Printed circuit boards (PCBs) are essential components in various electronic devices, playing a vital role in their functionality. Over time, PCBs have evolved significantly, becoming smaller, more complex, and multi-layered to meet the demands of advancing technology and consumer preferences. The quality of solder paste deposits is measured by circularity, volume, positioning, and the number of satellites. Mycronic is a supplier of jet printing machines for PCB manufacturers and needs to investigate and counteract an unwanted variation in volume and positioning within the first dot of the solder paste strip, and its so-called “sea saw” effect for the following three dots.  This master’s thesis has two aims. The first aim is to develop and evaluate an experimental method to reduce variation between the dots in the strip. The second aim is to reduce the variation between the 1st dot and the following three dots by finding a combination of pre-feed, first, second, and third waveforms to obtain improved precision, volume, circularity, and reduced volume variation. Using an experimental design a full factorial design was used, examining six experimental factors. The design was further augmented with a central composite design to describe the second-order model. The knowledge from the experiment was used to optimize and improve the quality factors of jet printing, which were verified with an additional experiment. The results of the study provided compelling evidence that only the selected experimental factors had a significant impact on improving the volume metric. It was observed that the presence or absence of satellites during the experiment did not have any effect on the results, and neither did the positioning and circularity factors contribute to any improvement or deterioration. Specifically, the most significant difference in volume between 1st and following three dots for the optimized solution is 0.5 nl, and the currently used settings have a difference of 2.65 nl. The experimental approach employed in this master's thesis holds excellent promise for Mycronic, as it paves the way for the future development of piezo-actuation profiles (i.e. specific settings for the jet printer). The potential contributions to the industry are significant, particularly in terms of advancing the methodology for investigating and enhancing the quality metrics of piezo-actuation profiles through experimental means. This research opens up new avenues for Mycronic to refine its printing processes and improve overall print quality, ultimately leading to better outcomes for their customers.

Nowadays it is more clear that the Internet of things (IoT) is not a transient trend but a completely new industry. The internet of things has the capability to enhance current industries (Industry 4.0), as well as to help protecting the environment and people. The latter is the case with the system developed and described in this thesis. The possibilities that IoT brings are due to the interconnection of heterogeneous embedded devices to the internet. This thesis focus on LPWANs (Low Power Wide Area Networks), which is a new set of technologies specifically design for the needs of IoT devices.Due to the recent deploy of NB-IoT (Narrow Band IoT) networks it has become more difficult to know what LPWAN is best for a certain application. Thus, the first half of this thesis involves the comparative study of NB-IoT and LoRaWAN LPWANs. This comparison required an in depth study of each technology, specially on the physical and datalink layers. The comparison briefly displays the main characteristics of each technology and explain the main conclusions in a concise manner. The second part of the thesis describes the development of a GNSS tracker. This tracker will be used on train wagons carrying goods that are dangerous for people and the environment. This thesis report describes the different steps taken, from the requirement specification to the partial development of the software.

The demand of smaller and portable electronic devices has contributed to the realisation of compact embedded systems using PCB miniaturization techniques. The commercial market is faced with competition of handheld users’ devices in medical, communication and automotive industries which are smaller and lighter electronic devices. The possibilities of higher degree of integration in planar technology using cost effective electronic components has lead to different art of design and fabrication of compact units. In this work, a central station and a base station front-end with small form factor have been realized using commercial components on PCBs. These electronic compacts units were integrated in the IF-over-Fiber system architecture. The IF-over-Fiber architecture comprised of miniaturized electronic components for quadrature modulation and upconversion. The central station supports multi-Gbps data rate modulation formats in order to increase the spectral efficiency of the transmitted information. Multilevel modulation formats are considered spectrally efficient and can double the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all. The BS front-end comprises of the 60 GHz upconverter and a 60 GHz planar 2×2 microstrip antenna. The 10 GHz IF carrier allows an optical transmission with higher spectral efficiency in optical domain, as well as it is less susceptible to dispersion induced power fading inherent in optical fiber. Characterization of the designed central station and base station front-end through measurements are presented and discussed. The IF-over-Fiber system analysis is made for the 2 Gbps QPSK transmission with respect to error vector magnitude (EVM), eye and constellation diagrams.

