Conductive adhesives are classified according to their conductivity direction into isotropic conductive adhesives (ICAs) and anisotropic conductive adhesives (ACAs). ICA refers to adhesives that conduct electricity in all directions and can be widely used in various electronic fields; ACA refers to adhesives that conduct electricity in only one direction, such as the Z-axis, but not in the X and Y directions. Generally, the preparation of ACA requires sophisticated equipment and processes, making it relatively difficult to achieve. It is mostly used in applications such as fine printing on boards, such as the printing of boards in flat panel displays (FPDs).
Conductive adhesives can also be classified according to their curing system into room temperature curing conductive adhesives, medium temperature curing conductive adhesives, high temperature curing conductive adhesives, and ultraviolet light curing conductive adhesives. Room temperature curing conductive adhesives are relatively unstable, and their volume resistivity is prone to change when stored at room temperature. High temperature conductive adhesives are prone to oxidation of metal particles during high-temperature curing, and the curing time must be short to meet the requirements of conductive adhesives. Medium-temperature curing conductive adhesives (below 150℃) are widely used both domestically and internationally. Their curing temperature is moderate, matching the temperature resistance and operating temperature of electronic components, and they also exhibit excellent mechanical properties, hence their widespread application. Ultraviolet (UV) curing conductive adhesives combine UV curing technology with conductive adhesives, giving them new properties and expanding their application range. They can be used in electronic display technologies such as liquid crystal displays and electroluminescence. Research on this technology began abroad in the 1990s, and my country has also started researching it in recent years.
