Electrolytic capacitor

Abstract

To provide an electrolytic capacitor with improved airtightness.SOLUTION: Electrolytic capacitor 1 includes capacitor element 10, lead terminal 16 connected to capacitor element 10, a liquid component with which capacitor element 10 is impregnated, case 20, and sealing body 30. The sealing body 30 closes the opening 24 of the case 20. The sealing body 30 includes a sealing plate portion 31 made of metal and a sealing rubber 40 attached to a first through-hole 33 penetrating the sealing plate portion 31 in the thickness direction. The lead terminal 16 protrudes to the outside of the case 20 through a second through hole 44 provided in the sealing rubber 40. The inner surface of the case 20 has a protrusion 26 protruding toward the inside of the case 20 between the opening 24 and the accommodation space 21. The sealing plate portion 31 is disposed inside the case 20 and is joined to the inner surface of the case 20 while being in contact with the protruding portion 26.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electrolytic capacitor, and more particularly to an electrolytic capacitor including a case that houses a capacitor element. [Background technology]

[0002] Patent Document 1 discloses a capacitor comprising a metal case that houses a capacitor element and a sealing body that closes the opening of the metal case. The sealing body comprises a substrate and rubber that is integrated with the substrate. The substrate is provided with a terminal insertion hole that is larger than the outer diameter of the lead terminal, and the rubber is attached to the terminal insertion hole. The lead terminal is inserted into the terminal insertion hole of the substrate. The sealing body is joined to the metal case by welding so as to close the opening of the metal case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-142424 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electrolytic capacitor such as that described in Patent Document 1, if the joining position of the sealing body relative to the metal case is misaligned, a gap may occur at the joining portion between the metal case and the sealing body, potentially reducing airtightness.

[0005] The present disclosure provides an electrolytic capacitor with improved hermeticity. [Means for solving the problem]

[0006] An electrolytic capacitor according to one aspect of the present disclosure includes a capacitor element, lead terminals, a liquid component, a case, and a sealing body. The lead terminals are connected to the capacitor element. The liquid component is impregnated into the capacitor element. The case accommodates the capacitor element and has an opening. The sealing body closes the opening of the case. The capacitor element is disposed in an accommodation space within the case. The sealing body includes a metal sealing plate and a sealing rubber attached to a first through hole that penetrates the sealing plate in the thickness direction. The lead terminals protrude to the outside of the case through a second through hole provided in the sealing rubber. The inner surface of the case has a protruding portion that protrudes toward the inside of the case between the opening and the accommodation space. The sealing plate is disposed inside the case and is joined to the inner surface of the case in contact with the protruding portion. [Effects of the Invention]

[0007] According to the present disclosure, an electrolytic capacitor with improved airtightness can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an exploded perspective view of an electrolytic capacitor according to an embodiment of the present disclosure, viewed from below. [Figure 2] FIG. 2 is an exploded perspective view of an electrolytic capacitor according to an embodiment of the present disclosure, viewed from above. [Figure 3] FIG. 3 is an external perspective view of the electrolytic capacitor according to the embodiment of the present disclosure. [Figure 4] FIG. 4 is a perspective view of the electrolytic capacitor according to the embodiment of the present disclosure in a state before the capacitor body is attached to the seat plate member. [Figure 5] FIG. 5 is a schematic cross-sectional view of a capacitor body included in an electrolytic capacitor according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is an enlarged view of a main portion of a capacitor element included in an electrolytic capacitor according to an embodiment of the present disclosure. [Figure 7]FIG. 7 is an exploded perspective view of an electrolytic capacitor according to a first modification of an embodiment of the present disclosure, as viewed from above. [Figure 8] FIG. 8 is a top view of a seat plate member included in an electrolytic capacitor according to a first modification of an embodiment of the present disclosure. [Figure 9] FIG. 9 is a side view of a sealing rubber included in an electrolytic capacitor according to a second modification of an embodiment of the present disclosure. [Figure 10] FIG. 10 is a side view of another sealing rubber included in the electrolytic capacitor according to the second modification of the embodiment of the present disclosure. [Figure 11] FIG. 11 is a schematic cross-sectional view of a capacitor body included in an electrolytic capacitor according to a third modification of an embodiment of the present disclosure. [Figure 12] FIG. 12 is a side view of a sealing rubber included in an electrolytic capacitor according to a third modification of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Electrolytic capacitors according to embodiments will be described in detail below with reference to the drawings. However, the drawings described in the following embodiments are schematic diagrams, and the dimensional ratios of the sizes of the components do not necessarily reflect the actual dimensional ratios. Furthermore, the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0010] (Embodiment) (1) Overview As shown in FIGS. 1 to 5, electrolytic capacitor 1 of this embodiment includes capacitor element 10, lead terminals 16, a liquid component (not shown), case 20, and sealing body 30.

[0011] The lead terminals 16 are connected to the capacitor element 10. The capacitor element 10 is impregnated with a liquid component. The case 20 houses the capacitor element 10 and has an opening 24. The sealing body 30 closes the opening 24 of the case 20. The capacitor element 10 is disposed in an accommodation space 21 within the case 20. The sealing body 30 has a metal sealing plate 31 and a sealing rubber 40 attached to a first through hole 33 that penetrates the sealing plate 31 in the thickness direction. The lead terminals 16 protrude to the outside of the case 20 through a second through hole 44 provided in the sealing rubber 40. The inner surface of the case 20 has a protrusion 26 that protrudes toward the inside of the case 20 between the opening 24 and the accommodation space 21. The sealing plate 31 is disposed inside the case 20 and is joined to the inner surface of the case 20 while in contact with the protrusion 26.

[0012] In the electrolytic capacitor 1 of this embodiment, the inner surface of the case 20 and the sealing plate 31 are joined together with the protrusion 26 on the inner surface of the case 20 in contact with the sealing plate 31. This reduces variation in the position of the sealing plate 31 relative to the inner surface of the case 20 and reduces the possibility of a gap occurring between the inner surface of the case 20 and the sealing plate 31. This improves the airtightness of the electrolytic capacitor 1. Furthermore, the sealing body 30 that closes the opening 24 of the case 20 includes the metal sealing plate 31 and the sealing rubber 40 attached to the first through hole 33 of the sealing plate 31. Therefore, compared to when the entire opening 24 is closed with an elastic resin such as rubber, the area of ​​the portion closed with the sealing rubber 40 can be reduced by the amount that is closed with the metal sealing plate 31. This reduces the area of ​​sealing rubber 40 through which liquid components such as volatilized electrolyte can easily permeate, thereby reducing the amount of volatilized liquid components that permeate sealing rubber 40 and leak to the outside of case 20. This allows the dielectric layer repair function of the liquid components impregnated in capacitor element 10 to be maintained for a long period of time, thereby extending the life of electrolytic capacitor 1.

