This paper describes work related to the “Miniature Student Satellite” (MIST) project and the ”SiC in Space” project, located at KTH, Stockholm, Sweden. The goal of the MIST project is to launch KTH’s first student satellite into space, carrying multiple scientific experiments where SiC in Space is included. This thesis contains a compilation of three MIST-related bachelor theses that were carried out at KTH in the spring of 2016, primarily consisting of constructing and testing circuits for power supply and measurements for the SiC in Space part of the satellite. A printed circuit board has been developed, which accommodates experiment circuits to evaluate the features and functionality of silicon carbide components in a space environment, and power the supply to the SiC in Space and the Piezo LEGS projects. The development includes designing, assembling and testing the PCB according to the MIST team’s demands and requirements. Emphasis has been laid on electrical safety to ensure that the design can not short circuit the satellite battery, as well as EMC considerations to minimize the EMI between different parts of the satellite. Final testing of the hardware has not been executed due to an ordering error and time shortage, wherefore the planned test protocol has been included for future work. / Denna kandidatuppsats beskriver arbete relaterat till “Miniature Student Satellite” (MIST)-, samt SiC in Space-projekten, vid KTH, Stockholm, Sverige. MIST-projektets mål är att skicka KTH:s första studentsatellit till rymden, där SiC in Space är ett av flera medföljande vetenskapliga experiment. Detta projekt sammanställer tre examensarbeten relaterade till MIST som genomfördes vid KTH under våren 2016, huvudsakligen bestående av att konstruera och testa kretsar för strömförsörjning samt mätningar för SiC in Space-delen av satelliten. Ett kretskort som innehåller experimentkretsar för att utvärdera egenskaper och funktionalitet för komponenter av materialet kiselkarbid i en rymdmiljö, samt strömförsörjningskretsar till SiC in Space- och Piezo LEGS-projekten har utvecklats. Utvecklingen omfattar design, montering and testning av kretskortet enligt MIST-gruppens krav. Tonvikt har lagts på elsäkerhet för att säkerställa att designen inte kan kortsluta satellitens batteri, såväl som EMC för att minimera EMI mellan olika delar av satelliten. Slutgiltig testning av hårdvaran har ej kunnat genomföras på grund av tidsbrist beroende på ett beställningsfel. Därför har det planerade testprotokollet inkluderats för framtida arbete.

Energy Harvesting, also known as power harvesting or ambient power, is the process of obtaining small amounts of power from secondary sources, such as vibrations, light, temperature variations and even radio-frequency emissions. These systems have been uncommon in personal and wearable electronics in the past, however they are slowly gaining traction. With the increasing sophistication of prosthetic limbs and implants, devices that in some cases require a consistent and reliable power source, the potential field of application for energy harvesting grows wider. This thesis project evaluates whether energy harvesting methods could be implemented in future prosthetic limb designs without significantly affecting weight, user comfort, complexity of design etc., and whether the gains of such an implementation would be worth the effort and cost put into it. For reference the project used the RHEO KNEE® by Össur Hf., a microcontroller controlled prosthetic knee, as a device that such a system could be integrated with. Energy harvesting is still an emerging field and is a long time away from being a viable primary power source for most electronic devices. However, it still might have potential as a supplementary source for extending charge cycles or making smaller (and therefore more lightweight) power cells viable. This master’s thesis project was broad in scope and included 3D-design; mechanical, electrical and embedded software design; and setting up a miniature kinetic power generator as well as a photovoltaic harvesting system. No amputees were available for testing the designs so the system was tested with a 3D-printed model that was moved by hand to simulate the generation process. Due to some incorrect inital assumptions, the final electronic design was not optimal for this kind of system. However, a kinetic generator that harvested power from a modeled heel striking the ground 50 times a minute produced about 23mW of power. 