|
|
Bismuth Low Temperature Solder Pastes
Hájka, Jan ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This bachelor thesis deals with low-temperature solder pastes with different bismuth content. It focuses on material, process and environmental influences that affect the reliability of the soldered joint. The practical part investigates the effect of isothermal aging and thermal cycling on the mechanical properties of solder joints formed by an eutectic tin-bismuth alloy. Furthermore, tin-bismuth solder pastes are compared to pastes with additives (TiO2 nanoparticles) and to SAC305 alloy. Technical adjustments are made to the measuring device in order to increase the accuracy of the measurement.
|
|
|
Inspection and optimization of soldering profiles of reflow furnaces
Flos, Milan ; Zatloukal, Miroslav (referee) ; Bača, Petr (advisor)
This thesis is focused on the implementation of solutions for the control of temperature profiles in an industrial environment. The theoretical part deals with the soldering process itself, individual types of soldering and their possible defects. Furthermore, the problem of temperature profiles, their division and the advantages and disadvantages of individual profiles were discussed. Subsequently, the measurement was performed on several remelting furnaces and its evaluation. Lastly, the design of the holder for the profilometer and the PCB itself was created.
|
|
|
Optimization of Factors that Affects the Reliability of Soldering of Modern Electronic Packages
Otáhal, Alexandr ; Pietriková,, Alena (referee) ; Blecha,, Tomáš (referee) ; Szendiuch, Ivan (advisor)
The work deals with research and development of a new method for ball-attach process, resp. reballing process of solder bumps on package with solder ball terminals (BGA, CSP, SOP, etc.), based on research and optimization of the parameters of the final terminals. The output is specially modified templates designed for placement of solder balls before reflow soldering. Three materially different templates were investigated in the work, in addition to the commonly used stainless steel, two other newly designed templates, which used ceramic materials (96% Al2O3a AlN) with thick-layer resistance heating. Proven advantages of the method using templates directly heated by electric current are the reduction of the thermal load of BGA packages in the first soldering process, as well as the creation of a better connection between the metallization of the case and the solder ball after final soldering to the printed circuit board. During the research, development and optimization of the method, tests of the created solder bumps were performed from the point of view of mechanical strength and internal structure. In the next part of the work, a research of solder bumps soldered using infrared heaters was performed in order to determine the influence of the heat flow direction in the process of reflow soldering. The heaters were successively placed in three positions, i.e. heating from the bottom of the housing, heating from the top and both heaters simultaneously. After sample preparation, metallographic cuttings and etching, the analysis of the internal structure of the entire solder ball and the intermetallic layer at the interface of the solder and the solder pad was performed. The work represents not only a new method of soldering solder bumps, but also new knowledge to create their internal structure, which contributes to meeting the increasingly demanding requirements to achieve the required reliability and quality.
|
|
|
Bismuth Low Temperature Solder Pastes
Vogel, Vojtěch ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This bachelor thesis deals with low-temperature soldering pastes with different bismuth content. It focuses on material, process and environmental influences that affect the reliability of the soldered joint. The effect of the elements on the eutectic solder alloy Sn-Bi58 is also described here. For the practical part two surface finishes (ENIG and immersion tin) and four solder pastes (PF743-PQ10, PF735-PQ10, PF734-PQ10, SAC305) are chosen. Tested PCBs are subjected to isothermal aging and cyclic temperature tests. Electrical resistance has changed during thermal aging.
|
|
|
Bismuth Low Temperature Solder Pastes
Švéda, Miloš ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This master´s thesis deals with bismuth low temperature solder pastes. Describes the properties of bismuth solder pastes. It shows the process of manufacturing a printed circuit board for test. The thesis also characterizes laboratory temperature profile setting for the BiSn soldering pastes. Solder paste printing and placement 0 ohm rezistors to printed circuit boards with different surface finishes in the manufacturing plant. Setting of solder profiles for low soldering pastes in reflow oven. Testing resistence of mounted zero resistor on the test board at different aging temperature were analysed. Resistance measurement after a specified time. Testing of solder joint strenght of printed circuit boards for different surface treatments. Changes in structure wereanalysed on microsections for solder pastes.
|
|
|
Design of Reflow Soldering Station for Reballing of BGA Packages
Janiš, Adam ; Szendiuch, Ivan (referee) ; Otáhal, Alexandr (advisor)
This thesis deals with the design of a soldering oven for BGA reballing in a nitrogen protective atmosphere. The principles of reflow soldering, the advantages of a nitrogen protective atmosphere on the quality of solder joints and the types of soldering devices are described. The BGA packages´ part consists of their characteristics, assembling methods, a rework and repair process and solder joint inspection methods. Design of the device, as well as heat flow simulations, are included in the experimental part and particularly it also describes the used structural elements and the principle of function of the individual parts of the device. At the end of this work, the soldering process was measured and the ability of the sample soldering was verified.
|
|
| |
|
|
Solder Joint Quality based on Heating Factor
Kučírek, Martin ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
Master’s thesis in the theoretical part analyses the heating factor (Q), which has significant share on quality of a solder joint. The practical part describes the design and production of test PCB and setting temperature profiles, SMD resistors soldering by using BiSn solder paste. Shear tests of SMD solder joints were realised and evaluated including isothermal ageing samples. At the end of master’s thesis solder joints visual aspects and defects were evaluated, measurement thickness of intermetallic compound by not only optical microscope but also SEM, discussion about results and Q was evaluated.
|
|
|
MOISTENING OF COMPONENT MATERIALS AND SPEED OF DEHUMIDIFICATION
Pospíšil, Tomáš ; Tomáš, Bžoněk (referee) ; Starý, Jiří (advisor)
This bachelor thesis deals with process associated with moisture in electrotechnics. The bachelor thesis is focused on the components and basic materials that are sensitive to moisture and defects caused by moisture in the reflow soldering process. The theoretical part describes the principles of measuring humidity and sorts of absorption. Furthermore this work described the basic classification and defects in components, base materials and packaging material sensitive to moisture and selection of standards dealing with this issue. Another theoretical part is focused on the manipulation with components and materials sensitive to moisture. The practical part deals with the methodology and practical measurement of moisture soaking in the components and materials with respect to their level of sensitivity to moisture. The following part is focused on the methodology of drying, practical measurement of drying and comparing two drying cabinets.
|
|
|
Lead Free Solder Joint Quality based on Heating Factor
Dosedla, Milan ; Zdeněk, Jurčík (referee) ; Starý, Jiří (advisor)
This bachelor’s thesis deals with influence of the heating factor on the quality of lead free solder joints in the reflow soldering process. It summarizes the basic knowledge and some requirements for soldered joints, analyses reflow profiles and presents some of the results published in the literature. Aim of the practical part is by samples soldered with different size of the heating factor determine and evaluate the impact of this factor to the strength and appearance of the final solder joint and the structure and thickness of the intermetallic layers.
|
guest ::
