Filler Particle Size Effect on Electrically and Thermally Properties of Thermal Conductive Thermoplastic Polyimide/Hexagonal Boron Nitride Composite Materials Fabricated by the Electrostatic Adsorption Method

Composite materials with high heat dissipation and acceptable insulating properties are being developed. Minimizing filler contacts in the composite and is crucial for composite insulating materials. Here, an electrostatic adsorption method was used to prepare thermoplastic polyimide (tpPI) / orientation micro‐sized hexagonal boron nitride (h‐BN) composite insulating materials. Then the effects of h‐BN particle size on the thermal conductivity and DC breakdown strength were investigated. Additionally, the finite element method was used for heat conduction analysis and the results were compared to the measurements. The particle size of the h‐BN significantly influences the dc breakdown strength and the thermal conductivity.