Capacitor

Abstract

To provide a capacitor of which a weight is lightened and a performance for protecting a capacitor element from water is improved, and a manufacturing method of the capacitor.SOLUTION: A capacitor 1 comprises a capacitor element 2, outer shell members 10 and 20, and a film 30. The capacitor element 2 includes: 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 that is extended between the first end surface and the second end surface. The outer shell members 10 and 20 are provided at the first and second end surfaces, and suppress permeation of water. The film 30 covers the side surface while being overlapped with the outer shell member, and has a weight per unit area lighter than that of the outer shell member, and suppresses permeation of water to the outer shell member and the capacitor element. Thus, the capacitor that can realize a right with and a performance of protection from water can be provided.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosure described in this specification relates to a capacitor.

Background Art

[0002] The case-molded 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 Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For the exterior of a capacitor, light weight and the performance of protecting the capacitor element from moisture are required. From such a perspective, further improvement of the capacitor is required.

[0005] The object of the present disclosure is to provide with a capacitor with improved light weight and performance of protecting the capacitor element from moisture.

Means for Solving the Problems

[0006] A capacitor according to one aspect of the present disclosure includes a capacitor element (2) having a first end face (4) with a first electrode (5), a second end face (6) with a second electrode (7), and a side face (3) extending between the first end face and the second end face, a first outer shell member (10) provided on the first end face for suppressing moisture permeation, a second outer shell member (20) provided on the second end face for suppressing moisture permeation, a film (30) that overlaps the first outer shell member and the second outer shell member and covers the side face, has a weight per unit area lighter than that of the first outer shell member and the second outer shell member, and suppresses moisture permeation into the capacitor element together with the first outer shell member and the second outer shell member, a resin member (70) disposed between the first outer shell member and the second outer shell member and the capacitor element, and further between the film and the capacitor element, a first conductive member (40) provided on the first electrode, and a second conductive member (50) provided on the second electrode. The first outer shell member includes a first opening (19) that overlaps a position where the first electrode and the first conductive member are welded. The second outer shell member includes a second opening (29) that overlaps a position where the second electrode and the second conductive member are welded. The first opening and the second opening are closed by a resin member or a sealing member (93) different from the resin member. and a first conductive member is insert-molded in the first outer shell member, and a second conductive member is insert-molded in the second outer shell member are.

[0007] It is possible to provide a capacitor with weight reduction and improved performance of protecting the capacitor element from moisture.

[0010] Note that the reference numerals in the parentheses above only indicate the correspondence with the configurations described in the embodiments below, and do not limit the technical scope in any way.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Embodiments for Carrying Out the Invention

[0012] Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described. In each embodiment, parts corresponding to those described in the preceding embodiments may be denoted by the same reference numerals and redundant descriptions may be omitted. When only a part of the configuration is described in each embodiment, other embodiments described previously can be applied to other parts of the configuration.

[0013] Also, not only combinations of parts clearly indicating that combinations are possible in each embodiment, but also combinations of embodiments, embodiments and modifications, and modifications themselves can be partially combined as long as there is no problem with the combination, even if not explicitly stated.

[0014] (First Embodiment) The capacitor 1 of the first embodiment in FIG. 1 will be described. FIG. 2 shows a cross section of the capacitor 1 in the direction of arrow II in FIG. 1. The capacitor 1 includes a capacitor element 2, a first outer shell member 10, a second outer shell member 20, a film 30, a first conductive member 40, a second conductive member 50, an insulating member 60, and a resin member 70.

[0015] When explaining each component, the short side direction of the film 30 and the axial direction extending between the end faces on which the electrodes described later are arranged may be conveniently referred to as the width direction WD. The depth direction orthogonal to the width direction WD may be referred to as the depth direction DP. The thickness direction orthogonal to the width direction WD and the depth direction DP may be referred to as the thickness direction TD. Also, the direction orthogonal to the axis along the width direction WD may be referred to as the radial direction.

[0016] The capacitor element 2 is a film capacitor. The film capacitor is formed by winding a dielectric film around which metal vapor deposition electrodes are provided such that the metal vapor deposition electrodes face each other. Metallicon electrodes are formed on both end faces of the film capacitor by thermal spraying of metal. One of the metal vapor deposition electrodes of one polarity is electrically connected to one of the metallicon electrodes. The other metal vapor deposition electrode of the other polarity is electrically connected to the other metallicon electrode.

