PCBA water cleaning technology

PCBA water cleaning technology

Principle, advantages and disadvantages of PCBA water cleaning technology

The PCBA water cleaning process uses water as the cleaning medium. A small amount (generally 2%~10%) of surfactant, corrosion inhibitor and other chemicals can be added to the water. The PCBA cleaning process is completed through washing, multiple source washing and drying with pure water or deionized water.

The PCBA water cleaning process uses water as the cleaning medium. A small amount (generally 2%~10%) of surfactant, corrosion inhibitor and other chemicals can be added to the water. The PCBA cleaning process is completed through washing, multiple source washing and drying with pure water or deionized water.

The advantage of water cleaning is that the cleaning medium for water cleaning is generally non-toxic, does not endanger workers' health, and is not flammable and explosive, so it has good safety. Water cleaning has good cleaning effect on particles, rosin type flux, water-soluble pollutants and polar pollutants. Water cleaning has good compatibility with the packaging materials of components and PCB materials, does not swell and crack rubber parts and coatings, and makes the marking on the surface of components, The symbol can be kept clear and complete and will not be washed away. Therefore, water cleaning is one of the main processes of non ODS cleaning.

Principle, advantages and disadvantages of PCBA water cleaning technology

The disadvantage of water washing is that the investment in the whole equipment is large, and it is also reasonable to invest in pure water or deionized water production equipment. In addition, it is not applicable to non airtight devices, such as adjustable potentiometers, inductors, switches and other water vapor entering the device is not easy to discharge, or even damage the components.

Water washing technology can be divided into two processes: pure water washing and water adding surfactant. The typical PCBA process flow is as follows: water+surfactant → water → pure water → ultrapure water → hot air washing → rinsing → drying.

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