Lead free flux removers can be troublesome for PCB cleaning. Lead free fluxes require high temperatures to reflow and so they are harder to clean. Many lead free fluxes and pastes produce white residues when cleaned which then require an aggressive cleaner to remove those residues. However, the best solvents are very aggressive cleaners and can damage plastic components and elastomers. Some of the ingredients may contribute to local, low-altitude smog with volatile organic compounds. Ordinary and inexpensive IPA alcohol generally is ineffective on lead free fluxes. Benchtop cleaning of lead free fluxes and pastes can be very time-consuming and labor intensive.
MicroCare offers a number of aerosol solvents optimized for lead free flux removing. Vapor degreasers with spray under immersion or ultrasonics also may be highly effective in order to reach the desired cleanliness specification.
Special feature: MicroCare Case Study #15 deals with the cleaning problems associated with mixed flux and solder paste residues, which can result in white residues.