Inhibition of Whisker Growth on the Surface of Sn-3Ag-0.5Cu-0.5Ce Solder Alloyed with Zn.

Solder alloys doped with rare-earth elements have been reported to show many beneficial effects. However, tin whiskers have been observed to appear on the surface of Sn-3Ag-0.5Cu-0.5Ce solder joints after air exposure for short periods. Such a phenomenon of abnormal whisker growth may significantly degrade the reliability of electronic packaging. The present study shows that the tin whiskers can be prevented by the addition of 0.5 wt.% Zn into a Sn-3Ag-0.5Cu-0.5Ce solder. The inhibition effect on the whisker growth is correlated to the refining of (Ce_0.9Zn_0.1)Sn₃ intermetallics in this Sn-3Ag-0.5Cu-0.5Ce-0.5Zn alloy. [ABSTRACT FROM AUTHOR]