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 >>> >>> ############################################################## >>> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c >>> ############################################################## >>> To subscribe/unsubscribe, send a message to [log in to unmask] with >>> following text in >>> the body: >>> To subscribe: SUBSCRIBE TECHNET <your full name> >>> To unsubscribe: SIGNOFF TECHNET >>> ############################################################## >>> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for >>> additional >>> information. >>> If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or >>> 847-509-9700 ext.5365 >>> ############################################################## >>> >> >>############################################################## >>TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c >>############################################################## >>To subscribe/unsubscribe, send a message to [log in to unmask] with >following text in >>the body: >>To subscribe: SUBSCRIBE TECHNET <your full name> >>To unsubscribe: SIGNOFF TECHNET >>############################################################## >>Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional >>information. >>If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or >>847-509-9700 ext.5365 >>############################################################## >> > >############################################################## >TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c >############################################################## >To subscribe/unsubscribe, send a message to [log in to unmask] with following >text in >the body: >To subscribe: SUBSCRIBE TECHNET <your full name> >To unsubscribe: SIGNOFF TECHNET >############################################################## >Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional >information. >If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or >847-509-9700 ext.5365 >############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. 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