ESD info ???

S

S Roby

Guest
I have to do a online 'training' course because I'll being doing (basic)
servicing for x brand of printers (part swaping)

The ESD info they gave had in the course
"make the least possible movements with you body to prevent an increase
in static electricity from clothing fibre carpets"
(perhaps if i sat down, stayed very still & just looked at the printer??)

""do not place the ESD-sensitive part on the printer cover or metal table..."
"..metal tables are electrical grounds. They increase the risk of damage.."
"if possible keep all ESD sensitive parts in grounded metal cabinet"

Is the above a bit of nonsense, ie the metal table & the contradtion with
using a metal cabinet.
 
S Roby wrote:
I have to do a online 'training' course because I'll being doing (basic)
servicing for x brand of printers (part swaping)

The ESD info they gave had in the course
"make the least possible movements with you body to prevent an increase
in static electricity from clothing fibre carpets"
(perhaps if i sat down, stayed very still & just looked at the printer??)

""do not place the ESD-sensitive part on the printer cover or metal table..."
"..metal tables are electrical grounds. They increase the risk of damage.."
"if possible keep all ESD sensitive parts in grounded metal cabinet"

Is the above a bit of nonsense, ie the metal table & the contradtion with
using a metal cabinet.
Click to expand...
They obviously don't know what they are talking about.
Proper ESD technique goes something like this:
1) Only work on equipment at an approved ESD handling station (grounded
mat at the very least)
2) Wear a wrist strap to dissipate your body to ground
3) Only use anti-static or conductive bags, bins, trays etc within the
ESD safe area.
4) Transport all items in ESD-safe bages AND conductive boxes.
5) Wear anti-stat coat if there is a chance of clothing coming in
contact with the ESD sensitive item.

There are various levels and techniques above this, but that's a
general situation.

One of the biggest misunderstandings is that "anti-static" bags and IC
tubes protect a device from damage - they don't. Only static-shielding
or conductive materials can do that. That is why when you get an IC
from Farnell it comes in its anti-staic tube (or whater) inside a
conductive bag.

Dave :)
 
On 16 Feb 2006 21:57:54 -0800, "David L. Jones" <altzone@gmail.com>
wrote:


SNIP
One of the biggest misunderstandings is that "anti-static" bags and IC
tubes protect a device from damage - they don't. Only static-shielding
or conductive materials can do that. That is why when you get an IC
from Farnell it comes in its anti-staic tube (or whater) inside a
conductive bag.

Dave :)
Click to expand...

What????

See http://www.ece.rochester.edu/~jones/demos/shielding.html

It is demonstrable that a sensitive electronic device placed inside a
shielding bag is impervious to an external electrostatic charge.
 
One of the biggest misunderstandings is that "anti-static" bags and IC
tubes protect a device from damage - they don't. Only static-shielding
or conductive materials can do that. That is why when you get an IC
from Farnell it comes in its anti-staic tube (or whater) inside a
conductive bag.

Dave :)


What????

See http://www.ece.rochester.edu/~jones/demos/shielding.html

It is demonstrable that a sensitive electronic device placed inside a
shielding bag is impervious to an external electrostatic charge.
Click to expand...
Thats what he said.
"That is why when you get an IC from Farnell it comes in its anti-staic tube
(or whater) inside a conductive bag."
 
Ross Herbert wrote:
On 16 Feb 2006 21:57:54 -0800, "David L. Jones" <altzone@gmail.com
wrote:


SNIP

One of the biggest misunderstandings is that "anti-static" bags and IC
tubes protect a device from damage - they don't. Only static-shielding
or conductive materials can do that. That is why when you get an IC
from Farnell it comes in its anti-staic tube (or whater) inside a
conductive bag.

Dave :)


What????

See http://www.ece.rochester.edu/~jones/demos/shielding.html

It is demonstrable that a sensitive electronic device placed inside a
shielding bag is impervious to an external electrostatic charge.
Click to expand...
Yes, that's what I said. A "static shielding" bag will protect a device
when in transit and storage. In fact a static sentive device must
*only* be transported in a "static shielding" bag.
A "static shielding" bag is different to an "anti-static" bag (the
common cheap "pink" bags, and pink bubble wrap). Anti-static bags do
not protect a device from an external static charge, they simply
prevent the build up of static when used within an ESD safe
environment.
Most IC tubes are also only "anti-static" and not "static shielding" so
therefore provide little protection to static discharge.

A bag must specifically state "static shielding" in order for a device
to be protected. If is just says "anti-static" then it's pretty much
useless outside of an ESD safe area.

This is the first thing you'll get a practical demo of when you do a
certified ESD course.

My former company actually failed Farnell on an ESD audit one time, and
we couldn't order anything from them for months until they fixed
whatever trival problem it was. ESD can be serious business.

Dave :)
 
On 17 Feb 2006 17:24:41 -0800, "David L. Jones" <altzone@gmail.com>
wrote:

Ross Herbert wrote:
On 16 Feb 2006 21:57:54 -0800, "David L. Jones" <altzone@gmail.com
wrote:


SNIP

One of the biggest misunderstandings is that "anti-static" bags and IC
tubes protect a device from damage - they don't. Only static-shielding
or conductive materials can do that. That is why when you get an IC
from Farnell it comes in its anti-staic tube (or whater) inside a
conductive bag.

