Thermal interaction of semiconductor devices on copper-clad ceramic substrates

The temperature rise due to the spacing between two heat-dissipating devices mounted on metallized or copper-clad alumina and beryllia ceramic substrates is presented. The thickness of the copper layer, the thermal conductivity of the substrate material, and the thermal resistance of the heat sink system are considered. The results show that increasing the thickness of the copper layer requires that the devices be placed farther apart to prevent thermal interaction. An increase in the copper layer thickness can significantly decrease the device temperatures on alumina but may increase temperatures on high-thermal-conductivity substrates. The results also demonstrate that the external heat sink resistance has a significant impact on the heat flow paths and temperatures in the substrate