An ultra-thin solid aluminum electrolytic capacitor

Abstract

The present invention relates to an ultra-thin solid aluminum electrolytic capacitor, comprising an outer shell and an element cover; an opening is provided on one side of the outer shell, and a flanged convex is provided at the opening; the cover and the opening are integrated by injection molding to encapsulate the element inside the outer shell; the cover comprises a substrate, an inner plug, and a side sealing wall; the upper end surface of the substrate is vertically provided with a side sealing wall and an inner plug; the inner plug is located on the inner side of the side sealing wall; the gap between the outer peripheral wall of the inner plug and the inner peripheral wall of the side sealing wall forms a groove; the groove is tightly combined with the inner and outer structures of the opening; the end surface of the inner plug is symmetrically provided with two lead holes that pass through the cover. Through the injection molding and integration of the cover and the outer shell opening structure, the cover can still meet the heat resistance and shock resistance conditions while reducing the thickness, so that the solid aluminum electrolytic capacitor using the cover can break through the product thinness limit while still having strong heat resistance and shock resistance, and achieve the ultra-thin effect of the solid aluminum electrolytic capacitor.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum electrolytic capacitors, in particular to an ultra-thin solid aluminum electrolytic capacitor. Background Art

[0002] Solid aluminum electrolytic capacitors are mainly used in electronic products. With the trend of thinning electronic products and electronic parts, capacitors are also thinning. Although the structure and manufacturing process of traditional solid aluminum electrolytic capacitors have been improved and upgraded, there are still technical bottlenecks that cannot be broken through in the thinning and miniaturization design of capacitors. The current SMD solid aluminum electrolytic capacitors are mainly based on the capacitor body after the aluminum electrolytic capacitor is packaged, and then the base is connected, and then the lead is bent to obtain the SMD solid aluminum electrolytic capacitor. The structure and process of the traditional solid aluminum electrolytic capacitor, which is to first package the rubber cover and then add the base, have the following defects. The current solid aluminum electrolytic capacitor is to cover the element with the rubber cover and squeeze and shrink the shell opening, and the thickness of the butyl rubber cover becomes the key point of the product height. In order to meet the conditions of air tightness and heat and shock resistance, and prevent product defects caused by moisture ingress and gas expansion, the thickness of the rubber cover must be kept at least 1.5mm, which limits the minimum height limit of the overall solid aluminum electrolytic capacitor product. Currently, the industry can produce solid aluminum electrolytic capacitors with a minimum height of 4.2mm. Solid aluminum electrolytic capacitors of this size cannot meet customers' demands for lower sizes. Breaking through this extreme thickness size has become a major problem in the industry. Summary of the invention

[0003] Based on this, it is necessary to provide an ultra-thin solid aluminum electrolytic capacitor, which is encapsulated by injection molding a cover body and an opening structure of a shell. The cover body can still meet the heat resistance and shock resistance conditions while reducing the thickness, so that the solid aluminum electrolytic capacitor using the cover body breaks through the product thinness limit while still having strong heat resistance and shock resistance, achieving the ultra-thin effect of the solid aluminum electrolytic capacitor.

[0004] The present invention solves the technical problem by adopting the following technical solutions:

[0005] An ultra-thin solid aluminum electrolytic capacitor, characterized in that it includes a shell, an element, and a cover body; an opening is opened on one side of the shell, and a flanged convex is arranged at the opening; the cover body and the opening are integrated by injection molding to encapsulate the element inside the shell; the cover body includes a substrate, an inner plug, and a side sealing wall; the side sealing wall and the inner plug are vertically arranged on the upper end surface of the substrate; the inner plug is located on the inner side of the side sealing wall; the gap between the outer peripheral wall of the inner plug and the inner peripheral wall of the side sealing wall forms a groove; the groove is tightly combined with the inner and outer structures of the opening; the end surface of the inner plug is symmetrically provided with two lead holes that penetrate the cover body; the lead holes are penetrated by leads as external lead-out electrodes.

[0006] Preferably, the cover body is formed by injecting molten plastic into the cavity between the opening of the shell and the element so that the plastic is tightly combined with the inner and outer components of the opening.

