List of Nomenclatures viii

About the Authors xix

Preface xxi

1 Introduction 1

1.1 Development History of Packaging 1

1.1.1 BGA 2

1.1.2 CSP 2

1.1.3 MCM 2

1.1.4 3D Packaging 3

1.2 Heat Generation in Opto-electronic Package 4

1.2.1 Heat Generation Due to Nonradiative Recombination 4

1.2.2 Heat Generation Due to Shockley-Read-Hall (SRH) Recombination 5

1.2.3 Heat Generation Due to Auger Recombination 5

1.2.4 Heat Generation Due to Surface Recombination 6

1.2.5 Heat Generation Due to Current Crowding and Overflow 6

1.2.6 Heat Generation Due to Light Absorption 8

1.3 Thermal Issues and Challenges 8

1.3.1 Thermal Management 8

1.3.2 Mechanical/Electrical Reliability 9

1.4 Organization Arrangement 10

References 10

2 Thermal Conduction and Solutions 13

2.1 Concept of Thermal Conduction 13

2.2 Thermal Resistance 14

2.2.1 Basic Concept of Thermal Resistance 14

2.2.2 Thermal Contact Resistance 16

2.2.3 Thermal Spreading Resistance 17

2.2.4 Thermal Resistance Network 18

2.2.5 Transient Thermal Conduction and Thermal Impedance 19

2.3 High Thermal Conductivity Materials 22

2.3.1 Structure and Materials of Chip 22

2.3.1.1 Structures of Chip 23

2.3.1.2 Material of LED Chip 23

2.3.1.3 Sapphire 23

2.3.1.4 Silicon 24

2.3.1.5 Silicon Carbide 24

2.3.1.6 GaN 25

2.3.1.7 ß-Ga₂O₃ 25

2.3.2 Solder 25

2.3.3 Heat Spreader 25

2.3.3.1 Graphene 25

2.3.3.2 h-BN 27

2.3.4 Package Substrate Materials 27

2.3.5 Thermal Conductive Polymer Composite for Encapsulation 28

2.3.6 Coolants 29

2.4 Thermal Interface Materials 30

2.4.1 Categories of Thermal Interface Materials 30

2.4.1.1 Carbon-Polymer TIMs 32

2.4.1.2 Metal-Polymer TIMs 32

2.4.1.3 Ceramic-Polymer TIMs 33

2.4.2 Strategies for Enhancing TC of Thermal Interface Materials 34

2.4.2.1 Surface Treatment 34

2.4.2.2 Filler Hybridization 34

2.4.2.3 Orientation and Network Engineering 34

2.4.3 Models for Thermal Conductivity of Thermal Interface Materials 35

2.5 Heat Pipe and Vapor Chamber 36

2.5.1 Heat Pipe 36

2.5.2 Vapor Chamber 36

2.6 Phase-Change Materials (PCMs) 37

2.6.1 Categories and Applications of PCMs 37

2.6.2 Thermal Conductivity Enhancement of PCMs 38

2.7 Thermal Metamaterials 38

2.7.1 Concept of Thermal Metamaterials 38

2.7.2 Thermal Metamaterial Design 39

2.8 Chapter Summary 40

References 40

3 Thermal Convection and Solutions 45

3.1 Basic Knowledge of Convection Heat Transfer 45

3.1.1 Basic Concepts of Convection Heat Transfer 45

3.1.2 Basic Theories of Convection Heat Transfer 46

3.1.2.1 Similar Theory of Convection Heat Transfer 46

3.1.2.2 Boundary Layer Theory of Convection Heat Transfer 47

3.1.3 Basic Calculation of Convection Heat Transfer 48

3.1.3.1 Forced Convection Heat Transfer of a Fluid Over an Object 48

3.1.3.2 Forced Convection Heat Transfer in the Duct 48

3.1.3.3 Natural Convection Heat Transfer of Vertical Plate 50

3.1.3.4 Pool Boiling Convection Heat Transfer 51

3.2 Air Cooling 53

3.2.1 Heat Sink Design and Optimization 53

3.2.2 Piezoelectric Fan Cooling 57

3.3 Liquid Cooling 59

