Preface xv 1 Overview of Flexible Electronic Encapsulating Technology 1 Zhenguo Liu and Yongji Chen 1.1 Flexible Electronics Overview 1 1.2 Development of Flexible Electronic Encapsulating Technology 5 1.2.1 Flip Chip Process 11 1.2.2 Progress of CIF-Based Flexible Electronic Encapsulating Technology 13 1.3 Encapsulating Technology of Several Important Flexible Electronic Devices 14 1.

3.1 Organic Light-Emitting Diode 14 1.3.2 Flexible Solar Cell Encapsulating 21 1.3.3 Flexible Amorphous Silicon Solar Cells 21 1.3.4 Flexible Perovskite Solar Cells 23 1.

4 Flexible Electronic Encapsulating Materials 26 1.4.1 Selection Principle of Flexible Electronic Encapsulating Materials 26 1.4.2 Desirable Properties of Flexible Electronic Encapsulating Materials 27 1.5 Overview of the Development of Flexible Electronic Packaging at Home and Abroad 28 References 29 2 Basic Concepts Related to Flexible Electronic Packaging 33 Peng-an Zong and Mengran Chen 2.1 Composition of Flexible Electronic Packaging 33 2.1.

1 Flexible Substrate 34 2.1.2 Electronic Components 35 2.1.3 Crosslinked Conductive Materials 36 2.1.4 Adhesive Layer 36 2.1.

5 Coating Layer 37 2.2 Flexible Electronic Packaging Structure 37 2.2.1 Curved Structures of Hard Thin Films 38 2.2.2 Island-Bridge Structure 39 2.2.3 Pre-strained Super-Soft Interconnect Structure 40 2.

2.4 Open Grid Structure 40 2.3 Encapsulation Principle 41 2.3.1 Basic Principle of Penetration 41 2.3.2 Permeation Mechanism of Water Vapor and Gas 43 2.3.

3 Barrier Performance Measurement 47 2.3.4 Thin-Film Barrier Technology for Organic Devices 49 2.3.4.1 Single-Layer Film Package 50 2.3.4.

2 Multilayer Film Packaging 53 2.3.5 Film Encapsulation Mechanics 58 2.4 Packaging Technology 62 2.4.1 Local Multilayer Packaging 62 2.4.2 Multilayer Barrier Film Packaging 62 2.

4.3 Online Thin-Film Encapsulation 63 2.4.4 Atomic Layer Deposition (ALD) Encapsulation 63 2.4.5 Inkjet Packaging 64 2.4.6 Flexible Glass Packaging 65 2.

5 Packaging Stability 65 2.6 Encapsulated Products 67 2.7 Chapter Summary 69 References 69 3 Flexible Substrates 77 Yanhui Chen, Xian Zhang, and Zhiqiang Wu 3.1 Concept and Connotation of Flexible Substrates 77 3.2 Development History of Flexible Substrates 78 3.3 Flexible Substrate Materials 82 3.3.1 Polydimethylsiloxane 82 3.

3.2 Polyvinyl Alcohol 82 3.3.3 Polycarbonate 84 3.3.4 Polyester 85 3.3.5 Polyimide 88 3.

3.6 Polyurethane 89 3.3.7 Parylene 91 3.3.8 Liquid Crystal Polymer 92 3.3.9 Hydrogel 93 3.

4 Molding Technology of Flexible Substrate 94 3.4.1 Coating Technology 94 3.4.1.1 Dip Coating Method 94 3.4.1.

2 Air Knife Coating Method 95 3.4.1.3 Scraper Coating Method 96 3.4.1.4 Rotary Coating Method 96 3.4.

2 Melt Extrusion Molding 96 3.4.3 Melt Extrusion Blow Molding 96 3.4.4 Solution Tape Casting 98 3.4.5 Bidirectional Drawing Molding 98 3.4.

6 Chemical Vapor Deposition 99 3.5 Performance Evaluation of Flexible Substrates 101 3.5.1 Mechanical Flexibility 101 3.5.2 Ductility 102 3.5.3 Adhesive Property 103 3.

5.4 Barrier Property 103 3.5.5 Electrical Property 105 3.5.6 Chemical Stability 105 3.5.7 Dimensional Stability 105 3.

5.8 Surface Smoothness and Thickness Uniformity 106 3.5.9 Optical Clarity (Transmittance) 106 3.5.10 Biocompatibility 107 3.5.11 Bioabsorbability 107 3.

6 Application of Flexible Substrates 108 3.6.1 Flexible Display Substrates 108 3.6.2 Flexible Electrode Substrates 109 3.6.3 Flexible Sensing Substrates 110 3.7 Development Trend of Flexible Substrates 111 3.

7.1 Intelligent and Functional Flexible Substrates 111 3.7.2 Green Degradable Flexible Substrates 112 3.7.3 Optimization of Interface Compatibility of Flexible Substrates 113 References 114 4 Test Methods 123 Junjie Yuan 4.1 Sealing Test 123 4.1.

1 Direct Diffusion Method 124 4.1.1.1 Weight Cup Test 124 4.1.1.2 Differential Pressure Method 124 4.1.

1.3 Balancing Method 124 4.1.1.4 Tunable Diode Laser Absorption Spectrometry 125 4.1.1.5 Isotope Labeling Mass Spectrometry 126 4.

1.2 Indirect Optical Method 128 4.1.3 Indirect Electrical Method 129 4.1.3.1 Calcium Electrical Test 129 4.1.

3.2 Dielectric Measurement Method 132 4.1.4 Indirect Electrochemical Method 133 4.1.4.1 Electrochemical Impedance Spectroscopy (EIS) 134 4.1.

