How about this for a backside VRM Block?

[starbuck3733t]

I want (or not...) to make a VRM block for the backside of my Abit IC7. I saw a guy on Overclockers.com do it to great result. I figured this can be pretty simple, and I mapped out the location of my fets on a piece of tape stuck to the backside of the motherboard, then stuck that tape to paper. The copper pipe is 1/2" ID (yeah, ID, its repair pipe) and the bar stock bits are 1/8" thick. You'll notice notches and holes in places on the bar stock parts, these are to accomodate the inductor coil leads coming out the back of the board.

As far as attaching it goes, I plan (if I do it) to use thermal tape since the OC.com guy had good luck with that.

The fittings on this will be 6mm ID pushfits, and this will be part of a 5-part (5x6mmID) loop. I plan on attaching the fittings at a 90* angle to the pipe, both on the same side, forming a "U" shape out of the pipe and the fittings. I'll cap the ends of the pipe with some copper caps and solder the whole thing shut (easy) and then solder the whole thing together.

Will this work ok? do I need to put some small copper pins through the pipe to introduce additional turbulance, or will the fact of so much copper between the board (not to mention the board itself) make this not too terribly worth it?

Pics:

[jaydee]

Looks like a plan, go with it. I assume you have to butcher the piss out of the mobo tray and maybe the case if you want to mount it in a case?

[starbuck3733t]

The piss has already been butchered out of my mobo tray:





And there's enough room between the side of the case and the back of the mobo to mount this without issue. Running tubing might get exciting, though.

So don't bother with the additional turbulators in the pipe? interesting. Probably due to my low-flow through that leg of the loop, maybe it'll have more 'time' (???) to take away heat? My theory on this stuff sucks!

[jaydee]

Not sure on the turbulator. I don't think the heat is going to spread far enough into the pipe to make use of it.

[bigben2k]

I think you'd benefit more from flattening that tube, to make better contact with the copper slugs; the solder adds a thermal layer.

Do these slugs need to be so thick?

I see no objection to the turbulators; it's not going to hurt anything, except flow.

[starbuck3733t]

The slugs are that thick as thats what I have. I could knock them down quite a bit on the belt sander, but then I'd have to make them smooth again. I've got some stuff to do that, but for the disc part of my belt/disc sander.

So no problem doing turbulators (which I assumed...) but will it hurt the performance if I don't, especially given the thickness of the slugs.

Edit: so crush the tube in my vice or something to make it more 'flat'? cutting the tube in half seems like a bad idea. I could, but the copper plate stock I have is thicker than the bar stock.

[bigben2k]

You'll get a bit more performance with the turbulators, I suspect, but it's not going to matter much unless you knock down those slugs; the sluga are going to have a thermal gradient (i.e. a high temp, and a low temp) that's going to be significant, to where turbulators wouldn't do much.

Yeah, crush them to give one side (at least) a flat spot, for better contact with the slugs; it'll give a better contact area.

I don't think there's much heat that can be dissipated that way, but these are simple mods to your original plan, so if you have the time, and the tools...

[starbuck3733t]

That all makes sense so far. what do you mean by "that way" in you last paragraph. Thanks for the input.

[bigben2k]

Originally Posted by starbuck3733t

That all makes sense so far. what do you mean by "that way" in you last paragraph. Thanks for the input.

Hum, yeah. There's a pretty big gap between the back of the mobo, and what you're trying to cool. We've got a few examples within this forum of cooling the MOSFETs directly, with great results.

Should I dig them up for ya?

[the jew (raven)]

Originally Posted by bigben2k

Should I dig them up for ya?

Sure, why not?

[bigben2k]

Ok.

Here's one that didn't work out so well:
http://forums.procooling.com/vbb/showthread.php?t=9254
(a valiant try Nico!)

Here's another, with a link to the Overclocker's article:
http://forums.procooling.com/vbb/showthread.php?t=9375
(Yay Captain Foo Foo!)
The full Cptn Foo Foo thread, and link:
http://forums.procooling.com/vbb/sho...&threadid=7933

This one is missing the critical images:
http://forums.procooling.com/vbb/showthread.php?t=9095
(you might want to buzz the member).


(Sorry, I thought there was more)

[starbuck3733t]

http://www.mca.ckras.com/z1/gallery_...php?id=nb-kk.1

Dude's gallery site has a the missing pix from the last thread, or something like it with the blocks installed.

