Carrie
Many voids are caused by poor through hole quality. The reasons are:
- Drills used too long
- Too high feeding rate in the drilling process
- Plating too thin
The voids are not caused necessarily by moisture but by outgassing of
the epoxy and plating residues penetrating along the glass fibres if the
holes are rather ripped than drilled.
I sent a figure from an old survey to Steve to put it on his homepage.
I called it Voids in Solder Joints.
Best regards
EMPA
Swiss Federal Laboratories for Materials Testing and Research
Centre for Reliability
Guenter Grossmann, Senior Engineer
8600 Duebendorf
Switzerland
Phone: xx41 1 823 4279
Fax : xx41 1 823 4054
mail: [log in to unmask]
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