Capacitor and method for manufacturing capacitor

Abstract

A capacitor (1) includes a capacitor element (2), case members (10, 20), and a film (30). The capacitor element (2) has: a first end surface (4) having a first electrode (5); a second end face (6) having a second electrode (7); and a side surface (3) extending between the first end face and the second end face. The housing members (10, 20) are provided on the first end surface and the second end surface, and suppress permeation of moisture. The film (30) overlaps the case member, covers the side surfaces, is lighter in weight per unit area than the case member, and suppresses the permeation of moisture into the capacitor element together with the case member. As a result, it is possible to provide a capacitor which is lightweight and has improved performance of protecting from moisture.

Description

Citation of related applications

[0001] This application is based on patent application No. 2022-134419 filed in Japan on August 25, 2022, and the contents of the basic application are cited as a whole by reference. Technical Field

[0002] The disclosure described in this specification relates to a capacitor. Background Art

[0003] The case mold type capacitor described in Patent Document 1 includes a capacitor element, a resin case for housing the capacitor element, and a filling resin filled in the case. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2010-251400 Summary of the invention

[0005] The outer packaging of capacitors is required to be lightweight and to protect capacitor elements from moisture. From this point of view, further improvements are required for capacitors.

[0006] An object of the present disclosure is to provide a capacitor which is lightweight and has improved performance in protecting a capacitor element from moisture, and a method for manufacturing the capacitor.

[0007] A capacitor according to one embodiment of the present disclosure includes: A capacitor element having a first end surface having a first electrode, a second end surface having a second electrode, and a side surface extending between the first end surface and the second end surface; a housing member disposed on the first end surface and the second end surface to inhibit water penetration; and The film overlaps with the outer shell member and covers the side surface, has a weight per unit area lighter than that of the outer shell member, and suppresses water permeation into the capacitor element together with the outer shell member.

[0008] A capacitor having improved performance in terms of weight reduction and protection of a capacitor element from moisture can be provided.

[0009] A method for manufacturing a capacitor according to one embodiment of the present disclosure, A housing member is provided on a first end surface of the capacitor element having the first electrode and a second end surface of the capacitor element having the second electrode; The side surface connecting the first end surface and the second end surface in the capacitor element is wrapped from the outside of the outer shell member with a film having a weight per unit area lighter than that of the outer shell member.

[0010] According to this manufacturing method, it is possible to provide a capacitor that is lightweight and has improved performance in protecting a capacitor element from moisture.

[0011] In addition, the reference numerals in parentheses in the appended claims merely indicate the correspondence with the configurations described in the embodiments described later, and do not limit the technical scope in any way. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a three-dimensional diagram of a capacitor. Figure 2 It is along Figure 1 A cross-sectional view along line II-II is shown. Figure 3 is a side view of a capacitor. Figure 4 is a flow chart illustrating a method for manufacturing a capacitor. Figure 5 It is a cross-sectional view explaining the method of manufacturing a capacitor. Figure 6 It is a side view explaining the manufacturing method of a capacitor. Figure 7 It is a perspective view of a capacitor according to a second embodiment. Figure 8 It is along Figure 7 A cross-sectional view taken along line VIII-VIII is shown. Fig. 9 It is a perspective view of a capacitor according to a third embodiment. Fig.10 It is along Fig. 9 A cross-sectional view along line XX is shown. Fig.11 It is a cross-sectional view of a capacitor according to a fourth embodiment. Fig.12 It is a perspective view of a capacitor according to a fifth embodiment. Fig.13 It is along Fig.12 A cross-sectional view taken along line XIII-XIII is shown. Fig.14 is a cross-sectional view of a capacitor according to a sixth embodiment. Fig.15 is a cross-sectional view of a capacitor according to a seventh embodiment. Fig.16 is a cross-sectional view of a capacitor according to an eighth embodiment. Fig.17 is a cross-sectional view of a capacitor according to a ninth embodiment. Fig.18 is a cross-sectional view of a capacitor according to a tenth embodiment. DETAILED DESCRIPTION

[0013] Hereinafter, a plurality of methods for implementing the present disclosure will be described. In each method, sometimes the same reference numerals are given to the parts corresponding to the matters described in the previous method, and repeated descriptions are omitted. In each method, when only a part of the structure is described, other methods previously described can be applied to other parts of the structure.

[0014] Furthermore, not only the combinations of parts that can be combined are explicitly described in each embodiment, but also embodiments, embodiments and modifications, and modifications may be partially combined even without explicit description as long as there is no obstacle to the combination.

[0015] (First Embodiment) right Figure 1 A capacitor 1 according to a first embodiment of the present invention will be described. Figure 2 Show Figure 1 The capacitor 1 includes a capacitor element 2, a first housing member 10, a second housing member 20, a film 30, a first conductive member 40, a second conductive member 50, an insulating member 60, and a resin member 70.

[0016] When describing each structural element, for convenience, the short side direction of the membrane 30 and the axial direction extending between the end faces where the electrodes described later are arranged are sometimes referred to as the width direction WD. The depth direction orthogonal to the width direction WD is sometimes referred to as the depth direction DP. The thickness direction orthogonal to the width direction WD and the depth direction DP is sometimes referred to as the thickness direction TD. In addition, the direction orthogonal to the axis along the width direction WD is sometimes referred to as the radial direction.

