阅读说明：本技术 一种高压叠片式铝电解电容器及其制备方法 (High-voltage laminated aluminum electrolytic capacitor and preparation method thereof ) 是由 艾燕 贾明 杨静如 潘振炎 于 2019-08-26 设计创作，主要内容包括：一种高压叠片式铝电解电容器,包括芯包和外壳,芯包被密封在外壳内；芯包由阳极箔、电解纸和阴极箔层叠而成,阳极箔包括基体和烧结在基体上的膜层,基体的一端留有裸露的基体为连接端,芯包成型后多块阳极箔的连接端和阳极引出片电性连接在一起；阴极箔和阴极引出片电性连接在一起；阳极引出片和阴极引出片伸出外壳；电解纸四周均伸出膜层的四周,电解纸完全盖住膜层；并且,电解纸完全罩住阴极箔。在本发明中不仅没有引线铆接带来的,阳极氧化膜开裂的情况；同时通过阳极箔的串联或者并联来增加电容器的耐压值和容量。电解纸尺寸的特殊设置保证连接端在热压铝塑封口的时候不会接触到阴极箔,从而避免短路的情况发生。(A high-voltage laminated aluminum electrolytic capacitor comprises a core bag and a shell, wherein the core bag is sealed in the shell; the core bag is formed by laminating an anode foil, electrolytic paper and a cathode foil, the anode foil comprises a base body and a film layer sintered on the base body, an exposed base body is left at one end of the base body and is used as a connecting end, and the connecting ends of a plurality of anode foils and the anode leading-out sheets are electrically connected together after the core bag is formed; the cathode foil and the cathode lead-out sheet are electrically connected together; the anode lead-out sheet and the cathode lead-out sheet extend out of the shell; the periphery of the electrolytic paper extends out of the periphery of the film layer, and the electrolytic paper completely covers the film layer; and, the electrolytic paper completely covers the cathode foil. In the invention, the condition that the anodic oxide film is cracked due to lead riveting is avoided; meanwhile, the voltage withstanding value and the capacity of the capacitor are increased by the serial connection or the parallel connection of the anode foils. The special setting of electrolytic paper size guarantees that the link can not contact the negative pole paper tinsel when hot pressing plastic-aluminum seals to avoid the condition of short circuit to take place.)

1. A high-voltage laminated aluminum electrolytic capacitor is characterized in that: comprises a core bag and a shell, wherein the core bag is sealed in the shell; the core bag is formed by laminating an anode foil, electrolytic paper and a cathode foil, the anode foil comprises a base body and a film layer sintered on the base body, an exposed base body is reserved at one end of the base body and serves as a connecting end, and the connecting ends of a plurality of anode foils and an anode leading-out sheet are electrically connected together after the core bag is formed; the cathode foil and the cathode lead-out sheet are electrically connected together; the anode lead-out sheet and the cathode lead-out sheet extend out of the shell; the periphery of the electrolytic paper extends out of the periphery of the film layer, and the electrolytic paper completely covers the film layer; and the electrolytic paper completely covers the cathode foil.

2. The high-voltage laminated aluminum electrolytic capacitor of claim 1, wherein: the two ends of the anode foils are provided with connecting ends exposed out of the matrix, the anode foils are connected in series through the connecting ends in an end-to-end manner, and the connecting ends at the two adjacent ends are electrically connected together; the cathode foil and the anode foil are also connected in series; the anode lead-out sheet and the cathode lead-out sheet are respectively and electrically connected to an anode foil and a cathode foil.

3. The high-voltage laminated aluminum electrolytic capacitor according to claim 1 or 2, characterized in that: the electrical connection comprises welding, glue contact connection and clamp contact connection.

4. The high-voltage laminated aluminum electrolytic capacitor according to claim 1 or 2, characterized in that: the shell is an aluminum-plastic shell, and the core bag is sealed in the aluminum-plastic shell through hot-pressing sealing or vacuum hot-pressing sealing.

5. The high-voltage laminated aluminum electrolytic capacitor according to claim 1 or 2, characterized in that: the film layer comprises a sintered body of at least one particle of aluminum powder or aluminum alloy; the film layer sintered body contains a gap which accounts for 25-40% of the volume of the sintered body.

6. The high-voltage laminated aluminum electrolytic capacitor according to claim 1 or 2, characterized in that: the thickness of the film layer on the anode foil is not less than 3 mu m.

7. The high-voltage laminated aluminum electrolytic capacitor according to claim 1 or 2, characterized in that: and lug glue is pasted on the aluminum-plastic sealing positions on the two sides of the anode lead-out piece and the cathode lead-out piece.

8. A method of manufacturing a high-voltage laminated aluminum electrolytic capacitor according to any one of claims 1 to 7, characterized in that: the method comprises the following steps: 1) uniformly mixing aluminum powder or aluminum alloy powder in slurry to obtain mixed coating, wherein the slurry comprises a binder and a solvent;

2) intermittently coating the mixed coating on an anode foil substrate;

3) pre-sintering the anode foil substrate coated with the mixed coating in a sintering furnace at the temperature of 200-350 ℃ for 5-30min;

4) carrying out vacuum sintering on the pre-sintered anode foil substrate in a vacuum sintering furnace, wherein the sintering temperature is not higher than the melting point of aluminum powder or aluminum alloy powder and is not lower than the temperature of-100 ℃ of the melting point of the aluminum powder or the aluminum alloy powder;

5) cutting the sintered anode foil into required sizes, and simultaneously cutting the cathode foil and the electrolytic paper into the required sizes; when cutting, the anode foil and the cathode foil are provided with connecting ends exposed out of the matrix;

6) stacking the anode foil, the electrolytic paper and the cathode foil into a core package, and electrically connecting the connecting ends on the anode foil, so that a plurality of anode foils are connected in series or in parallel; meanwhile, the connecting ends on the cathode foils are electrically connected, so that a plurality of cathode foils are connected in series or in parallel;

7) electrically connecting the anode lead-out sheet and the cathode lead-out sheet with the connecting ends on the anode foil and the cathode foil respectively;

8) impregnating with electrolyte;

9) the core bag impregnated with the electrolyte is packaged in an aluminum-plastic shell in a vacuum sealing manner; so that the anode lead-out sheet and the cathode lead-out sheet extend out of the aluminum-plastic shell.

9. The method for manufacturing a high-voltage laminated aluminum electrolytic capacitor according to claim 8, wherein: adding an annealing process between the step 4) and the step 5), and annealing the sintered anode foil for one time or two times, wherein the temperature of the annealing for one time is selected to be 250-350 ℃; when two times of annealing are selected, the first time temperature is selected to be between 300-400 ℃, and the second time annealing is selected to be between 200-300.

10. The method for manufacturing a high-voltage laminated aluminum electrolytic capacitor according to claim 8, wherein: the aluminum-plastic shells at the positions of the anode lead-out piece and the cathode lead-out piece are firstly pasted with tab glue, and then hot-pressed aluminum-plastic sealing is carried out.

Technical Field

The invention relates to an aluminum electrolytic capacitor, in particular to a high-voltage laminated aluminum electrolytic capacitor without riveting.

Background

The high-voltage aluminum electrolytic capacitor has particularly high requirements on the anode foil, and the anode foil needs to meet the requirement that the dielectric on the surface of the anode foil, generally the thickness of an oxide film on the surface of aluminum foil, is particularly thick. In order to prevent the etching pits from being masked by this thick oxide film, the etching pits for aluminum foil to be used for medium-voltage to high-voltage anodes are made into a tunnel type by performing direct current etching, and then processed to an appropriate size for the voltage to be used. In contrast, for use in low voltage capacitors, it is necessary to use small etching pits. Therefore, a sponge-like etching pit is generally formed by alternating current etching. In the cathode foil, the surface area is similarly increased by etching.

However, the conventional etching processes for the anode and the cathode require the use of an aqueous hydrochloric acid solution containing sulfuric acid, phosphoric acid, nitric acid, etc. in hydrochloric acid. Hydrochloric acid has a strong environmental impact and its disposal also impacts the production process or production cost. Therefore, there is a need to develop a new method for increasing the surface area of the aluminum foil without etching.

To meet such a demand, the japan eastern aluminum co has proposed sintering aluminum powder or aluminum alloy powder on an aluminum foil substrate (patent document 1). The sintered body is sintered on the substrate, so that the manufactured aluminum foil can obtain the same or larger electrostatic capacity than the conventional etched foil, and is particularly suitable for being used in medium-high voltage aluminum electrolytic capacitors.

