Sn-0.7Cu lead-free solder is an alternative solder material that suitable to replace Sn-Pb solder in electronic manufacturing. However, it has a weakness of high melting temperature and lower mechanical strength. In this study, the change in microstructure, elements, the structural and melting point of Sn-0.7Cu after the addition of different compositions of Zn element was discussed. The result shows that after adding a small amount of Zn, a refinement microstructure of Sn-0.7Cu-xZn solder alloy was obtained, and the melting point of the solder decreased from 227.7 °C to 225.7 °C. Besides, the formation new phase of was investigated by scanning electron microscope (SEM) followed by energy-dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD). Besides, the behaviour of Sn-0.7Cu-xZn solder alloy can be further studied via open circuit potential (OCP) to determine the corrosion potential.
