Zoschke K.,Fraunhofer Institute for Reliability and Microintegration |
Lang K.-D.,TU Berlin
Proceedings of the 2016 IEEE 18th Electronics Packaging Technology Conference, EPTC 2016 | Year: 2016
The paper reviews structuring methods of adhesive layers which can be subsequently used for thermo-compression type wafer to wafer bonding processes. With respect to limitations of the state-of-the-art adhesive structuring approaches laser direct patterning of polymer resins is introduced. The process features a 248 nm excimer laser stepper with mask based pattern projection and high speed XY-moving stage. Non-cured polymer precursors such as Cyclotene™ resins can be well structured with this direct ablation method. As additional feature of the new structuring method patterning of polymer compound layers is introduced and discussed. This approach enables structuring of polymer layer stacks having different cure conditions enabling adjusted material flow and squeeze capabilities in subsequent wafer bonding processes. The experimental setups as well as the results of structuring and bonding trials with different polymer layers are discussed in this work. © 2016 IEEE.
Iannacci J.,Fondazione Bruno Kessler |
Tschoban C.,Fraunhofer Institute for Reliability and Microintegration
Journal of Micromechanics and Microengineering | Year: 2017
RF-MEMS technology is proposed as a key enabling solution for realising the high-performance and highly reconfigurable passive components that future communication standards will demand. In this work, we present, test and discuss a novel design concept for an 8-bit reconfigurable power attenuator, manufactured using the RF-MEMS technology available at the CMM-FBK, in Italy. The device features electrostatically controlled MEMS ohmic switches in order to select/deselect the resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. The fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated with Ansys HFSS. The device exhibits attenuation levels (S21) in the range from -10 dB to -60 dB, up to 110 GHz. In particular, S21 shows flatness from 15 dB down to 3-5 dB and from 10 MHz to 50 GHz, as well as fewer linear traces up to 110 GHz. A comprehensive discussion is developed regarding the voltage standing wave ratio, which is employed as a quality indicator for the attenuation levels. The margins of improvement at design level which are needed to overcome the limitations of the presented RF-MEMS device are also discussed. © 2017 IOP Publishing Ltd.
News Article | October 9, 2016
« Uno-X Hydrogen awarded $2.45M grant for H2 production facility and two fueling stations in Bergen | Main | Neste to begin selling 100% renewable diesel in Finland » A German research alliance has developed the basis for smart, high-resolution active matrix LED headlights, which takes adaptive forward lighting to a new dimension. A demonstration model was developed by overall project manager Osram in collaboration with the project partners Daimler, Fraunhofer, Hella and Infineon. Both headlights contain three LED light sources, each with 1,024 individually controllable light points. This means that the headlight can be adapted very precisely to suit the respective traffic situation to ensure optimum light conditions at all times without dazzling other drivers. The light can be adapted to take account of every conceivable bend in the road so that there are no dark peripheral areas. In addition, with the aid of sensors in the vehicle, the surroundings can be analyzed in order to illuminate oncoming traffic. This allows the driver to see these vehicles more clearly. At the same time, the beam of light does not shine on the heads of oncoming drivers, which means they’re not dazzled. As a result, such shifting headlights no longer have to be dimmed on country roads. The μAFS (micro-structured Adaptive Front-lighting System) project, which was funded by the German Federal Ministry of Education and Research (BMBF), has now been successfully completed after three and a half years with the production and field test of headlight demonstrators. For the implementation, Osram Opto Semiconductors, Infineon, and the Fraunhofer Institute for Reliability and Microintegration (IZM) developed an innovative LED chip with 1,024 individually controllable light points. In the current generation of adaptive headlights on the market, several LED components are installed in the headlights side by side and on top of each other. Additional electronic components are required to switch light segments on and off. The number of segments is limited due to the restricted space in the headlight. In the new approach, electronic activation of the LED is integrated in the chip, resulting in a much higher resolution, while still meeting limited space requirements. For the innovative, high resolution, smart automotive lighting, in a second step, the Osram Specialty Lighting unit developed an LED module with an electrical and thermal interface that enables direct connection to the vehicle’s electronics. The feasibility of the system has now been demonstrated successfully in the project; when a smart, high resolution headlight is used, driving and weather conditions are continuously analyzed: What is the course of the road, how fast is the car driving, is there oncoming traffic, and what is the distance between the car and other vehicles? Based on these conditions, the variable, adaptive light distribution ensures tailor-made lighting in every situation. For example, at high speeds, the range of the light beam is increased automatically. In city traffic, on