As the name implies, PCBA vapor phase cleaning is a wave soldering process in which the solvent is heated by the equipment to vaporize the solvent, and the solvent vapor is used to continuously evaporate and condense, so that the cleaned printed circuit board workpieces constantly "sweat" and bring out pollutants. The cleaning method. In order to improve the cleaning effect of PCBA cleaning, it is usually combined with ultrasonic cleaning.

1. The principle of gas phase cleaning

The bottom of the gas-phase cleaning equipment is a heating soaking device and an ultrasonic cleaning tank. Several round cold meter tubes are installed around the wall of the upper tank to form a condensing temperature zone ring. When the solvent is heated to the vaporization temperature, it starts to evaporate and also evaporates to the workpiece to be cleaned. When the solvent vapor rises to the position of the annular condenser, the solvent vapor condenses and falls on the workpiece to be cleaned. Because the solvent vapor is very pure, the solvent vapor is used to continuously evaporate and condense, so that the cleaned work piece constantly "sweats" and brings out the contaminants generated during the SMT chip processing and post-chip welding.

2. Gas phase cleaning process

①First soak the workpiece in the heated cleaning solvent to make the contaminants like.

②Ultrasonic cleaning to free the contaminants on the surface of the workpiece.

③Gas phase cleaning. Gas phase cleaning is equivalent to Ge gas. The separation gas of the solvent is very pure. The separation gas of the solvent is used to continuously "sweat" the cleaned workpiece and bring out pollutants.

④ Rinse with a cleaner cleaning solvent.

⑤Finally spray with clean cleaning solvent.

PCBA gas-phase cleaning equipment has two structures: single tank and multi tank: when the single tank cleaning machine is cleaning, the cleaned workpiece moves up and down, and the bottom of the cleaning tank is heated and soaked and ultrasonically cleaned, and then the cleaned workpiece is lifted to the soaking sound Carry out vapor phase cleaning between the tank and the cold pipe, and finally use a clean cleaning solvent. When the multi-tank cleaning machine is cleaning, the workpiece to be cleaned moves laterally from the first tank to the last tank, and is heated and immersed in the first tank and ultrasonically cleaned. At the same time, gas-phase cleaning is performed, and rinsed in the second tank (some The equipment has three rinsing tanks), and then lift the cleaned workpiece up, spray it with a clean solvent, and finally dry it naturally in an exhausted environment.

However, the specific cleaning method used is determined by the cleaning quantity of the workpiece to be cleaned. Small batches generally use single and double tank cleaning, and large batches use multi-tank cleaning.