Sandwich-Structured Thermal Interface Materials with High Thermal Conductivity

As modern electronics advance toward miniaturization and integration, there is an increased demand for effective thermal management solutions. One of the most promising strategies to achieve this is to enhance the thermal transport capacity of thermal interface materials (TIMs) by incorporating fillers. In this study, carbon fiber was used as the framework, and a simple shear stress-oriented approach was employed to orient graphene flatly onto the carbon fiber surface, yielding high thermal conductivity ordered carbon fiber and graphene (OCF/G) films. A sandwich-structured thermal interface material was fabricated by vertically embedding laser-processed optical fibers (OCF/G) into a silicone gel matrix. The vertically arranged OCF/G films, as the heat transfer path, retained their high thermal conductivity, while the interconnected silicone gel network offered superior mechanical properties. The through-plane thermal conductivity of the composites is 37.26 W m–1 K–1, which is 226 times higher than pure PDMS and 68 times higher than the composite with only carbon fibers loading. Additionally, thermal management applications of the composites as thermal interface materials for electronic device cooling are demonstrated. This construction method provides an effective approach for designing thermal interface materials with enhanced thermal and mechanical performance.