Production of diamond/Cu composites with high thermal conductivity and low volume fraction using 3D direct ink writing technique

Efficient thermal management is critical for the performance and reliability of modern electronic systems. In this study, a pseudoplastic diamond suspension was engineered for DIW and printed into a continuous, 3D-interconnected diamond network, which served as a thermally conductive scaffold. Subsequent infiltration with molten copper enabled full densification of the composite without the need for external pressure. At room temperature, a thermal conductivity of 492.4 ± 20 W/m·K can be achieved at a low diamond loading of 29 vol.%, making a 30.9% enhancement over conventional copper matrix composites containing randomly dispersed diamond particles. This performance is attributed to the continuous and complete 3D diamond framework, which significantly enhances heat transfer while reducing interfacial thermal resistance. The proposed approach provides a new route for the design of diamond metal matrix composites for next-generation thermal management applications.