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Performance Improvement of High Frequency Aluminum Nitride Ultrasonic Transducers

Sensors and Transducers 2013年第SPEC.ISS.1期18卷 66-75页

作者： Wei, Yangjie Herzog, Thomas Heuer, Henning Gradate School of Chinese Academy of Sciences and the State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Nanta Str. 114 110016 China Fraunhofer Institute for Non-Destructive Testing Dresden Branch Maria-Reiche-Str. 2 01109 Dresden Germany

This paper presents three methods to improve the performance of a high frequency aluminum nitride (AlN) ultrasonic transducer. For a high frequency AlN ultrasonic transducer, its properties are related with its top electrode size, electrical impedance matching and layers of the piezoelectric plate. However, until now, no research has been published to analyze their influence on the performance of AlN ultrasonic transducers, especially in the frequency range above 200 MHz. First, two factors related with the top electrode size are proposed based on transmission coefficient and stored energy, and analysis is performed on an Al-AlN-Al on silicon wafers with different electrode sizes. The result proves when the electrode size is 1mm2, the transducer can provide the maximum output voltage and the maximal signal- to-noise ratio (SNR). Then, electrical impedance matching is conducted to improve the performance of transducers, and the experiment result shows that after matching, the resolution and sensitivity have been improved. Finally, a stacked AlN transducer is developed and its model is constructed to analyze its properties in time domain and frequency domain. The comparison between the simulation and the experiment shows the effectiveness of the proposed model, and a stacked structure can be used to improve the sensitivity of a high frequency AlN ultrasonic transducer. © 2013 IFSA.

关键词： Ultrasonic transducers

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Time reversal of lamb waves for damage detection in thermoplastic composites 24

Time reversal of lamb waves for damage detection in thermopl...

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24th International Conference on Adaptive Structures and Technologies, ICAST 2013

作者： Barroso-Romero, Maria Barazanchy, Darun Martinez, Marcias Groves, Roger M. Benedictus, Rinze Aerospace Non-Destructive Testing Laboratory Faculty of Aerospace Engineering Delft University of Technology Kluyverweg 1 Delft2600 GB Netherlands Faculty of Aerospace Engineering Delft University of Technology Kluyverweg 1 Delft2600 GB Netherlands

The objective of this study is to evaluate the use of correlation methods as a damage detection criterion in the application of the Time Reversal of Lamb Waves (TRLW) approach. The dispersion and attenuation characteristics of the waves are used for determining the maximum area to be inspected in a two transducers configuration. The Finite Element (FE) Model and experimental data are compared for verification of the method. The experimental setup consisted of a pair of piezoelectric transducers, working both as actuator and sensors, separated by a predetermined distance. Different defect sizes and positions with respect to the transducers were introduced on both aluminum and thermoplastic composite plates. A waveform generator was used to excite the piezoelectric actuators. An oscilloscope was used for acquiring the signals from the transducers. Those signals were processed in Matlab™ for the application of time reversal and a correlation analysis. The damage consisted of a hole through the thickness varying its diameter and location. The FEM simulates the propagation of Lamb waves in aluminum plates in order to analyze TRLW for damage detection. Lamb waves were generated using a 5 cycle Hanning window at different frequencies. The FEM consisted of standard 3D elements (C3D8I) for the plates and PZT elements (C3D8E) for the transducers. In order to simplify the model the PZTs were assumed to be perfectly bonded to the plates. The FEM analysis was mainly focused on the S0-wave. The indication of the presence of damage is performed using the correlation between the original actuation and the time reversed signal.

关键词： Surface waves

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Novel quick predict approach for identification of critical loadings in electronic components on PCB under vibration realized as design support tool

Novel quick predict approach for identification of critical ...

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Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems EuroSimE

作者： Mike Roellig René Metasch Angelika Schingale Andreas Schießl Karsten Meier Norbert Meyendorf Fraunhofer Institute for Non-Destructive Tcstina Dresden Branch (IZFP-D) Dresden Germany Fraunhofer Institute for Non-Destructive Testing Dresden Germany Continental Automotive GmbH Rezensbura Dresden Germany Dresden University of Technology Electronics Packaging Laboratory (IAVT) Dresden Germany

The paper presents an approach to bring numerical simulation and electronic design engineering closer together. In focus is the development of a design support tool, based on Finite Element Analysis as an automated running system behind an engineer adapted Graphical User Interface platform. The Quick Predict tool will have the capability to fast calculated mechanical stresses on PCB and electronic components, which are loaded by vibration. Vibration loading usually occurs in mobile transportation systems or mechanical motion systems. The paper presents the solution of the easy and quick input of geometry variations, material variation and different vibration scenarios reflected on the example of an Electronic Control Unit (ECU). The automated generation of the virtual model is based on the available general design parameter. A set of material data was determined experimentally. A suitable way to insert material data variations for PCB with low effort on measurements was developed and integrated. The engineers target to achieve, with the approach, is to improve vibration resistivity of electronic components or to design new configurations of PCB with vibration critical components with very low time consumption.

