Best heat sink compound?

[Costas Vlachos]

"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in message
news:umtnsvk15sqpqmb8jrsciapsk41apf0eau@4ax.com...

On Mon, 1 Dec 2003 18:24:28 +0000 (UTC), "Costas Vlachos"
c-X-vlachos@hot-X-mail.com> Gave us:


Agreed, I don't like them either... I'd avoid using them for any serious
heatsinking work.

They ARE in use, across the industry... for "Serious heat sinking
work". Doh!

Yes, they are... Main reason is convenience, NOT better thermal
conductivity! It's much easier and much less messy to use a pad than to have
to spread thermal paste during assembly. But I don't think they can beat
thermal paste in terms of thermal conductivity. For low/medium power devices
or when I need insulation I would use them, for high power stuff I prefer
the paste.

Costas

 

[DarkMatter]

On Tue, 2 Dec 2003 03:09:28 +0000 (UTC), "Costas Vlachos"
<c-X-vlachos@hot-X-mail.com> Gave us:

Yes, they are... Main reason is convenience, NOT better thermal
conductivity! It's much easier and much less messy to use a pad than to have
to spread thermal paste during assembly. But I don't think they can beat
thermal paste in terms of thermal conductivity. For low/medium power devices
or when I need insulation I would use them, for high power stuff I prefer
the paste.

There are plenty of places where paste is not acceptable or
permitted. Many assemblies which get encapsulated cannot have it as
it inhibits the cure of the encapsulant.

Pads are not merely a convenience or a measure to cut COM. They
cost MOE than does paste. Their function is not more than a few
percent off direct, paste infused contact. Perfectly acceptable, even
for large wattage devices.

As far as ease of manufacture paste is no ,more difficult to apply
than a sleeve, so that isn't the reason either.

The main reason is mess and chemical MSDS control requisites for the
cream.

I have seen pads over a quarter inch thick that carry heat from a
device just fine. Right to the case.

If it didn't function acceptably, it would never have made it into
regular use. It is in WIDE use... daily... thousands of 'em. All
over the world.

 

[DarkMatter]

On Mon, 01 Dec 2003 19:12:44 -0800, John Larkin
<jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> Gave us:

Just do the math.

Math? I see thousands of them in use daily.

Interesting too that they are used in military, and rugged
applications, and paste is not.

Don't be such a 'tard, boy.

 

[DarkMatter]

On Mon, 01 Dec 2003 18:20:13 -0900, Floyd Davidson <floyd@barrow.com>
Gave us:

DarkMatter <DarkMatter@thebarattheendoftheuniverse.org> wrote:
On Mon, 1 Dec 2003 8:12:04 -0800, DaveC <me@privacy.net> Gave us:

On Mon, 1 Dec 2003 7:37:23 -0800, Floyd Davidson wrote
(in message <87u14kblcc.fld@barrow.com&gt:

NAPA Item# 765-2569
Copper Anti-Seize Lubriant

and you recommend this as a head-sink compound for semiconductors?


You have obviously not been around very long.

The discussion is centering around a silver based media, so if
conductivity is what has your bloomers in a bunch, it is not an issue.

The material he mentions isn't a lube, it's a spray used to seal
high pressure metal gaskets, like a head gasket.

Actually this stuff is a lube. It comes in a little container
with a brush on the inside of the cap. It is kind of an oily
looking stuff, with a lot of what appears to be copper flakes
suspended in it. (And it is essential to mix it up very good
before applying it, or all the copper will be on the bottom of
the container.)

It is *not* used on head gaskets, but rather on head bolts. The
idea is to smear them with this stuff in hopes that 10 years
later you might be able to unscrew them all without breaking
half of them.

It works absolutely flawlessly.

It does indeed.

Ahhh... I had a spray can of copper filled tack media for the head
gasket seal application. I remember the stuff you refer to now.

An anti-sieze compound.

 

[qrk]

On Mon, 1 Dec 2003 0:10:21 -0800, DaveC <me@privacy.net> wrote:

White "tooth" paste kind, or clear greasy "hair stuff" kind?

I use the deodorant stick type. AAVID sells this stuff as
"ULTRAstick", p/n: 031117. It's really made by some other company
which I believe is Power Devices (bought by Loctite).
http://www.aavidthermalloy.com/products/options/greases.shtml#ultra
http://www.powerdevices.com/thermtc.htm
Both companies use the same pictures and graphs.

It works well, easy to apply, and doesn't create an oily mess. Easily
removed with acetone. Digi-Key sells this for $22. It will last for
hundreds of applications.

