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Planar metallization failure modes in integrated power electtonics modulesZhu, Ning 10 May 2006 (has links)
Miniaturizing circuit size and increasing power density are the latest trends in modern power electronics development. In order to meet the requirements of higher frequency and higher power density in power electronics applications, planar interconnections are utilized to achieve a higher integration level. Power switching devices, passive power components, and EMI (Electromagnetic Interference) filters can all be integrated into planar power modules by using planar metallization, which is a technology involving electrical, mechanical, material, and thermal issues. By processing high dielectric materials, magnetic materials, or silicon chips using compatible manufacturing procedures, and by carefully designing structures and interconnections, we can realize the conventional discrete inductors, capacitors, and switch circuits with planar modules. Compared with conventional discrete components, the integrated planar modules have several advantages including lower profiles, better form factors, and less labor-intensive processing steps. In addition, planar interconnections reduce the wire bond inductive and resistive parasitic parameters, especially for high frequency applications.
However, planar integration technology is a packaging approach with a large contact area between different materials. This may result in unknown failure mechanisms in power applications. Extensive research has already been done to study the performance, processing, and reliability of the planar interconnects in thin film structures. The thickness of the thin films used in integrated circuits (IC) or microelectronics applications ranges from the magnitude of nanometers to that of micrometers. In this work, we are interested in adopting planar interconnections to Integrated Power Electronics Modules (IPEM). In Integrated Power Electronics Modules (IPEMs), copper traces, especially bus traces, need to conduct current ranging from a few amps to tens of amps. One of the major differences between IC and IPEM is that the metal layer in IPEMs (normally >75µm) is much thicker than that of the thin films in IC (normally <1µm). The other major difference, which is also a feature of IPEM, is that the planar metallization is deposited on different brittle substrates. In active IPEM, switching devices are in a bare die form with no encapsulation. The copper deposition is on top of the silicon chips and the insulation polyimide layer. One of the key elements for passive IPEM and the EMI IPEM is the integrated inductor-capacitor (LC) module, which realizes equivalent inductors and capacitors in one single module. The deposition processes for silicon substrates and ceramic substrates are compatible and both the silicon and ceramic materials are brittle. Under high current and high temperature conditions, these copper depositions on brittle materials will cause detrimental failure spots.
Over the last few years, the design, manufacture, optimization, and testing of the IPEMs has been developed and well documented. Up to this time , the research on failure mechanisms of conventional integrated power modules has led to the understanding of failures centered on wire bond or solder layer. However, investigation on the reliability and failure modes of IPEM is lacking, particularly that which uses metallization on brittle substrates for high current operations. In this study, we conduct experiments to measure and calculate the residual stresses induced during the process. We also, theoretically model and simulate the thermo-mechanical stresses caused by the mismatch of thermal expansion coefficients between different materials in the integrated power modules. In order to verify the simulation results, the integrated power modules are manufactured and subjected to the lifetime tests, in which both power cycling and temperature cycling tests are carried out. The failure mode analysis indicates that there are different failure modes for copper films under tensile or compressive stresses. The failure detection process verifies that delamination and silicon cracks happen to copper films due to compressive and tensile stresses respectively.
This study confirms that the high stresses between the metallization and the silicon are the failure drivers in integrated power electronics modules.. We also discuss the driving forces behind several different failure modes. Further understanding of thesefailure mechanisms enables the failure modes to be engineered for safer electrical operation of IPEM modules and helps to enhance the reliability of system-level operation. It is also the basis to improve the design and to optimize the process parameters so that IPEM modules can have a high resistance to recognized failures. / Ph. D.
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Synthesis of Planar Microwave Circuits based on Metamaterial Concepts through Aggressive Space MappingRodríguez Pérez, Ana María 30 March 2015 (has links)
RF and microwave applications represent one of the fastest-growing segments of
the high performance electronics market, where ongoing innovation is critical.
Manufacturers compete intensively to meet market needs with reduced cost,
size, weight and many other performance criteria demands. Under this scenario,
transmission lines based on metamaterial concepts can be considered a very
interesting alternative to the conventional transmission lines. They are more
compact (compatible with planar manufacturing processes) and present higher
degrees of design flexibility. Furthermore, metamaterial transmission lines can
also provide many other unique properties not achievable with ordinary
transmission lines, such as dispersion or impedance engineering. Nevertheless,
the impact in the industry is still not relevant, mostly due to the complexity of
the related synthesis and design procedures. These procedures are mainly based
on the engineer’s experience, with the help of costly full-wave electromagnetic
(EM) simulators and parameter extraction methods.
The aim of this thesis is to contribute to simplify and speed up the synthesis
and design procedures of artificial transmission lines. In particular, the lines
obtained by periodically loading a conventional transmission line with
electrically small resonators, such as split ring resonators (SSRs) or its
complementary particle (CSRR). The design procedure is automated by using
Space Mapping techniques. In contrast to other alternative methods, real
synthesis is found from the circuit schematic (that provides a given target
response) and without need of human intervention. Some efforts to make the
method practical and useful have been carried out. Given a certain target
response, it is determined whether it can be physically implemented with a
chosen technology, and hence proceeding next to find the synthesis, or not. For
this purpose, a two-step Aggressive Space Mapping approach is successfully
proposed.
In contrast to other methods, the real synthesis is found from certain target
circuit values (corresponding to the equivalent circuit model that characterizes
the structure to be synthesized). Different efforts have been carried out in order
to implement a useful and practical method. Some of them were focused to determine if, given certain circuit parameters (which determine the target
response) and certain given technology specifications (permittivity and height of
the substrate, technology limits), that response is physically realizable
(convergence region). This technique was successfully formulated and it is
known as “Two-Step Aggressive Space Mapping Approach”.
In this work, the latest improvements made till date, from the synthesis of
basic unit cells until different applications and kinds of metamaterial-based
circuits, are presented. The results are promising and prove the validity of the
method, as well as its potential application to other basic cells and more complex
designs. The general knowledge gained from these cases of study can be
considered a good base for a coming implementation in commercial software
tools, which can help to improve its competitiveness in markets, and also
contribute to a more general use of this technology. / Rodríguez Pérez, AM. (2014). Synthesis of Planar Microwave Circuits based on Metamaterial Concepts through Aggressive Space Mapping [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48465
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Model and design of small compact dielectric resonator and printed antennas for wireless communications applications. Model and simulation of dialectric resonator (DR) and printed antennas for wireless applications; investigations of dual band and wideband responses including antenna radiation performance and antenna design optimization using parametric studiesElmegri, Fauzi January 2015 (has links)
Dielectric resonator antenna (DRA) technologies are applicable to a wide variety of
mobile wireless communication systems. The principal energy loss mechanism for this
type of antenna is the dielectric loss, and then using modern ceramic materials, this
may be very low. These antennas are typically of small size, with a high radiation
efficiency, often above 95%; they deliver wide bandwidths, and possess a high power
handling capability.
The principal objectives of this thesis are to investigate and design DRA for low profile
personal and nomadic communications applications for a wide variety of spectrum
requirements: including DCS, PCS, UMTS, WLAN, UWB applications. X-band and part
of Ku band applications are also considered. General and specific techniques for
bandwidth expansion, diversity performance and balanced operation have been
investigated through detailed simulation models, and physical prototyping.
The first major design to be realized is a new broadband DRA operating from 1.15GHz
to 6GHz, which has the potential to cover most of the existing mobile service bands.
This antenna design employs a printed crescent shaped monopole, and a defected
cylindrical DRA. The broad impedance bandwidth of this antenna is achieved by
loading the crescent shaped radiator of the monopole with a ceramic material with a
permittivity of 81. The antenna volume is 57.0 37.5 5.8 mm3, which in conjunction
with the general performance parameters makes this antenna a potential candidate for
mobile handset applications.
The next class of antenna to be discussed is a novel offset slot-fed broadband DRA
assembly. The optimised structure consists of two asymmetrically located cylindrical
DRA, with a rectangular slot feed mechanism. Initially, designed for the frequency
range from 9GHz to 12GHz, it was found that further spectral improvements were
possible, leading to coverage from 8.5GHz to 17GHz.
