Guidelines for thermal management of multichip modules

Thermal issues affecting MCM (multichip module) performance are addressed. The empirical data collected using a test chip, in accordance with SEMI-Standard measurement guidelines, are compared with the numerical values obtained using the finite element analysis software HYBRID THERMAL. Emphasis is placed in a low-cost MCM utilizing PCB (printed circuit board) and ceramic substrates where thermal management is most critical. Among the factors discussed are Si chip size, the distance of the chips from each other, heat spreading resistance throughout the package, substrate material, and thermal vias. The results obtained provide baseline guidelines which are valuable for small systems where low cost is key and thermal management options are limited. They are also useful for high-performance MCM applications, such as silicon-based substrates for high end application