研究了热循环过程中SnAgCu/Cu焊点界面金属间化合物的生长规律及焊点疲劳失效行为。提出了热循环条件下金属间化合物生长的等效方程以及焊点界面区不均匀体模型,并用有限元模拟的方法分析了热循环条件下焊点界面区的应力应变场分布及焊点失效模式。研究结果表明:低温极限较低的热循环,对应焊点的寿命较低。焊点的失效表现为钎料与金属间化合物的界面失效,且金属间化合物厚度越大,焊点中的累加塑性功密度越大,焊点越容易失效。
The growth kinetic of intermetallic compounds(IMCs) and fatigue failure behavior of SnAgCu/Cu solder joints subjected to thermal cycling have been investigated.An equivalent IMC growth equation for thermal cycling and a heterogeneous model for solder joint interface were proposed,and the finite element(FEM) simulation was applied to analyze the stress/strain field distribution on solder joint interface as well as the failure mode of solder joints subjected to thermal cycling.The results show that the lower the cryogenic temperature limit of the thermal cycling,the lower the fatigue life of the solder joint.Failure mode of solder joints exhibits solder fatigue failure with failure site close to solder/IMC interface.The thicker the IMC layer,the more accumulated plastic work density in solder joint,as a result,the solder joint with a thicker IMC layer is more prone to failure.