Research And Development
Uniting imagination, innovation and education The Fraunhofer-Gesellschaft Research Institute brings together a place of excellence, David Ridsdale, EuroAsia Semiconductor reports.
As it stands today, the Fraunhofer-Gesellschaft has attained a size and influence that makes it an undisputedly vital element in Germany's industrial and scientific landscape. But the early years were far from easy. The research organization was founded in 1949, in the same year as the Federal Republic of Germany, and started out as a small office with just three employees. The original purpose of the non-profit organization was to distribute grants and donations for research of direct relevance to industry. The Fraunhofer-Gesellschaft owes its name to Joseph von Fraunhofer (1787-1826), the successful Munich researcher, inventor and entrepreneur.
Fraunhofer IPMS carries out customer specific developments in the field of microelectronic and microsystem technology in Dresden. The aim is to act as a business partner in helping to transfer innovative ideas into new products. The Fraunhofer IPMS is prepared for serial production of modern CMOS compatible MEMS technology products in its own clean room facilities. About 180 scientists work with modern equipment to provide customer specific solutions in the field of circuit design, sensors and sensor systems, micromechanical actuators and actuator systems, lightmodulating microsystems, image processing and image transmission and organic electronics.
1. Organic light emitting diodes: Transparent displays and highest efficient light sources on low cost substrates
Light Emitting Diodes based on organic semiconductors (OLEDs) have many features, which show great promise for flat-panel display applications and lighting applications. Based on the very high efficiency of the diodes (e.g. for green diodes the efficiency is higher than for inorganic LEDs) a possible future market will be in lighting applications, since OLEDs are optimal for diffuse area lighting. Fraunhofer IPMS offers customer/application-specific developments based on highly efficient OLEDs in combination with the novel fabrication technology based on the world-wide first vertical In-line fabrication system for organic light emitting diodes.
Based on their excellent picture quality and low manufacturing costs OLED displays will be the right product for future multimedia and mobile communication applications. OLED based emissive displays show more excellent picture quality including large reading angle and excellent motion picture capability. Additionally OLED-displays are extremely thin and could be transparent. Transparent displays are a new type of display to read information from both sides. In off-condition such displays are nearly transparent, which gives new possibilities to show information to customers. At the fair the IPMS will demonstrate transparent OLED displays making both sides of information readable. Especially for OLED light sources the cost pressure on the fabrication is enormous. The Fraunhofer IPMS will show at the fair a novel fabrication combination to achieve low cost fabrication for lighting applications.
World record in OLED efficiency on low cost alternative substrates
One important aspect for fabrication cost is the used ground contact, which is commonly built by the use of ITO, a widely used contact material for LCD displays. Due to the growth of display fabrication the cost for ITO increased drastically over the past 3 years by a factor of three. For low cost fabrication a cheap alternative for ITO has to be used.
The Fraunhofer IPMS makes investigations, inside of the largest European OLED lighting projects named OLLA (High brightness OLEDs for ICT & Next Generation Lighting Applications), to replace ITO by a new low cost material named ZAO (Aluminium doped ZnO). The world wide highest efficient OLEDs on this low cost anode material will be shown at the fair.
Additionally for the lighting market it is generally expected that the manufacturing methods have to become more efficient to achieve large market penetration. OLED based on small-molecule organic semiconductors are currently manufactured by point-source evaporation using cluster equipment, leading to large losses of organic materials and long tact times. The Fraunhofer IPMS offers developments using a worldwide unique fabrication technology, the vertical In-Line deposition technique. The organic layers are dynamically deposited during the vertical transportation of the substrates inside the Applied Films Machine VES400. Based on this transportation principle and the use of organic line sources it is possible to improve throughput, masking and organic material usage. The Fraunhofer IPMS will show newest lighting demonstrators fabricated on this In-Line system.
2. Laser Projection modules
In modern information society display of digital data plays an important role, both in private and professional environments. Trends are high comfort, permanent accessibility and security. Corresponding display devices must follow trends to a steadily increasing miniaturisation. A very promising approach to tackle these requirements is the development of ultra compact projection systems.
The projection module developed by Fraunhofer IPMS and demonstrated at SID 2006 overcomes two common problems associated with this image generation technique. Firstly, instead of high power lighting devices that consume lots of power and dissipate a significant heat electrically modulated lasers are applied. Secondly, components for image generation with non-negligible spatial dimensions are replaced by a special MOEMS device developed at Fraunhofer IPMS, a resonant two-dimensional micro scanning mirror. Its main characteristics are small size, robustness, ease of electrical excitation and no need for complicated additional optical components.
At SID 2006, Fraunhofer IPMS demonstrates a full color laser based projection applying its two dimensional resonant micro scanning mirror for light deflection.
The demonstrator provides a geometrical image resolution of 640 x 480 pixels (VGA resolution) , 8 bit colour depth per elementary colour, and 50 Hz frame rate. Projection systems built upon these modules cover application areas like Infotainment (PDA, Laptop, Graphical User Interfaces), Automotive (driver assistance systems, Head-up displays), Medical Technology, Production Engineering, and Industrial Metrology.