Title Page
Contents
LIST OF ABBREVIATIONS 12
ABSTRACT 13
Ⅰ. INTRODUCTION 15
1. General introduction 15
1.1. Development of communication technology 15
1.2. Need for the development of a low dielectric Adhesive 16
2. Research objectives 19
Ⅱ. MATERIALS AND METHODS 22
1. Materials 22
2. Experimental methods 22
2.1. Synthesis of thiol-ene adhesive 22
2.2. Electrodeposition of thiol-ene Adhesive 23
2.3. Sample preparation 28
3. Instruments 29
3.1. Fourier transform infrared spectroscopy (FT-IR) 29
3.2. Nuclear magnetic resonance (NMR) 29
3.3. Gel permeation chromatography (GPC) 29
3.4. Differential scanning calorimetry (DSC) 29
3.5. Thermogravimetric analysis (TGA) 30
3.6. Field emission scanning electron microscope (FE-SEM) 30
3.7. Dielectric property analysis 30
3.8. 90 Degree Peel Test 30
3.9. Electrodeposition Test 31
3.10. X-ray Photoelectron Spectroscopy (XPS) 31
3.11. Vector Network Analyzer (VNA) 31
Ⅲ. RESULTS AND DISCUSSION 32
1. Characterizations of thiol-ene adhesive 32
1.1. FT-IR characterization 32
1.2. NMR characterization 32
1.3. GPC analysis 35
1.4. TGA analysis 35
1.5. DSC analysis 36
1.6. SEM analysis 37
2. Adhesion and electrical properties of thiol-ene adhesive 43
2.1. Adhesion properties 43
2.2. Dielectric properties 47
2.3. Transmission loss 51
3. Characterizations of electrodeposited thiol-ene adhesive 55
3.1. CV graph analysis 55
3.2. XPS graph analysis 60
3.3. Adhesion property 63
Ⅳ. CONCLUSION 65
REFERENCE 66
ABSTRACT IN KOREAN 71
Table 1. Characterization of thiol-ene adhesive with different molar ratios of thiol groups by GPC analysis. 38
Table 2. Peel strength of the thiol-ene adhesive samples with different thicknesses. 46
Figure 1. Performance required for 5G mobile communication compared to 4G mobile communication. 18
Figure 2. Bonding structure of thiol-ene adhesive in the (a) laminated sample with copper foils and (b) laminated sample with copper foil and the low dielectric polymer sheet. 21
Figure 3. Schematic illustration of electrodeposition of the thiol-ene adhesive layer on the copper foil using a potentiostat. 26
Figure 4. Schematic illustration of electrodeposition of thiol-ene adhesive layer using a power supply. Two-step process is obtained: (a) Cu-chitosan pretreatment... 27
Figure 5. FT-IR spectra of the thiol-ene oligomer before the reaction and after the reaction. 33
Figure 6. ¹H-NMR spectra of the thiol-ene oligomer before the reaction and after the reaction. 34
Figure 7. TGA profiles of the thiol-ene adhesive as a function of amount of thiol groups. 39
Figure 8. DSC analysis of the thiol-ene adhesive as a function of amount of thiol groups. 40
Figure 9. Thickness of thiol-ene adhesive layer on the copper foil using a spin coater with (a) 3000 rpm, (b) 5000 rpm and (c) 7000rpm speed. 41
Figure 10. SEM image of (a) non adhesive CCL sample, (b) CCL sample with an adhesive layer coated by 3000 rpm speed, (c) CCL sample with an adhesive layer... 42
Figure 11. Peel strength of the thiol-ene adhesive samples with different thicknesses and different molar ratios of thiol groups. 45
Figure 12. Dielectric properties of the thiol-ene adhesive as a function of the amount of thiol groups. 49
Figure 13. Dielectric properties of laminated samples with prepreg as a function of the amount of thiol groups. 50
Figure 14. Transmission loss of the reference CCL sample along the length of microstrip line. 53
Figure 15. Transmission loss of the B1T1 CCL sample along the length of microstrip line. 54
Figure 16. Cyclic voltammetry of the thiol-ene electrodeposition process in (a) none (DCE) solution, (b) BMI solution, (c) TMMP solution, and (d) BMI + TMMP solution. 57
Figure 17. Cyclic voltammetry of the thiol-ene electrodeposition process with different scan rate at (a) 20 mV/s, (b) 50 mV/s, (c) 80 mV/s, and (d) 100 mV/s. 58
Figure 18. Cyclic voltammetry of thiol-ene electrodeposition process after the pretreatment with chitosan. 59
Figure 19. Comparison of XPS graphs of the copper foil before and after the electrodeposition using a power supply. 61
Figure 20. XPS graphs of the electrodeposited thiol-ene adhesive layer on the copper foil. 62
Figure 21. Peel strength of electrodeposited thiol-ene adhesive layer on the copper foil. 64
Scheme 1. Mechanism of thiol-ene click-reaction via copper ions using BMI and TMMP. 25