2008 Volume 11 Issue 1 Pages 53-59
The local corrosion of nickel can occur during the gold plating in AU/Ni fabrication processes. The wire bonding strength decreases as the nickel is diffused to the gold surface by the heat treatment. Accordingly, palladium plating is generally applied as an interlayer between the nickel plating and the gold plating to avoid the local corrosion of nickel. However the influence of the nickel layer structure and the noble metal film thickness on the wire bonding strength has not been investigated in detail. In this study, we investigated how the structure of the deposited nickel and the thickness of the noble metal film influenced the wire bonding properties. The bonding strength of nickel was higher with a layered structure than with a columnar structure when the gold and palladium films were 0.05μm thick.