A conformal coating is a thin polymeric film applied to a printed circuit board (PCB) to protect the board and its components from the operating environment and corrosion. The film is typically applied at 25-250µm and ‘conforms’ to the shape of the board and its components, covering and protecting the PCB.
The main purposes of Conformal Coating include:
Improving the electrical properties of the PCB
Protecting the PCB from the harsh operating environment
Contributing to heat dissipation