Showing papers on "Tantalum capacitor published in 2002"

Use of KCl Aqueous Electrolyte for 2 V Manganese Oxide/Activated Carbon Hybrid Capacitor

Abstract: This study reports a hybrid capacitor in neutral KCI aqueous electrolyte, which consists of amorphous manganese oxide (a-MnO 2 .nH 2 O) as a cathode and activated carbon as an anode. The electrochemical performance of the hybrid capacitor is characterized by cyclic voltammetry and a dc charge/discharge test. The hybrid capacitor shows ideal capacitor behavior with an extended operating voltage of 2 V. The extended operating voltage is preferentially attributed to having asymmetric electrodes with different stable voltage windows and good electrochemical stability in neutral KCl aqueous electrolyte. According to the extended operating voltage, the energy density of the hybrid capacitor at a current density of 0.25 A/g, was found to be 28.8 Wh/kg which is comparable to that of an amorphous ruthenium oxide capacitor (26.7 Wh/kg). The hybrid capacitor also shows no degradation of capacitance during 100 cycles except an initial loss of 7% within a few cycles.

Realization of a smart electrolytic capacitor circuit

Abstract: The object of this paper is to present an economic electronic module integrated on an electrolytic capacitor that is able to indicate the moment when it must be changed. First, with a switchmode power supply as an example, the high probability of electrolytic capacitor failure with respect to other power components is noted. Second, the authors recall that the increase of the equivalent series resistance (ESR) of the capacitor is the best indicator of their faulty state. From the measurements of the voltage ripple and the capacitor current, one can deduce the ESR; the latter is compared to the ESR value of the sound capacitor deduced from the component case temperature. Thus, the capacitor deterioration can be diagnosed.

Tunable thin film capacitor

Abstract: It is an object of the invention to provide a variable capacitor constituted such that, even when an external control voltage is applied, a stable dielectric constant of the dielectric layer can be obtained. A variable capacitor constituted such that a dielectric layer whose dielectric constant is changed by the application of an external voltage is held between an upper electrode layer and a lower electrode layer, wherein a plurality of capacitance-producing regions a, b are connected to each other.

Dielectric laminate for a capacitor

Abstract: A dielectric composed of a core material between two polymer layers that have permittivity values less than the core material. The polymer layers provide structural integrity for the dielectric. The dielectric can be employed in a capacitor to fine tune the capacitance of the capacitor. The dielectric and the capacitor may have a thickness in the micron range. Accordingly, the dielectric and capacitor provide for the miniaturization of electronic devices. The dielectric may be employed in decoupling capacitors to reduce noise in electronic devices.

Monolithic ceramic capacitor with barium titinate dielectric curie point optimized for active implantable medical devices operating at 37° C.

Abstract: A feedthrough filter capacitor assembly for use in active implantable medical devices and a related process for manufacturing a monolithic ceramic capacitor utilizing dielectric materials having a dielectric constant greater than 7000, and preferably in the range of 8500 to 22,000. In the manufacture of the monolithic ceramic capacitor, one or more Curie point shifters and/or other dopants are added to the dielectric material to optimize the dielectric constant at the human body temperature of 37° C. For manufacturing purposes, dopants may be added to the dielectric material to broaden the Curie point peak or point of maximum dielectric constant thereof. The effect is that when such capacitors and terminal assemblies are utilized in a high-voltage defibrillator circuit of an implantable medical device, the dielectric material is optimized so that during the delivery of high-voltage electrical energy, capacitance value of the capacitor drops substantially.

Solid electrolytic capacitor and its manufacturing method

Abstract: A solid electrolytic capacitor of the present invention has a structure where respective anode sections of capacitor elements are joined to an anode lead frame by resistance welding via a through hole formed in the anode lead frame Current thus collects to the through hole during the welding to break a dielectric oxide film layer to expose aluminum foil, and the molten aluminum collects into the through hole Stable welding work is therefore allowed without splashing the aluminum, and a solid electrolytic capacitor having high welding strength, high reliability, and reduced ESR can be obtained

Capacitor and method for fabricating the same

Abstract: A capacitor which includes a lower electrode 12 formed on a substrate 10 ; an insulation film 16 having an opening 24 on the lower electrode 12 ; a capacitor dielectric film 30 formed on the lower electrode 12 in the opening 24 and having a larger thickness at a peripheral part of the opening 24 than at a central part of the opening; and an upper electrode 32 formed on the capacitor dielectric film 30 . Thus, degradation of the breakdown voltage and stress resistance of the peripheral part of the opening 24 , which is due to the coverage of the capacitor dielectric film, can be suppressed.

