Research of growth kinetics of cu/Sn intermetallic compounds in planar and curved cu/Sn diffusion couples

As a crucial bridge for heat dissipation, electrical transmission and mechanical interconnection between chips and substrates, interconnection interfaces have a close bearing on the interconnection quality and reliability of the solder joint. With the increasing diversity of electronic packaging configurations, the geometric shape of interconnection interfaces has a growing influence on the growth of Cu-Sn intermetallic compounds (IMCs). However, existing research has predominantly focused on planar Cu/Sn diffusion couples, with insufficient investigation into curved Cu/Sn interfaces. In this study, the growth kinetics of both planar and curved Cu/Sn diffusion couples were systematically examined under various reflow temperatures (250–350 °C) and holding durations (60–960 s). The effects of interface curvature on the diffusion rates, growth mechanisms, and activation energies of Cu₃Sn and Cu₆Sn₅ IMCs were elucidated.