Mark

 

[John Larkin]

On Mon, 01 Dec 2003 20:19:05 -0800, DarkMatter
<DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Mon, 01 Dec 2003 19:12:44 -0800, John Larkin
jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> Gave us:


Just do the math.


Math? I see thousands of them in use daily.

Interesting too that they are used in military, and rugged
applications, and paste is not.

Don't be such a 'tard, boy.

The best Bergquist or Chomerics sil-pad claims a thermal conductivity
of something like 3 w/m-K, although that's the premium stuff. 1.0 is
more affordable. Multiply these numbers by about 0.5, because they
both lie their asses off, or apply 500 PSI pressure, I'm not sure
which. A decent white thermal grease is maybe 1.6 w/m-K. So they are
in the same ballpark, grease actually better... maybe 200:1 or so
worse than aluminum.

But a sil-pad is typically 7-10 mils thick. I don't know how thin
silicone grease can be squeezed, but my measurements with a
micrometer, under very moderate pressure, are under 100 microinches,
about all I could fairly resolve. So that's about a 70 to 100:1 ratio
in thickness, and thermal resistance is proportional to thickness.

That is what we engineers call 'doing the math'.


So, if the heatsink is flat, the grease has roughly a 100:1 advantage
over a sil-pad. The phase-change stuff is similarly bad, mainly
because it doesn't really flow and remains several mils thick at best.
If the heat sink is small, this may be unimportant, as the heatsink
theta will dominate anyhow. But if you want to run a TO-220 or a
TO-247 anywhere near its rated max power, a sil-pad will be lethal.

John

 

[Steve J. Noll]

On Mon, 1 Dec 2003 0:10:21 -0800, DaveC <me@privacy.net> wrote:

White "tooth" paste kind, or clear greasy "hair stuff" kind?
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group

FWIW - there's a table comparing the thermal conductivities
of various materials and thermal interface materials at:

http://www.peltier-info.com/tims.html


Steve J. Noll | Ventura California |
| The Used High-Tech Equipment Dealer Directory
| http://www.big-list.com
| The Peltier Device Information Site:
| http://www.peltier-info.com

 

[Daniel L. Belton]

DaveC wrote:

White "tooth" paste kind, or clear greasy "hair stuff" kind?

Actually, the silvery kind

http://www.arcticsilver.com

 

[Daniel L. Belton]

Michael A. Terrell wrote:

Guy Macon wrote:

DaveC <me@privacy.net> says...


White "tooth" paste kind, or clear greasy "hair stuff" kind?

Neither.

http://www.ksbrainstorms.com/index.php?pagename=Arctic_Silver_5_Review
http://www.xbox-connection.com/hostedsites/hotlinesrc//reviews/arcticsilver5.php
http://www.overklokking.no/annet/arctic_silver_5/eindex.html
http://overclockersclub.com/reviews/articsilvercermaiquereview.php
http://www.modsynergy.com/Review%20109.htm

--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/


Make sure you use all the other over hyped crap so it doesn't get
lonely.

Actually, on my processor, the white thermal grease melts and runs out
all over the place, but the arctic silver remains in place... plus, my
cpu runs about 10 degrees C cooler with arctic silver... This is no
hyped crap... this is from my actual use and experience.

 

[Daniel L. Belton]

Floyd Davidson wrote:

Guy Macon <http://www.guymacon.com> wrote:

Michael A. Terrell <mike.terrell@earthlink.net> says...

Make sure you use all the other over hyped crap so it doesn't get
lonely.

I would find it easier to believe that it was overhyped crap if
I wasn't typing this on a quad processor Compaq Proliant that
has the CPUs runnin 10 degrees C cooler since I replaced the
OEM heat sink compound.


First, if you saw that much difference, then it is *obvious* that
the initial installation with OEM heat sink compound was flawed.
10C is *way* too much!

However, there *are* differences between the different heat sink
compounds. The question is, what is it worth to have 2 degrees
lower temperatures? If you have a one shot deal, and the price
is $10, why not??? That fact that for $6 you can do well enough
just isn't significant.

On the other hand, if you might do a dozen or more, it starts adding
up. Likewise if it ever comes to a question of delaying a project
until the "good stuff" can be obtained, that might not settle too
well either.

The most hilarious part of the whole thing though, is that the
difference between any of those silver based compounds that you
pay an arm and a leg for, is too small to be significant in most
cases compared to what you can find in virtually *any* automotive
shop.

NAPA Item# 765-2569
Copper Anti-Seize Lubriant

A 4 ounce bottle will last forwever unless you are in the business
of turning out multiple systems per day.

