Electrically conductive adhesives (ECA) are an alternative to tin/lead solders for attaching Surface Mount Devices (SMD) in electronic assemblies. ECAs are mixtures of a polymer binder (for adhesion) and conductive filler (for electrical conductivity). They bring more conductivity, higher strength, less weight and longer durability than metal alloys. ECAs can offer numerous advantages such as fewer processing steps, lower processing temperature and fine pitch capability. Multi walled carbon nanotubes (MWCNT) were used as conductive fillers in this research because of their novel electronic and mechanical properties. The high aspect ratio of the nanotubes makes it possible to percolate at low loadings to obtain good electrical and mechanical properties. Replacing the metal filler with CNTs in the adhesive made the ECA light weight, corrosion resistant, reduced processing temperature, lead free, electrically conductive and high mechanical strength. The MWCNTs at different loadings were mixed with epoxy and epoxy: heloxy to form a composite mixture. Different loadings, additives and mixing methods were used to obtain good electrical and mechanical properties and pot life. Pressure dispensing, screen and stencil printing were the processing techniques used for making the samples. The volume resistivity, contact resistance, die shear and lap shear tests were conducted on different surface finished Printed Circuit Boards (PCB) like silver, tin and Electro less Nickel Immersion Gold (ENIG). The results are summarized and compared with traditional methods.

In the past decade, the design and manufacturing of intelligent multipurpose underwater vehicles has increased significantly. In the wide range of studies conducted in this field, the flexibility and autonomy of these devices with respect to their intended performance had been widely investigated. This work is related to the design and manufacturing of a small and lightweight autonomous underwater vehicle (AUV) with vision capabilities allowing detecting and contouring obstacles. It is indeed an exciting challenge to build a small and light submarine AUV, while making tradeoffs between performance and minimum available space as well as energy consumption. In fact, due to the ever-increasing in equipment complexity and performance, designers of AUVs are facing the issues of limited size and energy consumption. By using a pair of thrusters capable to rotate 360o on their axis and implementing a mass shifter with a control loop inside the vehicle, this later can efficiently adapt its depth and direction with minimal energy consumption. A prototype was fabricated and successfully tested in real operating conditions (in both pool and ocean). It includes the design and embedding of accurate custom multi-purpose sensors for multi-task operation as well as an enhanced coordinated system between a high-speed processor and accustomed electrical/mechanical parts of the vehicle, to allow automatic controlling its movements. Furthermore, an efficient tracking system was implemented to automatically detect and bypass obstacles. Then, fuzzy-based controllers were coupled to the main AUV processor system to provide the best commands to safely get around obstacles with minimum energy consumption. The fabricated prototype was able to work for a period of three hours with object tracking options and five hours in a safe environment, at a speed of 0.6 m/s at a depth of 8 m.

Data de aprova??o ausente. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-03-29T18:49:58Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wagner_barbosa_souza.pdf: 2617971 bytes, checksum: 3d7e6b01cafdb0a61d93af504071663c (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-04-24T16:36:52Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wagner_barbosa_souza.pdf: 2617971 bytes, checksum: 3d7e6b01cafdb0a61d93af504071663c (MD5) / Made available in DSpace on 2017-04-24T16:36:52Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wagner_barbosa_souza.pdf: 2617971 bytes, checksum: 3d7e6b01cafdb0a61d93af504071663c (MD5) Previous issue date: 2016 / Com o avan?o exponencial da ind?stria de eletr?nicos, o consumo destes produtos tamb?m est? crescendo largamente. Com isso, os descartes destes equipamentos tamb?m crescem na mesma propor??o. Por ano, no mundo, estima-se que mais de 25 milh?es de toneladas de lixo eletr?nico sejam descartadas. Neste trabalho foi desenvolvido um novo m?todo hidrometal?rgico ambientalmente seguro para a extra??o seletiva de cobre, n?quel