Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.91-95).

Thesis (Ph. D.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.S.)--Michigan State University. Dept. of Electrical Engineering, 2008. / Title from PDF t.p. (viewed on Aug. 5, 2009) Includes bibliographical references (p. 76-77). Also issued in print.

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Includes bibliographical references. / by Michael Peter Manahan. / Sc.D.

Thesis (M.S.E.C.E.)--University of Delaware, 2007. / Principal faculty advisor: Michael W. Haney, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

Pulse tube refrigerators (PTR) are robust, rugged cryocoolers that do not have a moving component at their cold ends. They are often employed for cryogenic cooling of high performance electronics in space applications where reliability is paramount. Miniaturizing these refrigerators has been a subject of intense research interest because of the benefits of minimal size and weight for airborne operation and because miniature coolers would be an enabling technology for other applications. Despite much effort, the extent of possible PTR miniaturization is still uncertain. To partially remedy this, an investigation of the miniaturization of pulse tube refrigerators has been undertaken using several numerical modeling techniques. In support of these models, experiments were performed to determine directional hydrodynamic parameters characteristic of stacked screens of #635 stainless steel and #325 phosphor bronze wire mesh, two fine-mesh porous materials suitable for use in the regenerator and heat exchanger components of miniature PTRs. Complete system level and pulse tube component level CFD models incorporating these parameters were then employed to quantitatively estimate the effects of several phenomena expected to impact the performance of miniature PTRs. These included the presence of preferential flow paths in an annular region near the regenerator wall and increased viscous and thermal boundary layer thicknesses relative to the pulse tube diameter. The effects of tapering or chamfering the junctions between components of dissimilar diameters were also investigated. The results of these models were subsequently applied to produce successively smaller micro-scale PTR models having total volumes as small as 0.141 cc for which sufficient net cooling was predicted to make operation at cryogenic temperatures feasible. The results of this investigation provide design criteria for miniaturized PTRs and establish the feasibility of their operation at frequencies up to 1000 Hz with dimensions roughly an order of magnitude smaller than those that have recently been demonstrated, provided that challenges related to their regenerator fillers and compressors can be addressed.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI Company.

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Miniaturization and functionality have always governed advances in electronic system technology. To truly achieve the goal of a multi mega-functional system, advances must be made not just at the IC level, but at the system level too. This concept of tighter integration at the system level is called System-on-Package (SOP). While SOP has a wide range of applications, this work targets the mobile application space. The main driver in the mobile application space is package profile. Reduction in thickness is very critical for enabling next-generation ultra-high density mobile products. In order to pack more functionality into a smaller volume, it is absolutely imperative that package profiles are reduced. The NEMI roadmap projects that the package profile should be reduced to 200µm from the current 500µm by 2014. This work attempts to demonstrate the feasibility of ultra-thin substrates (<200µm) using a new advanced material system tailored for high-frequency mobile applications. The main barriers to adoption of thin substrates include processing challenges, concerns about via and through hole reliability and warpage. Each of these factors is studied and a full-fledged test vehicle built to demonstrate the reliability of thin substrates using the advanced low-loss RXP-4/RXP-1 material system. Finite element models are developed to provide an understanding of the factors that affect the reliability of these substrates. Finally, IC assembly is demonstrated on these substrates.

This project is a fundamental proof of concept to look at the feasibility of using field activated abrasive particles to achieve material removal on a substrate. There are a few different goals for this project. The first goal is to prove through visualization that particle movement can be influenced and controlled by changes in electric field. The second goal is to fundamentally prove that particles controlled by electric field can remove material from a substrate. Third, it should be shown that changes in electric field can control the amount of material being removed in a given amount of time. A mathematical model will be presented which predicts metallic material removal rates based on changes in electric field strength. In this project, a technique combining concepts from electrokinetics, electrochemical mechanical planarization, and contact mechanics is proposed, aiming at enhancing planarization performance. By introducing an AC electric field with a DC offset, we try to achieve not only a better control of metallic material removal but also more flexible manipulation of the dynamic behaviour of abrasive particles. The presence of electric field will lead to electrokinetic phenomena including electroosmotic flow of an electrolyte solution and electrophoretic motion of abrasive particles. As a result, we aim to improve both the mechanical performance of planarization that is largely determined by the polishing parameters (e.g. down pressure, rotation speed, pads, and types of abrasives) and the chemical performance of planarization that is governed by selective and collective reactions of different chemical ingrediants of the slurry with the sample surface. The aim is also to understand and improve the interactions of abrasive particles with the sample.