Abstract: Aluminum-base alloys containing Cu, Li, Zn and Mg are disclosed which possess highly desirable properties, such as relatively low density, high modulus, high strength/ductility combinations, strong natural aging response with and without prior cold work, and high artificially aged strength with and without prior cold work. In addition, the alloys possess good weldability, cryogenic properties, and elevated temperature properties. The alloys may comprise from about 3.5 to about 7 weight percent Cu, from about 0.1 to about 1.8 eight percent Li, from about 0.01 to about 4 weight percent Zn, from about 0.05 to about 3 weight percent Mg, from about 0.01 to about 2 weight percent grain refiner selected from Zr, Cr, Mn, Ti, Hf, V, Nb, B and TiB.sub.2, and the balance Al along with incidental impurities. Preferred alloys comprise from about 3.5 to 6.5 weight percent Cu, from about 0.5 to 1.8 weight percent Li, from about 0.3 to 2 weight percent Zn, from about 0.1 to 1.5 weight percent Mg, from about 0.05 to 0.

Abstract: A reconstructible electrical circuit module includes a substrate, at least one electrical circuit component and an electrical interconnection structure. The electrical interconnection structure includes at least one multiple ply sequence stacked over the component and substrate in which the portion of the module underlying a ply in the electrical interconnection structure is substantially unimpairable by a process for removing that ply.

Abstract: A method is disclosed for the production of aluminum-copper-lithium alloys that exhibit improved strength and fracture toughness at cryogenic temperatures. Improved cryogenic properties are achieved by controlling the composition of the alloy, along with processing parameters such as the amount of cold-work and artificial aging. The ability to attain substantially equal or greater strength and fracture toughness at cryogenic temperature in comparison to room temperature allows for use of the alloys in cryogenic tanks for space launch vehicles and the like.

Abstract: Display devices incorporating an improved working electrode are disclosed. The devices comprise a transparent outer layer, a first electrode having a reflective surface facing the transparent layer, an electrochromic material located between the reflective surface and the outer transparent layer, an electrolyte in contact with the electrochromic material and a second electrode located behind the first electrode. The first electrode is ion-permeable, allowing ions to pass through and contact the electrochromic material in order to alter the optical properties of the material. The electrochromic material is preferably a conductive polymer such, as polyaniline. The display devices are capable of changing reflectance and/or color by the application of an electric potential to the electrodes.

Abstract: A multichip module (incorporating a high density interconnect structure) has: a first portion containing a substrate with semiconductor chips therein, with each chip having contact pads; a second portion comprising a (HDI) structure interconnecting the chip pads; and a solvent-soluble release layer bonding the two portions together and allowing for easy removal of the HDI structure from the substrate of the module by immersion in an appropriate solvent for the release layer.

Abstract: In a method for preserving an air bridge structure on an integrated circuit chip used in an overlay process, a patternable protective layer is applied for providing mechanical strength to prevent deformation during subsequent processing. A polymeric film layer is applied over the chip and protective layer, and interconnections are fabricated through the polymeric film layer. The polymeric film layer is removed from the area over the air bridge structure. The patternable protective layer is then removed, leaving the resultant structure with an undamaged air bridge which is free of residue.

Abstract: By employing High Density Interconnect (HDI) multi-chip modules (MCMs) having elements of a distributed power supply embedded in the MCM itself, the functions of an MCM and a power converter are combined. The embedded power supply elements include DC-DC or AC-DC converters to convert an input voltage and input current to a relatively lower output voltage and relatively higher output current, thereby decreasing the current requirements of external power supply lines connected to the multi-chip module. The current and voltage outputs may be connected to chip power inputs through relatively short, low-impedance power distribution conductors comprising copper strips direct bonded to a ceramic substrate; alternatively, or in combination with direct bonded copper conductors, the low-impedance power distribution conductors may be situated within an HDI overcoat structure. The power supply elements may be placed within cavities formed in the substrate, or on a thinner portion of the substrate.

Abstract: In fabricating wafer scale integrated interconnects, a temporary or permanent dielectric layer and a pattern of electrical conductors are used to provide wafer scale integration or testing and burn-in. A resist can be used to cover the areas of IC pads on the wafer while the remainder of the pattern of electrical conductors is removed to provide for repair of the wafer scale integration structure. The pattern of electrical conductors may be configured so that the conductor lengths between at least some sub-circuits on a plurality of wafers are substantially electrically equal for signal propagation purposes; an additional wafer may be laminated to the wafer using an adhesive; controlled curfs may be cut into the wafer; and the wafer may be interconnected to an interface ring.

Abstract: A device for remote sensing utilizing fiber optic techniques is presented. This device makes use of multi-mode optic fibers in conjunction with light polarized in multiple directions. The device presents a platform which is insensitive to phenomena outside of the remote sensing region while capable of detecting and analyzing multiple phenomena within the sensing region. The device is also capable of inspecting multiple remote sensing regions simultaneously.

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 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 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.

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.