[0007] Preferably, the outer edge of the upper end of the inner plug is provided with a flange structure protruding outward, wherein the outer ring diameter of the flange structure is larger than the outer ring diameter of the inner plug.

[0008] Preferably, the side wall of the flange structure is provided with inner concave surfaces distributed around the circumferential direction, wherein the inner concave surfaces are in contact with the inner wall of the waist ring in the outer shell.

[0009] Preferably, a protrusion is provided on the inner wall of the side sealing wall away from one end of the base plate, wherein the protrusion is in contact with the outer wall of the waist ring in the outer shell.

[0010] Preferably, the groove portion includes a vertical groove and a horizontal groove, wherein the vertical groove and the horizontal groove intersect and penetrate in an L-shape, the vertical groove is embedded in the side wall of the shell, and the horizontal groove is embedded in the flanged protrusion at the opening.

[0011] Preferably, two lead grooves are arranged on the outer side of the bottom surface of the substrate, wherein one end of the lead groove is connected to the lead hole and one end away from the lead hole extends to the side wall of the substrate.

[0012] Preferably, a first gasket is provided between the end surface of the inner plug and the element, and a second gasket is provided between the end surface of the element and the top surface of the inner cavity of the outer shell.

[0013] Preferably, a clamping wall is extended from one end of the side sealing wall away from the base plate, wherein the inner wall of the clamping wall is tightly fitted with the outer wall of the shell.

[0014] Preferably, the lead includes a portion A, a welding portion, and a flattened portion, the portion A is a sheet-like structure connected to the element, the welding portion and the flattened portion are connected by the welding portion, and the flattened portion is provided with a bending portion.

[0015] The advantages and positive effects of the present invention are: an ultra-thin solid aluminum electrolytic capacitor is used to solve the problem in the prior art that the solid aluminum electrolytic capacitor needs to be connected to a base, which increases the total height of the product and makes it impossible to be thinner.

[0016] Compared with the prior art, the present invention has the following advantages: the present invention is encapsulated by injection molding the cover body and the shell opening, and the cover body can still meet the heat resistance and shock resistance conditions when the thickness is reduced, so that the solid aluminum electrolytic capacitor using the cover body breaks through the product thinness limit while still having strong heat resistance and shock resistance, and realizes the ultra-thin effect of the solid aluminum electrolytic capacitor. On the basis of the cover body of the present invention, the matching difference between the aluminum foil and the electrolytic paper in the element can be reduced to 0.5mm. The lead wire can adopt a flattening structure design without the B part, so that the lead wire structure can be miniaturized. The total height of the entire solid aluminum electrolytic capacitor can be controlled below 3.0mm, breaking through the current product size limit. The solid aluminum electrolytic capacitor using the cover body can significantly reduce its height while maintaining good heat resistance, shock resistance and sealing, and realize the thin design of the product. It meets the size requirements of the current electronic products with thinner designs, and at the same time improves its sealing, reflow soldering thermal stress and shock resistance stability, replacing the traditional packaging method of sealing with a rubber cover and then sleeved on the outer side with a shock-resistant seat plate. The service life of the solid aluminum electrolytic capacitor is extended, and the manufacturing process is simple, the operation is convenient, and the cost is low, which can meet the needs of the production field. The cover body 4 of the present invention can open up new application fields for chip-type solid aluminum electrolytic capacitors, solid-liquid hybrid aluminum electrolytic capacitors, and liquid aluminum electrolytic capacitors. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 the structures shown in these drawings without paying creative work.

[0018] Figure 1 It is a cross-sectional schematic diagram of the present invention.

[0019] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention.

[0020] Figure 3 It is a schematic diagram of the three-dimensional structure from another viewing angle of the present invention.

[0021] Figure 4 It is a schematic diagram of the three-dimensional structure of the cover body according to the first embodiment of the present invention.

[0022] Figure 5 It is a cross-sectional schematic diagram of the cover body of the present invention.

[0023] Figure 6 2 is a schematic cross-sectional view of a second embodiment of the present invention.

[0024] Figure 7 4 is a cross-sectional schematic diagram of a third embodiment of the present invention.

