Eeyore wrote in
:



gareth magennis wrote:

"orange" wrote in message

Is it safe to keep the CMOS chips (RAM) in plastic box?
if not, can it be modified to be safe somehow, I just don't have any
alternative..

Wrap some aluminium foil around a small piece of expanded polystyrene,
then you can just push the chips into the sandwich and keep the lot in
a plastic box. The foil shorts all the pins together so there can be
no potential difference between any.

Aluminium foil is a BAD idea. In the event that there is any appreciable
charge on a given pin, pushing it into aluminium foil will discharge it
*quickly* and the resulting current may kill it.


It is NOT the current that kills CMOS, it is high VOLTAGE that punches
holes in the insulating layers inside the chip. [I am not aware of ANY chip
families where tiny CURRENTS would be a hazard].

As the conductors are quite small, it only requires a surplus/deficit of a
"few" electrons to build up a high voltage.

When the chip is in a circuit, there will be much higher currents charging
and discharging the

You want to avoid anything that may have accumulated a large surplus or
deficit of electrons.

As long as the aluminum foil is not at a high static voltage, the chances
of damage are quite small.

Hold the chip in one hand, the aluminum foil in the other and run your
finger along the leads before you bring the chip into contact with the
aluminum foil, if you want to 'slowly discharge' any charge that might have
built up.
(this assumes clean hands with normal skin resistance)
If you want to be ULTRA safe, make sure you touch the Vcc and Gnd pins
FIRST.




Always use high resistance material for storing ICs like the anyi-static
black foam material. This allows any charge to 'leak' away slowly and
safely.






--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

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