Influence on Sn whiskering of controlled bismuth additions to sputtered Sn films

In 2006, the European Union restricted lead (Pb) to > 0.1% (by weight) in electronics. This caused a renewal of interest in Sn whiskers, as the absence of Pb in Sn films had been known for years to promote Sn whisker growth. The early work on Sn whiskers had suggested that elements other than Pb may suppress whiskers. Bi was chosen as an attractive candidate, as it has similar phase formation behavior to Pb, i.e., low solubility, eutectic...