The PCBA water cleaning process uses water as the cleaning medium. A small amount (usually 2% to 10%) of surfactants, corrosion inhibitors and other chemical substances can be added to the water. After washing, the source of pure water or deionized water Washing and drying complete the PCBA cleaning process.

The advantage of water cleaning is that the cleaning medium for water cleaning is generally non-toxic, does not endanger the health of workers, and is non-flammable and non-explosive, so it has good safety. Water cleaning has good safety on particles, rosin fluxes, water-soluble pollutants and polar pollution. Good cleaning effect for objects, etc.: the water clear makes it compatible with the packaging materials of the components and PCB materials, and does not swell or crack the rubber parts and coatings, so that the markings and symbols on the surface of the components can be maintained Clear and complete, will not be washed off please. Therefore, water cleaning is one of the main processes of non-ODS cleaning.

The disadvantage of water washing is that the investment in the entire equipment is large, and it is still necessary to invest in pure water or deionized water production equipment. In addition, it is not suitable for non-airtight devices, such as adjustable potentiometers, inductors, switches, etc. The water vapor entering the device is not easy to be discharged, and may even damage the ring components.

Water washing technology can be divided into pure water washing and water adding surfactants. The typical PCBA process is as follows: water + surface activity → water → pure water → ultrapure water → hot air washing → rinsing → drying.

Generally, an ultrasonic device is added in the washing stage, and an air knife (nozzle) device is added in addition to the super in the washing stage. The water temperature is controlled at 60-70℃, the water quality is very high, and the resistivity is 8-18MQ·cm. This alternative technology is suitable for SMT chip processing plants with large production batches and high product reliability requirements. For small batch cleaning, small cleaning equipment can be selected.