Engineering Commons^™

Electronic Package Comprising A Substrate And A Semiconductor Device Bonded Thereto, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A composition containing a polymeric matrix and a conductive filler component is provided. The conductive filler component comprises conductive particles and a polymer selected from the group consisting of substituted and unsubstituted polyanilines, substituted and unsubstituted polyparaphenylenevinylenes, substituted and unsubstituted polythiophenes, substituted and unsubstituted polyazines, substituted and unsubstituted polyparaphenylenes, substituted and unsubstituted polyfuranes, substituted and unsubstituted polypyrroles, substituted and unsubstituted polyselenophene, substituted and unsubstituted poly-p-phenylene sulfides and substituted and unsubstituted polyacetylenes, and mixtures thereof, and copolymers thereof. The compositions of the present invention are useful as adhesives for interconnecting a semiconductor chip to a substrate

Electronic Package Comprising A Substrate And A Semiconductor Device Bonded Thereto, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A composition containing a polymeric matrix and a conductive filler component is provided. The conductive filler component comprises conductive particles and a polymer selected from the group consisting of substituted and unsubstituted polyanilines, substituted and unsubstituted polyparaphenylenevinylenes, substituted and unsubstituted polythiophenes, substituted and unsubstituted polyazines, substituted and unsubstituted polyparaphenylenes, substituted and unsubstituted polyfuranes, substituted and unsubstituted polypyrroles, substituted and unsubstituted polyselenophene, substituted and unsubstituted poly-p-phenylene sulfides and substituted and unsubstituted polyacetylenes, and mixtures thereof, and copolymers thereof. The compositions of the present invention are useful as adhesives for interconnecting a semiconductor chip to a substrate

Acuta Enews July 1998, Vol.27, No. 5

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ACUTA Board of Directors '98-'99

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New Fiber Optics

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Connecting Off-Campus Housing to the Network

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In Situ Infrared And Visible-Light Ellipsometric Investigations Of Boron Nitride Thin Films At Elevated Temperatures, E. Franke, Mathias Schubert, J.-D. Hecht, H. Neumann, T. E. Tiwald, Daniel W. Thompson, H. Yao, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

In situ infrared (IR) spectroscopy and visible-light (VIS) spectroscopic ellipsometry over the spectral range from 700 to 2000 cm^-1 and 1.5–3.5 eV, respectively, were used to investigate the optical behavior of boron nitride (BN) thin films at temperatures from room temperature (RT) to 600 °C. The polycrystalline hexagonal (h) and mixed-phase h- and cubic (c)-BN thin films were deposited by magnetron sputtering on [001] silicon. We observe a reversible moisture incorporation process in as-grown h-BN samples. When stored in normal ambient, the h-BN thin films absorb water into thin-film micropores. When annealed in ultrahigh vacuum or a …

Runoff And Erosion Following Field Application Of Beef Cattle Manure And Compost, John E. Gilley, Bahman Eghball

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Manure or compost from beef cattle feedlots can be excellent sources of nutrients and organic matter when added to soils. This study was conducted to determine the effect of a single application of manure and compost on runoff and erosion under no-till and tillage conditions. Tillage consisted of a single disking operation up and down the slope on a Sharpsburg soil which was cropped to grain sorghum or wheat the previous season. Manure and compost were applied at rates required to meet corn fertility requirements. Additional experimental treatments included the application of inorganic fertilizer and an untreated check. The addition …

Minutes Of The June 23, 1998 Meeting Of The Friends Of The Tractor Test Museum, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Updated Membership Listing Foundation Budget Ageless Iron Article

System And Method For Performing Optical Code Division Multiple Access Communication Using Bipolar Codes, James F. Young, Benhaam Aazhnag, Lim Nguyen

Department of Electrical and Computer Engineering: Faculty Publications

An optical encoding and decoding system which performs code-division multiple access (CDMA) communication in the incoherent, or direct detection, optical domain using bipolar +1/-1 codes. The present invention uses code modu lation and detection principles that permit all-optical imple mentation of the bipolar. +1/-1. code and correlation detec tion that have been developed for the radio frequency (RF) systems. This is possible in spite of the non-negative, or unipolar, +1/0, nature of the incoherent optical system that only detects and processes the signal intensity. The unipolar optical system of the present invention is equivalent to the bipolar RF system in …

Sustainability And Resource Assessment: A Case Study Of Soil Resources In The United States, Dana L. Hoag, Jennie S. Hughes Popp, D. Eric Hyatt

