Inkjet-based Micromanufacturing

by Brand, Oliver; Fedder, Gary K.; Hierold, Christofer; Korvink, Jan G.; Tabata, Osamu; Smith, Patrick J.; Shin, Dong H.

• ISBN13: 9783527319046
• ISBN10: 3527319042
• Edition: 1st
• Format: Hardcover
• Copyright: 2012-05-14
• Publisher: Wiley-VCH

Summary

Inkjet-based Micromanufacturing Inkjet technology goes way beyond putting ink on paper: it enables simpler, faster and more reliable manufacturing processes in the fields of micro- and nanotechnology. Modern inkjet heads are per se precision instruments that deposit droplets of fluids on a variety of surfaces in programmable, repeating patterns, allowing, after suitable modifications and adaptations, the manufacturing of devices such as thin-film transistors, polymer-based displays and photovoltaic elements. Moreover, inkjet technology facilitates the large-scale production of flexible RFID transponders needed, eg, for automated logistics and miniaturized sensors for applications in health surveillance. The book gives an introduction to inkjet-based micromanufacturing, followed by an overview of the underlying theories and models, which provides the basis for a full understanding and a successful usage of inkjet-based methods in current microsystems research and development Overview of Inkjet-based Micromanufacturing: Thermal Inkjet Theory and Modeling Post-Printing Processes for Inorganic Inks for Plastic Electronics Applications Inkjet Ink Formulations Inkjet Fabrication of Printed Circuit Boards Antennas for Radio Frequency Identification Tags Inkjet Printing for MEMS

Author Biography

Jan G. Korvink holds a Chair for Microsystems Engineering at the University of Freiburg, Germany, where he also directs the Freiburg Institute for Advanced Studies - FRIAS. He has co-authored more than 160 papers in scientific journals, as well as numerous conference papers, book chapters and a book on semiconductors for engineers. His research interests cover the modeling, simulation and low cost fabrication of MEMS/NEMS, and applications in magnetic resonance. In 2011 he received a European Research Council (ERC) Advanced Grant, the Red Dot Design Concept Award and the University of Freiburg Teaching Award.

Patrick J. Smith is a Lecturer in Manufacturing Technology for the University of Sheffield, UK. He has published over 40 journal and conference papers, and has 3 patents. His main research interests are concerned with reactive inkjet printing, controlled crystallisation using inkjet and additive manufacture.

Dong-Youn Shin is Assistant Professor at the Pukyong National University in Busan, South Korea. Before his appointment, he was research engineer at LG Chem Research Park and then senior research scientist in the division of nanomechanical systems at the Korean Institute of Machinery and Materials in South Korea. He holds 38 patents and over 70 conference and journal papers. His research interests lie in maskless lithography and fine pattern generation for displays and electronics with the piezo inkjet printing technology.

Table of Contents

List of Contributors XIII

1 Overview of Inkjet-Based Micromanufacturing 1
David Wallace

1.1 Introduction 1

1.2 Inkjet Technology 1

1.2.1 Continuous Mode Inkjet (CIJ) Technology 2

1.2.2 Demand Mode Inkjet Technology 2

1.3 Fluid Requirements 3

1.4 Pattern Formation: Fluid/Substrate Interaction 5

1.5 Micromanufacturing 6

1.5.1 Introduction 6

1.5.2 Limitations and Opportunities in Micromanufacturing 7

1.5.3 Benefits of Inkjet in Microfabrication 8

1.6 Examples of Inkjet in Micromanufacturing 9

1.6.1 Chemical Sensors 9

1.6.2 Optical MEMS Devices 10

1.6.3 Bio-MEMS Devices 12

1.6.4 Assembly and Packaging 13

1.7 Conclusions 14

Acknowledgments 14

References 14

2 Combinatorial Screening of Materials Using Inkjet Printing as a Patterning Technique 19
Anke Teichler, Jolke Perelaer, and Ulrich S. Schubert