Because the oxide film on the surface of the traditional high-voltage aluminum electrolytic capacitor is thicker, when the capacitor is produced and the anode foil and the cathode foil are led out, the lead guide pin or the lead-out strip is riveted on the anode foil by adopting a rivet, otherwise, the lead guide pin or the lead-out strip is poor in electrical connection with the anode foil or the cathode foil. All techniques known at present are in the form of riveting, such as patent document 2 and patent document 3; the adoption of the riveting connection mode can increase the thickness of the rivet connection part, and other anode foils can be jacked up when the capacitor is laminated, so that the bulge is generated; the anode foil of the high-voltage aluminum electrolytic capacitor is very thick, which makes the anode foil very brittle, and cracks may be generated on the surface of the anode foil by the jacking force, even when riveting, for example, as described in patent document 4. When the anode foil is cracked, burrs are generated, and the burrs can cause the accumulation of electric charges, so that the electrolytic paper is broken down, and short circuit is caused. In the comparison document 4, a core package composed of a piece of anode foil is adopted, and the capacity of the core package is small; meanwhile, the electrolytic paper does not specially cover the whole anode foil, so that the matrix blank position is in contact with the cathode foil when the aluminum-plastic hot-press sealing is carried out, and the core cladding is short-circuited. In comparison with document 4, when the aluminum-plastic sealing is performed again, no other treatment is performed, and due to the difference between the material of the anode lead-out sheet and the material of the cathode lead-out sheet and the aluminum-plastic material, the poor sealing performance of the sealing is likely to occur during the aluminum-plastic sealing.

Patent document 1: 200880128783.4, an electrode material for aluminum electrolytic capacitors and a method of making the electrode.

Patent document 2: 201810753352.2, a 700V extra-high voltage aluminum electrolytic capacitor.

Patent document 3: 201810752682.X, a 600V high-voltage high-temperature-resistant long-life aluminum electrolytic capacitor and a manufacturing method thereof.

Patent document 4: 201910557345X, edge-whitening anode foil for aluminum electrolytic capacitors, method of making, and capacitor.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a high-voltage laminated aluminum electrolytic capacitor which is large in capacity, does not need lead riveting and is good in sealing performance.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a high-voltage laminated aluminum electrolytic capacitor comprises a core package and a shell, wherein the core package is sealed in the shell; the core bag is formed by laminating an anode foil, electrolytic paper and a cathode foil, the anode foil comprises a base body and a film layer sintered on the base body, an exposed base body is reserved at one end of the base body and serves as a connecting end, and the connecting ends of a plurality of anode foils and an anode leading-out sheet are electrically connected together after the core bag is formed; the cathode foil and the cathode lead-out sheet are electrically connected together; the anode lead-out sheet and the cathode lead-out sheet extend out of the shell; the periphery of the electrolytic paper extends out of the periphery of the film layer, and the electrolytic paper completely covers the film layer.

In the invention, the periphery of the electrolytic paper extends out of the periphery of the film layer, so that the tiny burrs on the periphery of the anode foil cannot touch the cathode foil. The position that the positive pole paper tinsel base member left white, that is to say bare base member, or link, because the banding brings the extrusion around the core package when carrying out hot pressing plastic-aluminum shaping, because the positive pole paper that the electrolytic paper covers completely, just so the condition that the link contacted the negative pole paper tinsel does not appear. In the present invention, the anode foil lead-out and the cathode foil lead-out are each arranged in a staggered manner in general.

In the invention, the connecting ends of the anode foils are electrically connected together, and the anode foils are actually connected in parallel, so that the capacity of the capacitor can be increased.

In the above high-voltage laminated aluminum electrolytic capacitor, preferably, the two ends of the anode foil are both provided with the connecting ends of the exposed substrate, the plurality of anode foils are connected in series by connecting the connecting ends end to end, and the connecting ends at two adjacent ends are electrically connected together; the cathode foil and the anode foil are also connected in series; the anode lead-out sheet and the cathode lead-out sheet are respectively and electrically connected to an anode foil and a cathode foil. Further, in order to increase the voltage of the capacitor, the two ends of the anode foils can be exposed out of the substrate, and the anode foils are connected end to end through the connecting ends and electrically connected together, so that the anode foils are actually connected in series, and the voltage withstanding value of the capacitor is increased.

In comparative document 4, one capacitor unit has only one anode foil; of course, the capacitor units can be used in series or in parallel and then packaged together in an aluminum case. But this tends to increase the volume of the capacitor.

Preferably, the electrical connection includes welding, glue contact connection and clamp contact connection.

In the above high-voltage laminated aluminum electrolytic capacitor, preferably, the casing is an aluminum-plastic casing, and the core package is sealed in the aluminum-plastic casing by hot-press sealing or vacuum hot-press sealing.

