Thanks for the assist, Joe.
Doug Pauls has been very active in clealiness issues for IPC committees.
He provided us with a small flock of documents discussing fluxes and
cleaning. I've put them all into a zip file of about 4 MB; download
using a browser from: http://files.ipc.org/cleaning_papers.zip
Jack
Jack Crawford, IOM
IPC Director Certification and Assembly Technology
[log in to unmask]
847-790-5393
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Kane, Joseph E (US
SSA)
Sent: Thursday, August 19, 2004 1:08 PM
To: [log in to unmask]
Subject: Re: [TN] Cleanliness Specs
Rich:
You can find the base value in J-STD-001C para. 8.3, but the limit of
1.56 micrograms per sq. cm. that is cited was developed back in the dark
ages for rosin based fluxes, after cleaning with a vapor degreaser. The
intent back then was to ensure that RMA residues on unobstructed
surfaces would not affect adhesion of conformal coat.
There seems to be no established standards for what the cleanliness
limit should be for water soluble fluxes or no-cleans. And if you ask
what the number should be, the first question back is - what is your
application? Does the service environment include condensing moisture?
Are you coating, and with what? What voltages are you running, and what
is the physical spacing?
How clean do you need to be? No easy answers.
By the way, the limit of 1.56 converts to 10 micrograms per square inch,
but the actual acceptance value will depend on the test equipment. The
equivalence limit of 14 that you mention applies to the Omega Meter, and
the only spec where I know that's documented is in the long-cancelled
MIL-P-29909A, Table V.
-Joe
-----Original Message-----
From: Macko, Joe @ IEC [mailto:[log in to unmask]]
Sent: Thursday, August 19, 2004 1:20 PM
To: [log in to unmask]
Subject: Re: [TN] Cleanliness Specs
Rich,
Look at J-STD-001, section 8, Cleanliness requirements. Good luck.
joe
-----Original Message-----
From: Rich Lasko [mailto:[log in to unmask]]
Sent: Thursday, August 19, 2004 10:15 AM
To: [log in to unmask]
Subject: [TN] Cleanliness Specs
Good afternoon all,
I am trying to track down the specific cleanliness specs for electronic
assemblies prior to conformal coating. (ie < 14 micrograms/cm sq).
What document is this actual measurement listed in? (MIL-STD-28809)?
Hasn't that been cancelled and superseded by another document?
Please advise where I can get a copy of this cleanliness spec.
Thanks,
Rich
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask]
or 847-509-9700 ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for
additional information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for
additional information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------
|
