Hexagonal boron nitride (h-BN) is proven to be one of the most attractive fillers for improving thermal conductivity while maintaining the electrical insulation of polymeric thermal interface materials (TIM) used in electronic devices. The crystal structures and properties of h-BN and its agglomerate are introduced in this presentation. The impact of compounding conditions on the morphology of agglomerate BN, which is critical to final composite thermal performance, is discussed herein. It is demonstrated that the final thermal conductivity of polymer composites filled with the same percentage of agglomerate BN could have as much as 4x difference in thermal conductivity depending on compounding conditions.
Thermal pyrolytic graphite (TPG), which has similar crystal structures to h-BN composed of highly oriented stacked planes, is thermally and electrically conductive. It typically exhibits excellent in-plane thermal conductivity (>1500 W/mK), which is about 4x the thermal conductivity (TC) of copper. Metal-encapsulated TPG can achieve high thermal conductivity from the TPG core and good mechanical strength from the metal shell simultaneously. The benefits of integrating TPG material into automotive LED headlight were investigated in this presentation. It was demonstrated that 2x of the power can be loaded to the LED by replacing the aluminum heat sink fins and base with the ones made of TPG.
In this presentation, the methods and benefits of using these two materials for making TIM, heat sink fins and heat spreader, etc. inside electronic device, are discussed.