Abstract: Thermal interface materials are essential for proper operation of electronic assemblies. They are used between surface mount components and printed wiring boards and between printed wiring boards and metal heat sinks. Their function is to bond the components together and allow good heat transfer between the parts being bonded. The approach disclosed in this invention is a fully-cured, flexible, filled elastomer that is coated on both sides with a partially cured, filled adhesive, which can be conveniently made by a low cost tape casting process. This unique approach offers a combination of good adhesion to both bonding surfaces, good heat transfer, compliance to accommodate mismatched coefficient of thermal expansion, rework capability, control of flow of the adhesive during cure, and easy handling of uncured material.

Abstract: There is disclosed herein a high voltage and high temperature power electronics capacitor which comprises one or more insulator layers of mica paper, and one or more metal conductor layers, all dispersed in a pressurized environment of a nonreactive and high voltage strength gas maintained at near ambient to about 405.2 kPa of pressure. The insulator and conductor layers are isolated and separated from one another by the alternating placement of conductor layers between said insulator layers. These capacitors are readily packaged for commercial use in containers or housings of almost any geometric form and any material of construction. Moreover, low inductance ceramic bushings can be employed on these containers for establishing external electrical contacts. These capacitors can be economically manufactured and used in large commercial volumes with currently available materials and production methods.

Abstract: There is disclosed herein a high voltage and high temperature power electronics capacitor which comprises one or more insulator layers of mica paper, and one or more metal conductor layers, all dispersed in a pressurized environment of a nonreactive and high voltage strength gas maintained at near ambient to about 405.2 kPa of pressure. The insulator and conductor layers are isolated and separated from one another by the alternating placement of conductor layers between said insulator layers. These capacitors are readily packaged for commercial use in containers or housings of almost any geometric form and any material of construction. Moreover, low inductance ceramic bushings can be employed on these containers for establishing external electrical contacts. These capacitors can be economically manufactured and used in large commercial volumes with currently available materials and production methods.

Abstract: A capacitor module having a solid dielectric is cleared in a gaseous environment having an electric strength greater than that of air at a pressure of one atmosphere. A plurality of such cleared capacitor modules is formed into a stack which itself is then cleared by the same clearing process. During intended operation in an electric circuit, the capacitor arrangement would be maintained in such gaseous environment having an electric strength greater than that of air at a pressure of one atmosphere.

Abstract: Materials and methods for the fabrication of high density, low temperature fired microwave ferrites for use in microwave power devices, transmission line elements, isolators, circulators, and phase shifters. Very fine (sub-micron) ferrite powders made by sol-gel methods are mixed with solvents and binders then tape-cast. Ferrite tapes in the unfired state are cut into complex shapes and may be provided with via holes. These ferrite sheets are fired discretely, or are laminated, cofired with printed metal pastes, or other active and passive ceramic tapes.

Abstract: We disclose a fabrication method for integrating passive devices such as capacitors, resistors and circulators into ceramic packages for electronic systems. The method utilizes a glass or glass/ceramic as a bonding agent which is incorporated as one of the layers in the multilayer package. The integration of such passive devices eliminates the tedious mounting of these devices on the package, permitting a smaller, more reliable, less expensive and lighter weight product. This method allows the integration of passive devices having firing temperatures far different from that of the ceramic package itself, permitting combinations of materials that cannot be densified, or cofired together.

Abstract: The invention provides for an electronic package having a buried passive component such as a capacitor therein, and a method for fabricating the same. The electronic package preferably includes a passive component portion which includes a plurality of layers of high K dielectric material, a signal processing portion which includes a plurality of layers of low K dielectric material, and at least one buffer layer interposed between the passive component portion and the signal processing portion. Metallization is preferably printed upon at least one of the layers of high K dielectric material and at least one of the layers of low K dielectric material. Preferably, the layers are co-fired at a temperature below approximately 1200.degree. C. to form the electronic package and each of the buffer layers contains approximately 25 to 100% barium compound.

Abstract: A method for forming a low temperature cofired ceramic package which is made using a multi-layered densified spherical powder formed via a sol-gel process. This densified powder is formed from layers of SiO.sub.2 reacted with trimethyl borate. The spherical powder has a preselected particle size and boron content sufficient to render the low temperature cofired ceramic package fully dense, even in the presence of a second phase filler ceramic, at a sintering temperature below 1000.degree. C. Binder material is added to the spherical powder and ceramic filler to form a plurality of tapes. A ceramic assembly is then formed by layering the plurality of tapes upon one another and firing the ceramic assembly at a temperature below 1025.degree. C. to form a fully dense cofired ceramic package. In order to form the multi-layered densified spherical powder, a silica core, which is formed using a sol-gel process, is reacted with trimethyl borate.

