2017-08-17 7:22 GMT+02:00 Luke Kenneth Casson Leighton lkcl@lkcl.net:
On Thu, Aug 17, 2017 at 12:01 AM, Richard Wilbur richard.wilbur@gmail.com wrote:
I would also look carefully at the GND traces separating the differential pairs from board edge and other circuitry. If we can't put 15mil between the differential pair traces and these GND traces, I would remove these GND traces as well. If we have to remove the GND traces between differential pairs and other circuitry, this will at least have the happy effect of providing 15mil spacing between the differential pair and that other circuitry.
flood-fill will just end up putting them back - i'd have to set a copper-to-trace separation @ 15mil as well.
Isn't there a option to create barriers or free form where the floodfill may not come, white spaces so to speak. Seems to me there should be. You should be able to create "white" spots on the GND planes for various reasons.