Aluminum electrolytic capacitor packaging cover and aluminum electrolytic capacitor

Abstract

The present invention discloses a package cover plate for an aluminum electrolytic capacitor, comprising a cover plate body, a terminal assembly mounted on the cover plate body, and a riot valve; wherein the cover plate body is circular, and comprises a substrate, a rubber layer and an insulating layer respectively arranged on the upper surface and the lower surface of the substrate; the rubber layer is applied to the surface of the substrate to seal the capacitor; the edge of the insulating layer is provided with a fitting surface that fits with the surface of the substrate. The present invention improves the safety performance of the cover plate by providing an insulating layer on the cover plate of the aluminum electrolytic capacitor, thereby improving the performance and life of the aluminum electrolytic capacitor.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum electrolytic capacitors, and in particular relates to an aluminum electrolytic capacitor packaging cover plate and an aluminum electrolytic capacitor. Background Art

[0002] With the continuous improvement of capacitor performance, aluminum electrolytic capacitors have been widely used in consumer electronics, communication products, computers and peripheral products, new energy, automation control, automotive industry, optoelectronic products, high-speed railways, aviation and military equipment, etc. In the field of consumer electronics technology, the application of aluminum electrolytic capacitors has been expanded in many emerging fields such as energy-saving lamps, inverters, new energy, etc. with the structural transformation and technological progress. It has the characteristics of small size, large storage capacity and high cost performance. The application range is getting wider and wider.

[0003] At present, large aluminum electrolytic capacitors are generally composed of a core package consisting of positive and negative aluminum foils and electrolytic paper, a cylindrical aluminum shell, and a sealing cover with positive and negative terminal terminals. The capacitor is installed and led out by flat plate inlaid with metal terminals. The cover is provided with positive and negative terminal lead-out holes, and the positive and negative terminals are installed on the cover through through holes.

[0004] However, the above-mentioned prior art aluminum electrolytic capacitor products are prone to electrolyte enrichment on the plate between the positive and negative electrodes when they are at ultra-high voltage and ultra-high temperature, forming a low-resistance bridge when powered on. The high-voltage creepage effect directly causes the capacitor to lose its filtering function. In addition, when the low-resistance bridge is powered on, the electrolyte will decompose at high temperature until it is ionized and carbonized. Especially under the action of high voltage (400VDC-800VDC) and large current, the positive and negative electrodes will loosen the rivet holes when overheated, causing the cover rubber to bulge or rupture, directly causing the physical sealing structure to fail. This hidden danger is more hidden and cannot be detected by conventional quality inspection methods, which is extremely hidden to the safe life of the capacitor.

[0005] Secondly, after the capacitor is charged, the two electrodes of the capacitor carry opposite charges, so that there is an electric potential between the two electrodes of the electrical appliance. Although there is no connection between the two electrodes, once the voltage between the electrodes reaches a certain intensity or the distance between the electrodes is too close, the electric potential is likely to break through the air and produce discharge, causing a short circuit between the two electrodes, thereby affecting the life of the capacitor. It can be seen that for the above-mentioned current existing technologies, it is necessary to carry out development and research to provide a solution, a safe and reliable cover plate, and improve the performance of aluminum electrolytic capacitors.

[0006] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0007] The object of the present invention is to provide an aluminum electrolytic capacitor package cover plate and an aluminum electrolytic capacitor to solve at least one of the above-mentioned background technical problems.

[0008] To achieve the above object, the technical solution of the embodiment of the present invention is implemented as follows:

[0009] A package cover plate for an aluminum electrolytic capacitor comprises a cover plate body, a terminal assembly mounted on the cover plate body, and an explosion-proof valve; wherein the cover plate body is circular, and comprises a substrate, a rubber layer and an insulating layer respectively arranged on the upper surface and the lower surface of the substrate; the rubber layer is applied to the surface of the substrate to seal the capacitor; a fitting surface that fits the surface of the substrate is arranged at the edge of the insulating layer; a dome-shaped convex surface is arranged in an arc-shaped transition from the fitting surface to the center of the insulating layer, and a gap is formed between the substrate and the convex surface; the middle part of the convex surface is a concave plane, and two concave through holes are symmetrically arranged on the concave plane; and positive and negative electrode lead-out holes are arranged on the substrate.

[0010] In some embodiments, the insulating layer is in a disk shape, and the bonding surface of the insulating layer is a circular ring-shaped plane.

