Evolution of High-Temperature and Low-Temperature High Strain Rate Properties for QSAC10 and QSAC20

Abstract

In oil exploration industries, military, automotive, avionics and space applications, electronic parts may be subjected to high loads during shock, vibration and drop-out conditions. These electronic parts can be subjected to strain rate of 1 to 100 per sec during those events as well as experiencing extreme high and low temperatures ranging from -65°C to 200°C. That is why a design optimization on electronic packaging at extreme temperature is necessary and for that studies on high strain rate at extreme temperatures are crucial. Data on the mechanical properties of lead-free solder alloys used for interconnection in electronic packaging at high strain rates is very relevant because SAC solders have shown degradation of mechanical properties at prolonged exposure to storage temperature. Industries have come up with a solution to reduce the degradation by using dopants in SAC solder. It has become imperative to know the material properties with respect to other materials in order to find a suitable material with less aging degradation. QSAC10 and QSAC20 are two such doped solders used for low package structural strength applications. There are no data available for the solder alloys QSAC10 and QSAC20 with extreme low to high operating temperatures. In this study, two doped QSAC solder called QSAC10 and QSAC20 have been subjected to high strain rate testing. Samples with no aging have been subjected to uniaxial tensile tests to measure the mechanical properties of QSAC10 AND QSAC20 for High and Low operating temperature ranging from -65°C to 200°C. The material data has been used to compute the constants for the Anand Visco-Plasticity model. The ability of the model to represent the material constitutive behavior has been quantified by comparing the model predictions of the uniaxial tensile test with the experimental data.