| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of obtaining a lead-free Sn-Bi plating film with improved adhesion to a lead frame. SOLUTION: Using a plating device with an anode and a cathode in which current value is adjustable, a plating film is deposited at a low current density in the initial stage, and the current density is stepwise increased to deposit a plating film. For example, the current density is changed into three stages, i.e., first, a plating film is deposited at a current density of 5 to 8 A/dm<SP>2</SP>, a plating film is successively deposited at a current density of 10 to 15 A/dm<SP>2</SP>, and a plating film is further successively deposited at a current density of >15 to 20 A/dm<SP>2</SP>. COPYRIGHT: (C)2007,JPO&INPIT
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