[0017] The capacitor element 2 has a three-dimensional shape with a certain volume. The capacitor element 2 may be provided by a three-dimensional shape such as a cylinder, an elliptical cylinder, a polygonal prism, a cube, a rectangular parallelepiped, etc. The capacitor element 2 has at least two end faces 4, 6 and a side face 3. One end face of the capacitor element 2 in the width direction WD is called the first end face 4. The metallicon electrode provided on the first end face 4 is called the first electrode 5. The other end face of the capacitor element 2 in the width direction WD is called the second end face 6. The metallicon electrode provided on the second end face 6 is called the second electrode 7. The first electrode 5 and the second electrode 7 are provided apart from each other 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 edges of the first end face 4 and the second end face 6. The side face 3 extends along the edges of the first end face 4 and the second end face 6 in the circumferential direction around the axis along the width direction WD.

[0018] The first outer shell member 10 is a bottomed cylindrical cap provided on the first end face 4. The first outer shell member 10 is made of an insulating member such as resin. The first outer shell member 10 includes a first bottom portion 11 and a first side portion 12. The first bottom portion 11 includes a first inner surface 11A facing the first electrode 5 and a first outer surface 11B on the back side thereof. The first bottom portion 11 and the first side portion 12 are continuous with each other by the same member. The first side portion 12 extends annularly along the peripheral edge of the first bottom portion 11. The first bottom portion 11 also has a first exposure hole 13 that opens to 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.

[0019] The second outer shell member 20 is a bottomed cylindrical cap provided on the second end face 6. The second outer shell member 20 is made of an insulating member such as resin. The second outer shell member 20 includes a second bottom portion 21 and a second side portion 22. The second bottom portion 21 includes a second inner surface 21A facing the second electrode 7 and a second outer surface 21B on the back side thereof. The second bottom portion 21 and the second side portion 22 are continuous with each other by the same member. The second side portion 22 extends annularly along the peripheral edge of the second bottom portion 21. Hereinafter, the first outer shell member 10 and the second outer shell member 20 may not be distinguished appropriately and may be simply referred to as outer shell members 10, 20.

[0020] The film 30 has a flat shape with a thickness between a front surface 30A and a back surface 30B. The film 30 has a structure in which a front resin layer, a metal layer, and a back resin layer are laminated and integrated. The front surface 30A corresponds to the front resin layer. The back surface 30B corresponds to the back resin layer. For example, polypropylene, nylon, etc. are used for the resin layer. For example, aluminum is used for the metal layer.

[0021] The front resin layer, the metal layer, and the back resin layer each have a thickness of several tens of micrometers. The film 30 has a thickness of several hundreds of micrometers. 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, together with the outer shell members 10 and 20, plays a role of protecting the capacitor element 2 from external moisture. The film 30 and the outer shell members 10 and 20 provide a required low moisture permeability. The film 30 has a property that moisture permeates less easily 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.

[0022] The film 30 has two ends in its short side direction. The film 30 has two ends in its long side direction. Hereinafter, one of the ends of the film 30 in the short side direction may be referred to as a first film end 31. Another one of the ends of the film 30 in the short side direction may be referred to as a second film end 32. One of the ends of the film 30 in the long side direction may be referred to as a third film end 33. Another one of the ends of the film 30 in the long side direction may be referred to as a fourth film end 34. Note that the film ends 31 to 34 each include a region having a width at the end side. At the end faces of the first film end 31 and the second film end 32, the first layer, the second layer, and the third layer are externally exposed. At the end faces of the third film end 33 and the fourth film end 34, the first layer, the second layer, and the third layer are externally exposed.

[0023] The first conductive member 40 is a conductive bus bar. 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 bus bar. 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 not be distinguished as appropriate, and may simply be referred to as conductive members 40 and 50.

[0024] 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 the conduction between the first conductive member 40 and the second conductive member 50. The resin member 70 is composed of components such as epoxy resin and urethane resin. The resin member 70 has the property of being curable at room temperature. The resin member 70 fixes the capacitor element 2 to the first outer shell member 10, the second outer shell member 20, and the film 30. Note that the resin member 70 may have the property of being curable by heat.

[0025] 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 provided 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.

