| 摘要 |
PROBLEM TO BE SOLVED: To provide performance equal to that of a Pb-Sn alloy plated lead by constituting an inner plating layer formed on a lead base material and an outer plating layer formed on the inner plating layer, and forming one plating layer with an Sn-Ag alloy and the other plating layer with an Sn-Bi alloy. SOLUTION: A lead for an electronic component has an inner plating layer 2 made of an Sn-Bi alloy having specified thickness formed by an electrolytic process on an acid-cleaned copper alloy wire 1 having a specified outer diameter, and an outer plating layer 3 made of an Sn-Ag alloy having specified thickness formed by an electrolytic process. The Sn-Ag alloy and the Sn-Bi alloy have a property mutually diffusing Ag, Bi, and Sn by wire drawing anneal and skin pass operation, the inner plating layer 2 and the outer plating layer 3 laminated up and down have excellent performance in adhesion, solder wettability, color changing resistance, and whisker characteristics, and are effectively used as the lead for an electronic component capable of replacing an Sn-Pb alloy plated lead.
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