Effect ff ect of Indium on Microstructures and Mechanical Properties of Bismuth-Based High Temperature Solders

With the rapid development of the electronic information industry, the reliability of electronic interconnection materials is crucial for the longevity of electronic components. Bi-based alloys have garnered significant fi cant attention as potential candidates for high-temperature solders. However, the inherent brittleness of Bi-based alloys has been a limiting factor in their application. In order to develop high-temperature Bi-based solders with superior performance, In element was chosen to modify the Bi-2Ag-0.5Cu alloy. Through the introduction of Ag2In 2 In and BiIn phases, much fi ner microstructure of Bi-based alloy can be achieved (grain size decreases from 80 mu m to 30 mu m). Adding 2% % Indium has led to notable improvements in ultimate tensile strength ( h UTS ) and fracture strain ( 3 / 4 f ), by 76.9% % and 55.1% % compared to Bi-2Ag-0.5Cu, respectively. Additionally, the melting point of the Bi-2Ag-0.5Cu-2In alloy is 534.3 K, meeting the specified fi ed requirements for a high-temperature solder. [doi:10.2320/matertrans.MT-M2024067] / matertrans.MT-M2024067]