The flexible film of SCF/BN/PDMS composites with high thermal conductivity and electrical insulation

Abstract The flexible heat dissipation material with high thermal conductivity and electrical insulation is ideal for highly integrated flexible electronic devices. In this study, the flexible polymer composite films were prepared by spin coating process, the thermal conductivity and electrical insulation of the composite film are significantly enhanced by adding short carbon fibers (SCF) and boron nitride (BN) particles to PDMS matrix. SCF and BN particles construct an effective thermal conduction path in the PDMS matrix, while highly insulating BN particles inhibit the formation of conductive paths. The thermal conductivity of 15%SCF/20%BN/PDMS film achieved 2.29 W/m·K when 15 wt% SCF and 20 wt% BN were loaded, which was 990% enhancement compared to pure PDMS. And its volume electrical resistivity and breakdown strength reached 2.11 × 1014 Ω·cm and 12.5 KV/mm respectively, showing excellent electrical insulation property.