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Solder Wave Process Optimization
Procházka, Martin ; Brno, Martin Štěpánek HONEYWELL (referee) ; Starý, Jiří (advisor)
This work describes solder wave process and it‘s optimalization. It informs us about wave soldering and describes it’s fragments. Next it is described partition of fluxes and their properties. In practical part is described researching of defects on PCB’s and analysis of possible reason of defects, measurement of the weight of sprayed flux and measurement of solderable profile.
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REBALLING OF BGA PACKAGES USING PACE TF2700 EQUIPMENT
Roháček, Peter ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The Diploma thesis is focused on reballing of BGA packages with the device PACE TF 2700. It describes the general types of BGA packages, their defects, importance of thermal management to the solder techniques, where it is also talked about the meaning of solders and fluxes for the joint. The work informs about the most common methods of reballing, the proper handling of components and the current situation with BGA stencils on the market. It briefly describes the device operation of PACE TF 2700, that is working on the convection and IR principle of heating components. It deals with the manufacturing of the template, dummy BGA packages, the test plates, creation of the thermo profile, comparing and examining the defects and their causes, which had the most significant impact on the results. The achievements would serve for comparing them with the results of the future laboratory exercises or as a subject for further works.
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Microdefects in Czochralski Silicon
Válek, Lukáš ; Fejfar, Antonín (referee) ; Mikulík, Petr (referee) ; Spousta, Jiří (advisor)
Disertační práce se zabývá studiem defektů v monokrystalech Czochralskiho křemíku legovaných bórem. Práce studuje vznik kruhových obrazců vrstevných chyb pozorovaných na povrchu křemíkových desek po oxidaci. Hlavním cílem práce je objasnit mechanismy vzniku pozorovaného rozložení vrstevných chyb na studovaných deskách a vyvinout metody pro řízení tohoto jevu. Na základě experimentálních analýz a rozborů obecných mechanismů vzniku defektů jsou objasňovány vazby mezi vznikem defektů různého typu. Tyto jsou pak diskutovány v souvislosti s parametry krystalu i procesu jeho růstu. Takto sestavený model je využit pro vývoj procesu růstu krystalů, kterým je potlačen nadměrný vznik defektů ve studovaných deskách. Za účelem studia defektů jsou zaváděny a vyvíjeny nové analytické metody. Disertační práce byla vytvořena za podpory ON Semiconductor Czech Republic, Rožnov pod Radhoštěm.
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The lamination of Low Temperature Co-fired Ceramic
Hudeček, Ondřej ; Klíma, Martin (referee) ; Kosina, Petr (advisor)
Master’s thesis deals with the optimalization of low-temperature cofired ceramic lamination process that affects the final quality of 3D structures (eg., channels, cavities, membranes, etc.). The paper evaluates the influence of lamination parameters (pressure, temperature, time) on the formation of defects in the structure, which were detected by appropriate methods. The last parts describes designed and simulation cooling water system using LTCC technology.
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The Tools and Equipment for a Bending of Tubes
Kašpárek, Jan ; Štroner, Marek (referee) ; Peterková, Eva (advisor)
The bachelor thesis is aimed to make a general overview of used tools and equipment for a bending of tubes. On the basis of literary evidence the list of basic methods used in bending tubes was created. By conducting a survey in bending tubes producers manufacturing programs, various principles of bending tubes were described, which are supplemented with picture documentation. To each method there were mentioned some of the OEMs. Accompanying pictures describe the construction of individual machines and used tools and equipment.
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Analysis of Defects on PCB Using X-RAY
Mlýnek, Martin ; Vala, Radek (referee) ; Řihák, Pavel (advisor)
This thesis is focused on BGA packages and fault detection after rework using X – Ray. There is a description of BGA packages by carrier substrate, techniques of connecting on chip, from mounting packages to repair printed circuit boards (hereafter PCB). Thesis summarizes description of defects, which are created after rework process. There is also description of X – Ray as method for analyzing defects. X – PLANE method used to detect internal structure of BGA packages and it was confirmed by microsection and by software for reconstruction. Description of automatic and manual measurement is follow.
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Set possible causes for capacity loss of capacitors
Fabiánek, Marcel ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This thesis deals with formation of defects on through-hole capacitors. Process of wave soldering and its steps are described in the first part. The listing and description of possilble defects caused by wave soldering is followed after the first part. There are several sources of potential causes of capacity loss and a separate chapter to these causes. The last part contains a proposal of testing individual potencional causes. Their purpose is to reveal the root causes of formation of the defects and then the practical solution is described.
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Study of hydrogen interaction with defects in thin metallic films
Hruška, Petr ; Čížek, Jakub (advisor) ; Krsjak, Vladimír (referee) ; Mathis, Kristián (referee)
Thin metallic films are particularly interesting as potential hydrogen storage materials as well as hydrogen sensitive optical sensors. Thin films with various microstructure from nanocrystalline to epitaxial can be relatively easily prepared by varying the deposition parameters. Deposition of multi-layers enables preparation of thin films with arbitrary composition. Defects structure plays a key role in hydrogen absorption. Hydrogen atoms segregated at open volume defects reduce their formation energy leading to enhan- ced concentration of hydrogen-induced defects in the material. Moreover hydrogen diffusion along dislocations and grain boundaries facilitates hydrogen absorption in the metal lattice. Thin films clamped to the stiff substrate undergo anisotropic volume expansion during the hydrogen loading. As a consequence high stresses are induced in the film and can result in detachment of the film from the substrate. In this work hydrogen absorption in Gd and Pd films and Pd-Mg multi-layers was studied. Development of the defect structure of hydrogen-loaded films was investigated by means of variable energy positron annihilation spectroscopy com- bined with X-ray diffraction, atomic force microscopy and optical transmittance measurement. Complementary studies of interaction of hydrogen with defects in...
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Investigation of defects in quasicrystals
Vlček, Marián ; Čížek, Jakub (advisor)
Název práce: Studium defekt· v kvazikrystalech Autor: Marián Vlček Katedra: Katedra fyziky nízkých teplot Vedoucí disertační práce: doc. Mgr. Jakub ížek, Ph.D., Katedra fyziky nízkých teplot Abstrakt: V predloženej práci boli pomocou spektroskopie doby života poz- itrónov a koincidenčnej spektroskopie Dopplerovského rozšírenia anihilačného píku študované zliatiny WE43 s prídavkom zinku a ternárne zliatiny Mg-Zn-Y. V týchto zliatinách bola nedávno zistená prítomnos' ikosahedrálnej fázy Mg3Zn6Y1 s kvázikryštalickou štruktúrou, čo pritiahlo pozornos' výskumníkov. Spektroskopia doby života pozitrónov preukázala prítomnos' unikátnych vakanciám podobných defektov na rozhraní ikosahedrálnej fázy a horčíkovej matrice, ktoré sú charakter- istické pre horčíkové zliatiny obsahujúce ikosahedrálnu fázu. Tepelné spracovanie skúmaných zliatin vedie k významným zmenám morfológie hraničných fáz. Ke¤že vakanciám podobné defekty spojené s ikosahedrálnou fázou sa vyskytujú na jej rozhraní s horčíkovou matricou, zmeny v morfológii ikosahedrálnej fázy vedú k výrazným zmenám koncentrácie týchto defektov. "alej boli skúmané vzorky pripravené uhlovým pretláčaním kanálom rovnakého prierezu. Typy defektov prítomné v týchto zliatinách a ich teplotná stabilita bola určená pomocou spektroskopie doby života pozitrónov a merania tvrdosti...
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