Enhanced heat transfer using wafer-scale crack-free well-ordered porous structure surface

Abstract

Boiling heat transfer through porous medium is one of the prevalent cooling strategies in electronic thermal management due to its superior heat transfer capability. However, multiple optimization goals generally have conflicting requirements for the physical design of surface structure during boiling heat transfer. In order to reveal the potential mechanism, the boiling characteristics of a heated surface composed of three-dimensional ordered porous inverse opal (IO) structure were studied. From a numerical perspective, the change in critical heat flux does not always have a linear relationship with the thickness of the structure. When the thickness approaches 4.1 μm, the maximum critical heat flux (CHF) of 122 W/cm2 was obtained at a lower superheat (<15 K). Compared with smooth surfaces, the heat transfer performance of IO structure was largely enhanced with a maximum heat transfer coefficient (HTC) improvement of 945%. For IO structures with the thickness of 3.3 μm, the simulated CHF value is 102 W/cm2 which is in close agreement with the experimental value of 103 W/cm2. Due to its uniform porous structure and high capillary capacity, it can persistently maintain small bubbles before approaching CHF, thereby improving heat transfer performance. This high-performance IO structure provides an alternative thermal dissipation method for electronics.