Showing papers on "Insulator (electricity) published in 1975"

Structural and electrical properties of granular metal films

Abstract: Granular metal films (50–200,000 A thick) were prepared by co-sputtering metals (Ni, Pt, Au) and insulators (SiO2, Al2O3), where the volume fraction of metal, x, was varied from x = 1 to x = 0.05. The materials were characterized by electron micrography, electron and X-ray diffraction, and measurements of composition, density and electrical resistivity at electric fields e up to 106 V/cm and temperatures T in the range of 1.3 to 291 K. In the metallic regime (isolated insulator particles in a metal continuum) and in the transition regime (metal and insulator particles in a metal continuum) and in the transition regime (metal and insulator labyrinth structure) the conduction is due to percolation with a percolation threshold at x⋍0.5. Tunnelling measurements on superconductor-insulator-granular metal junctions reveals that the transition from the metallic regime to the dielectric regime (10–50 A size isolated metal particles in an insulator continuum) is associated with the breaking up of a metal ...

Planar insulation of conductive patterns by chemical vapor deposition and sputtering

Abstract: A method using a chemically vapor deposited (CVD) insulator to form a substantially planar layer of insulative material atop a conductive pattern on the surface of a substrate. The invention also features the use of a photoresist both as a mask for forming apertures in an underlying insulating layer as well as a lift-off material for a subsequently deposited conductive layer. In the method, a first insulating layer is deposited atop the substrate. Photoresist is then deposited; the resist pattern is exposed and developed; and the insulator is etched to expose selected areas of the substrate. A conductive film, preferably metal, is then deposited in blanket fashion in such quantity as to achieve the same height as the first insulator within the exposed apertures. The resist is lifted off, thereby leaving metal in the exposed apertures only. The pattern at this point consists of a single level of a conductive pattern and the insulator pattern with gaps between the conductors and the insulator. The gaps are the result of the unavoidable removal of a portion of the insulator below the photoresist during the etching process. Another insulating film is chemically vapor deposited (pyrolytically deposited) in blanket fashion. Notwithstanding the gaps between the conductors and first insulator, the second film is substantially planar if the thickness of this second insulating film equals or exceeds one-half the width of the largest of said gaps. The method is applicable to any level of conductive patterns (metallization) atop the substrate.

Membrane keyboard apparatus having common apertured electrode, aperture inserted electrodes and conductive bubble contactors

Abstract: Membrane keyboard apparatus is disclosed as including an insulator having a conductive sheet thereon providing a plurality of first electrode members and a plurality of second electrode members to form an array of individual switching units. A membrane member is disposed in a spaced relation above and adjacent to the level of the top surfaces of the pluralities of first and second electrode members. The membrane member is formed of a flexible, plastic, insulative sheet member, and includes: an array of indicia corresponding to the array of individual switching units formed on the first, bottom surface of the sheet member; a background color layer formed on the bottom surface of the sheet member and over the array of indicia; a very thin, conductive layer formed on the background color layer and applied to form patterned areas for providing a conductive path between the first and second electrode members of the individual switching units selected; and height differential members formed in the membrane member. The height differential members formed in the membrane member have a first, actuated position where the conductive layer provides a conductive path between the associated first and second electrode members of the actuated individual switching unit and a second, nonactuated, normal position where the conductive layer is electrically spaced from at least the second electrode members to electrically insulate the first electrode members and the second electrode members.

Thin wire type of electric field curtain system

Abstract: In an electric field curtain system, a plurality of linear electrodes are embedded in an insulator layer in parallel to each other along the surface of said insulator layer so that silent discharge forming curved electric lines of force which are outwardly convex may be produced on the surface of said insulator layer, the width of each of said plurality of linear electrodes is chosen equal to or less than 3 mm, and the interval between the respective linear electrodes is selected within a limited range, whereby every charged particle may be floated away from the surface of the insulator layer so as not remain on said surface.

Mechanism of insulator flashover under artificial rain

Abstract: The paper gives a brief description of the variation of insulation-surface conductance under artificial rain from dry conditions until steady-state wetting is achieved. The effect of wetting on insulator voltage distribution is examined. Wet flashover tests with alternating voltage and switching impulses of both polarities on simple insulator models as well as long insulator chains and supporting columns are described with a view to clarifying the flashover mechanism. Comparison is made between conventional artificial rain and pulsating rain obtained from special wettest apparatus which permits longer spraying distances. An account is given of the variation of the dispersion of the flashover voltage under different test conditions.

