Synthesis and characterization of a novel addition silicone resin for high power LED packaging

The phenyl vinyl silicone pre-polymer was synthesized by phenyltrimethoxysilane, dimethyldimethoxysilane, methylvinyldimethoxysilane and hexamethyldisiloxane. The additional silicone resin has been cured with vinyl silicone pre-polymer and hydrogen silicone at a certain temperature, where chloroplatinic acid was used as catalyst. The influence of the structure of vinyl silicone pre-polymer and hydrogen silicone on the properties of silicone resin was studied by tensile test, impact test, light transmittance test, scanning electron microscopy, thermal gravimetric analysis, and so on. The results show that the tensile strength and heat resistance of the silicone resin can be improved by increasing the vinyl content of the vinyl silicone pre-polymer resin. With the increase of PhSiO_3/2 chain content in the vinyl silicone pre-polymer resin, the tensile strength of silicone resin first increases and then decreases, and the transmittance of silicone resin decreases gradually. Compared with the straight-chain hydrogen silicone, containing branched-chain hydrogen silicone had better compatibility with the matrix, and the tensile strength and the light transmittance of the silicon resin were increased by 202% and 485% respectively. A kind of addition silicone resin with high refractive index (1.52), tensile strength (6.28MPa), Shore D hardness (64), impact strength (15.61KJ/m²) and good transmittance of more than 91% at wavelength of 400nm was prepared, which is suitable for LED packaging.