LEDs
In the environment of pressure, extreme temperature cycle, humidity, ultraviolet radiation, etc., the aviation LED needs the protection of Parylene coating even more. Vapor deposition ensures the formation of a complete, ultra-thin and uniform coating on any shape surface, which avoids the effect of internal stress on the circuit and properties of the coating under temperature alternating conditions. It has excellent barrier and protection ability in the bad environment such as water vapor and salt mist, thus increasing the life of LED products and reducing the failure cost.
Parylene maintains room temperature during the deposition process and is solvent free, catalyst and plasticizer in the coating process. The meniscus, sedimentation or bridging of the liquid coating does not occur during the vapor deposition process. The growth of Parylene coating molecules not only forms a uniform conformal coating of a specific thickness, but also penetrates into each gap, ensuring complete packaging of the substrate, the coating is resistant to ultraviolet rays, and optical transparency also ensures the brilliant light of the LED.
Outdoor display has increasingly become a new favorite in the advertising industry, and its unique application environment required high reliability of the coating. The hydrophobic nature of Parylene surface makes it difficult to absorb moisture in the air. Vacuum coating can form a complete, ultra-thin, completely uniform coating on any shape surface without "blind zone". The coating is guaranteed to have no defects like cracks or pinholes, so the material performance advantage can be maximized, which is the preferred material for outdoor LEDs.
Parylene is a good alternative to heavy liquid coatings and potting materials. It is very thin, light weight, with good moisture, chemical and dielectric barrier property. In addition, Parylene F provides unparalleled stability in high temperature and ultraviolet environments, providing maximum protection for LED applications.
Parylene can effectively resist all kinds of chemical corrosion, electrochemical corrosion and mold damage, and has been listed in the U. S. standard MIL-I-46058C. The transmittance of water molecules is very low, which is only 1/1000 of the common organic silicone resin, and the surface hydrophobicity further reduces the adverse effects of moisture and ion pollution.