关键词： Load modeling Deformable models Abstracts Libraries Fixtures Vibrations Reliability

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non-destructive testing of GFRP materials by Fourier-domain infrared optical coherence tomography

Non-destructive testing of GFRP materials by Fourier-domain ...

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International Conference on Automatic Control and Artificial Intelligence, ACAI 2012

作者： Zhong, Shuncong Yan, Yongfu Shen, Yaochun Laboratory of Non-destructive Testing and Evaluation School of Mechanical Engineering and Automation Fuzhou University Fuzhou China Department of Electrical Engineering and Electrical Engineering University of Liverpool Liverpool L69 3BX United Kingdom Fujian Key Lab of Medical Instrument and Pharmaceutical Technology Fuzhou China Key Laboratory of Safety Science of Pressurized System of Ministry of Education Shanghai China

ISBN: (纸本)9781849195379

Fourier-domain (or spectral-domain) Infrared Optical Coherence Tomography (FDOCT) can penetrate into the scattering material noncontactly and therefore it can be used to characterize and image the inner structure of material in a non-invasive manner. In the paper, glass-fibre reinforced polymer (GFRP) materials were quantitatively characterized by using home-made FDOCT system. In the developed FDOCT system, a 50W Tungsten halogen lamp and a highperformance spectrometer are, respectively, employed as the light source and the detector. The broadband of the spectrometer and thermal light source results in the FDOCT system with high robust performance and an excellent depth resolution of 0.7 um. From the experimental results, the developed FDOCT system could be recommended in nondestructive testing or health monitoring of GFRP materials.

关键词： nondestructive examination

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Structural Properties of Zn Doped on Bi(Pb)2212 compound

Structural Properties of Zn Doped on Bi(Pb)2212 compound

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International Conference on Intelligent Computational Systems(ICICS’2012);International Conference on Mechanical,Automotive and Materials Engineering(ICMAME’2012);International Conference on Electronics,Biomedical Engineering and its Applications(ICEBEA’2012);International Conference on Ecological,Environmental and Biological Sciences(ICEEBS’2012);International Conference on Business,Economics,Management and Behavioral Sciences (ICBEMBS’2012);International Conference on Applied Mathematics and Pharmaceutical Sciences(ICAMPS’2012)

作者： Faiza.Bouacha M-Faycal.Mosbah Nora.Boussouf Abderrezak.Amira Yazid.Boudja Dja Abdelmalek.Saoudel the Faculty of Sciences Exactes and Natural Sciences and life Department of Materials Sciences University Larbi Ben M`hidi of Oum El-Bouaghi Laboratory of Thin Film and Interfaces University of Mentouri Faculty of Sciences Department of Physique Campus de Chaab-Erssas Laboratory of Non-Destructive Testing University of Jijel Faculty of Sciences and Technology

Doping by Zn in (Bi,Pb)2Sr2CaCu2O8 (Bi(Pb)2212) should give interesting results because the CuO2 superconducting planes are influenced. For that purpose, Bi1.6Pb0.4Sr2CaCu2-yZnyO8+d samples, with y= 0-0.04, have been prepared using the solid-state reaction technique. The samples have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Structural analysis shows that the crystalline lattice structure of the prepared samples belongs, mainly, to the superconductive tetragonal phase Bi(Pb)2212. The doping by Zn results in an unexpected decrease of the c cell parameter.

关键词： Bi-Pb-Sr-Ca-Cu-O system, Bi(Pb)-2212 phase, Pb and Zn substitution, high-T C superconductors.

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Packaging and characterisation of ultra low power VCSEL for sensor networks

Packaging and characterisation of ultra low power VCSEL for ...

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2011 International Students and Young Scientists Workshop "Photonics and Microsystems", STYSW 2011

作者： Sohr, S. Fischer, D. Rieske, R. Nieweglowski, K. Wolter, K.-J. Department of Electrical Engineering and Information Technology Electronics Packaging Laboratory TU Dresden Germany Fraunhofer Institute for Non-Destructive Testing Dresden Germany

ISBN: (纸本)9781457716522

In this paper an ultra-low power VCSEL with an electrical consumption of below 5 mW is characterised to electrical power, optical power, temperature as well as a spectral investigation. First the pigtail manufacture is described, where amongst others the VCSEL is bonded on a ceramic carrier and connected to an optical fibre by front surface coupling. Thereby the fibre-chip coupling is realised by using index matching adhesive as well as active alignment. Finally the results of the characterisation are analysed to find optimal operation conditions. For comparison results of a common VCSEL are shown. © 2011 IEEE.

关键词： Sensor networks

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Packaging and characterisation of ultra low power VCSEL for sensor networks

Packaging and characterisation of ultra low power VCSEL for ...