e prata provenientes de res?duos de placas de circuito impresso (PCI), empregando Sistemas Aquosos Bif?sicos (SAB) como t?cnica de extra??o. O comportamento de extra??o dos ?ons met?licos Cu (II), Ni(II), Fe(III) e Ag(I)em SAB formado por copol?mero tribloco L64 + MgSO4 + H2O foi avaliado para a otimiza??o do m?todo, verificando a influ?ncia dos seguintes par?metros experimentais sobre a extra??o dos analitos: valores de pH do SAB (3,0; 6,0; 9,0 e 11,0); natureza e concentra??o dos agentes extratores 1-(2-piridil-azo)-2-naftol (PAN) para os estudo de extra??o do Cu(II), 1-nitroso-2-naftol (1N2N) e dimetilglioxima (DMG) para a extra??o do ?on Ni(II), tiocianato (SCN) e ditizona (Dz) para a extra??o da Ag(I). A efici?ncia de recupera??o seletiva dos metais foi avaliada por meio da an?lise da porcentagem de extra??o (%E) e do fator de separa??o (S) entre os ?ons de interesse. As melhores condi??es para extra??o seletiva foram: PAN [3,5 mmol.Kg-1] em pH = 6,0 em 6 etapas consecutivas para separa??o do Cu(II), DMG [5,00 mmol.Kg-1] em pH = 9,0 para o Ni(II) e SCN[5,20 mmol.Kg-1] em pH = 9,0 para a Ag(I) . Em todas as situa??es foram obtidos valores de fator de separa??o(S) entre o analito e os concomitantes met?licos maiores que 103. As condi??es ?timas obtidas foram aplicadas ao lixiviado de PCI para a extra??o de cobre, n?quel e prata de forma sequencial, obtendo-se altos valores de S entre o analito e os concomitantes met?licos (SCu,Ni= 1,46 x 103, SCu,Fe= 1,55 x 104, SCu,Ag= 1,59 x 104, SNi,Fe= 3,27 x 104, SNi,Ag= 3,47 x 104 eSAg,Fe= 4,80 x 103).Ap?s a extra??o de cada metal foi realizado um estudo de stripping em uma ?nica etapa, onde 89,5%, 92,5% e 82,5% de Cu(II), Ni(II) e Ag(I), respectivamente foram disponibilizados para a etapa de eletrodeposi??o. Portanto o m?todo utilizando SAB se mostrou eficiente e dentro dos princ?pios da qu?mica verde, pois utiliza componentes at?xicos, biodegrad?veis e recicl?veis e de r?pida separa??o de fases sem a forma??o de emuls?es est?veis. Sendo um m?todo alternativo para a extra??o liquido ? liquido tradicional. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, [2016]. / With the exponential advancement of electronic industry, the consumption of these products is also growing wide. With this, the drops of this equipment also grow at the same rate. A year in the world, it is estimated that more than 25 million tons of electronic waste are disposed.This work developed a new environmentally safe hydrometallurgical method for the selective extraction of copper, nickel and silver from waste printed circuit board (PCB) using Aqueous Two-Phase Systems (SAB) as extraction technique. The extraction behavior of metal ions Cu (II), Ni (II), Fe (III) and Ag (I) SAB formed by tri-block copolymer L64 + MgSO4 + H2O was evaluated for the optimization of the method by checking the influence of the following experimental parameters on the extraction of analytes: the SAB pH (3.0, 6.0, 9.0 and 11.0); nature and concentration of agents extractors 1- (2-pyridyl-azo) -2-naphthol (PAN) Cu for the extraction method (II), the 1-nitroso-2-naphthol (1N2N) and dimethylglyoxime (DMG) for ion extraction Ni (II), thiocyanate (SCN) and dithizone (Dz) for the extraction of Ag (I).The selective metal recovery efficiency was evaluated by the percentage extraction analysis (% E) and separation factor (S) between the ions of interest. The best conditions for selective extractions were NAP [3,5 mmol.Kg-1] at pH 6.0 in 6 consecutive stages for separation of Cu (II) DMG [5.00 mmol.Kg-1] pH = 9.0 for Ni (II) and SCN [5,20 mmol.Kg-1] at pH = 9.0 for Ag (I). In all cases they were obtained separation factor values (S) between the analyte and the larger metal Concomitant 103. The obtained optimum conditions were applied to the PCI leached copper extraction, nickel and silver sequentially, yielding if high S values between the analyte and the metal concomitant (SCU, Ni = 1.46 x 103, SCU, Fe = 1.55 x 104, SCU, Ag = 1.59 x 104, SNI, Fe = 3.27 x 104, SNI, Ag = 3.47 x 104 and SAg, Fe = 4.80 x 103).After extraction of each metal it was made a study stripping in one step, where 89.5%, 92.5% and 82.5% Cu (II), Ni (II) and Ag (I), respectively, were available for the electroplating step. Therefore, the method using BSA was efficient and within the principles of green chemistry, because it uses non-toxic, biodegradable and recyclable and fast phase separation without the formation of stable emulsions components. As an alternative method for liquid - liquid extraction traditional.

