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。
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.
依据这种电子结构计算了晶格常数、结合能、势能曲线、体弹性模量和线热膨胀系数随温度的变化，理论值与实验值均符合较好。
At the same time we curve fit the bulk modulus B of these binary alloys using the results and least square mothod.
依据这种电子结构计算了晶格常数、结合能、势能曲线、体弹性模量和线热膨胀系数随温度的变化，理论值与实验值均符合较好。
At the same time we curve fit the bulk modulus B of these binary alloys using the results and least square mothod.
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