摘要
Pool boiling is a critical cooling strategy for high-power electronics. In this study, dendritic copper films were fabricated via two-step electrodeposition and reinforced with a Cu-Al2O3 composite layer and a conformal Ni coating to enhance mechanical robustness and oxidation resistance. Beyond evaluating robustness via tape peel tests, pool boiling experiments were conducted to characterize critical heat flux (CHF) and heat transfer coefficient (HTC) of the reinforced dendritic copper heat spreaders. High-speed visualization correlated bubble dynamics with surface morphology, revealing a distinct boiling-inversion phenomenon on optimized structures that significantly boosted heat-transfer performance. The representative sample achieved a CHF of 186.6 W cm−2 and a maximum HTC of 44.65 W cm−2 K−1 - indicating increases of 84% and 915%, respectively, compared to a flat Cu substrate. These results demonstrate that the reinforced dendritic copper architectures offer a robust and highly effective structural design for advanced thermal management technologies. The proposed structures show strong potential for practical two-phase immersion cooling applications in high-power electronic systems.
•Dendritic Cu films strengthened via Cu-Al2O3 passivation and Ni-coating.•Robust oxidation resistance of Cu films validated through repeated boiling tests.•Bubble dynamics over reinforced dendritic Cu films are investigated.•Boiling inversion enhances heat transfer performance of dendritic Cu films.•An optimized architecture achieves CHF of 186.6 Wcm−2 and HTC of 44.65 Wcm−2 K−1.