Hi Gene
The cabinet is grounded with a 1 mOhm resistor, and the drawer is on
metal slides - it has been tested and passed as a shelf / drawer. I
consider this the same as I would consider opening a closed tote bin or
ESD shielding bag.
regards,
- Graham
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Gene Felder
Sent: Wednesday, May 26, 2010 2:37 PM
To: [log in to unmask]
Subject: Re: [TN] ESD spec question
I agree with Joe.
Of course it would be better to have all personnel grounded
"The fundamental ESD control principles that form the basis of this
document
are:
A. All conductors in the environment, including personnel, shall be
bonded
or electrically connected and attached to a known ground..."
[ANSI/ESD S20.20 section Foreword]
The requirement is "All personnel shall be bonded or electrically
connected
to the grounding / equipotential bonding system when handling ESDS [ESD
sensitive] items." [ANSI/ESD S20.20-2007 section 8.1]
Is the drawer part of the ESD protected area. This may be in the
handbook
TR20.20 but I found this in ESD-ADV53.1-1995 ESD Protective Workstations
"Electrical Requirements
. Workstation elements shall be connected to, and maintain
electrical
continuity to, the common point ground as follows:
. Worksurfaces - Resistance: Between 1 x 10^6 ohms and 1 x 10^9
ohms
(as measured per para. 6.3 of this document).
. Surfaces of shelves and drawers intended to be used for
unprotected
ESD sensitive devices - Resistance: Between 1 x 10^6 ohms and 1 x 10^9
ohms"
Gene Felder
[log in to unmask]
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Kane, Joseph E (US
SSA)
Sent: 2010 - 05 - 26 10:21 AM
To: [log in to unmask]
Subject: Re: [TN] ESD spec question
You might be okay, but my somewhat strict reading of the standard, and
the
way we train, is this:
Items are protected if they are enclosed in ESD-protective packaging
(like a
closed metal cabinet that affords a Faraday cage).
An item may be removed from protective packaging only at an EPA, which
includes personal grounding for the operator.
So by extension, it's not okay to open an ESD protective bag or box and
look
at the item inside if you're not grounded. I know that people do this
sometimes when nobody's looking, but it's not an approved practice.
Therefore I don't think it's okay for an ungrounded person to open the
metal
cabinet and look inside. Touching the grounded handle will help bleed
off
any charge you might have, but parts won't be completely protected for
several reasons, including the possibility that eventually someone might
do
this while wearing gloves.
-Joe
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Collins
Sent: Wednesday, May 26, 2010 12:30 PM
To: [log in to unmask]
Subject: [TN] ESD spec question
Hey TechNet
It's been a quiet day on Technet!
I've got a question regarding ESD. I was taught that if I am not
grounded I
do not go near anything that is ESD . The example we are debating here
today concerns parts that are stored in metal cabinets.
The cabinet is grounded, and within the cabinet drawers there are ESD
sensitive parts in individual bins, not covered or packaged (no faraday
cage).
Is it OK to open the drawer and look into the cabinet without being
properly
grounded? I say no, but am I being overly cautious?
If "no" is the right answer, where would I find that in an ESD spec?
I've given ESD-S20.20 a quick peruse, nothing jumped out at me.
regards,
Graham Collins
Halifax Production Engineering
(902) 873-2000 ext. 6215
This message and any attachments are solely for the use of the
individual or
entity to which it is addressed and may contain information that is
privileged or confidential or controlled technical data that is subject
to
the laws of Canada or the United States. If you are not the intended
recipient, any disclosure, use or distribution of the information
contained
herein is prohibited. If you have received this communication in error,
please notify the sender by reply e-mail and immediately delete this
message
and any attachments.
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0 To
unsubscribe, send a message to [log in to unmask] with following text in
the
BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or
(re-start) delivery of Technet send e-mail to [log in to unmask]: SET
Technet
NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send
e-mail to [log in to unmask]: SET Technet Digest Search the archives of
previous posts at: http://listserv.ipc.org/archives Please visit IPC web
site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
ext.2815
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text
in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at:
http://listserv.ipc.org/archives
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask]
or
847-615-7100 ext.2815
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text
in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at:
http://listserv.ipc.org/archives
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
ext.2815
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
