Hermetically sealed aluminum electrolytic capacitor

Abstract

The invention discloses an air-tight seal aluminum electrolytic capacitor which comprises a capacitor body, the capacitor body comprises a cover plate, a shell and a capacitor core, the cover plate is arranged at the upper end of the shell, a sealed cavity is formed between the cover plate and the shell, the capacitor core is arranged in the sealed cavity, and the capacitor core is arranged in the sealed cavity. A leading-out end penetrates through the cover plate, an insulating ring is arranged between the leading-out end and the cover plate, the leading-out end comprises an anode leading-out end and a cathode leading-out end, the capacitor core is provided with an anode leading-out strip and a cathode leading-out strip, the anode leading-out strip is connected with the anode leading-out end, and the cathode leading-out strip is connected with the cathode leading-out end. The cathode leading-out strip is connected with the cathode leading-out end, and a heat shield is arranged above the capacitor core. According to the invention, the capacitor explosion-proof device is arranged on the metal shell, an original rubber explosion-proof device is omitted, rubber sealing is completely replaced, and the air tightness of the capacitor is improved.

Description

technical field [0001] The invention relates to the technical field of capacitors, in particular to a hermetically sealed aluminum electrolytic capacitor. Background technique [0002] At present, the existing aluminum electrolytic capacitors generally consist of an aluminum casing and a sealing rubber part to form a sealing body. A mechanical method is used between the aluminum casing and the sealing rubber part to make the casing press the sealing rubber part to form a sealed cavity, which isolates the inside and outside of the capacitor. To prevent the liquid electrolyte inside the capacitor from leaking out, and external impurities will not enter the capacitor. At the same time, in order to prevent the capacitor from exploding due to abnormal conditions, an explosion-proof device is usually installed. The explosion-proof device also uses rubber parts. [0003] Since in the prior art, the aluminum electrolytic capacitor seal is composed of an aluminum casing and a sealing...

AI Technical Summary

Problems solved by technology

[0004] 1. This sealing structure can effectively prevent the leakage of electrolyte liquid, but because the sealing rubber parts are non-airtight materials, such as the commonly used EPDM rubber, the air permeability itself is relatively high, reaching 7.9×108cm / s·MP , and the liquid electrolyte of aluminum electrolytic capacitors will generate gas during work, and at the same time, the liquid electrolyte will evaporate gas at high temperature, so the gas formed during long-term work will volatilize through the gaps between rubber molecular chains, reducing the amount of liquid electrolyte , Composition changes, resulting in a decrease in the capacitance of the capacitor and failure

[0005] 2. Due to the aging of the sealing rubber parts, the elasticity of the rubber parts decreases after working for a long time, especially at high temperature

In this way, the bonding force between the casing and the sealing rubber part decreases, resulting in a decrease in sealing performance, and the liquid electrolyte in the aluminum electrolytic capacitor leaks from the joint between the casing and the rubber part, resulting in a decrease in the capacitance of the capacitor and failure

[0006] 3. Since the explosion-proof device adopts rubber parts, there is also a risk of aging, resulting in the electrolyte leaking from the explosion-proof device and causing the capacitor to fail

[0007] Therefore, the service life of existing capacitors is generally not longer than 20 years

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