Optimal design of reliability and signal integrity for embedded micro-scale BGA solder joint

A finite element analysis model of ball grid array(BGA) solder joints and a three-dimensional electromagnetic simulation model were established, respectively. The radial dimension, the height and the pad diameter of the solder joint were selected as design variables. The thermal fatigue life and the return loss of the solder joint were selected as the target. The multi-objective optimization design of BGA solder joints was carried out by the combination of experiments and grey correlation analysis. The signal integrity optimization results were verified by experiment. The results show that: after optimization the maximum equivalent stress of solder joints was decreased by 8.2%. The return loss decreased by 11.8% and fatigue life increased 2.15 times. The signal integrity experiment verified the effectiveness of the optimization results.