Ok... Let me put it into numbers... when overclocking my computer, I
get approx. 400 mhz more out of it when using arctic silver over the
white goop...

 

[Daniel L. Belton]

Floyd Davidson wrote:

DarkMatter <DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Mon, 1 Dec 2003 8:12:04 -0800, DaveC <me@privacy.net> Gave us:


On Mon, 1 Dec 2003 7:37:23 -0800, Floyd Davidson wrote
(in message <87u14kblcc.fld@barrow.com&gt:


NAPA Item# 765-2569
Copper Anti-Seize Lubriant

and you recommend this as a head-sink compound for semiconductors?


You have obviously not been around very long.

The discussion is centering around a silver based media, so if
conductivity is what has your bloomers in a bunch, it is not an issue.

The material he mentions isn't a lube, it's a spray used to seal
high pressure metal gaskets, like a head gasket.


Actually this stuff is a lube. It comes in a little container
with a brush on the inside of the cap. It is kind of an oily
looking stuff, with a lot of what appears to be copper flakes
suspended in it. (And it is essential to mix it up very good
before applying it, or all the copper will be on the bottom of
the container.)

It is *not* used on head gaskets, but rather on head bolts. The
idea is to smear them with this stuff in hopes that 10 years
later you might be able to unscrew them all without breaking
half of them.


It works absolutely flawlessly.


It does indeed.

yep, and absolutly essential on exhaust manifold bolts...

 

[Robert Baer]

Miles Golding wrote:

This question is timely for me. I'm about to build my own (first time) and
have bought an Intel P4 2.4 /heatsink pack. Having researched a fair bit
before starting the job, I discovered thermal paste. Is it really necessary?
I don't intend to overclock, so will the thin film already attached to the
base of the heatsink do the job adequately?
Miles

"DaveC" <me@privacy.net> wrote in message
news:0001HW.BBF0376D003D7AA4F0080600@news.individual.net...
White "tooth" paste kind, or clear greasy "hair stuff" kind?
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group

As you mentioned, ther are some heatsinks with a rubbery-like surface,
and it is designed to be used "as-is"; *nothing* should be added in that
case - doing so could damage the thermal characteristics.

 

[Robert Baer]

Ed Anderson wrote:

DaveC <me@privacy.net> wrote in news:0001HW.BBF0376D003D7AA4F0080600
@news.individual.net:

White "tooth" paste kind, or clear greasy "hair stuff" kind?

I use thermally conductive glue or arctic silver compound.

The "arctic silver compound" is *bad* stuff.
It migrates all over hell and back, not only making a crappy looking
mess, but also has been reported to do damage to electrical contacts.

 

[Robert Baer]

Guy Macon wrote:

DaveC <me@privacy.net> says...

White "tooth" paste kind, or clear greasy "hair stuff" kind?

Neither.

http://www.ksbrainstorms.com/index.php?pagename=Arctic_Silver_5_Review
http://www.xbox-connection.com/hostedsites/hotlinesrc//reviews/arcticsilver5.php
http://www.overklokking.no/annet/arctic_silver_5/eindex.html
http://overclockersclub.com/reviews/articsilvercermaiquereview.php
http://www.modsynergy.com/Review%20109.htm

--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/

The "arctic silver compound" is *bad* stuff.
It migrates all over hell and back, not only making a crappy looking
mess, but also has been reported to do damage to electrical contacts.

 

[Robert Baer]

"Daniel L. Belton" wrote:

DaveC wrote:

White "tooth" paste kind, or clear greasy "hair stuff" kind?

Actually, the silvery kind

http://www.arcticsilver.com

The "arctic silver compound" is *bad* stuff.
It migrates all over hell and back, not only making a crappy looking
mess, but also has been reported to do damage to electrical contacts.

 

[Genome]

"John Larkin" <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote in
message news:445osvk824g54mduli758nij2uj5iq3sa6@4ax.com...

On Mon, 01 Dec 2003 20:19:05 -0800, DarkMatter

But if you want to run a TO-220 or a TO-247 anywhere near its rated >max
power, a sil-pad will be lethal. }~~~

John

Missing Dribbly Devil Smiley added.

AND

Ooooooo super cross post

 

[Floyd Davidson]

"Cameron Dorrough" <cdorrough@spamspamgoawayrmna.com.au> wrote:

"Floyd Davidson" <floyd@barrow.com> wrote:
The material he mentions isn't a lube, it's a spray used to seal
high pressure metal gaskets, like a head gasket.

Actually this stuff is a lube. It comes in a little container
with a brush on the inside of the cap. It is kind of an oily
looking stuff, with a lot of what appears to be copper flakes
suspended in it. (And it is essential to mix it up very good
before applying it, or all the copper will be on the bottom of
the container.)

