<p>This thesis presents a method of measuring the distribution of fiber bonding ability in mechanical pulp furnishes. The method is intended for industrial use, where today only average values are used to describe fiber bonding ability, despite the differences in morphology of the fibers entering the mill. Fiber bonding ability in this paper refers to the mechanical fiber’s flexibility and ability to form large contact areas to other fibers, characteristics required for good paper surfaces and strength.</p><p> </p><p>Five mechanical pulps (Pulps A-E), all produced in different processes from Norway spruce (<em>Picea Abies)</em> were fractionated in hydrocyclones with respect to the fiber bonding ability. Five streams were formed from the hydrocyclone fractionation, Streams 1-5. Each stream plus the feed (Stream 0) was fractionated according to fiber length in a Bauer McNett classifier to compare the fibers at equal fiber lengths (Bauer McNett screens 16, 30, 50, and 100 mesh were used).</p><p> </p><p>Stream 1 was found to have the highest fiber bonding ability, evaluated as tensile strength and apparent density of long fiber laboratory sheets. External fibrillation and collapse resistance index measured in FiberLab^TM, an optical measurement device, also showed this result. Stream 5 was found to have the lowest fiber bonding ability, with a consecutively falling scale between Stream 1 and Stream 5. The results from acoustic emission measurements and cross-sectional scanning electron microscopy analysis concluded the same pattern. The amount of fibers in each hydrocyclone stream was also regarded as a measure of the fibers’ bonding ability in each pulp.</p><p> </p><p>The equation for predicted Bonding Indicator (BIN) was calculated by combining, through linear regression, the collapse resistance index and external fibrillation of the P16/R30 fractions for Pulps A and B. Predicted Bonding Indicator was found to correlate well with measured tensile strength. The BIN-equation was then applied also to the data for Pulps C-E, P16/R30, and Pulp A-E, P30/R50, and predicted Bonding Indicator showed good correlations with tensile strength also for these fibers.</p><p> </p><p>From the fiber raw data measured by the FiberLab^TM instrument, the BIN-equation was used for each individual fiber. This made it possible to calculate a BIN-distribution of the fibers, that is, a distribution of fiber bonding ability.</p><p> </p><p>The thesis also shows how the BIN-distributions of fibers can be derived from FiberLab^TM measurements of the entire pulp without mechanically separating the fibers by length first, for example in a Bauer McNett classifier. This is of great importance, as the method is intended for industrial use, and possibly as an online-method. Hopefully, the BIN-method will become a useful tool for process evaluations and optimizations in the future.</p> / <p>Den här studien presenterar en metod för att mäta fördelning av fiberbindning i mekaniska massor. Metoden hoppas kunna användas industriellt, där i dagsläget enbart medelvärden används för att mäta fiberbindnings-fördelning, trots råvarans (fibrernas) morfologiska skillnader.</p><p> </p><p>Fem mekaniska massor (Massa A-E) från olika massaprocesser men från samma råvara, norsk gran (<em>Picea Abies</em>), har fraktionerats i hydrocykloner med avseende på fiberbindningsförmåga. Från hydrocyklon-fraktioneringen bildades fem strömmar, Ström 1-5. Varje ström plus injektet (Ström 0) fraktionerades också med avseende på fiberlängd i en Bauer McNett för att kunna jämföra fibrerna vid samma fiberlängd (Bauer McNett silplåtarna 16, 30, 50 och 100 mesh användes).</p><p> </p><p>Fiberbindingsförmåga i den här studien härrör till fiberns flexibilitet och förmåga att skapa stora kontaktytor med andra fibrer, vilket bidrar till papprets yt- och styrkeegenskaper.</p><p> </p><p>Ström 1 visade sig ha den högsta fiberbindningsförmågan, utvärderat som dragstyrka och densitet av långfiberark, samt yttre fibrillering och kollaps resistans index mätt i den optiska analysatorn FiberLab^TM. Akustisk emission och tvärsnittsanalyser visade samma resultat. Ström 5 visade sig ha den lägsta fiberbindningsförmågan, med en avtagande skala från Ström 1 till Ström 5. Andelen fibrer från injektet som gick ut med varje hydrocyklon-ström ansågs också vara ett mått på fibrernas bindningsförmåga i varje massa.</p><p> </p><p>Genom att kombinera fiberegenskaperna kollaps resistans och yttre fibrillering från den optiska mätningen på varje fiber genom linjär regression, kunde Bindnings Indikator (BIN) predikteras. Medelvärdet av Bindnings Indikator för varje hydrocyklon-ström korrelerar med dragstyrka för långfiber-labark.