Rhodium-rich oxygen barriers

Abstract: Structures and methods are disclosed for forming capacitors for integrated circuits. The capacitor includes a rhodium-rich structure (24), a rhodium oxide layer (26) in direct contact with the rhodium-rich structure (24), a capacitor dielectric (30) in direct contact with the rhodium oxide layer (26) and a top electrode (40) over the capacitor. The rhodium-rich structure (24) can include rhodium alloys and the capacitor dielectric (30) preferably has a high dielectric constant.

Dielectric filter, antenna duplexer

Abstract: A dielectric filter includes resonator electrodes, an inter-stage coupling capacitor electrode, and an input/output coupling capacitor electrode on dielectric substrates, respectively. The resonator electrodes are electro-magnetically coupled to each other to form a tri-plate structure, are made of a metallic foil embedded in a resonator dielectric substrate. Another dielectric filter includes an upper shield electrode dielectric substrate, an inter-stage coupling capacitor dielectric substrate, a resonator dielectric substrate, and an input/output coupling capacitor dielectric substrate which are made of a composite dielectric material including a high-dielectric-constant material and a low-dielectric-constant material. The above described arrangement provides the dielectric filter with an improved Q factor of a resonator, a low loss, and a high attenuation.

Improved Spice models of aluminum electrolytic capacitors for inverter applications

Abstract: Impedance modeling of aluminum electrolytic capacitors presents a challenge to design engineers, due to the complex nature of the capacitor construction Unlike an electrostatic capacitor, an electrolytic capacitor behaves like a lossy coaxial distributed RC circuit element whose series and distributed resistances are strong functions of temperature and frequency This behavior gives rise to values of capacitance, ESR (effective series resistance), and impedance that vary by several orders of magnitude over the typical frequency and temperature range of power inverter applications Existing public-domain Spice models do not accurately account for this behavior In this paper, a physics-based approach is used to develop an improved impedance model that is interpreted both in pure Spice circuit models and in math functions

Capacitor, circuit board with built-in capacitor and method for producing the same

Abstract: A capacitor is formed between a lower wiring layer and an upper wiring layer in an interior of a circuit board. The capacitor is formed of a lower metallic layer which is of at least one valve metal selected from the group consisting of aluminum, tantalum, niobium, tungsten, vanadium, bismuth, titanium, zirconium and hafnium, a dielectric layer which is of an oxide of the valve metal which may be the same as or different from the valve metal of the lower metallic layer, an intermediate layer which is of a solid electrolyte, and an upper metallic layer which is of an electrode metal, laminated in this order.

High voltage, high temperature capacitor structures and methods of fabricating same

Abstract: Capacitors and interconnection structures for silicon carbide are provided having an oxide layer, a layer of dielectric material and a second oxide layer on the layer of dielectric material. The thickness of the oxide layers may be from about 0.5 to about 33 percent of the thickness of the oxide layers and the layer of dielectric material. Capacitors and interconnection structures for silicon carbide having silicon oxynitride layer as a dielectric structure are also provided. Such a dielectric structure may be between metal layers to provide a metal-insulator-metal capacitor or may be used as a inter-metal dielectric of an interconnect structure so as to provide devices and structures having improved mean time to failure. Methods of fabricating such capacitors and structures are also provided.

Capacitor unit with electric double layer capacitors, control method and control apparatus for the same, and accumulator system for motor vehicles

Abstract: A capacitor unit with plural double layer capacitors eliminating irregularity in a state of charge of the respective double layer capacitor in the capacitor unit. A capacitor unit, a capacitor unit control method, a capacitor unit control apparatus and a vehicle charging system, wherein a chargeable and dischargeable capacitor unit 1 with plural electronic double layer capacitors 11 connected in series is characterized in that electric double layer capacitors 11 in a higher state of charge is subject to discharge so that a state of charging of the respective electric double layer capacitor 11 may become approximately equal to each other.

Damascene integration scheme for developing metal-insulator-metal capacitors

Abstract: The invention is directed to unique high-surface area BEOL capacitor structures with high-k dielectric layers and methods for fabricating the same. These high-surface area BEOL capacitor structures may be used in analog and mixed signal applications. The capacitor is formed within a trench with pedestals within the trench to provide additional surface area. The top and bottom electrodes are created using damascene integration scheme. The dielectric layer is created as a multilayer dielectric film comprising for instance Al2O3, Al2O3/Ta2O5, Al2O3/Ta2O5/Al2O3 and the like. The dielectric layer may be deposited by methods like atomic layer deposition or chemical vapor deposition. The dielectric layer used in the capacitor may also be produced by anodic oxidation of a metallic precursor to yield a high dielectric constant oxide layer.

