Parylene is fabricated by a unique vacuum vapor deposition (CVD) process, in which small active molecules "grow" on the surface of the substrate to produce a fully coated polymer film coating, which can be applied to various shapes of surfaces, including sharp edges. It is known as "all-in-all" and can penetrate into cracks and inner surfaces. The 0.1-100 micron film coatings deposited at room temperature under vacuum condition have uniform thickness, compactness, no pinholes, transparency, no stress, no additives, no damage to the workpiece, excellent electrical insulation and protection, and are even called the world's top moisture-proof, mildew-proof (zero grade), anti-corrosion and salt fog-proof special protective coatings.
The preparation process of poly (p-xylene) is vacuum vapor phase film forming method. The cyclic dimer of p-xylene is heated and vaporized, then pyrolyzed at high temperature to form a double free radical gas, which is directly condensated and polymerized into a film-forming chamber under vacuum conditions.The preparation process of poly (p-xylene) is vacuum vapor phase film forming method. The cyclic dimer of p-xylene is heated and vaporized, then pyrolyzed at high temperature to form a double free radical gas, which is directly condensated and polymerized into a film-forming chamber under vacuum conditions.
Dimer vaporization - - - cracking ring opening - - - polymer Parylene is a general term for a series of polymers. According to the different molecular structures, Parylene can be divided into N, C, D, HT and other types. At present, our company has developed four kinds of powder: N, C, D and HT.
Parylene N poly (p-xylene) has the strongest permeability and can effectively form thin films on various slits or blind holes. Its dielectric constant is very low (2.65) and dissipation factor is small, and changes little with the increase of external frequency. At the same time, it has the best lubrication effect, mainly used in rubber and optical fields.
Parylene C substitutes chlorine atom for hydrogen on aromatics, has very low permeability of water molecules and corrosive gases, and its deposition growth rate is much faster than that of N-type. It is the most widely used powder with the best protective effect at present.
Parylene F can replace SCS HT powder and has flame retardancy. It has relatively better physical and electrical properties at higher temperatures, and has better thermal stability and anti-UV ultraviolet radiation compared with N and C type. It is especially suitable for outdoor LED three-proof use.