Altium split planes problem

Hello friends,

We have a situation that requires due to 20H rule, power planes to be away from board edges.
In picture there are two splits 3v3 and 5v but Altium doesn't remove cooper on the edge.



This 3'rd split (board edge) has "no net" attribute and should be removed.

Any hint? Thanks

You have to fill in this region with a solid region or fill to remove the copper.

Thanks for reply,

I think this is a major mistake in Altium. If it's possible to have multiple planes on the same layer with very nice designed "draw line to split" feature, why plane's chunks are draw if tied to "no net". In OrCAD, such simple featured were implemented 10 years ago. If a cooper pour it's not assigned to a net, it's simply not drawn.

If I have to draw a fill, things are complicated and no more benefit of power planes at all because if want to re-shape the split, now it's easily to move the line. Then, you have to re-size the fill and this is a mess up.

My colleague already drop the planes and use normal layers... split planes got problem in Altium.


Best regards,

Assuming you only need a minimum, uniform, copper-less space between the board edge and the edge of your plane (and don't require that specific shape that you have drawn), then simply redefining the pullback parameter for the plane will get the job done. The pullback value defines the allowable distance a plane can be from the board edge, and is configurable in the layer stack manager. For instance, if you define the pullback as 20 mils, Altium will automatically add a 40 mil wide line centered at your board edge which will automatically void all plane copper 20 mils into your board. The pullback line is not editable directly on the board and can only be defined/adjusted in the layer stack manager. As you change the value, Altium will automatically adjust the pullback line width. Each plane layer can have its own pullback value.

Good luck.

Ok, thanks for tip, I tested today and it's quite nice. But only uniform cutout in all directions And now I wave a very ugly large border in 2D design mode. I still have a nice unknown piece of cooper on right, but I presume for 20H rule it's nice.

Hoping that Altium guys will correct this issue

Thanks very much for your complete post.

zuzu said:

I still have a nice unknown piece of cooper on right, but I presume for 20H rule it's nice.

Click to expand...

Yeah, in 2D mode with a large pullback, it can look pretty ugly with that huge wide border. I wish they would hide the portion of the pullback line that lies on the outside of the board area. It's not necessary and would look so much cleaner.

Anyway, you said that you still have a unknown/unassigned piece of copper after you adjusted the pullback. This is only true if you kept your old lines that you used to originally pullback the perimeter. If you delete those perimeter lines, and adjust the pullback value to the desired value, then you would only require the single line down the center of the board to divide the 3V3 and 5V plane areas. I assumed that your perimeter plane shape could be a simple square/rectangle and did not require any special shape.

FYI, there is also a DRC check that will identify all dead copper on the planes that is greater than a predefined area size. It's in the initial DRC settings page where you enable and disable specific DRC rules for the batch and online DRC modes. You can configure that to help you identify any unwanted regions of copper on the planes. It won't delete them automatically, but it will flag them so that you can take care of them manually.

Anyway, most of the time if I have a complicated "plane" layer, I will define the layer as a standard signal layer and define polygon regions accordingly. It requires more work, but you have more options in then end.