</p><p> </p><p>Det visade sig att predikterad Bindnings Indikator inte bara fungerade för Massa A och Massa B P16/R30 fraktionen, som var de fraktioner som användes i den linjära regressionen, utan även för Massa C-E, P16/R30, och Massa A-E P30/R50 som också visade goda korrelationer med långfiber-dragstyrka när de sattes in i BIN-formeln.</p><p> </p><p>BIN-formeln användes sedan för varje enskild fiber, i den rådata som levererats från FiberLab^TM. Detta gjorde det möjligt att få en BIN-distribution av fibrerna, d.v.s. en fördelning av fiberbindningsförmåga.</p><p> </p><p>Den här rapporten visar också hur det går att få BIN-distributioner också från mätningar på hela massan, för valbara fiberlängder, utan att först mekaniskt separera massan efter fiberlängd. Det är viktigt, då metoden är tänkt att användas som en industriell metod, och eventuellt som en online-metod. Förhoppningsvis kommer BIN-metoden att bli ett användbart verktyg för processutveckling- och optimering i framtiden.</p> / FSCN – Fibre Science and Communication Network / Bonding ability distribution of fibers in mechanical pulp furnishes

<p>Bonding techniques intended for assembling space microsystems are studied in this work. One of the largest problems in bonding pre-processed semiconductor wafers are the severe process restrictions imposed by material compatibility issues. Plasma processes have shown to be good for sensitive materials integration why the influence of different plasma parameters on the bondability of wafers is particularly studied. Conventional wet chemical and field-assisted methods are also examined. The resulting bond quality is assessed in terms of mechanical strength, homogeneity, and yield.</p><p>The effect of spaceflight environment on the reliability of wafer bonds is also investigated. Both high and low temperature annealed bonds are found to be very robust. Effects observed are that low temperature bonds are reinforced by thermal cycling in vacuum and that high temperature bonds degrade slightly by low dose γ irradiation.</p><p>Adhesion quantification is important for all bonding. Development of accurate quantification methods is considered necessary since most methods at hand are limited. This work includes the development of the blister test method. Former test structures are improved to be more practical to work with and to yield low experimental scatter. A physical stress model for the improved structure is suggested with which successful predictions of fracture for different test specimen configurations are made. The blister test method is used throughout this work to assess the strength of wafer bonds. The physics background and modelling of other common test methods are also thoroughly analysed. The methods’ practical capabilities and limitations are commented; origin and mitigation of measurement errors are discussed. It is shown that all methods can be significantly improved by small means.</p><p>Weibull statistics is introduced as a tool to characterise wafer bonds. This method is suitable to use in brittle materials design as the inherent variability in strength can be properly accounted for.</p>

This thesis presents a method of measuring the distribution of fiber bonding ability in mechanical pulp furnishes. The method is intended for industrial use, where today only average values are used to describe fiber bonding ability, despite the differences in morphology of the fibers entering the mill. Fiber bonding ability in this paper refers to the mechanical fiber’s flexibility and ability to form large contact areas to other fibers, characteristics required for good paper surfaces and strength.   Five mechanical pulps (Pulps A-E), all produced in different processes from Norway spruce (Picea Abies) were fractionated in hydrocyclones with respect to the fiber bonding ability. Five streams were formed from the hydrocyclone fractionation, Streams 1-5. Each stream plus the feed (Stream 0) was fractionated according to fiber length in a Bauer McNett classifier to compare the fibers at equal fiber lengths (Bauer McNett screens 16, 30, 50, and 100 mesh were used).   Stream 1 was found to have the highest fiber bonding ability, evaluated as tensile strength and apparent density of long fiber laboratory sheets. External fibrillation and collapse resistance index measured in FiberLabTM, an optical measurement device, also showed this result. Stream 5 was found to have the lowest fiber bonding ability, with a consecutively falling scale between Stream 1 and Stream 5. The results from acoustic emission measurements and cross-sectional scanning electron microscopy analysis concluded the same pattern. The amount of fibers in each hydrocyclone stream was also regarded as a measure of the fibers’ bonding ability in each pulp.   