I would also like to get a copy. Debbie Kenney Engineer M-Flex / AMT Direct (714) 688-5242 Fax (714) 996-3834 [log in to unmask] > -----Original Message----- > From: Gordon F. Davis Jr [SMTP:[log in to unmask]] > Sent: Friday, June 21, 2002 4:30 AM > To: [log in to unmask] > Subject: Re: [TN] Cleaning of Military PWAs That Have Been Soldered > withNo-CleanFlux > > May I get an e-copy of the paper you refered to as well. I also work for > a > military supplier, but we clean everything. I would like to get further > info on no-clean. > > Gordon Davis > Application Engineer > Rockwell Collins > > > > > David Douthit <[log in to unmask]>@ipc.org> on 06/20/2002 09:10:13 PM > > Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please > respond > to David Douthit <[log in to unmask]> > > Sent by: TechNet <[log in to unmask]> > > > To: [log in to unmask] > cc: > > Subject: Re: [TN] Cleaning of Military PWAs That Have Been Soldered > withNo-CleanFlux > > > You have landed in a very nasty area. You are correct to be concerned > about > contamination issues. > Even if the residues from the flux do not create migration/leakage current > problems they may > collect other airborne contaminates that can cause problems. > > Process, shipping, and storage control are critical to the reliability of > the circuitry. > > If you wish I have a paper I presented in May of 2001 titled > "Avionics Systems, Reliability, and Harsh Environments" > that I could e-mail you. The information in the paper will > give you a good idea of what type of airborne contamination > issues you may have to deal with. > > David A. Douthit > Manager > LoCan LLC > > Bogert wrote: 6/20/2002 Folks is anyone manufacturing military PWAs using > no-clean flux and not cleaning the PWAs prior to shipment? If so, what is > your reliability experience with this process? We are considering a > military application (Class 2) where mixed technology (SMT and PTH) PWAs > will be soldered using no-clean flux and then not conformal coated > (assuming the uncoated PWAs can pass our temperature/humidity > qualification > testing). Although the no-clean flux we will use should be benign (we are > having SIR testing performed to confirm this and Omegameter testing), I am > concerned that contamination may be introduced by other shop processes > such > as mechanical assembly, testing, etc., even if one uses gloves or fingere > cots during handling. One could argue that after shipment, since the PWAs > are not conformal coated, you can introduce contamination in the field and > therefore, why not not clean prior to shipment. We may be performing board > testing (boundry scan, bed-of-nails, etc) on PWAs that have been soldered > using no-clean flux. I understand that certain noclean flux can impede > this testing, and also, may cause problems in event we need to conformal > coat the PWAs. Any comments on this subject will be appreciated. > > > > -------------------------------------------------------------------------- > ------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > 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 delivery of Technet send e-mail to [log in to unmask]: > SET Technet NOMAIL > 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 1.8d 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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL 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 ---------------------------------------------------------------------------------