Synthesis and analysis of anodic aluminum oxide-nanopore structure on Al substrates for efficient thermal management in electronic packaging

Increased heat generated in high-density electronic devices has intensified the search for advanced thermal management solutions. This urge has prompted various studies in thermal pad, liquid thermal interface material, gap fillers, and thermal coating, etc., with enhanced thermal performance. In this article, anodic aluminum oxide-nanopore (AAO-np) structure was grown on Al5052 alloy substrate electrochemically using two-step anodization process and it is used for efficient electronic packaging applications. It is observed that AAO-np substrate shows significant impact in thermal resistance (R_th) and junction temperature (T_j) of an electronic package. At 3.5 W input power with 14, 29, and 43 psi pressure condition the experimental results of AAO-np substrate resulted 15.11%, 14.58%, and 13.89% reduction in thermal resistance (ΔR_th) and 15.53%, 14.85%, and 14.26% reduction in junction temperature (ΔT_j) compared to bare Al5052 substrate. This enhanced thermal performance of AAO-np layer are due to high crystallinity, honeycomb-like morphology, nanopore oxide layer, and 0.35 µm rough surface which are effectively acting towards directional heat transport.