Yes / In this research work, the transient liquid phase (TLP) bonding process was utilized to fabricate joints using thin (20μm) nickel and copper foils placed between two bonding surfaces to help facilitate joint formation. Two joint configurations were investigated, first, Ti- 6Al-4V/CuNi/Mg-AZ31 and second, Ti-6Al-4V/NiCu/Mg-AZ31. The effect of bonding time on microstructural developments across the joint and the changes in mechanical properties were studied as a function of bonding temperature and pressure. The bonded specimens were examined by metallographic analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD). In both cases, intermetallic phase of CuMg2 and Mg3AlNi2 was observed inside the joint region. The results show that joint shear strengths for the Ti-6Al-4V/CuNi/Mg- AZ31 setup produce joints with shear strength of 57 MPa compared to 27MPa for joints made using the Ti-6Al-4V/NiCu/Mg-AZ31 layer arrangement. / NSERC (Canada)

No description available.

Les travaux présentés dans ce mémoire visent à analyser et optimiser le comportement des composants de protection haute tension contre les décharges électrostatiques (ESD) à leur déclenchement. Pour cela, deux approches ont été suivies : Un outil de mesure dédié, le "transient-TLP", a été développé. Cet outil est basé sur la correction mathématique des données mesurées à l'oscilloscope avec un système de mesure vf-TLP standard. L'erreur de mesure est inférieure à 2 %. La méthode, d'abord conçue pour des mesures sur wafer, a ensuite été appliquée pour mesurer des composants sur boîtier. A l'aide de cet outil, le comportement transitoire des protections ESD utilisées à Freescale a pu être analysé. En particulier, la simulation physique a permis de mieux comprendre l'origine physique de l'apparition d'un pic de surtension au déclenchement de ces composants et des solutions de dessin ont été proposées pour en réduire l'amplitude.

L’architecture FDSOI (silicium sur isolant totalement déserté) permet une amélioration significative du comportement électrostatique des transistors MOSFETs pour les technologies avancées et est employée industriellement à partir du noeud 28 nm.L’implémentation de protections contre les décharges électrostatiques (ESD pour« Electro Static Discharge ») dans ces technologies reste un défi. Alors que l’approche standard repose sur l’hybridation du substrat SOI (gravure de l’oxyde enterré : BOX)permettant de fabriquer des dispositifs de puissance verticaux, nous nous intéressons ici à des structures dans lesquelles la conduction s’effectue latéralement, dans le film de silicium. Dans ces travaux, des approches alternatives utilisant des dispositifs innovants(Z²-FET et BBC-T) sont proposées. Leurs caractéristiques statiques, quasi-statiques et transitoires sont étudiées, par le biais de simulations TCAD et de caractérisations électriques. / FDSOI architecture (Fully Depleted Silicon On Insulator) allows a significantimprovement of the electrostatic behavior of the MOSFETs transistors for the advancedtechnologies. It is industrially employed from the 28 nm node. However, theimplementation of ESD (Electrostatic Discharges) protections in these technologies isstill a challenge. While the standard approach relies on SOI substrate hybridization (byetching the BOX (buried oxide)), allowing to fabricate vertical power devices, we focushere on structures where the current flows laterally, in the silicon film. In this work,alternative approaches using innovative devices (Z²-FET and BBC-T) are proposed. Theirstatic, quasi-static and transient characteristics are studied in detail, with TCADsimulations and electrical characterizations.

