| Abstract Scope |
Solders in microelectronic packaging not only provide electronic connections but also ensure the mechanical support reliability of solder joints. Sn-Bi solder has a lower melting point, which can reduce warpage during reflow and is suitable for temperature-sensitive devices or components, thereby minimizing thermal damage. However, after prolonged thermal aging, the Bi-phases in Sn-Bi solder tend to coarsen, leading to a decline in mechanical properties. According to literature reviews, adding trace elements to Sn-Bi solder can improve mechanical properties, potentially due to mechanisms such as microstructural refinement, IMC precipitation strengthening, or solid solution strengthening. Consequently, in this study, trace elements including Indium (In), Silver (Ag), Copper (Cu), Nickel (Ni), Antimony (Sb), and Zinc (Zn) are added to the Sn-Bi solder. Microstructural analysis, Vickers hardness tests, ball shear tests, and nanoindentation experiments are conducted to analyze the mechanisms that enhance mechanical properties. |