Make a Donut-Shaped Filled Zone with a Filled Hole

I want to use Filled Zone and Keepout Area to create a VCC donut, with another voltage zone inside the hole.

I usually start with a top fill for VCC and a bottom ground plane. I added a keepout zone to create the Hole for the Donut. Because it’s a Keepout Zone, I can’t put another Filled Zone in there.

In one application, I want to make a +12V zone inside a +5V zone. These are rails from an ATX power connector.

In another application, I need to isolate an analog AVCC zone, inside the top fill which is a digital VCC zone. (connected through a ferrite bead). The AVCC zone is for audio or video DACs. The video DACs have pixel clock up to 60MHz.

Is there a way to make a complex polygon Filled Zone, without using a Keepout Area?

The ideas I have so far are:

  1. Forget the +12V filled zone from the ATX power connector, and just use fat +12V traces. The +12V rails are primarily for fans or lamps, so I thought I should keep them away from any 3V3 or 5V digital traces. There is a picture below.

  2. Move the +12V or AVCC zones to the edge of the board, so I can draw simple polygons for each voltage zone.

So, is there is a general solution to the “Filled Donut Hole” problem?

Alternately, if you have an opinion, is a donut hole overkill here? I am one of those digital guys trying to get up to speed on the analog side.

I would appreciate any advice. (And now I’m thinking of going to Krispy Kreme.)

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You can place multiple overlapping zones - they can each be given a priority to determine which one ‘wins’. Each zone can have its own settings - clearance,thermal relief etc. No need for a keep out zone.


That did it. Quite easy to raise the Priority of the 12V filled zone.

Zone Priority is in Section 10.2.2 in the Help


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