almost splitting a power plane

[dbur]

I see a some discussion on splitting power planes going on in various threads.  Often I need to put a slot in a plane or cut out sections that are still connected at strategic locations.

A good way to do this I have found is to place a 1nm or very narrow trace along the path where I want the split.  The plane rules will open a slot 2x of the specifed clearance width.  Since the trace is so small it will not instantiate on the physical PCB.

This can be used to separate a digital and analog plane with a controlled connection at a desired location, or to isolate plane areas for low noise circuits, etc.

Anyone see any problem with this method?  Or is there a better way to 'paint' an arbitrary slot in a plane?

David B

[Tien_P]

Hi David, Have you tried using a keepout area to cut out a slot on the copper area? If the location of the slot is somewhere that will include other traces, you may have to create a net group (Tools>>Group Editor), when you create the net group only include the net belonging to the copper area. The reason for this is that now if you double click on the keep out area you have the option to say keep out only a specific group. I don't really see a problem with what you are doing, if you check the Gerber file generated by Ultiboard and don't see the small line than that's all the matter.