Thin-Film Electric Coolers for Thermal Management in Electronic Components

Generating higher efficiency and longer lifetimes for high-performance electronics

RTI Funded
University of Maryland

Because the efficiency of an electronic device is inversely proportional to its temperature, a rise in temperature leads to a subsequent drop in performance. High-performance electronic components generate heat loads that create excessive junction temperatures, compromise component lifetimes, and can lead to the premature failure of electronic devices.

As a result, there is a need to lower the temperature of and/or remove heat from the manufacture of objects ranging from semiconductor devices to car seats and beverage cans. Electronics engineers have been pursuing technology that can deliver enhanced thermal management able to boost efficiency and lengthen lifetimes for such electronic components.

Developing High Cooling-Flux Modules That Reduce Electrical Resistance and Increase Heat Pumping

As leaders in the development of thin-film-based thermoelectric (TE) materials, devices, and systems, our engineers have led and supported numerous government and commercial programs related to TE development for more than two decades. This experience has allowed us to make several scientific advancements in state-of-the-art thin-film TE, including the development of unique bismuth telluride material structures and significant improvements in metal–bismuth-telluride interface resistance.

While typical off-the-shelf thermoelectric coolers are manufactured using bulk TE materials that are several millimeters in thickness, our team has developed a metalorganic chemical vapor deposition (MOCVD) process that provides thinner, state-of-the-art TE materials. These MOCVD-grown materials—which range from 7–20 micrometres in thickness—can then be fabricated into our thermoelectric coolers with industry-leading performance.

In analyzing the problem of excess heating in high-performance electronics, our group identified specific applications that would be best served by thin-film TE, as opposed to competing cooling technologies such as bulk thermoelectrics or Stirling coolers. We determined a specific niche best suited for our technology’s differentiating characteristics, and our R&D led us to high-heat flux cooling as the application where thin-film TE could solve persistent unmet needs.

Demonstrating Thin-Film Thermoelectric Devices as Disruptive Technology in Thermal Management

Our thin-film-based thermoelectric coolers produce large cooling fluxes because of reduced electrical resistance of the device, allowing the use of larger electric currents that, in turn, lead to an increase in heat pumping. These coolers can remove up to 25 times more heat than conventional coolers, pumping 258 watts per square meter, as compared to the 10 watts per square meter typically seen in conventional devices.

One of the applications of our TE coolers is the thermal management of quantum cascade lasers (QCLs), which have potential as infrared countermeasure (IRCM) systems to combat man-portable air defense systems (MANPADS), which are shoulder-launched, infrared-guided, surface-to-air missiles. MANPADS are currently an extremely serious safety threat for commercial aircrafts in hostile regions of the world. Our next-generation TE coolers can enable high-power QCLs that could steer MANPADS away from aircraft and thus save lives. The technology could also be applied to advanced computer processors, radio-frequency power devices, quantum cascade lasers, and DNA micro-arrays.

The heat-pumping performance of our thermoelectric coolers has been demonstrated at our laboratory and verified at the University of Maryland. As we continue to develop our technology, our team is working to determine how to integrate these coolers with actual functional devices, such as solid-state lasers and microprocessors.