A hermetic packaged laminated solid aluminum electrolytic capacitor and preparation method thereof

Abstract

The invention discloses an airtight packaged laminated solid aluminum electrolytic capacitor and a preparation method thereof. The capacitor comprises a plurality of cores, a metal end cap, a ceramic tube shell and a rivet. The metal end cap and the ceramic tube shell are both square open structures. A U-shaped metal shrapnel is installed on the inner surface of the metal end cap away from the opening. The U-shaped metal shrapnel is electrically connected to the metal end cap. A cathode lead-out portion is arranged on the inner surface of the ceramic tube shell away from the opening. A plurality of cores are stacked in sequence and arranged in a cavity formed by fitting the metal end cap and the ceramic tube shell. The cathode portion of the core is in contact with and electrically connected to the cathode lead-out portion. The anode portion of the core is inserted into the opening of the U-shaped metal shrapnel. One end of the rivet penetrates the anode portion of each core in sequence. The capacitor of the invention uses the inorganic material of the metal end cap and the ceramic tube shell as an outer shell to realize the airtight connection of the capacitor. Compared with resin packaging, the capacitor has better airtightness and product reliability. The capacitor is more suitable for application in harsh environments such as high temperature and high humidity.

Description

Technical Field

[0001] The invention relates to the technical field of solid aluminum electrolytic capacitors, in particular to an airtight packaged laminated solid aluminum electrolytic capacitor and a preparation method thereof. Background Art

[0002] The laminated solid aluminum electrolytic capacitor uses a high-conductivity polymer material as a solid electrolyte, adopts a core package structure with multiple cores stacked in parallel, and uses epoxy resin as a packaging material to protect the core package while molding the finished product into a square structure suitable for surface mounting. Compared with traditional liquid aluminum electrolytic capacitors, laminated solid aluminum electrolytic capacitors have the advantages of better basic electrical performance, smaller size, longer service life, higher environmental protection and safety characteristics, and can better meet the development needs of the electronic information industry for miniaturization, thinness and high speed of the whole machine.

[0003] At present, the common process for preparing laminated solid aluminum electrolytic capacitors is: the cut chemical foil is divided into anode and cathode areas with barrier glue, and a conductive polymer solid electrolyte layer, a conductive carbon paste layer and a silver paste layer are formed in sequence on the surface of the cathode area of ​​the foil to form a core; the anode parts of multiple cores are welded, and the cathode parts are bonded with conductive silver glue, and they are stacked on the upper and lower surfaces of the external lead frame to form a core package, and the anode and cathode are led out, and then the mold is used to injection-mold the core package with epoxy resin packaging material, and the leads extend from the middle of the two ends of the core package out of the resin shell, and are bent toward the bottom for a second time to fit the resin shell to form external terminals.

[0004] The laminated solid aluminum electrolytic capacitor obtained by the above process has the following disadvantages:

[0005] (1) Impact on product reliability: Resin packaging is a non-airtight structure. In harsh environments such as high temperature and high humidity, it is easy for moisture or corrosive gases and liquids to penetrate into the capacitor, causing product performance to deteriorate or even fail.

[0006] (2) Impact on product yield: The organic encapsulation resin is in direct contact with the core and can easily squeeze in from the gap between the laminated cores during injection molding, causing extrusion deformation of the core, increasing leakage current and ESR, and even causing delamination and capacitor failure. The shrinkage and stress generated by the resin encapsulation material during curing also have a negative impact on product performance, causing performance deterioration or even failure.

[0007] The above disadvantages limit the application of traditional resin encapsulated chip-type laminated solid aluminum electrolytic capacitors in complex environments and fields with high reliability requirements, and affect the industrial production yield. Based on this, the present invention designs an airtight encapsulated laminated solid aluminum electrolytic capacitor and a preparation method thereof to solve the above problems. Summary of the invention

[0008] The purpose of the present invention is to provide an airtight packaged laminated solid aluminum electrolytic capacitor and a preparation method thereof, so as to solve the problem that the laminated solid aluminum electrolytic capacitor prepared by the prior art is easily invaded by moisture or corrosive gases and liquids in harsh environments such as high temperature and high humidity, causing product performance deterioration or even failure.

