A layer of diamond can prevent high-power electronic devices from overheating.
Powerful electronic components can get very hot. When many components are combined into a single semiconductor chip, heating can become a real problem. An overheating electronic component wastes energy and is at risk of behaving unpredictably or failing altogether. Consequently, thermal management is a vital design consideration.
This becomes particularly important in devices made from gallium nitride. “Gallium nitride is capable of handling high voltages, and can enable higher power capability and very large bandwidth,” says Yong Han from the Singapore's Agency for Science, Technology and Research (A*STAR) Institute of Microelectronics. “But in a gallium nitride transistor chip, the heat concentrates on tiny areas, forming several hotspots.” This exacerbates the heating problem.
Han and co-workers demonstrate both experimentally and numerically that a layer of diamond can spread heat and improve the thermal performance of gallium nitride devices.
The researchers created a thermal test chip that contained eight tiny hotspots, each 0.45 by 0.3 millimeters in size, to generate the heat created in actual devices. They bonded this chip to a layer of high quality diamond fabricated using a technique called chemical vapor deposition. The diamond heat spreader and test chip were connected using a thermal compression bonding process. This was then connected to a microcooler, a device consisting of a series of micrometer-wide channels and a micro-jet impingement array. Water impinges on the heat source wall, and then passes through the micro-channels to remove the heat and keep the structure cool.
Han and the team tried their device by generating 10–120 Watts of heating power in test chips of 100 and 200-micrometer thickness. To dissipate the heating power, the diamond heat spreading layer and microcooler helped maintain the structure at a temperature below 160 degrees Celsius. In fact, the maximum chip temperature was 27.3 per cent lower than another device using copper as the heat spreading layer, and over 40 per cent lower than in a device with no spreading layer.
The experimental results were further confirmed by thermal simulations. The simulations also indicated that the performance could be improved further by increasing the thickness of the diamond layer, and that good bonding quality between the gallium nitride chip and the diamond heat spreader was crucial to obtain the best performance.
“We next hope to develop a novel micro-fluid cooler of higher and more uniform cooling capability, and to achieve thermal management using a diamond layer of high thermal conductivity near an electronic gate,” says Han.
The A*STAR-affiliated researchers contributing to this research are from the Institute of Microelectronics
Han, Y. Lau, B. L., Tang, G. & Zhang, X. Thermal management of hotspots using diamond heat spreader on Si microcooler for GaN devices. IEEE Transactions on Components, Packaging and Manufacturing Technology 5, 1740–1746 (2015).
A*STAR Research | Research SEA
Studying how unconventional metals behave, with an eye on high-temperature superconductors
13.12.2018 | Princeton University
An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes
13.12.2018 | Rutgers University
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
13.12.2018 | Life Sciences
13.12.2018 | Physics and Astronomy
13.12.2018 | Earth Sciences