[0025] Figure 8 It is a schematic diagram of the three-dimensional structure of the shell of the present invention.

[0026] Fig. 9 It is a schematic diagram of the front and side structures of the lead of the present invention.

[0027] Explanation of the accompanying drawings: 1. shell; 2. element; 3. lead; 4. cover; 5. first gasket; 6. second gasket; 101. opening; 102. flange convex; 103. waist ring; 301. part A; 302. welding part; 303. flattening part; 304. bending part; 401. substrate; 402. inner plug; 403. side sealing wall; 404. groove; 405. lead hole; 4011. lead groove; 4012. cut corner; 4021. flange structure; 4022. inner concave surface; 4031. protrusion; 4032. clamping wall; 4041. vertical groove; 4042. horizontal groove. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are further described in detail in conjunction with the accompanying drawings: The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "bottom", "inner", "outer", etc. is based on the orientation or position relationship shown in the accompanying drawings. "Part A" and "Part B" are industry-specific designations for the structural names of the leads, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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. Example 1

[0029] The manufacturing process of the ultra-thin wound solid aluminum electrolytic capacitor of this embodiment is as follows:

[0030] S1: Prepare element 2, cut positive electrode aluminum foil, negative electrode aluminum foil and electrolytic paper according to preset size, nail positive electrode aluminum foil and negative electrode aluminum foil to lead wire 3 respectively, alternately stack positive electrode aluminum foil, electrolytic paper and negative electrode aluminum foil, and wind and fix them to obtain element 2.

[0031] S2: The element 2 is loaded into the inner cavity of the shell 1, and the opening 101 of the shell 1 is folded inwardly to form a flanged protrusion 102 by a sealing device.

[0032] S3: The housing 1 with the element 2 assembled therein is transferred into an injection mold, and the screw or plunger of the injection molding machine injects the molten plastic into the mold through the nozzle, and after cooling, a solid aluminum electrolytic capacitor sealed with a cover body 4 is obtained.

[0033] like Figure 1-Figure 4 As shown, an opening 101 is provided on one side of the shell 1, and a flanged protrusion 102 is provided at the opening 101; the cover body 4 and the opening 101 are integrated by injection molding to encapsulate the element 2 inside the shell 1; the cover body 4 includes a substrate 401, an inner plug 402, and a side sealing wall 403; the side sealing wall 403 and the inner plug 402 are vertically provided on the upper end surface of the substrate 401; the inner plug 402 is located on the inner side of the side sealing wall 403; the gap between the outer peripheral wall of the inner plug 402 and the inner peripheral wall of the side sealing wall 403 forms a groove 404; the groove 404 is tightly combined with the internal and external structures of the opening 101; the end surface of the inner plug 402 is symmetrically provided with two lead holes 405 that pass through the cover body 4; the lead hole 405 is penetrated by a lead 3 as an external lead-out electrode.

[0034] Specifically, the solid aluminum electrolytic capacitor is composed of a shell 1, an element 2, a lead 3, and a cover 4. The cover 4 hermetically seals the element 2 inside the shell 1, blocks external water vapor from entering the element 2, and keeps the inner cavity of the shell 1 and the element 2 dry. This prevents the conductive polymer in the element 2 from reacting with water vapor and failing. The opening 101 of the shell 1 is mainly formed by injection molding, and the cover 4 is embedded to form a sealed cavity in the inner cavity of the shell 1. The groove 404 is combined with the shell 1, wherein the inner plug 402 of the cover 4 forms a tight combination with the inner wall of the opening 101 of the shell 1 and the outer wall of the flange convex 102, which plays a role in sealing the inner side of the opening 101. The side sealing wall 403 of the cover 4 forms a tight combination with the outer wall of the shell 1, which plays a role in sealing the outside, and improves the sealing performance from the inside and outside respectively. At the same time, the flanged protrusion 102 is combined with the cover body 4 to prevent the solid aluminum electrolytic capacitor from deforming under high temperature and vibration environment, and prevent the cover body 4 from deforming and moving outward under high temperature or high pressure, thereby improving high temperature resistance and shock resistance.

