Abstract: In a method for preserving an air bridge structure on an integrated circuit chip, without sacrificing metallization routing area in an overlying high density interconnect structure, a protective layer is sublimed over the air bridge to provide mechanical strength while preventing contamination and deformation during processing. A high density interconnect structure is applied over the chip and protective layer. A small portion of the high density interconnect structure is removed from the area over the air bridge structure, and the protective layer is then sublimed away, leaving the resultant structure with an undamaged air bridge which is free of residue.

Abstract: Polyetherimide compositions are provided having condensed bis (4-aminophenyl) sulfone units, diaminophenylindane units or a mixture thereof. These polyetherimides compositions have been found useful for making high temperature chip adhesives, laminating adhesives and film adhesives for high density interconnects in electronic circuitry.

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 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: 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: Selective electrolytic deposition on either conductive or non-conductive bodies is provided by forming a layer of a metal which forms a plating-preventing compound on the surface of the body to be plated, and selectively interdiffusing a plating-enabling metal into the surface of that compound-forming metal in those locations where plating is desired and electroplating the body. The interdiffusion may be done before or after the plating-preventing compound has formed on the surface of the compound-forming layer. During the electroplating, the electroplating metal deposits only in those locations where the plating-enabling metal has interdiffused with the compound-forming metal. At the end of the process, the compound-forming metal may be removed in those locations where it is not covered by the electroplated metal to provide a plurality of separate plated conductors.

Abstract: Self-developing photoresists are developed by exposing the substrate on which they are exposed to a light beam or other energy source which is absorbed by the substrate and which raises the substrate temperature to the thermal decomposition temperature of the overlying photoresist. This exposure may be done through the photoresist layer with a light beam having a frequency to which the photoresist is substantially transparent or may be done from the backside of the substrate using a light beam which is absorbed by the substrate itself if it is sufficiently thin, or by a thin layer disposed on a transparent substrate.

Abstract: A high density interconnect structure incorporating a plurality of laminated dieletric layers is fabricated using thermoplastic adhesive layers of progressively lower glass transition temperature in order to maintain the stability of the already fabricated structure during the addition of the later laminations. This structure also facilitates the removal of only a portion of the high density interconnect structure where a fault in the system can be corrected in one of the upper layers of the high density interconnect structure.

Abstract: Selective electrolytic deposition on either conductive or non-conductive bodies is provided by forming a layer of a metal which forms a plating-preventing compound on the surface of the body to be plated, and selectively interdiffusing a plating-enabling metal into the surface of that compound-forming metal in those locations where plating is desired and electroplating the body. The interdiffusion may be done before or after the plating-preventing compound has formed on the surface of the compound-forming layer. During the electroplating, the electroplating metal deposits only in those locations where the plating-enabling metal has interdiffused with the compound-forming metal. At the end of the process, the compound-forming metal may be removed in those locations where it is not covered by the electroplated metal to provide a plurality of separate plated conductors.

Abstract: A dielectric layer comprising a plurality of sublayers of alternating composition can provide a reduced dielectric constant while providing the adhesion and laser drilling properties of a higher dielectric constant material. Such multi-sublayer dielectric layers may be formed in situ on a high density interconnect structure or may be laminated thereon after their own formation.

Abstract: A metal is electrolessly plated on a substrate which is first coated with at least one ablatively-removable layer that is selectively irradiated with laser radiation to obtain a pattern for the deposition of metal on the substrate. The electroless plating solution applied to the substrate after the irradiated substrate is coated with a catalyst also serves to remove the unirradiated portion of the ablatively-removable layer. The method is particularly suited for plating fine lines of metal, especially on non-planar surfaces.

Abstract: A method is provided for removing organic material from an organic film in a patterned manner using ultraviolet light at sufficient power density to effect the patterned ablative photodecomposition of an organic film in the form of a blend of aliphatic and aromatic organic material or a copolymer of chemically combined aliphatic units and aromatic units.

Abstract: A power outage indicator utilizes a smectic liquid crystal display cell, capable of storing information indefinitely, to provide a visual indication, of predetermined form, that power to a given installation has been interrupted. Prior to installation, the smectic liquid crystal display of the power outage indicator is heated and an appropriate voltage placed between the display electrodes to cause the liquid crystal material to align homeotropically, as the liquid crystal material cools to the smectic state; a clear stable texture results. Upon loss of power, stored charge, as in a storage capacitor, is enabled to flow through at least a portion of at least one of the display electrodes, reheating the liquid crystal material therebetween and, upon cooling without an applied field, converts a portion of the liquid crystal layer to a state having differing light-propagation properties than the remainder of the display.

