Visual Inspection Technology in the Hard Disc Drive Industry

PREFACE xi CHAPTER 1. FEATURE FUSION METHOD FOR RAPID CORROSION DETECTION ON POLE TIPS 1 Suchart YAMMEN and Paisarn MUNEESAWANG 1.1. Introduction 2 1.2. Algorithm for corrosion detection 6 1.2.1. Extraction of top-shield region 6 1.2.2. Area-based feature 9 1.2.3. Contour-based feature 13 1.3. Experimental result 19 1.3.1. Distribution of corrosion 20 1.3.2. Performance metric 20 1.3.3. Robustness 24 1.4. Conclusion 27 1.5. Bibliography 28 CHAPTER 2. NONLINEAR FILTERING METHOD FOR CORROSION DETECTION ON POLE TIPS 33 Paisarn MUNEESAWANG and Suchart YAMMEN 2.1. Introduction 33 2.2. Perpendicular magnetic recording 35 2.3. Perpendicular magnetic recorder and corrosion 37 2.3.1. Lubricant layer 38 2.3.2. Thermal effect results in corrosion 41 2.3.3. Recording head/slider manufacturing and corrosion 42 2.4. Length estimator for pole tip 44 2.5. Nonlinear filtering as a corrosion detector 48 2.5.1. Median filter techniques 48 2.5.2. Median "¸-Filter 50 2.5.3. Corrosion detection procedure 51 2.6. Application 54 2.7. Conclusion 62 2.8. Bibliography 63 CHAPTER 3. MICRO DEFECT DETECTION ON AIR-BEARING SURFACE 71 Pichate KUNAKORNVONG and Pitikhate SOORAKSA 3.1. Introduction 71 3.2. Air-bearing surface 74 3.3. Imaging system 75 3.4. Contamination detection 79 3.4.1. Texture unit texture spectrum 80 3.4.2. Graylevel co-occurrence matrix 82 3.4.3. Principle component analysis 85 3.4.4. Identification defect 88 3.5. Conclusion 92 3.6. Acknowledgment 93 3.7. Bibliography 93 CHAPTER 4. AUTOMATED OPTICAL INSPECTION FOR SOLDER JET BALL JOINT DEFECTS IN THE HEAD GIMBAL ASSEMBLY PROCESS 99 Jirarat IEAMSAARD and Thanapoom FUANGPIAN 4.1. Introduction 99 4.2. Head gimbal assembly 101 4.3. Vertical edge method for inspection of pad burning defect 102 4.3.1. Inspection procedure 103 4.3.2. Experimental result 107 4.4. Detection of solder ball bridging on HGA 108 4.4.1. Solder ball bridging defect 108 4.4.2. Chain code descriptor-based method 109 4.4.3. Morphological template-based method 112 4.4.4. Experimental result 114 4.5. Detection of missing solders on HGA 121 4.5.1. Image acquisition and enhancement 121 4.5.2. Clustering of image pixels 122 4.5.3. Decision making 123 4.5.4. Inspection result 124 4.6. Conclusion 126 4.7. Bibliography 127 CHAPTER 5. ANALYSIS METHODS FOR FAULT DEFORMATION OF SOLDER BUMP ON THE ACTUATOR ARM 131 Somporn RUANGSINCHAIWANICH 5.1. Introduction 132 5.2. Surface tension analysis 133 5.2.1. Model analysis 135 5.2.2. Simulation 138 5.3. Analysis of stress performance at different configurations of solder bump positions 140 5.3.1. Analysis model 144 5.3.2. Design and analysis using FEM 145 5.4. Experimental result 149 5.5. Conclusion 151 5.6. Bibliography 152 CHAPTER 6. ARTIFICIAL INTELLIGENCE TECHNIQUES FOR QUALITY CONTROL OF HARD DISK DRIVE COMPONENTS 155 Wimalin LAOSIRITAWORN 6.1. Introduction 155 6.2. Artificial intelligence tasks in quality control 157 6.2.1. Classification and prediction 157 6.2.2. Cluster analysis 159 6.2.3. Time series analysis 160 6.3. AI applications in HDD component quality control 161 6.3.1. Multipanel lamination process modeling using ANN 161 6.3.2. Control chart pattern recognition with AI in actuator production 168 6.3.3. Machine clustering using AI technique 174 6.4. Conclusion 179 6.5. Bibliography 180 CHAPTER 7. BOREHOLE DIAMETER INSPECTION FOR HARD DISK DRIVE PIVOT ARMS USING HOUGH TRANSFORM IN PANORAMA IMAGES 183 Sansanee AUEPHANWIRIYAKUL, Patison PALEE, Orathai SUTTIJAK and Nipon THEERA-UMPON 7.1. Introduction 183 7.2. Panorama image construction 185 7.3. Dimension estimation 189 7.4. Experiment result 190 7.5. Conclusion 195 7.6. Acknowledgment 195 7.7. Bibliography 195 CHAPTER 8. ELECTROSTATIC DISCHARGE INSPECTION TECHNOLOGIES 199 Nattha JINDAPETCH, Kittikhun THONGPULL, Sayan PLONG-NGOOLUAM and Pornchai RAKPONGSIRI 8.1. Introduction 199 8.2. ESD sensitivity test technologies 200 8.2.1. Human body model testing 201 8.2.2. Charged device model testing 202 8.2.3. Machine model testing 203 8.3. Monitoring of ESD prevention equipment 204 8.3.1. Grounding and equipotential bonding systems 205 8.3.2. Ionization 206 8.3.3. Packaging 209 8.4. ESD event localization technologies 211 8.4.1. EMI locators 212 8.4.2. High-speed oscilloscope-based ESD event localization systems 214 8.4.3. RFID localization systems 215 8.4.4. WSN-based localization systems 218 8.4.5. Hybrid localization systems 220 8.5. Conclusion 221 8.6. Bibliography 221 CHAPTER 9. INSPECTION OF STYROFOAM BEADS ON ADAPTER OF HARD DISK DRIVES 225 Suchart YAMMEN 9.1. Introduction 225 9.2. Morphological template-based method 227 9.2.1. Image subtraction 230 9.2.2. Otsu method 231 9.2.3. Morphological operation 232 9.2.4. Logical operation 233 9.3. Decision model 233 9.4. Application 234 9.5. Conclusion 234 9.6. Bibliography 235 CHAPTER 10. INSPECTION OF DEFECT ON MAGNETIC DISK SURFACE AND QUALITY OF THE GLUE DISPENSER ROUTE 237 Anan KRUESUBTHAWORN 10.1. Introduction 238 10.2. Computer vision technologies for scratch detection on media surfaces 239 10.3. Inspection of glue dispenser route 255 10.4. Conclusion 260 10.5. Bibliography 260 CHAPTER 11. INSPECTION OF GRANULAR MICROSTRUCTURE OF FEPT FILM IN HEAT-ASSISTED MAGNETIC RECORDING MEDIA 265 Paisarn MUNEESAWANG 11.1. Introduction 265 11.2. Heat-assisted media recording technology 268 11.2.1. HAMR 268 11.2.2. L10-ordered FePt as HAMR media candidate 268 11.2.3. Magnetic nanoparticle 270 11.3. Inspection procedure 272 11.3.1. Image segmentation 272 11.3.2. Separation of overlapping particles 273 11.4. Measurement of the size distribution 275 11.5. Measurement of dispersion 278 11.5.1. Lennard-Jones potential index 278 11.5.2. Experimental result 281 11.6. Conclusion 285 11.7. Bibliography 286 LIST OF AUTHORS 291 INDEX 295