3.3.1 Microchannel Liquid Cooling 59

3.3.2 Impingement Jet Liquid Cooling 60

3.3.3 Flow Boiling 61

3.3.4 Spray Cooling 62

3.3.5 Nanofluid 64

3.4 Chapter Summary 65

References 65

4 Thermal Radiation and Solutions 71

4.1 Concept of Thermal Radiation 71

4.2 Atmospheric Transparent Window 72

4.3 Spectra-Regulation Thermal Radiation 73

4.3.1 Deep Q-Learning Network for Emissivity Spectral Regulation 73

4.3.2 Design and Optimization of Radiative Cooling Radiators Based on DQN 76

4.3.3 Colored Radiative Cooling 79

4.3.3.1 Color Display Characterization 80

4.3.3.2 Influence of Structural Parameters on Colored Radiative Cooler 81

4.4 Near-Field Thermal Radiation in Thermal Management 85

4.5 Chapter Summary 86

References 86

5 Opto-Thermal Coupled Modeling 91

5.1 Opto-Thermal Modeling in Chips 91

5.1.1 Thermal Droop 91

5.1.2 Opto-Electro-Thermal Theory for LED 93

5.2 Opto-Thermal Modeling in Phosphor 95

5.2.1 Phosphor Heating Phenomenon 96

5.2.2 Phosphor Optical Model 98

5.2.3 Optical-Thermal Phosphor Model Considering Thermal Quenching 107

5.3 Opto-Thermal Modeling Applications in White LEDs 115

5.4 Chapter Summary 120

References 121

6 Thermally Enhanced Thermal Interfacial Materials 127

6.1 Modeling of TIM 127

6.1.1 Model of Thermal Contact Resistance 128

6.1.1.1 Theoretical Background 128

6.1.1.2 Topographical Analysis 129

6.1.1.3 Mechanical Analysis 130

6.1.2 Experiment for the Measurement of R c 131

6.1.2.1 Experimental Principles 131

6.1.2.2 Thermal and BLT Measurement 131

6.1.2.3 Sample Preparation 132

6.1.2.4 Error Analysis 133

6.1.3 Validation and Discussion 133

6.1.3.1 Comparison of Experimental Data with the Model 133

6.1.3.2 Influence of the Parameters on the Model Results 135

6.2 Thermal Conductivity Tunability of TIM 137

6.2.1 Thermal Conductivity Enhancement of BN-Composites Using Magnetic Field 139

6.2.1.1 Fabrication of the Composites 139

6.2.1.2 Characterization and Analysis 140

6.2.1.3 Thermal Properties of Composites 143

6.2.2 Thermal Conductivity Enhancement of BN-Composites Using Combined Mechanical and Magnetic Stimuli 146

6.2.2.1 Fabrication of the Composites 147

6.2.2.2 Characterization and Analysis 148

6.2.2.3 Thermal Properties of the Composites 150

6.2.2.4 Theoretical Analysis of Thermal Conductivity 150

6.2.3 Magnetic-Tuning TIMs for Local Heat Dissipation 154

6.2.3.1 Fabrication of the Composites 155

6.2.3.2 Evaluation for Thermal Performance of the Composites 156

6.2.3.3 Thermal Properties of the Composites 157

6.2.3.4 Finite-Element Analysis of Composites Loaded with Local Heat Source 157

6.2.4 Thermal Conductivity Enhancement of CFs-Composites Using Preset Magnetic Field 160

6.2.4.1 Fabrication of the Composites 161

6.2.4.2 Characterization and Analysis 162

6.2.4.3 Thermal and Mechanical Properties of Composites 165

6.2.5 Self-Assembly Design of TIMs for Hotspot Problem 169

6.2.5.1 Fabrication of the Composites 171

6.2.5.2 Characterization, Analysis, and Optimization 173

