Table of Content Abstract I Table of Content IV List of Figures VI List of Tables IX Chapter 1 Introduction 1 Chapter 2 Literature Review 3 2.1 PTH Process 3 2.2 Electroless Copper Deposition 4 2.3 Direct Plating 4 2.4 Pd Colloid Systems 5 2.5 Conductive Polymer System 5 2.6 Carbon colloid system 5 2.6.1 Black hole 6 2.6.2 Shadow Process 7 2.7 Introduction of CNT 14 2.8 Method to Synthesize Nanotube 15 2.8.1 Arc-Discharge 15 2.8.2 Laser Ablation (Laser Vaporization) 16 2.8.3 Catalytic Chemical Vapor Deposition (CCVD) 17 2.9 Properties of CNTs 18 2.9.1 Mechanical Properties 18 2.9.2 Electronic Properties 18 2.9.3 Bulk Density 19 2.9.4 Thermal Conductivity 19 2.9.5 Ballistic Conductor 20 2.10 Metallization of MWNTs 20 2.11 Motive and Scope of this Thesis 23 Chapter 3 Experiment Sections 24 3.1 Materials 24 3.2 Experimental Instruments 24 3.3 Principle and Measurement of Analytical Methods 25 3.3.1 Chronocoulometry 25 3.3.2 Chronopotentiometry 26 3.3.3 Two-point probe method 26 3.3.4 SEM 27 3.3.5 EDX 27 3.3.6 The Judgment for the Back-light Performance 28 3.3.7 Reliably-Thermal Stress Test 29 3.4 CNT suspension 29 Chapter 4 Results and Discussions 33 4.1 Comparison the Resistance between CNT and Graphite 33 4.2 Copper Electroplating on CNTs 34 4.3 Process for CNTs Adsorption 39 4.3.1 Electroplating Method- Chronocoulometry 39 4.3.2 Electroplating Method- Chronopotentiometry 42 4.4 Copper Deposition Rate and Relative Back Light Performance 48 4.4.1 Copper Deposition Rate 48 4.4.2 Back-Light Performance with different electroplating method 50 4.5 Different Types of Carbon Nanotubes 55 4.5.1 Basic properties of new kinds of carbon nanotube 55 4.5.2 Back-light Performances and SEM morphologies of different types of CNTs 58 4.6 Comparison of Commercial Product- Shadow Process 65 Chapter 5 Conclusions 68 Chapter 6 Future Work 69 References 70 List of Figures Fig. 2-1. The structure of (a) diamond, (b) carbon black, (c) graphite 6 Fig. 2-2. The procedures of Shadow processes. 7 Fig. 2-3. Shadow conditioner mechanism. 8 Fig. 2-4. The sketch diagram of the graphite colloid, the surface of the graphite is filled with binders. 10 Fig. 2-5. The sketch of graphite colloid and its adsorption condition. 10 Fig. 2-6. The sketch of the surface condition on the hole wall after fixer step. 11 Fig. 2-7. The mechanism of cross linking between graphite particles and PCB. 12 Fig. 2-8. The sketch of graphite layer coating after micro-etching. 12 Fig. 2-9. The sketch of the surface conditions of the hole wall in the shadow process, it can be distinguished into six steps, they are (a) After desmear and deburr, (b) Cleaner/ Conditioner step, (c) Graphite colloid, (d) After fixer and dry, (e) After micro-etching, (f) After Copper plating. 13 Fig. 2-10. SWNT can regard as a piece of graphene rolled up into a cylinder. 14 Fig. 2-11. (a) The two basis vectors a1 and a2 are shown. Folding of the (8,8),(8,0) and (10,-2) vectors leads to (b) armchair, (c) zigzag, and (d) chiral, respectively. 15 Fig. 2-12. Schematic diagram of the arc discharge apparatus. 16 Fig. 2-13. Oven laser-vaporization apparatus. 17 Fig. 2-14. The schematic diagram of catalytic chemical vapor deposition apparatus. 18 Fig. 2-15. The mechanism of CVD. 18 Fig. 2-16. It shows three kinds of tubes-armchair, zigzag, and chiral, respectively. 19 Fig. 2-17. The stages in the electroless plating-decoration process employing the two-step sensitization-activation approach. [31] 21 Fig. 2-18. Schematic of the growth process of the Cu-VGAF particles. (a) Carbon nanofibers become incorporate into the deposited Cu. (b) Cu deposits on the substrate and the ends of the carbon nanofibers. (c) Deposited Cu grows to incorporate the carbon nanofibers, resulting in a spiky ball structure. [36] 22 Fig. 2-19. Schematic of the selective deposition of Ni on the MWCNT. [38] 22 Fig. 3-1. Potential wave form of (a) the double potential step technique, (b) the current response, and (c) the charge response [39]. 25 Fig. 3-2. Current wave form of (a) constant current, (b) the potential response. 26 Fig. 3-3. Positions to measure the resistance on the two copper sides of a PCB 26 Fig. 3-4. The sketch for the measurement of the back-light performance by OM. 28 Fig. 3-5. The standard chart of the back-light performance in PCB industry. 29 Fig. 3-6. The sketch for a planar sample (a) positive side, (b) reverse side. 30 Fig. 3-7. The sketch for samples (a) porous sample, (b) side-view of sample, (c) the diameter of an aperture on the porous sample. 