We manufacture service repair parts for obsolete product line from
materials that are greater than 24 old. The boards and components are
stored in a factory without effective humidity control, though the plant
is air conditioned.

When we move a kit into production, we bake the boards at 140F for 24
hours. We increase the preheat to achieve a top side (these are through
hole assemblies) temperature to 235F, and (here's the kicker) use Alpha
Metals SA86 (AKA pink death) flux. Usually we achieve IPC-A-610 class 2
solder conformance.

> Subject:
>         Shelf Life
>     Date:
>         Thu, 7 Oct 1999 17:47:10 -0700
>    From:
>         Darrel Therriault
>
>
>
> TechNet,
>
> I need to tap a little expertise from the assemblers out there....
>
> I have a PWA kit to be built that has been sitting around for about 12-14
> months.
> No environmental storage of any kind, just in tubes and boxes in the stockroom.
> What dilemma's am I likely to encounter with these components, if any??  I
> suspect
> the boards will need to be baked, but normal duration or more based on length
> of time on the shelf?? Any worry about warp and coplanarity?
> Any issues with components that have not been stored
> with any dissicant or anti moisture protection?  Any worry about lead oxidation
> that requires cleaning/tinning for solderability/wetting concerns?
>
> Just wondering what kind of interesting things to expect or try and avoid,
> if any.
>
> Any suggestions or comments greatly appreciated.
>
> Tks......DT
>

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