The equation for predicted Bonding Indicator (BIN) was calculated by combining, through linear regression, the collapse resistance index and external fibrillation of the P16/R30 fractions for Pulps A and B. Predicted Bonding Indicator was found to correlate well with measured tensile strength. The BIN-equation was then applied also to the data for Pulps C-E, P16/R30, and Pulp A-E, P30/R50, and predicted Bonding Indicator showed good correlations with tensile strength also for these fibers.   From the fiber raw data measured by the FiberLabTM instrument, the BIN-equation was used for each individual fiber. This made it possible to calculate a BIN-distribution of the fibers, that is, a distribution of fiber bonding ability.   The thesis also shows how the BIN-distributions of fibers can be derived from FiberLabTM measurements of the entire pulp without mechanically separating the fibers by length first, for example in a Bauer McNett classifier. This is of great importance, as the method is intended for industrial use, and possibly as an online-method. Hopefully, the BIN-method will become a useful tool for process evaluations and optimizations in the future. / Den här studien presenterar en metod för att mäta fördelning av fiberbindning i mekaniska massor. Metoden hoppas kunna användas industriellt, där i dagsläget enbart medelvärden används för att mäta fiberbindnings-fördelning, trots råvarans (fibrernas) morfologiska skillnader.   Fem mekaniska massor (Massa A-E) från olika massaprocesser men från samma råvara, norsk gran (Picea Abies), har fraktionerats i hydrocykloner med avseende på fiberbindningsförmåga. Från hydrocyklon-fraktioneringen bildades fem strömmar, Ström 1-5. Varje ström plus injektet (Ström 0) fraktionerades också med avseende på fiberlängd i en Bauer McNett för att kunna jämföra fibrerna vid samma fiberlängd (Bauer McNett silplåtarna 16, 30, 50 och 100 mesh användes).   Fiberbindingsförmåga i den här studien härrör till fiberns flexibilitet och förmåga att skapa stora kontaktytor med andra fibrer, vilket bidrar till papprets yt- och styrkeegenskaper.   Ström 1 visade sig ha den högsta fiberbindningsförmågan, utvärderat som dragstyrka och densitet av långfiberark, samt yttre fibrillering och kollaps resistans index mätt i den optiska analysatorn FiberLabTM. Akustisk emission och tvärsnittsanalyser visade samma resultat. Ström 5 visade sig ha den lägsta fiberbindningsförmågan, med en avtagande skala från Ström 1 till Ström 5. Andelen fibrer från injektet som gick ut med varje hydrocyklon-ström ansågs också vara ett mått på fibrernas bindningsförmåga i varje massa.   Genom att kombinera fiberegenskaperna kollaps resistans och yttre fibrillering från den optiska mätningen på varje fiber genom linjär regression, kunde Bindnings Indikator (BIN) predikteras. Medelvärdet av Bindnings Indikator för varje hydrocyklon-ström korrelerar med dragstyrka för långfiber-labark.   Det visade sig att predikterad Bindnings Indikator inte bara fungerade för Massa A och Massa B P16/R30 fraktionen, som var de fraktioner som användes i den linjära regressionen, utan även för Massa C-E, P16/R30, och Massa A-E P30/R50 som också visade goda korrelationer med långfiber-dragstyrka när de sattes in i BIN-formeln.   BIN-formeln användes sedan för varje enskild fiber, i den rådata som levererats från FiberLabTM. Detta gjorde det möjligt att få en BIN-distribution av fibrerna, d.v.s. en fördelning av fiberbindningsförmåga.   Den här rapporten visar också hur det går att få BIN-distributioner också från mätningar på hela massan, för valbara fiberlängder, utan att först mekaniskt separera massan efter fiberlängd. Det är viktigt, då metoden är tänkt att användas som en industriell metod, och eventuellt som en online-metod. Förhoppningsvis kommer BIN-metoden att bli ett användbart verktyg för processutveckling- och optimering i framtiden. / FSCN – Fibre Science and Communication Network / Bonding ability distribution of fibers in mechanical pulp furnishes