[0026] The first outer shell member 10 is provided on the first end face 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 part of the first conductive member 40, a part of the second conductive member 50, and a part 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 part of the side face 3. In the radial direction, a part of the first conductive member 40, a part of the second conductive member 50, and a part of the insulating member 60 are provided within the projection area of the first side portion 12.

[0027] The second outer shell member 20 is provided on the second end face 6. In the width direction WD, the second bottom portion 21 overlaps with the second electrode 7. In the width direction WD, a part 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 part of the side face 3. In the radial direction, a part of the second conductive member 50 is provided within the projection area of the second side portion 22.

[0028] The film 30 is provided on the outer periphery of the capacitor element 2 such that the longitudinal direction thereof is along the longitudinal direction of the side face 3. The film 30 covers the side face 3. Also, in the radial direction, the film 30 is provided farther from the capacitor element 2 than the outer shell members 10, 20. The first film end portion 31 and the second film end portion 32 each include a region having a width in the short direction. The first film end portion 31 overlaps the first side portion 12 in a layered manner in the radial direction. The second film end portion 32 overlaps the second side portion 22 in a layered manner in the radial direction. Note that the film 30 may extend to the bottom portions 11, 21 side and overlap the bottom portions 11, 21 in a layered manner in the width direction WD.

[0029] FIG. 3 is a side view of the capacitor 1. The first side portion 12 and the first film end portion 31 are adhered. As an example, the first film end portion 31 and the first side portion 12 are thermally welded. The second side portion 22 and the second film end portion 32 are adhered. As an example, the second film end portion 32 and the second side portion 22 are thermally welded. The third film end portion 33 and the fourth film end portion 34 each have a region including a width in the longitudinal direction. The third film end portion 33 and the fourth film end portion 34 are abutted and overlapped so as to face each other. The outer peripheries of the third film end portion 33 and the fourth film end portion 34 are thermally welded. The third film end portion 33 and the fourth film end portion 34 are sealed at the outer periphery. The overlapping portion of the third film end portion 33 and the fourth film end portion 34 is fixed to the portion disposed on the side surface 3 of the film 30 using an adhesive member. In the drawing, the dotted line portion surrounded by a square corresponds to the portion where thermal welding is performed.

[0030] Note that the bonding method between the film end portions 31 and 32 and the side portions 12 and 22 is not limited to thermal welding. The bonding method between the third film end portion 33 and the fourth film end portion 34 is not limited to thermal welding. The film end portions 31 and 32 and the side portions 12 and 22 may be bonded using an adhesive member. The third film end portion 33 and the fourth film end portion 34 may be bonded using an adhesive member. The first film end portion 31 and the second film end portion 32 may not be distinguished and may simply be referred to as film end portions 31 and 32. The first side portion 12 and the second side portion 22 may not be distinguished and may simply be referred to as side portions 12 and 22.

[0031] The capacitor element 2 is covered by a first outer shell member 10, a second outer shell member 20, and a film 30. Hereinafter, for simplicity of explanation, the first outer shell member 10, the second outer shell member 20, and the film 30 may be collectively referred to as exterior members 10, 20, 30. A resin member 70 is disposed between the capacitor element 2 and the exterior members 10, 20, 30. The space between the first outer shell member 10 and the capacitor element 2 is called a first space 81. The space between the film 30 and the capacitor element 2 is called a second space 82. The space between the second outer shell member 20 and the capacitor element 2 is called a third space 83. The resin member 70 is provided across the first space 81, the second space 82, and the third space 83. Further, the resin member 70 enters the first exposed hole 13. The resin member 70 closes the first exposed hole 13. Note that the first exposed hole 13 may not be closed by the resin member 70. Note that the resin member 70 may not be provided in the second space 82.

[0032] <Method of manufacturing a capacitor> FIG. 4 shows a flow for explaining a method of manufacturing the capacitor 1. First, in step S110, the capacitor element 2 is prepared. Next, in step S120, the conductive members 40, 50 are connected to the electrodes 5, 7. Specifically, an end portion of the first conductive member 40 is connected to the first electrode 5. An end portion of the second conductive member 50 is connected to the second electrode 7. And an insulating member 60 is provided between the first conductive member 40 and the second conductive member 50. Note that the insulating member 60 may be provided in advance on the first conductive member 40 or the second conductive member 50. Note that the first electrode 5 and the second electrode 7 may be simply referred to as electrodes 5, 7 without distinction.

