Showing papers on "Film capacitor published in 1989"

Equivalent Circuit Model in Grain‐Boundary Barrier Layer Capacitors

Abstract: Electrical properties of BaTiO3-based capacitors are investigated. A new model is developed to explain the frequency response of the impedance of grain-boundary barrier layer (GBBL) capacitors. This model takes into consideration the dipole polarization effect and provides a simple and effective approach to evaluate the performance of GBBL capacitors with various dopants and sintering in different atmospheres. When sintered in a reducing atmosphere, doped BaTiO3 exhibits a higher dielectric constant and a relatively stable dieletric constant with respect to the frequency response and temperature dependence. Also, smaller grain resistivity is obtained with addition of both Dy2O3 and Nb2O5.

Electronic package with integrated distributed decoupling capacitors

Abstract: A semiconductor chip carrier includes a plurality of distributed high frequency decoupling capacitors as an integral part of the carrier. The distributed capacitors are formed as a part of the first and second layers of metallurgy and separated by a layer of thin film dielectric material built up on a substrate. The distributed capacitors are positioned to extend from a ground pin of one of the layers of metallurgy to a plurality of mounting pads which are intergral parts of the other of the layers of metallurgy. A semiconductor chip is mounted to the mounting pads and receives electrical power and signals therethrough. The distributed capacitors decrease electrical noise associated with simultaneous switching of relatively large numbers of off-chip drivers which are electrically connected to the semiconductor chip.

Polyester films, magnetic recording media and film capacitors produced therefrom

Abstract: Disclosed herein is a polyester film containing specific fine spherical silica particles. The film of the present invention is especially suitable as a base film for a magnetic recording medium or dielectric for a capacitor. The films of the present invention have the markedly improved properties such as surface properties, electromagnetic properties, electrical properties, etc. due to the excellent dispersibility of the particles in the film.

Short-resistant decoupling capacitor system for semiconductor circuits

Abstract: A decoupling capacitor system for improving the reliability of digital logic circuit boards such as single inline memory modules which use surface-mount decoupling capacitors. The system comprises one or more units of two or more series-connected capacitors connected between the chip supply voltage (Vcc) input and the chip ground (Vss) connection. Given no change in the reliability of the individual capacitors, the reliability of a circuit board can typically be improved by several order of magnitude.

High power, high temperature disassemblable ceramic capacitor mount

Abstract: A disassemblable capacitor mount for large, high power, high temperature ceramic capacitors is disclosed. The capacitor mount allows the capacitors to be mechanically secured to a printed circuit board or other planar surface and allows for good electrical contact to be made with the capacitors to handle high power. The capacitor mount comprises a pair of substantially parallel, spaced-apart conductors, the conductors provided with a plurality of corresponding spaced-apart lateral slots on facing planar sides thereof. A plurality of compressible contactors are disposed within the slots. A plurality of capacitors having opposed electrode ends are disposed between the conductors, the ends positioned within the slots and contacting the contactors. Finally, a rigid mechanism removably fixes the conductors to a planar surface. The conductors compressingly urge against the capacitors. The disassemblable capacitor mount provides a stress relieving, thermal expansion absorbing and heat dissipating structure for securing the capacitors to the planar surface. Specifically, the capacitor mount has a structure which allows faulty capacitors to be readily removed from the capacitor mount and replaced.

Device for automatically ascertaining capacitance, dissipation factor and insulation resistance of a plurality of capacitors

Abstract: An apparatus (Fig. 1, element 10) for automatically measuring characteristics, such as capacitance, dissipation factor and insulation resistance, of each one of a plurality of capacitors. The apparatus includes a predetermined number of test fixtures (38-1 to 38-N), each test fixture being adapted to receive one of the capacitors to be tested, and a plurality of measurement devices (20, 22 and 24) for measuring various parameters. A relay matrix (66), having a plurality of relays therein, is connected such that each test fixture may be connected to one of the measurement devices and to a high voltage source (12) of electrical potential. Also included in the test apparatus is a network (30) for energizing predetermined sequence thereby to connect the capacitor associated with each relay to the desired measurement devices and for controlling the output of the voltage source to apply a predetermined high voltage to each capacitor connected to the source by the energization of a relay. Recording device (26R) associated with the measurement devices for recording the measured values of the capacitor. In the preferred instance the network (30), the controller (26), and the recording device (26R) implemented using a digital computer (not shown) operating in accordance with a program.

