Capillary Trap – Vapor Pump for Hot Spot Cooling via Thin Film Evaporation

Technology #6272

Background: Very high performance electronics circuits and chips require enhanced cooling techniques to allow rapid heat dissipation and prevent any deleterious effect on the performance of the electronics. This is especially true for computers and communication devices and systems used by military and other specialized applications. Currently used two-phase cooling systems suffer from issues such as gravity dependence and inflexible nature of the interfaces to the underlying electronics. Both drawbacks limit the use of current two-phase cooling designs in newer, compact and high performance electronic systems.

Technology: Andrei G. Fedorov from the School of Mechanical Engineering at Georgia Tech has created a device and method that efficiently dissipates very large heat fluxes from hot spots in integrated chips and other devices. The method’s innovativeness arises from its ability to take advantage of highly efficient heat transfer via evaporation from an extended meniscus of a liquid bridge located above the hot spot. A wide range of operating parameters and working fluids, such as water or dielectric fluids, can be used in this design to achieve rapid heat dissipation.

The heat transfer is accomplished using capillary forces and enhanced vapor removal brought about by the large pressure differential produced when the capillary (Laplace) pressure rises above the background vapor pressure. The design exploits high cooling capabilities associated with the phase change heat transfer while avoiding detrimental effects, such as surface dry-out, when heat flux exceeds critical levels. The invention incorporates a novel cooling device design to promote efficient thermal management through capillary confinement of the evaporating film and efficient vapor removal using pumping action.

Potential Commercial Applications: Key areas for application of this invention would be in high performance computer and communication chips used in equipment for satellites and military applications. This cooling device design can be fabricated within the computer chip, located outside the chip and on the package or used as an array of multiple devices operating in parallel to achieve on-demand cooling with individual addressability.

Benefits / Advantages:

  • Highly efficient dissipation of very large heat fluxes produced by chips inside computers and other electronic devices
  • Prevents critical heat flux level causing device burn-out via coolant dry-out
  • Innovative design of the cooling devices exploits high cooling capabilities associated with phase change heat transfer through evaporation
  • Incorporation of fins and liquid phase coolant enables 3D heat spreading for increased rate of evaporative cooling