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Study of lead-free solder joints reliability
Pícha, Jan ; Starý, Jiří (referee) ; Szendiuch, Ivan (advisor)
The thesis deals with problems concerning lead free soldering especially the study of the structure of solder joints and their reliability. The thesis evaluates lead free solder alloys. The theoretical part includes basic principles of soldering and methods of investigating solder joints reliability. The experimental part deals with the impact of water cooling and vibration on solder joint structure. Both methods are tested and are evaluated with regard to their reliability. The used tests include X-ray inspection, optical inspection, mechanical tests, investigating joint structure with electrone microscope.
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Solder Joint Reliability and Wetting Characteristics Influence
Labaj, Radek ; Stejskal, Petr (referee) ; Starý, Jiří (advisor)
This thesis deals with the methodology of testing the wetting characteristics for different material and process effects in the double-plated base material. Testing is performed by wetting balance method. There is designed procedure to calculate the angles on each side of the non-homogeneous material. The Design of Experiments method is used to interpret the results, by using this method are also interpreted electrical and mechanical properties of solder joints. The correlation with wetting characteristics is discussed.
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Project prototype SMT line with application new technology
Hůrka, Radek ; Starý, Jiří (referee) ; Hanusová, Hana (advisor)
The general aim is the present proposal of technological machine surface mount line for small lot and prototype production. This project enables to expand production, application of new technology, increase of flexibility in companies which deals with prototype production. The practical part of this work give view on optimalization of leadfree process.
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Influence of Different Microetchants in Examination of Intermetallic Layers Morphology
Sčensný, Ľudovít ; Bayer, Robert (referee) ; Starý, Jiří (advisor)
This bachelor’s thesis deals with the problematics of micro-etchants and their composition. The suitability of different solutions intended for observing morphology of intermetallic compounds in a soldered joint is examined. Three surface finishes coated with solder alloys are used to form representative samples. The prepared and processed samples in the form of a metallographic specimen are subsequently suitable for examining the microstructure of the etched surface. Laser scanning microscopy is used to analyse and evaluate morphology of the shown intermetallic compounds.
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Bar Code Implemamtation to Production Process of Small Factory
Tihon, Karel ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
Target of my diploma thesis is barcode study and implementation to SMT assembly processes. This thesis contains two main parts. The first one is devoted to basic types of barcodes, reading technologies and industrial process mapping in PCB assembly. The second part is devoted to theoretical proposal and physical realization of system for materials flow monitoring. Barcode is contained in this system. Practical part of this thesis is tested in a company realizing contract manufacturing in PCB assembly - SMT and THT.
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Influence of Bottom Preheating in Rework of Assembled PCB
Čechák, Ondřej ; Bžoněk, Tomáš (referee) ; Starý, Jiří (advisor)
This bachelor's thesis introduces the problematics of physical mechanisms of heat transfer and the correlative mathematical formulas and the use of mentioned problematics in the technology of bottom preheating in the rework of assembled printed circuit boards. It explains the importance and reasons of use of this technology, not merely in the professional production. It focuses on expert analysis of the appliances based on their properties and clarifies the differences in basic types of the devices. The emphasis is then laid on a practical testing of the technical parameters of the preheating devices as well as on an experimental design and a practical testing of a local bottom printed circuit board preheater.
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Monitoring of Solder Spreading Velocity on Metal Surface
Růžička, Miroslav ; Dušek,, Karel (referee) ; Starý, Jiří (advisor)
This work deals with flushing monitoring of spreading velocity on solder finishes Niau, OSP, Sn deposited on copper plated base material FR4 using digital cameras. After the reflow process is measured by length of spreading solder and size of wetting angle. It evaluates and compares the time dependence of velocity of spreading solder, length of solder spreading and wetting angle for NiAu, OSP, Sn finishes at different temperatures reflow and surface treatment.
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Thermomechanical Stress of Lead Free Solder Joint
Libich, Jiří ; Šandera, Josef (referee) ; Starý, Jiří (advisor)
This diploma thesis deals with the reliability of lead-free solder joints at a different interconnection structures. The first goal is to design the test cases shape BGA (FC) for testing the strength of lead-free solder joints at shear test in link with design of measuring method to detection shear strength during isothermal aging of lead-free solder joints. Following this shear stressing is investigating influence material and process compatibility, ie. pads finishing, material of solder and integrate of temperature (this mean thermal energy supplied during soldering) to lead-free solder joint strength.
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Influence of printed board surface finishing on solderability with vapour soldering
Matras, Jan ; Starý, Jiří (referee) ; Šandera, Josef (advisor)
Thesis deals with vapor soldering and wetting the surface with solder during the soldering process. It describes in detail the advantages and disadvantages of various surface finishes on the PCB. Generally characterizes the properties of lead-free solders and fluxes. Describes vapor soldering process, including the properties of the liquid itself. It also focuses on a method of evaluating the wettability by using solder balls and its performance on individual samples surface finishes.
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Dielectric Elastomers
Fiala, Vojtěch ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The thesis contains extensive theoretical information and consist of several parts, where in the first part of the text are specified mainly general knowledges about electroactive polymers (EAP) and their different types. In this part, the reader should get a basic view of the issues and realize sense of these materials. The following text is more specifically addressed on one group of electrical EAPs called dielectric elastomers (DE). Introduction to DE is conceived comprehensively, that means from general information and principles of function to specific and deeper information. For example in the text are included information about individual materials and differences between them, particular application areas, etc. Above all, the text focuses on the fields of sensorics and energy generation.
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