[0035] The upper end surface of the substrate 401 is connected with the lower end surfaces of the inner plug 402 and the side sealing wall 403 respectively, so that the substrate 401, the inner plug 402, and the side sealing wall 403 are integrated. On the one hand, the sealing and rigidity are improved. Even if the thickness of the substrate 401 is reduced to less than 0.3 mm under the high temperature of reflow soldering, it will not be deformed. On the other hand, the substrate 401, the inner plug 402, and the side sealing wall 403 are integrated into one body. The substrate 401 increases the supporting force to protect the lead 3. The integrated structure of the substrate 401 and the inner plug 402 improves the sealing and heat resistance and shock resistance, so that the cover body 4 has both heat resistance and shock resistance. The cover body 4 can have both heat resistance and shock resistance without the need to add an additional shock-resistant seat plate. The cover body and the shell opening are injection-molded and integrated into one package, so that the cover body can still meet the heat resistance and firmness requirements while reducing the thickness. The inner plug 402 is coaxially arranged with the side sealing wall 403. In the present embodiment, the inner plug 402 is preferably a cylindrical structure, and the cross section of the side sealing wall 403 is an annular structure, and the axes of the inner plug 402 and the side sealing wall 403 coincide. In another embodiment, the cross sections of the inner plug 402 and the side sealing wall 403 can also be set to polygons. The total height of the entire solid-state aluminum electrolytic capacitor can be controlled below 3.0 mm, breaking through the current minimum height limit of the product, so that the cover body can be used in the solid-state aluminum electrolytic capacitor to have both heat resistance and shock resistance. The solid-state aluminum electrolytic capacitor using the cover body 4 can significantly reduce its height while maintaining good sealing, heat resistance and shock resistance, thereby realizing a thin design of the product.

[0036] The cover body 4 is formed by injecting molten plastic into the cavity between the opening 101 of the housing 1 and the element 2 so that the plastic is tightly combined with the inner and outer components of the opening 101 .

[0037] Specifically, after the shell 1 is assembled with the element 2, the shell 1 is placed in the injection mold. When the plastic melt reaches a predetermined temperature and pressure, the screw or plunger of the injection molding machine injects the molten plastic through the nozzle into the cavity between the outer side of the opening 101 and the mold to form a cavity. After injection molding, the side sealing wall 403, the cavity between the inner side of the opening 101 and the flanged convex 102 and the element 2 are formed. After injection molding, the base plate 401 and the inner plug 402 are formed. After cooling, the integrated cover body 4 is obtained. The plastic is tightly combined with the inner and outer components of the opening 101. The cover body 4 is embedded with the shell 1 and the opening 101 to form a whole. The cover body 4 hermetically seals the element 2 inside the shell. A thin solid aluminum electrolytic capacitor is obtained.

[0038] The outer edge of the upper end of the inner plug 402 is provided with a flange structure 4021 protruding outward, wherein the outer diameter of the flange structure 4021 is larger than the outer diameter of the inner plug 402. Specifically, after the injection molding is completed, the inner plug 402 is formed inside the opening 101. In this embodiment, the outer shell 1 is cylindrical, so the shape of the inner plug 402 is a columnar body, which fits tightly with the inner wall of the outer shell 1. In other embodiments, the cross-sectional shape of the outer shell 1 can be rectangular or triangular, and the cross-sectional shape of the inner plug 402 used is also matched to be rectangular or triangular. In addition, in this embodiment, the flanged card protrusion 102 at the opening 101 is folded inwardly, and in other embodiments, the flanged card protrusion 102 can be set to be folded outwardly, which can also play the role of clamping the cover body 4 to improve heat resistance and firmness.

[0039] The outer edge of the upper end of the inner plug 402 is provided with a flange structure 4021 protruding outward, the outer ring diameter of the flange structure 4021 is larger than the outer ring diameter of the inner plug 402, and the outer peripheral side wall of the flange structure 4021 and the lower end surface of the flange structure 4021 form a step structure. The step structure matches and engages with the flanged convex 102 to improve stability and heat-resistant sealing, and can also prevent the cover body 4 from slipping when the internal air pressure expands at high temperature. The outer peripheral side surface of the flange structure 4021 is tightly fitted with the inner peripheral wall of the shell 1, and the lower end surface of the flange structure 4021 is tightly fitted with the upper end surface of the flanged convex 102 at the opening 101, which improves the sealing effect.