the other hand, wider light distribution improves safety as, in addition to the road, the sidewalk and peripheral areas are also illuminated better. These functions are implemented fully electronically with no mechanical actuators. With glare-free full beam the driver always has the best possible light at night—with no adverse effects for other drivers. For motorists this is a clear benefit in terms of awareness—an important contribution towards reducing the risk of accidents when driving at night. Infineon Technologies AG developed the smart driver circuit in the innovative LED chip. This allows each of the 1,024 light points to be controlled individually. The semiconductor manufacturer has thus managed to design it in such a way that it can be connected directly in the LED chip with the light-emitting LED array above it. The technical challenge lay in reconciling the special requirements for this with the manufacturing technologies for LED drivers. With the smart driver circuit and its broad application knowledge in relation to automotive applications, Infineon is supporting the trend toward highly innovative, adaptive front lighting systems. HELLA KGaA Hueck & Co specified the main technical requirements for the light source based on the functional requirements from Daimler. The light and electronics expert developed the entire optical system for the light modules and its cooling concept and developed the prototype headlights. They are extremely efficient and generate a very homogeneous light pattern and, in addition, the individual light points have a good lighting quality. The different light patterns can thus be generated purely electronically with no mechanical actuators. This is a step towards digitalization in the lighting industry. With this development, Hella is living up to its own standards for developing innovative lighting systems with and for customers and not only producing them in series with the necessary accuracy and quality, but also consistently thinking ahead in terms of technology. In the research project, Daimler AG specified the functional requirements and the future vehicle properties for the complete headlight system. This was the basis for the components and module properties for the overall headlight system, which calculates the best light distribution with consideration of future sensors and vehicle architectures and passes this information on to the pixel headlights. As regards future electric vehicles, energy efficiency is an important requirement for the newly developed LEDs. A vehicle from Daimler with the smart LED headlights was used for the field trials under real traffic conditions. The current Mercedes-Benz E-Class contains MULTIBEAM LED headlights from Hella which each have 84 individually controllable Osram high performance LEDs. Daimler is continuing to develop LED headlights with more and increasingly finer pixels. Fraunhofer contributed its competence in connection technology (LED & ICs) and materials as well as in the detection and isolation of defects to the project. The very high resolution was achieved through even finer structuring with extraordinary, miniaturized connection technology. For this purpose, at the Fraunhofer Institute for Reliability and Microintegration (IZM) in Berlin, Germany LED arrays from Osram with 1,024 pixels were assembled on an active driver circuit from Infineon that actuates each pixel individually. With extremely good cooling, the chips were assembled to enable micrometer-sized height differences to be balanced out. Two different technologies were investigated: thermocompression bonding with porous gold nano-sponge and reflow soldering with highly reliable gold-tin. Both assembly techniques were used successfully with a high yield and proved to be a robust interface for the subsequent LED processes. One of the technological challenges of the high resolution LED headlight is the comparatively large chip with 1,024 individually controllable pixels. This is because as the LED chip size increases it raises the risk of failure or decreased luminosity of the individual light points in the pixel matrix during the production process. To overcome this problem, the Fraunhofer Institute for Applied Solid State Physics IAF in Freiburg, Germany developed a new technology to repair defects. It is based on ultraviolet laser microprocessing and enables defects in LED chips to be repaired during the production process. The microscopic defects are identified and removed with a UV laser through careful material removal or are electrically isolated without the laser inadvertently causing new defects, what are known as leakage current paths. When they have been repaired, the pixels regain their full luminosity – the “luminescence pattern” is homogeneous again. The economic benefits of laser microprocessing from the Fraunhofer IAF are not only in reducing defects during production and thus lowering production discard and costs for large LED chips: The process can also increase the average life of the LEDs, which is an important competitive advantage and raises customer satisfaction. The μAFS project was funded by the German Federal Ministry of Education and Research under funding ID 13N12510 and ran from February 2013 to September 2016. The aim was achieved by the project partners: to develop a smart lighting solution as the technical basis for a new class of energy-efficient LED headlights with additional road safety functions. Adaptive front-lighting systems (AFS) can be developed from this, which create more safety for drivers and passengers.