Dans l’industrie de la micro-électronique, les efforts à fournir pour les nouvelles applications développées deviennent de plus en plus contraignants et difficiles à supporter en terme de coût. Les agressions provenant des décharges électrostatiques (ESD) générées par l’environnement direct sur les puces constituent un facteur important de la chute de rendement et donc des coûts. Ces difficultés s’ajoutent aux limites physiques plus strictes pour fabriquer des transistors lorsque l’on aborde des échelles nanométriques. La technologie Silicium sur Isolant (SOI) a été développée afin de contourner cette difficulté, mais l’intégration des protections ESD limite son émergence du fait de la complexité de la mise au point et du développement d’un réseau de protection pour la puce.L’objectif annoncé de ce travail de recherche, effectué en collaboration entre STMicroelectronics le CEA et l’IMEP est d’évaluer les caractéristiques principales de la technologie pour la protection contre les décharges et de proposer une stratégie innovante de protection adaptée au SOI. En effet, à partir de résultats expérimentaux, nous avons pu constater que l’oxyde enterré, le BOX, limite les performances en robustesse et diminue la fenêtre de conception pour le déclenchement des protections. Pour y remédier, une structure commandée bidirectionnelle a été développée sur PDSOI afin de faciliter la dissipation thermique et améliorer la robustesse. Pour prolonger cette solution sur technologie FDSOI, une étude approfondie sur le thyristor afin a été menée afin de porter cette solution. L’analyse de simulation 3D et de résultats silicium ont permis de proposer une stratégie de protections innovantes pour le thyristor sur FDSOI. / In the microelectronics industry, the fabrication process for advanced technological nodes becomes more and more cumbersome and limiting in terms of cost. The electrostatic discharges (ESD) generated by the direct environment affect the circuits and constitute an important factor for the decrease of the yield and thus result in an increase of the costs. Apart from these difficulties, there are also issues arising from the physical limits of transistor integration when reaching the nanoscale.The Silicon on Insulator (SOI) technology was developed in order to bypass this difficulty. However, the integration of ESD protections limits its emergence due to the development complexity and the protection circuit needed. The goal of this work which was a collaboration between STMicroelectronics, CEA and IMEP was to evaluate the principal characteristics of this technology for electrostatic discharge protection and propose a novel protection strategy adapted for SOI.In fact, we were able to confirm from experimental results that the buried oxide (BOX) limits the performances in terms of robustness and narrows the window of conception for the triggering of the protections. A commanded bidirectional structure was developed on PDSOI and proposed as a solution to facilitate the thermal dissipation and improve the robustness.In order to extend this solution on FDSOI technology, a detailed study on the thyristor was performed. Analysis of the 3D simulations and experimental results permitted to propose an innovative strategy for ESD protections on FDSOI.

The energy transition is accompanied by massive electrification of uses and sectors such as transport. As a result, the pressure on the electricity grid is increasing, and the time to connect to the power system is lengthening. Deploying new infrastructure is a laborious and expensive process but there are alternatives to exploit the flexibility of the power grid. The deployment of smart meters opens the door to many applications related to flexibility on the consumer side, to reduce peak loads that threaten grid capacity. Targeting the right consumers for Demand-Side Management (DSM) is a prerequisite to maximizing the chances of success of such programs. This degree project replicates and adapts the method developed in [14] to segment residential customers. It consists of encoding Daily Load Curves (DLC) using a dictionary of Typical Load Profiles (TLP) and grouping consumers according to the distribution of their TLP. A temporal analysis of the main TLP reveals different consumption behaviors. Customers are segmented into groups that reflect the degree of volatility of their consumption. This enables a classification based on the potential for Energy Efficiency (EE) or Demand Response (D/R) programs. We address the issue of attribute detection using the distribution of TLP of customers. In particular, several classification algorithms are compared to detect TLP characteristic of Electric Vehicle (EV). The obtained load shapes show consumption peaks at night, which may correspond to the charging time of EV. The method is discussed, especially the choice of the number of load profiles to be included in the dictionary of TLP. It proves to be useful to group consumers with similar consumption profiles and opens the door to applications such as individual household consumption forecasting. / Energiomställningen kräver en massiv elektrifiering av användningsområden och sektorer som t.ex. transportsektorn. Detta leder till att trycket på elnätet ökar och att tiden för att ansluta sig till elnätet blir allt längre. Att bygga ut ny infrastruktur är en mödosam och dyr process, men det finns alternativ för att utnyttja elnätets flexibilitet. Utplaceringen av smarta mätare öppnar dörren för många tillämpningar som rör flexibilitet på konsumentsidan, för att minska toppbelastningar som hotar nätkapaciteten. Att rikta in sig på rätt konsumenter för DSM är en förutsättning för att maximera chanserna att lyckas med sådana program. I detta examensarbete replikeras och anpassas den metod som utvecklats i [14] för att segmentera hushållskunder. Den består av att koda DLC med hjälp av ett lexikon av TLP och gruppera konsumenter enligt fördelningen av deras TLP. En tidsmässig analys av de viktigaste TLP avslöjar olika konsumtionsbeteenden. Kunderna delas in i grupper som återspeglar graden av volatilitet i deras konsumtion. Detta möjliggör en klassificering baserad på potentialen för EE eller D/R-program. Vi tar upp frågan om attributdetektering med hjälp av fördelningen av TLP hos kunderna. I synnerhet jämförs flera klassificeringsalgoritmer för att upptäcka TLP som är karakteristiska för EV. De erhållna belastningsformerna visar konsumtionstoppar på natten, vilket kan motsvara laddningstiden för EV. Metoden diskuteras, särskilt valet av antalet belastningsprofiler som ska ingå i ordlistan för TLP. Metoden visar sig vara användbar för att gruppera konsumenter med liknande förbrukningsprofiler och öppnar dörren för tillämpningar som prognostisering av enskilda hushålls förbrukning.