United States Environmental Protection Agency: Publications

Assessment of environmental condition is critical to wise management and policy decisions. However, for some concerns such as sustainability, it is difficult to assess environmental condition because it involves disparate social objectives and an understanding of complex ecological systems. Here, a general framework is proposed to examine sustainability of environmental resources in objective, measurable ways. By using soil quality as an example, sustainability research is taken beyond theory and into application.
Sustainability depends on the quality of resource endowment. Endowment of a natural resource can be modeled as an index of quality to assess the degree of sustainable management. This …

Acuta Enews June 1998, Vol.27, No. 6

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CICs Go to 4 Digits June 30

Winners Announced in Second Annual Student Papers Competition

Board Report

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FYI: Digital Decay

PRI ISDN at UMSL

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Thickness Dependence Of Interfacial Magneto-Optic Effects, Xiang Gao, Michael J. Devries, Daniel W. Thompson, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Spectroscopic ellipsometry and magneto-optic Kerr effects are measured on Pt/Co multilayers with a series of Co layer thicknesses from 0.08 to 1 nm. An electromagnetic theory of multilayered structures allows regression analysis fits between acquired data and parameter dependent model analysis. Recently, we determined the single layer Co magneto-optic Voigt parameter and found that it depends on Co layer thickness. In the present work, we report an in-depth study of interfacial magneto-optic effects for a large number of Pt/Co multilayer samples. Kerr rotation and ellipticity were measured over the spectral range from 200 to 1700 nm. Voigt parameters of the …

System And Method For Improving Data Acquisition Capability In Spectroscopic Ellipsometers, Steven E. Green, Craig M. Herzinger, Blaine D. Johs, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The present invention is applicable generally to Spectroscopic Rotatable and Rotating Element Ellipsometers which utilize a relatively large range of wavelengths. Disclosed is a system and method for controlling the polarization state of a polarized beam of light so that it is in a range where the sensitivity of a Polarization State Detector used to measure changes in said polarized beam of light resulting from interaction with a Sample System. to noise and measurement errors etc.. is reduced. Exemplified is a system. and method of use, for simultaneously setting both measured ellipsometric ALPHA, and ellipsometric BETA parameter values, (or equivalents), …

The Effect Of Grain Size On Magnetic Properties In Sm2Fe17NX, Jeffrey E. Shield, D.J. Branagan, C.P. Li, R.W. Mccallum

Nebraska Center for Materials and Nanoscience: Faculty Publications

The microstructures of melt spun Sm11Fe89 and (Sm₁₁Fe₈₉)₉₄Ti₃C₃ have been investigated under different solidification conditions. The magnetic properties of the nitrided materials have been related to the observed microstructures. Melt spinning of the Sm₁₁Fe₈₉ alloys resulted in grain sizes at or above the single domain limit. The addition of Ti and C resulted in an order of magnitude refinement in the microstructural scale. The magnetic properties of the samples with grain sizes below the single domain limit decreased with decreasing grain size due to increased intergranular exchange coupling.

Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.

Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.

Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.

Acuta Enews May 1998, Vol.27, No. 5

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Board Approves Slate of Nominees

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Analysis Of Combustion-Driven Acoustics, Leonie Boshoff-Mostert, Hendrik J. Viljoen

Papers in Reaction Kinetics

Combustion-driven acoustic oscillations are investigated by performing a onedimensional stability analysis of a burner-stabilized premixed flame. In contrast to other investigators, no initial acoustic wave is assumed in the analysis; the downstream acoustic field results from flame instability. Two models are considered: the thermodiffusive model (uncoupled model) and the fully coupled thermodiffusive-hydrodynamic model. The fully coupled problem exhibits instability at a much lower critical Lewis number than the uncoupled problem.

Implementation Of A Database System With Boolean Algebra Constraints, András Salamon

School of Computing: Dissertations, Theses, and Student Research

This thesis describes an implementation of a constraint database system with constraints over a Boolean Algebra of sets. The system allows within the input database as well as the queries equality, subset-equality and monotone inequality constraints between Boolean Algebra terms built up using the operators of union, intersection and complement. Hence the new system extends the earlier DISCO system, which only allowed equality and subset-equality constraints between Boolean algebra variables and constants. The new system allows Datalog with Boolean Algebra constraints as the query lan- guage. The implementation includes an extension of Naive and Semi-Naive evaluation methods for Datalog programs …

Nebraska Tractor Test Museum Committee Minutes April 14, 1998, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Treasurer's Report Preparation for Dedication Fund Raising Issues

Acuta Enews April 1998, Vol.27, No. 4

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Achievement Award Nominations

Cornell to Host Local Event June 8 and 9

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Ellipsometric Determination Of Optical Constants For Silicon And Thermally Grown Silicon Dioxide Via A Multi-Sample, Multi-Wavelength, Multi-Angle Investigation, C. M. Herzinger, B. Johs, W. A. Mcgahan, John A. Woollam, W. Paulson

