Northrop Grumman Systems Corporation

Martin Marietta Corporation

Norhtrop Grumman Corporation

Northrop Grumman Cropration

Northrop Grumman Corporaiton

Alex E Bailey

Tapan K Gupta

Cynthia W Berry

Deborah P Partlow

Audrey E Sutherland

Andrew Paul Ritter

Andrew J Piloto

Ronnie L Starling

Stephen R Winzer

John Chino

Kenneth C Radford

Stephen R Gurkovich

Andrea Curbean

Steven N Stitzer

Keith Bridger

Theodore R Vasilow

Allan S Gelb

Paul J Caldwell

William B Yablon

Herbert Jefferson Henderson

Daniel Bobowicz

Norman E Thurlow

Robert H Fisher

Jose Armando Coronado

Jeffrey J Dickstein

Lawrence J Hunter

Dennis A Grube

William A Thomas

Dennis Grube

Timothy M Fertiq

Eric M Fiore

Julie A Christodoulou

Steve M Smalley

Thomas C Dula, Iii

Inam Jawed

Robert G Schmier

Daniel Brosey

Terry L Reeve

An LTCC (low temperature cofired ceramic) structure which has conductors to which leads are to be bonded for connection to external circuitry. The conductors include additives to promote adhesion to the ceramic layer. The presence of these additives degrade bonding performance. For better bondability of the leads, a pure conductor metal layer, devoid of the additives is placed on the conductors in areas where leads are to be bonded. This pure conductor metal layer may be cofired with the stack of ceramic layers or may be post fired after stack firing.

Method for LTCC circuitry

A method of producing an LTCC substrate having improved cavity bondability is disclosed that involves providing a stack of green ceramic tape sheets having a cavity, placing a template having an opening corresponding to the cavity over the stack, placing a stretchable sheet of material coated with graphite or zinc stearate over the template, isostatically laminating the stack to produce an LTCC substrate having a cavity, and removing the template and sheet of stretchable material from the stack.

Method of producing an LTCC substrate with cavities having improved bondability

A method of forming an LTCC structure having at least one open cavity on each of first and second opposing sides is disclosed that includes the steps of forming a first LTCC structure including a first side having a plurality of cavities and a second side, subjecting the first LTCC structure to a first pressure, forming a second LTCC structure including a first side having a plurality of cavities and a second side, subjecting the second LTCC structure to a second pressure, arranging the first LTCC structure and the second LTCC structure such that the first LTCC structure second side faces the second LTCC structure second side, and subjecting the placed-together first and second LTCC structures to a third pressure to join the first LTCC structure to the second LTCC structure. A product formed by the subject method is also disclosed.

Method of laminating low temperature co-fired ceramic (LTCC) Material

An LTCC module includes a base on one or more surfaces for receiving one or more external components to be attached to the module. A base is formed of a plurality of layers of metallization in a predetermined pattern. The layers include an adhesion layer on the LTCC module surface, with one or more intermediate layers, followed by a top layer. The module is fired with each application of the layers at a reduced temperature lower than the normal cofiring temperature of the LTCC module, but of sufficient value to partially sinter the layers. After the last applied top layer, the module is fired once at an elevated temperature to fully sinter the layers.

Method of forming one or more base structures on an LTCC cofired module

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 phased array includes a first plurality of radiators having a first polarization and a second plurality of radiators having a second polarization, different from said first polarization. The phased array is constructed such that radiating patterns of the first and second plurality of radiators are congruent. The radiators are constructed so that they radiating apertures thereof can occupy virtually the same space, i.e., the spacing of the radiating elements is less than a wavelength. Other features provided allow this compactness to be achieved. Impedance matching features are integrated into the radiators themselves. The elevation assemblies of the radiators are mated together, and then are coupled across to their respective azimuth assemblies. Two azimuth assemblies for either type of polarization may be provided when monopulse operation is required. Assemblies for both polarizations transmit sequentially, but receive simultaneously, thus allowing a complete polarization matrix to be collected with two pulse transmissions.