La problématique des agressions par décharges électrostatiques (ESD) est un facteur critique dans la fiabilité des circuits intégrés. Ce document effectue la synthèse des travaux menés au LAAS-CNRS dans ce domaine. Les points suivants seront plus particulièrement abordés : - L'étude des mécanismes physiques qui gèrent le comportement d'un composant lors d'une décharge ESD - La mise en place d'une méthodologie de conception de structures de protection - Son application au développement de solutions de protection innovantes La dernière partie de ce document propose les perspectives de cet axe de recherche qui sont principalement motivés par les progrès technologiques des circuits intégrés, l'évolution des normes de robustesse et l'extension de nos travaux au niveau du système.

Tie-down systems are used to fasten drilling rigs to the deck of offshore structures during harsh environmental conditions such as hurricanes. During Hurricane Ivan (2004) and Katrina (2005), a number of offshore structures were moved and several tie-down systems were damaged. In the present study, the reaction force and connection capacity of tie-down systems for a TLP and SPAR are investigated. The environmental conditions are taken from the API Bulletin 2INT-MET which has been updated after several major storms during 2004-2005. The hydrodynamic coefficients of the TLP and SPAR are obtained using a 3D diffraction/radiation panel method. The motions of the TLP and SPAR are then simulated in the time domain by using the hull-mooring-riser coupled dynamic analysis tool CHARM3D. Based on the simulated motion and acceleration time series, the inertial and gravity loads on derrick and skid base footing are calculated. In addition to the inertial-gravity loads, wind forces exerted on the derrick are also calculated. All the external forces and resultant hull motions are simulated for 100-year, 200-year and 1000-year storms to observe the derrick structural integrity with increasing environmental intensity. Various environmental headings are also considered to find the maximum reaction forces. In the present method, the phase differences between gravity-inertia forces and wind forces are taken into consideration to obtain more realistic loads on derrick and skid base footings. This research shows that the maximum and minimum load values are appreciably higher for the SPAR. In addition, the direction of external forces is also important to determine maximum reaction forces on footings. The capacities of the clamps in slip, bolt tension, and bolt shear can be also analyzed using the resultant data to provide guidance on appropriate design values.

This study presents the results of an extraction of the 2nd-order nonlinear responses from model test data. Emphasis is given on the effects of assumptions made for the Gaussian and non-Gaussian input on the estimation of the 2nd-order response, employing the quadratic Volterra model. The effects of sea severity and data length on the estimation of response are also investigated at the same time. The data sets used in this study are surge forces on a fixed barge, a surge motion of a compliant mini TLP (Tension Leg Platform), and surge forces on a fixed and truncated column. Sea states are used from rough sea (Hs=3m) to high sea (Hs=9m) for a barge case, very rough sea (Hs=3.9m) for a mini TLP, and phenomenal sea (Hs=15m) for a truncated column. After the estimation of the response functions, the outputs are reconstructed and the 2nd order nonlinear responses are extracted with all the QTF distributed in the entire bifrequency domain. The reconstituted time series are compared with the experiment in both the time and frequency domains. For the effects of data length on the estimation of the response functions, 3, 15, and 40- hour data were investigated for a barge, but 3-hour data was used for a mini TLP and a fixed and truncated column due to lack of long data. The effects of sea severity on the estimation of the response functions are found in both methods. The non-Gaussian method for estimation is more affected by data length than the Gaussian method.

The frequent use of two or more closely positioned vessels during offshore operations makes the study of multi-body hydrodynamics an important topic, especially for the design of deepwater offshore systems. This research investigation studies the response behavior of a coupled mini-TLP / barge system in both head and beam sea conditions. The design sea conditions were selected to represent the combined wind, wave and current conditions for a target location off the coast of West Africa. Both the mini-TLP and the barge were designed to have independent mooring systems. Coupling between the two vessels is introduced through a connection consisting of two breast lines and a fender system. This connection is designed to restrain the horizontal movements of the two vessels while keeping a constant distance between them and avoiding collisions. The main focus of this study is to analyze the experimental data obtained during the model testing, especially the motions of the two bodies and the values related to the fender system, in order to characterize the behavior of the uncoupled and coupled system configurations. A statistical approach is used for the data analysis and interpretation. Statistical parameters are used to provide an overall characterization of system behavior, and Gaussian and Weibull distribution functions are utilized to detect the importance of non-linearity in the data with particular attention to extreme values. Correlations between the two vessels in time domain and frequency domain are investigated. In addition, auto and cross spectrum analyses of the data are used to contrast the motion behavior of the uncoupled and coupled configurations. It is shown that the connection system reduces the horizontal vessel motions; however the forces exerted on the fender system show significant variation depending on sea heading conditions.