Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Systems Science and Industrial Engineering, 2008. / Includes bibliographical references.

Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engfineering and Applied Science, Department of Systems Science and Industrial Engineering, 2009. / Includes bibliographical references.

L'assemblage tridimensionnel des circuits microélectroniques et leur utilisation dansdes conditions environnementales extrêmement sévères nécessitent ledéveloppement d’alternatives plus robustes pour les contacts électriques. Unetechnique prometteuse est la transformation des contacts de brasure conventionnelleen composés intermétalliques (IMC). Ce processus est appelé « Transient LiquidPhase Soldering » (TLPS).Dans ce contexte, des tests accélérés permettant la formation d’IMC parélectromigration et thermomigration ont été effectués sur des structures « Packageon Package ». L'objectif principal est le développement d'un modèle généralpermettant de décrire la formation des IMC dans les joints de brasure. Combiné avecune analyse par éléments finis ce modèle pourra être utilisé pour prédire la formationdes IMC dans les joints de brasure pour des structures et des profils de missiondifférents. Le modèle de formation des IMC pourra être utilisé pour optimiser unprocessus TLPS. / A further miniaturization of microelectronic components by three dimensionalpackaging, as well as the use of microelectronic devices under harsh environmentconditions, requires the development of more robust alternatives to the existing Snbased solder joints. One promising technique is the diffusion and migration driventransformation of conventional solder bumps into intermetallic compound (IMC)connections. The related process is called transient liquid phase soldering (TLPS).Against this background an investigation of the IMC formation under consideration ofelectromigration and thermomigration was performed. For the stress tests Packageon Package structures are used. The final result is a general model for the IMCformation in solder joints. Combined with a Finite Element Analysis (FEA) this modelis used to predict the IMC formation in solder joints for a broad range of boundaryconditions. In future the model of the IMC formation can be used to optimize a TLPSprocess.

Made available in DSpace on 2016-06-02T20:16:54Z (GMT). No. of bitstreams: 1 6611.pdf: 4783832 bytes, checksum: 1dc280ff47cc4df343ea92399b40fdd5 (MD5) Previous issue date: 2015-03-09 / Financiadora de Estudos e Projetos / The search for new lead-free piezoelectric materials has been a major goal of many scientists in recent years. The main cause is the replacement of widely used lead zirconate titanate (PZT) based ceramics due to the highly toxic characteristics of the lead element. Potassium sodium niobate based ceramics have shown high piezoelectric coefficients and a morphotropic phase boundary close to the composition (K0.5Na0.5)NbO3 (KNN), similar to that found in lead zirconate titanate. However, the preparation of highly dense KNN based ceramics is extremely difficult. In this work, the structural, mechanical and electrical properties of lead free ferroelectric ceramics with compositions Li0,03(K0,5Na0,5)0,97Nb0,8Ta0,2O3 + xwt% CuO (x = 0; 2 and 3.5) were studied. All the compositions, sintered at 1050ºC for 2 hours had high density, approximately 95% of the theoretical value. Rietveld refinement of the X ray diffraction patterns showed a mixture of both orthorhombic Bmm2 and tetragonal P4mm phases, for all compositions. Nevertheless, compositions with high CuO contents have mainly the tetragonal phase. Dielectric and dynamic mechanical analysis (DMA) measurements showed two polymorphic phase transitions with increasing temperature. Both phase transitions have diffuse character and they can be related with the transformation of the orthorhombic phase fraction in the tetragonal one, and with the transformation of the tetragonal ferroelectric phase to a cubic