1. Product Description

UV40 is designed to protect printed circuit boards operating in harsh environments. It provides excellent high- and low-temperature resistance, weather resistance, electrical insulation, and conformal protection against moisture, salt spray, and fungal growth.

The product contains a fluorescent UV tracer for convenient coating inspection under ultraviolet light. It is fully compliant with the requirements of the EU RoHS Directive.

2. Product Features

2.1. Environmentally friendly, solvent-free, and low-odor formulation. The coating rapidly becomes tack-free under UV irradiation and subsequently completes its secondary moisture cure through exposure to ambient moisture. It offers fast curing and convenient application and is suitable for spraying, brushing, dipping, and other coating processes.

2.2. Provides good adhesion to most materials and does not corrode the substrate.

2.3. Offers excellent high- and low-temperature resistance, weather resistance, electrical insulation, moisture resistance, fungal resistance, salt-spray resistance, corrosion resistance, and resistance to electrical leakage and tracking.

2.4. Provides long-lasting protection for printed circuit boards and electronic components, thereby extending their service life.

2.5. Allows direct soldering through the protective coating for convenient rework and repair.

3. Typical Applications

UV40 is widely used for protecting electronic components and fully assembled printed circuit board assemblies. It provides effective protection against chemical corrosion, salt spray, moisture, heavy dust and contamination, vibration, and extreme temperatures without adversely affecting circuit operation or signal transmission.

4. Curing Conditions

4.1. Mixing and Preparation

Stir and degas the product at 40–60°C while protecting it from light. Avoid contact with moisture and hydroxyl-containing contaminants.

4.2. Recommended Coating Thickness by Protection Level

• Below 30 μm: Provides basic moisture protection and limited electrical insulation. It is not suitable for salt-spray exposure and offers limited chemical resistance.

• 30–80 μm: Provides moisture protection, electrical insulation, and general salt-spray resistance. It is recommended for most conventional PCB applications.

• 80–120 μm: Provides enhanced salt-spray resistance, chemical resistance, and vibration resistance. It is recommended for automotive and industrial applications.

• Above 150 μm: Increased risk of cracking and excessive internal stress. Use only for special heavy-duty outdoor applications.

4.3. UV Curing

• Wavelength: 365 nm

• UV energy dose: 1,000–1,500 mJ/cm²

• Peak irradiance: 80–120 mW/cm²

• Exposure time: 30–60 seconds

4.4. Post-Curing

Post-cure at 80°C for 30–60 minutes to improve the degree of cross-linking and coating stability.

5. Typical Properties Before And After Curing

The values shown above are typical data and should not be interpreted as product specifications unless otherwise agreed in writing.