Showing papers on "Tantalum capacitor published in 1988"

Electrolytic capacitor and method of preparing it

Abstract: The present invention is an electrolytic capacitor comprising a titanium-deposited aluminum foil used as the cathode. An aluminum foil is subjected to vacuum deposition of titanium with a deposition angle, thereby obtaining an electrolytic capacitor having a larger electrostatic capacitance than the conventional.

Semiconductor capacitor device with dual dielectric

Abstract: A semiconductor device having a large-capacitance capacitor in which an insulator film is formed underneath a film made of a material having a high dielectric constant, such as tantalum oxide, in such a manner that a portion of the insulator film underneath a defect region which is undesirably thin is thicker than other portions of the insulator film, thereby preventing occurrence of a failure in terms of dielectric strength and deterioration of the lifetime of the capacitor which would otherwise be caused by the existence of the defect region. Also disclosed is a process for producing such semiconductor device. Thus, it is possible to effectively prevent occurrence of problems which would otherwise be caused when a material having a high dielectric constant, such as tantalum oxide, is employed as a dielectric film of a capacitor, so that the reliability of a semiconductor having a large-capacitance capacitor is greatly improved.

Aluminum solid electrolytic capacitor and manufacturing method thereof

Abstract: An aluminum foil type solid electrolytic capacitor wherein the distance between the two foils (1,2) in the capacitor element (10) to be determined by the thickness of separator (3) being kept at a value between ten to sixty micrometers, solid electrolyte being formed between the two foils (1,2) by the thermal decomposition of electrolytic solution impregnated in the capacitor element (10). Manufacturing methods of an aluminum foil type solid electrolytic capacitor with a manganese dioxide electrolytic layer (9) between the electrode foils (1, 2), wherein the layer is formed by decomposing the electrolytic solution (8) thermally under conditions of a temperature between 200 and 260 °C and of a time interval between 20 and 40 minutes, wherein the layer (9) is formed by decomposing electrolytic solution (8) with fine powders of manganese dioxide, wherein lithium is doped in the layer or wherein electrochemical conversion processes are used for restoring an aluminum oxide film. Manufacturing methods of a chip type aluminum solid electrolytic capacitor (20), wherein a capacitor element (40, 60, 70) is fixed in a case (21, 41, 63, 73) with resin (42, 64) around the center of the case or wherein one lead (61, 71) of a capacitor (60, 70) element is connected electrically to a metallic case (21, 41, 63, 73) into which the capacitor (60, 70) element is inserted.

Electrical capacitor having improved dielectric system

Abstract: An electrical capacitor (10) having an improved dielectric system. The capacitor includes layers of metal foil (15, 16) and dielectric sheet material (17) which is impregnated with a liquid dielectric composed of a mixture of phenyl xylyl ethane and phenyl tolyl methanes.

High performance sputtered/anodized tantalum oxide capacitors

Abstract: High-performance films (400-1600 AA) were formed by anodizing sputtered tantalum oxide films The electrical properties of these two-step oxidized and sputtered/anodized films are compared with those of films prepared by anodization of sputtering only The sputtered/anodized tantalum oxide capacitors have lower dissipation factors, higher breakdown fields, narrower breakdown distributions, and lower leakage currents The sputtered/anodized tantalum oxide films have shown to be useful for high-charge-storage capacitor applications >

Method for producing an electrolytic capacitor

Abstract: In an electrolytic capacitor, the present invention uses a titanium vacuum deposition aluminum foil as a cathode. The present invention obtains an electrolytic capacitor having a greater electrostatic capacity than conventional capacitors by vacuum depositing titanium onto an aluminum foil substrate with a vacuum deposition angle.

Semiconductor memory device with improved capacitor structure

Abstract: A semiconductor device provided with capacitors which have accurate and reliable capacitance ratio, is disclosed. The semiconductor device comprises first and second capacitors. The first and second capacitors have substantially the same physical configuration but they have different dielectric layers of different values of dielectric constant. Thus, a capacitance ratio of the first capacitor to the second capacitor is determined in accordance with the dielectric constant ratio of the dielectric layers thereof.

Method of fabricating tantalum electrolytic capacitors

Abstract: A description is given of a method of fabricating tantalum electrolytic capacitors having an anode comprising tantalum sintered bodies and a manganese dioxide solid electrolyte, by impregnating the tantalum sintered body with an aqueous manganese nitrate solution and pyrolytically decomposing the latter. The method is characterised in that an organic acid selected from the group comprising carboxylic acids and hydroxycarboxylic acids is added to the aqueous manganese nitrate solution. As a result, it is possible to increase the coverage of the internal surface of the tantalum sintered body and thereby improve the electrical characteristics of the tantalum electrolytic capacitor.

