Parameter identification for interface delamination processes in molded electronic packages

The goal of the documented analysis is the buildup of an appropriate mechanical model and the parameter identification for the shear button test. The test has been performed at different hammer positions in order to identify the shear and tensile strength parameter of the interface between mold compound and copper substrate. The parameter identification process contains a sensitivity analysis and fit-optimization which was carried out with optiSLang. To simulate the crack behavior of the interface and the mold compound the material library multiPlas is applied that uses multi-surface plasticity models at continuum element level. Finally a parameter set has been identified that allows for the fitting of all test shear forces. In addition to the interface and crack properties the contact modeling at the hammer tip has been found as a key factor for a successful identification of the model parameter. Other than expected this is especially true for the high hammer positions and can be explained by a local stress resp. a local contact problem. Here also the strength properties of the mold compound play an important role.