Development of a high-performance heat dissipation sheet with three-dimensional alumina fibrous structure fabricated by freeze-drying

Heat dissipation ability plays a vital role in the performance of the electronic devices. In this study, the author tried to develop a high-performance heat dissipation sheet after preparing α-alumina nanofibers mat. Three-dimensional polyvinyl alcohol/boehmite precursor nanofibers were fabricated by freeze-drying machine followed by hot-pressing and heat treatment at various temperatures to produce α-alumina nanofibers mat. The aligned nanofibers mat were impregnated with polyurethane, which showed good thermal conductivity in the planar (7.9–14.4 W/mK) and thickness directions (5.1–15.6 W/mK) at 35–64 vol% α-alumina nanofibers content. The heat-dissipating sheet also showed superior electrical insulating property (2.2 × 1012 Ω/□). Hence, the author tried to develop a thermally conductive but electrically insulating heat spreader sheet so that electric devices can effectively eliminate generated heat from it.