Abstract: Active components of a microwave system are interconnected on a substrate by a dielectric-overlay, high-density-interconnect structure in a manner which provides close impedance matching, minimizes impedance discontinuities and substantially increases the yield of good circuits.

Abstract: Substrate material is molded directly to semiconductor chips and other electrical components that are positioned for integrated circuit module fabrication. Chips having contact pads are placed face down on a layer of adhesive supported by a base. A mold form is positioned around the chips. Substrate molding material is added within the mold form, and the substrate molding material is then hardened. A dielectric layer having vias aligned with predetermined ones of the contact pads and having an electrical conductor extending through the vias is situated on the hardened substrate molding material and the faces of the chips. A thermal plug may be affixed to the backside of a chip before substrate molding material is added. A connector frame may be placed on the adhesive layer before substrate molding material is added. A dielectric layer may be placed over the backsides of the chips before the substrate molding material is added to enhance repairability.

Abstract: A method for attaching a chip to a substrate includes providing the substrate with an outer layer of an electrical conductor which is not wettable by solder and which has a window exposing an inner layer of electrical conductor that is wettable by solder. A solder preform is placed on the window exposing the inner layer, and the chip is placed on the solder preform. The substrate is then heated so as to melt the solder preform. To achieve planarity, the substrate is be positioned in a pressurizing chamber with a film overlay having higher pressure above the film overlay than underneath the overlay, and heated above the melting point of the solder.

Abstract: A multi-chip module includes a substrate supporting a plurality of chips. A dielectric layer which overlies the chips and the substrate has a connection surface and a substrate surface with metallization planes having plane openings patterned on each surface and vias aligned with predetermined pads on the chips and predetermined portions of the metallization plane of the substrate surface. An adhesive layer is situated between the substrate and the substrate surface of the dielectric layer, and a pattern of electrical conductors extends through the vias to interconnect selected chips and selected portions of the metallization planes. In a related design, the dielectric layer may be a board having chip openings and conductive through-connections aligned with predetermined portions of the metallization plane of the substrate surface.

Abstract: A retractable distributed array antenna has a multiplicity of radiative elements arranged in a beam-forming array of desired configuration and resolvable into a plurality C of columns, with each column having at least one of the antenna radiator elements. Each of a number P of elongated column members, up to but not exceeding C in number, supports the antenna elements of an associated column. The column members are arranged with their elongated dimension generally parallel to one another. The adjacent end portions of each pair of column member, or of a column member and a central stowage module, are joined by a spring-loaded hinge assembly, which urges the joined column member end portions away from each other, to place the columns of elements into the desired distributed array antenna configuration, if no retroactive forces are present.

Abstract: A mixture for affixing dice to a substrate includes a thermoplastic polyimide, a solvent for the polyimide, and a solvent which does not dissolve the polyimide but adds thixotropicity to the mixture. The mixture is applied to the substrate, the dice are placed thereon, and the solvents are evaporated to bond the dice to the substrate. The bond is radiation hard and exhibits high shear pull strength. A poor solvent for the polyimide, sprayed over the dice and exposed portions of die attach material, causes some polyimide to precipitate out of solution in the exposed portions of die attach material to form a grid that extends between the dice and prevents the dice from "swimming together" during high temperature processing. In a solvent die-attachment method, the substrate is first coated with a mixture of die attach material, and the mixture is dried. Spraying a solvent over the die attach material causes the material to soften so that the dice applied thereto may adhere.

Abstract: A multi-layer composite gun barrel has an integral metal alloy jacket portion, forming the exterior cylinder of the entire barrel, with a forebarrel interior liner cylinder substantially bonded within the jacket portion, and an unbonded breech portion liner, made from a high melting temperature refractory metal alloy able to resist erosion by hot gun gases in the barrel breech area.

Abstract: A method and apparatus for masking the presence and content of data transmissions includes a mobile transmitter which encodes the data by means of a pseudorandom spreading (PRS) code having a chip rate, and which transmits it at a carrier frequency. A masking transmitter remote from the mobile transmitter encodes a carrier at the same frequency with a second PRS sequence having the same chip rate, and transmits it at a power level higher than the power level of the mobile transmitter. A signal interceptor cannot separate the mobile and masking station carriers on a frequency basis. The relatively low-power mobile station PRS signal is difficult to detect in the presence of the high-power masking station code. The intended receiver (master station) receives an ensemble signal which is principally masking station signal. The master station regenerates the known masking station PRS code and subtracts it from the ensemble signal to leave a residue signal which contains the data-bearing mobile station PRS signal.

Abstract: A controlled agitation cleaning system, for cleaning parts with a flammable cleaning liquid, has a container with an interior volume sufficient to accept a quantity of the cleaning liquid and an opening through which an item to be cleaned can be placed in the cleaning liquid. A lid closes the container opening. Several agitation nozzles extending in liquid-tight manner through a wall of the container, with each nozzle arranged to direct the volume of cleaning liquid flowing through that nozzle toward an associated container volume portion, when an air-operated pump moves the cleaning liquid through the nozzles. The pump is activated only when the lid has provided a positive closure of the container opening.

Abstract: A high frequency electronic component which is interconnected with other components through a high density interconnect structure sees only an air dielectric constant in the high density interconnect structure because a spacer structure disposed on the electronic component spaces the dielectric of the high density interconnect structure from the surface of the electronic component by a sufficient distance that the higher dielectric constant of the polymer dielectric layers of the high density interconnect structure only minimally affects the operating characteristics of the electronic components.

