Thermal analysis of multi-finger GaInP collector-up heterojunction bipolar transistors with miniature heat-dissipation packaging structures

We build up a finite element modeling (FEM) approach to analyze the thermal performance of collector-up (C-up) heterojunction bipolar transistor (HBTs) with a heat-dissipation via configuration. Highly compact heat-dissipation packaging structures of GaInP/GaAs C-up HBTs have been designed and evaluated systematically. In this work, we devise the 2-D and 3-D models to simulate the actual devices and to investigate the temperature distribution behavior. Results from 2-D model indicate that the large heat-dissipation via configuration can be further reduced by 29% to meet the requirement of HBT-based small high-power amplifiers (HPAs) for the cellular phones. Further-more, the demonstrated results show that the maximum temperature within the collector calculated from 3-D model is lower than that from 2-D model. In the 3-D analysis, it is revealed that the configuration can be reduced by 32%. Therefore, thinning the heat-dissipation via constructed underneath the GaInP/GaAs C-up HBT should be helpful for miniaturization of HBT-based HPAs in future mobile communication systems. Copyright (C) 2009 John Wiley & Sons, Ltd.