1. 1 Fall, 2013 Instructor: J.-W. John Cheng Mech. Engr. Dept., Nat ’ l Chung Cheng Univ. Interfacial Physics and Thin-Film Processing Ch 1 Intro. to Flexible Electronics and Printing Technology

2. JCheng201309 2 Outline 1.1 Prospects and Fabrication Challenge of Flexible Electronics 1.2 Overview of Printing Technologies Flexography, gravure printing, screen printing Inkjet printing, micro-contact printing References

3. 3 1.1 Prospect and Fabrication Challenge of Flexible Electronics

4. JCheng201309 4 What Is Flexible Electronics? Flexible electronics Electronics “ can be bent, flexed *, conformed or rolled without losing functionality ” Closely related names Organic electronics Electronics made of organic materials, non-silicon Printed electronics Electronics fabricated using printing method * flex = bend repeatedly

5. JCheng201309 5 OE-A Roadmap for Organic and Printed Electronics Applications Source: Organic and Printed Electronics, 4th ed., OE-A (Organic Electronics Association), 2011

6. JCheng201309 6 Applications – Flexible Displays Samsung full-color flexible display 2011 http://www.tomshardware.com/news/flexible-amoled-oled- screen-folding,12929.html Sony full-color flexible display 2007 (http://pinktentacle.com/2007/05/flexible-full-color- organic-el-display/)

7. JCheng201309 7 Applications – Flexible Photovoltaics Organic solar bag by Neuber 2010 (http://www.energyharvestingjournal.com/articles/pro gress-with-flexible-photovoltaics- 00002212.asp?sessionid=1)

8. JCheng201309 8 Applications – Flexible Lighting Prototype OLED lamps by China’s Visionox (http://www.oled-info.com/oled-light)

9. JCheng201309 9 Applications – Flexible RFID Flexible RFID by Kovio 2010 with inkjet printed nanosilicon transistors on stainless steel foil (http://www.printedelectronicsworld.com/articles/printed_rfid_in_20 10_00001961.asp) The bottom line The bad news is that, highest volume RFID is all about tag cost, not multiple benefits from printing such as tightly rollable, invisible, stretchable or edible. The good news is that fully printed RFID can be one tenth or less of the cost of the conventional silicon chip based tag # of proj on RFID China: 267

10. JCheng201309 10 A Turning Point of Flexible Electronics First commercial success – AMOLED AMOLED was adopted by Samsung Galaxy series smart phones 4/2009 – Galaxy (3.2 ”, 320x480 pixel) 3/2010 – Galaxy S (4 ”, 480x800) 2/2011 – Galaxy S II (4.3 ”, 480x800) 5/2012 – Galaxy S III (4.8 ”, 1280x720) 4/2013 – Galaxy S IV (5 ”, 1920x1080) Samsung became world leading smart phone providers in Q3, 2011 Sources: http://en.wikipedia.org/wiki/Samsung_i7500, http://en.wikipedia.org/wiki/Galaxy_S, http://en.wikipedia.org/wiki/Samsung_Galaxy_S_II, http://en.wikipedia.org/wiki/Samsung_Galaxy_S_III, http://en.wikipedia.org/wiki/Galaxy_S_IV, http://wallcapture.com/wallpaper/samsung-galaxy-s4-wallpaper.htmlhttp://en.wikipedia.org/wiki/Samsung_i7500http://en.wikipedia.org/wiki/Galaxy_S http://en.wikipedia.org/wiki/Samsung_Galaxy_S_IIhttp://en.wikipedia.org/wiki/Samsung_Galaxy_S_III http://en.wikipedia.org/wiki/Galaxy_S_IVhttp://wallcapture.com/wallpaper/samsung-galaxy-s4-wallpaper.html ~58x58  m 2 /pixel Samsung Galaxy S4

11. JCheng201309 11 Samsung 2011 Success Heralding Arrival of Flexible Electronics From plenary speech of Prof. Karl Leo at LOPE-C 2012

12. JCheng201309 12 What Is Next and When? Time Roof top grid connected Organic Backplane E-ink display RFID ， OTFT… General lighting (flexible)technology Rollable OLED TVs From Prof. Karl Leo 2011

13. JCheng201309 13 Future Market Size of Flexible Electronics 依據 IdTechex 研究預測 2027 年全球產值約 3,300 億美元 比較重要產品市場為 - 邏輯記憶體 - OLED 顯示器 - 太陽能電池 Semiconductor industry revenue in 2012: USD $312.8 billions http://www.isuppli.com/Semiconductor-Value-Chain/News/Pages/Semiconductor-Industry-Revenue-to- Endure-Slow-Growth-in-2012.aspx

14. JCheng201309 14 Vacuum-Based vs. Printing-Based Suitable for large-area roll-to-roll fabrication Source: Nikkei Electronics Asia Complex processes and equipment Inconvenient for large-area fabrication Simplified manufacturing processes and equipment

15. JCheng201309 15 Expectation of Printing-Based Fab Comprising only coating and printing steps Reliable large-scale processing *Vacuum deposition is not applicable to polymers; printing is the only possibility [Kre2009] Krebs, Solar Energy Materials & Solar Cells, 93 (2009) 394–412 http://www.gm.dk/en/solar/http://www.gm.dk/en/solar/, 20121025 “ If large-scale processing proves to be problematic or impossible, the concept of polymer solar cells would become a scientific curiosity …. ” * [Kre2009]

16. JCheng201309 16 Challenge: < 10  m Resolution Time Roof top grid connected Organic Backplane E-ink display RFID ， OTFT… General lighting (flexible)technology Rollable OLED TVs From Prof. Karl Leo 2011 ~5  m resolution ~20  m resolution Resolution spec’s based on Galaxy S4 requirements 58 x 58  m 2 /pixel, PenTile RGBG guessing ~66% light output PenTile RGBG OLED subpixel OTFT http://en.wikipedia.org/wiki/PenTile_matrix_family#PenTile_RGBG