Film capacitor and method of making the same

Abstract: A film capacitor which has a plurality of electrodes; at least one layer of dielectric member made of organic material and interposed between each pair of neighboring electrodes; impreganated members made of organic material and disposed in a gap between the electrode and the dielectric layer or between the dielectric layers; and end electrodes applied respectively to opposite electrode drawout end faces and connected alternately with the electrodes. The dielectric layers and the impregnated members alternate with each other and have respective end faces. The end portions of the dielectric layers and impregnated members are indented to provide respective indented end face.

MOS type semiconductor device potential stabilizing circuit with series MOS capacitors

Abstract: A MOS type semiconductor device forming an insulated gate field effect transistor and a potential stabilizing circuit connected between power voltage supply lines is disclosed. The potential stabilizing circuit includes first and second MOS type capacitors connected in series each other, and the dielectric film of each of the MOS type capacitors has the same thickness and is made of the same material as the gate insulating film of the transistor.

Stable gas-dielectric capacitors of 5- and 10-pF values

Abstract: Gas-dielectric capacitors of 5 and 10-pF are described. With Zerodur as the structural material, the capacitors are stable with time, have small temperature and voltage coefficients, and have been used successfully as traveling standards. A relatively large sensitivity to ionizing radiation is observed in these capacitors. >

Measurement of capacitances and their loss factors

Abstract: A method is described for measuring the capacitance values and the loss factors of a pair of capacitors simultaneously. The method uses the principle of oscillators. No standard capacitor is required. The possible errors introduced in the measurements are discussed. Both theoretical and experimental results are provided. The method can be used with any other oscillator circuit that contains only two capacitors. >

Thin-film capacitor and method of manufacturing a hybrid microwave integrated circuit

Abstract: A thin-film capacitor which has excellent withstand voltage characteristic, dielectric loss characteristic and production yield can be obtained by forming its dielectric film with a 3-layered structure comprising a first silicon oxide film formed on a polycrystalline sintered body substrate by a chemical vapor-phase deposition method, a second silicon oxide film formed by coating on the first silicon oxide film a solution state silicon oxide precursor followed by denaturing by heat treatment, and a third silicon oxide film formed on the second silicon oxide film by a chemical vapor-phase deposition method. A hybrid microwave integrated circuit is manufactured in which the above-mentioned thin-film capacitors are used as input/output coupling and DC blocking capacitors, bypass capacitors and impedance matching capacitors.

Film capacitor, method of and apparatus for manufacturing the same

Abstract: A film capacitor having metallic layer electrodes, organic dielectric films interposed between the metallic layer electrodes, and a pair of end surface electrodes disposed at the opposite ends of the capacitor and alternately connected to the metallic layer electrodes. The end surfaces of the dielectric films adjacent to each other and located at the opposite end surfaces of the capacitor are formed with irregularities. This capacitor is manufactured by a method including: the steps of preparing a lamination or roll of a plurality of electrodes and organic dielectric films interposed between the electrodes, selectively removing portions of the dielectric films at the electrode-lead-out-end sides of the roll or lamination where end surfaces of the dielectric films are flush with those of the electrodes by bringing surfaces of the roll or lamination at the electrode-lead-out-end sides in contact with a gas having at least a component reactive with the organic dielectric; and forming end-surface electrodes at the electrode-lead-out-end sides.

