i have successfully put an exposed copper pad with a esd device connected to chassis ground to bleed off any charge incurred (generated) by the lightpipe POF. the light pipe holder (LED holder) is placed flush with the surface of the PCB. The esd gap is very small and the static charge jumps the air gap - then dissipated through the diode array to chassis gnd. Not GND - keeping it "isolated" - kinda ..... it works really well with light pipes (no mask in that area of the exposed copper), oxidation of the copper has yet to be a problem. I hope this gives you an idea or two. keith kowal keith@xxxxxxxxxxxxxxxxxxx > Date: Tue, 23 Sep 2014 16:20:27 -0700 > From: weirsi@xxxxxxxxxx > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Re: ESD failure - need advise > > CM ESD energy is converting to DM noise. Your flex cable should be an > immediate suspect. That said, you could suffer from any of the many > ills that Doug Smith regularly writes about. > > Going after the problem with software now that the product has already > been designed is probably not a very productive approach. Software is a > good way to test ideas and assess risk while you are still making design > decisions. If you go the software route now, it will after you learn to > use it and get your models set-up properly tell you what you already > know: Your design fails. > > Steve. > On 9/23/2014 3:48 PM, Ramesh N wrote: > > Hello Experts, > > Greetings!!! > > we are having ESD fail (in regulatory testing) in one of our design. > > It's simple wireless DAQ system with 2 boards [controller PCB + LED/Sensor > > PCB]. FPC cable (5") is used as interconnect.Package is abs plastics. > > Light-pipe is used for the for led indication. When +8kV is applied through > > air discharging, inadvertent LED trigger occurs . Randomly, system is also > > hanging when multiple zapping applied (especially for 8kV voltage level). > > I have tried to limit airgaps, added filter caps, etc but issue is not > > entirely solved. > > > > Is there any ESD simulation/analysis tool available for addressing this > > failure analysis? > > Any help/debug tips related to this would be very helpful. > > > > Thanks and regards, > > Ramesh > > > > > > ------------------------------------------------------------------ > > To unsubscribe from si-list: > > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > > > or to administer your membership from a web page, go to: > > //www.freelists.org/webpage/si-list > > > > For help: > > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > > > > List forum is accessible at: > > http://tech.groups.yahoo.com/group/si-list > > > > List archives are viewable at: > > //www.freelists.org/archives/si-list > > > > Old (prior to June 6, 2001) list archives are viewable at: > > http://www.qsl.net/wb6tpu > > > > > > > > > -- > Steve Weir > IPBLOX, LLC > 1580 Grand Point Way > MS 34689 > Reno, NV 89523-9998 > www.ipblox.com > > (775) 299-4236 Business > (866) 675-4630 Toll-free > (707) 780-1951 Fax > > All contents Copyright (c)2013 IPBLOX, LLC. All Rights Reserved. > This e-mail may contain confidential material. > If you are not the intended recipient, please destroy all records > and notify the sender. > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu