Thermal Design of Power Semiconductor Modules for Mobile Communication Systems

TL;DR

This paper analyzes the thermal performance of power semiconductor modules with HBTs for mobile communication, using FEM to evaluate how design parameters affect thermal resistance.

Contribution

It introduces a finite element method-based analysis of thermal resistance in HBT modules, identifying key design parameters influencing thermal performance.

Findings

GaAs substrate thickness significantly affects thermal resistance

Multi-layer PCB thickness impacts heat dissipation

Thermal via alignment influences overall thermal performance

Abstract

We will describe the thermal performance of power semiconductor module, which consists of hetero-junction bipolar transistors (HBTs), for mobile communication systems. We calculate the thermal resistance between the HBT fingers and the bottom surface of a multi-layer printed circuit board (PCB) using a finite element method (FEM). We applied a steady state analysis to evaluate the influence of design parameters on thermal resistance of the module. We found that the thickness of GaAs substrate, the thickness of multi-layer circuit board, the thermal conductivity of bonding material under GaAs substrate, and misalignment of thermal vias between each layer of PCB are the dominant parameter in thermal resistance of the module.