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January 2000

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Subject:
From:
Gabriela Bogdan <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Fri, 28 Jan 2000 00:44:32 +0200
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text/plain
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Alain,
A cross section of the capacitors without desoldering could give you a better image of
your problem.
John Maxwell is the GURU in capacitors, and beside his answer to you, he has written
many articles which can enlighten you in ceramic capacitors failure modes. Just for
your information - some time ago somebody gave me a board with "separation of endcap"
which proved to be crack in the capacitor under the endcap . If you have more than one
capacitor on the board and the defect occurs always in the same location , you should
suspect something in your process.
Gaby

Alain Mathieu wrote:

> Hi TechNetters.
>
> We recently discovered a problem on chip capacitors:  when examine carefully
> with magnifying glass, we found a separation (Gap)  between the endcap
> (metallization) and the ceramic.
>
> When capacitors were pried with tweezers, the whole ceramic part came off,
> leaving both, complete endcap in the solder joints.
>
> Removed caps were examined under microscope and all we could see was a
> brownish deposit ( look like glue ) where the two endcaps were.
>
> I think it is a part manufacturing problem. Am I right to think that or can
> something else have cause the separation of the endcaps ?
>
> Alain Mathieu
>
>
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