Moro A.J.,Friedrich - Schiller University of Jena |
Cywinski P.J.,University of Potsdam |
Korsten S.,Friedrich - Schiller University of Jena |
Mohr G.J.,Friedrich - Schiller University of Jena |
Mohr G.J.,Fraunhofer Institute for Reliability and Microintegration
Chemical Communications | Year: 2010
A fluorescent naphthalimide chemosensor for ATP bearing a dipicolylamine group complexed with a Zn(ii) metal as a receptor moiety was synthesized and its sensing properties regarding ATP and other related phosphate species were evaluated. © 2010 The Royal Society of Chemistry.
Fitzpatrick C.,University of Limerick |
Hickey S.,University of Limerick |
Schischke K.,Fraunhofer Institute for Reliability and Microintegration |
Maher P.,MicroPro Multimedia Computers
Journal of Cleaner Production | Year: 2014
This paper describes the life cycle engineering of an integrated desktop computer system from the perspective of a small to medium enterprise (SME). Using a novel approach which considers the motivations of actors at various stages during the life cycle of the PC it attempts to engineer the lifecycle through design features which have been chosen to influence these critical decision points leading to more desirable pathways from an environmental perspective. Using these motivations it extracts design principles and ultimately design and service features to (1) promote long lifetime with the original user (2) facilitate refurbishment and reuse (3) be easy to disassemble and (4) contain minimal valueless fractions at end of life. This has been achieved largely through two specific design features and supported by post-sale services to the consumer. The first of these features is a high quality finish using a solid hardwood chassis to create an emotionally durable product that is easy to refurbish and eliminates negative value plastic fractions at end of life. The second feature is a strong focus on ease of disassembly to facilitate upgrade, refurbishment and deep disassembly at end of life. The service offering is also crucial and upgrade services and buy back are available. © 2014 Elsevier Ltd. All rights reserved.
Oppermann H.,Fraunhofer Institute for Reliability and Microintegration
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012
Integration of MEMS and MOEMS requires very compact packages with short interconnects which are found in 3D packages. We will give an overview on assembly methods like chip-to-chip, chip-to-wafer and wafer-to-wafer. For the variety of applications different interconnection methods are shown: reflow soldering, transient liquid phase bonding and transient liquid phase soldering, thermocompression and thermosonic bonding as well as sintering of silver paste or new materials like nanosponge. © 2012 SPIE.
Klumpp A.,Fraunhofer Institute for Reliability and Microintegration |
Ramm P.,Fraunhofer Institute for Reliability and Microintegration |
Wieland R.,Fraunhofer Institute for Reliability and Microintegration
Proceedings -Design, Automation and Test in Europe, DATE | Year: 2010
3D integration is a key solution to the predicted performance increase of future electronic systems. It offers extreme miniaturization and fabrication of More than Moore products. This can be accomplished by the combination of Through-Silicon-Via (TSV) technologies for shortened electrical signal lines and Solid Liquid Interdiffusion (SLID) for highly reliable assembly. Depending on the chosen technology concept, TSVs are filled with either tungsten or copper metal. Thinning of silicon as part of the process flow enables devices as thin as 30 μm, so multilayer stacking will result in ultra-thin systems. All these 3D integration concepts focus on wafer level processing to achieve the highest miniaturization degree and highest processing reliability as well as enabling high volume cost-effective fabrication. © 2010 EDAA.