Submitted by André Bianchi Laraia (andreblaraia@yahoo.com.br) on 2018-08-29T22:49:26Z No. of bitstreams: 1 Dissertacao-Andre-Bianchi-Laraia.pdf: 2142300 bytes, checksum: 9264414d38ac4ce5ec3be46acb98ca44 (MD5) / Rejected by Pamella Benevides Gonçalves null (pamella@feg.unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: • Necessário fazer ajuste no sumario na lateral direita nas numerações. • A palavra APÊNDICE A deve ser centralizada A palavra APÊNDICE A deve ser centralizada • Referências. A palavra Referências deve ser centralizada, As referencias devem ser justificadas, espaço simples com um espaço simples(enter) entre elas. • Sobre a elaboração das referencias e citações favor solicitar orientação para ajuste com a bibliotecária Pâmella - pamella.benevides@unesp.br • A palavra APÊNDICE A deve ser centralizada Mais informações acesse o link: http://www2.feg.unesp.br/Home/Biblioteca21/diretrizes-2016.pdf Agradecemos a compreensão. on 2018-08-30T12:07:55Z (GMT) / Submitted by André Bianchi Laraia (andreblaraia@yahoo.com.br) on 2018-09-12T01:58:28Z No. of bitstreams: 1 Tese-Andre-Bianchi-Laraia-v20-converted.pdf: 2144718 bytes, checksum: eef37a1c04c8a387ddbff2e31f67db35 (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-09-12T17:38:03Z (GMT) No. of bitstreams: 1 laraia_ab_me_guara.pdf: 2144718 bytes, checksum: eef37a1c04c8a387ddbff2e31f67db35 (MD5) / Made available in DSpace on 2018-09-12T17:38:03Z (GMT). No. of bitstreams: 1 laraia_ab_me_guara.pdf: 2144718 bytes, checksum: eef37a1c04c8a387ddbff2e31f67db35 (MD5) Previous issue date: 2018-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho apresenta o desenvolvimento de um processo de tratamento com plasma para melhorar ametalização química de placas de circuito impresso (PCI). A pluma de plasma é gerada em argônio a partir da descarga de barreira dielétrica (DBD) promovida entre uma agulha cirúrgica e um cilindro usando capilar de borosilicato como dielétrico. A tensão picoa-pico aplicada foi de 5 kV, com forma de onda senoidal na frequência de 37 kHz e potência de descarga em torno de 765 mW. O substrato é um composto de fibra de vidro e resina epóxi. Com incidência perpendicular da pluma de plasma na superfície, o diâmetro da área tratada circular é de 10 mm. Desta forma, o ângulo de contato reduz de 75 ° a 45 ° com 3 s de interação entre superfície da amostra e a ponta do plasma e o ângulo atinge o mínimo de 33 ° após 180 s de tempo de tratamento. A metalização química foi feita com banhos seqüenciais de solução de paládio e finalizada com banho de solução aquosa de cobre. Testes de adesão padrão mostraram uma forte adesão das camadas de metal nas superfícies previamente tratadas com as plumas de plasma. Esta adesão melhora com o tempo de tratamento. A melhoria na metalização foi observada em superfície plana e também em furos usados para conectar diferentes camadas em PCIs. A área metalizada na superfície dos buracos é maior nos orifícios tratados. Quanto maior o tempo de tratamento, maior é essa área. Todos os resultados indicaram que a técnica de tratamento por plasma de placas de fibra de vidro melhora a sua metalização química pelo cobre, levando a uma adesão mais uniforme e eficaz do metal à superfície com um método ambientalmente amigável / This work reports the development of a plasma treatment process to improve the chemical metallization of printed circuit boards (PCB). The plasma plume is generated in argon from a dielectric barrier discharge (DBD) promoted between a surgical needle and a cylinder using a borosilicate capillary as dielectric. The applied peak-to-peak voltage was 5 kV, with sinusoidal waveform at 37 kHz frequency and power in the discharge around 765 mW. The substrate was a composite of fiberglass and epoxy resin. With perpendicular incidence of the plasma plume on the surface the diameter of the circular treated area was 10 mm. In this area the contact angle reduces from 75° to 45° with 3 s of the plasma-surface interaction and the angle reaches the minimum of 33° after 180 s of treatment time. Chemical metallization was made with sequential baths of solution of palladium and finished with bath of aqueous solution of copper. Standard adhesion tests showed a strong adhesion of the metal layer on surfaces previously treated with the plasma plumes. This adhesion improves with the treatment time. The improvement in the metallization was observed on flat surface and also in holes used to connect different layers in PCB’s. The metallized area on the surface of the holes is larger in treated holes. The longer the treatment time the larger is this area. All these results indicated that the technique of plasma treatment of fiberglass boards improves its chemical metallization by copper leading to a more uniform and effective adhesion of the metal to the surface with an environmental friendly method

