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ESD risks/ do I need an ESD lab coat?
Posted by
ECEdesign
on 02 Oct, 2016 22:27
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In the summer I have done just fine with a simple wrist strap and ESD matting but in the winter I usually wear synthetic jackets to keep warm. I am wondering if this will present a significant ESD risk even with my wrist strap and esd mat. Should I wear an ESD coat over my fleece jacket?
FYI, in the winter my lab has extremely low humidity and almost every time I get up from my chair I have a rather large discharge when I touch the nearest metal object. A few times I forgot to discharge after getting up and still had my headphones on and got shocked on the ear from my headphones!
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#1 Reply
Posted by
JoeN
on 02 Oct, 2016 22:31
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If you want to look cool, yes, labcoat is mandatory. Otherwise, I wouldn't worry about it.
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#2 Reply
Posted by
Skimask
on 03 Oct, 2016 02:12
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Yes, you absolutely need an ESD lab coat.
However, it will only function correctly if you take pictures of you wearing aforementioned lab coat and posting those pictures to these forums.
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havent you heard? Lab coats are a fashion nowadays. You are likely to get girls using a lab coat and a pair of glasses.
ESD is important to consider when handling sensitive stuff, like sensor chips.
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#4 Reply
Posted by
zapta
on 03 Oct, 2016 03:59
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I don't wear a lab coat and things seem to be OK ESD wise. This is in a hobby setting. YMMV.
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#5 Reply
Posted by
Jeroen3
on 03 Oct, 2016 04:34
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Yes, you will need a lab coat while your building your humifinator.
Or you can buy a humidifier and skip the lab coat. Since it already seems like you don't have esd safe chairs.
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#6 Reply
Posted by
tszaboo
on 03 Oct, 2016 09:47
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And make sure you dont have any change in your pocket, because that can cause ESD events. And also, getting up from your chair, so replace that with an ESD chair. And the lights. And the floor. Make sure to use the right softener, because I've noticed some might make the clothes more ESDy. This is not a joke. I seriously experienced this.
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Buy a humidifier and fix the root cause of the problem.
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#8 Reply
Posted by
setq
on 03 Oct, 2016 14:24
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I worked at a place in an IT capacity where we had those horrible blue ESD coats to wear. This was a big defence company in the 1990s.
Got my heel strap on, ESD coat on and walked up to the lab as required by policy. Walked up to the first bench and the guy was sitting there in a nylon sweater, crocs and shorts eating a sandwich out of a plastic bag while his immediate colleague was wearing a nylon suit and was sliding a new bit of Agilent gear out of the box on the bench and chucking the polystyrene on top of his breadboard.
And then I was told "well the chairs aren't safe and floor isn't ESD safe as they cleaned it wrong so who gives a fuck?"
And thus a lesson was learned.
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#9 Reply
Posted by
ECEdesign
on 03 Oct, 2016 15:14
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haha I guess I won't worry about it then!
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#10 Reply
Posted by
wraper
on 03 Oct, 2016 15:20
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haha I guess I won't worry about it then!
IMO those people who wrote it is completely fine wearing synthetic jacket are clueless as minimum, and make stupid jokes when there isn't anything to joke about really. This is serious matter. You can somewhat get away without ESD protective measures in most cases but wearing clothes which produce electric charge easily, and combined with low humidity, very likely will give you a trouble.
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#11 Reply
Posted by
wraper
on 03 Oct, 2016 15:27
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I worked at a place in an IT capacity where we had those horrible blue ESD coats to wear. This was a big defence company in the 1990s.
Got my heel strap on, ESD coat on and walked up to the lab as required by policy. Walked up to the first bench and the guy was sitting there in a nylon sweater, crocs and shorts eating a sandwich out of a plastic bag while his immediate colleague was wearing a nylon suit and was sliding a new bit of Agilent gear out of the box on the bench and chucking the polystyrene on top of his breadboard.
And then I was told "well the chairs aren't safe and floor isn't ESD safe as they cleaned it wrong so who gives a fuck?"
And thus a lesson was learned.
The lesson should be, that place should be shut down low quality of working standards and sabotaging reliability of defense equipment.
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#12 Reply
Posted by
nanofrog
on 03 Oct, 2016 15:30
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For a home lab, you don't need to go this far as a general rule IME. However, you do need to have both an ESD strap on your body (direct skin contact), as well as an ESD mat; both properly grounded of course.
