Enhanced heat dissipation in graphite-silver-polyimide structure for electronic cooling

Thermal dissipation has become a vital issue in electronic devices with highly miniaturization and integration. As a high thermal conduction material, graphite has been used widely in these devices. However, heat dissipation of graphite is limited by the poor thermal radiation in serving as a heat sink. In this work, we proposed a novel composite foil with a sandwich structure of graphite-silver-polyimide, exhibiting high thermal conductivity and excellent selective emission property, which is attractive for application in outdoor space. The heat dissipation performance of the foil was numerically and experimentally investigated. Our simulations confirmed that employing a selective thermal emitter in the sandwich structure prevented object surface from overheating under direct sunlight, augmenting the dissipated heat generated by heat source, reducing the local high temperature of surface. By the solar simulator and infrared camera, we experimentally demonstrated the numerical prediction that the heat dissipation ability of sandwich structure is much better than the graphite.