Thermal cycling solder joint reliability reduction due to PCB bending introduced during product assembly

BGA board level solder joint reliability in thermal cycling is investigated after application of strain controlled PCB bending, which reflects frequent mode of deformation and is regarded as example of PCB permanent strain after assembly. It was shown that local maximal principal strain on PCB can reach several hundred micro strains without significant damage introduced to the solder joints at room temperature as compared to damage generated during subsequent thermal cycling.