[volt-nuts] PCBs with ceramic substrates

[Chuck Harris]

Hi John,

I am not advocating ceramics in place of FR4, or vice versa.
That was someone else wondering why ceramics weren't used in
metrology...

As to what you can use that isn't brittle, that is up to your
imagination.  Unlike common FR4 materials, ceramics don't do
well with the usual FR4 process of thermally bonding a thin
sheet of copper to each side, masking, etching, and being happy.

Ceramic PCB's, in my experience, are more of a silk screen
a silver ore gold bearing "glaze" on the surface of the ceramic,
and fire in a kiln process.

Any ceramic you can get in a thin sheet the thickness you desire,
and in the shape/size you desire is a candidate.

Some ceramics might not do well with drilling, or other machining
processes, so may have to be formed, drilled, etc. while in the
greenware state.

I shudder to think what machining ceramic armor plate, as is
used for the breastplate in a "bullet proof vest" might be like.

There are some ceramics that would eat tungsten carbide drills
for breakfast, so diamond tooling is probably essential.

-Chuck Harris

John Devereux wrote:
> 
> 
> Hi Chuck
> 
> But the context is "PCBs with ceramic substrates". Are any of *those*
> tough? They may well be, perhaps you know of some? It does not help us
> with the subject much if there are ceramics with these amazing
> properties if they are not available as PCBs.
> 
> There is also the question of exactly what properties of FR4 are
> limiting for "metrology" use.
> 
> John