Very interesting Phil. I haven't gotten involved with ESD policies very
much, but I would very much like to know how you conducted your
measurements. Every now and then questions come up on the factory
floor. I would like to be able to dispel or confirm whatever belief
people have concerning ESD.
Thanks
Ryan Grant
Process Development Engineer
MCMS
(208) 898-1145
FAX (208) 898-2789
[log in to unmask]
>-----Original Message-----
>From: Phil Bavaro [SMTP:[log in to unmask]]
>Sent: Friday, November 05, 1999 10:13 AM
>To: [log in to unmask]
>Subject: Re: [TN] Wrist wraps for seated operators
>
>It has been my experience that the ESD policy needs to be set by
>measurements, data, and more measurements, not logic. Otherwise, ESD
>programs can get very expensive to implement.
>
>One of my many hats as a process engineer has been ESD Program Manager, and
>while I agree that the aforementioned rationales seem totally logical, I'd
>like to know if Mike and Howard have actually measured the voltage
>potentials involved.?
>
>I've studied this particular situation very extensively and every time find
>that there is no difference between standing, sitting, or even sitting with
>their feet in the air.
>
>My conclusion has always been that the large hull effect of the dissipative
>floor does not allow for the potentials to accumulate on the operators
>above it.
>
>If anyone does have data contrary to this, I'd appreciate a chance to
>discuss this with them.
>
>
>Phil Bavaro
>"ESD Program Manager"
>____
>
>
>At 08:47 AM 11/5/99 -0500, Cyker, Howard A (Howie) wrote:
>>The rationale for using a wrist strap when seated is to provide a consistent
>>and constant level of grounding. Grounding through conductive chairs would
>>rely on grounding through the clothing, which is unpredictable and
>>unreliable. Grounding through conductive shoes, of course, requires
>>constant contact with the floor, which cannot be guaranteed while sitting.
>>
>>> Howard A. Cyker
>>> Lucent Technologies
>>> Email [log in to unmask]
>>> Phone 978-960-2964
>>>
>>>
>>>
>>> ----------
>>> From: d. terstegge[SMTP:[log in to unmask]]
>>> Reply To: TechNet E-Mail Forum.;d. terstegge
>>> Sent: Friday, November 05, 1999 4:27 AM
>>> To: [log in to unmask]
>>> Subject: [TN] Wrist wraps for seated operators
>>>
>>> Hello Technet,
>>>
>>> We've recently received some complaints from a customer who is not happy
>>> with the fact that our operators don't wear wrist wraps during seated
>>> operations like handsoldering and inspection. Our factory relies on
>>> grounding through the (conductive) chairs, ESD-shoes, conductive floor and
>>> ESD-workbenches, but the chairs are tested only once per year, which is
>>> obviously less frequent then one would test wrist wraps.
>>> Is the customers concern justified, and should we introduce wrist wraps ?
>>>
>>> Daan Terstegge
>>> Unclassified
>>>
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