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Ultra-Thin Flexible Glass: Potentials and Challenges for Vacuum Thin Film CoatingManuela Junghähnel, Matthias Fahland, Nicolas Schiller
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP
AIMCAL R2R Asia ConferenceRoll to Roll Web Coating and FinishingMay 28 - 30, Daejeon, South Korea
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page 2Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Introductionglass
flat curved flexible
thickness > 1 mm thickness 1 … 0.2 mm thickness < 0.2 mm
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page 3Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Diversity of flexible glass in FLEX Applications
PhotovoltaicsThin film solar cellsOrganic solar cells
LightingOLED
Lighting panels
Smart WindowsArchitectural glazing
ElectrochromicsThermochromics
High-Tec OpticsMicro lensesFilter opticsMicro displaysMicro cameras
AutomotiveMirrors
LightingDisplays
ElectronicsInterior
DisplayCover glass
Smart PhonesTablets
TVHead-up
Energy StorageThin-film batteriesSuper capacitorsMicro batteries
WearablesSmart Watch
Smart GlassesFitness armband
Move tracker
Smart curved SurfacesInterior
Wall panelsLaminated panels
Room dividersRailings
SensorsFingerprint sensorsAntennasLabelBio-sensor
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page 4Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Glass will find in new form-factor devices due to its superior application performance shows superior haptics and customer experience with high scratch resistance UTG allows highest optical quality, longer-living and reliable OLED displays due to high
temperature resistance during processing and unsurpassed barrier properties
Application example: Display and Cover
Cover Glass – ultra-thin glass
Touch Sensor
UTG Substrate
Active matrix OLED Layers
Glue
UTG BarrierCourtesy of SCHOTT AG
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page 5Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Properties of ultra-thin flexible glass
Ultra-thinHigh transparencySuperior surface qualityPerfect water vapour and oxygen
hermeticityHigh-temperature processing Low surface roughness – aesthetic
appeal
Glass thickness < 200 µm flexible glass
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page 6Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Main flexible glass suppliers
Nippon Electric Glass Co., Ltd.: G-Leaf™
Asahi Glass Co., Ltd.: SPOOL™
Corning Inc.: Corning® Willow® Glass
Schott AG: AF 32 eco , D 263 eco, AS 87 eco
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page 7Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Properties of diverse UTGs – thermal propertiesCorning®
Willow® GlassNEGG-LeafTM
AGCSpoolTM
SchottAF 32® eco
SchottD 263® T eco
SchottAS 87® eco
Density [g/cm³]
2.3 - 2.5 2.46 2.51 2.43 2.51 2.46
CTE [K-1] 3 - 5 x 10-6 3.8 x 10-6 3.8 x 10-6 3.2 x 10-6 7.2 x 10-6 8.7 x 10-6
Tg [°C] 717 557 621Strain point [°C]
650 - 700 650 670 594
Annealing point [°C]
700 - 750 705 720 633
Softening point [°C]
940 950 872
Thicknesses [µm]
200; 100; (50) 100; 70; 50; 30 200; 100; 50 100; 70; 50; 25 100; 70; 50; 25 100, 145, 175, 210, 250, 330,
350, 400Glass width of rolls
max. 1.3 m 0.6 m (1 m) max. 0.5 m max. 0.5 m rectangular: 5~580, round: Ø
50~410 Majority of the data are coming from fact sheets
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page 8Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Properties of diverse UTGs – mechanical propertiesCorning®
Willow® GlassNEGG-LeafTM
AGCSpoolTM
SchottAF 32® eco
SchottD 263® T eco
SchottAS 87® eco
Young's modulus [GPa]
70 - 80 73 77 66 72,9 73.3
PoissonRatio
0.20 - 0.25 0.2 0.22 0.235 0.208 0.216
Hardness 555 590 500 (560*)
Surface roughness RMS
Ra < 0.5 nm Ra < 0.2 nm < 1 nm < 1 nm < 0.5
Totalthickness variation
± 10% ≤ 5 µm ≤ 5 µm ≤ 10 µm
Thicknesstolerance
± 10 µm ± 10 µm ± 10 µm ± 10 µm
Majority of the data are coming from fact sheets *) hardness measured at chemical strengthened condition
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page 9Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Manufacturing MethodsDown-Draw Process
www.schott.com www.neg.co.jp
annealingfurnace
glass ribbon
roller
roller
molten glass Overflow on both sidesflow of molten glasseven overflowsfrom both sides
direction in which it is drawn
treams fuse at the bottomof the wedgs
Overflow Process
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page 10Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Challenges for processing on ultra-thin flexible glassMain challenges: Improvement of reliability Reduction of bending radius key is thickness reduction
Management of loads on the glass Stress control: tension,
compression Process procedure: substrate
handling, transport, cleaning, cutting, coatings
Bending, the combination of stress
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page 11Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Properties of ultra-thin flexible glass – bending of glass
0 10 20 30 40 500
20
40
60
80
100
120
0.1 mm0.2 mm
0.5 mm
0.05 mm
bend
ing
stre
ss [M
Pa]
bending radius [cm]
0.03 mm
𝜎𝜎 =𝐸𝐸 𝑑𝑑2𝑟𝑟
σ … bending stressE … Young's modulusd … thickness substrater … bending radius
0 5 10 15 200
20
40
60
80
100
120 100 µm PET Melinex 400 @ RT 100 µm flexible glass
bend
ing
stre
ss [M
Pa]
bending radius [cm]
Calculation of bending stress
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page 12Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Properties of ultra-thin flexible glassSurface roughness Dimension stability
100 µm flexible glass 100 µm PET webTmax during deposition < 50°C!!!