[0017] The capacitor element 2 is a film capacitor. The film capacitor is a dielectric film in which metal vapor-deposited electrodes are arranged on the dielectric film, and the dielectric film is wound in a manner such that the metal vapor-deposited electrodes face each other. Metal sprayed electrodes are formed on both end surfaces of the film capacitor by spraying metal. One metal sprayed electrode is electrically connected to a metal vapor-deposited electrode of one polarity. Another metal sprayed electrode is electrically connected to a metal vapor-deposited electrode of another polarity.

[0018] The capacitor element 2 is a three-dimensional shape having a certain volume. The capacitor element 2 can sometimes be provided by a three-dimensional shape such as a cylinder, an elliptical cylinder, a polygonal prism, a cube, a cuboid, etc. The capacitor element 2 has at least two end faces 4, 6 and a side face 3. An end face of the capacitor element 2 associated with the width direction WD is called the first end face 4. The metal sprayed electrode arranged on the first end face 4 is called the first electrode 5. The other end face of the capacitor element 2 associated with the width direction WD is called the second end face 6. The metal sprayed electrode arranged on the second end face 6 is called the second electrode 7. The first electrode 5 and the second electrode 7 are separately arranged in the width direction WD. The side face 3 connects the first end face 4 and the second end face 5. The side face 3 extends along the edge of the first end face 4 and the second end face 6. The side face 3 is centered on the axis along the width direction WD and extends circumferentially along the edge of the first end face 4 and the second end face 6.

[0019] The first shell member 10 is a bottomed cylindrical cover provided on the first end surface 4. The first shell member 10 is made of an insulating member such as resin. The first shell member 10 includes a first bottom 11 and a first side portion 12. The first bottom 11 includes a first inner surface 11A opposite to the first electrode 5 and a first outer surface 11B on the back side thereof. The first bottom 11 and the first side portion 12 are continuous through the same member. The first side portion 12 extends annularly along the periphery of the first bottom 11. In addition, the first bottom 11 has a first exposure hole 13 opened on the first inner surface 11A and the first outer surface 11B. The first exposure hole 13 is a hole for exposing the first conductive member 40, the second conductive member 50 and the insulating member 60.

[0020] The second shell member 20 is a bottomed cylindrical cover provided on the second end surface 6. The second shell member 20 is made of an insulating member such as resin. The second shell member 20 includes a second bottom 21 and a second side 22. The second bottom 21 includes a second inner surface 21A opposite to the second electrode 7 and a second outer surface 21B on the back side thereof. The second bottom 21 and the second side 22 are continuous through the same member. The second side 22 extends annularly along the periphery of the second bottom 21. In the following, the first shell member 10 and the second shell member 20 may be appropriately not distinguished and simply referred to as shell members 10, 20.

[0021] The film 30 is a flat shape having a thickness between the surface 30A and the back surface 30B. The film 30 is a structure in which the surface side resin layer, the metal layer and the back side resin layer are stacked and integrated. The surface 30A is equivalent to the surface side resin layer. The back side 30B is equivalent to the back side resin layer. As an example, the resin layer can use polypropylene or nylon. As an example, the metal layer can use aluminum.

[0022] The surface side resin layer, the metal layer and the back side resin layer have a thickness of several tens of microns. The film 30 has a thickness of several hundred microns. The outer shell members 10 and 20 have a thickness of several millimeters. The weight per unit area of ​​the film 30 is lighter than the weight per unit area of ​​the outer shell members 10 and 20. The film 30 and the outer shell members 10 and 20 together play a role in protecting the capacitor element 2 from external moisture. The film 30 and the outer shell members 10 and 20 provide the required lower moisture permeability. The film 30 has a property that is more difficult to penetrate moisture than the outer shell members 10 and 20. The moisture permeability of the film 30 is lower than the moisture permeability of the outer shell members 10 and 20.

[0023] The membrane 30 has two ends in the short side direction of itself. The membrane 30 has two ends in the long side direction. Hereinafter, one of the ends of the membrane 30 related to the short side direction is sometimes referred to as the first membrane end 31. Sometimes the other of the ends of the membrane 30 related to the short side direction is referred to as the second membrane end 32. Sometimes one of the ends of the membrane 30 related to the long side direction is referred to as the third membrane end 33. Sometimes the other of the ends of the membrane 30 related to the long side direction is referred to as the fourth membrane end 34. In addition, the membrane ends 31 to 34 include an area having a width on the end side. At the end face of the first membrane end 31 and the end face of the second membrane end 32, the first layer, the second layer and the third layer are exposed to the outside. At the end face of the third membrane end 33 and the end face of the fourth membrane end 34, the first layer, the second layer and the third layer are exposed to the outside.

[0024] The first conductive member 40 is a conductive busbar. The first conductive member 40 is electrically and mechanically connected to the first electrode 5. As an example, the end of the first conductive member 40 and the first electrode 5 are joined by welding. The second conductive member 50 is a conductive busbar. The second conductive member 50 is electrically and mechanically connected to the second electrode 7. As an example, the end of the second conductive member 50 and the second electrode 7 are joined by welding. Hereinafter, the first conductive member 40 and the second conductive member 50 may be appropriately not distinguished and simply referred to as conductive members 40, 50.

[0025] The insulating member 60 is a member provided between the first conductive member 40 and the second conductive member 50. The insulating member 60 suppresses conduction between the first conductive member 40 and the second conductive member 50. The resin member 70 is composed of a component such as an epoxy resin or a polyurethane resin. The resin member 70 has a property of being able to cure at room temperature. The capacitor element 2 is fixed to the first housing member 10, the second housing member 20 and the film 30 by the resin member 70. In addition, the resin member 70 may also have a property of being able to cure by heat.

