Study on the Luminous Efficiency of Different White LED Packaging Structure

• Main Authors: Yuan-Ting Chang, 張媛婷
• Other Authors: 唐自標
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/8tnb97

碩士 === 國立臺北科技大學 === 材料及資源工程系研究所 === 101 === White LED is with simple process, low cost, and easy to mass production, so this is popular to use. For current now, this is used in lighting product, back light of display, light source of commutation electronic product etc…, however there are still thermal radiating, reliability not so good, and optical efficiency too low problems exist. This experiment is considered LED chip thermal radiating and side of LED chip light output problems, so select different thermal conductivity and higher optical output dies mount glue. Also add different curing conditions of encapsulation material to find out the best reliability solution, and then fixed these materials and curing conditions. Consider the phosphor efficiency; bottom side phosphor emission light would be blocked by top side phosphor particles, so did different phosphor layer position of LED package experiments, and then analysis to get the best efficiency method. For the experiment result, die mount glue was used transparent silicone and silver epoxy, transparent silicone got better result in long time burn-in and thermal shock test. Curing conditions of epoxy is used 120 ℃/2hours, 120℃/2hours+150℃/4hours, and 120℃/2hours+150℃/8hours. From 7 items reliability tests result, the best curing condition is 120℃/2hours+150℃/4hours. For phosphor layer position experiment, there were all phosphors, bottom side phosphor layer and top side transparent epoxy, and top side phosphor layer and bottom side transparent. Used Gauss’s function to analysis, the best efficiency is bottom side phosphor layer and top side transparent epoxy.