Dave :)


What????

See http://www.ece.rochester.edu/~jones/demos/shielding.html

It is demonstrable that a sensitive electronic device placed inside a
shielding bag is impervious to an external electrostatic charge.

Yes, that's what I said. A "static shielding" bag will protect a device
when in transit and storage. In fact a static sentive device must
*only* be transported in a "static shielding" bag.
A "static shielding" bag is different to an "anti-static" bag (the
common cheap "pink" bags, and pink bubble wrap). Anti-static bags do
not protect a device from an external static charge, they simply
prevent the build up of static when used within an ESD safe
environment.
Most IC tubes are also only "anti-static" and not "static shielding" so
therefore provide little protection to static discharge.

A bag must specifically state "static shielding" in order for a device
to be protected. If is just says "anti-static" then it's pretty much
useless outside of an ESD safe area.

This is the first thing you'll get a practical demo of when you do a
certified ESD course.

My former company actually failed Farnell on an ESD audit one time, and
we couldn't order anything from them for months until they fixed
whatever trival problem it was. ESD can be serious business.

Dave :)
Click to expand...

Sorry for my confusion David...

When I was using "anti-static" bags prolifically the only type
available was the metallised "shielding" bag. The pink poly and
bubble-wrap types were either not available and/or not recommended so
I hadn't come across them until relatively recently and so they didn't
occur to me as being the types you were talking about. Since your
original reply didn't specifically mention the pink poly and b/w bags
I thought you were referring to metallised shielding bags.

Looking at this page
http://www.esdjournal.com/techpapr/ryne/esdbags.htm it seems that the
problem with the pink poly and bubble wrap types is that they dry out
with age and can themselves become generators of huge static charges.
The b/w type relies upon air gap spacing to prevent static discharges
from getting to the contents so it doesn't actually provide
(conductive) "shielding" at all (as you correctly stated).
 
"David L. Jones" <altzone@gmail.com> wrote in news:1140225881.393800.119140
@g44g2000cwa.googlegroups.com:
My former company actually failed Farnell on an ESD audit one time, and
we couldn't order anything from them for months until they fixed
whatever trival problem it was. ESD can be serious business.
Click to expand...
To some. Many years ago when working for an electronics R&D
mob, I took a 'technician' from AVO Computers (still operating
in North Sydney I believe) to task after he leaned back in to
his van, picked up a rubber-banded bundle of RAM from the centre
console and shoved it in his pocket before turning to me and
asking "Right, where's the PC for the memory upgrade?".

His response: "Look mate, these people who get all uptight
about static electricity really give me the shits.".

GB
 
"GB" <g.b@sonicresearch.mailme.org> wrote in message
news:43fd81ce$1@news.comindico.com.au...
"David L. Jones" <altzone@gmail.com> wrote in
news:1140225881.393800.119140
@g44g2000cwa.googlegroups.com:
My former company actually failed Farnell on an ESD audit one time, and
we couldn't order anything from them for months until they fixed
whatever trival problem it was. ESD can be serious business.

To some. Many years ago when working for an electronics R&D
mob, I took a 'technician' from AVO Computers (still operating
in North Sydney I believe) to task after he leaned back in to
his van, picked up a rubber-banded bundle of RAM from the centre
console and shoved it in his pocket before turning to me and
asking "Right, where's the PC for the memory upgrade?".

His response: "Look mate, these people who get all uptight
about static electricity really give me the shits.".

GB
Click to expand...
Sad truth is the average computer tech doesn't even have A+ certification,
let alone training on how to protect components against ESD damage. Your
story is highly plausible, and unfortunately the norm in the industry. When
the RAM fails (usually just outside the 30 or 90 day repair warranty) the
dickhead who repaired the PC usually tries to chock it up to "bad luck" or
the "you get that / shit happens" routine, citing that unfortunately
something else has failed, ten bills you again for "fixing" his stuff up :-(

Ignorance is bliss to some of these guys. The customer is usually not
technically aware enough to know that these dickheads are committing what
amounts to "professional vandalism" on their equipment. Unfortunately
almost anyone can set up shop and service PCs with zero qualifications to do
so. This became evident to me a few years back when I returned a CD burner
for repair / replacement under warranty. To cut a long story short, they
sent the same unit back saying NFF and an invoice for $25. Giving them the
benefit of the doubt I re-installed it only to find it had the same problem.
On returning it an other customer was returning a PC that was supposed to
have been repaired. Whilst waiting I peeked at the repair docket - "replace
HDD, format and reload OS". Customer told the guy over the counter it won't
boot up. Tech came out with a screwdriver, took the side cover off to
discover both the IDE cable and the power connector dangling in the breeze.
Hmmmm.... checked and tested before leaving the workshop - my arse!

Being singularly unimpressed by my own experience and seeing what the other
customer had experienced I asked to see the service manager. I then popped
the question as to what percentage of staff in the workshop were qualified
to service PCs. The silence was deafening and when pressed for a response
in front of other waiting customers he developed a rather embarrassed look
and scurried off back into his office.

Cheers,
Alan
 
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