Further Enhancement of Thermal Conductivity through Optimal Uses of h-BN Fillers in Polymer-Based Thermal Interface Material for Power Electronics

Due to the demand of miniaturization and increasing functionality in power electronics, thermal dissipation becomes a challenging problem for thermal management and reliability. To enable effective heat transfer across the interconnect interfaces, thermal interface materials (TIMs) are required. Electrically insulating TIMs are primarily polymer-based composites which use conductive fillers to enhance thermal conductivity (TC). In this study, the optimal hybrid filler constituents, achieved through mixing spherical and platelet h-BN particles with different ratios, in polymer-based TIM was predicted using finite element (FE) simulations. The underpinning mechanisms of the variation in TC of the TIMs were analyzed from the temperature distribution patterns and micro heat flux paths. Results showed that with the same total volume fraction of h-BN, mixed spherical and platelet h-BN fillers of a certain ratio can further improve the thermal properties of the TIMs compared with those with spherical or platelet h-BN particles alone.