In the intricate domain of Printed Circuit Boards (PCBs), object detection poses unique challenges, particularly given the broad size spectrum of components, ranging from a mere 2 pixels to several thousand pixels within a single high-resolution image, often averaging 4000x3000 pixels. Such resolutions are atypical in the realm of deep learning for computer vision, making the task even more demanding. Further complexities arise from the significant intra-class variability and minimal inter-class differences for certain component classes. In this master thesis, we rigorously evaluated the performance of a CNN-based object detection framework (FCOS) and a transformer model (DETR) for the task. Additionally, by integrating the novel foundational model from Meta, named ”Segment Anything,” we advanced the pipeline to include instance segmentation. The resultant model is proficient in detecting and segmenting component instances on PCB images, achieving an F1 score of 81% and 82% for the primary component classes of resistors and capacitors, respectively. Overall, when aggregated over 18 component classes, the model attains a commendable F1 score of 74%. This study not only underscores the potential of advanced deep learning techniques in PCB analysis but also paves the way for future endeavors in this interdisciplinary convergence of electronics and computer vision / I det komplicerade området med kretskort (PCB) innebär objektdetektering unika utmaningar, särskilt med tanke på det breda storleksspektrumet av komponenter, från bara 2 pixlar till flera tusen pixlar i en enda högupplöst bild, ofta i genomsnitt 4000x3000 pixlar. Sådana upplösningar är atypiska när det gäller djupinlärning för datorseende, vilket gör uppgiften ännu mer krävande. Ytterligare komplexitet uppstår från den betydande variationen inom klassen och minimala skillnader mellan klasserna för vissa komponentklasser. I denna masteruppsats utvärderade vi noggrant prestandan hos ett CNNbaserat ramverk för objektdetektering (FCOS) och en transformatormodell (DETR) för uppgiften. Genom att integrera den nya grundmodellen från Meta, med namnet ”Segment Anything”, utvecklade vi dessutom pipelinen för att inkludera instanssegmentering. Den resulterande modellen är skicklig på att upptäcka och segmentera komponentinstanser på PCB-bilder och uppnår en F1-poäng på 81% och 82% för de primära komponentklasserna resistorer respektive kondensatorer. När modellen aggregeras över 18 komponentklasser uppnår den en F1-poäng på 74%. Denna studie understryker inte bara potentialen hos avancerade djupinlärningstekniker vid PCB-analys utan banar också väg för framtida insatser inom denna tvärvetenskapliga konvergens av elektronik och datorseende.

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This report describes the design and implementation of a prototype for an amplitude modulated laser rangefinder, which is made on a PCB consisting of a laser module emitting light, a photodiode receiving the light reflected from the target, and other components. The design is made for the different power levels, generation of the modulation output and the reception of the signal. The sinusoidal wave is generated with an oscillator circuit and filtered out to produce a pure sine signal. The system requires different voltage levels and current values, which is done with DC-DC converters. Finally, a receiver circuit is implemented to detect the modulation, which needs a device that transfers light energy into voltage. Many tests have been made to optimize the analog circuit for a stable output. The prototype was created as a PCB design with a laser module and a photodiode mounted on it. In the end, satisfactory results were obtained up to the receiving part, however, the prototype was tested with an external circuit for light detection. There is considerable room for improvement, e.g., signal sampling, working receiver and use of standard voltage levels, but this thesis intends to provide a basis for future work.

