FRAUNHOFER INSTITUTE FOR
R E L I A B I L I T Y A N D M I C R O I N T E G R AT I O N I Z M
Micro batteries with interdigitated electrodes
Bluetooth low energy sensor module uses IZM micro battery for energy
storage
EXPERTISE AND SOLUTIONS
CONTACT
Our customers can choose between a number of different
Fraunhofer Institute for
cooperation models: from direct contract research by
Reliability and Microintegration IZM
the Fraunhofer IZM through to joining an EU, federal or
Gustav-Meyer-Allee 25
national government funded scientific research project.
13355 Berlin
Germany
-------------------------------------Services
-------------------------------------• Design and technology development for custom size
Dr. Robert Hahn
robert.hahn@izm.fraunhofer.de
Phone: +49 30 46403-611
lithium ion micro batteries
• 2.5 V or 3.7 V systems
www.smart-power.de
• Consulting and application advice for micro batteries
www.izm.fraunhofer.de
• Primary and secondary battery testing services
• Research on battery life time issues like diffusion barriers, encapsulation, and material compatibility
• Silicon and PCB development for battery integration and
In cooperation with
packaging
• Electrochemical test cells and material development for
novel battery chemistries
Cover: Micro battery fabrication on silicon wafer substrate
MICRO BATTERY
PROTOTYPING LINE
The Fraunhofer IZM’s 10 m battery development and assembly line for the high-precision manufacturing of minute custom-design micro batteries
APPLICATIONS
CHALLENGES
PROTOTYPE MANUFACTURING
Micro battery technology is a pathbreaking technology for
Microelectronics packaging technology has produced several
The facilities for prototype manufacturing include:
extremely miniaturized electronics and energy autarkic micro
solutions for the unique challenges in manufacturing micro
systems. Very small batteries can be used where smallest
batteries. Microfluidic electrolyte handling and battery encap-
commercial batteries are too unwieldy. Current developments
sulation are key technologies for a successful implementation.
at the Fraunhofer IZM reach a minimum size of 2 x 2 mm²
electrodes and solder frames in the case lids.
• Substrate bonding for a secure assembly and sealing of
with a diameter of only 2 mm and a thickness of 200 µm.
The greatest challenge when producing micro batteries is the
Their footprint can easily be tailored to the scale of the
production of virtually hermetically sealed casings. Even tiny
application by changing the lithography masks. Direct battery
amounts of humidity entering the unit can harm the life time
integration saves packaging material and allows better
of the battery. The reactive nature of the lithium needs the
miniaturization.
entire assembly process to be conducted in high-purity Argon
Our micro battery technology results in higher energy density
gas containment units.
when compared to thin film solid state batteries due to the
use of thicker electrodes.
The technology can only be commercially viable if entire
--------------------------------------Advantages for new applications
---------------------------------------
batches of batteries can be produced simultaneously on a
base and top substrates and battery lid.
• Microfluidic electrolyte injection, capable for filling several
hundred micro batteries simultaneously.
--------------------------------------Integrated micro battery
--------------------------------------Photovoltaic chip
IC
Microphone
shared substrate.
• Miniaturized and form factor specific batteries
The Fraunhofer IZM uses a 10 metre battery development
• Medical electronics (implanted sensors, hearing aids)
and assembly line for this purpose, allowing the production
• Miniaturized sensor nodes (Internet of Things, Industry 4.0)
of miniature custom-designed micro batteries with unrivalled
• Miniaturized energy autarkic systems
precision.
• Smart watches
• Precision screen printer for the integration of battery
Spacer
Piezo
Opening for pressure relief
Silicone
• Textile electronics, wearables
• Special sensors/actuators for research
Design of a miniaturized hearing aid with integrated battery (diameter: 6 mm)
• Electrochemical test cell arrays for battery research
Copyright: TU Berlin