Department of Electrical and Computer Engineering: Faculty Publications

Optical constant spectra for silicon and thermally grown silicon dioxide have been simultaneously determined using variable angle of incidence spectroscopic ellipsometry from 0.75 to 6.5 eV. Spectroscopic ellipsometric data sets acquired at multiple angles of incidence from seven samples with oxide thicknesses from 2 to 350 nm were analyzed using a self-contained multi-sample technique to obtain Kramers–Kronig consistent optical constant spectra. The investigation used a systematic approach utilizing optical models of increasing complexity in order to investigate the need for fitting the thermal SiO₂ optical constants and including an interface layer between the silicon and SiO₂ in modeling …

Nebraska Tractor Test Useumcommittee Minutes March 10, 1998, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Hitchcock Foundation Big Red Collectors Dedication of Museum

Acuta Enews March 1998, Vol.27, No. 3

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Nominate Now for Board of Directors

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Studies Of Metallic Multilayer Structures, Optical Properties, And Oxidation Using In Situ Spectroscopic Ellipsometry, Xiang Gao, Jeff Hale, Scott Heckens, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

In situ spectroscopic ellipsometry (SE) has been successfully used to accurately measure sputter deposition rates and optical constants of un-oxidized metal layers and to control the growth of magnetic multilayers. The structures include [Co/Cu] _n , [Co/Au] _n , [Co/Ni] _n , [Co/Pd] _n and [Co/Pd/ Au] _n . Layer thickness precision is better than ±0.05 nm for layer thicknesses in the range of 0.2 nm to 10 nm. Closed-loop feedback control of layer thickness is also demonstrated. Good consistency was obtained by comparing the in situ SE results to x-ray diffraction measurements. Dynamic oxidation studies of [Co/Au] _n and …

Two-Dimensional Ferroelectric Films, Alexander V. Bune, Vladimir M. Fridkin, Stephen Ducharme, Lev M. Blinov, Serguei P. Palto, Alexander V. Sorokin, S. G. Yudin, A. Zlatkin

Stephen Ducharme Publications

Ultrathin crystalline films offer the possibility of exploring phase transitions in the crossover region between two and three dimensions. Second- order ferromagnetic phase transitions have been observed in monolayer magnetic films [1,2], where surface anisotropy energy stabilizes the two-dimensional ferromagnetic state at finite temperature [3]. Similarly, a number of magnetic materials have magnetic surface layers that show a second-order ferromagnetic–paramagnetic phase transition with an increased Curie temperature [4]. Ferroelectricity is in many ways analogous to ferromagnetism, and bulk-like ferroelectricity and finite-size modifications of it have been seen in nanocrystals as small as 250 Å in diameter [5], in perovskite films …

Design, Performance, And Applications Of A Coherent Ultra-Wideband Random Noise Radar, Ram M. Narayanan, Yi Xu, Paul D. Hoffmeyer, John O. Curtis

Department of Electrical and Computer Engineering: Faculty Publications

A novel coherent ultra-wideband radar system operating in the 1- to 2-GHz frequency range has been developed recently at the University of Nebraska. The radar system transmits white Gaussian noise. Detection and localization of buried objects is accomplished by correlating the reflected waveform with a time-delayed replica of the transmitted waveform. Broadband dual-polarized log-periodic antennas are used for transmission and reception. A unique signal-processing scheme is used to inject coherence into the system by frequency translation of the ultrawideband signal by a coherent 160-MHz phase-locked source prior to performing heterodyne correlation. The system coherence allows the extraction of a target’s …

Tractor Test Museum Committee February 10, 1998, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Heating Issues Handouts for visitors Big Red Club

Acuta Enews February 1998, Vol.27, No. 2

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Call for Nominations

ACUTA Board of Directors 1998-1999

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International Project Aims to Determine What IT Services Really Cost

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A Study Of Piezoelectric Orthorhombic Ta2O5, B. R. Jooste, Hendrik J. Viljoen

Hendrik J. Viljoen Publications

In 1985 it was first reported that monoclinic Ta₂O₅ has piezoelectric properties comparable to ZnO. In this work we report on the deposition, characterization, and qualitative assessment of the piezoelectric behavior of orthorhombic Ta₂O₅. Reactive magnetron sputtering was used to deposit thin films of Ta₂O₅ onto substrates of 316L stainless steel. Without substrate heating the crystallinity was poor. A rapid thermal anneal improved the crystallinity. The orthorhombic phase was dominantly present on all substrates. The piezoelectric property was qualitatively assessed, including a high temperature test at 650 °C.

Nebraska Tractor Test Museum Committee Minutes January 20th, 1998, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Roof Repair Big Red Convention Dedication Ceremony