footprint-level DRC exceptions (ie: to disable courtyard checking)

[Dick Hollenbeck]

I am using a CPU boardlet called the Nanopi NEO2 and made a footprint for it that essentially locates the pin headers on a carrier card for it. These are like supporting beams so the card can hang above the carrier on the two headers. Naturally this footprint has a courtyard. But I also put stuff between the two pin headers underneath the suspended daughter CPU boardlet. I am getting DRC courtyard collisions on scores of small caps used to support a bigger chip on the back side of the carrier. The big chip is on the back side, some of the caps are on the front, the same side as the CPU daughter board.

Is there a way to flag some footprints to be omitted from the courtyard collision tests? Like a hyperspace omission. Without this, I'd have to call this a bug.

[Seth Hillbrand (sethh)]

Hi Dick-

Can you make multiple courtyards for the pin headers and let the caps sit between them? I think that the courtyard algorithm allows this.

[Rene Poeschl (poeschlr)]

Yes the algorithm allows this. It even allows cutouts. (The emc shields in the official library use this fact.)

[Wayne Stambaugh (stambaughw)]

Tthe nested courtyards are a solution to some problems, its doesn't solve all of them. I think a flag in the footprint definition in the board something like (drc-ignore a b c) where a, b, and c are drc footprint tests to ignore could prove useful I actually have a use case were I place a SMT resistor in the middle of an opto-isolator footprint to allow for isolated and non-isolated variants of a design. Disabling the courtyard drc test in this case would be helpful. Since this will require a board file format change, it will have to wait until v6 development. This could be done as part of the v6 DRC changes.

[Rene Poeschl (poeschlr)]

Would it maybe be better to have this as part of DRC instead of the footprint? Maybe a DRC message manager that allows permanently ignoring a specific error message could be the way to go. (It would allow ignoring specific messages that are not connected to a footprint. This might become handy if DRC capabilities are expanded.)

[KiCad Janitor (kicad-janitor)]

KiCad bug tracker has moved to Gitlab. This report is now available here: https://gitlab.com/kicad/code/kicad/-/issues/2340