Home made heat sink pads

[default]

It's expensive. It has to be mined from the earth.

Uneconomic in the US perhaps, but the world price for sheet mica was
about 50 cents a pound in 2005. That doesn't seem overly expensive.

It has been supplanted by other materials that work better, are less
fragile, and sometimes cheaper.

 

[JoeBloe]

You probably want the extra-virgin stuff from the first squeezing.

That only sounds "hot" to an Italian.

 

[JoeBloe]

Uneconomic in the US perhaps, but the world price for sheet mica was
about 50 cents a pound in 2005. That doesn't seem overly expensive.

Considering that the deposits of it are not overtly large, it is.
Copper was that price at one time. For an insulator material to be
half the price of copper tells me that it is fairly expensive.

Die cut items from sheet stock cleavings of it would seem even more
expensive.

 

[John Larkin]

That only sounds "hot" to an Italian.

Regular virgins are OK, but the extra virgins are usually just too
fussy.

John

 

[joseph2k]

hmm... your starting to sound like your getting mad because I don't take
everything you say on faith. hmm. I wonder what that means?

I asked if anyone knew of heat sink pads that could be made from common
materials. I mentioned silicone and immediately you and Eeyore jumped on
that saying that it was crap. I have web sites that disagree with you.
Now, instead of proving with reason that the sites are wrong I get
insulted into trying to believe you are right. Now maybe most people will
roll over and play dead but I won't. Do you really expect me to believe
you when you reason through "muscle" instead of logic and observation?
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


omg, I guess that proves beyond any reasonable doubt that you are an
expert in heat sink pads of all kinds of materials?

Well, some of the posters are starting to provide links. Where are yours?
You have quacked on this twice now, but still no links of your own.

Due to physics (that i still cannot follow all of, though electron mobility
is a common theme) electrical conductors make the best thermal conductors,
and electrical insulators make the best thermal insulators. It is also an
empirical fact. Electrical insulators that are decent thermal conductors
are very difficult to find or manufacture.

 

[John Larkin]

Due to physics (that i still cannot follow all of, though electron mobility
is a common theme) electrical conductors make the best thermal conductors,
and electrical insulators make the best thermal insulators. It is also an
empirical fact. Electrical insulators that are decent thermal conductors
are very difficult to find or manufacture.

The ceramics BeO and AlN are unusually good thermal conductors, both
in the ballpark of aluminum.

The opposite case, electrical conductors that are thermal insulators,
is even nastier. Most metals run around 160,000 degC/watt per ohm of
resistance. Brass seems better, at around 230,000. Superconductors
have an infinite ratio, zero resistance but finite theta.

John

 

[JoeBloe]

Regular virgins are OK, but the extra virgins are usually just too
fussy.

Taken one at a time... they all end up saying...

Don't... stop... don't... stop...

 

[Jeff L]

The best insulator is of course none; float the heat sink and use a
dab of grease under the semi.

John

I prefer a blob of solder paste under the semi, on top of a large copper
heat spreader, run through an oven.to reduce thermal impedance! Rework /
repair can be a bitch though.

Jeff

 

[JoeBloe]

I prefer a blob of solder paste under the semi, on top of a large copper
heat spreader, run through an oven.to reduce thermal impedance! Rework /
repair can be a bitch though.

Jeff

It can also be a bitch if it must be electrically insulated from the
heat sink. Say... 2kV. Oooops

 

[Jeff L]

So get man-made ones...

They don't work as well.