Evaluation of structural design methodologies for predicting mechanical reliability of solder joint of BGA and TSSOP under launch random vibration excitation

The fatigue damage that accumulates on a solder joint under a launch vibration environment is a major cause of failure in spaceborne electronics. Thus, predicting the mechanical safety of the solder joint in the structural design phase is important to guarantee a successful space mission. This paper proposes a mechanical design methodology to predict and ensure more reliable mechanical safety of the solder joints of a plastic ball grid array (PBGA) and a thin-shrink small outline package (TSSOP) under launch random vibration excitation. Random vibration fatigue tests for a sample printed circuit board (PCB) assembly were performed to assess the fatigue life of BGA and TSSOP solder joints. The effectiveness of the proposed structural design methodologies was evaluated by comparing the margin of safety calculated from various analysis approaches and the random vibration fatigue test results of the PCB specimen.