| dc.description.abstract | In recent years, due to the rapid development of technology, the demand for power devices has increased significantly. However, the materials currently available for high-temperature electronic packaging are quite limited. Among them, Cu nanoparticle (NP) paste has emerged as a promising packaging material owing to its excellent thermal and electrical conductivity, high electromigration and electrochemical migration, and its ability to prevent the formation of intermetallic compounds (IMCs) with the bonded copper wires. Therefore, enhancing the reliability of Cu sintering joints has become a crucial issue. Literature indicates that various factors such as the sintering atmosphere, particle geometry, and the microstructure of the substrate can all influence the joint strength. NPs have high surface energy, making them tend to aggregation and sintering, while the substrates they bond with are bulk materials with more stable properties. Improving the level of sintering between particles and the substrate would significantly contribute to the development of joint reliability.
This study aims to investigate the influence of residual stress in Cu substrates on joint strength and to provide a fundamental understanding from the perspective of atomic diffusion dynamics for future theoretical research. By annealing the substrate for different durations, the residual stress can be effectively adjusted. Through shear tests and numerical analysis, a correlation between the level of stress and joint strength is found. The results show that longer annealing time reduce residual stress, which in turn lowers the joint strength. Additionally, this study proposes a detailed mechanism for explaining how residual stress affects atomic diffusion behavior during the sintering process. Through an in-depth discussion of material, the findings of this research are significant and further advance the field of electronic packaging. | en_US |