Any one know what this acronym stands for? In particular, there is an LM340MP and an LM340MP/NOPB.

 

No Pb, lead free

 

Probably "No Lead (No Pb)"

 

Hello there Physical characteristics of the element in its pure form. Their symbols are taking from the periodic table of elements so that there is no confusion on the composition of what makes up product specific materials..Find Pb here.

 

It was so much more logical when the 5A and 5B system was in use.

 

Was there ever any lead in Integrated circuits?

 

Yes, that and other heavy (restricted) metals. Legs were lead-solder plated/coated.

 

Was there ever any lead in Integrated circuits?

Yes. The C4 bumps were solder with lead. I recall some issue when we tried to remove the lead in the early 00's.

 

There is still an issue with the lead-free solders, which is why in anything that must be reliable lead solder is still used. That includes pacemakers and space satellites.
And of course that old warning still applies, even with lead-free electronics: "never pull parts off the circuit board and eat them." They are still bad for one's health.

 

Thanks for all the replies.

 

Note that not all parts or manufacturers will use a NOPB designator and that it can mean more than just no lead: