臺灣博碩士論文加值系統

現今可攜式電子產品朝向小型化以及高可撓性的需求發展，為了達到這個目標，超薄晶片於軟板構裝技術(Ultra Thin Chip on Flex, UTCOF)被視為一個有前景且可行的封裝解決方案，原因來自於它的高可撓性，以及相容於目前的半導體封測產業的優勢。這項新技術主要應用的範圍包含了薄如紙的智慧型標籤，特別是無線射頻辨識標籤(RFID)、微型化醫療用電子系統以及堆疊式記憶晶片…等等。
在本篇論文中，將首先介紹此一型UTCOF構裝技術及其製程。這項技術採用了一種以環氧化物為主的異向性導電薄膜(Anisotropic conductive film, ACF)，以建構一個具細微間距且可靠接點的構裝。ACF是一種由環氧樹脂黏著劑以及在表面電鍍上金屬的高分子導電微粒所組成的複合材料。一個新技術的出世會面臨許多的困難及挑戰，例如良率及可靠度有待努力解決。構裝良率與可靠度與其本身之熱機械行為如應力/應變息息相關，而這些熱機械行為又與構裝本身在製程或測試運作時的外力載重，如溫度及熱機械載重相關。因此本論文將藉由數值分析及實驗驗證的方法分析此構裝體於製程過程中之熱機械行為的特性。為了達成此一目標，本文提出一新的製程力學求解方法，此方法整合三維非線性有限元素分析搭配所謂的網格生死技術(death-birth meshing scheme)，實驗驗證則採用熱電偶實驗及晶片/基板翹曲實驗。最後，利用參數化有限元素探討改善此一構裝於製程中熱-機械行為(含翹曲量/凸塊接觸應力/ACF膠剝離應力)的影響因子，含幾何/材料/製程參數。
值得一提的是，從模擬以及實驗的結果均顯示銅跑線是一個影響整體翹曲的重要因素，所以不能從分析中忽略。此外，壓合力量、加熱頭溫度以及元件材料參數及幾何都是影響整體構裝熱機械行為表現的重要因素。

Nowadays, the pursuit toward the miniaturization and flexibility of portable electronics has driven a high demand for new advanced packaging solution based on ultra-thin silicon. The UTCOF technology is a very promising and feasible packaging solution for attaining the goals due to its high flexibility, and more importantly compatible to the current semiconductor fabrication and packaging industry. The key applications of the new technology include the paper-thin smart labels, particularly the RFID labels, miniaturized medical electronic systems and memory chip stacking etc.
In this study, a novel adhesive UTCOF technology is developed. The technology implements an epoxy-based anisotropic conductive film (ACF), which are composite materials composed of an adhesive polymer resin and conductive particles of metal-coated polymer particles, to form fine-pitch and reliable interconnects of IC bumps on flex substrates. As a new technology, there are still many challenging technical issues, such as yield and reliability, remaining in concern and expecting to be solved prior to its practical applications in IC industry. Poor yield and reliability can be largely resulted from process- and/or thermal-induced stress/strain/deformation. Hence, it is necessary to improve its thermal-mechanical behaviors for the yield and reliability requirements. In this study, we attempt to characterize the process-dependent, thermal-mechanical behaviors of the packaging technology in manufacturing process through three–dimensional (3-D), nonlinear finite element (FE) analysis together with the so-called “death–birth” simulation technique. The validity of the modeled results is verified by using a thermal couple experiment for temperature measurement and the Micro Figure Measuring Instrument and Laser scanner for warpage measurement of the chip and substrate, respectively. Finally, in order to seek a design guideline for better thermal-mechanical performance, parametric FE study is performed, which investigates the dependence of the warpage of the substrate and the contact stress at the interconnects and the peeling stress at the ACF on a number of geometry and material design parameters.
Both the modeled and experimental results show that copper wire is a key factor affecting the overall warpage of assembly, and should not be neglected from the analysis. In addition, the bonding force, heating temperature and material parameters are the key factors affecting the overall contact performance of the assembly.

誌謝 2
摘要 3
ABSTRACT 5
目錄 7
圖目錄 9
表目錄 11
第一章、 導論 12
第二章、 問題描述 21
2.1 結構以及材料 21
2.2 晶圓薄化以及切割製程 22
2.3 ACF型態壓合製程 24
第三章、 理論基礎 27
3.1 有限元素分析 27
3.1.1基板等效材料性質 29
3.2 接觸理論 31
3.3 有限體積加權平均法 32
第四章、 UTCOF構裝之力學行為分析 34
4.1 ACF型態UTCOF構裝的有限元素模型建構 34
4.1.1暫態熱傳分析模型 35
4.1.2熱-機械力學分析模型 37
4.2 實驗驗證 38
第五章、 結果與討論 41
5.1. 製程溫度場分析與實驗驗證 41
5.2. 基板翹曲量分析與實驗驗證 43
5.3. ACF壓合製程之翹曲量探討 43
5.4. 晶片翹曲量分析與實驗驗證 44
5.5. ACF壓合製程之接觸應力探討 44
5.6. ACF壓合製程之剝離應力探討 45
5.7. 參數化分析 46
5.7.1.ACF膠熱膨脹係數影響 46
5.7.2.ACF膠楊氏係數影響 47
5.7.3.金凸塊熱膨脹係數影響 47
5.7.4.金凸塊高度影響 47
5.7.5.晶片熱膨脹係數影響 48
5.7.6.晶片楊氏係數影響 48
5.7.7.晶片高度影響 48
5.7.8.PI軟性基板熱膨脹係數影響 49
5.7.9.PI軟性基板楊氏係數影響 49
5.7.10. PI軟性基板高度影響 50
第六章、 結論與展望 51
致謝 54
參考文獻 55
附錄 60
附錄1 圖 60
附錄2 表 87

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