>>> Earl Moon <[log in to unmask]> 09/19/01 11:56AM >>>
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Some kind folks have, or had, a patent on the material you talk about. 5
core material (using two plies of 1080 or a single ply of 2116, as examples)
is readily available but does not get the job done.

Though a board shop might creat the required, very thin core material, it
wouldn't be prudent as usually placing, say, a single ply of 106 (less than
2 mils thick) between ED copper could cause significant shorting
possibilities as the rough side faces the preg and the spikes and valleys
offer the challenges. If rolled/annealed copper was used, the problem would
be eliminated. Still, the board shop may not be the way to go.

Various laminate suppliers, to board shops, have been licensed to sell
capacitive types. The folks at the old Zycon got the patent. They then
took it to Praegetzer who was bought by Plexus, and on it goes. You may wish
to start with the laminate suppliers for your research.

Merrix, and other board shops and laminate suppliers, offer material
thicknesses based on various constructions. You should look at these and
notice the DK's for various types and the capacitance numbers, and others,
as well. I'll send you one of my favorite matrices, good last week at least,
if you wish.

Earl Moon (POD)

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