Syed, Hussain2026-05-222026-05-222026-05-22http://hdl.handle.net/10393/51699https://doi.org/10.20381/ruor-31991The rapid advancement of modern electronics has intensified thermal management challenges, driving the need for heat sink materials with high thermal conductivity and efficient heat removal. Electrodeposited copper-diamond (Cu-D) composites show strong potential for next-generation electronic applications, offering thermal conductivities exceeding those of conventional metals while remaining more economical than composites produced through high-temperature-high-pressure methods. Despite this promise, most studies emphasize intrinsic material properties rather than evaluating practical cooling performance. This thesis investigates the heat sink behavior of electrodeposited Cu-D composites under realistic operating conditions using LED junction-to-ambient thermal resistance. Cu-D samples containing uncoated and TiC-coated diamond particles, arranged in single-layer and multi-layer architectures, were fabricated and assessed. Uncoated composites exhibited poorer heat sink performance than pure copper due to small, equiaxed copper grains near the Cu-D interface, which limited thermal boundary conductance despite being free of interfacial voids. In contrast, TiC-coated diamond particles significantly lowered steady-state LED temperatures, demonstrating the importance of interfacial engineering in improving phonon transport across metal-diamond interfaces. The influence of thermal interface materials (TIMs) was also examined. Incorporating 10-30 wt.% diamond particles into the commercial thermal paste further reduced LED temperatures, even though the thicker bond-line would typically increase thermal resistance. This shows that TIM formulation plays an additional role in determining overall heat sink effectiveness. Overall, this work advances electrodeposited Cu-D composites toward practical heat sink applications and shows that interfacial coatings, copper microstructure, and TIM design collectively influence thermal performance.enAttribution-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nd/4.0/ElectrodepositionCopper-diamond compositesHeat sinkThermal managementThermal conductivityThermal interface materialsThermal boundary conductanceTiC-coated diamondMetal matrix compositesThesis