[0033] Next, in step S130, the outer shell members 10 and 20 are provided for the capacitor element 2. Specifically, the first outer shell member 10 is provided on the first end face 4. The second outer shell member 20 is provided on the second end face 6. The first outer shell member 10 is provided on the first end face 4 while passing the first conductive member 40, the second conductive member 50, and the insulating member 60 through the first exposed hole 13. FIG. 5 shows a fixing method of the outer shell members 10 and 20 and the capacitor element 2 in step S130. The first outer shell member 10 is fitted to the end on the first end face 4 side like a cap. The second outer shell member 20 is fitted to the end on the second end face 6 side like a cap. Note that the first outer shell member 10 may be fixed to a jig. The second outer shell member 20 may be fixed to a jig.

[0034] Next, in step S140, the film 30 is wrapped from the outside of the outer shell members 10 and 20. While overlapping the first film end 31 on the first side portion 12 and overlapping the second film end 32 on the second side portion 22, the film 30 is wound along the side surface 3. At this time, the first side portion 12 and the second side portion 22 serve as guides. The film 30 is wrapped from the outside of the outer shell members 10 and 20 so that the third film end 33 and the fourth film end 34 overlap each other.

[0035] Next, in step S150, the film 30 and the outer shell members 10 and 20 are adhered. FIG. 6 shows a fixing method of the film 30 and the outer shell members 10 and 20 in step S150. The first film end 31 and the first side portion 12 are adhered by heat welding. The second film end 32 and the second side portion 22 are adhered by heat welding. Next, in step S160, the resin member 70 is filled into the spaces 81, 82, and 83 between the capacitor element 2 and the exterior members 10, 20, and 30. Note that in step S150, the third film end 33 and the fourth film end 34 are non-adhered. In step S160, the resin member 70 is filled into the spaces 81, 82, and 83 from the location of the white arrow shown in FIG. 6. Note that the resin member 70 may not be provided in the second space 82.

[0036] When the third film end portion 33 and the fourth film end portion 34 are separated from each other so as to be spaced apart, a void is formed between the third film end portion 33 and the fourth film end portion 34 to such an extent that the resin member 70 can be poured thereinto. In step S160, the resin member 70 is filled into the spaces 81, 82, 83 from this void and cured. After curing, in step S170, the third film end portion 33 and the fourth film end portion 34 are heat welded along the outer periphery. When heat welding the outermost ends in the longitudinal direction of the third film end portion 33 and the fourth film end portion 34, vacuum sealing is performed. Thereby, the capacitor element 2 can be pressed by the film 30. After heat welding the third film end portion 33 and the fourth film end portion 34, the third film end portion 33 and the fourth film end portion 34 are tilted toward the side surface 3 and fixed to the portion disposed on the side surface 3 of the film 30 using an adhesive member. Note that the step of curing the resin member 70 may be performed after step S170.

[0037] In a case-molded capacitor, the 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 have problems such as a decrease in capacitance. Therefore, in a case-molded capacitor, the capacitor element is covered with the case and the filling resin so that moisture does not enter the capacitor element. In particular, in a configuration in which the case has an opening and a part of the filling resin is exposed to the outside, the filling resin facing the opening comes into contact with the outside air. Therefore, the thickness of the filling resin facing the opening is increased so that moisture does not enter the capacitor element. However, in this case, although the entry of moisture into the capacitor element can be suppressed, there has been a problem that the overall weight increases.

[0038] <Function and effect> In this embodiment, the capacitor 1 includes a capacitor element 2, outer shell members 10 and 20, and a film 30. The first outer shell member 10 is provided on the first end face 4 of the capacitor element 2. The second outer shell member 20 is provided on the second end face 6 of the capacitor element 2. The film 30 is provided on the outer periphery of the capacitor element 2 so as to follow the side face 3. The first film end portion 31 and the first side portion 12 overlap in a layered manner in the radial direction. The second film end portion 32 and the second side portion 22 overlap in a layered manner in the radial direction. According to this, the end faces 4 and 6 are covered by the outer shell members 10 and 20, and the side face 3 is covered by the film 30. Also, 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. Furthermore, the film 30 and the outer shell members 10 and 20 provide a required low moisture permeability. Therefore, the weight of the capacitor 1 can be reduced, and the performance of protecting the capacitor element 2 from moisture can be improved. By replacing the case in the case-molded capacitor with the outer shell members 10 and 20 and the film 30, the weight of the capacitor 1 can be reduced, and the performance of protecting the capacitor element 2 from moisture can be improved.

[0039] Furthermore, in this embodiment, the outer shell members 10 and 20 ensure a mechanical strength sufficient to protect the capacitor element 2 from mechanical external forces. Therefore, in the resin member 70, a high mechanical strength is less required. Accordingly, the amount of the resin member 70 can be reduced. According to this, the curing time can be shortened. The energy consumption of the equipment associated with curing can be suppressed. It is also excellent from the viewpoint of carbon neutrality.

[0040] The first film end portion 31 and the first side portion 12 are adhered. The second film end portion 32 and the second side portion 22 are adhered. According to this, the generation of a gap between the first film end portion 31 and the first side portion 12 is suppressed. The generation of a gap between the second film end portion 32 and the second side portion 22 is suppressed. The intrusion of moisture between the capacitor element 2 and the exterior member 80 from the gaps between the film end portions 31 and 32 and the side portions 12 and 22 is suppressed.

[0041] The resin member 70 is provided in the first space 81 and the third space 83. Since the outer shell members 10 and 20 overlap the resin member 70 in multiple layers in the width direction WD, it is possible to efficiently suppress the intrusion of moisture into the capacitor element 2 from the width direction WD.

[0042] The resin member 70 is provided in the second space 82. Since the film 30 overlaps the resin member 70 in layers in the radial direction, it is possible to efficiently suppress the intrusion of moisture into the capacitor element 2 from the radial direction. Also, the resin member 70 is provided across the first space 81, the second space 82, and the third space 83. It is possible to efficiently suppress the intrusion of moisture into the capacitor element 2 from the width direction WD and the radial direction. Also, the film 30 has a property that moisture permeates less easily than the outer shell members 10 and 20. Even if the thickness of the resin member 70 in the second space 82 is made 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 moisture. The weight of the capacitor 1 can also be reduced by the amount by which the coating resin 70 is thinned.

[0043] A first exposed hole 13 that opens to the first inner surface 11A and the first outer surface 11B is provided in the first bottom portion 11. The first conductive member 40, the second conductive member 50, and the insulating member 60 are exposed from the first exposed hole 13. The first exposed hole 13 is blocked by the resin member 70. According to this, the intrusion of moisture between the capacitor element 2 and the exterior member 80 from the first exposed hole 13 is suppressed.

[0044] 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 region of the first outer shell member 10. The parasitic inductance between the first conductive member 40 and the second conductive member 50 can be reduced with the minimum necessary amount.

[0045] (Second Embodiment) The capacitor 1 of the second embodiment in FIG. 7 will be described. FIG. 8 shows a cross-section of the capacitor 1 in the direction of arrow VIII in FIG. 7. In FIG. 8, the thickness of the film 30 is slightly exaggerated in order to illustrate the multilayer structure of the film 30. The capacitor 1 in the second embodiment does not include an insulating member 60. A first exposed hole 213 penetrating the inner surface and the outer surface is provided on the top side of the first side portion 12. A second exposed 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 exposed hole 213. The tip of the first conductive member 40 is exposed from the first exposed hole 213. The first exposed hole 213 is blocked by the resin member 70.

[0046] The second conductive member 50 extends toward the second exposed hole 223. The tip of the second conductive member 50 is exposed from the second exposed hole 223. The second exposed hole 223 is blocked by the resin member 70. The first conductive member 40 and the second conductive member 50 are separated with respect to the width direction WD. Note that the first exposed hole 213 and the second exposed hole 223 may be blocked by a sealing member 93 different from the resin member 70.

[0047] A first extension wall 14 extending along the edge of the first exposed 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 exposed hole 213. The first extension wall 14 includes two first side walls 15 and one first connecting wall 16. The two first side walls 15 each extend from the first end surface 4 toward the second end surface 6. The first connecting wall 16 connects the two first side walls 15 along the edge on the side away from the first end surface 4 in the width direction WD in the first exposed hole 213. The first conductive member 40 exposed from the first exposed hole 213 and the first connecting wall 16 face each other with respect to the width direction WD.