Abstract: A microwave phase shifter has a plurality of sequentially arranged, independently-actuatable sectiions, the total phase shift is the sum of all of the sections. The phase shifter has a common substrate, supporting several switching elements, with at least one switching element being assigned to each phase section; the switching elements are fastened to the common substrate with the element connections are all substantially in a first plane above the substrate. A first layer of a dielectric material is affixed adjacent to the first plane. Phase shift elements, such as microstriplines of a known length or inductive patterns of conductor, imparting the desired section phase shift, are fabricated upon a surface of the first dielectric layer furthest from the substrate, and are interconnected to and from the sections, or onto or off of the phase shifter at this level.

Abstract: A hermetically sealed electronic package particularly adapted for high density interconnect (HDI) electronic systems, employs a ceramic substrate as the package base. The substrate is provided with module contact pads. A barrier support frame on the module contact pads divides them into inner and outer portions. A plurality of electronic components, such as integrated circuit chips, are fastened to the substrate within the perimeter of the barrier support frame, and interconnections are provided between inner portions of the module contact pads and contact pads on the electronic components. A polymer barrier layer is deposited over the area enclosed by the barrier support frame as well as a portion of the frame itself, and is overlaid with a metal barrier layer. A protective solder layer is deposited on the metal barrier layer to bridge any voids in the metal barrier layer.

Abstract: A high density interconnect structure is rendered suitable for the packaging of overlay sensitive chips by providing a cavity in the high density interconnect structure which spaces the sensitive surface of such chips from the overlying high density interconnect structure in a manner which prevents undesired interactions between the dielectric of the high density interconnect structure and the chip.

Abstract: An enhancement and retrieval method for natural language data using a computer is disclosed. The method includes executing linguistic analysis upon a text corpus file to derive morphological, part-of-speech information as well as lexical variants corresponding to respective corpus words. The derived linguistic information is then used to construct an enhanced text corpus file. A query text file is linguistically analyzed to construct a plurality of trigger token morphemes which are then used to construct a search mask stream which is correlated with the enhanced text corpus file. A match between the search mask stream and the enhanced corpus file allows a user to retrieve selected portions of the enhanced text corpus.

Abstract: A method of thinning dice or integrated circuit chips used in producing lightweight packaged electronic systems, such as HDI circuits and systems produced therefrom provides for positioning dice in a die carrier layer that allows for easy separation from the dice after completion of the die thinning step. A holding layer is then attached to the die carrier layer for ease of attaching it to a material removal device, such as a lapping machine or an ultrasonic milling machine. A portion of the die carrier layer, along its exposed side, is then removed by the material removal device as a consequence of removal, by the material removal device, of an expendable portion of the dice positioned within the die carrier layer. The holding layer and the die carrier layer are then separated from the thinned dice by a conventional method, such as chemical etching, solvent soaking or induction heating.

Abstract: A Kalman filter, for a dynamic system having a number N of different states and another number M of observational components, uses a fixed rectangular systolic array of N.times.(N+1) parallel data processing elements for a regular filter, and uses an array of (N+2).times.(N+3) processing elements for a fault-tolerant filter; the processing elements in either configuration are connected in a four-nearest-neighbors network. Each processor is capable of carrying out a commanded one of a plurality of different vector-data operations sets during each of eight passes through the array. The systolic array operates on the matrices in a pipeline manner, so that each pass through the processor array feeds the result back into the array to begin the next computation.

Abstract: A method for distortion correction of computer-generated textured images maps vertices and texture coefficients from viewer space to projector space, so that environmental objects are pre-distorted upon the projection raster in order to appear in their proper form and perspective when the raster is projected onto a curved surface in viewer space, and viewed therefrom. Distortion correction is carried out by utilizing a piecewise-linear approximation for smoothly, continuously and closely approximating the required pre-curvature. The viewing space raster is subdivided into a number of triangles, within each of which a linear approximation is applied to the image mapping: the raster faces are first subdivided along the lines of a rectangular grid and the face fragments falling within each rectangle are then subdivided along the grid diagonal. This produces face fragments which are small enough so that a linear approximation provides an accurate transformation of each fragment.

Abstract: A Gatling-type gun mechanism has a stationary housing having a camming channel and at least one loading/unloading port. A rotor is mounted inside the housing and can be rotated about a longitudinal axis; the rotor carries a plurality of gun barrels, each fixed to the rotor with a respective barrel axis substantially parallel to the rotor longitudinal axis; a like number of stud assemblies, each having a respective axis aligned with the axis of an associated gun barrel; and a like number of cartridge chambers, each interacting with the housing camming channel, during each rotation of said rotor, for reciprocal motion between a rearward location substantially coaxial about the associated stud assembly and a forward location substantially in abutment with the associated gun barrel and enclosing a volume into which a round of ammunition can be placed and removed by radial movement through the loading/unloading port.

Abstract: A hermetic package particularly adapted for high density interconnect (HDI) electronic systems employs a ceramic substrate which serves as a base for the hermetic package. The substrate comprises a cofired body including buried conductors which provide electrical continuity between a set of inner contact points and a set of outer contact points bridging a seal ring that comprises either a solder seal or a weldable seal for the hermetic package lid. The outer contact points may be directly connected to a leadframe. The leadframe leads, after severing, can be directly attached to a printed circuit board.

Abstract: Polyimides useful in electronic applications are prepared by the reaction of at least one aromatic tetracarboxylic acid or functional derivative thereof with at least one diamine in benzonitrile solution. The preferred tetracarboxylic acid derivative and diamine are 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride and bis(4-aminophenyl) sulfone, respectively. A second organic liquid, such as toluene, which is miscible with and has a lower boiling point than benzonitrile and which preferably forms an azeotropic mixture with water, is preferably also present.