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Fall, 2013

Instructor: J.-W. John ChengMech. Engr. Dept., Nat’l Chung Cheng Univ.

Interfacial Physics and Thin-Film Processing

Ch 1 Intro. to Flexible Electronics and Printing

Technology

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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

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1.1 Prospect and Fabrication Challenge of Flexible

Electronics

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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

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OE-A Roadmap for Organic and Printed Electronics Applications

Source: Organic and Printed Electronics, 4th ed., OE-A (Organic Electronics Association), 2011

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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/)

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Applications – Flexible PhotovoltaicsOrganic solar bag by Neuber 2010 (http://www.energyharvestingjournal.com/articles/progress-with-flexible-photovoltaics-00002212.asp?sessionid=1)

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Applications – Flexible Lighting

Prototype OLED lamps by China’s Visionox (http://www.oled-info.com/oled-light)

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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_2010_00001961.asp)

The bottom line• The bad news is that, highest volu

me 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

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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.html

~58x58 m2/pixel

Samsung Galaxy S4

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Samsung 2011 Success Heralding Arrival of Flexible Electronics

From plenary speech of Prof. Karl Leo at LOPE-C 2012

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What Is Next and When?

Time

Roof top grid connected

Organic Backplane E-ink displayRFID ， OTFT…

General lighting(flexible)technology

Rollable OLED TVs

From Prof. Karl Leo 2011

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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 billionshttp://www.isuppli.com/Semiconductor-Value-Chain/News/Pages/Semiconductor-Industry-Revenue-to-Endure-Slow-Growth-in-2012.aspx

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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

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Expectation of Printing-Based Fab

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/, 20121025

“If large-scale processing proves to be problematic or impossible,

the concept of polymer solar cells would become a scientific curiosity ….”* [Kre2009]

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Challenge: < 10 m Resolution

Time

Roof top grid connected

Organic Backplane E-ink displayRFID ， 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 m2/pixel, PenTile RGBG• guessing ~66% light outputPenTil

e RGBG

OLED subpixel

OTFT

http://en.wikipedia.org/wiki/PenTile_matrix_family#PenTile_RGBG