Characterizations of Physical Properties of Sn-Bi Solder Alloy

Abstract

As the electronic packaging industry is vastly being developed, the solder plays a crucial role in providing integrity electronic assemblies. Unfortunately, the traditional Sn-Pb solder is harmful to the environment and human due to lead (Pb) it contains. Hence, in this study, the Sn-Bi lead free solder alloy is investigated based on its physical properties together with melting temperature, hardness and microstructure. Investigation shows that this solder provides a low melting temperature of, Tm=141.08°C which is lower than the most used Sn-Pb, Tm=183°C and Sn-Ag-Cu, Tm=227°C. Moreover, the Sn-Bi solder also produces well-defined microstructures with Sn-matrix and bismuth precipitation on the matrix. The Sn-Bi solder also provides a higher hardness with average of 11.8Hv for Vickers hardness and 3.87BHN for Brinell hardness. All this results seem to satisfies the environment as well as producing better physical properties.