Conformal Coating
Conformal coating is a polymer layer that is applied to the surface of an assembled printed circuit board (PCB). It shields the PCB from environmental pollutants like moisture, dust, salt spray, chemical, and temperature variations, which can all have an impact on the reliability and life of an electronic product.
Applications of Conformal Coatings
Moisture and Mildew Protection
Conformal coating on the circuit surface acts as an excellent barrier for moisture and air borne contaminates and it prevents shorting and corrosion due to moisture.
Dust and Shock Protection
The application of the product on the component surface ensures that the component is held firmly to the substrate, protecting it from vibration and preventing entry of dust, which results in a clean circuit surface free from contamination.
Chemical Corrosion Resistance
The circuit can resist corrosion caused by chemical gas, oil, salt spray and other substances because of the protect layer, which is conducive to circuit protection.
Improved Insulation Performance
Improves insulation properties to avoid short circuit or malfunction due to moisture or dust inside of the system.
Extended Service Life
Stable and reliable performance of electronic products exposed to severe environments such as high temperature, high humidity, and vibration, which can effectively prolong the running time of equipment.
Conformal Coating Process Flow
Pretreatment
The PCB surface must be cleaned well for dust, residue of flux, grease and any other contaminant before spraying. With this excellent wettability, the coating not only has strong adhesion, but also can form a uniform protective film.
Masking and Protection
Apply specialized tape or use masking covers for connectors, sockets, test points, and any other location that should not be coated. This avoids the material of the coating to run into working areas.
Selection of Coating Method
Select suitable installation method considering product design, process needs, production volume, and product features:
- Spray Coating:Good-fit for medium / large production, uniform in application.
- Dip Coating:Offers complete protection and covers the entire PCB.
- Brush Coating:Ideal for small batches or localized repair work.
- Fully Automated Selective Coating:Utilizes automated equipment for precise control, ensuring stable, high-quality, and high-standard production.
Curing and Drying
After coating, the boards are cured by heating or with UV light. During solvent evaporation the coating layer builds up a strong protective layer. Various coating materials need to be cured under different conditions.
Inspection and Testing
Finally, the coating thickness, coverage uniformity and adhesion are checked by visual and functional inspection. So the protective result satisfies design.
Characteristics of common coating types
Acrylic coatings
Dries quickly, good workability; can be reworked and scraped; adapted to neutral environment of outdoors and indoors.
Silicone Coating
The heat resistance is excellent (-60 ~ 200°C), and moisture proof and salt spray proof. Applicable: For product in the harsh environment for a long time. Specially formulated for items that are subjected to severe conditions.
Polyurethane coating
It has very high resistance to chemical corrosion, toughness and strong adhesion, is difficult to repair, but can supply long- term protection. It is best for industrial electronic equipment, aircraft, ship and so forth.
LingKey’s Conformal Coating Capabilities
LingKey is your one stop shop for professional conformal coating service solutions for high-reliability electronics assembly in many industries. With state-of-the-art machinery, rigorous quality assurance, and veteran engineering teams, we ensure each PCB is provided with the best environmental protection.
Advanced Coating Equipment
Selective coating machines are fully automated and designed for accurate dispensing, controlled coating patterns, and uniform film thickness. This means accuracy even for complicated PCB layouts.
Multiple Coating Materials Supported
Acrylic, silicone, polyurethane, UV-curable coatings – carefully chosen for your product’s environment and the performance needs.
Strict Pre-Coating Preparation
Surface cleaning, plasma treatment (optional), full masking and other procedures are applied by LingKey to ensure adhesion of the coating and quality of coverage.
UV & Automated Inspection
Every coated board is subjected to UV inspection, AOI inspection and random cross-sectioning to make sure the coating is free of defects and that the film thickness is accurate.
High-Reliability Standards
Our coating services comply with:
- IPC-CC-830
- UL94V-0 (for compatible coatings)
- RoHS / REACH Environmental Standards
Full Manufacturing Integration
Conformal coating is part of LingKey’s end-to-end PCBA manufacturing process from PCB fabrication, SMT assembly, testing, coating, guaranteeing stable quality and fast response.
Conclusion
Conformal coating is essential for extending the life, safety, and dependability of contemporary electronics. With advanced coating technology, rigorous quality control and over 10 years professional engineering experience at LingKey, we can provide high performance protective solution for high demand applications. Whether your products are used in industrial, automotive, medical or even outdoor applications, Lingkey offers dependable conformal coating services to help guarantee your products will maintain long term stability and performance.
