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No description available.

This master‘s thesis deals with the solution of the production of the given part "APZ13". The structural analysis of the component is followed by the choice of the available manufacturing technology. The following is a theoretical description of the chosen technology and injection mold. Its solution is practically described in the following chapter and then the creation of TPV documentation of the whole project. The conclusion of this master’s thesis is a technical-economic evaluation of the chosen technology and discussion.

Cette thèse porte sur l’étude du comportement au moussage d’un élastomère silicone et de thermoplastiques vulcanisés (TPV) à base de silicone. Le moussage a été réalisé à l’aide des procédés batch et d’extrusion moussage en utilisant le CO2 comme agent moussant. Lamicrostructuration de fluorosilicone, ayant une grande affinité avec le CO2, dans la silicone favorise grandement le moussage par nucléation hétérogène. La morphologie du mélange et des mousses résultantes ainsi que la rhéologie en cisaillement et en écoulement biélongationnelont été améliorés en élaborant sous cisaillement des structures branchées de chaines silicones en présence d’un faible taux de peroxyde. En effet, la modification chimique sous écoulement permet de réduire la taille des nodules de fluorosilicone augmentant ainsi la densité volumique de sites de nucléation potentiels. Elle permet également de créer des structures hyperbranchées générant des propriétés de durcissementdes contraintes en écoulement bi-élongationnel ce qui a pour effet de réduire la croissance cellulaire et la coalescence lors de l’expansion de la mousse.La deuxième partie est dédiée à l’étude du moussage de TPV silicone pour lesquels la phase silicone est partiellement réticulée. Ces TPV ont étonnement le même comportement en rhéologie élongationnelle que la matrice polyéthylène basse densité (PEBD). Bien que les TPVs atteignent des bonnes propriétés en termes d’élongation à rupture à l’état fondu, leur comportement au moussage est très différent. En effet il est principalement lié à leur viscosité sous fort taux de cisaillement ainsi qu’aux conditions d’extrusion i.e. la pression avant filière et la détente en sortie de filière. Avec un taux de réticulation approprié de laphase élastomère, le TPV mousse de manière similaire que le PEBD / This work is devoted to the study of the foaming behavior of a silicone elastomer and thermoplastic vulcanizates (TPV) based silicone. The foaming step was carried out by batch and extrusion foaming processes with CO2 as blowing agent. The foamability of silicone elastomer was improved by a microstructuration of fluorosilicone which is a highly CO2-philic elastomer through heterogeneous nucleation. The foam and blend morphologies as well as the rheology in shear and bi-elongation modes were further fitted by branching silicone chains under shearing conditions in a roll mill with a small amount of peroxide. Indeed, this dynamic chemical modification reduces the size of fluorosilicone droplets which leads to increase the volume density of nucleating sites and consequently lowers the mean bubble size. Furthermore, it allows also the formation of multi-scale branched structures inducing a strain hardening behavior in bi-elongational flow which restrict the cell growth and coalescence during foam expansion.The second part deals with the foaming behavior of TPV silicone in which partially crosslinked silicone nodules are dispersed. Surprisingly, formulations exhibit close rheological behavior in elongation modes that the neat polyethylene (LDPE) matrix and reach prerequisites for foaming applications in terms of elongation at break. However, their foaming behavior are far different and are correlated to the extrusion foaming parameters which are known to control the nucleation i.e. the pressure before the die and the depressurization rate at the die exit. A proper choice of the gel content allows a TPV foamability close to that of LDPE

Ce travail de thèse vise la définition et la mise au point de technologies pour l'empilement depuces microélectroniques dans un polymère et connectées électriquement par des viastraversants. Il explore deux voies : l’une de caractère industriel, utilisant une résine époxychargée en billes de silice E2517, l'autre, plus exploratoire, est basée sur l'utilisation de laSU8.Nous avons travaillé sur la mise au point des différentes étapes permettant d'empiler 4niveaux de puces amincies à 80 microns (enrobées) et empilées sur des épaisseurs de l'ordredu millimètre. Le problème du perçage des vias a été abordé et étudié à travers la mise aupoint de procédés d'usinage au laser des résines de type industriel. La métallisation encouches minces de ces trous de facteur de forme élevée (20) a été menée de sorte à atteindredes valeurs de résistance d'accès les plus faibles possibles.Un comparatif des deux voies utilisant la SU8 et la résine E2517 a été effectué et ses résultatscommentés en termes de faisabilité techniques et ses projections dans le domaine industriel.Des tests de fiabilité thermomécaniques ont été menés de concert avec une modélisation paréléments fini afin de valider les résultats des expérimentations réalisées dans le cadre de cetteétude / The subject of this thesis is the definition and development of TPV (Through Polymer Via)technology to stacking chips. The principal objective is to increase the potentialities of thevertical staking (complex IC; multiple I/O...) of Si chips without loss of performance or yield.The technique used consists to surround the IC chips by using particular resin and to fill (withmetallic films) the vertical holes drilled in this material. It explores two ways: one of anindustrial character, using an epoxy resin filled with silica beads E2517, other, moreexploratory, is based on the use of SU8.We worked on the development of different stages to stack four levels of chips thinned to 80microns (coated) and stacked on the thickness of one millimeter. The problem of drilling viashas been discussed and studied through the development of laser drilling processes ofindustrial resins. The thin-film metallization of the holes of high aspect ratio (20) wasconducted in order to reach values of access resistance as low as possible.A comparison of the two channels using SU8 resin and E2517 was carried out and the resultsdiscussed in terms of technical feasibility and its projections in the industrial field.Thermomechanical reliability tests were conducted in conjuction with finite element modelingto validate the results of experiments conducted in this study.