[0011] In some embodiments, the edge of the raised surface is raised.

[0012] In some embodiments, an isolation structure is disposed between the two recessed through holes, and the isolation structure protrudes from the plane of the recess.

[0013] In some embodiments, the recessed through holes on the insulating layer correspond to the positive and negative electrode lead-out holes.

[0014] In some embodiments, the terminal assembly includes positive and negative electrodes; the positive and negative electrodes respectively penetrate the recessed through holes and the positive and negative electrode lead-out holes; the positive and negative electrodes are isolated by an isolation structure between the two recessed through holes.

[0015] In some embodiments, the terminal assembly further includes a lead terminal, a metal rivet sheet, and a current collecting electrode sheet; the lead terminal, the metal rivet sheet, and the current collecting electrode sheet are provided with punching holes.

[0016] Another technical solution of the embodiment of the present invention is:

[0017] An aluminum electrolytic capacitor comprises a shell, a capacitor core package installed inside the shell, a cover plate, and a terminal assembly installed on the cover plate; wherein the core package comprises a core package body formed by stacking and coaxially winding an electrolytic paper layer and an aluminum foil layer; the cover plate comprises a cover plate body, a terminal assembly installed on the cover plate body, and a riot valve; the cover plate body is circular, and comprises a substrate, a rubber layer and an insulating layer respectively arranged on the upper surface and the lower surface of the substrate; the rubber layer is applied to the surface of the substrate to seal the capacitor; a fitting surface that fits the surface of the substrate is provided at the edge of the insulating layer; a dome-shaped convex surface is provided on the insulating layer in an arc-shaped transition from the fitting surface to the center of the insulating layer; the middle part of the convex surface is a concave plane, and two concave through holes are symmetrically arranged on the concave plane; positive and negative electrode lead-out holes are provided on the substrate; there is a gap between the insulating layer and the core package.

[0018] In some embodiments, the edge of the raised surface is raised.

[0019] In some embodiments, an isolation structure is disposed between the two recessed through holes, and the isolation structure protrudes from the plane of the recess.

[0020] The beneficial effects of the technical solution of the present invention are:

[0021] Compared with the prior art, the present invention improves the safety performance of the cover plate by providing an insulating layer on the cover plate of the aluminum electrolytic capacitor, thereby improving the performance and life of the aluminum electrolytic capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a three-dimensional structural diagram of an aluminum electrolytic capacitor package cover according to an embodiment of the present invention.

[0024] Figure 2 It is a structural diagram from another angle of the aluminum electrolytic capacitor package cover according to one embodiment of the present invention.

[0025] Figure 3 The figure is a structural diagram of the insulating layer of the aluminum electrolytic capacitor package cover according to one embodiment of the present invention.

[0026] Figure 4 FIG. 1 is a structural diagram of an aluminum electrolytic capacitor according to another embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present invention clearer and more understandable, and to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing or for circuit connection.

[0029] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, unless otherwise clearly specified and defined, the meaning of "multiple" is two or more, and the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral whole; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0031] As an embodiment of the present invention, a package cover plate for an aluminum electrolytic capacitor is provided, which has higher safety performance and can effectively prevent creepage between the positive and negative electrodes of the aluminum electrolytic capacitor, thereby improving the service life of the aluminum electrolytic capacitor.

[0032] Please refer to Figure 1-Figure 4 As shown, the aluminum electrolytic capacitor package cover plate 100 of the embodiment of the present invention includes a cover plate body, a terminal assembly installed on the cover plate body, and a riot valve (not shown); wherein the cover plate body is circular, and includes a substrate 10, a rubber layer 11 and an insulating layer 12 respectively arranged on the upper surface and the lower surface of the substrate.

[0033] The rubber layer 11 is applied to the surface of the substrate 10 to seal the capacitor, prevent the evaporation of the liquid electrolyte in the capacitor, and ensure that the capacitance and other electrical properties of the capacitor are not reduced. The material of the rubber layer 11 depends on the electrolyte solvent of the capacitor. In some embodiments, the material of the rubber layer 11 can be fluororubber, butyl rubber, EPDM rubber, or a composite rubber of the first two or the three.

[0034] The thickness of the substrate 10 is greater than that of the rubber layer 11. In some embodiments, the thickness h of the substrate 10 is: 5mm≤h≤8mm; the material of the substrate 10 is a composite of epoxy resin and fiber tissue density textile or papermaking; in some embodiments, the substrate 10 is made of low-chlorine phenolic resin.

