Study on the Interfacial Residual Stress of Flip-Chip Joints Based on Anisotropic Conductive Adhesive

Interfacial residual stress resulting from coefficient of thermal expansion mismatch between different layers of the flip-chip joint is induced during the bonding process. The flip-chip joints suffer residual stresses that may cause cracking or delamination, which is one of the major reliability issues in electronic packaging. This paper theoretically analyzes the interfacial residual stress of the flip-chip joint based on anisotropic conductive adhesive (ACA). The residual stress model is established based on refined zigzag theory (RZT). Results show that the theoretical model and the simulation analysis are consistent. It is found that the interfacial thermal residual stress in the ACA layer is uneven and reaches its peak at the end of the bump. The RZT model is validated by experiments, and the model prediction agrees well with the test results.