Cleaning "is often neglected in the PCBA manufacturing process of circuit boards (circuit boards). Cleaning is not the key step. However, with the long-term use of products on the client side, the problems caused by the previous invalid cleaning caused many failures, and the operating costs caused by repairing or recalling products increased sharply. Next, with you to understand the role of PCBA cleaning circuit boards (circuit boards).
PCBA (Printed Circuit Component) production process passes through several stages, each stage is polluted to varying degrees, so PCBA surface residual sediments or impurities, these pollutants will reduce product performance, and even cause product failure. For example, solder paste and flux are used to assist welding in the process of welding electronic components. Residues are produced after welding. The residues contain organic acids and ions, among which organic acids can corrode PCBA of circuit boards, and the existence of electric ions may lead to short circuit, resulting in product failure.
There are many kinds of pollutants on PCBA, which can be classified into two categories: ionic and non-ionic. Ionic pollutants are exposed to humidity in the environment and migrate electrochemically after electrification, forming dendritic structures, resulting in low resistance paths and destroying PCBA functions of circuit boards (circuit boards). Non-ionic pollutants can penetrate the insulation layer of PCB and grow dendrites under the surface layer of PCB. In addition to ionic and non-ionic contaminants, there are also granular contaminants, such as solder balls, floating points in solder tanks, dust, dust and so on. These contaminants can lead to many undesirable phenomena, such as quality reduction of solder joints, solder point sharpening, gas holes, short circuit and so on.
So many pollutants, what is the concern? Fluxes or solder pastes are widely used in reflow and wave soldering processes. They are mainly composed of solvents, wetting agents, resins, corrosion inhibitors and activators. Thermal modification products must exist after welding. These substances dominate in all pollutants. From the point of view of product failure, post-weld residue is the main factor affecting product quality. Ionic residue tends to cause electromigration, which reduces insulation resistance. Residual rosin resin tends to adsorb dust or impurities, which increases contact resistance. Seriously, it leads to open circuit failure. Therefore, strict cleaning must be carried out after welding. Only in this way can the quality of PCBA be guaranteed.
To sum up, the cleaning of PCBA of circuit board (circuit board) is very important, and "cleaning" is an important process directly related to the quality of PCBA of circuit board (circuit board), which is indispensable.
