Not just a coldplate?

[Thrilla]

You know how traditional coldplates are just like a piece of copper, nothing special?

What if I make my cold plate into some shapes? You know how CPU die is only the size of a peanut, then why use all the rest? I'm thinking

http://img485.imageshack.us/img485/4025/wc5be.jpg

Btw, how much lbs of pressure does a TEC require?

[.sentinel]

the lbs of pressure need are something in the 100s or more. NoL puts it in a press until he can't turn it any more then he takes a hammer and hit the press handle until that can't move.

[Thrilla]

So I'll just put the cold and hot plate on, then press them together very hard? When does the TEC crash? I can do over 500lbs with that steel bender thing.

[speed bump]

Swiftech build coldplates like that for their MCW-50t VGA pelt blocks. Also for pressure it doesn't matter if you put a ton of pressure on your pelt you run a risk of cracking it or crushing the pelt. Really its not the pressure that matters is the contact pressure is just a way of ensurung good contact.

[STEvil]

You would want to shape the peltier element, not the cold plate. The plate itself cannot direct energy movement, only provide a buffer for it for the peltier which is not shaped to do this..

[Aphex_Tom_9]

You would want to shape the peltier element, not the cold plate. The plate itself cannot direct energy movement, only provide a buffer for it for the peltier which is not shaped to do this..
qft

[Thrilla]

You would want to shape the peltier element, not the cold plate. The plate itself cannot direct energy movement, only provide a buffer for it for the peltier which is not shaped to do this..

Agreed.


btw, what's qft?

[Kasparz]

There's a big risk to crush a core if you apply this to naked chip.

[Thrilla]

Quick question for those of you who runs "naked":
What's between the core and IHS?

[Premmer]

the lbs of pressure need are something in the 100s or more. NoL puts it in a press until he can't turn it any more then he takes a hammer and hit the press handle until that can't move.
The recommended compression for a TEC assembly is 150 to 300 pounds per square inch of module surface area. Using the following formula, you can calculate the torque setting per screw:

T = (C x D x F x in^2) / (# of screws)

T = torque per screw (in-lbs)
C = torque coefficient; generalized values for copper/mild steel (0.36 dry, 0.18 lubricated)
D = nominal screw size (8 = 0.164, 10 = 0.190, 1/4 = 0.250)
F = Force (lbs / in^2)
in^2 = module surface area (length x width)

Check the torque setting after one hour and retighten if necessary.

Example: Assuming (4) # 8 screws are used to secure a coldplate used with a 62mm (2.44 in) square module surface area and a surface force of 300 lbs per in^2 is required, what is the torque setting required per screw?

T = (0.36 x 0.164 x 300 x 5.95) / 4 = 26.35 in-lbs per screw



If a torque wrench/screwdriver is not available, a properly-ranged pull spring scale attached to the end of an L-shaped hex wrench can be used to establish the screw torque setting. To calculate the required spring scale pull force, apply this formula:

F = T / D

F = Force (lbs)
T = Torque (in-lbs)
D = Distance (in)

Example: What is the spring scale pull force required at the end of a 3.75 inch long L-shaped hex wrench to produce a 26.35 in-lbs screw torque setting?

F = 26.35 in-lbs / 3.75 in = 7.02 lbs pull force

[Thrilla]

Alrighty, thanks!

[speed bump]

QFT means quoted for truth.

[Carlz0r]

Quick question for those of you who runs "naked":
What's between the core and IHS?
Thermal compound approved by AMD for A64s, thermal compound approved by Intel for s423 and s478 P4s, and some form of solder on LGA775 Intel cpu's iirc.

[Piper]

Wait up now, let's think this through a little more. Although the cold plate does not direct the flow of energy/heat, it is providing a medium for heat transfer from the CPU to the TEC,

Since the TEC typically has a much larger surface area then the CPU core/IHS, the "border area" will initially cool faster then it will heat up from underneath. This improves thermal transfer through those regions so that heat does not travel straight through the cold plate without also radiating outward as well.

In the end, the heat will travel toward and colder areas of the cold plate and then be transfered throught the TEC. Think of it as the TEC having the ability to chill more of the cold plate and provide more mass for heat transfer.

That doesn't mean that shaping the bottom of the cold plate like Swiftech did is a bad idea, but changing the surface area of the TEC or the cold plate surface it mates with is. That is, even if you could shape the TEC without destroying it.

This is my understanding of the dynamics involved, I welcome any additional info I might be overlooking.