[0013] Furthermore, because the sealing plate 31 that closes the opening 24 of the case 20 is made of a metal material, the material strength of the member that closes the opening 24 is improved compared to when the entire opening 24 is closed with an elastic resin such as rubber. Therefore, even if the internal pressure of the case 20 increases due to the evaporation of liquid components or the generation of gas due to a side reaction of the liquid components inside the case 20, the possibility of deformation of the sealing plate 31 is reduced. Furthermore, if the sealing plate 31 expands outward while the electrolytic capacitor 1 is mounted on a substrate, the sealing plate 31 may interfere with the substrate, causing problems such as peeling of the lead terminals 16 from the substrate. In contrast, in this embodiment, deformation of the sealing body 30 can be suppressed, thereby improving the reliability of the electrical connection between the lead terminals 16 and the substrate.

[0014] (2)Details The electrolytic capacitor 1 according to this embodiment will be described in detail below with reference to Figures 1 to 6. In this embodiment, as a representative example, the electrolytic capacitor 1 will be described as a hybrid electrolytic capacitor 1 including a liquid component (not shown) such as an electrolytic solution and a conductive polymer as an electrolyte.

[0015] (2.1) Configuration The electrolytic capacitor 1 of this embodiment includes a capacitor body 2 (see FIGS. 3 and 4) and a seat plate member 3 to which the capacitor body 2 is attached. The capacitor body 2 includes the above-described capacitor element 10, lead terminals 16, a case 20, and a sealing body 30.

[0016] The seat plate member 3 is used to convert the electrolytic capacitor 1 into a surface-mount type capacitor. In the case of insertion mounting, in which the lead terminals 16 of the electrolytic capacitor 1 are inserted into through-holes in a printed wiring board and soldered, the seat plate member 3 is not necessary, and the electrolytic capacitor 1 only needs to include the capacitor body 2.

[0017] In this embodiment, the electrolytic capacitor 1 includes multiple (e.g., two) lead terminals 16. Hereinafter, the lead terminal 16 connected to the anode of the capacitor element 10 may be referred to as a first lead terminal 16A, and the lead terminal 16 connected to the cathode of the capacitor element 10 may be referred to as a second lead terminal 16B.

[0018] In the following description, the X-axis direction in Figures 1, 2, 3, 5, etc. is defined as the left-right direction, the Y-axis direction as the front-rear direction (depth direction), and the Z-axis direction as the up-down direction. The positive X-axis direction is defined as the right side, the positive Y-axis direction as the front side, and the positive Z-axis direction as the top side. However, these directions are merely examples and are not intended to limit the directions in which the electrolytic capacitor 1 is used. The arrows indicating the various directions in the drawings are merely shown for explanatory purposes and have no substance.

[0019] (Capacitor element) 5 shows a schematic cross-sectional view of a plane including the center of capacitor body 2. Capacitor element 10 is disposed in housing space 21 inside case 20, as shown in FIG.

[0020] A plurality of (for example, two) lead terminals 16 (including a first lead terminal 16A and a second lead terminal 16B) are connected to the capacitor element 10.

[0021] 6 is an enlarged view of a main portion showing the configuration of components constituting capacitor element 10. Capacitor element 10 includes anode foil 11, cathode foil 12, and separator 18 and a conductive polymer disposed between anode foil 11 and cathode foil 12 (see FIG. 6). Anode foil 11, cathode foil 12, and separator 18 are wound around winding axis Ax1 (see FIG. 5), and capacitor element 10 is disposed in housing space 21 with winding axis Ax1 aligned along the thickness direction of sealing plate 31. First lead terminal 16A is connected to anode foil 11 by an appropriate method such as welding, soldering, or crimping. Second lead terminal 16B is connected to cathode foil 12 by an appropriate method such as welding, soldering, or crimping.

[0022] The anode foil 11 includes a metal foil containing a valve metal such as aluminum, tantalum, or niobium, and a dielectric layer formed on the surface of the metal foil. The anode foil 11 has the dielectric layer on its surface, and at least a portion of the surface of the dielectric layer is covered with a solid electrolyte layer. The solid electrolyte layer contains a conductive polymer component.

[0023] The dielectric layer provided on the surface of the anode foil 11 contains an oxide of a valve metal. The solid electrolyte layer may be formed so as to cover at least a portion of the dielectric layer. The solid electrolyte layer contains a conductive polymer component. For example, the solid electrolyte layer is formed by attaching the conductive polymer component to at least a portion of the surface of the dielectric layer. The conductive polymer component may further contain an additive, if necessary. The conductive polymer component may be attached to the surface of the separator 18.

[0024] The conductive polymer component includes, for example, a conjugated polymer component. Examples of the conjugated polymer component include π-conjugated polymer components. Examples of the conjugated polymer component include polymer components having a basic skeleton of polypyrrole, polythiophene, polyaniline, polyfuran, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, and polythiophene vinylene. One type of conjugated polymer component may be used alone, or two or more types may be used in combination.

[0025] The cathode foil 12 includes a metal foil such as aluminum.

[0026] In this embodiment, a separator 18 is disposed between the anode foil 11 and the cathode foil 12. The separator 18 may be made of, for example, a nonwoven fabric containing fibers of cellulose, polyethylene terephthalate, vinylon, or polyamide (e.g., aliphatic polyamide, aromatic polyamide such as aramid).

[0027] Furthermore, a liquid component, which is an electrolyte, is accommodated inside case 20. In other words, electrolytic capacitor 1 has a liquid component accommodated in case 20, and capacitor element 10 is impregnated with the liquid component.

[0028] The liquid component may contain a solute. That is, the liquid component is, for example, an electrolyte solution containing a solvent and a solute. For example, an organic solvent or the like is used for the electrolyte solution. Examples of the organic solvent include polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; sulfone compounds such as sulfolane, dimethyl sulfoxide, and diethyl sulfoxide; lactone compounds such as γ-butyrolactone and γ-valerolactone; carbonate compounds such as dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, and fluoroethylene carbonate; diether compounds of polyhydric alcohols such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; and monohydric alcohols such as methanol, ethanol, and propanol.

[0029] The electrolytic solution may contain a solute, such as an acid component such as an organic acid, an inorganic acid, or a complex acid compound of an organic acid and an inorganic acid; a base component such as an amine or a quaternary ammonium salt; a salt of an acid and a base; a nitro compound; or a phenol compound.

