Flexible Flat Panel Displays Wiley– SID Series in Display Technology Series Editor: Dr. Ian Sage Advisory Board: Paul Drzaic, Ioannis (John) Kymissis, Ray Ma, Ian Underwood, Michael Wittek, Qun (Frank) Yan Flexible Flat Panel Displays, Second Edition Darran R. Cairns, Dirk J. Broer, and Gregory P. Crawford Liquid Crystal Displays - Addressing Schemes and Electro-Optical Effects, Third Edition Ernst Lueder, Peter Knoll, and Seung Hee Lee Amorphous Oxide Semiconductors: IGZO and Related Materials for Display and Memory Hideo Hosono, Hideya Kumomi Introduction to Flat Panel Displays, Second Edition Jiun-Haw Lee, I-Chun Cheng, Hong Hua, and Shin-Tson Wu Flat Panel Display Manufacturing Jun Souk, Shinji Morozumi, Fang-Chen Luo, and Ion Bita Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO: Application to Displays Shunpei Yamazaki, Tetsuo Tsutsui OLED Displays: Fundamentals and Applications, Second Edition Takatoshi Tsujimura Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO: Fundamentals Noboru Kimizuka, Shunpei Yamazaki Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO: Application to LSI Shunpei Yamazaki, Masahiro Fujita Interactive Displays: Natural Human-Interface Techniques Achintya K. Bhowmik Addressing Techniques of Liquid Crystal Displays Temkar N. Ruckmongathan Modeling and Optimization of LCD Optical Performance Dmitry A. Yakovlev, Vladimir G. Chigrinov, and Hoi-Sing Kwok Fundamentals of Liquid Crystal Devices, Second Edition Deng-Ke Yang and Shin-Tson Wu 3D Displays Ernst Lueder Illumination, Color and Imaging: Evaluation and Optimization of Visual Displays P. Bodrogi, T. Q. Khan Liquid Crystal Displays: Fundamental Physics and Technology Robert H. Chen Transffective Liquid Crystal Displays Zhibing Ge and Shin-Tson Wu LCD Backlights Shunsuke Kobayashi, Shigeo Mikoshiba, and Sungkyoo Lim (Eds.) Mobile Displays: Technology and Applications Achintya K. Bhowmik, Zili Li, and Philip Bos (Eds.) Photoalignment of Liquid Crystalline Materials: Physics and Applications Vladimir G. Chigrinov, Vladimir M. Kozenkov, and Hoi-Sing Kwok Projection Displays, Second Edition Mathew S. Brennesholtz and Edward H. Stupp Introduction to Microdisplays David Armitage, Ian Underwood, and Shin-Tson Wu Polarization Engineering for LCD Projection Michael G. Robinson, Jianmin Chen, and Gary D. Sharp Digital Image Display: Algorithms and Implementation Gheorghe Berbecel Colour Engineering: Achieving Device Independent Colour Phil Green and Lindsay MacDonald (Eds.) Display Interfaces: Fundamentals and Standards Robert L. Myers Reffective Liquid Crystal Displays Shin-Tson Wu and Deng-Ke Yang Display Systems: Design and Applications Lindsay W. MacDonald and Anthony C. Lowe (Eds.) Flexible Flat Panel Displays Edited by Darran R. Cairns University of Missouri, Kansas City, USA Dirk J. Broer Eindhoven Technical University, Netherlands Gregory P. Crawford Miami University, Florida, USA Second Edition This edition first published 2023 © 2023 John Wiley & Sons Ltd Edition History © 1e, 2005 John Wiley & Sons Ltd All rights reserved. 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Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. Library of Congress Cataloging-in-Publication Data Names: Cairns, Darran R., editor. | Broer, Dirk J., editor. | Crawford, Gregory P., editor. Title: Flexible flat panel displays / edited by Darran R. Cairns, Dirk J. Broer, Gregory P. Crawford. Description: Second edition. | Hoboken, NJ : John Wiley & Sons, 2023. | Includes bibliographical references and index. Identifiers: LCCN 2021052707 (print) | LCCN 2021052708 (ebook) | ISBN 9781118751114 (hardback) | ISBN 9781118751060 (pdf) | ISBN 9781118750889 (epub) | ISBN 9781118751077 (ebook) Subjects: LCSH: Information display systems. | Liquid crystal displays. | Electroluminescent display systems. Classification: LCC TK7882.I6 F55 2023 (print) | LCC TK7882.I6 (ebook) | DDC 621.3815/422--dc23/eng/20211116 LC record available at https://lccn.loc.gov/2021052707 LC ebook record available at https://lccn.loc.gov/2021052708 Cover Image: © metamorworks/Shutterstock Cover Design: Wiley Set in 9.5/12.5pt STIXTwoText by Integra Software Services Pvt. Ltd, Pondicherry, India vii Contents Series Editor’s Foreword xv List of