SMT焊点形态对热应力分布影响的有限元分析

采用线性有限元方法研究了ＳＭＴ焊点形态与热应力之间的关系，得到了不同外观形状和元件－焊盘间隙的ＳＭＴ焊点在受交变热作用时焊点内部的热应力分布情况。结果表明，焊点内的应力集中受到这两个形态参数的影响并且存在着最佳的区间，这一结果对于ＳＭＴ－ＰＣＢ上的焊盘设计和优化以及进一步的钎焊工艺规范的制定都具指导意义。

FEM Analysis of the Influence of SMT Solder Joint Shape to the Internal Thermal Stress of the Joint

The relation of SMT solder joint shape of ceramic chip component to the thermal stress inside the joint has been developed in FEM. The stress distribution of various joint shapes or the gap between the pad and the component (C-P gap)has been obtained when the joint endures alternating thermal action. The stress concentration inside the joint is influenced by the shape parameters (joint shape,C-P gap),and can be decreased through optimizing joint shape design.The results are of importance to pad design and potimization of SMT-PCB and further formulating the soldering process.