Hi Steve,

Sorry for getting in so late in this discussion but I just got back from
vacation today.

I looked up your pics and I was wondering if you investigated a possible
moisture problem. I looked up on the supplier web site and found out that
this part is an SOIC 16 pin but it was not specified whether it is
classified as moisture-sensitive. The broken wires on the "bad" part look
like a typical damage caused by internal cracks and delaminations due to
excessive moisture absorption prior to reflow aka "popcorning". Large
delaminations are sometimes visible as a small bulge on the bottom side of
the package (only visible after component removal of course).

If the parts were indeed moisture-sensitive this problem may also have been
induced during the removal process if the defective boards were not baked
prior to component removal, thereby hiding the original failure mode.

Another tip that may indicate moisture-related failure is if you had a large
quantity of defects in one production batch. Typically you will find a
complete tube, tray or reel of components that has been overexposed prior to
assembly.

I apologize if this information is redundant as I may have missed some of
the other replies.

Regards,
Francois


Date:    Wed, 28 Aug 2002 16:16:43 EDT
From:    Steve Gregory <[log in to unmask]>
Subject: MUX Failures...an update.

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Hi All!

The the first results back from failure analysis on the On Semiconductor
MC14051BD
parts. I sent 4 parts out that were removed from confirmed test failures.

On 2 of the parts the problem was determined at level 1 analysis. The other
2
parts will need to go on to level 2 analysis as nothing was spotted at level
1.

Go to: http://www.stevezeva.homestead.com and look at the pictures of "The
Good, The Bad, and The Ugly" and see if you can spot why these parts
failed...

You might have to look really, really close to see the problems...but then
again you might not.

-Steve Gregory-

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