[0030] The electrolyte solution permeates the solid electrolyte layer that covers at least a portion of the dielectric layer provided on the surface of the anode foil 11, and is in contact with the solid electrolyte layer that is partially covered with a conductive polymer component and the dielectric layer. The separator 18 can also hold the electrolyte solution and an electrolyte such as a conductive polymer. The electrolyte solution is present inside the case 20 in a state where it is impregnated in the capacitor element 10, and therefore the electrolyte solution components are not shown in Figures 1, 2, 5, etc.

[0031] (case) The case 20 is a member that contains the capacitor element 10 and the liquid component. The case 20 has a cylindrical shape with a bottom and an opening 24 formed over the entire surface of one side (for example, the bottom surface).

[0032] Case 20 has bottom surface portion 22 that is circular in plan view, and cylindrical side surface portion 23 that extends from the edge of bottom surface portion 22. Side surface portion 23 extends in one direction (e.g., downward) from the edge of bottom surface portion 22 along the normal direction of bottom surface portion 22.

[0033] By drawing the case 20, a recess 25 extending in the circumferential direction is formed on the side surface 23 of the case 20. The inner portion of the recess 25 formed on the outer surface of the case 20 by drawing the case 20 becomes a protrusion 26. Therefore, the protrusion 26 protrudes from the inner surface of the case 20 by a dimension between 0.5 and 10 times the thickness of the material constituting the case 20. Specifically, if the thickness of the material constituting the case 20 is, for example, 0.5 mm, the protrusion 26 protrudes from the inner surface of the case 20 by a dimension between 0.2 and 5 mm. The protrusion 26 is formed in the circumferential direction around the entire inner surface of the case 20. In conventional electrolytic capacitors, the entire opening 24 of the case 20 is sealed with a rubber seal, and the case 20 is drawn to pressurize and secure the rubber seal. In this embodiment, since case 20 is drawn to provide protrusion 26, there is no need to significantly change the configuration and manufacturing method of conventional electrolytic capacitors, which has the advantage of not requiring a major design change. Furthermore, by changing the location where drawing is performed, the position of recess 25 in the vertical direction can be easily changed, making it easy to change the volume of accommodation space 21. Therefore, electrolytic capacitor 1 of this embodiment has the advantage of being able to easily accommodate changes in the size of capacitor element 10 placed in accommodation space 21, i.e., changes in capacitance.

[0034] Examples of materials that can be used to form the case 20 include aluminum, stainless steel, copper, iron, brass, and alloys of these.

[0035] (sealing body) The sealing body 30 is a member that closes the opening 24 of the case 20. The sealing body 30 includes a metal sealing plate portion 31 and sealing rubbers 40 that are attached to two first through holes 33 provided in the sealing plate portion 31, respectively.

[0036] The sealing plate portion 31 is composed of a single sealing plate 32 that is, for example, circular in plan view. The sealing plate 32 is sized to fit into the opening 24 of the case 20. The diameter of the sealing plate 32 is set to be slightly larger than the inner diameter (diameter) of the side surface portion 23 of the case 20. This allows the side end surface of the sealing plate 32 to be tightly attached to the inner surface of the side surface portion 23 of the case 20 due to stress from the case 20 when the sealing plate 32 is placed inside the case 20. The thickness of the sealing plate 32 is preferably equal to or greater than the thickness of the material constituting the case 20 so that the sealing plate 32 can withstand the stress from the case 20 when placed inside the case 20. Specifically, if the thickness of the material constituting the case 20 is, for example, 0.5 mm, the thickness of the sealing plate 32 is, for example, 0.5 mm to 1 mm.

[0037] The sealing plate 32 is made of metal. Examples of materials that can be used to form the sealing plate 32 include aluminum, stainless steel, copper, iron, brass, and alloys of these.

[0038] The sealing plate 32 has two first through holes 33 arranged side by side in the left-right direction, penetrating the sealing plate 32 in the thickness direction (vertical direction). One sealing rubber 40 is attached to each of the two first through holes 33. Here, in a plan view, the ratio of the total area of ​​the two first through holes 33 to the entire area of ​​the sealing plate 32 (including the areas of the two first through holes 33) is, for example, 10% or more and 30% or less.

[0039] The sealing rubber 40 includes a first portion 41, a second portion 42, and a third portion 43. The second portion 42 is cylindrical and is inserted into the first through-hole 33 of the sealing plate 32. The outer diameter (diameter) of the second portion 42 is set to be slightly larger than the inner diameter of the first through-hole 33. The first portion 41 is provided at a first end (the end portion closer to the capacitor element 10) in the axial direction of the second portion 42, and the third portion 43 is provided at a second end in the axial direction of the second portion 42.

[0040] The first portion 41 has a donut-like (annular) shape in a plan view, and protrudes radially from a first end of the second portion 42. The outer diameter (diameter) of the first portion 41 is set to be larger than the inner diameter (diameter) of the first through-hole 33 and the outer diameter (diameter) of the second portion 42.

[0041] The third portion 43 has a donut shape in a plan view and protrudes radially from the second end of the second portion 42. The outer diameter (diameter) of the third portion 43 is set to be larger than the inner diameter (diameter) of the first through hole 33 and the outer diameter (diameter) of the second portion 42.

[0042] The sealing rubber 40 is made of, for example, butyl rubber. However, the material of the sealing rubber 40 is not limited to butyl rubber, and may be nitrile rubber, fluororubber, silicone rubber, or the like. The first portion 41, the second portion 42, and the third portion 43 are integrally molded from resin, and the sealing rubber 40 is provided with a second through hole 44 that passes through the sealing rubber 40 in the vertical direction. The inner diameter (diameter) of the second through hole 44 is set to be slightly smaller than the outer diameter (diameter) of the lead terminal 16. Therefore, when the lead terminal 16 is inserted into the second through hole 44 of the sealing rubber 40, the lead terminal 16 is in close contact with the inner surface of the second through hole 44.

[0043] The sealing rubber 40 is press-fitted and fixed into the first through hole 33 of the sealing plate 32. That is, the sealing rubber 40 fits into the first through hole 33 of the sealing plate part 31. When the sealing rubber 40 is attached to the sealing plate 32, the second portion 42 of the sealing rubber 40 is inserted into the first through hole 33. Furthermore, the first portion 41 is in contact with the surface (upper surface) of the sealing plate 32 that faces the capacitor element 10, and the third portion 43 is in contact with the surface (lower surface) of the sealing plate 32 opposite to the surface (upper surface) that faces the capacitor element 10.

[0044] The outer diameter (diameter) of the second portion 42 is slightly larger than the inner diameter (diameter) of the first through hole 33, so that when the sealing rubber 40 is attached to the sealing plate 32, the second portion 42 is pressed inward by the inner surface of the first through hole 33. Furthermore, the difference between the outer diameter of the second portion 42 and the inner diameter of the second through hole 44 before the sealing rubber 40 is attached to the sealing plate 32 is slightly larger than the difference between the inner diameter of the first through hole 33 and the outer diameter of the lead terminal 16. Therefore, the second portion 42 of the sealing rubber 40 is compressed between the inner surface of the first through hole 33 and the lead terminal 16, maintaining the airtightness of the first through hole 33.

