Analysis of PCBA pollution hazard
First, PCBA pollution
Contaminants are defined as any surface deposits, impurities, slag inclusions, and adsorbates that reduce the chemical, physical, or electrical properties of PCBA to undesirable levels. There are mainly the following aspects:
1. The components that make up PCBA, the pollution or oxidation of the PCB itself will bring PCB surface contamination;
2. The residue generated by the flux during the manufacturing process is also the main pollutant;
3, handprints, chain claws and fixture marks generated during the welding process, and other types of pollutants, such as plugging glue, high temperature tape, handwriting and flying dust;
4. Dust, water and solvent vapors in the workplace, smoke, tiny particulate organic matter, and contamination of charged particles attached to PCBA caused by static electricity.
Second, the harm of pollution
Contamination can directly or indirectly cause potential risks to PCBA, such as:
1. The organic acid in the residue may cause corrosion to PCBA;
2. During the energization process, the ions in the residue cause electromigration due to the potential difference between the solder joints, causing the product to be short-circuited;
3. The residue affects the coating effect;
4. After the change of time and ambient temperature, the coating cracks and wobbles, which causes reliability problems.