Stress analyses in HPC-soldered assemblies by optical measurement and FEA

During the course of the publicly funded project ""HotPowCon"" (HPC) a two-phase transient liquid phase soldering technology had been developed [1], with the advantage of processing conditions being close to those for conventional soldering. Further developments of this HPC solder material have been made resulting in a stable process with increased quality of the interconnection layer, i.e. better homogeneity and less voiding. The mechanical properties of the multi-phase materials are different from traditional soft solders and depend strongly on the process, in particular the phase proportions. Materials with different proportions were produced and their properties were studied both experimentally and by FE-simulations. A parametric 3x3 particles model was used for the latter. Measurements on the thermo-mechanical deformation behavior were made by a grey scale correlation method, which is behind the microDAC ® system applied. Good agreement was achieved, which allows future HPC solder properties prediction and design.