4.2 Leakage Current Monitoring Method (LCM) 134 4.1.4.3 Linear Scanning Voltammetry (LSV) 135 4.1.5 Indirect Electromechanical Method 136 4.2 Bending Test 136 4.

2.1 Static Bending and Dynamic Bending 137 4.2.2 Three-Point Bending and Four-Point Bending 138 4.2.3 Push Bending and Roll Bending 140 4.2.3.

1 Push Bending 140 4.2.3.2 Rolling Bend 141 4.3 Mechanical Performance Testing 143 4.4 Stability Testing 147 References 149 5 Flexible Electronic Encapsulation 157 Tao Yu 5.1 Inorganic Encapsulating Material 158 5.1.

1 Metal Encapsulating Material 158 5.1.1.1 Copper, Aluminum 158 5.1.1.2 Favorable Alloys 160 5.1.

1.3 Copper-Tungsten Alloy (Cu-W) 160 5.1.2 Ceramic Encapsulating Material 161 5.1.2.1 Al 2 O 3 Ceramic Encapsulation Material 161 5.1.

2.2 AlN Ceramic Encapsulation Materials 161 5.1.2.3 BeO Ceramic Encapsulation Material 161 5.1.2.4 BN Ceramic Encapsulation Materials 161 5.

1.3 New Trend in Inorganic Encapsulating Materials Combined with Flexible Electronic Technology 162 5.2 Organic Encapsulating Material 164 5.2.1 Polymer Encapsulating Material 164 5.2.1.1 Epoxy Resins 165 5.

2.1.2 Polyimide Resins 165 5.2.1.3 Organic Silicon 166 5.2.1.

4 Bismaleimide 167 5.2.1.5 Bismaleimide Triazine Resin 168 5.2.2 Development Trend of Organic Encapsulating Materials in Flexible Electronic Devices 169 5.3 Organic-Inorganic Hybrid Encapsulating Material 170 5.3.

1 Application of Organic-Inorganic Hybrid Materials in Flexible Electronics 170 5.3.1.1 Strain and Pressure Sensors 171 5.3.1.2 Temperature Sensor 172 5.3.

1.3 Humidity Sensor 173 5.3.1.4 Optical Sensors 173 5.3.1.5 Other Types of Sensing Devices 174 5.

3.2 Development Trends of Organic-Inorganic Hybrid Materials 174 References 175 6 Development of Flexible Electronics Packaging Technology 179 Qiushi Rao 6.1 Flexible Electronics Packaging 179 6.1.1 Single-Layer Thin-Film Packaging 179 6.1.2 Multi-Layer Thin-Film Packaging 180 6.1.

2.1 Barix Multilayer Thin-Film Packaging 180 6.1.2.2 Other Multilayer Thin-Film Packaging 182 6.2 Thin-Film Packaging Technology 183 6.2.1 PECVD Atomic Layer Deposition Packaging Technology 183 6.

2.1.1 Introduction to PECVD Technology 183 6.2.1.2 Development of PECVD Technology 184 6.2.2 ALD Atomic Layer Deposition Packaging Technology 185 6.

2.2.1 Introduction to ALD Technology 185 6.2.2.2 Development of ALD Technology 186 6.2.3 Inkjet Packaging Technology 189 6.

2.3.1 Introduction to Inkjet Encapsulation Technology 189 6.2.3.2 Continuous Inkjet Printing 189 6.2.3.

3 Drop-on-Demand Inkjet Printing 190 6.2.3.4 Development of Inkjet Printing Technology 191 References 192 7 Application of Flexible Electronics Packaging 195 Yuezhou Zhang 7.1 Industry Chain Analysis of Flexible Electronics Packaging 195 7.1.1 Upstream, Midstream, and Downstream of the Flexible Electronics Industry Chain 195 7.1.

2 Overview of the Development of Flexible Packaging Materials 196 7.2 Packaging Applications of Flexible OLED Devices 197 7.2.1 Stability Issues of Flexible OLED Devices 198 7.2.2 Flexible OLED Packaging Technology 201 7.2.2.

1 Lack of Breakthrough in Encapsulating Technology 202 7.2.2.2 Low Yield Rate 203 7.3 Packaging Applications for Flexible Solar Cells 208 7.3.1 Inorganic Flexible Solar Cells 209 7.3.

2 Organic Flexible Solar Cells 211 7.3.3 Dye-Sensitized Solar Cells 213 7.3.3.1 Structure of Dye-Sensitized Solar Cells 213 7.3.3.

2 Light Anode 215 7.3.3.3 Counter Electrode 216 7.4 Packaging Applications for Flexible Electronic Devices 217 7.4.1 Basic Structure of Flexible Electronic Devices 217 7.4.

2 Application of Flexible Electronic Devices 218 7.4.2.1 Optoelectronics 219 7.4.2.2 Robot 220 7.4.

2.3 Biomedical 221 7.4.2.4 Energy Equipment 223 7.5 Packaging Applications for Flexible Electronics Sensors 226 7.5.1 Common Materials of Flexible Sensors 228 7.

5.1.1 Flexible Substrate 228 7.5.1.2 Metal Materials 228 7.5.1.

3 Inorganic Semiconductor Materials 229 7.5.1.4 Organic Materials 229 7.5.1.5 Carbon Materials 230 7.5.

2 Flexible Gas Sensors 230 7.5.3 Flexible Pressure Sensors 230 7.5.4 Flexible Humidity Sensor 232 7.5.5 Normal Sensors Compare with Flexible Sensors 232 References 233 8 Testing Standards 239 Junjie Yuan 8.1 Terminology and Alphabetic Symbols 240 8.

1.1 Scope 240 8.1.2 Terms.