So what if thermal compound spreads?

"Piotr Makley" wrote in message
...
Conor wrote:

Hmmm greasy finger goop, damn boy if you worked in my place
and used your bare hands you'd be getting a **** round the
back of your head...

Why is that? Is it because you buy into the hype of the
anti-static wristband manufacturers lies?

And yes I know all about static damage...


I don't think he is referring to damage by static. I think there
is something "bad" about even a trace of grease like that from a
finger. I don't know why this is though.


The reason for that is that you have no idea what you're talking about.
Until they dry out, vegemite and toothpaste work better than AS3 !



Can anyone enlighten me (gently)?

"Piotr Makley" wrote in message
...
"QBall" wrote:

I have fine, non-greasy skin.
I notice other people's mice and keyboards are always covered
in a sort of greasy/grainy mix ..... disgusting.
You could always wash your finger first, you know.
Using an implement allows the introduction of coarse
particulate matter (which will screw the interface) - which a
finger can easily detect.

Anyway, the addition of a
microscopic quantity of skin oil makes no difference
whatsoever.

But why do people seem to worry about it?


Simple.
Because they spend too much time with their fingers stuck up their backsides
!

In article ymoec.80914$Pk3.59130@pd7tw1no, says...

Please start with this: In what way does 3 contradict 2?

How can you have capacitive properties if a compound is not conductive?

Precisely.

--
Conor

If you're not on somebody's **** list, you're not doing anything
worthwhile.

In article , says...
Conor wrote:

Hmmm greasy finger goop, damn boy if you worked in my place
and used your bare hands you'd be getting a **** round the
back of your head...

Why is that? Is it because you buy into the hype of the
anti-static wristband manufacturers lies?

And yes I know all about static damage...


I don't think he is referring to damage by static. I think there
is something "bad" about even a trace of grease like that from a
finger. I don't know why this is though.

Can anyone enlighten me (gently)?

Paranoia or believing the latest old wives tale.

--
Conor

If you're not on somebody's **** list, you're not doing anything
worthwhile.

"Queve Tientoo" wrote:

No matter how much you put on, the excess will get squeezed
out buy the pressure from the HS hold down clip, your layer will always
end up the same thickness. I have removed several and the "layer" looks the
same on both the carefully applied with no squizz-out and the sloppy with
heavy squizz.

If too much is applied the excess won't be squeezed out. If it's
applied properly their should be so little between the contact areas
that it'll be barely visible when you remove the heatsink.

--
iv Paul iv

Matt wrote:

Conor wrote:
In article ,
says...

CrackerJack wrote:

What exactly is the problem if too much cpu compound is put on the
core and it gets squashed out onto the surrounding area?

Apart from looking messy, is there any real problem with this?

I propose this answer:

1) If the compound is not too viscous, and the heatsink is clamped on
with some force, and you apply enough compound, the thickness of the
layer of compound does not depend on the amount applied, which is to say
that the excess gets squeezed out.

2) Thermal compounds are not electrically conductive.

3) Some thermal compounds (notably those containing silver compounds)
have capacitative properties that can be problemmatic if compound gets
between the chip's leads.

4) If you use a compound that doesn't have the problemmatic capacitative
properties and is not too viscous, in general it won't hurt to use too much.



1) WRONG
2) WRONG
3) If 3 is true then 2) is wrong. You've just proved that yourself.
4) WRONG.


Your reply is practically content-free.

Please start with this: In what way does 3 contradict 2?

Apart from the above, the word you're looking for is 'dielectric'. Look
up any elementary physics text book.

On Mon, 12 Apr 2004 09:26:44 +0000 (UTC), "QBall"
wrote:

And it's so thick, there's no metal-metal contact.

Metal to metal eh? Obviously you're only talking about CPUs with a heat
spreader on them. It makes a much greater difference how thick the
compound is when there's a spreader, because the retention force per sq.
mm is so much lower.

It's difficult enough to rub the goop away with a finger - try it for
yourself.

