7. Electrolytic metallization

After electroless plating, the parts are generally subjected to electrolytic treatment in a pre-copper or pre-nickel plating bath. Waiting too long between the electroless bath and the first bath of the electrolytic line, or handling the parts, can lead to passivity of the deposit. This must be avoided at all costs to ensure good adhesion between the electroless nickel deposit and the electrolytic deposit. The purpose of these pre-copper or pre-nickel plating baths is to reinforce the thickness of the conductive layer on the surface of the non-conductive material. Deposition is initiated at low current density to avoid burning at contact points. After a few minutes, the current density is increased to create a sufficient thickness of metal to withstand the current densities of successive baths. This deposit, 1 to 2 µm thick, is then covered with a 10 to 40 µm-thick electrolytic deposit...