What is the pollution of PCBA circuit board?

Pollutants are defined as any surface deposits, impurities, slag inclusions and adsorbates that reduce the chemical, physical or electrical properties of PCBA to an unacceptable level.

Pollutants in PCBA manufacturing are mainly applied to cleaning process in the following aspects:

① PCBA surface pollution will be caused by the pollution or oxidation of components and parts constituting PCBA and PCB itself.

② During the production and manufacturing of PCBA, solder paste, solder wire, etc. shall be used for welding. The flux in the welding process will produce residues on the surface of PCBA to form pollution, which is the main pollutant.

③ Hand marks will be produced during manual welding, and some wave soldering pawl marks and welding pallet (fixture) marks will be produced during wave soldering. Other types of pollutants may exist on the surface of PCBA, such as hole plugging adhesive, residual adhesive of high-temperature tape, hand marks and flying dust.

④ Dust in the workplace, water and solvent vapor, smoke, small particulate organic matter, and electrostatic pollution caused by charged particles attached to PCBA.

⑤ SMT solder paste printing steel screen cleaning as a routine maintenance, it is essential to clean the solder paste residue on the steel screen to prevent pollution and ensure the printing quality.