Quick Electroless Tin Plating on PCB by Fractionated Catalysis Mothod

A tin coating was deposited on printed circuit board (PCB) by electroless plating, using thiourea as complexing agent, sodium hypophosphite as reducing agent and K2PdF6 as catalytic agent. The microstructure and thickness of tin coating were investigated by means of SEM and XRF. The surface morphology of tin coating obtained from different deposition times when using K2PdF6 as catalytic agent to conduct fractionated catalysis was studied, the different depositional rates of tin coating with and without catalyst were studied too. The results show that K2PdF6 acted as catalytic agent can facilitate the continuous depositing of tin coating on PCB during electroless plating tin, and the depositional rate was improved.