[0035] The insulating layer 12 is in the shape of a disk, and a bonding surface 120 is provided at the edge thereof to be bonded to the surface of the substrate 10, and the bonding surface 120 is a circular annular plane; a dome-shaped convex surface 121 is provided in an arc-shaped transition from the bonding surface 120 to the center of the insulating layer, and the edge of the convex surface 121 is convex, and the middle part of the convex surface is a concave plane 122; as an embodiment, the concave plane 122 and the bonding surface 120 are in different horizontal planes, so that when the insulating layer 12 is bonded to the surface of the substrate 10, a gap is formed between the substrate 10 and the convex surface 121. Two concave through holes 1220 are symmetrically provided on the concave plane 122, and the concave through holes 1220 gradually decrease from the concave plane toward the surface of the substrate 10, that is, the aperture of the concave through hole 1220 gradually decreases from the concave plane toward the substrate. As an embodiment, the concave through hole gradually decreases by shrinking in an inclined manner from the concave plane. A stopper 1221 is provided at the bottom end of the recessed through hole 1220. The stopper 1221 is designed as a circular ring. The bottom surface of the stopper 1221 is in the same horizontal plane as the bonding surface 120. When the insulating layer is bonded to the substrate surface, the bottom surface of the stopper is also tightly bonded to the substrate surface.

[0036] An isolation structure 123 is provided between the two recessed through holes, and the isolation structure 123 protrudes from the recessed plane 122. In one embodiment, the isolation structure 123 includes an isolation channel 1230 and a wall structure 1231, and the isolation channel 1230 is in a groove shape. It is understood that in other embodiments, the isolation structure 123 can be adjusted accordingly depending on the arrangement of the capacitor terminal pins, and can be designed into a geometric structure of any other shape. In the present invention, there is no special limitation on its structure, and as long as it is a structure that realizes the corresponding function, it should belong to the protection scope of the present invention.

[0037] The substrate 10 is provided with positive and negative electrode lead-out holes (not shown), and the recessed through holes 1220 on the insulating layer correspond to the positive and negative electrode lead-out holes (not shown). The terminal assembly includes positive and negative electrodes 13, 14; the insulating layer is fitted on the substrate, and the positive and negative electrodes respectively penetrate the recessed through holes and the positive and negative electrode lead-out holes; a fixing gasket 15 is provided at the stopper at the bottom of the recessed through hole to fix the positive and negative electrodes, and the insulating layer 12 is connected and fixed to the substrate 10 through the positive and negative electrodes. With such a design, the positive and negative electrodes are isolated by the isolation structure 123 between the two recessed through holes, and the local creepage structures of the positive and negative electrodes are alienated, thereby solving the creepage problem between the positive and negative electrodes and preventing a short circuit between the positive and negative electrodes of the capacitor; and, due to the special structural design of the insulating layer, after the insulating layer is fitted and installed on the substrate, there is a gap between the raised surface of the insulating layer and the surface of the substrate, and the isolation structure 123 is provided with a groove-shaped isolation channel, and the groove-shaped isolation channel is connected to the gap, which can play an effective explosion-proof role.

[0038] In addition, by providing a concave plane 122 on the convex surface of the insulating layer and by specially designing the concave through-hole, when the cover is installed on the aluminum shell of the aluminum electrolytic capacitor, there is a tiny gap between the insulating layer and the core package to play a role of micro-liquid storage. At high temperatures, a small amount of extruded electrolyte can be stored in the gap of the cover. Secondly, by fitting the insulating layer on the substrate, it is prevented that the electrolyte in the core package of the aluminum electrolytic capacitor leaks out and corrodes the substrate, thereby affecting the performance of the electrolytic capacitor.

[0039] As an embodiment of the present invention, the insulating layer 122 is designed as an insulator, the insulator is made of engineering plastic, and the manufacturing process is hot stamping molding. In other embodiments, the insulating layer is a PET film with a thickness of 25um-250um; the PET film has high corrosion resistance to the electrolyte and is not easily corroded by the electrolyte.

[0040] It is understandable that in some embodiments, the insulating layer 122 can be designed to be embedded in the positive and negative electrode terminals, or directly mounted on the positive and negative electrode terminals, so as to alienate the local creepage structure of the positive and negative electrodes and prevent the electrolyte from corroding the substrate.

