Preface xi 1 Introduction 1 1.1 Introduction 1 1.2 Impact of Moore’s Law on Si Technology 3 1.3 5G Technology and AI Applications 4 1.4 3D IC Packaging Technology 7 1.5 Reliability Science and Engineering 11 1.6 The Future of Electronic Packaging Technology 13 1.7 Outline of the Book 14 References 15 Part I 17 2 Cu-to-Cu and Other Bonding Technologies in Electronic Packaging 19 2.1 Introduction 19 2.2 Wire Bonding 20 2.3 Tape-Automated Bonding 23 2.4 Flip-Chip Solder Joint Bonding 26 2.5 Micro-Bump Bonding 32 2.6 Cu-to-Cu Direct Bonding 35 2.6.1 Critical Factors for Cu-to-Cu Bonding 36 2.6.2 Analysis of Cu-to-Cu Bonding Mechanism 39 2.6.3 Microstructures at the Cu-to-Cu Bonding Interface 46 2.7 Hybrid Bonding 51 2.8 Reliability – Electromigration and Temperature Cycling Tests 54 Problems 56 References 57 3 Randomly-Oriented and (111) Uni-directionally-Oriented Nanotwin Copper 61 3.1 Introduction 61 3.2 Formation Mechanism of Nanotwin Cu 63 3.3 In Situ Measurement of Stress Evolution During Nanotwin Deposition 67 3.4 Electrodeposition of Randomly Oriented Nanotwinned Copper 69 3.5 Formation of Unidirectionally (111)-oriented Nanotwin Copper 71 3.6 Grain Growth in [111]-Oriented nt-Cu 75 3.7 Uni-directional Growth of η-Cu 6 Sn 5 in Microbumps on (111) Oriented nt-Cu 77 3.8 Low Thermal-Budget Cu-to-Cu Bonding Using [111]-Oriented nt-Cu 78 3.9 Nanotwin Cu RDL for Fanout Package and 3D IC Integration 83 Problems 86 References 87 4 Solid–Liquid Interfacial Diffusion Reaction (SLID) Between Copper and Solder 91 4.1 Introduction 91 4.2 Kinetics of Scallop-Type IMC Growth in SLID 93 4.3 A Simple Model for the Growth of Mono-Size Hemispheres 95 4.4 Theory of Flux-Driven Ripening 97 4.5 Measurement of the Nano-channel Width Between Two Scallops 100 4.6 Extremely Rapid Grain Growth in Scallop-Type Cu6Sn5 in Slid 100 Problems 102 References 103 5 Solid-State Reactions Between Copper and Solder 105 5.1 Introduction 105 5.2 Layer-Type Growth of IMC in Solid-State Reactions 106 5.3 Wagner Diffusivity 111 5.4 Kirkendall Void Formation in Cu 3 Sn 113 5.5 Sidewall Reaction to Form Porous Cu 3 Sn in μ-Bumps 114 5.6 Effect of Surface Diffusion on IMC Formation in Pillar-Type μ-Bumps 120 Problems 124 References 125 Part II 127 6 Essence of Integrated Circuits and Packaging Design 129 6.1 Introduction 129 6.2 Transistor and Interconnect Scaling 131 6.3 Circuit Design and LSI 133 6.4 System-on-Chip (SoC) and Multicore Architectures 139 6.5 System-in-Package (SiP) and Package Technology Evolution 140 6.6 3D IC Integration and 3D Silicon Integration 144 6.7 Heterogeneous Integration: An Introduction 145 Problems 146 References 146 7 Performance, Power, Thermal, and Reliability 149 7.1 Introduction 149 7.2 Field-Effect Transistor and Memory Basics 151 7.3 Performance: A Race in Early IC Design 155 7.4 Trend in Low Power 157 7.5 Trade-off between Performance and Power 159 7.6 Power Delivery and Clock Distribution Networks 160 7.7 Low-Power Design Architectures 163 7.8 Thermal Problems in IC and Package 166 7.9 Signal Integrity and Power Integrity (SI/PI) 168 7.10 Robustness: Reliability and Variability 169 Problems 171 References 172 8 2.5D/3D System-in-Packaging Integration 173 8.1 Introduction 173 8.2 2.5D IC: Redistribution Layer (RDL) and TSV-Interposer 174 8.3 2.5D IC: Silicon, Glass, and Organic Substrates 176 8.4 2.5D IC: HBM on Silicon Interposer 177 8.5 3D IC: Memory Bandwidth Challenge for High-Performance Computing 178 8.6 3D IC: Electrical and Thermal TSVs 180 8.7 3D IC: 3D-Stacked Memory and Integrated Memory Controller 182 8.8 Innovative Packaging for Modern Chips/Chiplets 183 8.9 Power Distribution for 3D IC Integration 186 8.10 Challenge and Trend 187 Problems 188 References 188 Part III 191 9 Irreversible Processes in Electronic Packaging Technology 193 9.1 Introduction 193 9.2 Flow in Open Systems 196 9.3 Entropy Production 198 9.3.1 Electrical Conduction 199 9.3.1.1 Joule Heating 201 9.3.2 Atomic Diffusion 203 9.3.3 Heat Conduction 203 9.3.4 Conjugate Forces When Temperature Is a Variable 205 9.4 Cross-Effects in Irreversible Processes 206 9.5 Cross-Effect Between Atomic Diffusion and Electrical Conduction 207 9.5.1 Electromigration and Stress-Migration in Al Strips 209 9.6 Irreversible Processes in Thermomigration 211 9.6.1 Thermomigration in Unpowered Composite Solder Joints 212 9.7 Cross-Effect Between Heat Conduction and Electrical Conduction 215 9.7.1 Seebeck Effect 216 9.7.2 Peltier Effect 218 Problems 219 References 219 10 Electromigration 221 10.1 Introduction 221 10.2 To Compare the Parameters in Atomic Diffusion and Electric Conduction 