Effect of plating temperature on Sn surface morphology

The present study documents the effect of electroplating bath temperature on the surface brightness/reflectivity and the evolution of surface morphology of electrodeposited pure Sn films, and its subsequent effect on whisker formation. The brightness/reflectivity of the films increased with increase in temperature. Detailed microstructural analysis of the electroplated Sn films showed that unique pyramid shaped features formed at elevated temperatures (below 85 °C) and the underlying surface became increasingly smooth with temperature. The plating temperature also affected the morphology of the whiskers that formed upon aging at room temperature. The whisker diameter increased whereas the size decreased with increase in plating temperature. It was also observed that the diameter and length of each whisker depend on the Sn grain size.