Chris, Two points of perspective are:
1 Solderability: The shelf life of components has elapsed when they are no longer solderable. There's tons of variables that affect this, but keys are: * Intermetalics grow as a function of temperature. * Thickness of intermetalic layer versus non-intermetalic layer when put into storage 2 Moisture Absorbtion: Boards and some plastic ICs absorb moisture as a function of exposure to humidity. These require baking prior to soldering.
Good luck on finding data. Date codes on boards are useful. We've stored components for over 5 years now. There's been conversations on SMTnet about board storage and moisture absorbtion previously.
Good luck
Dave F
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