Fill zone overlap issue

For some reason my fill zones overlap when filled, even though they are different nets (VCC and GND). Why is this? How can I fix it?

Thanks!

You have to set the zone priority level accordingly under the property menu (or press E after clicking on the zone).

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Does DRC give an error when two zones with different nets but with the same priority overlap?

In past versions I couldnā€™t create zones like that without having set priority correctlyā€¦ maybe it changed?

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I tried setting different priorities. That fixed it! Thank you everyone! I did have to clear and fill again to see the priorities take effect.

Thanks again!

Can you share more details? (I havenā€™t encountered this situation yet but I see it approaching on the horizon.)

Referring to the image in your original post . . . and extrapolating from previous experience with other EDA tools Iā€™d expect the behavior to be:

  1. If the ā€œVCCā€ zone was filled first Iā€™d expect the ā€œGNDā€ zone to leave the VCC fill intact, flowing around the VCC fill while honoring all the constraints for clearance, minimum line widths, etc. In a logical sense, the zones filled first take precedence over later fill operations.

  2. If ā€œGNDā€ was filled first Iā€™d expect the ā€œVCCā€ zone to fill only the areas (within its defined zone) that hadnā€™t already been claimed by the GND fill. In many situations (like your example) this will make the actual VCC fill smaller than its zone definition. This seems consistent with the ā€œprecedenceā€ concept I mentioned above.

Alternatively, I can imagine the VCC fill acting to ā€œpush backā€ the GND fill as necessary so that VCC can occupy the full extent of its defined zone. This essentially inverts the order-of-precedence I mentioned above but itā€™s consistent with other human experiences, e.g. the idea that when a government makes a law, it takes precedence over any conflicting portions of earlier laws.

The situation shown in your image - where the VCC copper occupies the same space occupied by GND copper - is simply improper at the most fundamental understanding of clearances, interference, etc.

Like @cioma, Iā€™d like to know how DRC reacts to situations like this. If KiCAD is known to produce the kind of unacceptable behavior shown in your example, Iā€™d at least like to have some confidence that DRC will alert me.

Dale

I can reproduce this issue on r6643. But at least DRC troughs up the following type of errors:
ā€œCopper area inside copper areaā€
ā€œCopper areas intersect or are too closeā€

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Can you use this functionality with zones over zones to create voids in GND plane?

But the void will not have a net as it is void.
Maybe covered some where in documentation.

Need to make some voids in a place.

Need to make some voids in a place.

Use the route keepout functionality.

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dosent work on planes
at least noit in cairo mode

it just quits the operation silently

Sounds like the behavior when I tried to create a zone overlapping another zone without setting the priority right in BZR60xxā€¦ BZR66xx does bring up a warning when I try to do this now and works afterwards normally when I set the priority.
Only thing that helped to get the zone module back working again was to restart pcbnew and try againā€¦

Anyhow, keep out area works in default canvas, no probs:

can you confirm it not working in cairo ?

if so i submit a bug

just to check its not user error on my part

It did fill the zones during creation automatically and had no warning when I didnā€™t set the prio for the smaller copper zone (left at 0 as the larger one when I made it).
Looked like in the OP, so DRC should catch thisā€¦ but I donā€™t use Cairo, soā€¦

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In a 30-second test, I was able to create a keepout area while using Cairo, though I couldnā€™t seem to repour the copper (and make the zone obvious) until I switched back to Default.

In my work pattern I regularly switch between Default and OpenGL. I havenā€™t found any feature or capability thatā€™s unique to Cairo, and it seems to run slower than the others on my machines. Does Cairo offer some advantage Iā€™m not aware of?

Dale

cant say for sure

the other look horrible but thats just subjective

i will try the other more further on.

ever tried in the middle of a GND plane ?

Drawing either a keep out or another filled zone in the middle of a bigger zone do not cause a ā€˜silent operation quitā€™.
It draws the zones (no matter if prio is set correctly or all 0).

For me OpenGL and Cairo look the same.
Need to play a bit more in OpenGL, canā€™t put my finger on what ā€˜feelā€™ it is that Default has that I prefer, as the look of OpenGL is nicer than Default. Only thing I miss there is the color mixing for overlapping features (Red + Green = Yellow) and the grid is a bit to prominent in OpenGL (on darkest grey) vs black backgroundā€¦ just dotā€™s as in Default would be nice.

A post was split to a new topic: Possible Zone Bug

Resurrecting a 6.5 year old thread regarding a possible zone issue in the current Kicad version serves no purpose.