[Elecraft] Humidity and ESD

Sat Mar 15 19:29:00 2003

A few years ago (15?) I ran the engineering department of a semiconductor
burn in lab in Dallas. I had to implement an anti-static program. Wrist
straps, mats, chairs with metal fibers in the fabric with little drag chains
on the floor and special antistatic floor wax. The operators even wore
smocks with stainless steel thread woven into them. The shipping department
only had antistatic bags and labels. When something is packaged up the
shipping clerk didn't know anything about static sensitive parts so
everything went into a static shielding bag with static labels because
that's all she had to use for packaging. I think that is what is going on
here with Mouser and other suppliers. We burned in mostly 2N2222 and 2N2907
(by the millions) in the military TO18 package. Not normally considered
static sensitive but we also burned in CMOS parts and FET's so everything
got lumped into the same category. I get resistors and capacitors shipped in
antistatic bags with labels from FAI Electronics!

Don Brown

----- Original Message -----
From: "Ron D'Eau Claire" <[email protected]>
To: <[email protected]>
Sent: Saturday, March 15, 2003 5:59 PM
Subject: RE: [Elecraft] Humidity and ESD

> Today a package arrived from Mouser. One of the things inside were some
> packages of common rectifier diodes.
>
> What I noticed was that the seal on the packets read "ATTENTION! OBSERVE
> PRECAUTIONS WHEN HANDLING ELECTROSTATIC SENSITIVE DEVICES".
>
> True enough. But that doesn't mean that the contents of those packages
> are "electrostatic sensitive" by any normal definition of the term.
>
> Oh, I guess if I'm hit with lightning while holding the package, neither
> I or the diodes might be much good afterwards.
>
> My point is that manufacturers and distributors are labeling many things
> that we'd never have considered sensitive it the past. It helps mask
> those items (like IC's with unprotected CMOS gates at the inputs) that
> really ARE sensitive.
>
> Because of that we must either be aware of what is or is not sensitive,
> or take extreme precautions about everything.
>
> The latter may work, but it's sort of like wearing a crash helmet when
> sitting on the couch.
>
> Ron AC7AC
> K2 # 1289
>
>
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