Recent Progress in Nanocomposite Structural Regulation and Interfacial Engineering of Metal-Based Thermal Interface Materials

With the continuous development of electronic devices toward high integration, high power density, and miniaturization, interfacial heat dissipation has become a critical issue affecting device stability and long-term reliability. Metal-based thermal interface materials (TIMs) have attracted increasing attention owing to their high intrinsic thermal conductivity, ability to form continuous heat-conduction pathways, and suitability for high-heat-flux thermal management. However, their practical performance is governed not only by the thermal conductivity of the metallic phase, but also by overall thermal resistance, contact thermal resistance, bond-line thickness, interfacial conformability, internal porosity, oxidation-induced degradation, and long-term reliability. This review summarizes the heat-transfer fundamentals and key scientific issues of metal-based TIMs, with emphasis on four representative categories: particle-based, three-dimensional skeleton-based, unidirectionally conductive, and phase-change metallic TIMs. Their structural characteristics, performance limitations, and engineering application scenarios are discussed, and the synergistic role of nanocomposite structural regulation and interfacial engineering in reducing overall thermal resistance is highlighted. In addition, thermal, mechanical, and reliability characterization methods are summarized, and the potential and practical constraints of AI-assisted design for metal-based TIMs are discussed. Overall, future development of metal-based TIMs should move beyond the pursuit of higher intrinsic thermal conductivity and focus instead on the integrated optimization of low overall thermal resistance, high interfacial compliance, long-term stability, and manufacturability.