Finally, a new low cost dual-segmented S-slot coupled dielectric resonator antenna
design is proposed for wideband applications in the X-band region, covering 7.66GHz
to 11.2GHz bandwidth. The effective antenna volume is 30.0 x 25.0 x 0.8 mm3. The DR
segments may be located on the same side, or on opposite sides, of the substrate. The
end of these configurations results in an improved diversity performance. / General Secretariat of Education and Scientific Research Libya
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Estudio de la estabilidad del macizo rocoso, medidas de mejora y protección del Cerro Colorado de la provincia de Bagua, departamento de Amazonas - 2022Collazos Palomino, Lider David January 2024 (has links)
La presente tesis analizó la calidad de la roca mediante los principales índices geológicos como son el RMR índice de Bianowski y el índice de Q de Barton. Esto se dividió en 8 zonas, desde la zona I a zona IV que tiene una meteorización muy alta, la meteorización disminuye hasta llegar a la zona 8 dónde es un macizo más consolidado, esto se refleja en los índices geológicos, para la zona I se obtuvo un RMR de 31% y un índice de Q de Barton de 0.194 mientras que en la zona 7 se obtuvo un RMR de 57% un índice de Q de Barton de 7.433 siendo estas las zonas con valores mínimos y máximos respectivamente.
Se obtuvieron en campo el dip y el dip direction de todo el macizo, dividiéndose en 8 zonas como se mencionó anteriormente, del análisis mediante el software dips se obtuvo que existe deslizamientos planares, por lo tanto, se optó por analizar todo el macizo por el programa lo rocfall 3, el cual se obtuvo los resultados con una gran similitud a lo real en campo.
Además de la clasificación geológica también se ensayaron muestras de roca para conocer sus propiedades físicas y mecánicas, entre los ensayos está el ensayo triaxial, el ensayo de compresión simple, ensayo de peso específico, ensayo de porcentaje de humedad y ensayo de porcentaje de absorción, el resultado del ensayo triaxial se obtuvo el ángulo de fricción interna de 45.7º con una cohesión de134.04 kg/cm2 datos importantes qué serán usados como datos de entrada en el programa rocfall 3.
Para la zona que presenta desprendimientos de bloques de roca analizadas en el programa rocfall3 se empleara el sistema de BARRERA DE PROTECCIÓN CONTRA CAÍDAS DE ROCAS GBE-500ª, son mallas de triple torsión esta medida de mejora soporta la capacidad de hasta 500KJ De energía a comparación del resultado que se obtuvo el software que es de 88.97 KJ con una distancia de salida de 80.83 m. / This thesis analyzed the quality of the rock using the main geological indices such as the Bianowski RMR index and the Barton Q index. This was divided into 8 zones, from zone I to zone IV which has a very high weathering, the weathering decreases until it reaches zone 8 where it is a more consolidated massif, this is reflected in the geological indices, for zone I it is obtained an RMR of 31% and a Barton's Q index of 0.194, while in zone 7 an RMR of 57% and a Barton's Q index of 7.433 were obtained, these being the areas with minimum and maximum values respectively.
The dip and dip direction of the entire massif were obtained in the field, dividing it into 8 zones as mentioned above. From the analysis using the dips software it was obtained that there are gradually planes, therefore, it was decided to analyze the entire massif by the rocfall 3 program, which obtained the results with great similarity to what is real in the field.
In addition to the geological classification, rock samples were also tested to know their physical and mechanical properties, among the tests are the triaxial test, the simple compression test, specific weight test, humidity percentage test and absorption percentage test, The result of the triaxial test was the internal friction angle of 45.7º with a cohesion of 134.04 kg/cm2, important data that will be used as input data in the Rocfall 3 program.
For the area that presents rock block detachments analyzed in the rocfall3 program, the GBE-500ª ROCK FALL PROTECTION BARRIER system will be used, they are triple twist
meshes, this improvement measure supports the capacity of up to 500KJ Energy compared From the result obtained by the software, it is 88.97 KJ with an exit distance of 80.83 m.
