Author Topic: It appears that Jim Williams wasn't a big fan of anti-static mats.  (Read 13443 times)

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Offline JoeNTopic starter

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It appears that Jim Williams wasn't a big fan of anti-static mats.
« on: September 19, 2015, 09:59:14 am »
Should I be?



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Offline george graves

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #1 on: September 19, 2015, 10:18:24 am »
I don't know?  Are you as good as Jim Williams?   :-//  Most like not. O0

I've never fried a chip by just handling it - not even when I was working in the dry California Sierra Mountains air.  And that's about as dry as you can get in the summer. Before then I was next to the beach.  And now in Seattle - so you can't even rub a ballon on your hair to make static! 

I run anti-static mats because they are cheap given that if you treat them well, and buy the right type they will last for 10's of years.  With that said, on my main work surface, on top of the mat, I have a Fiskars cutting mat - but I do a lot of micro-scale "manufacturing" - if all I was doing was design, I wouldn't need it I suppose. But as soon as you start making things - you'll destroy any mat.

I was able to buy 60 feet or so of the same stuff Dave uses, but in "no-lead" green color.  It's the same stuff - just the color is to say "NO lead here" in a mixed enviroment.  Yet - I only use lead solder.  Whoops!  IMHO - get the green stuff.  It's really pleasing to the eye.  Was never a fan of the blue stuff. I think I paid $60 shipped for the roll some company was getting rid of - the box had never been open.

BTW - make sure you check the surface hardness.  That's really one of the most important specs IMHO.
« Last Edit: September 19, 2015, 11:01:06 am by george graves »
 

Offline Chris C

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #2 on: September 19, 2015, 10:46:16 am »
Wow!  :o

But maybe an analog engineer's desk isn't the best indication of whether you need an anti-static mat, if you're going to be working with digital.

I've never used an anti-static mat, and never had a problem (yet).  I'm always aware of when myself or the stuff I'm handling may be at different potentials, and equalize them if necessary.  That's the most important thing.

Plus it's a clear day here, and the relative humidity outside is 91%.  Inside, probably around 30%.  That's pretty typical for my locale, and it helps.  The few months of the year the humidity drops enough to accumulate a charge, I crank up a humidifier when working with static sensitive parts.  When working with something known to be very sensitive on a dry day, sometimes I do the fidgety bits in the bathroom, door closed and vent off, and a fine spray of hot water from the showerhead.  But that's rare.

Now if I were to move to a dryer location, I would gear up with a static mat and wrist strap.  Still, there will come a time when you have to work without those niceties, so it's better not to have absolute reliance on them.
 

Offline KJDS

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #3 on: September 19, 2015, 11:29:12 am »
A wooden bench is reasonably static dissapative, so long as it isn't very dry. Metal frames and wooden tops can be better. Plastic topped benches are horrible and really need mats no matter what the humidity.

ESD often just weakens an IC, you may not know if it's damaged unless you spend a good while looking at the silicon under a microscope or you use it for a few years and it dies early. Do you feel lucky?

Online DimitriP

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #4 on: September 19, 2015, 11:51:03 am »
Should I be?



When you are Jim Williams no one gives two hoots whether you are using a mat or not.
The value of his work was not measured by how many chips he fried (if any, ever)

He also , probably , didn't rub his feet on the carpet before touching the pins of an IC in the dark to see if it will spark, he knew better :)

Only you can decide ...




One of many bench technicians employed  at some ISO certified facility
or a Jim Williams?
 
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Offline Cliff Matthews

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #5 on: September 19, 2015, 02:37:13 pm »
Impressive! That photo's a keeper.  :-+  I see a copper strip running down the wall. I see organized probes, adapters and leads on the drawer handle in front of him.
Maybe he wanted a mat to be installed, but had a messy junior apprentice (like me) always piling up stuff around him..  :palm:
 

Offline Ryano

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #6 on: September 19, 2015, 05:35:47 pm »
The entire bench top might be anti-static as well with no need for a mat. My bench at work is connected via a very large copper wire to ground. Every part of it is anti-static.

