本論文係多層壁奈米碳管 (MWCNT) - 塑膠複合材料之電磁屏蔽效應 (SE) 及其在光電傳送接收模組電磁干擾 (EMI) 的防治及電磁耐受性 (EMS) 應用之研究。實驗結果顯示以液晶高分子聚合物 (LCP) 為基材之多層壁奈米碳管複合材料，其電磁屏蔽效應在頻率 1 GHz 到 3 GHz範圍內可達到38 dB至 45 dB。而多層壁奈米碳管複合材料的電磁屏蔽能力也表現在以此複合材料進行封裝的光電傳送接收模組的電磁耐受性上。其電磁耐受性的效果是操作在2.5 Gbps傳輸速度下藉由比較有、無電磁屏蔽封裝之光電傳送接收模組量測到的信號眼圖及誤碼率差異來呈現。結果顯示以較高重量百分比多層壁奈米碳管複合材料封裝而成的光電傳送接收模組具有較高的電磁屏蔽效應，並有較佳的電磁耐受性，較大的眼圖遮蔽幅度(mask margin),及較少的光功率補償 (power penalty)。
另外使用一種高分子塑膠材料-聚醘亞胺 (PI) 複合經離子液體 (IL) 分散的多層壁奈米碳管，其可以在多層壁奈米碳管相對較低重量百分比下達到相當程度的電磁屏蔽效應。實驗結果顯示經由離子液體分散的多層壁奈米碳管-聚醘亞胺複合材料在頻率 1 GHz 到 3 GHz 的範圍內可達到40 dB至 46 dB 的電磁屏蔽效應。相較之下，沒有使用分散製程製造的複合材料須使用較高重量百分比的多層壁奈米碳管才可達到此電磁屏蔽效應。
為了深入了解多層壁奈米碳管分子間的作用力，本研究對多層壁奈米碳管的分散機制作定性地分析。多層壁奈米碳管的聚集是由於碳管間的凡得瓦力(van der Waals forces)吸引所致，而IL可用來分散多層壁奈米碳管。這主要是由於離子液體中的陽離子與碳管表面

The shielding effectiveness (SE) of the novel multiwall carbon nanotube (MWCNT) plastic composites is studied for the purpose of the electromagnetic interference (EMI) protection and the electromagnetic susceptibility (EMS) improvement in the application of the optical transmitter and receiver modules. The experimental results showed that the liquid crystal polymer (LCP) based MWCNT composites can exhibit a high SE of 38 dB ~ 45 dB within the frequency range of 1 GHz ~ 3 GHz. The shielding capability was demonstrated by examining the electromagnetic susceptibility performance of the optical transmitter and receiver modules, which were packaged by the MWCNT-LCP composites. The EMS performance was evaluated by eye diagram and bit-error-rate test in a 2.5 Gbps lightwave transmission system. The results showed that the MWCNT-LCP composite packaged modules with more weight percentage of the MWCNTs can exhibit a higher SE, and hence showed effective EMS performance, a better mask margin, and a lower power penalty.
A novel polyimide (PI) plastic consisting of finely ionic liquid (IL) dispersed MWCNTs was also demonstrated to have high SE under a lower MWCNT loading. The experimental results showed that the IL dispersed MWCNT-PI composite can exhibit a high SE of 40 dB ~ 46 dB within the frequency range of 1 GHz ~ 3 GHz. By comparison, the composite fabricated by non-dispersed process required a higher loading of MWCNTs than the dispersed one.
To understand the detailed intermolecular forces among MWCNTs, the dispersion mechanism of the MWCNTs is studied qualitatively. The aggregation of MWCNTs is from van der Waals forces among MWCNTs, and it can be dispersed by using IL dispersant. This is due to the predominant cation-

TABLE OF CONTENTS
ABSTRACT
ACKNOWLEDGEMENTS
TABLE OF CONTENTS………………………………………………………………...i
LIST OF FIGURES……………………………………………………………………...v
LIST OF TABLES………………………………………………………………………xi

CHAPTER 1 INTRODUCTION………………………………………………………1
1.1 Background………………………………………………………………1
1.2 Motivation………………………………………………………………..2
1.3 Objective…………………………………………………………………3
1.4 Organization…….………………………………………………………..6
References..….…………………………………………………………….....6