2.1 Introduction 19

2.2 Inkjet Printing – from Well-Defined Dots to Homogeneous Films 20

2.3 Thin-Film Libraries Prepared by Inkjet Printing 25

2.4 Combinatorial Screening of Materials for Organic Solar Cells 28

2.5 Conclusion and Outlook 34

References 35

3 Thermal Inkjet 41
Naoki Morita

3.1 History of Thermal Inkjet Technology 41

3.2 Market Trends for Inkjet Products and Electrophotography 42

3.3 Structures of Various TIJ Heads 43

3.4 Research on Rapid Boiling and Principle of TIJ 44

3.5 Inkjetting Mechanism of TIJ 47

3.6 Basic Jetting Behavior of TIJ 48

3.6.1 Input Power Characteristics 48

3.6.2 Frequency Characteristics 49

3.6.3 Dependency on Temperature 49

3.7 TIJ Behavior Analysis Using Simulation 51

3.7.1 Cylindrical Thermal Propagating Calculation Based on the Finite Element Method (Software Name: Ansys) 51

3.7.2 Fluidic Free Boundary Calculation Based on the Finite Differentiation Method (Software name: Flow3D) 51

3.8 Issues with Reliability in TIJ 53

3.9 Present and Future Evolution in TIJ Technology 54

References 55

4 High-Resolution Electrohydrodynamic Inkjet 57
Park Jang-Ung and John A. Rogers

4.1 Introduction 57

4.2 Printing System 57

4.3 Control of Jet Motions 59

4.4 Drop-on-Demand Mode Printing 60

4.5 Versatility of Printable Materials and Resolutions 62

4.6 Applications in Electronics and Biotechnology 64

4.7 High-Resolution Printing of Charge 69

References 70

5 Cross Talk in Piezo Inkjet 73
Herman Wijshoff

5.1 Introduction 73

5.2 Electrical Cross Talk 73

5.3 Direct Cross Talk 74

5.4 Pressure-Induced Cross Talk 76

5.5 Acoustic Cross Talk 78

5.6 Printhead Resonance 81

5.7 Residual Vibrations 83

References 84

6 Patterning 87
Patrick J. Smith and Jonathan Stringer

6.1 Introduction 87

6.1.1 Droplet Impact and Final Droplet Radius 88

6.1.2 Evaporation of Inkjet-Printed Droplets at Room Temperature 90

6.1.3 Morphological Control for Ink Droplets, Lines, and Films 91

6.2 Conclusion 94

References 95

7 Drying of Inkjet-Printed Droplets 97
Hans Kuerten and Daniel Siregar

7.1 Introduction 97

7.2 Modeling of Drying of a Droplet 98

7.2.1 Fluid Model 98

7.2.2 Lubrication Approximation 99

7.2.3 Solute Concentration 101

7.2.4 Evaporation Velocity 102

7.2.5 Numerical Method 103

7.3 Results 103

7.3.1 Droplet Shape Evolution 104

7.3.2 Layer Thickness 106

7.3.3 Effect of Diffusion 108

Acknowledgments 109

References 109

8 Postprinting Processes for Inorganic Inks for Plastic Electronics Applications 111
Jolke Perelaer

8.1 Introduction 111

8.1.1 Inkjet Printing 111

8.1.2 Printed Electronics 111

8.2 Inkjet Printing and Postprinting Processes of Metallic Inks 112

8.2.1 Choice of Metal 112

8.2.2 Postprinting Processes to Convert Inorganic Precursor Ink 115

8.2.3 Conventional Sintering Techniques 116

8.2.4 Alternative and Selective Sintering Methods 116

8.2.5 Room-Temperature Sintering 119

8.3 Conclusions and Outlook 121