[0026] The end of the first conductive member 40 is electrically and mechanically connected to the first electrode 5. The first conductive member 40 includes a portion extending along the first end face 4 and a portion extending in the width direction WD away from the first end face 4. The end of the second conductive member 50 is electrically and mechanically connected to the second electrode 7. The second conductive member 50 includes a portion extending along the second end face 6, the side face 3 and the first end face 4, and a portion extending in the width direction WD away from the first end face 4. The insulating member 60 is disposed between the first conductive member 40 and the second conductive member 50. The insulating member 60 includes a portion extending along the side face 3 and the first end face 4, and a portion extending in the width direction WD away from the first end face 4.

[0027] The first housing member 10 is provided on the first end surface 4 in such a manner that the first conductive member 40, the second conductive member 50, and the insulating member 60 are exposed from the first exposure hole 13. In the width direction WD, the first bottom portion 11 overlaps with the first electrode 5. In the width direction WD, a portion of the first conductive member 40, a portion of the second conductive member 50, and a portion of the insulating member 60 are provided within the projection area of ​​the first bottom portion 11. In the radial direction, the first side portion 12 overlaps with a portion of the side surface 3. In the radial direction, a portion of the first conductive member 40, a portion of the second conductive member 50, and a portion of the insulating member 60 are provided within the projection area of ​​the first side portion 12.

[0028] The second housing member 20 is provided on the second end surface 6. In the width direction WD, the second bottom portion 21 overlaps with the second electrode 7. In the width direction WD, a portion of the second conductive member 50 is provided within the projection area of ​​the second bottom portion 21. In the radial direction, the second side portion 22 overlaps with a portion of the side surface 3. In the radial direction, a portion of the second conductive member 50 is provided within the projection area of ​​the second side portion 22.

[0029] The film 30 is arranged on the periphery of the capacitor element 2 in such a way that the long side direction is along the long side direction of the side surface 3. The film 30 covers the side surface 3. In addition, in the radial direction, the film 30 is arranged farther from the capacitor element 2 than the housing members 10 and 20. The first film end 31 and the second film end 32 include an area including a width in the short side direction. The first film end 31 overlaps with the first side portion 12 in a layered manner in the radial direction. The second film end 32 overlaps with the second side portion 22 in a layered manner in the radial direction. In addition, the film 30 may also extend to the bottom 11 and 21 side and overlap with the bottom 11 and 21 in a layered manner in the width direction WD.

[0030] Figure 31 is a side view of the capacitor 1. The first side portion 12 and the first film end portion 31 are bonded. As an example, the first film end portion 31 and the first side portion 12 are heat-fused. The second side portion 22 and the second film end portion 32 are bonded. As an example, the second film end portion 32 and the second side portion 22 are heat-fused. The third film end portion 33 and the fourth film end portion 34 include an area including a width in the long side direction. The third film end portion 33 and the fourth film end portion 34 are overlapped in a butt-joined manner. The periphery of the third film end portion 33 and the fourth film end portion 34 is heat-fused. The third film end portion 33 and the fourth film end portion 34 are sealed at the periphery. The overlapping portion of the third film end portion 33 and the fourth film end portion 34 is fixed to a portion of the film 30 arranged on the side 3 using an adhesive member. In addition, in the accompanying drawings, the dotted line portion surrounded by the quadrilateral corresponds to the portion that is heat-fused.

[0031] In addition, the bonding method of the film ends 31, 32 and the side parts 12, 22 is not limited to heat welding. The bonding method of the third film end 33 and the fourth film end 34 is not limited to heat welding. The film ends 31, 32 and the side parts 12, 22 can also be bonded using an adhesive member. The third film end 33 and the fourth film end 34 can also be bonded using an adhesive member. Sometimes, the first film end 31 and the second film end 32 are not distinguished and are simply referred to as film ends 31, 32. Sometimes, the first side part 12 and the second side part 22 are not distinguished and are simply referred to as side parts 12, 22.

[0032] The capacitor element 2 is covered by the first housing member 10, the second housing member 20 and the film 30. Hereinafter, for the sake of convenience, the first housing member 10, the second housing member 20 and the film 30 are sometimes collectively referred to as the outer packaging members 10, 20, and 30. A resin member 70 is arranged between the capacitor element 2 and the outer packaging members 10, 20, and 30. The space between the first housing member 10 and the capacitor element 2 is referred to as the first space 81. The space between the film 30 and the capacitor element 2 is referred to as the second space 82. The space between the second housing member 20 and the capacitor element 2 is referred to as the third space 83. The resin member 70 is provided in the first space 81, the second space 82, and the third space 83. In addition, the resin member 70 enters the first exposure hole 13. The resin member 70 closes the first exposure hole 13. In addition, the first exposure hole 13 may not be closed by the resin member 70. In addition, the resin member 70 may not be provided in the second space 82.

[0033] <Capacitor Manufacturing Method> Figure 4A flow chart for explaining a method for manufacturing the capacitor 1 is shown. First, in step S110, the capacitor element 2 is prepared. Next, in step S120, the conductive members 40 and 50 are connected to the electrodes 5 and 7. Specifically, the end of the first conductive member 40 is connected to the first electrode 5. The end of the second conductive member 50 is connected to the second electrode 7. Furthermore, an insulating member 60 is provided between the first conductive member 40 and the second conductive member 50. In addition, the insulating member 60 may also be provided in advance on the first conductive member 40 or the second conductive member 50. In addition, sometimes the first electrode 5 and the second electrode 7 are not distinguished and are simply referred to as electrodes 5 and 7.

