Development and reliability of a direct access sensor using flip chip on flex technology with anisotropic conductive adhesive

Technological developments in biomedical microsystems are opening up new opportunities to improve healthcare procedures. Swallowable diagnostic sensing capsules are an example of these. In none of the diagnostic sensing capsules, is the sensor’s first level packaging achieved via Flip Chip Over Hole (FCOH) method using Anisotropic Conductive Adhesive (ACA). In a capsule application with direct access sensor (DAS), ACA not only provides the electrical interconnection but simultaneously seals the interconnect area and the underlying electronics. The development showed that the ACA FCOH was a viable option for the DAS interconnection. Adequate adhesive formed a strong joint that withstood a shear stress of 120N/mm2 and a compressive stress of 6N required to secure the final sensor assembly in place before encapsulation. Electrical characterization of the ACA joint in a fluid environment showed that the ACA was saturated with moisture and that the ions in the solution actively contributed to the leakage current, characterized by the varying rate of change of conductance. Long term hygrothermal aging of the ACA joint showed that a thermal strain of 0.004 and a hygroscopic strain of 0.0052 were present and resulted in a fatigue like process. In-vitro tests showed that high temperature and acidity had a deleterious effect of the ACA and its joint. It also showed that the ACA contact joints positioned at around or over 1mm would survive the gastrointestinal (GI) fluids and would be able to provide a reliable contact during the entire 72hr of the GI transit time. A final capsule demonstrator was achieved by successfully integrating the DAS, the battery and the final foldable circuitry into a glycerine capsule. Final capsule soak tests suggested that the silicone encapsulated system could survive the 72hr gut transition.

Taajuusmuttajan vanheneminen syklisissä käytöissä

Tässä työssä tarkastellaan taajuusmuuttajan vanhenemista syklisissä käytöissä puolijohdetehokomponenttien osalta. Laitteiden vikaantumisprosessien analysoimiseksi työssä suunnitellaan syklinen kestotestausjärjestelmä, joka mahdollistaa useamman taajuusmuuttajan yhtäaikaisen vanhentamisen. Jaksottaisesti toistuvat kuormitussyklit rasittavat termomekaanisesti taajuusmuuttajan tehomoduulin sisäisiä rakenteita suurten lämpötilavaihtelujen johdosta. Teoriaosuuden pääpaino kohdistuu puolijohdetehokomponenttien rakenteeseen, vikaantumisprosesseihin ja eliniän kartoittamiseen. Työssä käydään läpi yleisimpien pienijännitteisten moottorinohjausinverttereiden tehomoduulien mekaaniset rakenteet, tyypillisemmät syklisestä kuormituksesta johtuvat vikaantumisprosessit sekä puolijohdetehokomponenttivalmistajien käyttämät syklisen eliniän testausmenetelmät. Loppuosassa työtä suunnitellaan taajuusmuuttajan syklinen kestotestausjärjestelmä laitteiden keinotekoista vanhentamista varten. Testausjärjestelmällä voidaan kuormittaa useampaa taajuusmuuttajaa vuorottain mielivaltaisella kuormitusvirtaprofiililla. Laitteita vanhennettiin kaksi testierää kuormittamalla niitä jaksottaisesti hissikäytön tyypillisellä kuormitusprofiililla. Puolijohdetehokomponentin vanhenemisen edistystä seurattiin termisen impedanssiketjun mittausmenetelmällä, joka perustuu IGBT:n kollektoriemitterijännitteen lämpötilariippuvuuteen. Testilaitteiden puolijohdetehokomponentit hajosivat syklisen eliniän päättymiseen teoriassa esitettyjen vikaantumisprosessien seurauksesta. Tehomoduulien vika-analyysi osoittaa syklisen kestotestausjärjestelmän soveltuvaksi menetelmäksi tutkia erilaisten kuormitusprofiilien vaikutusta taajuusmuuttajan vanhenemiseen.