[0009] To achieve the above object, the present invention provides the following technical solution: an airtight packaged laminated solid aluminum electrolytic capacitor, comprising a plurality of cores, a metal end cap, a ceramic tube shell and a rivet, wherein the metal end cap and the ceramic tube shell are both square open structures, and the two openings of the metal end cap and the ceramic tube shell are mutually nested and airtightly connected;

[0010] A U-shaped metal spring is installed on the inner surface of the metal end cover away from the opening, and the opening of the U-shaped metal spring faces the opening of the metal end cover, and the U-shaped metal spring is electrically connected to the metal end cover;

[0011] The inner surface of the ceramic tube shell away from the opening is provided with a cathode lead-out portion, and the cathode lead-out portion passes through the side wall of the ceramic tube shell away from the opening;

[0012] A plurality of cores are stacked in sequence and arranged in a cavity formed by fitting a metal end cover and a ceramic tube shell, the cathode portion of the core is in contact with and electrically connected to the cathode lead-out portion, the anode portion of the core is inserted into the opening of the U-shaped metal spring sheet, one end of the rivet passes through the anode portion of each core in sequence, and the two ends of the rivet are in contact with and electrically connected to the opposite side walls of the U-shaped metal spring sheet.

[0013] Preferably, the opposite ends of the rivet pass through the anode portion of the core and are bent toward the cathode portion of the core, and the two bent portions of the rivet are in contact with the opposite side walls of the U-shaped metal spring sheet respectively.

[0014] Preferably, the open end of the ceramic tube shell includes a first open portion and a second open portion connected in sequence, the opening of the first open portion is smaller than the opening of the second open portion, and the first open portion is arranged at an end close to the metal end cover, the opening of the metal end cover and the outer surface of the first open portion are mutually nested, the inner surface of the first open portion is in contact with the outer surfaces of the opposite side walls of the U-shaped metal spring sheet, and a rectangular metal ring is embedded in the outer surface of one end of the first open portion close to the second open portion.

[0015] Preferably, the outer surfaces of the metal end caps are provided with a tin layer.

[0016] Preferably, the cathode lead-out portion includes a cathode tongue, a cathode connecting portion, a cathode pin vertical portion and two cathode pin horizontal portions that are connected to each other, the cathode tongue and the cathode pin vertical portion are connected via the cathode connecting portion, and the cathode connecting portion is passed through the interior of the ceramic tube shell, the cathode tongue and the cathode pin vertical portion are respectively arranged on the inner surface and outer surface of the ceramic tube shell away from the open end, the two cathode pin horizontal portions are respectively arranged on the upper and lower surfaces of the ceramic tube shell away from the open end, and one end of the two cathode pin horizontal portions are both connected to the cathode pin vertical portion.

[0017] Preferably, the outer surfaces of the vertical portion of the cathode pin and the two horizontal portions of the cathode pin are both provided with a tin layer.

[0018] Preferably, the length of the horizontal portion of the cathode pin is 20%-30% of the length of the finished capacitor.

[0019] Preferably, the length of the metal end cover is 20% to 25% of the length of the finished capacitor.

[0020] A method for preparing a hermetically packaged laminated solid aluminum electrolytic capacitor, the method comprising the following steps:

[0021] S1, punching the formed aluminum foil into a rectangle with a through hole at one end, coating a barrier adhesive to form an anode portion with a through hole and a cathode region without a through hole, and then sequentially forming a conductive polymer layer, a conductive carbon paste layer and a conductive silver paste layer on the surface of the cathode region to prepare a cathode portion and obtain a core;

