The effects of 1 wt.%, 5 wt.%, and 10 wt.% additions of indium (In) on the microstructure and compound morphology of Sn-Ag-Sb lead-free solder joints were examined. The results showed that In prompts the formation of Ag 3(Sn,In), Ag 2(In,Sn), and InSb compounds within the solder matrix. As the amount of In was increased, the Sn atoms in the Ag 3Sn compound were gradually replaced by In atoms, prompting a transformation from Ag 3Sn to Ag 3(Sn,In) and finally to Ag 2(In,Sn). This transformation occurs more readily under high-temperature conditions. The Ag 2(In,Sn) compound formed in Sn-Ag-Sb-xIn/Cu solder joints was found to have either a leaf-like morphology or an antler-like morphology. Finally, with In additions greater than 5 wt.%, the Cu 6Sn 5 interfacial compounds in the solder/Cu joints transformed into Cu 6(Sn,In) 5.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry