製備白光LED 均勻出光螢光薄膜之研究

A Study of Fabrication Phosphor Membrane with Even Exit Light

傳統白光LED混膠－－點膠方式，無法控制螢光粉層厚度，經混膠後會產生沉澱；以致於色溫分散不均勻，無法集中、產生黃圈光暈；且螢光粉直接接觸晶片，易出現發熱量過大，螢光粉散熱不良，效率降低，因而提高了製作成本。利用模具真空成膜技術，將螢光粉均勻分散在高透光性、高阻水性及高阻氣性封裝材料中，以模具真空充填乾燥形成螢光薄膜，達到分散均勻、色溫及厚度一致之成果；藉由矽樹脂耐高溫特性、良好機械性質及高柔軟度，可增長螢光粉出光效率之壽命，不受晶片所散發出來的熱所影響；並利用螢光粉光電色綜合性能測試系統、TGA、面板阻隔氧氣、阻隔水氣透過率分析儀等測試儀器驗證本研究之螢光薄膜的物性與光學特性。

The traditional fabrication of white light LEDs involves mixing glue andphosphor powder. This method can’t control glue-phosphor layer thicknessdue to precipitation after thorough mixing of glue-phosphor products. So,the color temperature can’t be dispersed evenly and centrally. Meanwhile,those products also can cause a yellow ring halo, because the phosphorpowder contacts the chip directly. So, glue-phosphor products can cause a lotof heat, bad heat dispersion and low energy efficiency. Therefore, traditionalfabrication of white light LEDs can raise the cost of LEDs.In this study, utilizing a vacuum mould membrane technology, phosphorpowders can be dispersed homogenously, with good water and gas barrierproperties in high photo transmission materials. Also, vacuum mouldphosphor membranes can reach an even dispersion, good color temperatureand uniform thickness. The silicon resin has high temperature endurance,flexibility and good mechanical properties. So, the phosphor membrane canimprove the life-span of the exit light efficiency. Therefore, vacuum mouldphosphor membranes were checked for those photo-electric, barrier, thermaland mechanical properties in this research.