La thèse s’intéresse au comportement thermomécanique des circuits imprimés pour des applications spatiales hyperfréquences. Dans cette étude, les circuits imprimés sont des assemblages multi-matériaux faisant intervenir des substrats diélectriques (composites tissés) et des connexions en cuivre. Les circuits étudiés sont des multicouches et l’information électrique transite d'une couche à l'autre par le biais de trous traversants : des perçages réalisés à travers les différentes couches, recouverts de cuivre par électrodéposition. Tout satellite comporte de l’électronique embarquée dont le circuit imprimé constitue le support et les connexions. Dans le cadre des applications spatiales, le circuit imprimé subira des variations importantes de température. Ces chargements engendrent des déformations qui ne sont pas homogènes dans les différents matériaux, pouvant mener à des contraintes importantes qui seront source de défaillances. En effet, les coefficients d'expansion thermique des substrats diélectriques et du cuivre sont différents. À chaque cycle thermique, le cuivre est alors entrainé sous chargement alterné. Suivant les configurations, le cuivre peut se plastifier et rompre après quelques centaines ou milliers de cycles thermiques (fatigue oligo-cyclique). On remarque que les ruptures sont souvent observées dans les trous traversant. Deux volets sont identifiables dans la thèse : un premier volet de caractérisation du comportement thermomécanique des matériaux présents dans les circuits imprimés hyperfréquences (substrats composites et cuivre), et un second volet concernant les simulations de configurations stratégiques à partir des comportements identifiés / In this thesis, the thermomechanical behavior of Printed Circuit Boards with high frequency space applications is assessed. A printed circuit board is a multi-material assembly, linking dielectric substrates and copper paths. The studied PCBs are multilayers, thus drills are made through these layers with copper electrodeposited on the wall of the hole, allowing the electrical signal to go from one layer to the other. Any satellite carries embedded electronics and the PCB is the link and the support of these electronics. During the life of the PCB in space applications, important temperature changes will drive strains which are inhomogeneous in the different materials and thus will lead to important stresses, root of the observed failures. Indeed, the coefficients of thermal expansion of the dielectric substrates are different than the one of copper. For each thermal cycle, the copper undergoes thus an alternate loading. Depending on the configuration, the copper may endure plastic strain and break after hundreds or a few thousands of cycles (oligo-cyclic fatigue). These failures happen often in the copper barrels linking the different layers.Two phases are distinguishable in the thesis: a first phase in which the thermomechanical behaviors of the materials constituting high frequency printed circuit boards is assessed (composites substrates and copper), and a second phase concerning the simulations of crucial configurations thanks to the identified behaviors of the materials

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / Technological development and intensive marketing support the growth of demand for electrical and electronic equipment (EEE), which have as a primary component printed circuit boards (PCBs). These devices have become obsolete in a shorter period of time, then residual PCBs become a problem, requiring recycling. The PCBs are composed of ceramic, polymers and metals, especially copper, metal present in the highest percentage. In addition they contain toxic substances such as brominated flame retardants and heavy metals. So the PCBs represent a problem and an opportunity at the same time, they require proper treatment and they are composed for materials with economic value. Therefore the aim of this study was to evaluate the application of supercritical