CN215834419U

CN215834419U - Aluminum electrolytic capacitor

Info

Publication number: CN215834419U
Application number: CN202122034576.8U
Authority: CN
Inventors: 张凤; 林明杰
Original assignee: Xiamen Yankon Energetic Lighting Co Ltd
Current assignee: Xiamen Yankon Energetic Lighting Co Ltd
Priority date: 2021-08-26
Filing date: 2021-08-26
Publication date: 2022-02-15
Anticipated expiration: 2031-08-26

Abstract

The utility model relates to the technical field of capacitors, in particular to an aluminum electrolytic capacitor. The utility model discloses an aluminum electrolytic capacitor, which comprises a shell, electrolyte and a capacitor core, wherein the capacitor core is hermetically arranged in the shell, the electrolyte is filled between the capacitor core and the shell, the shell is an aluminum shell, an aluminum oxide film is formed on the inner surface of the shell, and the shell is electrically connected with a positive electrode pin. The aluminum electrolytic capacitor has larger capacitance value and higher ripple current resistance under the same volume, and the aluminum electrolytic capacitor cannot be exploded due to the current formed in the electrolysis when the shell is in short circuit with an external circuit.

Description

Aluminum electrolytic capacitor

Technical Field

The utility model belongs to the technical field of capacitors, and particularly relates to an aluminum electrolytic capacitor.

Background

The capacitor has the characteristics of alternating current and direct current resistance, is an indispensable component of an electronic product, and is applied more and more along with rapid development and popularization of various electric products, and the demand is larger and larger. The aluminum electrolytic capacitor is one of the capacitors, and is widely used due to its advantages of large capacity, low price, etc.

The volume (size) of the aluminum electrolytic capacitor is an important factor for restricting the performance of the aluminum electrolytic capacitor, and the smaller the volume of the aluminum electrolytic capacitor is, the smaller the capacitance value and the ripple current resistance of the aluminum electrolytic capacitor are. However, the driving circuit is designed to be more and more miniaturized, and the aluminum electrolytic capacitor is required to have a smaller volume and a larger capacity, and the existing aluminum electrolytic capacitor cannot meet the requirement. In addition, when the shell of the existing aluminum electrolytic capacitor is connected with a high-voltage circuit, the shell belongs to a negative electrode, so that large current flows into electrolyte from the shell and flows out from a negative electrode pin, and the aluminum electrolytic capacitor is finally failed due to the fact that impedance between the shell and the negative electrode pin is low, current is large, heat is high, and the aluminum electrolytic capacitor is bulged.

Disclosure of Invention

The present invention is directed to an aluminum electrolytic capacitor to solve the above problems.

In order to achieve the purpose, the utility model adopts the technical scheme that: an aluminum electrolytic capacitor comprises a shell, electrolyte and a capacitor core, wherein the capacitor core is hermetically arranged in the shell, the electrolyte is filled between the capacitor core and the shell, the shell is an aluminum shell, an aluminum oxide film is formed on the inner surface of the shell, and the shell is electrically connected with a positive pin.

Further, the inner surface of the housing is a corroded surface, and the aluminum oxide film is formed on the corroded surface.

Furthermore, the thickness of the aluminum oxide film is more than or equal to 2 mu m.

Further, the aluminum oxide film is formed through a formation process.

Further, the shell is electrically connected with the positive electrode pin through a lead.

Further, the leads are connected to the case and the positive electrode lead, respectively, by ultrasonic bonding.

Further, the lead is made of an aluminum material.

Further, the capacitor core is formed by winding an anode aluminum foil, a cathode aluminum foil and electrolytic paper, the anode aluminum foil and the cathode aluminum foil are respectively riveted with an anode pin and a cathode pin, the capacitor core is sealed in the shell through a sealing cover, and the anode pin and the cathode pin respectively penetrate through the sealing cover and extend out of the shell.

