Now showing 1 - 10 of 4399
  • Publication
    Sensor Systems for Extremely Harsh Environments
    Sensors are key elements for the detection of environmental properties and are indispensable in industrial applications for process monitoring and intelligent control of processes. While highly integrated sensor systems are already state -of-theart in many everyday areas, the situation in an industrial environment is significantly different. The use of sensor systems is often not possible because the extreme environmental conditions of industrial processes such as high operating temperatures or strong mechanical loads do not allow the reliable operation of sensitive electronic components. As part of the Fraunhofer Lighthouse project eHarsh, eight institutes have bundled their competencies and created a technology platform as a basis for the development of sensor systems for extremely harsh environments.
  • Publication
    Catastrophic Optical Damage in Semiconductor Lasers: Physics and New Results on InGaN High-Power Diode Lasers
    ( 2022)
    Hempel, M.
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    Dadgostar, S.
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    Jimenez, J.
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    Kernke, R.
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    Gollhardt, A.
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    Tomm, J.W.
    Among the limitations known from semiconductor lasers, catastrophic optical damage (COD) is perhaps the most spectacular power-limiting mechanism. Here, absorption and temperature build up in a positive feedback loop that eventually leads to material destruction. Thus, this is truly an ultimate mechanism, and its continued suppression is a manifestation of progress in device design and manufacturing. After an overview of the current state of knowledge, new investigations of COD using artificially micrometer-sized starting points created within the active zone in the cavity of 450 nm GaN semiconductor lasers are reported on. Defect growth mechanisms and characteristics are studied during 800 ns current pulses. The defect growth follows the highest light intensity. Secondary defect patterns are studied: complete destruction of the active zone and generation of a point defect cloud at least ≈10 μm into the remaining surrounding material. Extremely large angles (>90°) of damage growth are traced back to the material properties and the aging scenario. The results are compared with former experiments with GaAs-based lasers.
  • Publication
    A New Filter Concept for High Pulse-Frequency 3-Phase AFE Motor Drives
    ( 2021)
    Hoffmann, S.
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    Bock, M.
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    Hoene, E.
    The size of back-to-back converters with active front end is significantly determined by the size of the passive filter components. This paper presents a new complete EMC filter concept for this type of converter system that is effective on the input and the output. This involves filtering the main common mode interferences from the grid and motor sides with a single CM choke. Since only the difference of the generated common mode voltage-time areas of both converters is absorbed by this component, the size of the required filter can be greatly reduced compared to conventional filter concepts. The concept is validated on a grid feeding inverter that can be connected to the public distribution network with an output power of 63 kW. The size reduction is demonstrated by means of a design example on a system with the same power and electrical requirements. It is elaborated why, applying the new filter concept, the impedance of the DC link potentials to ground and other electrical potentials should be as high as possible and therefore associated parasitic capacitances should be minimized. From this requirement, rules for the design of the power modules of PFC and motor converters for the application of this filter concept are derived.
  • Publication
    Co-Package Technology Platform for Low-Power and Low-Cost Data Centers
    ( 2021)
    Papatryfonos, K.
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    Selviah, D.R.
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    Maman, A.
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    Hasharoni, K.
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    Brimont, A.
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    Zanzi, A.
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    Kraft, J.
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    Sidorov, V.
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    Seifried, M.
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    Baumgartner, Y.
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    Horst, F.
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    Offrein, B.J.
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    Lawniczuk, K.
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    Broeke, R.G.
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    Terzenidis, N.
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    Mourgias-Alexandris, G.
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    Tang, M.
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    Seeds, A.J.
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    Liu, H.
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    Sanchis, P.
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    Moralis-Pegios, M.
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    Manolis, T.
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    Pleros, N.
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    Vyrsokinos, K.
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    Sirbu, B.
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    Eichhammer, Y.
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    Oppermann, H.
    ;
    Tekin, T.
    We report recent advances in photonic-electronic integration developed in the European research project L3MATRIX. The aim of the project was to demonstrate the basic building blocks of a co-packaged optical system. Two-dimensional silicon photonics arrays with 64 modulators were fabricated. Novel modulation schemes based on slow light modulation were developed to assist in achieving an efficient performance of the module. Integration of DFB laser sources within each cell in the matrix was demonstrated as well using wafer bonding between the InP and SOI wafers. Improved semiconductor quantum dot MBE growth, characterization and gain stack designs were developed. Packaging of these 2D photonic arrays in a chiplet configuration was demonstrated using a vertical integration approach in which the optical interconnect matrix was flip-chip assembled on top of a CMOS mimic chip with 2D vertical fiber coupling. The optical chiplet was further assembled on a substrate to facilitate integration with the multi-chip module of the co-packaged system with a switch surrounded by several such optical chiplets. We summarize the features of the L3MATRIX co-package technology platform and its holistic toolbox of technologies to address the next generation of computing challenges.
  • Publication
    Ecological Cost-Benefit Analysis of a Sensor-Based Parking Prediction Service
    ( 2021)
    Druschke, J.
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    Fath, S.
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    Stobbe, L.
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    Nissen, N.F.
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    Richter, N.
    ;
    Lang, K.-D.
