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Adding pours on 2 layer board

Message 1 of 2
149 Views, 1 Reply

Adding pours on 2 layer board

I recently completed my first PCB design and have sent it for manufacturing. It is a 2 layer board. I did not use any pours on either the top or bottom layer. Should I have added them? 


I do not know whether my board will work or not. I was rushed and it is possible there is a mistake on it that will cause me to redo it. If I have to do this, should I add pours to the top and bottom layers? Should one pour be 3V3 and the other be GND? Or both GND. Or only a GND pour on the bottom? How do I get the pour connected to either 3V3 or GND? Is there some way to tell the router that the top pour is 3V3 and the bottom pour is GND? Actually I don't think this is possible because I think the pours have to be added after the board is routed. 


I would certainly appreciate a bit of help here. Thanks in advance!


Message 2 of 2
in reply to: acsann

To pour or not to pour. That is the question......
It depends completely on your design, what your board does, frequencies involved e.t.c.
But without going into details, a GND pour is usually a good idea.
It will save copper, reduce inductance and noise.
On two layer boards (and most 4 layer), I use a GND pour on both top and bottom. Perhaps some area with 3.3V (or whatever supply there is).
To make a pour, draw a polygon (pour) around your outer board edges, I usually put it 1mm out. 
The right-click on the polygon and use the NAME command to name it GND (or whatever net you want to connect it to.).
Simple as that.


You don't need to wait until the board is routed. Sometimes, it's an advantage to see the pour, as it will help you take decisions on how to route a track to keep complete pours.
You want the pour to be as complete as possible, with the fewest "breaks".

You might then want to look at the properties of the polygon pour and set a suitable width (0.254-0.3048 is usually a good choice). The other options are usually left as they are, except in special cases.
Look up the POLYGON docs if you want to know more.

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