DARPA, Lockheed Developing Ways to Keep Chips Cooler
By Engineering360 News Desk | March 23, 2016Lockheed Martin is working with the Defense Advanced Research Projects Agency (DARPA) to develop a lighter, faster and cheaper way to cool high-powered microchips—by cooling the chips with microscopic drops of water. The technology has potential applications in electronic warfare, radars, high-performance computers and data servers.
The project is part of DARPA’s Inter/Intra Chip Enhanced Cooling (ICECool) program to enhance the performance of radio frequency monolithic microwave integrated circuit (RF MMIC) power amplifiers and embedded high-performance computing systems through chip-level heat-removal techniques. Thus far, Lockheed Martin has demonstrated the effectiveness of a microfluidic cooling approach that resulted in a fourfold reduction in thermal resistance and a corresponding sixfold increase in RF output power when compared to conventional cooling techniques.
“Right now, we’re limited in the power we can put into microchips,” says John Ditri, principal investigator on Lockheed Martin’s ICECool effort. “One of the biggest challenges is managing the heat. If you can manage the heat, you can use fewer chips and that means using less material, which results in cost savings as well as reduced system size and weight. If you manage the heat and use the same number of chips, you’ll get even greater performance in your system.”
The density of components in electronics has increased heat generation and power dissipation. Image credit: DARPA.Phase I of the ICECool program verified the effectiveness of Lockheed’s embedded microfluidic cooling approach by demonstrating a fourfold reduction in thermal resistance while cooling a thermal demonstration die dissipating 1 kW/cm2 die-level heat flux with multiple local 30 kW/cm2 hot spots. This is about four to five times more heat per unit area than most current chips dissipate, paving the way for future chip advancements.
In Phase II of the program, the team has moved on to cooling high-power RF amplifiers to validate the electrical performance improvements enabled by enhanced thermal management. Utilizing its ICECool technology, the team has been able to demonstrate a greater than sixfold increase in RF output power from a given amplifier, while still running cooler than its conventionally cooled counterpart.
In its ongoing effort to move the technology out of the laboratory and into the field, Lockheed Martin is developing a fully functional, microfluidically cooled transmit antenna prototype to increase the technology readiness level of this technology. This will lay the foundation for possible insertions into future electronics systems.
Lockheed Martin is also working with Qorvo to integrate its thermal solution with Qorvo’s high-performance GaN process—a relationship that should help unleash the full potential of GaN semiconductors by removing current thermal barriers. Lockheed Martin's approach is also applicable to other current and future die technologies, such as existing Gallium Arsenide and future GaN on Diamond when it becomes available.
Lockheed’s ICECool embedded thermal management approach removes thermal barriers to harness GaN’s full RF power-handling capability. In addition to potentially revolutionizing the way GaN amplifiers are implemented, this technology will benefit any high-heat-flux integrated circuit application, including signal processing and high-performance computing.