Make a Donut-Shaped Filled Zone with a Filled Hole

[FarmerPotato]

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.)

[John_Pateman]

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.

Strange behavior of the copper fill tool

I have designed a board with a small switching power supply, doing the placement of components and adding the 3D models when not already available. However, I want to fill some areas of the PCB with copper, following the layout recommendations found in the switching power supply IC datasheet. I successfully succeeded in adding a ground plane on the back side of the board. However, when I try to fill ground areas on the front side, a strange phenomenon occurs: when I try to create and fill separa…

[FarmerPotato]

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

[davidsrsb]

Zone Priority is in Section 10.2.2 in the Help