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SMT electrolytic capacitor lead classification is???

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#57279

SMT electrolytic capacitor lead classification is??? | 14 November, 2008

What is the spec or true classification for the leads for an Electrolytic capacitor? Is it a :

1)Flattened coined lead???

or

2)Flat Lug Lead???

There is some confusion as to how we should be inspecting & accepting the toe overhang on these per IPC specs (class2).

Any links providing me with a legit resource showing an electrolytic capacitor's lead classification would greatly be appreciated. It would make references back to IPC standards a whole lot easier. Thanks!

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#57285

SMT electrolytic capacitor lead classification is??? | 14 November, 2008

Section 9 of J-STD-001 gives you what you need. Further: * Flattened [coined] lead: http://workmanship.nasa.gov/lib/insp/2%20books/links/sections/files/711.pdf

* Flat lug lead: Look for the Package Designator �LT� on page 7 of http://www.allegromicro.com/en/Products/Packaging/pkgdes.pdf

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#57294

SMT electrolytic capacitor lead classification is??? | 14 November, 2008

So would you side to say that electrolytic capacitors have Flattened coined leads & should follow specs under that classification?

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#57295

SMT electrolytic capacitor lead classification is??? | 15 November, 2008

A tenative yes. The hesitance comes because it seems that you're setting us up for something. So, howbout you tell us just what's going on?

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#57307

SMT electrolytic capacitor lead classification is??? | 17 November, 2008

That's what I was wondering too....

Just what the hell is going on here !!

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#57327

SMT electrolytic capacitor lead classification is??? | 18 November, 2008

I'm just wanting something solid to show my workplace. I am under the belief that it is a flattened coined lead. But like how i've been trained in IPC, I have to be able to prove that it is true... or that IPC says it is false. We have a customer that has had some complaints about how our Electrolytic caps hang a bit over the toe end of the pad. It is to my belief & understanding that the customer's Quality personel might be unknowledgable in this area. I am merely putting in my 2cents as to what my experience has worked with. We have had assemblies (numerous ones) where customers have not complained about it. I noticed the other day when we came across this & discovered that our process book stated that the Electrolytic Capacitor had to be tweaked exactly to being all within the pads without any overhang... (here's the kicker) per IPC. I disagree with that notation & wanted to look for resources on the internet (data sheet, part specs, etc...). I've had no luck whatsoever. I'd like to write the IPC specialists but have no contact info. So i thought I'd come to the forum for other industry experts knowledge. No surprises... Just straight forward reasoning. Thanks for your input so far. ANy further additional support/opposition in this would be greatly appreciated for debating purposes. Thanks again.

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#57328

SMT electrolytic capacitor lead classification is??? | 18 November, 2008

Here are people at IPC that can direct you to the people you need to talk to about the issues that you have with the standards: * Jack Crawford, IOM, IPC Director Certification and Assembly Technology, crawja@ipc.org 847-597-2893, 847-615-5693 * David W. Bergman, CAE, Vice President, Standards, Technology and International Relations 847-597-2840 F 847-615-5640 C 847-867-1388 bergda@ipc.org

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#57330

SMT electrolytic capacitor lead classification is??? | 19 November, 2008

#57467

SMT electrolytic capacitor lead classification is??? | 2 December, 2008

Thanks for the resources. I plan on contacting them to get some answers. I hope this all works out for us & can help others someday should they come accross similar issues too. Thanks again.

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#57468

SMT electrolytic capacitor lead classification is??? | 2 December, 2008

Wow, rocket science with Nasa specs! I like it. I don't see the trick question here, so I'll continue....

IPC simply states over hang of round or flattened (coined) leads is acceptable (class 1, 2, & 3) if it "does not violate minimum electrical clearance". Page 8-56 of IPC-A-610D.

So simply put, it doesn't matter if it's round or flat - the same requirement covers it.

If this is a trick question, fire awa Sparky......

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