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Mechanical and Electrical Properties of Thin Metal Films Deposited by Vacuum Evaporation
W. F. Yahya, Doaa ; Kolařík, Vladimír (referee) ; Štencl,, Jiří (referee) ; Šandera, Josef (advisor)
Thin layers are widely used in many fields of technology and today we can say that they are found in all modern technologies. Thin layers can be created in two ways, namely by chemical or physical means. This work focuses on the latter method, more particularly a technology of thermal evaporation of thin layers in a vacuum. The work focuses on the process principles during and after the evaporation. Much of the work focuses on the development and design of experiments. These experiments illustrate some of the phenomena that take place on thin films produced by the aforementioned technology. Work helps to better understand processes during formation of thin layers and properties that influence the quality and stability of thin films. In conclusion we describe results of experiments and new developments in the field of thin films deposition using evaporation under vakuum are summarized.
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Design and properties of low-frequency amplifier with vacuum valves
Piroha, Ladislav ; Musil, Vladislav (referee) ; Šandera, Josef (advisor)
The purpose of the bachelor’s thesis is explanation of theory and construction of low frequency tube audio amplifier with UV meter. Main focus is on history and development of vacuum circuits from its early beginning, on electrical parameters and applied physical principles. Explanation of operating characteristics of amplifier classes and comparison of vacuum tube sound acoustic performance against transistor amplifier one. Finally, there is build description of single ended amplifier class A.
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Influence of printed board surface finishing on solderability with vapour soldering
Matras, Jan ; Starý, Jiří (referee) ; Šandera, Josef (advisor)
Thesis deals with vapor soldering and wetting the surface with solder during the soldering process. It describes in detail the advantages and disadvantages of various surface finishes on the PCB. Generally characterizes the properties of lead-free solders and fluxes. Describes vapor soldering process, including the properties of the liquid itself. It also focuses on a method of evaluating the wettability by using solder balls and its performance on individual samples surface finishes.
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Temperature Control of Heating Element with Thermocouple
Spáčil, Michal ; Novotný, Radovan (referee) ; Šandera, Josef (advisor)
Goal of this work is to develop and then build system that would keep constant temperature in a given place or that of a given material (item), in this case it would be control system for a hot air soldering station heater with output up to 600W, with required adjustable temperature range of 150-500°C. Second goal of this work is to develop and then build this device using possibly simplest wiring and as small amount of components as possible.
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Design and realization of electronic modules
Matula, Tomáš ; Adámek, Martin (referee) ; Šandera, Josef (advisor)
This thesis discusses interconnection electronic and microelectronic modules with Printed Board Circuit(PCB). The first part contains of definition of module, thermomechanical stress, analysis of bacic materials, characterization of interconnection using solder balls, pins, edge PCB, and new method for interconnection using chip component. The practical part is to design an intelligent controller module and color detector. Color detector module is connected to the motherboard using the edge PCB pins and shoulder into the socket PLCC 68.
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Insulating Properties of Flip Chip Structures
Dóczy, Robert ; Šandera, Josef (referee) ; Pulec, Jiří (advisor)
This work deals with the insulation properties of microelectronic structures. Specifically, insulation resistance of the gap that separates the conductive parts of the system. There are also described the influences, which have the effect on insulation resistance and the methods by which the insulation resistance is measured. There are also slightly described the issues of designing microelectronic packages and ways in which the microelectronic chip can be connected to the circuit. In the experimental part, the thesis deals with specific design of microelectronic structure such as flip-chip. Conductive pattern of this structure was made to allow the measurement of insulation resistance which depends on the application materials which were used in structure assembly. For this purpose, the structures also undergo a series of cleaning, whose influence is also discussed.
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Planar LED Display Application
Houserek, Jiří ; Kosina, Petr (referee) ; Šandera, Josef (advisor)
This coursework deals theoretical with design and construction of the electronic clocks controlled by DCF77 signal, which is broadcasted from Germany. This device will be used as alarm and is able to show date. There is used display, which consists of 8x32 LED matrix in a modular, which is connected to main board over the edge. This device is controlled by microcontoller PIC16F887A. There are described displays, microcontrollers and DCF time signal.
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Termomechanical reliability soldered connections in electronic
Novotný, Václav ; Psota, Boleslav (referee) ; Šandera, Josef (advisor)
The diploma thesis deals with the sphere of solder joints reliability. The narrower focus is use of lead-free solder alloy SAC305 in the production process and parameters of its reliability. The text describes the main factors, which have the influence on the reliability of solder joints under conditions of thermal cycling. These factors also relate with choice of substrates and technological processes of preparation, which are characterized and described. Another part is devoted to estimating the reliability of soldered connections and are listed the fatigue model to estimate reliability. These fatigue models are categorized based on different physical mechanisms that operate in the soldered joints during operation. Based on the comparison of different models is selected the most appropriate model and in conjunction with simulation in ANSYS is estimated reliability. For this purpose is selected soldered connection of the FR-4 substrate and ceramic substrate via SMD component. They are manufactured test kits and subjected to conditions of temperature cycling. Results obtained from experimental measurements are compared with results obtained by simulation and calculation.
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Extending the functionality of LaiPen
Trtílek, Jakub ; Šandera, Josef (referee) ; Hejátková, Edita (advisor)
The main goal of bachelor thesis was extending functionality of LaiPen LP 100 with voice recognition module, that would help to insert names of plants, while working with the device. Manual selection of vegetation is in the current version of the instrument barely used, cause of long time demands. Selecting, implementing and programming the voice recognition module EasyVR 2.0, was the topic of my work. Also the design of controlling menu and integration of the module to the LaiPen device. For the integration was necessary to design module, that would mediate communications between CPU and voice recognition module. The work includes also a design of I2C/UART convertor. For this design of the convertor was used microcontroller Max3109, that required to program main controlling functions.
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