The hard gold PCB process is a PCB manufacturing process that mainly covers the PCB surface with a layer of hard gold (Gold) through hard gold plating to increase its hardness and wear resistance and prevent oxidation and corrosion of the PCB surface. This process has extremely strong conductivity and excellent corrosion resistance, can provide good welding performance, and is suitable for circuit boards that require frequent repair and disassembly. It is often used in high-end electronic products, such as communication equipment, military equipment, etc., and has excellent performance in electrical performance and reliability.