Phil
Welcome to Board Talk. This is Phil Zarrow and Jim Hall, the Assembly Brothers, also known by day as ITM Consulting. We're here to answer process questions to do with SMT. Today's question comes from a Mr. P.H., in Texas, who writes –
Jim
I have a closed-loop batch wash system used in SMT, running a water-soluble process. An associate wants to clean assemblies that were hand-soldered with a no-clean to our batch wash. The solder chemistry is the same, 6337, but the manufacturers are different. Of course, one is no-clean and one is water-soluble. Does this pose potential problems for the assembly or equipment? I prefer not to introduce the no-clean into my SMT environment, since the system is closed-loop.
Phil
Hey, good for you, Mr. P.H. Keep them the heck away from your cleaner with that stuff. What the heck? You don't want him messing that thing up.
Jim
Well, the most important thing, though, is that he's not going to clean his no-clean residues with a straight water cleaner.
Phil
No, he's going to make one hell of a mess, is what he's gonna do.
Jim
I suppose that you could say, "I'll run everything with a saponifier," but that's an additional cost and maintenance, and you've got to make sure that your closed-loop system will handle it. There are just a whole lot of issues. So I guess our advice is no, don't try it. It's not going to clean a no-clean, and it could potentially mess up your pure water batch system, even with a closed-loop.
Phil
Yep, and that hopefully answers this question. And on that note, this is Phil Zarrow with Jim Hall, your Assembly Brothers, bidding you farewell, and remember, whatever you do –
Jim
Don't solder like my brother.
Phil
And don't solder like my brother.












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The big problem was cleaning a board after rework, you can not remove the no clean flux, it makes a mess. So we gave up and used WS, late parts became hand soldered parts.
Is there anything out there that you know of that is a "None Complete Dry Out" WS flux? I would love to know.
I deal with loads of quick turn proto and short runs. Holding a placed job before reflow is important.
Bob Kondner