Electromagnetic interference filter protection circuit

Abstract: A protection circuit for use with an electromagnetic interference filter used in conjunction with a three phase power circuit operating at a particular line frequency includes three capacitors which are coupled to the output terminals of the electromagnetic interference filter. The electromagnetic interference filter and the power circuit have a resonant frequency which is substantially equal to the line frequency. The capacitors of the protection circuit have values which are selected to change the resonant frequency of the electromagnetic interference filter and power circuit such that the resonant frequency is not substantially equal to the line frequency. A protection circuit assembly for use with an electromagnetic interference filter includes a base plate, three ceramic capacitors, three heat conducting substrates, and a protective cover which is mounted on the base plate. The capacitors are mounted on the heat conducting substrates, and the substrates are mounted on the base plate.

Double capacitor and manufacturing method thereof

Abstract: A double capacitor and the method of manufacturing the same contains two capacitors connected in parallel within a semiconductor integrated circuit. A common ground conductor used by both capacitors is formed using a tri-layer mask and sputtering process that gives the conductor a U shape, which results in a larger charging capacity compared with a conventional capacitor using the same chip area.

In situ observation of electrode melting in multilayer ceramic capacitors

Abstract: In the usage of multilayer ceramic capacitors, we are concerned with the intrinsic dielectric properties of the ceramic and its long-term stability/reliability under external stresses in service conditions. Of equal importance to long-term reliability is the short-term survivability under current (power)-surge conditions. It differs from the ability to withstand voltage surge, which is determined by the dielectric strength of the ceramic. In this paper, we present some observations on sectioned and polished multilayer ceramic capacitors, which were subjected to “controlled” current-surge test conditions. Capacitors from several vendors were examined. The samples were examinedin situ under an optical microscope while current pulses of varying magnitude were applied at a constant voltage. Subsequently some samples were further examined by scanning electron microscopy. The failure mechanism appeared to be the heat-induced local melting of internal electrodes, which might then lead to a blow-out or charring of the capacitor. In less severe cases, we observed local melting and crack formation in the surrounding ceramic as well. The primary change in capacitor properties was in the degradation of the insulation resistance. In severe cases, this also led to an increase in the dissipation factor.

Method for producing a metallized film for laminated chip capacitors

Abstract: A metallized film for laminated chip capacitors obtained by depositing metal films (23, 24) on a belt-like dielectric film (21) in a direction at right angles with the lengthwise direction of the film mantaining a predetermined independent pattern, such as a skewered pattern or a backbone pattern, and a method of producing the metallized film by forming a film of a masking oil on the surface of dielectric film using a pattern roll (36) with rugged portions and then depositing a metal thereon.

Measurement of electrode surface effects in air capacitors using a precise Coulombmeter

Abstract: A method by which air capacitor electrodes are charged with a DC voltage and then quickly discharged is described. Immediately afterwards, a very sensitive Coulombmeter is switched on to measure the additional discharging of thin dielectric films on the electrodes. The method makes possible the measurement of effects having a time constant of several milliseconds to several thousand seconds, and also enables the frequency dependence of the capacitance to be determined, even for time constants below 1 ms. >

Metalized film capacitor and method of manufacturing the same

Abstract: A metalized film capacitor according to the present invention includes a capacitor element obtained by winding or stacking metalized films, solder layers respectively formed on outermost layers on both end faces of the capacitor element, and a coating resin which coats the capacitor element. Exposed electrodes of the capacitor are obtained by polishing and removing the coating resin from the solder layers to entirely or partially expose the solder layers. The melting point of the exposed electrode is slightly higher than that of a surface-mounting solder, and therefore good soldered portions can be obtained without causing fusing or deformation of the electrodes.

Metallized film capacitor

Abstract: PURPOSE:To suppress the growth of a transparent insulating film, to reduce the size and the cost of a metallized film capacitor by employing a dielectric film and electrodes formed by depositing manganese or alloy containing manganese on the film. CONSTITUTION:Manganese or an alloy of manganese and platinum, nickel, aluminum or the like is deposited to form an electrode 2 on a dielectric film 1, and a metallized film capacitor is compose by employing the electrodes 2. Thus, the manganese having low specific resistance of oxide is employed as the electrode thereby to reduce the concentration of an electric field to a boundary between the electrodes and an insulating film. Accordingly, the reduction of the effective area of the electrode 2 due to the generation of the transparent insulating film when it is employed as a high potential trend, i.e., the reduction of the electrostatic capacity of the capacitor can be suppressed. Thus, the high potential trend design of the capacitor can be performed, thereby reducing the size and the cost of the capacity.

