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QFN Packages Soldering and Technology Procedures
Jakub, Miroslav ; Brno, Petr Martinec, HONEYWELL (referee) ; Starý, Jiří (advisor)
This master´s thesis deals with QFN packages soldering and technology procedures optimization. The aim of theoretical part is description of QFN packages, their assembly and reflow soldering on PCB in HONEYWELL. The aim of the practical part is to propose a method of measuring temperature and optimizing the thermal profiles of selected PCB with QFN packages by using convection (HONEYWELL) and infrared (BUT) reflow ovens. Comparison and evaluation of thermal profiles for 3 production PCBś with QFN packages using solder paste AIM NC257-2 were realised. The main part of master´s thesis are appearance evaluation of solder joints, preparing microsection and measuring intermetallic layers thickness by using the optical and the scanning electron microscopes, analysation and study of QFN defects created during soldering proces. These tests were performed with 2 production PCB´s. Optimization of SPI and soldering technology procedures where were analyzed QFN packages were processed on one type of PCB. Interesting part of this diplomma thesis is creating of the 3D heat transfer model of QFN package during the reflow soldering in SolidWorks.
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Steam turbine
Šamalík, Jakub ; Martinec, Jiří (referee) ; Fiedler, Jan (advisor)
In this master’s thesis, I made a thermodynamic calculation of a steam turbine under the parameters given. In order to increase the efficiency of the low-pressure turbine section and to reduce axial length of the low-pressure rotor, a radial stage is designed in this section. The master’s thesis also includes a design of the low-pressure section. The thesis is divided into chapters, which contains a calculation of the single sections of the turbine. In the introductory chapters, the single sections of the turbine engineered are theoretically discussed. In the conclusion, assessments of the benefits of the use of radial stage are made.
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Evaluation of Usefulness of Debugging Tools
Martinec, Tomáš ; Děcký, Martin (advisor) ; Yaghob, Jakub (referee)
Debugging is a very time-consuming activity for programmers. Although the number of proposed debugging tools is large, the number of tools that are actually adopted by practitioners and used during development of software is less than one may expect. Many believe that one reason for the situation is that it is hard to estimate whether the implementation efforts of proposed debugging tools or approaches are worth the gain. The first goal of this thesis is to propose a methodology for the evaluation of usefulness of debugging tools. To provide an exemplary usage of the methodology, a study of usefulness of typical debugging tools for development of operating systems is conducted. Secondly, the thesis also explores and documents further aspects of how programmers debug software. Powered by TCPDF (www.tcpdf.org)
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Evaluation of Usefulness of Debugging Tools
Martinec, Tomáš ; Děcký, Martin (advisor) ; Yaghob, Jakub (referee)
Debugging is a very time-consuming activity for programmers. Although the number of proposed debugging tools is large, the number of tools that are actually adopted by practitioners and used during development of software is less than one may expect. Many believe that one reason for the situation is that it is hard to estimate whether the implementation efforts of proposed debugging tools or approaches are worth the gain. The first goal of this thesis is to propose a methodology for the evaluation of usefulness of debugging tools. To provide an exemplary usage of the methodology, a study of usefulness of typical debugging tools for development of operating systems is conducted. Secondly, the thesis also explores and documents further aspects of how programmers debug software. Powered by TCPDF (www.tcpdf.org)
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Barotropní oceánický slapový model
Einšpigel, David ; Martinec, Zdeněk (advisor) ; Velímský, Jakub (referee)
Title: Barotropic ocean tide model Author: David Einšpigel Department: Department of Geophysics Supervisor: prof. RNDr. Zdeněk Martinec, DrSc., Department of Geophysics Abstract: The main aim of this thesis is developing of a numerical model of an oceanic circulation forced by the lunisolar tidal potential. The circulation is described by the shallow water equations which are derived from the fundamental balance laws assuming that the ratio of the vertical and horizontal dimension of the investigated problem is small, which leads to the formulation of the 2- D task. Furthermore, programs for solving the shallow water equations were written. Their functionality is demonstrated on several examples. The programs include an ephemeridal tidal modul which computes the complete lunisolar tidal potential. Keywords: oceanic flow, shallow water equations, lunisolar tidal potential
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Steam turbine
Šamalík, Jakub ; Martinec, Jiří (referee) ; Fiedler, Jan (advisor)
In this master’s thesis, I made a thermodynamic calculation of a steam turbine under the parameters given. In order to increase the efficiency of the low-pressure turbine section and to reduce axial length of the low-pressure rotor, a radial stage is designed in this section. The master’s thesis also includes a design of the low-pressure section. The thesis is divided into chapters, which contains a calculation of the single sections of the turbine. In the introductory chapters, the single sections of the turbine engineered are theoretically discussed. In the conclusion, assessments of the benefits of the use of radial stage are made.
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QFN Packages Soldering and Technology Procedures
Jakub, Miroslav ; Brno, Petr Martinec, HONEYWELL (referee) ; Starý, Jiří (advisor)
This master´s thesis deals with QFN packages soldering and technology procedures optimization. The aim of theoretical part is description of QFN packages, their assembly and reflow soldering on PCB in HONEYWELL. The aim of the practical part is to propose a method of measuring temperature and optimizing the thermal profiles of selected PCB with QFN packages by using convection (HONEYWELL) and infrared (BUT) reflow ovens. Comparison and evaluation of thermal profiles for 3 production PCBś with QFN packages using solder paste AIM NC257-2 were realised. The main part of master´s thesis are appearance evaluation of solder joints, preparing microsection and measuring intermetallic layers thickness by using the optical and the scanning electron microscopes, analysation and study of QFN defects created during soldering proces. These tests were performed with 2 production PCB´s. Optimization of SPI and soldering technology procedures where were analyzed QFN packages were processed on one type of PCB. Interesting part of this diplomma thesis is creating of the 3D heat transfer model of QFN package during the reflow soldering in SolidWorks.
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