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New photonic architectures for mid-infrared gaz sensors integrated on silicon / Nouvelles architectures photoniques pour capteurs de gaz infrarouge intégrés sur siliciumKoshkinbayeva, Ainur 10 March 2017 (has links)
Les travaux portent sur les multiplexeurs optiques fonctionnant à mi-IR pour la source à large bande dans l'application de détection de gaz. Deux configurations ont été étudiées: réseau de guides d'onde (AWG) et réseau concave planaire (PCG). Premièrement, le principe du fonctionnement a été compris afin de développer une solution analytique pour le champ de sortie en utilisant une approximation gaussienne du champ et de l'optique de Fourier. Ensuite, un outil de simulation semi-analytique de la réponse spectrale pour les deux configurations de multiplexeur a été développé dans MATLAB. La distribution normale des erreurs de phase a été introduite dans le modèle semi-analytique AWG, ce qui nous a permis d'étudier la corrélation entre l'écart-type des erreurs de phase et le niveau de diaphonie de la réponse spectrale AWG. AWG à 5,65 μm a été fabriqué à partir de la technologie SiGe / Si à l'aide de l'outil MATLAB pour le calcul des paramètres de conception et de l'outil P.Labeye pour le calcul de la géométrie AWG. Les dispositifs avec des paramètres légèrement variables ont été caractérisés: AWG1 avec guides d'ondes de 4,6 μm et MMI de 9 μm; AWG2 avec guides d'ondes de 4,6 μm et MMI de 11 μm; AWG3 avec guides d'ondes de 4,8 μm et MMI de 9 μm. Des mesures des dispositifs sur la puce 36 (centre de la plaquette) et sur la puce 32 (côté de la plaquette) ont été effectuées et analysées. Les mesures de température de AWG2 et AWG3 (puce 32 et puce 36) aux points cinq points de température ont montré une dépendance linéaire du déplacement spectral avec la température qui a une bonne corrélation avec les prédictions de simulation. / The work focuses on optical multiplexers operating in mid-IR for broadband source in gas sensing application. Two configurations were studies – arrayed waveguide grating (AWG) and planar concave grating (PCG). First, principle of operation was understood in order to develop analytical solution for output field using Gaussian approximation of the field and Fourier Optics. Then, semi-analytical simulation tool of the spectral response for both multiplexer configurations was developed in MATLAB. Normal distribution of phase errors was introduced to semi-analytical AWG model, which allowed us to study the correlation between standard deviation of phase errors and the level of crosstalk of AWG spectral response. AWG at 5.65 µm was fabricated based on SiGe/Si technology using the MATLAB tool for design parameters calculation and P.Labeye’s tool for AWG geometry calculation. Devices with slightly varying parameters were characterized: AWG1 with 4.6 µm waveguides and 9µm MMI; AWG2 with 4.6 µm waveguides and 11µm MMI; AWG3 with 4.8 µm waveguides and 9µm MMI. Measurements of devices on chip 36 (center of the wafer) and chip 32 (side of the wafer) were performed and analyzed. Temperature measurements of AWG2 and AWG3 (chip 32 and chip 36) at points five temperature points showed linear dependence of spectral shift with the temperature which has a good correlation with simulation predictions.
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Funktionelle Rekonstitution von Connexonen in artifizielle Membranen: Expression, Reinigung und Charakterisierung von Connexin 43 / Functional reconstitution of connexons in artificial membranes: expression, purification and characterization of connexin 43Carnarius, Christian 11 June 2012 (has links)
No description available.
