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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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Investigation of Reliability for Solder Joints in Nitrogen Atmosphere
Šefara, Petr ; Otáhal, Alexandr (referee) ; Szendiuch, Ivan (advisor)
This thesis examines the inuence of nitrogen atmosphere on the quality of the solder joint lead-free solder paste. For the solder paste were measured and set temperature proles. Thesis includes the implementation and measurement of samples in a protective nitrogen atmosphere and without a protective atmosphere. These measurements are compared, and the conclusions were drawn for the inuence of nitrogen atmosphere. The reliability and the quality of the soldered joints were investigated.
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Reliability of Lead-free Solders and the Selected Methods to Estimate its Lifetime
Švecová, Olga ; Kolařík, Vladimír (referee) ; Urbánek,, Jan (referee) ; Šandera, Josef (advisor)
The doctoral thesis is focused on reliability of lead-free solder SAC 305. Knowledge in the field of fatigue models used in determining the lifetime of solder joints are observed in this thesis. Also such methods of predicting reliability as numerically-analytical methods or reliability experimental tests are mentioned. Practical results of reliability measurement are presented. Experimental data served as the foundation for determining empirical coefficients for the fatigue model based on deformation induced by creep of the solder, which was implemented in the ANSYS environment. Results from different methods were compared and conclusions discussing the suitability of the presented prediction methods are formulated.
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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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Investigation of Reliability for Solder Joints in Nitrogen Atmosphere
Vala, Martin ; Adámek, Martin (referee) ; Szendiuch, Ivan (advisor)
This thesis examines the influence of nitrogen atmosphere on the quality of the solder joint lead-free solder paste. For the solder paste were measured and set temperature profiles. Thesis includes the implementation and measurement of samples in a protective nitrogen atmosphere and without a protective atmosphere. These measurements are compared, and the conclusions were drawn for the influence of nitrogen atmosphere. The reliability and the quality of the soldered joints were investigated.
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Termomechanical reliability soldered connections in electronic
Novotný, Václav ; Psota, Boleslav (referee) ; Šandera, Josef (advisor)
The diploma thesis deals with the sphere of solder joints reliability. The narrower focus is use of lead-free solder alloy SAC305 in the production process and parameters of its reliability. The text describes the main factors, which have the influence on the reliability of solder joints under conditions of thermal cycling. These factors also relate with choice of substrates and technological processes of preparation, which are characterized and described. Another part is devoted to estimating the reliability of soldered connections and are listed the fatigue model to estimate reliability. These fatigue models are categorized based on different physical mechanisms that operate in the soldered joints during operation. Based on the comparison of different models is selected the most appropriate model and in conjunction with simulation in ANSYS is estimated reliability. For this purpose is selected soldered connection of the FR-4 substrate and ceramic substrate via SMD component. They are manufactured test kits and subjected to conditions of temperature cycling. Results obtained from experimental measurements are compared with results obtained by simulation and calculation.
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Mechanical Properties of solder joint
Meliš, Josef ; Starý, Jiří (referee) ; Stejskal, Petr (advisor)
This thesis deals with the differences between the mechanical properties of surface conditionings of the printed circuit boards and various types of soldering pastes. The practical part of the thesis describes all the steps necessary to conduct the experiment. The experiment will evaluate the measured mechanical strength of the solder joint for each surface conditioning, the types of solders, the increase in thickness of the intermetalic layer during long-term aging and the change in the structure of the solder joint.
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Manual Soldering Station - Evaluation of Selected Parameters
Němec, Ivo ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This semestral work deals with the investigation of different principles of heating elements control in soldering stations and the influence of lead-free solder alloy on the life of soldering tips. The thesis summarizes the description of the sub-elements of the soldering stations and explains their functions. The defects of the soldering tips due to the use of lead-free solder alloys are also described. Last but not least, European directives governing the use of lead-free solder alloys in electronic and electrical products are mentioned.
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Visual comparison of lead-free connections for different material combinations
Šula, Matěj ; Starý, Jiří (referee) ; Schnederle, Petr (advisor)
Bachelors thesis describes problems soldering process. It summarizes the knowledge from soldering process, lead-free alloys and solder joint visual testing. The paper compares the influence of protective nitrogen atmosphere to the visual properties of lead-free solders for different base materials. It focuses mainly on assessment of the quality of solder joints in accordance with global standards IPC-A-610.The work includes the recommendations of material combinations.
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Creep-fatigue models for solder joints reliability prediction
Novotný, Václav ; Šandera, Josef (referee) ; Švecová, Olga (advisor)
This project is focused on utilization of creep-fatigue models for estimate of reliability lead-free solder joints. It describes basic groups of creep-fatigue models, their usage for estimate of reliability solder joint, advantages and disadvantages. There are discusssed properties of single models, which are on different base. Purpose of this project is find optimal creep-fatigue model for lead-free solder and devise a test structure to which the model will be verified. Results are compared with theoretical calculations.
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