Mark:

The goal is to pass SIR/ionic residue tests, and failures here are usually
the result of metallic salt residues that dissolve slowly in water, thus
rinse poorly, but will screw up (a technical term) test results.

These residues are really only soluble in full aqueous cleaners.  Yes, some
people have used simple machine dishwash cleaners and have been highly
successful, as long as you change out the cleaner on every batch of boards,
as they do not have much capacity to pick up metal residues.

This approach was so successful, we copied it, with some reformulation (you
don't need any Chlorine source to clean PCB) and sell such a product.

However, if you are going to want to reuse the product many times before
dumping, you need a cleaner with a BIG capacity to pick up metal salts, which
means something that has a good load of chelates, making it "an issue" with
your waste treatment people.

Remember that your model "soil" in this may well be Lead Chloride, which is
marginally soluble, and thus any cleaner is likely going be a "waste
treatment issue", although the advantage of the "one-shot" cleaner has is
that the Lead levels may be low enough that simple dilution (which we are NOT
supposed to use as a waste treatment method) may well prove adequate to get
you below the legal minimums.

Rudy Sedlak
RD Chemical Company

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