Heatsinks are a staple of PC cooling technology as we know it. Both passive and active coolers make use of heatspreaders and heatsinks, but a team of researchers from the University of Illinois at Urbana-Champaign and the University of California, Berkeley (UC Berkeley) recently found what looks like a far better, all-encompassing, and sleeker solution.
The researchers describe their experiments and findings in a paper entitled "High-efficiency cooling via the monolithic integration of copper on electronic devices," as spotted by Science Daily. Highlights of the new copper conformal coating technology are that it takes up little in the way of physical space in a device and that it is much more efficient than current copper heatsinks. The researchers demonstrated a 740% increase in the power per unit volume.
There are three main issues with conventional heatsinks, explained Tarek Gebrael, the lead author of the paper and a UIUC Ph.D. student in mechanical engineering. First, the most advanced heatsinks using exotic and highly efficient conducting materials can be expensive and difficult to scale up. Gebrael mentioned heatspreaders containing diamonds as one rival tech, clearly illustrating his point.
Secondly, conventional designs combine a heatspreader and heatsink in tandem, and "in many cases, most of the heat is generated underneath the electronic device," lamented Gebrael. Thirdly, the best heat spreaders can't be installed directly onto electronics but require a thermal interface material, inhibiting optimal performance.
So, how does the new technology address all the above drawbacks of current heat sinking methods? The new heatsink coating covers the entire device, creating a large cooling surface area.
"The approach first coats the devices with an electrical insulating layer of poly(2-chloro-p-xylylene) (parylene C) and then a conformal coating of copper," says the research paper. "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 compared with existing technologies."
This coating technique does away with any large outcrops of copper or aluminum, so it is a much more compact solution to wick heat away from fast-running processors and memory. According to the researchers, the thin conformal coating and lack of a bulky traditional heatsink deliver a much higher power per unit volume, up to 740% better. "You can stack many more printed circuit boards in the same volume when you are using our coating, compared to if you are using conventional liquid- or air-cooled heat sinks," asserted Gebrael.
The researchers next plan to verify the coating's durability, which is an important step to industry acceptance. Additionally, the researchers plan to test with immersion cooling and in high voltage environments. For their initial tests, the researchers used "simple" PCBs, but they hope to scale up testing of the cooling tech on hotter running electronics like "full-scale power modules and GPU cards."
In summary, the technology sounds promising without being too expensive or complicated for component makers to consider for practical use. Until this new heat sinking tech arrives, you will have to contend with conventional CPU cooling and GPU cooling.
It wouldn't be any different than adding another ground plane on the PCB. If your electronic device is that sensitive to capacitance, it's probably not a consumer device anyway.
Breakdown voltages are typically in the kilovolt range. I don't know about you, but if my computer is generating kilovolts somewhere, I'd stay clear away from it.
Which is why manufacturers design electronics based around an expected temperature range, along with some wiggle room. If you design your circuits to exact tolerances, your design sucks.
Also the PCB is already absorbing and distributing quite a bit of heat anyway through the aforementioned ground planes.
Your not fully understanding the article, they are eliminating the solder, heat spreader and thermal paste and creating a direct contact heat transferring coating.
On top of that most heat is generated downward and this allows a full coating around the object rather than just on top.
This makes the thermal transfer much better.
Adding more air flow does not mean it will get better and better cooling, airflow has its limits, your contact transfer point is what is being improved here.
For example, if I had a component that was only 1 inch, and it generated 5000 watts of heat, I don't care what you do. You will never be able to cool that component with a current day air cooler setup.. even if you made a heat sink the size of a house, the object would still be overheating.
However if you somehow made a system that could pull heat off the object into the heatsink faster....
We won't mention a certain fruit-brand, running their processors with just enough cooling, so they hover just below thermal throttling, so they can just make base performance. All so it can be a fraction mm thinner.
Same company is probably salivating over this.
From a heat flow perspective this idea that heat is generated downward is nonsense - heat flows everywhere. And the cross-section of that copper coat must be pretty thin - which limits heat flow.
Frankly this is not much different to relying on the heat spreading ability of the PCBs second copper layer, which is often attached to by thermal vias.
TLDR limited usefulness, hardly revolutionary.
It's not going to replace the actual heatsink in a desktop or laptop, or even server, though because of the very poor thermal conductivity of air. It needs that large surface area. Immersion cooling is a different story.
At least with a ground plane you have a layer of substraight between the layers. This coating will presumably be right on top of the components. If it's truly grounded then it may not be a problem.
Being is such close contact with components I don't think it would not take much to jump the gap. In the kilovolt range you could see the arc, that doesn't mean there aren't leakage currents your can't see in the low voltage range.
True, which is why I said this would add design challenges.
True, but like I said, there are insulating layers between the ground plane and components. The ground plane doesn't have near direct contact with the components. Its a difference of having your component on top of a hot stove or in the stove.