[0034] Next, in step S130, the outer shell members 10 and 20 are provided on the capacitor element 2. Specifically, the first outer shell member 10 is provided on the first end surface 4. The second outer shell member 20 is provided on the second end surface 6. The first outer shell member 10 is provided on the first end surface 4 while the first conductive member 40, the second conductive member 50, and the insulating member 60 are passed through the first exposure hole 13. Figure 5 The method of fixing the outer shell members 10, 20 and the capacitor element 2 in step S130 is shown. The first outer shell member 10 is embedded in the end of the first end face 4 like a cover. The second outer shell member 20 is embedded in the end of the second end face 6 like a cover. In addition, the first outer shell member 10 can also be fixed by a clamp. The second outer shell member 20 can also be fixed by a clamp.

[0035] Next, in step S140, the film 30 is wrapped from the outside of the outer shell members 10, 20. The film 30 is wound along the side 3 while the first film end 31 overlaps the first side portion 12 and the second film end 32 overlaps the second side portion 22. At this time, the first side portion 12 and the second side portion 22 play a guiding role. The film 30 is wrapped from the outside of the outer shell members 10, 20 in a manner that the third film end 33 and the fourth film end 34 are attached and overlapped.

[0036] Next, in step S150 , the film 30 and the outer shell members 10 , 20 are bonded together. Figure 6 The method of fixing the film 30 to the outer casing members 10, 20 in step S150 is shown. The first film end 31 and the first side portion 12 are bonded by heat welding. The second film end 32 and the second side portion 22 are bonded by heat welding. Next, in step S160, the resin member 70 is filled in the spaces 81, 82, 83 between the capacitor element 2 and the outer casing members 10, 20, 30. In addition, in step S150, the third film end 33 and the fourth film end 34 are not bonded. In step S160, the film ends 31 and the second side portions 22 are bonded. Figure 6 The spaces 81, 82, and 83 are filled with the resin member 70 at the positions indicated by the hollow arrows. In addition, the resin member 70 may not be provided in the second space 82.

[0037] When the third film end 33 and the fourth film end 34 are separated from each other, a gap of a degree that the resin member 70 can be injected is generated between the third film end 33 and the fourth film end 34. In step S160, the resin member 70 is filled into the spaces 81, 82, and 83 from the gap and cured. After curing, in step S170, the third film end 33 and the fourth film end 34 are heat-fused along the periphery. When the third film end 33 and the fourth film end 34 are heat-fused at the end in the long side direction, vacuum sealing is performed. Thus, the capacitor element 2 can be pressed by the film 30. After the third film end 33 and the fourth film end 34 are heat-fused, the third film end 33 and the fourth film end 34 are tilted toward the side 3 and fixed to the portion of the film 30 arranged on the side 3 using an adhesive member. In addition, the process of curing the resin member 70 can also be performed after step S170.

[0038] In a case molded capacitor, a capacitor element is housed in a resin case. The capacitor element and the case are fixed to each other by filling the case with a filling resin. In a high humidity environment, the capacitor element may sometimes experience undesirable conditions such as reduced capacity. Therefore, in a case molded capacitor, the capacitor element is covered with a case and a filling resin to prevent moisture from invading the capacitor element. In particular, in a structure in which the case includes an opening and a portion of the filling resin is exposed to the outside, the filling resin facing the opening is in contact with the outside air. Therefore, the thickness of the filling resin facing the opening is thickened to prevent moisture from invading the capacitor element. However, in this case, although the intrusion of moisture into the capacitor element can be suppressed, the problem of an overall increase in weight is generated.

[0039] <Effects> In the present embodiment, the capacitor 1 includes a capacitor element 2, a shell member 10, 20 and a film 30. A first shell member 10 is provided at the first end face 4 of the capacitor element 2. A second shell member 20 is provided at the second end face 6 of the capacitor element 2. The film 30 is provided on the outer periphery of the capacitor element 2 along the side 3. The first film end 31 and the first side portion 12 overlap in a radial direction. The second film end 32 and the second side portion 22 overlap in a radial direction. Thus, the end faces 4, 6 are covered by the shell members 10, 20, and the side 3 is covered by the film 30. In addition, the weight per unit area of ​​the film 30 is lighter than the weight per unit area of ​​the shell members 10, 20. In addition, the film 30 and the shell members 10, 20 provide the required lower moisture permeability. Therefore, the lightweight of the capacitor 1 and the performance of protecting the capacitor element 2 from moisture can be improved. By replacing the shell in the shell molded capacitor with the shell members 10, 20 and the film 30, the lightweight of the capacitor 1 and the performance of protecting the capacitor element 2 from moisture can be improved.

[0040] In addition, in this embodiment, the mechanical strength of the capacitor element 2 is ensured to a degree that it is protected from mechanical external forces by the outer shell members 10 and 20. Therefore, in the resin member 70, a high mechanical strength is not required. As a result, the amount of the resin member 70 can be reduced. Thus, the curing time can be shortened. The energy consumption of the equipment accompanying the curing can be suppressed. It is also excellent from the perspective of carbon neutrality.

[0041] The first film end 31 is bonded to the first side portion 12. The second film end 32 is bonded to the second side portion 22. Thus, the generation of a gap between the first film end 31 and the first side portion 12 is suppressed. The generation of a gap between the second film end 32 and the second side portion 22 is suppressed. The intrusion of moisture from the gap between the film ends 31, 32 and the side portions 12, 22 into the space between the capacitor element 2 and the exterior member 80 is suppressed.

