No abstract

In a previous publication [l], a finite element study was presented on the thermal performance of several substrate materials in a simple package application. Materials examined were aluminum nitride, alumina, epoxy-glass, refractory-glass, and a composite consisting of alumina fibers in a polyimide matrix. Three cooling approaches were addressed: natural convection, forced convection, and a heat sink placed o n the substrate face opposite the chip.In this recent work, we describe experiments to confirm these model predictions. Actual packages were prepared, closely resembling those addressed in the previous model study. "Thermal TestChips" were used to make the measurements. These chips are designed for this purpose, containing both resistive heating elements and temperature sensing elements. The test packages of each material were successively placed in natural convection, forced convection, and heat sink environments, and their respective performances were monitored. The results closely support the conclusions of the earlier model study, although numeric differences were noted.