In article p2sDh.16179$z6.1559@bigfe9, ess
(known to some as mc) scribed...

snippety

Precisely -- I asked the question because I wanted to know the answer.

Can anyone tell me what happens, physically, to solder paste that gets old,
and why it's no longer considered suitable for use? I know the
specifications say not to use it.

More generally, if I didn't know whether some solder paste was fresh, what
changes should I look for?

I'd like to know this myself, as I'm in the final stages of getting
set up to do SMD work and I just spent $250 for supplies (solder paste,
flux, wetting solution, tools, etc.)

Simply being told "How important is reliability and traceability?"
doesn't cut it with me, any more than pointing to the expiration date on
a tube of solder paste and saying "Never use this after this date!"

I want to know what, exactly, changes, and how it affects
reliability (I don't give a flying poof-ball about traceability as long
as the solder holds). I also want to know how these alleged changes will
affect the stuff in terms of making simple repairs with (mostly) PLCC's
and QFP's.

I'm not doing mil-spec production here... just trying to do decent
repairs.

Keep the peace(es).



--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute
(Known to some as Bruce Lane, KC7GR)
http://www.bluefeathertech.com -- kyrrin a/t bluefeathertech d-o=t calm
"Salvadore Dali's computer has surreal ports..."