PRINTED WIRING BASE MATERIAL AND ELECTROLYTIC TIN-BASE ALLOY PLATING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a printed wiring base material having tin-base alloy plating to obviate the production of lance-like deposits and an electrolytic tin-base alloy plating method. SOLUTION: The printed wiring base material 10 includes an insulating base material 11 and wiring patterns 12 formed from conductive layers 20 on one surface of the insulating base material 11 and includes tin-base alloy plating layers 25 consisting of the tin-base alloy in at least portions of the wiring patterns 12. The average plating film grain size of the tin-base alloy plating layers 25 is <=2μm.