Hughes Electronics Corporation

Hughes Aircraft Company

Other

The Boeing Company

Mir Akbar Ali

Carl W Peterson

Harry C Jones

Gerald Wayne Swift

Clark A Saito

William W Milroy

Ronald I Wolfson

Jason M Wakugawa

Florentino V Lee

Ronald E Robbins

A microwave monolithic integrated circuit assembly includes a microwave monolithic integrated circuit having an MMIC circuit plane and having a first region of relatively high heat production and a second region of relatively low heat production. A heat-dissipating assembly is in thermal contact with the microwave monolithic integrated circuit. The heat-dissipating assembly has at least two pieces of pyrolytic graphite embedded within a casing. The pieces of pyrolytic graphite include a first piece of pyrolytic graphite underlying the first region and having a high-thermal-conductivity x-direction of the first piece lying within about 20 degrees of a perpendicular to the MMIC circuit plane, and a second piece of pyrolytic graphite underlying the second region and having a high-thermal-conductivity x-direction of the second piece lying within about 20 degrees of the MMIC circuit plane. The heat-dissipating assembly is preferably fabricated by hot isostatic pressing.

Microwave monolithic integrated circuit assembly with multi-orientation pyrolytic graphite heat-dissipating assembly

A phased array (20) and method for constructing the same are disclosed. The phased array (20) includes a superstructure (22) with cavities (40) therein. A cover plate (28) is mounted to the superstructure (22) and cooperates with the cavities (40) to form cavity style filters therebetween and to form a box-beam type superstructure. Ideally, the superstructure (22) is self supporting. Electronic modules (32) and amplifiers (33) are mounted to the superstructure (22). The method includes machining a block of material to form a webbed superstructure with cavities (40) therein. A cover plate (28) is mounted to the superstructure (22) over the cavities (40) to form cavity style filters. Amplifiers (32) and antenna elements (30) are then affixed to the superstructure (22) and cover plate (28). Ideally, the cover plate (28) is affixed to the superstructure (22) using an electrically conductive adhesive. Preferably, a capacitive probe is inserted into the cavities (40) to electrically couple the filters to the antenna elements (30) and amplifiers (33).

Phased array with integrated bandpass filter superstructure

A ceramic-polymer composite material such as part of a microelectronics package is formed of a ceramic mixture of aluminum nitride and boron nitride, and a low-loss polymeric material. The amount of aluminum nitride is preferably from about 50 to about 90 weight percent of the ceramic mixture, but the relative amounts of the two ceramics may be adjusted to achieve thermal expansion and thermal conductivity properties required for a particular application. A mixture of the ceramics and uncured thermosetting polymeric resin is formed, pressed into the shape of the microelectronics base and/or lid, and heated (either concurrently or subsequently) to compress the mixture and cure the polymer.

Ceramic-polymer composite material and its use in microelectronics

An electronic structure is formed of alternating layers of a metal and a cured ceramic-polymer mixture. The ceramic-polymer mixture is prepared by mixing small ceramic particles into a flowable, curable polymer. The mixture is spread over a first metallic layer and, optionally, B-stage cured. Additional metallic layers and ceramic-polymer layers are added in alternating fashion. Metallic interconnects may be provided through overlying ceramic-polymer layers to a particular metallic layer. The resulting structure is heated to a moderate temperature to cure the polymer.

Multilayer electronic structure and its preparation

Spatial thinning in no more than two dimensions is used in order to lower both the effective dielectric constant and the dielectric loss tangent of ferroelectric ceramics, while retaining a substantial fraction of their tunability. By not thinning in the third direction, along which the dc bias field is applied, the ferroelectric material maintains the connectivity between elements of the ferroelectric structure that is essential to retaining the tunability. Examples of one-dimensional structures (30) include small diameter columns (28, 32) of dielectric material embedded in a dielectric matrix (26, 34). Examples of two-dimensional structures (21) include square (22) and hexagonal (24) cells comprised of ferroelectric material filled with inert dielectric material or vice versa.

Enhanced tunability for low-dielectric-constant ferroelectric materials

An electrochemical storage cell (20) includes ceramic housing frame (22) with a flat plate solid ceramic electrolyte (32) bonded to a internal shoulder (26) of the housing frame (22) with a glassy seal (33). A metallic weld ring (34) is bonded to each end of the housing frame (22). Each weld ring (34) has a welding flange (36) disposed parallel to a respective end of the housing frame (22) and also has a bonding flange (40). The bonding flange (40) lies parallel and adjacent to an internal surface (24) of the housing frame (22) if the coefficient of thermal expansion of the weld ring (34) is less than that of the housing frame (22), and parallel and adjacent to an external surface (28) of the housing frame (22) if the coefficient of thermal expansion of the weld ring (34) is greater than that of the housing frame (22). A glassy seal (42) is formed between the bonding flange (40) of each weld ring (34) and the respective adjacent surface (24 or 28) of the housing frame (22). The glassy seals (33 and 42) are formed by heating an assembly of the components to the glass transition temperature of the glassy seal material to effect bonding and then slowly cooling to minimize thermal stresses.

Glass sealing of electrochemical storage cell structures

An electrochemical storage cell (20) includes a ceramic housing frame (22) with a flat plate solid ceramic electrolyte (32) bonded to a internal shoulder (26) of the housing frame (22) with a glassy seal (33). A metallic weld ring (34) is bonded to each end of the housing frame (22). Each weld ring (34) has a welding flange (36) disposed parallel to a respective end of the housing frame (22) and also has a bonding flange (40). The bonding flange (40) lies parallel and adjacent to an internal surface (24) of the housing frame (22) if the coefficient of thermal expansion of the weld ring (34) is less than that of the housing frame (22), and parallel and adjacent to an external surface (28) of the housing frame (22) if the coefficient of thermal expansion of the weld ring (34) is greater than that of the housing frame (22). A glassy seal (42) is formed between the bonding flange (40) of each weld ring (34) and the respective adjacent surface (24 or 28) of the housing frame (22). The glassy seals (33 and 42) are formed by heating an assembly of the components to the glass transition temperature of the glassy seal material to effect bonding and then slowly cooling to minimize thermal stresses.

A filler composition having a coefficient of thermal expansion substantially equivalent to that of SiC foam and capable of fusing and integrally bonding to SiC foam. The filler composition is useful for bonding a surface layer to a SiC foam core for optical mirrors which are used in space applications and cryogenic detectors.

Glass bonded filler compositions for silicon carbide foam core mirrors

A flexible endoscope with a carbon dioxide laser connected thereto for simultaneous viewing and performance of a surgical operation on either exterior or interior tissue of a patient. The laser operates at 10.6 microns, with the laser beam being transmitted through a flexible bundle of drawn fiber optics that are held in adjacently disposed fixed relationship by a flexible sheath. Each laser beam transmitting fiber optic has a core of infra red transmitting true amorphous chalcogenide glass that is clad by a thin flexible film of material having a lesser refractive index. The infra red transmitting glass will preferably have a transmission efficiency of between 38 to 62 percent.

Growing community of inventors

Lomita, CA, United States of America

Mir Akbar Ali