Abstract ▼ AI-Helper

High thermal conductivity films with electrically insulating properties have a great potential for the effective heat transfer as substrate and thermal interface materials in high density and high power electronic packages. There have been lots of studies to achieve high thermal conductivity composi...

High thermal conductivity films with electrically insulating properties have a great potential for the effective heat transfer as substrate and thermal interface materials in high density and high power electronic packages. There have been lots of studies to achieve high thermal conductivity composites using high thermal conductivity fillers such alumina, aluminum nitride, boron nitride, CNT and graphene, recently. Among them, hexa-boron nitride (h-BN) ceramics is a promising candidate for high thermal conductivity with electrically insulating filler materials. This work presents an enhanced heat transfer properties of ceramic/polymer nanocomposite films using h-BN nanosheets and polymer resins. The h-BN nanosheets were prepared by a mechanical exfoliation using organic media and subsequent ultrasonic treatment. High thermal conductivity over 2.8W/m?K in transverse and 10W/m?K in in-plane direction of the cast films were achieved for h-BN nanosheet/PVA composites that were prepared at 50?C. Further improvement of thermal conductivity up to 14W/m?K at in-plane mode was achieved by applying uniaxial compression at above the glass transition temperature of PVA to enhance the 3D interconnection between the h-BN particles. The thermal compression resulted in a positive effect on improving the thermal conductivity at the in-plane direction, however a reversal effect was observed at the transverse direction of the composite films. The evaluation method of the degree of h-BN alignment in the composite films by using a simple XRD measurement technique is firstly suggested.