In a message dated 96-12-30 20:39:59 EST, you write:

<< I would like to know the causes of solder blow-out in soldered PTH 
      assemblies other than the insufficient copper thickness of PTH. 
      We are encountered this kind of soldering problem on PCB with 
      0.8mil(average) in PTH copper thickness.
      Any help to identify the problem would be highly appreciated
      
      Best Regards,
      
      KP Chan
      Email: [log in to unmask]
  >>

KP Chan

It sounds like you have excess moisture in your boards try backing the boards
at 125F for 3 hours and see if this dosen't improve your problem.  The
temperature is low enough to drive the moisture out, but not high enough to
form a thick oxide layer that may reduce the boards solderability.

Terry Munson
[log in to unmask]

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