vii 4.4.1
τptimization 56
4.5 The Spatter Deposition Area of Laser Drilling Hole
58
CHAPTER 5 : CONCLUSION 61
5.1 Conclusion
61 5.2
Recommendation 62
6. APPENDIX A
70 7.
APPENDIX B 73
8. APPENDIX C
75
viii
4. LIST OF FIGURES
2.0μ Micromotor as one of the MEMS product 5
2.1μ Basic formation of laser λ
2.2μ Electromagnetic spectrum wavelength for several laser types λ
2.3μ Absorption mechanism 10
2.4μ Spontaneous emission process 11
2.5μ Stimulated emission mechanism 11
2.6μ Various techniques in laser drilling 13
2.7μ Laser drilling process diagram 13
2.8μ Silicon wafer 20
2.λμ Percentage of silicon reflectivity versus laser wavelength 21 2.10μ Difference number of cycle that produce in one second
26 2.11μ Laser pulse
27 2.12μ Measuring process of hole diameter on silicon wafer
28
3.0μ Research flow chart 31
3.1μ Central composite design 35
3.2μ Box-behnken design for three factors 35
3.3μ Experimental parameters setup 37
3.4μ Experiment response setup 37
3.5μ Table of run for experiment 38
3.6μ Laser cutting machine Helius 2513 3λ
3.7μ The experimental setup flow chart 40
3.8μ AUTτCAD drawing for the laser drilling process 42
3.λμ Schematic diagram of Cτ
2
laser micromachining setup 43
3.10μ Laser beam nozzle 43 3.11μ X and Y direction of drilling hole 45
3.12μ Meiji Techno Microscope
45
ix 4.0μ Drilled hole on a silicon wafer
47 4.1μ The experimental value and predicted value of d
entrance
52 4.2μ Effects of Laser power to the d
entrance
of drilling holes 53
4.3μ Effects of pulse frequency to the d
entrance
of drilling holes 54
4.4μ Effects of duty cycle on the d
entrance
of drilled hole 55
4.5μ Interaction of laser power and pulse frequency to the d
entrance
56 4.6μ Suggested parameter value of laser drilling process
57 4.7μ Predicted entrance diameter of drilling hole
58 4.8μ Spatter deposition area for different silicon wafer side
5λ
x
5. LIST OF TABLES
Kategori