A Review of Dielectric Polymer Composites With High Thermal Conductivity

The dielectric polymer composites with high thermal conductivity are making inroads into electronic industry. The effective thermal conductivity of a composite composed of particles of one material embedded in a polymer matrix is a function of the thermal conductivity of the constituents, the particle loading level, the particle shape and size, the particle dispersion, and the thermal interfacial resistance. Boron nitride (BN) is suitable as filler for highly conductive composites. Silicon nitride (Si3N4) has a low coefficient of thermal expansion and a low dielectric constant. Silicon carbide (SiC) has high thermal conductivity and high temperature stability, making it attractive for high-thermal-conductivity composites. Fillers with high aspect ratio, such as whiskers and platelets, can form more continuous thermally conductive pathways in the polymer matrix and thus are more effective in enhancing the thermal transfer.