CO2 and co-solvents in the recovery of copper and polymers from mobile phone PCBs, for the development of a more efficient and environmentally friendly recycling process. The study involved the mechanical processing of PCBs separated from discarded mobile phones; the characterization of PCBs; copper recovery using the CO2 supercritical leaching and H2O2 and H2SO4 as cosolvents, this method was conducted comparatively with leaching at atmospheric pressure using H2O2 and H2SO4 as leaching agents; Electrowinning of copper supercritical leached; and recovering the polymer fraction contained in the PCBs, using ethanol as cosolvent. The results indicated that mechanical processing in two milling, carried out in a hammer mill and knives mill were important for the reduction of PCBs to particle diameter less than 2 mm. From the leaching with aqua regia, it was determined that the PCBs containing 34.83 wt% copper. The characterization steps have demonstrated that PCBs are composed of 64.02% of metal, 20.51% of ceramics and 15.47% of polymers. The results showed that the supercritical leaching is 9 times faster than the atmospheric leaching. About 90% of copper was extracted from PCBs in 20 min of supercritical leaching, employing a solid:liquid ratio of 1:20, 20% (v/v) H2O2 and H2SO4 (2.5M). From the electrowinning, performed in a current density of 250 A / m², the copper metal form was recovered with 95.97% purity, reaching a current efficiency of 99%. It was extracted 69.53% of the polymers present in the PCBs using supercritical CO2 and ethanol co-solvent at 170 ° C and 7.5 MPa. Therefore the application of supercritical CO2 and co-solvents is a promising method and efficient to PCBs recycling. / O desenvolvimento tecnológico e marketing intenso propiciam o crescimento da demanda por equipamentos elétricos e eletrônicos (EEE), os quais apresentam como componente primário as placas de circuito impresso (PCIs). Como esses equipamentos vêm se tornando obsoletos em um menor intervalo de tempo, as PCIs residuais tornam-se um problema, necessitando de reciclagem. As PCIs são compostas por cerâmicos, polímeros e metais, com destaque para o cobre, metal presente em maior percentual, além de conterem substâncias tóxicas como os retardantes de chama bromados e os metais pesados. De modo que as PCIs representam um problema e uma oportunidade ao mesmo tempo, pois requerem tratamento adequado e são compostas por materiais com valor econômico agregado. Diante disso, o objetivo deste trabalho foi avaliar a aplicação de CO2 supercrítico na presença de cosolventes para a recuperação do cobre e na remoção dos polímeros de PCIs de celulares, visando o desenvolvimento de um processo de reciclagem mais eficiente e ambientalmente aceitável. O estudo compreendeu o processamento mecânico das PCIs separadas manualmente de celulares descartados; a caracterização das PCIs; a recuperação do cobre a partir da lixiviação com CO2 supercrítico e H2O2 e H2SO4 como cosolventes, realizada de forma comparativa com a lixiviação à pressão atmosférica utilizando H2O2 e H2SO4 como agentes lixiviantes; a eletro-obtenção do cobre lixiviado supercriticamente; e a recuperação da fração polimérica contida nas PCIs, empregando etanol como cosolvente. Os resultados obtidos no processamento mecânico indicaram que as duas moagens, realizadas em moinho de martelos, seguido de facas, foram importantes para a redução das PCIs a partículas de diâmetro inferior a 2 mm. A partir das lixiviações com água régia, determinou-se que as PCIs contêm 34,83% em massa de cobre. As etapas de caracterização demonstraram que as PCIs são compostas por 64,02% de metais, 20,51% de cerâmicos e 15,47% de polímeros. Os resultados mostraram que a lixivação supercrítica é 9 vezes mais rápida do que a lixiviação à pressão atmosférica. Extraiu-se, em 20 minutos de lixiviação supercrítica, cerca de 90% do cobre contido nas PCIs, empregando uma razão sólido:líquido de 1:20, 20% (v/v) de H2O2 e H2SO4 (2,5M). A partir da eletro-obtenção, realizada em uma densidade de corrente de 250 A/m², recuperou-se o cobre na forma de depósito metálico com 95,97% de pureza, alcançando uma eficiência de corrente de 99%. Extraiu-se 69,53% dos polímeros presentes nas PCIs, a partir de CO2 supercrítico modificado com etanol, a 170°C e 7,5 MPa. Portanto a aplicação de CO2 supercrítico na presença de cosolventes é um método promissor e eficiente à reciclagem das PCIs.

