Title :
Thermal characterization of power amplifiers for CDMA cellular phone applications
Author_Institution :
Semicond. Co., Toshiba Corp., Kawasaki, Japan
Abstract :
Thermal characterization of InGaP/GaAs HBT power amplifiers for CDMA cellular phone handsets has been demonstrated on the basis of DC measurements of the HBTs and 3D finite element modeling, which made the treatment of non-uniform heat flow in this problem possible. Evaluation of conductive adhesives in the actual power amplifier environment has also been carried out. The finite element modeling including thermal contact resistance was applied to the HBTs with various numbers of emitter fingers and good agreement with measurements was obtained. For an adhesive with a high thermal conductance, it was found that 1/3 of the total thermal resistance of the power amplifier was attributable to the contact thermal resistance around GaAs/adhesive/heat sink bond line and that the bulk thermal contribution was negligible.
Keywords :
adhesives; bipolar transistor circuits; cellular radio; code division multiple access; conducting materials; finite element analysis; gallium arsenide; gallium compounds; heat transfer; heterojunction bipolar transistors; indium compounds; power amplifiers; thermal resistance; 3D finite element modeling; CDMA cellular phone; InGaP-GaAs; conductive adhesives; contact thermal resistance; emitter fingers; indium gallium phosphide/gallium arsenide HBT; nonuniform heat flow; power amplifier thermal characterization; thermal conductance; thermal contact resistance; Cellular phones; Contact resistance; Electrical resistance measurement; Finite element methods; Gallium arsenide; Heterojunction bipolar transistors; Multiaccess communication; Power amplifiers; Thermal conductivity; Thermal resistance;
Conference_Titel :
Semiconductor Thermal Measurement and Management Symposium, 2005 IEEE Twenty First Annual IEEE
Print_ISBN :
0-7803-8985-9
DOI :
10.1109/STHERM.2005.1412179
