Julie,

Well said.

My short response is Ditto.

My longer response is I don't like soldering iron repairs primarily because of the localized heating a (i.e., "too hot" if you touch a component and can cause thermal damage and "not hot enough" if you want to remove N0-Clean flux that spread a little ways away from where you applied the flux.  Our preference is non-contact hot air heating for repair.

Regards,
George
George M. Wenger
Senior Principal Reliability / FMA Engineer
Andrew Corporation - Wireless Network Solutions
40 Technology Drive, Warren, NJ 07059
(908) 546-4531 Office (732) 309-8964 Mobile
E-mail: [log in to unmask]

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Julie Silk
Sent: Tuesday, April 24, 2012 3:37 PM
To: [log in to unmask]
Subject: Re: [TN] No-Clean Flux

I agree with the majority of the group that no-clean liquid flux that has not been deactivated is a reliability issue.  It remains conductive, and is tacky enough to collect debris and dust to make an additional conductive path.  It's a poor practice to use liquid flux for hand-rework, and yet seems prevalent.  

Since I intensely dislike spot-cleaning operations (too variable, operator-dependent, spreads gunk in a broader area and under parts), I prefer to ban liquid flux use in rework in settings where an automated cleaning process is not available.  Even a single drop applicator gives enough flux to spread into regions that will not be heated by a soldering iron.  I have never seen an operator wait a couple of minutes after fluxing before going in to solder, either.  The flux pen is the best bet, and yet I've seen it swiped liberally all over the region to be soldered and not just the local area.  

I think the IPC 610 10.6.4 standard that was referenced is inadequate (one of the few places where Agilent disagrees with IPC and our internal standards are tighter).  It sounds like wet, tacky or excessive flux residues are only a defect when they may spread onto other surfaces.  Wet and tacky residues -- or ones that were tacky enough to exhibit fingerprints (!) -- are unacceptable.  Period.

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________