Designers of electronic devices are pushing to install higher power processors and components into smaller packages. Increasingly, these devices must run continuously, and survive in harsh environments that limit the opportunities to stay cool. When components start to over-heat, the devices must throttle their performance to prevent damage and failure. These challenges are most acute in notebook computers, tablets and smartphones with power-hungry processors and thin, dust-proof enclosures. Gaming computers, cloud servers, LED stage lights and solid state power electronics also face severe thermal constraints.
Today’s advanced thermal management systems use heat pipes and vapour chambers to extract heat from critical components and carry it to remote heat sinks, external surfaces or coolant circuits. These passive two-phase components use water vapour to transport heat along an internal space and are limited by the capillarity of their internal porous wick media. To achieve higher performance, device designers are forced to dedicate significant space for bulky heat pipe assemblies or incur significant cost and complexity by jumping to pumped liquid cooling.
A small UK company now offers micron-scale metal foam wicks that combine small pores (see the Picture) to generate high capillary pressure with large voids to enable high permeability and flow, effectively breaking the trade-off that limits performance of conventional sintered, mesh and grooved wicks. The foam is deposited directly onto the internal surface of a vapour chamber casing and offers high surface area for heat transfer into the working fluid, thereby limiting thermal resistance at the evaporator and condenser. Together, these properties enable an increase in component heat transfer capacity and effective thermal conductivity of between two and four times versus conventional wicks.
The foams can be deposited on a wide variety of pre-formed components in a low-energy, scalable electrochemical process. The company has a potential partner for the scale up and fabrication of the foams with lots of experience in the field. Through this partner, technical cooperation and supply of components can be offered.
The company offers licenses to thermal solutions companies that design thermal circuits for OEMs, or OEMs who do the design in-house.