[sdiy] electrosensitive devices

[Magnus Danielson]

From: "Stephen Begin" <trypannon at hotmail.com>
Subject: [sdiy] electrosensitive devices
Date: Fri, 4 Apr 2003 21:31:20 -0500

> I've read a couple pages on the net about how to handle electrosensitive
> devices, and I'm wondering how much of it applies to the kind of things I
> work with.  A lot of parts come shipped in those anti-static bags with
> electrostatic sensitivity warning stickers on them, but seeing as pretty
> much anything you buy nowadays comes with a warning or two, I thought maybe
> I'd ask to see what experience has taught.
> 
> Do you generally leave parts in their static-free bags until they are
> needed, or is it fine just to store them like anything else (in a plastic
> drawer in an parts cabinet).
> 
> And I'd just like to confirm, from what I understand, if I run a wire
> straight into the ground of an outlet with at least a one million ohm
> resistor, i can make sure I don't have any charge by touching that?

This is a slightly messy topic.

Different components have different sensitivty. Where passive components isn't
sensitive semiconductor devices have different levels of sensitivity depending
on their characteristics. A FET transistor is much more sensitive and a
bipolar, and that will count in things like CMOS chips.

The main problem people seem to fail to understand is that what is an issue is
the relative potential differance between the component and soemthing else
(you included). You can have a component charged with many kV at it would be
just fine until you come at ZAP it even if you where grounded to earth.
Much of the work done in ESD is to avoid the buildup of charge to start with,
and when there is a charge it shall slowly leak out. When you set your mind to
think in that direction it becomes easier and easier what to do and what not to
do. You want to avoid quick changes of charge.

You can dig in the Synth-DIY archives. Just recently we had a discussion on it
I think I recall, but then as a side-topic to a side-topic or something. What
the topic was really about I think we better not discuss again... since that
sidetracked itself too ;O)

Cheers,
Magnus