Investigation of the Microstructure, Thermal Properties, and Mechanical Properties of Sn-Bi-Ag and Sn-Bi-Ag-Si Low Temperature Lead-Free Solder Alloys

In this study, we investigated the microstructure, mechanical properties, and thermal performance of Sn-xBi-1Ag (x = 35, 37, 45, 47 wt.%) solders, with a particular focus on effect adding trace Si atoms. The impact different Ag concentrations properties Sn-xBi-Ag-0.5Si solders was also studied. results indicated that as amount Bi added to solder alloys increased, tensile strength, microhardness, melting temperature, range decreased somewhat, but wettability improved. Cu6Sn5 layer between soldering alloy Cu substrate became thinner upon increasing content. Adding microcrystalline atoms Sn-Bi-1Ag improved strength point were not significantly changed. optimized, diffusion formed matrix thinner. By content in Sn-Bi-(1,3)Ag-0.5Si alloy, continuously strengthened, while hardness slightly increased slightly. greatly improved,