The University of North Carolina at Charlotte

Mcnc

The University of North Carolina at Chapel Hill

Microelectronics Center of N.c.

Mcnc and University of Nc at Charlotte

Unc at Charlotte

Thomas D DuBois

Stephen M Bobbio

Farid M Tranjan

Susan K Jones

Rudolf G Frieser

Richard F Greene

Scott Halden Goodwin-Johansson

Mark D Kellam

George K Lucey, Jr

Bruce W Dudley

Kasra Daneshvar

James D Jacobson

Youssef Bousaba

Kerstin McKay

Timothy Piekarski

Robert F Lipscomb

James D Geis

A method of forming hydrogen fluoride (HF), to allow fluxless soldering, from a solid source such as potassium hydrogen fluoride (KF.HF) using a specialized apparatus, including a cartridge which is heated in a controlled atmosphere apparatus. The gaseous reaction product, HF, may be extracted from the apparatus either by itself or in a carrier gas (such as argon or nitrogen). The solid reaction product, potassium fluoride (KF), is an inert material which remains in the cartridge. The combination of the cartridge and KF may be safely disposed of as a unit or refilled with KF.HF under controlled conditions.

Method and apparatus for forming hydrogen fluoride

A field emitter flat panel display and associated method of operation provides an electron emission path along which a beam of electrons emitted by a microelectronic field emitter travels such that the electrons impinge upon a light emitting element without passing through a mirror. The light emitting element is spaced apart from the microelectronic field emitter and includes a mirror and a luminescence layer on the mirror. The flat panel display can also include a deflector, such as a deflector electrode, which is spaced apart from both the microelectronic field emitter and the associated light emitting element and which controllably deflects the beam of electrons emitted by the microelectronic field emitter toward the luminescent layer of the associated light emitting element and along a curved electron emission path which is independent of the underlying mirror. Since the energy of the electrons is not dissipated by passing through a mirror prior to impinging upon the luminescent layer, the field emitter flat panel display and, more particularly, the microelectronic field emitter can be efficiently driven at relatively low voltage levels while still producing a relatively bright display.

Field emitter flat panel display device and method for operating same

A fluxless soldering method utilizing a strongly internally bonded fluorine containing gas such as hydrogen fluoride (HF). The solder surface is exposed to the gas in place of a flux treatment, resulting in a modified surface layer which allows reflow or joining for an extended period.

Fluxless soldering method

An electrically and mechanically robust microelectromechanical transducer is formed of a pleated dielectric sheet having patterned electrical conductors on the opposing faces thereof. The pleats define a plurality of spaced apart walls, with each wall including an electrically conductive portion at one side thereof. Positive and negative voltages, applied to opposite faces of the pleated sheet, cause the walls to move towards one another by electrostatic attraction. The walls can also move away from one another by electrostatic repulsion upon application of appropriate voltages. The microelectromechanical transducer may be fabricated by fabricating a sheet with integral pleats or by forming a 'self-pleating' flat sheet which forms pleats after conductor fabrication thereon.

Pleated sheet microelectromechanical transducer

A microelectromechanical transducer including a plurality of parallel electrically conductive strips maintained in closely spaced relation by a plurality of spacers can generate useful displacements and forces. The transducer can be strengthened by arranging the conductive strips in cells surrounded by unidirectional cell stiffening members and unidirectional displacement limiting members. The unidirectional cell stiffening members may include notches. The unidirectional displacement limiting members may include unidirectional buckling straps or flexible arches. The cells of electrically conductive strips can be organized in modular or fractal arrays.

Unidirectional supporting structure for microelectromechanical

A photoresist composition is disclosed that comprises an organic resin that is thermoset by acid catalysis and a photoactive, etch-resistant ionic modifier formed of an anion and a cation. The modifier is present in the organic resin in an amount effective to produce substantial photoreactivity and etch resistance in a mixture of the resin and the modifier. The cation will, upon exposure to electromagnetic radiation, produce a species that is weakly basic or neutral, and the anion will, upon exposure to electromagnetic radiation, produce an acid precursor that will form a relatively strong acid in an acid-base solvent system. As a result, the relatively strong acid will catalyze the organic resin upon exposure to an appropriate frequency of electromagnetic radiation and the relatively weak base or neutral species formed by the cation will not substantially neutralize the acid or interfere with the acid catalyzed reaction of the organic resin.

Ionic modification of organic resins and photoresists to produce

The invention comprises curing polyamic acid solutions into polyimide solutions by adding a hydrophilic reagent to a polyamic acid solution. The hydrophilic reagent is selected to have little or no reactivity with amines or carboxylic acids, and is of the type that will react with water to form by-products that shift the equilibrium between polyamic acid as a reactant and polyimide and water as products toward the production of polyimide.

Chemically cured low temperature polyimides

The invention is a modified organic photoresist which is resistant to etching in oxygen-containing plasmas and therefore particularly useful for masking and etching organic polymer materials in VLSI and advanced packaging applications. The invention comprises adding a phosphorous-containing compound to a conventional photoresist. The phosphorous-containing compound is of a type and in an amount effective to substantially prevent etching of the modified photoresist in an oxygen-containing plasma without substantially adversely affecting the photosensitivity of the photoresist or the elasticity or the adhesion of the etch resistant film formed during oxygen-containing plasma exposure to an underlying material to be patterned and etched.

Growing community of inventors

Charlotte, NC, United States of America

Thomas D DuBois