Scalable and tunable micro/nanostructuring of aluminum surfaces via chemical etching for enhanced heat dissipation

Abstract

Effective thermal management is crucial for modern electronics, such as display devices, to ensure performance and longevity as devices become smaller and thinner. Conventional cooling methods, relying on heat sinks or spreaders, often face limitations due to spatial constraints and intrinsic material properties. Herein, we present a simple, scalable and tunable micro/nanostructuring strategy for aluminum surfaces via chemical etching process using hydrochloric acid to enhance heat dissipation. This facile approach enables precise tuning of surface roughness parameters, including peak-to-valley height, interfacial area ratio, surface slope, and arithmetic mean height, by controlling etching time. The resulting surface morphology enhances emissivity and induces localized flow disturbances, significantly improving radiative and convective heat transfer performance. The practicality of the proposed etching-based micro/nanostructuring strategy is demonstrated by incorporating the modified aluminum surfaces into light-emitting diode heat sinks to reduce operating temperatures. By systematically varying the etching duration (2–14 min), the optimal processing conditions (6)-min etching) achieve a convective heat transfer enhancement of 5.37 % and a significant radiative heat transfer increase of 179.9 %, demonstrating the dominant role of surface emissivity in passive thermal performance. Conversely, over-etching causes performance degradation owing to reduced material thickness and excess structure complexity, emphasizing the importance for precise process control. This cost-effective and scalable micro/nanostructuring for advanced thermal management offers a viable solution to enhance heat dissipation in various electronic devices with compact and thin form factors.