MLC capacitors for switch mode power supply and related large signal applications

Abstract: The construction and characteristics of a multilayer ceramic (MLC) capacitor are reported. Results are presented from studies of MLC capacitors used in several power supply (large-signal) applications. These are described along with measurement techniques suited to large-signal devices. A variety of device ratings have been attained for both X7R and COG dielectrics. Capacitance values up to several hundred microfarads have been obtained in ratings from 25 to over 500 V. >

Metallized film capacitor

Abstract: PURPOSE:To eliminate the defective contact of a metal thin film with an end electrode and to obtain a capacitor with a good characteristic by a method wherein a biaxial-orientation polyether ketone resin film which is highly strong and whose thermal contraction rate in the transverse direction has been adjusted so as to balance with a residual compressive stress inside the metal thin film is used for a dielectric layer. CONSTITUTION:An organic polymer film is used for a dielectric layer; a metal is evaporated on the dielectric layer; a capacitor is obtained. During this process, the film constituting the dielectric layer is formed by a biaxial-orientation polyether ketone resin film whose thermal contraction rate in the transverse direction at 150 deg.C is 2-8% and whose F-5 values in the longitudinal direction and the transverse direction are both 11kg/mm or more. A constituent unit (A) is used singly or a polymer composed of the constituent unit (A) and another constituent unit (B) is used as the polyether ketone resin. By this setup, the detective contact of a metal film with an end electrode is eliminated; a capacitor with a good characteristic can be obtained.

Laminated film capacitor

Abstract: PURPOSE: To obtain a laminated film capacitor having excellent electrostatic capacitance characteristics, excellent tanδ characteristics and high reliability by a method wherein the surface roughness of a thin film dielectric coated layer is maintained at a specific value, and deformation of layer and delamination can be prevented CONSTITUTION: A vapor deposited metal electrode 2 is formed on both sides of a polyester film 1 using a vacuum deposition method, an electrode lead-out part is left on its one surface, a polycarbonate thin film dielectric coated layer 3 is provided, and a composite metallized plastic film is formed In this case, the air intruded between film layers can be reduced by forming the film in the surface coarseness of 01μm or less Consequently, as films are closely adhered easily with each other, generation of interlayer exforiation of a capacitor can be prevented Besides, by the enhancement of close adhesion between films, the beat sound of the capacitor can be reduced when AC voltage is applied COPYRIGHT: (C)1991,JPO&Japio

Manufacture of laminated film capacitor

Abstract: PURPOSE: To enhance an insulation resistance by a method wherein a mother- body capacitor is cut and divided, inessential parts of a high-polymer film exposed on both laminate cut-end faces of each unit capacitor are removed and inessential parts of metal films exposed on the laminate cut-end faces are removed. CONSTITUTION: A plurality of metallized plastic film layers 1 on which metal films 3 have been formed are laminated on a high-polymer film 2 as a dielectric to form a mother-body capacitor 4. Then, capacitor electrodes are formed on both end faces of the mother-body capacitor 4; after that, the mother-body capacitor 4 including the electrodes 5 is cut and divided by using a cutting blade C to form a plurality of unit capacitors 6. Then, inessential parts of the high-polymer film 2 exposed on both laminate cut-end faces 7 are removed by a chemical selection. After that, an etching treatment by using a plasma is executed onto the laminate cut-end faces 7; inessential parts of metal films 3a exposed on the laminate cut-end faces 7 are exposed. COPYRIGHT: (C)1991,JPO&Japio

Method and apparatus for the contactless checking of the insulation of insulated electric conductors and for the detection and classification of insulation faults

