- Manual cleaning - This can involve aerosol or pump sprays, or solvents in a pan or tray. Agitation can be applied with a brush, swab or wipe. This method is best for low volume cleaning of non-critical electronics (e.g. IPC class 1), because it is operator dependant, so not easily repeatable.
- Ultrasonic - This method uses sonic (sound) waves to create bubbles, which implode on the PCBA surface to break up the flux residues. This is an aggressive cleaning method, which can be a problem for sensitive components (e.g. ceramic). Because the dissolved flux residues flow back into the cleaning solution, the cleaner needs to be monitored and changed often to prevent cross-contamination.
- Vapor degreasing - The cleaning is done either in the vapor phase of a solvent, or submerged in a sump, which often includes ultrasonic action. Since the final rinse always happens in the vapor phase, this is an ideal cleaning method for critical applications where residue cannot be accepted.
- Batch or inline systems - Spray equipment is used to wash, rinse, and dry the PCBAs. Water or water-based cleaners are most commonly used as the cleaning solution. This cleaning method is good for high volume cleaning, and is repeatable enough for critical applicaitons.