paraelectric one. The origin of the difference observed between the temperatures where both techniques, dielectric and mechanical, see the diffuse phase transition is discussed. The ceramic with 2wt% of CuO is electrically softer than the other compositions and it has the highest value of the piezoelectric coefficient d31. Also, in this work we studied the possibility of using high contents of CuO to promote the formation of liquid phase for obtaining and extracting single crystal seeds, which can be used for the texture of KNN-based ceramics. The ceramic Li0,03(Na0,5K0,5)0,97Ta0,2Nb0,8O3 + x wt% CuO with x=16, sintered at 1090ºC for 2 hours, is a perfect candidate for extracting grains which may be used as seeds. Furthermore, ceramics with x=13, sintered at 1110ºC for 2 hours, showed a partial melting of the material, which caused the growth of highly oriented grains. This material can be practically considered as a single crystal and, with a proper cut procedure, the desired single crystal seeds can be obtained. This method to obtain single crystal seeds, as proposed in this work, is very simple and novelty. / Nos últimos anos, o foco principal de muitos cientistas tem sido a procura de novos materiais piezoelétricos livres de chumbo. A causa principal é a substituição dos materiais baseados em titanato zirconato de chumbo (PZT), os quais são amplamente utilizados em aplicações piezoelétricas, devido à alta toxicidade do elemento chumbo. Cerâmicas baseadas em niobato de sódio e potássio têm mostrado altos coeficientes piezoelétricos e um contorno de fases morfotrópico próximo da composição (K0.5Na0.5)NbO3 (KNN), similar ao encontrado no titanato zirconato de chumbo. Porém, a preparação de cerâmicas baseadas em KNN com alta densidade é extremamente dificultosa. Neste trabalho foram estudadas as propriedades estruturais, mecânicas e elétricas de cerâmicas ferroelétricas livres de chumbo com composições Li0,03(K0,5Na0,5)0,97Nb0,8Ta0,2O3 + x %P CuO (x = 0; 2 e 3,5). Todas as cerâmicas sinterizadas a 1050ºC durante 2 horas apresentaram altas densidades, sendo aproximadamente 95% da densidade teórica. O refinamento pelo método de Rietveld dos perfis de difração de raios X mostrou que todas as composições apresentam uma mistura de ambas as fases, ortorrômbica Bmm2 e tetragonal P4mm. Porém, composições com altos teores de CuO apresentam a fase tetragonal como sendo majoritária. As medidas dielétricas e as de análise mecânico dinâmico (DMA) mostraram duas transições de fase polimórficas com o aumento da temperatura. Ambas transições de fase têm caráter difuso e estão relacionadas com a transformação da fração de fase ortorrômbica em tetragonal e com a transformação da fase tetragonal ferroelétrica para cúbica paraelétrica. Foi discutida a origem da diferença observada, nas temperaturas em que ambas as técnicas, dielétrica e mecânica, enxergam a transição de fase difusa. A cerâmica com 2%P de CuO mostrou-se mais mole eletricamente e apresentou um valor maior de coeficiente piezoelétrico d31 do que as outras composições estudadas. Também, neste trabalho foi estudada a possibilidade de usar altos teores de CuO para promover a formação de fase líquida e conseguir a formação e extração de sementes monocristalinas que possam ser utilizadas na textura de cerâmicas baseadas em KNN. A cerâmica de Li0,03(Na0,5K0,5)0,97Ta0,2Nb0,8O3 + x % P CuO com x=16, sinterizada a 1090ºC durante 2 horas, mostrou-se a candidata perfeita para a extração de grãos que possam ser utilizados como sementes. Por outro lado, a cerâmica com x=13, sinterizada a 1110ºC durante 2 horas, apresentou fusão parcial de material, o que promoveu o crescimento dos grãos altamente orientados de forma que esse material já pode ser considerado como sendo praticamente um monocristal e com um procedimento de corte adequado, podem ser obtidas as sementes monocristalinas desejadas. Esse procedimento de obtenção de sementes monocristalinas, proposto neste trabalho, é totalmente simples e inovador.