If you're working with exceptionally sensitive components however, greater precautions would be in order.
A humidifier in the winter wouldn't be a bad idea, and they're not expensive either. Particularly useful for those that experience nose bleeds during the winter months from low humidity.
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#13 Reply
Posted by
setq
on 03 Oct, 2016 15:38
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The lesson should be, that place should be shut down low quality of working standards and sabotaging reliability of defense equipment.
Actually no, that wasn't the lesson. The lessons which took some thinking were:
1. There are levels of ESD safety appropriate for different environments. They still had wrist straps and used them when needed.
2. They knew what was likely to go pop and when it was going to be a problem.
3. This wasn't a production line, so it mattered less. At best your kill your breadboard. If you're on the production floor, it matters. If you're in the lab, not as much. In fact it's quite handy to blow the odd thing up with static as you know which bits are going to cause production issues when your design hits it.
4. The company put all the cash in the production line, which is where this sort of protection belongs.
If you're at home, it's a matter of economy. If you can afford to blow a few ICs and overstock, it's probably not worth the hassle. I run with this. None of my stuff is production or shipped outside my house. I've never blown a thing up. That's not necessarily the right solution. Obviously you take very basic 1970s style precautions i.e. no synthetics, work on cardboard rather than plastic surfaces, avoid handling CMOS parts too much but that's about it.
The thing that gets me when it comes to safety is the biggest risk everywhere is to yourself, particularly your eyes. I see people doing all sorts of things with all the safety and protection equipment yet never bother with the eyes. Doing a board wash with solvents? Hell yes, wear a lab coat, gloves and your birthday suit on your face. Soldering? Nope I can afford to have have a flux spurt go in my eye...
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#14 Reply
Posted by
rrinker
on 03 Oct, 2016 18:37
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For a commercial environment it probably makes a lot of sense, for a home user - I think sometimes we get carried away. In 1980 I built my first computer, which was almost entirely CMOS (I think there is maybe 1 TTL chip in it). I was 13 and did not have an ESD mat, or a wrist strap. The only hints the kit manual gave was to lay the finished board on a sheet of tinfoil and dump the chips from their ESD tubes to the foil before touching them. The computer worked, and STILL works today (can't believe the massive Mallory cap in the power supply is still good (enough)), so even if minor damage was done that reduced the life of some of those CMOS logic chips or the CMOS CPU itself, it still hasn't shown up more than 36 years later.
My new bench does have an ESD mat and a connection for a wrist strap, though I almost never use the wrist strap. I usually work with my forearms wresting on the bench, and I never wear long sleeve clothing, so I have contact with the mat. Can't say I've ever zapped a component ever, starting with that computer and through all sorts of projects built in different places on different work surfaces, not to mention uncountable computer I've built and upgraded, going back to 8088 systems where the memory was installed a chip at a time, long before SIMM and DIMM modules became common.
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#15 Reply
Posted by
SteveyG
on 03 Oct, 2016 19:16
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Can't say I've ever zapped a component ever, starting with that computer and through all sorts of projects built in different places on different work surfaces, not to mention uncountable computer I've built and upgraded, going back to 8088 systems where the memory was installed a chip at a time, long before SIMM and DIMM modules became common.
Have you ever had one of those computers crash or BSOD?
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#16 Reply
Posted by
rrinker
on 03 Oct, 2016 19:32
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Not from faulty hardware, other than something like a dead hard drive.
And I tend to use them for a long time, relatively longer than many people who upgrade every time a new CPU comes out. My current main machine is 4 years old now, and I just retired one that was 8 years old. My server is about 7 years old now and has been completely swapped from one case to another a few years ago - all done sitting on my living room rug.
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#17 Reply
Posted by
suku
on 03 Oct, 2016 20:51
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Good old ESD... Today I tried to convince my boss to get me a 25 feet long ESD mat for the workstation... he wasn't really into the whole idea... (surly not because of the price... it was the color:D)
eh whatever, a cool coat will do I guess
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#18 Reply
Posted by
ECEdesign
on 03 Oct, 2016 23:12
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I actually think my DAC chip died from ESD. It was fine a while ago but now it doesn't output anything and gives missing acknowledgement over I2C. I took it on the breaboard with some other circuits in a cardboard box fo show to someone but I didn't shield it in a bag... I figured that it would be fine. I guess not. Better take more precautions! I can't think what else it could be besides ESD.