[0042] The resin member 70 is provided in the first space 81 and the third space 83. Since the outer shell members 10 and 20 and the resin member 70 are overlapped in multiple layers in the width direction WD, it is possible to effectively suppress the intrusion of moisture into the capacitor element 2 from the width direction WD.

[0043] The resin member 70 is arranged in the second space 82. In the radial direction, the film 30 and the resin member 70 overlap in layers, so it is possible to effectively suppress the intrusion of moisture into the capacitor element 2 from the radial direction. In addition, the resin member 70 is arranged in the first space 81, the second space 82 and the third space 83. It is possible to effectively suppress the intrusion of moisture into the capacitor element 2 from the width direction WD and the radial direction. In addition, the film 30 has the property that it is more difficult for moisture to penetrate than the outer shell members 10 and 20. Even if the thickness of the resin member 70 in the second space 82 is thinner than the thickness of the resin member 70 in the first space 81 and the third space 83, the capacitor element 2 can be protected from the influence of moisture. The thinning of the covering resin 70 can reduce the weight of the capacitor 1 accordingly.

[0044] The first bottom portion 11 is provided with a first exposure hole 13 opened at the first inner surface 11A and the first outer surface 11B. The first conductive member 40, the second conductive member 50, and the insulating member 60 are exposed from the first exposure hole 13. The first exposure hole 13 is sealed by the resin member 70. Thus, it is possible to suppress the intrusion of moisture from the first exposure hole 13 into between the capacitor element 2 and the outer packaging member 80.

[0045] The insulating member 60 is provided between the first conductive member 40 and the second conductive member 50. The insulating member 60 is provided in the projection area of ​​the first housing member 10. The parasitic inductance between the first conductive member 40 and the second conductive member 50 can be reduced to a necessary minimum amount.

[0046] (Second Embodiment) right Figure 7A capacitor 1 according to a second embodiment of the present invention will be described. Figure 8 Show Figure 7 A cross section of capacitor 1 in the direction of arrow VIII. Figure 8 In order to illustrate the multilayer structure of the film 30, the thickness of the film 30 is slightly exaggerated. The capacitor 1 of the second embodiment does not include the insulating member 60. A first exposure hole 213 penetrating the inner surface and the outer surface is provided on the top side of the first side portion 12. A second exposure hole 223 penetrating the inner surface and the outer surface is provided on the top side of the second side portion 22. The first conductive member 40 extends toward the first exposure hole 213. The front end of the first conductive member 40 is exposed from the first exposure hole 213. The first exposure hole 213 is closed by the resin member 70.

[0047] The second conductive member 50 extends toward the second exposure hole 223. The front end of the second conductive member 50 is exposed from the second exposure hole 223. The second exposure hole 223 is sealed by the resin member 70. The first conductive member 40 and the second conductive member 50 are separated in the width direction WD. In addition, the first exposure hole 213 and the second exposure hole 223 may also be sealed by a sealing member 93 different from the resin member 70.

[0048] A first extension wall 14 extending along the edge of the first exposure hole 213 is provided on the first side portion 12. The first extension wall 14 is provided in a U-shape along the edge of the first exposure hole 213. The first extension wall 14 includes two first side walls 15 and a first connecting wall 16. The two first side walls 15 extend from the first end face 4 to the second end face 6. The first connecting wall 16 connects the two first side walls 15 along the edge of the first exposure hole 213 on the side away from the first end face 4 in the width direction WD. The first conductive member 40 exposed from the first exposure hole 213 is opposite to the first connecting wall 16 in the width direction WD.

[0049] A second extension wall 24 extending along the edge of the second exposure hole 223 is provided on the second side portion 22. The second extension wall 24 is provided in a U-shape along the edge of the second exposure hole 223. The second extension wall 24 includes two second side walls 25 and a second connecting wall 26. The two second side walls 25 extend from the second end face 6 to the first end face 4. The second connecting wall 26 connects the two second side walls 25 along the edge of the second exposure hole 223 on the side away from the second end face 6 in the width direction WD. The second conductive member 50 exposed from the second exposure hole 223 is opposite to the second connecting wall 26 in the width direction WD.

[0050] The multilayer structure constituting the film 30 is exposed from the end face of the first film end 31. The film 30 is provided with a second layer 30D as a metal layer stacked between the first layer 30C as a surface resin layer and the third layer 30E as a back resin layer. The second layer 30D composed of a metal member is exposed from the end face of the first film end 31. A first connecting wall 16 is provided between the first conductive member 40 exposed from the first exposure hole 213 and the end face of the first film end 31. The presence of the first connecting wall 16 lengthens the creepage distance between the first conductive member 40 and the first film end 31 to a corresponding degree. The formation of an undesired current path between the first conductive member 40 and the second layer 30D is suppressed. The physical increase of the capacitor 1 in the width direction WD is suppressed.

[0051] The multilayer structure constituting the film 30 is exposed from the end face of the second film end 32. The second layer 30D constituted by the metal member is exposed from the end face of the second film end 32. A second connecting wall 26 is provided between the second conductive member 50 exposed from the second exposure hole 223 and the end face of the second film end 32. The presence of the second connecting wall 26 lengthens the creepage distance between the second conductive member 50 and the second film end 32 by a corresponding degree. The formation of an undesired current path between the second conductive member 50 and the second layer 30D is suppressed. The size increase of the capacitor 1 in the width direction WD is suppressed.