222 10.3 Basic of Electromigration 224 10.3.1 Electron Wind Force 225 10.3.2 Calculation of the Effective Charge Number 227 10.3.3 Atomic Flux Divergence Induced Electromigration Damage 228 10.3.4 Back Stress in Electromigration 230 10.4 Current Crowding and Electromigration in 3-Dimensional Circuits 231 10.4.1 Void Formation in the Low Current Density Region 234 10.4.2 Current Density Gradient Force in Electromigration 238 10.4.3 Current Crowding Induced Pancake-Type Void Formation in Flip-Chip Solder Joints 242 10.5 Joule Heating and Heat Dissipation 243 10.5.1 Joule Heating and Electromigration 244 10.5.2 Joule Heating on Mean-Time-to-Failure in Electromigration 245 Problems 245 References 246 11 Thermomigration 249 11.1 Introduction 249 11.2 Driving Force of Thermomigration 249 11.3 Analysis of Heat of Transport, Q* 250 11.4 Thermomigration Due to Heat Transfer Between Neighboring Pairs of Poweredand Unpowered Solder Joints 253 Problems 255 References 255 12 Stress-Migration 257 12.1 Introduction 257 12.2 Chemical Potential in a Stressed Solid 258 12.3 Stoney’s Equation of Biaxial Stress in Thin Films 260 12.4 Diffusional Creep 264 12.5 Spontaneous Sn Whisker Growth at Room Temperature 267 12.5.1 Morphology 267 12.5.2 Measurement of the Driving Force to Grow a Sn Whisker 271 12.5.3 Kinetics of Sn Whisker Growth 272 12.5.4 Electromigration-Induced Sn Whisker Growth in Solder Joints 275 12.6 Comparison of Driving Forces Among Electromigration, Thermomigration, and Stress-Migration 277 12.6.1 Products of Force 278 Problems 279 References 280 13 Failure Analysis 281 13.1 Introduction 281 13.2 Microstructure Change with or Without Lattice Shift 285 13.3 Statistical Analysis of Failure 287 13.3.1 Black’s Equation of MTTF for Electromigration 287 13.3.2 Weibull Distribution Function and JMA Theory of Phase Transformations 289 13.4 A Unified Model of MTTF for Electromigration, Thermomigration, and Stress-Migration 290 13.4.1 Revisit Black’s Equation of MTTF for Electromigration 290 13.4.2 MTTF for Thermomigration 292 13.4.3 MTTF for Stress-Migration 292 13.4.4 The Link Among MTTF for Electromigration, Thermomigration, and Stress-Migration 293 13.4.5 MTTF Equations for Other Irreversible Processes in Open Systems 293 13.5 Failure Analysis in Mobile Technology 293 13.5.1 Joule Heating Enhanced Electromigration Failure of Weak-Link in 2.5D IC Technology 294 13.5.2 Joule Heating Induced Thermomigration Failure Due to Thermal Crosstalk in 2.5D IC Technology 298 Problems 301 References 302 14 Artificial Intelligence in Electronic Packaging Reliability 303 14.1 Introduction 303 14.2 To Change Time-Dependent Event to Time-Independent Event 304 14.3 To Deduce MTTF from Mean Microstructure Change to Failure 305 14.4 Summary 306 Index 307

Discover a comprehensive exploration of the materials science and technology of electronic packaging In Electronic Packaging Science and Technology, an expert team of researchers delivers an insightful presentation of the modern state of electronic packaging and the role it plays in moving technology forward. The authors provide an overview of electronic packaging and provide the reader with the fundamentals of the most important packaging techniques such as wire bonding, tap automatic bonding, flip chip solder joint bonding, microbump bonding, and low temperature direct Cu-to-Cu bonding. The book also offers descriptions of the concepts and theory of electronic circuit design and its role in low power devices, biomedical devices, and circuit integration. Finally, the authors provide descriptions of the current state of the science of electronic packaging and its reliability. The authors include real-world case studies at the end of each chapter to reinforce and illustrate the concepts contained within. The book also includes: A thorough introduction to the state-of-the-art of electronic packaging, including the impact of big data and discussions of packaging techniquesA comprehensive exploration of electrical circuits in electronics packaging, including the principles of electronic circuit design, the design of redistribution layers, and the design of low power devices and circuitsA practical discussion of the science of electronic packaging, including Joule heating, reliability issues in packaging technology, and solid-state reactions intrinsic diffusivity Perfect for scientists and engineers in research and industry labs, Electronic Packaging Science and Technology will also earn a place in the libraries of advanced undergraduate and graduate students studying materials science, physics, and electrical engineering.