Low-leakage polymer aluminum electrolytic capacitor and manufacturing method thereof

Abstract

The invention relates to the technical field of electronic component manufacturing, in particular to a low-leakage polymer aluminum electrolytic capacitor and a manufacturing method thereof, and solves the technical problems of low energy efficiency ratio and short service life caused by problems in leakage control of a solid polymer aluminum electrolytic capacitor in the prior art. The invention relates to a low-electric-leakage polymer aluminum electrolytic capacitor and a manufacturing method thereof, and the low-electric-leakage polymer aluminum electrolytic capacitor comprises a multi-stage passivated positive electrode aluminum foil, a high-formation low-electric-leakage series positive electrode guide pin and a special coating, and is manufactured through a high-performance formation liquid and a fine aging treatment process. By optimizing the material and the manufacturing process, the leakage current of the capacitor is remarkably reduced, the energy efficiency ratio is increased, the service life is prolonged, and the stability and the reliability of the capacitor are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic component manufacturing, and in particular to a low leakage polymer aluminum electrolytic capacitor and a manufacturing method thereof. Background Art

[0002] As an important electronic component, polymer aluminum electrolytic capacitors play a key role in various electronic devices, especially in application scenarios that require high energy density, long life and low leakage characteristics. Their performance and quality have a decisive impact on the stability and reliability of the entire system. In particular, how to effectively control leakage current and maintain its long-term stability during the manufacturing process has become one of the core challenges in the current technology field.

[0003] Specifically, most solid polymer aluminum electrolytic capacitors currently have problems with leakage control. These capacitors may show low leakage current in the initial state, but after being placed for a long time or experiencing a short period of high temperature environment, the leakage current will rebound significantly, sometimes even up to 3 times the initial leakage current. This phenomenon is particularly prominent in industrial automation control systems such as PLC (programmable logic controller), because these systems have extremely high requirements for the stability of power modules, and any increase in leakage current may cause system performance degradation or even failure. In addition, the large differences in leakage current parameters in the electrical performance of existing capacitor products have further exacerbated this challenge.

[0004] What is more serious is that due to the small capacity of products that can be achieved under the same volume conditions, conventional solid polymer aluminum electrolytic capacitors are difficult to meet the needs of various parts such as the central processing unit and input and output interfaces in the power module for stable power supply. At the same time, in the signal processing circuit, conventional solid capacitors are also difficult to effectively reduce noise, thus affecting the accuracy and reliability of the signal. These problems not only limit the promotion and use of polymer aluminum electrolytic capacitors in high-end application fields, but also increase the overall design difficulty and cost of electronic equipment.

[0005] Therefore, in view of the above-mentioned deficiencies in the prior art, a low leakage polymer aluminum electrolytic capacitor and a manufacturing method thereof are urgently needed. This method should be able to effectively reduce the leakage current of the capacitor and maintain its stability under long-term storage or high temperature environment, while improving the capacity and performance consistency of the product. By solving these key problems, more reliable and efficient capacitor solutions can be provided for industrial automation control systems, high-end power modules, signal processing circuits and other fields, promoting the continuous development and technological progress of related industries. Summary of the invention

[0006] The purpose of the present invention is to provide a low leakage polymer aluminum electrolytic capacitor and a manufacturing method thereof, which solves the problem of leakage control of solid polymer aluminum electrolytic capacitors in the prior art.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A low leakage polymer aluminum electrolytic capacitor, comprising a capacitor core package, the capacitor core package is composed of a positive aluminum foil, a negative aluminum foil and electrolytic paper, wherein the positive aluminum foil and the positive guide needle are both of the low leakage series, and the positive aluminum foil is subjected to a special multi-stage passivation treatment;

[0009] A guide pin connection structure, wherein the positive guide pin of the capacitor core package is connected to the galvanized iron bar by welding;

[0010] High-performance chemical forming liquid, used to repair the defects of aluminum foil during the chemical forming process, reduce the capacitor leakage current and the leakage current recovery rate;

[0011] The polymerized core package is encapsulated in a coated aluminum shell and is sealed and waisted;

[0012] Aging treatment, by adjusting the aging temperature, time and voltage, multi-stage boost and constant voltage treatment, as well as high temperature constant voltage treatment, to ensure the low leakage current and low leakage recovery characteristics of the capacitor.

[0013] Preferably, the positive electrode aluminum foil is subjected to multi-stage passivation treatment using phosphorus-containing mixed acid chemicals, so that its leakage current is 30% lower than that of ordinary aluminum foil.

[0014] Preferably, the positive guide needle is a high-chemical-low-leakage series, and an extremely thin coating is attached to the cylindrical aluminum stem and the welding point of the positive electrode guide needle, and the extremely thin coating is hydrophobic polydimethylsiloxane (PDMS).

[0015] A method for manufacturing a low leakage polymer aluminum electrolytic capacitor comprises the following steps:

[0016] The positive electrode aluminum foil and the negative electrode aluminum foil are riveted to the formation guide pins respectively and isolated by electrolytic paper;

[0017] Weld the positive guide pin of the capacitor core package to the galvanized iron bar;

[0018] Put the fixed core package and iron bars into the integrated equipment of chemical formation-high temperature treatment-rechemical formation, and carry out chemical formation operation through high-performance chemical formation liquid;

[0019] The formed core package is subjected to pre-treatment, impregnation and polymerization operations;

[0020] The polymerized core package is encapsulated in a coated aluminum shell, and then sealed and waisted;

[0021] Print relevant logos on the assembled bare capacitors;

[0022] Aging treatment is carried out by adjusting the aging temperature, time and voltage, performing multi-stage boost and constant voltage treatment, and high temperature constant voltage treatment.

[0023] Preferably, in the chemical conversion operation, the high-performance chemical conversion liquid contains chemical substances such as citric acid, ammonium adipate, ammonium dihydrogen phosphate, boric acid, ammonium pentaborate, etc., which are used to repair the defective points of the aluminum foil.

[0024] Preferably, during the aging treatment, multi-stage voltage boost and constant voltage treatment, as well as high temperature constant voltage treatment, are used to ensure the compactness and insulation strength of the repaired oxide film, thereby achieving low leakage current and low leakage recovery characteristics of the capacitor.

[0025] Preferably, the pre-treatment step also includes treating the surface of the aluminum foil with a coupling agent to enhance the bonding strength between the aluminum foil and the subsequent coating.

[0026] Preferably, after the polymerization operation, the core package is dried to remove residual moisture and solvent to ensure the stability and reliability of the core package.

[0027] The present invention has at least the following beneficial effects:

[0028] By adopting a low-leakage series of positive aluminum foil and positive guide pins, as well as a special multi-stage passivation treatment, the initial leakage current of the capacitor is significantly reduced, and the recovery rate of the leakage current is effectively controlled under long-term storage or high-temperature environment, solving the system performance degradation and failure risks caused by the leakage current problem, and improving the stability and reliability of the capacitor.

[0029] By integrating high-performance chemical forming liquid, sophisticated chemical forming operations, multi-stage boosting and constant voltage treatment in aging treatment, and optimized pre-treatment and polymerization operation steps, not only the leakage current of the capacitor is further reduced, but also the capacity and performance consistency of the product are improved, meeting the high requirements of high-end application fields for power modules and signal processing circuits, and promoting the continuous development and technological progress of related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0031] Figure 1 It is a schematic diagram of the manufacturing method of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] Embodiment 1

[0034] See also Figure 1 As shown, a low leakage polymer aluminum electrolytic capacitor of this embodiment includes a capacitor core package, wherein the capacitor core package is composed of a positive aluminum foil, a negative aluminum foil and an electrolytic paper, wherein the positive aluminum foil and the positive guide needle are both of the low leakage series, and the positive aluminum foil is subjected to a special multi-stage passivation treatment;

[0035] A guide pin connection structure, wherein the positive guide pin of the capacitor core package is connected to the galvanized iron bar by welding;

[0036] High-performance chemical forming liquid, used to repair the defects of aluminum foil during the chemical forming process, reduce the capacitor leakage current and the leakage current recovery rate;

[0037] The polymerized core package is encapsulated in a coated aluminum shell and is sealed and waisted;

[0038] Aging treatment, by adjusting the aging temperature, time and voltage, multi-stage boost and constant voltage treatment, as well as high temperature constant voltage treatment, to ensure the low leakage current and low leakage recovery characteristics of the capacitor.

[0039] First, a low leakage series of positive aluminum foil and positive guide pins are selected. These materials have low leakage current characteristics. Then, the positive aluminum foil is subjected to a special multi-stage passivation treatment. This step usually involves the use of phosphorus-containing mixed acid chemicals for treatment. Through multi-stage treatment, the leakage current of the positive aluminum foil can be reduced by more than 30% compared with ordinary aluminum foil. The treated positive aluminum foil is isolated from the negative aluminum foil by electrolytic paper, and riveted to the formation guide pins respectively to form the basic structure of the capacitor core package.

[0040] Subsequently, the positive guide pin of the capacitor core package is connected and fixed to the galvanized iron bar through a welding process to ensure that the electrical connection between the guide pin and the iron bar is stable and reliable. Next, the fixed core package and iron bar are placed in an all-in-one device that integrates the functions of formation, high temperature treatment, and re-formation. In this step, a high-performance formation liquid is used to form the core package. The formation liquid contains chemical substances such as citric acid, ammonium adipate, diammonium phosphate, boric acid, and ammonium pentaborate. These ingredients can effectively repair the defects of the aluminum foil, thereby reducing the leakage current of the capacitor and the leakage current recovery rate.

[0041] After the formation process is completed, the core package is pre-treated, including the coupling agent treatment of the aluminum foil surface to enhance the bonding strength of the subsequent coating. Then the impregnation and polymerization process are carried out to form a stable structure of the core package. The polymerized core package is encapsulated in the coated aluminum shell, and its sealing is ensured by sealing and waist treatment.

[0042] In the final manufacturing stage of the capacitor, the relevant logo is printed on the assembled bare capacitor and aging treatment is carried out. The aging treatment adjusts the aging temperature, time and voltage, performs multi-stage boost and constant voltage treatment, and high temperature constant voltage treatment. These steps work together to ensure the density and insulation strength of the repaired oxide film, thereby achieving low leakage current and low leakage recovery characteristics of the capacitor.

[0043] Embodiment 2

[0044] See also Figure 1 As shown, in the low leakage polymer aluminum electrolytic capacitor of this embodiment, the positive aluminum foil is subjected to multi-stage passivation treatment by phosphorus-containing mixed acid chemicals, so that its leakage current is 30% lower than that of ordinary aluminum foil.

[0045] The positive guide pin is of high chemical formation and low leakage series, and an extremely thin coating is attached to the cylindrical aluminum stem and the welding point of the positive electrode guide pin, and the extremely thin coating is hydrophobic polydimethylsiloxane (PDMS).

[0046] In this embodiment, a low leakage polymer aluminum electrolytic capacitor is used. The positive aluminum foil is subjected to multi-stage passivation treatment with phosphorus-containing mixed acid chemicals, and an extremely thin hydrophobic polydimethylsiloxane (PDMS) coating is attached to the positive guide pin. We have optimized the leakage current control mechanism of the capacitor. In the workflow, these structural combinations ensure that a denser oxide film is formed on the surface of the positive aluminum foil, effectively blocking the abnormal leakage path of the current. At the same time, the PDMS coating provides an additional moisture-proof and insulating barrier to prevent the increase in leakage current caused by environmental humidity or chemical corrosion at the welding points and aluminum stems. The effect achieved is that the initial leakage current of the capacitor is significantly reduced, and the leakage current recovery rate after long-term placement or high temperature environment is effectively controlled, which is better than traditional capacitors. This not only improves the energy efficiency ratio of the capacitor, but also extends its service life and reduces energy loss and equipment failure caused by leakage current.

[0047] Embodiment 3

[0048] A method for manufacturing a low leakage polymer aluminum electrolytic capacitor comprises the following steps:

[0049] The positive electrode aluminum foil and the negative electrode aluminum foil are riveted to the formation guide pins respectively and isolated by electrolytic paper;

[0050] Weld the positive guide pin of the capacitor core package to the galvanized iron bar;

[0051] Put the fixed core package and iron bars into the integrated equipment of chemical formation-high temperature treatment-rechemical formation, and carry out chemical formation operation through high-performance chemical formation liquid;

[0052] The formed core package is subjected to pre-treatment, impregnation and polymerization operations;

[0053] The polymerized core package is encapsulated in a coated aluminum shell, and then sealed and waisted;

[0054] Print relevant logos on the assembled bare capacitors;

[0055] Aging treatment is carried out by adjusting the aging temperature, time and voltage, performing multi-stage boost and constant voltage treatment, and high temperature constant voltage treatment.

[0056] During the chemical conversion operation, the high-performance chemical conversion liquid contains chemical substances such as citric acid, ammonium adipate, ammonium dihydrogen phosphate, boric acid, and ammonium pentaborate, which are used to repair the defective points of the aluminum foil.

[0057] During the aging treatment, multi-stage voltage boost and constant voltage treatment, as well as high-temperature constant voltage treatment, are used to ensure the compactness and insulation strength of the repaired oxide film, thereby achieving low leakage current and low leakage recovery characteristics of the capacitor.

[0058] The pre-treatment step also includes treating the surface of the aluminum foil with a coupling agent to enhance the bonding strength between the aluminum foil and the subsequent coating.