53cm2 of photovoltaic panels produced 42μW of power in an ambient light setting. For comparison, a low-power microcontroller needed about 119μW of power on average to do some simple processing and send Bluetooth transmissions once every two seconds. / Energiinsamling (e. Energy Harvesting), är processen för att erhålla små mängder kraft från sekundära källor, såsom vibrationer, ljus, temperaturvariationer och utstrålning i radiofrekvens. Dessa system har varit ovanliga i hemelektronik och bärbar teknik, men de vinner sakta dragkraft. Med den ökande förfining av proteser och implantat, som i vissa fall kräver en jämn och pålitlig strömkälla, växer det potentiella användningsområdet för energiinsamling. Detta examensarbete utvärderar huruvida energiinsamlingsmetoder skulle kunna implementeras i framtida proteskonstruktioner utan att nämnvärt påverka vikt, användarkomfort, komplexitet i design etc., och om vinsterna med en sådan implementering skulle vara värd ansträngningen och kostnaden. Som exempel använde detta projekt en datoriserad knäprotes av Össur HF, RHEO KNEE®, som exempel på ett system som energiinsamling skulle kunna integreras med. Energiinsamling är fortfarande ett växande forskningsområde och är långt ifrån att en strömkälla för det mesta elektronik.. Det kan ändå ha potential som en kompletterande strömkälla som kan förlänga laddningscykler eller göra mindre (och därför lättare) batterier möjliga. Detta examensarbete var brett i omfattning och inkluderade 3D-design; mekanisk-, elektrisk- och mjukvara-design; och inrättning av en kinetisk kraftgenerator i miniatyr samt ett ljusdrivet energiinsamlingssystem. Inga amputerade var tillgängliga för att testa designen, därför så testades systemet med en 3D-printad modell som rördes för hand för att simulera strömförsörjelseprocessen. På grund av några felaktiga initiala antaganden var den slutliga elektroniska designen inte optimal för denna typ av system. Ändå lyckades en kinetisk generator som använde energiinsamlingsprinciper producera cirka 23mW ström genom en simulerad häl som träffade marken cirka 50 gånger i minuten. 53cm2 solcellspaneler producerade 42μW energi i en ljussatt miljö. Som jämförelse behövde en strömsnål styrkrets i genomsnitt cirka 119μW effekt för att genomföra enkla programprocesser och skicka Bluetooth-överföringar en gång varannan sekund. / Hliðarorkuöflun (e. energy harvesting), sem einnig bætti kalla umhverfisöflun, er ferlið við að fá lítið magn af orku frá óbeinum aflgjafa, svo sem frá hristingi, ljósi, hitabreytingum og jafnvel útvarpsbylgjum. Þessi kerfi hafa verið sjaldgæf í raftækjum hingað til, þó þau eru hægt og rólega að fá hlutdeild. Með nýrri og fágaðri gervilimum og ígræðslum, tæki sem í sumum tilvikum þurfa samfellda og áreiðanlega orkjugjafa, víkkar mögulegt notkunarsvið hliðarorkuöflunar. Þetta lokaverkefni metur hvort aðferðir við hliðarorkuöflun gætu verið notaðar í hönnun gervilima framtíðarinnar án þess að hafa neikvæð áhrif á þyngd, þægilegheit, flóknun hönnunar o.þ.h., og hvort hagur sé í samræmi við framlag og kostnað. Þetta verkefni notar RHEO KNEE® frá Össuri Hf. sem viðmið, sem er gervihné stjórnað af örtölvu. Viðmiðinu er ætlað að sýna notagildi kerfisins. Hliðarorkuöflun er ennþá svið í þróun og er nokkuð í að það geti orðið frumorkugjafi fyrir flest raftæki. Hins vegar þá gæti það enn átt möguleika á að vera aukaorkugjafi til að auka tímalengd hverrar hleðslu eða gera minni og léttari rafhlöður raunhæfari. Þetta meistaraverkefni var viðamikið að því leiti að það fól í sér þrívíddarhönnun; vél-, raf- og hugbúnaðarhönnun; og uppsetningu á hreyfirafal ásamt ljósorkuöflunarkerfi. Engir einstaklingar sem misst hafa fót voru til staðar til að prófa hannanir þessa verkefnis. Þ.a.l. voru þær prófaðar með þrívíddarprentuðum líkönum sem hreyfð voru með handafli til að líkja eftir orkuframleiðsluferlinu. Vegna rangrar upprunalegrar forsendu þá var endanleg rafhönnunin ekki ákjósanleg fyrir slíkt kerfi. Hreyfirafall tengdur við gervihæl sem sló jörðu 50 sinnum á mínútu framleiddi þó 23mW af orku. 53cm2 af ljósorkueiningum framleiddu 42μW af afli í meðal herbergisbirtu. Til samanburðar þá eyðir skilvirk örtölva u.þ.b. 119μW af afli í einfaldri tölvuvinnslu ásamt því að senda Bluetooth sendingu á tveggja sekúnda fresti.

