A Dynamic Bending Method for PoP Package Board Level Reliability Validation

In the study, a proprietary strain-controllable dynamic bending method was adopted to verify the memory package effects on the solder joint reliability in the PoP package, instead of electrical resistance monitoring in the JESD22-B111 using mechanical shock testing of package on board at a single shock pulse for handheld electronic device dropping simulation. Two test vehicles were designed for comparison. One is flip chip BGA as bottom package with memory package stacked on the top, another one is same flip chip BGA package. The PoP package with SnAgCu based interconnection on the bottom and top package underperformed same bottom flip chip BGA package in terms of solder joint life between package and PCB in the dynamic bending test, which illustrated the top memory package will affect adversely the solder joint reliability of bottom package.