[0041] In one embodiment, the terminal assembly further includes lead terminals 130, 140, metal rivets (not shown) and current collecting electrode sheets (not shown). The lead terminals, metal rivets and current collecting electrode sheets are provided with punching holes (not shown). The cover plate 100 is provided with corresponding through holes, the lead terminals 130, 140 are installed at the corresponding through hole positions on the upper surface of the cover plate, and the current collecting electrode sheet is installed at the corresponding through hole positions on the lower surface of the cover plate. The positive and negative electrodes pass through the lead terminal punching holes from top to bottom, penetrate the through holes on the cover plate and the punching holes on the current collecting electrode sheet, and the positive and negative electrodes are tightly riveted to the current collecting electrode sheet through the metal rivets.

[0042] Reference Figure 4 As shown, as another embodiment of the present invention, an aluminum electrolytic capacitor 200 is also provided, including a housing 201, a capacitor core package (not shown) installed inside the housing, a cover plate 100, and a terminal assembly (not numbered) installed on the cover plate. The core package includes a core package body formed by stacking and coaxially winding an electrolytic paper layer and an aluminum foil layer; the cover plate includes a cover plate body, a terminal assembly installed on the cover plate body, and a riot valve; the cover plate body is circular, and includes a substrate, a rubber layer and an insulating layer respectively arranged on the upper and lower surfaces of the substrate; the rubber layer is applied to the surface of the substrate to seal the capacitor; the edge of the insulating layer is provided with a bonding surface that is bonded to the surface of the substrate.

[0043] The rubber layer is applied to the surface of the substrate to seal the capacitor, prevent the evaporation of the liquid electrolyte in the capacitor, and ensure that the capacitance and other electrical properties of the capacitor are not reduced.

[0044] The insulating layer is in the shape of a disk, and a bonding surface is provided at the edge thereof to be bonded to the surface of the substrate, and the bonding surface is a circular annular plane; a dome-shaped convex surface is provided in an arc transition from the bonding surface to the center of the insulating layer, and the edge of the convex surface is convex, and the middle part is a concave plane; as an embodiment, the concave plane and the bonding surface are in different horizontal planes, so that when the insulating layer is bonded to the surface of the substrate, a gap is formed between the substrate and the convex surface. Two concave through holes are symmetrically provided on the concave plane, and the concave through holes gradually decrease from the concave plane to the surface of the substrate, that is, the aperture of the concave through hole gradually decreases from the concave plane toward the substrate. As an embodiment, the concave through hole gradually decreases from the concave plane in an inclined contraction. A stopper is provided at the bottom end of the concave through hole, and the stopper is in a circular annular design, and the bottom surface of the stopper is in the same horizontal plane as the bonding surface, and when the insulating layer is bonded to the surface of the substrate, the bottom surface of the stopper is also tightly attached to the surface of the substrate.

[0045] The terminal assembly also includes a lead-out terminal, a metal rivet sheet, and a current collecting electrode sheet. The lead-out terminal, the metal rivet sheet, and the current collecting electrode sheet are provided with punching holes. The cover plate is provided with corresponding through holes, the lead-out terminal is installed at the position of the corresponding through hole on the upper surface of the cover plate, and the current collecting electrode sheet is installed at the position of the corresponding through hole on the lower surface of the cover plate. The positive and negative electrodes pass through the lead-out terminal punching holes from top to bottom, penetrate the through holes on the cover plate and the punching holes on the current collecting electrode sheet, and the positive and negative electrodes are tightly riveted to the current collecting electrode sheet through the metal rivet sheet.

[0046] The top of the core package body is provided with a cathode lead-out strip and an anode lead-out strip; the aluminum foil layer includes a negative aluminum foil layer and a positive aluminum foil layer, wherein the cathode lead-out strip is led out from the negative aluminum foil layer; and the anode lead-out strip is led out from the positive aluminum foil layer. The electrolytic paper layer is arranged between the negative aluminum foil layer and the positive aluminum foil layer. The lead-out electrode includes a cathode lead-out electrode and an anode lead-out electrode; corresponding to the cathode lead-out electrode and the anode lead-out electrode, the current collecting electrode sheet includes a cathode current collecting electrode sheet and an anode current collecting electrode sheet; wherein the cathode lead-out strip of the core package is one or more, all the cathode lead-out strips are gathered together and connected to the cathode current collecting electrode sheet; correspondingly, the anode lead-out strip of the core package is one or more, all the anode lead-out strips are gathered together and connected to the anode current collecting electrode sheet.

