In our daily production, we will pay attention to the quality control of SMT processing, and ignore the cleaning process after PCBA manufacturing. We believe that cleaning is not a key technical step. So, where is the importance of PCBA cleaning for circuit boards?
1. PCBA production goes through multiple stages, and each stage is polluted to different degrees. Therefore, various deposits or impurities remain on the surface of the circuit board, which can reduce product performance and even lead to product failure.
2. Ionic pollution and non-ionic pollution have always been important sources of pollution on PCB and PCBA circuit boards. Ionic pollutants come into contact with moisture in the environment, and electrochemical migration forms a dendritic structure after electrification, which affects the resistance path and destroys the function of the circuit board. Non-ionic pollutants can penetrate the insulating layer of the PCB and form growth dendrites under the surface layer. In addition, there are contaminants such as solder balls, solder bath floats, dust, dirt, etc., which will result in lower solder joint quality, and many undesirable phenomena such as pores and short circuits in solder joint icicles.
3. Flux or solder paste in SMT processing is commonly used in reflow soldering and wave soldering processes. They are mainly composed of solvents, wetting agents, resins, corrosion inhibitors, activators, etc.; Thermal modification products dominate all contaminants and are the most important factor affecting product quality management; easy to adsorb dust or impurities, which will cause the resistance to gradually increase, and severe cases will lead electronic parts wrong. Therefore, strict cleaning must be carried out after welding.
To sum up, the cleaning of the circuit board PCBA is very important, which is directly related to the quality of the circuit board, and it is indispensable.