Diseño y simulación térmica de HB-LEDs con Autodesk y PCB para ensayos

Este PFC es un trabajo muy práctico, los objetivos fueron impuestos por el tutor, como parte del desarrollo de herramientas (software y hardware) que serán utilizados posteriormente a nivel de docencia e investigación. El PFC tiene dos áreas de trabajo, la principal y primera que se expone es la utilización de una herramienta de simulación térmica para caracterizar dispositivos semiconductores con disipador, la segunda es la expansión de una tarjeta de adquisición de datos con unas PCBs diseñadas, que no estaban disponibles comercialmente. Se ha probado y configurado “Autodesk 2013 Inventor Fusion” y “Autodesk 2013 Simulation and Multiphysics” para simulación térmica de dispositivos de alta potencia. Estas aplicaciones son respectivamente de diseño mecánico y simulación térmica, y la UPM dispone actualmente de licencia. En esta parte del proyecto se realizará un manual de utilización, para que se continúe con esta línea de trabajo en otros PFC. Además se han diseñado mecánicamente y simulado térmicamente diodos LED de alta potencia luminosa (High Brightness Lights Emitting Diodes, HB-LEDs), tanto blancos como del ultravioleta cercano (UVA). Las simulaciones térmicas son de varios tipos de LEDs que actualmente se están empleando y caracterizando térmicamente en Proyectos Fin de Carrera y una Tesis doctoral. En la segunda parte del PFC se diseñan y realizan unas placas de circuito impreso (PCB) cuya función es formar parte de sistemas de instrumentación de adquisición automática de datos basados en LabVIEW. Con esta instrumentación se pueden realizar ensayos de fiabilidad y de otro tipo a dispositivos y sistemas electrónicos. ABSTRACT. The PFC is a very practical work, the objectives were set by the tutor, as part of the development of tools (software and hardware) that will be used later at level of teaching and research. The PFC has two parts, the first one explains the use of a software tool about thermal simulation to characterize devices semiconductors with heatsink, and second one is the expansion of card data acquisition with a PCBs designed, which were not available commercially. It has been tested and configured "Autodesk 2013 Inventor Fusion" and "Autodesk 2013 Simulation Multiphysics” for thermal simulation of high power devices. These applications are respectively of mechanical design and thermal simulation, and the UPM has at present license. In this part of the project a manual of use will be realized, so that it is continued by this line of work in other PFC. Also they have been designed mechanically and simulated thermally LEDs light (High Brightness Lights Emitting Diodes , HB- LEDs) both white and ultraviolet. Thermal simulations are several types of LEDs are now being used in thermally characterizing in Thesis and PhD. In the second part of the PFC there are designed and realized circuit board (PCB) whose function is to be a part of instrumentation systems of automatic acquisition based on LabVIEW data. With this instrumentation can perform reliability testing and other electronic devices and systems.

Fiabilidad de minimodulos de silicio

El objetivo de este Proyecto Final de Carrera es la realización de un ensayo de fiabilidad de componentes electrónicos, más concretamente de Minimódulos de Silicio, con el fin de estudiar su comportamiento a lo largo del tiempo de vida. Debido a la larga duración de los Minimódulos de Silicio , un ensayo de este tipo podría durar años, por lo que es necesario realizar un ensayo acelerado que acorte significativamente el tiempo del experimento, para ello, han de someterse a esfuerzos mayores que en condiciones normales de funcionamiento. A día de hoy, los Minimódulos de silicio, que conocemos como placas solares fotovoltaicas, se usan en infinidad de dispositivos debido a las múltiples ventajas que conllevan. La principal ventaja es poder llevar electricidad a cualquier parte del planeta sin necesidad de tener que hacer unas elevadas inversiones. Esta electricidad proviene de una fuente de energía inagotable y nada contaminante, con lo que ayudamos a mantener el equilibrio del planeta. La mayoría de las veces estas placas solares fotovoltaicas se usan en el exterior, soportando cambios de temperatura y de humedad elevados, de ahí, la importancia de realizar ensayos de fiabilidad, que muestren sus posibles causas de fallo, los efectos que producen estos fallos y los aspectos de diseño, fabricación y mantenimiento que puedan afectarles. Los Minimódulos de silicio utilizados en este proyecto son el modelo MC-SP0.8-NF-GCS de la empresa fabricante Multicomp. Para realizar el Proyecto hubiéramos necesitado una cámara climática que simulara unas condiciones ambientales determinadas, pero debido a la dificultad de iluminar el módulo dentro de la cámara climática hemos desarrollado un nuevo sistema de ensayos acelerados en temperatura. El nuevo sistema de ensayos acelerados consiste en: •Colocar los módulos fotovoltaicos en el laboratorio con un foco de 500W que irradia lo equivalente al sol. •Los tres módulos trabajarán a tres temperaturas diferentes para simular condiciones ambientales distintas, concretamente a 60°C, 72°C y 84°C. •Mediante un sistema automático de medida diseñado en LabVIEW, de manera simultánea tomará medidas de tensión en las tres placas y estudiaremos el grado degradación en cada placa. Se analizaran los resultados obtenido de cada una de las medidas y se realizará un estudio de fiabilidad y del proceso de degradación sufrido por los Minimódulos de silicio. Este PFC se puede dividir en las siguientes fases de trabajo siendo el ensayo la parte más larga en el tiempo: •Búsqueda de bibliografía documentación y normas aplicables. •Familiarización con los equipos y software, estudiando el manejo del software que viene con el Multímetro Keithley 2601 y el programa LabVIEW. •Desarrollo del hardware y sistemas necesarios para la realización del ensayo. •Montaje del ensayo •Realización del ensayo. •Análisis de resultados. ABSTRACT. The objective of this Final Project is conducting a test reliability of electronic components, more specifically Silicon minimodules, in order to study their behavior throughout the life span. Due to the long duration of Silicon minimodules a test like this could take years, so it is necessary to perform an accelerated significantly shorten the time of the experiment, testing for it, should be subjected to greater efforts than in normal operating. Today, the mini-modules, silicon is known as photovoltaic solar panels are used in a multitude of devices due to the many advantages they bring. The main advantage is to bring electricity to anywhere in the world without having to make high investments. This electricity comes from an inexhaustible source of energy and no pollution, thus helping to maintain the balance of the planet. Most of the time these solar photovoltaic panels are used on the outside, enduring changes in temperature and high humidity, hence, the importance of reliability testing, showing the possible causes of failure, the effects produced by these faults and aspects of design, manufacturing and maintenance that may affect them. The silicon mini-modules used in this project are the MC-SP0.8-NF-GCS model Multicomp manufacturing company. To realize the project we would have needed a climatic chamber to simulate specific environmental conditions, but due to the difficulty of illuminating the module in the climate chamber we have developed a new system of accelerated tests in temperature. The new system is accelerated tests: •Place the PV modules in the laboratory with a focus on the equivalent 500W radiating sun. •The three modules work at three different temperatures to simulate different environmental conditions, namely at 60 °C, 72 °C and 84 °C. •Automatic measurement system designed in LabVIEW, simultaneous voltage measurements taken at the three plates and study the degradation degree in each plate. The results obtained from each of the measurements and a feasibility study and degradation suffered by the silicon is performed minimodules were analyzed. This PFC can be divided into the following phases of the test work the longest part being overtime: •Literature search and documentation standards. •Familiarization with equipment and software, studying management software that comes with the Keithley 2601 multimeter and the LabVIEW program. •Development of hardware and systems necessary for the conduct of the trial. •Experiment setup •Carrying out the experiment. •Analysis of results.

