Preparation of Silanes Modified Zirconium Dioxide/Silicone Resin Composite Materials and Its Evaluation on LED Encapsulating Materials
Date Issued
2014
Date
2014
Author(s)
Li, YEN-HSIEN
Abstract
In this research, the main purpose is the development of high refractive index and reliable encapsulating material of light emitting diodes (LEDs).
Zirconium dioxide (ZrO2) nanoparticles with high refractive index are synthesized by sol-gel reaction of zirconium propoxide in suitable solution. Acetic acid is used as chelating agent to control the particle size of ZrO2 and then the surface of ZrO2 is modified by silane molecule to provide the linkages between the water phase of ZrO2 and the oil phase of silicone resin. The ZrO2-silane particles are subsequently mixed with commercial-grade silicone resin to obtain the ZrO2-silane/silicone hybrid materials (ZrO2-silane/AB). These high-refractive-index ZrO2-silane/AB hybrids are used as encapsulating materials to improve the luminous flux of the LEDs. From the result of the luminous flux measurement, the LED encapsulated with the pure silicone resin only has luminous flux of 4.11 lm. After being encapsulated with the ZrO2-silane/AB hybrid, the luminous flux of the LED raises to 4.52 lm, which reveals that increasing in the refractive index of the encapsulating materials by the incorporation of the ZrO2-silane can improve the luminous flux of the LED. The results of Dynamic Mechanical Analyzer and Thermal Mechanical Analyzer on ZrO2-silane/AB hybrids tell us that the ZrO2-silane/AB hybrids have lower thermal stress than that of ZrO2 /AB hybrids. We believe that encapsulating materials with lower thermal stress have a better mechanical resistance against the thermal shock .The result of thermal shock experiment also shows that LED encapsulated with ZrO2-silane/AB hybrids have better reliability than the ZrO2 /AB hybrids.
Subjects
LED封裝材料
無機/有機複合材料
二氧化鋯
矽烷
表面改質
Type
thesis
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