Contaminants are defined as any surface deposits, impurities, slag inclusions and adsorbates that reduce the chemical, physical or electrical properties of the PCBA to unacceptable levels.
The pollutants in PCBA manufacturing are mainly applied to the cleaning process in the following aspects:
① The components that make up the PCBA, the contamination or oxidation of the PCB itself, etc. will bring pollution to the surface of the PCBA.
② In the production process of PCBA, solder paste, solder, solder wire, etc. need to be used for soldering, and the flux in the soldering process will produce residues on the PCBA board surface to form pollution, which is the main pollutant.
③ Fingerprints produced during manual soldering, wave soldering claw footprints and soldering tray (jig) marks will be produced in the wave soldering process, and other types of contaminants may also exist on the PCBA surface to varying degrees, such as plugging holes glue, residual glue of high temperature tape, handwriting and flying dust, etc.
④ Dust, water and solvent vapor, smog, micro-particle organic matter, and charged particles caused by static electricity in the workplace adhere to the PCBA pollution.
⑤ SMT solder paste printing stencil cleaning As daily maintenance, it is essential to clean the solder paste residue on the stencil to prevent pollution and ensure printing quality.
