Kevin
See below:
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Kevin Glidden
Sent: Monday, July 23, 2007 4:39 PM
To: [log in to unmask]
Subject: [TN] Anti-Static Bags
Hello 'Netters...
Question: Does anyone have experience or recomendations in controlling
the
supply chain of the pink poly anti-static bags?
Yes. We had quite the bit of excitement a few years ago. A lady in the
plant was pulling ESD bags out a new box that arrived and soon the ends
of her fingers were itching, then a rash, then to the first knuckles,
2nd, third, wrist, elbow, shoulders! She had to be taken to the
hospital.
All ESD bags were quarantined and using FTIR we were able to separate
out the bags similar to the ones that gave her a problem from others
with different spectra. We dumped those suppliers that had the
questionable IR signature. She has never had a problem since. This was
five years ago, but I believe the additive was thought to be a
particular amine. Remember FTIR is not much good for anything below
about 5%, so most of the peaks were swamped by the signal for the
polyethylene.
And even farther back while I was at Nortel in the 90's we had a problem
similar to yours. The bags were coated so thick I thought I was
touching the inside surface of roasted Thanksgiving turkey skin. We
dropped that supplier.
I think what is important is what is the coating material and how thick
have they applied it. I wouldn't rule out all topically coated ones
just on the basis of this one experience.
We currently purchase them
per MIL-PRF-81705 Ty II. But, it has come to our attention (via
Customer
Returns and Corrective Action) that some of the bags we were getting
were
leaving a sticky residue on the parts. Investigation has led to the
discovery that the anti-static properties of the bags can be attained
via
one of two major ways: 1) an anti-static topical coating or 2)
anti-static
"materials" (carbon?) impregnated into the bag itself. Apparently the
MIL-spec only specifies the finished properties, not the process. I
have
been told the coating is a cheaper method than the impregnated. I would
like to prevent purchase of the topically coated bags, and only purchase
the
impregnated versions, but how to specify it? I have found several
vendors
and / or manufacturers who claim their bags are impregnated. But I am
reluctant to to tie my Purchasing groups hand by limiting such a
commodity
item (there are apparently a thousand manufacturers and a million more
distributors) to a few vendors.
So why tie them to a few? Try 20 and pick the best dozen. That should
be enough for any buyer!
I am also uncertain that most (if any)
distributors would a) see my requirement for the impregnated version,
and if
they did b) even know what type they sell. In lieu of the above issues,
it
has been proposed we implement more stringent incoming inspection to
visually inspect for oily residues. While this works, it would also let
the
supplier off the hook, so to speak, if we found bad bags that were still
compliant to the purchase spec (MIL).
Right, a waste of time. Do some initial work (inspection, chemical
analysis, whatever) and then trust the good suppliers you pick.
Has anyone faced this same problem? Any recommended vendors?
I will ask our ESD to write you with some choices.
Control Plans?
Nope
Thanks!
Kevin Glidden
Manufacturing Engineer
Luminescent Systems Inc.
Bev RIM
---------------------------------------------------
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 transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.
---------------------------------------------------
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
-----------------------------------------------------
|