[0045] The sealing body 30 is press-fitted into the case 20 through the opening 24 of the case 20. The press-fitted sealing body 30 is placed inside the case 20 with the protrusion 26 in contact, and the entire periphery of the sealing plate 32 (sealing plate portion 31) is joined to the inner surface of the case 20 by laser welding. In this embodiment, by press-fitting the sealing body 30 into the case 20, the outer surface of the sealing body 30, i.e., the sealing plate 32, can be tightly attached to the inner surface of the case 20. This reduces the variation in the gap between the outer surface of the sealing plate 32 and the inner surface of the case 20, reducing the variation in welding quality during laser welding, thereby improving the airtightness of the electrolytic capacitor 1. Note that in this embodiment, "joining" refers to joining two members together. The method of joining the sealing plate 32 (sealing plate portion 31) to the case 20 is not limited to laser welding; any suitable joining method may be used.

[0046] The outer surface of sealing plate 32, which is sealing plate portion 31 (the surface opposite to the surface facing capacitor element 10), is located inside edge 27 of case 20 on the opening 24 side. However, the position of sealing plate 32 can be adjusted by adjusting the position of protrusion 26. Because protrusion 26 is formed by drawing case 20, the position of protrusion 26 can be changed simply by changing the position of protrusion 26 by drawing, without changing the overall design of case 20. For example, by providing protrusion 26 on the inner surface of case 20 at a position spaced apart from edge 27 of case 20 by the thickness of sealing plate 32, the outer surface of sealing plate 32 and edge 27 of case 20 can be made flush with each other. In this way, the outer surface of sealing plate portion 31 may be flush with edge 27 of case 20 on the opening side. By making the outer surface of sealing plate 31 flush with end 27 of case 20, the difference in level between the outer surface of sealing plate 31 (the outer surface of sealing plate 32 in this embodiment) and end 27 of case 20 can be reduced, and variations in welding quality can be suppressed when laser welding is performed. Note that in this embodiment, the outer surface of sealing plate 31 being flush with end 27 does not necessarily mean that the outer surface of sealing plate 31 and end 27 are completely flush with each other, and there may be a difference in level between the outer surface of sealing plate 31 and end 27 that is the extent of a manufacturing error.

[0047] (Lead terminal) The plurality of lead terminals 16 are each formed into a round bar shape from a metal material and include a first lead terminal 16A electrically connected to the anode foil 11 and a second lead terminal 16B electrically connected to the cathode foil 12.

[0048] The first lead terminal 16A and the second lead terminal 16B protrude downward from the underside of the capacitor element 10. The first lead terminal 16A is inserted into a second through hole 44 of the sealing rubber 40 fitted into the first through hole 33 on the left side of the sealing plate 31, and protrudes through the second through hole 44 to the outside of the case 20. The second lead terminal 16B is inserted into the second through hole 44 of the sealing rubber 40 fitted into the first through hole 33 on the right side of the sealing plate 31, and protrudes through the second through hole 44 to the outside of the case 20.

[0049] (Seat plate material) The seat plate member 3 is used to make the capacitor body 2 a surface-mounted component. The seat plate member 3 is, for example, a molded product made of synthetic resin. The seat plate member 3 includes a rectangular seat plate 50 on which the capacitor body 2 is placed, and four guide walls 51 protruding upward from the four corners of the seat plate 50. In other words, the electrolytic capacitor 1 further includes the seat plate 50 to which the case 20 is attached.

[0050] The capacitor body 2 is placed on one surface (for example, the upper surface) of the seat plate 50. The seat plate 50 has terminal insertion holes 52 into which the lead terminals 16 are inserted. In this embodiment, the seat plate 50 is provided with two terminal insertion holes 52 into which two lead terminals 16 protruding downward from the lower surface of the sealing body 30 are respectively inserted. The two terminal insertion holes 52 are provided so as to penetrate the seat plate 50 in the up-down direction (the normal direction to the main surface of the seat plate 50). The two terminal insertion holes 52 are provided side by side in the left-right direction, and the terminal insertion hole 52 into which the first lead terminal 16A is inserted may be referred to as the first terminal insertion hole 52A, and the terminal insertion hole 52 into which the second lead terminal 16B is inserted may be referred to as the second terminal insertion hole 52B.

[0051] Four guide walls 51 protruding upward from four corners are provided on the surface 50A of the seat plate 50 facing the sealing body 30. Inner surfaces 56 (surfaces facing the case 20) of the four guide walls 51 are formed into curved surfaces that follow the side surface 23 of the case 20. Therefore, when the capacitor body 2 is attached to the seat plate member 3, the four guide walls 51 support the side surface 23 of the case 20, and vibration of the capacitor body 2 can be suppressed.

[0052] Furthermore, a groove 54 connected to the terminal insertion hole 52 is provided on a surface 50B of the base plate 50 opposite to the surface 50A facing the sealing body 30. The bent portions 17A and 17B of the lead terminal 16 inserted into the terminal insertion hole 52 are inserted into the groove 54. In this embodiment, the base plate 50 is provided with a plurality of (e.g., two) terminal insertion holes 52, and therefore a plurality of (e.g., two) grooves 54 are provided on the surface 50B of the base plate 50. The plurality of grooves 54 include a first groove 54A extending leftward from the first terminal insertion hole 52A on the left side and a second groove 54B extending rightward from the second terminal insertion hole 52B on the right side. The bent portion 17A of the tip portion of the first lead terminal 16A protruding downward from the first terminal insertion hole 52A is inserted into the first groove 54A. A bent portion 17B, which is formed by bending the tip portion of the second lead terminal 16B protruding downward from the second terminal insertion hole 52B, is inserted into the second groove 54B. When the bent portions 17A and 17B of the two lead terminals 16 are inserted into the two grooves 54, the lower surfaces of the bent portions 17A and 17B are arranged parallel to the surface 50B of the seat plate 50 and positioned slightly below the surface 50B of the seat plate 50. This allows the bent portions 17A and 17B of the first lead terminal 16A and the second lead terminal 16B, which are arranged along the surface 50B of the seat plate 50, to be surface-mounted on a printed wiring board.

[0053] When electrolytic capacitor 1 is inserted and mounted, seat plate member 3 is not attached to capacitor body 2, and lead terminals 16 are used in a state where they extend straight.

[0054] (2.2) Manufacturing method of electrolytic capacitor A method for manufacturing the electrolytic capacitor 1 of this embodiment will be described. Note that the manufacturing method described below is an example, and the order of the steps may be changed, or some steps may be omitted or added.

