Novel miniature aluminum electrolytic capacitor

Abstract

The invention relates to a novel miniature aluminum electrolytic capacitor, which comprises a shell, a packaging body, an element, a positive electrode pin and a negative electrode pin, and is characterized in that the element is arranged in the shell, the shell is sealed and wrapped in a containing cavity of the packaging body, the top end of the shell penetrates out of the upper end of the packaging body and is exposed out of the packaging body, and the positive electrode pin is arranged in the shell. The positive electrode pin and the negative electrode pin respectively penetrate out of the outer side of the packaging body to be exposed, and the shell and the packaging body are of a heterogeneous integrally-formed structure. According to the aluminum electrolytic capacitor, the integrally-formed packaging structure in which the shell is wrapped by the packaging body is adopted, the height of the aluminum electrolytic capacitor is further reduced by adopting the packaging structure, the micro design of the aluminum electrolytic capacitor is realized, and meanwhile, the aluminum electrolytic capacitor still has relatively high anti-pressure capability and a relatively high sealing effect. Meanwhile, under the condition of the same size and the same electrical parameter, the manufacturing cost of the aluminum electrolytic capacitor is lower than that of a tantalum capacitor, the preparation process is simpler than that of the tantalum capacitor, and the aluminum electrolytic capacitor can completely replace the tantalum capacitor in practical application.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum electrolytic capacitors, in particular to a novel miniature aluminum electrolytic capacitor. Background Art

[0002] Aluminum electrolytic capacitors are mainly used in electronic products. With the rapid development of artificial intelligence, related electronic products are entering the trend of intelligent and miniaturized design, which also puts forward higher requirements for the reliability and miniaturization design of aluminum electrolytic capacitors. Although the structure and manufacturing process of traditional aluminum electrolytic capacitors have been improved and upgraded, there are still technical bottlenecks that cannot be broken through in the miniaturization design of aluminum electrolytic capacitors. The traditional aluminum electrolytic capacitors are first encapsulated with a rubber cover and then a base. The current manufacturing process in the industry still cannot produce aluminum electrolytic capacitors with a height of less than 2.8mm. For example, in the disclosed patent, patent number CN202122660389.0 is a seismic capacitor seat plate. The seismic seat plate is additionally sleeved on the bottom of the capacitor body to enhance the seismic effect. However, the seat plate sleeved on the bottom will increase the total height of the capacitor, so it cannot be used in electronic devices with thin designs. For another example, patent number CN202411623591.8 is an ultra-thin solid-state aluminum electrolytic capacitor, which integrates the cover and substrate into one design. Although this reduces the overall height of the capacitor, when the total height of the capacitor designed in this scheme is less than 3.0 mm, the force between the capacitor shell and the cover is insufficient. In a high-temperature environment, when the internal pressure of the capacitor increases and expands, the shell and the cover are likely to separate. For another example, in the prior art, the purpose of thin design is achieved by reducing the thickness of the capacitor's sealing cover. However, when the thickness of the sealing cover is reduced to a certain extent, its sealing cannot be guaranteed, which limits further thinning of the design. Therefore, existing aluminum electrolytic capacitors still cannot break through the thin design barrier. Even if a thin design is adopted, there are still problems with poor pressure resistance and moisture resistance. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides a new miniature aluminum electrolytic capacitor. By adopting an integrated packaging structure in which the packaging body wraps the shell, the height of the aluminum electrolytic capacitor is further reduced, thereby achieving a miniature design of the aluminum electrolytic capacitor while still having strong pressure resistance and stability.

[0004] The present invention solves the technical problem by adopting the following technical solutions: A novel miniature aluminum electrolytic capacitor includes a shell, an encapsulation body, an element, a positive electrode pin, and a negative electrode pin. The characteristic is that the element is arranged inside the shell, the shell is sealed and wrapped in the cavity of the encapsulation body, the top end of the shell passes through the upper end of the encapsulation body to be exposed, the positive electrode pin and the negative electrode pin respectively pass through the outside of the encapsulation body to be exposed, and the shell and encapsulation body are a heterogeneous integrated molding structure.

