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From [log in to unmask] Wed Aug 7 08: |
41:39 1996 |
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id m0unzUl-0000KLC; Tue, 6 Aug 96 22:41 CDT |
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Dom Bragge asked:
>Using 1.6mm FR4 with LPISM, we need information on how to prevent
>breakdown between tracks on the outside layer separated by 12thou,
>when subjected to 1500V continuously. What sort of coatings/processes
>aid this?
I'd sure want a big fire extinguisher handy!
You'd want the board scrupulously cleaned, then have something like
Parylene conformal coating applied post assembly - something thicker and
with a higher dielectric than a normal solder mask. Thin coatings like SM
are not really occlusive enough to prevent moisture penetration in even
fairly benign environments. That's a bunch of EMF and a pretty small gap.
You must be talking about a tiny current?
You could consider using a laminate other than FR-4, again - the best
possible dielectric rating. FR4 works real nice at about 5 V.
(warning, the above opinion might be disclaimed instantly, and can only be
offered in a highly secret environment like TechNet)
Let's hope you get a better suggestion...
73,
Jerry Cupples
KC5SXA
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