Electronics Forum | Mon Mar 29 11:15:58 EST 2004 | davef
Grant & JDumont: You should not have this white residue on your wave soldered connections, using VOC flux [but you know that, anyhow]. Applying too much flux is the likely cause. Other possibilities are: * flux contamination * solder contamination
Electronics Forum | Mon Mar 29 11:20:04 EST 2004 | jdumont
Hi Dave, its not the connections that have the white residue. It is the surface of the board. The whole thing turns a milky white color. I have pictures if anyone would like to see them... Josh
Electronics Forum | Mon Mar 29 13:16:10 EST 2004 | russ
The only time I have ever had this happen was with un/not fully cured solder resist. Only shows up after wave. I believe that is because of the higher temp than reflow but don't know for sure. No help but what the hey Russ
Electronics Forum | Mon Mar 29 13:59:27 EST 2004 | jdumont
Well how can I correct this? Would baking the board prior to any operations help? Is this an issue I should get the PCB manufacturer involved with, or something that is common and just live with it?
Electronics Forum | Tue Mar 30 07:20:20 EST 2004 | davef
If you can rub it off, it's unlikely to be a solder mask problem. Try the "excess flux, flux contamination, solder contamination" angle.
Electronics Forum | Fri Apr 02 01:05:34 EST 2004 | Grant Petty
Hi, Thanks for the info. How clean can wave soldering get? We are looking at a carrier that masks off most of the board when we run it through the wave, so hopefully this works. Regards, Grant Blackmagic Design
Electronics Forum | Fri Apr 02 01:11:29 EST 2004 | Grant Petty
Hi, We have the spray fluxer, and I will have a look for the manifold. The guys thought they had purged the system but it's worth checking. Regards, Grant Blackmagic Design
Electronics Forum | Fri Apr 02 06:26:13 EST 2004 | Phil James
Take a look at the downloadable paper on the subject of "White residues" available from NPL www.npl.co.uk/ei (Downloads) By the way, we also suffer from this problem!
Electronics Forum | Fri Apr 02 12:40:59 EST 2004 | Ron Herbert
White residue can often be caused by overheating the flux. When this occurs the flux is polymerized, basically turning it into an epoxy. You can usually determine if this is the problem by taking a pencil eraser to it. If it comes off, you have overh
Electronics Forum | Mon Apr 05 08:21:14 EDT 2004 | Grant Petty
Hi, Thanks for the tip, and I will check that out! We have some heavy BNC type connectors, so they need a bit of heat, and this could be right that we are then overheating the flux. Regards, Grant Blackmagic Design
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