Despite being a film of less than 5 μm, the liquid boiling on the surface of Sugo-Hie has finer bubbles, denser nucleate boiling sites, and high velocity convection of bubbles and liquid. This results in boiling temperature characteristics that exceed the critical heat flux compared to smooth surfaces.
It has also been observed that increasing the refrigerant flow velocity improves heat transfer in the low-superheat range.
Heat transfer through the topmost surface and interface
Micro-texture by design engineering
Approximately 90,000 to 200,000 microfins/㎠.
The surface area is two to three times larger.
Example of special shape plating
(convex 80μm, ditch 10μm)
Micro-textured microprojectile shapes formed by laser processing or pressing have been reported to exhibit special heat transfer characteristics and improve the efficiency of heat dissipation and heat removal.*1)
Through the microtexture effect on heat sinks, heat transfer characteristics change. That is, when the proper microtexture is formed through wet plating, this is a surface treatment technology that alters heat transfer characteristics.*2) *3)
In addition, the industrial wet plating method enables instant and stable micromanufacturing on large areas and can be applied to large and small parts in a variety of shapes.
Boiling Heat Transfer Surface Model
*1) Japan Heat Transfer Symposium: Flow Boiling Heat Transfer in Mini-Channels Utilizing Micro-Protrusive Surfaces
*2) WCMNM 2021.Boiling Heat Transfer Control by Micro-/Nano-Texturing of Metallic Heat Spreading Devices
*3) WCMNM 2022. Manufacturing and Characterization of Acicular Fe-Ni Micro-Textured Heat-Transferring Sheets
Water Cooling Evaluation Test
On Sugo-Hie-treated surfaces, water boils in a shorter time due to the formation of microbubbles when boiling. The surface characteristics increase the heat of vaporization, resulting in a water cooling capacity 20-30% higher than that of untreated (smooth) surfaces.
Air Cooling Evaluation Test
Compressed air was sprayed on a sample placed on a hot plate, and the temperature of the sample was measured with a thermal camera. As a result, the temperature of the Sugo-Hie-treated sample was confirmed to be up to about 3 times lower than that of the untreated sample.