Friday, June 28th 2019

AMD Files a Patent for Cooling of 3D Stacked Memory

Scaling and manufacturing of ever shrinking semiconductor devices is becoming more challenging as smaller nodes are introduced. As we have approached 7 nanometers, economies of scale are becoming more influential than scales of manufacturing. For example, the development of the 7 nm node development cost more than 3 billion USD, while smaller nodes are expected to see that price cross the 5 billion USD mark. So given that we are approaching the limit where we can't squeeze more transistors in two-dimensional space without huge economical impact, we have to utilize another dimension in order to keep performance improvements coming.

AMD has filed a patent for cooling a 3D stacked memory with thermo-electric coolers - TECs, also known as Peltier devices. Being that TECs are made out of P-type and N-type semiconductors, they can easily be integrated into existing silicon manufacturing methods and controlled like a regular device. The process AMD has patented basically describes how to insert the TEC between memory and logic devices, where it draws heat from either logic or memory with each side being able to dissipate the heat. That effect is possible due to nature of TEC, where the direction of heat flow is changed inverting the voltage.
As you can see, this is the high-level overview of what AMD proposes, with constant measurements of both the logic stack and memory stack, to determine which one is hotter. The hotter side gets heat drawn away from it to the colder side, which can dissipate that heat.

This solution would be useful in devices that are similar to Intel's Foveros, where you have a memory die on top of logic:
However, thermoelectric cooling is not free - it does consume power, and generates some heat on its own, so we'll have to wait and see whether this can actually turn into a useful technology.

You can read the whole patent here.
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17 Comments on AMD Files a Patent for Cooling of 3D Stacked Memory

#1
DeathtoGnomes
Integrated Cooling. Will still need external cooling but not as dramatic as water cooling.
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#2
yakk
Looks interesting, can't wait for 512 core cube CPUs!
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#3
Mistral
This is certainly not going to do any wanders for power consumption, but it's not like you have many other options for cooling stacked chips...
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#4
Litzner
Anytime I see patent's today I always find myself thinking "Should you be able to patent that?"

Patent putting a peltier cooler between dies?

Patent putting a water pump on top of the waterblock?

Patent a rectangle with rounded corners?

Patent putting cheese in between the meats instead of on top?

I really think the engineers and scientists should be part of the patent approval process to deem whether or not a patent should exist for something.
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#5
phanbuey
Litzner, post: 4071711, member: 101570"
Patent putting cheese in between the meats instead of on top?
lmao
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#6
HTC
This may well be the precursor to Zen 3 server CPUs.

In fact, these patents are in the video as well, @ around 19:50 or so.
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#7
bonehead123
Maybe they will patent it & then be like the fruity boys, just bury it for several years while they decide whether or not to actually make something from it.... That way if anyone else brings up the same or similar idea, they can sue the crap out of them :eek:
Posted on Reply
#8
Totally
Litzner, post: 4071711, member: 101570"
Anytime I see patent's today I always find myself thinking "Should you be able to patent that?"

Patent putting a peltier cooler between dies?

Patent putting a water pump on top of the waterblock?

Patent a rectangle with rounded corners?

Patent putting cheese in between the meats instead of on top?

I really think the engineers and scientists should be part of the patent approval process to deem whether or not a patent should exist for something.
This is actually a new and novel idea. If someone asked to create a list of 10 ways to cool 3d memory this probably wouldn't even be on the list. I agree with everything else.
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#9
RealNeil
bonehead123, post: 4071744, member: 139670"
That way if anyone else brings up the same or similar idea, they can sue the crap out of them :eek:
Like Asetek?
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#10
oxidized
They're on fire, i like this.
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#11
Midland Dog
yakk, post: 4071678, member: 158293"
Looks interesting, can't wait for 512 core cube CPUs!
no point using cpus at all at that point, just use a gpu
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#12
silentbogo
TEC elements still need to be cooled, and when it's sandwiched between layers, something is gonna get cooled and something - heated.
I think now I'm starting to like the old idea of liquid cooling w/ inter-layer vias.
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#13
r.h.p
Midland Dog, post: 4071890, member: 168254"
no point using cpus at all at that point, just use a gpu
dosnt the cpu do anthing ...
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#14
Imsochobo
silentbogo, post: 4071946, member: 141875"
TEC elements still need to be cooled, and when it's sandwiched between layers, something is gonna get cooled and something - heated.
I think now I'm starting to like the old idea of liquid cooling w/ inter-layer vias.
I think it's viable for IE the I/O die, imagine having 4gb of L4 cache on the I/O die achieving 40ns latencies, you've effectively killed all drawbacks of having seperate I/O die, all the benefits.
also the power consumption of such a configuration isn't too horrible to make it too costly with said solution.

I cannot see a high performance cpu core being in a stacked environment personally.
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#15
Grog6
The big problem with this is that peltiers are really inefficient.

Liquid sodium/potassium running thru the chips might make it workable, but to pump a watt with a peltier takes several watts.

10A@12v will cool a 5W IR camera to (ambient - 60degrees C), but that's not really a workable solution for something that draws 150W in a package.

Freon would work really well, tho. :)

I'd love to have another gallon of Freon TF...
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#16
quadibloc
Litzner, post: 4071711, member: 101570"
Anytime I see patent's today I always find myself thinking "Should you be able to patent that?"
Looking at the patent, it seems they've patented the idea of taking excess heat from the memory layters and dumping it into the logic layers.

That probably is something nobody else had thought of, since usually one expects the logic layers to be the hot ones. Look inside your PC: the processor has this huge fan thingy on top of it, but the memory just sits there.
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#17
forman313
If AMD and Samsung are planning on stacking RAM, GPU and CPU for their future mobile processors, it might make sense to transport trapped heat to the PCB. Using the PBC to dissipate heat is very common. Since BGA chips wont allow a thermal pad, they are using the logic layers and connections insted .... just guessing here.
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