Assessment on Reliability of BGA Package Double-Sided Assembled

A series of accelerated temperature cycling tests (ATC) and finite element analysis (FEA) were carried out to investigate the impact of double-side BGA assembly configuration on the solder joint reliability. 1.0mm&1.27mm pitch, SnAgCu and SnPb solder ball, daisy chained BGA package mounted on a 1.6mm thick PCB by SnAgCu and SnPb paste respectively, which included three configurations such as double-side mirror assembly, double-side offset assembly and single-side assembly, were used for ATC test. In the case of current BGA package structure, test results showed that mirror assembly will reduce significantly solder joint fatigue life compared to single-sided assembly, offset assembly can improve slightly the reliability of solder joints because of only 0.5 pitch offset. Based on FEA, the effect of PCB thickness, solder alloy, substrate rigidity on reliability of solder joint was studied.