A thermal evaluation of multichip module (MCM) materials and designs

The authors discuss the thermal performance of multichip module (MCM) materials and designs. Particular emphasis is placed on the effects of polyimide lamination and various substrate materials. Because of the thermal characteristics of these new materials and designs selected in MCMs, a thermal study was performed comparing various assembly techniques and substrate materials available. Initial modeling was done comparing the heat removed from an MCM die by conduction, convection, and radiation. Wire bond, tape automated bonding, and flip-chip attachment were compared. Subsequent modeling was performed to more accurately predict heat removed by conduction. Test circuits were built to evaluate the thermal performance of alternate substrate materials and to verify the accuracy of previous conduction models