WB2SRF:
>Using a conductor for a ESD ground pad is not a good idea. >Besides the obvious short circuit or electric shock hazard that could occur. >I learned from taking ESD courses at Lucent Technology and Motorola where I was employed. that slow gradient discharge of the static electric buildup is required otherwise a high peak current can destroy semiconductors. That is why it is called (ESD) electrostatic dissipative Which is why the 1M series resistor is inserted between the foil and ground. I like a dead short between my body and the foil (to absolutely eliminate any potential difference) and then 1M from the foil to ground for the reasons you stated above. I usually even touch one hand to the foil before touching extremely ESD sensitive devices just in case my wrist strap is faulty! I never apply power to anything (except my ESD-safe soldering iron) when I work on the surface to prevent shorts or shocks. I've burned my fingers many times but haven't killed myself (yet). :-) I've also never zapped any semiconductors in several SMD projects, although I've found less exotic ways to destroy parts, such as mounting them in the wrong place! As I said before, you can certainly spend more but IMHO it's unnecessary. I use the $35 CSI clone of the Hakko 936 for the same reason. I would rather spend my money on other things, but that's an individual choice. 73, Bill W4ZV _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
I have used a large, shallow aluminium tray similar to the cooker tray
mentioned and I place all components in the tray still within their a/s bags. With my hands in the tray and the external connections to soldering iron etc thro wrist strap etc, this is my defence against ESdischarge. Everything at one potential is the secret. David G3UNA ----- Original Message ----- From: "Bill Tippett" <[hidden email]> To: <[hidden email]> Sent: Saturday, September 15, 2007 9:26 PM Subject: [Elecraft] Looking for static dissipative bench pad > WB2SRF: > > >Using a conductor for a ESD ground pad is not a good idea. > > >Besides the obvious short circuit or electric shock hazard that could > occur. > > >I learned from taking ESD courses at Lucent Technology and Motorola > where I was employed. that slow gradient discharge of the static > electric buildup is required otherwise a high peak current can destroy > semiconductors. That is why it is called (ESD) electrostatic dissipative > > Which is why the 1M series resistor is inserted > between the foil and ground. I like a dead short between > my body and the foil (to absolutely eliminate any potential > difference) and then 1M from the foil to ground for the > reasons you stated above. I usually even touch one hand > to the foil before touching extremely ESD sensitive devices > just in case my wrist strap is faulty! I never apply power > to anything (except my ESD-safe soldering iron) when I work > on the surface to prevent shorts or shocks. I've burned my > fingers many times but haven't killed myself (yet). :-) > I've also never zapped any semiconductors in several SMD > projects, although I've found less exotic ways to destroy > parts, such as mounting them in the wrong place! > > As I said before, you can certainly spend more but > IMHO it's unnecessary. I use the $35 CSI clone of the > Hakko 936 for the same reason. I would rather spend my > money on other things, but that's an individual choice. > > 73, Bill W4ZV > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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