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I'd like to add six rectangular-shaped 2.2 µF MKP capacitors used as coupling caps for an audio circuit to my PCB in Kicad, but I'm not quite sure about the right footprint.

What makes the choice even harder, is the fact that these caps are very big, yet are equipped with fairly long terminals, so that I could make them stand in the air somehow.

Any idea?

UPDATE: I've now made Pcbnew generate a PCB layout, but now all these caps occupy the complete PCB surface underneath them, so that the somehow remain on the ground floor. Also, the regulator in the top left corner appears to lie on the board instead of standing on it. This may make the board grow too large. See the screenshot attached:

enter image description here

UPDATE #2: There is in fact a vertical footprint for the regulator, and when it comes to the big coupling caps, distributing them over the board in a smart way is the clue. I did some manual replacement work and then used Freeroute to draw the conductors:

enter image description here

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    \$\begingroup\$ Do you expect any strong forces or vibrations on your PCB? If yes then you can use those long terminals to your advantage, by mechanically mounting the caps on a side. \$\endgroup\$
    – Maple
    Dec 4, 2021 at 8:41
  • \$\begingroup\$ I don't really know what a "strong force" means in your opinion, but the PCB is gonna be part of an automotive application, so it's gonna be exposed to vibrations and slight shocks. \$\endgroup\$
    – Neppomuk
    Dec 4, 2021 at 23:47
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    \$\begingroup\$ It's not so much a matter of matching a component to the right footprint, it's more about deciding how you want the part to be mounted, and then finding/making a footprint that works for that. Is your actual question "how to get the capacitors and the regulator to use less space"? \$\endgroup\$
    – DamienD
    Dec 5, 2021 at 0:27
  • \$\begingroup\$ What is U2? If these are coupling capacitors why do some of them only connect to U2 and not couple two audio components together? \$\endgroup\$ Dec 5, 2021 at 0:55
  • \$\begingroup\$ U2 ist the mixer IC. Capacitors start with C. \$\endgroup\$
    – Neppomuk
    Dec 5, 2021 at 14:39

3 Answers 3

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You are looking for a footprint with 27.5mm pitch (Rastermaß) between pins and 32mm length.

The closest two footprints in KiCad are:

  • C_Rect_L31.5mm_W13.0mm_P27.50mm_MKS4
  • C_Rect_L33.0mm_W13.0mm_P27.50mm_MKS4

You can use either of these and modify it to the exact dimensions

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    \$\begingroup\$ I'd make it "make a copy and modify to exact dimensions", just in case \$\endgroup\$
    – Maple
    Dec 4, 2021 at 8:38
  • \$\begingroup\$ See the Pcbnew screenshot in my orig. question. \$\endgroup\$
    – Neppomuk
    Dec 4, 2021 at 23:54
  • \$\begingroup\$ @Neppomuk You can always overlap footprints in the design. It is usually not good practice be KiCad won't stop you. "Just enough rope" and all that \$\endgroup\$
    – Seth
    Dec 6, 2021 at 23:23
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It appears that those capacitors are intended to be mounted with the base (where the leads come out) flat against the board. However, if you really need to place smaller components under them, you could space them off the board, but this would be an unusual way of doing things.

I would expect the KiCAD libraries to have a vertical-mount footprint for the LM317 in a TO-220 package. If not, you can always make your own.

If you do any amount of PC layout work, you WILL have to make your own footprints (and schematic symbols) for some parts.

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  • \$\begingroup\$ it does, TO-220-*_Vertical. The wrong footprint was chosen for the need \$\endgroup\$
    – user16222
    Dec 5, 2021 at 0:52
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This will sound like I'm being a smart-ass, that I'm make more of a comment than an answer, but I'm not. The right Kicad footprint for those caps is the one you create with the Kicad footprint editor. Honestly and seriously, creating both schematic symbols and PCB footprints for parts that aren't in the standard library is part of using any EDA tool. I'd be surprised if things only get easier as time goes forward, but don't expect them to be available for every component you use, at least not if you're designing anything interesting. Expect to have to create them yourself sometimes.

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