Cu Electrodeposition on Polypyrrole Precoat for the Metallization of Printed Circuit Boards

Abstract

To explore an alternative green metallization strategy for nonconductive plastics, a conductive polypyrrole (PPy) precoat was prepared by in-situ interfacial polymerization of pyrrole on printed circuit boards (PCBs) and the electrodeposition of Cu on PPy precoat was investigated using both voltage-controlled method and current-controlled method. A uniform PPy film was successfully obtained on the PCB surface through modifying the PCB wettability and optimizing the pyrrole solution. Electrochemical measurements showed that sufficient polarization was necessary for the electroreduction and growth of Cu crystals on the PPy precoat due to its high electrical resistance. The presence of through-holes adjacent to copper in PCB boards demonstrates that constant-current electroplating enables effective deposition of uniform, adherent copper layers on polypyrrole (PPy) - pretreated substrates, establishing a viable alternative to conventional electroless copper plating for through-hole metallization in PCB manufacturing.