Three proofing paint is also called PCB electronic circuit board protective oil, coating oil, moisture-proof paint, three proofing paint, waterproof glue, insulating paint, anti-corrosion paint, anti salt spray paint, dust-proof paint, protective paint, coating paint, three proofing glue, etc. PCB circuit board that has used three proofing paint has water-proof, moisture-proof, dust-proof “three proofing” performance, cold and hot impact resistance, aging resistance, radiation resistance, salt spray resistance, ozone corrosion resistance, corrosion resistance Vibration, good flexibility, strong adhesion and other properties.
Moisture is the most common and destructive factor to PCB. Excessive moisture will greatly reduce the insulation resistance between conductors, accelerate high-speed decomposition, reduce Q value, and corrode conductors. We often see that the metal part of PCB board is green, which is caused by the chemical reaction of copper with water vapor and oxygen without coating three proofing paint.
Hundreds of pollutants found on printed circuit boards have the same destructive power. They can lead to the same results as moisture erosion – Electronic decay, corrosion of conductors and even irreversible short circuit. The most common pollutants found in the electrical system may be chemical substances left in the process. These pollutants, for example, flux, solvent release agent, metal particles and marking ink. There are also major pollution groups caused by human carelessness, such as human body fat, fingerprints, cosmetics and food residues. There are also many pollutants in the operating environment, such as salt spray, sand, fuel, acid, and other corrosive steam and mold.
When the three proofing paint is coated on the printed circuit board and components, the deterioration of electronic operation performance can be reduced or eliminated when it may be affected by the adverse factors of the operating environment. If the coating can maintain its function for a satisfactory period of time, such as longer than the service life of the product, it can be regarded as having achieved its coating purpose.
Even if the coating is very thin, it can withstand mechanical vibration, swing, thermal shock and operation at high temperature to a certain extent. Of course, the idea that film can be used to make the individual parts inserted in the printed circuit board have mechanical strength or sufficient insulation is wrong. The parts and components must be firmly inserted by mechanical means, and they must have their own suitable caulking agent, so as to have double insurance to prevent accidents.