Esd questions

Thread Starter

Greasepaintmug

Joined May 19, 2023
15
Hey there so I’m setting up a station at home and one small spot in the maint shop at work( for soldering after my shift ends long story)

wondering what you would suggest for a mat are those bertech mats with the snap to common point ground two Banana plug connections one for mat one for wrist strap the ones to go for ? Any other suggestions if not?

and what’s the best practice for esd work like bread boarding soldering etc handling components

pink poly bags for stuff like resistors and caps
Silver shielding bags for ics diodes transistors and electrolytic caps ?

transport them in whatever plastic bin they are in sealed in bags place on mat remove when bag is on mat to work with them?

I have those Leviton style outlets with nocenter screw so just confirm that the outlet is properly wired with ground wise with an outlet tester then check continuity between mounting screws and the ground hole in the receptacle.
At work they have the gfci outlets mounted in metal boxes same procedure but check the mounting screw is grounded as well?

Sorry for all the questions just want to make it as ideal as I can with what I have to work with.
 

Thread Starter

Greasepaintmug

Joined May 19, 2023
15
It depends. What kinds of components will you be working with?
In the beginning, just simple stuff bjts , diodes, resistors, capacitors ( electrolytic and ceramic) ics ( some cmos based as well) relays, pretty much the regular gamut in addition to micro controllers eventually.
 

DickCappels

Joined Aug 21, 2008
10,152
As for ESD concerns, you should be mostly concerned with semiconductors - integrated circuits, diodes, and transistors of various types. If you live in a climate with high humidity, just handle them carefully, don't wear shoes on a carpet, touch a groundpoint on a chassis you are working on occasionally to make sure you are at the same potential and you should be ok.

In the case of dry air such as you might have in the winter a ground strap WITH A RESISTOR IN SERIES WITH THE GROUND CONNECTION so you don't get electrocuted should be enough.

I have been working in a high humidity environment, bare foot on an earthed tile floor of the last 16 years and have not had any problems with ESD. Others have other experiences.
 

ThePanMan

Joined Mar 13, 2020
773
wondering what you would suggest for a mat are those bertech mats with the snap to common point ground two Banana plug connections one for mat one for wrist strap the ones to go for ? Any other suggestions if not?
The extra plug point is commonly used for a second operator or an inspector.
what’s the best practice for esd work like bread boarding soldering etc handling components
Prevention of buildup of static is best approach. Minimize it by keeping foam and plastic away from the work station. And as DickCappels said - (touch a ground point on a chassis you are working on occasionally to make sure you are at the same potential and you should be ok.) maintain a common potential with the work piece. One thing I've usually done is to use the wrist strap and an alligator clip and clip to the chassis of - say - a computer frame. When working with a breadboard you can't do that. That's where a mat and wrist strap properly wired is most useful.
pink poly bags for stuff like resistors and caps
Silver shielding bags for ics diodes transistors and electrolytic caps ?
I hate pink polly. Many people think it's ESD shielding. It's not. The positive of PP is that it does not generate static. The negative is that it is not shielding. The metalized bags, often referred to by manufacture name "Velostat" offers best shielding for storage and transportation.
transport them in whatever plastic bin they are in sealed in bags
Avoid plastics as much as possible. When not possible, use conductive foam (black stuff - note: not all black foam is conductive). I happen to have dozens of IC's on conductive foam in plastic storage containers. Move the containers as little as possible.
I have those Leviton style outlets with nocenter screw so just confirm that the outlet is properly wired with ground wise with an outlet tester then check continuity between mounting screws and the ground hole in the receptacle.
At work they have the gfci outlets mounted in metal boxes same procedure but check the mounting screw is grounded as well?
None of us here can tell for sure if you have a properly grounded system. Best approach is to have a licensed electrician confirm you are properly grounded. (taken from IPC-610 rev C (up to or past rev G at present but this section hardly ever changes)
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Thread Starter