Brusberg L.,Fraunhofer Institute for Reliability and Microintegration |
Whalley S.,ILFA Feinstleitertechnik GmbH |
Herbst C.,TU Berlin |
Schroder H.,Fraunhofer Institute for Reliability and Microintegration
Optics Express | Year: 2015
Parallel optical interconnects on-board level requires low propagation loss in wavelength range between 850 and 1550 nm to be compatible with datacom and telecom optical engines. For highest integration density tight waveguide bends and a scalable number of optical layers should be manufacturable for 2D interfaces to optical fiber array connectors and photonic assembly I/O's. We developed a glass waveguide panel process for double-sided processing of commercial available display glass by applying a two-step thermal ion-exchange process for low-loss multi-mode graded-index waveguides. Multiple glass waveguide panels can be embedded between electrical layers. The generic concept enables fabrication of high-density integration (HDI) electro-optical circuit boards (EOCB) with high number of optical and electrical layers. Waveguides with high NA of 0.3 for low bend losses could be achieved in glass with propagation loss of 0.05 dB/cm for all key wavelengths. Four of those glass waveguide panels were embedded in an EOCB demonstrator with size of 280 × 233 mm2 providing eight optical layers with 96 channels in an area of 2.8 × 1.5 mm2. To the best of our knowledge it's the highest number of layers that has ever been demonstrated for an EOCB. © 2015 Optical Society of America.
Oppermann H.,Fraunhofer Institute for Reliability and Microintegration |
Dietrich L.,Fraunhofer Institute for Reliability and Microintegration
Microelectronics Reliability | Year: 2012
Nanoporous gold bumps have been deposited on silicon wafers by electroplating a silver-gold alloy followed by etching the silver. An open-porous cellular structure of gold at meso-scale is left on top of the bumps. For flip chip bonding we found low temperature and low force bonding conditions. The porous interconnects have very promising properties, like compressibility and reduced stiffness, which should result in higher bond yield and extended reliability. © 2011 Elsevier Ltd. All rights reserved.
Schmitz S.,Fraunhofer Institute for Reliability and Microintegration |
Schneider-Ramelow M.,Fraunhofer Institute for Reliability and Microintegration |
Schroder S.,Fraunhofer Institute for Reliability and Microintegration
Microelectronics Reliability | Year: 2011
Wire bonding remains the predominant interconnection technology in microelectronic packaging. Over the last 3 years a significant trend away from Au and towards Cu wire bonding has become apparent. This has been due to general efforts to lower manufacturing costs and price increases for raw materials like Au. Although much research has been carried out into wire bonding over recent decades, most has focused on Au ball/wedge bonding. The results of this research have shown that bonding parameters, bonding quality and reliability are closely interconnected. However, the different material properties of Cu compared to Au, such as affinity to oxidation and hardness, mean that these insights cannot be directly transferred to Cu bonding processes. Thus, further research is necessary. This paper discusses a study of bonding interface formation under various bonding parameters. Cu wire was bonded on AlSiCu0.5 metallization and a bonding parameter optimization was carried out to identify useful parameter combinations. On the basis of this optimization, different samples were assembled using parameter combinations of low, medium and high US-power and bonding force. An interface analysis was subsequently carried out using shear testing and HNO3 etching. Intermetallic phase growth was analyzed on cross sections of devices annealed at 200 °C for 168 h and 1000 h. Contacts bonded with low bonding force and high US-power tended towards cratering during shear testing. Bonding force proved to have a significant effect on intermetallic phase formation whereas US-power was found to exert only a minor influence. The intermetallic phase formation of annealed samples was analyzed using EDX and interpreted on the basis of phase formation kinetics. Three main intermetallic phases were identified. © 2010 Elsevier Ltd. All rights reserved.