Functional printing using screen or digital printing

Functional printing
using screen or digital printing
March 6th 2013
Hochschule der Medien Stuttgart
Nobelstr. 10
Prof. Dr.-Ing. Gunter Hübner
Agenda
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Own projects at HdM
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IAF= Institute for Applied Scince
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general
Screen vs. Inkjet and others
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Comparison
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IAD= Institute for Innovative Applications of the Printing Technologies
Applications
Process limits
Conclusion
Hochschule der Medien (HdM)
Hochschule für angewandte Wissenschaften (HAW)
•  3 Faculties:
- Druck und Medien
- Electronic Media
- Information und Kommunikation
•  >4000 students
•  21 accredited study programs,
14 Bachelor and 7 Master-Programs
•  125 Professors, 170 Employees,
numerous guest lecturers
Overview Projects at IAD
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Printed antennae for automotives
Hirschmann Car Communication GmbH
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“BatMat”
printed rechargeable batteries
Screen
Screen
BMBF (main partner: VARTA)
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KoSiF complex systems in foil
BMBF
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Printed Thermoelements
BMBF
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Demonstrators for Heraeus (H.C. Starck)
Microstructures with Clevios (OE-A),
Touchpads, Sensors
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Carbo-TCF Conductive and transparent films
based on CNT-Hybrids BMBF
Antenna integrated in boot lid
Screen
Screen
Printed NiMH rechargeable
thin film battery
Screen
Gravure e.a.
printed
Thermogenerator
100nm
Carbon Nano Tubes CNT
Bildquelle: http://technokaksha.blogspot.com/
OE-A Demonstrator
Source-Drain-Structure
Printed with Clevios (PEDOT/PSS)
Why our Projects use Screen-Printing
Needs:
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Conductive lines, structures
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Print coarse pigments
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Productivity
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Easy adjustment of ink deposit thickness
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Price
Examples…
Example printed battery
Battery design “Stack”-Type
Substrate
Current Collector
Anode
Kathode
Separator
In case of Ni/MH-Cell
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Current Collectors: Carbon Black, Ag-Paste
≈20µm
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Anode: printed Ni-Paste
≈150µm
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Cathode: printed MH-Paste
≈100µm
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Separator: printed separator/electrolyte
≈50µm
Example printed battery
Assembly
Substrate
Seal
Collector
Anode
Kathode
Separator
Example printed battery
NiMH-Cell Collector, Anode, Cathode and Seal
Example printed battery
Very high layer thickness
Profile, layer thickness of printed Ni electrode
Example printed battery
Pigments must pass through mesh
Rule of thumb:
Mesh opening 3 - 4 x larger than
largest grain
Bildquelle: Saati
Example printed battery
Printed Separator/Electrolyte
Example Printed Thermogenerator
Basic Principle Thermoelectric Generator
Using Seebeck effect for „Waste Energy Harvesting“
Electrical Load
Image source: wikipedia
Example Printed Thermogenerator
Reverse of Seebeck Effekts = Peltier
Coomercially available Peltier-Element consisting
of hundreds of thermocouples in series
Example Printed Thermogenerator
Principle of „vertical“ Design
Example Printed Thermogenerator
Assembly sequence
Substrate
Conductor
Example Printed Thermogenerator
150-200µm
Thermal
insulator
Cavities
(openings)
Example Printed Thermogenerator
Thermal
Insulator
cavities
Example Printed Thermogenerator
n-Leg
Example Printed Thermogenerator
p-Leg
Example Printed Thermogenerator
conductor
Example Printed Thermogenerator
Hot
Side
Cold
Side
2nd Substrate
(Cover)
Example Printed Thermogenerator
Switch off heater
conductor: Ag-paste
leg 1: Nickel-Paste
leg 2: PEDOT:PSS (Clevios SV 3)
Insulator: UV-Ink
Switch on heater
Functionable, fully printed Thermogenerator
PET Melinex (175 µm), 100 Thermocouples, 1 mm2 cavities,
cavity spacing= 1 mm
Thermovoltage ~ 120 µV
time
Example CarboTCF
Carbon Nano Tubes / Carbo TCF
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TCF= Transparent Conductive Films
CNT properties:
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Project goals
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SWCNT: highly conductive (better than Cu)
high Aspect ratio (ca.1:1000)
temperature resistant (up to 300°C in air)
pure carbon („green“)
Replace ITO
Hybrid dispersion CNT and PEDOT:PSS
Applications:
(Touch) Displays (Handy, Navigation, PC)
Photovoltaics
oLEDs
(transparent) heating elements
CNT (Spinning)
Source: wikipedia
Example CarboTCF
Carbon Nano Tubes
Goal:
85% Transparency and <<200Ω/□
requires very thin layers
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§  Dispersion of CNTs in Ethanol or H2O <0.1% wt.