[0005] Preferably, the packaging body is made of insulating material, the cavity is surrounded by a bottom wall and side walls, and an opening is formed at the upper end of the cavity.

[0006] Preferably, a closing structure for limiting the outward movement of the shell is provided at the opening, and the inner diameter of the closing structure is smaller than the outer diameter of the shell.

[0007] Preferably, a filling body for sealing and fixing the element is provided between the inner peripheral wall of the shell and the outer peripheral wall of the element.

[0008] Preferably, the inner peripheral side wall of the cavity is provided with a plurality of flange structures.

[0009] Preferably, a waist structure is provided on the outer periphery of the shell, and the waist structure is matched and combined with the flange structure.

[0010] Preferably, the bottom surface of the package body is provided with a plurality of protruding structures, and the outer side surface of one end of the package body is provided with a cut-off structure for distinguishing the positive and negative poles.

[0011] Preferably, the height of the side wall of the packaging body is consistent with the height of the shell, and the upper end surface of the packaging body is horizontally aligned with the upper end surface of the shell.

[0012] Preferably, the element comprises a positive foil, a negative foil and electrolytic paper, wherein the positive foil, the negative foil and the electrolytic paper are stacked at intervals and then wound to form the element, the positive foil is connected to a positive electrode pin, and the negative foil is connected to a negative electrode pin.

[0013] Preferably, the positive electrode pin and the negative electrode pin pass through the bottom of the package body, and the exposed portions are bent in opposite directions and attached to the bottom of the package body as electrode leads.

[0014] The advantages and positive effects of the present invention are: a new type of miniature aluminum electrolytic capacitor is used to solve the problem in the prior art that aluminum electrolytic capacitors are prone to structural disintegration when they are thinly designed, resulting in poor compressive resistance of the aluminum electrolytic capacitors.

[0015] Compared with the prior art, the present invention has the following advantages: the present invention adopts injection molding to integrate the shell and the package into a heterogeneous whole, thereby realizing the preparation of an aluminum electrolytic capacitor with a height of less than 2.8 mm. This not only reduces the total height of the aluminum electrolytic capacitor but also improves the compressive strength by 30%.

[0016] 1. The design of the package body wrapping the shell increases the sealing area. The package body is made of insulating material, and only the top surface of the entire aluminum electrolytic capacitor shell is exposed, which increases the insulation and sealing performance. The sealing performance is improved by 20%, which improves the safety performance of the aluminum electrolytic capacitor.

[0017] 2. The package body wraps the outer side of the aluminum electrolytic capacitor shell through the package body design. When the entire aluminum electrolytic capacitor is operating in a high-temperature environment, the package body can effectively isolate the high temperature of the external environment from entering, allowing the aluminum electrolytic capacitor to maintain stable operation in a high-temperature environment of 170°C, achieving a high-temperature resistance effect, and the temperature resistance is improved by 25%.

[0018] 3. The aluminum electrolytic capacitor adopts a square design that is similar to a tantalum capacitor through the packaging body wrapping the shell design. The total height of the aluminum electrolytic capacitor can be less than 2.8mm, so that the aluminum electrolytic capacitor can be miniaturized in design and preparation. Compared with tantalum capacitors in the same industry, under the same size and volume, the aluminum electrolytic capacitor has a larger capacity and better electrical parameters. At the same time, under the same size and electrical parameters, the manufacturing cost of the aluminum electrolytic capacitor is lower than that of tantalum capacitors, and the preparation process is simpler than that of tantalum capacitors. In practical applications, it can completely replace tantalum capacitors. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0021] Figure 2 It is a bottom view schematic diagram of the present invention.

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure of the package body of the present invention.

[0023] Figure 4 This invention Figure 1 Schematic diagram of the cross section along the aa direction.

[0024] Figure 5 It is a schematic diagram of the explosion of parts of the present invention.

[0025] Figure 6 This invention Figure 4 A partial enlarged schematic diagram of the middle A.