Tunable capacitors using fluid dielectrics

Abstract: Capacitors (10,20,40,50,70,80) having a fluid dielectric material that is transported or undergoes a phase change are disclosed. The dielectric medium change results in a change in the total dielectric constant of the material between the electrodes (12, 14, 72, 74, 81, 82), thus changing the capacitance of the capacitors. Transporting or phase changing the dielectric fluids into and out of a the electric field of the capacitor, changes the effective dielectric constant and the capacitance of the capacitor.

Simulation and dielectric characterization of reactive dc magnetron cosputtered (Ta2O5)1−x(TiO2)x thin films

Abstract: New capacitor material with high dielectric constant is needed for future integrated capacitor structures. Tantalum pentoxide (Ta2O5) is considered as one of the most promising candidates. In this article, thin films of (Ta2O5)1−x(TiO2)x were grown utilizing reactive dc magnetron cosputtering of tantalum and titanium in an argon/oxygen atmosphere. By varying the input power at the targets, the composition of the thin film is easily controlled. The composition of the films was analyzed with elastic recoil detection analysis revealing the titanium oxide content (x ranging from 0 to 0.40). The presented results indicate that reactive sputter deposited tantalum pentoxide, with or without the addition of titanium, exhibits the properties required to meet the demands for future dielectric materials in integrated capacitors. The dielectric constant for metal-insulator-semiconductor structures is about 20 and the leakage current density is below 10 nA/cm2 at 0.5 MV/cm, if the annealing temperature does not exceed...

Semiconductor high dielectric constant decoupling capacitor structures and process for fabrication

Abstract: Apparatus and method for providing high dielectric constant decoupling capacitors for semiconductor structures. The high dielectric constant decoupling capacitor can be fabricated by depositing high dielectric constant material between adjacent conductors on the same level, between conductors in successive levels, or both, to thereby provide very large capacitance value without any area or reliability penalty.

Integrated semiconductor product comprising a metal-insulator-metal capacitor

Abstract: According to the invention, in order to produce an integrated semiconductor product comprising integrated metal-insulator-metal capacitors, a dielectric protective layer (5) and a dielectric auxiliary layer (16) are first deposited on a first electrode (2). Said protective layer and said auxiliary layer (16) are then removed (17) from the region above the first electrode, and a dielectric layer (6) is produced, the pile of metallic strips (7, 8, 9) for the second electrode being applied to said dielectric layer. The metal-insulator-metal capacitor is then structured according to known etching methods. Dielectric capacitor layers consisting of freely selectable materials and having any thickness can be formed in this way. The present invention is especially advantageous in that it enables via holes to be etched in a significantly more simple manner than according to prior art, as the remaining dielectric capacitor layer covering the metallic strips does not need to be etched through.

Electrode for electrolytic capacitor, electrolytic capacitor, and manufacturing method therefor

Abstract: An electrode for electrolytic capacitors having a large capacitance and having excellent tan δ, heat resistance, humidity resistance and stability. An electrolytic capacitor using the electrode. An electrode obtained by attaching a compound having a siloxane bond onto the surface of an electrode body comprising a valve-acting metal having formed thereon a dielectric film. The compound having a siloxane bond is attached by coating, dipping or vapor deposition. A solid electrolytic capacitor obtained by forming an electrolyte comprising an electrically conducting polymer on the electrode.

Methods of forming a capacitor with substantially selective deposite of polysilicon on a substantially crystalline capacitor dielectric layer

Abstract: A method of forming a capacitor includes forming a first capacitor electrode over a substrate. A substantially crystalline capacitor dielectric layer is formed over the first capacitor electrode. The substrate with substantially crystalline capacitor dielectric layer is provided within a chemical vapor deposition reactor. A gaseous precursor comprising silicon is fed to the chemical vapor deposition reactor under conditions effective to substantially selectively deposit polysilicon on the substantially crystalline capacitor dielectric region, and the polysilicon is formed into a second capacitor electrode.

Microelectronic fabrication having sidewall passivated microelectronic capacitor structure fabricated therein

Abstract: Within a method for fabricating a microelectronic fabrication, and the microelectronic fabrication fabricated employing the method, there is formed within the microelectronic fabrication a capacitor structure which comprises a first capacitor plate layer having formed thereupon a capacitor dielectric layer in turn having formed thereupon a second capacitor plate layer, wherein each of the foregoing layers having an exposed sidewall to thus form a series of exposed sidewalls. The capacitor structure also comprises a silicon oxide dielectric layer formed passivating the series of exposed sidewalls of the first capacitor plate layer, the capacitor dielectric layer and the second capacitor plate layer a silicon oxide dielectric layer.