Small Y5V chip-capacitors with very large capacitance

Abstract: A multilayer ceramic capacitor with high specific capacitance was fabricated using 15- mu -thick green sheets. The composition of the dielectric material used was Pb(Mg/sub 1/3/Nb/sub 2/3/)/sub 0.2/(Ni/sub 1/3/ Nb/sub 2/3/)/sub 0.6/Ti/sub 0.2/O/sub 3/ ( epsilon =20000 at 20 degrees C). The single-layer thickness of the dielectric material was 11 mu m after sintering. This capacitor has 50% of the volume of a tantalum electrolytic capacitor with the same capacitance. The temperature variation of the capacitance meets Y5V specifications. The frequency-dependences of the capacitance, dissipation factor, and impedance were better than those of the tantalum electrolytic capacitor. In accelerated load-life tests (125 degrees C, 50 V) and the load-humidity tests (85 degrees C, 90 to 95% RH, 25 V), no degradation of the insulation resistance was found during 1000 hours of testing. A multilayer ceramic capacitor with 10- mu F capacitance was also fabricated using 10- mu m-thickness green sheets. The dimensions of the capacitor were (3.2*2.5*1.5) mm/sup 3/ and the (postsintering) single-layer thickness of the dielectric ceramic was 6 mu m. >

Electrolytic capacitor and production method thereof

Abstract: In an electrolytic capacitor, the present invention uses a titanium vacuum deposition aluminum foil as a cathode. The present invention obtains an electrolytic capacitor having a greater electrostatic capacity than conventional capacitors by vacuum depositing titanium onto an aluminum foil substrate with a vacuum deposition angle.

Effects of heat‐treatment on dielectric properties of anodized Al‐Ta double oxide layer thin‐film capacitors

Abstract: The effect of the heat-treatment on the dielectric properties of capacitors with the structures of Al-Ta2O5-Al2O3-Al and Al-Al2O3-Ta2O5-Ta were investigated. The Ta and Al films were deposited by sputtering in the Ar-N2 gas mixture (2.5% N2 in volume) and Ar gas, respectively. The layers of Ta and Al were anodized to form Ta2O5 and Al2O3. As the treatment temperature is increased up to 200°C, the improvements on tan δ and TCC were observed. However, when the capacitors were treated at 300°C, the loss characteristic of the Al-Ta2O5-Al2O3 type capacitor degraded. However, the Al-Al2O3-Ta2O5- type capacitor did not show any degradation and tan δ decreased to 0.0023. To discuss the difference in the losses between the two capacitors, the devices were investigated by Auger analysis. The loss degradation in the Al-Ta2O5-Al2O3-Al type capacitor was related to the nonstoichiometric interface layer between the aluminum oxide and the base metal layers, while the decrease of the loss in the Al-Al2O3-Ta2O5-Ta type capacitor was due to both the recovery of the stoichiometry in the interface between the tantalum oxide and the base metal and the decrease of the metallic aluminum atoms in the aluminum oxide which degraded the stoichiometry of the aluminum oxide layer.

A survey of internal fuses for solid tantalum capacitors

Abstract: Reasons for fusing solid tantalum capacitors are discussed, stressing that they are only required where there is a low series impedance and a high current availability and where a failed capacitor can overheat due to the fault power dissipation The two main types of fuses which can be used, ie electrically or thermally actuated, are examined The main advantage of an electrical version is more rapid operation while the advantage of a thermal fuse is lower resistance As a rough guide the electrical fuse should operate when the fault current reaches 1 amp after 1 second but should survive the initial charging current, which can be tens or hundreds of amps for a very short period The thermal fuse should prevent the body temperature from exceeding 300 degrees C >

Self-healing electric capacitor

Abstract: A self-healing electric capacitor having a dielectric composed of plastic strips and a solid encapsulation compound between winding and capacitor can is proposed in which, if the dielectric is damaged, the overpressure gases produced in the process are conducted into a capture volume, which enables the capacitor to be switched off, by fusible particles which are embedded in the encapsulation compound. The particles have a dropping or melting point in the range from 10 K to 90 K above the maximum temperature of the capacitor.