Joint failure prediction of BGAs via failure force mapping

Single solder interconnects were subjected to a series of combined tension-shear and compression-shear tests to determine their failure load. The failure map of the interconnects were obtained by plotting the normal component against the shear component of the failure load. The interconnect failure force map was found to follow an elliptical surface typical of many material failure criteria which can be similarly described by a simple mathematical expression. Computational simulations of actual board tests show that the failure map gives good predictions of interconnect failure and hence suggest that such failure maps are useful in the analyses of the mechanical reliability of board assemblies.