Lead-free cleaning flux residue removal

Spray batch and spray in-line cleaning systems for OA, no-clean, and RMA pastes and lead-free flux residues Removes all types of flux residues including lead-free in batch washing Flux residue removal in ultrasonic immersion cleaning systems requiring no sump side additives... 

With the move to lead-free solder pastes, problems in the cleaning and removal of flux residues from soldered assemblies are to be expected due to soldering-process variations. Because of the change of flux formulations, especially with respect to new components or changes in solvents used, resin, and thixotropic concentrations, the removal of unsoldered solder paste also may be affected. The lead-free pastes used in this study were tested additionally for the ease of removal from stencils and misprinted circuit boards. 

As noted earlier, lead-free alloys require high reflow temperatures compared to eutectic Sn-Pb— with thermal profile plateaus in the range of 180-190°C, which are too high for fluxes formulated for eutectic Sn-Pb solder. The oxidation of rosin in air and the increased polymerization at elevated temperatures result in residues that are very difficult to clean with standard solvents. Flux vehicles selected for use in lead-free solder pastes are dramatically different from those used in eutectic Sn-Pb solder pastes. It was determined that cleaning products that preformed very well with eutectic Sn-Pb technology did not remove some residues left as a result of the new flux vehicle formulated for a lead-free solder [11]. 

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