The utility model has the beneficial technical effects that:

according to the utility model, the aluminum oxide film is formed on the inner surface of the shell and the shell is electrically connected with the anode pin, so that the aluminum electrolytic capacitor has a larger capacitance value under the same volume, and can resist larger ripple current.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a partial cross-sectional view of an aluminum electrolytic capacitor according to an embodiment of the present invention;

fig. 2 is a partially exploded view of a capacitor core according to an embodiment of the present invention.

Detailed Description

To further illustrate the various embodiments, the utility model provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the utility model and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The utility model will now be further described with reference to the accompanying drawings and detailed description.

As shown in fig. 1 and 2, an aluminum electrolytic capacitor comprises a housing 1, an electrolyte 2 and a capacitor core 3, wherein the capacitor core 3 is hermetically arranged in the housing 1, the electrolyte 2 is filled between the capacitor core 3 and the housing 1, the housing 1 is an aluminum housing, an aluminum oxide film 11 is formed on the inner surface of the housing 1, and the housing 1 is electrically connected with a positive electrode pin 4 of the aluminum electrolytic capacitor.

Through the two aluminium oxide films 11 that are formed with high dielectric constant at the internal surface of shell 1 and be connected shell 1 and positive pole pin 4 electricity, just so formed shell 1 and electrolyte 2 to the electric capacity between negative pole pin 5, parallelly connected with the electric capacity between original positive pole pin 4 and negative pole pin 5, just improved the capacitance value, increased rated ripple current, circulating current's area also grow, it also correspondingly reduces to generate heat. Meanwhile, the shell 1 is connected with the anode pin 4, when the shell 1 is contacted with a high potential and a low potential, current is directly led away from the anode pin 4, and large current in electrolysis cannot be generated, so that explosion and electrolysis failure cannot be caused.

Preferably, in this embodiment, the inner surface of the outer shell 1 is a corrosion surface, and the aluminum oxide film 11 is formed on the corrosion surface, so as to further increase the capacitance value and increase the rated ripple current. The corrosion surface can be obtained by a corrosion process, which can refer to the existing corrosion processes of anode aluminum foil and cathode aluminum foil of the capacitor core, and is a very mature process, and can be easily realized by a person skilled in the art without being detailed.

Preferably, in this embodiment, the thickness of the aluminum oxide film 11 is greater than or equal to 2 μm, so as to further increase the capacitance, increase the rated ripple current, and improve the voltage endurance.

In this embodiment, the aluminum oxide film 11 is preferably formed by a chemical process, which is mature, easy to implement and low in cost. The formation process can refer to the existing formation process of the anode aluminum foil of the capacitor core, which is a well-established process and can be easily realized by a person skilled in the art without being described in detail.

Preferably, in this embodiment, the housing 1 and the positive electrode pin 4 are electrically connected through the lead 6, which is simple in structure, easy to implement, and low in cost, but not limited thereto, and in some embodiments, the housing 1 and the positive electrode pin 4 may also be electrically connected by using other existing electrical connection methods, such as direct welding.

In this embodiment, the lead 6 is preferably made of aluminum material, which has good conductivity and is cheap, and no other material is needed to be introduced, so as to further reduce the cost, but not limited thereto, and in some embodiments, the lead 6 may also be made of other conductive material.

Preferably, in this embodiment, the lead 6 is respectively connected to the housing 1 and the positive electrode lead 4 by ultrasonic bonding, so that the electrical contact effect is good, the process is simple, the implementation is easy, and the cost is low, but not limited thereto, and in some embodiments, the lead 6 may also be respectively connected to the housing 1 and the positive electrode lead 4 by using other electrical connection methods.

In this embodiment, the capacitor core 3 is formed by sequentially stacking and winding an anode aluminum foil 31, a cathode aluminum foil 32 and electrolytic paper 33, the anode aluminum foil 31 and the cathode aluminum foil 32 are respectively riveted with the anode pin 4 and the cathode pin 5, and a more specific structure can refer to the core of the existing aluminum electrolytic capacitor, which is a well-established prior art and can be easily realized by those skilled in the art, and will not be described in detail.

