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Defects caused of Solder Paste Application and Process Optimizing
Štichová, Zuzana ; Žilina, Michal Staník, EMTEST (referee) ; Starý, Jiří (advisor)
The aim of this work is documentation of cases, where the problems appear of solder paste reflow process, evaluation and recommendation for increasing quality of proposal PCB. This work contains also recommendation of process using adhesives for double-sided SMD assembly. At the cooperation with the firm Emtest, a.s. in Žilina, I mostly intent on optimalization of proposal footprints and realization of their changes as the one way of solving the problem. I made also statistics of solder paste reproducibility by JetPrinting technology.
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Solder Joint Conductivity - Influence of Solder Volume and Isothermal Aging
Mach, Ladislav ; Schnederle, Petr (referee) ; Starý, Jiří (advisor)
The master thesis analyses electrical conductivity of lead-free solder joints. The test method design for monitoring the electrical conductivity of the soldered joint is described in the practical part. Simulated BGA package with four pin (BGA4) is used for experiments. Tested PCBs are subjected to isothermal aging and current load. During isothermal aging is measured electrical conductivity and optical microscope is used for intermetallic layer (IMC) growth observation. Two types of surface finish (OSP and ENIG) are used for tests and three diameters of solder terminal balls (solder alloy SAC405). The influence of the ratio area connection / solder volume (ratio S / V) on lead-free solder joints conductivity was evaluated.
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Immersion Tin Surface Finish of PCB
Karzel, Vítězslav ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
The aim of this work is to study and more deeply understand everything about surface finishing of the printed circuit boards, that are used for lead-free soldering. Mainly we should focus on immersion tin and prepare some fundamental information for future measurement. Therefore, in the first part of the thesis is our main task is to create a~sufficient theoretical background for printed circuit boards, immersion tin and solderability. Then we are able to use previously created theoretical background to measure selected samples. Thereafter the measured data can be used for more strict evaluation, from which the results of measurement can be obtained.
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X-ray Defectoscopy
Velím, Michael ; Ondřej, Šimeček (referee) ; Starý, Jiří (advisor)
This diploma thesis deals with a defect detection with X-rays in the manufacturing procedure in the electrotechnical field. The work summarises the knowledge about technical possibilities of an X-ray device Cougar of YXlon company. Part of the work is focusing on scanning in 2D, 3D visualization and automatic analysis. The thesis describes inspection methods of a connector connection, the quality of a soldered joint and an encapsulated product.
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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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Set possible causes for capacity loss of capacitors
Fabiánek, Marcel ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This thesis deals with formation of defects on through-hole capacitors. Process of wave soldering and its steps are described in the first part. The listing and description of possilble defects caused by wave soldering is followed after the first part. There are several sources of potential causes of capacity loss and a separate chapter to these causes. The last part contains a proposal of testing individual potencional causes. Their purpose is to reveal the root causes of formation of the defects and then the practical solution is described.
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SnBi Solder Paste and Influence of Reactive Nanoparticles
Rychlý, Ivo ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This work deals with effects of nanoparticles, mainly copper and silver, on properities of lead-free solder pastes. It describes basic tests done on solder pastes according to IPC-TM-650 standards. In practical section this work focuses on the preparation of Sn-Bi solder paste and the measuring of viscosity. After that different concentrations of silver copper alloy nanoparticles are added to the SnBi solder paste. These solder pastes are tested by the IPC standarts and mechanical and resistive tests are done on printed circuit boards where the effects of mixed in nanoparticles are observed.
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Inspection of PCB with SMT by using comparative method
Hejdiš, Roman ; Stejskal, Petr (referee) ; Starý, Jiří (advisor)
The first part of the bachelor´s thesis discuss AOI, types of AOI, its utilization and importance in the industrial production. The second part is devoted to realization of simple comparative inspection method. There were testing effects of ambient light to record photographs of PCB and also artificial light was used. There was problems indication of PCB lit and PCB fixturing. At last, there are discussed some technical problems of this simple comparative method.
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