Quasi-Periodic Surface Functionalization by Ultra-Short Pulsed Laser Processing: Unlocking Superior Heat Transfer in Vapor Chambers

Abstract

High-power-density modern electronics necessitate efficient and reliable heat removal at heat fluxes exceeding 1 kW cm−2, a demand that challenges the limits of conventional cooling strategies. The precise functionalization of surfaces is pivotal in developing advanced thermal management solutions for next-gen electronics cooling. Herein, it is demonstrated for the first time that picosecond-laser functionalization of copper surfaces—comprising densely packed, self-organized, quasi-periodic microstructures—results in surfaces that are highly suited for such applications. The methodology uses large laser beams (typical radius of 150µm or higher) to facilitate the self-organization of laser-formed surface features that are orders of magnitude smaller. The resulting laser-functionalized surfaces not only exhibit excellent fluid transport capabilities, but also demonstrate exceptional heat transfer performance. Integrated into wickless vapor chambers (VCs), these surfaces enable device thermal resistances as low as 0.12 K W−1 at 0.3 MW m−2 load, and values ≈0.2 K W−1 across the range 0.3–1.5 MW m−2—corresponding to almost 80% reduction compared to the thermal resistance of conventional wick-lined VCs, as attested by a benchmarking study. Additionally, these functionalized surfaces have reduced sensitivity to working-fluid charge ratio, proving their operational robustness. This work establishes a versatile, open-atmosphere manufacturing route to functionalize surfaces for enhanced phase-change heat transfer, unlocking low-profile, high-efficiency cooling solutions for next-generation electronics.