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Temperature Profile in Reflow Soldering and Influence of Different PCBś and ComponentsThermal Capacities
Procházka, Martin ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This thesis mainly deals with the prediction of temperature on the components and the PCB during reflow soldering. The theoretical part describes the particular solder reflow process, types of heat transfer and temperature profiles. The practical part is divided into forecasting temperatures if the conveyor is stopped and the temperature predictions when the conveyor is in motion. In both parts of the measured temperature is compared with the predicted temperatures, which show the success rate of prediction. The last part of this work is part of the simulation, which helps in proper understanding of the issues discussed.
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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.
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PCBs Repairs with BGA and FC Packages
Buřival, Tomáš ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
Graduation thesis is specialized on dilemma of the integrated circuits with ball grid array. Chapter two describes several types of packages and confrontation of their characteristics. Chapter three considers possibilities of corrections these boards bedded with packages, mounting and demounting of these packages, method of camera control and also inspection of the soldering process. Chapter four attend to practical measuring of thermal profiles and their optimalization.
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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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Research of the influence of a new method for ball-attach process on BGA packages on intermetallic layers
Gregor, Adam ; Jankovský, Jaroslav (referee) ; Otáhal, Alexandr (advisor)
This work deals with exploring a new method of ball-attach process on BGA packages using a directly heated stencil. The existing procedures of making solder bumps were compared with possible benefits of using this new method. The methodology was established to create samples using a new reflow method and its effect on the formation and strength of intermetallic layers of solder bumps, due to the set height of the heated template, which was designed for reflow of BGA terminals. In addition to the design of the methodology, shear tests and metallographic sections of the samples were also performed. The thickness of the intermetallic layer and its roughness were examined. An evaluation of the results was performed on the basis of which a new method of reflow soldering of solder balls on BGA packages was optimized.
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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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Flux Residues after Reflow Soldering
Uhlář, Vít ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The aim of this bachelor thesis is to solve flux residue characteristics on PCBś after reflow soldering and compare different solder pastes. The first part deals with the issue of solder paste application and flux residues. The second part focuses on the process of reflow soldering. The third part is devoted to the measurement methodology of flux residues. Finally, project is a practical part, which is summarized in the production of test samples and contains measurement results.
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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.
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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.
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Lead-Free Voids Cause Mechanisms and Influence on Reliability
Šimon, Vojtěch ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The aim of this work is to analyze reliability of lead-free solder join, in particular the voids generated during the soldering process. The main target of the theoretical part of the work is to isolate basic mechanisms of formation of the voids and optimize the soldering process. The practical part of the paper is based on monitoring the count and size of the voids in a solder join. An X-Ray tomograph has been chosen as a non-destructive method of detection. The statistical part of this work compares conventional soldering of the entire board with local soldering by IR radiation.
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