[0055] First, anode foil 11 and cathode foil 12 are wound around winding axis Ax1 with separator 18 interposed between anode foil 11 and cathode foil 12 to produce capacitor element 10. First lead terminal 16A connected to anode foil 11 and second lead terminal 16B connected to cathode foil 12 protrude downward from the bottom surface of capacitor element 10.

[0056] Next, capacitor element 10 is inserted into case 20 through opening 24. Then, lead terminal 16 is inserted into second through-hole 44 of sealing rubber 40 attached to sealing plate portion 31 (sealing plate 32), and sealing body 30 is inserted (press-fit) into case 20 so that sealing body 30 closes opening 24 of case 20. At this time, the outer periphery of sealing plate 32, which is sealing plate portion 31, is in contact with protrusion 26 provided on the inner surface of case 20, and the contact portion between sealing plate 32 and the inner surface of case 20 is joined by, for example, laser welding. As a result, opening 24 of case 20 is closed by sealing body 30 with capacitor element 10 placed in accommodation space 21 of case 20.

[0057] Here, the contact portions of the sealing plate 32 and the inner surface of the case 20 are joined together with the outer peripheral portion of the sealing plate 32 in contact with the protrusion 26 provided on the inner surface of the case 20, so that gaps are less likely to occur between the sealing plate 32 and the inner surface of the case 20, improving airtightness. Furthermore, the outer diameter of the second portion 42 of the sealing rubber 40 is set to be larger than the inner diameter of the first through hole 33, and the inner diameter of the second through hole 44 provided in the second portion 42 is set to be smaller than the outer diameter of the lead terminal 16. Therefore, the second portion 42 of the sealing rubber 40 is compressed between the inner surface of the first through hole 33 and the lead terminal 16, allowing the second portion 42 of the sealing rubber 40 to be in close contact with the inner surface of the first through hole 33 and the lead terminal 16. This reduces the amount of electrolyte contained in the case 20 that permeates the sealing rubber 40 and leaks out of the case 20, improving airtightness.

[0058] The capacitor body 2 assembled as described above is placed on the opposing surface 50A of the seat plate 50 so that the first lead terminal 16A and the second lead terminal 16B are inserted into the first terminal insertion hole 52A and the second terminal insertion hole 52B, respectively, of the seat plate member 3. Then, the tip portions of the first lead terminal 16A and the second lead terminal 16B exposed from the surface 50B of the seat plate 50 are bent, and the bent portion 17A of the first lead terminal 16A is inserted into the first groove 54A, and the bent portion 17B of the second lead terminal 16B is inserted into the second groove 54B.

[0059] At this time, the capacitor body 2 is attached to the seat plate member 3 by sandwiching the seat plate 50 between the sealing body 30 and the bent portions 17A, 17B of the first lead terminal 16A and the second lead terminal 16B.

[0060] The electrolytic capacitor 1 of this embodiment is attached to a printed wiring board by surface-mounting the bent portions 17A, 17B of the first lead terminal 16A and the second lead terminal 16B on the printed wiring board.

[0061] In the electrolytic capacitor 1 of this embodiment, the sealing plate 31 (i.e., the sealing plate 32) that closes the opening 24 is made of a metal material. This improves the material strength of the member that closes the opening 24 compared to when the entire opening 24 is closed with rubber. Therefore, even if the internal pressure of the case 20 increases due to the evaporation of the electrolyte or the generation of gas due to a side reaction of the electrolyte inside the case 20, the possibility of the sealing plate 31 deforming can be reduced. If the internal pressure of the case 20 increases and the sealing plate 31 bulges outward, the bent portions 17A and 17B of the first lead terminal 16A and the second lead terminal 16B may be displaced and come off the printed wiring board. In this embodiment, by increasing the material strength of the sealing plate 31, deformation of the sealing plate 31 can be suppressed even when the internal pressure of the case 20 increases. Therefore, in this embodiment, the possibility that the bent portions 17A, 17B of the first lead terminal 16A and the second lead terminal 16B will come off the printed wiring board can be reduced.

[0062] When the electrolytic capacitor 1 is insert-mounted, the electrolytic capacitor 1 does not include the seat plate member 3, and is inserted and mounted with the underside of the case 20 facing the printed wiring board. In this case, the third portion 43 of the sealing rubber 40 comes into contact with the printed wiring board, which has the advantage of suppressing the transmission of vibrations to the electrolytic capacitor 1 and improving the reliability of the electrical connection of the electrolytic capacitor 1 to the printed wiring board. In addition, by increasing the material strength of the sealing plate 31, deformation of the sealing plate 31 is suppressed even when the internal pressure of the case 20 increases, thereby reducing the possibility of the first lead terminal 16A and the second lead terminal 16B coming off the printed wiring board.

[0063] (3) Variations The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Note that the above embodiment may be referred to as a basic configuration below.

[0064] (3.1) Variation 1 The electrolytic capacitor 1 of the first modification will be described with reference to FIGS.

[0065] 7 and 8, in the electrolytic capacitor 1 of the first modification, a fitting recess 53 is provided around the terminal insertion hole 52 on a surface 50A (e.g., the upper surface) of the seat plate 50 facing the sealing body 30. Note that the configuration other than the seat plate member 3 is the same as the basic configuration, and therefore the same reference numerals are used to designate the common components, and their description will be omitted.

[0066] The fitting recess 53 has a circular shape in a top view that is concentric with the terminal insertion hole 52 and has a larger diameter than the terminal insertion hole 52. At least a portion of the sealing rubber 40 is inserted into the fitting recess 53. More specifically, the third portion 43 of the sealing rubber 40 is inserted into the fitting recess 53. The inner diameter of the fitting recess 53 is set to be slightly smaller than the outer diameter of the third portion 43 of the sealing rubber 40.

[0067] The outer diameter of third portion 43 is set to be slightly larger than the inner diameter of fitting recess 53, so that third portion 43 is disposed in a compressed state on the inner surface of fitting recess 53. This further reduces the amount of electrolyte contained in case 20 that permeates sealing rubber 40 and leaks out of case 20, thereby further improving airtightness.

[0068] (3.2) Variation 2 The shape of the sealing rubber 40 is not limited to the shape described in the basic configuration, and can be changed as appropriate.

[0069] For example, as shown in FIG. 9 , the sealing body 30 may have a sealing rubber 40A including a first portion 41 and a cylindrical second portion 42 that is longer than the thickness of the sealing plate 32, which is the sealing plate portion 31. A protrusion 45 is provided around the entire periphery of the surface of the second portion 42. When the sealing rubber 40A is attached to the first through hole 33 of the sealing plate 32, the protrusion 45 of the second portion 42 contacts the inner surface of the first through hole 33. By inserting the lead terminal 16 into the second through hole 44, the second portion 42 of the sealing rubber 40A is compressed between the inner surface of the first through hole 33 and the lead terminal 16, and the protrusion 45 further maintains the airtightness of the first through hole 33.

