In order to improve the adaptability of the veneer, human adopts the process of coating after cleaning for PCBA boards. However, during the actual use , it is still found that some products can’t work in the warranty period, which has a great relationship with the cleaning process. Cleaning is the process of removing pollutants. Successful cleaning can ensure the reliability and operating life of electronic products. Now BQC will explain the hazards and sources of PCBA pollutants.

The pollutants in PCBA not only will result in decreased of insulation resistance, chemical corrosion or electrochemical migration, will also affect the back of the three anti-coating.

The main sources of pollutants are:

1. Pollution of components and components processing.

The most common pollutants are surface oxide and fingerprints.The formation of surface oxidation layer is due to the components of the storage time, environment, packaging and so on.The main ingredients of fingerprints are water, skin oil , sodium chloride and hand protection products.

2, Flux pollution

Flux in the PCB components have two kinds of pollution, one is the flux caused by the proliferation of pollutants, the second is flux residue after welding.

3, Pollution during welding process

PCBA pollution generated in the welding process, mainly is tiny solder ball, solder tank scum, solder in the metal slag etc on PCB boards.

4, Working environment pollution

Dust in workplaces, steam of water and solutions, smoke, tiny particulate organic matter, and charged particles caused by static electricity.