Black oxide can passivate the copper surface, enhance the surface roughness of the inner copper foil, and then enhance the bonding force between the epoxy resin and the inner copper foil.
The founction of copper plating line is thicken the copper layer in the panel surface and conductivity holes. The panels themselves act as cathodes for electroplating and we can plate the hole walls thanks to the conductive carbon layer or thin copper layer already deposited there. The operator starts the automated plating line. The copper surface of the panels is cleaned and activated in a number of baths and then electroplated. . The whole process is computer controlled to ensure that each set or flight of panels stays in each bath exactly the right amount of time.