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  • Cutout

    Need to make a cutout in the internal planes, should we use "place -> ploygon pour cutout"? or another command exit?
    How we can verify the effect on layer print outs?

  • #2
    Hi @JohnsonMiller,

    If you are using Altium planes, those are negative layers so you can just use normal polygons for the cutout (since positive copper shapes like polygons, fills, regions, tracks, etc. create a cutout on a negative layers). I am not sure what will happen if you use polygon cutout on a plane layer, you can test it with a dummy PCB by exporting gerber files and checking what happens.

    If you are using signal layers and big polygons for your planes, then you can use polygon cutouts.


    • #3
      Hi Mariomaster,

      Thank you, I did "place -> ploygon pour cutout" and tested with Gerber plots,

      I would like to focus on your last sentence, does it mean we can define all the stackup as signal layer, then use polygon instead of plane, and make sure that it will be manufactured without problem? or we need to cal manufacturer and inform them about changes?



      • #4
        Manufacturers generally care only about the gerber files and not how you achieve what is on them, so you don't need to inform them about that. You just need to make sure that everything is how it is supposed to be.

        For more complex boards I tend to only use signal layers and polygons for the planes. Polygons behave a bit more logically in my experience. I forgot what was it exactly, but I remember that if you use micro vias in your design, it is strongly recommended to use polygons instead of planes. Also you can easily have tracks and other primitives on the polygon layer and the polygon just pours around them, while it is a bit more confusing/impractical with planes. Another thing is that polygons are distinct objects and you can do smart operations with them, like using filters, see when they've been modified, etc.

        Planes have their advantages as well, and I prefer them for simple boards. They re-pour automatically when you do changes and are less performance heavy. They are also easier to use if you have many split planes and need to often modify them - with polygons you would need to re-draw them which could be time consuming.


        • #5
          I just would like to confirm mairomaster's approach, we do it same.

          - in case you would like to place a cutout on a plane layer, you can just draw a square / rectangle. It is not necessary to use a polygon, polygon is an object with some properties (e.g. Net name) and this is not really required to make cutout in plane layer. But you still probably get the same result.

          - we mostly use Altium "plane" layers for a solid PCB plane layers assigned to one net. If there are many polygons or if there are some tracks, we always use Altium "layer". Polygons can be annoying because Violations when you place VIAs later and you need to keep refreshing them, but they are easy objects to manipulate with. I think, manipulation with Altium "planes" is getting more simple by now, so you may want to try them too.