A new method of computer cooling results in a 740% increase in power per unit

We have all had the experience of one of our electronic devices overheating. Needless to say, when this happens, it becomes dangerous for both the device and its surroundings. But given the speed at which devices operate, is overheating preventable?

A 740% increase in power per unit

Researchers from the University of Illinois at Urbana-Champaign (UIUC) and the University of California, Berkeley (UC Berkeley) have recently developed an invention that could cool electronics more efficiently than other solutions alternatives and allow a 740% increase in power per unit. , according to a statement from the institutions released on Thursday.

Tarek Gebrael, the lead author of the new research and a UIUC Ph.D. mechanical engineering student, explained that current cooling solutions have three specific problems. “First, they can be expensive and difficult to develop,” he said.

He cited the example of diamond heat sinks which are obviously very expensive. Second, he described how conventional heat diffusion approaches typically place the heat sink and a radiator (a device to efficiently dissipate heat) above the electronic device. Unfortunately, “in many cases, most of the heat is generated underneath the electronic device,” meaning the cooling mechanism isn’t where it’s needed most.

Third, Gebrael explained, heat sinks cannot be installed directly on the surface of the electronics. They require a layer of “thermal interface material” to be placed between them to ensure good contact. However, this material has poor heat transfer characteristics, which negatively impacts thermal performance.

A solution to all common problems

Fortunately, researchers have found a new solution that solves all three problems.

They started by using copper as the main material, which is obviously inexpensive. Next, they made the copper coating “engulf” the entire device, Gebrael said – “covering the top, bottom and sides…a conformal coating that covers all exposed surfaces” ensuring that no heat-producing region is left unprotected. . Finally, the new solution eliminates the need for a thermal interface material and a heat sink. What innovation!

“In our study, we compared our coatings to standard heat dissipation methods,” Gebrael said. “What we’ve shown is that you can get very similar, if not better, thermal performance with coatings compared to heatsinks.”

The removal of the heatsink and thermal interface also ensures that the device using the new solution is considerably smaller than its conventional counterparts. “And that translates into much higher power per unit volume. We were able to demonstrate a 740% increase in power per unit volume,” Gebrael added.

Co-author Nenad Miljkovic, who is an associate professor of mechanical science and engineering at UIUC and an advisor to Gebrael, concluded by saying, “Tarek’s work in collaboration with the UC Berkeley team has given us enabled the use of an electro-thermo-mechanical technology development approach to develop a solution to a difficult problem for multiple industries.”

The study is Posted in Natural electronics.

Abstract:

Electrification is essential to the decarbonization of society, but managing the increasing densification of energy in electrical systems will require the development of new thermal management technologies. One approach is to use monolithic metal-based heat sinks that reduce thermal resistance and temperature fluctuations in electronic devices. However, their electrical conductivity makes them difficult to implement. Here, we report co-designed electronic systems that monolithically integrate copper directly onto electronic devices for heat propagation and temperature stabilization. The approach first coats the devices with an electrically insulating layer of poly(2-chloro-p-xylylene) (parylene C) followed by a copper conformal coating. This allows the copper to be in close proximity to the heat generating elements, eliminating the need for thermal interface materials and providing improved cooling performance over existing technologies. We test the approach with gallium nitride power transistors and show that it can be used in systems operating up to 600 V and provides a low junction-ambient specific thermal resistance of 2.3 cm2KW-1 in the air at rest and 0.7 cm2KW-1 in calm water.

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