There has been a few questions about impedance calculation software.  I
have been using the formulas in IPC-D-275, without out any problems.  Do
the IPC formulas use assumptions which the impedance calculation software
do not?  Are there times when I sould not use these equations?  Do they
work at 10+ Ghz, linewidths >> dielectric, in a vacuum, etc.?

Thanks for the responces.  I just realized I was using these formulas
without understanding any of the assumptions or limitations.

Todays Quote:  "Chemical Engineers never die, they just fail to react!"  -
off the walls of Roger Adams Lab, Univ. of Illinois.


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