FUNCTIONAL PRINTING SERVICES
Equipped with an excellent infrastructure
and long-standing expertise, Fraunhofer ISE
offers a variety of services for challenging
functional printing applications like silicon
solar cells, printed circuit boards (PCBs), fuel
cells, batteries, sensors, electronic devices
and more. We support material, equipment
as well as device manufacturers in selecting
suitable printing technologies, developing
functional materials or innovative processes.
We offer a wide range of characterization
methods covering all relevant aspects from
material and surface characterization to an
in-depth analysis of electrical, optical and
functional properties.
Silicon solar cells serve as a well-known
example for printed devices produced on an
industrial level. Printing ultrafine line con-
tacts with good conductivity on textured
silicon surfaces is a supreme discipline of
functional printing, in which Fraunhofer ISE
has gathered extensive experience.
Our PV-TEC – Photovoltaic Technology Eval-
uation Center features a variety of different
state-of-the-art printing technologies which
can be applied for various applications. We
can offer research services and in-depth
knowledge covering the following printing
technologies:
n flatbed screen
n stencil printing
n rotary screen
n flexographic printing
n inkjet printing
n multi-nozzle parallel dispensing
n FlexTrail
The multi-nozzle dispensing activities have
been recently commercialized successfully by
our spin-off HighLine Technology GmbH.
1 Flatbed screen printing unit for solar
cell metallization.
2 Fine line front side metallization using
rotaryflexographicprintingtechnology.
3 Ultrafinelinescreenprintedcontact
fingerontexturedSiliconsurface.
Fraunhofer Institute for Solar
Energy Systems ISE
Heidenhofstr. 2
79110 Freiburg, Germany
Silicon Photovoltaics –
Pilot Processing of Industrial
Silicon Solar Cells
Dr. Florian Clement
Phone +49 761 4588-5050
Printing Technology
Dr. Andreas Lorenz
Phone +49 761 4588-5299
www.ise.fraunhofer.de
01-271-20
31 2
F R A U N H O F E R I N S T I T U T E F O R S O L A R E N E R G Y S Y S T E M S I S E
4 Scanningelectronmicroscopeimageofa
finelinescreenforthefrontsidemetallization
of silicon solar cells.
5 Finite elements simulation of dispensing
nozzle tip.
In-depth Simulation Services
n computational fluid dynamics (CFD)
simulation of paste and fluid flow
behavior for dispensing, screen printing
and rotary printing
n optimization of screen and stencil con-
figurations for individual applications by
in-depth screen pattern simulation
n analytic grid design tool “Grid-master”
enables optimal design of contact
structures
Characterization Services
n in-depth analysis of all relevant rheo-
logical parameters using rotational
rheometer and capillary viscosimeter
n contact angle measurement
n laser beam reflection for measuring
particle size
n statistical analysis of 3D geometry of
printed structures using laser-scanning
3D microscopy and image analysis
algorithms
n optical microscopes for all types of
applications
n scanning electron microscope (SEM)
including EDX detector and FIB
(Focused Ion Beam)
n contact and sheet resistance
measurements for printed structures
n statistical measurement of metal-semi
conductor contact resistance and lateral
line resistance
Inkjet and FlexTrail Technology
n industrial inkjet printing equipment
with modification for integrating
various printheads
n customized development of solutions
for specific inkjet applications
n innovative FlexTrail technology for ultra
fine line structures below 10 µm
Drying and Firing Equipment
n inline and offline drying, curing
and firing equipment for low and high
temperature sintering pastes including
inert high-temperature sintering
n fast firing furnace with extended peak
firing zone and integrated IR camera for
process monitoring
n special drying/firing technology
(UV, intense pulsed light (IPL) and
VCSEL-Technology)
Infrastructure and Expertise
Fraunhofer ISE has a wide range of high-
quality printing equipment available to
perform a variety of different processes.
Most of our printers feature high precision
optical alignment which allow for custom-
ized structures requiring multiple printing
or structuring steps. Simulation and
characterization also play an important role
in our service offering.
Screen and Stencil Printing
n fully automated industrial screen
printing lines for high-precision
thick-film printing processes (i.e. solar
cell metallization, functional layers)
n inline inspection system with high-
precision detection of printing quality
and defects
n semi-automatic high precision
screen printer
n in-house screen development
Multi-Nozzle Dispensing
n industrial platform with high-precision
3-axis positioning system and multi-
nozzle dispensing print-head
n high-throughput inline multi-nozzle
parallel dispensing unit
n lab devices for single-nozzle and
multi-nozzle dispensing
Rotary Printing
n high-throughput shuttle-transport
rotary printing platform for rotary
screen printing and flexo printing
n laboratory rotary printing device for
flexo, rotary screen and gravure
printing tests
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3D analysis tool “FineUp” using image analysis
algorithmsdevelopedatFraunhoferISE.