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ATTA , 07-14-2024, 12:58 PM

Hello everyone
I am confusing to understand the difference between polygon and power plan because it looks same to me. Can any body help me to understand the difference between these two

QDrives , 07-14-2024, 03:00 PM

A "plane" is a layer that is 'connected' to a single net (unless split plane is used) and covers the entire layer. You are not allowed to 'draw' on a plane layer.
A polygon pour can be any shape on all signal layers.
I never use planes, but have the 'Gnd layer' as one big polygon.

Robert Feranec , 07-17-2024, 08:51 AM

plane layer is in Altium negative - what you draw is without copper, empty space is copper. Polygons are created on positive layer - what you draw is going to be copper, empty space is removed copper.

fanwind , 07-17-2024, 11:48 AM

Why don’t you use planes? I think it’s convenient to have a power and ground plane, so that you can just use a via to connect from anywhere

fanwind , 07-17-2024, 11:48 AM

What are the downsides?

Robert Feranec , 07-17-2024, 12:18 PM

re-shaping or re-drawing planes may be in some software more difficult than re-shaping polygons. plane is ok for full GND layer, but may be complicated to work with if there are many small power polygons on the layer - that is how I see it

QDrives , 07-17-2024, 08:08 PM

You can place a polygon that covers the entire board. In effect creating the same as a plane layer.

As to the downsides:
1) By default, Altium is on stack symmetry. So if you create a 4 layer board, and want layer 2 and 4 as planes, that is not possible.
2) I work heavily with polygons, so a Gnd polygon can be treated the same a as any of the other polygons.
3) On my current design, I 'swap' layers for the return (Gnd) 'planes'. This is impossible with planes.