The oxidation properties of Sn-8.5Zn-0.5Ag-0.1Al-xGa lead-free solders in the liquid state (250 °C) under O 2 atmosphere were investigated using a thermal gravimetric analyzer. The Ga content of the investigated solders was 0.05-2 wt%. The results indicate that Ga enhances the oxidation resistance of Sn-Zn-Ag-Al solder. Cross-sections of the solder surfaces were examined using focus ion beam milling. The thickness of the oxidation layer, which was about 30-100 nm, increased with increasing Ga content. The oxidation layer was found to be nonuniform at low Ga content. The oxide layers on the surface of solders were investigated using Auger electron spectroscopy and thin-film XRD. The results showed that the oxide layer formed was ZnO. Al and Ga tended to segregate on the surface of the solder.
All Science Journal Classification (ASJC) codes
- Inorganic Chemistry
- Metals and Alloys
- Materials Chemistry