Made available in DSpace on 2016-12-08T17:19:16Z (GMT). No. of bitstreams: 1 CAPA-INTRO.pdf: 65338 bytes, checksum: 29ebb2d21aacfe78d6df0edf9d832a57 (MD5) Previous issue date: 2012-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this work is evaluate the effect of incorporation of waste printed circuit boards (WPCB) in physical and mechanical properties of triaxial ceramics for coating. Through the technique of experiment with mixtures seven formulations were developed with clay (40, 53, 60 e 80%); phyllite (20, 33, 40 e 60%) and waste (0, 14, 20 e 40%). The WPCB was characterized by their particle size, chemical composition and thermal behavior. The mixtures were processed by wet milling, drying, granulation, uniaxial compaction and sintering at 1180 ° C. Properties measured were dried modulus of rupture (DMoR), linear firing shrinkage (LFS), fired modulus of rupture (FMoR) and water absorption (WA). Microstructures were analyzed by SEM and XRD. The thermal behavior was also studied. The WPCB showed melting behavior in the sintering process, but its addition to the material prejudice the DMoR. After firing, the FMoR is improved if are added moderate amounts of waste, but it decreases when there is an excess of waste. Was observed that the interaction between the phyllite and the waste increases the LFS, what is linked to the closing of the pores in the samples, and hence the flux characteristics of these materials. The WA also refers to this conclusion, since the addition of the waste decreases the absorption of 8.0 to 0.5%. Due the found behavior, it is possible to say that there are mixtures of clay-phyllite-WPCB, in certain proportions, that can be classified according to NBR 13818:1997 as stoneware. Microstructural characterization showed that the addition of the waste improves the sinterability of the material, however, in excess are formed glassy phase, not desired, weakening the material. The main phases present, verified by XRD are quartz and mullite, showing that the addition of the waste does not affect the formation of the main phases of interest ceramic. Thermal analysis showed that there is mass loss to 600 ° C, which can be related to the fraction of the polymer in the waste and the loss of water of constitution of the ceramics. In all cases there was an exothermic peak above 950 ° C which is related to the phase transformation of the ceramic material during sintering. / Este trabalho tem como objetivo avaliar o efeito da incorporação de resíduos de placas de circuito impresso (RPCI) nas propriedades físicas e mecânicas de misturas cerâmicas triaxiais para revestimento. Por meio da técnica de experimento com misturas foram desenvolvidas sete formulações com teor de argila de 40, 53, 60 e 80%, teor de filito de 20, 33, 40 e 60% e teor de resíduo de 0, 14, 20 e 40%. O resíduo foi caracterizado quanto à sua granulometria, constituição química e comportamento térmico. As misturas foram processadas por moagem à úmido, secagem, granulação, compactação uniaxial e sinterização a 1180°C. Foram medidas as propriedades de resistência mecânica a seco (RMS), retração linear no sinterizado (RLSi), resistência mecânica do sinterizado (RMSi) e absorção de água (AA). A verificação das microestruturas obtidas foi realizada por MEV, DRX e o comportamento térmico também foi analisado. O RPCI apresentou comportamento fundente no processo de sinterização, mas sua adição ao material prejudica a RMS. Após a sinterização, a RMSi é melhorada desde que sejam adicionadas quantidades moderadas de resíduo, pois este em excesso fragiliza o material. Observou-se que a interação entre o filito e o resíduo aumenta a RLSi, fato ligado ao fechamento dos poros nas amostras, e, portanto, às características fundentes desses materiais. A AA também remete a esta conclusão, pois a adição do resíduo diminui a absorção de 8,0 para 0,5%. Devido ao comportamento encontrado, verificou-se que a mistura de argila-filito- RPCI, em determinadas proporções, pode ser classificada, segundo a NBR 13818 : 1997 como semi-grês ou grês. A caracterização microestrutural mostrou que a adição do resíduo melhora a sinterabilidade do material, no entanto, em excesso, há formação de fase vítrea além do desejado, fragilizando o material. As principais fases presentes, verificadas por DRX, são quartzo e mulita, evidenciando que a adição do resíduo não prejudica a formação das principais fases de interesse cerâmico. A análise térmica mostrou que há perda de massa até 600°C, o que pode estar relacionado à fração polimérica do RPCI e à perda da água de constituição das cerâmicas. Para todos os casos ocorreu um pico exotérmico acima de 950°C, que está relacionado à transformação de fase do material cerâmico durante a sinterização.

