Thermal performance analysis for packaging configuration design of multifinger GaInP collector-up HBTs as small high-power amplifiers

A finite-element modeling (FEM) methodology was utilized to investigate the thermal performance of GaInP collector-up heterojunction bipolar transistors (C-up HBTs) with thermal-via packaging configurations. The thermal interaction between HBT fingers was examined based on the temperature distribution phenomena in multifinger C-up HBTs. The results obtained from the C-up HBT with a three-finger structure indicate that the thickness of thermal-via configuration can be further reduced by 33% without deteriorating the thermal performance. Thinning of the thermal-via packaging design is an effective approach for miniaturization of C-up HBTs as high-power amplifiers in cellular-phone communication systems.