Copper pours do not connect to pads with custom shapes

I was editing an old KiCAD 5.1 project (using KiCAD 5.1 in order to avoid to preserve the project as is) and I needed to change the pad shape so I have created a pad using a custom polygonal shape.

The top layer (F.Cu) pad is thru-hole, on “All copper layers,” F.Mask is the only checkbox enabled. The bottom layer (B.Cu) pad is a regular rectangular thru-hole pad on All copper layers, B.Mask is the only checkbox enabled. Both are in the ground (GND) net and have the same pin number.

I do not know why but the ground plane on the top layer (F.Cu) fills everything and connects to any GND pad but this custom shaped one.

I know I may draw a track from the pad to any other pad connected to ground as a workaround and it seems to work but I would like to know if there is a proper way to do it.

Thanks in advance

What KiCad verson of V5.1 are you using? The third number is quite important. Personally I would rather do the uptate to V8 then stay with such an old KiCad version. Conversion is mostly automatic and painless, but that is under the assumption you do it right, if the project is damaged or incomplete you may encounter problems during a conversion. (especially the [project]-cache and [project]-rescue files are important.)

I don’t know what the actual problem is from your description. Have you ran DRC? Does it have anything to say?

It’s normal practice to make bigger pads either by combining multiple pads (with the same pad number!) but only one of the pads should be a THT pad if they are in the same location. You do not want multiple drilled holes in the same location.

The most logical explanation is that the polygon you have drawn has not been made a part of the pad explicitly. KiCad V5 is also so old now that I forgot the details of how to do that.

I don’t remember if polygons could be used in V5 to made custom shape pad.

If KiCad don’t assume this polygon being pad than avoids connecting zone to it.

In V8 you certainly can have custom shape pads containing polygons.

Thank you for your replies.

What KiCad verson of V5.1 are you using?

5.1.12

Personally I would rather do the uptate to V8 then stay with such an old KiCad version.

The requirement is that the result files must be compatible with KiCAD 5.1.12

Have you ran DRC?

Yes, I did it.

Check this example.

schematics + top layer + bottom layer

** Found 0 DRC errors **

** Found 4 unconnected pads **
ErrType(2): Unconnected items
@(3.000 mm, 4.000 mm): Pad 1 of TP1 on B.Cu and others
@(3.000 mm, 4.000 mm): Pad 1 of TP1 on F.Cu and others
ErrType(2): Unconnected items
@(9.000 mm, 4.000 mm): Pad 1 of TP2 on F.Cu and others
@(9.000 mm, 4.000 mm): Pad 1 of TP2 on B.Cu and others
ErrType(2): Unconnected items
@(3.000 mm, 4.000 mm): Pad 1 of TP1 on B.Cu and others
@(9.000 mm, 4.000 mm): Pad 1 of TP2 on B.Cu and others
ErrType(2): Unconnected items
@(4.730 mm, 10.000 mm): Pad 1 of J1 on All copper layers
@(3.000 mm, 4.000 mm): Pad 1 of TP1 on B.Cu and others

** End of Report **

As you see the octogonal pads in the top layer are not automatically connected (using thermal relief connections) to the top layer ground plane.

I don’t remember if polygons could be used in V5 to made custom shape pad.

Yes, it allows to use polygons, arcs, segments,… as custom pad primitives.

If KiCad don’t assume this polygon being pad than avoids connecting zone to it.

At least I may edit the pad settings as any other regular pad.

That’s good. It’s the latest of that mayor version and thus has the least bugs.

With such a small / simple (test?) project, the most logical is to zip up and upload the project itself. For a V5 project, also include the cache file.

I will try to upload it. Thanks. (Edit: “Sorry, new users can not upload attachments”)

Partial solution: Set “Pad connection” to “Solid” but I am not able to find a way to get “Thermal relief”. I guess it is not possible to do it with KiCAD 5.1

This automatic anti-spam measure is sometimes a bit annoying. For more info read:

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