[0052] The first housing member 10 includes, in addition to the first bottom portion 11 and the first side portion 12, a first fastening portion 17 fastened to an external housing or the like. The first fastening portion 17 is provided on the first bottom portion 11. The first fastening portion 17 extends in the width direction WD in a manner away from the first bottom portion 11. A through hole penetrating in thickness TD is provided on the first fastening portion 17. A metal bearing 17A through which the shaft portion of a bolt passes is provided in the through hole. The first housing member 10 is fixed by fixing the shaft portion of the bolt to an external housing or the like. In addition, the bearing 17A is separated from the first electrode 5 to the extent that insulation is possible.

[0053] The second housing member 20 includes a second fastening portion 27 fastened to an external housing or the like in addition to the second bottom portion 21 and the second side portion 22. The second fastening portion 27 is provided at the second bottom portion 21. The second fastening portion 27 extends in the width direction WD in a manner away from the second bottom portion 21. A through hole penetrating in the thickness direction TD is provided in the second fastening portion 27. A metal bearing 27A through which the shaft of the bolt passes is provided in the through hole. The second housing member 20 is fixed by fixing the shaft of the bolt to an external housing or the like. In addition, the bearing 27A is separated from the second electrode 7 to the extent that insulation is possible.

[0054] In addition, when viewed from above in the thickness direction TD, the first fastening parts 17 and the second fastening parts 27 are arranged at diagonals of the capacitor 1. When viewed from above, the first fastening parts 17 and the second fastening parts 27 are arranged alternately. By arranging the first fastening parts 17 and the second fastening parts 27 in this way, vibration of the capacitor 1 relative to an external housing or the like is effectively suppressed.

[0055] In addition, the thickness of the film 30 is constant. The film 30 is recessed toward the capacitor element 2 between the first shell member 10 and the second shell member 20. The film 30 is offset toward the capacitor element 2 side between the first shell member 10 and the second shell member 20. The film 30 is recessed in a step-like manner toward the capacitor element 2 side between the first shell member 10 and the second shell member 20. Hereinafter, for the sake of convenience, the portion of the film 30 that is recessed toward the capacitor element 2 is sometimes referred to as a recess 35. The recess 35 is provided between the first film end 31 and the second film end 32. The recess 35 is embedded between the first side portion 12 and the second side portion 22. The first side portion 12 and the second side portion 22 are closed by the recess 35.

[0056] The distance between the concave portion 35 in the radial direction and the capacitor element 2 is shorter than the distance between the film ends 31 and 32 in the radial direction and the capacitor element 2. The resin member 70 is filled in the first space 81, the second space 82, and the third space 83. In addition, the resin member 70 may not be provided in the second space 82. When the resin member 70 is filled in the first space 81 to the third space 83, the amount of the resin member 70 filled between the concave portion 35 and the capacitor element 2 can be reduced compared to the case where the film 30 is not offset to the capacitor element 2 side at the center. As a result, the capacitor 1 is lightweight.

[0057] (Third Embodiment) right Fig. 9 A capacitor 1 according to a third embodiment of the present invention will be described. Fig.10 Show Fig. 9 A cross section of the capacitor 1 in the direction of the arrow X. In the third embodiment, the capacitor 1 further includes a first covering member 91 and a second covering member 92. The first covering member 91 and the second covering member 92 are made of the same material as the film 30. In addition, the first covering member 91 and the second covering member 92 may not be made of the same material as the film 30. The first covering member 91 and the second covering member 92 only need to be made of a material having a lower water permeability than the outer shell members 10 and 20.

[0058] The first covering member 91 is arranged on the first outer surface 11B of the first bottom 11. The second covering member 92 is arranged on the second outer surface 21B of the second bottom 21. Thus, the first end face 4, the resin member 70, the first bottom 11 and the first covering member 91 overlap in layers in the width direction WD. The second end face 6, the resin member 70, the first bottom 11 and the first covering member 91 overlap in layers in the width direction WD. The moisture permeability of the covering members 91 and 92 is lower than that of the outer shell members 10 and 20. It is possible to effectively suppress moisture from invading the capacitor element 2 from the width direction WD. Even if the amount of the resin member 70 arranged between the bottom 11 and 21 and the end faces 4 and 6 is reduced, the performance of protecting the capacitor element 2 from the influence of moisture can be maintained. It is possible to take into account both the lightweight of the capacitor 1 and the performance of protecting the capacitor element 2 from the influence of moisture.

[0059] In addition, in the third embodiment, the first housing member 10 has a first locking portion 18. In the width direction WD, the first locking portion 18 extends away from the first bottom 11. The first locking portion 18 is formed into a shape that becomes narrower and more pointed as it moves away from the first bottom 11. The second housing member 20 has a second locking portion 28. In the width direction WD, the second locking portion 28 extends away from the second bottom 21. The second locking portion 28 is formed into a shape that becomes narrower and more pointed as it moves away from the second bottom 21. In the case where there are a plurality of capacitors 1 and the plurality of capacitors 1 are sealed in a large housing with resin, the first locking portion 18 and the second locking portion 28 exert an anchoring effect on the sealing resin. The bonding area with the sealing resin in the first housing member 10 increases. The bonding area with the sealing resin in the second housing member 20 increases. As a result, the capacitor 1 is firmly fixed to the sealing resin.

