Drawing Rigid-Flex Design in Kicad 5

I did a search and I did not see anything new, or with a real answer, but is there a method for drawing a rigid-flex design in KiCAD 5? Looking at the layer configuration I do not see a way to partition the design between the rigid areas and the flex areas. Coming to KiCAD form Allegro, you can tell the software to have different layer counts in different areas.

It is not possible to do that in KiCAD. The layer stack definition is valid for the whole board.

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This is unfortunate. I wonder if this is in the pipeline for future revisions.

I don’t find that kind of report in the bug database. Please do it:


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While KiCad does not currentlty have native support for Rigid-Flex or other types of heterogeneous stackups, it is still possible to do these designs in KiCad.

The approach I would take is to define your KiCad stackup to include all possible layers, and then do a careful mechanical drawing (i.e. fab drawing) identifying the extents of the various sections. If you have good communication with your fabricator, they should be able to work with this.

You can make a stackup drawing (like the one you included in the bug report), and a top-down fabrication drawing with different areas hatched out, etc. I recommend doing this in a dedicated 2D cad tool, as KiCad’s drafting tools are not the best currently.

Yes this is possible, but so much easier with you can section off the stack-up:

I know this is a competing too that cost a-lot of money but…

Even many commercial tools lacked dedicated rigid-flex support until recently :slight_smile: Allegro is the Mercedes S-class of layout tools, they always get the best features years before everyone else.

Thanks for filing the feature request. I’m kind of surprised it wasn’t there already, as this is something we’ve talked about in the past. It’s a complicated feature to implement properly, so I think it will be some time before anyone sees this in KiCad (especially since we have a big list of other things that have already been prioritized). I merely wanted to point out that it is entirely possible to design Rigid-Flex boards without “native” support in the CAD tool, in case it’s useful for users in the meantime. While I haven’t done this approach with KiCad, I have done it in other commercial tools that lacked rigid-flex support (older versions of Altium, Mentor PADS, etc)

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That workaround really only works if components are only on the rigid part of the PCB because KiCad can not have pads at any layers other than the external layers.

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This can be worked around if you have a manufacturer who is willing to be flexible and work with you. They can copy the data around from one Gerber layer to another according to the stackup zones defined by you.

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Completely understand that this is complicated and not a quick fix.

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