Diode footprint Chaos. "SMAF"

I hereby certify that I am not simply asking someone else to design a footprint for me.

This is an auto-generated message that is in place on the “footprints” section of the KiCad.info forum. If I remove it and ask for a footprint to be designed anyway, I understand that I will be subject to forum members telling me to go design my own footprint or referring me to a 3rd party footprint site.

The one thing I just cannot wrap my head around are diode footprints and their names. SMA, SMB, SMC, DO215AC, DO214AA, SOD-xxx, the metric designations to name just a few of the 10 million :frowning: The names I find in Kicad are always different than the names I find @ jlcpcb and vice versa.

I thought I started to understand but now I found a diode that meeds my demands and it has a “SMAF” package. And as usual… it is not there in KiCad. Ofcourse I don’t blame any party here. There are obvious many standards, but it is a royal payne in the ***

afbeelding

I was about to make my own footprint when I had the hunch to ask chatgpt.
Here’s a simplified version of these steps:

  1. Open KiCad PCB Footprint Editor.
  2. Search for DO-214AC (SMA) or DO-221AC (SMA-W) footprints.
  3. Compare footprint dimensions with the SMAF diode datasheet.
  4. Modify an existing footprint or create a new one if necessary.
  5. Save and verify the footprint.

Not stupid advice though :stuck_out_tongue: I looked, SMA came a bit close. So I am going to copy paste that one and change it a little.

Besides making your own footprints are there any wisdoms to be found on this here forum concerning this diode chaos? I have the feeling that KiCad’s libaries have some room for improvement when it comes to diodes?

:tumbler_glass:
Bas

What those letters mean to the manufacturers component dimensions is inconsistent. The recommended footprints then vary even more.

Is this really all chat :face_vomiting: :face_vomiting: :face_vomiting: could suggest?

Well, us humans might as well stop answering forum questions then.

When I compare the documents below, the footprints are the same for SMA and SMAF. The difference is in the height of the package, and how it’s build. SMA has leads coming out of the sides, which are then folded under the package, while SMAF is a much thinner package and the leads are moulded into the body of the package itself.

https://www.diodes.com/assets/Package-Files/SMA.pdf
https://www.diodes.com/assets/Package-Files/SMAF.pdf

Yes, KiCad and it’s libraries have been improving for 30+ years and there is still plenty of room for improvement left.

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If only there were a place to gather information for the developers to help them know what the end user wants. I guess we can dream. :wink:

In case of SMAF I translate it as SMA Flat. The same footprint, but flat element.

Improving heat transfer from chip to pad and PCB, I think.

so far I find the AI only usefull for small coding tasks. It is actually quite good in that sort of stuff. I have those scripts for uploading things and all, but I had to manually enter the comport number. Now the scripts can do it them selves thnx to chat :face_vomiting: :face_vomiting: :face_vomiting: .

But for circuit designing it knows next to nothing. For the fun I asked about a short circuit proof circuit. And one of his replies was to ask an electronics developer, that sanava… it was not only the information from stack overflow that I got, now I got that typical SO negativity along with it :joy:

I think I would start with what the most popular PCB vendors sell. Diode bridge footprints are even worse :rofl: If you would single out the basic parts that JLCPCB offer for… well diodes to start with, than you would put me in my happy space.

Kind regards :tumbler_glass:

Bas

They are consistently inconsistent.

image

Don’t pick on just diodes. I think that IC packages and their names are similarly chaotic. Think about TSOP, TSSOP, VSOP. Then look at some MOSFET packages. Yetch!

I have never recently designed a board for mass production. For my own assembly I like to use footprints which can cover a reasonable range of packages. For example a MOSFET might show four drain pins but I just use one big rectangular pad. This seems to work well enough for hand soldering. Not being a manufacturing engineer, I am not certain what are the tradeoffs. But it seems that commercial operations do not like to do what I do with respect to using versatile footprints.

The manufacturers need a SMAK.

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i find that digikey does a pretty good job of “translating” the name the manufacturer uses for the footprint into a more standard “package name”
so if you find the part you want you can go back and find other parts that have the same footprint by using that filter for package/case. (mouser only lists whatever name the manufacturer lists, which you’ve found out is almost worthless.)

image

Unless the parts in question are made by Wurth. :crazy_face:

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:smirk: hey mods, what’s the punalty for this?

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The wurst possible. -----

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3 months duty reviewing the footprint merge queue

I am off the hook because I do not know what that means.

You will certainly know after three months.

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