Greasepaintmug

Joined May 19, 2023
15
Copy that so my best bet for storage for large amounts of parts would be an esd safe bin if anything basically or just regular plastic tubs but have semi conductor / sensitive parts in the metalized esd storage bags and non sensitive parts resistors regular ceramic capacitors etc in just regular baggies or pink poly bags they come in and transport them to the station in either the esd safe bin, or the other option would be to just store them under the desk in the esd safe bins and reach down grounded by the strap to grab them in their shielding bag/ other storage bag and place it on the mat before working with them?

what do you suggest for storing the bags containing parts (wether they are poly for non sensitive parts or the shielding bags for sensitive parts) inside of ? Are regular plastic storage tubs ok for this ? Or go for esd bins for both ?
Thanks again

for now I’ll have to rely on and outlet tester and continuity check between the ground part of the outlet and the screw to test the ground I figure most people do that anyway for hobby level stuff.
 

ThePanMan

Joined Mar 13, 2020
773
non sensitive parts resistors regular ceramic capacitors etc in just regular baggies or pink poly bags they come in
OK to store non-sensitive parts in PP. Remember, PP does not generate static. As for simple plastic bags - nawh - the plastic on the bench could pose a risk to any sensitive components on the bench.

Defense contractor I worked for - a woman went bopping through the test department with her lunch in a grocery plastic bag. Passing less than 12 inches put thousands of dollars of equipment and boards at risk. She was fired. 1) she had no business cutting through test, 2) she should have known better than to even bring a grocery bag into the shop, let alone pass by bins of stored parts and assemblies.
 

Thread Starter

Greasepaintmug

Joined May 19, 2023
15
Cool appreciate you, so I’ll just go with regular plastic bins like those at Walmart to store stuff in but make sure to store sensitive stuff in shielding bags non sensitive stuff in pp bags and make sure to grab from either box WHILE strapped to the grounded mat, place the bag wether it’s pp or shielded on the mat to equalize the potential to me/mat and then remove components rinse and repeat ?
 

DickCappels

Joined Aug 21, 2008
10,152
Sounds good enough. Earth is not the thing, minimizing potential differences is the thing, but keeping everything at earth potential is a good way of doing that. Also sliding thing our of the wrong kinds of bags can sometimes generate enough voltage to damage things, you idea of using anti-static bags sounds good.
 

ThePanMan

Joined Mar 13, 2020
773
minimizing potential differences is the thing,
Yes, that's the big thing. Energy moves from the higher potential to the lower potential. It likes the path of least resistance. Sometimes that's through your components and that's when damage happens. Even if the part still works, damage MAY have been done. It's called EOS (Electrical Over Stress). Imagine a highway alongside a hill. Heavy rains may wash out part of the road. You can still get through but the ability of that highway to handle traffic is diminished. Same is true of an electrical pathway. It may be damaged but not broken. Electrons can still get through. But when it's needed to perform at a rating you believe it to be capable of you may suddenly find a latent failure. Even if you don't run it to its max capacity, having that weakened pathway can generate more heat which can lead to further damage and eventual premature failure. It's MY opinion that EOS is far more insidious than outright failure due to catastrophic static discharge. Often bench testing doesn't reveal EOS. The part passes tests but hides a flaw that if life critical or mission critical use depends on it - someone may not like the outcome. If a pilot pushes a button to launch a missile or a countermeasure and it doesn't work then his (or her) mission and life may hang in the balance.
 

DickCappels

Joined Aug 21, 2008
10,152
I used to work with an engineer who worked for operations. His job was to monitor the development of products and provide feedback if he saw problems developing. He told one of our Japanese vendors how to correct their high field failure rates by incorporating various types of ESD control. On his next visit to the vendor they treated him as if he were a god.

His philosophy was that accidentally shipping circuits with parts that were electrically overstressed was just setting up for failure, referring to zapped yet still working parts as “The walking wounded”.
 