Acknowledgments 122

References 122

9 Vision Monitoring 127
Kye-Si Kwon

9.1 Introduction 127

9.2 Measurement Setup 127

9.3 Image Processing 130

9.4 Jetting Speed Measurement 134

9.5 Head Normalization and Condition Monitoring 139

9.6 Meniscus Motion Measurement and Its Application 141

References 144

10 Acoustic Monitoring 145
Herman Wijshoff

10.1 Introduction 145

10.2 Self Sensing 145

10.3 Measuring Principle 146

10.4 Drop Formation, Refill, and Wetting 150

10.5 Dirt 152

10.6 Air Bubbles 153

10.7 Printhead Control 156

References 157

11 Equalization of Jetting Performance 159
Man-In Baek and Michael Hong

11.1 Equalization of the Droplet Volume on the Fly 160

11.1.1 Components of a Drop Watcher 160

11.1.2 Equalization through Volume Control 160

11.1.3 Results of the Droplet Volume Measurement and Equalization Process 161

11.1.4 Speed Equalization 164

11.1.5 Problems with the Droplet Equalization Methods on the Fly 164

11.1.5.1 Distortion of the Captured Droplet Images 166

11.1.5.2 Relation between Droplet Volume and Speed 166

11.2 Droplet Volume Equalization with Sessile Droplets 166

11.2.1 Equalizing the Droplet Volume with the Measurement of Sessile Droplets 167

11.2.2 Results of the Sessile Droplet Measurement and Equalization Process 168

11.2.3 Usefulness of the Sessile Droplet Measurement and Equalization Process 169

11.2.4 The Droplet Volume Equalization Process Using Light Transmittance 170

11.2.5 Result of the Droplet Volume Equalization Process Using Light Transmittance 171

Further Reading 171

12 Inkjet Ink Formulations 173
Alexander Kamyshny and Shlomo Magdassi

12.1 Introduction 173

12.2 Ink Formulation 174

12.2.1 Functional Materials 176

12.2.2 Solvents 177

12.2.2.1 Solvent-Based Inks 177

12.2.2.2 Water-Based Inks 178

12.2.3 Hot-Melt (Phase-Change) Inks 178

12.2.4 UV-Curable Inks 178

12.3 Ink Parameters and Additives 179

12.3.1 Rheology Control 179

12.3.2 Surface Tension Modifiers 180

12.3.3 Electrolytes and pH 180

12.3.4 Foaming and Defoamers 181

12.3.5 Humectants 181

12.3.6 Binders 181

12.3.7 Biocides 182

12.3.8 Examples of Inkjet Ink Formulations 182

12.4 Jetting Performance 182

12.4.1 Drop Formation 183

12.4.2 Ink Latency 183

12.4.3 Recoverability 184

12.4.4 Ink Supply 184

12.5 Ink Interaction with Substrates 185

12.6 Nongraphic Applications 186

12.7 Conclusions 187

References 187

13 Issues in Color Filter Fabrication with Inkjet Printing 191
Dong-Youn Shin and Kenneth A. Brakke

13.1 Introduction 191

13.2 Background 191

13.3 Comparison of Printing Technologies 195

13.4 Printing Swathe due to Droplet Volume Variation 199

13.5 Subpixel Filling with a Designed Surface Energy Condition 204

13.6 Other Technical Issues 212

13.7 Conclusion 213

References 213

14 Application of Inkjet Printing in High-Density Pixelated RGB Quantum Dot-Hybrid LEDs 217
Hanna Haverinen and Ghassan E. Jabbour

