Thermal paste application

[L.G. John J. Yeosock]

From a physics point of view,
1) the thinner the layer of thermal compound, the better;
2) air gaps are bad, even microscopic air gaps;
3) for very thin gaps between planar surfaces, viscosity
is a very strong impediment to fluid flow.

Conclusion: If it oozes without pressure, it's definitely
too thick. If it oozes with applied pressure, it's thicker
than it has to be. If it doesn't ooze at all, even with
applied pressure, it may be too thin. Therefore,
just a little ooze with applied pressure is probably
the best one can do for peace of mind.

From a manufacturer's point of view:
1) People are idiots;
2) People are fumble-fingers;
3) The product has to work even when applied by People.

Conclusion: It doesn't matter too much HOW the
friggin' thermal compound is applied, just keep
out the bubbles.


*TimDaniels*

You should ask youself why the paste ?

The white paste or thermal compound is used to help in the heat transfer
between to object, the CPU and the Heatsync. All electronic technician
knows that little secrets.

Since no surface are perfectly flat ! The white paste is there to make sure
that no gaps or void will exist when the two object (CPU/HEATSYNC) will be
secured together.

And if you want little ooze, just do that, you apply an even thin coat of
the thermal paste with a small flexible spatula, and lay the heat sync on it
and just move it in a "+" motion about 1/32 of an inch in all direction
while you press on it.

Just like a ceramic floor tile with you may lift the heatsync to see if the
coverage is ok. and lay it back on the CPU or wipe it clean and start over.
if you feel or see a air space.

TIPS from a tech: When I spread the paste on a CPU (Core), I use a small
piece of thin flexible plastic as a spatula and spread the paste on the CPU
core.

The paste will spread evenly and you should have just a little ooze visible,
That technic is valid for all type of CPU.

But becareful with the P4 or any CPU that have the core raised above the
packaging, you don't want the white past off the flat surface of the core.

And don't worry, if you use the right kind of past, the one that doesn't dry
after a few week, you should get the best heat transfer.

But If the past dry's out after a few weeks, and you have to remove the
heatsync/fan assembly for some reason, make sure to clean both surfaces and
re-apply some paste that way the heat transfere will be secured.

And some times, the best paste come in small pots not in syringe, and please
no metal tape.

JJY

 

[HMSDOC]

Now this is interesting. I finally opened fully my box with processor and read
the manual as well as going to the Intel site. For one thing there is
definitely no thermal tape and there is a syringe of thermal "interface
material". Both on the website and in the manual it clearly and spoecifically
says to put ALL the material in the syringe (it isn't a huge syringe but has
more than I would have put on based on the Arctic Silver website that says half
a pea if I remember) on the top of the processor. It also then clearly says
to put the processor directly on top of the paste (no razor or credit card edge
spreading) and to apply it straight down...no starting at an angle and pushing
down from one side to the other to remove bubbles, though it does say to close
the retention clips one side at a time and I suppose that might push any
bubbles out. Anyway, this is in direct contradiction to some of the info in
the Arctic Silver site, if I remember correctly. But the Intel instructions
and website http://www.intel.com/support/processors/pentium4/intnotes478.htm
are very clear. Perhaps they use a different type of thermal interface
material or perhaps the top of the P4 is different than prior Pentiums.
Nonetheless, I think I should use the Intel material and instructions.

Howard

 

[L.G. John J. Yeosock]

Hi Howard,

You are lucky because you are building your PC, but others don't know that
many Technician don't use the syringe that come in the box or many time they
buy CPU in bulk (OEM). That mean no syringe ! So they use a cheap thermal
compound.

And many times I have to repair those chop chop job done by those garage
type Tech, when they build that PC.

But when I repair those system, I clean it up and use the good stuff, I use
what every good electronic technician use for heat transfer for electronic
components.

So if you have to change the heatsync along the way, during the life you
have that PC, make sure to put new paste. and my suggestion is to put the
best stuff.

But be sure to clean the inside of the housing once a month with compressed
"dry" air. And make sure that those fans stay clean.

That way your PC will have a better life in the worst heat condition.

John

 

[E. Harris]

Here's a new one, though... the retail HSF that comes with the 3.2/800
has a copper core AND a thermal pad.... :)
Earl