I am working with a manufacturer on a flexible pcb with stiffeners. They require a non plate through hole for registration of the stiffener to the flex pcb. How do I place a NPTH? Thanks!
Looks to me like the Mounting_Holes library, are NPTH ?
Just use one of those of required size.
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And if there are none of adequate size/form you can always make one yourself with the footprint editor 
Thanks! I found the Mounting_Holes library and can certainly make a custom sized hole. However when I look at the 3D image it doesnât go all the way through, as there is a green dot on the back side where my ground plane is.
I checked the Properties and the Pad Type is âThrough-holeâ. I tried changing it to NPTH, Mechanical and there doesnât seem to be any difference in the 3D view. I believe to serve as a registration hole for the stiffener the hole must also go through the copper. It also must be non plated because of the order of manufacturing process.
Also, in the PCB editor if I turn off the Non plated layer, the hole does not disappear. This all leaves me wondering if the final Gerber will indeed be non plated hole.
Iâm not sure Iâd read that much into any 3D rendering
Testing a MountingHole_2.5mm here, I see that Render.Nonplated toggle works find in View.Default,
(hole toggles) but Render.Nonplated toggle has no effect in View.OpenGL
You can also generate files, and check with an editor for non-plated.
It should appear in the NPTH excellon drill file.
Sometimes NPTH holes end up plated anyway, laziness by the PCB fab
If stuff like this happens - run a plot and look at the gerbers - thatâs what the fab will be seeing and creatng your boards from. If they show what you want, itâs good. Donât forget to create and load the drill file for that step as well.
Thanks all. Just FYI, when the hole parameters are correctly set, the 3D view does show the hole all the way through.
However, my stiffener (on tthe Dwgs.User layer) is displaying on the top rather than the bottom in the 3D view. Will the fab shop be able to tell which side of the flex pcb that the stiffener belongs just from the Gerber files? Is there some property or configuration in Kicad to set the layer order? Iâve read about and seen some stack up drawings. Is this the only way to communicate that the stiffener is on the bottom?
Yeah, those layers are there and set up âfixedâ.
You have to tell your fab house what they mean when you plot them. For the standard copper, silkscreen, soldermask, etc. layers thatâs usually not needed. But for special stuff it is.
So I understand I can inform the fab house of the various layers and could even put it on separate a stack up drawing. Is there a way in Kicad to change the order so that they can be viewed âcorrectlyâ in the 3D viewer?
I donât think so.
Why not simply place some text under the stiffener, that says âfit stiffener this sideâ ?
Might be needed to even give them some more info than just gerbers⌠do you have CAD people who can make you a drawing for that purpose (like a cable assembly)?
Yes, I have a mechanical CAD program⌠I ultimately created a âstack upâ diagram showing the side (cut away) view indicating layer names, layer order and material and omitted layers such as silk etc, and layer thicknesses. Thanks!
Hi,
maybe this can help anyone nextâŚ
I found that NPTH are really there on PCB 3D viewer like holes, and to be seen like holes on Footprint Editor, you just need to go to 3D viewer; â3D display optionsâ on preferences menu => display options, than on âboarder layersâ options, just click the box to un-select âshow solder mask layersâ. Check 3D view again and NPTH will be seen like normal holes.