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

Abstract

Abstract: 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.

Key words: welded joint, intermetallic compound (IMC), diffusion-induced stress, finite element method

CLC Number:

TG454

LIU Wen-bin, LI Hong-ping, ZHANG Xu-dong, SUN Xue-min, REN Jun-qiang. Influence of the morphology of intermetallic compound layer in the soldering joint on diffusion concentration and stress[J]. Journal of Lanzhou University of Technology, 2022, 48(1): 14-19.

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