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I plan on using this capacitor on my project: https://datasheet.lcsc.com/lcsc/2209011730_KNSCHA-RVT330UF50V167RV085_C5155333.pdf

This is an electrolytic capacitor (this means it has polarity.).

The datasheet marks it as an SMD,10x10.2mm footprint. However, when i try to select a footprint from Kicad, these are the two options:

enter image description here

AS you can see, the 10X10.2 footprint, is only available for the C capacitor (which means non polarized). However, since I am using an electrolytic one, I want the CP capacitor - with polarity. However, the CP one has only 10X10 footprint available.

So what should be the correct course of action here? Should I just select C 10X10.2 which is the correct dimensions, but incorrect polarity? Or should I select the CP 10X10, which is the incorrect dimensions, but correct polarity wise?

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    \$\begingroup\$ Make your own footprint? \$\endgroup\$
    – Hearth
    Jun 13, 2023 at 21:06

2 Answers 2

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Compare the actual dimensions instead of the name of the footprints.

The CP_Elec_10x10 footprint matches the datasheet recommendation perfectly.

The CP_Elec_10x10.5 footprint is slightly larger, but would be easier to solder by hand, as it has more pad space for getting a good contact with the soldering iron.

The second number in the footprint name is actually the height of the component, which is relevant only for the 3D model. But it tends to correlate with the recommended pad sizes also.

Kicad footprint dimensions vs. datasheet dimensions

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Use the correct sized footprint and modify it so it has polarity markings on the silkscreen. Part of using CAD programs is making custom parts.

Be sure the footprint you're pulling from the library matches what the component data sheet recommends. In the data sheet referenced: page 10.

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  • \$\begingroup\$ Thanks! Something for clarification. You said modify it so it has polarity markings on the silkscreen. I opened both footprints and they look similar. It is not clear to me what exactly I have to add on the silkscreen.. Seems that the C version has polarity markings as well... \$\endgroup\$ Jun 14, 2023 at 7:03
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    \$\begingroup\$ @user1584421 In your post you said that one footprint was non-polarized, the other was polarized. If both have silkscreen showing that they are polarized (inconsistency in naming convention), there is no need to modify the silkscreen. You still need to check the CAD program library footprint against the recommended footprint in the datasheet. I normally make my own footprints as canned libraries can have errors and I like to have certain features in my footprints that the canned libraries don't have. \$\endgroup\$
    – qrk
    Jun 14, 2023 at 15:31

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