Vertically Aligned Boron Nitride Nanosheets Films for Superior Electronic Cooling

Thermally conductive and electricallyinsulating thermal interfacematerials (TIMs) are highly desired for electronic cooling. To improveheat transfer efficiency, thermally conductive fillers with a highloading content have been incorporated into the polymer-based TIMs.However, this is usually at the expense of the interfacial thermalresistance reduction and reliability. In this study, vertically alignedboron nitride nanosheet films (VBNFs) have been prepared by a scalablemicrofluidic spinning process and template-assisted chemical vapordeposition conversion method. A further high-temperature annealingwas applied to achieve high crystallinity. VBNFs have been appliedas fillers to fabricate TIMs and achieve a superior through-planethermal conductivity of 6.4 W m(-1) K-1 and low modulus of 2.2 MPa at low BN loading of 9.85 vol %, benefittingfrom the well-aligned vertical sheet structure and high crystallinity.In addition, the fabricated TIMs present high-volume resistivity andbreakdown strength, satisfying the electrical insulation demands.The high thermal conductivity and low modulus contribute an outstandingcooling performance to the TIMs in the heat dissipation applicationfor high-power LEDs. This template-assisted conversion technologyfor the fabrication of orientated BN nanosheets structure and theprepared high-performance TIMs pave the way for efficient thermalmanagement of high-power electronics.

Automated summary

Vertically aligned boron nitride nanosheet films (VBNFs) were prepared using a scalable microfluidic spinning process and template-assisted chemical vapor deposition conversion method. The VBNFs were then used as fillers to fabricate thermally conductive and electrically insulating thermal interface materials (TIMs). The TIMs exhibited superior thermal conductivity and low modulus at a low boron nitride loading, satisfying the heat dissipation requirements for high-power electronics.