PCB coating with three proof paint can protect PCBs from harsh environmental erosion and extend the lifespan of electronic products. Before coating, it is necessary to clean, dehumidify, and shield. Brushing, spraying, dipping, and other methods can be used. After curing, the quality should be checked. The operation should be carried out in a dust-free environment, paying attention to personal protection and waste disposal.

Three proof paint, also known as electronic circuit board protective oil, moisture-proof paint, three proof coating, etc., is a single component, low viscosity acrylic resin or other special resin material. Its main function is to form a transparent protective film on the surface of the PCB, preventing external factors such as moisture, salt spray, and chemicals from corroding the circuit board, while providing additional functions such as electrical insulation, dust prevention, and shock resistance.

Before applying the three proof paint, pay attention to the following preparation work
1. Cleaning PCB board: Before applying the three proof paint, the PCB board must be thoroughly cleaned; 2. Drying and dehumidification: The cleaned PCB board needs to be dehumidified in an oven; 3. Shielding protection: For components and areas that do not require coating with three proof paint, adhesive film or anti-static paper tape should be used for shielding protection.

There are various coating methods for PCB three proof paint, including brush coating, spray coating, dip coating, and selective coating. The specific choice of method depends on the structure of the PCB board, production batch, and coating requirements.

1. Brush coating: Brush coating is the simplest and most direct method, suitable for small batch production and structurally complex PCB boards. Pay attention to controlling the coating thickness to avoid dripping and sagging.
2. Spraying: Spraying is one of the most commonly used coating methods, which can be divided into manual spraying and automatic spraying. Manual spraying is suitable for local coating of small batches or complex workpieces; Automatic spraying is suitable for large-scale production and can achieve efficient and uniform coating effects. Attention should be paid to controlling the spread of paint mist during spraying to avoid contaminating other components.
3. Dip coating: Dip coating is suitable for PCB boards that require comprehensive coating, ensuring that every corner is evenly covered. Immerse the PCB board vertically into the three proof paint groove, and slowly lift it up after the bubbles disappear, allowing the excess three proof paint to naturally flow back into the groove. Pay attention to controlling the lifting speed to avoid generating bubbles.
4. Selective coating: Selective coating is a high-precision, low waste coating method suitable for applications that require extremely high coating accuracy. By programming and controlling the coating equipment, the three proof paint is accurately applied to the designated area to avoid contamination of components that do not require coating.