If the adhesive tape is too slow to apply and there is too much residual adhesive when tearing, consider making a combination cover according to the shape, size, and position of the connector, and positioning it with installation holes. Cover areas that do not require painting. Now let's take a look at the process requirements for the three proofing paint.

(1) Construction process of three proofing paint
1. Brushing - The simplest three proof paint process can produce excellent coating effects on smooth surfaces.
2. Spraying - Spraying is the most commonly used coating method in the industry, which is divided into two types: machine automatic spraying and manual spraying. Machine spraying, achieving automatic feeding, saving labor and material costs, improving production efficiency, ensuring product consistency, product quality, and surface spraying effect.
3. Dip coating - Dip coating ensures complete film coverage and does not cause material waste due to excessive spraying.
4. Selective coating - Accurate coating without wasting materials, suitable for large-scale film covering, but with high requirements for coating equipment. Most suitable for large-scale lamination. Using a prepared XY table can reduce masking. When painting PCB boards, there are many connectors that do not require painting. If the adhesive tape is too slow to apply and there is too much residual adhesive when tearing, consider making a combination cover according to the shape, size, and position of the connector, and positioning it with installation holes. Cover areas that do not require painting.

(2) Precautions during operation
1. Clean and dry the board to remove moisture and moisture. It is necessary to first remove dust, moisture, and oil stains from the surface of the object to be coated, in order to fully utilize its protective effect. Thorough cleaning can ensure that corrosive residues are completely removed and that the three proofing paint adheres well to the surface of the circuit board. Drying conditions: 60 ° C, 10-20 minutes, take it out in the oven and apply it while it is hot;

2. When using the brushing method to apply the three proofing paint, the brushing area should be larger than the area occupied by the device to ensure full coverage of the device and solder pad;

3. When applying the three proofing paint, the circuit board should be laid flat as much as possible, and there should be no dripping after brushing. The brushing should be flat and there should be no exposed parts, preferably between 0.1 and 0.3mm.

4. Before brushing and spraying the three proofing paint, ensure that the diluted three proofing paint is thoroughly stirred, and let it stand for 2 hours before brushing or spraying. Use a high-quality natural fiber brush to gently brush and dip at room temperature. If using machinery, the viscosity of the coating should be measured (using a viscosity agent or flow cup), and a diluent can be used to adjust the viscosity.

5. The circuit board components should be vertically immersed in the paint residue. Do not immerse the connector unless carefully covered. The circuit board should be immersed for 1 minute until the bubbles disappear, and then slowly removed. A uniform film will form on the surface of the circuit board. Most of the paint residue should be allowed to flow back from the circuit board to the impregnation machine. The immersion speed of circuit boards or components should not be too fast to avoid excessive bubbles.

6. If there is any skin formation on the surface after the dip coating is completed and reused, remove the skin and continue to use.

7. After brushing, lay the circuit board flat on the bracket and prepare for curing. The method of heating is to accelerate the curing of the coating. If the surface of the coating is uneven or contains bubbles, it should be left at room temperature for more time to allow the solvent to flash out before curing in a high-temperature furnace.

(3) Operating environment requirements
1. The application of three proofing paint should be carried out in a separate enclosed room, and the operating room must have good ventilation facilities.

2. Smoking, eating, and drinking are prohibited in the operation room, and alcoholic beverages should not be used before work.

3. Wear protective equipment such as masks or gas masks, rubber gloves, chemical protective glasses, etc. during operation to avoid injury to the body.

4. After completing the work, it is necessary to clean the used utensils in a timely manner, organize and wipe the tools and equipment, and tightly cover the containers containing the three proofing paint.

5. The workplace should be clean and dust-free, with no flying dust, and unrelated personnel are prohibited from entering.

6. Tools and equipment should be fully grounded, and electrostatic protection measures should be taken.

7. Do not overlap the circuit boards during operation; The PCB board should be placed horizontally.

8. Before use, each batch of raw materials should undergo a small sample curing test.

(4) Places where three proofing paint cannot be applied
1. High power with heat dissipation surface or radiator components, power resistors, power diodes, and cement resistors.

2. Dial switch, adjustable resistor, buzzer, battery holder, fuse holder (tube), IC holder, and touch switch.

3. All types of sockets, pins, wiring terminals, and DB heads.

4. Plug in or mount LED, digital tube.

5. Other parts and components that cannot use insulation paint as specified in the drawings.

6. The screw holes of the circuit board card cannot be painted with three proofing paint.

(5) Requirements for PCB boards coated with three proofing paint
1. The surface of the circuit board should be free of paint flow, dripping, and semi wetting.

2. The three prevention paint layer should be flat, bright, and even in thickness, protecting the surface of solder pads, adhesive components, or conductors.

3. The surface of the paint layer should not have orange peel, bubbles, pinholes, or ripples.

4. Devices or components that do not require protection do not need to be painted with three proofing paint.

5. The printed board after the three prevention measures should be clean and tidy, without any damage to components.

In addition, there are no defects such as dirt, fingerprints, ripples, shrinkage holes, dust, and foreign objects on the board and components, and there is no powdering or peeling phenomenon. Alright, the above are the process requirements for the three proof paint that I have brought to you. Let's go and buy it now.