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

sipv.pilot@ise.fraunhofer.de

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

54

3D analysis tool “FineUp” using image analysis

algorithmsdevelopedatFraunhoferISE.