Ed,
the water should be tested every week (if it is large production).
Particles, Becteria, (I believe there is a water test spec. in the
industry) etc. For applicaiton like the one you have, you may have to
install the filter system right before the cleaning tank. UV may kill some,
make sure you have no shadows... you still need to get rid of the "dead
body" bacteria, otherwise, you may end up some "flowers"...
Good luck for Gardening using PWB...
jk
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Ed Popielarski
Sent: Wednesday, July 17, 2002 2:54 PM
To: [log in to unmask]
Subject: [TN] Bacteria
Hi 'netters,
I have a client that is building extremely high impedance low voltage
assemblies (counting electrons from a photomultiplier type circuit) that
recently are failing test due to "leakage" They are running water soluble
flux with an SMT type aqueous cleaner fed by closed loop D.I. water 1Meg/cm3
or better. Dynamic Ion testing shows very good results. They ran a culture
and found very high bacteria counts, well beyond fed drinking water
standards.Subsequent cleaning at the end user site (conditions unknown at
this time) seems to resolve the failures. I suggested UV sterilization (not
too expensive/risky) and also to verify "under soldermask" cleanliness as
well as "localized" contamination sites which "average" into the overall
assembly.
My question is if anyone has had any electrical failures due to bacteria
in the rinse water and what solution(s) were successful. Any other
suggestions or suspicions would be appreciated.
Regards,
Ed Popielarski
QTA Machine
10 Mc Laren, Ste D
Irvine, Ca. 92618
Phone:949-581-6601
Fax: 949-581-2448
Cel: 949-337-2578
WWW.QTA.NET
--------------------------------------------------------------------------
------- Technet Mail List provided as a free service by IPC using LISTSERV
1.8e 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/html/forum.htm for additional information, or
contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315 -------------------------------------------------------------------
--------------
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------