[sdiy] Static Damage to ICs

[epeasant at telusplanet.net]

  3M came to our plant to demo their
>anti static equipment.  For their demo, they would put a JFET into an
>instrument to measure the gate leakage current.  I can't remember the FET,

>but the bias current was something like 1 pico amp.  They would take the part

>and put it into a "pink" anti static bag (this was the product they were
>competing against).  The would then take a roll of scotch tape, and pull off

>a strip of it about 1 foot away from the pink bag.  They would then take the

>FET back out of the bag and put it into the test instrument, and the Gate
>leakage would be about 1 nano amp.  The same experiment using the 3M metal

>coated bag would result in no increase in the gate leakage.  Mind you, nobody

>ever touched the fets physically to ZAP them.

We have a 3M static meter at work here, measures to 20KV. It relies on an internal
radioactive source to function, fun stuff. To check it's calibration you do
the following:

"measure the voltage on a piece of Scotch Brand #810 magic mending tape. Pull
8" to 10" of tape from the roll and hold in the air so the strip of tape hangs
down from the hand. The reading should be at least 5000 volts positive at a
distance of two inches"

So ordinary scotch tape can easily generate over 5KV. And you thought tube circuits
were dangerous!!!!

Take care,
Doug

______________________
The Electronic Peasant

www.electronicpeasant.com