In the PCB process, the conversion film mainly plays the role of protecting circuits, enhancing circuit adhesion and preventing the outward diffusion of copper ions. Conversion coatings usually consist of an electroless copper plating layer that provides conductivity, and an organic protective layer that prevents copper ions from reacting with other substances, such as acids or alkalis that may be exposed during post-processing. solution. In addition, the conversion coating can also improve the wear resistance and corrosion resistance of the circuit, thereby extending the service life of the PCB. Therefore, conversion coating is a very important component in the PCB manufacturing process.