Bonding techniques intended for assembling space microsystems are studied in this work. One of the largest problems in bonding pre-processed semiconductor wafers are the severe process restrictions imposed by material compatibility issues. Plasma processes have shown to be good for sensitive materials integration why the influence of different plasma parameters on the bondability of wafers is particularly studied. Conventional wet chemical and field-assisted methods are also examined. The resulting bond quality is assessed in terms of mechanical strength, homogeneity, and yield. The effect of spaceflight environment on the reliability of wafer bonds is also investigated. Both high and low temperature annealed bonds are found to be very robust. Effects observed are that low temperature bonds are reinforced by thermal cycling in vacuum and that high temperature bonds degrade slightly by low dose γ irradiation. Adhesion quantification is important for all bonding. Development of accurate quantification methods is considered necessary since most methods at hand are limited. This work includes the development of the blister test method. Former test structures are improved to be more practical to work with and to yield low experimental scatter. A physical stress model for the improved structure is suggested with which successful predictions of fracture for different test specimen configurations are made. The blister test method is used throughout this work to assess the strength of wafer bonds. The physics background and modelling of other common test methods are also thoroughly analysed. The methods’ practical capabilities and limitations are commented; origin and mitigation of measurement errors are discussed. It is shown that all methods can be significantly improved by small means. Weibull statistics is introduced as a tool to characterise wafer bonds. This method is suitable to use in brittle materials design as the inherent variability in strength can be properly accounted for.

Over the past two decades, India has become an international hub of cross-border surrogacy. The extreme economic and cultural differences between international couples seeking surrogacy and the surrogates themselves, clinics compromising health of surrogates for profit, the stigmatisation of surrogacy in India, and the constant surveillance of these women living in a ‘surrogate house’, have raised concerns regarding the potentially negative psychological impact of surrogacy on Indian surrogates. The primary aims of the thesis were (i) to conduct a longitudinal assessment of surrogates’ psychological problems (anxiety, depression and stress) from pregnancy until several months after relinquishing the baby to the intended parents, (ii) to examine the nature of the bond formed between surrogates and the unborn baby and establish whether this prenatal bond contributes to their psychological problems, and (iii) to explore the experiences of surrogates during and post-surrogacy. Fifty surrogates were compared with a matched group of 69 expectant mothers during pregnancy. Of these, 45 surrogates and 49 compairson group of mothers were followed up 4-6 months after the birth. All surrogates were hosting pregnancies for international intended parents and had at least one child of their own. Data were obtained using standardised questionnaires and in-depth interviews and were analysed using quantitative and qualitative methods. Indian surrogates were found to be more depressed than the comparison group of mothers, both during pregnancy and after the birth. However, giving up the newborn did not appear to add to surrogates’ levels of depression. There were no differences between the surrogates and the expectant mothers in anxiety or stress during either phase of the study. The examination of risk factors for psychological problems among the surrogates showed that anticipation of stigma, experiences of social humiliation and receiving insufficient support during pregnancy were associated with higher levels of depression following the birth. With respect to bonding with the unborn child, surrogates experienced lower levels of emotional bonding (e.g. they interacted less, and wondered less about, the foetus), but exhibited higher levels of instrumental bonding (e.g. they adopted better eating habits and avoided unhealthy practices during pregnancy), than women who were carrying their own babies. Contrary to concerns, greater bonding with the unborn child was not associated with increased psychological problems post-relinquishment. All surrogates were able to give up the child. Meeting the intended parents after the birth positively contributed towards surrogates’ satisfaction with relinquishment whereas meeting the baby did not. The qualitative findings on surrogates’ experiences showed that the majority lacked basic medical information regarding surrogacy pregnancy; hid surrogacy from most people; felt positive and supported at the surrogate house; lived in uncertainty regarding whether or not they would be allowed to meet the intended parents and the baby; and did not actually get to meet them. These findings have important implications for policy and practice on surrogacy in the Global South.