The capacitor core 3 is hermetically arranged in the shell 1 through the sealing cover 7, the positive electrode pin 4 and the negative electrode pin 5 respectively penetrate through the sealing cover 7 and extend out of the shell 1, the sealing cover 7 can be made of rubber materials, and the more specific structure can refer to the sealing structure of the existing aluminum electrolytic capacitor, which is the mature prior art and can be easily realized by a person skilled in the art without detailed description.

The preparation method of the aluminum electrolytic capacitor comprises the following steps:

s1, preparing the outer case 1, and forming the aluminum oxide film 11 on the inner surface of the outer case 1 by chemical conversion.

In this embodiment, step S1 specifically includes: and S11, corroding the inner surface of the shell 1 to form a corroded surface. The corrosion process can refer to the existing corrosion process of anode aluminum foil and cathode aluminum foil of the capacitor core, which is a well-established process and can be easily realized by a person skilled in the art without being described in detail.

S12, forming aluminum oxide film 11 on the corrosion surface of the shell 1 by formation, wherein the formation process can refer to the formation process of the anode aluminum foil of the existing capacitor core, which is a well-established process and can be easily realized by the technical personnel in the field, and is not described in detail.

S2, the electrolyte 2 and the capacitor element 3 are sealed in the case 1 prepared in step S1, and the case 1 is electrically connected to the positive electrode lead 4.

In this embodiment, the sealing cap 7 is used to seal the electrolyte 2 and the capacitor core 3 in the case 1 prepared in step S1, the sealing cap 7 may be made of rubber, and the sealing operation may refer to the sealing operation of the existing aluminum electrolytic capacitor, which is a well-established prior art and can be easily implemented by those skilled in the art, and will not be described in detail.

In this embodiment, the case 1 is electrically connected to the positive electrode lead 4 by using the lead 6, the lead 6 is respectively connected to the case 1 and the positive electrode lead 4 by ultrasonic bonding, and the lead 6 is located outside the case 1.

According to the utility model, the aluminum oxide film 22 is formed on the inner surface of the shell 2, and the shell 2 is electrically connected with the anode pin 4, so that the aluminum electrolytic capacitor has a larger capacitance value under the same volume, and can resist larger ripple current, and when the shell 1 is in short circuit with an external circuit, current cannot be formed in electrolysis, so that the aluminum electrolytic capacitor cannot burst.

While the utility model has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims

1. The utility model provides an aluminum electrolytic capacitor, includes shell, electrolyte and capacitor core, and the sealed setting of capacitor core is in the shell which characterized in that: the electrolyte is filled between the capacitor core and the shell, the shell is an aluminum shell, an aluminum oxide film is formed on the inner surface of the shell, and the shell is electrically connected with the positive electrode pin.

2. The aluminum electrolytic capacitor of claim 1, wherein: the inner surface of the shell is a corrosion surface, and the aluminum oxide film is formed on the corrosion surface.

3. The aluminum electrolytic capacitor of claim 2, wherein: the thickness of the aluminum oxide film is more than or equal to 2 mu m.

4. The aluminum electrolytic capacitor of claim 1, wherein: the aluminum oxide film is formed through a formation process.

5. The aluminum electrolytic capacitor of claim 1, wherein: the shell is electrically connected with the positive electrode pin through a lead.

6. The aluminum electrolytic capacitor of claim 5, wherein: the lead is respectively connected with the shell and the anode pin through ultrasonic bonding.

7. The aluminum electrolytic capacitor of claim 5, wherein: the lead is made of aluminum material.

8. The aluminum electrolytic capacitor of claim 1, wherein: the capacitor core is formed by winding an anode aluminum foil, a cathode aluminum foil and electrolytic paper, the anode aluminum foil and the cathode aluminum foil are respectively riveted with an anode pin and a cathode pin, the capacitor core is sealed in the shell through a sealing cover, and the anode pin and the cathode pin respectively penetrate through the sealing cover and extend out of the shell.