[0040] The groove portion 404 includes a vertical groove 4041 and a horizontal groove 4042 , wherein the vertical groove 4041 and the horizontal groove 4042 intersect and penetrate in an L-shape, the vertical groove 4041 is embedded in the side wall of the housing 1 , and the horizontal groove 4042 is embedded in the flanged protrusion 102 at the opening 101 .

[0041] Specific as Figure 4-Figure 5 As shown, the groove 404 is formed by embedding the peripheral wall of the shell 1 and the flange protrusion 102 when the cover body 4 is injection-molded, and the groove 404 forms a heterogeneous and seamless fit with the peripheral wall of the shell 1 and the flange protrusion 102, wherein the vertical groove 4041 and the horizontal groove 4042 intersect and penetrate in an L-shape to form a matching fit with the flange protrusion 102 of the opening 101 of the shell 1. On the one hand, the path for external water vapor to enter is extended to improve the sealing and heat resistance effects, and on the other hand, the L-shaped structure improves the structural stability and heat and shock resistance effects.

[0042] The lead 3 includes a portion A 301 , a welding portion 302 , and a flattened portion 303 . The portion A 301 is a sheet-like structure connected to the element 2 . The welding portion 302 is connected to the flattened portion 303 . The flattened portion 303 is provided with a bending portion 304 .

[0043] Specifically, when the lead 3 is processed, the A portion 301 is specifically a structure formed by flattening the aluminum column. The lower end of the A portion 301 is welded to the flattened portion 303 through the welding portion 302, which shortens the longitudinal length of the lead 3. The flattened portion 303 is a flat structure that can reduce the longitudinal height. The structural design of the lead 3 is matched with the cover 4 to reduce the longitudinal height of the lead 3 and the cover 4. In addition, the lead 3 is preset with a bending portion 304, so that the lead 3 does not need to be bent again after the cover 4 is injection molded, avoiding damage to the thin solid aluminum electrolytic capacitor body structure caused by the secondary bending. Therefore, the structural design of the lead 3 of the present invention provides a necessary condition for the thinning of the product.

[0044] Two lead holes 405 penetrating the cover body 4 are symmetrically arranged on the end face of the inner plug 402; the lead holes 405 are penetrated by leads 3 as external lead electrodes, and two lead grooves 4011 are arranged on the outer side of the bottom surface of the substrate 401, wherein one end of the lead groove 4011 is connected to the lead hole 405 and extends to the side wall of the substrate 401 away from one end of the lead hole 405.

[0045] The element 2 is formed by stacking positive foil, electrolytic paper, and negative foil, and winding them. The lead 3 is divided into a positive lead and a negative lead, wherein the positive foil is connected to the positive lead, and the negative foil is connected to the negative lead. When the cover 4 is injection molded, the lead 3 is pre-buried in the cover 4. After injection molding, the lead 3 runs through the inner plug 402 and the substrate 401. The positive and negative leads 3 pass through one end of the substrate 401 and are bent and attached to the lead groove 4011. The lead 3 extends along the lead groove 4011 to the side wall of the substrate 401 and is exposed. The positive and negative leads 3 exposed from the substrate 401 are welded and fixed to the PCB board. The lead wire 3 is led out from the element 2, passes through the inner plug 402 and the substrate 401, and is directly welded and fixed to the PCB board. Since the inner plug 402 and the substrate 401 are integrally formed, they have heat resistance and shock resistance, and do not require an additional socket base, which can meet the heat resistance and shock resistance application conditions of the chip-type solid aluminum electrolytic capacitor. Therefore, the total height of the cover body 4 can be greatly reduced while ensuring that the cover body 4 has good sealing heat resistance and shock resistance and heat resistance, replacing the traditional butyl rubber plug plus base combination design. When the design of the cover body 4 is applied to the solid aluminum electrolytic capacitor, the matching gap between the aluminum foil and the electrolytic paper can be reduced to 0.5mm, which can further reduce the total height of the solid aluminum electrolytic capacitor, and the aluminum foil cutting width can be set to less than 1.6mm. At the same time, since the substrate 401, the inner plug 402, and the side sealing wall 403 of the cover body 4 of the present invention are integrally formed, based on the structure of the cover body 4 of the present invention, the total thickness of the inner plug 402 can be reduced to below 1.3 mm, and the thickness of the substrate 401 can be reduced to below 0.3 mm. Based on the integral structure of the substrate 401, the inner plug 402, and the side sealing wall 403, even if the total thickness of the inner plug 402 can be reduced to below 1.3 mm, the thickness of the substrate 401 can be reduced to below 0.3 mm. The total height of the assembled wound solid aluminum electrolytic capacitor can be controlled below 3.0 mm, breaking through the limit size, and the product can still resist the gas expansion shock after reflow soldering at high temperature, and still maintain its heat resistance and shock resistance. Example 2