CHAPTER 2 ELECTROMAGNETIC SHIELDING THEORY…………………..10
2.1 Mathematic Model of Shielding Effectiveness…………………………11
2.2 Shielding Effectiveness in Far Field……………………………………14
2.3 Shielding Effectiveness in Near Field…………………………………. 19
2.4 Shielding Effectiveness Model for Mixing Materials…………………..21
2.5 Shielding Effectiveness of Stacked Films………………………………25
References….....…………………………………………………………….27

CHAPTER 3 FABRICATION OF MULTIWALL CARBON NANOTUBE
COMPOSITES………………………………………………………...29
3.1 Carbon Nanotube ………………………………………………………30
3.1.1 Single Wall Carbon Nanotube……………………………………31
3.1.2 Multiwall Carbon Nanotube……………………………………...35
3.2 Liquid Crystal Polymer…………………………………………………37
3.3 Polyimide……………………………………………………………….39
3.4 Carbon Nanotube Fabrication…………………………………………..40
3.4.1 Chemical Vapor Deposit Method………………………………...41
3.4.2 Arc-Discharge Deposit Method…..………………………………43
3.4.3 Laser Ablation Method……………..…………………………….46
3.5 Multiwall Carbon Nanotube Composite Fabrication…..……………….47
3.5.1 Thermal Compression……………………………..……………...47
3.5.2 Film Coating……………………………………….……………..48
References…..…....……………………………….…………..……………49

CHAPTER 4 MEASUREMENT AND PACKAGE OF CARBON NANOTUBE
LIQUID CRYSTAL POLYMER COMPOSITES…………………..51
4.1 Microstructure………………………………………………………….52
4.2 Electrical Conductivity………………………………………………....53
4.2.1 Four-point-probe Method………………………………………...54
4.2.2 Measurement Result……………………………………………...56
4.3 Electro-Magnetic Interference Shielding Effectiveness…………….….57
4.3.1 Far Field…………………………………………………………..57
4.3.1.1 Experiment Setup…………………………………………..57
4.3.1.2 Equivalent Electrical Circuit Model……………………….58
4.3.1.3 Measurement Result………………………………………..60
4.3.2 Package…………………………………………………………...63
4.3.3 Near Field………………………………………………………....64
4.3.3.1 Experiment Setup…………………………………………..64
4.3.3.2 Regulation………………………………………………….65
4.3.3.3 Measurement Result………………………………………..67
4.3.4 Summary………………………………………………………….74
4.4 Electro-Magnetic Susceptibility Measurement…………………………75
4.4.1 Introduction………………………………………………………..75
4.4.2 Experiment Setup………………………………………………….76
4.4.3 Mask Margin………………………………………………….…...77
4.4.4 Power Penalty……………………………………………………..78
4.4.5 Summary…………………………………………………………..81
References.……………..……………………………………….…………..81

CHAPTER 5 DISPERSION OF CARBON NANOTUBES………………………..84
5.1 Introduction……………………………………………………………..84
5.1.1 Aggregation of Carbon Nanotube…………………………………85
5.1.2 Dispersion Model……………………………………………….…87
5.2 Dispersion Measurement…………………………………….………....92
5.2.1 Raman Spectroscopy Investigation………………………………..92
5.2.2 Uniformity Investigation by UV-vis Spectrometer………………..93
5.2.3 Percolation Phenomenon of Electrical Conductivity……………...94
5.3 Summary………………………………………………………………..95
References..…………………………………………..……………………..96

CHAPTER 6 MEASUREMENT AND PACKAGE OF DISPERSED CARBON NANOTUBE POLYIMIDE COMPOSITES…………………………99
6.1 Uniformity of Dispersion……………………………………………...100
6.2 Microstructure…………………………………………………………102
6.3 Electrical Conductivity………………………………………………..104
6.4 Electro-Magnetic Interference Shielding Effectiveness……………....105
6.4.1 Far Field………………………………………………………....105
6.4.2 Package………………………………………………………….106
6.4.3 Near Field………………………………………………………..107
6.5 Electro-Magnetic Susceptibility Measurement………………………..108
6.5.1 Experiment Setup………………………………………………..108
6.5.2 Mask Margin…………………………………………………….109
6.5.3 Power Penalty…………………………………………………...111
6.6 Summary………………………………………………………………112
References………..………………………………………………………..113

CHAPTER 7 CONCLUSION………………………………………………………115
7.1 Conclusion...…………………………………………………………..115
7.2 Discussion.…………………………………………………………….117
APPENDICES…………………………………………………………………………119
LIST OF PUBLICATIONS…………………………………………………………..121
BIOGRAPHY OF AUTHOR…………………………………………………………123

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