[0070] 10, the sealing body 30 may have a sealing rubber 40B including a first portion 41 and a second portion 42 having a truncated cone shape whose diameter increases with increasing distance from the first portion 41.

[0071] When the sealing rubber 40B is attached to the first through hole 33 of the sealing plate 32, the peripheral surface of the second portion 42 contacts the end face of the first through hole 33, thereby holding the sealing plate 32 between the first portion 41 and the second portion 42.

[0072] (3.3) Variation 3 Electrolytic capacitor 1 of Modification 3 will be described with reference to Figures 11 and 12. Electrolytic capacitor 1 of Modification 3 differs from the basic configuration described above in that sealing body 30 includes first sealing plate 32A, second sealing plate 32B, and sealing rubber 40C. Note that the configuration other than sealing body 30 is the same as the basic configuration, and therefore common components are denoted by the same reference numerals and their description will be omitted.

[0073] In Modification 3, sealing plate portion 31 included in sealing body 30 includes first sealing plate 32A and second sealing plate 32B. First sealing plate 32A is disposed inside case 20 in a state of contact with protrusion 26. Second sealing plate 32B is disposed at a position closer to opening 24 than first sealing plate 32A. Second sealing plate 32B is joined to the inner surface of case 20.

[0074] The first sealing plate 32A and the second sealing plate 32B are each made of metal. The first sealing plate 32A and the second sealing plate 32B are each circular in plan view. The diameters of the first sealing plate 32A and the second sealing plate 32B are set to be slightly larger than the inner diameter (diameter) of the side surface portion 23 of the case 20. Examples of materials that can be used to form the first sealing plate 32A and the second sealing plate 32B include aluminum, stainless steel, copper, iron, brass, and alloys thereof.

[0075] The first sealing plate 32A is provided with two first through holes 33A aligned in the left-right direction, which penetrate the first sealing plate 32A in the thickness direction (vertical direction).

[0076] The second sealing plate 32B is provided with two first through holes 33B aligned in the left-right direction, which penetrate the second sealing plate 32B in the thickness direction (vertical direction).

[0077] The sealing rubber 40C is disposed between the first sealing plate 32A and the second sealing plate 32B. The sealing rubber 40C has a cylindrical shape and is provided with a second through-hole 44 into which the lead terminal 16 is inserted.

[0078] A cylindrical first protrusion 47 having an outer diameter smaller than that of an intermediate portion 46 of the sealing rubber 40C in the axial direction is provided at a first end of the sealing rubber 40C. The first protrusion 47 is inserted into the first through hole 33A of the first sealing plate 32A. The outer diameter of the first protrusion 47 is set to be slightly larger than the inner diameter of the first through hole 33A.

[0079] A cylindrical second protrusion 48 having an outer diameter smaller than that of the middle portion 46 of the sealing rubber 40C is provided at a second axial end of the sealing rubber 40C. The second protrusion 48 is inserted into the first through hole 33B of the second sealing plate 32B. The outer diameter of the second protrusion 48 is set to be slightly larger than the inner diameter of the first through hole 33B.

[0080] First sealing plate 32A is placed inside case 20 with protrusion 26 in contact with it, and second sealing plate 32B is joined to the inner surface of case 20 at a position closer to opening 24 than first sealing plate 32A. Two lead terminals 16 connected to capacitor element 10 protrude to the outside of case 20 through two first through holes 33A provided in first sealing plate 32A and two first through holes 33B provided in second sealing plate 32B. Note that the two lead terminals 16 are each inserted into second through holes 44 of sealing rubber 40C, and sealing rubber 40C attached to lead terminals 16 is placed between first sealing plate 32A and second sealing plate 32B. The first protrusion 47 of the sealing rubber 40C is inserted into the first through hole 33A of the first sealing plate 32A, and the second protrusion 48 of the sealing rubber 40C is inserted into the first through hole 33B of the second sealing plate 32B. Note that a spacer 60 disposed between the capacitor element 10 and the first sealing plate 32A may be attached to the lead terminal 16. Note that the spacer 60 is not an essential component of the electrolytic capacitor 1, and the spacer 60 can be omitted as appropriate.

[0081] Here, second sealing plate 32B is joined to edge 27 of case 20, and first sealing plate 32A is pressed against protrusion 26 of case 20 by sealing rubber 40C disposed between first sealing plate 32A and second sealing plate 32B. In this manner, second sealing plate 32B is joined to the inner surface of case 20 while protrusion 26 on the inner surface of case 20 is in contact with first sealing plate 32A, so misalignment of second sealing plate 32B is unlikely to occur. As a result, a gap is unlikely to occur between the inner surface of case 20 and second sealing plate 32B. Therefore, the airtightness can be improved in electrolytic capacitor 1 of variation 3 as well.

[0082] Furthermore, the axial length of the intermediate portion 46 of the sealing rubber 40C before it is attached between the first sealing plate 32A and the second sealing plate 32B is made slightly larger than the gap between the first sealing plate 32A and the second sealing plate 32B when it is attached to the case 20. Therefore, the sealing rubber 40C is disposed between the first sealing plate 32A and the second sealing plate 32B in a state in which it is compressed by the first sealing plate 32A and the second sealing plate 32B. When the sealing rubber 40C is compressed between the first sealing plate 32A and the second sealing plate 32B, the first protrusion 47 of the sealing rubber 40C comes into close contact with the first through hole 33A of the first sealing plate 32A, and the second protrusion 48 of the sealing rubber 40C comes into close contact with the first through hole 33B of the second sealing plate 32B. This makes it possible to further reduce the amount of volatilized electrolyte that permeates the sealing rubber 40C and leaks out of the case 20.

[0083] Furthermore, a first end (first protrusion 47) of the sealing rubber 40C fits into the first through hole 33A of the first sealing plate 32A, and a second end (second protrusion 48) of the sealing rubber 40C fits into the first through hole 33B of the second sealing plate 32B. Here, the outer diameter of the first protrusion 47, which is the first end of the sealing rubber 40C, is set to be larger than the inner diameter of the first through hole 33A, and the outer diameter of the second protrusion 48, which is the second end of the sealing rubber 40C, is set to be larger than the inner diameter of the first through hole 33B. This allows the first end (first protrusion 47) and the second end (first protrusion 47) of the sealing rubber 40C to be tightly fitted to the first through hole 33A and the first through hole 33B, respectively. This reduces the amount of electrolyte contained in the case 20 that permeates the sealing rubber 40C and leaks out of the case 20, improving airtightness.