Role of trap states in the insulator region for MIM characteristics

Abstract: A theoretical study of the trap‐assisted charge injection in a blocking contact metal‐insulator‐metal (MIM) structure is made. In this mechanism a charge first tunnels to the vacant trap states in the insulator and is subsequently thermally excited or is tunneled to the conduction band of the insulator. A comparison is made between different contact current mechanisms for such sturctures and it is found that this mechanism is very important for the insulators containing trap states of the order of 1018 cm−3 and more, at low contact voltages. Finally we compare the current‐voltage characteristics of various devices containing different density of trap states in the insulator region, with reference to the present theory. We find that the I‐V characteristics of solid‐state devices strongly depend on the trap density of the insulator region near the cathode

Insulator for covering electric conductors

Abstract: An insulator for covering electric conductors is used to cover, for the purpose of providing insulation, lead wires of the coils in rotary electric machines or stationary induction motors or conductors for connecting various electrical machinery and apparatus. The insulator is comprised of a flexible plastic film tube provided with a soft material on its inner surface. Such a construction prevents the insulation from being damaged even if the electric conductor has corners or bends or even if an external force is applied to the electric conductor because the soft material is compressed and deformed to absorb the applied force.

Dielectric for gas discharge panel

Abstract: A high resolution gaseous discharge display and/or memory device comprises a panel array of bistable charge storage areas designated gaseous discharge cells or sites, each cell having an associated pair of coordinate orthogonal conductors defining the cell walls which, when appropriately energized, produce a confined gaseous discharge in the selected sites. The conductors are insulated from direct contact with the gas by a dielectric insulator, the dielectric insulator being composed of a layer of refractory material having high secondary emission characteristics such as magnesium oxide doped with gold to prevent degradation of the dielectric layer during operation, to increase the memory margin and extend the life of the gaseous discharge panel, and to control the secondary emission characteristics and provide stable operating voltages for the panel.

Electrical insulator for armature shafts and method of installation

Abstract: Disclosure is made of a universally fitting electrical insulator for mounting between the armature shaft and the windings and laminations of an armature. The disclosure is also of a method for mounting the insulator in the armature. The insulator and method are particularly useful in the production of double insulated electrical hand tools.

Flashovers of insulators under natural pollution and HVDC

Abstract: In the Dossenwald test station, near Mannheim, an insulator testfield for more than 30 test objects was constructed, fed by a stiff d.c. voltage source and controlled by an automatic test program installation. The tested types, 7 post insulators (porcelain) and 3 suspension insulators (porcelain, glass, silicone rubber), two specimen of each type in parallel, were continuously under 400 kV d.c. voltage, positive polarity, for more than 8000 h. Flashovers during that time were analysed.

High resistance cermet film and method of making the same

Abstract: A cermet film includes metal particles in an insulator with the metal particles having an average diameter of from about 30A to about 120A. The cermet film has a high resistivity, and low temperature coefficient of resistivity, and is stable under electric fields of up to 105 volts/cm. The cermet film can be formed by co-sputtering the metal and the insulator onto a substrate. The sputtered cermet film is then annealed in a reducing atmosphere whereby its resistivity is increased without a corresponding change in its temperature coefficient of resistivity.

Antistatic capacitance probe

Abstract: There is disclosed an antistatic capacitance probe including an electrically conductive gland for receipt in a port formed in the wall of a vessel for receiving a flowable material. A tubular central conductor projects axially from the gland and into the vessel and has its projecting extremity encapsulated in a dielectric insulator. An equalizer conductor wire is connected on one end to the gland and is spiral wound around the insulator throughout its length and is in electrical contact with such insulator to thus remove any static charge therefrom and conduct it into the gland, thus preventing static charge buildup on such insulator.

Microwave band-pass filter

Abstract: PURPOSE:To obtain good pass characteristics as well as to ensure an easy electric adjustment through a simple constitution by combining the cavity resonator with use of both the magnetic and electric field combinations together in order to obtain the attenuation pole. CONSTITUTION:The 1st-4th cavity resonator 2-5 are installed in box 1; the longitudinal connection is given via coupling windows 8-10 between resonators 2 and 3, 3 and 4 and 4 and 5 respectively; and 1st and 4th resonators 2 and 5 are put to be adjacent to each other. Thus, the microwave entered through waveguide 10 of the input side is connected to resonator 2 and 2 via window 6 and then delivered through the waveguide of the output side through resonators 3-5 and via window 7. The above connections are all given via the magnetic field combination. Here, metal bar 21 which is insulated from the metal wall via insulator 23 is pierced through between resonator 2 and 5 in order to secure the electric field combination between these two resonators. In such way, the opposite phase is secured between the signals of the magnetic field and electric field cominations, thus producing the attenuation poles with the frequency with which the same amplitude is obtained for both cominations. The frequency is adjusted via screw 22.

