Showing papers on "Tantalum capacitor published in 2020"

Characteristics of Capacitor: Fundamental Aspects

Abstract: The capacitor is a passive electrical device, used to collect electrical energy by generating a potential difference. It is generally consisting of combination of two conductors placed next to each other separated by dielectric medium. The performance of a capacitor expressed in terms of the capacitance (C) depends on the dimension/geometry of the plate/electrode and the dielectric constant of the material, where the dielectric can be defined by insulating medium having permittivity, with no AC power losses or DC leakage. The capacitor shows different response to AC and DC sources. These are mainly used to supply power in several electronic and electrical systems. Therefore, this chapter provides the fundamental aspects of the capacitors and their basic properties. It emphasizes on the parallel plate model, the basic terminologies associated with the capacitors along with the equivalent circuits of the capacitor and its response to the externally applied AC and DC sources. It also describes about different types of capacitors that are being fabricated using different materials and different construction techniques. These different types of capacitors provide some unique properties.

Physics Based Degradation Models for Electrolytic Capacitor Prognostics under Thermal Overstress Conditions

Abstract: Electronics subsystems play an increasingly important role in safety critical systems for monitoring, control, and enhanced functionality. Electrolytic capacitors are an important component in ,amy subsystems that range from power supplies on safety critical avionics equipment to power drivers for electro-mechanical actuators. These capacitors are ideal forpassing or bypassing low-frequency signals in power supplies but are known to have lower reliability compared to ceramic and tantalum capacitors, and given their criticality in electronicssubsystems they are a good candidate for component level monitoring and prognostics. Prognostics provides a way to assess remaining useful life of components and systems based on their current state of health and their anticipated future use and operating conditions. Past experiences have shown that capacitor degradation and failures are quite prevalent under high electrical and thermal stress conditions that they experience during operations. Our focus in this work is on deriving a physics-based degradation model for electrolytic capacitors under thermal stress conditions. As part of our methodology, we study the effects of accelerated aging due to thermal stress on a batch of capacitors stored at high ambient temperature conditions. This provides a framework for supplementing theoretical modeling with data collected from simultaneous experiments, which is then used to validate the derived models. This work represents a first step toward combining data driven and physics-based approaches for modeling capacitor degradation. The case study shows how the proposed technique is applied to a batch of identically manufactured capacitors.

Chip tantalum capacitor made of water-phase electrochemical polymerized thiophene and manufacturing method thereof

Abstract: The invention provides a preparation method of a chip tantalum capacitor made of water-phase electrochemical polymerized thiophene, which comprises the steps of S1, pressing tantalum metal powder intoa square block, and sintering into a porous matrix; S2, soaking the matrix in a forming solution, and performing electrochemical treatment to form a tantalum pentoxide dielectric film; S3, dissolving3,4-ethylenedioxythiophene and iron p-toluenesulfonate, putting the dissolved 3,4-ethylenedioxythiophene and iron p-toluenesulfonate into the tantalum block forming the dielectric film, taking out the tantalum block, and heating the tantalum block to decompose the tantalum block into poly 3,4-ethylenedioxythiophene; dissolving a substance with a structure shown as a formula I defined in the description, and adding p-nitrophenol, sodium sulfonate or sodium benzenesulfonate; electroplating the tantalum block after the conductive polymer is generated to generate a structural formula shown as a formula II defined in the description; cleaning with pure water and drying; and welding tantalum wires and a lead frame on the tantalum core block on which a conductive polymer cathode layer is formed,and carrying out mould pressing, packaging and curing. The preparation method has the characteristics of high-temperature stability, rapid discharge, small size and no liquid leakage phenomenon, andthe service life can be up to 40000 hours in a working environment of 85 DEG C.

Rotary tantalum capacitor packaging robot and packaging method

Abstract: The invention discloses a rotary tantalum capacitor packaging robot and a packaging method. The device comprises a bottom plate, a fixing frame, a cam divider, an upper rotating plate, a lower rotating plate, a first welding station, a silver paste coating station, a second welding station, a longitudinal welding station and a transverse welding station, the upper rotating plate is provided with at least one lifting mechanism, and the at least one lifting mechanism is used for bearing tantalum core carriers and driving the tantalum core carriers to move up and down; the first welding station is used for welding a nickel strip and an anode tantalum core and welding a connecting lead and an anode tantalum wire; the silver paste coating station is used for coating the bonding silver paste inthe ceramic shell; the second welding station is used for welding and fixing the connecting lead and the anode leading-out end and fixing the cover plate on the ceramic shell through spot welding; thelongitudinal welding station and the transverse welding station are used for sealing welding; the tantalum capacitor packaging device can realize continuous packaging production of tantalum capacitors, is high in production efficiency, suitable for batch production, good in product consistency and compact in structure, and saves the space occupied by equipment.