    The fast-growing sector of smart city applications resulting from the ongoing digitalization has a huge impact on our society. They use innovative technologies to improve for example mobility, optimize shopping or offer intelligent travel guide assistance. However, these applications have not only the potential to benefit our daily life with precisely targeted services, but also to reduce the environmental impact we create. In this paper the authors present the proceeding for a simplified life cycle assessment on the special case of a sensor-based parking prediction service of the Deutsche Telekom called "Park&Joy".
  • Publication
    Investigation of Wafer Dicing and Cleaning Processes for Die-to-die Oxide direct Bonding Technology
    ( 2021)
    Khurana, G.
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    Hanisch, A.
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    Rudolph, C.
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    Meyer, J.
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    Wieland, M.
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    Panchenko, I.
    A feasibility study of die-to-die (D2D) direct bonding with oxide surface is conducted using regular industrial cleanroom tools for wafer processing. The study highlights the influence of different wafer dicing, die handling and cleaning methods on the die surface quality and the quality of D2D bonding. The presented work features particle control as the biggest challenge and current bottleneck in D2D direct oxide bonding. The successful bonding of the known good dies (KGD's) with minimum defects on the bonding surface, sufficiently clean die surface, suitable roughness and sufficiently high hydrophilicity is achieved. Techniques such as stealth dicing for wafer singulation, modified RCA-SC1 (Radio Corporation of America - Standard Clean 1) recipe for cleaning and tuned plasma activation resulted in the successful D2D direct bonding. Thus, the presented work enables various applications to benefit from higher degree of design flexibility provided by D2D direct bonding approach.
  • Patent
    Verbindungsmethode für Leistungsmodule mit einer Zwischenkreisverschienung
    System umfassend ein Leistungsmodul umfassend einen Halbleiter und eine erste Verbindungsstelle und eine zweite Verbindungsstelle, die mit dem Halbleiter elektrisch leitend verbunden ist sowie eine Zwischenkreisverschienung umfassend zumindest zwei Schienen, wobei eine erste der zwei Schienen zumindest ein Kontaktelement aufweist, und wobei das zumindest eine Kontaktelement mit der ersten Verbindungsstelle eine elektrisch leitende Kaltverschweißverbindung formt.
  • Publication
    Generative Machine Learning for Resource-Aware 5G and IoT Systems
    Extrapolations predict that the sheer number of Internet-of-Things (IoT) devices will exceed 40 billion in the next five years. Hand-crafting specialized energy models and monitoring sub-systems for each type of device is error prone, costly, and sometimes infeasible. In order to detect abnormal or faulty behavior as well as inefficient resource usage autonomously, it is of tremendous importance to endow upcoming IoT and 5G devices with sufficient intelligence to deduce an energy model from their own resource usage data. Such models can in-turn be applied to predict upcoming resource consumption and to detect system behavior that deviates from normal states. To this end, we investigate a special class of undirected probabilistic graphical model, the so-called integer Markov random fields (IntMRF). On the one hand, this model learns a full generative probability distribution over all possible states of the system-allowing us to predict system states and to measure the probability of observed states. On the other hand, IntMRFs are themselves designed to consume as less resources as possible-e.g., faithful modelling of systems with an exponentially large number of states, by using only 8-bit unsigned integer arithmetic and less than 16KB memory. We explain how IntMRFs can be applied to model the resource consumption and the system behavior of an IoT device and a 5G core network component, both under various workloads. Our results suggest, that the machine learning model can represent important characteristics of our two test systems and deliver reasonable predictions of the power consumption.
  • Publication
    Methodology for Modeling the Energy and Material Footprint of Future Telecommunication Networks
    ( 2021)
    Stobbe, L.
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    Nissen, N.F.
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    Druschke, J.
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    Zedel, H.
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    Richter, N.
    ;
    Lang, K.-D.
    This paper presents important methodical aspects in conjunction with the ongoing development of a novel multi-level-model in support of lifecycle environmental assessments of telecommunication networks. The new approach is, to some extent, emulating the OSI-layer model (Open Systems Interconnection), starting at the bottom with the main physical components, followed by product configurations, network architecture and control. On the top layer, the model scales through application and use case scenarios. This complex inventory model furthermore distinguishes between constructive (hardware-defined) elements on the one hand and operational (software-defined) elements on the other. By combining technical data as fixed values with application data as variable values, it is now possible to analyze the causal interaction between different technology generations, network configurations, and utilization intensity. It will allow identifying the best starting point for eco-design and improvement measures. Due to fact that the new methodology is not limited to energy consumption only, it supports a holistic understanding of the environmental impact of telecommunication networks.
  • Publication
    Fan-Out Wafer and Panel Level Packaging - A Platform for 3D Integration
    ( 2021)
    Braun, T.
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    Becker, K.-F.
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    Töpper, M.
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    Aschenbrenner, R.
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    Schneider-Ramelow, M.
    The constant drive to further miniaturization and heterogeneous system integration leads to a need for new packaging technologies that also allow large area processing and 3D integration with strong potential for low cost applications. Here, Fan-Out Wafer Level Packaging [FOWLP] is one of the latest packaging trends in microelectronics. The technology can be also used for multi-chip packages or System in Package (SiP). 3D integration is typically done by package on package (PoP) stacking where the electrical 3D routing is done by through mold (TMV) or through package vias (TPV) and a redistribution layer on both sides of the FOWLP. In summary the paper will give a review of the different technology approaches for through mold vias in a Fan-out Wafer or Panel Level Package.