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#19 Reply
Posted by
Tinkerer
on 04 Oct, 2016 00:28
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Commerical environment where you handle many many electrical things, yea probably a good idea as you will end up zapping something eventually and of course it will be the exact wrong thing at the exact wrong time. At home? Probably nothing more than the absolute basics would be ok.
Pretty sure my old job had a high rate of ESD issues, they didnt really enforce anything save for the absolute minimum in ESD protection and there were alot of unexplained failures about.
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#20 Reply
Posted by
GreyWoolfe
on 04 Oct, 2016 00:53
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Living in Florida, we consider anything under 90% humidity to be low. I still have a mat across my bench and I use a wrist strap, especially when I handle mainboards for the printers we deploy. The boards cost us over $1200 USD so better safe than sorry.
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You need to think about your work habits and risks. Will there be charge pockets on your ESD prone jacket? Of course. Do you bring all parts of your jacket in contact with the things you work with? Only you can answer that. For most people wearing a wrist strap will solve the problem. You aren't risking a multi-million dollar development program or someone's life or bank account if you slip up and zap a component. Most IC's aren't so expensive that replacing one is a bad trade for a bit of comfort and convenience.
In industry the answers are different. I have watched literally millions of dollars pissed down the drain because someone thought since it wasn't production it didn't need as much care. It isn't a program that I am involved in but think how many billion dollars was spent on the F-35 before their first production article. Or think how many weeks of delay in product development a commercial product can afford.
A little thought about what is at risk is well worth the effort. Fortunately for most of us, most of the time it isn't much.
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#22 Reply
Posted by
m98
on 04 Oct, 2016 06:07
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That synthetic jacket is going to charge up and zap something in close proximity. So why not simply solve that problem by wearing a jacket made out of a material that naturally doesn't charge up too much, like cotton?
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#23 Reply
Posted by
SteveyG
on 04 Oct, 2016 09:55
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Not from faulty hardware, other than something like a dead hard drive.
How do you know? ANY crash can be caused by ESD damage. Remember ESD damage very rarely renders a device inoperable, and may for example just puncture a layer on just one transistor and may go completely unnoticed until a certain sequence of instructions or data appear resulting in a piece of software crashing, or windows not responding etc.
There was a paper in a journal from the IEEE about this.
I had an odd one where Windows wouldn't get past a part in the install with one particular PSU. Swap it out and it would install just fine, put the old PSU back and the PC ran fine for years. I had to re-install and had the same problem, same fix. Happened to upgrade the RAM and never saw the issue again. When I disassembled that PC before the first re-install I didn't take much in the way of ESD precautions and it's likely the RAM was damaged then, but I never experienced any stability issues the whole time that RAM was installed.
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#24 Reply
Posted by
rrinker
on 05 Oct, 2016 14:20
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I'm still skeptical about any of my PC failures being the result of ESD. I've only had one hard drive fail (I guess I change them out for larger ones before they have a chance to die in most cases - though my server still has some originals that are plugged in and running 24/7 for 7 years now. No SMART issues so far so I have a feeling that when they go it will be catastrophic, not a gradual failure. Data is safe though, duplicated on another physical disk in the server AND backed up with a cloud backup (that works). Plus I'm about due to add a new larger drive and replace at least one of them anyway. I did have a power supply fry once, somewhat literally as the magic smoke did come out. Amazing it didn't take anything else with it, I replaced it and the same machine continued on for 3 more years. Doubt that was ESD as I don't tend to open up a new power supply and poke around. Salvaged ones from old machines - yes, I have turned some of them into power supplies for various uses with the addition of a switch to toggle them on, a load resistor, and some binding posts mounted to the case.
I can't say I've had many "mystery" crashes. Most anything that has happened to be has been fairly repeatable and usually a driver fault of some sort. Repeatable as in, driver install crashes system, reboot, restore to previous driver, repeat new install - same crash. I've perhaps just had good luck with various versions of Windows but my systems have always been quite stable, without periodic reinstalls, and the ones that are always under my control have always been virus-free. Same exact hardware, OS version, and virus protection software built for others - not so much. Stable hardware, but no matter how much I try to educate, they still manage to virus infect their machines on a regular basis. Once or twice I've had issues with expanding the RAM using mismatched memory - different specs on one pair of DIMMS vs the other, but with matched sets (or at least same type/speed) everything works fine, and the ones that didn't work work fine in a different MB. Not been an issue lately as the past few machines I've built I just went with the expected total RAM right off the bat instead of building it small and adding later.