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Degradation test of polymer material
Darebný, Tomáš ; Špinka, Jiří (referee) ; Vaněk, Jiří (advisor)
Basic knowledge of photovoltaic energy transformation, devices and materials, used in photovoltaics are summarized in this bachelor’s thesis. Sort of degradation factors of the photovoltaic panels and the norm ČSN EN 61215, are described there. The main purpose of this research is monitoring the change of volume and surface resistivity of selected covering materials. These covering materials were influenced of increased humidity.
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Semiconductor devices production on silicon
Ježek, Vladimír ; Mikulík, Petr (referee) ; Špinka, Jiří (advisor)
This work deals with the basic technologies and processes of manufacturing semiconductor devices on a silicon substrate. Deals with the processes from creating a layer of silicon dioxide by oxidation, through the creation of structures using photolithography, the doping of additives into defined areas of diffusion, up to creating contacts and conductive pathways by sputtering. It also deals with the technological production process for silicon devices, description of devices and measurement, calculation layers of silicon dioxide, calculated of diffusion and measured characteristics of components and their evaluation.
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Trends in Solder Paste Area and Nanoparticles Influence
Dosedla, Milan ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This thesis deals with novel trends in solder paste technology. It focuses on nanoparticle applications used as a tool for improving a state of the art lead free solder alloys. The recently published results about the impact of different types of nanoparticles on properties of newly-emerged nanocomposite solders are discussed and summarized in the thesis. Preparation, practical application and testing of new solder paste based on low temperature SnBi alloy with an admixture of titanium dioxide are also discussed. Finally, properties of solder joints using these solder pastes are investigated and the results are evaluated.
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Scintillation SE detector for ESEM
Odehnal, Adam ; Špinka, Jiří (referee) ; Jirák, Josef (advisor)
Thesis deals with theoretical knowledge about scanning electron microscopy and environmental scanning electron microscopy. It describes principle of operation, signals generated by interaction between primary electron beam and specimen and means of detection of secondary electron signal in environmental conditions using scintillation detector. Furthermore, thesis focuses on optimization of detection od secondary electrons by adjusting electrode system of scintillation detector. Computer program Simion is used for modelling signal electron trajectories for proper adjustments. Simulation were starting-point for adjusting the design of the detector. Detection efficiency of adjusted detector was determined by evaluating signal magnitude from captured images, secondary electron detection capability from voltage contrast and quality of the captured images from signal/noise ratio.
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Measurement of insulation and dielectric properties of water.
Žvátora, Jaroslav ; Starý, Jiří (referee) ; Špinka, Jiří (advisor)
This bachelor thesis deals about dielectric and insulation properties of water. It describes the structure of water, hydrogen bonds. It explains primary physical and chemical properties of water and then it describes parameters of water such as dynamic viscosity, conductivity, surface pension, loss factor, polarization. Part of the work is practical section, which deals measurements of water and shows primary dependence such as capacity dependence on frequency or loss factor on frequency.
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Detection of signal electrons in ESEM
Šváb, Martin ; Špinka, Jiří (referee) ; Jirák, Josef (advisor)
This bachelor's thesis deals with problems of environmental scanning electron microscopy and with detection of signal electrons at higher pressure in working chamber. In this thesis I will focus on comparison of detected signal level achieved under different working conditions.
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Flux Residues after Reflow Soldering
Uhlář, Vít ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The aim of this bachelor thesis is to solve flux residue characteristics on PCBś after reflow soldering and compare different solder pastes. The first part deals with the issue of solder paste application and flux residues. The second part focuses on the process of reflow soldering. The third part is devoted to the measurement methodology of flux residues. Finally, project is a practical part, which is summarized in the production of test samples and contains measurement results.
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Lead Free Solder Joint Strength and Cooling Gradiient Influence
Vítek, Jiří ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The object of this work is to monitor the impact of gradient cooling on the strength of the solder joint and its crystalic structure. Dummy packages BGA4 were soldered on PCBs with test structure. Base material FR4, Cu interconnections were protected with OSP and Ni – Au surface finishes and SAC405 solder was used. The samples were made in three different cooling gradients, 6.80 °C/s, 2.00 °C/s and 0.16 °C/s. The bond strength was measured by using the shear strength test on device DAGE PC 2400. Realised microsections were studied on an optical microscope OLYMPUS GX 51.
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Semiconductor properties
Řihák, Pavel ; Frk, Martin (referee) ; Špinka, Jiří (advisor)
This bachelor's project deals with methodology for determination the semiconductors parameters. Particularly, it deals with methods of diffusion length measurrement. Various methods of measurement were studied for this purpose and selected the most suitable one. Which was carried measurements on a sample of silicon using IR power LEDs.
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Evaluation of Gas Flow at the Proposed Shapes of Scintillation Detector Aperture Sieves
Matloch, Roman ; Špinka, Jiří (referee) ; Maxa, Jiří (advisor)
This work describes briefly electron microscopy issue and physical model of fluid flow. Then the simplified three-dimensional model of scintillation detector will be created in SolidWorks system for 3D cubical models. The gas flow behind the screening in this 3D model will be analyzed and compared by method of finite cube method in SolidWorks Flow Simulation system. This screening will be analyzed in several variants: the screening with 0.6 mm opening and the screening with net-like openings. The results of analyses will be compared according to the requirements. The appropriate shapes from the analyzed parts will be practically measured.
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