Recently I ordered some tiny SMD MOSFETs (AO3400) I never paid any attention to ESD. After soldering several MOSFETs on SMD to DIP conversion boards for prototyping I noticed they didn't function correctly after some searching I found out that it is because of ESD.
I understand the gate pin is the most sensitive but what about drain and source, how does the sensitivity different pins compare? if I finally solder them on PCB and the drain is to be an output (to be connected to LED strips) do I have to provide ESD protection for this pin? What about touching the board? Is putting some glue or epoxy on the MOSFET any good?
Best Answer
If you exceed the Vgs voltage given in the datasheet, you can blow through the gate insulation layer. You will never feel 200V of static charge, but it will ruin a MOSFET. As Respawn pointed out, they are not as sensitive after being soldered in because there are other places for charges to go besides right through the FET.
If you're going to be working with stuff like this a lot, you'll probably want to set up an anti-static mat, get a wrist strap, and reduce influence from carpet and clothing while you're building the PCBs.
And always transport your boards in metallized mylar bags!