What Are the Methods of UV Coating?

UV coating, also known as UV conformal coating or UV three-proof glue, is a type of coating commonly used in the electronics industry to protect circuit boards from environmental damage. The application methods of UV coating mainly include the following types:

Brush Coating

Description: This method involves using a brush to apply the coating evenly onto the surface of the object.

Advantages: It is widely used and can produce good coating effects on smooth surfaces. It is suitable for coating large-area devices.

Tips: When brushing, the board should be placed as flat as possible. There should be no droplets after brushing, and the brushing should be flat without any exposed parts.

Spray Coating

Description: This method involves using a spray can or spray gun to apply the coating.

Advantages: Spray coating is convenient for small-scale production using spray cans, while spray guns are suitable for large-scale production.

Requirements: High accuracy is required for both spray can and spray gun applications.

Dip Coating

Description: This method involves immersing the object in a coating tank filled with coating material.

Advantages: It ensures complete coating and avoids material waste caused by over-spraying.

Steps: The circuit board components should be vertically immersed in the coating tank. Connectors should not be immersed unless they are carefully covered. The circuit board should be immersed for 1 minute until the bubbles disappear, and then slowly taken out. A uniform film will form on the surface of the circuit board.

Tips: Let most of the coating residue flow back into the dipping machine. The immersion speed of the circuit board or components should not be too fast to avoid generating too many bubbles.

Selective Film Application

Description: This method involves using specialized equipment to apply the coating accurately only to the desired areas.

Advantages: It is accurate and does not waste material, making it suitable for large-batch coating.

Requirements: High requirements for coating equipment.

In addition, here are some general steps and considerations for UV coating application:

Cleaning and Drying: Before applying UV coating, the dust, moisture, and oil contamination on the surface of the object to be coated must be removed to allow the coating to fully exert its protective effect.

Coating Storage: If there is skinning on the surface of the UV coating when it is used again after dip coating, the skin can be removed and the coating can be continued to be used.

Curing: After the UV coating is applied, it should be cured by UVLED curing machine irradiation. If some gaps are not completely cured, the PCB board can be placed to wait for secondary moisture curing.

Overall, the choice of UV coating method depends on factors such as the size and shape of the coated object, production scale, and coating requirements. The above methods have their own advantages and are suitable for different situations.