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Creep-fatigue models for solder joints reliability prediction
Novotný, Václav ; Šandera, Josef (referee) ; Švecová, Olga (advisor)
This project is focused on utilization of creep-fatigue models for estimate of reliability lead-free solder joints. It describes basic groups of creep-fatigue models, their usage for estimate of reliability solder joint, advantages and disadvantages. There are discusssed properties of single models, which are on different base. Purpose of this project is find optimal creep-fatigue model for lead-free solder and devise a test structure to which the model will be verified. Results are compared with theoretical calculations.
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Optimalization of soldering process on IR-400
Otáhal, Alexandr ; Nicák, Michal (referee) ; Szendiuch, Ivan (advisor)
This project deals with innovation of IR-400 equipment which is based on design and installation of temperature regulation, in both top and bottom side. This innovation enables adjustment of reflow temperature profile for repair and rework of SMD components by lead-free solder materials for both, FR4 and alumina substrates, as assembly of some special packages.
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Reliability of Lead-free Solders and the Selected Methods to Estimate its Lifetime
Švecová, Olga ; Kolařík, Vladimír (referee) ; Urbánek,, Jan (referee) ; Šandera, Josef (advisor)
The doctoral thesis is focused on reliability of lead-free solder SAC 305. Knowledge in the field of fatigue models used in determining the lifetime of solder joints are observed in this thesis. Also such methods of predicting reliability as numerically-analytical methods or reliability experimental tests are mentioned. Practical results of reliability measurement are presented. Experimental data served as the foundation for determining empirical coefficients for the fatigue model based on deformation induced by creep of the solder, which was implemented in the ANSYS environment. Results from different methods were compared and conclusions discussing the suitability of the presented prediction methods are formulated.
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Optimizing of QFN Package Assembly Process
Šváb, Martin ; Jankovský, Jaroslav (referee) ; Szendiuch, Ivan (advisor)
The Master thesis deals with technology of mounting QFN packages on to the printed circuits boards. Describes also influence of shape and size of soldering pads and the amount of soldering paste with respect to the quality and the reliability. In first part overview of existing packages is summarised. Second part describes design of testing board and the factors which leads to eliminating errors during manufacturing process.
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The possibilities of SMD components soldering by equipment Fritsch
Juračka, Martin ; Šandera, Josef (referee) ; Adámek, Martin (advisor)
This thesis focuses on soldering technology in microelectronics. It describes in detail the basic ways of soldering and repairs in electronics. This piece of work shows the principles of technological equipment for bulk soldering and used repairing devices. In the theoretical part of this work there are also briefly described the packages for integrated circuits that were used in the practical part of the thesis. The practical part of the thesis deals with setting of the heat profiles for hot air repair station Fritsch Mikroplacer for LQFP64, SOIC16, TSSOP14, QFN16 and DSBGA5 packages. The heat profiles for assembly and disassembly of the particular types of the packages on designed and manufactured test printed circuit board were set and tested. The resulting heat profiles are compared with the recommended heat profile of an ordinary solder paste SnAg3Cu0,5 which was used for the test. This thesis can serve as an aid for the further settings of heat profiles in other types of packages not only on Fritsch Mikroplacer devices, but also on other repairing devices of this type.
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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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Optimization of soldering process in the production of instrument transformers
Šula, Matěj ; Schnederle, Petr (referee) ; Szendiuch, Ivan (advisor)
This diploma thesis deals with the soldering process in manufacturing instrument transformers. It summarizes the knowledge of soldering process, lead-free alloys and test methods selected solder joint. In the practical part is the analysis the manufacturing process in terms of soldering operations, testing of selected lead-free alloys, which are considered as a replacement for lead-based alloy - now used in the manufacturing process. The conclusion is optimized manufacturing process to reduce operating costs and improve quality.
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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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Machanical testing of solder joints
Drab, Tomáš ; Šandera, Josef (referee) ; Szendiuch, Ivan (advisor)
The project contains theoretical research of electrotechnical manufacture for lead-free reflow soldering. It contains characterization of soldering processes. Includes variations of solder paste printing, principles of part placing and also reflow soldering process. The project appoints possibilities of testing solder joints strength, mainly focused on mechanical vibrations. It describes a design and preparation of solder joint strength test methods by mechanical vibrations. It compares influence of vibrations on part types and solder alloys.
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Research of the Quality of Solder Joints by BGA and QFN Packages
Otáhal, Alexandr ; Adámek, Martin (referee) ; Szendiuch, Ivan (advisor)
This diplomas thesis deals with specific technologies and manufacture of BGA and QFN packages. Also summarizes the most used test methods for assessing the reliability for. Describes the making of equipment for soldering in a nitrogen atmosphere, followed by comparison solder joints of BGA and QFN forming in different atmosphere. Finally, summarizes knowledge about the process of soldering and desoldering lead-free solders for BGA packages, followed by experimental evaluation of the causes of malfunction of repaired samples.
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