Diamond Thermal Conductivity: A New Era in Chip Cooling

75 pointsposted 5 days ago
by rbanffy
(spectrum.ieee.org)

32 Comments

0cf8612b2e1e

5 days ago

Have diamonds found their way into other industrial cooling solutions? With the research into gem grade diamonds, I have been expecting cheap ugly synthetic diamonds to be used in more products. I have long joked that I want a diamond frying pan.

gpm

13 hours ago

3D printer nozzles, which is sort of the opposite (industrial heating products).

Part of the argument is that better heat conduction means that you can run the nozzle cooler resulting in less heat conduction to the cold side (above where you want the filament to melt) so I guess its "cooling" in a sense too.

Atomic_Torrfisk

17 hours ago

> ugly synthetic diamonds

Not any more, their quality has increased recently. Not that I care, wife and I did without them during our engagement.

jrk

14 hours ago

I think the point was not that gem-grade synthetic diamonds are ugly, but that, as industry masters gem-grade production, presumably below-gem-grade production (“ugly synthetic diamonds”) would become cheap enough to deploy in more engineering settings where diamond’s other unique properties were the key concern.

Yossarrian22

13 hours ago

I’m surprised nobody has done a phone screen yet

Tuna-Fish

11 hours ago

Large single crystal diamond, what is required for a nice transparent screen, is still quite expensive. This article is about polycrystalline diamond, which is not really that transparent, but is nearly as good at thermal conduction as monocrystalline diamond.

akshatjiwan

8 hours ago

Your comment reminds me of apple's attempt to make sapphire screens. That didn't turn out so well.

https://www.theguardian.com/technology/2014/feb/10/sapphire-...

addaon

8 hours ago

Apple still uses sapphire screens on the nicer watches.

KiwiJohnno

41 minutes ago

I have a Garmin with a sapphire screen. I've worn it every day for over 5 years, working on cars, in the garden, snorkelling on coral reefs.

In short, I my watch has NOT had an easy life. I've made no attempt to protect it or taken it off for anything except charging. There is barely a mark on the screen. A sapphire screen will be a hard requirement for my next watch.

rowanG077

9 hours ago

Even if that were cheap I don't think diamond would excel in this use case. It's of course extremely hard but I'd expect that it would be extremely prone to cracking. In addition the high index of refraction would make the diamond screen very reflective and you would need some fancy coating which of course wouldn't be as strong as diamond.

rbanffy

3 days ago

> I have long joked that I want a diamond frying pan

As long as you don’t use it on a gas stove, you should be fine.

kees99

17 hours ago

Why? Diamond has very low thermal expansion, so no risk of stress/embrittlement/cracks from uneven heating.

Or you mean it'll catch fire? Also not a concern. That is supposed to happen at a temperature well above anything useful for cooking.

rbanffy

16 hours ago

The temperature of the blue flame on a stove should be above 1000 Celsius, well above what’s required to oxidise diamonds. They won’t catch fire, but your diamond pan will erode. Once you remove it from the flame, it won’t continue “burning”.

Should be safe on electrical stoves though.

kees99

15 hours ago

Would that >1000°C reach the surface though?

There are some heady boundary-layer effects and temperature/temp-conductivity gradient physics involved here. For simplicity sake, consider a plastic [1] bag full to the brim with water, held over open flame. Will bag melt (oxidize, erode)?

[1] polyethylene melts around 120-ish °C and ignites around 220-350 °C (sources vary)

LtdJorge

16 hours ago

I think because it will burn your hand?

rbanffy

16 hours ago

It’s safe to assume the handle is made from something else.

lateforwork

11 hours ago

> But my research group at Stanford University has managed what seemed impossible.

Wait a minute, others have been doing this already: https://www.df.com/

How is this different?

See also: https://youtu.be/ggQKZDZsDec

mutagenesis

8 hours ago

What you linked is bonding a diamond substrate to the back of your IC. What's in the post is growing diamond lattice/features directly on your wafer. With the new way, you can get diamond closer to your heat sources, increase contact area, etc.

No idea if it actually matters. Is this a single digit percentage increase in thermal conductivity by messing with a finicky, temperamental process? I don't know. What the paper writers are proposing is under the limit of when transistor structures break down, but not by much.

lightedman

13 hours ago

Nothing new, Applied Diamond has made this stuff for several years and it is incredible. Imagine putting a 15w LED on a typical 20mm star board made of diamond - you do not need a heat sink. Just minor air flow over the package is enough.

A little unlike IEEE to be nearly half a decade out of the loop.

Tuna-Fish

11 hours ago

The invention is a fast, low-temperature deposition process, which can then be used directly on a semiconductor device.

lateforwork

10 hours ago

Diamond Foundry achieves the same end goal even if the deposition methods and technical processes may differ: https://df.com

Tuna-Fish

10 hours ago

They produce the diamond wafers separately and then later bond them, a process that is dramatically more expensive and results in a worse bond.

akshatjiwan

9 hours ago

I think what they have grown diamond on the transistor which then bonds to the substrate through a SIC interlayer.

From what I understand their idea seems to be that since most heating occurs at channels they act like hotspots and therefore it would be much better to drain away heat from them directly.

This is different from creating transistors on a diamond substrate.

yorwba

12 hours ago

The new thing here is growing a thin layer of diamond directly on top of a chip.

trhway

9 hours ago

naturally, graphite has similarly high thermal conductivity along the layer direction (which is basically graphene), and one would think that there should be some way to put such a thin layer of graphite/graphene on top (or inside) the chip to achieve similar results.

gpm

3 hours ago

Would the electrical conductivity be an issue?

NedF

15 hours ago

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