[0022] S2. According to the designed number of layers, the cathode parts of the plurality of core pieces are bonded and cured by conductive silver glue, and then rivets are sequentially passed through the through holes of the anode parts of the plurality of core pieces, and the exposed parts at both ends of the rivets are bent toward the cathode part and closely attached to the surface of the anode part to form a group of bent parts, so that the anode parts of the plurality of core pieces are fixedly connected and electrically connected to obtain a first core package;

[0023] S3, fixing and electrically connecting the rivet bent portion on the first core package and the two side surfaces of the U-shaped metal spring by welding, so as to achieve connection between the first core package and the metal end cover, thereby forming a second core package;

[0024] S4, combining the second core package with the external ceramic tube shell and sealing them together to obtain a semi-finished capacitor;

[0025] S5. Electroplating the capacitor semi-finished product to form a tin layer on the outer surface of the metal end cover, the vertical portion of the cathode pin and the outer surface of the two horizontal portions of the cathode pins, to obtain an airtight packaged laminated solid aluminum electrolytic capacitor.

[0026] Preferably, the step S4 is specifically:

[0027] S41, filling the end of the ceramic tube shell away from the open end with conductive silver paste, so that the conductive silver paste covers the surface of the cathode tongue;

[0028] S42, extending the cathode portion of the second core package into the cavity of the ceramic tube shell, so that the cathode portion of the second core package is bonded to the cathode tongue portion in the ceramic tube shell;

[0029] S43, fitting the metal end cover of the second core package with the first opening of the ceramic tube shell, and then fixing the opening edge of the metal end cover with the rectangular metal ring on the first opening by welding, so that an airtight seal is formed between the metal end cover and the ceramic tube shell.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The capacitor of the present invention uses a metal end cap and an inorganic material of a ceramic tube shell as a shell to achieve an airtight connection of the capacitor, which has better airtightness than resin packaging, better product reliability, and is more suitable for applications in harsh environments such as high temperature and high humidity;

[0032] At the same time, during the preparation of the capacitor of the present invention, the capacitor core package is first pre-stacked and then installed as a whole in a protective cavity formed by a metal end cover and a ceramic tube shell, thereby avoiding the extrusion damage to the core package by the liquid resin packaging material in the traditional resin injection molding packaging process, and the damage to the core performance by the stress generated during the curing process of the resin packaging material, solving the problems of leakage current and increased ESR caused by packaging, and significantly improving the industrial yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only 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 creative work.

[0034] Figure 1 It is a schematic structural diagram of the solid aluminum electrolytic capacitor of the present invention;

[0035] Figure 2 It is a schematic diagram of the front cross-section structure of the solid aluminum electrolytic capacitor of the present invention;

[0036] Figure 3 It is a schematic structural diagram of a metal end cover in a solid aluminum electrolytic capacitor of the present invention;

[0037] Figure 4 It is a schematic diagram of the structure of the ceramic tube shell in the solid aluminum electrolytic capacitor of the present invention;

[0038] Figure 5It is a schematic cross-sectional structure diagram of a ceramic tube shell in a solid aluminum electrolytic capacitor of the present invention;

[0039] Figure 6 It is a schematic structural diagram of the cathode lead-out portion in the solid aluminum electrolytic capacitor of the present invention;

[0040] Figure 7 The present invention is a schematic diagram of the process flow of the method for preparing the solid aluminum electrolytic capacitor.

[0041] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0042] 1. Core; 2. Metal end cap; 3. Ceramic tube shell; 31. Rectangular metal ring; 4. Rivet; 5. U-shaped metal spring; 6. Cathode lead-out part; 61. Cathode tongue; 62. Cathode connecting part; 63. Cathode pin vertical part; 64. Cathode pin horizontal part. Implementation

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] See also Figure 1-6 As shown, a technical solution provided by the present invention is:

[0045] A hermetic packaged laminated solid aluminum electrolytic capacitor comprises a plurality of cores 1, a metal end cap 2, a ceramic tube shell 3 and a rivet 4, wherein the metal end cap 2 and the ceramic tube shell 3 are both square open structures, and the two openings of the metal end cap 2 and the ceramic tube shell 3 are mutually nested and hermetically connected;

