Hi Ken,
From your description, you have solder joints that are NOT really solder
joints because the solder never wetted to the component leads. Properly wetted
solder joints of leaded components would not fail in either mecghanical shock
or vibration testing, the leads would fail first. This has been shown by
AT&TBell Labs in extensive studies.
Your problem could stem from (a) an inadequate reflow soldering profile, (b)
contamination of the leads to render them non-solderable, or (c) they are made
of a material, like Alloy 42, that is difficult if not impossible to solder.
My money is on cause (c); hold a magnet to the component leads, if they are
magnetic they are either Alloy 42 or Kovar.

Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL  32174  USA
Phone: 904-437-8747, Fax: 904-437-8737
E-mail: [log in to unmask]

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