Thermal Management for Boron Nitride Filled Metal Core Printed Circuit Board

Abstract

This study aims at investigating novel thermal material based on filled epoxy for metal-core printed circuit boards (PCBs). The next generation PCB materials are expected to possess high heat dissipation capability in addition to low coefficient of thermal expansion (CTE) as the accumulated heat from high performance electronic devices should be removed for proper operation. In this study, boron nitride (BN) filler with different size (from micro to nano size) and content were employed to prepare thermally conductive polymer composites. Various percentage of coupling agent was used for the surface treatment of fillers in order to produce homogenous composites with lower CTE. The effect of filler and coupling agent to thermal conductivity of composite are discussed. It indicated that the experimental results fit well with the Bruggeman model with variety filler size. The use of 1% of couple agent was found to be more effective in increasing thermal conductivity of the composite. Despite the maximum content of the BN allowed to be added into the epoxy is about 30% due to the comparatively high viscosity of the varnish, as low as 13% of the micron-sized BN-filled dielectric is enough to fulfil the requirement of thermal conductivity larger than 1 W/m K and balance other critical properties used for PCB application. It is feasible to be a cost-effective advanced thermal material.