Thread Starter

Greasepaintmug

Joined May 19, 2023
15
Awesome appreciate you guys so an esd mat (one of the decent ones from elimstat) none of the hokey ones off Amazon a strap from them tied with a common ground snap on the mat going to the outlet screw (check for ground continuity and proper wiring there first) and then using the shielding bags for sensitive stuff and pp bags for non sensitive components removing both types of bag to the mat while grounded ( id want to retrieve them from the box while grounded correct regardless which bag type they are in? And then removing what I need onto the mat should equalize the potential between the mat (by extension of the strap myself) and then the outside of the bags and by removing parts onto the surface the parts as well which will be safe to then work on? ( basically doing as much as I can as a hobbyist to prevent eos or esd damage ?) just to make sure I’m not missing anything.

as far as a soldering iron if it’s a decent one ( haako fx888d with a grounded plug that’s in the same outlet the mat is grounded to) I should be good to work with that as well?
 

Thread Starter

Greasepaintmug

Joined May 19, 2023
15
Also buying esd shielding bags from Desco (what digikey sells) or uline is cheap enough in bulk where if putting everything regardless of sensitivity in those bags would help avoid what dick mentioned about sliding parts out (of pp bags I assume) causing damage that may be something I do as well. Last thing is if I’m working on a breadboard project and gotta scoot is it cool to put it in an esd bag ( battery removed obviously) until I can get back to it ?
 

MrChips

Joined Oct 2, 2009
30,720
What a lot of folks fail to understand is that ESD damage is not necessarily revealed in a pass-fail test.

In a greater percentage of cases, the internal damage is in microscopic structures of the semiconductor device. An assembled unit might pass QA at the factory but fail later in the field.

A $1 component that has failed later could easily cost $1000 to replace in the field.
 

ThePanMan

Joined Mar 13, 2020
773
you're making this more complicated than it needs to be. As for PP, you can use that for non-sensitive components. Having sensitive components in or near PP is NOT a problem either. PP does not generate static. It's neutral on the "Triboelectric" scale. It won't harm parts. However, it won't protect parts either. So putting sensitive components in PP is a bad idea. Regular plastic should be kept as far away as possible.

Triboelectric effect describes what happens when you rub or pull parts away from each other. Electrons on the first surface are stripped away to a second surface giving the first surface a positive charge while the second surface is negative. The charges want to neutralize by jumping from one surface to the other. That's where ESD presents its danger.
 

Thread Starter

Greasepaintmug

Joined May 19, 2023
15
Understood just want to do what I can to avoid as much damage as possible. As far as pulling parts away from each other it would still be to remove parts from the bag as long as the bag is on the mat ( I kind of answered my own question here since I have to be able to get them out somehow lol) as far as the soldering iron I’m safe as long as it’s on the mat as well?
 

Tonyr1084

Joined Sep 24, 2015
7,853
Taking parts out of a conductive bag will produce no harmful ESD or EOS. Taking parts out of pink polly will produce no harmful ESD or EOS. Sliding parts around on your workbench with a static mat will produce no harmful effects.

Sitting at my wife's computer, her plastic carpet protector on the floor, me in socks and hands on the keyboard: Slide my feet side to side produces one hell of a shock to my hands and the keyboard. Part of the reason as explained above is separating electrons from their protons. The computer properly grounded provided a pathway for the charges stored in my body. Cabling protected my keyboard and my computer. Even shuffling around in your clothes can generate static charges. The human body can easily store up to 50KVS (Kilo Volts Static). You definitely feel that when it suddenly and completely discharges, like when you get out of the car and reach for the gas tank cover - BOOM! You get that huge static snap. However, charges as low as 3KVS are almost completely imperceptible. You'll never notice a discharge at that low voltage. But your components won't like it one bit.

