OT - Shelf Life of Electronic Components

[Ed Arnold]

I would like to inquire about the average shelf life of electronic components. Specifically surface mount components. IC, Semiconductors, Caps, and Resistors. I did a search on Google and found several good links. Some results were app notes from T.I. that explained about new lead free components. I also found a good website devoted to SMD in general. It had a forum, but not as easy to use as this one. Also very slow searches. Never the less, I didn't find any answers. So, I thought it couldn't hurt to ask here. Anyone who knows the answer to my question or can point me in the right direction, please post. I am interested in a general overall answer, which I know has many variable. Like storage temp, moisture, and in some cases static. Assume that all of these conditions are within spec to render your answer.

Thanks in advance,

Ed Arnold

[StuH_CC]

I'm not sure about "shelf life" of the silicon itself, the main issue is oxidisation and contamination of the connecting leads which can render a part unsolderable. I have seen packaged parts which quote a shelf life of less than 48 hours from the time of opening the bag - on the other hand, I recently needed a 74LS04 in a big hurry for a prototype, the only one I could find in the "junk box" had a 1975 date code - nearly 30 years old! After cleaning the crud from the pins so it could be soldered, it worked perfectly!

Stu.

[SherpaDoug]

The only components I would worry about age with are electrolytic capacitors because the liquid electrolyte can leak or dry out. Even with them; ten or twenty years should not be bad if they were stored in any reasonable manner.

Other than that there is only the matter of corrosion of the solderable surfaces which others have mentioned. With care and skill that can usually be overcome.
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