[TechAssist] Re: Heat sink compound
- From: "J Silverman" <greentron@xxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Fri, 8 Oct 2004 12:48:11 -0400
I usually apply so little that I can see metal. Then when the clamp gets
tightened the excess flows into the low spots and maximizes the metal to
metal contact. There is no need to clean off any excess that squeezes out.
Some people have mentioned that they just use clear grease. As I mentioned
before, anything is better than air, but the filler is what does most of the
heat transfer where there is not metal to metal contact.
The efficiency of the modern power supplies and deflection circuits is so
good that the heat sinking is not critical which is why so many different
approaches seem to work.
But it wasnt always that way. A long time ago we used to design and build
things for industrial applications and we had to fiddle quite a bit with
heat sinks and blowers to keep the tempertures at levels where the
semiconductors could operate reliably. Even painting the heat sinks with the
right kind of dull black paint could drop the temperature 10 degrees or so.
For heat sink compound we formulated some with berylium oxide, boron
nitride, and even diamond dust for superior heat transfer.
Jerry Silverman
Greentron Inc
4 Newland Ave
Greenville SC 29609
Fax/Phone 864 232 3889
mail to: greentron@xxxxxxx
----- Original Message -----
From: "Wayne Vanaman" <Wayne@xxxxxxxxxxxxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Thursday, October 07, 2004 4:46 PM
Subject: [TechAssist] Re: Heat sink compound
> Good points, Jerry.
>
> I use Thermalloy's Thermalcote. It is available in large cans and small
> squeeze tubes, and is very good stuff. This stuff does not thin, run,
> or dry out.
>
> From the can, "Directions: Apply thin, even coating to mating
> surfaces. After making joint secure, remove excess compound with
solvent."
>
> Wayne Vanaman
> Omega Electronics
> 6904 W Fairfield Dr
> Pensacola, Fl. 32506-3310
>
> Wayne@xxxxxxxxxxxxxxxxxxxxx
> WWW.PensacolaTVRepair.Com
>
> 850-456-5995 voice
> 850-458-6369 fax
>
>
> J Silverman wrote:
> > There is a lot of misunderstanding about "heat sink compound". The best
heat
> > transfer is metal to metal. Both surfaces need to be highly polished and
> > clamped firmly together. Anything else is a compromise. If the surfaces
are
> > not perfectly flat and highly polished, they will only touch at the high
> > spots, so if you can fill in the low spots with almost anything it will
be
> > better than air.
> > The "grease" is just there to to keep the powder filler from falling
away.
> > Aluminum oxide is the most common filler. Its not a very good heat
conductor
> > but it is none-conducting, none toxic, and cheap. There are many other
> > fillers that could be used that are better heat conductors but they are
> > either conducting, toxic, or expensive. But there are special situations
> > where they are used.
> > So the best way to use a heat sink compound is to use as little as
possible
> > so as not to interfere with the metal to metal contact. Some devices are
in
> > plastic cases so that a heat transfer as good as metal to metal could
never
> > be obtained, but the above advice is still applicable. The reason I say
that
> > there is a lot of misunderstanding is that I see a lot of units that
have
> > come from the manufacturer with the compound globbed on thickly, and I
> > frequently see the incorrect advice "Be sure to apply lots of heat sink
> > compound".
> > Jerry Silverman
> > Greentron Inc
> > 4 Newland Ave
> > Greenville SC 29609
> > Fax/Phone 864 232 3889
> > mail to: greentron@xxxxxxx
> > ----- Original Message -----
> > From: "al m" <ampm@xxxxxxx>
> > To: <techassist@xxxxxxxxxxxxx>
> > Sent: Thursday, October 07, 2004 8:34 AM
> > Subject: [TechAssist] Heat sink compound
> >
> >
> >
> >>I know it's off topic but I haven't thought of what I was buying before.
> >>Which is better the non silicone or the silicone compound?
> >>Al Marquardt
> >>ampm@xxxxxxx
> >>Al Marquardt Electronic Repair
> >>206 W Main
> >>Girardville Pa. 17935
> >>
> >>
> >>
>
>>--------------------------------------------------------------------------
> >
> > ---
> >
> >>Lost Password:
> >>http://www.tech-assist.org and select "Login Problems?".
> >>Email Archives:
> >>//www.freelists.org/archives/techassist/
> >
> >
> >
>
> --------------------------------------------------------------------------
---
> > Lost Password:
> > http://www.tech-assist.org and select "Login Problems?".
> > Email Archives:
> > //www.freelists.org/archives/techassist/
> >
> >
>
> --------------------------------------------------------------------------
---
> Lost Password:
> http://www.tech-assist.org and select "Login Problems?".
> Email Archives:
> //www.freelists.org/archives/techassist/
-----------------------------------------------------------------------------
Lost Password:
http://www.tech-assist.org and select "Login Problems?".
Email Archives:
//www.freelists.org/archives/techassist/
Other related posts:
