This diploma thesis deals with a defect detection with X-rays in the manufacturing procedure in the electrotechnical field. The work summarises the knowledge about technical possibilities of an X-ray device Cougar of YXlon company. Part of the work is focusing on scanning in 2D, 3D visualization and automatic analysis. The thesis describes inspection methods of a connector connection, the quality of a soldered joint and an encapsulated product.

Project is focused on describe modern assembly of microelectronic and electronic modules in electronic devices. Sense of the project is analyse reliability and inadequacies electronic devices assembled by modern technogies. Inadequacies modern technologies are impulse for design, implementation and testing new our way of assembly microelectronic modules. Main kind of materials which are used in this project are ceramics Al2O3 and printed circuit board FR4.

These thesis deals with electromigration in solder joint. In theoretical part are described lead-free solders, surface finish, formation of solder joint, intermetallic compounds a electromigration. In practical part is investigated a effect of electromigration on growth intermetallic compounds in solder jsoint.

This diploma thesis deals with the reliability of lead-free solder joints at a different interconnection structures. The first goal is to design the test cases shape BGA (FC) for testing the strength of lead-free solder joints at shear test in link with design of measuring method to detection shear strength during isothermal aging of lead-free solder joints. Following this shear stressing is investigating influence material and process compatibility, ie. pads finishing, material of solder and integrate of temperature (this mean thermal energy supplied during soldering) to lead-free solder joint strength.

This master´s thesis dealing with study of influence of inert atmosphere on the wettability of soldered surfaces. The theoretical part is discussed the issue of the soldering, solder joint, oxidation, and inert atmosphere. The glass cover with internal inert gas preheating for the wetting balance testing was prepared in the practical part. With this adjustment were realised tests, in which was examined the effect of the inert gases on the wettability of different materials combination. Further experiments were focused on plasma surface cleaning as possible flux substitution. The evaluation of these experiments were discussed in the end of this master´s thesis. Some of topics were designed for further experiments.

This master's thesis deals with issue of lead-free soldering in protective atmosphere with focus on wetting test. Theorethical part is focused on the types of lead-free solders, wettability tests performed on solder joints, different types of soldering or comparison of influence of the base material in regards to the wetting of the solder. The goal of practical part is testing and comparison of spreadability of selected lead-free solder on two conductive surfaces with different concentration of oxygen in protective nitrogen atmosphere. Testing has been performed on ceramic substrate which differs this method from others, performed on organic substrate. For an over-melted solder, the crystal-growth on surface in regards to protective atmosphere concentration is shown.

The diploma work is focused to evaluation of contemporary state of sealing system solution of high speed turbine engines in the world and, newly suggesting nontraditional design of labyrinth sealing lining for turbine side of small turbojet engine, including the production technology, technical-economic classification and experimental verification.

The doctoral thesis is focused on research on application possibilities of soldered interconnection structures especially for the use with innovative 3D structures assembled using the LTCC ceramic materials, PVD deposited and galvanically modified pads, solid core solder balls. It consists of several main parts. Introduction is followed by theoretical survey of current situation and technologies. Thesis continues with introduction of main goals and with summary of successively performed experiments and their results. End of the work belongs to summary of results and gained knowledge.

De nos jours, une des stratégies pour améliorer les propriétés des brasures sans plomb est d'introduire en petites quantités certains éléments d'alliage. Dans notre étude, deux nouveaux types de brasures, dénommés Innolot et SAC-Bi et dont l'utilisation dans diverses applications électroniques augmente, sont caractérisées. En particulier, l'effet des éléments Ni, Sb et Bi sur les propriétés mécaniques est analysé. L'étude vise également à évaluer l'influence des facteurs de sollicitation, du vieillissement en température sur la réponse des matériaux et leurs évolutions microstructurales. A cet effet, une machine permettant de réaliser des essais de micro-traction sur éprouvettes miniatures a été conçue et fabriquée. Les sollicitations qu'elle permet d'appliquer sont multiples (traction, cisaillement et cyclage) et des conditions en température et en vitesse de déformation peuvent être imposées lors de l'essai. La fabrication des éprouvettes nécessaires aux essais a également été entreprise dans cette étude afin d'avoir un matériau similaire à celui issu du process industriel et de disposer d'une géométrie adaptée au type de caractérisation souhaitée (éprouvettes massives, à simple recouvrement, etc.).Après ces étapes préparatoires, des tests ont été réalisés sous sollicitations de traction, cisaillement, fluage et fatigue en faisant varier les conditions d'essais. Le premier objectif a été l'identification du comportement des brasures, y compris en prenant en compte l'effet du vieillissement. Ces données ont permis ensuite de réaliser des simulations thermo-mécaniques sur les matériaux utilisés sous forme de joints de brasure dans un module de puissance sous cyclage thermique. Les analyses de microstructure (SEM/EDS et EPMA) faites par la suite ont montré le rôle des éléments d'alliage (Ni, Sb et Bi) sur les performances mécaniques des brasures en termes de résistance, limite élastique et rigidité. Le rôle des facteurs d'essai, comme la température, la vitesse de sollicitation et la durée de vieillissement, a également été mis en évidence au niveau des propriétés obtenues et des changements dans la microstructure. Il a été établi que l'élément Sb permet de favoriser le durcissement par écrouissage des brasures, tandis que l'ajout des éléments Ni et Bi permettent un raffinement de la microstructure. Les essais ont aussi permis d'identifier les 9 paramètres de la loi d'Anand par une procédure numérique s'appuyant sur les données de traction et de cisaillement, permettant ainsi de réaliser des simulations par éléments finis. Ces dernières suggèrent un meilleur comportement à la fatigue pour la brasure Innolot qui bénéficie est effets favorables des additifs. / Nowadays, one of the strategies to improve the reliability of lead-free solder joints is to add minor alloying elements to solders. In this study, new lead-free solders, namely InnoLot and SAC387-Bi, which have begun to come into use in the electronic packaging, were considered to study the effect of Ni, Sb and Bi, as well as that of the testing conditions and isothermal aging, on the mechanical properties and microstructure evolution. A new micro-tensile machine are designed and fabricated, which can do tensile, compressive and cyclic tests with variation of speeds and temperatures, for testing miniature joint and bulk specimens. Additionally, the procedure to fabricate appropriate lap-shear joint and bulk specimens are described in this research. The tests, including shear, tensile, creep and fatigue tests, were conducted by micro-tensile and Instron machine at different test conditions. The first study is to characterize, experimentally, the mechanical behaviors and life time of solder joints submitted to isothermal aging and mechanical tests. The second goal of the project is to perform thermo-mechanical simulations of IGBT under thermal cycling. The experimental results indicate that, with addition of Ni, Sb and Bi in to SAC solder, the stress levels (UTS, yield stress) are improved. Moreover, testing conditions, such as temperature, strain rate, amplitude, aging time, may have substantial effects on the mechanical behavior and the microstructure features of the solder alloys. The enhanced strength and life time of the solders is attribute to the solid hardening effects of Sb in the Sn matrix and the refinement of the microstructure with the addition of Ni and Bi. The nine Anand material parameters are identified by using the data from shear and tensile tests. And then, the obtained values were utilized to analyze the stress-strain response of an IGBT under thermal cycling. The results of simulations represent that the response to thermal cycling of the new solders is better than the reference solder, suggesting that additions of minor elements can enhance the fatigue life of the solder joints. Finally, the SEM/EDS and EPMA analysis of as-cast, as-reflowed as well as fractured specimens were done to observe the effects of these above factors on the microstructure of the solder alloys.

L’étude de ce mémoire concerne l’élaboration d'un alliage alternatif sans plomb pour l’électronique de puissance, celui-ci sera utilisé à des fins de brasures. Les brasures actuelles sont composées d’alliages comportant du plombet sont peu résistantes en cas de travail à haute température. Ces systèmes seront progressivement éliminés, ils ne respectent plus la Directive Européenne sur l’environnement (RoHS) et les normes de santé publique en raison de la toxicité du plomb (cancérogène, mutagène, accumulation dans l’environnement …). Le travail a été réalisé avec l’alliage Ag-Sn, l’objectif principal de cette thèse a été d’élaborer le composé Ag3Sn, en raison de sa grande résistance thermique (température de fusion élevée de 480°C). Ses meilleures performances sont avantageuses pour les brasures situées dans des environnements difficiles comme l’aéronautique ou l’automobile. La première partie de ce manuscrit détaille la synthèse du composé Ag3Sn réalisée via la méthode polyol, une voie de chimie douce. Il s’agit d’une technique différente des techniques classiques, comme la voie métallurgique. La synthèse a été réalisée en plusieurs étapes et une méthode d’approches successives a été utilisée afin de déterminer les paramètres de synthèse optimums.Deux protocoles particuliers se détachent et ils permettent d’élaborer des phases résistantes à haute température. Lepremier permet d’élaborer une phase pure d' Ag3Sn, tandis que le second permet d’élaborer deux phases de solutionssolides. Les composés ont été caractérisés par DRX, par imagerie MEB-FEG et MET et par analyse thermogravimétrique.La seconde partie de ce travail est la consolidation de ce composé Ag3Sn par une technique de frittage particulière :le die-bonding, afin de réaliser la connexion entre la puce électronique et un susbtrat de cuivre recouvert d'argent.Une étape de dépôt des poudres sur le substrat a été nécessaire avant de réaliser la consolidation, elle a été réalisée selon différentes techniques : le spin-coating ou le dépôt par sérigraphie. Puis, les paramètres de frittage par die-bonding ont été affinés selon les techniques de dépôt. Enfin, des essais de cisaillement ont été réalisés sur certains échantillons. / The study of this memoir concerns the development of an alternative lead-free alloy for power electronics, which will be used for solders. Nowadays, current solders are composed of alloys containing lead, and aren't resistant at high work temperature. These systems will be phased out, because they no longer comply with the European RoHS Directive and public health standards due to the toxicity of lead (carcinogenic, mutagenic, accumulation in the environment, etc.). This work was carried out with the Ag-Sn alloy, and the main objective was to develop the elaboration of the Ag3Sn compound, due to its high thermal resistance (high melting point of 480°C). Its best performance is an advantage for solders located in difficult work environments such as aeronautics or automobile. First part of this thesis describes the synthesis of Ag3Sn compound with the polyol process, a soft-chemistry routine. It is different from the conventional techniques, like the metallurgical way. Polyol synthesis was realized by following several steps. A method of successive approaches wasdetermine optimum synthesis parameters. Two specific protocols stand out, and they allow the development of high-temperature resistant phases. The first one allows the elaboration of an Ag3Sn pure phase, an the second one allows the development of two compounds of solid solutions. The compounds were characterized by XRD, FEG-SEM, TEM and thermogravimetric analysis. The second part of this work is the consolidation of the Ag3Sn compound with a special sintering technique : the die-bonding, in order to realize the connexion between the electronic chip and the copper substrate coated silver. A first step of depositing powder on the substrate was necessary before carrying out the implementation. It was carried out with various techniques : spin-coating orthe serigraphy deposition. Then, sintering parameters were refined according to the deposition techniques. Finally, shear tests were performed on different samples