Is there a way to specify a minimum size for polygon orphans?

[Anonymous]

When using the polygon tool to fill, I've found that in some cases it is useful to keep orphans turned on so it will fill areas that are cut off from the rest of the ground plane. However, it seems to fill in a bunch of small orphans that are nothing more than little slivers here and there that happen to be larger than my width + isolation spec. Is there some way to specify a minimum area for orphans so it will still fill in the larger areas (which I can then connect to the ground plane on the other side with vias so they are not floating) while ignoring the negligible areas? I've thought of doing this with two polygons, one with a larger width property, but then that changes how well it fills in the orphaned areas. I can also draw a separate polygon for the areas where I need it, but that would take a bit more time. Any thoughts?

I included two examples of the problems. One with orphans turned off (which leaves large chunks without fill) and one with orphans turned on (which leaves little orphaned pieces everwhere, even in places small enought that I can't put a via).

[Anonymous]

When using the polygon tool to fill, I've found that in some cases it is useful to keep orphans turned on so it will fill areas that are cut off from the rest of the ground plane. However, it seems to fill in a bunch of small orphans that are nothing more than little slivers here and there that happen to be larger than my width + isolation spec. Is there some way to specify a minimum area for orphans so it will still fill in the larger areas (which I can then connect to the ground plane on the other side with vias so they are not floating) while ignoring the negligible areas? I've thought of doing this with two polygons, one with a larger width property, but then that changes how well it fills in the orphaned areas. I can also draw a separate polygon for the areas where I need it, but that would take a bit more time. Any thoughts?

I included two examples of the problems. One with orphans turned off (which leaves large chunks without fill) and one with orphans turned on (which leaves little orphaned pieces everwhere, even in places small enought that I can't put a via).

[jorge_garcia]

Hi @Anonymous,

I hope you're doing well. At this point in time we don't have a way to specify a minimum area for the polygon orphans. This is the first time I've encountered this request. For now you could use two polygons as you have mentioned or use the Restrict layers to cover the areas where the undesired orphans form. The Restrict will keep the polygon from filling in.

Please let me know if there's anything else I can do for you.

Best Regards,

[jorge_garcia]

Hi @Anonymous,

I hope you're doing well. At this point in time we don't have a way to specify a minimum area for the polygon orphans. This is the first time I've encountered this request. For now you could use two polygons as you have mentioned or use the Restrict layers to cover the areas where the undesired orphans form. The Restrict will keep the polygon from filling in.

Please let me know if there's anything else I can do for you.

Best Regards,

[Anonymous · Accepted solution]

Since there are so many small orphans (the width size of the polygon is 8 mil) the restrict option would be a lot of work. I managed to find a workaround using named vias in the larger regions (there are far fewer of these) with orphans turned off to force the polygon to show up there (and eventually they all get tied together with enough vias added).

[Anonymous · Accepted solution]

Since there are so many small orphans (the width size of the polygon is 8 mil) the restrict option would be a lot of work. I managed to find a workaround using named vias in the larger regions (there are far fewer of these) with orphans turned off to force the polygon to show up there (and eventually they all get tied together with enough vias added).

[one-of-the-robs]

Good, I'm glad you found that solution. Because it is the solution, it is not a "work around". You should not, in general, have orphans switched on, because the orphan'd copper is not acting as a ground plane. If you want your ground plane to work, you need to make sure it's all actually connected to ground, which is what the named via's do.

[one-of-the-robs]

Good, I'm glad you found that solution. Because it is the solution, it is not a "work around". You should not, in general, have orphans switched on, because the orphan'd copper is not acting as a ground plane. If you want your ground plane to work, you need to make sure it's all actually connected to ground, which is what the named via's do.

[Anonymous]

Yeah, that's what I decided after a while of thinking about it. It seems weird to have the orphan functionality as it is because with them turned on it gives no indication which are connected and which are not. The via placing method works well, and if an area is isolated from the rest, it will show up in the DRC.

As a general feature request, I could see a minimum area option for orphans, and then for orphans of a ground plane to show up as drc errors (standard airwire error).  But it really isn't necessary since we can just place vias and get the same result.

[Anonymous]

Yeah, that's what I decided after a while of thinking about it. It seems weird to have the orphan functionality as it is because with them turned on it gives no indication which are connected and which are not. The via placing method works well, and if an area is isolated from the rest, it will show up in the DRC.

As a general feature request, I could see a minimum area option for orphans, and then for orphans of a ground plane to show up as drc errors (standard airwire error).  But it really isn't necessary since we can just place vias and get the same result.

[C.Nicks]

I've actually mentioned this a long long time ago and is a feature in other tools. I use the restrict layers extensively when making final touches to a board before shipping out, however it can be a lot of work to maintain when making changes. The other problem with the restrict workaround, is all of the new "smart" routing tools use those layers as drc violations and make them unusable.

Have you seen the polygon manager in Altium? That neck down copper setting is very handy.

Polygon pour options

[C.Nicks]

I've actually mentioned this a long long time ago and is a feature in other tools. I use the restrict layers extensively when making final touches to a board before shipping out, however it can be a lot of work to maintain when making changes. The other problem with the restrict workaround, is all of the new "smart" routing tools use those layers as drc violations and make them unusable.

Have you seen the polygon manager in Altium? That neck down copper setting is very handy.

Polygon pour options