[0047] It is understandable that the above content is a further detailed description of the invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the invention is limited to these descriptions. For ordinary technicians in the technical field to which the invention belongs, without departing from the concept of the invention, they can also make several substitutions or modifications to the described embodiments, and these substitutions or modifications should be deemed to belong to the scope of protection of this patent. In the description of this specification, the description of reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention.

[0048] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradicting each other. Although the embodiments and advantages of the invention have been described in detail, it should be understood that various changes, substitutions and modifications may be made herein without departing from the scope defined by the appended claims.

[0049] Furthermore, the scope of the invention is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, means, methods, and steps described in the specification. One of ordinary skill in the art will readily appreciate that the above disclosures, processes, machines, manufactures, compositions of matter, means, methods, or steps currently existing or to be developed that perform substantially the same functions as the corresponding embodiments described herein or obtain substantially the same results as the embodiments described herein may be utilized. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, means, methods, or steps within their scope.

Claims

1. A package cover plate for an aluminum electrolytic capacitor, characterized in that: It includes a cover plate body, a terminal assembly installed on the cover plate body, and an explosion-proof valve; wherein the cover plate body is circular, and includes a substrate, a rubber layer and an insulating layer respectively arranged on the upper surface and the lower surface of the substrate; the rubber layer is applied to the surface of the substrate to seal the capacitor; the edge of the insulating layer is provided with a fitting surface that fits with the surface of the substrate; the insulating layer is provided with a dome-shaped convex surface in an arc-shaped transition from the fitting surface to the center of the insulating layer, and a gap is formed between the substrate and the convex surface; the edge of the convex surface is convex, and the middle part of the convex surface is a concave plane, and two concave through holes are symmetrically arranged on the concave plane; the substrate is provided with positive and negative electrode lead-out holes, and the concave through holes on the insulating layer correspond to the positive and negative electrode lead-out holes.

2. The aluminum electrolytic capacitor package cover plate according to claim 1, characterized in that: The insulating layer is in a disk shape, and the bonding surface of the insulating layer is a circular ring-shaped plane.

3. The aluminum electrolytic capacitor package cover plate according to claim 2, characterized in that: An isolation structure is arranged between the two recessed through holes, and the isolation structure protrudes from the plane of the recess.

4. The aluminum electrolytic capacitor package cover plate according to claim 3, characterized in that: The terminal assembly includes positive and negative electrodes; the positive and negative electrodes respectively penetrate the recessed through-holes and the positive and negative electrode lead-out holes; the positive and negative electrodes are isolated by an isolation structure between the two recessed through-holes.

5. The aluminum electrolytic capacitor package cover plate according to claim 4, characterized in that: The terminal assembly also includes a lead-out terminal, a metal rivet sheet and a current collecting electrode sheet; the lead-out terminal, the metal rivet sheet and the current collecting electrode sheet are provided with punching holes.

6. An aluminum electrolytic capacitor, characterized in that: The invention comprises a shell, a capacitor core package installed inside the shell, a cover plate, and a terminal assembly installed on the cover plate; wherein the core package comprises a core package body formed by stacking and coaxially winding an electrolytic paper layer and an aluminum foil layer; the cover plate comprises a cover plate body, a terminal assembly installed on the cover plate body, and a riot valve; the cover plate body is circular, and comprises a substrate, a rubber layer and an insulating layer respectively arranged on the upper surface and the lower surface of the substrate; the rubber layer is applied to the surface of the substrate to seal the capacitor; a fitting surface is provided at the edge of the insulating layer to fit with the surface of the substrate; a dome-shaped convex surface is provided on the insulating layer from the fitting surface to the center of the insulating layer in an arc-shaped transition, the edge of the convex surface is convex, the middle part of the convex surface is a concave plane, and two concave through holes are symmetrically arranged on the concave plane; the substrate is provided with positive and negative electrode lead-out holes, and the concave through holes on the insulating layer correspond to the positive and negative electrode lead-out holes; there is a gap between the insulating layer and the core package.

7. The aluminum electrolytic capacitor according to claim 6, wherein: An isolation structure is arranged between the two recessed through holes, and the isolation structure protrudes from the plane of the recess.

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