> Van: Benjamin Petersen > Aan: PICLIST@MITVMA.MIT.EDU > Onderwerp: [OT] What is ESD and EOS > Datum: woensdag 19 mei 1999 9:47 > > I'll be damned, i know it. > > But : > > What is ESD and EOS. ESD is Electro Static Discharge. A High-voltage, low power discharge experienced mostly on dry days when when walking plastic materials. The "pok" you get when touching anything metal. A sort of Micro-lightning. EOS does ring a bell, but I can't tell you _what_ it is. :-( > What does it do. What does normal lightning do with tree's ? It mostly destroys them. If you take a Micro-lightning on a miniature PCB (the inards of a IC or Chip) it will wreak havok there. Holes in conductive traces, maybe even melting them away (and then you are LUCKY). > Is it bad ?.... Sorry , why is it bad ? Yes. The component ceases to function, or, if your not that lucky, it's life-span decreases dramatically. If you are _real_ unlucky it does not die, but does not work well either. I don't know if it's bad, but I surely don't like it :-) > Where does it exist ? Everywhere where a static charge can develop. A dry-air environment with non-conductive floor-coverings. That means anywhere where there are no means to keep the charge between the human and the electronics he's handling equal. (so no egalisation charges can occur.) > How to prevent it ? Simple by not allowing a charge to develop (taking a somewhat conductive floor covering for example) or by discharging yourself to a level equal to the electronics you are using. That's why people working with ESD sensitive materials have wrist-bands connected to a Earth-terminal (a 1 MOhm resistor in series !) and a conductive plate, also connected to a Earth-terminal (again a 1 MOhm resistor), to work on. Their tools (soldering iron, Scope, etc.) are allso connected to the Earth-terminal. > Is this a new knowledge ? Yes. It's knowledge exist a merely 20 to 30 years. Before that whe had Radio-tubes that did have no problem with ESD :-) > Why am I OT ? That's because you forgot to tell us that you where looking at a PIC (not that that mattered, but you had to look _somewhere_ ) when you had the tought about ESD and EOS :-) > Regards > Benjamin Petersen Greetz, Rudy Wieser