Not intending to undercut Mike's offer, but to compliment it. Consider asking Heraeus for guidance about cleaning the residues from reflowing your paste. Some NC flux res: * Cannot be cleaned. * Can be cleaned after a relatively short period of time after soldering. After that period, the res becomes very hard and glassy. * Can be cleaned, but leave behind residues that are very corrosive. * Can be cleaned well using a saponifier with a good surfactant constituent that are heated 140-145�F.
Actually, we just wash the solder balls from our boards using an aqueous cleaner. A gross filter in the washer collects the solder balls. Periodically, we dispose of this filter as a hazardous material. Works GREAT.
According to Microcare [ http://www.microcare.com/product/pg-fastdry-solvents.html ], Genesolv 2004 might not be a good choice for a variety of reasons. Scratching the surface, Microcare says, �A fast-drying azeotrope of HCFC-141b and methanol. Hugely popular. Aerosol only � available for use in vapor degreasers in Europe until 2001, and in certain exempted categories until 2006, but banned in the U.S. and Canada after 2002. Mainly used as a defluxer of rosin fluxes; not compatible with most no-clean fluxes. Very aggressive. Mil-spec approved. Superior toxicity ratings. Low aroma. Nonflammable. Neutral pH. Affordably priced.� And all of that becomes particularly scary when you consider that Microcare sells the stuff [Genesolve 2004].
Yano, you really should consider working to improve your soldering process so NOT to leave solder balls. It probably would be a lot less work and lower cost.
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