Is it really important to clean the circuit board (circuit board) PCBA?

　　"Cleaning" is often ignored in the PCBA manufacturing process of circuit boards (circuit boards), and it is considered that cleaning is not a critical step. However, with the long-term use of products on the client side, the problems caused by the ineffective cleaning in the early stage have caused many failures, and the repair or recall of the products has caused a sharp increase in operating costs. Next, let’s take a look at the role of PCBA cleaning for circuit boards (circuit boards).

　　PCBA (printed circuit assembly) production process goes through multiple process stages, and each stage is polluted to different degrees. Therefore, various deposits or impurities remain on the surface of the circuit board (circuit board) PCBA. These pollutants will reduce product performance , And even cause product failure. For example, in the process of soldering electronic components, solder paste, flux, etc. are used for auxiliary soldering. After soldering, residues are generated. The residues contain organic acids and ions. Among them, organic acids will corrode the circuit board (circuit board) PCBA. The presence of electric ions may cause a short circuit and cause the product to fail.

　　Circuit board) There are many kinds of pollutants on PCBA, which can be classified into two categories: ionic and non-ionic. Ionic pollutants come into contact with the humidity in the environment, and electrochemical migration occurs after electrification, forming a dendritic structure, resulting in a low-resistance path, and destroying the PCBA function of the circuit board (circuit board). Non-ionic pollutants can penetrate the insulating layer of the PCB and grow dendrites under the surface of the PCB. In addition to ionic and non-ionic pollutants, there are also granular pollutants, such as solder balls, floating points in the solder bath, dust, dust, etc. These pollutants can reduce the quality of solder joints, sharpen the solder joints during soldering, and produce Various undesirable phenomena such as pores and short circuits.

　　With so many contaminants, which ones are the most concerned? Flux or solder paste is commonly used in reflow soldering and wave soldering processes. They are mainly composed of solvents, wetting agents, resins, corrosion inhibitors and activators, etc. A variety of components, thermally modified products are bound to exist after welding, and these substances are dominant in all pollutants. From the perspective of product failure, post-weld residues are the most important factor affecting product quality, and ionic residues Substances can easily cause electromigration and decrease the insulation resistance. The rosin resin residue can easily absorb dust or impurities to increase the contact resistance. In severe cases, it will cause open circuit failure. Therefore, strict cleaning must be carried out after welding to ensure the PCBA of the circuit board (circuit board). quality.

　　In summary, the cleaning of the circuit board (circuit board) PCBA is very important. "Cleaning" is an important process directly related to the quality of the circuit board (circuit board) PCBA and is indispensable.

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