Abstract: The previously known methods used in practice for checking the insulation of insulated electrical conductors are not yet satisfactory. According to the invention, a method having the following features is proposed: - The conductor extends axially through at least two annular probes located one behind the other which in each case form capacitors with the conductor as the opposite pole, the capacitors being charged up by means of at least one voltage source in such a manner that the capacitor is short-circuited by a breakdown current in the case of faults in the insulation, - By detecting the flash-overs and their evaluation at the individual capacitors, location-specific signals are in each case obtained in correlation with the forward movement of the conductor, - By logically combining the location-specific signals at the individual capacitors, test quantities are derived for the longitudinal extent of the insulation fault. In the associated device, the probes form mutually insulated part capacitors (11, 12, 13) of a tubular capacitor (10), which have the same length (L) and only a small separation (d) in the axial direction, the outer part capacitors (11, 13) at the inlet and outlet (11a, 12a) of the conductor (1) being shaped in such a manner that a uniform field distribution is obtained.

Temperature stable ceramic dielectric compositions

Abstract: A ceramic dielectric composition useful in the manufacture of compact ceramic capacitors consisting essentially of barium titanate and zirconium dioxide has a dielectric constant ranging from 1800 to 3500 and a heat dissipation factor, tangent delta, less than 3% over the operating temperature range of electronic circuit components.

A ceramic capacitor for AC applications

Abstract: A description is given of a multilayer ceramic capacitor developed for AC voltage operation by using a dielectric characterized by very low loss, even at large signal amplitudes. The result is a new class of ceramic capacitors useful in many medium power AC application such as line isolation and bypass to ground, small motor controls, etc. The dF of these ceramic capacitors compares favorably with that of small aluminium electrolyte capacitors. Comparable films are much larger, and the ceramic devices can be rated for much higher ambient temperature operation. Novel approaches to large-signal capacitor measurement, under conditions closely approximating use conditions, are presented for a range of low frequencies up to at least 10 kHz. It is demonstrated that at high frequencies, high resonant frequency and low series resistance are good figures of merit for capacitors. >

Method for the manufacture of layered capacitors having a thickness of inactive layers

Abstract: Metallized dielectric film is employed to manufacture capacitors. In order to attach a certain number of inactive layers to the capacitors, the method comprises a stage which consists in displacing the layers laterally during the winding operation in order to obtain a determined thickness of inactive layers, the lateral displacement causing the prevention of the connection of the metallizations of the films to the lateral Schoop coatings.

High temperature studies of perfluoroalkoxy (PFA) film (for HV capacitors)

Abstract: Teflon perfluoroalkoxy (PFA) film was characterized electrically to explore the possibility of its use for high-temperature high-voltage capacitors for space applications. The properties measured at temperatures up to 250 degrees C included the AC breakdown voltage and the dielectric constant and dissipation factor at frequencies up to 100 kHz. To understand the breakdown mechanism taking place at these higher temperatures, the prebreakdown conduction currents were also monitored. The results show a drastic reduction in the dielectric strength, as well as an increase in dissipation factor and conduction current with increasing temperature. The results are explained in light of the breakdown models available. >

On the evaluation of ferroelectric nonlinear capacitors for application in power circuits

Abstract: A method for selecting ferroelectric capacitors as nonlinear components for application in turn-off snubber circuits for power electronic switches is investigated. By initiating, without destroying, localized events in the dielectric layer of a multilayer capacitor, such capacitors can be selected (and some of them also stabilized) by observing the number of events and the rate of events. This is achieved by exposing them to a high field strength by means of the application of a high voltage from ahigh-impedance source. The observed phenomena confirm that the conduction is mainly by electrons. An explanation for the instabilities in the steady-state DC current under increasing voltage as observed by other authors is proposed. Components which have been selected in this manner allow the usage of these capacitors at extremely high voltages (approximately 4 to 6 times the rated voltage for linear applications). An apparatus for the selection and stabilization is developed. The selected capacitors have a ratio of capacitance at zero voltage to that at the maximum operating voltage of approximately 10:1. The criteria for selecting capacitors for nonlinear applications (these applications are at high field strengths) are discussed. Preliminary results are given for applications of these capacitors in power electronic switching circuits. >