Contributors xvii 1 Introduction 1 Darran R. Cairns, Gregory P. Crawford, and Dirk J. Broer 1.1 Toward Flexible Mobile Devices 1 1.2 Flexible Display Layers 2 1.3 Other Flexible Displays and Manufacturing 2 2 Engineered Films for Display Technology 5 W.A. MacDonald 2.1 Introduction 5 2.2 Factors Influencing Film Choice 5 2.2.1 Application Area 5 2.2.2 Physical Form/Manufacturing Process 6 2.2.3 Film Property Set 7 2.2.3.1 Polymer Type 7 2.2.3.2 Optical Clarity 9 2.2.3.3 Birefringence 10 2.2.3.4 The Effect of Thermal Stress on Dimensional Reproducibility 10 2.2.3.5 Low-bloom Films 11 2.2.3.6 Solvent and Moisture Resistance 12 2.2.3.7 The Effect of Mechanical Stress on Dimensional Reproducibility 16 2.2.3.8 Surface Quality 18 2.3 Summary of Key Properties of Base Substrates 19 2.4 Planarizing Coatings 21 2.5 Examples of Film in Use 23 2.6 Concluding Remarks 24 Acknowledgments 25 3 Liquid Crystal Optical Coatings for Flexible Displays 27 Owain Parri, Johan Lub, and Dirk J. Broer 3.1 Introduction 27 3.2 LCN Technology 27 3.3 Thin-film Polarizers 29 viii Contents 3.3.1 Smectic Polarizers 29 3.3.2 Cholesteric Polarizers 32 3.4 Thin-film Retarders 34 3.4.1 Reactive Mesogen Retarders 35 3.4.2 Chromonic Liquid Crystal-based Retarders 37 3.4.3 Liquid Crystal Alignment and Patterned Retarders 37 3.5 Color Filters 41 3.6 Conclusion 43 4 Large Area Flexible Organic Field-effect Transistor Fabrication 47 Zachary A. Lamport, Marco Roberto Cavallari, and Ioannis Kymissis 4.1 Introduction 47 4.2 Substrates 48 4.3 Photolithography 49 4.4 Printing for Roll-to-roll Fabrication 52 4.4.1 Inkjet Printing 52 4.4.2 Gravure and Flexographic Printing 55 4.4.3 Screen Printing 56 4.4.4 Aerosol Jet Printing 56 4.4.5 Contact Printing 58 4.4.6 Meniscus Dragging 60 4.5 Conclusions 62 5 Metallic Nanowires, Promising Building Nanoblocks for Flexible Transparent Electrodes 67 Jean-Pierre Simonato 5.1 Introduction 67 5.2 TEs Based on Metallic Nanowires 68 5.2.1 Metallic Nanowires, New Building Nanoblocks 68 5.2.2 Random Network Fabrication 69 5.2.3 Optical Characterization 70 5.2.4 Electrical Characterization 71 5.2.5 Mechanical Aspect 73 5.3 Application to Flexible Displays 73 5.3.1 Touch Screens 73 5.3.2 Light-emitting Diodes Displays 74 5.3.3 Electrochromic Flexible Displays 76 5.3.4 Other Displays 77 5.4 Conclusions 78 6 Optically Clear Adhesives for Display Assembly 85 Albert I. Everaerts 6.1 Introduction 85 6.2 OCA Definition and General Performance Specifications 86 6.3 Application Examples and Challenges 89 6.3.1 Outgassing Tolerant Adhesives 90 Contents ix 6.3.2 Anti-whitening Adhesives 91 6.3.3 Non-corrosive OCAs 92 6.3.4 Compliant OCAs for High Ink-step Coverage and Mura-free Assembly of LCD Panels 94 6.3.5 Reworkable OCAs 102 6.3.6 Barrier Adhesives 103 6.4 Summary and Remaining Challenges 104 7 Self-healing Polymer Substrates 107 Progyateg Chakma, Zachary A. Digby, and Dominik Konkolewicz 7.1 Introduction 107 7.2 General Classes of Self-healing Polymers 108 7.2.1 Types of Dynamic Bonds in Self-healing Polymers 109 7.2.2 Supramolecularly Crosslinked Self-healing Polymers 109 7.2.2.1 Hydrogen Bonding 110 7.2.2.2 π–π Stacking 110 7.2.2.3 Ionic Interactions 111 7.2.3 Dynamic-covalently Crosslinked Self-healing Polymers 111 7.2.3.1 Cycloaddition Reactions 111 7.2.3.2 Disulfides-based Reversible Reactions 112 7.2.3.3 Acylhydrazones 113 7.2.3.4 Boronate Esters 113 7.3 Special Considerations for Flexible Self-healing Polymers 114 7.4 Incorporation of Electrically Conductive Components 115 7.4.1 Metallic Conductors 115 7.4.2 Conductive Polymers 116 7.4.3 Carbon Materials 118 7.4.4 Polymerized Ionic Liquids 119 7.5 Additional Possibilities Enabled by Three-dimensional Printing 119 7.6 Concluding Remarks 121 8 Flexible Glass Substrates 129 Armin Plichta, Andreas Habeck, Silke Knoche, Anke Kruse, Andreas Weber, and Norbert Hildebrand 8.1 Introduction 129 8.2 Display Glass Properties 129 8.2.1 Overview of Display Glass Types 129 8.2.2 Glass Properties 130 8.2.2.1 Optical Properties 130 8.2.2.2 Chemical Properties 130 8.2.2.3 Thermal Properties 131 8.2.2.4 Surface Properties 132 8.2.2.5 Permeability 133 8.3 Manufacturing of Thin “Flexible’’ Glass 134 8.3.1 Float and Downdraw Technology for Special Glass 134 8.3.2 Limits 135