Satellite technology has progressed to where they can operate on very low power. 5 watts or less. That means the components in them can be susceptible to charges as low as 50 static volts. Or so I hear. Most of the chips you work with likely have some internal way of discharging static without harming the main functions of the chip. However, again as explained above, repeated discharges can degrade the chip performance; even the internal protection. Burn through the protection and the next ESD event can render it dead like a roach eating baking soda. (Roaches can't fart).

I agree, you're making this a far more serious issue than you need to. DC said to keep your potential the same as the device you're working on and you should be good to go. I've done that many times when working on a computer. Keeping a bare arm resting on the frame of the computer while I change out memory chips or add or remove modules. I have yet to blow out a computer. Even my wife's computer - remember? The plastic floor protector?
 

tindel

Joined Sep 16, 2012
936
ESD is somewhat overrated.

I would recommend having a ESD mat and ESD wrist strap in a professional setting, perhaps with a constant monitor, depending on the setting.
For a small home lab where you're learning about electronics/soldering/both - ESD precautions are 100% optional.

As an aside - You shouldn't be soldering for your company after your shift. Work without compensation is a very serious crime (assuming you're in the US and an hourly employee).
 

Thread Starter

Greasepaintmug

Joined May 19, 2023
15
Copy that, I’ll just leave it at making sure I do everything on the mat. Last question would anyone bother with esd totes or the esd (cardboard?) boxes for storing bulk components in shielding bags ? Or just regular run of the mill plastic totes under my bench and let the shielding bags do their thing. Sorry for all the questions as an outsider it’s a lot to parse lol.

oh no I’m not soldering for my employer my shift as maintenance ends an hour and half before my wifes in operations, we carpool so id be soldering for my hobby stuff in the shop to pass the time after my shift ends.
 

Tonyr1084

Joined Sep 24, 2015
7,853
Last question would anyone bother with esd totes or the esd boxes for storing bulk components in shielding bags?
For a home hobby - no.
In a business that manufactures PCB's - yes. Why yes? Because non-ESD totes might end up on the work bench and they can be loaded with static charges. Your parts will be protected as long as they are in the ESD bags. But as soon as you take them out, if the plastic box is right there - you're exposed to hazardous ESD and EOS.

Just so happens I have a lot of parts in standard plastic. The static sensitive ones are on conductive foam. And I only take them off the foam when I have them well away from the plastic storage.

Did this demonstration a couple decades ago. Two guys wearing sweat pants and shirt, sitting on plastic lawn chairs. Each had a brass rod to use for discharging static. Had a metal file cabinet next to the two guys who were facing each other sitting in their chairs. First they both discharged their charges to the filing cabinet. This was in the winter months when air is dry and more prone to generating static charges. Then one guy stood up and held out the brass rod. The other guy, still sitting held his out. As soon as they came in close contact there was an audible snap. Then the standing guy sat and the sitting guy stood up. Repeated the outreach with the rods and there was a hell of a snap and both twinged from the massive charge.

Here's what was going on: When one stood up he stripped away electrons (or deposited them - don't remember for sure which). The guy sitting was basically neutral in charge. When the standing guy sparked his static to the sitting guy the chair took on some of the charge. When they reversed positions the now charged chair added to the charge its own charge when the guy stood up. Kind of like pouring a glass of water into a bucket. Then when the second guy stood up he not only had his bucket but also the water from the first. The charges added up. The estimated static charge alternating between them may have been in excess of 75KVS. Later I was chastised for shocking people. OSHA would not approve. After that I was limited to demonstrating static charges using neon lamps.

To use a neon lamp as an indicator you can build a relaxation oscillator. It will flash at its rate, whatever that is. If you're statically charged, when you put your finger near the glass bulb the flash rate will significantly increase. This is because the neon lamp takes a typical 70 volts to ignite. When you present a static field nearby that lamp is now closer to its flash point. Flashing sooner means draining the voltage from the circuit sooner, and thus, a faster flash rate. Perhaps that would be an interesting video to make. Will have to order some neon lamps and build one. Then shoot the video.
 
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