隨著發光效率的提升，LED目前已大量用於一般照明。然而，在傳統的散熱方法之下，高功率LED燈具仍然難以克服晶片溫度過高的缺點，導致晶片的效能與壽命均有明顯的衰減，因此熱管理對於LED的應用成為核心關鍵。
本文利用有限元素法進行高功率LED燈具的熱分析，首先對垂直結構晶片內的錫金銲料厚度於四種燈具結構的晶片溫度與熱應力之變化趨勢做比較，根據模擬的結果選出較佳的厚度範圍與結構設計。之後分析均溫板在不同尺寸下所造成的熱傳導係數差異對於系統之影響。最後利用田口式直交表實驗法將所有設計參數直交組合，得到一系列的結果值，並與初步的分析結果作對照討論，嘗試找出最佳化設計。
本文提出以田口法來改善LED燈具的品質特性，以實驗的方法測定各項控制因子對於燈具效能的影響程度。針對不同的功能需求，可利用本文的方法制定一實驗規劃，進而得到理想的產品設計規格。
　　
關鍵字：有限元素法、高功率LED燈具、田口式直交表實驗法

Due to the improvement of luminous efficiency, LED has been applied in general lighting nowadays. However, the efficacy and life of high power LED lamps are degraded for the problem of overheat temperature of the chips. In accordance with the above reason, the thermal management has been important in LED application.
The thesis aims to analyze the thermal problem of high power LED lamp by FEM. In the beginning, we analyzed the temperature curves and thermal stress curves of chips by changing the thickness of AuSn solder in 4 structures. According to the results, the better thickness range and structures were chosen. In the second step, the effect of different sizes of a vapor chamber on the different thermal conductivities of lamp system was discussed. Finally, we orthogonalized all the designed parameters by Taguchi orthogonal array method, and then found the optimal design by comparing the results with the initial analyses.
In this study, we proposed a solution to improve the quality characteristics of LED lamp by Taguchi method. So the effect of each control factors on the performance was able to be determined. For different features of demand, the present study is helpful to achieve the ideal design in manufacturing.

Key words: FEM, high power LED lamps, Taguchi orthogonal array method

謝詞 i
摘要 ii
Abstract iii
目錄 iv
圖次 vi
表次 ix
第一章 緒論 1
1-1 前言 1
1-2 LED 的優點 2
1-3 文獻回顧 3
1-4 研究動機 5
第二章 理論基礎 6
2-1 熱傳遞理論 6
2-1-1 熱傳導公式 6
2-1-2 熱對流公式 7
2-2 鰭片方程式 7
2-3 von-Mises 降伏應力準則 11
2-4 有限元素法 12
2-5 LED 封裝介紹 13
2-6 熱管與均溫板原理 17
2-6-1 熱管介紹 17
2-6-2 均溫板介紹 18
2-7 實驗設計方法 21
第三章 研究方法與分析流程 23
3-1 LED 燈具模型建立 23
3-2 基本假設與分析流程 25
3-3 實驗方法與燈具設計 27
3-4 模型之材料參數 30
3-5 模擬設定 33
3-5-1 熱源與熱傳遞條件 33
3-5-2 應力場與結構拘束條件 35
3-6 有限元素模型 36
第四章 結果與討論 40
4-1 散熱系統設計分析 40
4-1-1 元素量之收斂性分析 40
4-1-2 結構設計與溫度場關係 43
4-1-3 結構設計與應力場關係 48
4-2 均溫板之設計選擇 51
4-2-1 均溫板尺寸與等效熱傳係數關係 51
4-2-2 均溫板尺寸對性能之影響 53
4-3 田口式直交表實驗設計法 56
4-3-1 實驗因子水準值 56
4-3-2 各參數之因子反應分析 58
第五章 結論與後續研究工作 65
5-1 結論 65
5-2 後續研究工作 66
參考文獻 68

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