Conformal coating material is a thin polymeric film which conforms to the contours of a printed circuit board to protect the board’s components. Typically applied at 25-250 μm (micrometres) thickness, it is applied to electronic circuitry to protect against moisture, dust, chemicals, and temperature extremes.
Coatings can be applied in a number of ways, including brushing, spraying, dispensing and dip coating. Furthermore, a number of materials can be used as a conformal coating, such as acrylics, silicones, urethanes and perylene. Each has their own characteristics, making them preferred for certain environments and manufacturing scenarios. Most circuit board assembly firms coat assemblies with a layer of transparent conformal coating, which is lighter and easier to inspect than potting.