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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The field of neuromorphic computing concerns simulating the information processing of a brain in software or hardware on a computing platform. One neuromorphic platform that uses specialized hardware is SpiNNaker. It is an integrated circuit consisting of multiple general purpose processing cores that can run simulations of neurons. A custom on-chip network mimics the high level of neuron interconnectedness in a brain. The second generation of this chip is currently in development and a prototype, JiB 2, is used in this thesis. This chip has a Ball Grid Array (BGA) footprint and requires several supply voltage levels to operate making implementation more complex. To use such a chip in an autonomous robot, the hardware needs to be in a small form factor. It is beneficial to use an intermediary platform with support for many actuators and sensors to avoid having to develop new drivers (and because the processing power of individual blocks in JiB 2 is not well suited to these tasks). This thesis shows how a platform for autonomous use in robots can be designed with the current prototype chip. It details the design decisions made for the power supply and using the footprint. The existing software is explained and modifications made are shown. Some performance metrics (memory requirements, power and cost) are characterized. A simple program running on the prototype chip with input and output from a microcontroller development board using STM32 is demonstrated. This project suggests a path to deploy software on the JiB 2 and let it interact with the physical world. / Att i en dator eller speciell hårdvara simulera hur neuroner i en hjärna interagerar i sitt informationsutbyte studeras inom fältet neouromorfisk databehandling. Eftersom utbytet sker med snabba länkar mellan många oberoende enheter är traditionell datorhårdvara inte lämpad att implementera sådana skeenden. Därför finns specialhårdvara som bättre efterlikar detta utbyte genom att, till exempel, använda många enkla processorkärnor (för att simulera neuroner) tillsammans med ett snabbt nätverk på kretsen (och mellan flera kretsar). Ett användningsområde är i större komplexa system men det finns en efterfrågan att kunna använda den även i mer begränsade kontexter. En sådan specialhårdvara är den integrerade kretsen SpiNNaker (Spiking Neural Network Architecture). En andra generationen av den kretsen är under utveckling och projektet i denna uppsats har arbetat med en begränsad prototyp kallad JiB2. Målet har varit att bygga en plattform som visar hur JiB 2 kan utnyttjas fristående i en robot. Detta kräver hårdvara som är möjlig att enkelt ladda med nya program. Den behöver klara att strömförsörja kretsen från exempelvis ett batteri. Den ska också ha möjlighet att koppla in- och utsignaler till programmet som körs i specialkretsen. Detta arbete visar att hårdvara går att tillverka i en storlek som lämpar sig för använding i robotar. Ett flöde för utveckling och drifttagning av programvara till plattformen demonstreras.

