Abstract: A method of forming metallization patterns on a block of dielectric material wherein the entire surface area of the dielectric block is encased with a conductive material and unwanted conductive metal is ablatively etched from a designated surface area of the dielectric block to form desired metallized circuit patterns.

Abstract: A method of forming metallization patterns on a block of dielectric material wherein the entire surface area of the dielectric block is encased with a conductive material and unwanted conductive metal is ablatively etched from a designated surface area of the dielectric block to form desired metallized circuit patterns. The invention also comprises a filter and a duplexer formed by the method of the present invention.

Abstract: A method of forming metallization patterns on a block of dielectric material wherein the entire surface area of the dielectric block is encased with a conductive material and unwanted conductive metal is ablatively etched from a designated surface area of the dielectric block to form desired metallized circuit patterns.

Abstract: A monolithic circuit, such as a piezoelectric device, semiconductor, or the like, may be fabricated by forming an operational metallization layer (12) on a substrate (10). A subsequent layer (40), such as a sealing ring pattern (42) may then be applied using a thin film deposition technique. A thin film material is applied through a mask assembly (28). The mask assembly (28) includes a mask material (30) that has been applied to a screen (24) and patterned as desired. The mask material (30) extends beyond the screen (24) so that only the mask material contacts the substrate (10) during thin film deposition. Preferably, the screen (24) is woven from individual wires (26) having circular cross-sectional shapes. The subsequent layer (40) is applied both through perforations (18) in the screen (24) and under the screen's wires (26).

Abstract: An aluminum nitride ceramic body with a thermal conductivity of at least 0.5 W/cm.K at 25.degree. C. is produced by shaping a particulate mixture of aluminum nitride powder and an additive selected from the group consisting of CaF.sub.2, SrF.sub.2, BaF.sub.2 and mixtures thereof into a compact and liquid phase sintering the compact.

Abstract: A process for producing an hermetic feedthrough in a ceramic substrate by providing a sheet of liquid phase sinterable ceramic composition having a feedthrough hole, filling the feedthrough hole with refractory metal metallization material, firing the resulting structure to produce a sintered substrate and adherent metallization wherein the metallization is comprised of continuous phases of refractory metal and glass, contacting the refractory metal with electrically conductive intrusion metal and heating the resulting structure to a temperature at which the glassy phase is fluid, the refractory metal is solid, and the intrusion metal is liquid whereby the liquid metal preferentially wets the refractory metal, migrates into the metallization displacing glass and, upon subsequent solidification, partially or wholly occupies the volume space originally containing the continuous glass phase.

Abstract: An aluminum nitride ceramic body with a thermal conductivity of at least 0.5 W/cm.multidot.K at 25.degree. C. is produced by shaping a particulate mixture of aluminum nitride powder and an additive selected from the group consisting of YF.sub.3, ScF.sub.3, LF.sub.3 where L is La, Ce, Pr, Nd, Sm, Gd, Dy, Ho and Er and a mixture thereof into a compact and liquid phase sintering the compact.

Abstract: A process for producing an hermetic feedthrough in a ceramic substrate by providing a sheet of liquid phase sinterable ceramic composition having a feedthrough hole, filling the feedthrough hole with refractory metal metallization material, firing the resulting structure to produce a sintered substrate and adherent metallization wherein the metallization is comprised of continuous phases of refractory metal and glass, contacting the refractory metal with electrically conductive intrusion metal and heating the resulting structure to a temperature at which the glassy phase is fluid, the refractory metal is solid, and the intrusion metal is liquid whereby the liquid metal preferentially wets the refractory metal, migrates into the metallization displacing glass and, upon subsequent solidification, partially or wholly occupies the volume space originally containing the continuous glass phase.

Abstract: A process for increasing electrical conductance of a metallization on a ceramic substrate wherein the metallization is an intermixture of continuous phases of refractory metal and glass which comprises contacting the refractory metal with an electrically conductive intrusion metal and heating the resulting structure to a temperature at which the glassy phase is fluid, the refractory metal is solid, and the intrusion metal is liquid whereby the liquid metal preferentially wets the refractory metal, migrates into the metallization displacing glass and, upon subsequent solidification, partially or wholly occupies the volume space originally containing the continuous glass phase.

Abstract: A cofired structure comprised of a refractory metal metallization supported by a substrate free of large voids is produced by forming a liquid phase sinterable ceramic composition containing SiO.sub.2 in some form and a sulfate of an alkali metal and/or an alkaline earth metal, admixing the composition with an organic binding medium, shaping the mixture into a thin sheet, contacting the sheet with refractory metal metallization material, and cofiring the resulting structure whereby the free carbon produced by pyrolysis of the organic medium is removed by reaction with the sulfate before closed porosity is initiated.

Abstract: A process of making a porous carbonate-containing structure for use in a molten carbonate fuel cell, wherein a suitable porous structure is prepared having disposed therein a metal salt selected from the alkali metals and the alkaline earth metals or mixtures thereof with at least a portion of the salt being a monobasic organic acid salt. The monobasic acid salt is converted to the carbonate in situ by heating in the presence of oxygen. Both electrode and electrolyte structures can be prepared. Formic acid is preferred.

Abstract: A particulate mixture of an alkali metal carbonate solvent, titanium oxide, and an alkaline earth reactant selected from the group consisting of barium oxide, strontium oxide, and mixtures thereof, is heated to melt the alkali metal carbonate solvent in which the reactants dissolve and react precipitating a titanate selected from the group consisting of barium titanate, strontium titanate and mixtures thereof.

Abstract: An alumina investment casting mold has a microstructure characterized by the porous nature of the interconnecting alumina grains which is indicative of alumina-silica molds fired in a reducing atmosphere to remove the silica.

Abstract: A method of firing alumina-based ceramic core compacts includes firing the compact in a controlled atmosphere in a closed retort whereby at least a portion of the gas of the controlled atmosphere is caused to flow down, around and through the porous compact by aspiration.

Abstract: A reactant fugitive filler material is employed in a material composition which includes alumina-based ceramics of one or more particle sizes. The reactant fugitive material provides sufficient reactant material at an elevated temperature to form a fired ceramic article which has a porous microstructure in which the grain morphology is characteristic of grains which have undergone vapor phase transport action.

Abstract: A method for simultaneously forming an integral porous outer barrier layer having a density gradient therein on selected external surfaces of a fired ceramic article and for increasing the porosity content and crushability characteristics thereof embodies the firing of a ceramic compact comprising a reactant fugitive filler material and a ceramic material in a controlled atmosphere.

Abstract: A setter is configured to minimize distortion of a core supported during firing. The configuration also provides for adequate gas flow both to envelope the core and to provide an aspiration effort to cause the gas to be drawn downwardly through and about the core structure to the interior of the setter to enhance the removal of reaction products therefrom. A retort, preferably made of molybdenum, is provided to enhance the effects of the setter configuration.

Abstract: A method for simultaneously forming an integral barrier layer on selected external surfaces of a fired ceramic article and for increasing the porosity content and crushability characterstics thereof embodies the firing of a ceramic compact comprising a reactant fugitive filler material and a ceramic material in a controlled atmosphere.

Abstract: A method for increasing the porosity and crushability characteristics thereof embodies the firing of a ceramic compact comprising a reactant fugitive filler material and a ceramic material in a controlled atmosphere.

Abstract: A method for simultaneously forming an integral barrier layer on selected external surfaces of a fired alumina-based compound ceramic article and for increasing the porosity and crushability characteristics thereof embodies the sintering of a ceramic compact comprising a reactant fugitive filler material and the alumina-based compound ceramic material in a controlled atmosphere.