[0026] Figure 7 FIG. 4 is a schematic cross-sectional view of a third embodiment of the present invention.

[0027] Figure 8 This invention Figure 7 A partial enlarged schematic diagram of B in the figure.

[0028] Figure 9 It is a schematic diagram of the three-dimensional structure of the fourth embodiment of the present invention.

[0029] Figure 10 FIG. 4 is a schematic cross-sectional view of a fourth embodiment of the present invention.

[0030] Figure 11 It is a schematic cross-sectional view of Comparative Example 1 of the present invention.

[0031] Explanation of the accompanying reference numerals: 1. Shell; 101. Waist structure; 102. Chamfer structure; 2. Package body; 201. Cavity; 202. Opening; 203. Closing structure; 204. Protruding structure; 205. Cut-angle structure; 206. Flange structure; 2011. Bottom wall; 2012. Side wall; 3. Element; 301. Positive foil; 302. Negative foil; 303. Electrolytic paper; 4. Filler; 5. Positive electrode pin; 6. Negative electrode pin; 7. Rubber plug; 8. Seat plate. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are further described in detail with reference to the accompanying drawings: The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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 in no way 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 this field without making any creative work are within the scope of protection of the present invention. Example 1

[0033] Specifically, this embodiment takes the preparation of an aluminum electrolytic capacitor with a total height of 2.6 mm and a width of 6.6 mm as an example.

[0034] In this embodiment, the element 3 includes a positive foil 301 , a negative foil 302 , and an electrolytic paper 303 , wherein the positive foil 301 , the negative foil 302 , and the electrolytic paper 303 are stacked at intervals and then wound to form the element 3 . The positive foil 301 is connected to a positive electrode pin 5 , and the negative foil 302 is connected to a negative electrode pin 6 .

[0035] Step 1: Prepare the element 3. Cut the positive foil 301 to a height of 1.5 mm and the negative foil 302 to a height of 1.5 mm, and the corresponding electrolytic paper 303 to a height of 1.7 mm. Connect the positive lead 5 to the positive foil 301 as the positive lead, and connect the negative lead 6 to the negative foil 302 as the negative lead. Then, stack the positive foil 301, electrolytic paper 303, and negative foil 302 in intervals and wind them together to form the shaped element 3.

[0036] Step 2: Weld the positive electrode pin 5 or the negative electrode pin 6 of the element 3 to the iron bar at intervals, and then immerse the element 3 in electrolyte.

[0037] Step 3: Place the electrolyte-impregnated element 3 into the inner cavity of the housing 1. Then, add filler 4 until the filler 4 completely fills the gap between the outer periphery of the element 3 and the inner wall of the housing 1. Once the filler 4 solidifies, it effectively secures the element 3 within the housing 1, facilitating bending of the positive and negative leads 5 and 6 without damaging the element 3.

[0038] Step 4: Cut element 3 from the iron bar, then bend the positive and negative leads 5 and 6 in opposite directions. In this embodiment, the positive and negative leads 5 and 6 are bent at an angle of approximately 90 degrees toward the outer sidewalls of element 3. This prepares the package 2 for the next step.

[0039] Step 5: Place the semi-finished product prepared in the third step, i.e., the combination of the shell 1, element 3, and filler 4, into an injection mold. Then, inject molten insulating material into the mold. After cooling, the aluminum electrolytic capacitor with the shell 1 and the encapsulation body 2 heterogeneously integrated is obtained. After cutting and demolding, the individual aluminum electrolytic capacitor bodies are obtained.

[0040] The aluminum electrolytic capacitor obtained after casting is as follows Figure 1 、 Figure 4 As shown, the element 3 is arranged inside the shell 1, and the shell 1 is sealed and wrapped in the cavity 201 of the package body 2. The top end of the shell 1 passes through the upper end of the package body 2 and is exposed. The positive pin 5 and the negative pin 6 pass through the outside of the package body 2 and are exposed. The shell 1 and the package body 2 are heterogeneous integrated molding structures.

