High refractive index adamantane‐based silicone resins for the encapsulation of light‐emitting diodes

摘要

>The encapsulation of high power light emitting diode (LED) needs the silicone resins to have relative high refractive index and thermal‐aging properties. Herein, high refractive index adamantane‐based phenyl epoxy‐silicone (APES) resins for LED encapsulation were synthesized by the sol‐gel condensation of 1‐adamantane methanol propyltrimethoxysilane‐3‐urethane, γ‐(2,3‐epoxypropoxy)propytrimethoxysilane and diphenylsilanediol. These adamantane‐based silicone resins have multifunctional groups including adamantyl group, phenyl group, and epoxy group in order to meet the various requirements for LED encapsulation. Importantly, the adamantane group in the silicone resins benefits for high refractive index and anti‐thermal properties. These APES resins were characterized by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. When APES resins were cured by methylhexahydrophthalic anhydride, they showed relatively high refractive index of 1.56, high hardness, and high thermal resistance. The encapsulated LED demonstrated high adhesion properties by red‐ink tests. These merits make adamantane‐based silicone resins promising candidates as LED encapsulation materials.