Interfacial engineering in diamond/cu composites: from W-WC single-layer optimization to WCu dual-layer Interface for high-temperature thermal properties and stability

Abstract

Diamond/Cu composites are ideal materials for thermal management in high-power electronic devices. The use of W coating can enhance the interfacial bonding of the composites and improve the room temperature thermal performance. However, its high-temperature thermal performance cannot be guaranteed. This study constructs diamond/W-Cu/Cu dual-layer interface structures based on coated W to further optimize the high-temperature thermal performance of the composites. This work synthesized diamond/Cu composites with various interface structures by varying the sintering temperature and time. The results indicate that the W-WC composite interface has a higher thermal conductivity than the W-W₂C-WC interface structure, and a peak thermal conductivity of 660 W/(m·K) is achieved at an interface structure of 52 nm W-108 nm WC, corresponding to a thermal expansion coefficient of 5.2 ppm/K. A dual-layer interface structure was next constructed. While the results show that the dual-layer interface composites have better high-temperature thermal properties and bonding with the interface. The relative density of the composite was increased by nearly 2.8 % and its thermal conductivity was increased to 698 W/(m·K), while the high-temperature thermal conductivity degradation (at 200 °C) was reduced from 33.5 % to 29.5 %. Additionally, it achieves a 25 % reduction in high-temperature coefficient of thermal expansion (CTE) and improves thermal stability by 50 %. Its low thermal resistance and high thermal stability provide an innovative solution for the thermal management of high heat flow density electronics.