14.1 Introduction 217

14.2 Background 218

14.3 Experimental Procedure and Results 220

14.3.1 Role of Droplet Formation 221

14.3.2 Atomic Force Microscopy 222

14.3.3 Electroluminescence 225

14.4 Inkjet-Printed, High-Density RGB Pixel Matrix 229

14.5 Conclusion 234

Acknowledgment 234

References 234

Further Reading 236

15 Inkjet Printing of Metal Oxide Thin-Film Transistors 237
Jooho Moon and Keunkyu Song

15.1 Introduction 237

15.2 Materials for Metal Oxide Semiconductors 237

15.3 Inkjet Printing Issues 239

15.3.1 Ink Printability 239

15.3.2 Influence of Substrate Preheat Temperature 242

15.4 Solution-to-Solid Conversion by Annealing 247

15.5 All-Oxide Invisible Transistors 251

15.6 Summary 254

References 254

16 Inkjet Fabrication of Printed Circuit Boards 257
Thomas Sutter

16.1 Introduction 257

16.2 Traditional Printed Circuit Board Processes 257

16.3 Challenges for Inkjet in Printed Circuit Boards 258

16.4 Legend-Marking Processes 261

16.4.1 Cost Comparison 262

16.4.2 Materials for Legend Printing 262

16.5 Innerlayer Copper Circuit Patterning 263

16.5.1 Materials for Copper Etch Resists 264

16.5.2 Substrate Modification 265

16.6 Copper Plating Resist 266

16.7 Waste Reduction Using Inkjet Printing 268

16.8 Solder Mask Printing 269

16.9 Metallic Inks 273

16.10 Theoretical Printing Example for PCB Manufacturing 275

16.11 Digital Printing Alternatives to Inkjet Fabrication 276

16.12 Future Applications for Inkjet in Printed Circuit Boards 276

References 277

17 Photovoltaics 279
Heather A.S. Platt and Maikel F.A.M. van Hest

17.1 Introduction 279

17.2 Device Structures 280

17.3 Small- and Large-Area Printing for Photovoltaics 283

17.4 Commercial Inkjet for Photovoltaics 289

17.5 Summary and Perspective 291

References 292

18 Inkjet Printed Electrochemical Sensors 295
Aoife Morrin

18.1 Introduction 295

18.2 Printed Sensor Manufacturing 297

18.3 Inkjet Printing of Sensor Components 298

18.3.1 Substrates 299

18.3.2 Conducting Tracks 300

18.3.3 Transducer Materials 300

18.3.4 Biomolecules 305

18.4 Inkjet-Printed Sensor Applications 306

18.5 Future Commercial Projection 306

Abbreviations 309

References 309

19 Antennas for Radio Frequency Identification Tags 313
Vivek Subramanian

19.1 Introduction 313

19.1.1 Introduction to RFID 313

19.1.1.1 RFID Tag Classification 314

19.1.2 Applications of Printing to RFID Antenna Production 317

19.1.2.1 An Overview of RFID–HF versus UHF 318

19.1.2.2 Silicon-Based RFID Tag Construction – from Chip to Tag 319

19.2 Printed Antennas 319

19.2.1 HF Tag Antenna Considerations 320

19.2.2 UHF Tag Antenna Considerations 321

19.2.3 Application of Printing to Antenna Fabrication 322

19.2.4 Materials for Printed Antennas 323

19.2.4.1 Metallic Pastes 324

19.2.4.2 Particle-Based Inks 325

19.2.4.3 Organometallic Precursors 326

19.3 Summary of Status and Outlook for Printed Antennas 327

References 328

20 Inkjet Printing for MEMS 331
K. Pataky, V. Auzelyte, and J. Brugger

20.1 Introduction 331

20.2 Photolithography and Etching 331

20.2.1 Photolithography 332

20.2.2 Etching 332

20.3 Direct Materials Deposition 333

20.4 Optical MEMS 336

20.5 MEMS Packaging 339

20.6 Functionalization and Novel Applications 340

20.7 Conclusion 342

References 342

21 Inkjet Printing of Interconnects and Contacts Based on Inorganic Nanoparticles for Printed Electronic Applications 347
Jolke Perelaer and Ulrich S. Schubert

21.1 Introduction 347

21.2 Inkjet Printing of Metallic Inks for Contacts and Interconnects 348

21.2.1 Inkjet Printed Contacts and Interconnects for Microelectronic Applications 348

21.3 Inkjet Printing in High Resolution 351

21.3.1 Surface Wetting and Ink Modifications 351

21.3.2 Reduced Printed Droplet Diameter 353

21.3.3 Physical Surface Treatment 357

21.3.4 Inkjet-Printed Ionogels 359

21.4 Conclusions and Outlook 361

Acknowledgments 362

References 362

Index 365