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[en] KINEMATIC ANALYSIS OF A MOTION SIMULATOR OF SIX DEGREE OF FREEDOM, TYPE PARALLEL STRUCTURE / [pt] ANÁLISE CINEMÁTICA DE UM SIMULADOR DE MOVIMENTOS DE SEIS GRAUS DE LIBERDADE COM ESTRUTURA PARALELAFLAVIO LUIZ VAZ VIANNA 07 November 2002 (has links)
[pt] Esta tese tem como principal objetivo o estudo do
comportamento cinemático de um simulador de movimentos de 6
(seis) graus de liberdade, utilizando um novo conceito de
análise computacional.Inicialmente, foi apresentado um
software comercial, Working Model 3D, que teve seu
desempenho matemático validado comparando-se seus
resultados computacionais com os de outro software
comercial, conhecido como Matlab.Foi introduzido, então, o
conceito de mecanismos paralelos. Analisou-se,
primeiramente, o mecanismo paralelo planar com três juntas
rotacionais, conhecido como 3RRR. Foram feitas
as análises cinemáticas e os estudos de algumas
singularidades, apresentando-se ainda algumas recomendações
para futuros trabalhos. O estudo do mecanismo paralelo
usado em aplicações como simuladores de movimentos foi
também apresentado, através da análise plataforma Stewart-
Gough. A exeqüibilidade deste novo conceito de análise
cinemática foi comprovada através de diversas simulações,
incluindo o acoplamento de um objeto, representado por um
chassi veicular, na plataforma. / [en] This thesis presents the kinematic behavior of a motion
simulator with six degrees of freedom,using a new
computational analysis approach. A well-known simulation
software with proven performance, Matlab, is used to
validate another software environment, Working Model 3D,
which is used to develop and study kinematic models of
parallel mechanisms.Planar mechanism using three rotational
joints, 3RRR, are studied through kinematic analysis
and some singularity studies are developed, which resulted
in some suggestions for future analysis and studies. Also,
an introductory study of spatial-parallel mechanisms is
presented regarding motion simulators with six degrees of
freedom through simulation studies of Stewart-Gough
platform. The feasibility of this new kinematic analysis
was proven by means of several simulations, including the
coupling of a vehicular chassis in the platform modeling.
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Optimal Synthesis of Adjustable Four-Link Planar and Spherical Crank-Rocker Type Mechanisms for Approximate Multi-Path GenerationVilas, Chanekar Prasad January 2013 (has links) (PDF)
The well known synthesis problem of obtaining dimensions of a four-link mechanism such that a point on the coupler link traces a desired path has been extensively studied. There are two types of path generation–path specified by a finite number of precision points where the prescribed points must be exactly traced, and continuous path generation where the path is approximately traced by the coupler point. In various application, more than one or multiple paths are required to be traced by the coupler point and in such cases, adjustable four-link mechanisms where one of the dimension or parameters of the mechanism can be changed is a possible solution. This thesis deals with the synthesis of planar and spherical adjustable four-link crank-rocker type mechanisms for multiple continuous path generation. Approximate multiple path generation is typically solved as an optimization problem where the dimensions and parameters of the four-link mechanism are obtained such that the objective functions, typically in terms of an error between the desired and obtained path, is minimized. In this thesis, we present a two-stage optimization to obtain four-link mechanism dimensions such that the adjustable four-link mechanism can approximately trace multiple desired paths. In the first stage, the parameters in the driving side of the four-link mechanism is obtained and in the second stage, the parameters of the driven side are obtained. In case of adjustable planar four-link mechanism, a novel optimization objective function based on circle-fitting is used and for spherical adjustable mechanisms a novel plane-fitting based objective function is used. The use of these objective functions results in a lesser number of variables to be searched and thus the method presented in this work is more efficient than existing optimization based algorithms available in literature. Several examples are presented for synthesis of adjustable planar and spherical four-link mechanism for tracing multiple paths. In particular, a spherical mechanism which can generate an oval and an‘ 8’shaped path by one single adjustment is synthesized. This mechanism has been made using 3D printing and it is shown that the mechanism indeed traces the desired oval and ‘8’ shaped paths. This mechanism is being planned for use in a flapping wing micro air vehicle where the oval shaped path is known to make the vehicle to move forward while the ‘8’ shaped path results in a hovering motion.
