白光LED不同封裝結構之發光效率研究

Study on the Luminous Efficiency of Different White LED Packaging Structure

張媛婷(Yuan-Ting Chang)

指導教授 ： 唐自標

國立臺北科技大學/工程學院/材料及資源工程系研究所/碩士(2013年)

https://doi.org/10.6841/NTUT.2013.00008

摘要

白光LED，因具有製程簡單、成本低等優點，利於量產，已被大家廣泛使用，LED目前常製作成照明產品、顯示器背光源、通訊電子產品光源等，然而確有產品散熱性及耐候性不佳及發光效率低等問題的存在。
本實驗首先考慮晶片散熱及晶片側向光導出問題，由固晶材料不同挑選出的散熱性質佳或者亮度高的固晶膠。加上封裝材料與固化時間不同搭配的影響，以尋求最佳的可靠度條件。然後固定此固化時間再次考慮螢光粉被激發的光會被其更上層之螢光粉遮蔽，導致發光效率降低；故實驗不同螢光層位置，來分析較佳之螢光膠層位置的封裝方式。
實驗結果顯示，固晶膠分別以透明矽膠及導電銀膠試之，透明矽膠在於出光、長時間點亮及冷熱衝擊下有較優的表現。環氧樹脂的固化條件，分別以120 ℃/2小時、120℃/2小時+150℃/4小時、120℃/2小時+150℃/8小時等三種時間的固化條件，從7項可靠度條件結果可得知環氧樹脂固化條件最佳為120℃/2小時+150℃/4小時，在封裝體螢光層的位置上，分別有全螢光層、底部透明層上部螢光層、底部螢光層上部透明層三種封裝方式。在封裝體螢光層的位置以底部螢光層上部透明層可得最高的發光效率。

關鍵字

LED封裝 ； 螢光粉 ； 發光效率

並列摘要

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.

並列關鍵字

LED Packaging ； Phosphor ； Luminous efficiency

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