Thermal Simulation into the Effect of Varying Encapsulant Media on Wire Bond Stress Under Temperature Cycling

Mechanical failures of wedge bonded aluminium wire interconnects are identified as a failure mode in power electronics modules and these wirebonds are often encapsulated in a variety of insulating media to improve electrical isolation and lifetime. Thermal/mechanical simulations have identified the effects of these encapsulating media on the stress induced during thermal load application and have shown that the choice of encapsulating media, as well as method of application, greatly affect the stress induced under thermal load.