Locally reinforced polymer-based composites for efficient heat dissipation of local heat source

Local heat source in electronic device is likely to produce hot spot which can degrade the reliability and performance of the device. Various materials have been attempted to enhance the heat dissipation of local heat source. Many theoretical studies have demonstrated that the heterogeneous composite materials with fillers concentrated at the preferential paths of heat flux are effective in cooling the local heat source. However, this unique control of microstructure and property for polymer-based composites has less been achieved in practice due to the technical difficulties in controlling the fillers positions. In this paper, a locally reinforced heterogeneous composite with conductive particles concentrated at the preferential path of heat flux was fabricated to cool the local heat source. The local reinforcement was achieved by using magnetically responsive particles as reinforcing elements and a specific magnetic field to organize the elements into the predefined structure. To evaluate the thermal performance of the proposed material, we performed the comparative thermal tests. The results show that compared to the homogeneous composites, the present composites with local reinforcement can significantly enhance the heat dissipation of local heat source. When heat flux is 5840 W m−2, the locally reinforced composites with a fillers volume fraction of 5% reduced the average and maximum temperature of heater 7.7 °C and 8.7 °C, respectively.