Semiconductor devices having surface state control

Abstract: A semiconductor structure having a surface insulating layer formed as a grid with charges implanted in the insulating material to prevent inversion and, hence, channeling between adjacent semiconductor regions, preferably for use in a non-blooming vidicon. The method of manufacturing such a structure uses ion implantation to create immobile positive charges in a grid pattern in an insulating layer in regions spaced from the interface between the insulating layer and the semiconductor body. The insulating layer is of sufficient thickness that substantially all of the charge sites in the insulating layer are separated from the outer surface of the insulator by a sufficient distance to effectively prevent a negative electric field from reaching into the silicon.

Slow states in InSb/SiOx thin film transistors

Abstract: An investigation of the slow decay in conductivity modulation observed in InSb/SiO x thin film field effect transistors has been carried out. The decay is ascribed to “slow” trapping states, with a characteristic trapping time of > 1 msec. These are postulated to be due to tunnelling of electrons from the semiconductor into traps in the insulator and this theoretical model is used to analyse the experimental results and to obtain a density, N t , of traps in the insulator. N t was found to be ∼ 10 20 cm −3 and the capture cross-section referred to the semiconductor/insulator interface was ∼ 10 −20 cm 2 . The traps were found to be filled to a depth of ∼ 20 A into the insulator.

Electric treater system

Abstract: A B S T R A C T Electric treater system for resolving an emulsion in a vessel with an electric field created by an ener-gized electrode receiving current from an external power source via a feed-through insulator, an electrical conductor and a high voltage bushing within a sidewall of the vessel. A pressure conduit extends between the entrance bushing and the feed-through insulator, and it contains the electrical conductor within a dielectric liquid. A heat sink on the entrance bushing maintains its plastic insulation parts at substantially the tem-perature of the emulsion. System means maintain the dielectric liquid within the pressure conduit at sub-stantially the fluid pressure of the emulsion. Also, a heat exchanger on the pressure conduit maintains the feed-through insulator at substantially the same temp-erature at its pressure conduit and power source term-inals. As a result, the entrance bushing can operate at elevated emulsion temperatures (500°F) but at insig-nificant pressure differential whereas the feed-through insulator can operate at the ambient temperatures (80°F) of the power source but at substantially the fluid pressure of the emulsion (500 psi). Neither the bushing nor feed-through insulator must withstand simultaneously high pressure (500 psi) and high temperature (500°F) conditions. The present electrical treater system oper-ates at elevated temperatures and pressures with the relative safety of low pressure, low temperature conditions.

Static characteristics of metal-insulator-semiconductor-insulator-metal (MISIM) structures—I. Electric field and potential distributions

Abstract: The static characteristics (potential and electric field distributions) of sandwich structures of a metal 1-insulator 1-nondegenerated semiconductor-insulator 2-metal 2 (M 1 I 1 S I 2 M 2 )-type are analyzed. A theory is given with help of which the semiconductor surface potentials ψ 1 and ψ 2 as a function of applied voltage, type and thickness of insulator and semiconductor layers, metal-semiconductor work function difference and effective density of surface charges, can be found. Numerical calculations and diagrams with corresponding approximated analytical expressions are given for the case of a symmetrical MISIM structure with intrinsic semiconductor.

Creeping discharge and partial discharge prevention means for a coil end of a rotary electric machine

Abstract: A creeping discharge and partial discharge-prevention means for a stator coil end of a rotary electric machine is disclosed. It includes an grounding electrode on an insulator of the stator coil end of the rotary electric machine, a first electrical stress grading coated layer on the insulator of the coil end including the end of the grounding electrode, a shield insulator made of insulation material around the first electrical stress grading coated layer including the end of the grounding electrode, a shield electrode electrically connected to the grounding electrode around the shield insulator, and a second electrical stress grading coated layer coated on the shield insulator including the end of the shield electrode.

