Study on low silver Sn-Ag-Cu-P alloy for wave soldering

In recent years, it's a tendency that many researchers are focusing on low Ag lead-free solder due to high cost of silver. However, it's inevitable that the oxidation may arise because of higher content of tin, especially in wave soldering. In this study, the melting point, hardness, microstructure, wettability and anti-oxidation property of Sn-0.3Ag-0.7Cu-0.004P solder (SACP) were researched and compared with those of Sn-0.3Ag-0.7Cu (SAC). SACP had better oxidation resistance and poorer wettability than SAC, and their melting characteristics were similar.