The Investigation On Modifying Organic Silicon Adhesive For Encapsulation By Ceria-based Nanometer Oxide

Light Emitting Diode (LED) has become the fourth generation of lighting devices that greatly promoted in China, because of its green, environmental protection and energy efficient as well many other advantages. With the fast development of high power white LEDs, people need better LED packaging material. Developing encapsulation resin with excellent properties has become the focus of technology research related to LED downsteam industry. Organic silicone encapsulating resin could own higher refractive index together with enhancement of heat-resisting and ultraviolet (UV) resistance abilities with the filling of inorganic nanometer material. The significance of this thesis is improve anti-ultraviolet aging ability of the market organic silicone encapsulating materials, in the premise that have not affect LED’s luminous efficiency. We chose ceria-based nanometer oxides as modifying agent that possessed admirable UV absorbing effect and low photo-catalytic capability as much as possible. We studied the impacts of composition and content of nanomaterials for LED’s luminous efficacy and UV shielding ability, which were packaged by modified silicone packaging materials. The work of this paper is as follows:(1) Synthesized nano cerium oxide (CeO2) has the function of improving silicone resin. CeO2were prepared by precipitation method, sol-gel route and microemulsion process, and we investigated their morphology and UV absorption performance. Sol-gel technique was intended to be optimal choice for preparation of CeO2nanomaterials about resin modification. We inspected the effects of production factors on the products size distribution and UV defending capability. CeO2particles were about56nm in diameter and own the strongest UV absorption ability, under the optimum baking temperature600℃.(2)Adjusted and controlled anti-UV and photocatalytic properties of CeO2by doping metal ions. We investigated the role of ions’density on UV shielding and light catalytic ability in nanometer CeO2, which doping calcium ions and zinc ions and prepared by sol-gel method. UV absorption peaks appeared when Ca ions content is50mol%and Zn ions content is30mol%. In addition, doping with calcium element can effectively reduce the photocatalytic activity of CeO2.(3) Examined the influences of luminous efficacy and UV defending ability for LED packing by modified materials. Added cerium based oxide nanoparticles into organic silicone resin by directly blending, we studied the influence of doping ions’species and content of modified rosin on LED’s luminous efficiency. With modifying, silicone resin’s functions in thermal stability and UV resistance enhanced. The luminous efficacy of modified materials packaging LED had been increased1—3lm/W than the pure silicone glue encapsulating one. In addition, UV-light protective ability of LED would be reinforced by filling nanometer oxides in silica rosin.