Advances in passive PCB thermal control

In this paper, the author discusses the use of carbon composites, metal carbon composites and two types of carbon Nanopapers in Printed Circuit boards as a thermal control method. The emphasis is on directly mounting active power components on the thermal control layer to minimize cost and assembly complexity. Metal carbon composites, Bucky paper and Long Wall Carbon nanomaterials were acquired from commercial vendors and processed through a commercial PCB facility. A number of issues were confronted and solved to make these materials compatible with PCB fabrication, and all are now potentially available for use in military or commercial systems. The resultant PCB´s were then thermally tested and modeled to give in-situ thermal performance. Measured and predicted thermal conductivity for commercial products was excellent, giving confidence that the measured number for the carbon material is accurate. Given that carbon papers have not been optimized for thermal conductivity, there exists a significant potential for even better performance in the near future.