Orientador: Luiz Carlos Kretly / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T12:34:11Z (GMT). No. of bitstreams: 1 Silva_MauricioWeberBenjoda_M.pdf: 7910629 bytes, checksum: ba689f61e380994adce43b3aad0b347c (MD5) Previous issue date: 2009 / Resumo: O desenvolvimento de chaves MEMS (Micro Electro Mechanical System) de RF, usando os conceitos e a tecnologia de placa de circuito impresso (PCB) é objeto desta pesquisa. Foram fabricadas micro-chaves na configuração paralela, sobre guias de onda coplanares (CPW). Recentemente, suas aplicações vêm sendo direcionadas a circuitos mais sofisticados, onde são monoliticamente integrados com outros componentes de RF, como antenas e deslocadores de fase. As chaves desenvolvidas são projetadas para operar com baixa tensão de ativação, e fabricadas usando a técnica surface micromachining, que consiste em construir as estruturas em camadas de filmes finos, e removendo as camadas sacrificiais até a liberação da parte flexível do dispositivo. Neste trabalho é apresentada toda a metodologia do projeto, incluindo as simulações eletromecânicas e eletromagnéticas das chaves MEMS em PCB, bem como s caracterizações. As chaves mostraram desempenho compatível com dispositivos equivalentes comerciais de RF, apresentando larga banda de operação de 1,8 - 18 GHz. Tendo em vista o desempenho físico e operacional dos dispositivos fabricados, essa tecnologia mostra-se viável com tecnologias dominadas localmente e se aplica tanto para Rádio Freqüência como para micro-ondas. / Abstract: The development of RF MEMS (Micro Electro Mechanical System) switches, using the concepts and technology of Printed Circuited Board (PCB) is the object of this research. Micro switches in the shunt configuration through the Coplanar Waveguide (CPW) were manufactured. Recently, its applications have been directed to more sophisticated circuits, which are monolithic integrated with other RF components such as antennas and phase shifters. The developed switches are designed to operate with low actuation voltage and manufactured using the surface micromachining technique, which consists to build the structures in thin film layers, and removing the sacrificial layers to the release of the flexible device part. In this work is presented all the methodology of the project, including the electromechanical and electromagnetic simulations of the MEMS switches on PCB, as well as the characterizations. The switches had shown compatible performance when compared with equivalent RF devices available in the market, showing broadband operation from 1,8 - 18 GHz. Due the physical and operational performance of the manufactured devices, this technology shows viable with locally known technologies and feasible for applications in both Radio Frequency and microwave. / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

Les travaux présentés dans ce manuscrit traitent de l’enfouissement dans un circuit imprimé de convertisseurs de puissance, paradigme visant l’insertion de composants électroniques au sein du circuit imprimé.Une structure simple et économique de composant inductif enfoui, pouvant être employé comme inductance, coupleur, ou résonateur monolithique, est tout d’abord décrite. Un modèle analytique complet est développé. Des prototypes sont réalisés, validant le modèle et démontrant l’intérêt de la topologie.L’agencement des composants de puissance constituant une cellule de commutation est ensuite étudié. En particulier, un modèle analytique permettant une compréhension intuitive des mécanismes oscillatoires dans le cadre de l’emploi de transistors rapides est décrit.Une technique de reprise de contact de face avant pour puce enfouie, basée sur un morceau de mousse pressée, est proposée. Une étude préliminaire, à forte composante expérimentale, est présentée. Elle démontre que certains prototypes enfouis présentent des caractéristiques électriques et une fiabilité similaires à celles obtenus avec des fils de bonding.Enfin, les résultats de l’étude sur l’agencement des composants d’une cellule de commutation sont appliqués pour concevoir et réaliser un hacheur basé sur des transistors SiC connectés par mousse pressée. La structure délivre 3 kW sous 600 V en continu, démontrant la viabilité du procédé de reprise de contact proposé. / This thesis deals with Printed-Circuit Board (PCB) embedding of power converters, paradigm according to which electronic components are placed within the substrate itself.First, a simple and economical structure of inductive component, which can be used either as an inductor, a coupler, or a monolithic resonator, is described. A comprehensive analytical model is developed. Prototypes are manufactured, validating the analytical model and highlighting the value of the topology.The arrangement of the power components of a switching cell is then studied. In particular, an analytical model offering an intuitive understanding of the oscillation mechanisms in cells using fast transistors is proposed.A simple and economical top-side connection technic for PCB-embedded power dies using a pressed piece of metal foam is described. A preliminary study, with strong experimental component, is proposed. It shows that the embedded prototypes have electrical performances and a reliability close to that of wire-bonded dies.Finally, the results from the study on the arrangement of the components of a switching cell are used to design and manufacture a chopper based on SiC transistors connected using a piece of pressed metal foam. This chopper proved to be able to continuously deliver 3 kW under 600 V to a load, thereby validating the proposed top-side connection technic.

