New lead-free solder alloy

Abstract

As the electronics industry is moving towards lead-free manufacturing processes, a new lead-free solder alloy based on Sn-9Zn-1Bi-2Cu-In is described. The quaternary alloy with indium additions exhibits melting, wetting, and mechanical properties superior to those in binary, ternary, and quaternary alloys. Indium as a penternary addition decreases the melting point of this alloy to 181 °C which it is a lower value when compared with the eutectic Sn-Pb solder (183 °C), it decreases the contact angle to 23° which is very close to that for Sn-Pb solder alloy, it increases the Young's modulus to higher values, and it increases its hardness to 19 kgf/mm2 when compared with 12.9 kgf/mm2 for the Sn-Pb solder alloy.