“…To date, extensive research has been actively conducted on Pb-free alloys, particularly focusing on the corrosion resistance, mechanical properties, and physical characteristics of binary, ternary, and multicomponent Pb-free solder alloys like Sn–Cu, Sn–Ag, and Sn–Zn. 2–7 Among these, the Sn–Cu series Pb-free alloy emerges as a promising material to replace Pb-based alloys due to its lower cost, reduced melting temperature, enhanced electrical conductivity, and ductility compared with the Sn–Ag and Sn–Zn systems. 8–10 Nevertheless, an excess of Cu content in Sn–Cu series Pb-free alloys leads to the formation of coarse crystals, adversely affecting wettability and mechanical strength.…”