[0041] Preferably, the package body 2 is made of an insulating material. In this embodiment, the package body 2 is formed by injection molding of a plastic material. Depending on actual needs, the package body 2 can also be made of an insulating and heat-insulating plastic material. This serves to block the external temperature from entering the capacitor, preventing the external high temperature from affecting the internal elements 3, thereby improving the stability of the aluminum electrolytic capacitor.

[0042] Preferably, a filling body 4 for sealing and fixing the element 3 is provided between the inner peripheral wall of the housing 1 and the outer peripheral wall of the element 3 .

[0043] Before injection molding the package body 2, a filler 4 needs to be added to the inner cavity of the shell 1 until the filler 4 fills the gap between the outer periphery of the element 3 and the inner cavity wall of the shell 1. After the filler 4 is cured, the element 3 can be effectively fixed in the shell 1, and at the same time, a support and fixing point is provided for the bending processing of the positive and negative pins, which improves the problem of damaging the element 3 during the bending processing of the positive pin 5 and the negative pin 6. On the other hand, the filler 4 can also block high temperature and enhance the sealing effect.

[0044] More specifically, the filler 4 can be made of an insulating material, such as epoxy resin or thermally conductive silicone. The specific material of the filler 4 is not specifically limited. The filler 4 of this embodiment is made of epoxy resin. After the epoxy resin is solidified, the element 3 is initially encapsulated inside the shell 2. When this design is used in liquid aluminum electrolytic capacitors, the filler 4 can effectively prevent the high temperature during the pouring of the package 2 from causing the electrolyte in the element 3 to vaporize and dry up, resulting in failure. Similarly, when this design is used in solid or solid-liquid hybrid aluminum electrolytic capacitors, the filler 4 can effectively prevent the high-temperature molten material during the pouring of the package 2 from invading the interior of the element 3 and destroying the conductive polymer layer on the aluminum foil. Therefore, the package 2 can be formed by high-temperature melt injection molding.

[0045] Preferably, the package body 2 is made of insulating material, the cavity 201 is surrounded by a bottom wall 2011 and side walls 2012 , and an opening 202 is formed at the upper end of the cavity 201 .

[0046] Specifically, the package body 2 is made of an insulating material, and in some embodiments, an insulating heat-dissipating material can also be used. The package body 2 is formed by integral injection molding. Furthermore, the element 3 is placed in an injection mold for injection molding. The package body 2 is combined with the opening and peripheral sidewalls of the shell 2 by injection molding, so that the shell 1 and the package body 2 form a heterogeneous integrally molded structure, resulting in an aluminum electrolytic capacitor with a rectangular outer contour of the package body 2. The element 3 is double-sealed from the inside to the outside by the shell 1 and the package body 2. This packaging structure not only reduces the height of the aluminum electrolytic capacitor, but also enhances the sealing effect and improves the pressure resistance.

[0047] Preferably, the shell 1 is sealed and wrapped in the cavity 201 of the package body 2, and the top of the shell 1 is exposed through the upper end of the package body 2. A closing structure 203 is provided at the opening 202 of the package body 2 to limit the outward movement of the shell 1. The inner diameter of the closing structure 203 is smaller than the outer diameter of the shell 1.

[0048] Specifically, the package body 2 is formed on the outer periphery of the shell 1 by injection molding, that is, the package body 2 and the shell 1 are integrated, and the bottom wall 2011 of the package body 2 is combined with the opening of the shell 1 to seal the opening of the shell 1, thereby improving the defects of traditional aluminum electrolytic capacitors that use a rubber plug 7 combined with a necking method to seal the capacitor, such as complex process and inability to use a thin rubber plug for packaging.