Mt home bench has a mat on wood bench top, sitting on a wood floor.
 

Offline sarepairman2

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #7 on: September 19, 2015, 06:00:11 pm »
I like the antistatic rubber mat because it is extremely durable and the table underneath survived. My mat looks like it has seen better days lol... its ALL fucked up
 

Offline electr_peter

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #8 on: September 19, 2015, 06:34:47 pm »
What are you talking about? Of course, Jim Williams used antistatic mat - just look at all those wire nests and copper clad boards (= antistatic mats) on his desk.
Conventional rubber antistatic mats are only suited for needs of common folk here (with semi-clean desk and plastic items), not for masters like Jim.
 

Offline george graves

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #9 on: September 20, 2015, 10:11:58 am »
The value of his work was not measured by how many chips he fried (if any, ever)

I'm sure he fried a metric-shit-load. 

Online DimitriP

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #10 on: September 20, 2015, 11:55:02 am »
The value of his work was not measured by how many chips he fried (if any, ever)

I'm sure he fried a metric-shit-load.

Grounded soldering iron is as far as I will go.
If a monstrously messy bench was good enough for him, it's good enough for me.
   If three 100  Ohm resistors are connected in parallel, and in series with a 200 Ohm resistor, how many resistors do you have? 
 

Offline Marco

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #11 on: September 20, 2015, 12:27:38 pm »
Should I be?

With small signal/rf mosfets with unprotected gates, yes.
 

Offline con-f-use

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #12 on: September 20, 2015, 12:29:11 pm »
I'd suspect, that Mr. Williams did the gross of his work before the advent of small package SMDs. I'd say, ESD isn't that much of an issue with robust old through holes.
 

Offline AF6LJ

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #13 on: September 20, 2015, 12:36:51 pm »
I have seen garbaged up benches before, even had a few myself but NEVER that bad.
Sue AF6LJ
 

Offline Nerull

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #14 on: September 21, 2015, 12:51:10 am »
Wow!  :o

But maybe an analog engineer's desk isn't the best indication of whether you need an anti-static mat, if you're going to be working with digital.

I've never used an anti-static mat, and never had a problem (yet).  I'm always aware of when myself or the stuff I'm handling may be at different potentials, and equalize them if necessary.  That's the most important thing.

Plus it's a clear day here, and the relative humidity outside is 91%.  Inside, probably around 30%.  That's pretty typical for my locale, and it helps.  The few months of the year the humidity drops enough to accumulate a charge, I crank up a humidifier when working with static sensitive parts.  When working with something known to be very sensitive on a dry day, sometimes I do the fidgety bits in the bathroom, door closed and vent off, and a fine spray of hot water from the showerhead.  But that's rare.

Now if I were to move to a dryer location, I would gear up with a static mat and wrist strap.  Still, there will come a time when you have to work without those niceties, so it's better not to have absolute reliance on them.

I'm kind of amazed at the effort people will put into avoiding basic precautions. At some point it becomes easier just to get a mat.

I have a mat cause its pretty cheap, its nice to work on, protects the desktop, keeps parts from sliding around, and I don't feel like messing with a dehumidifier or building circuits in the shower just so I can brag about not using a mat.

Looking at that desk, I would be surprised if he ever saw the same IC twice, so it probably didn't matter if he fried them. Once used, they just became a new layer of desktop...
« Last Edit: September 21, 2015, 12:56:11 am by Nerull »
 

Offline rs20

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #15 on: September 21, 2015, 01:03:51 am »
I've never fried a chip by just handling it - not even when I was working in the dry California Sierra Mountains air.

So, discussion of ESD aside, you've never had a chip fail, ever? Not once? Because I'm curious to know how you established with 100% confidence that none of those chips that have failed on you didn't have a little bit of latent ESD damage contributing to their ultimate failure mode.