As much as I'd like to cool the front of the fets, the layout isn't conducive to it like on an NF7 or that guy's server board.

Check it:


See how the inductor coils and caps are between the FETs themselves, and the fets aren't all in a line. I could see doing this as a 3 layer block, but it would be mighty difficult.

[MadHacker]

Originally Posted by starbuck3733t

See how the inductor coils and caps are between the FETs themselves, and the fets aren't all in a line. I could see doing this as a 3 layer block, but it would be mighty difficult.

Why not use Ram blocks? like the one's used here.
Gratuitous Bling? thread
I think they would fit..
or make your own simular to them only smaller

[starbuck3733t]

Well... I could. but its a bit messy. And I know you (madhacker) are an electronics type too - where do they attach heatsinks on FETs? To the tab, as that's the hottest part.

But it is another thing to consider. especially since I do have some nice 1/4" OD copper tubing left over from a ice dispenser install. I could make some blocks out of copper 1/2"x1/2" barstock and drill holes through the center.

*HRM*

edit: nice big image of how the IC7 is layed out on the front.
http://www.ixbt.com/mainboard/images...c7-g-board.jpg

[MadHacker]

Originally Posted by starbuck3733t

Well... I could. but its a bit messy. And I know you (madhacker) are an electronics type too - where do they attach heatsinks on FETs? To the tab, as that's the hottest part.

First off.. The electronics stuff I know is from some basic stuff I learned in college for system programming… I played a bit with some and gates, or gates and multiplexers but that is going back 7-8 years ago…

I would think that attaching the heat sink to the tab would be ideal. But they are soldered to the MB. Currently they are using the MB as a heat sink. I believe that attaching the heat sink to the top area on the FET would be better then the bottom of the board cause you are now cooling the FET directly and not through a multilayer board.
my 2¢

[maxSaleen]

I think you'd benefit more from flattening that tube, to make better contact with the copper slugs; the solder adds a thermal layer.

I agree. The flattened tube will give you more surface area and will have a minimal effect on flow. Should be pretty easy to do. Look over on the extreme systems forums. Try to find some of weapon's work as he has made a RAM waterblock with the exact same design principals. Sand the slugs down as much as you can. I, personally, don't think turbulators will be worth the effort.

[starbuck3733t]

what would be the ideal thickness for the slugs? 1mm? I figure I should order some stuff from online metals - nice to have it around in the future.

[bigben2k]

Well, the only purpose for the slugs really, is to give you some clearance on the mobo's backside; the tube wall is thick enough as it is, really.

[starbuck3733t]

Well, they're also sorta acting like heat collectors. the tube doesn't sit over all of the fet area. I see your point though.

[Cptn. Foo Foo]

Hey guys...just stumbled across the thread...thought i'd drop in and leave my $0.02.

Back when I was thinking about making my VR blocks I considered something similar to what you are planning starbuck3733t. However I was considering something a little different. I was thinking I could take a piece of copper pipe and file flat spots into it (actually right through the wall of the pipe) where flat copper bar would go. That way the water would make direct contact with the copper flat bar (or copper slugs as is mentioned in this thread).

I made a quick graphic to demonstrate the idea. You would have to solder all around where the "slugs" make contact with the pipe of course. Also if the slugs were a lot thicker than the wall of the pipe then they would stick up into the water flow somewhat...kind of acting like "turbulators."

I cant remember why I did not do it this way. Maybe I just forgot

[TerraMex]

#2 redux.
maybe?

[starbuck3733t]

Now that's just tooooooo clever! The only part I'll have to look out for, and of course check to see if its feasible, is the big legs of the inductors comeing through they board. They're about 1/8" diameter and stick up pretty far.

The copper 1/4" idea for the frontside is still something I'm kicking around..

[bigben2k]

The setup that our dear Cptn FooFoo proposes is an excellent idea. A little bit more work, but not unnecessarily so.

Pressure test the thing before putting it into service.

[starbuck3733t]

is it possible to get copper all-thread or copper bolts to make turbulators over the slugs?

[Cptn. Foo Foo]

I found some copper nails in the plumbing section at my local hardware store once. Thought I could solder them down (like sticking up vertically with the head soldered down).