30 Fig. 4-1. SEM images of (a) FR-4, (b) CNTs adsorbed on the FR-4, (c) steel plate, (d) CNTs were adsorbed on the steel plate (magnification:1000X), (e) CNTs were adsorbed on the steel plate (magnification:3000X) 36 Fig. 4-2. SEM images showing the growth of Cu-CNTs at (a) 0.5C cm-2 , (b) 1.5C cm-2 , (c) 2.5C cm-2 , (d) 5C cm-2. 37 Fig. 4-3. EDX data of Cu-CNTs at (a) 0.5C cm-2, (b) 5C cm-2. 37 Fig. 4-4. SEM images showing the growth of Cu-graphite at(a) graphite adsorbed on FR-4, (b) 0.5C cm-2, (c) 1.5C cm-2, (d) 2.5C cm-2. 38 Fig. 4-5. Different choices of cleaner/conditioner step resulted in chronocoulometry. 41 Fig. 4-6. Chronocoulometry with different choices of cleaner/conditioner step resulted in back-light performance. 41 Fig. 4-7. Different conditions of cleaner/ conditioner step resulted in chronopotentiometry. 43 Fig. 4-8 Chronopotentiometry with different choices of cleaner/conditioner step resulted in back-light performance. 43 Fig. 4-9. Various conditions of Cleaner/ Conditioner and Fixer steps (a) CCIII 30℃, (b) CCIII 50℃, (c) CCIII 60℃, (d) CCIII 60℃+ Fixer, (e) ML371 30℃, (f) ML371 50℃, (g) ML371 60℃, (d) ML371 60℃+ Fixer. 46 Fig. 4-10. The back light performance of various conditions of Cleaner/ Conditioner and Fixer steps (a) CCIII 30℃, (b) CCIII 50℃, (c) CCIII 60℃, (d) CCIII 60℃+ Fixer, (e) ML371 30℃, (f) ML371 50℃, (g) ML371 60℃, (d) ML371 60℃+ Fixer. 47 Fig. 4-11. The net Cu deposition on the CNTs, which electroplated under various potentials (-0.26, -0.28,-0.3,-0.32 V vs. SCE) and the duration time was 5 minutes. 49 Fig. 4-12. The net Cu deposition on the CNTs, which electroplated under various current (15, 20, 25, 30, 35 ASF) and the duration time was 5 minutes. 49 Fig. 4-13. Total current with time of various potentials which electroplated under -0.26, -0.28,-0.3,-0.32 V vs. SCE and the duration time was 5 minutes. 51 Fig. 4-14. The back light performance of drilled hole samples with various potentials (-0.26, -0.28,-0.3,-0.32 V vs. SCE) 51 Fig. 4-15 Potential with time of different media (graphite and CNT) for PTH. 53 Fig. 4-16. Potential with time of various current densities which electroplated under 15, 20, 25, 30, 35 ASF and the duration time was 5 minutes. 53 Fig. 4-17. The back light performance of drilled hole samples with various current densities (15, 20, 25, 30, 35 ASF). 54 Fig. 4-18. The morphologies of new CNTs (a) thin CNTs film, (b) thick CNTs film. 55 Fig. 4-19. SEM images showing the growth of Cu-Thin CNTs (a) 0.5C cm-2 , (b) 1.5C cm-2 , (c) 2.5C cm-2 , (d) 5C cm-2. 56 Fig. 4-20. SEM images showing the growth of Cu-Thick CNTs (a) 0.5C cm-2 , (b) 1.5C cm-2 , (c) 2.5C cm-2 , (d) 5C cm-2. 57 Fig. 4-21. The back-light performance of three kinds of carbon nanotubes (normal, thin and thick CNTs). 58 Fig. 4-22. (a) The profile of a hole of a PCB, the morphologies of (b) thin CNTs adhered to the epoxy; (c) thin CNTs adhered to the glass fiber. 59 Fig. 4-23. The morphologies of (a) thick CNTs adhered to the epoxy; (b) thick CNTs adhered to the glass fiber. 60 Fig. 4-24. The back-light performance of twice dipped carbon nanotubes (the combination is as following: thick-thin, thick-thick and thin-thick CNTs). 61 Fig. 4-25. SEM morphologies of (a) the cross-section view of a PCB hole which covered with thick-thin CNT, (b) enlargement of a crevice in thick-thin film. 62 Fig. 4-26. The SEM morphologies of (a) thick CNTs in epoxy part; (b) thick CNTs in fiber part. 63 Fig. 4-27. Chronopotentiometry method-twice dipped thick CNTs compared with single dipped. 63 Fig. 4-28. SEM morphologies of (a) the cross-section view of a PCB hole which covered with thin-thick CNTs in epoxy region, (b) thin-thick CNTs film in fiber region. 64 Fig. 4-29. Contrast the back-light performance of thin, thick, thin-thick and graphite. 65 Fig. 4-30. The thermal stress test results observed by OM. 66 List of Tables Table 2-1 Elecroless copper deposition procedures 4 Table 2-2 Thermal conductivities of three material-MWCNT, nature diamond and graphite. 19 Table 4-1 Different colloids (CNT. Graphite and their combination) have different resistance 33 Table 4-2 Various conditions of Cleaner/ Conditioner step 39 Table 4-3 Various conditions of Cleaner/ Conditioner and Fixer steps 44 Table 4-4 Basic properties of three kinds of carbon nanotubes. 55