The chemical composition of PCB includes:
1. Metals: including common metals such as aluminum, copper, iron, nickel, lead, tin and zinc, and precious metals such as gold, palladium, platinum and silver. These metals mainly play the role of electrical and thermal conductors in PCBs.
2. Organic materials: including phenolic resin (Bakelite) and polyimide (PI), etc. These organic materials are mainly used as insulation materials. Among them, phenolic resin (bakelite) is a colorless or yellow-brown transparent substance. The ones sold on the market often add colorants to make them red, yellow, black, green, brown, blue and other colors. Polyimide (PI) is a thermoplastic polymer with a high calorific value.
3. High molecular polymer: mainly derived from petroleum products, such as polystyrene (PS), polyvinyl chloride (PVC), etc. These high molecular polymers have high calorific value and can generate energy and produce related chemical products.
Please note that PCBs also contain other elements and compounds, and the specific composition may vary depending on the type of PCB and application scenario.