[0046] The manufacturing process of the ultra-thin wound solid aluminum electrolytic capacitor of this embodiment is as follows:

[0047] S1: Prepare element 2, cut positive electrode aluminum foil, negative electrode aluminum foil and electrolytic paper according to preset size, nail positive electrode aluminum foil and negative electrode aluminum foil to lead wire 3 respectively, alternately stack positive electrode aluminum foil, electrolytic paper and negative electrode aluminum foil, and wind and fix them to obtain element 2.

[0048] S2: The element 2 is loaded into the inner cavity of the shell 1, and the opening 101 of the shell 1 is folded inwardly by a sealing device to form a flanged convexity 102, and the outer peripheral wall of the shell 1 is squeezed by a waisting wheel to form a waisting ring 103.

[0049] S3: The housing 1 with the element 2 assembled therein is transferred into an injection mold, and the screw or plunger of the injection molding machine injects the molten plastic into the mold through the nozzle, and after cooling, a solid aluminum electrolytic capacitor sealed with a cover body 4 is obtained.

[0050] Reference Figure 6 , which is the second embodiment of the present invention. This embodiment is based on the previous embodiment. The side wall of the specific flange structure 4021 is provided with inner concave surfaces 4022 distributed around the circumferential direction, wherein the inner concave surface 4022 is in contact with the inner wall of the waist ring 103 in the outer shell 1.

[0051] Furthermore, the outer shell 1 is provided with an inwardly contracted waist ring 103 near the opening 101, and the waist ring 103 is formed by a waist wheel before the cover body 4 is injection molded. The inner wall of the waist ring 103 is convex, and the outer wall of the waist ring 103 is concave. During injection molding, the molten plastic immerses the inner wall of the waist ring 103, which is convex. After cooling, the inner concave surface 4022 distributed around the circumferential direction of the side wall of the flange structure 4021 is formed. The existence of the inner concave surface 4022 further extends the path for water vapor to enter, strengthens the sealing performance between the outer peripheral wall of the flange structure 4021 and the inner wall of the outer shell 1, and at the same time, the inner concave surface 4022 is combined with the inner wall of the waist ring 103 of the outer shell 1, further improving the structural stability.

[0052] The inner wall of the side sealing wall 403 away from the substrate 401 is provided with a protrusion 4031, wherein the protrusion 4031 is in contact with the outer wall of the waist ring 103 in the housing 1. Specifically, the side sealing wall 403 is a structure formed by injection molding of the cavity between the injection mold and the outer wall of the housing 1, and the outer wall of the waist ring 103 is concave. During injection molding, the molten plastic immerses the concave surface of the outer wall of the waist ring 103, and after cooling, the protrusion 4031 on the inner wall of the side sealing wall 403 is formed. The existence of the protrusion 4031 further extends the path for water vapor to enter, strengthens the sealing and shock resistance of the inner peripheral wall of the side sealing wall 403 and the outer peripheral wall of the housing 1, and at the same time, the protrusion 4031 meshes with the concave surface of the outer wall of the waist ring 103 of the housing 1, further improving the stability of the structure. Example 3

[0053] The manufacturing process of the ultra-thin wound solid aluminum electrolytic capacitor of this embodiment is as follows:

[0054] S1: Prepare element 2, cut positive electrode aluminum foil, negative electrode aluminum foil and electrolytic paper according to preset size, nail positive electrode aluminum foil and negative electrode aluminum foil to lead wire 3 respectively, alternately stack positive electrode aluminum foil, electrolytic paper and negative electrode aluminum foil, and wind and fix them to obtain element 2.

