Thermal modeling and performance of high heat flux SOP packages

This paper explores the thermal challenges in advanced system-on-package (SOP) electronic structures, as well as candidate thermal solutions for these highly demanding cooling needs. The heat fluxes on the active surfaces are expected to approach 100 W/cm². The impact of this high flux is exacerbated by the relatively low thermal conductivity of the organic materials in SOP packaging. Detailed three-dimensional (3-D) finite element simulations were used to study the temperature distributions in a typical SOP package, and to provide guidance for the development and implementation of "compact thermal models". These models were used to evaluate and compare the performance of various thermal technologies and to establish the most promising thermal management alternatives. The use of direct liquid cooling, by immersion of the components in inert, nontoxic, high dielectric strength perfluorocarbon liquids was seen to provide effective cooling over a range of anticipated SOP power dissipations.