Effects of tin particles addition on structural and mechanical properties of eutectic Sn–58Bi solder joint

Due to the inherent environmental and health toxicities associated with lead, the use of environmental friendly lead-free solder materials has become an unavoidable trend in the electronic packaging industry. Sn-58Bi alloy is gaining attention for its good material properties such as low melting point, reliability and high tensile strength. The presence of the bismuth-rich phase increases the brittleness of Sn-58Bi alloy. The purpose of this study is to suppress the brittleness of Sn-58Bi alloy by the addition of different wt% (0, 10, 20, 30) of Sn powder. The powder metallurgy method was used to prepare the samples. Scanning electron microscopy and energy-dispersive X-ray analysis were done to study the structural properties and a tensile test was done by a universal tensile machine to study the mechanical properties. The results reveal that the Sn particles partially dissolved in the Sn-58Bi solder matrix. The dissolution of Sn particles significantly improved the mechanical strength by 30%, suppressed the brittleness and improved the strain value by 1.3 times.