Flex Circuit Cover

[ldboehm]

Still relatively new to circuit design and KiCAD, but making progress.
I’ve been designing a flex circuit to replace an old blue foil circuit in my old car.
Attached is a simplified version and picture of an actual.

How do I add a cover to my design, like in the picture?

4 Pin Flex Test.zip (26.3 KB)

[der.ule]

Maybe this FAQ will help you if I understood the question correctly:

How does solder mask layer work?

What is soldermask and how does these layers work in KiCad? Solder mask is physical substance applied to the physical board. There are holes in this mask which expose copper pads. [image] In KiCad (and other EDA) the graphical layer which represents solder mask is negative. Where there is graphics in this layer, the physical solder mask isn’t applied and there will be a hole in the solder mask. There are two values for solder mask in Board Setup: clearance and minimum width. [image] IMPOR…

[maui]

would you mind to get a more accurate picture? (i.e. from top and with a rules aside)
Here a first attempt using FreeCAD and StepUp to align the KC board to mechanical dimensions
4 Pin Flex Test modified.zip (2.0 MB)

[ldboehm]

I already have the full drawing done in KiCAD of the actual circuit, so no need to import it into FreeCAD or duplicate it.
Just looking for help on the cover then generating the proper files for manufacturing.
Thx

[Sprig]

@ldboehm You might want to reconsider your previous answer.

@ldboehm

Just looking for help … generating the proper files for manufacturing.

If @maui offered to help me and all I need to provide was a better picture that included a ruler I’d be out of my chair and grabbing my good camera and my best ruler.

[maui]

i.e.:

​KiCad 5.1.5 - Generating Gerber and Drill Files - JLCPCB: Help & Support

[der.ule]

@ldboehm

Just looking for help on the cover then generating the proper files for manufacturing.
Thx

@ldboehm

How do I add a cover to my design, like in the picture?

Sorry but I still do not understand what do you mean with “cover”

EDIT:
If what you want is to expose the copper, you should check in your pad properties F.Mask instead of F.Adhes

This is the 3D viewer of your board now.

[der.ule]

Did you trace an sketch from the picture ? Is it possible to correct the perspective later on ?

[maui]

@der.ule

Did you trace an sketch from the picture ?

Yes, I used FC Image Workbench
https://wiki.freecadweb.org/Image_Module…

It is possible to scale the image to a known dimension
https://wiki.freecadweb.org/Image_Scaling

[der.ule]

Thanks a bunch for the detailed response!

However i doesn’t seem to be able to compensate for the skew of the picture (it wasn’t taken from the top, but more from the top-side, making rectangles look like parallelograms)

[ldboehm]

Maui and Der.Ule,

1st Maui, my apologies for the misunderstanding and thank you so much for the effort you were about to put in to sketch my project for me! Wow…that is going the extra mile! I have lots of CAD background and am a big FreeCAD user. I have all the CAD work done in KiCAD for the actual model I’m creating, so again thank you so much! This file is being used as a test, so I can make small adjustments on it to learn, then apply my knowledge to the actual project.

Looks like I was not up on all the layers and am learning that. I’ve adjusted my model so the f.mask layer is associated to all the pads. I think it looks correct now per Der.Ule’s comments. And thank you Der.Ule as well for helping with that.

So now I need to look at PCBWay to see how they want output files so it is created the way I want. Any suggestions with that?

4 Pin Flex Test.zip (39.7 KB)

[ldboehm]

How I created my actual model direcly in KiCAD.

1. Scanned an image.
2. Opened it in GIMP
3. Scaled it to correct size in mm
4. Set an origin point as 0,0
5. Set different X.Y points on my image based on the origin marking the outline and any points for pad or components,
6. I then created a footprint in KiCAD using the same exact method based on my GIMP file. Lots of manual effort, but it came out great! I marked the edge outline and placed an X or circle on places where components or pads would go using the Dwgs.User layer.
7. Manually edited the library file to change my footprint outline to Edge.Cuts. I prefer VI as I’m an old UNIX guy.
8. Opened the foot print to ensure all the lines were properly connected.
9. Then created the PCB. Dragged the footprint on first, then placed all the components using the markings I made.
10. Exported the PCB to a step file, then opened in FreeCAD.
11. Output to stl and printed a version to test the footprint to ensure it was a 100% fit match. Worked great!

[ldboehm]

Thank you! Very helpful to fill in my learning!

[der.ule]

@ldboehm

So now I need to look at PCBWay to see how they want output files so it is created the way I want. Any suggestions with that?

Did you check the link posted by Maui ? it gives you a step by step for generating the gerber and drill files for jlcpcb

https://forum.kicad.info/t/flex-circuit-cover/27667/6?u=der.ule

[ldboehm]

Will be looking at that next.
Thx!

[maui]

@der.ule

However i doesn’t seem to be able to compensate for the skew of the picture (it wasn’t taken from the top, but more from the top-side, making rectangles look like parallelograms)

this is not available in FC, it could be done in an image editing sw, but the best is to get a picture from top.