Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration IZM

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  • Publication
    Sensornetzwerk zum Monitoring von Hochspannungsleitungen
    ( 2012)
    Voigt, S.
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    Wolfrum, J.
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    Pfeiffer, M.
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    Keutel, T.
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    Brockmann, C.
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    Grosser, V.
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    Lissek, S.
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    During, H.
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    Rusek, B.
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    Braunschweig, M.
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    Kurth, S.
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    Gessner, T.
    In diesem Beitrag wird ein autarkes Sensornetzwerk zur Überwachung und Optimierung der Auslastung von Hochspannungsleitungen vorgestellt sowie Ergebnisse aus Tests im Hochspannungslabor und auf 110-kV-Hochspannungsleitungen diskutiert. Das Sensornetzwerk besteht aus zahlreichen Sensorknoten, die direkt am Leiterseil der Freileitung montiert sind. Zusätzliche Komponenten am Mast werden nicht benötigt. Das System arbeitet autark. Die Energieversorgung der Sensorknoten erfolgt aus dem elektrischen Streufeld der Hochspannungsleitung. Die Knoten nehmen die Temperatur, die Neigung des Leiterseils sowie den Strom, der durch die Leitung fließt, auf. Diese Messdaten werden anschließend von Sensorknoten zu Sensorknoten bis zur Basisstation per Funk im 2,4 GHz-ISM-Band übertragen. In der Basisstation, welche sich im Umspannwerk befindet, werden die Daten aufbereitet und in Form eines Webservers mit Datenbanksystem der Leittechnik zur Verfügung gestellt.
  • Publication
  • Publication
    A MEMS friction vacuum gauge suitable for high temperature environment
    ( 2008)
    Tenholte, D.
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    Kurth, S.
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    Gessner, T.
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    Dötzel, W.
  • Publication
    Continuously tunable RF-MEMS varactor for high power applications
    ( 2008)
    Leidich, S.
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    Kurth, S.
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    Gessner, T.
    A high power continuously tunable RF-MEMS capacitor (varactor) for frequencies from DC-4.0 GHz is presented. The device is specified for 0.8-1.6 pF analog tuning range and provides a Q factor of ?100 for frequencies below 2.0 GHz. Using silicon bulk technology and wafer bonding techniques, RF and electrostatic actuation electrodes are arranged vertically. It enables controlled counteracting the attractive electrostatic forces generated by high RF signal amplitudes (self actuation). Using a time domain reflectometer based measurement setup and a resonating test circuit, stability against CW signals of up to 55 V rms has been shown. Due to the highly damped mechanical response, the capacitance setup is intrinsically insensitive to RF bursts (tp=20 ?s) of more than 120 V rms.
  • Publication
    Reliability of MEMS devices in shock and vibration overload situations
    ( 2008)
    Kurth, S.
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    Shaporin, A.
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    Hiller, K.
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    Kaufmann, C.
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    Gessner, T.
    This contribution describes the investigation of the reasons for overload failure and overload reaction based on linear vibration theory by decomposition of the complex reaction into resonant mode reactions and on observation of the reaction. An impulse specific peak deflection (ISPD) is derived as a general characteristic property of a certain shock. It is applicable to predict the mechanical deflection of a certain resonant mode of an arbitrary resonant frequency due to a shock. This is further analyzed and proofed by scanning Laser Doppler interferometer (SLDI) measurement on the example of a Fabry Perot interferometer based tunable infrared filter. The results from ISPD prediction are compared to SLDI measurements and to finite element analysis results.
  • Publication
    Performance and reliability test of MEMS optical scanners
    ( 2007)
    Kurth, S.
    ;
    Kaufmann, C.
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    Hahn, R.
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    Mehner, J.
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    Dötzel, W.
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    Gessner, T.
    MEMS scanners are among the devices which have been investigated since the very beginning of MEMS development. The main concern of this paper is to report and discuss suitable measurement techniques and to compare and verify this methods on different scanners for examples. Analysis of scanner reaction based on image processing is covered in a first section. It is shown that an Electronic Speckle Interferometer (ESPI), a Scanning Laser Doppler Interferometer (SLDI) and a phase shift interferometer are suitable for measuring different motion characteristics. The SLDI is used for rapid measurement of FRF at a large number of locations at the scanner. A phase shift interferometer with stroboscopic illumination has been utilized for measuring the deformation of scanners operating them at resonant frequency. Measurement of static displacement and of thermal deformation is the main application of ESPI technique and shown on the example of a galvanometric scanner. A next sectio n is dedicated to functional tests and to qualification of methods for wafer level test. The application of a tilt angle measuring set up containing a position sensitive semiconductor device and a laser diode and of a laser Doppler interferometer is analyzed. Measurement of resonant frequencies in an early production state is the topic of a third section. It provides information about geometry properties of the scanners suspension and about mechanical stress inside suspending torsion or bending beams. Moreover it enables selection of scanner chips with characteristics which do not meet the specification and the cost for packaging of this bad dies is saved.
  • Publication
    Design and fabrication of a micromechanical vertical resonator
    ( 2007)
    Jia, C.
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    Wiemer, M.
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    Kurth, S.
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    Otto, T.
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    Gessner, T.
  • Publication
    MEMS based laser display system
    ( 2007)
    Specht, H.
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    Kurth, S.
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    Kaufmann, C.
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    Gessner, T.
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    Dötzel, W.
  • Publication
    Laser-Display-System auf Basis von MEMS-Scannern
    ( 2007)
    Specht, H.
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    Kurth, S.
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    Kaufmann, C.
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    Hahn, R.
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    Dötzel, W.
    ;
    Gessner, T.
    ;
    Mehner, J.