Flexible glass or PET webTiO2, 30 nm
SiO2 , 300 … 500 nm
TiO2, 30 nm
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page 13Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Properties of ultra-thin flexible glass - transmittance
200 250 300 350 4000
20
40
60
80
100
AF32, 50 µm AF32, 100 µm D263T, 50 µm D263T, 100 µm
trans
mitt
ance
[%]
wave length [nm]Schott Product AF32eco D263Teco
CTE (20 - 300 °C) x10-6/°K 3.2 7.2Tg [°C] 715 557Alkaline Content no yes
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page 14Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Vacuum thin film coating on flexible glass: R&D platform @ Fraunhofer FEP
Inor
gani
c th
in-fi
lms
Org
anic
dev
ices
sheet-to-sheet processes roll-to-roll processes
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page 15Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
current voltage lum.efficacy Color coordinates CCT CRI
[mA] [V] [lm/W] C.I.E. x C.I.E. y [K] [%]
80 8.19 32.4 0.386 0.382 3895 83
OLED on Ultra Thin Glass @ Fraunhofer FEP
2 x 100 µm UTG Active area: 62 cm² Module size: 18.3 x 66.3 cm²
Performance @ 1000 cd/m² :
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page 16Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
In-line coater FOSA LabX 330 Glass for R2R processes Flexible glass, polymer film, metal foil
up to 330 mm deposition width
Substrate temperature up to 350 °C
up to 4 coating zones
Dual Anode Sputtering
Front-side touchless
BMBF – KONFEKT (FKZ 13N13818)
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page 17Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
TCOs for transparent flexible electrodes – ITO
flexible glass
polymersLa
yer t
hick
ness
ITO
250 nm
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page 18Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
ITO on flexible glass – stress management Main factors: Process pressure Type of powering Reactive working point Layer Thickness Process temperature …
10 mm
dITO ~ 1000 nm
ITO on 100 µm glass
ITO on 50 µm glass
dITO ~ 750 nm10 mm
ITO thin-films: d ~ 1000 nm ρ ~ 2…5∙10-3 Ωcm
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page 19Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Thermal annealing of ITO on flexible glass
Method: magnetron sputtering 150 nm thick ITO Substrate: 200 µm Corning® Willow® Glass Substrate size: 600 x 600 mm² Thermal annealing in
Vacuum @ 400°C after coating ITO properties: Rsq. ~ 12 Ω TVIS ~ 87.3% ρ ~ 1.7·10-4 Ω·cm
Source: M. Junghähnel et al.; 59th SVC 2016
process time of7…15 minutesup to 1 hour!
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page 20Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
“hot” ITO films on ultra-thin flexible glass3 mm thick low iron glass 100 µm thick flexible glass
Process temperature [°C] RT 400°C RT 400°C
Film thickness [nm] 174 172 174 173
Pretreatment [°C] RT 450 RT 450
Sheet resistance [Ω] 37.7 8.5 29.3 9.3
Resistivity [Ω cm] 6.6 x 10-4 1.5 x 10-4 5.0 x 10-4 1.6 x 10-4
TVIS [%] 76.9 85.7 80.9 86.9
k @ 550 nm 0.015 0.005 0.015 0.009
n @ 550 nm 2.04 1.90 2.03 1.84
T_L* 90.3 94.2 92.1 94.7
T_a* 3.68 0.19 0.45 -0.08
T_b* 6.74 6.58 5.85 7.22
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page 21Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
R2R process of ITO Glass: SCHOTT AF32 Glass thickness:100 µm ITO: In2O3: SnO2 wt.% 90:10 Power 3 kW Argon 350 sccm Process pressure 0.3 …0.4 Pa
sheet resistances of 10 Ω at a heater temperature of 550°C
BMBF – KONFEKT (FKZ 13N13818)
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page 22Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Dynamic FLA for in-line S2S and R2R processes
Main process parameters:
Energy density Pulse duration time Repetition rateSubstrate speed
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page 23Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Dynamic FLA of ITO on ultra-thin flexible glassas deposited state: dITO ~ 150 nm
Rsq. ~ 55 ΩTvis ~ 69.4%
© 2016 Fraunhofer FEP
after FLA: Rsq. ~ 16 Ω
Tvis ~ 79.1%
© 2016 Fraunhofer FEP
M. Junghähnel et al., SVC 2016, Proceedings, Ref.-Id.: L-7
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page 24Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
FOSA LabX 330 Glass – Example AR coating
400 500 600 700 8000
10
20
80
90
100
T R
Tran
smis
sion
/Ref
lect
ion
[%]
Wavelength [nm]
100 µm Schott glass
Single side coated
BMBF – KONFEKT (FKZ 13N13818)
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page 25Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Example – AR Coatings on Ultra-Thin Flexible GlassAnti-reflective coating on 50 µm flexible glass
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page 26Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Summary
flexible glass
vacuum thin film coating
processing
application
mechanical, optical and
thermal properties surface
production technologies
R2R S2SITOAR FLA
cuttingcleaning
laminating
OLED
sensorsbatteries
Ongoing R&D to meet the challenges and explore the opportunities of an exciting material
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page 27Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Flexible Glass: Enabling Thin, Lightweight, and Flexible Electronics
Edited by Sean Garner
ISBN-13: 978-1118946367Publisher: Wiley-Scrivener; 1 edition (August 21, 2017)
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page 28Nicolas Schiller, AIMCAL R2R Asia Conference, Roll to Roll Web Coating and Finishing, May 28 - 30, Daejeon, South Korea
Acknowledgements:
Our partners:Corning Inc.Nippon Electric Glass Inc.SCHOTT AGVON ARDENNE GmbH
Thank you very much for your attention!
CONTACT:[email protected] Flexible Glass Activities @ [email protected]
BMBF – KONFEKT (FKZ 13N13818)