[0059] After the polymerization operation, the core package is also dried to remove residual moisture and solvents to ensure the stability and reliability of the core package.

[0060] This program has the following working process:

[0061] Each step is closely connected to ensure the quality control of the capacitor from material preparation to finished product output. In particular, the use of high-performance chemical liquid not only repairs the defects of the aluminum foil, but also enhances the compactness and insulation strength of the oxide film; and the multi-stage boost and constant voltage treatment in the aging treatment, as well as the high-temperature constant voltage treatment, further consolidate the stability of the oxide film and prevent the long-term increase of leakage current. The effect achieved is that the manufactured capacitor not only has extremely low initial leakage current and leakage current recovery rate, but also has high capacity, long life and stable electrical properties. In addition, through the coupling agent treatment in the pre-treatment and the drying treatment after the polymerization operation, the bonding force and stability of the internal structure of the capacitor are enhanced, its ability to resist environmental interference is improved, and the reliable operation of the capacitor in various application environments is ensured.

[0062] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A low leakage polymer aluminum electrolytic capacitor, characterized in that: include: The capacitor core pack is composed of positive aluminum foil, negative aluminum foil and electrolytic paper, wherein the positive aluminum foil and the positive guide needle are both of low leakage series, and the positive aluminum foil is subjected to a special multi-stage passivation treatment; A guide pin connection structure, wherein the positive guide pin of the capacitor core package is connected to the galvanized iron bar by welding; High-performance chemical forming liquid, used to repair the defects of aluminum foil during the chemical forming process, reduce the capacitor leakage current and the leakage current recovery rate; The polymerized core package is encapsulated in a coated aluminum shell and is sealed and waisted; Aging treatment, by adjusting the aging temperature, time and voltage, multi-stage boost and constant voltage treatment, as well as high temperature constant voltage treatment, to ensure the low leakage current and low leakage recovery characteristics of the capacitor.

2. A low leakage polymer aluminum electrolytic capacitor according to claim 1, characterized in that: The positive electrode aluminum foil is subjected to multi-stage passivation treatment using phosphorus-containing mixed acid chemicals, so that its leakage current is 30% lower than that of ordinary aluminum foil.

3. The low leakage polymer aluminum electrolytic capacitor according to claim 1, characterized in that: The positive guide pin is of high chemical formation and low leakage series, and an extremely thin coating is attached to the cylindrical aluminum stem and the welding point of the positive electrode guide pin, and the extremely thin coating is hydrophobic polydimethylsiloxane (PDMS).

4. A low leakage polymer aluminum electrolytic capacitor according to any one of claims 1 to 3, wherein the manufacturing method thereof comprises the following steps: The positive electrode aluminum foil and the negative electrode aluminum foil are riveted to the formation guide pins respectively and isolated by electrolytic paper; Weld the positive guide pin of the capacitor core package to the galvanized iron bar; Put the fixed core package and iron bars into the integrated equipment of chemical formation-high temperature treatment-rechemical formation, and carry out chemical formation operation through high-performance chemical formation liquid; The formed core package is subjected to pre-treatment, impregnation and polymerization operations; The polymerized core package is encapsulated in a coated aluminum shell, and then sealed and waisted; Print relevant logos on the assembled bare capacitors; Aging treatment is carried out by adjusting the aging temperature, time and voltage, performing multi-stage boost and constant voltage treatment, and high temperature constant voltage treatment.

5. The method for manufacturing a low leakage polymer aluminum electrolytic capacitor according to claim 4, characterized in that: During the chemical conversion operation, the high-performance chemical conversion liquid contains chemical substances such as citric acid, ammonium adipate, ammonium dihydrogen phosphate, boric acid, and ammonium pentaborate, which are used to repair the defective points of the aluminum foil.

6. The method for manufacturing a low leakage polymer aluminum electrolytic capacitor according to claim 5, characterized in that: During the aging treatment, multi-stage boost and constant voltage treatment, as well as high-temperature constant voltage treatment, are used to ensure the compactness and insulation strength of the repaired oxide film, thereby achieving low leakage current and low leakage recovery characteristics of the capacitor.

7. The method for manufacturing a low leakage polymer aluminum electrolytic capacitor according to claim 4, characterized in that: The pre-treatment step also includes treating the surface of the aluminum foil with a coupling agent to enhance the bonding strength between the aluminum foil and the subsequent coating.

8. The method for manufacturing a low leakage polymer aluminum electrolytic capacitor according to claim 4, characterized in that: After the polymerization operation, the core package is also dried to remove residual moisture and solvents to ensure the stability and reliability of the core package.

Images