Hi all,

Thanks for all replies to my original question about chip capacitor
failure rates.  I am currently involved in an issue where high leakage
current failures (~300 microamps at 50V) occur at a fairly significant
rate on chip caps that are on the top side of a mixed PTH/SMT assembly.
SMT components are reflowed in an IR oven and then the PTH components
are stuffed and wave soldered.  I read through John Maxwell's (AVX)
papers and it appears that he recommends a solder wave temperature of
232 +/- 2 degrees C for assemblies with chip capacitors.  My clients use
a 260 degree C wave (which I have always thought was typical).  Do any
of you follow Maxwell's recommendations?

Best regards,
Ed
--

               SEM Lab, Inc.
Scanning Electron Microscopy and Failure Analysis
               Snohomish, WA
               (425)335-4400
           http://www.sem-lab.com

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