Made available in DSpace on 2016-06-02T20:16:54Z (GMT). No. of bitstreams: 1 6698.pdf: 13275782 bytes, checksum: 2c4bbd5a5c838552f7cbf82ce709e116 (MD5) Previous issue date: 2015-03-09 / Financiadora de Estudos e Projetos / In this work, the lead-free ceramic powders of xBi0,5Na0,5TiO3 - (0,7186 - 0,7143x) Bi0,5K0,5TiO3 - (2814 - 2857x) BaTiO with x = 0,8200; 0,8625; 0,8792, 0,9126 and 0,9300 (BNBK1000x) were prepared by the solid state reaction method, followed by conventional densification. The ceramic bodies showed high density, which was higher than 95% in obtained samples. For the all ceramics were performed structural, micro structural, electric and anelastic characterizations. The X-ray diffraction (XRD) analysis indicated the formation of the complex perovskite type crystaline structure for all compositions analyzed without the presence of spurious phases. By the structural refinement by the Rietveld method of XRD data and by Raman spectroscopy were observed that for BNBK912 and BNBK930 compositions, at room temperature, the predominant symmetry is rhombohedral (R3c), while the BNBK820 composition exhibits a tetragonal crystalline symmetry (P4mm). For the BNBK879 and BNBK826 compositions presented a mixture of phases, possibly with rhombohedral and tetragonal symmetry, reaveling the morphotropic phase boundary (MPB) of this system. The microstructure of BNBK1000x ceramics was investigated by scanning electron microscopy (SEM), where the morphology grains with irregular sizes and shapes, where the increased levels of K+ and Ba2+ ions suppressed the growth of the grains. The characterizations by Raman spectroscopy at room temperature showed broad Raman modes, due to the chemical and/or structural disorder related to the substitution of elements Bi and Na for Ba and K. The ferroelectric characterizations at room temperature of the BNBK1000x ceramics showed that all compositions studied are ferroelectric. Through the comparison among the measurements of electrical impedance and mechanical spectroscopy, was possible to identify the different structural and electric phase transitions that were employed in the construction of a pseudodiagram of phases for the BNBK1000x compositions. / Neste trabalho, os pós-cerâmicos livres de chumbo xBi0,5Na0,5TiO3 - (0,7186 - 0,7143x) Bi0,5K0,5TiO3 - (2814 - 2857x) BaTiO com x = 0,8200; 0,8625; 0,8792, 0,9126 e 0,9300 (BNBK1000x) foram obtidos através do método de reação de estado sólido, seguido por densificação convencional. Os corpos cerâmicos obtidos apresentaram elevada densificação, sendo maior que 95% nas amostras produzidas. Para todas as cerâmicas foram realizadas caracterizações estruturais, microestruturais, elétricas e anelásticas. As análises por difração de raios-X (DRX) indicaram a formação da estrutura cristalina tipo perovkista complexa para todas as composições analisadas, sem a presença de fases espúrias. O refinamento estrutural, pelo método de Rietveld, dos resultados de DRX e os resultados de espectroscopia Raman apontam que para as composições BNBK930 e BNBK912 a simetria predominante em temperatura ambiente é romboédrica (R3c), enquanto que a composição BNBK820 apresenta a simetria cristalina tetragonal (P4mm). Já as composições BNBK879 e BNBK862 apresentaram uma mistura de fases, possivelmente com simetrias romboédrica e tetragonal, evidenciando o contorno de fase morfotrópico (CFM) deste sistema. A microestrutura das cerâmicas de BNBK1000x foi investigada por microscopia eletrônica de varredura (MEV), onde a morfologia apresentada pelas diferentes composições estudadas possuíam grãos com tamanhos e formatos irregulares, sendo que o aumento dos teores dos íons de K+ e Ba2+ inibiram o crescimento dos grãos. A caracterização por espectroscopia Raman, em temperatura ambiente, apresentou modos Raman amplos, mostrando um elevado grau de desordem química e/ou estrutural devido à substituição dos elementos Bi e Na por Ba e K. As caracterizações ferroelétricas, também em temperatura ambiente das cerâmicas de BNBK1000x mostraram que todas as composições estudadas possuem propriedades ferroelétricas. Através da comparação entre as medidas de impedância elétrica e anelástica, levando em consideração as caracterizações estruturais e ferroelétricas com temperatura, foi possível identificar diferentes transições de fase estruturais e elétricas, que foram empregadas na construção de um pseudo-diagrama de fases para as composições de BNBKx.

