Synthesis And Properties Of High Performance Silicone Materials For LED Encapsulation

With the development of high-power LED,synthesis of high-performance LED encapsulation materials has become the focus of current research.Silicone resin is gradually replacing the widely used epoxy resin in the high-requirement packaging field,but it still has some defects.The modification of the silicone resin can make it more excellent performance and meet the demanding requirements of LED encapsulation.This paper focuses on the preparation of high performance adamantane modified silicone resin for LED encapsulation by introducing amantadane and epoxy group into the molecule.The main research contents are shown as follows:1-adamantane methanol propyltrimethoxysilane-3-urethane was synthesized via the reaction between 1-adamantane methanol and 3-isocyanatopropyltrimethoxysilane.Then,adamantane-based phenylvinyl polysiloxane for LED encapsulation was synthesizedbythesol-gelcondensationof1-adamantanemethanol propyltrimethoxysilane-3-urethane,diphenylsilanediol and vinyltrymethoxysilane.Finally,a high refractive index adamantane modified silicone material for LED encapsulation was prepared by the hydrosilylation of the APVS resin and methylphenyl hydrogen-containing silicone resin.The modified material exhibited high refractive index(about 1.57),high hardness(50 D~59 D),high transparency(above 80%in the range of 400~800 nm)and excellent thermal-aging property(small change after thermal aging at 150~°C for 48 h)and excellent thermal stability.A series of adamantane-based phenyl epoxy-silicone resins with different adamantane contents and epoxy value were were synthesized by the sol-gel condensation of 1-adamantane methanol propyltrimethoxysilane-3-urethane,γ-(2,3-epoxypropoxy)propytrimethoxysilane and diphenylsilanediol using barium hydroxide monohydrate as a catalyst.The adamantane-based phenyl epoxy-silicone resins were cured with methylhexahydrophthalic anhydride.The obtained encapsulation materials have high refractive index(about 1.56),good transmittance,high hardness(61 D~71 D),good adhesive property with LED lead frame,low water absorption rate(minimum 0.2%after immersing for 168 h),good thermal-aging property and excellent thermal stability(the temperature of 5%weight loss was283~360~°C).It is expected to be used in the field of LED encapsulation field.