钎焊接头金属间化合物层形貌对扩散浓度和应力的影响

结合实验结果,建立了芯片封装技术中焊点金属间化合物(IMC)界面模型,采用有限元方法计算了模型中Sn钎料与Cu焊盘形成IMC层时Cu原子的扩散过程以及扩散应力大小与分布.结果表明:IMC层与钎料的界面形貌可显著影响Cu原子扩散浓度及应力行为.凹凸界面形貌会严重阻碍Cu原子的扩散,且靠近界面影响更为显著;扇贝形界面模型比...

Influence of the morphology of intermetallic compound layer in the soldering joint on diffusion concentration and stress

Combining the experimental results, the intermetallic compound (IMC) interface model of welded joint in chip packaging technology was established. The diffusion process of Cu atoms during the formation of IMC layer between Sn solder and Cu substrate was calculated by finite element method, including the diffusion-induced stress and stress distribution. The results show that the interface morphology of IMC layer can significantly affect the behavior of Cu atoms diffusion and diffusion-induced stress. The concave-convex morphology of interface seriously obstructs the diffusion of Cu atoms, and the effect is more significant near the interface. The scallop morphology interface reaches diffusion stabilization faster than the flat morphology interface. The Cu atom concentration in the scallop interface is smaller than that in the flat interface, which makes the diffusion stress-affected region in the scallop interface smaller than that in the flat interface model.