Dual polarized electronically scanned antenna

A method of fabricating ferrite toroids used in ferrite phase shifters. The method employs fabrication techniques found in low temperature cofired ceramics (LTCC) tape technology and involves fabricating long rectangular through-holes, as is required by the toroid design, in layers of green ceramic tape and maintaining the integrity of the through-holes during a firing process wherein ferromagnetic ceramic oxide in the tape is converted to ferrite.

Fabrication of ferrite toroids

A cavity pattern for a laminated structure such as a substrate for integrated circuitry is formed in a sheet of unfired low temperature cofired ceramic (LTCC) material also known as 'green' tape. One sheet at a time is placed in a flexible ram forming die including a resilient rubber pressure pad and a template including the pattern to be formed in the sheet. A pair of outer pressure plates hold the pressure pad and template in place. When a sheet of unfired LTCC material is placed between the pressure pad and template and pressurization is applied to the outer plates, extrusion of the rubber material through the template causes the tape to be sheared off at the edges of the holes in the template, thus effectively cutting the required pattern in the sheet. Following pressurization, the sheet now with the pattern cut therein is removed from the die and the residual tape cut-outs are subsequently removed from the template by a vacuum.

Template type cavity-formation device for low temperature cofired

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

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 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

This invention relates to new ceramic piezoelectric compositions having superior electrical properties, processes for the preparation of the new piezoelectric composition and applications for the new compositions. Specifically, a solid solution composition of 85.5-87.5 molar percent lead zinc niobate, 9.5-9.7 molar percent lead titanate and 3-5 molar percent of a barium titanate dopant or strontium titanate dopant has exhibited desirable electrical properties. This specific composition is well suited for use in a 3-1 connectivity composite, which can be used as a hydrophone. These compositions may be prepared by oxide sintering techniques utilizing extremely high purity materials, or alternatively, by a sol gel process.

Piezoelectric ceramic material including processes for preparation

Total internal light spatial light modulation apparatus includes a light source for projecting infrared light; a prism for reflecting the projected light from an internal surface therein; and an array of pixel posts made of electrostrictive material and positioned proximate a back face of the internal surface for selectively eliminating pixel areas of reflection of the projected light to form an image thereby. A multiplexer is provided to select a set of pixel posts to be electrically charged which corresponds with the image, and electrical contacts are formed on each pixel post no permit electrical charging of each selected pixel post. Method of fabricating the pixel post array, wherein each row of the pixel post array is formed as a monolithic structure, includes the steps of providing a slab of alternate layers of ferroelectric and electrically-conductive material; vapor-depositing electrical contacts on the slabs in electrical communication with the layers of electrically-conductive material at locations corresponding to the pixel posts to be fabricated; securing the slabs together in a front-to-back relationship with divider plates positioned therebetween; and cross-cutting a number of grooves through the slabs to define the pixel posts of each row.

Total internal reflection spatial light modulation apparatus and method

A dielectric ceramic composition is disclosed comprising lead magnesium niobate and strontium titanate, barium titanate or a combination thereof. Dopants such as Ta, La, Y, Eu, Nd, Sm, Gd, W, Si, Zr and Sb may also be included in the composition. The lead magnesium niobate with strontium titanate and/or barium titanate composition has been found to possess extremely favorable properties such as high dielectric constant, low dielectric loss, high breakdown strength, low field-induced strain, high electrical resistivity and exceptionally high energy storage capacity. A process is also disclosed for the production of dielectric ceramic materials which includes the use of hot isostatic pressing in an oxygen-containing atmosphere. The disclosed dielectric compositions are useful in capacitors for many applications, including medical devices such as defibrillators and pacemakers.

High energy density lead magnesium niobate-based dielectric ceramic and

The invention relates to new ceramic electrostrictive compositions having superior electrical properties, a process for the preparation of the new electrostrictive compositions and applications for the new compositions. Specifically, a solid solution composition of lead magnesium niobate-lead titanate - (barium titanate or stronium titanate) has exhibited desirable electrostrictive properties. This composition shows a diminished dependence of dielectric constant on temperature.

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Hampstead, MD, United States of America

Alex E Bailey