中文摘要：

通过对超声波线焊中的界面接触，以及拉脱实验中的界面分离现象进行分子动力学模拟，从微观角度探讨了超声波线焊的机理。由于实际焊接区域处于平面应变的受力状态，模拟时建立两维的原子模型，采用Sutton—Chen势能函数描述金原子之间的相互作用。模拟结果表明，超声波线焊时由于金线与焊盘之间的紧密接触，产生强大的原子间作用力，从而导致牢固的界面键合，这是超声波线焊的微观机理。将有限元分析和分子动力学模拟相结合，可以计算超声波线焊的界面焊接强度，其结果与拉脱实验相符合。

英文摘要：

The microscopic mechanism of ultrasonic wire bonding was investigated by molecular dynamics simulation on the interracial 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.