Experimental characterization of thermo-mechanical properties of lead-based solders for power electronics packaging reliability applications

This paper deals with the thermo-mechanical properties experimental characterization of solder alloys used in power electronics packaging, and especially for TRIAC. The lead-based solder - Pb_92.5Sn_5.0Ag_2.5 - is evaluated. The Young´s modulus, the yield strength, the mechanical strength, and the elongation at break are measured from 25degC up to 150degC. Additional creep measurements are performed to explain the differences between static and dynamic measurements at high temperatures. Finally, fatigue tests are presented. The fatigue lifetime could be correlated with some power cycling reliability test results. All these data could be implemented into some thermo-mechanical simulations using finite elements to predict TRIAC lifetime in real applications.