This document discusses roll-to-roll printing as a technology for manufacturing electronic devices. It notes that roll-to-roll printing has advantages over other techniques like photolithography in that it can achieve very low production costs due to its continuous, high-throughput process. However, it has lower resolution. Key challenges include developing materials that can be easily printed from a roll and that have the necessary electronic properties. The document provides examples of how roll-to-roll printing could be applied to products like organic displays, solar cells, and integrated circuits. It also compares the scaling and costs of roll-to-roll equipment to traditional manufacturing methods.

1. A/Prof Jeffrey Funk
Division of Engineering and Technology Management
National University of Singapore

2. This is the Fifth Session in MT5009
Session Technology
1 Objectives and overview of course
2 Two types of improvements: 1) Creating materials that
better exploit physical phenomena; 2) Geometrical scaling
3 Semiconductors, ICs, electronic systems
4 MEMS and Bio-electronic ICs
5 Lighting and Displays (also roll-to roll printing)
6 Nanotechnology, 3D printing and DNA sequencing
7 Human-computer interfaces
8 Superconductivity, fusion, energy storage
9 Solar cells, wind turbines
10 Telecommunications and Internet

3. Roll to Roll Printing
 Relevant for many technologies
 Organic displays including flexible ones
 Organic solar cells
 Integrated Circuits (maybe with organic materials)
 Advantages
 Very low cost
 Disadvantages
 Much lower resolution than some techniques such as
photolithography
 Challenges
 Find materials that can be easily roll printed and that have
the necessary electronic and other characteristics
 For example, nano-particles are a major topic

7. Roll-to roll (R2R) printing
Introduction to Printed Electronics and Intelligence, Jukka Hast

8. R2R Process for Manufacturing Active Matrix Backplanes
Based on Plasma Processing and Self-Aligned Imprint Lithography
deposition imprint etch
Vacuum deposition of Multiple mask
Patterning completed
metals, dielectrics, & levels imprinted
w/ wet & dry
semiconductors as single 3D
processes
structure
5μ
Conventional Photo-Lithography SAIL
deposit deposit imprint etch
strip/clean spin resist
align/expose etch
etch
mask
develop
Source: Roll-to-Roll Manufacturing
of Flexible Displays, Hewlett Packard, Phicott

9. SAIL solves alignment problem & saves money
Web cost
Strip-off 2P
RIE etch oxide
Multiple Under-cut Al (1-3 um)
RIE etch n+
photoresist applications Wet etch Cr
R2R SAIL
Thin down 2P (clear gate-pad)
dominate photolithography RIE etch n+&Si&SIN
Pre-Cr-etch Cleaning
process materials costs Thin down 2P (clear gate-pad)
Plasma etch Al
RIE etch oxide
RIE etch n+&Si&SIN
Wet etch Cr
Imprint SAIL structure
SD metal deposition (Cr)
PECVD oxide/nitride/Si/N+ deposition
Gate metal deposition (Al)
Condition web (de-hydro)
Backplane materials costs $0.0 $0.5 $1.0 $1.5 $2.0 $2.5
for R2R photolith & SAIL Web cost
$18.00
Cost of Patterning Align and Expose
R2R photolith (AGI)
$16.00 Sputter Dep Interconnect
$14.00
cost per ft2
Align and Expose
$12.00 Sputter Dep/ ITO
$10.00 Align and Expose
$8.00 Ultrasonic Clean
Si RIE & Resist Strip
$6.00
Align and Expose
$4.00
SiN, a-Si, N+ dep
$2.00
Align and Expose
$0.00
Sputter Gate 1 Metal
Photolithography SAIL Web preparation
$0.0 $0.5 $1.0 $1.5 $2.0 $2.5 $3.0

10. Equipment Cost Comparison for Different Levels of Scale
(comparison made at equal throughput)
equipment cost scaling comparison: panel stepper vs R2R imprinter
0
10
equipment cost [M$] / throughput [cm 2 / S]
-1
10
-2
10
100 mm R2R imprinter
330 mm R2R imprinter
-3
10
2 3 4 5 6 7 8 9 10
generation
Scaling similar for R2R printer and panel stepper; cost much lower for R2R
Source: Roll-to-Roll Manufacturing of Flexible Displays, Hewlett Packard, Phicott

11. PECVD Scaling: R2R photovoltaic compared to LCD panel
(comparison made at equal throughput)
0
equipment cost scaling comparison: panel CVD vs R2R CVD
10
equipment cost [M$] / throughput [cm2 / S]
-1
10
330 mm R2R PECVD
1 m R2R PECVD
-2
10
1 2 3 4 5 6 7 8 9 10
generation
PECVD: plasma enhanced chemical vapor deposition. Again; benefits from scaling
similar for R2R and panel; cost much lower for R2R
Source: Roll-to-Roll Manufacturing of Flexible Displays, Hewlett Packard, Phicott

12. R2R (L) equipment is still smaller than flat panel display ones (R)
330mm imprint system Gen10 cluster tool
Source: Roll-to-Roll Manufacturing of Flexible Displays, Hewlett Packard, Phicott

13. Evolution of R2R tool development
13” production solar cell
deposition
13” wet etcher
13” imprinter
4” imprinter
10” drum PECVD
13” RIE
2005 2006 2007 2008 2009

14. Conclusions and Relevant Questions for
Your Projects
 Roll-to roll printing can be much cheaper than other forms
of printing (e.g., photolithographic) and its performance is
undergoing rapid improvements
 These advantages will increase as the scale of R2R printers
are increased
 What do these trends mean for
 Organic displays including flexible ones
 Organic solar Cells
 Integrated Circuits (maybe with organic materials)
 Other applications?
 How will roll-to roll printing impact on the cost and thus
the usage of these technologies?

15.  Appendix

16. http://deviceguru.com/euro-project-
slashes-flexible-display-costs/
Light emitting electrochemical cells
http://www.oled-info.com/tags/technical-
research/frontplane/roll-roll

17. Observatory Nano
ICT Sector Focus Report
Printed Electronics
April 2010

22.  What kinds of materials
can be roll printed?
 Do these materials have the
right characteristics for the
electronic product?
 Applications: flexible
displays, organic solar cells,
amorphous silicon thin-
film transistors, liquid
crystal displays, or solar-
powered flexible displays