Buried Capacitance

Don Abernathey (dla@pyramid.com)
Fri, 31 May 1996 16:15:21 -0700

Hello!

About four or five years ago Zycon Corp began licensing it's buried
capacitance technology to other PCB manufacturers. The technology was
simple, a very thin (~2mil) layer of FR4 sandwiched by 1oz copper
layers. The technology received a somewhat lukewarm reception in the
industry as the max capacitance per square inch was way lower than
what people needed for the mean operating frequency and device
technologies then in vogue. It required about 3 BC stacks to achieve a
usable capacitance (usable means that all the .001uf and .01uf caps
went away). I think Zycon showed a technology roadmap where the dielectric
constant of the laminate material continued to increase over time.

Has anyone out there used BC? Can you give me a little update, from a
user's perspective, of where BC is going? I would really like to know
if the qualifications of the higher dielectric laminate materials ever
finished, or if the FR4 laminate is all they have. Any negative
experiences with BC? (I ask this because people are always afraid of
power/ground plane shorts). Any hassles getting the PCB fab yields
stabilized? Any experience on the usability in general?

Any and all feedback is welcome.

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Thank you |
Don Abernathey |
(503)690-6234 |
dla@pyramid.com |
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