Jim Kelley wrote:
The question was excellent. 'Impedance discontinuity points' is nonsense.

It is common practice during an analysis to consider
the impedance discontinuity where Z0 changes to be point
connections at a plane. All of my technical books draw
the connections that way. None of them attempt to
treat the connection as anything other than points.
If you choose to analyze what happens at a 1 mm drop
of solder, be my guest.
--
73, Cecil http://www.w5dxp.com