Elimination of critical raw material Palladium during activation

The surface activation step follows the etching step in the surface-pretreatment process, introducing the initial metal nucleation sites on the etched surface. The most common activation system is an aqueous colloidal solution of hydrochloric acid, stannous chloride (SnCl₂) and palladium chloride (PdCl₂). During this step, Pd²⁺ cations are adsorbed onto the etched surface of the plastic substrate and are subsequently reduced by SnCl₂ to metallic Pd⁰. Even though Pd has consistently been used in the PoP industrial processes for over 50 years, it must be replaced because it is considered a critical raw material, i.e. it is expensive and has a high supply risk.

Within the FreeMe Project, Creative Nano has successfully replaced palladium with nickel, which is highly abundant and cheaper.