Aging effect on defect evolution and shear strength of nano-silver solder joint

This paper focus on investigating the aging effect on defect evolution and shear strength of nano-silver solder joint. The thermal aging experiments and uniaxial shear experiments were conducted on 7 groups of articulated sintered nano-silver shear specimens. The test conditions were: a) aging temperature is room temperature, 50°C, 150°C, and 275°C respectively, and aged for 24h; b) aging temperature is 275°C for 24h, 48h, 72h, and 96h, respectively. As the increase of aging temperature and time, the mean shear strength decreases gradually, and the fracture form converts from the nano-silver interlayer fracture to the copper substrate-nano-silver layer interface fracture. In this paper, the corresponding fracture section and evolution of different defects were analyzed. Furthermore, the extended Weibull model, which considers the aging effect on failure of joint, was proposed to analyze the mean shear strength.