Lets say for example, that I had a box full of transistors, resistors, capacitors, diodes, leds, this and that, and left it in a cool, average environment for lets say… 50 years.
Do these components have a lifespan while been unused? Do the insides end up degrading and become unusable like cars? Or do they just… Sit there?
I'm asking this, because I just got a thought that struck me, being that if you kept today's components, (and kept them for 50 years) will you be able to use them in the future?
Best Answer
Yes, they will degrade little by little; they will grow tin whiskers, maybe oxidize little by little because their casing will never be 100.00% sealed. Also the pin plating will oxidize, so you'll have to treat them before soldering. Also moisture can creep in, little by little... difficult to say if it would affect discretes like transistors a lot, but ICs will suffer.
Oxidization plays a role in IC degradation if the passivation layer has defects, but the killer is metal whiskers between pins, pads and bond wires. It doesn't cause gradual degradation; basically the chip works fine until finally a whisker causes a short circuit between pads and the chip dies.
Image: whiskers on a piece of zinc. Source: http://commons.wikimedia.org/wiki/File:Zinc_whiskers.jpg