Extreme Two‐Phase Cooling from Laser‐Etched Diamond and Conformal, Template‐Fabricated Microporous Copper

Palko, Lee, Zhang, Dusseault, Maitra, Won, Agonafer, Moss, Houshmand, Rong, Wilbur, Rockosi, Mykyta, Resler, Altman, Asheghi, Santiago, Goodson, 2017, “Extreme Two‐Phase Cooling from Laser‐Etched Diamond and Conformal, Template‐Fabricated Microporous Copper,” Advanced Functional Materials, Vol. 27, 1703265.

Download PDF

This paper reports the first integration of laser-etched polycrystalline diamond microchannels with template-fabricated microporous copper for extreme convective boiling in a composite heat sink for power electronics and energy conversion. Diamond offers the highest thermal conductivity near room temperature, and enables aggressive heat spreading along triangular channel walls with 1:1 aspect ratio. Conformally coated porous copper with thickness 25 µm and 5 µm pore size optimizes fluid and heat transport for convective boiling within the diamond channels. Data reported here include 1280 W cm−2 of heat removal from 0.7 cm2 surface area with temperature rise beyond fluid saturation less than 21 K, corresponding to 6.3 × 105 W m−2 K−1
.
This heat sink has the potential to dissipate much larger localized heat loads with small temperature nonuniformity (5 kW cm−2 over 200 µm × 200 µm with <3 K temperature difference). A microfluidic manifold assures uniform distribution of liquid over the heat sink surface with negligible pumping power requirements (e.g., <1.4 × 10−4 of the thermal power dissipated). This breakthrough integration of functional materials and the resulting experimental data set a very high bar for microfluidic heat removal.

Related Projects

The development of high performance heat exchangers has enjoyed a long tradition of research at Stanford University dating back to the early work by Kays and London (Compact Heat Exchangers, 1984)...
A variety of modern high-power electronic devices are based on high electron mobility transistors (HEMT) and generate enormous heat fluxes that can approach tens of kW/cm2. The overall power...
Thermal-power challenges and increasingly expensive energy demands pose threats to the historical rate of increase in processor performance. Energy-efficient computing schemes and heterogeneous...