Effect of Low Bi Content on Reliability of Sn-Bi Alloy Joints Before and After Thermal Aging

Abstract Sn-58Bi, an eutectic alloy, has been explored for use as a low-temperature lead-free solder alloy. However, the properties of Sn-Bi alloys well those their joints need to be improved significantly so that these can applicable practical use. In particular, two drawbacks addressed: intrinsic brittleness Bi and microstructure coarsening during aging. this study, Sn-Bi-Zn (SBZ) SBZ-In (SBZI) with low contents were examined elucidate effects addition Zn Sn-45Bi alloy on interface shear strengths Cu/Cu before after case SBZ/Cu SBZI/Cu joints, was not observed either near or at interfaces joints. The SBZ SBZI remained unchanged aging 1008 h, suggesting demonstrated highest long-term reliability among all examined.