Characterization methods for metallic wires in electronic packages

摘要

The precise experimental determination of material properties is a prerequisite for FEM simulations estimating the reliability of electronic packages. Thereby, thin metallic wires are a major concern, because they often represent the weakest link of electronic devices. Therefore, we have performed tensile tests with copper wires with diameter of 25 μm. The microstructure of the wires was determined by EBSD. In order to mimic the effect of grain growth caused by thermosonic bonding, some wires were exposed to heat treatment. In conclusion, material models for FEM simulations were developed. The first model was defined in the framework of multi-linear kinematic hardening using the commercial software ANSYS. The second model is a crystal plasticity model implemented through user subroutine UMAT in the FEM code ABAQUS.