超声波线焊, 分子动力学, 接触压力, 焊接强度 

 The microscopic mechanism of ultrasonic wire bonding was investigated by molecular dynamics simulation on the interfacial contact and adhesion. Considering that the real bonding area was in the state of plane strain, a two-dimensional atomic model was presented. Sutton-Chen potential was adopted for the interaction among gold atoms. Computational results indicate that after intimate contact between the wire and the bond pad, a strong adhesion generates at the interface, and the adhesion force will be the mechanism of ultrasonic wire bonding. Combining the real contact area from the finite element analysis before, the bonding strength of ultrasonic wire bonding was estimated, which was partially validated by experiments.

ultrasonic wire bonding, molecular dynamics, contact pressure, bonding strength