Conformal coatings
Conformal coatings are used to protect electronic assemblies from environmental damage, including moisture, chemicals, dust, and temperature variations. Each type of conformal coating has unique properties, advantages, and application areas. Below is a comparison of silicone conformal coating, UV-cured conformal coating, and acrylic conformal coating, along with guidelines for product recommendation.
How to Choose the Right Conformal coating?
Silicone Conformal Coating
- Properties:
- High flexibility and elasticity.
- Excellent thermal stability (operates in a wide temperature range, typically -55°C to +200°C or higher).
- Outstanding moisture and chemical resistance.
- Moderate dielectric strength.
- Applications:
- Electronics exposed to extreme temperatures (e.g., automotive, aerospace, outdoor equipment).
- Environments with high humidity or chemical exposure.
- Components requiring mechanical stress relief.
- Advantages:
- Long-lasting protection in harsh environments.
- Excellent adhesion to a variety of surfaces.
- Tolerant to thermal cycling.
UV-Cured Conformal Coating
- Properties:
- Rapid curing under UV light (seconds to minutes).
- High clarity and smooth finish.
- Good abrasion and scratch resistance.
- Moderate thermal resistance (temperature range usually up to 120°C-150°C).
- Applications:
- High-volume manufacturing where fast throughput is critical.
- Electronics that require clear coating for visual inspection or optical clarity.
- Boards with tight tolerances needing a precise coating thickness.
- Advantages:
- Extremely fast curing, ideal for automated processes.
- Low energy consumption during curing.
- Easily repairable in certain formulations (via localized UV or manual removal).
Acrylic Conformal Coating
- Properties:
- Moderate thermal resistance (up to 125°C-150°C).
- Good dielectric properties and moisture resistance.
- Easy to apply and repair (removable with solvents).
- Applications:
- Consumer electronics and general-purpose applications.
- Boards operating in moderate environments (indoor use, controlled temperatures).
- Cost-sensitive projects.
- Advantages:
- Simple application process (spray, dip, or brush).
- Cost-effective and readily available.
- Good balance of protection and ease of repair.
- High temperature, high humidity, or chemically aggressive environments: Silicone conformal coating is the best choice.
- Mass production with fast curing needs: UV-cured coatings are optimal.
- General-purpose use in moderate environments: Acrylic coatings offer a cost-effective solution.
For boards that may require frequent repairs, recommend silicone coatings designed for easy removal.
- If the facility lacks UV curing equipment, UV-cured coatings may not be feasible.
- Silicone and acrylic coatings are more versatile in terms of application methods.
- Some applications (e.g., medical or military electronics) may require specific certifications or adherence to standards, influencing the choice of coating.
