Copper heatpipes are commonly seen winding their way around heatsinks these days, but even copper’s thermal conductivity
looks decidedly feeble in comparison to that of diamond. Of course, a diamond-encrusted heatsink would be ridiculously expensive, but researchers are slowly finding ways to access the thermal properties of diamond. Sparkle recently announced that it had successfully tested coolers using a diamond-like carbon coating
, and now researchers in Germany claim to have achieved decent cooling results by adding diamond powder to copper.
Developed by scientists at the Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research (IFAM
) in Dresden, the new material was researched as a part of the ExtreMat
The group claims to have already surpassed the high thermal conductivity of copper by adding diamond powder to the material. IFAM’s project manager, Dr Thomas Schubert, explained that “diamond conducts heat roughly five times better than copper. The resulting material expands no more than ceramics when heated, but has a conductivity one-and-a-half times superior to copper. This is a unique combination of properties.”
So why has no one thought of this before? Schubert explains that bonding diamond with copper isn’t an easy job, as you also need a third material to chemically unite the diamond and copper. Schubert managed to cleave the two using chrome as a third material and, according to IFAM, samples of the material have already been successfully produced and demonstrated.
Explaining the need for a new thermally-conductive material, IFAM points to the shrinking process technologies used in silicon, resulting in densely packed integrated circuits that can generate an increasing amount of heat. “The more components are packed into a limited space, the more difficult it is to dissipate the heat,”
“Manufacturers therefore mount a small copper or aluminum plate underneath them to conduct the heat away. The plate, in turn, is soldered to ceramic components or silicon (the main constituent of the chip). If this system heats up, the metal plate expands about three or four times as much as the silicon or the ceramics. This causes tension which can lead to cracks in the soldered joints, so there are limits to how far components can be miniaturised.”
According to IFAM, the new material was a response to requests to discover “a material with special properties that can efficiently dissipate heat even in devices with densely packed components and that can give increasingly miniaturised electronics a longer life.”
As well as being able to conduct heat more efficiently than copper, the new material also couldn’t expand to more than ceramics or silicon at high temperatures.
The group hasn’t announced any plans for mass production of the material yet, or how much it’s likely to cost, but the group’s industrial partners include Siemens, so it’s likely to get some good investment. Are you excited about the prospect of new materials with superior thermal conductivity to copper? Let us know your thoughts in the forums