[0060] (Fourth Embodiment) right Fig.11 The capacitor 1 of the fourth embodiment in the embodiment is described. In the fourth embodiment, the first covering member 91 is provided on the first inner surface 11A of the first bottom 11. The second covering member 92 is provided on the second inner surface 21A of the second bottom 21. In the fourth embodiment, the same effect as the third embodiment is also exerted. In addition, the first covering member 91 can also be provided on the first inner surface 11A of the first bottom 11, and the second covering member 92 can be provided on the second outer surface 22B of the second bottom 21. The first covering member 91 can also be provided on the first outer surface 11B of the first bottom 11, and the second covering member 92 can be provided on the second inner surface 21A of the second bottom 21. Thus, the same effect can also be exerted.

[0061] (Fifth Embodiment) right Fig.12 A capacitor 1 according to a second embodiment of the present invention will be described. Fig.13Show Fig.12 In the fifth embodiment, the first conductive member 40 is insert-molded in the first housing member 10. The first conductive member 40 is insert-molded in the first side portion 12. The second conductive member 50 is insert-molded in the second housing member 20. The second conductive member 50 is insert-molded in the second side portion 22.

[0062] The first bottom portion 11 is provided with a first opening 19 through which a welding arm can enter and exit on the first inner surface 11A and the first outer surface 11B. The second bottom portion 21 is provided with a second opening 29 through which a welding arm can enter and exit on the second inner surface 21A and the second outer surface 21B. The first electrode 5 and the first conductive member 40 are welded at a position overlapping with the first opening 19 in the width direction WD. The second electrode 7 and the second conductive member 50 are welded at a position overlapping with the second opening 29 in the width direction WD. Furthermore, the first opening 19 and the second opening 29 are closed by the resin member 70. Since the positional deviation of the conductive members 40 and 50 is suppressed, the occurrence of poor connection between the conductive members 40 and 50 and the electrodes 5 and 7 is suppressed. In addition, the first opening 19 and the second opening 29 may not be closed by the resin member 70.

[0063] (Sixth Embodiment) right Fig.14 The capacitor 1 of the sixth embodiment in the embodiment will be described. In the sixth embodiment, a sealing member 93 different from the resin member 70 may be provided at the first opening 19 and the second opening 29. The first opening 19 and the second opening 29 are sealed by the sealing member 93. In addition, the first opening 19 may be sealed by the resin member 70, and the second opening 29 may be sealed by the sealing member 93. The first opening 19 may be sealed by the sealing member 93, and the second opening 29 may be sealed by the resin member 70.

[0064] (Seventh Embodiment) right Fig.15The capacitor 1 of the seventh embodiment in the embodiment is described. In the seventh embodiment, the capacitor 1 includes a first covering member 91 and a second covering member 92 of the same material as the film 30. The size of the first covering member 91 is large enough to cover the first opening 19. The size of the second covering member 92 is large enough to cover the second opening 29. The covering members 91 and 92 are arranged on the bottoms 11 and 21 in a manner to close the openings 19 and 29. As an example, the first covering member 91 is arranged on the first outer surface 11B of the first bottom 11. The second covering member 92 is arranged on the second outer surface 21B of the second bottom 21. Thus, it is easy to suppress moisture from contacting the capacitor element 2. In addition, the covering members 91 and 92 only need to be arranged on the bottoms 11 and 21, and the surfaces on which they are arranged can be the outer surfaces 11B and 21B or the inner surfaces 11A and 21A. They can also be arranged on both the outer surfaces 11B and 21B and the inner surfaces 11A and 21A.

[0065] (Eighth Embodiment) right Fig.16 The capacitor 1 of the eighth embodiment shown in FIG. 8 is described. In the eighth embodiment, compared with the structure of the first embodiment, the resin member 70 is provided only in the first space 81 and the third space 83. It is also possible to have a structure in which the resin member 70 is not provided in the first space 81, the second space 82, and the third space 83. In addition, the resin member 70 may not be provided in the first space 81, the second space 82, and the third space 83.

[0066] (Ninth Embodiment) right Fig.17 In the tenth embodiment, compared with the structure of the fifth embodiment, the resin member 70 is provided only in the first space 81 and the third space 83. In addition, in the capacitor 1 of the tenth embodiment, the resin member 70 may not be provided in the first space 81, the second space 82, and the third space 83.

[0067] (Tenth Embodiment) right Fig.18 The capacitor 1 of the tenth embodiment shown in FIG. 10 is described. In the tenth embodiment, the first exposure hole 13 is sealed by a sealing member 93 different from the resin member 70. This also makes it possible to suppress the intrusion of moisture into the capacitor element 2.

[0068] (Other embodiments) In the embodiments described so far, a method of wrapping the capacitor element 2 with a continuous film 30 is described. However, the film 30 is not limited to a continuous structure. It is also possible to have a plurality of films 30. The capacitor element 2 can also be wrapped with a plurality of films 30. For example, it can also be a structure as follows: there are two films 30, and the film end of one film and the film end of another film are heat-fused to wrap the capacitor element 2. The number of films 30 is not limited. In addition, the film 30 can also be composed of a thin film that shrinks due to heat. In this case, the film 30 is also called a so-called shrink label. Even if a film 30 having the property of shrinking due to heat is used, the above-mentioned effects can be exerted.

[0069] (Disclosure of technical ideas) This specification discloses multiple technical ideas recorded in the following multiple items. Some items are sometimes recorded by selectively citing a multiple dependent form of a previous item in a subsequent item. Some items are sometimes recorded by citing a multiple dependent form of an item in another multiple dependent form. These items recorded in multiple dependent forms define multiple technical ideas.

