Moisture sensitive devices warning

[ledtester]

I bought some LDO regulators and they came with this warning...

I can't make out what the guy wrote for 3a - what do you think it says?

[Siwastaja]

168 hours. LEVEL 3, i.e., MSL 3 says it all.

[jmelson]

But, really, people go crazy over this stuff.  There are some large FPGAs and such that will suffer damage if left out for weeks and then reflowed without baking.  But, I routinely leave parts like this out for MONTHS in my basement (it is "conditioned air space, but a bit humid in summer) and have NEVER had any issues.  And, it is not just tinkering in my basement, I am a small manufacturer, and have a pick and place machine and a homemade reflow oven.

I HAVE had PC boards that have sat around for a year blister in the reflow oven, so I bake those out at 50 C then 70 C for an hour or two before stuffing and reflowing them.

Jon

[David Hess]

That has to do with reflow soldering requirements.  If the plastic packaging encapsulation absorbs too much water from the atmosphere, then the parts will "popcorn" during soldering.