LOC diodes question

[carmangary]

The only ESD protection I use is to make sure that I touch something metal that is grounded before working with sensitive components. As long as you aren't sitting there doing something like rubbing balloons or shuffling your feet on the carpet you shouldn't be building up any static while working on your laser. So, once you discharge initially, you should be good for a bit. ESD bracelets and mats are nice if you have them but I think that if you just ground yourself like I said you should be OK. That's just my theory, though. So, don't hold me to it. Works for me, though.

 

[Benm]

Never ground yourself directly for ESD protection, its a very bad practice, and can get you injured when ever working on mains-fed equipment or in case of wiring failures. The wrist wraps have builtin resistors to prevent this.

As said before, the need for ESD measures depends greatly on climate and other factors, probably more so than on how sensitive the component is. You -will- generally notice circumstances where ESD protection is really needed, the times of year where you get a cracke/spark/jolt stepping out of your car and closing the door, or even from touching someting grounded like a tap.

Another problem is floor materials: some carpets have a tendency to cause you to build up charge when walking on them, especially with shoes on.

 

[Krutz]

well, i use radiators to ground myself, never felt comfortable with anything near a wall outlet..
sure, we could argue what has to go wrong that the physical house.ground holds a charge.. but then a 1 meg resistor is just a few cents, so i will simply wire one in between, next time i order stuff..

for ESD handling, it would even be sufficient to strictly touch everything in the right order. first the diode lays on a conductive mat. you touch/hold the mat. then move or pick up the diode. then in reverse, first touching the mat (while still holding the diode), then place the diode back on the mat, then finally let the mat go. in that procedure it doesnt matter if you are charged or not, in no point can current flow from you into the diode.
but then, when i already use a conductive mat, i can as well wire myself up to it, and the mat (now through a 1 meg resistor) to a radiator or tap..

manuel

 

[Benm]

I suppose it depends on how you do things as well... i have a tendency to avoid grabbing things by the esd sensitive end at first. Once you are holding, for example, a sled by its bulk metal with one hand, its hardly possible to do ESD damage by handing the diode with the other.

ESD issues arise mostly when discharching -through- a sensitive device, somewhich which could happened when you are charged, and touch the positive lead on the diode before touching the sled.

That said, if you are using a conductive mat, there is no need or use to connect that to ground by any means. Both the mat, you, and all device on it can have a potential relative to ground, but within the parts being worked on that potential is equal, and it only differences in potential that can do any damage.

Such a situation is actually very common, you'd have to be at a potential of at least several thousand volts to get noticable discharges when grounding. If you're charged to 500 volts and then touch a grounded object, its likely you'll discharge without ever knowing.

 

[ElektroFreak]

ESD isn't as worrying as you may think. Once the diode is in the Aixiz module, the only way you could kill it from ESD is if you were to touch the bare wires. Once it's inside the host, there isnt really any way for you to come into contact with the wires.

Not entirely true. ESD poses a serious risk to diodes with "floating" inputs like most hobbyist blu-ray diodes. In these cases ESD can discharge directly through the diode junction to ground. A good way to get around this is to connect the diode's negative connection to the case pin on the diode.

During the winter, when static electricity buildup is at it's peak, I killed several diodes in modules and heatsinks just by picking them up. A tiny spark would appear and bam.. LED. Since I started grounding the negative pin I have yet to have killed a diode from ESD.

 

[Krutz]

thank you both!

makes sense.. i will probably still use my diy mat, but just connected to my fingerring, and not to any house' ground.
makes total sense, with the free-floating br diodes! i normally connect the negative to the ground anyway, when installing the diode. so i will connect that directly when removing the diode from its sled/cable, from now on!

interesting threads, with many hints and facts that i didnt know or recognized yet, thank you all!

manuel