Revolutionizing Electronic Cooling: Ultra-short-pulsed Laser Processed Surfaces in Wick-Free Vapor Chambers

In the ever-evolving landscape of modern high-power electronics, efficient thermal management solutions play a pivotal role in determining device performance and longevity. Vapor chambers have long been heralded as effective tools for managing high heat-flux scenarios. Traditionally, vapor chambers are wick-lined; however, they have some inherent limitations. These chambers rely on wick structures to resupply liquid to the evaporator, where the fluid undergoes vaporization due to the heat generated by the electronic components. While the effectiveness of vapor chambers has been demonstrated, wick-lined vapor chambers face challenges, such as the capillary limit, pore blocking, and added weight. To address these limitations, researchers have turned to wick-free vapor chambers (WFVC). These systems eliminate the need for wick structures, relying instead on the surface properties of the evaporator and condenser surfaces to drive liquid flow. The success of wick-free vapor chambers hinges on the skin-deep surface microstructures present on these surfaces and wettability patterning. In this study, we explore wick-free vapor chambers equipped with uniformly superhydrophilic evaporators created through ultra-short pulsed laser surface processing (ULSP), utilizing two different laser processing methods to functionalize the evaporators. Our findings reveal that ULSP surfaces used in wick-free vapor chambers produce VC thermal resistances as low as 0.12 K/W. What sets the present approach apart is the absence of surface wettability patterning, unlike previous wettability-patterned vapor chambers that combined distributed philic and phobic domains to move condensate as needed in the device, in turn improving performance, as quantified by thermal resistance.