Исследование электрических свойств танталовый конденсаторов циклическими поляризационными и импедансными измерениями

Abstract: The automization complex device SOLARTRON-1280C was used for measurement electrical parameters of the industrial tantalum electrolytic capacitors. It was shown that the method for detection of the defective products is applied to constant current mode and impedance measurements. The impedance measurements was used for determination of the electric capacity tantalum capacitors and how it depends on the aperiodic current frequency. In addition impedance method is able to indicates on the secondary processes that occurs in the capacitor when it works in electric circuit. The general parameters of the tantalum capacitors in direct current were determined by polarization methods.

Tantalum capacitor shell extrusion forming process and device

Abstract: The invention relates to the technical field of tantalum capacitor production and machining, and in particular relates to a tantalum capacitor shell extrusion forming process and device, which simplify the machining process and reduce waste materials so as to reduce the material cost. The process comprises the steps of A bar slicing: cutting a bar into sheets with required thickness; B coating oilon the surface of the sheet: coating lubricating oil on the surface of the sheet; and C, cold extrusion forming: carrying out cold extrusion and one-time forming on the sheet coated with the lubricating oil to acquire the needed tantalum capacitor shell. The device comprises a workbench, a hydraulic device, a rotating device and an oiling device. The hydraulic device comprises a mounting frame, ahydraulic cylinder, a mounting plate, a hydraulic rod and a male die; the rotating device comprises a rotating motor, a speed reducer, a rotating disc, a supporting column, a rotating disc bearing, afluted disc, a rotating shaft, a driving gear, a containing table and a female die; the oiling device comprises a containing frame, an oil storage bottle and a quantitative conveying device.

Screening method of high-reliability tantalum capacitor

Abstract: The invention discloses a screening method of a high-reliability tantalum capacitor. The screening method comprises the following steps that the capacitor is placed in a temperature impact box; the anode and cathode ends of the capacitor are connected with the output end of a power meter and the test end of a leakage current meter correspondingly; a certain direct current voltage is applied to thecapacitor; high and low temperature impact is performed on the capacitor through the temperature impact box when the direct current voltage is applied; a leakage current value is detected at low temperature/high temperature in the last temperature circulation process, and the capacitor exceeding a standard value is removed; and the leakage current value is detected at room temperature, and the capacitor exceeding a standard value is removed. According to the screening method of the high-reliability tantalum capacitor, the direct current voltage is applied to the capacitors under high-low temperature impact to perform high-low temperature voltage aging screening, the capacitors with poor temperature impact resistance are removed, and the capacitors with high temperature impact resistance are selected, so that the reliability of the qualified selected capacitors is ensured.

Tantalum and aluminum capacitor and preparation method thereof

Abstract: The invention discloses a tantalum and aluminum capacitor and a preparation method thereof. The tantalum and aluminum capacitor comprises an internal shell and an outer shell, the outer part of the inner shell is covered by the outer shell, and four side walls of the inner shell are respectively provided with a group of front plate and rear plate which are symmetrical to each other. A limiting rodpenetrating through the front plate and the rear plate is arranged on the inner wall of the outer shell, the outer part of the outer shell is also coated with epoxy resin, and a middle plate connected with the outer shell is fixed to the outer wall, located between the front plate and the rear plate, of the limiting rod. According to the present invention, springs sleeving the limiting rods are connected between the middle plate and the front plate and between the middle plate and the rear plate; the inner shell and the outer shell can be connected in an elastic connection mode through the springs additionally arranged on the tantalum capacitor; with the absorption effect between the springs, the vibration kinetic energy is absorbed; a conduction polymer based on bisamide bond hydrogen bond enhancement is added into an aluminum capacitor and covers the surface of an oxide film, the hydrogen bonds can be damaged and recombined in the heating and cooling process, and the mechanical property and the electrical property of the capacitor are recovered, so that the safety of the capacitor is improved, and the service life of the capacitor is prolonged.

Composite wire for anode lead of tantalum capacitor and preparation method thereof

Abstract: The invention discloses a composite wire for an anode lead of a tantalum capacitor and a preparation method thereof. The composite wire for the anode lead of the tantalum capacitor comprises: a core body which is made of other metal, tantalum alloy or other metal alloy except pure tantalum; and a tantalum metal layer which is coated on the outer surface of the core body. The technical scheme of the invention is applied, the composite wire for the anode lead of the tantalum capacitor comprises a core body made of other metal or alloy except pure tantalum and a tantalum metal layer coated on theouter surface of the core body, so that the characteristic that the tantalum metal on the surface layer can form an oxide film with high dielectric constant and high reliability on the surface of thetantalum metal through anodic oxidation is fully utilized, and the core part of the tantalum metal is filled with cheap metal or alloy, so that the requirement of the tantalum capacitor on the high dielectric constant of the anode lead is met, and meanwhile, the cost is greatly reduced.

