| Abstract Scope |
Sn–Bi low-temperature solders are promising for advanced electronic packaging because their low melting temperature can reduce reflow-induced thermomechanical damage. However, the brittleness and limited creep resistance of eutectic Sn–58Bi remain reliability concerns. In this study, Sn–58Bi, Sn–57Bi–1Sb, and Sn–55Bi–3Sb alloys were designed to investigate the composition-dependent effects of Sb on crack evolution, tensile deformation, and creep behavior. The alloys were fabricated by melting and casting high-purity Sn, Bi, and Sb elements, followed by SEM/EDS, XRD, DSC, and CALPHAD-based phase analyses. Room-temperature in-situ tensile testing inside a scanning electron microscope was conducted to observe local deformation and crack propagation. Tensile testing at 80 °C and creep tests at 60, 70, and 80 °C were used to evaluate macroscopic and time-dependent deformation. The results show that Sb addition modifies microstructure, crack evolution, and creep behavior in a composition-dependent manner. |