Made available in DSpace on 2016-06-02T20:19:24Z (GMT). No. of bitstreams: 1 6248.pdf: 27691207 bytes, checksum: cc929611cc4e506743fb3b9ce1730858 (MD5) Previous issue date: 2014-08-07 / Universidade Federal de Sao Carlos / Motivated by the great growth presented in the last decade in research on lead-free piezoelectric ceramics and the fact that some ceramic systems, as those based on bismuth, have been identified as promising candidates to substitute the lead zirconate titanate (PZT) in their present technological applications, was proposed as the objective of this work, study the effect of adding 𝐵𝑎𝑇 𝑖𝑂3 (BT) on the structural, electrical and anelastic properties exhibit by the system (1−𝑥)𝐵𝑖0.5𝑁𝑎0.5𝑇𝑖𝑂3−𝑥𝐵𝑎𝑇 𝑖𝑂3 (BNT-BT). The structural characterization was performed by the techniques of X-ray diffraction (XRD) and Raman spectroscopy. The morphological and compositional aspects (qualitative), in the calcined powders, and the sintered samples were studied by scanning electron microscopy (SEM). The ferroelectric and dielectric character of the compositions were obtained through characterization of ferroelectric hysteresis exhibit and using the technique of electrical impedance spectroscopy, respectively. Phase transitions and the possible mechanisms of anelastic relaxation were studied by the technique of mechanical spectroscopy. Samples were obtained by the method of solid state reaction, where it was possible to obtain compositions with 0.00 ≤ 𝑥 ≤ 0.08 with relative density greater than 95% and without the presence of spurious or secondary phases. On profiles of X-ray diffraction for the different studied sintered compositions was applied the method of Rietvelt refinement which allow the determination and confirmation of the crystal structures in the samples under study, and the presence of a morphotropic phase boundary (MPB) for the BNT-BT. The XRD results were corroborated by the results of Raman spectroscopy. The ferroelectric nature of the different compositions of BNT-BT system studied was confirmed. Electrical phase transitions (F-Af and Af-P) and structural transitions (R-T and T-C) exhibited by the BNT-BT were characterized by mechanical spectroscopy (using a dynamical mechanical analyzer (DMA)), and by electrical impedance spectroscopy, employing the results in complementing the electrical and structural phase diagram of this system. In addition to the phase transitions obtained, the technique of mechanical spectroscopy for compositions between 0.00 ≤ 𝑥 ≤ 0.03, allowed the observation of a complex process of anelastic relaxation that was associated with interactions and mobility of different defects present, which possibly contribute significantly to an increase of conductivity in these materials, which had not been previously reported in the literature. / Motivados pelo grande crescimento apresentado na última década nas pesquisas em cerâmicas piezoelétricas livres de chumbo e o fato de alguns sistemas cerâmicos, como os baseados em bismuto, já terem sido identificados como promissores candidatos à substituição do titanato zirconato de chumbo (PZT) em suas atuais aplicações tecnológicas, foi proposto como objetivo deste trabalho, estudar a influência da adição de 𝐵𝑎𝑇 𝑖𝑂3 (BT) sobre as propriedades estruturais, elétricas e anelásticas exibidas pelo sistema (1 − 𝑥)𝐵𝑖0,5𝑁𝑎0,5𝑇𝑖𝑂3 − 𝑥𝐵𝑎𝑇 𝑖𝑂3 (BNT-BT). A caracterização estrutural foi realizada por meio das técnicas de difração de raios-X (DRX) e espectroscopia Raman. Os aspectos morfológico e composicional (qualitativo), tanto dos pós calcinados, quanto das amostras sinterizadas foram estudados mediante microscopia eletrônica de varredura (MEV). O caráter ferroelétrico e dielétrico das composições estudadas foram obtidos por meio da caracterização da histerese ferroelétrica exibida e da técnica de espectroscopia de impedância elétrica, respectivamente. As transições de fase e os possíveis mecanismos de relaxação anelástica foram estudados utilizando a técnica de espectroscopia mecânica. As amostras foram obtidas pelo método de reação de estado sólido, onde foi possível obter composições com 0, 00 ≤ 𝑥 ≤ 0, 08 com densidades relativas maiores que 95% e sem a presença de fases espúrias ou secundárias. Aos perfis de difração de raios-X