Showing papers on "Film capacitor published in 1979"

Optimization of Interdigital Capacitors

Abstract: The variation of Q and capacitance slope for series- and shunt-connected interdigital capacitors is shown. A theory suitable for interactive design of capacitors is given.

Thick film capacitor having very low internal inductance

Abstract: A decoupling capacitor for highly integrated, fast switching logic circuit modules. The capacitor comprises stacked ceramic sheets having metallized surfaces. The sheets are connected together in groups. Alternate groups are connected to a first electrode. Intervening alternate groups are connected to a second electrode. The connections are all made to the same ends of all the sheets so that the current flows in opposite directions through adjacent facing plates.

Ultrasonic Sensing of Partial Discharges within Microfarad Value AC Capacitors

Abstract: As new dielectric fluids and materials are introduced, partial discharge (P.D.) testing of microfarad value capacitors in the factory is assuming greater importance. However, the large capacitance restricLs the use of the common electrical methods for detecting small (1-20 pC) discharges, and bridge techniques are not economical for production line tests. For these reasons, the use of ultrasonic sensors for detecting P.D. within microfarad value capacitors was studied, and this resulted in the development of a combined acoustic waveguide probe, ultrasonic sensor and indicating meter, suitable for factory P.D. testing of capacitors.

Losses in Electrode Surface Films in Gas Dielectric Capacitors

Abstract: The surface characteristic of a number of electrode materials including stainless steel, brass, brass whit various plated surfaces, aluminum, and anodized aluminum has been examined over a wide range of humidity. The measurements of surface charcteristic, expressed in microradian millimeters, have an estimated uncertainty of 0.01 ?rad · mm.

Compensation for parasitic capacitances in switched-capacitor filters

Abstract: Three methods are described for eliminating the effects of parasitic capacitances associated with floating capacitors in switched-capacitor filters.

Method of trimming thick film capacitor

Abstract: An adjustable thick film capacitor includes a conductive paste layer which is fired to form a first electrode on a substrate, at least one dielectric paste layer over the conductive electrode which is also fired, and an organo-metallic paste layer over the dielectric layer, which is fired at high temperature to form a very thin sintered metallic conductive layer for the second electrode. The organo-metallic paste includes molecules having conducting particles, such as gold atoms, which after firing form a residue layer having a thickness of the order of 1 micron. This thin electrode can be trimmed by an accurately controlled low energy laser beam to adjust the capacitor value.

Metallized film capacitor

Abstract: PURPOSE: To provide a metallized film capacitor wherein a metallized film is improved in self-recovery properties through a fuse effect and which is kept high in reliability to dielectric breakdown and least lessened in capacity due to a fuse action. CONSTITUTION: A metallized surface is split into unit capacitors 3a by cross- shaped slits 2b on which no metal is deposited, and the unit capacitors 3a are connected together in parallel through fuses 3b formed of small metallized part located between the cross-shaped slits 2b. The split unit capacitor 3a is so set as to be 10 to 1000mm 2 in deposition area, 130V/μm to 350Vμm in potential gradient (rated charge voltage/nominal thickness of plastic film), and less than 0.03J in storage energy obtained based on its area, resultant dielectric constant of dielectric, and rated charge voltage. COPYRIGHT: (C)1994,JPO

Manufacturing method for metalized plastic dielectric capacitors for improved current capabilities

Abstract: An improved method for the attachment of lead electrodes to metallized film capacitors is disclosed herein. Capacitors of this type are formed by winding thermoplastic dielectric films, each having a conductive coating, into a coil and applying conductive electrodes to the opposite axial ends of the coil, forming an electrical bond with the metallized surfaces of the dielectric windings. The invented method provides for a two part heat curing of the capacitor. After the capacitor is wound into a coil, it is clamped and then heated at a moderate temperature below its rated operating temperature for a sufficient period of time so as to impart mechanical stability to the device. A "schooping" material is then sprayed on the axial ends of the capacitor, allowing for the deep penetration of the material between offset layers of the capacitor. Finally the capacitor is heated at a temperature above its rated operating temperature for a period of time sufficient to cause the dielectric films to contract into a tightly wound coil. The leads for the capacitor are then soldered onto the coil. The two part heat cure prevents the curling of the edges of the capacitor before the schooping process, allowing for greater penetration of the schooping material. This increase in penetration of the schooping material allows the capacitor to be used in applications requiring a higher current density then is possible by prior art methods.

Method and apparatus for manufacturing boxed encapsulated capacitors

Abstract: A boxed and encapsulated rolled metallized film capacitor susceptible to facile machine insertion is fabricated by cyclically advancing a lead frame 32 through a number of stations (36,37) whereat pairs of leads (24,26) of the lead frame are bent downwardly and secured to end electrodes (22,23) formed on the capacitors, and then boxes (29) partially filled with encapsulant are moved over each capacitor secured to a pair of leads. Next, the lead frame is advanced to move each box and capacitor into position to receive additional encapsulant from a nozzle (38) which is projected through a feed hole (34) formed in the lead frame.

