How ot use a rule area to avoid everything except ground

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1

Hi,
I’ve creating a board to close an alumunium extrusion.
So my board will be screwed to the aluminium extrusion box, and I want to ground the the box via the screw.
But I don’t want any track other than ground on the bottom layer, because the aluminium can rub on the PCB and the soldermask might not be enough to avoid a short circuit.

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My first idea is to create a rule area around the corner of my extrusion box, to avoid putting any track or via or pad. But I still want to have a ground connection.

Is it possible to allow the GND net inside the rule area and create a DRC error for any other ?

Or should I just ignore the DRC violation for the GND.

2

I think that I would be not using any rule area for this, but:

  • mounting hole with enough big pad (grounded), or
  • mounting hole with user defined pad shape if you don’t accept pads being cut by board edge.
3

My issue, is not really with the pad.
But I want to avoid to put any track where I’ve draw my arrow.

Right now I’m doing it with a visual check, but it’s easy to do a mistake.

4

But you have written:

So you need pad.
I don’t have KiCad here to check it, but I suppose you can assign bigger clearance to the pad (I think I have used it defining fiducials). If the pad will be GND than GND will connect to it, but any other net will have to keep specified clearance.

5

If you can have ground via a zone fill then you can use a keepout zone to keep out tracks but allow zone fills.

6

Thanks, I didn’t think of it, as It allows to create an unwanted zone. But it is quite unlikely that I’ll mess up with another zone other than GND

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