Improving the heat conduction and mechanical properties of thermal interface materials by constructing diphase continuous structure reinforced by liquid metal

Based on the existence of self-gap and bridging effect during powder compaction, chromium-coated diamond particles and gallium-based liquid metal are selected to prepare an inter-connective porous structure, and then polydimethylsiloxane is filled into this porous medium by vacuum infiltration to fabricate co-continuous thermal pads. The results show that the reinforcing phase of diamond particles bridged by liquid metal is responsible for ensuring heat-transfer performance, while the polymer matrix imparts a certain degree of softness, elasticity, and strength. The thermal conductivity of composites with great conformability can go as high as 29 W/(m·K). Furthermore, once thermal pads are applied on substrates under pressure, a small amount of liquid metal will seep out from the composite surfaces, which is beneficial to obtaining a low interface thermal resistance. This work provides a novel approach for fabricating high-performance composites which may further advance their applications in thermal management of electronic industry.