[0046] A U-shaped metal spring 5 is installed on the inner surface of the metal end cover 2 away from the opening, and the opening of the U-shaped metal spring 5 faces the opening direction of the metal end cover 2, and the U-shaped metal spring 5 is electrically connected to the metal end cover 2;

[0047] A cathode lead-out portion 6 is provided on the inner surface of the ceramic tube shell 3 away from the opening, and the cathode lead-out portion 6 passes through the side wall of the ceramic tube shell 3 away from the opening;

[0048] A plurality of cores 1 are stacked in sequence and arranged in a cavity formed by fitting a metal end cover 2 and a ceramic tube shell 3. The cathode portion of the core 1 is in contact with and electrically connected to the cathode lead-out portion 6, and the anode portion of the core 1 is inserted into the opening of the U-shaped metal spring sheet 5. One end of the rivet 4 passes through the anode portion of each core 1 in sequence, and the two ends of the rivet 4 are in contact with and electrically connected to the opposite side walls of the U-shaped metal spring sheet 5.

[0049] Specifically, the opposite ends of the rivet 4 pass through the anode portion of the core 1 and are bent toward the cathode portion of the core 1 , and the two bent portions of the rivet 4 are in contact with the opposite side walls of the U-shaped metal spring 5 .

[0050] From the above description, it can be seen that the rivet increases the contact area with the U-shaped metal spring after being bent, thereby ensuring a stable connection between the rivet and the U-shaped metal spring and achieving a stable electrical connection.

[0051] Specifically, the open end of the ceramic tube shell 3 includes a first open portion and a second open portion connected in sequence, the opening of the first open portion is smaller than the opening of the second open portion, and the first open portion is arranged at an end close to the metal end cover 2, the opening of the metal end cover 2 and the outer surface of the first open portion are mutually fitted, the inner surface of the first open portion is in contact with the outer surfaces of the opposite side walls of the U-shaped metal spring sheet 5, and a rectangular metal ring 31 is embedded in the outer surface of one end of the first open portion close to the second open portion.

[0052] From the above description, it can be seen that the open part of the ceramic tube shell is composed of a first open part and a second open part to form a two-level stepped structure to increase the matching degree of the metal end cover structure, and a metal ring is used to achieve a sealed connection between the ceramic tube shell and the metal end cover, thereby improving the airtightness of the metal end cover and the ceramic tube shell.

[0053] Specifically, the outer surfaces of the metal end caps 2 are all provided with a tin layer.

[0054] Specifically, the cathode lead-out portion 6 includes a cathode tongue 61, a cathode connecting portion 62, a cathode pin vertical portion 63 and two cathode pin horizontal portions 64 that are connected to each other. The cathode tongue 61 and the cathode pin vertical portion 63 are connected via the cathode connecting portion 62, and the cathode connecting portion 62 is passed through the interior of the ceramic tube shell 3. The cathode tongue 61 and the cathode pin vertical portion 63 are respectively arranged on the inner surface and the outer surface of the ceramic tube shell 3 away from the open end. The two cathode pin horizontal portions 64 are respectively arranged on the upper and lower surfaces of the ceramic tube shell 3 away from the open end, and one end of the two cathode pin horizontal portions 64 are both connected to the cathode pin vertical portion 63.

[0055] From the above description, it can be seen that the anode of the capacitor is a terminal wrapped by five vertical surfaces formed by a metal end cover, while the cathode adopts the terminal structure of the above three vertical surfaces, so that the anode and cathode of the capacitor are both symmetrical structures on the front and back sides. There is no need to distinguish between the front and back sides when welding the upper plate, and the anode terminal and the cathode terminal can be significantly distinguished in appearance, which is easy to identify, effectively preventing the reverse connection of the positive and negative poles, and is suitable for the anti-mistake needs of industrial production.

