尺寸效应对焊点热循环可靠性影响的仿真分析

摘要

The stress and strain distribution of 70 µm and 55 µm solder joints under thermal cycling loading were predicted and analyzed by finite element simulation software ANSYS, the solder joints on both sides of the packaging model have the region of stress concentration and the interfaces between the solder and pads will become the sickness which will promote germination and expansion of the crack. It is also found that stress and plastic strain of 55 µm solder joints are larger than those of 70 µm solder joints, as well as the greater stress and strain distribution area.%利用有限元模拟软件ANSYS预测分析了70μm和55μm两种尺寸焊点在热循环载荷的作用下的应力应变分布，发现封装体两侧的焊点应力应变集中较为明显，而钎料与焊盘界面处则是焊点的薄弱位置，裂纹最可能在两侧焊点沿着钎料与焊盘界面处扩展。同时发现55μm焊点所受到的应力和塑性应变比70μm焊点大，且较大应力和应变的分布区域更广。