Keepout, and restrict polygons are powerful tools at your disposal as a PCB designer. Keepout is used when you don’t want components placed within an area, like edges of a board, or where your heatsink will be placed.
Restrict polygons make sure the specific copper layer cant be placed within the polygon. We use them to keep other traces away from noise sensitive traces and parts. Both keepout, and restrict together are used to keep part, and copper away from metal standoffs on our Sick of Beige cases.
How to use
Create a polygon with one of the layers described below, covering an area for which you need keepout, or restrict. For more information on polygons in general check out our polygons guide.
Special Layers you could use
tKeepout / bKeepout
When a component contains a keepout layer on its perimeter, the DRC checks if there are overlaps with your keepout polygon. If there are overlaps, you will be informed about it through the DRC error report.
‘Keepout clearance for components overlaps’
These layers check for overlap of top copper, bottom copper, and vias when running a DRC with “Check Restrict” toggled under Misc. Tab in DRC. Also informing you about overlaps in the DRC error report.
‘DRC window, Miscellaneous Tab’
This will also cut through, or prevent power planes. Great for protecting noise prone areas.
You can turn-off tKeepout/bKeepout layers under ‘View>Display/Hide Layers’ to bypass the check.
Restrict will still be checked even it’s layer is off, you should un-check it in the DRC menu if bypassing is required.
Here’s an interesting use of Restrict layer. You could etch away your logo or text using restrict.