The Reliability of Complex Printed Circuit Board Assembly under Thermal Cycling, Random Vibration, Electromigration and Combined Loads

The solder joints of military PCBA (Printed Circuit Board Assembly) suffer harsh environmental conditions, such as temperature cycling, great random vibration, and electromigration. In this study, the reliability of solder joints in military PCBA under single loading (including electromigration, temperature cycling, and random vibration) and combined loads has been studied by finite element simulation and experimental tests. The failure time under different loads have been calculated and compared, respectively. The failure positions have been analyzed and discussed. The results of simulation and test showed that the failure time of solder joints under comprehensive environment was much shorter than that under single loading. The failure position was located at the interface between the solder joint and the pad. In most cases, the location of the failed solder joints was at the corner of the device. A series of models such as the atomic flux divergence model were used to calculate the failure time under single loading (electromigration, thermal cycling, and random vibration) and combined loads. The life testing was carried out according to the relevant standards, and the fatigue test life was obtained. The effectiveness of the simulation life was verified.