§  Very low viscosity, high surface tension
§  Avoid additives and surfactants
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Spraying or gravure coating/printing
Inkjet possible but removal of surfactants
after printing required
Gravure printed layers at HdM
Innovative Anwendungen der Drucktechnologie / IAD
24
Example for High Productivity
LTCC Low Temperature Cofired
Ceramics
20mm
Engine control circuit LTCC frontside
Bild aus http://ltcc-consulting.com/imgs/what_is_LTCC/complex_ltcc.jpg
LTCC backside
black= printed resistors (Ruthenium-Paste)
Comparison of printing technologies for
Printronics
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Gravure
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Flexography
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Very fine lines possible down to 10µm
Waterbased offset difficult to use (2 liquids), high viscous inks
Inkjet
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Similar to gravure, disadvantage: silicon residuals
Offset, waterless offset
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Very flexible, very high layer thicknesses, lines down to 30µm (10µm)
Recent improvements in mesh manufacturing e.g. Asada mesh
Pad printing
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Lines down to 30-40µm,
disadvantage: photopolymerplate susceptible for a lot of solvents
Screen printing
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Very fine lines possible down to 10µm.
Recent improvements in cylinder making
Very flexible structures, no printing form, lines down to 50µm
Inks very low viscous <20mPas
Low production velocity
Others
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Aerosol jet
Laserprinter (Electrophotography)
Lasersonic
Aerosol Jet
Source:
http://www.optomec.com
Example Electrophotography
Peptide Printing
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www.pepperprint.com
24 electrophotographic printing units in a row
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24 amino acid printing units for the 20 main L-amino acids as well as
additional other monomers like D-amino acids and citrulline .
Length: 4.5 m, weight 3.5 tons.
on-glass printing of peptide microarrays based on amino acid
microparticles (“toner”).
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Up to 275,000 spots with arbitrary combinations of amino acids.
Lasersonic Process
www.aurentum.de
first implementation
for very thin wafer in
photovoltaics
Item
Inks
Inkjet
colorant Dye or pigment
Pigmentsize pigments must be able to
pass the nozzle <<10µm.
Nano scale
Viscosity <10 (20)mPas
Rheology nearly Newtonian
Problems
Resolution
wet layer thickness
printing form
Screen Printing
Pigments. very seldom dye
must be able to pass mesh
opening. Up to 500µm
50-100.000mPas
wide range, mostly shear thinning,
thixotropic
Banding, Mottling
Meshmarking
standard is around 50µm.
standard: >80µm
Drop size down to 1pl-> slow finest structures at 30-50µm
> 1µm. x passes on same
from 8µm to 200 (500)µm.
spot increase thickness ->very Depending on stencil and layout
slow
n/a
Expertise Know-How required for
excellent results.
speed
rollfed 20-300m/min CD graphic
applications
sheetfed LFP: 20-1000m²/h
variety of substrates large, may not be too
absorbant
variety of inks
small
costs
printer high
inks/pastes high
Label printing: 200m/min
LFP:>1000m²/h
very large
very large
small
small/medium
Functional Printing Applications
conductive structures in
general
Smooth homogeneous layers
>100µm width, thickness≈10µm ,
high productivity
Photovoltaics
Smooth homogeneous layers <80µm screen
Integrated Smart Systems
(ISS, including smart objects,
sensors and smart textiles)
oFETs: line spacings <<20µm;
Screen,
Sensors: various materials
IJ, others
Batteries
Coarse pigments
screen
Lighting
OLED: Thin transparent and
conductive layers
EL: Smooth, rather coarse layers
IJ, others
Thin, transparent and conductive
layers, very fine structures
IJ, screen,
others
Flexible Displays
screen
screen
Example Inkjet Application
Inkjet R2R on textile
Example: D-gen printer 140m²/h
Source: www.dgen.com
Source:
http://www.basf.de/de/corporate/innovationen/erklaert/
kleidung/
competes with rotary screen printing
Quelle: www.cibasc.com
Example Inkjet Application
Personalised clothing, shoes
http://www.zazzle.com/
or
http://www.tshirtstudio.com/
Example Inkjet Application
Print on Ceramics
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www.kerajet.com
Nanopigment inks from Ferro
Durst gamma www.durst.it
19-74m/min (depending on resolution)
Integration in tile manufacturing line
Competes with screenprinting and gravure
Example Inkjet Application
3-D Printing
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Rapid Prototyping
Rapid Manufacturing
Source: http://objet.com
Source: www.contex.com
Example Inkjet Application
Event cake
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Videoclip on http://de.youtube.com/watch?v=a9MvdFpAxz4
Competes to screen printing if # of copies >>1
Example Inkjet Application
Inkjet on Latte
http://opikalo.wordpress.com/
Or watch video on
http://www.youtube.com/watch?v=PjgVeJkdBn0
Prof. Dr.-Ing. Gunter Hübner
Example Inkjet Application
Inkjet on Nails
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10 Finger nails in 7 minutes
using special varnish
First primer, then decor
protective lacquer on top
Protective laquer
Thanks for your attention
contact:
[email protected]
Source: Imaginail (www.imaginail.com ).
Prof. Dr.-Ing. Gunter Hübner