DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?)

[Vigil]

I have some questions before I can accurately model the board:

1) What is the thickness of the silicon?
2) What is on the under-side of the board?
3) How are TerraHash, yourself and others expecting to transfer heat from the components, through the silicon, to the aluminum heat sinks? Thermal pads, paste?
4) What material covers the avalon chips and why can't heatsinks be attached directly to them?
5) This is only a single layer board with no trace or components on the under-side or internal layers?

[Defkin]

I have some questions before I can accurately model the board:

1) What is the thickness of the silicon?
2) What is on the under-side of the board?
3) How are TerraHash, yourself and others expecting to transfer heat from the components, through the silicon, to the aluminum heat sinks? Thermal pads, paste?
4) What material covers the avalon chips and why can't heatsinks be attached directly to them?
5) This is only a single layer board with no trace or components on the under-side or internal layers?

1) the K16 eagle files have been posted, with the Burnin we don't know yet.
2) PCB flat with though hole pads
3) Most likely thermal insulation interface material, silicone sheet possibly, going to see what Burnin and Bkkcoins use and/or what i can get a good price on.
4) some sort of plastic and not a good heat transfer medium, chip is designed to shed head though the base into the vias in the pcb
5) multi layer boards both

[Defkin]

3) Thermal insulation? Maybe not

opps my bad

[dani]

Hi,

very interested in this. I will try to create my own DIY cooling device for burnins bitburner. For the main body I would use this: http://www.aluminium-online-shop.de/de/shop-aluminium-kleinstmengen/-Rechteckrohre---Vierkantrohre-_-20/index.html
It's pretty cheap for where I live, 100x50x5 should be good enough, maybe less. 14 Burnin boards would easily fit per 1 meter. For improved turbulence someone recommended this:

what about this


layed diagonal? maybe a X-pattern applies better in terms of even better distribution of turbulence reducing local hotspots.
Obviously cool water should get in from the bottom. Any thoughts on putting cold water in from the top? (maybe this way heat won't be too high on the upper end, resulting in a better distributed temperature?

I also thought of putting a second cold water inlet half the way of the tube to get temps on the upper end lower

[prodigits7]

I'm designing water cooling systems as well...would love to collaborate.

Keep up the good work!

[Vigil]

I am close to having any kind of model you want whether water-cooled, fan, heat-sink only, etc. but I cannot get Kicad to load the K16 cad. I need info on the dimensions and specifics of the parts and board (i.e., materials). If I can get this board modeled I will be able to run predictions on many different designs within minutes. I can change fin sizes and all sorts of stuff.

Die pad thickness and area?

Edit: Nevermind about the die pad - I got it.

[Ente]

dani,

I would make very sure to only stuff aluminum *into* the waterblock. The second pic looks like steel mesh. The "local elements" would kill the whole block on the long run.
You can get away with several metals in one cooling rig if they do not touch each other, like a copper radiator and aluminum waterblocks, separated by non-conductive silicone/pvc/plastic tubing. Even then you need to add anti-corrovion-agents to the water.

Ente

[Vigil]

I am aware you are trying to keep this thread to the electronics and testing, but just wanted to give you guys a heads-up on a simplified model of the K16 I've made using only the Avalon chips. I have them generating 2W each. They are modeled as QFN chips with most of the details and majority of the dimensions correct. I have modeled the lands that go through the board but they may not be meshing correctly so I will continue to look at that. I can add other chips and more detail if I can get the measurements and power output. The more exact I make the model, the more realistic the results will be.

This model uses an aluminum heat-sink which covers the entire bottom surface, the fins and base are 2mm thick - it is based off the heat-sink posted about 20 pages ago. I can alter this to any type of design: change fin size and number, change to fingers, etc. Additionally, this model is cooling only from the heat-sink, i.e., there are no fans or any air movement except that from buoyant convection. It is actually a transient scenario but here I am only using a steady-state model, but I can look at transient.

The temps seem a little high to me, 148 C (300 F), but of course this is without any air movement. However, many GPUs can get to 120 C or more if heat-sinks aren't attached or no air. This was just a first shot and I am going try some other things and recheck this solution, etc.


Avalon chips wire-frame.


Simplified board model with heat-sink.


Heat-transfer analysis showing temps of chips with no forced convective flow air exchange. Temps of chips reach approx. 150 C while operating at 2W with this heat-sink.

[Vigil]

I can model water-blocks, heat-exchangers, all kinds of stuff, fans, etc. all in one model.

[rethaw]

Heat-transfer analysis showing temps of chips with no forced convective flow air exchange. Temps of chips reach approx. 150 C while operating at 2W with this heat-sink.

Nice, keep it up. Looking forward to seeing with just air flow. Burnin appears to have put some thought into the thermal exchange of the PCB.

What software are you using?

[Bicknellski]

I am aware you are trying to keep this thread to the electronics and testing, but just wanted to give you guys a heads-up on a simplified model of the K16 I've made using only the Avalon chips. I have them generating 2W each. They are modeled as QFN chips with most of the details and majority of the dimensions correct. I have modeled the lands that go through the board but they may not be meshing correctly so I will continue to look at that. I can add other chips and more detail if I can get the measurements and power output. The more exact I make the model, the more realistic the results will be.

This model uses an aluminum heat-sink which covers the entire bottom surface, the fins and base are 2mm thick - it is based off the heat-sink posted about 20 pages ago. I can alter this to any type of design: change fin size and number, change to fingers, etc. Additionally, this model is cooling only from the heat-sink, i.e., there are no fans or any air movement except that from buoyant convection. It is actually a transient scenario but here I am only using a steady-state model, but I can look at transient.

The temps seem a little high to me, 148 C (300 F), but of course this is without any air movement. However, many GPUs can get to 120 C or more if heat-sinks aren't attached or no air. This was just a first shot and I am going try some other things and recheck this solution, etc.


Avalon chips wire-frame.


Simplified board model with heat-sink.


Heat-transfer analysis showing temps of chips with no forced convective flow air exchange. Temps of chips reach approx. 150 C while operating at 2W with this heat-sink.

Be nice to start this a new thread or put it in the Klondike heat sink thread. I added this to the REFERENCE page for DIY Klondikes.

[tom_o]

Vigil, have you included any thermal via's in your model?

[Vigil]

Vigil, have you included any thermal via's in your model?

The thermal vias are accounted for through the "lands" that go through the PCB. They are outlined in red in that first pic on the underside of the chips.

[tom_o]

Ah cool, would be interesting to see results with some air moving across them as that's going to be the most common usage of these heatsinks, fully passive ones have to be quite large normally.

[Vigil]

Ah cool, would be interesting to see results with some air moving across them as that's going to be the most common usage of these heatsinks, fully passive ones have to be quite large normally.

I will look at this. I have changed the size of the heatsink to one which was discussed in the Klondike DIY thread and the temps are down to 78C without any air movement. I will post on the heat-sink thread.