[0084] Furthermore, the sealing body 30 that closes the opening 24 of the case 20 includes a first sealing plate 32A and a second sealing plate 32B, and a space SP1 is provided between the first sealing plate 32A and the second sealing plate 32B. For example, even if the internal pressure of the storage space 21 increases due to volatilization of electrolyte components or gas generation due to a side reaction of the electrolyte, the first sealing plate 32A can absorb the increase in internal pressure in the storage space 21 by deforming or moving toward the second sealing plate 32B. This prevents the second sealing plate 32B from being deformed due to the increase in internal pressure of the storage space 21. Furthermore, even if the electrolyte permeates the portion of the sealing rubber 40C inserted into the first through-hole 33A of the first sealing plate 32A, the electrolyte is retained in the space SP1 between the first sealing plate 32A and the second sealing plate 32B, reducing the possibility of the electrolyte leaking outside the second sealing plate 32B. Furthermore, when an increase in the internal pressure of the housing space 21 causes the first sealing plate 32A to expand toward the second sealing plate 32B, the sealing rubber 40C disposed between the first sealing plate 32A and the second sealing plate 32B becomes further compressed. When the sealing rubber 40C is compressed between the first sealing plate 32A and the second sealing plate 32B, the first protrusion 47 of the sealing rubber 40C comes into closer contact with the first through-hole 33A of the first sealing plate 32A, and the second protrusion 48 of the sealing rubber 40C comes into closer contact with the first through-hole 33B of the second sealing plate 32B. This further reduces the amount of volatilized electrolyte that permeates the sealing rubber 40C and leaks out of the case 20.

[0085] In this modification, the outer surface of second sealing plate 32B may be flush with edge 27 of case 20 on the opening 24 side. The outer surface of second sealing plate 32B is the surface of second sealing plate 32B opposite the surface facing first sealing plate 32A. When the outer surface of second sealing plate 32B is flush with edge 27 of case 20, the difference in level between the outer surface of second sealing plate 32B and edge 27 of case 20 can be reduced, and a decrease in bonding quality can be suppressed. Note that "the outer surface of second sealing plate 32B being flush with edge 27" does not necessarily mean that the outer surface of second sealing plate 32B and edge 27 are completely flush with each other; there may be a difference in level between the outer surface of second sealing plate 32B and edge 27, the difference being the extent of a manufacturing error.

[0086] (3.4) Other Modifications In the above embodiment, the capacitor element 10 uses both a conductive polymer and an electrolytic solution as the electrolyte, but this is not limited to this, and the electrolyte may be, for example, one of a conductive polymer and an electrolytic solution.

[0087] In the above embodiment, there is no need to perform a process of curling the end 27 of the case 20. Since there is no process of curling the end 27 of the case 20 after welding the sealing plate 31 to the case 20, it is possible to prevent a gap from being generated between the inner surface of the case 20 and the sealing plate 31 due to curling.

[0088] (summary) The above-described embodiments and the like disclose the following aspects.

[0089] The electrolytic capacitor (1) of the first embodiment includes a capacitor element (10), lead terminals (16), a liquid component, a case (20), and a sealing body (30). The lead terminals (16) are connected to the capacitor element (10). The liquid component is impregnated into the capacitor element (10). The case (20) houses the capacitor element (10) and has an opening (24). The sealing body (30) closes the opening (24) of the case (20). The capacitor element (10) is disposed in a housing space (21) within the case (20). The sealing body (30) includes a metal sealing plate (31) and a sealing rubber (40) attached to a first through hole (33) that penetrates the sealing plate (31) in the thickness direction. The lead terminal (16) protrudes to the outside of the case (20) through a second through-hole (44) provided in the sealing rubber (40). The inner surface of the case (20) has a protrusion (26) that protrudes toward the inside of the case (20) between the opening (24) and the storage space (21). The sealing plate (31) is disposed inside the case (20) and is joined to the inner surface of the case (20) while being in contact with the protrusion (26).

[0090] According to this embodiment, the inner surface of the case (20) and the sealing plate (31) are joined together with the protrusion (26) provided on the inner surface of the case (20) in contact with the sealing plate (31). This reduces variation in the position of the sealing plate (31) relative to the inner surface of the case (20) and reduces the possibility of a gap occurring between the inner surface of the case (20) and the sealing plate (31), thereby improving the airtightness of the electrolytic capacitor (1). Furthermore, the sealing body (30) includes the metal sealing plate (31) and the sealing rubber (40) attached to the first through hole (33) of the sealing plate (31). This reduces the area of ​​the portion sealed by the sealing rubber (40) compared to when the entire opening (24) is sealed with rubber. This reduces the area of ​​the rubber seal (40) through which the volatilized liquid component easily permeates, thereby reducing the amount of the volatilized liquid component that permeates the rubber seal (40) and leaks out of the case (20). This allows the liquid component impregnated in the capacitor element (10) to maintain its function of repairing the dielectric layer for a long period of time, thereby extending the life of the electrolytic capacitor (1).

[0091] In the electrolytic capacitor (1) of the second aspect, in the first aspect, the sealing rubber (40) is fitted into the first through-hole (33) of the sealing plate portion (31).

[0092] According to this embodiment, the process for bonding by chemical bonding is not required, as compared with the case where the sealing rubber (40) is bonded to the sealing plate portion (31) by chemical bonding. Therefore, it is possible to provide an electrolytic capacitor (1) with improved airtightness while suppressing a decrease in productivity.

[0093] In the electrolytic capacitor (1) of the third embodiment, in the first or second embodiment, the outer surface of the sealing plate (31) is flush with the end (27) of the case (20) on the opening (24) side.

[0094] According to this embodiment, the step between the end (27) of the case (20) on the opening (24) side and the sealing plate portion (31) can be reduced, and deterioration in the joining quality when joining the sealing plate portion (31) and the case (20) can be suppressed.

[0095] In the electrolytic capacitor (1) of the fourth aspect, in any one of the first to third aspects, the protrusion (26) is an inner portion of a recess (25) formed on the outer surface of the case (20) by drawing the case (20).

[0096] According to this embodiment, the case 20 can be manufactured in the same manner as conventional electrolytic capacitors, in which the case 20 is drawn to pressurize and fix a rubber sealing body placed in the opening 24 of the case 20. This has the advantage that there is no need to make major design changes to the case 20.