[0049] It should be emphasized that the traditional capacitor sealing structure uses a rubber plug 7 inserted into the opening of the housing 1 and then applying a necking structure to seal the capacitor. This sealing structure has certain requirements for the thickness of the rubber plug 7. When the thickness of the rubber plug 7 is less than the limit, the necking package cannot be achieved. Therefore, this rubber plug 7 plus necking structure packaging cannot meet the requirements of the miniature design of aluminum electrolytic capacitors. Traditional packaging structures require the thickness of the rubber plug 7 to be maintained at more than 1.5mm to prevent product defects caused by external moisture intrusion and internal gas expansion. However, with this packaging design, the thickness of the bottom wall 2011 of the package body 2 can be reduced to less than 0.5mm, which not only reduces the overall height of the aluminum electrolytic capacitor, but also ensures its pressure resistance and moisture resistance, meeting the requirements of miniature design.

[0050] In addition, the inner sidewall 2012 of the package body 2 completely covers and bonds with the outer peripheral side of the housing 1, making the housing 1 and the package body 2 a heterogeneous integrated structure, further increasing the sealing and pressure resistance between the housing 1 and the package body 2, and further improving the pressure resistance effect.

[0051] like Figure 6 As shown, a closing structure 203 for limiting the outward movement of the shell 1 is provided at the opening 202 of the packaging body 2. When the inner diameter of the closing structure 203 is smaller than the outer diameter of the shell 1, the closing structure 203 has a limiting function. The closing structure 203 is a ring-shaped protruding structure. The inner side surface of the closing structure 203 and the chamfered structure 102 at the end of the shell 1 form a bite-and-tighten structure, which improves the force effect. When the internal pressure of the shell 1 increases, it can effectively prevent the shell 1 from moving outward or detaching from the packaging body 2, thereby enhancing the ability to resist internal pressure.

[0052] More specifically, the inner side of the closing structure 203 forms a snap-fitting and tightening structure with the chamfered structure 102 at the end of the housing 1. This design fully utilizes the space in the chamfered structure 102 at the end of the housing 1 to accommodate the closing structure 203, forming a structure that prevents the housing 1 from moving outward. This allows the top of the housing 1 to be flush with the top of the side wall 2012 of the package body 2, while still providing a strong force-bearing effect. This also helps maintain a strong pressure-resistant effect while reducing the overall height of the aluminum electrolytic capacitor.

[0053] like Figures 1 to 4 As shown, the top end of the shell 1 passes through the upper end of the package body 2 and is exposed, and the positive electrode pin 5 and the negative electrode pin 6 pass through the outside of the package body 2 and are exposed.

[0054] Specifically, after the shell 1 and the element 1 inside it are integrally formed with the package body 2 by injection molding, the top end of the shell 1 passes through the upper end of the package body 2 and is exposed to dissipate heat. At the same time, the exposed end surface of the shell 1 is convenient for marking the model and performance parameter information of the aluminum electrolytic capacitor.

[0055] Furthermore, the height of the side wall 2012 in the package body 2 is consistent with that of the shell 1 , a closing structure 203 for limiting the outward movement of the shell 1 is provided at the opening 202 , and the upper end surface of the package body 2 is horizontally aligned with the upper end surface of the shell 1 .

[0056] On the one hand, the inner side of the closing structure 203 is an arc-shaped surface or an inclined surface, which just fits in with the surface of the chamfered structure 102 at the end of the shell 1, forming a force-bearing structure to prevent the shell 1 from moving outward or falling off when the internal pressure increases. On the other hand, the closing structure 203 is set below the upper end surface of the package body 2, which can effectively clamp the shell 1 to form a force-bearing structure to prevent the shell 1 from moving outward and falling off, so that the upper end surface of the package body 2 is flush with the upper end surface of the shell 1, eliminating the need to add an additional limiting structure on the upper end surface of the package body 2, thereby further reducing the overall height of the aluminum electrolytic capacitor. At the same time, the closing structure 203 can simplify the manufacturing process and improve production efficiency.

[0057] The positive electrode pin 5 and the negative electrode pin 6 pass through the bottom of the package body 2 , and the exposed portions are bent in opposite directions and attached to the bottom of the package body 2 as electrode leads.