Solid tantalum capacitor and manufacturing process thereof

Abstract: The invention discloses a solid tantalum capacitor and a manufacturing process thereof. The tantalum capacitor comprises a tantalum capacitor body. The tantalum capacitor body comprises tantalum cores, an anode lead-out plate, a cathode lead, a metal shell and a glass powder insulator. The plurality of tantalum cores are sequentially fixed in the metal shell through tin solder or conductive silverpaste; the metal shell is packaged through the glass powder insulator; the anode lead-out plate is arranged in the metal shell and is positioned between the glass powder insulator and the tantalum cores; an anode wire of the anode lead-out plate penetrates out of the glass powder insulator to serve as an anode lead of the capacitor; the cathode lead is inserted into the metal shell and welded tothe glass powder insulator and the metal shell; the tantalum core is a porous substrate formed by sintering a cuboid formed by pressing high-specific-volume tantalum powders under high-temperature vacuum; the tantalum core is covered with a conductive polymer layer in an electroplating, coating or dipping mode; and the tantalum core has sawtooth-shaped side faces which are distributed in a convex-concave alternating mode. According to the invention, the capacitor provides large capacitance, and meanwhile, the ESR value of the capacitor is greatly reduced; and the use reliability of the capacitor is higher.

Tantalum capacitor anode and enabling process thereof, tantalum capacitor and preparation method thereof

Abstract: The invention provides a tantalum capacitor anode and an enabling process thereof, a tantalum capacitor and a preparation method thereof. The enabling process comprises the steps of acid pickling, forming, heat treatment and complementary forming. According to the enabling process, impurities, especially metal impurities, in the sintered tantalum core are removed through acid pickling, and by optimizing the conditions of current density, boosting time, liquid forming temperature, heat treatment temperature and the like, a more uniform and compact dielectric oxide film is obtained, so that theprobability of short-circuit breakdown when a conducting polymer chip tantalum capacitor is electrified for the first time after high-temperature welding is reduced, and the welding heat resistance ofthe dielectric oxide film of the conducting polymer chip tantalum capacitor is improved.

Tantalum core coating method, tantalum core, tantalum capacitor comprising tantalum core and application

Abstract: The invention provides a tantalum core coating method, a tantalum core, a tantalum capacitor comprising the tantalum core and an application, and relates to the technical field of capacitor preparation. The coating method comprises the following steps: a tantalum core is dipped into a manganous nitrate solution, and then thermal decomposition is performed on the tantalum core dipped with the manganous nitrate solution, so that manganous nitrate is thermally decomposed into manganese dioxide, and coating is completed. According to the coating method, a manganese dioxide layer can be formed on the outer layer of the tantalum core, so that a tantalum pentoxide dielectric layer of the tantalum core is protected, and the reliability of the tantalum capacitor is improved.

Preparation method of high-voltage ultra-small-capacity non-solid electrolyte tantalum electrolytic capacitor

Abstract: The invention belongs to the technical field of tantalum capacitor preparation and particularly relates to a preparation method of a high-voltage ultra-small-capacity non-solid electrolyte tantalum electrolytic capacitor. The method is characterized in that pressing density is improved, a molding mode is changed, the increasing sintering temperature and sintering time are increased, so the strength of a tantalum core is enhanced, tantalum cores are not easy to fall off and have unfilled corners, impurities in tantalum powder are effectively removed, a tantalum core with excellent electrical performance is obtained through an improved forming method, aging process treatment is combined, so the voltage of the prepared non-solid electrolyte tantalum capacitor can reach 180V, the capacitance can reach 0.047 mu F, and the non-solid electrolyte tantalum capacitor has the characteristics of high voltage and ultra-small capacitance.

Thermodynamic Analysis and Assembly Optimization of Large-Scale Solid Electrolyte Tantalum Capacitor welded on the LTCC substrate

Abstract: LTCC multilayer substrate (LTCC, Low Temperature Co-fired Ceramic) is one of the most widely used substrate in the high performance MCM (MCM, multi-chip module). Many kinds of passive elements and active devices can be integrated on the surface of the substrate. As one kind of the passive element, solid tantalum electrolytic capacitor has many advantages such as the bigger capacity per unit volume and the lower resistivity impedance, which are benefit for the emission performance of the MCM modules. In this paper, two kinds of process are used for the assembly of large-scale solid tantalum electrolytic capacitor surface mounted on the LTCC multilayer substrate. Verified experiments are carried out on the basis of soldering and experimental process analysis. A new soldering method is creatively proposed to solve the reliable problem of the soldering of solid tantalum electrolytic capacitors on the LTCC substrate. After environment tests, the resistance between tantalum capacitor lead and soldering pad is less than 100 milliohm, the shear strength of tantalum capacitor joint is larger than 50N. And this method is successfully applied in the existing products.

Anode tantalum block, preparation method and application thereof, non-solid tantalum electrolytic capacitor and electronic product

Abstract: The invention relates to the field of capacitors, and particularly provides an anode tantalum block, a preparation method and application thereof, a non-solid tantalum electrolytic capacitor and an electronic product. The anode tantalum block comprises a tantalum core and a tantalum wire fixedly connected with the tantalum core, a groove is formed in the surface of the tantalum core, the tantalumwire comprises a spiral end or a spiral-like end, and the spiral end or the spiral-like end is arranged in the groove. The anode tantalum block is low in electric leakage rate during vibration, can effectively reduce the failure rate of the capacitor after vibration, improves the percent of pass of the capacitor after vibration, and further improves the reliability of products.