Le collage par adhérence moléculaire est un collage basé sur la mise en contact de deux surfaces sans l'utilisation de colle ou matériaux additionnels. Ce procédé de collage est utilisé dans de nombreuses applications, notamment dans les domaines de l'optique terrestre et spatiale. Bien qu'un prototype ait déjà passé avec succès l'environnement spatial - où les contraintes d'utilisations sont différentes de celles rencontrées sur Terre - la spatialisation de cette technologie nécessite une caractérisation plus fine du procédé ainsi qu'une amélioration de la tenue mécanique des interfaces adhérées afin de valider les normes de l'Agence spatiale Européenne. Pour répondre à cette problématique de spatialisation de la technologie, des essais mécaniques ainsi que des analyses chimiques ont été réalisés dans le but d'étudier l'influence de certains paramètres du procédé ) sur la tenue mécanique et l'énergie de collage. Ces essais ont également été réalisés afin de comparer les deux matériaux étudiés : le verre de silice et le Zérodur vis-à-vis de l'adhésion. A l'issue de ces essais, les paramètres à appliquer permettant de doubler la tenue mécanique des interfaces adhérées ont été déterminés. Parallèlement, une loi phénoménologique reliant l'énergie de collage aux précédents paramètres du procédé a été développée ainsi qu'un modèle macroscopique visant à décrire l'intensité d'adhésion. Ces deux modèles une fois couplés permettent de modéliser le comportement normal de l'interface en fonction des paramètres du procédé. Enfin, ces deux lois sont implémentées dans un code éléments finis afin de simuler la propagation de la fissure lors de l'essai de clivage au coin. / Direct bonding consists in joining two surfaces without the use of any adhesive or additional material. This process is used in several applications, particularly in terrestrial and spatial optics. Although a prototype passed with success spatial environment - where constraints involved are very different from those encountered on Earth - this technology requires a more detailed characterization and an improvement of the mechanical strength of bonded interfaces in order to validate the European Space Agency standards. To address this issue, mechanical tests (double shear tests, cleavage tests and wedge tests) and chemical analysis (wetting tests and XPS spectroscopy) were performed in order to study the influence of some process parameters (roughness, relative air humidity during room temperature bonding, the annealing temperature and time) on the mechanical strength and the bonding energy. These tests compared the two materials used: fused silica glass and Zerodur glass. As a result of these tests, optimal parameters doubling the mechanical strength were also obtained. In the same time, a phenomenological law relating the bonding energy to the previous parameters is developed as well as a macroscopic model to describe the adhesion intensity. Both models when coupled describe the normal behavior of the bonded interface depending on the process parameters. Then, the both laws are implemented in a finite elements model in order to simulate the crack propagation during the wedge test.

Introducción: La técnica de arco recto es una de las técnicas más utilizadas para la corrección de maloclusiones en ortodoncia; sin embargo, el éxito de la técnica radicará en la exactitud en que se posicionan los brackets. Este artículo presenta un protocolo de cementación indirecta, el cual, adicionalmente, permite una mayor accesibilidad a los materiales requeridos para este procedimiento. Objetivo: Presentar un protocolo efectivo y accesible de cementación indirecta. Material y métodos: Para este protocolo se ha utilizado materiales como resina de cementación de brackets (Transbond XT, 3M Unitek, EEUU), aislante de acrílico para separar los brackets del modelo de yeso y silicona líquida, utilizada habitualmente para autos (Kit Silicona, Johnson, Chile), para separar los brackets del soporte termoplástico, el cual fue realizado con silicona termofusible. Conclusión: El protocolo de cementación indirecta permite un buen posicionamiento de los brackets, reduciendo la posibilidad de reposicionar durante las fases de alineamiento y nivelado. / Introduction: The straight arch technique is one of the most used techniques for the correction of malocclusions in orthodontics; however, the success of the technique will lie in the accuracy in which the brackets are positioned in the correct position. This article presents an indirect cementation protocol which additionally allows greater accessibility to the materials required for this procedure. Objective: Present an effective and accessible indirect cementation protocol. Material and methods: For this protocol, materials such as brace cementation resin (Transbond XT, 3M Unitek, USA), acrylic insulator have been used to separate the brackets from the gypsum and liquid silicone model, usually used for cars (Silicone Kit, Johnson, Chile), to separate the brackets from the thermoplastic support, which was made with hot melt silicone. Conclusion: The indirect cementation protocol allows a good positioning of the brackets, reducing the possibility of repositioning during the alignment and leveling phases. / Trabajo académico

