Design of Experiment Based Evaluation of the Thermal Performance of a Flipchip Electronic Assembly

Abstract

A finite element method based design of experiment (DOE) study was conducted to evaluate the thermal performance of an automotive electronic assembly. The assembly design consists of a flipchip IC mounted on a thin FR-4 PCB bonded to an aluminum backplate. The study captures the influence of the number of thermal vias present in the substrate, the thermal conductivity and thickness of the epoxy layer between the substrate and the backplate, the IC active area, thermal conductivity of the underfill marterial and the power dissipation of the IC, on the thermal performance of the assembly. Single factor analysis of various design parameters indicates that the thermal conductivity and thickness of the epoxy layer are the most critical parameters of the design from a thermal performance viewpoint.