Solder joint crack propagation in plastic and ceramic packaged diodes mounted on insulated metal substrate

The first objective of this paper is to identify some key design parameters for ceramic and plastic packaged diodes mounted on insulated metal substrate (IMS). The second objective is to predict their solder joint life. IMS is a metal substrate used to enhance heat dissipation in high power application. The key parameters analyzed are dielectric thickness, solder thickness and board material. Identifying the critical parameters is useful to increase the solder joint life especially for a ceramic package, which has a high CTE mismatch with the aluminum substrate. Experiments are conducted to study the crack growth rate and identify solder joint failure. Two models to predict the crack propagation in eutectic solder joint are considered, the Darveaux and the Energy Partitioning model.