PROJECT TITLE :

Compact Thermal Resistor-Capacitor-Network Approach to Predicting Transient Junction Temperatures of a Power Amplifier Module

ABSTRACT:

Junction temperature is an important issue for a semiconductor package, influencing the package's thermal, mechanical, and reliability performance. An correct prediction of junction temperature provides informative steering in style, development and operation of the package. A compact thermal resistor-capacitor (RC) network approach is presented during this paper to accurately predict transient junction temperatures. The thermal RC network in this approach could be a nongrounded Foster network. This approach consists of extraction of the thermal Foster network and prediction of the transient junction temperature response to a given power input using the extracted network. The network extraction part is based on Kirchhoff's current law and Laplace transformation technique, and uses the Foster network to facilitate changes of the RC network structure. The temperature prediction part could be a direct substitution-and-calculation process, and therefore is quick to hold out. Since Laplace transforms are directly or indirectly obtainable for many power inputs, their transient temperatures might be predicted by the proposed approach. Superposition is utilized in cases where the Laplace rework of a given power input isn't directly found in Laplace tables, or where the junction temperature is suffering from multiple heat sources. The proposed approach is demonstrated with a power amplifier (PA) module; predicted junction temperatures are correct in both single and multiple heat supply cases.