Les énergies fossiles (Pétrole, Charbon, …) représentent 80 % des énergies consommés. Malheureusement pour l’environnement, elles sont les plus polluantes. Le remplacement actuel des énergies fossiles permet au marché de l’électronique de puissance de grandir d’année en année. L’électronique de puissance permet d’adapter l’énergie électrique à son utilisation finale. Dans la pratique, l’adaptation de l’énergie électrique utilise des convertisseurs. En plus de respecter le volume, l’efficacité et la fiabilité imposés par le cahier des charges pour chaque application, l’électronique de puissance doit aussi permettre de réduire sensiblement les coûts. Le convertisseur doit assurer le fonctionnement électrique du circuit, le support mécanique des composants et la gestion thermique. Le package utilisé par les nouveaux composants à grand gap limite leurs performances. L’intégration des convertisseurs doit développer des méthodes d’interconnexion permettant d’éliminer ce package. L’objectif de la recherche sur l’intégration des convertisseurs est de repousser les limites imposées par un cahier des charges standard tout en assurant ces 3 fonctions principales. Parmi les nombreuses techniques d’intégration, le circuit imprimé (PCB) est mature industriellement, permet la fabrication collective et un assemblage automatisé. L’intégration utilisant le PCB a développé la technique d’enfouissement de puce avec laquelle la puce est directement enfouie dans le PCB sans son package. Cette thèse va étudier la méthode d’enfouissement pour les autres composants nécessaires à la réalisation d’un convertisseur (Condensateurs, Composants Magnétiques). Une optimisation du convertisseur qui doit être réalisé permet de prendre en compte les avantages de cette nouvelle technologie. Un prototype de convertisseur intégré a été réalisé avec des composants utilisant cette technologie. / With the endangering of the environment due to the use of fossil fuels, the power electronics market is growing through the years. The number of applications is increasing in numerous field as, for example, transport (electric car, "more electric" aircraft) or energy (photovoltaic, smart grid). Beyond meeting the volume, efficiency and reliability specifications for each application, power electronics should also reduce substantially costs. Today, the managing of the electric energy uses power electronic converters. The conception of a converter is a multiphysic problem. The converter has to ensure electrical functionality, mechanical support and proper thermal management.The new wide-band gap components are limited in performance by their package. The integration of a converter should use new interconnection methods to avoid the use of packaged components. The trend is to integrate the maximum of components into a single system. This integration can offer benefits such as size and weight reduction, cost saving and reliability improvement by managing the complexity and the high density of interconnection. Among many integration technologies available, Printed Circuit Board (PCB) is well known in the industry, allowing mass production with automated manufacturing and assembly. The PCB integration was developed with the “Die Embedding” technology in which a bare die in embedded directly in the PCB to not use package. This thesis studied the embedding technology on others components necessary to the realization of a converter (Capacitors, Magnetics, …). An optimization of the converter is done taking into account the advantages of this new technology. A prototype of an AC/DC bidirectional converter fully integrated using this technology was realized.