Northrop Grumman Systems Corporation

Westinghouse Electric Corporation

United States of America As Represented by the Secretary of the Air Force

Other

The United States of America As Represented by the United States

North American Philips Lighting Corp.

Norhtrop Grumman Corporation

Northrop Grumman Cropration

Deborah P Partlow

Kenneth C Radford

Andrew J Piloto

Stephen R Gurkovich

Bulent E Yoldas

Alex E Bailey

Clarence A Andersson

Theodore R Vasilow

Edward Jean Lahoda

John D Adam

David C Grant

Karl F Schoch, Jr

Steven N Stitzer

Jeffrey David Hartman

Thomas J Knight

Michael R Daniel

Cynthia W Berry

Raymond J Bratton

Salvador H Talisa

Godfrey Augustine

Alfred Paul Turley

Leland L Learn

Jayashri N Iyer

Jay E Lane

Carol J Painter

Wei-Fang Su

Michael A Janocko

Shih-Ming Ho

High-speed silicon CMOS circuits and high-power AlGaN/GaN amplifiers are integrated on the same wafer. A thin layer of high resistivity silicon is bonded on a substrate. Following the bonding, an AlGaN/GaN structure is grown over the bonded silicon layer. A silicon nitride or a silicon oxide layer is then deposited over the AlGaN/GaN structure. Following this, a thin layer of silicon is bonded to the silicon nitride/silicon oxide layer. An area for the fabrication of AlGaN/GaN devices is defined, and the silicon is etched away from those areas. Following this, CMOS devices are fabricated on the silicon layer and AlGaN/GaN devices fabricated on the AlGaN/GaN surface.

Method for integrating silicon CMOS and AlGaN/GaN wideband amplifiers on engineered substrates

A fabrication process for ferrite toroids which utilizes ferrite ceramic tape having an improved elongation characteristic. The process utilizes a set of rigid mandrels which are employed in the final lamination to support the rectangular cross section of the internal cavity of a respective ferrite tube, thereby reducing stress concentration and permitting the highest lamination pressure to be used in the final step. The mandrels are removed prior to panel densification. The tape and mandrels operate together to minimize cracks and pores in the toroids and provide an added advantage of maintaining high tolerances in the internal cavity dimensions as well as the cavity-to-cavity alignment.

Method of manufacturing ferromagnetic toroids used in ferrite phase shifters

A planar phase shifter formed of multiple layers of a ferrite. Selected layers of the ferrite are patterned with a conductor and the multiple layers of magnetic dielectric and conductor are cofired. The phase shifter is fabricated by first obtaining ferrite powder. Then, layers of the ferrite are made, preferably by tape casting. Next the ferrite layers are metallized by applying selected amounts of conductive metals in a selected pattern upon the tape. Selected numbers of vias are placed through selected layers of tape and conductive metal is placed in the vias to provide vertical connections through the layers. The tape layers are then stacked in a predetermined order and are laminated. The laminated stack of layers is then fired to a temperature of approximately 800.degree. C. to 1000.degree. C., sintering the laminated layers into one integrated structure.

Planar phase shifters using low coercive force and fast switching,

Materials and methods for the fabrication of high density, low temperature fired microwave ferrites for use in microwave power devices, transmission line elements, isolators, circulators, and phase shifters. Very fine (sub-micron) ferrite powders made by sol-gel methods are mixed with solvents and binders then tape-cast. Ferrite tapes in the unfired state are cut into complex shapes and may be provided with via holes. These ferrite sheets are fired discretely, or are laminated, cofired with printed metal pastes, or other active and passive ceramic tapes.

Process for fabricating a microwave power device

We disclose a fabrication method for integrating passive devices such as capacitors, resistors and circulators into ceramic packages for electronic systems. The method utilizes a glass or glass/ceramic as a bonding agent which is incorporated as one of the layers in the multilayer package. The integration of such passive devices eliminates the tedious mounting of these devices on the package, permitting a smaller, more reliable, less expensive and lighter weight product. This method allows the integration of passive devices having firing temperatures far different from that of the ceramic package itself, permitting combinations of materials that cannot be densified, or cofired together.

Post-firing method for integrating passive devices into ceramic

A method for producing ceramic tape used to fabricate electronic devices while eliminating continued shrinkage of the unfired tape. Chemical agents are added to a mixture of ceramic powder and binder to manipulate the crosslinking of the binder. A first approach involves promoting the crosslinking reaction to completion quickly. The second approach involves preventing the crosslinking reaction during the tape slurry mixing and casting processes. A solvent is used to accelerate the crosslinking of the binder in which the solvent may include one or more of acetone, acetylacetone, toluene and ethanol. Preferably, the solvent is a combination of acetone and acetylacetone. A polyhydroxy compound, such as glycerine, may be added to accelerate the crosslinking reaction of the binder. The boron in the tape may alternatively be rendered inoperative as a crossing agent for the binder by pre-reacting the boron with the Lewis base prior to contact with the binder. The preferred Lewis base is an organic amine, such as piperidine.

