[sdiy] electrosensitive devices

[Czech Martin]

After my experiments, you will feel it on your finger before
you hear it. You start to feel something about 10kV.

A  sensitive device may get an input short (dead short)
as low as 500V precharge level.

So, yes, it is possible to destroy something without
feeling or hearing anything.

m.c.

-----Original Message-----
From: Stephen Begin [mailto:trypannon at hotmail.com]
Sent: Montag, 7. April 2003 18:47
To: synth
Subject: Re: [sdiy] electrosensitive devices


One more question about static then...is it possible for a significant
amount of static to transfer from say...my finger to an expensive cmos chip,
without that audible "zap" sound?
-steve

----- Original Message -----
From: "Peter Grenader" <petergrenader at mksound.com>
To: "Stephen Begin" <trypannon at hotmail.com>; "synth"
<synth-diy at dropmix.xs4all.nl>
Sent: Friday, April 04, 2003 10:43 PM
Subject: Re: [sdiy] electrosensitive devices


>
> Many suppliers, Mouser among them, put a blanket control system on all
> semiconductors.  It's less expensive for them to put all semi's into the
> costly nickel plated anti static bags than it is to concoct some large
scale
> sorting/segregation system, because it has to carry not only to the final
> shipment, but through their entire warehousing/receiving system as well.
> You can only imagine how hard it would be to assure that all static
> sensitive parts, and only those parts, received special handling
procedures,
> are kept in a separate stores locations, etc.
>
> So,  if you are unsure which are and are not problematic for static, as
> impractical as this may be, the best solution would be to carry out their
> system in your lab and for you to treat everything as static sensitive as
> well.   Yeah, I know...a drag.
>
> Problem is, and this came up a few months ago...99.99999999 to the tenth %
> of the failures from the initial static discharge is not catastrophic.  It
> merely degrades the part so it will lean towards infant mortality
somewhere
> down the road.  And when it does, it's hard to determine if ESD was the
> cause unless you pop the top off and have a look under an extremely
powerful
> microscope. Even more impractical in my book.
>
> Two general rules of thumb will help you out a lot:
>
> 1)  Treat static like a virus and take the necessary precautions to keep
it
> from spreading.
>
> 2)  Get your hands around which parts are and are not susceptible and make
> damn sure you at least keep them in foam when not in boards and wear a
> ground strap when inserting them or when handling a board that has them
> inserted, even if you are planning of fooling with those parts directly at
> the time.
>
> I worked for a company (Western Digital) whose first products were
> controller LSI chips.  This is what they started off doing and what put
them
> on the map. This was years before they purchased the Tandon hard drive
> division. You have no idea what you have to go through to create a truly
> static free environment.  We're talking heels straps, nickel faraday bags,
> heel straps, wrist wraps, conductive booties, grounded forklifts, grounded
> storage racks, grounded soldering irons, air ionizers, conductive mats,
> anitstatic spraying of work benches - it's a complete mess.
>
> hope this helps - remember, it's not only 4000 series CMOS you have to
worry
> about!
>
> Peter
>
>
>