[0048] On the second side portion 22, a second extension wall 24 extending along the edge of the second exposure hole 223 is provided. 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 one second connecting wall 26. The two second side walls 25 each extend from the second end face 6 toward 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 and the second connecting wall 26 face each other in the width direction WD.

[0049] The multilayer structure constituting the film 30 is exposed from the end face of the first film end portion 31. The film 30 has a second layer 30D, which is a metal layer, laminated between a first layer 30C, which is a surface resin layer, and a third layer 30E, which is a back surface resin layer. The second layer 30D made of a metal member is exposed from the end face of the first film end portion 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 portion 31. Due to the presence of the first connecting wall 16, the creepage distance between the first conductive member 40 and the first film end portion 31 becomes longer. The formation of an unintentional current conduction path between the first conductive member 40 and the second layer 30D is suppressed. The increase in the size of the capacitor 1 in the width direction WD is suppressed.

[0050] The multilayer structure constituting the film 30 is exposed from the end face of the second film end portion 32. The second layer 30D made of a metal member is exposed from the end face of the second film end portion 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 portion 32. Due to the presence of the second connecting wall 26, the creepage distance between the second conductive member 50 and the second film end portion 32 becomes longer. The formation of an unintentional current conduction path between the second conductive member 50 and the second layer 30D is suppressed. The increase in the size of the capacitor 1 in the width direction WD is suppressed.

[0051] The first outer shell member 10 includes, in addition to the first bottom portion 11 and the first side portion 12, a first fastening portion 17 that is fastened to an external case 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 so as to be away from the first bottom portion 11. A through hole penetrating in the thickness direction TD is provided in 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 outer shell member 10 is fixed by fixing the shaft portion of the bolt to an external case or the like. Note that the bearing 17A and the first electrode 5 are separated from each other to such an extent that they can be insulated from each other.

[0052] The second outer shell member 20 includes, in addition to the second bottom portion 21 and the second side portion 22, a second fastening portion 27 that is fastened to an external case or the like. The second fastening portion 27 is provided on the second bottom portion 21. The second fastening portion 27 extends in the width direction WD so as to be 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 a bolt passes is provided in the through hole. The second outer shell member 20 is fixed by fixing the shaft portion of the bolt to an external case or the like. Note that the bearing 27A and the second electrode 7 are separated from each other to such an extent that they can be insulated from each other.

[0053] Also, the first fastening portion 17 and the second fastening portion 27 are provided diagonally on the capacitor 1 in a plan view in the thickness direction TD. The first fastening portion 17 and the second fastening portion 27 are staggeredly arranged in a plan view. By arranging the first fastening portion 17 and the second fastening portion 27 in this way, the capacitor 1 is efficiently suppressed from vibrating with respect to an external case or the like.

[0054] Also, the thickness of the film 30 is constant. The film 30 is recessed toward the capacitor element 2 between the first outer shell member 10 and the second outer shell member 20. The film 30 is offset toward the capacitor element 2 between the first outer shell member 10 and the second outer shell member 20. The film 30 is recessed stepwise toward the capacitor element 2 between the first outer shell member 10 and the second outer shell member 20. Hereinafter, for the sake of simplicity of explanation, the portion of the film 30 that is recessed toward the capacitor element 2 may be referred to as the recess 35. The recess 35 is provided between the first film end 31 and the second film end 32. The recess 35 is fitted between the first side portion 12 and the second side portion 22. The space between the first side portion 12 and the second side portion 22 is closed by the recess 35.

[0055] The distance between the recess 35 and the capacitor element 2 in the radial direction is shorter than the distance between the film ends 31, 32 and the capacitor element 2 in the radial direction. The resin member 70 is filled over the first space 81, the second space 82, and the third space 83. Note that the resin member 70 may not be provided in the second space 82. When the resin member 70 is filled over the first space 81 to the third space 83, the amount of the resin member 70 filled between the recess 35 and the capacitor element 2 can be reduced as compared with the case where the film 30 is not offset toward the capacitor element 2 at the center. Accordingly, the capacitor 1 can be made lighter.