[0056] Specifically, the outer surfaces of the cathode pin vertical portion 63 and the two cathode pin horizontal portions 64 are both provided with a tin layer.

[0057] Specifically, the length of the cathode pin horizontal portion 64 is 20%-30% of the length of the finished capacitor.

[0058] Specifically, the length of the metal end cover 2 is 20% to 25% of the length of the finished capacitor.

[0059] From the above description, it can be seen that: considering the requirements of the operability of the welding process, the end of the U-shaped metal spring needs to extend beyond the edge of the metal end cover, that is, the length of the metal end cover determines the length of the anode part of the core. When the total length of the core is fixed, the longer the anode part of the core leads to the shorter cathode part of the core, and the effective area of ​​the cathode is reduced, which is manifested as a reduction in capacitance; there needs to be a sufficient distance between the metal end cover as the anode pin and the horizontal part of the cathode pin to prevent short circuit due to solder paste diffusion contact after the upper plate is welded; as a pin, sufficient welding area needs to be provided to ensure the firmness of the welding; therefore, by selecting a suitable metal end cover length and matching the length of the horizontal part of the cathode pin, the length of the cathode part of the core can be increased as much as possible on the basis of meeting the process operability to increase the capacitance of the capacitor, and at the same time meet the welding area requirements of the anode pin and the cathode pin to prevent short circuit between the two poles.

[0060] See also Figure 7 As shown, another technical solution provided by the present invention is:

[0061] A method for preparing a gas-tight packaged laminated solid aluminum electrolytic capacitor, the preparation method comprising the following steps:

[0062] S1, punching a chemically formed aluminum foil into a rectangle with a through hole at one end, coating a barrier adhesive to form an anode portion with a through hole and a cathode region without a through hole, and then sequentially forming a conductive polymer layer, a conductive carbon paste layer and a conductive silver paste layer on the surface of the cathode region to prepare a cathode portion, thereby obtaining a core 1;

[0063] S2, according to the designed number of layers, the cathode parts of the plurality of core pieces 1 are bonded and cured by conductive silver glue, and then rivets 4 are sequentially passed through the anode part through holes of the plurality of core pieces 1, and the exposed parts at both ends of the rivets 4 are bent toward the cathode part and closely attached to the surface of the anode part to form a group of bent parts, so that the anode parts of the plurality of core pieces 1 are fixedly connected and electrically connected to obtain a first core package;

[0064] S3, fixing and electrically connecting the bent portion of the rivet 4 on the first core package and the two side surfaces of the U-shaped metal spring sheet 5 by welding, so as to achieve the connection between the first core package and the metal end cover 2, and form a second core package;

[0065] S4, combining the second core package with the external ceramic tube shell 3 and sealing and connecting them to obtain a semi-finished capacitor;

[0066] S5. Electroplating the capacitor semi-finished product to form a tin layer on the outer surface of the metal end cover 2, the cathode pin vertical portion 63 and the outer surface of the two cathode pin horizontal portions 64, to obtain an airtight packaged laminated solid aluminum electrolytic capacitor.

[0067] Specifically, step S4 is as follows:

[0068] S41, filling the end of the ceramic tube shell 3 away from the open end with conductive silver paste, so that the conductive silver paste covers the surface of the cathode tongue 61;

[0069] S42, extending the cathode portion of the second core package into the cavity of the ceramic tube shell 3, so that the cathode portion of the second core package is bonded to the cathode tongue 61 in the ceramic tube shell 3;

[0070] S43, fit the metal end cover 2 of the second core package and the first opening of the ceramic tube shell 3 together, and then fix the opening edge of the metal end cover 2 to the rectangular metal ring 31 on the first opening by welding, so that an airtight seal is formed between the metal end cover 2 and the ceramic tube shell 3.

