[SI-LIST] Effects of solder layer on exposed traces

My question is in reference to previous posts that asked about the
effects of solder mask (or silkscreen) on the impedance of lines for
high frequency ( >2 GHz) lines.  The general consensus I took was that
solder mask could greatly effect the expected impedance of the traces
as another dielectric is introduced.

In my application we have etched antennas on a 60mil FR4 board.=20
Normally, I have made antennas in house using a simple acid etch bath
(crude but effective).  However, when we order boards from a PCB
house, any exposed traces are normally covered in a layer of solder
(including our antennas, but there is no soldermask on the antennas).

Now given that solder is not copper and thus it will have different
electrical properties, how will this effect the expected performance
of the board, and will it be a noticeable effect?

Regards,
Sean McDevitt
Student
University of Colorado - Boulder
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