|
|
The conductive layers in LTCC
Poledník, Tomáš ; Psota, Boleslav (referee) ; Kosina, Petr (advisor)
The bachelor thesis was focused on a determination of the limits of screen printing and on estabilishing a power loading of layers on LTCC. It describes the print of the conductive themes via the screen-printing method on the substrata. The thesis contains the description of a measuring on the conductive layers, and a processing its results. It was also performed the printing of layers on a corundum ceramics in order to compare the results. From the measured values were formed the graphs, which represent the possibility of the power loading of layers depending on the temperature and on the width of the thick-layer guide.
|
|
| |
|
|
Study of BGA and QFN package properties
Skácel, Josef ; Psota, Boleslav (referee) ; Szendiuch, Ivan (advisor)
This work deals with the issue of packaging and heat transfer. Especially this work focused on QFN and BGA packages. Nowadays most sophisticated conventional solution. First part deals with analysis of the current status of packages. Next part is analyze the issue of heat transfer in electronic systems. The following section is an experimental dealing with simulation in ANSYS Workbench and validation of these simulations by designed test structures. At the end is evaluated properties and behavior of these packages.
|
|
|
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.
|
|
| |
|
|
Flow sensor
Symerský, Tomáš ; Psota, Boleslav (referee) ; Kosina, Petr (advisor)
This diploma thesis is divided into two parts - theoretical and practical. In its first, theoretical part, deals with the theory of fluid and gas flow, heat transfer and diversification of sensors for flow measurement working on the electrical principle. It also deals with thermodynamic principle, which can be used for measuring very small flow and low-temperature ceramics that is used to implement microcanals for sensing very low flows. The practical part of the thesis deals with the very simulation of the entire structure in the program “COMSOL Multiphysics” - both in 2D and 3D views. Then there is shown the implementation and measurement of the flow sensor in a low-temperature ceramics, working on a thermodynamic principle.
|
|
| |
|
| |
guest ::
