Heat transfer and thermal stress analysis in the new generation quasi-monolithic integration technology (QMIT)

Static heat transfer and thermal stress analysis for the new generation quasi-monolithic integration technology (QMIT) have been performed using a three-dimensional finite element simulator. To confirm the simulation results, white-light interferometry measurement along with a Peltier element and a Pt-temperature sensor have been used. It has been shown that thermal resistances of 11°C/W and 8.5°C/W are possible using 200 μm electroplated gold heat-spreader and diamond-filled polyimide on the backside of the active device, respectively. This promises successful realization of the high frequency circuits containing power active devices using the novel QMIT. Simulation and measurement results demonstrate a great decrease of thermal stress in the new generation QMIT in comparison to the earlier concept which extremely improves life-time of the packaging. A remarkable agreement between calculated and measured results was found.