One of the greatest fallacies to do with ESD is the idea that it's black-and-white: the idea that ESD damage either totally bricks the chip, or the chip is perfectly fine. That is nonsense. ESD can make one I/O pin a little bit leaky; create a slight fault in a MOSFET that only truly fails when it's pushed to 50% of design load; lead to destructive latchup in an otherwise nominally safe situation; push a voltage reference slightly outside of spec or cause it to drift over time; etc bla bla bla. See one of Dave's recent videos where he put 10V into a 5V part and it end up kinda working, but outside of spec. Not ESD per se, but the same story. With all that in mind, confidently asserting that you've never caused ESD damage to any chip is, well... brave.

Now of course, you used the word "fried", so you might argue that you're not claiming not to have caused damaged. That'd be beside the point  :)
 

Offline bitseeker

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #16 on: September 21, 2015, 02:39:31 am »
Should I be?



The layers and layers of circuit boards with their myriad components provide plenty of places for static to go. :-DD
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Offline AF6LJ

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #17 on: September 23, 2015, 03:32:53 pm »
There comes a point when a cluttered workstation becomes less and less productive.
I can see he reached that point four layers ago.
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Offline rsjsouza

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #18 on: September 23, 2015, 04:32:26 pm »
I'd suspect, that Mr. Williams did the gross of his work before the advent of small package SMDs. I'd say, ESD isn't that much of an issue with robust old through holes.
That is not true. The initial CD4k series of devices of early 70s were terribly sensitive before the industry started adopting protection diodes - not to mention the early mosfets mentioned by Marco. Being fully bipolar, early TTLs were a bit more robust but still could be fried.

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Offline Tomorokoshi

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #19 on: September 23, 2015, 04:36:30 pm »
"Now where did I put that resistor..."
 

Offline krivx

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #20 on: September 23, 2015, 04:42:19 pm »
W can't see the floor. That could be an ESD safe environment if he is wearing ESD safe shoes, like is standard in cleanrooms.
 

Offline AF6LJ

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #21 on: September 23, 2015, 05:07:25 pm »
W can't see the floor. That could be an ESD safe environment if he is wearing ESD safe shoes, like is standard in cleanrooms.
Maybe it is concrete and he is barefoot.
Sue AF6LJ
 

Offline free_electron

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #22 on: September 23, 2015, 05:21:26 pm »
jim wandered around in shorts and birkenstocks...

but : jim did a lot of very low current stuff. antistatic mats caus eleakage. that why his boards almost always sit clamped in a panavise and use dead bug construction.
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Offline SeanB

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #23 on: September 23, 2015, 05:25:26 pm »
He did not have to worry about it. Remember these were all new design chips, fresh from a fab line or developed in house, and he was doing both application notes and reference designs for them. Single circuit, or a few dozen iterations till it did as desired, or blew up the chip by accident. Then it was written up on paper as a design, had some drawings done ( photos as well in many cases, and scope polaroid shots for those which needed it) and then was sent off to a draughtsman to produce a proof set of application notes to be included in a library.

If he did more than 3 of the same circuit it would be considered a lot, though he probably did do at least 2 of all, just so he could characterise after the initial very dead bug work, then have one good enough to show off in the application note as a design reference layout.
 

Offline mzzj

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Re: It appears that Jim Williams wasn't a big fan of anti-static mats.
« Reply #24 on: September 24, 2015, 07:50:35 am »
I'd suspect, that Mr. Williams did the gross of his work before the advent of small package SMDs. I'd say, ESD isn't that much of an issue with robust old through holes.
Quite opposite. He probably has had experience with everything starting from ancient cmos chips without any protection diodes.  SMD vs trough hole has not much to do with it.
Nowadays only small rf fets are  really sensitive, pretty much all logic chips are protected at some level.

some fiqures for esd sensitivity:
ancient cmos logic, rf fet's   10...100V
modern HCMOS 2000-3000V
 


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