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http://dx.doi.org/10.4191/kcers.2014.51.6.533

Effect of Heat Treatment Temperature and Coating Thickness on Conversion Lens for White LED  

Lee, Hyo-Sung (Optic & Display Material Team, Korea Institute of Ceramic Engineering and Technology)
Hwang, Jong Hee (Optic & Display Material Team, Korea Institute of Ceramic Engineering and Technology)
Lim, Tae-Young (Optic & Display Material Team, Korea Institute of Ceramic Engineering and Technology)
Kim, Jin-Ho (Optic & Display Material Team, Korea Institute of Ceramic Engineering and Technology)
Jung, Hyun-Suk (Department of Materials science and Engineering, Sungkyunkwan University)
Lee, Mi Jai (Optic & Display Material Team, Korea Institute of Ceramic Engineering and Technology)
Publication Information
Journal of the Korean Ceramic Society / v.51, no.6, 2014 , pp. 533-538 More about this Journal
Abstract
Today, silicon and epoxy resin are used as materials of conversion lenses for white LEDs on the basis of their good bonding and transparency in LED packages. But these materials give rise to long-term performance problems such as reaction with water, yellowing transition, and shrinkage by heat. These problems are major factors underlying performance deterioration of LEDs. In this study, in order to address these problems, we fabricated a conversion lenses using glass, which has good chemical durability and is stable to heat. The fabricated conversion lenses were applied to a remote phosphor type. In this experiment, the conversion lens for white LED was coated on a glass substrate by a screen printing method using paste. The thickness of the coated conversion lens was controlled during 2 or 3 iterations of coating. The conversion lens fabricated under high heat treatment temperature and with a thin coating showed higher luminance efficiency and CCT closer to white light than fabricated lenses under low heat treatment temperature or a thick coating. The conversion lens with $32{\mu}m$ coating thickness showed the best optical properties: the measured values of the CCT, CRI, and luminance efficiency were 4468 K, 68, and 142.22 lm/w in 20 wt% glass frit, 80 wt% phosphor with sintering at $800^{\circ}C$.
Keywords
Remote phosphor; White LED package; Color glass; Coating thickness; Conversion lens;
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Times Cited By KSCI : 1  (Citation Analysis)
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