En struktur analys på Ericssons MINILINK-6352 har utförts för att undersöka spänningar och deformationer på enheten, främst med fokus på de termiska gränskiktsmaterialen och buktningar av kretskortet. Dessa är viktiga aspekter när man överväger om enheten är termiska lämpad ur en mekanisk synvinkel, där god ytkontakt mellan de olika kropparna är avgörande för ordentlig kylning genom värmeledning. Analysen kräver tillräcklig materialdata till gränskiktsmaterialen och kretskortet för att kunna skapa lämpliga matematiska modeller. Enaxliga kompressionstester har genomförts för att karakterisera de hyperelastiska och viskoelastiska lagar för fyllda silikongummimaterial som används som termiska gränskiktsmaterial, som ibland kallas för gappad. Böjning av ett kretskort simulerades och jämfördes med ett tre--punkts böjtest för att verifiera om befintlig materialdata i beräkningsprogrammen var tillräcklig, jämförelsen visade god överensstämmelse. Kretskortet med dess komponenter, som modellerades som styva block, med gappads ovanpå som komprimeras av en platta simulerades och ett svagt område hittades. Detta område var sedan tidigare känt och har i ett senare skede eliminerats genom att tillsätta ytterligare en stödpelare. Därav visar denna studie en metod för att hitta intressanta regioner tidigt i konstruktionsfasen som lätt kan ändras för att uppfylla nödvändiga krav och undvika brister i konstruktionen. Arbetet har visat sig användbart genom att hitta detta svaga område i exempel produkten, arbetet ger även tillräckligt med information och exempeldata för att ytterligare utreda liknande produkter. Kombinationen av erfarenhet och simulering möjliggör smartare designval. / A structural analysis on Ericssons MINILINK-6352 has been performed in order to investigate stresses and deformations of the unit, mainly focusing on the thermal interface materials and warpage of the printed circuit boards. These are important aspects when considering if the unit is thermally adequate from a mechanical point of view, where good surface contact between various bodies are critical for proper cooling through heat conductivity. The analysis requires sufficient materal data for the interface material and the circuit board in order to create suitable mathematical models. Uniaxial compression tests have been conducted to characterise the hyperelastic and viscoelastic constitutive laws of a filled silicone rubber material used as a thermal interface material, commonly referred to as a thermal pad. Bending of a printed circuit board was simulated and compared to a three-point bend test on the circuit board in order to verify material data already available in the computational software, which showed good agreement. The entire radio unit was mechanically analysed during its sealing process. The circuit board with attached components modelled as stiff blocks with thermal pads on top compressed by plates was simulated and a weak area was found. This area in question was already known and has in a later stage been eliminated by adding an additional supporting pillar. Hence this study shows a methodology to find regions of interest at an early design phase which can easily be altered to fulfil necessary requirements and eliminate design flaws. This work has proven useful in finding weak regions in the example product, it also provides enough information and example data to further investigate similar products. The combination of experience and simulation allows for smarter design choices.

Trend towards downsizing the product size and at the same time to bring more functionality in electronic products, demands electrically interconnecting several miniaturized electronic components with high counts of I\Os (Input/Out put) on smaller and smaller size printed wiring boards [PWB]. These miniature components occupy lower foot print area but require higher routing interconnection densities. However, the conventional multilayer board technologies exhibit limitations when there is need to connect very high I\O components such as ball grid arrays, which require blind and buried interconnections within the multilayer mono-block. This limitation has given raise to newer methods of multi layer construction. Build–up multilayer PWB is now the technology of choice for enhanced routing capability including blind and buried interlayer connections. Build up methods are based on making very small vias within dielectric layers followed by metalisation. Typically blind and buried vias are very small, and hence called “micro vias” connecting the layers selectively within the multilayer mono-block. Buried vias make the interconnection between the consecutive layers, and blind vias connect the surface layers to any one of the interior layers in the build up multilayer board. If the blind vias are filled with a dielectric, the entire top and bottom surface area becomes available for high -density component mounting. The crux in build up board technologies is the method of creating micro-holes; a micro hole is a hole, which is less than 150 micro meter in diameter. Efforts are made to replace existing metalising techniques with “paste filling” methodologies, which would result in “SOLID CONDUCTING VIAS” CALLED AS “MICRO -INTERCONNECTS” The work reported in this thesis aims at demonstrating one such innovative ‘solid conducting via’ formation without using any of the known micro-hole formation techniques. Based on the results obtained some useful conclusions have been drawn which will perhaps go a long way in the name of “PRINTED PILLAR TECHNOLOGY” a novel methodology for building multilayer suitable for very high I\O components such as “ball grid arrays.”

