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Solderability of PCBs Surface Treatments and Environmental Influences
Jičínský, Jiří ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This bachelor’s thesis deals with the properties of surface treatment of printed circuit boards. The main purpose of this work is to compare the OSP coating applied under laboratory conditions and the technological procedure established in the company ČEMEBO Blansko. Samples of ENIG, immersion tin and OSP compare due to their critical aspects. In the practical part, the samples au exposed to various elements of nature according to ČSN EN 60068-2. The surface wetting balance method will be used for better comparison and evaluation.
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Wettability of PCB Surface Finishes and Comparison of Methods
Vídeňský, Ondřej ; Přikryl, Tomáš (referee) ; Starý, Jiří (advisor)
This bachelor´s thesis deals with testing methods for surface finishe´s wettability PCB. For this tests has been designed and created testing board which contains testing coupons for testing methods. Boards have been created and covered by surface finishes by Gatema Boskovice. In this thesis electroless nickel with immersion gold (ENIG) and immersion tin have been tested. For simulation of reflow soldering have been used test methods solder indicator, solder spread test and dewetting test. Wetting balance test method has been used as simulation of wave soldering.
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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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Surface Finishes of Copper in PCBś Production
Bedlek, Marek ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This work examines and compares properties of different types of surface finishes, their qualities and shortcomings and perspective for future use. Emphasis is placed on new product in the field of OSP, Glicoat F2 from SHIKOKU CHEMICALS CORPORATION and immersion tin. It evaluates their influence on solderability and its changes after several reflow cycles and isothermal aging.
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Negative emotions in swimming lessons for people with mental disability
Kovařovic, Vojtěch ; Čechovská, Irena (advisor) ; Miler, Tomáš (referee)
Title: Negative emotions in swimming lessons for people with mental disability Objectives: The aim of this diploma thesis is to determine the occurrence of negative emotions associated with swimming lessons in people with mental disabilities through selected methods. Other goals are to find out the nature of the occurrence and the possibility of influencing these emotions. The result of guided interviews and the subsequent synthesis of knowledge should be the development of principles that are causal for the prevention and possible positive influence of negative emotions associated with swimming instruction in people with mental disabilities. Research questions 1. Do people with mental disabilities experience negative emotions in connection with swimming lessons? 2. On what basis do these emotions arise? 3. How can these emotions be prevented? 4. How can these emotions be positively influenced? Hypotheses I. In the swimming lessons of people with mental disabilities, we encounter negative emotions. II. It is possible to find out on the basis of what these emotions arise. III. Negative emotions can be positively influenced. IV. If these emotions are positively influenced, the individual's motor learning will be accelerated. Methods: Semi-structured interview, which will be evaluated on the basis of...
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Wettability of PCB Surface Finishes and Comparison of Methods
Vídeňský, Ondřej ; Přikryl, Tomáš (referee) ; Starý, Jiří (advisor)
This bachelor´s thesis deals with testing methods for surface finishe´s wettability PCB. For this tests has been designed and created testing board which contains testing coupons for testing methods. Boards have been created and covered by surface finishes by Gatema Boskovice. In this thesis electroless nickel with immersion gold (ENIG) and immersion tin have been tested. For simulation of reflow soldering have been used test methods solder indicator, solder spread test and dewetting test. Wetting balance test method has been used as simulation of wave soldering.
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Solderability of PCBs Surface Treatments and Environmental Influences
Jičínský, Jiří ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This bachelor’s thesis deals with the properties of surface treatment of printed circuit boards. The main purpose of this work is to compare the OSP coating applied under laboratory conditions and the technological procedure established in the company ČEMEBO Blansko. Samples of ENIG, immersion tin and OSP compare due to their critical aspects. In the practical part, the samples au exposed to various elements of nature according to ČSN EN 60068-2. The surface wetting balance method will be used for better comparison and evaluation.
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|
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Surface Finishes of Copper in PCBś Production
Bedlek, Marek ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This work examines and compares properties of different types of surface finishes, their qualities and shortcomings and perspective for future use. Emphasis is placed on new product in the field of OSP, Glicoat F2 from SHIKOKU CHEMICALS CORPORATION and immersion tin. It evaluates their influence on solderability and its changes after several reflow cycles and isothermal aging.
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|
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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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Flagellin and outer surface proteins from Borrelia burgdorferi are not glycosylated
ŠTĚRBA, Ján
Glycosylation of four proteins from Borrelia burgdorferi s.s. was investigated ? flagellins FlaA, FlaB, and outer surface proteins OspA and OspB. Glycosylation of these four proteins was not proved by any of the used techniques. However, other glycan-staining positive proteins were present in the borrelia samples. These proteins were suggested to originate in the culture medium.
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