[0058] Specifically, such as Figure 4 、 Figure 5 As shown, since the positive electrode pin 5 and the negative electrode pin 6 in the element 3 are bent before the package body 2 is cast, the upper end surfaces of the positive electrode pin 5 and the negative electrode pin 5 after bending are embedded in the bottom surface of the package body 2, and the lower end surfaces of the positive electrode pin 5 and the negative electrode pin 6 are exposed at the bottom surface of the package body 2, serving as the lead-out ends of the positive and negative pins.

[0059] The bottom surface of the package body 2 is provided with a plurality of protruding structures 204 , and the outer side surface of one end of the package body 2 is provided with a cut-off structure 205 for distinguishing the positive and negative poles.

[0060] The bottom surface of the package 2 is provided with a raised structure 204. This maintains a certain gap between the bottom surface of the package 2 and the circuit board, improving heat transfer. During installation, the solder more fully covers the positive and negative pins 5 and 6, enhancing the soldering effect. A chamfered structure 205 is provided on the outer surface of one end of the package 2 to distinguish the positive and negative terminals of the aluminum electrolytic capacitor. Example 2

[0061] In Example 2, an aluminum electrolytic capacitor having a total height of 2.2 mm and a width of 5.6 mm is prepared as an example.

[0062] The difference between Example 2 and Example 1 is that in step 1, when preparing the element 3, the height of the positive foil 301 and the height of the negative foil 302 are cut according to the preset size to be 1.3 mm, and the height of the electrolytic paper 303 of the corresponding size is 1.5 mm. The other steps 2 to 4 are the same as those in Example 1.

[0063] In step 5, the material used to prepare the package 2 is a ceramic material. The ceramic material can be a non-high-temperature fired ceramic material, such as glass ceramic, which is obtained by controlling the crystallization of glass with specific components. The preparation process does not require high-temperature sintering to avoid high temperature damage to the electrolyte or conductive polymer layer in the element 3. Instead, through heat treatment within a certain temperature range, the crystal phase in the glass is gradually precipitated to form a material with dual properties of ceramic and glass, thereby obtaining a ceramic material for packaging used in the electrical field. The ceramic material as the package 2 is heterogeneously combined with the aluminum material of the shell 1 to form an integrated molding. The ceramic material package 2 is combined with the aluminum shell 1, which improves the sealing and structural rigidity of the entire aluminum electrolytic capacitor, making the aluminum electrolytic capacitor have stronger pressure resistance and moisture resistance.

[0064] In some embodiments, the package body 2 can also be made of organic ceramics, specifically a composite of organic polymer materials and inorganic ceramic fillers. The preparation process does not require high-temperature firing, but is prepared through processes such as solution mixing, molding and curing. By injection molding, the liquid ceramic composite material is coated on the outer periphery of the shell 1 to form a ceramic package body 2 for encapsulating aluminum electrolytic capacitors, which has good rigidity and sealing. The ceramic package body 2 has a better sealing effect and better mechanical stress, which can effectively prevent the problem of increased internal pressure at high temperatures causing the package body 2 to separate from the shell 1, further improving the pressure resistance and moisture resistance. At the same time, ceramics have good insulation properties and increase the safety factor. This preparation process is relatively simple and can replace the complex process of sealing the traditional rubber plug 7. At the same time, it can solve the problem that the traditional rubber plug 7 will fall off when the rubber plug 7 is packaged at high temperatures. Example 3

[0065] like Figure 7 、 Figure 8 As shown, the difference between Example 3 and Example 1 is that the inner sidewall 2012 of the cavity 201 is provided with a plurality of flange structures 206. The outer periphery of the housing 1 is provided with a waist structure 101, which is matched with the flange structure 206.

[0066] Specifically, the waist structure 101 on the outer periphery of the shell 1 is necked using a waist wheel before the package body 2 is injection-molded to obtain the waist structure 101. When the shell 1 has the waist structure 101, it is injection-molded through a mold to obtain the package body 2 heterogeneously combined with the shell 1.

