Validation study of compact thermal resistance models of IC packages

Accurate estimation of the operating temperature of a semiconductor IC device encapsulated within an electronic package is necessary to ensure reliable performance over the life of the product. The common lumped constant Theata JA (φja) characterized in laboratory setups, was found to be too dependent on mounting and environmental conditions to be effective in practical system applications. Two improved compact models of electronic package thermal characteristics, the Bar-Cohen and Lasance, were analyzed for accuracy in particular situations. A further refinement of the Bar-Cohen and Lasance compact models proposed in this paper was found to be more robust and valid in complicated system applications. The less used but effective lumped constant, Theata JL (φjl), which describes the junction to package lead relationship, was also studied. It was found to be useful for quick determination of junction temperature in equilibrium system mounted operating condition. Also covered in this work is a discussion from the theoretical network point of view as well as suggestions of modeling methodologies for board mounted plastic packages