Thermal Management Performance of Epoxy Composites with Boron Nitride and Boron Phosphide Hybrid Fillers

Thermal interface materials with high thermal conductivity are the best choice to solve the current overheating problem of electronic devices, and the choice of thermal conductive filler is a key factor affecting the performance of thermal interface composites. Hexagonal boron nitride sheet is considered to be ideal thermal conductive filler, but the thermal conductive effect of single filler is still insufficient to meet actual needs. Here, a new type of hybrid filler mixed with boron nitride sheet and boron phosphide particles is used to prepare epoxy based composites. When the filler volume fraction is 40%, the thermal conductivity of composites reaches 3.18 W m⁻¹ K⁻¹. Under the same content, the thermal conductivity of the composites with mixed fillers outperforms those with boron nitride sheet alone. At the same time, the composite material shows high breakdown strength of 46 kV mm⁻¹. This work provides a new way to prepare thermal interface materials with high thermal conductivity for modern electronic packaging. Graphical Abstract: [Figure not available: see fulltext.].