A multivariate examination of the relationship between strategic planning and organisational performance

Strategic planning and more specifically, the impact of strategic planning on organisational performance has been the subject of significant academic interest since the early 1970's. However, despite the significant amount of previous work examining the relationship between strategic planning and organisational performance, a comprehensive literature review identified a number of areas where contributions to the domain of study could be made. In overview, the main areas for further study identified from the literature review were a) a further examination of both the dimensionality and conceptualisation of strategic planning and organisational performance and b) a further, multivariate, examination of the relationship between strategic planning and performance, to capture the newly identified dimensionality. In addition to the previously identified strategic planning and organisational performance constructs, a comprehensive literature based assessment was undertaken and five main areas were identified for further examination, these were a) organisational b) comprehensive strategic choice, c) the quality of strategic options generated, d) political behavior and e) implementation success. From this, a conceptual model incorporating a set of hypotheses to be tested was formulated. In order to test the conceptual model specified and also the stated hypotheses, data gathering was undertaken. The quantitative phase of the research involved a mail survey of senior managers in medium to large UK based organisations, of which a total of 366 fully useable responses were received. Following rigorous individual construct validity and reliability testing, the complete conceptual model was tested using latent variable path analysis. The results for the individual hypotheses and also the complete conceptual model were most encouraging. The findings, theoretical and managerial implications, limitations and directions for future research are discussed.

Implications of high power losses in IR femtosecond laser inscribed fibre Bragg gratings

We report on high power issues related to the reliability of fibre Bragg gratings inscribed with an infrared femtosecond laser using the point-by-point writing method. Conventionally, fibre Bragg gratings have usually been written in fibres using ultraviolet light, either holographically or using a phase mask. Since the coating is highly absorbing in the UV, this process normally requires that the protective polymer coating is stripped prior to inscription, with the fibre then being recoated. This results in a time consuming fabrication process that, unless great care is taken, can lead to fibre strength degradation, due to the presence of surface damage. The recent development of FBG inscription using NIR femtosecond lasers has eliminated the requirement for the stripping of the coating. At the same time the ability to write gratings point-by-point offers the potential for great flexibility in the grating design. There is, however, a requirement for reliability testing of these gratings, particularly for use in telecommunications systems where high powers are increasingly being used in long-haul transmission systems making use of Raman amplification. We report on a study of such gratings which has revealed the presence of broad spectrum power losses. When high powers are used, even at wavelengths far removed from the Bragg condition, these losses produce an increase in the fibre temperature due to absorption in the coating. We have monitored this temperature rise using the wavelength shift in the grating itself. At power levels of a few watts, various temperature increases were experienced ranging from a few degrees up to the point where the buffer completely melts off the fibre at the grating site. Further investigations are currently under way to study the optical loss mechanisms in order to optimise the inscription mechanism and minimise such losses.