Abstract: Liquid crystal compositions having guest perylene-based dichroic dyes dissolved therein. The perylene dichroic dyes have symmetrically-disposed substituents which are preferably a group forming with the 3,4 and 9, 10 carbons, respectively, a 5 or 6 membered cyclic ring which is substituted by, or fused to, a phenyl ring. The perylene-based dyes of the invention can be used alone or with other compatible dyes as guest dyes to form various colors for coloring the host liquid crystal compositions.

Abstract: Novel tris-azo dyes and a liquid crystal composition containing the tris-azo dyes. The tris-azo dyes are of the general formula: ##STR1## wherein R.sub.1 and R.sub.2 are various aromatic groups including aromatic amines, substituted aromatic amines, hydroxy-substituted aromatic groups and substituted hydroxy-containing aromatic groups. When the tris-azo dichroic dyes are used as a guest dye in a host liquid crystal material, they form a novel liquid crystal composition for use in liquid crystal displays.

Abstract: Liquid crystal compositions having guest anthraquinone-based dyes dissolved therein, are disclosed. The anthraquinone-based dyes have the general formula: ##STR1## wherein at least one of X and X' is a 5-membered ring connected to the lateral positions of the lateral benzene rings in the anthraquinone molecule, the five membered ring having the structure: ##STR2## wherein R is an alkoxy alkyl radical, a straight chain or branched chain alkyl radical, a phenyl radical, a benzyl radical and/or substituted derivatives of the foregoing radicals. The anthraquinone-based dyes of the invention may be used alone or with other compatible dyes as guest dyes to form various colors for coloring the host liquid crystal compositions. One preferred class of guest anthraquinone-based dyes which are dissolved in the host liquid crystal material, are various derivatives of 1,4-diamino-2,3-anthraquinone-dicarboximide.

Abstract: Homeotropic surface alignment is provided in liquid crystal display cells, utilizing high temperature peripheral sealing material, by fabricating the empty cell prior to introducing a solution of a homeotropic-aligning surfactant dissolved in a volatile solvent. The solvent is evaporated to provide a surfactant film on the cell cavity interior surfaces. The cell is then filled with the liquid crystal material and the cell is sealed.

Abstract: Novel tris-azo dye compositions and a liquid crystal composition containing the tris-azo dye compositions are disclosed. The tris-azo dye composition having terminal aromatic groups has the general formula: ##STR1## wherein R.sub.1 and R.sub.2 are various aromatic compounds including aromatic amines, substituted aromatic amines, hydroxy-substituted aromatic compounds and substituted hydroxy-containing aromatic compounds. When the tris-azo dichroic dyes are used as a guest dye in a host liquid crystal material, they form a novel liquid crystal composition for use in liquid crystal displays. Examples of R.sub.1 and R.sub.2 include organic radicals of aminoquinoline, tetrahydroquinoline, N-ethyl-1-naphthylamine and 1,8-diaminonaphthalene.

Abstract: Novel yellow azo dye compositions and novel liquid crystal compositions containing the yellow azo dye composition. The yellow azo dye composition, having terminal ester groups, has the general formula: ##STR1## wherein R and R' are alkyl or substituted alkyl wherein the alkyl has at least 4 carbon atoms, aryl, arylalkyl, substituted aryl or substituted arylalkyl. When the yellow azo dichroic dyes are used alone, or in combination with other dyes, as a guest in a host liquid crystal material, they form a novel liquid crystal composition for use in liquid crystal displays. An invention method of improving the black color of dichroic dyes for use in black liquid crystal displays, wherein a dye composition having a mixture of dichroic dyes of various colors and containing at least one yellow azo dichroic dye, as described above, is added to a host liquid crystal material.

Abstract: Novel liquid crystal compositions having extended temperature ranges, without sacrifice of stability, are provided by mixing 10-25%, by weight, of a terphenyl liquid crystal material with 75-90%, by weight, of a four-component liquid crystal composition of cyclohexanes.