The result shows that the plastic strain at the heel region induced by wire bonding process, molding process and the thermal stress and strain in solder reflow are the main causes of heel crack.

• 结果显示由于引线键合工艺、注塑工艺以及回流焊中封装体各部分不同的热膨胀系数引起的热应力和塑性变形是产生引脚跟断裂的主要因素。