topic Problem with polygon in EAGLE Forum

Problem with polygon

Anonymous — Wed, 15 Jan 2020 15:33:22 GMT

Hello sir/madam,

I've designed a 2-layer PCB and now I've faced a problem when I draw a polygon and use Ratsnest to fill it with GND, it just does not fill all the surface with polygon GND as you can see in the images I've attached here.

Could you suggest me a solution, please?

Re: Problem with polygon

one-of-the-robs — Wed, 15 Jan 2020 17:04:04 GMT

You really need to upload the actual board file to get a correct answer, as the screen shot doesn't tell us nearly enough. However...

The reason the polygon stops is because something is blocking it. This could be another polygon, that can't get into that part of the board for other reasons, or one that's marked as a cutout. The rank system for polygons allows you to place a higher priority flood of a different signal into a section of a wider fill. What it doesn't do is "fall back" to the lower priority flood when the high priority one can't get in.

Re: Problem with polygon

C.Nicks — Wed, 15 Jan 2020 20:41:53 GMT

Also check the Restrict layers. Anything drawn into those layers will block all polygons. I regularly use those layers to clean up pours.
Also check if orphans are turned on. Since you do not have any vias connecting the pours between layers, it may not want to pour in areas that are not connected. You can toggle that in the properties dialog and see if the pour continues. If that's the case I would suggest adding some stitching vias. In general you should put a gnd via as close to the part as possible and not leave a large plane connecting them. That will limit the loop currents. During routing I would suggest adding them as you go along.