[0055] S2: The element 2 is loaded into the inner cavity of the shell 1, and the opening 101 of the shell 1 is folded inwardly by a sealing needle to form a flanged convexity 102, and the outer peripheral wall of the shell 1 is squeezed by a waisting wheel to form a waisting ring 103.

[0056] S3: The housing 1 with the element 2 assembled therein is transferred into an injection mold, and the screw or plunger of the injection molding machine injects the molten plastic into the mold through the nozzle, and after cooling, a solid aluminum electrolytic capacitor sealed with a cover body 4 is obtained.

[0057] Reference Figure 7 , which is the third embodiment of the present invention. This embodiment is based on the previous embodiment. Specifically, a clamping wall 4032 is extended from one end of the side sealing wall 403 away from the substrate 401, wherein the inner wall of the clamping wall 4032 is tightly fitted with the outer wall of the housing 1.

[0058] The side sealing wall 403 and the clamping wall 4032 are integrally formed by injection molding, and the inner peripheral wall of the clamping wall 4032 is tightly fitted with the outer peripheral wall of the housing 1. The total height of the side sealing wall 403 and the clamping wall 4032 is more than half of the longitudinal height of the housing 1. On the one hand, the path for water vapor to enter is extended, and the sealing effect is improved. On the other hand, the side sealing wall 403 is combined with the clamping wall 4032 to increase the force-bearing area, improve the heat stress and mechanical stress resistance to high-temperature reflow soldering, and improve the anti-seismic effect.

[0059] like Figure 2 As shown, the substrate 401 at the bottom of the cover body 4 is rectangular, and its thickness can be set below 0.3mm. The corners at one end of the substrate 401 are set as cut corners 4012 to distinguish the positive and negative poles of the solid aluminum electrolytic capacitor. The entire cover body 4 is integrally injection molded using plastic sealing materials such as epoxy resin. The substrate 401 is integrally molded with the inner plug 402 and the side sealing wall 403. The upper end surface of the substrate 401 is combined with the support of the inner plug 402 and the side sealing wall 403 to form an interaction force to maintain a stable structure, so that the substrate 401 is set below 0.3mm and will not produce thermal deformation during reflow soldering. If the thickness of the traditional split seat plate is set below 0.3mm, it will deform at high temperatures and cannot meet the requirements of sealing and heat resistance. On the other hand, after the substrate 401 of the present invention is welded and combined with the PCB board, the substrate 401 increases the force-bearing area, prevents the lead 3 from being broken by external force, and improves the shock resistance. The integrated design of the base plate 401, the inner plug 402 and the side sealing wall 403 replaces the traditional separate assembly method of the rubber cover and the base plate, so that the solid aluminum electrolytic capacitor still has strong sealing, heat resistance and shock resistance when it is reduced to the extreme height.

[0060] like Figure 7 As shown, a first gasket 5 is arranged between the end surface of the inner plug 402 and the element 2, and a second gasket 6 is arranged between the end surface of the element 2 and the top surface of the inner cavity of the shell 1.

[0061] The first gasket 5 is placed at the end face of the element 2 before injection molding, and the lead 3 passes through the first gasket 5. During injection molding, the first gasket 5 blocks the molten plastic and prevents the molten plastic from flowing into the interior of the element 2, thereby playing a blocking and heat-insulating role, thereby preventing the occurrence of plastic penetration between the positive aluminum foil, negative aluminum foil, electrode paper and conductive polymer inside the element 2.

[0062] A second gasket 6 is provided between the end face of the element 2 and the top face of the inner cavity of the shell 1. Since the gap between the aluminum foil and the electrolytic paper is reduced to 0.5 mm, the distance between the end of the positive aluminum foil and the inner wall of the shell 1 is close. The second gasket 6 is provided to prevent the end of the positive aluminum foil from contacting the inner wall of the shell 1 and causing a short circuit, thereby improving safety. In an embodiment, the thickness of the first gasket 5 and the second gasket 6 can be set to an insulating material between 0.03-0.04 mm. In another embodiment, the material of the first gasket 5 and the second gasket 6 can be an insulating thermal conductive material, which can further improve heat resistance and heat dissipation.

