Hello Tony,
It's well known that ESD damaged components can fail months or years
later. In fact, ESD damaged components can cause intermittant problems
that drive Customers and Service people up the wall. If in doubt,
shotgun repair is sometimes the best way to fix ESD damaged products.
Believe me, I've been there.
To stay on the subject of zapping connector pins, if the risk is high
that the End-User will come in contact with exposed pins, you should
at least test the pins to see what happens. It's better to know than
not know. Unfortunately, we are at the mercy of D-shell connectors and
their like because they are Industry Standard and everyone uses them.
One could design an ESD robust connector. However, is the expense and
the possibility of having a non-standard connector worth it?
I believe that everyone contributing to this thread knows that zapping
pins of exposed connector pins is almost always a guaranteed failure.
Whether you fix it or not is a business decision, hopefully based on
the intended market, previous product history, and what you know about
your competition. However, the bottom line is always Customer
satisfaction and whether your Customers will accept the risk.
Regards,
Ron Wellman
+============================================================+
|Ronald R. Wellman |Corporate Quality Department|
|Hewlett-Packard Company |External Product Regulations|
|Product Processes Organization |Voice : 415-857-6059 |
|1501 Page Mill Road, MS 5UL |FAX : 415-857-6340 |
|Palo Alto, California 94304 USA|E-Mail: [email protected] |
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| age eighteen." - Albert Einstein |
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______________________________ Reply Separator _________________________________
Subject: Re: ESD testing on exposed connector pins
Author: Non-HP-Tony-Fredriksson ([email protected]) at
HP-PaloAlto,uugw3
List-Post: [email protected]
Date: 4/18/96 9:38 AM
Ron,
Often times, ESD related failures can't be traced to the event because they can
stress semiconductor junctions without causing an immediate failure. Then a
short time later--days, weeks, even months-the stressed component fails
prematurely for no apparent reason. So even if a specific case can't be named,
it doesn't mean that I/O pin discharges
in real life don't cause failures.
Concerning removal of the cover, the assumption is that one is removing
the cover to connect a cable. At the time of removal, the charged
individual
will discharge to the D-shell or chassis, assuming the individual is not
using a non-conductive stick to remove the cover. The pins will not be
subjected to the discharge.
Of course a cover would not do much if there is no alternate discharge
path nearby or if the customer removes the cover just for the heck of
it.
We should consider that one can always find a way to break something.
I would hope we design for the majority of events rather than for making
things 100% foolproof.
regards,
[email protected]
