No Clean Flux Residues from PCBs
Removing no clean fluxes on PCBs is a sub-set of electronics manufacturing and repair. It requires special consideration. Most no clean fluxes stay on the board uncleaned. But if they need cleaning they are more difficult than old-style rosin-based fluxes. This is because no clean materials are prone to leaving white residue. They also contain activators. If the activators are not fully encapsulated, they may cause corrosion on the boards. So, these contaminants need a cleaner formulated with aggressive solvency. And if possible, one using inorganic fluids to fully remove any white residue.
For automated cleaning of large numbers of PCBs, use a vapor degreaser. A vapor degreaser with spray under immersion will also help reach the desired cleanliness specification. MicroCare offers several cleaning fluid formulations to remove no clean fluxes from PCBs. They are strong candidates for replacing nPB in these applications.
Special feature: MicroCare Case Study #15. This video deals with the cleaning problems associated with mixed flux and solder paste residue. Mixed flux and solder paste can result in white residue.