CPU thermal paste?

[R. Anton Rave]

Silicone rubber is a stupid choice for thermal compound.

Then why does almost every switcher use it? Do you know something
that the engineers of Astec and Delta don't?

 

[kony]

Then why does almost every switcher use it? Do you know something
that the engineers of Astec and Delta don't?

They are not paranoid about temp like PC users are, and it allows
electrical isolation if/when needed.

 

[Ralph Wade Phillips]

Howdy!

"Noozer" <[email protected]> wrote in message

Then why does almost every switcher use it? Do you know something
that the engineers of Astec and Delta don't?

Electrical insulation.

That's almost a "D'oh!" innit?

RwP

 

[w_tom]

And you *know* this is silicon rubber? Or it just looks
like silicon rubber?

 

[Richard Brooks]

I'm coming in late on this thread but try your local hobby shop which deals
with transistors. Thermal paste was used for heatsinks on power transistors
and amplifier ICs.

Richard Brooks.

 

[kony]

And you *know* this is silicon rubber? Or it just looks
like silicon rubber?

Many are, silicone rubber on a fiberglass matting.

http://209.98.79.41/objects/SilPad_SelGuide_PDFs/SilPadOverview.pdf

 

[R. Anton Rave]

They are not paranoid about temp like PC users are, and it allows
electrical isolation if/when needed.

They're more paranoid than PC users are about actual temperature
issues, less than they are about trivial ones, and if electrical
isolation were the only reason for that silicone rubber, why is it
always found against a heatsink?

 

[R. Anton Rave]

And you *know* this is silicon rubber? Or it just looks
like silicon rubber?

Opaque, rubbery, and either grey, light blue, or red - definitely not
Kapton, mica, ceramic, aluminum oxide, or beryllium oxide. Every
catalog and application note mentioning the composition said it was
silicone rubber (Allied Electronics: Aavid brand IN-SIL-8 pads,
"Thermally Conductive Composite of Silicone Rubber and Fiberglass
Provides Better Thermal Conduction Than Mica and Grease"). If it's
not silicone rubber, what could it be? Teflon?

 

[kony]

They're more paranoid than PC users are about actual temperature
issues, less than they are about trivial ones, and if electrical
isolation were the only reason for that silicone rubber, why is it
always found against a heatsink?

They are not paranoid, they consult specs and follow them, unlike PC users
who try to get the lowest CPU temp possible for no good reason while
ignoring CPU manufacturer spec or threshold for stability. I literally
meant "paranoid". A "PC" user may try for 30-50C temps but a power supply
designer has no such illusions that a regulator needs to stay under 50C.