2019 Volume 65 Issue 4 Pages 67-72
The performance of an electronic product depends on how efficiently it can dissipate the heat of its parts. As a result, intensive ongoing research seeks to improve the thermal conductivity of polymeric materials. In this study we investigated alumina nanofibers as thermal conductive filler in resin and compare them to conventional spherical filler. Aligned α-alumina nanofiber mats were fabricated by electrospinning PVA and boehmite dispersion; they were then impregnated with resins to obtain a composite sheet. We assessed the thermal conductivities of the sheet. Resin sheets with alumina nanofiber content (33 vol.%) had high thermal conductivity (19.7 W/mK) in the direction parallel to the aligned alumina nanofibers. Conductivity increased in proportion to alumina nanofiber content. In addition, the alumina nanofiber composite sheet showed anisotropic thermal conductivity derived from the fiber direction, and had electrical insulating property (2.7×1013 Ω/□) and flexibility. This electrically insulating sheet with anisotropy in thermal conductivity would be useful in designing effective heat-removal paths in electronic devices.