[0071] Embodiment 1 of the present invention is ( Figure 1-7 shown):

[0072] A hermetic packaged laminated solid aluminum electrolytic capacitor, comprising a plurality of cores 1, a metal end cap 2 (the length of the metal end cap 2 is 23% of the length of the finished capacitor, and the main body is made of copper and copper alloy), a ceramic tube shell 3 and a rivet 4 (made of copper and copper alloy), the metal end cap 2 and the ceramic tube shell 3 are both square open structures, and the two openings of the metal end cap 2 and the ceramic tube shell 3 are mutually nested and hermetically connected;

[0073] A U-shaped metal spring 5 is installed on the inner surface of the metal end cover 2 away from the opening, and the opening of the U-shaped metal spring 5 faces the opening direction of the metal end cover 2. The U-shaped metal spring 5 is electrically connected to the metal end cover 2, and the outer surface of the metal end cover 2 is provided with a tin layer;

[0074] A cathode lead-out portion 6 (made of copper and copper alloy) is provided on the inner surface of the ceramic tube shell 3 away from the opening, and the cathode lead-out portion 6 passes through the side wall of the ceramic tube shell 3 away from the opening, and the open end of the ceramic tube shell 3 includes a first open portion and a second open portion connected in sequence, the opening of the first open portion is smaller than the opening of the second open portion, and the first open portion is provided at an end close to the metal end cover 2, the opening of the metal end cover 2 and the outer surface of the first open portion are mutually fitted, the inner side surface of the first open portion is in contact with the outer side surfaces of the opposite side walls of the U-shaped metal spring sheet 5, and a rectangular metal ring 31 (made of Kovar alloy) is embedded in the outer side surface of one end of the first open portion close to the second open portion;

[0075] like Figure 2As shown: a plurality of cores 1 are stacked in sequence and arranged in a cavity formed by fitting a metal end cap 2 and a ceramic tube shell 3, the cathode portion of the core 1 is in contact with and electrically connected to the cathode lead-out portion 6, the anode portion of the core 1 is inserted into the opening of the U-shaped metal spring sheet 5, one end of the rivet 4 passes through the anode portion of each core 1 in sequence, and the opposite ends of the rivet 4 pass through the anode portion of the core 1 and are bent toward the cathode portion of the core 1, and the two bent portions of the rivet 4 are in contact with and electrically connected to the opposite side walls of the U-shaped metal spring sheet 5 respectively;

[0076] like Figure 5 and 6 As shown: In this embodiment, the cathode lead-out portion 6 includes a cathode tongue 61, a cathode connecting portion 62, a cathode pin vertical portion 63 and two cathode pin horizontal portions 64 (the length of the cathode pin horizontal portion 64 is 25% of the length of the finished capacitor), the cathode tongue 61 and the cathode pin vertical portion 63 are connected through the cathode connecting portion 62, and the cathode connecting portion 62 is penetrated into the ceramic tube shell 3, the cathode tongue 61 and the cathode pin vertical portion 63 are respectively arranged on the inner surface and the outer surface of the ceramic tube shell 3 away from the open end, the two cathode pin horizontal portions 64 are respectively arranged on the upper and lower surfaces of the ceramic tube shell 3 away from the open end, and one end of the two cathode pin horizontal portions 64 are connected to the cathode pin vertical portion 63, and the outer surfaces of the cathode pin vertical portion 63 and the two cathode pin horizontal portions 64 are provided with a tin layer.

[0077] like Figure 7 As shown: The preparation method of the above-mentioned laminated solid aluminum electrolytic capacitor is as follows:

[0078] A method for preparing a gas-tight packaged laminated solid aluminum electrolytic capacitor, the preparation method comprising the following steps:

[0079] S1, punching a chemically formed aluminum foil into a rectangle with a through hole at one end, coating a barrier adhesive to form an anode portion with a through hole and a cathode region without a through hole, and then sequentially forming a conductive polymer layer, a conductive carbon paste layer and a conductive silver paste layer on the surface of the cathode region to prepare a cathode portion, thereby obtaining a core 1;

