Skip to content
This repository has been archived by the owner on Oct 2, 2020. It is now read-only.

SMD Feedthrough Capacitors #2473

Open
jamesrlucas opened this issue Sep 18, 2020 · 2 comments
Open

SMD Feedthrough Capacitors #2473

jamesrlucas opened this issue Sep 18, 2020 · 2 comments
Labels
Question Issue: request for clarification or support, PR: There is an open question (by author or maintainer)

Comments

@jamesrlucas
Copy link
Contributor

I am looking to use some feedthrough capacitors in some design I am working on, however there are currently no footprints in the libraries. Before I start creating & submitting footprints, I'd like to ask for opinions on how to go about it.

Example devices

Murata 0603
TDK 0603 & 0805
Murata 0805
AVX 0805 & 1206
Knowles 0805, 1206, 1806 & 1812
Murata 1206

All have slightly different recommendations on land patterns (if any!)

Questions:

1: Does anyone have access to the IPC recommendations? (if any!) - I have no idea if feedthrough caps are included or not.
2: Are these footprints we could script?
3. Would a single generic footprint be OK, or should we use manufacturer-specific footprints?
4. What library to put them in - Capacitor_SMD or Filter?

Thanks,

James

@cpresser
Copy link
Contributor

Questions:

1: Does anyone have access to the IPC recommendations? (if any!) - I have no idea if feedthrough caps are included or not.

See pointhi/kicad-footprint-generator#438, at least one outdated IPC-SM-782 document is linked there.
That generator is also partially related, it does RLC footprints.

2: Are these footprints we could script?

Yes but .... AFAIK there is no script that can handle it. It needs to be created. Those parts a rather special, so it is not mandatory to script them.

  1. Would a single generic footprint be OK, or should we use manufacturer-specific footprints?

Depends. I would start comparing them and see if there can be a consensus footprint.

  1. What library to put them in - Capacitor_SMD or Filter?

Everything is a filter if you are brave enough!
Capacitor_SMD sounds better to me, but I have no arguments.

@cpresser cpresser added the Question Issue: request for clarification or support, PR: There is an open question (by author or maintainer) label Sep 19, 2020
@cpresser
Copy link
Contributor

From the Murata 1206 Datasheet. Quite interesting, since there is more paste than copper area:
image
image

Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Labels
Question Issue: request for clarification or support, PR: There is an open question (by author or maintainer)
Projects
None yet
Development

No branches or pull requests

2 participants