Le multi-colaminage est connu pour pouvoir créer des composites ayant une résistance mécanique améliorée et coupler les bonnes propriétés des deux métaux utilisés. L’étude s’est focalisée sur l’élaboration à froid et à chaud de deux composites fonctionnels à base d’aluminium : Al6061/ Al5754 et Al6061/Acier IF. Sur le premier composite, une comparaison a été faite entre le procédé classique et le multi-colaminage croisé, où la direction de laminage est tournée de 90° entre chaque passe. Ce dernier s’est avéré plus apte à hyperdéformer et donc à améliorer la résistance mécanique à température ambiante alors qu’une élaboration à chaud limite cette augmentation par rapport au procédé classique. Au niveau de l’architecture des composites, une réalisation à l’ambiante strictionne puis fractionne la phase dure occasionnant une chute de la résistance mécanique pour le second composite, tandis qu’une réalisation en température conserve la stratification et permet la disparition des interfaces pour le premier composite et l’apparition d’intermétalliques pour le second. Enfin, le composite Al6061/Al5754 s’est montré apte à résister à la fissuration à chaud tandis que le composite Al6061/Acier IF est capable de blinder magnétiquement. / The Accumulative Roll Bonding (ARB), consisting in a repetition of roll bonding, is known as a suitable process to work out composite with tailored properties and higher mechanical strength. The present study aimed to develop two functional composites at room and hot temperatures: AA6061/AA5754 and AA6061/IF steel. The first one was developed with both ARB and Cross-ARB (CARB). The Cross-ARB changes the rolling direction by 90° between each pass. As a result, the second process showed higher strength at room temperature. A hotter temperature of process prevented a further enhancement of the strength. According to the temperature of the process, different architectures were obtained. Indeed, ARB at room temperature led to the necking then to the fragmentation of the hard phase and, as a consequence to the collapse of the strength of the composite AA6061/IF steel. The temperature preserved the stratification in the AA6061/AA5754 composite but favored the appearance of intermetallic phase in the AA6061/ IF steel composite. Eventually, the first composite was able to resist to the hot cracking while the second showed magnetic shielding effectiveness.

La protection de nombreux capteurs de pression en milieux hostiles se résume souvent en un boitier métallique hermétique rempli d’huile enveloppant la puce. La pression agit alors sur une membrane métallique qui agit sur la puce par l’intermédiaire de l’huile jugée incompressible. Cette encapsulation présente des difficultés de réalisation non négligeables et surtout une limitation des capteurs en température. Les travaux réalisés au cours de cette thèse concernent une encapsulation au niveau wafer du capteur de pression. L’idée principale est d’intégrer la protection de la puce dans le processus de fabrication sur wafer. L’intérêt est alors d’obtenir une protection réalisée de manière collective, réduisant ainsi drastiquement les coûts de production. De plus, une encapsulation au niveau wafer offre la possibilité de réduire considérablement les dimensions du capteur tout en le gardant résistant. La suppression d’éléments intermédiaires telle que l’huile entre la pression et la puce en elle même permet enfin d’espérer des applications possibles à température plus élevée. Une fois l’encapsulation réalisée au niveau wafer, il est nécessaire de réaliser le packaging de premier niveau. Le packaging de premier niveau offre un support à la puce, ce qui la rend manipulable et testable, tant par ses dimensions que par la présence de connexions électriques. L’assemblage au niveau wafer et de premier niveau constituent donc les deux niveaux de packaging qui peuvent avoir une influence directe sur le comportement de la puce.Au niveau de l’encapsulation de niveau wafer, trois techniques d’assemblage (wafer bonding) ont été analysées : le scellement anodique, le scellement eutectique et le scellement direct. Le scellement anodique est la technique la plus éprouvée pour assembler un wafer de verre sur un wafer de silicium. Le scellement eutectique représente une technique moins commune mais offrant l’intérêt d’utiliser deux wafers silicium, limitant la différence de dilatation thermique entre les deux wafers et permettant d’usiner plus facilement le wafer d’encapsulation. Enfin la technique du direct