[0063] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive, and therefore the present invention is not limited to the embodiments described in the specific implementation manners. Any other implementation manners derived by those skilled in the art based on the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. An ultra-thin solid aluminum electrolytic capacitor, characterized in that: The invention comprises an outer shell (1), an element (2), and a cover (4); an opening (101) is provided on one side of the outer shell (1), and a flanged protrusion (102) is provided at the opening (101); the cover (4) and the opening (101) are integrally joined by injection molding to encapsulate the element (2) inside the outer shell (1); the cover (4) comprises a base plate (401), an inner plug (402), and a side sealing wall (403); the side sealing wall (403) and the inner plug (402) are vertically provided on the upper end surface of the base plate (401); the inner plug (402) is located on the inner side of the side sealing wall (403); a flange structure (4021) protruding outward is provided on the outer edge of the upper end of the inner plug (402), wherein the outer diameter of the flange structure (4021) is larger than the outer diameter of the inner plug (402); the side wall of the flange structure (4021) is provided with a circumferentially shaped flange structure (4021) and a flange structure (4021) protruding outwardly. The inner concave surface (4022) is distributed in the direction of the outer shell (1), wherein the inner concave surface (4022) and the inner wall of the waist ring (103) in the outer shell (1) fit into the gap between the outer peripheral wall of the inner plug (402) and the inner peripheral wall of the side sealing wall (403) to form a groove portion (404); the groove portion (404) is tightly combined with the inner and outer structures of the opening (101); the groove portion (404) comprises a vertical groove (4041) and a horizontal groove (4042), wherein the vertical groove (4041) and the horizontal groove (4042) intersect and penetrate in an L-shape, the vertical groove (4041) is embedded in the side wall of the outer shell (1), and the horizontal groove (4042) is embedded in the flanged protrusion (102) at the opening (101); the end surface of the inner plug (402) is symmetrically provided with two lead holes (405) penetrating the cover body (4); the lead holes (405) are penetrated by leads (3) as external lead-out electrodes.

2. The ultra-thin solid aluminum electrolytic capacitor according to claim 1, characterized in that: The cover body (4) is formed by injecting molten plastic into the cavity between the opening (101) of the shell (1) and the element (2), so that the plastic is tightly combined with the inner and outer components of the opening (101).

3. The ultra-thin solid aluminum electrolytic capacitor according to claim 1, characterized in that: A protrusion (4031) is provided on the inner wall of the side sealing wall (403) at one end away from the base plate (401), wherein the protrusion (4031) fits with the outer wall of the waist ring (103) in the outer shell (1).

4. The ultra-thin solid aluminum electrolytic capacitor according to claim 1, characterized in that: Two lead grooves (4011) are arranged on the outer side of the bottom surface of the substrate (401), wherein one end of the lead groove (4011) is connected to the lead hole (405), and the end away from the lead hole (405) extends to the side wall of the substrate (401).

5. The ultra-thin solid aluminum electrolytic capacitor according to claim 1, characterized in that: A first gasket (5) is provided between the end surface of the inner plug (402) and the element (2), and a second gasket (6) is provided between the end surface of the element (2) and the top surface of the inner cavity of the outer shell (1).

6. The ultra-thin solid aluminum electrolytic capacitor according to claim 1, characterized in that: A clamping wall (4032) is provided extending from one end of the side sealing wall (403) away from the base plate (401), wherein the inner wall of the clamping wall (4032) is tightly fitted with the outer wall of the housing (1).

7. The ultra-thin solid aluminum electrolytic capacitor according to claim 1, characterized in that: The lead (3) comprises a portion A (301), a welding portion (302), and a flattened portion (303); the portion A (301) is a sheet-like structure connected to the element (2); the welding portion (302) and the flattened portion (303) are connected by the welding portion (302); and the flattened portion (303) is provided with a bending portion (304).

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