Determination of Temperature Dependent Young's Modulus of Sintered Silver (SAG) by Vibration Tests

New generations of power modules incorporating wide bandgap semiconductor materials like silicon carbide (SiC) feature higher operating temperatures and require new packaging technologies, ready to handle the heavy duty conditions. To withstand the stress resulting from the large temperature cycles as well as the overall miniaturization, sintered materials like nowadays sintered silver (SAG) or the upcoming sintered copper (SCU) will be used to replace soldered die attaches and Al wire bonds. However, detailed knowledge of the mechanical behavior of such porous materials is necessary to master the sinter processes and to develop final pastes. The severe process influence on the formation of the interfaces, the pore and grain sizes, and sinter homogeneity could cause reliability problems otherwise. The Young's modulus is hereby the most important mechanical parameter. Often neglected, it is nonetheless the key to calculate the plastic strain out of stress-strain curves in physics of failure (PoF) bases approaches, since it separates plasticity from the elastic strain components. However, the measurement of it in common tensile tests is quite a challenge for thin sintered metal foils. In this paper, we show the weakness of the usage of tensile tests for sintered metals and introduce a suitable, versatile characterization method to determine the temperature-dependent Young's modulus in form of vibration tests as alternative.