bonding donne l’opportunité d’éviter d’utiliser une couche intermédiaire métallique entre les deux wafers, à condition d’avoir deux surfaces à assembler très propres et de très bonne qualité. La technique de soudure anodique a permis de livrer les capteurs qui ont pu confirmer l’intérêt des capteurs WLP pour des applications hautes températures. Les techniques silicium-silicium ont été évaluées mais n’ont pas donné lieu à des capteurs WLP testables.Au niveau de l’encapsulation de niveau un, la technique de Flip-Chip à été utilisée pour reporter la puce sur son support. Cette technique consiste à retourner la puce et l’assembler par thermocompression. Les plots de connexions de la puce pour cet assemblage ont pu être réalisés par ball bumping. Des cycles en température (-55°C à +125°C ou 150°C) ont pu être réalisés sur les puces scellées par scellement anodique. L’erreur totale en précision de ces capteurs WLP est du même ordre que les capteurs Auxitrol actuels avec une compensation numérique. Le principal atout des capteurs WLP est une non-linéarité de l’offset en température divisée par deux. Cette caractéristique est importante dans le cas où l’on utilise une compensation analogique qui peut résister à des températures plus élevées que la compensation numérique. Les capteurs WLP offre donc l’opportunité d’avoir des applications au-delà de 200°C, chose alors jusqu’alors prohibée par l’utilisation de l’huile / Protection of most of the pressure sensors working in harsh environment consist in oil filled metallic unit including the sensor die. In that case, pressure is applied on a metallic membrane moving the silicon membrane of the die across an incompressible fluid. The main drawbacks of the standard encapsulation are a complex fabrication process and most of all a sensor limitation in high temperatures. The topic of this PhD thesis is about wafer-level packaging (WLP) of the pressure sensor. The main idea is to integrate the die protection in the fabrication process at wafer level. Advantage is to obtain a collective protection fabrication reducing production costs. Moreover, a wafer-level encapsulation allows a possible reduction of sensor dimensions keeping it reliable. Removing intermediary elements allows also high temperature applications. Once encapsulation realised on the wafer, it is necessary to build the first-level packaging. First-level packaging makes the die usable in terms of electrical connection and dimensions. Wafer and first-levels are both packaging levels with important impact on the die behaviour.At wafer-level packaging, three wafer bonding technologies have been investigated: anodic bonding, Au-Si eutectic bonding and direct bonding. Anodic bonding is the most known technology to assemble a glass wafer with a silicon wafer. Eutectic bonding represents a promising technique to bond two silicon wafers allowing less CTE mismatch between wafers material and an easier micromachining of silicon instead of glass material. Direct bonding is also interesting to bond two silicon wafers, without using intermediary metallic layer but needing really clean surfaces to assemble. Anodic bonding process gave us the opportunity to deliver WLP sensors showing interest for high temperature applications. Silicon-Silicon technologies have been evaluated but did not give representative WLP sensors.At first-level packaging, the Flip-chip technology have been used for die attach. This technique consists in flipping the die and making the die attach by thermocompression with stud bumps on the die connection pads.Temperature cycling (-55°C to +125°C or more) have been realised on anodic WLP sensors. Accuracy total error of these WLP sensors is in the same order than standard Auxitrol sensors with digital compensation. the main advantage of the WLP sensors is a offset non-linearity in temperature divided by two. This characteristic is important in the case of analogical compensation that can resist to higher temperatures than digital compensation elements. In definitive, WLP sensors offer a good opportunity to have application over 200°C, prohibited at present with the presence of oil for standard Auxitrol sensor