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Záření soustav antén v blízké zóně / Radiation of antenna array in near-field areaHermany, Jiří January 2008 (has links)
The aim of my diploma thesis is to analyze the antenna array radiation and to produce the antenna array radiation computation program. The program should display the electric and magnetic intensity and radiation power density distribution over the planar or cylindrical surface in the near-field area. The antenna array analyzed in this paper consists of a number of elementary dipoles placed in a row with a reflector which represents the conductive board situated in parallel to the row of dipoles. The demonstration program was built in MATLAB and allows computing and displaying the computed values components of antenna array radiation on the planar or the cylindrical surface. The program also allows saving computed values, saving displayed graphs, or saving the adjusted parameters of antenna array. The created program can be used for the presentation of the antenna array radiation in a school laboratory or for the graphical representation when a new antenna is designed.
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MASCOT Follow-on Mission Concept Study with Enhanced GNC and Propulsion Capability of the Nano-lander for Small Solar System Bodies (SSSB) MissionsChand, Suditi January 2020 (has links)
This thesis describes the design, implementation and analysis for a preliminary study for DLR's MASCOT lander's next mission to Small Solar System Bodies (SSSB). MASCOT (Mobile Asteroid Surface Scout) is a nano-lander that flew aboard Hayabusa2 (JAXA) to an asteroid, Ryugu. It is a passive nano-spacecraft that can only be deployed ballistically from a hovering spacecraft. Current research focusses on optimizing similar close-approach missions for deploying landers or small cubesats into periodic orbits but does not provide solutions with semi-autonomous small landers deployed from farther distances. This study aims to overcome this short-coming by proposing novel yet simple Guidance, Navigation and Control (GNC) and Propulsion systems for MASCOT. Due to its independent functioning and customisable anatomy, MASCOT can be adapted for several mission scenarios. In this thesis, a particular case-study is modelled for the HERA (ESA) mission. The first phase of the study involves the design of a landing trajectory to the moon of the Didymos binary asteroid system. For a preliminary analysis, the system - Didymain (primary body), Didymoon (secondary body) and MASCOT (third body) - are modelled as a Planar Circular Restricted Three Body Problem (PCR3BP). The numerical integration methodology used for the trajectory is the variable-step Dormand–Prince (Runge Kutta) ODE-4,5 (Ordinary Differential Equation) solver. The model is built in MATLAB-Simulink (2019a) and refined iteratively by conducting a Monte Carlo analysis using the Sensitivity Analysis Tool. Two models - a thruster-controlled system and an alternative hybrid propulsion system of solar sails and thrusters - are simulated and proven to be feasible. The results show that the stable manifold near Lagrange 2 points proposed by Tardivel et. al. for ballistic landings can still be exploited for distant deployments if a single impulse retro-burn is done at an altitude of 65 m to 210 m above ground with error margins of 50 m in position, 5 cm/s in velocity and 0.1 rad in attitude. The next phase is the conceptual design of a MASCOT-variant with GNC abilities. Based on the constraints and requirements of the flown spacecraft, novel GNC and Propulsion systems are chosen. To identify the overriding factors in using commercial-off-the-shelf (COTS) for MASCOT, a market survey is conducted and the manufacturers of short-listed products are consulted. The final phase of the study is to analyse the proposed equipment in terms of parameter scope and capability-oriented trade-offs. Two traceability matrices, one for devised solutions and system and another for solutions versus capabilities, are constructed. The final proposed system is coherent with the given mass, volume and power constraints. A distant deployment of MASCOT-like landers for in-situ observation is suggested as an advantageous and risk-reducing addition to large spacecraft missions to unknown micro-gravity target bodies. Lastly, the implications of this study and the unique advantages of an enhanced MASCOT lander are explored for currently planned SSSB missions ranging from multiple rendezvous, fly-by or sample-return missions. Concluding, this study lays the foundation for future work on advanced GNC concepts for unconventional spacecraft topology for the highly integrated small landers. / <p>This thesis is submitted as per the requirements for the Spacemaster (Round 13) dual master's degree under the Erasmus Mundus Joint Master's Degree Programme. </p> / MASCOT team, DLR
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