What is Coating
Coating is the application of a protective film or layer onto a circuit board. This film, known as a conformal coating, acts as a barrier between contaminants and the board, providing insulation and safeguarding the PCB surface. Conformal coatings are typically in a liquid state before application and can be made from various materials such as acrylics, polyurethanes, silicons, epoxy, or combinations of resins.
Coating enhances the durability and reliability of the PCB by preventing environmental damage and corrosion, ultimately extending its working life. It is applied using different methods, including automated robotic spray nozzles or selective coating, depending on the specific assembly areas and requirements of the board. Selective coating, for instance, is a high-volume method that accurately applies the coating directly to the areas of the board where it is needed, eliminating the need for masking.
The conformal coating acts as an insulation layer and protects the PCB surface from contaminants by creating a protective layer. It is designed to conform to the shape of the board and its components, covering and protecting solder joints, exposed traces, leads of electronic components, and other metallized areas. This thin polymeric film, typically applied at 25-250µm, not only provides corrosion resistance but also extends the working life of the PCB.