This thesis presents a method of measuring the distribution of fiber bonding ability in mechanical pulp furnishes. The method is intended for industrial use, where today only average values are used to describe fiber bonding ability, despite the differences in morphology of the fibers entering the mill. Fiber bonding ability in this paper refers to the mechanical fiber’s flexibility and ability to form large contact areas to other fibers, characteristics required for good paper surfaces and strength. Five mechanical pulps (Pulps A-E), all produced in different processes from Norway spruce (Picea Abies) were fractionated in hydrocyclones with respect to the fiber bonding ability. Five streams were formed from the hydrocyclone fractionation, Streams 1-5. Each stream plus the feed (Stream 0) was fractionated according to fiber length in a Bauer McNett classifier to compare the fibers at equal fiber lengths (Bauer McNett screens 16, 30, 50, and 100 mesh were used). Stream 1 was found to have the highest fiber bonding ability, evaluated as tensile strength and apparent density of long fiber laboratory sheets. External fibrillation and collapse resistance index measured in FiberLabTM, an optical measurement device, also showed this result. Stream 5 was found to have the lowest fiber bonding ability, with a consecutively falling scale between Stream 1 and Stream 5. The results from acoustic emission measurements and cross-sectional scanning electron microscopy analysis concluded the same pattern. The amount of fibers in each hydrocyclone stream was also regarded as a measure of the fibers’ bonding ability in each pulp. The equation for predicted Bonding Indicator (BIN) was calculated by combining, through linear regression, the collapse resistance index and external fibrillation of the P16/R30 fractions for Pulps A and B. Predicted Bonding Indicator was found to correlate well with measured tensile strength. The BIN-equation was then applied also to the data for Pulps C-E, P16/R30, and Pulp A-E, P30/R50, and predicted Bonding Indicator showed good correlations with tensile strength also for these fibers. From the fiber raw data measured by the FiberLabTM instrument, the BIN-equation was used for each individual fiber. This made it possible to calculate a BIN-distribution of the fibers, that is, a distribution of fiber bonding ability. The thesis also shows how the BIN-distributions of fibers can be derived from FiberLabTM measurements of the entire pulp without mechanically separating the fibers by length first, for example in a Bauer McNett classifier. This is of great importance, as the method is intended for industrial use, and possibly as an online-method. Hopefully, the BIN-method will become a useful tool for process evaluations and optimizations in the future. / Den här studien presenterar en metod för att mäta fördelning av fiberbindning i mekaniska massor. Metoden hoppas kunna användas industriellt, där i dagsläget enbart medelvärden används för att mäta fiberbindnings-fördelning, trots råvarans (fibrernas) morfologiska skillnader.  Fem mekaniska massor (Massa A-E) från olika massaprocesser men från samma råvara, norsk gran (Picea Abies), har fraktionerats i hydrocykloner med avseende på fiberbindningsförmåga. Från hydrocyklon-fraktioneringen bildades fem strömmar, Ström 1-5. Varje ström plus injektet (Ström 0) fraktionerades också med avseende på fiberlängd i en Bauer McNett för att kunna jämföra fibrerna vid samma fiberlängd (Bauer McNett silplåtarna 16, 30, 50 och 100 mesh användes). Fiberbindingsförmåga i den här studien härrör till fiberns flexibilitet och förmåga att skapa stora kontaktytor med andra fibrer, vilket bidrar till papprets yt- och styrkeegenskaper. Ström 1 visade sig ha den högsta fiberbindningsförmågan, utvärderat som dragstyrka och densitet av långfiberark, samt yttre fibrillering och kollaps resistans index mätt i den optiska analysatorn FiberLabTM. Akustisk emission och tvärsnittsanalyser visade samma resultat. Ström 5 visade sig ha den lägsta fiberbindningsförmågan, med en avtagande skala från Ström 1 till Ström 5. Andelen fibrer från injektet som gick ut med varje hydrocyklon-ström ansågs också vara ett mått på fibrernas bindningsförmåga i varje massa. Genom att kombinera fiberegenskaperna kollaps resistans och yttre fibrillering från den optiska mätningen på varje fiber genom linjär regression, kunde Bindnings Indikator (BIN) predikteras. Medelvärdet av Bindnings Indikator för varje hydrocyklon-ström korrelerar med dragstyrka för långfiber-labark.  Det visade sig att predikterad Bindnings Indikator inte bara fungerade för Massa A och Massa B P16/R30 fraktionen, som var de fraktioner som användes i den linjära regressionen, utan även för Massa C-E, P16/R30, och Massa A-E P30/R50 som också visade goda korrelationer med långfiber-dragstyrka när de sattes in i BIN-formeln. BIN-formeln användes sedan för varje enskild fiber, i den rådata som levererats från FiberLabTM. Detta gjorde det möjligt att få en BIN-distribution av fibrerna, d.v.s. en fördelning av fiberbindningsförmåga. Den här rapporten visar också hur det går att få BIN-distributioner också från mätningar på hela massan, för valbara fiberlängder, utan att först mekaniskt separera massan efter fiberlängd. Det är viktigt, då metoden är tänkt att användas som en industriell metod, och eventuellt som en online-metod. Förhoppningsvis kommer BIN-metoden att bli ett användbart verktyg för processutveckling- och optimering i framtiden. / <p>FSCN – Fibre Science and Communication Network</p> / Bonding ability distribution of fibers in mechanical pulp furnishes