Electrostatics

[killian6pk]

Tell me how prevalent is it for passive components and IC's etc. to be harmed by Electrostatic Discharge from a person or tool? Also should I worry about storing components in some kind of special container? As of this time I have always stored my components in regular off the shelf plastic boxes (with dividers) that you buy at Walmart etc.

[brethin]

Re: Electrostatics

A few simple steps taken to prevent damage from ESD is never a bad thing if you ask me. I guess it really depends on how lucky you feel.

[ipman]

Re: Electrostatics

That depends on your environment. A dry environment, with a non-conductive floor will be very prone to accidents.

[skystormfarms]

Re: Electrostatics

metal container

[Derek23]

Re: Electrostatics

I use those ESD bags to store IC, or PC components

However I store passive elements like capacitors, diodes, resistors and rectifiers in the same box you're talking about, those who have compartments.

[kc8adu]

Re: Electrostatics

ic's,mosfets,ect in pink bags.everything else not critical.
most parts i buy already come in good packages.
i did buy a fuji 3ph rectifier/igbt module off ebay that was tossed in a box with packing peanuts.i was pissed but used it anyway as the client assumed the risk due to being down.its still fine but i wonder for how long.
i stick loose ic's in sheets of black foam.
just like hdd's you never know how the parts were treated and whether the failure was due to mishandling.

[kc8adu]

Re: Electrostatics

bad idea.the container will transfer the zap to the parts.might help with an emp if the parts are in good esd packing first.

metal container

[momaka]

Re: Electrostatics

bad idea.the container will transfer the zap to the parts.might help with an emp if the parts are in good esd packing first.

But wouldn't the container act as a Faraday cage?
As far as I know, that's the reason why computers are in metal boxes (aside from shielding from EMI). You can zap a computer even if it's unplugged from the wall and ungrounded and it will still be fine.

[Derek23]

Re: Electrostatics

But wouldn't the container act as a Faraday cage?
As far as I know, that's the reason why computers are in metal boxes (aside from shielding from EMI). You can zap a computer even if it's unplugged from the wall and ungrounded and it will still be fine.

Correct, the same applies for those ESD bags (gray and metallized) that come with the PC components.

[PCBONEZ]

Re: Electrostatics

But wouldn't the container act as a Faraday cage?

Yes but that won't help static discharge.
.
If the Faraday cage is at a different potential than your body when you put the part in the cage you may zap it.
.

[PCBONEZ]

Re: Electrostatics

Correct, the same applies for those ESD bags (gray and metallized) that come with the PC components.

To -properly- use metalized bags [for static discharge purposes] you need a grounded ESD table to set the bag on and a wrist strap between you and the table anytime you open or close a bag.
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Fortunately most parts aren't as ESD sensitive as the industry selling ESD equipment makes them out to be.
Some are, most not.
.

[Toasty]

Re: Electrostatics

Faraday cages are also grounded, not sitting on a insulator like a shelf...

[Derek23]

Re: Electrostatics

To -properly- use metalized bags [for static discharge purposes] you need a grounded ESD table to set the bag on and a wrist strap between you and the table anytime you open or close a bag.
.
Fortunately most parts aren't as ESD sensitive as the industry selling ESD equipment makes them out to be.
Some are, most not.
.

lol I don't have a grounded ESD table (I work on a wooden one) and I don't have a ESD wrist strap nor ESD special mat, I work with the PC plugged in (with the surge suppressor switch off, of course) so the case is grounded and touching the no painted zones often to discharge ESD, including when opening the bags.

[PCBONEZ]

Re: Electrostatics

Me too pretty much. Works fine because, like I said, most parts aren't as ESD sensitive as the industry selling ESD equipment makes them out to be.

Important to understand what 'proper' is though because knowing the whys behind it helps figure out alternate workable precautions.
A metallic bag is a conductor so if you have a difference in potential it will conduct/pass the static vice blocking it.
.

[delaware74b]

Re: Electrostatics

I have a 2'x4' blue ESD mat on my work table (an old 8' table with folding metal legs). The frame is grounded through the cord set and 4 duplex outlets in metal boxes mounted to the horizontal tabletop braces. I also have a wrist strap.

The down side is my office has carpeting (renting the house for now and can't pull the carpet). I use the ground strap during the winter but not in the humid weather like the east coast has had lately.

I do most of my repairs on the mat, which always tied to the grounding kit that came with the mat.

[PCBONEZ]

Re: Electrostatics

The down side is my office has carpeting (renting the house for now and can't pull the carpet).

Been there done that.
I emptied the room then laid 5/8" particle board over the carpet for the entire room and put the furniture back in on top.
Helped a lot.
Also easier to find small screws and so forth when you drop one.
.

[Derek23]

Re: Electrostatics

Me too pretty much. Works fine because, like I said, most parts aren't as ESD sensitive as the industry selling ESD equipment makes them out to be.

Important to understand what 'proper' is though because knowing the whys behind it helps figure out alternate workable precautions.
A metallic bag is a conductor so if you have a difference in potential it will conduct/pass the static vice blocking it.
.

Totally true... Once (before I know all these stuff about ESD) I put a video card (9500gt) on a plastic shopping bag, touched it a lot without discharging, placed on a bed, and it still worked fine.

[riotpack]

Re: Electrostatics

I use aluminum tape on thin strips of styrofoam. The reason it protects from electrostatic discharge is all pins are now shorted so there can be no potential difference between any pins thus no overvoltage to destroy the IC.

[Radio Fox]

Re: Electrostatics

We were shown a video at my workplace many years ago about the damage caused to IC's by static discharge. An experiment was done, whereby a number of components were handled/stored using ESD precautions, and another set of components were handled without any precautions.

The components were all tested afterwards. All the components that were handled & stored correctly still worked. Most of the components that were handled incorrectly also still worked, & some failed.

The packaging of the components was then removed to reveal the electronics inside, & inspected with a microscope. All the correctly handled ones looked fine. The failed ones showed obvious signs of damage, but the ones that still worked, but were handled without ESD precautions, also showed signs of damage.

The video set out to show us that even though static might not cause a component to fail instantly, it renders the component unreliable, & shortens it's life.

[PCBONEZ]

Re: Electrostatics

There's a big difference between handling an uninstalled bare chip and a PCB with that chip installed on it.

I'm not going to wrap a mobo in an ESD bag to move it from one work table to another but if moving just a BIOS chip from one table to another I'd bag it or use an ESD tray.
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