACA refers to an adhesive that conducts electricity in one direction, such as Z direction, but does not conduct electricity in X and Y directions. Generally speaking, the preparation of ACA requires high equipment and technology, and it is difficult to realize. ACA is mostly used for fine printing of plates, such as plate printing in flat panel display (FPD).

According to the curing system, conductive silver paste can be divided into room temperature curing conductive silver paste, medium temperature curing conductive silver paste, high temperature curing conductive silver paste, ultraviolet curing conductive silver paste and so on. Conductive silver paste cured at room temperature is unstable, and the volume resistivity is easy to change when stored at room temperature. When high-temperature conductive silver paste is solidified at high temperature, metal particles are easy to oxidize. The curing time must be short to meet the requirements of conductive silver paste. Conductive silver paste cured at medium temperature (below 150℃) is widely used at home and abroad. Its curing temperature is moderate, which matches the temperature resistance and service temperature of electronic components, and its mechanical properties are excellent, so it is widely used. Ultraviolet curing conductive silver paste combines ultraviolet curing technology with conductive silver paste. Conductive silver paste has been endowed with new properties and expanded its application range. It can be used in electronic display technologies such as liquid crystal display and electroluminescence. Foreign countries began to study it in the 1990s, and there are also studies at home. Conductive silver paste is mainly composed of resin matrix, conductive particles, dispersion additives and additives. Most conductive silver pastes used in the market are fillers.

In principle, the resin matrix of filled conductive silver paste can be made of various types of adhesives, such as thermosetting adhesives such as epoxy resin, silicone resin, polyimide resin, phenolic resin, polyurethane, acrylic resin and other adhesive systems. After curing, these adhesives form the molecular skeleton structure of conductive silver paste, which guarantees the mechanical properties and bonding properties. Because epoxy resin can be cured at room temperature or below 150℃ and has rich formula design, epoxy resin-based conductive silver paste is dominant.

Conductive silver paste requires that the conductive particles themselves should have good conductivity, and the particle size should be within a suitable range, which can be added to the conductive silver paste matrix to form a conductive path. The conductive filler can be powders of gold, silver, copper, aluminum, zinc, iron and nickel, graphite and some conductive compounds.