Abstract: A ceramic capacitor suitable for high energy density and high temperature application is disclosed. Such a capacitor is prepared by producing the selected ceramic powder via the sol-gel process forming the capacitor to the desired shape with the resulting powder using tape casting technology and firing the "green" form so produced.

Abstract: A dual mode radar transparency allowing passage of both RF radiation and IR radiation comprises an aerogel base and ceramic skin overlaying the aerogel base. The aerogel base comprises a low density ceramic material. A method of fabricating a dual mode radar transparency allowing passage of both RF radiation and IR radiation comprises the steps of preparing a colloidal dispersion of a ceramic material in a medium, increasing a concentration of the colloidal dispersion by evaporation to create a suspension, and placing the suspension in a mold. The suspension is solidified to form an aerogel and the aerogel is joined to a ceramic skin.

Abstract: A multi-layer capacitor comprising a stack of sheet electrodes with an insulating dielectric layer sandwiched between these layers is disclosed. The dielectric layer formed on the electrode is prepared by the "sol-gel" process.

Abstract: A battery, having a plurality of cells stacked in series. Each of the cells having a positive electrode, a negative electrode and a separator that contain an electrolyte. The battery utilizes a thin section of carbon provided between adjacent cells as the bipolar walls. The bipolar wall may be a thin, preferably flexible, sheet of graphite. The carbon bipolar wall may also be formed by tape casting.

Abstract: A vanadium oxide compound having the formula VO.sub.2 is disclosed for the purpose of selectively shielding an electromagnetic transmitter or receiver. Vanadium oxide exhibits a marked and rapid transition from dielectric and transparent to electromagnetic radiation to metallic and impervious to such radiation at a specific temperature, 68.degree. C. The compound is preferably mounted as a thin layer on a substrate which has been specifically selected for the desired application. The transmission of radiation is then temperature selected. The preferred method of deposition is an organic hydrolysis reaction.

Abstract: A vanadium oxide compound having the formula VO.sub.2 is disclosed for the purpose of selectively shielding an electromagnetic transmitter or receiver. Vanadium oxide exhibits a marked and rapid transition from dielectric and transparent to electromagnetic radiation to metallic and impervious to such radiation at a specific temperature, 68.degree. C. The compound is preferably mounted as a thin layer on a substrate which has been specifically selected for the desired application. The transmission of radiation is then temperature selected. The preferred method of deposition is an organic hydrolysis reaction.

Abstract: A method of manufacturing a varistor utilizes preselected amounts of ZnO which are combined with specified amounts of additives including B, Na, Bi.sub.2 O.sub.3 and BaO to form a variety of compositions. Each composition is pressed into a disc. The disc is then sintered at a first selected temperature. Afterwards, the disc is annealed at a second selected temperature. The specific compositions disclosed render a varistor with improved high temperature performance when the annealing step is followed with a low temperature tempering cycle at approximately 250.degree. C.

Abstract: A method for producing varistors having high energy absorption. The high energy absorption is achieved by combining predetermined quantities of Bi.sub.2 O.sub.3, BaO, SiO.sub.2 and Sb.sub.2 O.sub.3 with ZnO to produce a mixture which is sintered to produce a varistor disc having high energy absorption.

Abstract: A wound thin film capacitor is formed by the method of applying a solution of a metal-organic alkoxide composition to at least one flat surface of an electrically conductive metal strip and heating the coated strip so as to remove the organic component of the metal-organic alkoxide composition and produce a thin, electrically non-conductive metal oxide film on the flat surface. The metal strip with the metal oxide coating is then wound on a spool to form a wound thin film capacitor.

Abstract: A switchable shield which precludes transmission or receipt of radio frequency or microwave energy. The shield comprises a substrate of highly transmissive material with an active film layer disposed on the substrate. This active film layer is switchable upon heating from a high transmissivity, high resistivity mode which permits transmission or receipt of rf or microwave radiation, to a low transmissivity, low resistivity mode which precludes transmission or receipt of rf or microwave radiation through the shield.

Abstract: The invention provides a disc for use in varistors. The disc is primarily composed of ZnO and includes predetermined concentrations of Bi.sub.2 O.sub.3 in a selected ratio with Sb.sub.2 O.sub.3.

Abstract: A varistor utilizing a disc of mainly ZnO in combination with preselected combinations of Bi.sub.2 O.sub.3, Sb.sub.2 O.sub.3, SiO.sub.2, MgO and CaO.