[0080] S2, according to the designed number of layers, the cathode parts of the plurality of core pieces 1 are bonded and cured by conductive silver glue, and then rivets 4 are sequentially passed through the anode part through holes of the plurality of core pieces 1, and the exposed parts at both ends of the rivets 4 are bent toward the cathode part and closely attached to the surface of the anode part to form a group of bent parts, so that the anode parts of the plurality of core pieces 1 are fixedly connected and electrically connected to obtain a first core package;

[0081] S3, fixing and electrically connecting the bent portion of the rivet 4 on the first core package and the two side surfaces of the U-shaped metal spring sheet 5 by welding, so as to achieve the connection between the first core package and the metal end cover 2, and form a second core package;

[0082] In this embodiment, the welding method may be brazing, fusion welding, resistance welding, etc.;

[0083] S4, combining the second core package with the external ceramic tube shell 3 and sealing and connecting them to obtain a semi-finished capacitor;

[0084] In this embodiment, step S4 is specifically as follows:

[0085] S41, filling the end of the ceramic tube shell 3 away from the open end with conductive silver paste, so that the conductive silver paste covers the surface of the cathode tongue 61;

[0086] S42, extending the cathode portion of the second core package into the cavity of the ceramic tube shell 3, so that the cathode portion of the second core package is bonded to the cathode tongue 61 in the ceramic tube shell 3;

[0087] S43, fitting the metal end cap 2 of the second core package with the first opening of the ceramic tube shell 3, and then fixing the opening edge of the metal end cap 2 with the rectangular metal ring 31 on the first opening by welding, so that an airtight seal is formed between the metal end cap 2 and the ceramic tube shell 3

[0088] S5. Electroplating the capacitor semi-finished product to form a tin layer on the outer surface of the metal end cover 2, the cathode pin vertical portion 63 and the outer surface of the two cathode pin horizontal portions 64, to obtain an airtight packaged laminated solid aluminum electrolytic capacitor.

[0089] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hermetic packaged laminated solid aluminum electrolytic capacitor, characterized in that: It comprises a plurality of core pieces (1), a metal end cover (2), a ceramic tube shell (3) and a rivet (4), wherein the metal end cover (2) and the ceramic tube shell (3) are both square open structures, and the two open ends of the metal end cover (2) and the ceramic tube shell (3) are mutually nested and airtightly connected; A U-shaped metal spring sheet (5) is installed on the inner surface of the metal end cover (2) away from the opening, and the opening of the U-shaped metal spring sheet (5) faces the opening of the metal end cover (2), and the U-shaped metal spring sheet (5) is electrically connected to the metal end cover (2); A cathode lead-out portion (6) is provided on the inner surface of the ceramic tube shell (3) away from the opening, and the cathode lead-out portion (6) passes through a side wall of the ceramic tube shell (3) away from the opening; A plurality of cores (1) are stacked in sequence and arranged in a cavity formed by fitting a metal end cover (2) and a ceramic tube shell (3); the cathode portion of the core (1) contacts and is electrically connected to a cathode lead-out portion (6); the anode portion of the core (1) is inserted into an opening of a U-shaped metal spring sheet (5); one end of the rivet (4) passes through the anode portion of each core (1) in sequence, and the two ends of the rivet (4) contact and are electrically connected to opposite side walls of the U-shaped metal spring sheet (5).

2. The hermetic packaged laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The opposite ends of the rivet (4) pass through the anode portion of the core (1) and are bent toward the cathode portion of the core (1), and the two bent portions of the rivet (4) are in contact with the opposite side walls of the U-shaped metal spring sheet (5).

3. The hermetic packaged laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The open end of the ceramic tube shell (3) comprises a first open portion and a second open portion which are connected in sequence, the opening of the first open portion is smaller than the opening of the second open portion, and the first open portion is arranged at an end close to the metal end cover (2), the opening of the metal end cover (2) and the outer surface of the first open portion are mutually fitted, the inner surface of the first open portion is in contact with the outer surfaces of the opposite side walls of the U-shaped metal spring sheet (5), and a rectangular metal ring (31) is embedded in the outer surface of one end of the first open portion close to the second open portion.

