David,
I would also like to get a copy of your paper since we have experience
issues associated with contamination on mil spec CCA's
Thanks,
Jack Lusby
Northrop/Grumman ESSS
[log in to unmask]
direct (410)552-2886
fax (410)981-5361
> -----Original Message-----
> From: Debbie Kenney [SMTP:[log in to unmask]]
> Sent: Monday, June 24, 2002 2:16 PM
> To: [log in to unmask]
> Subject: Re: [TN] Cleaning of Military PWAs That Have Been Soldered
> withNo -CleanFlux
>
> 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.
> >
> >
> >
> >
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the BODY (NOT the subject field): SIGNOFF Technet
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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
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