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(micrometers) thickness, it is applied to electronic circuitry to act as protection against moisture, dust, chemicals, and temperature extremes that, if uncoated (non-protected), could result in damage or failure of the electronics to function. When electronics must withstand harsh environments or impact, protection is provided with conformal coatings or potting compounds. Most circuit board assembly houses coat assemblies with a layer of transparent conformal coating, which is lighter and easier to inspect than potting.
Because of the vast range of electronics in today's world, a printed circuit board is expected to perform in a huge range of environments. Circuit boards then are exposed to a vast array of different conditions such as moisture, salt, chemicals and temperature changes to name but a few, conformal coatings are designed to protect the electronic components from these varying conditions and prevent the board from corroding.More recently, conformal coatings are being used as a mitigation to reduce the potential of whiskers