- 學位論文
具不同型態螢光粉之白光發光二極體信賴性之探討
The Investigation of Reliability of White Light Emitting Diode with Different Types of Phosphors
摘要
面對能源供應即將短缺與過度碳排放的問題，努力節能減碳是大家的共識；有鑑於全球能源短缺與碳排放問題日益嚴重，大家都應響應並親身力行節能減碳，發光二極體(light emitting diode; LED) 優點有反應速度快、體積小、電省、污染低、適合量產，其元件容易配合應用在體積小的組裝等，可以解決過去白熾燈泡所難以克服的應用問題，是兼具省電與環保概念的新照明光源選擇。 本論文中採用四種型態之螢光體，分別為YAG(Yttrium Aluminum Garnet, Y3Al5O12；釔鋁石榴石)、TAG(Terbium Aluminum Garnet,Tb3Al5O12；鋱鋁石榴石)、矽酸鹽類、氮氧化物。利用分析儀器來了解螢光體特性，例如：光激發光光譜儀、掃描式電子顯微鏡、能量分散光譜儀、粒徑分析儀等。選用一種尺寸為實驗封裝平台，單顆晶片矽膠封裝、烘烤後，確認成品初始的發光效率，搭配選擇不同溫度與濕度環境的信賴性實驗，利用光通量量測儀可以量測出光衰退程度等重要數據，針對發光二極體信賴性與不同型態螢光粉之間相關分析探討。 YAG、TAG結構的螢光粉譜形之半波寬最大，實封後演色性表現較佳，合適應用於照明產品上；而矽酸鹽類譜形之半波寬較窄，實封後演色性較差，可運用在不計演色性數值的背光產品中。粒徑分佈波形越窄表示粒徑分佈趨勢集中，在封裝體量產時，其產出分佈之落Bin集中，相對能提高產出於規格內。 由於矽酸鹽類、氮氧化物類的組成成分中包含Sr元素，此元素對濕度、溫度敏感，故建議將此兩類型螢光粉運用在背光模組產品為佳。針對粉體外觀型態、粒徑大小、組成元素與封裝後的產品信賴性之間相關性，還需要在更深入的分析與改善。
並列摘要
It has been a common view to work on energy efficiency and carbon reduction while facing the issue of energy supply shortage and excess carbon emission. In response to the worse problem of global energy shortage and carbon emission, everyone should take some actions of energy efficiency and of carbon emission reducing. The advantages of LED are quick response, small size, energy saving, electricity saving, low pollution and could be made in mass production. Besides, the LED can be easily assembled on small components, which solved the formidable issue of white bulb applied in the past. It is the new lighting choice including environment protection and electricity saving. There are four types of phosphor. YAG (Y3Al5O12), TAG (Tb3Al5O12), Silicate, Oxy-nitride respectively. We use equipments to analyze the specialty of the phosphor. That is including some information photoluminescence (PL), scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDX), Beckman Coulter Multisizer. We have chosen as one package size, then checked it before reliability test and collected the first data of luminous flux by integrating sphere. We can set difference temperature and humidity conditions of reliability test. And then collected the data luminous flux, value (X,Y), decay state etc after reliability test. We can compare difference phosphor and reliability of LED. For YAG, the half band width of its spectrum is the widest. After being packaged, the CRI is better, which is more suitable for lighting products. As for Silicate, the half band width of its spectrum is narrower, which can be used for backlighting products that CRI will not be taken into consideration. The wave pattern is narrower; the distribution of the particle size will be more centralized. Namely, after being packaged, the main production delivery distribution will be more focused, which means the possibility to produce within spec products would be much higher. For both Silicate and Oxy-nitride, Sr is one of the elements contained. Since this element is sensitive to humidity and temperature, it would be better to use these two kinds of phosphor in backlighting products. For the relationship among package reliability, phosphor’s surface, particle size, and composed elements, more studies would be necessary.