piclist 2001\01\11\234410a >
Thread: Opinions spought on Electrostatic dissipation·
picon face BY : Russell McMahon email (remove spam text)

I'd be interested in opinions (backed by any available hard data) on what
constitutes an adequate dissipative surface for a storage container used for
electronic components.

I have a number of plastic containers which I wish to use for component
I have lightly sprayed the interior of a number of these with a thin layer
of Nickel spray (intended for EMI/EMC shielding purposes.
While this produces an adequately conductive container, the spray is
horrendously expensive for this purpose and not always readily available.

As a possible alternative I have a rub-on paint like which is intended to
produce a metallic "copper" finish for decorative purposes. It;'s high
density suggests a metallic base. It rubs on to an extremely thing but
opaque and fairly permanent finish. It uses Turpentine as a solvent - this
evaporates rapidly on application.

The resultant finish produces a resistance of around 200 megohms (!!!)
across a 1cm distance using standard meter test probes touching the surface.
(The resistance seems to increase roughly linearly with separation) .
While this is much higher than any normal resistive materials the resistance
is repeatable at various places on the box and at various times. A similar
test under the same humidity conditions on a wooden varnished surface or the
box's raw plastic produces a reading of o/c (>400 Mohm) no matter how close
the probes are brought to each other.

A 1 nanofarad cap would have a discharge time constant of around 0.1s over a
1cm distance or 1 second over a 10cm path.

Is this very high resistance considered adequate for electrostatic
protection purposes?
Why not?


     Russell McMahon

What can one man* do?
Donate food daily free !!! -  http://www.thehungersite.com/
Donate Vitamin A!  http://www.thechildsurvivalsite.com/
http://www.rawa.com  - one perspective on Afghanistan
http://www.changingourworld.com    http://www.easttimor.com   http://www.sudan.com

(* - or woman, child or internet enabled intelligent entity :-))

http://www.piclist.com hint: To leave the PICList

<00bf01c07c52$ca51e0e0$0100a8c0@mkbs> 7bit

See also: www.piclist.com/techref/index.htm?key=opinions+spought
Reply You must be a member of the piclist mailing list (not only a www.piclist.com member) to post to the piclist. This form requires JavaScript and a browser/email client that can handle form mailto: posts.
Subject (change) Opinions spought on Electrostatic dissipationĚ

month overview.

new search...