EEVblog Electronics Community Forum
Electronics => PCB/EDA/CAD => KiCad => Topic started by: perdrix on June 03, 2022, 03:55:01 pm
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I'm doing my 1st KiCad PCB and want a standard 1.57mm/0.062" thick board with 4 layers.
How should I configure the stackup in KiCad to get this in the "standard" way the board makers do it?
It's asking me for each dielectric layer whether it should be "core" or "prepreg" and how thick it should be. It also wants the thickness of each copper layer - is 1.38mils == 1 oz. copper?
What are the "standard" answers for a standard thickness board?
Thanks
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The only answer to this is: Ask your fabricator.
Random example: https://www.pcbway.com/multi-layer-laminated-structure.html (https://www.pcbway.com/multi-layer-laminated-structure.html)
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I just used the KiCad defaults in the PBC editor (File / Board Setup, Board Stackup, Physical Stackup : Copper Layers = 4). I've done several 4-layer boards like this, sending the Gerbers to JLCPCB and they come back fine. When setting up the JLCPCB job you have to assign each layer to a particular Gerber file, but that's pretty obvious.
I'm not doing anything fancy with controlled impedance or the like. I could give you the thickness numbers that KiCad uses, but they are just the defaults, I haven't changed a thing.
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The physical board setup in KiCAD is mostly irrelevant for your PCB. At best it will give you a more accurate 3D rendering. KiCad doesn't use the information elsewhere.
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As thinkfat already mentioned, the exact thickness does not matter much, these thicknesses do not show up in Gerber files.
KiCad does keep track of the length of via's and I think it also adjust for these during length matching, but when length matching is important (such as differential pairs) you you should use symmetry anyway.
There is also a button for Adjust Dielectric Thickness in the board setup dialog which lets you enter a total thickness for the PCB and adjusts the rest to match that.