中文摘要：

粗铝丝使用V型劈刀键合时,键合区域中心应力应变较小不易形成键合,而周边部位应力应变较大容易发生有效结合。在热循环应力作用下,键合焊点的中心区域易形成＂裂纹＂迅速向前端扩展,最后引发焊点脱离。对根部断裂断口分析发现,热应力疲劳是其断裂的主要原因,裂纹源在焊点根部与劈刀边缘接触部位。ANSYS分析得出的键合区域应力分布与变形情况解释了产生上述现象的原因。

英文摘要：

Thick aluminum wire bonded with V-groove wedge was studied.It was showed that the central area of the bond point was difficult to form a bond,while the peripheral area can form an effective bond easily,because the stress and strain of the peripheral area was larger than the central area.When the bond point was subjected to thermal cycle stress,the ＂crack＂ can easily initiated from the central area and propagate rapidly until bond lift formed.The heel crack fracture was analyzed,it was found that the thermal stress fatigue is the main reason of heel crack,and the crack was initiated from the bond heel surface where contact with the edge of the wedge.The phenomena mentioned above was explained by the stress and deform distribution of bond point simulated by ANSYS analysis.