Conformal Coating, also known as circuit board protective adhesive, is coated on the surface of the circuit board to form a film of a certain thickness, which is used to protect the circuit board and its related devices from the erosion of harsh environments. Under conditions such as chemicals (eg fuel, coolant, etc.), vibration, moisture, salt spray, humidity and high temperature, the circuit board may corrode, grow mold and create short circuit, etc., which can lead to circuit board failure. Conformal coating film can effectively protect the circuit from the erosion of chemicals, moisture and other contaminants, thereby improving the reliability of the circuit board, increasing its safety factor, and ensuring its service life. Conformal Coating can be widely used in the protective coatings for (flexible, rigid) circuit boards, aviation instruments, computer control panels, industrial control panels, semiconductor circuit protection, home appliance controllers and other electronic parts and various circuits.