Double cantilever beam (DCB) specimens with distinct intermetallic microstructures and different geometries were fractured under different mode ratios of loading, ψ, to obtain critical strain energy release rate, Jc. The strain energy release rate at crack initiation, Jci, increased with phase angle, ψ, but remained unaffected by the joint geometry. However, the steady-state energy release rate, Jcs, increased with the solder layer thickness. Also, both the Jci and Jcs decreased with the thickness of the intermetallic compound layer. Next, mode I and mixed-mode fracture tests were performed on discrete (l=2 mm and l=5 mm) solder joints arranged in a linear array between two copper bars to evaluate the J = Jci (ψ) failure criteria using finite element analysis. Failure loads of both the discrete joints and the joints in commercial electronic assemblies were predicted reasonably well using the Jci from the continuous DCBs. In addition, the mode-I fracture of the discrete joints was simulated with a cohesive zone model which predicted reasonably well not only the fracture loads but also the overall load-displacement behavior of the specimen. Additionally, the Jci calculated from FEA were verified estimated from measured crack opening displacements in both the continuous and discrete joints. Finally, the pad-crater fracture mode of solder joints was characterized in terms of the Jci measured at various mode ratios, ψ. Specimens were prepared from lead-free chip scale package-PCB assemblies and fractured at low and high loading rates in various bending configurations to generate a range of mode ratios. The specimens tested at low loading rates all failed by pad cratering, while the ones tested at higher loading rates fractured in the brittle intermetallic layer of the solder. The Jci of pad cratering increased with the phase angle, ψ, but was independent of surface finish and reflow profile. The generality of the J =Jci(ψ) failure criterion to predict pad cratering fracture was then demonstrated by predicting the fracture loads of single lap-shear specimens made from the same assemblies.

Double cantilever beam (DCB) specimens with distinct intermetallic microstructures and different geometries were fractured under different mode ratios of loading, ψ, to obtain critical strain energy release rate, Jc. The strain energy release rate at crack initiation, Jci, increased with phase angle, ψ, but remained unaffected by the joint geometry. However, the steady-state energy release rate, Jcs, increased with the solder layer thickness. Also, both the Jci and Jcs decreased with the thickness of the intermetallic compound layer. Next, mode I and mixed-mode fracture tests were performed on discrete (l=2 mm and l=5 mm) solder joints arranged in a linear array between two copper bars to evaluate the J = Jci (ψ) failure criteria using finite element analysis. Failure loads of both the discrete joints and the joints in commercial electronic assemblies were predicted reasonably well using the Jci from the continuous DCBs. In addition, the mode-I fracture of the discrete joints was simulated with a cohesive zone model which predicted reasonably well not only the fracture loads but also the overall load-displacement behavior of the specimen. Additionally, the Jci calculated from FEA were verified estimated from measured crack opening displacements in both the continuous and discrete joints. Finally, the pad-crater fracture mode of solder joints was characterized in terms of the Jci measured at various mode ratios, ψ. Specimens were prepared from lead-free chip scale package-PCB assemblies and fractured at low and high loading rates in various bending configurations to generate a range of mode ratios. The specimens tested at low loading rates all failed by pad cratering, while the ones tested at higher loading rates fractured in the brittle intermetallic layer of the solder. The Jci of pad cratering increased with the phase angle, ψ, but was independent of surface finish and reflow profile. The generality of the J =Jci(ψ) failure criterion to predict pad cratering fracture was then demonstrated by predicting the fracture loads of single lap-shear specimens made from the same assemblies.

This thesis deals with design of a laser position detector. Different types of sensor are mentioned and compared at the beginning. Special attention is paid to quadrant sensor. Its pros and cons are discussed with designing methods. The sensor is simulated in Matlab to test its output response. Then the laboratory tests follow to meassure real response of the chip. Then follows the design of the detector based on measured and simulated data. In the conclusion of this thesis parameters of created device are evaluated.