6.2.5.3 Thermal and Mechanical Properties of Composites 177

6.2.5.4 Experiment Section 180

6.3 Interfacial Thermal Transport Manipulation of TIM 182

6.3.1 Synthesis of Interface Systems 183

6.3.2 Measurement of Interfacial Thermal Conductance 183

6.3.3 Characterization of Interfacial Bonds 184

6.3.4 Importance of Covalent Bonds 187

6.3.5 Manipulation of the Thermal Properties of Nanocomposites 187

6.4 Chapter Summary 188

References 189

7 Packaging-Inside Thermal Management for Quantum Dots-Converted LEDs 197

7.1 Thermally Conductive QDs Composite 197

7.2 Heat Transfer Reinforcement Structures 206

7.2.1 Directional Heat Conducting QDs-Polymer 206

7.2.2 Thermally Conductive Composites Annular Fins 212

7.2.3 Packaging Structure Optimization for Temperature Reduction 215

7.3 3D-Interconnected Thermal Conduction of QDs 220

7.4 Chapter Summary 232

References 232

8 Thermal Management in Downhole Devices 237

8.1 Experimental Analysis of Passive Thermal Management Systems 237

8.1.1 Experimental Setup 238

8.1.2 Experimental Results 240

8.1.3 Finite-element Analysis 242

8.2 Thermal Modeling for Downhole Devices 244

8.2.1 Thermal Modeling 244

8.2.2 Experimental Setup 247

8.2.3 Experimental and Simulated Results 248

8.3 Phase-Change Materials Design 255

8.3.1 Material Preparation 255

8.3.2 Characteristics and Thermal Performance 255

8.4 Distributed PCM-Based Thermal Management Systems 260

8.4.1 System Design 260

8.4.2 Simulated and Experimental Results 261

8.5 Thermal Optimization of High-Temperature Downhole Electronic Devices 267

8.5.1 Optimization Method 267

8.5.2 Experimental Setup 270

8.5.3 Thermal Optimization Results 270

8.6 Chapter Summary 275

References 276

9 Liquid Cooling for High-Heat-Flux Electronic Devices 279

9.1 Double-Nozzle Spray Cooling for High-Power LEDs 279

9.1.1 Spray Cooling System 280

9.1.2 Data Analysis Method and Uncertainty Analysis 281

9.1.3 Simulations for Junction Temperature Evaluation 282

9.1.4 Characteristics of High-Power LEDs Module and Spray Droplets 283

9.1.5 Results and Discussion 284

9.1.5.1 Effect of Nozzle Configuration and Flow Rate 285

9.1.5.2 Effect of Nozzle-to-Surface Distance 288

9.1.5.3 Validation Study 289

9.1.5.4 Estimation of Junction Temperature 290

9.2 Direct Body Liquid Cooling 290

9.2.1 Calculation of Surface Heat Transfer Coefficient 292

9.2.2 Body Cooling Thermal Conductive Model 294

9.2.3 Experiment 295

9.2.4 Numerical Simulation 296

9.2.5 Performance of the Developed JIBC Device 297

9.3 Integrated Piezoelectric Pump Cooling 303

9.3.1 Design and Fabrication of JAICIPM 303

9.3.2 Numerical Simulation 305

9.3.3 Experiment 307

9.3.4 Results and Discussion 309

9.4 Microchannel Cooling for Uniform Chip Temperature Control 313

9.4.1 Bilayer Compact Thermal Model 314

9.4.2 Heat Transfer in the Solid Layer 314

9.4.3 Heat Transfer in the Convection Layer 317

9.4.4 Heat Flux Iteration 318

9.4.5 Genetic Algorithm Optimization 318

9.4.6 Validation 319

9.5 Chapter Summary 327

References 328

Index 333