Plate-out is defined, in the context of this research, as a hard deposit that can be found adhered to the surface of screw, barrel and die resulting in the loss of output performance and ultimate extrude quality. It is typically is seen as a coloured deposit, ranging from white through to brown that can occur at any time in the process. Plate-out occurs randomly with SantopreneTM TPV products within a manufactured lot, or from lot-to-lot without any changes to the base formulation or manufacturing procedures or practices. The aim of the research was firstly to understand the influences of various elements of the extrusion process and any interactions on the formation of plate-out. The second aspect of the research was to investigate whether deposited plate-out had in itself any form and structure. Two experimental routes were taken. The first was a university based small scale laboratory extrusion study; the second complementary approach was industrially based; involving the ExxonMobil Newport manufacturing plant supported by the company analytical laboratories based in Brussels. The programme of work explicitly excluded in depth analysis of the chemistry involved in the manufacture of SantopreneTM TPV, this remaining proprietary to the company. The results of the study of the effects of the processing variables conclude that plate-out formation is complex and no single variable removed or reduced it. With a combination of lower process temperature, longer residence times and higher melt compression there is an increased likelihood that plate-out will form. For the film type deposit which contains novolac resin and zinc chloride, the onset of migration of these materials is seen to occur in the transition zone. This is believed to be the tie-layer precursor to plate-out deposition further along the screw. Two types of plate-out were identified, a powdery deposit and a film deposit. Both contained clay filler, stannous chloride, zinc oxide but the film deposit also contained traces of novolac resin and zinc chloride. The plate-out was confirmed to have its own distinct cross sectional structure.

<div>Thin films with selective spectral properties have great potential for use in applications such as solar thermal absorbers, selective thermal emitters, thermal barrier coatings, and thermophotovoltaics. Understanding the dependence of their optical properties with temperature is crucial for practical applications. Relatively less-used films with high thermal stability, high refractive index, and infrared transparency, such as cerium oxide CeO2 and magnesium oxide (MgO) have not been studied extensively for high-temperature applications. In this paper, CeO2, MgO, and several multilayer samples containing these compounds will be studied their change of optical properties with increasing temperature across the visible and infrared spectrum. In this work, I introduce Spectroscopic Ellipsometry (SE) to analyze dielectric constants of films and measure its thickness at multiple incident angles in visible and near-Infrared (IR) wavelengths both at room temperature and elevated temperatures. Using ellipsometry, several single and multilayer thin films (CeO2 and other transparent materials-based) have been measured their dielectric constants and thickness at room temperature and high temperature up to 500°C using thermal control stages called INSTEC. The change of their optical properties with temperatures has been characterized using theoretical modelling. Fitting their optical properties have been observed by changing thickness of each layer and calculating the corresponding Cauchy parameters in transparent material. Finally, FTIR measurements will be used to further characterize direct emission of these films at higher temperatures. This will be performed at room temperature and high temperature up to 1400 °C.</div>

This thesis describes the fabrication of an induction heating apparatus and its use to directly heat small platinum and gold electrodes in electrolyte solution. The heating characteristics of the electrodes were studied via the entropic shift of redox potential with temperature and change in Faradaic current. Temperature pulse voltammetry (TPV) and cyclic voltammetry were used for temperature calibration under various heating conditions. The maximum temperature reached at a 0.25 mm diam platinum electrode surface in solution was 84 degrees C. At heated electrodes an increase in current was found to be due to convection and diffusion. TPV was performed with inductively heated gold (0.5 mm diam) and platinum electrodes, which gave complete current-potential-temperature information. Induction heated Pt electrodes were employed to investigate the kinetics and mass transfer process of oxygen reduction reaction (ORR) in acidic and alkaline media.

No description available.

A TPV-system consists of a hot surface emitting heat radiation on a solar cell with a narrow bandgap.  A unit consisting of a boiler and a TPV-system has been constructed for testing of the performance of TPV cells. The emitter is heated by a fuel consisting of RME-oil. The radiation is collected and concentrated through two reflecting cones formed like a Faberge-egg, with an edge-type optical filter between the cones. The Faberge-egg is treated with electro-polishing in order to obtain a high reflectance of radiation. The edge filter transmits radiation of short wavelengths towards the solar cells and reflects long wavelengths back to the emitter. This increase the temperature of the emitter to prevent the TPV-cells to be overheated. The construction made was working as expected and can be used for further experiments. The performance of the TPV-cells were however very poor because of a low emitter temperature. The main problem was to obtain a good heat transport from the flame to the emitter. It is required that the emitter temperature is considerably increased for justifying a continued work on TPV-systems in combination with boilers.