Now, Parylene is the best protective coating in electronic, aerospace and medicinal fields. In normal condition, most of protective coatings are liquid, but Parylene is one kind of high pure powder called as dimer, without liquid phase. It can form a film by aerification and crack on the surface of parts, this film is thin and spreading shape, without any pinholes, thus this film cab resist organic solvents, inorganic solvents, strong acid, strong alkali and oxidization (prevent parts from air). .Parylene can be used in electrical insulation, moisture-proof, chemicals-proof, mechanical protection, polish, surface reinforcement and coating protection, including printed plate board, SMD, microelectronic semiconductor, medical appliance, cultural relic protection and textile industry, etc.