Thermal management coatings via combustion chemical vapor deposition (CCVD)

Abstract

Thermal management, especially for power systems, is a major issue for electronic packaging. It requires electrically insulating and thermally conductive materials with high breakdown strength and thermal conductivity. Conventional insulator materials for circuits such as epoxy, FR5, and gas, are poor thermal conductors. The alternatives, aluminum nitride, synthetic diamond and beryllia, are expensive, limited in size, and difficult to process. MCT, in conjunction with the U.S. Office of Naval Research and the University of Arkansas, is modifying its patented CCVD process to create an electrically insulating coating with relatively high thermal conductivity and breakdown voltage directly on to the base plate with no post deposition processing. The power and control circuit interconnects and components are to be applied directly onto the insulating layer. The preliminary results, measured on one-inch square coupons, are promising. The ceramic/polymer composite has excellent adhesion to polished Al-SiC substrate (>25 MPa), a breakdown voltage of higher than 1000 V, a leakage current less than 20 nA at 1000 V bias, and a substrate/coating thermal conductivity of 110 W/m K.