E.U.N.U.C.H. (Cooling)

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Thu Nov 18 13:13:03 1999

Yes, by me.

It was a suspension so dust was not possible. I also have silicone grease
with BEO for apps. Used to do things like cunduction cooled tube amps and
Water cooled tube amps so I know that stuff is dangerous. Blocks of the
stuff would be machined in a special negative pressure room with HEPA
filters, operator is in class-A garb for protection. If an insulator with
good thermal propterties is required the choices are small.

It's still used for those SOT RF power transistors.

Allison


On Thu, 18 Nov 1999, Sipke de Wal wrote:

> Beware !!!!!!!!!!!!!!!!!!!
>
> Beryllium was mentioned here. Beryllium Oxide was used in the thermal
> conduction stuff HF-transistors decades ago, but this ceramic stuff can
> be quite lethal. If it breaks and you inhale a few microns of the dust
> there off, lungcancer can almost be guarantied within a decade !!!!
>
> Stay away from BEO !!!!!
>
> Sipke de Wal
>
>
>
> Hans Franke wrote:
> >
> > > At -100 Celsius: Al, 241; Cu, 420, Ag, 432. Interestingly enough, at these low
> > > temperatures Beryllium is pretty good at 367.
> >
>
Received on Thu Nov 18 1999 - 13:13:03 GMT