JPH05235513

PURPOSE:To restrain whisker-shaped abnormal deposition, by performing electro lytic copper plating by using acid copper plating solution containing an organic additive, after substitution palladium plating is performed, when electrolytic copper plating is performed by using acid copper plating solution. CONSTITUTION:After a copper-clad laminated board which has been subjected to boring, polishing, chemical plating, panel electrolytic copper plating, polishing, and resist pattern formation is subjected to acid degreasing, soft etching, and sulfuric acid treatment, pattern electrolytic copper plating is performed by using acid copper plating solution, after the board is dipped in substitution palladium plating solution at a room temperature for 2-10 minutes. The composition of plating solution is as follows; caper sulfate 60g/l, sulfuric acid 180g/l, chlorine ion 50mg/l and brightener 10mg/l. Plating conditions are as follows; current density is 0.1-3A/dm , plating time is 60 minutes, and an anode consists in copper containing phosphorus. The obtained board is subjected to solder plating, resist peeling, and etching, thereby obtaining a printed wiring board, in which whisker-shaped abnormal deposition is not found.