Hi Patti,
What you have is most likely a combination of the large ceramic/FR-4 thermal
expansion mismatch causing cyclic creep-fatigue and tensile displacements
frozen-in during hand-soldering causing creep rupture.
"More ductile solder" is not a solution. More uniform soldering and lower
thermal expansion mismatch strains are; the latter can be accomplished by
more compliant lead geometries, and if that is not possible, to a lesser
extent by an increased stand-off to increase solder joint thickness.

Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL  32174  USA
Phone: 386-437-8747, Fax: 386-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com

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