4. The hermetic packaged laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The outer surfaces of the metal end covers (2) are all provided with a tin layer.

5. The hermetic packaged laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The cathode lead-out portion (6) comprises a cathode tongue portion (61), a cathode connecting portion (62), a cathode pin vertical portion (63) and two cathode pin horizontal portions (64) which are connected to each other; the cathode tongue portion (61) and the cathode pin vertical portion (63) are connected via the cathode connecting portion (62), and the cathode connecting portion (62) is arranged inside the ceramic tube shell (3); the cathode tongue portion (61) and the cathode pin vertical portion (63) are respectively arranged on the inner surface and the outer surface of the ceramic tube shell (3) away from the open end; the two cathode pin horizontal portions (64) are respectively arranged on the upper and lower surfaces of the ceramic tube shell (3) away from the open end; and one end of each of the two cathode pin horizontal portions (64) is connected to the cathode pin vertical portion (63).

6. The hermetic packaged laminated solid aluminum electrolytic capacitor according to claim 5, characterized in that: The outer surfaces of the cathode pin vertical portion (63) and the two cathode pin horizontal portions (64) are both provided with a tin layer.

7. The hermetic packaged laminated solid aluminum electrolytic capacitor according to claim 5, characterized in that: The length of the cathode pin horizontal portion (64) is 20%-30% of the length of the finished capacitor.

8. The hermetic packaged laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The length of the metal end cover (2) is 20% to 25% of the length of the finished capacitor.

9. A method for preparing the airtight packaged laminated solid aluminum electrolytic capacitor according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1, punching a chemically formed aluminum foil into a rectangle with a through hole at one end, coating it with a barrier adhesive to form an anode portion with a through hole and a cathode portion without a through hole, and then sequentially forming a conductive polymer layer, a conductive carbon paste layer and a conductive silver paste layer on the surface of the cathode portion to prepare a cathode portion, thereby obtaining a core (1); S2, according to the designed number of layers, the cathode parts of the plurality of core pieces (1) are bonded and cured by conductive silver glue, and then rivets (4) are sequentially passed through the anode part through holes of the plurality of core pieces (1), and the exposed parts at both ends of the rivets (4) are bent toward the cathode part and closely fit the surface of the anode part to form a group of bent parts, so that the anode parts of the plurality of core pieces (1) are fixedly connected and electrically connected to obtain a first core package; S3, fixing and electrically connecting the bent portion of the rivet (4) on the first core package and the two side surfaces of the U-shaped metal spring sheet (5) by welding, thereby achieving connection between the first core package and the metal end cover (2), and forming a second core package; S4, combining the second core package with the external ceramic tube shell (3) and sealing them together to obtain a semi-finished capacitor; S5. Electroplating the capacitor semi-finished product to form a tin layer on the outer surface of the metal end cover (2), the outer surface of the cathode pin vertical portion (63) and the outer surface of the two cathode pin horizontal portions (64), thereby obtaining an airtight packaged laminated solid aluminum electrolytic capacitor.

10. The method for preparing the airtight packaged laminated solid aluminum electrolytic capacitor according to claim 9, characterized in that: The step S4 is specifically as follows: S41, filling the interior of the ceramic tube shell (3) at the end away from the opening with conductive silver paste, so that the conductive silver paste covers the surface of the cathode tongue (61); S42, extending the cathode portion of the second core package into the cavity of the ceramic tube shell (3), so that the cathode portion of the second core package and the cathode tongue portion (61) in the ceramic tube shell (3) are bonded together; S43, fitting the metal end cover (2) of the second core package and the first opening of the ceramic tube shell (3) together, and then fixing the edge of the opening of the metal end cover (2) to the rectangular metal ring (31) on the first opening by welding, so that an airtight seal is formed between the metal end cover (2) and the ceramic tube shell (3).

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