para as diferentes composições sinterizadas estudadas foi aplicado o método de refinamento Rietvelt que permitiu a determinação e confirmação das estruturas cristalinas nas amostras em estudo, além da presença de contorno de fase morfotrópico (CFM) para o BNT-BT. Os resultados de DRX foram corroborados por meio dos resultados de espectroscopia Raman. O carácter ferroelétrico das diferentes composições do sistema BNT-BT estudadas foi confirmado. Tanto as transições de fase elétricas, ferroelétricaantiferroelétrica (F-Af) e antiferroelétrica-paraelétrica (Af-P), quanto as transições estruturais, romboédrica-tetragonal (R-T) e tetragonal-cubica (T-C), exibidas pelo BNT-BT foram caracterizadas por espectroscopia mecânica (por meio de um analisador dinâmico mecânico(DMA)) e por espectroscopia de impedância elétrica, empregando-se os resultados obtidos na complementação do diagrama de fase elétrico e estrutural deste sistema. Além das transições de fase obtidas, a técnica de espectroscopia mecânica, para composições entre 0, 00 ≤ 𝑥 ≤ 0, 03, propiciou a observação de um processo de relaxação anelástica complexo que foi associado a interações e mobilidade de diferentes defeitos presentes, que possivelmente contribuem significativamente para um aumento de condutividade nestes materiais, que não haviam sido reportado anteriormente na literatura.

Orientadores: Amauri Garcia, Wislei Riuper Ramos Osorio / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T22:54:52Z (GMT). No. of bitstreams: 1 Garcia_LeonardoRicheli_M.pdf: 15499869 bytes, checksum: 1afa8bd79812971da1e6fac7f4fed383 (MD5) Previous issue date: 2008 / Resumo: Sabe-se que existem tendências de leis e diretrizes que restringem o uso e aplicação de certas substâncias perigosas utilizadas em processos de fabricação de componentes em geral. Como exemplo, podem-se citar produtos contendo cádmio, mercúrio, cromo hexavalente, bifenilos polibromatos, éteres difenil-polibromato e chumbo. Devido a essas restrições, fabricantes de produtos eletrônicos têm que adequar seus produtos às novas diretrizes e desenvolver novas ligas de solda sem chumbo. Estudos preliminares indicam que ligas Sn-Zn, particularmente a eutética, consistem em alternativas promissoras para a substituição das ligas de solda contendo chumbo. Entretanto, é necessário avaliar influências das taxas de resfriamento do processo sobre a microestrutura formada e as propriedades mecânicas dessas ligas. O presente trabalho tem exatamente esse objetivo, e para cuja consecução foram planejadas as seguintes atividades: i) solidificação unidirecional de ligas Sn-Zn (Sn-4%Zn, Sn-9%Zn e Sn-12%Zn) e da liga eutética Sn-Pb (para comparação), ii) mergulho de lâminas de cobre em banho das ligas Sn-Zn e Sn- Pb por intermédio de imersão à quente e iii) por deposição em substrato de cobre. Para a fase inicial utilizou-se de um dispositivo de solidificação unidirecional vertical ascendente, para obtenção dos lingotes e registro dos respectivos perfis térmicos experimentais. Foram determinadas as variáveis térmicas de solidificação: coeficiente de transferência de calor metal/molde, velocidades de deslocamento da isoterma liquidus e taxa de resfriamento para as ligas do sistema Sn-Zn e para a liga Sn-Pb (Sn-40%Pb). Estas variáveis foram confrontadas com as previsões teóricas de um modelo numérico de solidificação e, em seguida, correlacionadas com os espaçamentos dendríticos secundários (?2) e equações experimentais de crescimento dendrítico foram determinadas. Foram realizados ensaios de mergulho utilizando-se lâminas (substrato) de cobre, a diferentes temperaturas de mergulho, em que foi possível avaliar a espessura da camada depositada sobre o substrato, a porcentagem da área recoberta pelas ligas e verificar as respectivas microestruturas. Foram também realizados ensaios de molhabilidade para avaliação do ângulo de contato entre cada liga e os respectivos substratos / Abstract: A number of laws and guidelines have been restricted the application of hazardous substances in manufacturing processes of components. This is the case of products containing cadmium, mercury, hexavalent chromium, polibromates biphenyls, polibromate-diphenyl ethers and lead. In order to adequate products to such restriction