[0067] The waist structure 101 and the flange structure 206 are matched and combined to further improve the sealing effect. The waist structure 101 and the flange structure 206 form a bite structure, which effectively prevents the shell 1 from detaching when the internal pressure increases, and further improves the pressure resistance effect. Example 4

[0068] like Figure 9 、 Figure 10 As shown, the difference between Example 4 and Example 1 is that the outer contour of the package body 2 adopts a cylindrical design, and the positive pin 5 and the negative pin 6 led out from the bottom adopt a vertical needle-shaped structure, that is, a guide-pin type aluminum electrolytic capacitor. The structure of the package body 2 also has the function of integrating the sealing plug 7 and the anti-vibration base 8 into one body. The structure of the package body 2 does not require complex structures and processes such as the necking sealing of the plug 7 and the additional sleeve anti-vibration base 8. While reducing the total height of the aluminum electrolytic capacitor, it also achieves the effect of increasing the pressure resistance. Comparative Example 1

[0069] Comparative Example 1 illustrates a conventional aluminum electrolytic capacitor structure. An element 3 having the same height as Example 1 was prepared. Specifically, the width of the positive foil 301 was 1.5 mm, the width of the negative foil 302 was 1.7 mm, and the width of the electrolytic paper 302 was 1.5 mm. This comparative example utilizes an aluminum electrolytic capacitor with a total height and width of 6.6 mm.

[0070] Step 1: Cut the positive foil 301 to a width of 1.5 mm, the negative foil 302 to a width of 1.7 mm, and the electrolytic paper 302 to a width of 1.5 mm according to the preset size.

[0071] Step 2: Connect the positive foil 301 to the positive electrode pin 5 and the negative foil 302 to the negative electrode pin 6. Then, stack the positive foil 301, the electrolytic paper 302, and the negative foil 302 and wind them to form the element 3.

[0072] Step 3: After the element 3 is impregnated with the electrolyte, the rubber plug 7 is inserted into the positive electrode pin 5 and the negative electrode pin 6 of the element 3 , and then the element 3 is placed into the inner cavity of the shell 1 .

[0073] Step 4: Insert the rubber plug into the opening of the shell 1 for preliminary packaging, and then use a waisting wheel to neck the shell 1 to form a waisted structure 101 to further fix and seal the rubber plug 7.

[0074] The aluminum electrolytic capacitor prepared in Comparative Example 1 utilizes a rubber plug 7 with a necked packaging structure. It should be noted that because the waisting wheel extrudes to form a waisted structure 101, which compresses the rubber plug 7 to enhance sealing, the thickness of the rubber plug 7 must be greater than 2.5 mm to meet the necking and waisting requirements. Furthermore, the sealing edge of the housing 1 is also subjected to an inward flange treatment, with the inward flange occupying 0.5 mm.

[0075] The structure and preparation method of Comparative Example 1 result in an aluminum electrolytic capacitor body with a total height of at least 4.7 mm. Furthermore, to meet seismic requirements during use, an additional base plate 8 must be attached. Attaching the base plate 8 further increases the total height of the aluminum electrolytic capacitor. This comparative example uses a base plate 8 with a thickness of 1.0 mm. By attaching a base plate 8 with a thickness of 1.0 mm to the 4.7 mm aluminum electrolytic capacitor body, the resulting aluminum electrolytic capacitor has a total height of at least 5.7 mm.

[0076] In summary, when the element 3 of the same height as that of Example 1 is used for manufacturing and packaging in Comparative Example 1, the total height of the aluminum electrolytic capacitor finally obtained is at least 5.7 mm, which cannot reach the 2.6 mm aluminum electrolytic capacitor of Example 1.

[0077] In addition, the aluminum electrolytic capacitors prepared in Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 were subjected to pressure and temperature resistance tests. Specifically, they were tested in a high temperature environment for a certain period of time. The test results are as follows:

[0078] It can be seen from the test data of the above embodiments and comparative examples that as the temperature rises, the packaging structure of Examples 1 to 4, which uses one-piece molding to integrate the packaging body 2 and the shell 1, has a small displacement of the packaging body 2 relative to the shell 1 when the internal pressure increases at high temperature, which is not enough to affect the sealing between the packaging body 2 and the shell 1, and the packaging body 2 and the shell 1 will not separate. However, in Comparative Example 1, the aluminum electrolytic capacitor encapsulated by the plug 7 plus the necking structure has a large displacement of the plug 7 when the internal pressure increases at high temperature, affecting its sealing. If the displacement is large, there is a risk of the plug 7 detaching. In addition, the packaging body 2 of the aluminum electrolytic capacitors of Examples 1 to 4 has a certain barrier effect against external high temperatures. This reduces the impact of external temperature on the aluminum electrolytic capacitor.

