There are many lead-free finish options such as pure Sn, Sn-Ag, Sn-Bi and Sn-Cu post-mold plating and Pd pre-plating. In the present work, Sn-Bi pre-plating technology for alloy 42 leadframe have been investigated. The electrodeposition was done by two-tone selective plating, namely, Ag was plated on internal lead only and Sn-Bi on external lead using various Sn-Bi plating solution. Surface and cross sectional morphology was observed by SEM. Finally solderability, bending crack and whisker performance after temperature cycles have been evaluated.
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