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

The Electrostatic adsorption method can minimize filler contacts, which is an important problem for composite insulating materials. A thermoplastic polyimide (tpPI) / Orientation Micro Hexagonal Boron Nitride (h- BN) composite insulating material was produced by the electrostatic adsorption method. The thermal conductivity was measured. In addition, the heat conduction analysis is performed using the finite element method and their analyzed results of the thermal conductivity are compared with the thermal conductivity estimated from experimental results. When compared with the same aspect ratio, the measured thermal conductivity of CMP45 is higher than that of CMP12 in the high h-BN content region. Compared with the same particle size, the measured thermal conductivity of CMP12 is higher than that of CMP13 due to the thicker h- BN in the high h- BN content region. When the measured thermal conductivity is compared with the analyzed thermal conductivity, they are almost similar for the CMP13 sample. On the other hand, in the CMP45 sample, the slope of the analyzed thermal conductivity for the h-BN content is smaller than that of the measured thermal conductivity due to the orientation, the contact, and the percolation of the heat flow. From these results, it is cleared that the size of the h-BN influences to the thermal conductivity significantly.