Steve, can't answer your question, but on a related note, we specify that
we will not accept any material that has more than 1/3 of the shelf life
used up. Perhaps you should consider this also.
Jim Marsico
Senior Engineer
Production Engineering
EDO Electronics Systems Group
[log in to unmask] <mailto:[log in to unmask]>
631-595-5879
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Steve
Gregory
Sent: Wednesday, February 19, 2003 8:31 PM
To: [log in to unmask]
Subject: [TN] A generic question about solder paste shelf
life..
Hi all!
I have a generic question about solder paste shelf life.
Should one hold as gospel, the shelf-life that is stated by the
manufacturer?
I know many will say yes, because that is what the
manufacturer says they will guarantee. But this seems to me, maybe, could
be, a marketing strategy.
Situation:
We ordered solder paste in January 2003, and received the
paste from distribution that was made October 17, 2002. According to the
datasheet, the paste has a shelf-life of 4-months in proper storage
conditions. So when we received the paste in January, we had less than one
and a half months to use it up. Well, we didn't use it all up, due to some
production push-outs from our customers, and some production being put on
hold because of engineering issues, also customer related.
In calling the paste manufacturer, we were told that the
paste is probably good for 6-months, but they wouldn't be able to give us
anything to document that because their internal procedures prevented that.
I'm just wondering if anybody else has run into this
situation, and maybe questioned it...
The way solder paste is packaged seems to me, a very robust
way to keep it from deteriorating. The jar normally has a tight-fitting
plastic insert that will not allow excess air to be in contact with the
paste, and then on top of the plastic insert, there usually is a sealed foil
cover over the opening of the jar. To me, that is very good packaging that
should allow solder paste to remain good for more than 4-months. My mom cans
vegetables and home-made soup with less packaging and it lasts for at least
a few years, I eat it and it's wonderful!
My real concern is that we throw-away perfectly good solder
paste because of what we're told what the shelf life is by the vendors.
After all, who's best interests is it in, if there's a short shelf-life? Has
anybody done and real studies of solder paste shelf life vs. performance?
At $70 a jar, this is not a cheap matter, and doesn't help
with all this lead-free craziness when you have to throw away perfectly-good
paste...
-Steve Gregory-
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