Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 230-242). Also available via the Internet.

Methods of noise coupling in high speed thick film circuits has been investigated. Parasitic coupling parameters have been experimentally determined for a variety of single and multilayer thick film layouts. In addition, the severity of the problem has been studied by measuring coupled noise induced on carefully constructed test cards. Curves are presented as an aid for predicting noise levels as a function of conductor spacing and signal edge speed. The measurements are discussed quantitatively and guidelines for the design of high speed thick film circuits are summarized.

Thesis (PhDElectronicEngineering)--University of South Australia, 2003.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 77-81). Also available via the Internet.

This Dissertation is a study of Switched Mode Power Supply (SMPS) miniaturization and how to effectively use the available technologies to achieve the ultimate goal of a reduced size without loss of functionality while maintaining a cost effective design. This research investigates several methods used to obtain low loss, highly compact power supplies. Within these constraints, the Dissertation investigates the issues of design, materials, and cost in order to design and achieve these miniaturized power supplies. This research addresses high performance ceramic, passive component integration. Three key issues; electrical characterization, thermal analysis and simulation, and material characterization, are examined in this work. Thick film passive components (capacitors and resistors) on AlN have been developed. Also, guidelines for the design implementation and steps necessary to integrate these passive components on prefired alumina (Al2O3) and aluminum nitride (AlN) ceramic surfaces, for power electronic applications, have been generated. The use of aluminum nitride, as a high performance ceramic substrate and the resulting issues concerning compatible inks, have been investigated. Since a sizable amount of heat is generated by power electronic circuits, the integrated components are analyzed with respect to tolerance and degeneration over a range of temperatures and frequencies. Thick film capacitors on the order of 120pF/mm2 with breakdown voltage ratings of 250V have been developed on prefired AlN. Resistors were developed with impedances ranging from 10W to 10MegW. Thermal measurements, of these resistors, show that the thermal conductivity of the aluminum nitride with passivation layer is two to three times that of alumina. Several versions of a typical SMPS boost circuit have been generated using Direct Bond Copper (DBC) on ceramic, Insulated Metal Substrate (IMS), Printed Circuit Boards (PCB), and prefired ceramic thick film technology. The integrated passive components developed are applied on prefired ceramic versions and compared to the DBC, IMS and PCB versions. A small daughter board consisting of the boost circuit control is introduced to further supplement miniaturization and reduce cost. The daughter board uses thick film technology with integrated thick film resistors. The design of the mother board, which houses the power boost section,can be designedand implemented on virtually any type of substrate (PCB, DBC, IMS, or conventional thick film). The fabrication and testing of each version is reported in this work. / Ph. D.

No description available.

<p> Thick-film resistors are being used in the hybrid microelectronics industry. One characteristic that has been considered for the thick film resistor i s the reproduceability in resistor value associated with the production techniques employed in the reproduceability in resistor value associated with the production techniques employed in the resistor manufactured. </p> <p> One parameter that has been associated with reproduceability is the yield figure; another parameter is the width of the resistance distribution for a given resistor production. These parameters can be used to identify the degree of reproduceability for the resistor production. A high yield figure or a small spread figure indicates a high degree of reproduceability. </p> <p> The effect of aspect ratio and sheet resistivity on the reproduceability has been evaluated for paste system A. Aspect ratios of 10, 5, 2 and 0.7 for a range of sheet resistivities (100, 1K, 10K, 100K, and 1M ohms per square) were investigated. Results show that for a given aspect ratio the amount of variation in spread for the range of sheet resistivities is negligible within the limits of error in the experiment. For a given sheet resistivity, the variation in spread for the range of aspect ratios is considerable. The spread of an aspect ratio of 10 is 25 ± 4%. For an aspect ratio of 0.7 the spread is 59± 7%. </p> <p> The effect of resistor location on spread for a 2" x 2" substrate has been studied. Results indicate that a higher degree of reproduceability can be associated with resistors located near the central (1" x 1") region of the substrate than the resistors located near the perimeter. </p> <p> The effect of increasing the resistor width on the reproduceability has been evaluated for resistors having aspect ratios near unity. Results show that as the resistor width is increased the spread in resistance decreases. For a width of 30 mil the spread in resistance is 37%. When the width is increased to 100 mil, the spread decreases to 21%. </p> / Thesis / Master of Engineering (MEngr)

Thesis (Ph. D.)--Brigham Young University Dept. of Chemical Engineering, 2006. / Includes bibliographical references (p. 155-165).

Abstract In gravure offset printing, ink is transferred with the help of an offset material from a patterned gravure plate to a substrate. This thesis is concerned with the study and further development of this printing process for electronics; on alumina, glass and polymers. The work has been divided into five parts. In the first section, the printing process is described. The second section describes the composition of the inks for gravure offset printing and the resulting ink properties. It also presents the ink transfer mechanism; the model that explains how the ink is transferred between an offset material and a substrate. The third chapter details the printing process explained by a solvent absorption mechanism. The forth chapter describes the firing/curing of printed samples and their properties. The last chapter describes applications of the method. The inks used to produce conductors on ceramics (ceramic inks) and conductors on polymers (polymer inks) contain silver particles, and were under development for gravure offset printing. The major achieved properties were the high ink pickup to the offset blanket and high transfer percentage to the substrate. 100% ink transfer from blanket to substrate for ceramic inks and almost 100% ink transfer for polymer inks was obtained. The printing of ceramic inks was able to produce 8 μm of relatively thick, 300 μm wide lines with &lt; 10 mΩ/sq. resistance. The minimum line width for conducting lines was 35 μm, with one printing. Multi printing was applied producing as many as 10 times wet-on-wet multiprinted lines with 100 % ink transfer from blanket to substrate resulting in a square resistance of 1mΩ/sq. Polymer inks were able produce a square resistance of 20 mΩ/sq. for 300 μm wide lines after curing at 140 °C for about 15 min, and the minimum width was down to 70 μm. In the optimised manufacturing process, the delay time on the blanket was reduced to 3 s. In addition to ultra-fine-line manufacturing of conductors, the method enables the manufacture of special structures e.g. laser-solder contact pads with 28/28 μm lines/spaces resolution. With industrial printing equipment it is possible to produce 100 m2/h with the demonstrated printing properties.

Inductors and transformers constitute two important magnetic components In RF and power hybrids electronic circuitry. Thick film inductors have been subject of extensive research in recent years because they significantly reduce the weight and size, and increase the frequency of operation of electronic circuits. The research work in this dissertation is aimed at the formulation of thick film ferrite pastes and ferrite epoxies and the design, construction, and evaluation of thick film spiral inductors. Wideband characterization (DC - 2GHz) of ferrite pastes, ferrite epoxies, and ferrite substrates is performed using two techniques. These techniques are based on current image and transmission line (coaxial cavity) concepts for low (DC-IOOMHz) and high (50MHz-2GHz) frequency regions, respectively. They are used to evaluate the permeability spectra of formulated and commercially available thick film magnetic materials in respective frequency ranges. A method to numerically calculate the inductance of thick film circular spiral inductors based on modeling the spiral as concentric circles is presented. A novel method for fine as well as coarse tuning of thick film inductors is also introduced. The tunable inductors are constructed using formulated ferrite epoxies and magnetic cores. The method of analysis of variance is used to investigate the variation significance of tunable inductors. Finally, chemical and mechanical properties of developed magnetic materials are discussed. The studied properties include, glass transition temperature, degradation temperature, thermal coefficient of expansion, adhesion, particle-size distribution and particle densification , grain size, and compositional constituents of the magnetic materials. / Ph. D.