Showing papers on "Tantalum capacitor published in 1981"

Solid state electric double layer capacitor

Abstract: A solid state electric double layer capacitor comprising a polarization electrode, a non-polarization electrode, and a solid electrolyte disposed at least between the polarization electrode and the non-polarization electrode, the polarization electrode being a mixture of carbon and the solid electrolyte, mixed with each other in a predetermined ratio, the non-polarization electrode being another mixture of the solid electrolyte and a composition containing Cu and a substance selected from a group consisting of Cu 2 S and TiS 2 , and the solid electrolyte having a chemical composition of K x Rb 1-x Cu 4 I y Cl 5-y (0.1≦x ≦0.25, 1.25≦y≦1.67).

Large Capacitance Multilayer Ceramic Capacitor

Abstract: Large capacitance multilayer ceramic capacitors were made using a ceramic dieletric in the binary system Pb(Fe 2/3 W l/3 )O 3 -Pb(Fe l/2 Nb l/2 )O3. The new capacitors used silver alloy as an internal electrode, reducing the capacitor cost significantly. It was then possible to make economical 10 µF ~ 400 µF muitilayer ceramic capacitors. Typical electrical properties of the new capacitors are listed below: Size 4.5 cm3Capacitance at 20° C, 1 kHz 400 µF Dissipation factor at 1 V rms, 1 kHz 0.6 percent Insulation resistance 5000 \Omega -F Capacitance change with temperature change (-30° C ~ +85° C) -83 to 0 percent Impedance at 100 kHz 2m \Omega 2 Equivalent series resistance at 100 kHz 0.8 m \Omega Maximum permissible ripple current 20 A. The new multilayer ceramic capacitors exhibit the following benefits in comparison with conventional multilayer ceramic capacitors, tantalum electrolytic capacitors, and aluminum electrolytic capacitors. a) Dimensions are small and capacitance is large; b) impedance at high frequency band is small; c) equivalent series resistance is small; d) maximum permissible ripple current is large. The new multilayer ceramic capacitors are useful in various electronic circuits, particularly in switching regulators, in place of tantalum electrolytic capacitors and aluminum electrolytic capacitors.

Multiple electrode series capacitor

Abstract: This specification discloses a multigap series construction for multiple electrode monolithic capacitor structures employing ceramics. The voltage rating of such capacitors increases with each gap added across the dielectric. Additionally, the amount of piezoelectric activity occurring in a piezoelectric dielectric is limited by the series gap arrangement to be below that which causes deleterious spurious signals to be generated when said capacitor vibrates.

Fabrication of film circuits having a thick film crossunder and a thin film capacitor

Abstract: A method of fabricating film circuits whereby thick film crossunders may be included with thin film capacitors (22) on a single substrate (10). At least one dielectric layer (12) is formed on the crossunder electrode (11) and a layer capable of smoothing irregularities (13) is also formed in the area of capacitor formation. Firing of the capacitor underlayer is compatible with the dielectric layer. A layer such as beta tantalum (14) is formed over essentially the entire circuit and etched from the contact areas (21) of the crossunder electrode. The layer is oxidized to form a protective layer (15) for the previously deposited layers as well as an underlay for subsequently formed thin film components.

Electrical properties of pyrolytic MnO2 layers

Abstract: MnO2 samples have been prepared by the pyrolytic decomposition of manganese nitrate in different atmospheres: dry air and air saturated with water vapour. The influence of the atmosphere on the kinetics of the manganese nitrate decomposition and on several physical properties of the resulting MnO2, such as density, grain size, crystalline structure, resistivity and activation energy for electrical conduction, has been studied. The dielectric and breakdown properties of Ta-Ta2O5-MnO2 capacitive structures, using MnO2 as a solid electrolyte, are also strongly affected by the atmosphere in which the MnO2 layers are prepared. It has been found that the electrical conductivity of the MnO2 samples is greater when they are formed in a saturated water vapour atmosphere, resulting in substantially improved characteristics for the power losses and scintillation voltage of the corresponding tantalum capacitors.

