Ultra-low impedance aluminum electrolytic capacitor for switching power supply

Abstract

The invention discloses an ultra-low impedance aluminum electrolytic capacitor for a switching power supply. The ultra-low impedance aluminum electrolytic capacitor comprises a shell with an opening,a core arranged in the shell and a rubber plug connected with the opening of the shell in a sealed mode. The core is soaked with an electrolyte, the electrolyte comprises the following components in percentage by weight of 5%-25% of solute, 1%-10% of additive and the balance of solvent, wherein the solute is ethylene glycol ammonium, ammonium formate, ammonium maleate and o-benzoic acid, the additive is a passivator, ammonium dihydrogen phosphate and nitrobenzoic acid, and the solvent is ethylene glycol, gamma-butyrolactone, glycerol and water. In the present invention, by developing the high-performance electrolyte, selecting the proper electrode foil and controlling sealing, the prepared aluminum electrolytic capacitor is low in impedance, can bear larger ripple current, and can meet therequirements of miniaturization, large capacity, ripple current resistance, high-frequency low impedance, high temperature, long service life and better adaptability to high-density assembly of an existing switching power supply.

Description

technical field [0001] The invention relates to the technical field of aluminum electrolytic capacitors, in particular to an ultra-low impedance aluminum electrolytic capacitor for switching power supplies. Background technique [0002] Switching power supply is the main category of electronic power supply products. Because of its wide input voltage range, small size, light weight, high power conversion efficiency, and low standby power consumption, it has developed rapidly and gradually replaced linear power supplies. Frequency power supply, used in almost all electronic equipment such as various intelligent electronic terminal equipment and communication equipment, is an indispensable device in the rapid development of today's electronic information industry. As switching power supplies gradually become more high-frequency, thinner, and smaller, the proportion of thin switching power supplies in the entire power supply industry will increase. [0003] As an aluminum elect...

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Problems solved by technology

[0004] However, the inventors of the present application found in the process of implementing the embodiments of the present application that: for electrolytic capacitors for switching regulated power supplies with high power and high current output, due to the defects in the current design, the core of the capacitor heats up severely, and the high temperature makes the oxidized The dielectric properties of the film decrease. For aluminum electrolytic capacitors with defects in the original dielectric oxide film and large leakage current and loss tangent, high temperature further deteriorates the dielectric properties of the oxide film, which increases the leakage current and loss tangent of the capacitor. The value increases, causing the capacitor core to heat up further, so that the cycle continues, and the capacitor will eventually be burned

The existing aluminum electrolytic capacitors cannot meet the miniaturization, large capacity, ripple current resistance, high frequency and low impedance, high temperature and long life of the current switching power supply, and are more suitable for high-density assembly