LEAD-FREE TIN ALLOY PLATING METHOD

摘要

PROBLEM TO BE SOLVED: To perform uniform alloy plating by suppressing abnormal precipitation, in a lead-free tin alloy plating method. SOLUTION: Plating current value control is conducted so that an ON-OFF mode is intermittently repeated in plating current. The ratio a/b between the OFF time (a) and the ON time (b), is desirably controlled to≥0.2. It is desirably controlled to about 0.3 for preventing the extension of the total plating time as for the MAX side. The period of repeating the OFF-ON is desirably controlled to 5 times/sec or lower. Further, not simple ON-OFF but ON-OFF in which reverse potential is made on the OFF time is performed. COPYRIGHT: (C)2004,JPO&NCIPI