Influence of Electrolytes in the Electrical Characteristics of Anodic Films on Tantalum

Abstract: The electrical characteristics of anodic oxide films formed on tantalum are investigated in anodes oxidized in the standard electrolytes for low-voltage (001% H3PO4 in water) and high-voltage (same plus ethylene glycol) applications It is found that small additions (about 01%) of certain organic acids such as citric acid to the above electrolytes greatly improves the leakage current, the scintillation voltage and the dielectric losses of tantalum capacitors Furthermore, the use of these organic acids makes it possible to extend to higher voltages the use of the low-voltage electrolyte, and allows, in the case of the high-voltage electrolyte, a substantial diminution in the ethylene glycol concentration without impairing the characteristics of the resulting capacitors Finally, the effect of the citric acid and the ethylene glycol in the anodizing electrolytes is discussed

Breakdown Voltage of Discrete Capacitors Under Single-Pulse Conditions

Abstract: Capacitors subjected to short, constant current pulses will fail when the voltage reaches the breakdown value. A summary of experimental results on breakdown in glass, mica, plastic film, ceramic disc, ceramic multilayer, aluminum electrolytic, and tantalum capacitors is presented. The relationship between breakdown voltage and dielectric material, dielectric thickness, voltage rating, capacitance value, and capacitor construction is discussed.

Detecting method for leakage current and/or polarity of capacitor

Abstract: PURPOSE:To achieve leakage current and polarity detection in a short time, by measuring the difference between transient currents flowing to a reference capacitor connected in series with a resistor and a capacitor to be measured which are designed for equal time constant. CONSTITUTION:Time constants consisting of a resistor 17 having a low impedance negligible in comparison with a capacitor 6 corresponding to an equivalent resistor 16 generating the leakage current of a capacitor 13 to be measured for the leakage current, a resistor 10 and the reference capacitor 6 connected to a one end of a DC power supply 9 and those consisting of a capacitor 13 and a resistor 15 are set equal to each other. When a switch 8 is closed and a voltage corresponding to the difference between transient currents flowing to the capacitors 6, 13 connected to one end of the power supply 9 is measured at a voltmeter connected between other ends of the capacitors 6, 13, the capacitor leakage current can be detected in a short time. On the other hand, since the transient current changes for tantalum capacitors depending on the polarity, the polarity detection can similarly be made in a short time.

Method for destructive testing of dielectric ceramic capacitors

Abstract: This invention covers a destructive testing procedure in which a voltage 2.5 times the rated voltage is applied to the capacitor, at a relatively high current. The resistance in series with capacitors being tested is reduced step-by-step until the resistance value is reached such that the percentage of capacitor failures on any given sample of capacitors remains constant. Thereafter, all similar capacitors are tested at that resistance value and at 2.5 times the rated voltage. Those which do not explode exhibit remarkable reliability.

Aluminium Electrolytic Capacitors-An Alternative to Tantalum Electrolytic Capacitors?

Abstract: The inherent qualities, performance characteristics and limitations of solid tantalum and aluminum electrolytic capacitors are assessed. Various types of aluminum electrolytic capacitors are characterized and rated in terms of how well each type approximates the characteristics of solid-tantalum electrolytic capacitor.

Wound electrolytic capacitor and process for its production

Abstract: The invention relates to a wound electrolytic capacitor and a process for its production. The capacitor consists of wound layers of anode foils (1), provided with a dielectric oxide layer, and cathode foils (2), the foils being separated from one another by paper spacers (3), soaked in an operating electrolyte. The cathode foils (2) and/or the paper spacers (3) have transversely-running indentations. The invention is applied to electrolytic capacitors with "wet" operating electrolytes.

Solid tantalum capacitor having a riser and welded lead and production thereof

Abstract: not available for EP0039221Abstract of corresponding document: US4344107The anode riser of a solid tantalum capacitor is cleaned by means of a laser beam which removes all coatings from the riser in the area of the weld between the riser and an external lead so as to leave no conducting path from the riser to the cathode.

Tantalum capacitors prodn. - by impregnating an oxidised porous anode with manganese nitrate soln. contg. a surfactant and pyrolysing to form manganese di:oxide cathode

Abstract: In the prodn. of tantalum condensers with a solid electrolyte (made e.g. as described in FR 1091097 by forming a sintered porous tantalum anode, forming a layer of tantalum oxide on this as electrolyte, impregnating the prod. with a Mn salt and pyrolysing to form a layer of Mn02 as cathode), at least one of the last impregnations of the anode is carried out using high density manganese nitrate soln. contg. at least one surface active additve in an amt. of less than 1000 ppm. Process increases the contact surface between the Mn02 layer and subsequent graphite layers, which reduces the series resistance (ESR) by increasing the section of the negative output conductor, and improves the adhesion of subsequent metallic layers such as layers of Ag or Sn/Pb deposited on the graphite layer and thus the mechanical strength of the cathode connection.