[0070] (Technical Thought 1) A capacitor comprises: a capacitor element (2) having: a first end surface (4) having a first electrode (5), a second end surface (6) having a second electrode (7), and a side surface (3) extending between the first end surface and the second end surface; an outer shell member (10, 20) provided on the first end surface and the second end surface to suppress the penetration of water; and A film (30) overlaps the outer shell member and covers the side surface, has a weight per unit area lighter than that of the outer shell member, and together with the outer shell member, suppresses the water from penetrating into the capacitor element.

[0071] (Technical Thought 2) The capacitor according to technical idea 1 includes an adhesive portion between a portion of the outer shell member that overlaps with the film and a portion of the film that overlaps with the outer shell member.

[0072] (Technical Thought 3) The capacitor according to technical idea 1 or 2, further comprising a resin member (70) arranged between the case member and the capacitor element.

[0073] (Technical Thought 4) The capacitor according to technical idea 3, wherein the resin member is further disposed between the film and the capacitor element.

[0074] (Technical Thought 5) The capacitor according to technical idea 3 or 4, further comprising: a first conductive member (40) disposed on the first electrode; and a second conductive member (50) disposed at the second electrode, The housing member includes an exposure hole (13, 213, 223) for exposing the conductive members (40, 50) extending from the first electrode and the second electrode. The exposure hole is closed by the resin member or a sealing member (93) different from the resin member.

[0075] (Technical Thought 6) The capacitor according to technical idea 5, wherein the outer shell member includes openings (19, 29) for exposing the first electrode and the second electrode, The opening is closed by the resin member or the sealing member.

[0076] (Technical Thought 7) The capacitor according to technical idea 5 or 6, wherein the casing member is insulating, The film allows the metal member (30D) to be exposed from the end surface of the film end portion (31, 32) overlapping with the shell member, The housing member includes a wall (16, 26) at a portion closer to the film end than the exposure hole, and the wall (16, 26) is located between the first conductive member and the metal member and between the second conductive member and the metal member.

[0077] (Technical Thought 8) The capacitor according to any one of technical concepts 1 to 7, wherein the film includes a recess (35) between the casing members that is recessed toward the capacitor element.

[0078] (Technical Thought 9) A capacitor according to any one of technical concepts 1 to 8, further comprising a covering member (91, 92) on the inner surface (11A, 21A) or the outer surface (11B, 21B) of the shell member, which together with the shell member inhibits moisture permeation at the first end face and the second end face.

[0079] (Technical Thought 10) A method for manufacturing a capacitor, comprising providing a casing member (10, 20) on a first end surface (4) of a capacitor element (2) having a first electrode (5) and a second end surface (6) of the capacitor element having a second electrode (7); A side surface (3) connecting the first end surface and the second end surface in the capacitor element is wrapped from the outside of the outer shell member by a film (30) having a weight per unit area lighter than that of the outer shell member.

Claims

1. A capacitor, comprising: A capacitor element (2) comprising a first end surface (4) having a first electrode (5), a second end surface (6) having a second electrode (7), and a side surface (3) extending between the first end surface and the second end surface; An outer shell member (10, 20) is provided on the first end surface and the second end surface to inhibit water penetration; as well as A film (30) overlaps the outer shell member and covers the side surface, has a weight per unit area lighter than that of the outer shell member, and together with the outer shell member, suppresses the water from penetrating into the capacitor element.

2. The capacitor according to claim 1, characterized in that An adhesive portion is provided between a portion of the outer shell member that overlaps with the film and a portion of the film that overlaps with the outer shell member.

3. The capacitor according to claim 1 or 2, characterized in that: A resin member (70) is also included which is arranged between the case member and the capacitor element.

4. The capacitor according to claim 3, characterized in that The resin member is further arranged between the film and the capacitor element.

5. The capacitor according to claim 4, characterized in that Also includes: A first conductive member (40) disposed on the first electrode; as well as a second conductive member (50) disposed at the second electrode, The housing member includes an exposure hole (13, 213, 223) for exposing the conductive members (40, 50) extending from the first electrode and the second electrode. The exposure hole is closed by the resin member or a sealing member (93) different from the resin member.

6. The capacitor according to claim 5, characterized in that The housing member includes openings (19, 29) for exposing the first electrode and the second electrode. The opening is closed by the resin member or the sealing member.

7. The capacitor according to claim 5, characterized in that The housing member is insulating, The film allows the metal member (30D) to be exposed from the end surface of the film end portion (31, 32) overlapping with the shell member, The housing member includes a wall (16, 26) at a portion closer to the film end than the exposure hole, and the wall (16, 26) is located between the first conductive member and the metal member and between the second conductive member and the metal member.

8. The capacitor according to claim 5, characterized in that The membrane includes a recess (35) between the housing members that is recessed toward the capacitor element.

9. The capacitor according to claim 5, characterized in that The outer shell member further includes a covering member (91, 92) on the inner surface (11A, 21A) or the outer surface (11B, 21B) of the outer shell member, which, together with the outer shell member, suppresses moisture permeation at the first end surface and the second end surface.

10. A method for manufacturing a capacitor, A casing member (10, 20) is provided on a first end surface (4) of a capacitor element (2) having a first electrode (5) and a second end surface (6) of the capacitor element having a second electrode (7). A side surface (3) connecting the first end surface and the second end surface in the capacitor element is wrapped from the outside of the outer shell member by a film (30) having a lighter weight per unit area than the outer shell member.

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