Fabrication of Passive Components for High Temperature Instrumentation

Abstract: Thin-film resistors and capacitors have been fabricated for use in geothermal well-logging tools. The resistors can operate from 25°C-500°C with a temperature coefficient below 100 ppm/°C; capacitors can operate from 25°C-350°C with a similar temperature coefficient. Chemical vapor deposition (CVD) is used to fabricate both resistors and capacitors. The processing is compatible with most microcircuit processes; and resistors, capacitors, interconnecting metallization, and possivation are all produced by CVD and can be integrated on a single substrate. Resistor material is tungsten-silicon, capacitor electrodes and metallization are tungsten, and dielectric material is silicon nitride. Photolithography is used to delineate component geometry.

Piezo-vibrator unit ceramic package with integral capacitor

Abstract: A ceramic package includes a ceramic case for installing a piezo-vibrator therein. Capacitors are formed directly on the bottom surface of the ceramic case through the multi-layer printing method. Electrodes of the capacitors also function as input and output electrodes for the piezo-vibrator.

Development of the Thick - Film Capacitor and Its Application for Hybrid Circuit Modules

Abstract: New dielectric pastes with high and low dielectric constants and an advanced passivation system have been developed for highly reliable capacitors and crossovers in thick-film circuit modules. Colloidal magnetite has been found to be a good sintering agent in BaTiO 3 -based high-K dielectric paste, and a crystallized low-K glass paste has been found to be suitable for small capacitors and crossovers. Alloyed Ag/Pd and Ag/PdO have been developed for conducting electrodes, which are compatible with the dielectric materials and the firing process. Physical defects are the critical factors in the glass passivation systems for the reliability because of possible moisture diffusion into the dielectrics. A new two-layered passivation system has been adopted. The capacitor system has been applied to an RF/IF thick-film hybrid module for radio-cassette recorders.

Compact bandpass filters for 800-MHz band land mobile radio equipments

Abstract: Compact bandpass filters for 800-MHz land mobile radio equipment has been developed using coaxial resonators with a high dielectric constant material of e r = 35. The use of dielectric material of high Q and a dielectric substrate for coupling capacitors made possible the construction of compact low-insertion-loss filters. The performance characteristics of these filters are described.

Method for forming voltage-invariant capacitors for MOS type integrated circuit device utilizing oxidation and reflow techniques

Abstract: For an integrated circuit semiconductor device having a multiplicity of MOSFET elements, voltage-invariant capacitors, each with metal as one plate and either polysilicon or source-drain diffusion as the second plate, are created by regrowing a thin oxide layer to provide the dielectric of the capacitor during the normal MOSFET processing sequence.

Multilayer film capacitor - with polypropylene foil metallised on both sides and polypropylene dielectric

Abstract: A multi-layer film capacitor is made of a polypropylene film which has been metallised on both sides between the metallised coating. The dielectric foil separating them is also made of polypropylene. The metal vapour deposition of the polypropylene foil first on one side and then on the other overcomes the earlier difficulties of uniform metallisation of polypropylene. The use of the same material for the metallised foil and the dielectric foil simplifies the winding technique and improves the temp. characteristics of these capacitors.

Thin film capacitor integrated circuit

Abstract: PURPOSE:To inexpensively obtain electrode structure for a thin film capacitor integrated circuit by forming confronting electrodes of aluminum thin film on a dielectric film anodized on the surface of a thin film electrode provided on an insulating substrate and forming a leading electrodes at the confronting electrodes through the through holes of an insulating protective film. CONSTITUTION:A thermal Ta oxide film 2 is formed on a glazed ceramic substrate 1, and a Ta nitride film 3 is formed thereon as a lower capacitor electrode. The Ta nitride film is patterned, is partly anodized to form a TaO5 film 4. There are provided Ni-Cr film 5 and Al film 12 as the conductive film of confronting electrode A, a hole is perforated at a polyimide insulating film 13 coating the film 12, and leading electrode B made of Cr film 8, Ni film 9 and solder bump 11 is formed. In this manner, since the main conductor of the capacitor confronting electrode is made of aluminum, inexpensive electrode structure can be obtained. Since the hole of the protective insulating film is coated with leading electrode, it can prevent corrosion of aluminum film.

Process for the manufacture of tantalum solid electrolyte capacitors

Abstract: Accelerated ageing of solid electrolyte tantalum capacitors in batches by immersion of the capacitors in a semiconducting powder contained in a conductive receptacle connected to one terminal of a d.c. voltage source, the other terminal of which is connected to the anode leads of the capacitors. The voltage of the source is between 1.2 and 1.8 the capacitor rated voltage. The receptacle is maintained between 25° C. and 180° C. Ageing lasts for at least two hours.