In the above high-voltage laminated aluminum electrolytic capacitor, preferably, the film layer comprises a sintered body of at least one particle of aluminum powder or aluminum alloy; the film layer sintered body contains a gap which accounts for 25-40% of the volume of the sintered body.

In the above high-voltage laminated aluminum electrolytic capacitor, preferably, the thickness of the film layer on the anode foil is not less than 3 μm.

In the above high-voltage laminated aluminum electrolytic capacitor, preferably, tab glue is pasted on the aluminum-plastic sealing positions on both sides of the anode lead-out piece and the cathode lead-out piece. The tab glue can adopt the traditional tab glue, such as the following patents: low temperature tab glue, 201721448197.0.

A manufacturing method for preparing a high-voltage laminated aluminum electrolytic capacitor comprises the following steps: 1) uniformly mixing aluminum powder or aluminum alloy powder in slurry to obtain mixed coating, wherein the slurry comprises a binder and a solvent;

2) intermittently coating the mixed coating on an anode foil substrate;

3) pre-sintering the anode foil substrate coated with the mixed coating in a sintering furnace at the temperature of 200-350 ℃ for 5-30min;

4) carrying out vacuum sintering on the pre-sintered anode foil substrate in a vacuum sintering furnace, wherein the sintering temperature is not higher than the melting point of aluminum powder or aluminum alloy powder and is not lower than the temperature of-100 ℃ of the melting point of the aluminum powder or the aluminum alloy powder; in the present invention, since the melting points of different aluminum alloys are different when the aluminum alloy is used, the sintering temperature in the present invention is not higher than the melting point of the aluminum powder or the aluminum alloy powder and is not lower than the temperature of-100 degrees centigrade of the melting point of the aluminum powder or the aluminum alloy powder.

5) Cutting the sintered anode foil into required sizes, and simultaneously cutting the cathode foil and the electrolytic paper into the required sizes; when cutting, the anode foil and the cathode foil are provided with connecting ends exposed out of the matrix; in the present invention, the size of the anode foil is slightly larger than that of the anode foil, and the cathode foil can completely cover the anode foil; the size of the electrolytic paper is slightly larger than that of the cathode foil, namely the electrolytic paper can completely cover the cathode foil.

6) Stacking the anode foil, the electrolytic paper and the cathode foil into a core package, and electrically connecting the connecting ends on the anode foil, so that a plurality of anode foils are connected in series or in parallel; meanwhile, the connecting ends on the cathode foils are electrically connected, so that a plurality of cathode foils are connected in series or in parallel;

7) electrically connecting the anode lead-out sheet and the cathode lead-out sheet with the connecting ends on the anode foil and the cathode foil respectively;

8) impregnating with electrolyte;

9) the core bag impregnated with the electrolyte is packaged in an aluminum-plastic shell in a vacuum sealing manner; so that the anode lead-out sheet and the cathode lead-out sheet extend out of the aluminum-plastic shell.

In the manufacturing method of the high-voltage laminated aluminum electrolytic capacitor, preferably, an annealing process is added between the step 4) and the step 5), the sintered anode foil is annealed once or twice, and the temperature of the once annealing is selected to be 250-350 ℃; when two times of annealing are selected, the first time temperature is selected to be between 300-400 ℃, and the second time annealing is selected to be between 200-300.

In the manufacturing method of the high-voltage laminated aluminum electrolytic capacitor, preferably, the tab glue is firstly pasted on the aluminum plastic shells at the positions of the anode lead-out piece and the cathode lead-out piece, and then hot-pressing aluminum plastic sealing is carried out.

Compared with the prior art, the invention has the advantages that: in the invention, the condition that the anodic oxide film is cracked due to lead riveting is avoided; meanwhile, the voltage withstanding value and the capacity of the capacitor are increased by the serial connection or the parallel connection of the anode foils. The special setting of electrolytic paper size guarantees that the link can not contact the negative pole paper tinsel when hot pressing plastic-aluminum seals to avoid the condition of short circuit to take place.

Drawings

Fig. 1 is a schematic diagram of an anode foil after sintering.

Fig. 2 is a photographic image showing the appearance of cracks in the anode foil in comparative example 2.

Detailed Description

In order to facilitate an understanding of the present invention, the present invention will be described more fully and in detail with reference to the preferred embodiments, but the scope of the present invention is not limited to the specific embodiments described below.

It should be particularly noted that when an element is referred to as being "fixed to, connected to or communicated with" another element, it can be directly fixed to, connected to or communicated with the other element or indirectly fixed to, connected to or communicated with the other element through other intermediate connecting components.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.