Thermal Grease

[J. Forster]

It is possible that at one time BeO was used in grease, but I've never seen it and
I've been using the stuff since 1963. I very much doubt it's in commercial use
anymore. In the late 60s, I was using BeO washers on TO-3 transistors.

FWIW,
-John


Garey Barrell wrote:

> Wes -
>
> That makes me feel better.   I thought I remembered beryllium oxide
> grease.  NASA certainly was well above us "mere mortals!"   At least in
> the 60's when I was there...
>
> Garey - K4OAH
>
> W. Kranitz wrote:
>
> >
> > The "new" style white silicon grease is called "Type Z9"
> > Silicon Heat Sink Compound. Some special application versions
> > of this compound used beryllium oxide, but these were not available
> > to us mear mortals. Most common versions use aluminum or zinc
> > compounds. Some of the newer types use Micronized Silver (eg, DYNEX
> > Silver Thermal Compound). These are used for the high heat transfer
> > needed for modern microprocessors.
> >
> >
> > Garey Barrell wrote:
> >
> >> Jerry -
> >>
> >> There are at least two types that I am aware of.
> >>
> >> The "old" style was clear silicone grease.
> >>
> >> The "new" style is white silicone grease loaded with beryllium oxide.
> >>
> >> Both work pretty much the same, the purpose being to fill any  TINY  air
> >> pockets trapped between what ideally would be two "perfectly" flat
> >> surfaces.  The idea is that the grease is a better at heat transfer than
> >> air.  It is NOT a better conductor than metal, so a big blob of grease
> >> isn't going to transfer much heat between two surfaces that don't
> >> touch.!
> >>
> >> Proper use calls for only a VERY thin smear.  Most people use WAY too
> >> much, which of course gets squeezed out when the two pieces are clamped
> >> together.
> >>
> >> By the way, beryllium oxide DUST is considered very toxic if inhaled, so
> >> I guess you wouldn't want to eat the stuff!
> >>
> >> 73, Garey - K4OAH
> >> Atlanta

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