I believe most people are familiar with the three-proof paint process. PCB circuit boards treated with three-proof paint offer waterproof, moisture-proof, and dust-proof protection. Additionally, they exhibit excellent resistance to thermal and cold shock, as well as aging. Generally speaking, the three-proof paint processes include brushing, spraying, automatic dipping, and selective coating, each with its own set of characteristics. Choosing the appropriate process depends on the specific requirements of the situation. Spraying three-proof paint is particularly technical. The following sections will cover the requirements, operations, and quality standards for spray painting as outlined by SMT chip processing manufacturers.
1. **Requirements for Painting**
1. **Spray Paint Thickness**: The paint film thickness should be controlled within the range of 0.05mm to 0.15mm, with a dry film thickness of 25μm to 40μm.
2. **Secondary Coating**: To ensure the desired thickness for products requiring high protection, a secondary coating may be applied once the initial paint film has cured (decide whether a secondary coating is necessary based on the specific needs).
3. **Inspection and Repair**: Visually inspect the coated circuit board to ensure it meets quality standards and address any issues. For instance, if the pins or other protected areas are stained with three-proof paint, use tweezers to hold a cotton ball or clean cotton swab dipped in cleaning solution to gently clean the area. Be careful not to remove the proper paint film during cleaning.
4. **Component Replacement**: Once the paint film has cured, if component replacement is necessary, follow these steps: (1) Solder the components directly with an electric soldering iron, then clean the surrounding area of the pad using a cotton cloth dipped in cleaning solution; (2) Replace the components; (3) Use a brush dipped in three-proof paint to coat the soldered area and ensure the paint film dries and solidifies properly.
2. Operational Requirements
1. The three anti-paint workplaces must be clean, dust-free, and well-ventilated. Access should be restricted to relevant personnel only.
2. During operation, wear masks or gas masks, rubber gloves, chemical protective glasses, and other appropriate protective equipment to prevent injury.
3. After work is completed, promptly clean the used tools and securely close and cover the container with the three-proof paint.
4. Implement anti-static measures for the circuit boards. Do not stack the boards; ensure they are placed horizontally during the coating process.
Three, Quality Requirements
1. The PCB surface must be free of paint drips or flows. Avoid dripping paint onto partially isolated areas.
2. The three-proof paint layer should be smooth, bright, and of uniform thickness to adequately protect the surface of pads, components, or conductors.
3. The paint layer and components must be free of defects such as bubbles, pinholes, ripples, shrinkage holes, dust, or foreign objects. Ensure no chalking or peeling occurs. Note: Avoid touching the paint film before it is fully dry.
4. Do not apply three-proof paint to partially isolated components or areas.
5. If conventional non-coatable devices need coating, use the three-proof coating specified by the R&D department or the design drawings.
The above information outlines the three-proof paint spraying process as provided by SMT chip processing manufacturers. Brushing is a common painting method that yields good results on smooth surfaces. Spraying requires precise operation to avoid paint shadows, while automatic dip coating ensures an even film without material waste, making it an excellent option.
1. **Requirements for Painting**
1. **Spray Paint Thickness**: The paint film thickness should be controlled within the range of 0.05mm to 0.15mm, with a dry film thickness of 25μm to 40μm.
2. **Secondary Coating**: To ensure the desired thickness for products requiring high protection, a secondary coating may be applied once the initial paint film has cured (decide whether a secondary coating is necessary based on the specific needs).
3. **Inspection and Repair**: Visually inspect the coated circuit board to ensure it meets quality standards and address any issues. For instance, if the pins or other protected areas are stained with three-proof paint, use tweezers to hold a cotton ball or clean cotton swab dipped in cleaning solution to gently clean the area. Be careful not to remove the proper paint film during cleaning.
4. **Component Replacement**: Once the paint film has cured, if component replacement is necessary, follow these steps: (1) Solder the components directly with an electric soldering iron, then clean the surrounding area of the pad using a cotton cloth dipped in cleaning solution; (2) Replace the components; (3) Use a brush dipped in three-proof paint to coat the soldered area and ensure the paint film dries and solidifies properly.
2. Operational Requirements
1. The three anti-paint workplaces must be clean, dust-free, and well-ventilated. Access should be restricted to relevant personnel only.
2. During operation, wear masks or gas masks, rubber gloves, chemical protective glasses, and other appropriate protective equipment to prevent injury.
3. After work is completed, promptly clean the used tools and securely close and cover the container with the three-proof paint.
4. Implement anti-static measures for the circuit boards. Do not stack the boards; ensure they are placed horizontally during the coating process.
Three, Quality Requirements
1. The PCB surface must be free of paint drips or flows. Avoid dripping paint onto partially isolated areas.
2. The three-proof paint layer should be smooth, bright, and of uniform thickness to adequately protect the surface of pads, components, or conductors.
3. The paint layer and components must be free of defects such as bubbles, pinholes, ripples, shrinkage holes, dust, or foreign objects. Ensure no chalking or peeling occurs. Note: Avoid touching the paint film before it is fully dry.
4. Do not apply three-proof paint to partially isolated components or areas.
5. If conventional non-coatable devices need coating, use the three-proof coating specified by the R&D department or the design drawings.
The above information outlines the three-proof paint spraying process as provided by SMT chip processing manufacturers. Brushing is a common painting method that yields good results on smooth surfaces. Spraying requires precise operation to avoid paint shadows, while automatic dip coating ensures an even film without material waste, making it an excellent option.
