Creating a Flex PCB with very specific shape

[guillaume_tyto]

Hello everyone,

I was wondering if there is any way to import a very specific shape from, let’s say SolidWorks, to define my board outline and shape.

I also want to know the kind of layer I should use when it comes to creating the footprint of my FPC Connector.

[Rene_Poschl]

@guillaume_tyto

I was wondering if there is any way to import a very specific shape from, let’s say SolidWorks, to define my board outline and shape.

You can use the dxf import functionality.

Holes with a small diameter (<6mm or so) should be drilled not routed. (the maximum drill diameter depends on your manufacturer)

for such holes i would use a work-flow as described by @Joan_Sparky in this thread:

Import dxf of holes for precise mounting hole placement

I do the same. The dxf import has got very tiny marker holes in it (0.4mm) and the footprint for the NPTHs has got a cross hair. The hole from the dxf file that’s on the edge.cuts layer will ‘vanish’ in the drill hole definition that way, but I can leave it there for reference (surely could go for 0.1mm or less even). Considering the tolerances of the fab house for drilling the placement at 0.01mm grid is better by a factor of 10 or more. [image]

@guillaume_tyto

I also want to know the kind of layer I should use when it comes to creating the footprint of my FPC Connector.

What do you mean by that?
Do you mean what layer does what?
(Silk: silk layer, Fab: fab info, …)

Or do you want to know where to place it from the point of view of your mcad world?

[guillaume_tyto]

Thank you very much for the fast answer.

@Rene_Poschl

What do you mean by that?Do you mean what layer does what?(Silk: silk layer, Fab: fab info, …)

Or do you want to know where to place it from the point of view of your mcad world?

This PCB will serve as a breakout board to connect the main control board to several sensors. Since it is a flex PCB the male connectors will be a part of the PCB and not soldered connectors and I’m a little bit lost when it comes to selecting the right layers.

[Rene_Poschl]

I would create a footprint with smd pads on top and bottom.
To ensure that there is no soldermask between the pads i would fill the area between this pads with graphical lines on the appropriate mask layers.

I played around a bit and made a connector to show you how something like that could look like.

I assume you want an endresult looking somwhat like that.

A screenshot of this test pcb in pcb new.

And here my connector so that you can play around with it:
edge_connector.kicad_mod (11.4 KB)

Edit:
if you have the pins on both sides or just one depends on your specific usecase.
If you use both sides you could also have different pins on top and bottom and double your connector pins. Again depends on your application.
(Or in other words: it depends on the female side of your connector.)

[aarago0]

Did you ever get this built?

[Rene_Poschl]

It was an example pcb just for this post. (To showcase features of kicad.)

I personally never used edge connectors nor flex pcbs. (So i did not even get something similar to this produced.)

Did you run into any trouble or do you just see anything wrong with the proposed workflow?