At 03:54 PM 11/1/2004 +0000, you wrote:

>One finding at SEM/EDX was the identification of high levels of Carbon and
>Oxygen - presumably this is an indication of organic contamination?


  Long ago and far away we muddled through a similar problem manifest at
least 2 different ways.  One on an SMOBC design, another on ENIG then SM.

Here's a couple possible lines of inquiry...
Are these SMOBC then ENIG?
1. If not SMOBC, then perhaps LPI residue remains in the gold -- not fully
developing out of the Au pores.  This is we insist on SMOBC with ENIG.

2. If SMOBC, then are vias plugged with LPI after ENIG?  If so, maybe a
case of soldermask residue from the plugging operation (esp, if a flood and
develop vs. a dot pattern process)?


cheers,
Dwight

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