Electrostatic printer support with controlled electrostatic surface voltage

Abstract: A line printing apparatus in which spot patterns of ink or toner particles are formed on a moving paper sheet. A modulator defined by a corona source and an electric shield which has a multiplicity of linearly arranged apertures is spaced from one side of the paper. The voltage at each aperture is individually controlled so that ions from the corona are permitted or prevented from passing through preselected apertures. The passing ions impinge certain particles in a toner particle cloud between the modulator and the one side of the paper sheet. A paper support bar is positioned on the other side of the paper and constructed of an insulator and an elongate electrode is secured to the back side of the insulator and positioned parallel to the aperture array. Lateral sides of the insulator are grounded and a high voltage applied to the electrode results in a high surface voltage on the paper support surface of the insulator which gradually drops off to zero or opposite potential from a maximum along a line aligned with the aperture array to the lateral sides of the insulator. Those toner particles impinged by ions are attracted to the high surface voltage on the insulator and deposited on the side of the sheet facing the modulator to sequentially form spot patterns and generate a line print. In one embodiment, the paper support bar is stationary and the paper sheet slides across its surface. In another embodiment, the paper support bar is a rotatable cylinder, preferably supported by rotatable support cylinders with electrically insulative surfaces.

Experiments on M-I-M-I-M triode structures using SiOx/B2O3 as the insulating material

Abstract: Thin film metal-insulator-metal-insulator-metal structures are examined and their characteristic curves after electroforming processes are studied. The metals used are Al, Au and Cu and the insulator is o co-evaporated oxide Complex of 70% SiO and 30% B2O3. The effects of varying the forming voltage, forming direction and the applied ‘ grid ’ voltage on the potential distribution and the high- and low-resistance regions are studied.

Heat insulating device

Abstract: PURPOSE: A heat insulating device which can be easily constructed by arranging smaller blocks of shaped heat insulator arround the body to be insulated, (e.g. turbine casing), then holding the blocks with wire netting, and piling up larger blocks of shaped heat insulator around the smaller blocks so as to form a desired number of heat insulating layers. COPYRIGHT: (C)1977,JPO&Japio

Wireguide-transport apparatus

Abstract: A temporary guide support adapted to be removably connected to a high top insulator for guiding and transporting a wire or high voltage electrical line while it is being strung in place on its insulators. After the line is positioned on the insulators, the guide is removed and the line permanently connected to the insulators.

Local fields at the cathode-insulator junction as a cause of breakdown of shaped insulators in vacuum

Abstract: High-voltage holdoff of solid insulators bewteen electrodes in vacuum depends strongly on insulator shape. The angle between the applied field and the insulator interface is believed to be the fundamental dependence. A detailed calculation of the electric fields about solid insulators of various shapes gives us insight as to the reason for this dependence. The breakdown field near the cathode-insulator junction appears to be constant if the enhancement of the applied field is considered. This enhancement is created not only by insulator geometry, but also by insulator surface charging effects.

Injection current flow through thin insulator films

Abstract: The equations and boundary conditions describing injection current flow through insulators are investigated for the case of thin insulator films. The carrier mobility is assumed to be constant and trapping is neglected. The thickness of the insulator film is taken to be small enough so that surface properties are significant. It is found that electrons flowing in from the metal contacts can increase the insulator conductivity by orders of magnitude. The diffusion term in the current equation is not neglected, and it is found that this enhances the quadratic Mott-Gurney current term. The theoretical results are compared with previous experimental results.

High voltage electrical cables

Abstract: High voltage electrical cable comprising an inner elongated conductive member, a corrugated metallic tubular member positioned about such inner member, and a plurality of nonconductive spacers each positioned along the longitudinal axis of the electrical cable and extending between said members through a nonconductive environment comprising, for example, a gaseous, foam or liquid insulator. To avoid premature insulation breakdown or sparkover in the vicinity of the spacers, such spacers are so configurated and positioned that their end portions coming into engagement with the corrugations of the surrounding tubular member follow the profile of the engaged corrugations so as to extend into the corrugation troughs thereof.

Boundary conditions for thin imperfect conductors and insulators

Abstract: Consider a thin, plane, finite sheet of material of thickness 2t whose electrical resistivity is σ2. It is surrounded by a medium of resistivity σ1 in which there is an electric field whose length scale is L. We consider the limit t/L o with , or fixed. In the former case the sheet is an imperfect conductor and it is shown that it may be modelled by a surface on which the boundary condition is , where φ and Z are the (nondimensional) electrical potential and distance measured normal to the surface, and the subscripts + and − denote values on either side of the surface. In the latter case the sheet is an imperfect insulator and the boundary condition is