Solid electrolytic capacitor, and method for preparing the same

Abstract: A solid electrolytic capacitor is disclosed which combines low LC with Low ESR and which has good characteristics even in a high frequency range, and a method for preparing the same is also disclosed. In the solid electrolytic capacitor whose electrolytic layer contains electrically conductive particles, non-conductive particles are present in at least a part of an interface between a dielectric layer and the electrolyte layer. By employing the structure, local intensifications of field strength in the dielectric layer are prevented to enable a problem of increase in LC to be overcome while keeping ESR low. By the method which comprised a step of applying a colloidal dispersion containing the non-conductive particles in the form of colloidal particles to the post-electrolytic layer formation step product, the solid electrolytic capacitor having the above-mentioned structure can be prepared efficiently.

Anode member for a solid electrolytic capacitor, an electrolytic capacitor using the same, and a method of making the same

Abstract: The anode member for a solid electrolytic capacitor according to the present invention comprises an anode body made of a valve metal foil having a purity of not less than 99 wt %, and an anode layer formed on the anode body and made of a sintered body of a valve metal powder. By limiting the amount of impurity contained in the valve metal foil to an amount of not more than 1 wt %, impurities in a dielectric oxide film formed by anodic oxidation, namely defects in the dielectric oxide film can be suppressed, so that the resultant solid electrolytic capacitor can have its leakage current lowered with its ESR (equivalent series resistance) being kept low, and that the electrolytic capacitor can be made to have a smaller size and a higher capacitance. The present invention also provides an electrolytic capacitor having a low leakage current, a low ESR, a small size and a high capacitance by using the above novel anode member as well as a method of making the same.

Method for forming a tantalum oxide capacitor

Abstract: A method for forming capacitor using a tantalum oxide (TaO5) layer is disclosed. Tantalum oxide is deposited by an atomic layer deposition ALD process so that the step-coverage of the tantalum oxide layer is improved, and accordingly the electrical characteristics of the capacitor are improved.

Storage capacitor structure

Abstract: A storage capacitor structure comprising a first capacitor electrode on a substrate, a capacitor dielectric layer on the first capacitor electrode and a second capacitor electrode on the capacitor dielectric layer, a passivation layer on the second capacitor electrode and a pixel electrode layer on the passivation layer. The second capacitor electrode has an area smaller than the first capacitor electrode. The passivation layer has an opening that exposes a portion of the second capacitor electrode. The pixel electrode layer and the second capacitor electrode are electrically connected through the opening in the passivation layer.

Depolarizers for hybrid capacitors

Abstract: The present invention is directed to a water based electrolyte used in a hybrid-type capacitor. The hybrid-type capacitor has an electrolytic anode and an electrochemical cathode. The difference resides in the electrolyte for this type of capacitor. The electrolyte has water, a water soluble inorganic and/or organic acid and/or salt, and a water soluble nitro-aromatic compound. Such a hybrid capacitor (1) improves energy density by significantly reducing volume of the separator and cathod material often used in conventional electrolytic capacitors and (2) has an electrochemical cathode that undergoes an electrochemical reduction without generating gassing. For example, ruthenium oxide, RuO2, is reduced to ruthenium hydroxide, Ru(OH)2, when passing a cathodic current. However, the present invention discovered that without the present electrolyte, the RuO2 cathode does generate gassing if it is sufficiently depleted. The gassing degrades capacitor performance and even casuse failure, which is decreased with the present electrolyte solution.

Method for producing aluminum foil for capacitor and solid electrolytic capacitor

Abstract: A method for producing an aluminum foil for solid electrolytic capacitors, comprising the steps of cutting an aluminum foil into a shape of a capacitor element, etching a cut end part formed by said cutting, and then electrochemically forming the etched aluminum foil, aluminum foil for solid electrolytic capacitors obtained by the method, solid electrolytic capacitor using the aluminum foil, and method for producing such a solid electrolytic capacitor are disclosed. By use of the aluminum foil for solid electrolytic capacitors according to the present invention, capacitor characteristics such as an increase in the capacitor capacitance and a decrease in the leakage current from the cut end part of a stacked type aluminum solid electrolytic capacitor can be efficiently improved, the anode moieties can be efficiently connected without fail on stacking elements and the productivity of stacked type aluminum solid electrolytic capacitor can be elevated.