NP0, stacked film cap orientation

Do manufacturers (or any manufacturer) unambiguously specify which terminal is "outside" on such SMT caps?

I don't see it on the Panasonic Stacked film or Samsung MLCC datasheets I looked at.

Is outside on the bottom also outside on the top, or does that vary?

--sp

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Best regards,  
Spehro Pefhany
Reply to
Spehro Pefhany
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We've found that surface-mount stacked film caps tend to fall apart when soldered and washed.

The ends are usually visually symmetrical, so there's no way to identify things.

This one is falling apart already!

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

Ugh. Thanks for reminding me of the last time I had to rework a precision anti-aliasing filter. 8-(

I guess the best solution is to use NP0 caps so small nobody would dare try to run a trace under them.

--sp

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Best regards,  
Spehro Pefhany
Reply to
Spehro Pefhany

Tell them not to do that. Or make them run a ground.

We run traces under 0805s and sometimes 0603s.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

I have seen some PDFs that indicate (say) left terminal being the "wrap-around". I think that typical construction is like taking your fingers and interleaving them, making (say) left terminal being the top foil. Check the PDFs carefully; different manufacturers will do this differently even among capacitive lines and values.

Reply to
Robert Baer

What's the reason?

Best regards, Piotr

Reply to
Piotr Wyderski

Fantastic, was that an April 1st joke which someone forgot to remove?

I just forwarded it to a colleague who's a bit of capacitor specialist suggesting we might consider using it and he Skyped me back wanting to know what was so great about it. Then he clicked on the image.

Cheers

--
Clive
Reply to
Clive Arthur

That's a riot. At least it's truth in advertising!

Cheers

Phil Hobbs

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Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

Sort of like pre-washed jeans, with the knees ripped out.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

Troubleshooting is so much easier when you know in advance which part is dead.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

The layers aren't stuck together very well. They seem to be made in long bars and then sawed up into individual caps. Most are sold like that, no side sealing. They delaminate and water can get inside and cause electrical leakage. Nasty little things.

When I need film caps, I usually go through-hole with epoxy-dipped parts.

This works ok,

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but manufacturing has to be very careful with these, reflow temp and washing and inspection.

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John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

They are usable (well, not the pre-damaged ones) but you've got to be very careful about the assembly process. Never water wash if leakage matters.

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John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

Hardware expands to fill available space?

Thank you,

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Don Kuenz KB7RPU
Reply to
Don Kuenz

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