Well that's just a sign that your heatsink compound is too thick. If it
can't even be rubbed with a finger it's not going to be getting into the
crevasses very well either until it heats up, at which point it would also
tend to ooze out from between the 'sink and cpu too.

Try my method and watch your temps drop 5C !

On a P4, using very thick compound, I'll believe it makes a 5C difference.
With compound of the proper consistency on an Athlon XP, maybe 1C if that,
though it might take a couple thermal cycles for some of the excess to
seep out.

"Johannes H Andersen" wrote in message
...


Matt wrote:

Conor wrote:
In article ,
says...

CrackerJack wrote:

What exactly is the problem if too much cpu compound is put on the
core and it gets squashed out onto the surrounding area?

Apart from looking messy, is there any real problem with this?

I propose this answer:

1) If the compound is not too viscous, and the heatsink is clamped on
with some force, and you apply enough compound, the thickness of the
layer of compound does not depend on the amount applied, which is to
say
that the excess gets squeezed out.

2) Thermal compounds are not electrically conductive.

3) Some thermal compounds (notably those containing silver compounds)
have capacitative properties that can be problemmatic if compound gets
between the chip's leads.

4) If you use a compound that doesn't have the problemmatic
capacitative
properties and is not too viscous, in general it won't hurt to use too
much.



1) WRONG
2) WRONG
3) If 3 is true then 2) is wrong. You've just proved that yourself.
4) WRONG.


Your reply is practically content-free.

Please start with this: In what way does 3 contradict 2?

Apart from the above, the word you're looking for is 'dielectric'. Look
up any elementary physics text book.


Hehe ..... LOL
The contemporary edukation system has a lot to answer for.
Bad spelling is so freaking irritating.

"kony" wrote in message
...
On Mon, 12 Apr 2004 09:26:44 +0000 (UTC), "QBall"
wrote:

And it's so thick, there's no metal-metal contact.

Metal to metal eh? Obviously you're only talking about CPUs with a heat
spreader on them. It makes a much greater difference how thick the
compound is when there's a spreader, because the retention force per sq.
mm is so much lower.

It's difficult enough to rub the goop away with a finger - try it for
yourself.

Well that's just a sign that your heatsink compound is too thick.


Hehem .... I'm the guy who's been saying that it should be applied so it's
invisible.
Rubbing it off the point of invisibility takes a little application of
effort and could no way be achieved by squeezing with a sink clip.
You've gotten the complete wrong end of the stick, sir !


If it
can't even be rubbed with a finger it's not going to be getting into the
crevasses very well either until it heats up,


This is a problem with crappy, coarse goops like Ceramique.
For the CPU, a fine goop like AS3 should be used.



at which point it would also
tend to ooze out from between the 'sink and cpu too.

Try my method and watch your temps drop 5C !

On a P4, using very thick compound, I'll believe it makes a 5C difference.
With compound of the proper consistency on an Athlon XP, maybe 1C if that,
though it might take a couple thermal cycles for some of the excess to
seep out.

On Mon, 12 Apr 2004 12:19:51 +0100, Conor wrote:

In article ymoec.80914$Pk3.59130@pd7tw1no, says...

Please start with this: In what way does 3 contradict 2?

How can you have capacitive properties if a compound is not conductive?

Precisely.

Actually, you can have a "capacitive property" without being conductive. Do
some research on dielectric constant. Every substance has one. Even a
vacum has one. Some substances with high dialectric constants, such as
silicones, have such high resistances they are effectively non-conductive
(you won't read any resistance with a standard ohmmeter), yet they do
increase the capacitance between between conductors. So there are 2 points

1. Everything has a capacitive property. It is called the dielectric
constant. It is not directly related to conductance or resistance.

2. Everything is also to some degree conductive. When the resistance (the
inverse of conductance) is high enough we can't practically measure it we
call that substance non-conductive.

http://www.rfcafe.com/references/ele..._strengths.htm
JT