It is *not* used on head gaskets, but rather on head bolts. The
idea is to smear them with this stuff in hopes that 10 years
later you might be able to unscrew them all without breaking
half of them.

.. it's also used on large battery banks to anti-seize the
bus-bar-to-battery terminal bolts and to protect the connections from
corrosion.

Really? I don't think I'd do that. I'm a telephone plant guy,
and No-ox is the only thing I'd even begin to think of putting on
battery terminals etc.

It works absolutely flawlessly.

It does indeed.

Most certainly - though it's not cheap.

It is *way* cheaper than Arctic Silver compound. I can't
remember what I paid for the 4 Oz bottle I've got, but I think
it was something like $6. If that is right, it must cost $3 for
the same thing anywhere else in the US.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[Floyd Davidson]

DarkMatter <DarkMatter@thebarattheendoftheuniverse.org> wrote:

On Mon, 01 Dec 2003 18:20:13 -0900, Floyd Davidson <floyd@barrow.com
Gave us:

DarkMatter <DarkMatter@thebarattheendoftheuniverse.org> wrote:
On Mon, 1 Dec 2003 8:12:04 -0800, DaveC <me@privacy.net> Gave us:

On Mon, 1 Dec 2003 7:37:23 -0800, Floyd Davidson wrote
(in message <87u14kblcc.fld@barrow.com&gt:

NAPA Item# 765-2569
Copper Anti-Seize Lubriant
^^^^^^^^^^^^^^^^^^^^^^^^^^

Ahhh... I had a spray can of copper filled tack media for the head
gasket seal application. I remember the stuff you refer to now.

An anti-sieze compound.

Yeah, that's the stuff.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[DarkMatter]

On Mon, 01 Dec 2003 21:05:19 -0800, John Larkin
<jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> Gave us:

So, if the heatsink is flat, the grease has roughly a 100:1 advantage
over a sil-pad.

Hey retard. "The math" you jack off at the mouth about doesn't pan
out in reality.

The same transistor on the same sink varies by far less than a 100:1
difference. All the way up until the friggin solder is reflowing.

If one uses the "math" you refer to one can easily see that 7 mils
of sil-pad performs quite similarly to your 0.1 mil interface.
Actually better, since the temperature difference is only a few
degrees on the device. Why for a 70 times thickness, it conducts
across its thickness very nearly the same amount of heat. That
suggests, by the math, that the pad media is BETTER at the job. It is
certainly better when electrical isolation is involved, which often
times it is. Multiply your goop at 70 times the gap and watch it NOT
pass the heat the same, if at all. It is made ONLY for filling
micro-crevaces in the mating interface. If the interface has ANY gap,
the stuff is virtually worthless.

The conductivity, and efficiency of the sink to carry off the heat
is far more important.

We run large high power devices on sinks all the time. We operate
them at proper design maximum levels, however. Not the scenarios you
suggest.

If one designs or uses such devices AT their rated power, one is
asking for a failure mode. DOH!

You need to get a clue. Pads are much more stable over a much
longer period, and even withstand service operations.

Your brain obviously doesn't deal with FACT operations though, so I
guess you won't be learning anything anytime this decade.

 

[DarkMatter]

On Tue, 02 Dec 2003 09:05:40 GMT, "Daniel L. Belton" <abuse@spam.gov>
Gave us:

Michael A. Terrell wrote:

Guy Macon wrote:

DaveC <me@privacy.net> says...


White "tooth" paste kind, or clear greasy "hair stuff" kind?

Neither.

http://www.ksbrainstorms.com/index.php?pagename=Arctic_Silver_5_Review
http://www.xbox-connection.com/hostedsites/hotlinesrc//reviews/arcticsilver5.php
http://www.overklokking.no/annet/arctic_silver_5/eindex.html
http://overclockersclub.com/reviews/articsilvercermaiquereview.php
http://www.modsynergy.com/Review%20109.htm

--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
have an "impossible" engineering project that only someone like
Doc Brown can solve? My resume is at http://www.guymacon.com/


Make sure you use all the other over hyped crap so it doesn't get
lonely.

Actually, on my processor, the white thermal grease melts and runs out
all over the place, but the arctic silver remains in place... plus, my
cpu runs about 10 degrees C cooler with arctic silver... This is no
hyped crap... this is from my actual use and experience.

The reason is because people are so poor at actually mating two
surfaces together in a co-planar manner, that the metal filled shit
works better, since it fills gaps, and passes heat across that fill,
whereas the others bake out or perform quite poorly in the same
setting.