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The strength of soldered joints on ceramic substrates
Jansa, Vojtěch ; Nicák, Michal (referee) ; Adámek, Martin (advisor)
This thesis deals with problematic of lead – free soldering and consequent testing of mechanical characteristics of solder joints. The theoretical part is focused on various types of lead – free solders, influence of protective atmosphere on the solders characteristics and mechanical testing of solder joints. Basic materials and thick - films making technology is mentioned. Practical part contains a design of topology that was used for mechanical strength testing of solder joints connecting SMD component and ceramic substrate. Properties of lead – free solder pastes was investigated on various concentrations of O2 and compared with lead soldering paste.
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Formula Student Composite Battery Pack
Hagara, Matej ; Šebela, Kamil (referee) ; Janoušek, Michal (advisor)
The main goal of the presented thesis is the design and solution to a riddle of a constructive design of a „battery pack“ (battery container) and its installation into the student formula Dragon eD2. The introduction part of the thesis describes the basic FSAE rules, with a focus on the design of the above-mentioned component regarding the pilot’s safety. The main aim of the theoretical part is to introduce the essential and convectional typology and manufacturing processes of composite material’s production, while special attention is given to prepreg technology. The knowledge that was derived from the first part was used to perform a set of mechanical tests and analytical computations. Based on gathered data and information the following simulations were adjusted with intention of maintaining simplicity and efficiency. The emphasis is places on easy and maintainable design, good structural strength, and low weight. The final part of the thesis offers the conclusion based on the obtained results and presents theoretically optimal design in terms of production and installation for low-cost production in small series.
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The comparison of properties of solder joints on ceramic substrates by shear tests
Lipavský, Lubomír ; Schnederle, Petr (referee) ; Adámek, Martin (advisor)
This thesis deals with issues lead – free soldering in a protective atmosphere with a focus on mechanical tests. The theoretical part is focused on the types of lead-free solders, mechanical tests carried on the solder joints and various methods reflow soldering. It is also discussed reliability and durability of solder joints. Aim of the practical part is to compare the strength of solder joints using shear tests for various sizes of components, various concentrations of protective nitrogen atmosphere and various types of solder pastes. Testing is performed on a ceramic substrate, which differs from the works being carried on an organic substrate. For each type of solder paste is further processed by the percentage occurrences of each type tearing of solder joint.
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Analysis of the procedure for design of trackbed
Svobodová, Nikola ; Břešťovský,, Petr (referee) ; Plášek, Otto (advisor)
The diploma thesis focuses on analysing the current Railway Infrastructure Administration methodology for designing the sleeper substructure concerning the construction's deformation resistance, its comparison with the multi-layered method, which is used in the road engineering and finite element method. It deals with various methodologies of determining the deformation resistance of the track substructure.
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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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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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Verification of nonlinear material models
Prokš, Tomáš ; Němec, Ivan (referee) ; Hradil, Petr (advisor)
The bachelor thesis deals with verification of nonlinear material model of soil FHWA SOIL during shear test. The nonlinear problem was being solved by software LS-DYNA using explicit formulation of finite elements method. The values of horizontal displacements during the direct shear test were compared with the results listed by the developer of the material. The considerable difference in the results led to focusing on the settings of the material model and influence of application of load, geometry and type of finite elements on the monitoring values.
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Verification of setting speed and building adhesion of PU adhesives depending on external conditions
Slatinská, Jana ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The company IFE a. S. (Knorr - Bremse) in Modřice needed to verify the curing process of glued joints with the used adhesive Sikaflex®-265. The aim was to find out whether a controlled environment is needed for curing and mainly find out influence of factors on the curing process and the velocity of building adhesion. The main factors that were investigated were temperature, humidity, the ratio of the Sikabooster® P-50 to the tested adhesive and the curing time. The result then shows which factors have an influence and which only minimal. The aim was also to verify the strength of the joint, which is stated by the manufacturer after a specific time. The impact on open technology time has not been measured.
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Lead Free Solder Joint Strength and Cooling Gradiient Influence
Vítek, Jiří ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The object of this work is to monitor the impact of gradient cooling on the strength of the solder joint and its crystalic structure. Dummy packages BGA4 were soldered on PCBs with test structure. Base material FR4, Cu interconnections were protected with OSP and Ni – Au surface finishes and SAC405 solder was used. The samples were made in three different cooling gradients, 6.80 °C/s, 2.00 °C/s and 0.16 °C/s. The bond strength was measured by using the shear strength test on device DAGE PC 2400. Realised microsections were studied on an optical microscope OLYMPUS GX 51.
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Verification of setting speed and building adhesion of PU adhesives depending on external conditions
Slatinská, Jana ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The company IFE a. S. (Knorr - Bremse) in Modřice needed to verify the curing process of glued joints with the used adhesive Sikaflex®-265. The aim was to find out whether a controlled environment is needed for curing and mainly find out influence of factors on the curing process and the velocity of building adhesion. The main factors that were investigated were temperature, humidity, the ratio of the Sikabooster® P-50 to the tested adhesive and the curing time. The result then shows which factors have an influence and which only minimal. The aim was also to verify the strength of the joint, which is stated by the manufacturer after a specific time. The impact on open technology time has not been measured.
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