Materials Science Forum, Vol.486-487, 269-272, 2005
Optimum shear height for evaluation of Pb-free solder ball shear strength
Ball shear test was investigated in terms of the effects of important test parameter, i.e., shear height, with an experimental and non-linear finite element analysis for evaluating the solder joint integrity of area array packages. The substrate was a common SMD type with solder bond pad openings of 460 mu m in diameter. It was observed that increasing the shear height, at a fixed shear speed, has the effect of decreasing the shear force. The high shear height could cause some bad effects on the test results such as unexpected high standard deviation values or shear tip sliding from the solder ball surface. The low shear height conditions were favorable for screening the type of brittle interfacial fractures or the degraded layers in the interfaces.