Ceramic tape formulations with green tape stability

The invention provides for an electronic package having a buried passive component such as a capacitor therein, and a method for fabricating the same. The electronic package preferably includes a passive component portion which includes a plurality of layers of high K dielectric material, a signal processing portion which includes a plurality of layers of low K dielectric material, and at least one buffer layer interposed between the passive component portion and the signal processing portion. Metallization is preferably printed upon at least one of the layers of high K dielectric material and at least one of the layers of low K dielectric material. Preferably, the layers are co-fired at a temperature below approximately 1200.degree. C. to form the electronic package and each of the buffer layers contains approximately 25 to 100% barium compound. Via conductors may also be provided through the buffer layers to electrically couple the passive component portion and the signal processing portion and the metallization and the via conductors may be selected from highly conductive materials such as gold, silver, copper and alloys thereof.

Electronic package having buried passive components

A system for incorporating superconductor circuits and semiconductor circuits in multilayered structures. A carrier material is chosen that is a good thermal match with the preferred superconductor substrates. The preferred superconductor substrate materials are lanthanum aluminate, magnesium oxide and neodymium gallate. The substrate carrier material should provide adequate thermal match through the range of operating temperatures which are preferably from room temperature to 77K. The preferred carrier material is a low temperature cofired ceramic (LTCC) which allows for multilayered structures to be developed which incorporate the superconductor circuitry and the semiconductor elements. The LTCC is composed of crystalline quartz particles in a borosilicate glass matrix. The percentage of quartz may be adjusted to adjust the thermal expansion characteristics of the LTCC.

Technique for fabricating hybrid high-temperature

A thick film metallization compatible with low temperature cofired ceramics (LTCC) that displays very low microwave insertion losses commensurate with those of thin film gold. However, the disclosed metallization is applied similar to conventional metallizations by screen printing and has no limit to the number of layers achievable. The electrical performance of the metallization is attained by using a spherical metal particle shape and uniform particle size distribution in the thick film paste. The advantage of this invention is that superior microwave performance can be achieved in electronic packages without the cost and limitations imposed by thin film metallization techniques.

Low loss, thick film metallizations for multilayer microwave packaging

A method for forming a low temperature cofired ceramic package which is made using a multi-layered densified spherical powder formed via a sol-gel process. This densified powder is formed from layers of SiO.sub.2 reacted with trimethyl borate. The spherical powder has a preselected particle size and boron content sufficient to render the low temperature cofired ceramic package fully dense, even in the presence of a second phase filler ceramic, at a sintering temperature below 1000.degree. C. Binder material is added to the spherical powder and ceramic filler to form a plurality of tapes. A ceramic assembly is then formed by layering the plurality of tapes upon one another and firing the ceramic assembly at a temperature below 1025.degree. C. to form a fully dense cofired ceramic package. In order to form the multi-layered densified spherical powder, a silica core, which is formed using a sol-gel process, is reacted with trimethyl borate. An additional layer of silica is provided upon the reacted product which, in turn, is reacted with trimethyl borate. This process is continued until a spherical powder of desired size is formed.

Method for manufacturing a low loss, low temperature cofired ceramic

A ceramic capacitor suitable for high energy density and high temperature application is disclosed. Such a capacitor is prepared by producing the selected ceramic powder via the sol-gel process forming the capacitor to the desired shape with the resulting powder using tape casting technology and firing the 'green' form so produced.

High power capacitor

A dual mode radar transparency allowing passage of both RF radiation and IR radiation comprises an aerogel base and ceramic skin overlaying the aerogel base. The aerogel base comprises a low density ceramic material. A method of fabricating a dual mode radar transparency allowing passage of both RF radiation and IR radiation comprises the steps of preparing a colloidal dispersion of a ceramic material in a medium, increasing a concentration of the colloidal dispersion by evaporation to create a suspension, and placing the suspension in a mold. The suspension is solidified to form an aerogel and the aerogel is joined to a ceramic skin.

Dual mode radar transparency and method of fabricating same

A multi-layer capacitor comprising a stack of sheet electrodes with an insulating dielectric layer sandwiched between these layers is disclosed. The dielectric layer formed on the electrode is prepared by the 'sol-gel' process.

High capacitance thin film capacitor

A vanadium oxide compound having the formula VO.sub.2 is disclosed for the purpose of selectively shielding an electromagnetic transmitter or receiver. Vanadium oxide exhibits a marked and rapid transition from dielectric and transparent to electromagnetic radiation to metallic and impervious to such radiation at a specific temperature, 68.degree. C. The compound is preferably mounted as a thin layer on a substrate which has been specifically selected for the desired application. The transmission of radiation is then temperature selected. The preferred method of deposition is an organic hydrolysis reaction.

Method of preparing a switchable shield

Solutions such as for example drinking water, ground water and extracting solutions contaminated with heavy metals and radioactive species, singly or in combination, are treated by first treating the contaminated solution with silicate and ammonium hydroxide solution precipitants. Then the contaminated solution is separately treated with an acid which gels, polymerizes and/or precipitates the contaminant-containing silica matrix to form an easily dewaterable and separable solid. The solid contaminants are readily removed from the cleansed solution by filtration means. The process utilizes a novel combination of steps which maximizes contaminant removal, minimizes waste volume, and produces a treatable waste solid. The preferred precipitants are sodium silicate, and ammonium hydroxide. The preferred mineral acid is hydrochloric acid.

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Export, PA, United States of America

Deborah P Partlow