| 摘要 |
PROBLEM TO BE SOLVED: To improve peeling resistance, solder wettability, color fastness, and migration characteristics by having nickel alloy plating layer interpose between a nickel plating layer and a first precious metal plating layer, and forming a second precious metal plating layer which is different from the first precious metal plating layer on the nickel alloy plating layer. SOLUTION: A copper alloy conductor 1 of 0.6 mm outside diameter is degreased and acid pickled, and then a nickel plating layer 2 is formed into a thickness of 0.5 μm on the copper alloy conductor 1. Furthermore, a palladium nickel alloy plating layer 3 of 0.05 μm in thickness is formed on the nickel plating layer 2 through electrolytic plating, over which a palladium plating layer 4 of 0.05 μm in thickness is formed as a first precious metal plating layer through electric plating. A gold plating layer (flash plating layer) 5 of 50 Åin thickness is formed on the outermost layer as a second metal plating layer. Thus, a lead wire showing superior performance for all the characteristics such as peeling resistance, solder wettability, color fastness, and migration is provided. |