requirements, electronic components manufacturers have to meet such requirements by developing new lead-free solder alloys. Preliminary studies have indicated that Sn-Zn alloys, in particular the eutectic composition, are promising alternatives to the replacement of solder alloys containing lead. However, studies focusing on the influence of the cooling rate on the resulting microstructures and on the mechanical properties of these alloys need to be carried out. This work has precisely such objective, and the following activities have been planned to attain such purpose: i) unidirectional solidification of Sn-Zn alloys (Sn-4wt%Zn, Sn-9wt%Zn, Sn-12wt%Zn) and of the Sn-Pb eutectic (for comparison purposes), ii) copper blades dipped in molten Sn-Zn and Sn-Pb alloys (hot dipping) and iii) deposition on copper substrate. For the initial experimental step an upward vertical solidification system has been used to obtain the alloys ingots and their correspondent thermal profiles. Solidification thermal variables such as: metal/mold heat transfer coefficient, tip growth rates and cooling rates have been determined for Sn-Zn and the Sn-40wt%Pb alloys. Such experimental variables have been compared with predictions from a solidification numerical model and correlated to secondary dendrite arm spacings (?2) and experimental equations of dendritic growth have been proposed. The thickness of the coating layers, the spreading areas and the resulting microstructures of the alloys on the copper substrates (blades) were evaluated after the hot dipping procedures at different temperatures. Wetting tests have also been carried out in order to evaluate the contact angle between drop and substrate for each alloy / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Abstract The target of this dissertation is to propose a new qualification tool (QT) for component package (CP) feasibility qualification in telecommunication infrastructure products. The primary reason for the introduction of the QT is the Electrical and Electronic Equipment (EEE) manufacturers’ continuing development of new products with tighter product requirements, e.g. compact size, environmental friendliness and cost-efficiency. CP’s need to match these requirements and thus they need to be developed further and qualified/re-qualified continuously. This qualification process with the new component package needs to be done in as early phase as possible, enabling EEE manufacturers to implement component packages into use with minimal risk. Qualification of a CP to match with these requirements is usually done with the qualification expert’s possessed know-how. However, this process takes a lot of time as all the possible data must be collected or even created. Thus a new method needs to be introduced for early phase qualification. The QT proposed here contains eight qualification sub-areas for feasibility qualification of the CP and it uses three qualification principles. Including all these sub-areas to the feasibility qualification clearly enables more reliable and trustworthy conclusions. The QT is required as an assisting qualification tool for specialists and as a preliminary qualification tool, e.g. for hardware (HW) designers or component engineers. It could be used also as a requirement communication tool between customers and component package manufacturers. After the QT’s sub-areas and functionality were developed, functionality and approval limits were set-up with 44 different widely used commercial CPs. This historical data is recorded for future use in its own database. The QT is a unique tool as there are no competing open-source tools available in the market that can be tailored to match with the user’s own requirements. / Tiivistelmä Työn tarkoituksena oli esittää uusi kvalifiointityökalu (QT) infrastruktuurituotteiden komponenttikoteloiden käytettävyyden arviointiin. Laitevalmistajien kehittäessä uusia pienempiä, ympäristöystävällisempiä ja kustannustehokkaampia laitteita asettavat he samalla vastaavia vaatimuksia myös komponenttikoteloille. Vastaavasti komponenttien valmistajat joutuvat kehittämään komponentteja ottamalla käyttöön uusia materiaaleja ja kotelorakenteita ja kvalifioimaan niiden ominaisuuksia asiakkaiden vaatimuksien