[0097] In the electrolytic capacitor (1) of a fifth aspect, in any one of the first to fourth aspects, the sealing plate portion (31) includes a first sealing plate (32A) and a second sealing plate (32B). The first sealing plate (32A) is disposed inside the case (20) in contact with the protrusion (26). The second sealing plate (32B) is disposed at a position closer to the opening (24) than the first sealing plate (32A). The second sealing plate (32B) is joined to the inner surface of the case (20). The sealing rubber (40C) is disposed between the first sealing plate (32A) and the second sealing plate (32B) in a state of being compressed by the first sealing plate (32A) and the second sealing plate (32B).

[0098] According to this embodiment, the first sealing plate (32A) is disposed inside the case (20) in contact with the protrusion (26), and the second sealing plate (32B) is disposed inside the case (20) with the sealing rubber (40C) disposed between the first sealing plate (32A) and the second sealing plate (32B). The second sealing plate (32B) is bonded to the inner surface of the case (20). This reduces variation in the position of the second sealing plate (32B) relative to the inner surface of the case (20), reducing the likelihood of a gap occurring between the inner surface of the case (20) and the second sealing plate (32B). Since the sealing rubber (40C) is compressed between the first sealing plate (32A) and the second sealing plate (32B), the airtightness of the first through hole (33) can be improved.

[0099] In the electrolytic capacitor (1) of the sixth embodiment, in the fifth embodiment, the outer surface of the second sealing plate (32B) is flush with the end (27) of the case (20) on the opening (24) side.

[0100] According to this embodiment, the step between the outer surface of the second sealing plate (32B) and the end portion (27) of the case (20) can be reduced, and deterioration in the joining quality when joining the sealing plate portion (31) and the case (20) can be suppressed.

[0101] The electrolytic capacitor (1) of a seventh aspect is any one of the first to sixth aspects, further comprising a seat plate (50) to which the case (20) is attached. The seat plate (50) has terminal insertion holes (52) into which the lead terminals (16) are inserted.

[0102] According to this aspect, when the electrolytic capacitor (1) is mounted in a device or the like, it is possible to reduce adverse effects on the electrolytic capacitor (1) due to vibrations of the device or the like.

[0103] The electrolytic capacitor (1) of the eighth aspect is the same as that of the seventh aspect, except that a fitting recess (53) is provided around the terminal insertion hole (52) on the surface of the base plate (50) facing the sealing body (30). At least a part of the sealing rubber (40) is inserted into the fitting recess (53).

[0104] According to this embodiment, at least a portion of the sealing rubber (40) is fitted into the fitting recess (53), thereby further improving the airtightness.

[0105] In the electrolytic capacitor (1) of the ninth aspect, in the seventh aspect, a groove (54) connected to the terminal insertion hole (52) is provided on the surface of the base plate (50) opposite to the surface facing the sealing body (30). The bent portions (17A, 17B) of the lead terminal (16) passed through the terminal insertion hole (52) are inserted into the groove (54).

[0106] According to this embodiment, the electrolytic capacitor (1) can be surface mounted.

[0107] In a tenth aspect of the electrolytic capacitor (1), in any one of the first to ninth aspects, the capacitor element (10) includes an anode foil (11), a cathode foil (12), and a separator (18) and a conductive polymer disposed between the anode foil (11) and the cathode foil (12). The anode foil (11), the cathode foil (12), and the separator (18) are wound around a winding axis (Ax1). The capacitor element (10) is disposed in the housing space (21) so that the winding axis (Ax1) is aligned along the thickness direction of the sealing plate portion (31).

[0108] According to this embodiment, similar to the first embodiment, an electrolytic capacitor (1) with improved airtightness can be provided.

[0109] The configurations according to the second to tenth aspects are not essential for the electrolytic capacitor (1) and can be omitted as appropriate. [Explanation of symbols]

[0110] 1 electrolytic capacitor 10 Capacitor element 11 Anode foil 12 Cathode foil 16 Lead terminal 17A, 17B Bending parts 18 Separator 20 cases 21 Containment Space 24 Aperture 25 recess 26 Protrusion 27 End 30 Sealing body 31 Sealing plate part 32A 1st sealing plate 32B 2nd sealing plate 33 First through hole 40 Sealing rubber 44 Second through hole 50 seat board 52 Terminal insertion hole 53 Fitting recess 54 Groove Ax1 Winding shaft

Claims

1. A capacitor element; a lead terminal connected to the capacitor element; a liquid component impregnated in the capacitor element; a case that houses the capacitor element and has an opening; a sealing body that closes the opening of the case, the capacitor element is disposed in an accommodation space within the case, the sealing body includes a metal sealing plate portion and a sealing rubber attached to a first through hole that penetrates the sealing plate portion in a thickness direction, the lead terminal protrudes to the outside of the case through a second through-hole provided in the sealing rubber, the inner surface of the case has a protrusion that protrudes toward the inside of the case between the opening and the storage space, the sealing plate portion is disposed inside the case and is joined to the inner surface of the case in a state of contact with the protrusion portion. Electrolytic capacitor.

2. the sealing rubber is fitted into the first through hole of the sealing plate portion; 2. The electrolytic capacitor according to claim 1.

3. The outer surface of the sealing plate is flush with the end of the case on the opening side.

2. The electrolytic capacitor according to claim 1.

4. The protrusion is an inner portion of a recess formed on the outer surface of the case by drawing the case.

2. The electrolytic capacitor according to claim 1.

5. the sealing plate portion includes a first sealing plate that is disposed inside the case in a state of contact with the protruding portion, and a second sealing plate that is disposed at a position closer to the opening than the first sealing plate, the second sealing plate is joined to the inner surface of the case, the sealing rubber is disposed between the first sealing plate and the second sealing plate in a state where it is compressed by the first sealing plate and the second sealing plate.

2. The electrolytic capacitor according to claim 1.

6. an outer surface of the second sealing plate is flush with the end of the case on the opening side; 6. The electrolytic capacitor according to claim 5.

7. The case further includes a seat plate to which the case is attached, the seat plate has a terminal insertion hole into which the lead terminal is inserted; 2. The electrolytic capacitor according to claim 1.

8. a fitting recess is provided around the terminal insertion hole on a surface of the seat plate facing the sealing body, At least a portion of the sealing rubber is inserted into the fitting recess.

8. The electrolytic capacitor according to claim 7.

9. a groove connected to the terminal insertion hole is provided on a surface of the base plate opposite to a surface facing the sealing body, The bent portion of the lead terminal that has been passed through the terminal insertion hole is inserted into the groove.

8. The electrolytic capacitor according to claim 7.

10. the capacitor element includes an anode foil, a cathode foil, and a separator and a conductive polymer disposed between the anode foil and the cathode foil; the anode foil, the cathode foil, and the separator are wound around a winding axis, the capacitor element is disposed in the accommodation space so that the winding axis is aligned along the thickness direction of the sealing plate portion.

2. The electrolytic capacitor according to claim 1.

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