Hello

I would suspect a manfactuer's defect.  These parts should
be able to handle the thermals of a through-the-wave process.
It should take the heat from IR as well. However, check your temps.
When I decap is use BOE Glass etchant(a hydrophloric).  A very
nasty chemical.   If you use it be careful.  But it takes off the glass
and preserves the silicon chip.  The other best way for F/A would
be a visual examination.  Sometimes you can see the die attach.
For visual:  lightly sand the glass to get a flat end for viewing.
then examing with your microscope 50 to 100X+ should do
the trick.
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      Don F. Fumia
      [log in to unmask]
      Schneider Automation
      No. Andover MA
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