mukaisesti. Laitevalmistajien riski uusien komponenttikoteloiden käyttöönotossa pystytään minimoimaan, kun komponenttikoteloiden kvalifiointi tehdään mahdollisimman aikaisessa vaiheessa. Kvalifioinnit tehdään yleensä kvalifiointiasiantuntijoiden tietotaidon perusteella. Tämä prosessi on kuitenkin perinteisesti hidas, joten nopeammalle arviointimenetelmälle on selkeä tarve. Työssä kehitettyyn kvalifiointityökaluun määritettiin kahdeksan arviointialuetta. Lisäksi sitä voidaan käyttää kolmella eri kvalifiontiperiaatteella. Näiden arviointialueiden huomioiminen kvalifiointiprosessin aikana parantaa selkeästi tuloksen luotettavuutta ja todenmukaisuutta. Työkalu on määritetty siten, että sitä voivat käyttää asiantuntijat avustavana kvalifiointityökaluna sekä suunnittelijat / komponentti-insinöörit alustavana kvalifiointityökaluna. Lisäksi sitä voidaan myös käyttää asiakasvaatimusten määrityksessä ja tiedonvälityksessä asiakkaan ja toimittajan välillä. QT:n kvalifiointialueiden määrittelyn ja toiminnallisuuden rakentamisen jälkeen, hyväksyntäkriteerit tutkittiin ja arvioitiin käyttäen 44 erilaista kaupallista komponenttikoteloa työkalun lopullisen hienosäädön tekemiseksi. Koska kvalifioinnin tiedot tallennetaan QT:n tietokantaan, pystyy laitevalmistajat hyödyntämään aikaisemmat historiatiedot tulevissa kvalifioinneissa. QT on ennen näkemätön työkalu, sillä markkinoilla ei ole vastaavia avoimen lähdekoodin kvalifiointityökaluja tarjolla, jota voidaan räätälöidä asiakkaan omien tarpeiden mukaisesti.

Ce travail a pour objectif d’élaborer de manière contrôlée différentes microstructures de (K0,5Na0,5)NbO3 non dopées par différentes mises en forme, bien caractérisées structuralement et microstructuralement, afin d’étudier et d’éclaircir l’influence de la densification et de la taille des grains sur les propriétés piézoélectriques. Il s’agit pour cela de produire des microstructures, avec une composition maitrisée, ayant d’abord des grains de taille micrométrique, ensuite millimétrique et enfin si possible des grains centimétriques de KNN et d’atteindre des densifications allant de 80 % à plus de 95 %. Au-delà de l’ingénierie des microstructures de KNN, l’obtention de monocristaux du composé (K0,5Na0,5)NbO3 de plusieurs mm3, de bonne qualité cristalline et bien caractérisés structuralement et microstructuralement permettrait de caractériser l’ensemble des tenseurs élastiques, diélectriques et piézoélectriques ainsi que de valider des méthodes de caractérisation originales développées au sein du laboratoire GREMAN. / The purpose of this work is to elaborate different controlled microstructures of undoped (K0,5Na0,5)NbO3 by different methods, with full structural and microstructural characterization in order to study and to elucidate the influence of the densification and grain size effect on the piezoelectric properties. For this, it is necessary to produce KNN microstructures with controlled composition, starting with micrometer grain size, then millimeter and if possible centimeter grain size and to attain densification ranging from 80 % up to 95 % of the theoretical one. Beyond the KNN microstructure engineering, the growth of large (K0,5Na0,5)NbO3 single crystals about several mm3 with good crystallinity and full structural and microstructural characterization would enable the elastic, dielectric and piezoelectric tensors to be fully characterized as well as to validate the original characterization methods developed within the GREMAN laboratory.

The aim of this masterś thesis is to investigate properties of lead-free low-temperature solders after termal aging. The theoretical part is focused on various types of lead - free solders, pastes used for the manufacture of electrical circuits by thick-film technology and methods of testing the properties of the soldered joints. The practical part deals with the design and production of test substrates for testing the solder joints formed between the SMD component and the ceramic substrate. Two solder bismuth-containing solder was selected for testing, the SAC solder was selected as the reference. After aging with temperature cycling from -30 ° C to 115 ° C, the data obtained by testing the mechanical strength of the solder joint by the shear test is evaluated.