How to create slot through one layer of a 4-layer stack up

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Hello everyone,

I am new on the forum and pretty excited to use Kicad.

I am currently designing a 4-layer PCB with a dipole that is between FR4 layers. I need to create a slot on the FR4 top layer only in order to add a diode on the dipole but I can’t find a way to do it properly. I can only create a hole through the whole PCB with the edge cuts.

Does anyone have done it successfully ?

Thank you,

Ludo.

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That’s not possible (or very difficult) to manufacture if the board will ever be physically made.
Use slots or vias through all the layers (or blind vias if your PCB manufacturer supports them and you are happy to pay extra).

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Here are some ideas:

but it depends on your manufacturer and on the size of the feature you want to make.

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This is called Z-axis milling and/or embedded components, and has to be defined separately. You can create a user layer, define the dimensions of the slot and make notes on the depth of the milling. It’s also a good idea to talk to the PCB manufacturer regarding this service. They might have a standard way they prefer to get such information.
And as mentioned before - this is not cheap, so if you are planing volume production, take this into account.

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Another very custom way to do this would be to manufacture the inner layers as usual, but to mill out the window in the outer layer prepreg and copper sheet before bonding to the inner layer stack. This would then require the exposed aperture to be protected from the outer layer etching step.
Seems very awkward and expensive to me.

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Thanks a lot for all your comments, I will try a new design due to cost constraint.

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