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International Students and Young Scientists Workshop Photonics and Microsystems

作者： S. Sohr D. Fischer R. Rieske K. Nieweglowski K.-J. Wolter Department of Electrical Engineering and Information Technology Electronics Packaging Laboratory TU Dresden Germany Fraunhofer Institute of Non-Destructive Testing (IZFP) Dresden Germany

关键词： Vertical cavity surface emitting lasers Optical fibers Semiconductor diodes Temperature measurement Optical variables measurement Stimulated emission

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Determination Of Thermal And Mechanical Properties Of Packaging Materials For The Use In FEM‐Simulations

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AIP Conference Proceedings 2011年第1期1378卷

作者： Mike Roellig Bjoern Boehme Karsten Meier René Metasch Fraunhofer Institute for Non‐Destructive Testing 01109 Dresden Germany Dresden University of Technology Electronics Packaging Laboratory 01062 Dresden Germany

Conventional and future electronic packages merge several different materials. Polymers, metals, solders, dielectrics, glasses, silicon, composites come together and show strong mechanical and material interaction. These interfacial effects increase if the miniaturization and diversification keep on rising as it is proposed. Many efforts have to be done to assure the system reliability of new electronic packages. The Finite Element Simulation has the ability to support the development process of new packages. The application of the FEM‐analysis requires the knowledge about the precise mechanical and thermal behaviour of the materials. The paper presents different measurement methods to determine accurate mechanical material properties of moulding compound polymers, underfillers, solder mask, and wafer photo resist and solder joints. The temperature dependency is essential to be respected. The polymer materials moulding compound as well as solder mask were characterized by Dynamic Mechanical Analysis under humidity influences to determine mechanical properties as function of moisture and temperature. Further experiments on polymer were conducted to extract the cure kinetics by Differential Scanning Calorimetry and to determine Bulk Modulus by Pressure‐Volume‐Temperature experiments (PVT). Altogether, these material properties need to be modeled in a comprehensive way fitting to each other. The common practice of just compiling data from different sources has been found to fail yielding in reliable and accurate results. The conditions under which the data were determined may cause mismatches between them and cause inconsistencies within the model. If a convergent solution was obtained at all, much simulation time would be needed as many iterations with small time steps were needed. In order to avoid this, the paper reports an approach of characterizing the temperature and time dependent mechanical material properties in one comprehensive scheme. The solder measurement

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Time And Temperature Dependent Micromechanical Properties Of Solder Joints For 3D‐Package Integration

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AIP Conference Proceedings 2010年第1期1300卷 176-185页

作者： Mike Roellig Karsten Meier Rene Metasch aFraunhofer Institute for Non‐Destructive Testing Dresden branch (IZFP‐D) bDresden University of Technology Electronics Packaging Laboratory IAVT

The recent development of 3D‐integrated electronic packages is characterized by the need to increase the diversity of functions and to miniaturize. Currently many 3D‐integration concepts are being developed and all of them demand new materials, new designs and new processing technologies. The combination of simulation and experimental investigation becomes increasingly accepted since simulations help to shorten the R&D cycle time and reduce costs. Numerical calculations like the Finite‐Element‐Method are strong tools to calculate stress conditions in electronic packages resulting from thermal strains due to the manufacturing process and environmental loads. It is essential for the application of numerical calculations that the material data is accurate and describes sufficiently the physical behaviour. The developed machine allows the measurement of time and temperature dependent micromechanical properties of solder joints. Solder joints, which are used to mechanically and electrically connect different packages, are physically measured as they leave the process. This allows accounting for process influences, which may change material properties. Additionally, joint sizes and metallurgical interactions between solder and under bump metallization can be respected by this particular measurement. The measurement allows the determination of material properties within a temperature range of 20° C–200° C. Further, the time dependent creep deformation can be measured within a strain‐rate range of 10−31/s−10−81/s. Solder alloys based on Sn‐Ag/Sn‐Ag‐Cu with additionally impurities and joint sizes down to O/ 200 μm were investigated. To finish the material characterization process the material model coefficient were extracted by FEM‐Simulation to increase the accuracy of data.

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Characterization methods for determination of temperature depended electrical, thermal, mechanical and fatigue properties of SnAg3.5 solder

Characterization methods for determination of temperature de...

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Electronics System-Integration technology Conference, ESTC

作者： Mike Roellig René Metasch Karsten Meier Falko Alt Fraunhofer Institute of Non-Destructive Testing (IZFP) Dresden Germany Fraunhofer Institute for Non-Destructive Testing (IZFP-D) Dresden Dresden University of Technology Electronics Packaging Laboratory Germany

The application of solder joints for electrical and mechanical interconnections between two functional layers in electronic packages will be present in future devices, even in 3D-electronic devices. Very different approaches are investigated such as copper pillar, full inter-metallic joints or Au-Sn nanosponge. But the interconnection realization by μ-solder bumps as well as Flip-Chip solder joints will be one high potential connection method. The fundamentals about the solder alloy properties are necessary for material selection at product planning phase and further for the reliability estimations. Modern simulation tools are used for weak point estimations as well as for lifetime estimations (e.g. FEM). Any simulation software demands martial properties. The paper presents an excerpt of characterization techniques and results for the following physical data of SnAg3.5 solder: (1) Elastic modulus (2) Poisson ratio (3) Creep (4) Lin. thermal expansion (CTE) (5) Thermal conductivity (6) Electrical conductivity (7) Fatigue.

关键词： Variable speed drives Displacement measurement Joints Creep Fatigue Through-silicon vias Copper

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