Master’s thesis deals with thick/film sensor’s electrodes optimization. The aim of this work is to determine how the geometric size and shape of the electrodes affect the output current response. Technology and electro-analytical method is described in the theoretical part. The practical part is aimed at thick-films electrodes and sensors optimalization. It is here each optimization TLV electrodes in terms of their impact on the size of the output current response three-electrode electrochemical system using standard electrodes. Similarly, there is a study of the effect size performed on one common electrode free-electrodes sensor. Finally, there are studied various forms of electrode area three-electrode thick-film sensor in terms of their effect on the output current response. Summarized results are described in the final part of the work.

Diploma thesis solves how to create system for measurement of little liquid flows. The basic types of liquid flowmeter, which are possible used for measurement of little liquid flows, are described in the introduction part of thesis. The limit for little flow is often determined as flow 100 mg.min-1 and low. Second part of this thesis describes the ways of capillary production and practical experiments with them. Thesis is focused to thick film technology and LTCC technology. Next part of this work is solution of simple measuring unit for measurement of little flows less than 100 mg.min 1, which is controlled by microprocessor ATmega16. The measuring unit can be worked separately or can be connected to PC. The next possibility of flowmeter optimisation is summarized in end of thesis.

Miniature electrochemical sensors can be produced by thick-film technology. The optimal properties of thick-film electrode system, the production technology optimization of thick-film sensors and the adjustment of optimal technological properties are main problems of sensor design. An area of working electrode and an electrode topology design is the important parts in design of electrode system optimization. The rules for optimization of electrode systems in classical electrochemistry exist. The design of standard thick-film electrode construction is limited (2-D construction, substrate dimensions, resolution, paste parameters …). Therefore rules for classical electrode systems cannot be used fully in this case and larger electrode area can be making by 3D structure only. One of resolutions is unconventional method. The increase of working electrode surface by unconventional method – ball and wire bonding is discussed in this work.

The work is dedicated to the production of a thick film with resinate paste on a ceramic substrate based on a proposal test motive. It introduced the optimization of the workflow leading to the successful realization of the layer. Using an electron microscope, it is performed evaluation of the quality of resultant layer and analysis of the composition of the paste. In the last part of the work it is carried out measurements of temperature and electrical properties of resinate paste.

Doctoral thesis deals with the deposition of special thixotropic materials for microelectronic technology. The aim of the work is the development of the new method optimizing the dosing process in order to achieve a print resolution of better than 100 microns. The work includes the development of a special dispensing head (UZD) using the influence of ultrasonic energy. These results demonstrate the possibility of a newly developed method that is able to print thixotropic materials with a resolution of 65 microns. Compared to other methods achieves these results with the commonly used materials for thick film technology with particle size up to 5 microns.

This dissertation describes the development of a high-power, plastic-based, thick-film lithium-ion microbattery for use in a hybrid micropower system for autonomous microsensors. A composite porous electrode structure and a liquid state electrolyte were implemented in the microbatteries to achieve the high power capability and energy density. The use of single-walled carbon nanotubes (SWNTs) was found to significantly reduce the measured resistance of the cathodes that use LiAl0.14Mn1.86O4 as active materials, increase active material accessibility, and improve the cycling and power performance without the need of compression. Optimized uncompressed macro cathodes were capable of delivering power densities greater than 50 mW/cm2, adequate to meet the peak power needs of the targeted microsystems. The anodes used mesocarbon microbeads (MCMB) with multi-walled carbon nanotubes (MWNTs) and had significantly better power performance than the cathodes. The thick-film microbattery was successfully fabricated using techniques compatible with microelectronic fabrication processes. A Cyclic Olefin Copolymer (COC)-film was used as both the substrate and primary sealing materials, and patterned metal foils were used as the current collectors. A liquid-state electrolyte and Celgard separator films were used in the microbatteries. These microbatteries had electrode areas of c.a. 2 mm x 2 mm, and nominal capacities of 0.025-0.04 mAh/cell (0.63-1.0 mAh/cm2, corresponding to an energy density of ~6.3-10.1 J/cm2). These COC-based batteries were able to deliver constant currents up to 20 mA/cm2 (100% depth of discharge, corresponding to a power density of 56 mW/cm2 at 2.8 V) and pulse currents up to 40 mA/cm2 (corresponding to a power density of 110 mW/cm2). The high power capability, small size, and high energy density of these batteries should make them suitable for the hybrid micropower systems; and the flexible plastic substrate is also likely to afford some unique integration possibilities for autonomous microsystems. The mechanism by which the SWNTs improved the rate performance of composite cathodes was studied both experimentally and theoretically. It was concluded that the use of SWNT improved cathode performance by improving the electronic contacts to active material particles, which consequently improved the accessibility of these particles and improved the rate capability of the composite cathodes.

No description available.

This work presents introductory research to provide the relationship between electrical measurements and residual stresses caused by hybrid processing. X-ray diffraction is used to measure residual stresses in the ceramic substrate as well as metallization of wideband coplanar thick film probes. The probes are also tested for electrical performance using Time Domain Reflectometry (TDR) technique. This thesis presents results that indicate that significant tensile residual stresses were generated on the back of the substrate, particularly during the laser scribing phase of the finished device. Significant tensile stresses were also observed in the Silver-Palladium (Ag-Pd) metallization. TDR measurements indicated significant response variations which were attributed to these induced stresses. Attempts were also made to reduce these stresses by an annealing process in order to improve the TDR response uniformity. / Master of Science

This work deals with the problem of the thick-film pastes and their printing. In the main chapter of this work, the realization of a workplace for thick-film pastes' printing is described. The construction of the realized plotter and the controlling electronics of the plotter is depicted in detail.In the following chapter, the console, through which the plotter is controlled via PC, and the CAD program, which serves for projecting of the motives printed, are described.In the final chapter of this work, the measured profiles of the paste printed for various settings of printing parameters and the photographs of the motives printed are stated.

This work deals with the problem of the thick-film pastes and their printing. In the main chapter of this work, the realization of a workplace for thick-film pastes' printing is described. The construction of the realized plotter and the controlling electronics of the plotter is depicted in detail.In the following chapter, the console, through which the plotter is controlled via PC, and the CAD program, which serves for projecting of the motives printed, are described.In the final chapter of this work, the measured profiles of the paste printed for various settings of printing parameters and the photographs of the motives printed are stated.