The design of series-loaded resonant converters using the state of the art SiC power transistorsis investigated in the thesis. SiC devices are chosen as they offer lower switching losses comparedto conventional Si based devices A very detailed study about the working and differentmodes of operation of the resonant converter is carried out. The thesis further explains how thehigh speed switching capabilities of the SiC devices remain untapped owing to the presence ofstray inductances in the switch-snubber layout. A comparison of all the commercially availableSiC devices are carried out to find the most suitable switch for the resonant converter. Thethesis also carries out a very detailed step by step design of the circuit and the PCB layout forthe resonant converter. Two different layouts are proposed and then compared for their strayinductance and power losses. Finally, based on the experiments the thesis validates the suitabilityof using discrete SiC power transistors in place of power modules. / Utformningen av serie-belastade resonansomvandlare med hjälp av toppmoderna SiC högeffekttransistorernaundersöks i denna avhandlingen. SiC-enheter väljs eftersom de erbjuderlägre switch-förluster jämfört med konventionella Si-baserade enheter.En mycket detaljeradstudie om funktionen och de olika operationella tillstånden hos resonansomvandlare utförs.Avhandlingen förklarar vidare hur förmågan till högfrekvent switchning hos SiC-enheterförblir ofullständigt utnyttjad på grund av förekomsten av ströinduktanser i switch-snubberlayouten.En jämförelse av alla kommersiellt tillgängliga SiC-enheter genomförs för att hittaden mest lämpliga switchen för resonansomvandlaren. Avhandlingen utförs också en mycketdetaljerad steg-för-steg-utformning av resonansomvandlaren kretsschema och kretskortlayout.Två olika layouter föreslås och jämförs därefter utifrån deras ströinduktanser ocheffektförluster. Slutligen, baserat på experimentella resultat bekräftar avhandlingen.Lämpligheten att använda diskreta SiC-effekttransistorer istället för effektmoduler medintegrerade drivarsteg för styrelektroderna.

This paper describes the design, fabrication, and testing of a 1.2 kV, 6.5 mΩ, half-bridge, SiC MOSFET power module to evaluate the impact of parametric device tolerances on electrical and thermal performance. Paralleling power devices increases current handling capability for the same bus voltage. However, inherent parametric differences among dies leads to unbalanced current sharing causing overstress and overheating. In this design, a symmetrical DBC layout is utilized to balance parasitic inductances in the current pathways of paralleled dies to isolate the impact of parametric tolerances. In addition, the paper investigates the benefits of flexible PCB in place of wire bonds for the gate loop interconnection to reduce and minimize the gate loop inductance. The balanced modules have dies with similar threshold voltages while the unbalanced modules have dies with unbalanced threshold voltages to force unbalanced current sharing. The modules were placed into a clamped inductive DPT and a continuous, boost converter. Rogowski coils looped under the wire bonds of the bottom switch dies to observe current behavior. Four modules performed continuously for least 10 minutes at 200 V, 37.6 A input, at 30 kHz with 50% duty cycle. The modules could not perform for multiple minutes at 250 V with 47.7 A (23 A/die). The energy loss differential for a ~17% difference in threshold voltage ranged from 4.52% (~10 µJ) to -30.9% (~30 µJ). The energy loss differential for a ~0.5% difference in V_th ranged from -2.26% (~8 µJ) to 5.66% (~10 µJ). The loss differential was dependent on whether current unbalance due to on-state resistance compensated current unbalance due to threshold voltage. While device parametric tolerances are inherent, if the higher threshold voltage devices can be paired with devices that have higher on-state resistance, the overall loss differential may perform similarly to well-matched dies. Lastly, the most consistently performing unbalanced module with 17.7% difference in V_th had 119.9 µJ more energy loss and was 22.2°C hotter during continuous testing than the most consistently performing balanced module with 0.6% difference inV_th. / Master of Science / This paper describes the design, construction, and testing of advanced power devices for use in electric vehicles. Power devices are necessary to supply electricity to different parts of the vehicle; for example, energy is stored in a battery as direct current (DC) power, but the motor requires alternating current (AC) power. Therefore, power electronics can alter the energy to be delivered as DC or AC. In order to carry more power, multiple devices can be used together just as 10 people can carry more weight than 1 person. However, because the devices are not perfect, there can be slight differences in the performance of one device to another. One device may have to carry more current than another device which could cause failure earlier than intended. In this research project, multiple power devices were placed into a package, or "module." In a control module, the devices were selected with similar properties to one another. In an experimental module, the devices were selected with properties very different from one another. It was determined that the when the devices were 17.7% difference, there was 119.9 µJ more energy loss and it was 22.2°C hotter than when the difference was only 0.6%. However, the severity of the difference was dependent on how multiple device characteristics interacted with one another. It may be possible to compensate some of the impact of device differences in one characteristic with opposing differences in another device characteristic.