Discriminant validity and test-retest reliability of a self-administered Internet-based questionnaire testing doctors' knowledge in evidence-based medicine.

Aims and objectives  This study aimed to determine the discriminant validity and the test-retest reliability of a questionnaire testing the impact of evidence-based medicine (EBM) training on doctors' knowledge and skills. Methods  Questionnaires were sent electronically to all doctors working as residents and chief residents in two French speaking hospital networks in Switzerland. Participants completed the questionnaire twice, within a 4-week interval. The discriminant validity was examined in comparing doctors' performance according to their reported EBM previous training. Proportion of agreement between both sessions of the questionnaire, Cohen's kappa and 'uniform kappa' determined its test-retest reliability. Results  The participation rate was 9.8%/7.1% to first/second session. Performance increased according to the level of doctors' previous training in EBM. The observed proportion of agreement between both sessions was over 70% for 14/19 questions, and the 'uniform kappa' was superior to 0.60 for 15/19 questions. Conclusion  The discriminant validity and test-retest reliability of the questionnaire were satisfying. The low participation rate did not prevent the study from achieving its aims.

Test-retest reliability of thermal quantitative sensory testing on two sites within the L5 dermatome of the lumbar spine and lower extremity.

INTRODUCTION: Quantitative sensory testing (QST) is widely used in human research to investigate the integrity of the sensory function in patients with pain of neuropathic origin, or other causes such as low back pain. Reliability of QST has been evaluated on both sides of the face, hands and feet as well as on the trunk (Th3-L3). In order to apply these tests on other body-parts such as the lower lumbar spine, it is important first to establish reliability on healthy individuals. The aim of this study was to investigate intra-rater reliability of thermal QST in healthy adults, on two sites within the L5 dermatome of the lumbar spine and lower extremity. METHODS: Test-retest reliability of thermal QST was determined at the L5-level of the lumbar spine and in the same dermatome on the lower extremity in 30 healthy persons under 40 years of age. Results were analyzed using descriptive statistics and intraclass correlation coefficient (ICC). Values were compared to normative data, using Z-transformation. RESULTS: Mean intraindividual differences were small for cold and warm detection thresholds but larger for pain thresholds. ICC values showed excellent reliability for warm detection and heat pain threshold, good-to-excellent reliability for cold pain threshold and fair-to-excellent reliability for cold detection threshold. ICC had large ranges of confidence interval (95%). CONCLUSION: In healthy adults, thermal QST on the lumbar spine and lower extremity demonstrated fair-to-excellent test-retest reliability.

Gaze stabilization testing: The efficiency and test-retest reliability of user operated control versus the parameter estimation (PEST) algorithm

The primary objective of this research study is to determine which form of testing, the PEST algorithm or an operator-controlled condition is most accurate and time efficient for administration of the gaze stabilization test

Reliability of the AASHTO temperature shift in material toughness testing /

Includes bibliographical references.

Testing the reliability of a new ultrasonic cardiac output monitor, the USCOM, by using aortic flowprobes in anesthetized dogs

We have used an animal model to test the reliability of a new portable continuous-wave Doppler ultrasonic cardiac output monitor, the USCOM. In six anesthetized dogs, cardiac output was measured with a high-precision transit time ultrasonic flowprobe placed on the ascending aorta. The dogs' cardiac output was increased with a dopamine infusion (0-15 mug (.) kg(-1) (.) min(-1)). Simultaneous flowprobe and USCOM cardiac output measurements were made. Up to 64 pairs of readings were collected from each dog. Data were compared by using the Bland and Altman plot method and Lin's concordance correlation coefficient. A total of 319 sets of paired readings were collected. The mean (+/-SD) cardiac output was 2.62 +/- 1.04 L/min, and readings ranged from 0.79 to 5.73 L/min. The mean bias between the 2 sets of readings was -0.01 L/min, with limits of agreement (95% confidence intervals) of -0.34 to 0.31 L/min. This represents a 13% error. In five of six dogs, there was a high degree of concordance, or agreement, between the 2 methods, with coefficients >0.9. The USCOM provided reliable measurements of cardiac output over a wide range of values. Clinical trials are needed to validate the device in humans.