[0079] The present invention adopts injection molding to integrate the shell 1 and the packaging body 2 into a heterogeneous whole, thereby realizing the preparation of an aluminum electrolytic capacitor with a height of less than 2.8 mm. Not only can it withstand higher internal pressure, but it can also improve the pressure resistance while reducing the overall height of the aluminum electrolytic capacitor, thereby realizing the miniaturized design and preparation of the aluminum electrolytic capacitor.

[0080] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention is not limited to the embodiments described in the specific implementation methods. Any other implementation methods 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. A novel miniature aluminum electrolytic capacitor, comprising a housing (1), a package (2), an element (3), a positive electrode pin (5), and a negative electrode pin (6), characterized in that: The element (3) is arranged inside the shell (1), and the shell (1) is sealed and wrapped in the cavity (201) of the package body (2). The top end of the shell (1) passes through the upper end of the package body (2) and is exposed. The positive electrode pin (5) and the negative electrode pin (6) respectively pass through the outside of the package body (2) and are exposed. The shell (1) and the package body (2) are a heterogeneous integrated molding structure.

2. A novel miniature aluminum electrolytic capacitor according to claim 1, characterized in that: The packaging body (2) is made of insulating material, the cavity (201) is formed by a bottom wall (2011) and a side wall (2012), and an opening (202) is formed at the upper end of the cavity (201).

3. A novel miniature aluminum electrolytic capacitor according to claim 2, characterized in that: A closing structure (203) for limiting the outward movement of the shell (1) is provided at the opening (202), and the inner diameter of the closing structure (203) is smaller than the outer diameter of the shell (1).

4. A novel miniature aluminum electrolytic capacitor according to claim 2, characterized in that: A filling body (4) for sealing and fixing the element (3) is provided between the inner peripheral wall of the shell (1) and the outer peripheral wall of the element (3).

5. A novel miniature aluminum electrolytic capacitor according to claim 1, characterized in that: The inner peripheral side wall (2012) of the cavity (201) is provided with a plurality of flange structures (206).

6. A novel miniature aluminum electrolytic capacitor according to claim 1, characterized in that: A waist structure (101) is provided on the outer periphery of the shell (1), and the waist structure (101) is matched and combined with the flange structure (206).

7. A novel miniature aluminum electrolytic capacitor according to claim 1, characterized in that: The bottom surface of the package body (2) is provided with a plurality of protruding structures (204), and the outer side surface of one end of the package body (2) is provided with a cut-off structure (205) for distinguishing between positive and negative poles.

8. The novel miniature aluminum electrolytic capacitor according to claim 1, characterized in that: The height of the side wall (2012) in the package body (2) is consistent with the height of the shell (1), and the upper end surface of the package body (2) is horizontally aligned with the upper end surface of the shell (1).

9. A novel miniature aluminum electrolytic capacitor according to claim 1, characterized in that: The element (3) comprises a positive foil (301), a negative foil (302), and electrolytic paper (303), wherein the positive foil (301), the negative foil (302), and the electrolytic paper (303) are stacked at intervals and then wound to form the element (3), the positive foil (301) is connected to a positive electrode pin (5), and the negative foil (302) is connected to a negative electrode pin (6).

10. A novel miniature aluminum electrolytic capacitor according to claim 1, characterized in that: The positive electrode pin (5) and the negative electrode pin (6) pass through the bottom of the package body (2), and the exposed portions are bent in opposite directions and attached to the bottom of the package body (2) as electrode leads.

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