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Comparison of solders for power modules
Spaček, Marek ; Boušek, Jaroslav (referee) ; Hejátková, Edita (advisor)
Táto práca podáva náhľad na výkonové polovodičové moduly, technológie v nich požívané a niektoré procesy používané na ich výrobu. Popisuje aj niektoré kvalitatívne kritériá pre spájkovaný spoj medzi DBC substrátom modulu a jeho základovou doskou a metódy používané na ich inšpekciu. Na koniec porovnáva vlastnosti 6-zložkovej vysoko spoľahlivostnej spájky 90iSC vyvinutej firmou Henkel so štandardnou spájkou požívanou na výrobu modulov vo firme SEMIKRON pri použitím rôznych spájkovacích programov, použitím röntgenovej inšpekcie, SAM a metalurgických rezov.
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Mini reflow oven
Pavelka, Radek ; Jelínek, Aleš (referee) ; Burian, František (advisor)
This thesis is aimed to design a small oven for PCB soldering using the reflow method. It contains description of the oven’s construction, it’s thermodynamic parameters and the design of the control and power unit PCB as well as their control software. A remote PC control and monitoring application is also a part of this thesis.
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Mechanical Properties of solder joint
Meliš, Josef ; Starý, Jiří (referee) ; Stejskal, Petr (advisor)
This thesis deals with the differences between the mechanical properties of surface conditionings of the printed circuit boards and various types of soldering pastes. The practical part of the thesis describes all the steps necessary to conduct the experiment. The experiment will evaluate the measured mechanical strength of the solder joint for each surface conditioning, the types of solders, the increase in thickness of the intermetalic layer during long-term aging and the change in the structure of the solder joint.
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THE APPLICATION OF NANOMATERIALS FOR LEAD FREE SOLDERS DEVELOPMENT
Pešina, Zbyněk ; Pinkas, Jiří (referee) ; Spousta, Jiří (referee) ; Sopoušek, Jiří (advisor)
The present dissertation is motivated by the search for alternatives of lead-free soldering by nanoparticles of metals and their alloys. The research focuses on the possibility of replacing lead-free solders by nanoparticles. This issue is currently being addressed by the use of lead-free solders but their properties are not entirely equivalent to properties of lead-tin based alloys. The theoretical part of the dissertation first summarizes up-to date knowledge on the development of lead-free alloys currently used for soldering in the electronics. The work compares these lead-free solder candidates with previously used Pb-Sn alloys. The second section of the theoretical part is devoted to nanotechnology that offers possible solutions of problems associated with the use of lead-free solders. The text contains a description of the properties of nanocrystalline materials in comparison with those of compact alloys having the same chemical composition. The possibility of preparation of nanoparticles and potential problems associated with small particle sizes are also presented. Introduction of the experimental part focuses on the preparation of nanoparticles of pure metals and alloys by chemical and physical ways as well as on an instrumentation for characterisation and analysis. Attention is focused on the silver in nanoparticle form that exhibits the low temperature sintering effect, which is thermally activated by decomposition of oxide envelope covering the Ag nanoparticles. This factor is critical for low-temperature sintering and thus also for possible future applications. The thermal effects of the low sintering process were studied by methods of thermal analysis. The preparation of the Cu / Ag nano / Cu joints was carried out in-situ in inert atmosphere and under the action of atmospheric oxygen. In both cases varying conditions of thermal treatment were used. The cross sections of the prepared joints were then used for the metallographic analysis of the local mechanical properties of the resulting silver layer, for the chemical composition evaluation of the resulting layers of the joint, and for the microstructure study. Strength characteristics are represented by testing shear strength of individual joints.
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Analysis of Defects on PCB Using X-RAY
Mlýnek, Martin ; Vala, Radek (referee) ; Řihák, Pavel (advisor)
This thesis is focused on BGA packages and fault detection after rework using X – Ray. There is a description of BGA packages by carrier substrate, techniques of connecting on chip, from mounting packages to repair printed circuit boards (hereafter PCB). Thesis summarizes description of defects, which are created after rework process. There is also description of X – Ray as method for analyzing defects. X – PLANE method used to detect internal structure of BGA packages and it was confirmed by microsection and by software for reconstruction. Description of automatic and manual measurement is follow.
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Testing of Solders in Protection Atmosphere
Vala, Radek ; Jankovský, Jaroslav (referee) ; Szendiuch, Ivan (advisor)
The project deals with the overall design and construction of equipment called the desiccators for brazing in a protective atmosphere. The device was designed and manufactured cooling and heating element. For the soldering various temperature profiles have been defined and adjusted, as for SnPb as well for lead-free solders. There was a realization of samples were measured and analyzed. Finally were realized micro sections for lead free solder.
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Laser diode soldering
Straka, Michal ; Holík, Milan (referee) ; Stejskal, Petr (advisor)
This work deals with the laser diode soldering. The theoretical part summarizes general and acquired findings about soldering technology and materials that occur in this process. It also describes factors that affect the reliability of solder joints. It is closely focused to the shaping of the solder joint and structure of intermetallic layer. The practical part of this work is focused on the design of equipment for laser diode soldering and subsequent shaping of the samples. The quality of soldered joint is compared against the quality of joint created using re-flow technology - remelting in in-line smelter. The structure and thickness of the intermetallic layer, the number and shape of the voids in the solder joints are compared.
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Design of Soldering Gun
Běhal, Tomáš ; Křenek, Ladislav (referee) ; Ondra, Martin (advisor)
This bachelor thesis deals with the design of transformer soldering gun. The product is analyzed from the historical, technical and design ways at first. Subsequently, the new design of this product is proposed, with respect to ergonomic, technical, aesthetic and psychological aspects.
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