The numerical simulation and reliability analysis of through-hole solder joints

In this paper, numerical simulation was performed on the through-hole solder joints of a LED driver, and reliability analysis was carried out. Taking the simulation speed and time into account, firstly the thermal field of the LED driver was simulated, which was then verified by infrared thermograph. Then the thermal-stress simulation was conducted on the solder joints which were of the highest temperature. The results demonstrated that the failure of through-hole solder joints mainly occurred in the interface between solder and substrate, which is the crack initiation zone. Analyzing the stress and strain of solder joints under temperature cycling, this paper used the modified Coffin-Manson formula to predict the life expectancy, and provided an assessment methodology of reliability analysis for through-hole solder joints.