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Wetting and Spreading of Solder on PCB Surface
Wiesner, Lukáš ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This work deals with the metal surface wetting problems of molten lead-free solder and monitoring of ongoing processes at the inter-phase interface. This work also deals with flushing monitoring of spreading velocity on solder finishes Ni/Au and Immersion Sn deposited on copper plated base material FR4 using digital cameras. Measurement is performed at the improved workplace. After the reflow process is measured by length of spreading solder. It evaluates and compares the time dependence of velocity of spreading solder for Ni/Au and Immersion Sn finishes.
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Influence of Bottom Preheating in Rework of Assembled PCB
Čechák, Ondřej ; Bžoněk, Tomáš (referee) ; Starý, Jiří (advisor)
This bachelor's thesis introduces the problematics of physical mechanisms of heat transfer and the correlative mathematical formulas and the use of mentioned problematics in the technology of bottom preheating in the rework of assembled printed circuit boards. It explains the importance and reasons of use of this technology, not merely in the professional production. It focuses on expert analysis of the appliances based on their properties and clarifies the differences in basic types of the devices. The emphasis is then laid on a practical testing of the technical parameters of the preheating devices as well as on an experimental design and a practical testing of a local bottom printed circuit board preheater.
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Wave Soldering Fluxes Comparison
Stoklásek, Lukáš ; Martinec, Petr (referee) ; Starý, Jiří (advisor)
Semestral thesis introduces the problematics of wave soldering fluxes, flux residues and problems of electromigration. Practical part describes measuring of ionic contamination by using conductometric method, measuring the wettability by the wetting balance method and amount of failures on wave soldered printed circuit boards with these fluxes. The main object is to compare quality of the fluxes.
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Wettability of PCB Surface Finishes and Comparison of Methods
Vídeňský, Ondřej ; Přikryl, Tomáš (referee) ; Starý, Jiří (advisor)
This bachelor´s thesis deals with testing methods for surface finishe´s wettability PCB. For this tests has been designed and created testing board which contains testing coupons for testing methods. Boards have been created and covered by surface finishes by Gatema Boskovice. In this thesis electroless nickel with immersion gold (ENIG) and immersion tin have been tested. For simulation of reflow soldering have been used test methods solder indicator, solder spread test and dewetting test. Wetting balance test method has been used as simulation of wave soldering.
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PCB s Cleaning from Prototypes to Low Series Production
Švéda, Miloš ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This bachelor thesis deals with the construction of the cleaning unit for prototype and low series production PCB cleaning. It describes the methods used for PCB cleaning, mainly for removing flux residues. It briefly describes the test methods for measuring contamination. It deals with the selection of individual components for cleaning equipment construction and compatible chemistry for flux residues cleaning.
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Solder Joint Quality based on Heating Factor
Kučírek, Martin ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
Master’s thesis in the theoretical part analyses the heating factor (Q), which has significant share on quality of a solder joint. The practical part describes the design and production of test PCB and setting temperature profiles, SMD resistors soldering by using BiSn solder paste. Shear tests of SMD solder joints were realised and evaluated including isothermal ageing samples. At the end of master’s thesis solder joints visual aspects and defects were evaluated, measurement thickness of intermetallic compound by not only optical microscope but also SEM, discussion about results and Q was evaluated.
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Reliability of LED Panels Solder Joints
Šimon, Vojtěch ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
Thesis is focused on the effect of heating factor on quality of solder joints. In theoretical part is solved reflow soldering technology, problematice of solder paste choice or criteria of soldering profile setting. The practical part is dedicated to demonstrating the impact of heating factor on solder joint quality. There are used X-Ray analysis, microsections and electron microscopy. In the final part of this thesis are summarized knowledge from theoretical part and experimental obtained results to defend of next steps in diploma thesis.
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Comparison of Old Norse and Proto-Norse Noun Declension
Šimeček, David ; Starý, Jiří (advisor) ; Štajnerová, Petra (referee)
Comparison of Old Norse and Proto-Norse Noun Declension The purpose of this thesis is to follow the development of noun declensions from Proto-Norse to the Old Norse (Old Icelandic) language. The first of the three chapters seeks to give a comprehensive overview of Proto-Norse noun declensions. This overview is based on the evidence of the older runic inscriptions and on reconstruction using relevant linguistic literature. Each of the declensions is presented in the form of a paradigm accompanied by commentary and quotations of preserved grammatical forms. The second and largest chapter presents a survey of Old Norse (Old Icelandic) noun declensions. The survey has two aims. The first aim is to provide a synchronic description of the Old Norse noun declension system which would not be encumbered by an excess of diachronic approach as is often the case in the traditional grammars of Old Norse. At the same time, however, it should show how Old Norse inflectional exponents and classes continue the Proto-Norse declensions as presented in the first chapter. There is also a discussion of some of the systemic causes leading to morphological changes in inflection. The third chapter sums up the previous diachronic analysis and questions the validity of the traditional designations of declension classes based on...
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"He was a good farmer, he died in Greece." Activities of people of the Viking age and their appreciation in runic inscriptions and sagas
Podolská, Markéta ; Starý, Jiří (advisor) ; Kadečková, Helena (referee)
This thesis is an analysis of the activities of people of the Viking Age based on runic inscriptions and selected sagas of Icelanders and one kings' saga. The first chapter classifies the activities mentioned in the complete runic corpus as well as the appreciated qualities of the commemorated ones. The second part focuses on the frequency of particular activities in the Icelandic sagas. The sagas are divided into groups according to the emphasis laid on certain activities. Subsequently, the results of both analyses are set in contrast and the differences in their idealised view on the activities of the Viking Age are examined. While the runic inscriptions emphasize the Viking and trade voyages and the ability of householders, the sagas' focus is on the voyages as well as on the fights, legal disputes and feud. Although both sources par- tially correspond, they accent different aspects of reality and are mutually complementary. Keywords: Old Norse literature, Old Norse society, runic inscriptions, sagas of Icelanders, kings' sagas
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The influence of Latin on North Germanic languages, especially on Norwegian
Koliášová, Klára ; Štajnerová, Petra (advisor) ; Starý, Jiří (referee)
The thesis concentrates on Latin influence on North Germanic languages, especially on Norwegian. First part deals with this topic from sociolinguistic point of view: relationship between Latin and domestic languages in Middle Ages, discerning contexts, where Latin was used, emphasizing the role of church, schools and literature. Second part concentrates on concrete examples of Latin influence, persisting to the modern times, especially loanwords, prefixes and suffixes, irregular declension, idioms. Original research concentrates on Norwegian letters from Middle Age, in Diplomatarium Norwegicum. Research about numbers of Latin letters and letters in domestic language, according to topic and time, in comparison with similar informations from Denmark and Sweden.
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