[0056] (Third Embodiment) The capacitor 1 according to the third embodiment in FIG. 9 will be described. FIG. 10 shows a cross section of the capacitor 1 in the direction of arrow X in FIG. 9. 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. Note that the first covering member 91 and the second covering member 92 do not necessarily have to be made of the same material as the film 30. The first covering member 91 and the second covering member 92 may be made of a material having a lower water permeability than the outer shell members 10 and 20.

[0057] The first covering member 91 is provided on the first outer surface 11B of the first bottom portion 11. The second covering member 92 is provided on the second outer surface 21B of the second bottom portion 21. According to this, in the width direction WD, the first end face 4, the resin member 70, the first bottom portion 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 portion 11, and the first covering member 91 overlap in layers. The water permeation rates of the covering members 91 and 92 are lower than the water permeation rates of the outer shell members 10 and 20. It is possible to efficiently suppress the intrusion of moisture into the capacitor element 2 from the width direction WD. Even if the amount of the resin member 70 provided between the bottom portions 11 and 21 and the end faces 4 and 6 is reduced, the performance of protecting the capacitor element 2 from moisture can be maintained. It is possible to achieve both weight reduction of the capacitor 1 and performance of protecting the capacitor element 2 from moisture.

[0058] Also, in the third embodiment, the first outer shell member 10 has a first locking portion 18. In the width direction WD, the first locking portion 18 extends so as to be away from the first bottom portion 11. The first locking portion 18 has a shape that becomes narrower and pointed as it moves away from the first bottom portion 11. The second outer shell member 20 has a second locking portion 28. In the width direction WD, the second locking portion 28 extends so as to be away from the second bottom portion 21. The second locking portion 28 has a shape that becomes narrower and pointed as it moves away from the second bottom portion 21. In the case where a plurality of capacitors 1 are provided and the plurality of capacitors 1 are resin-sealed in a large case, the first locking portion 18 and the second locking portion 28 exhibit an anchor effect on the sealing resin. The adhesion area between the first outer shell member 10 and the sealing resin increases. The adhesion area between the second outer shell member 20 and the sealing resin increases. According to this, the fixing of the capacitor 1 and the sealing resin becomes strong.

[0059] (Fourth Embodiment) The capacitor 1 of the fourth embodiment in FIG. 11 will be described. In the fourth embodiment, the first covering member 91 is provided on the first inner surface 11A of the first bottom portion 11. The second covering member 92 is provided on the second inner surface 21A of the second bottom portion 21. The fourth embodiment has the same effects as the third embodiment. Note that the first covering member 91 may be provided on the first outer surface 11B of the first bottom portion 11, and the second covering member 92 may be provided on the second inner surface 21A of the second bottom portion 21. The same effects can also be achieved in this case. Also, the first covering member 91 may be provided on the first inner surface 11A of the first bottom portion 11, and the second covering member 92 may be provided on the second outer surface 22B of the second bottom portion 21. The same effects can also be achieved in this case.

[0060] (Fifth Embodiment) The capacitor 1 of the second embodiment in FIG. 12 will be described. FIG. 13 shows a cross section of the capacitor 1 in the direction of arrow XIII in FIG. 12. In the fifth embodiment, the first conductive member 40 is insert-molded in the first outer shell 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 outer shell member 20. The second conductive member 50 is insert-molded in the second side portion 22.

[0061] A first opening 19 through which a welding arm can be inserted and removed is provided in the first bottom portion 11 between the first inner surface 11A and the first outer surface 11B. A second opening 29 through which a welding arm can be inserted and removed is provided in the second bottom portion 21 between 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 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 the second opening 29 in the width direction WD. Further, the first opening 19 and the second opening 29 are closed by a resin member 70. Since displacement of the conductive members 40 and 50 is suppressed, occurrence of connection failure between the conductive members 40 and 50 and the electrodes 5 and 7 is suppressed. Note that the first opening 19 and the second opening 29 do not necessarily have to be closed by the resin member 70.

[0062] (Sixth Embodiment) The capacitor 1 of the sixth embodiment in FIG. 14 will be described. In the sixth embodiment, a sealing member 93 different from the resin member 70 may be provided in the first opening 19 and the second opening 29. The first opening 19 and the second opening 29 are closed by the sealing member 93. Note that the first opening 19 may be closed by the resin member 70 and the second opening 29 may be closed by the sealing member 93. The first opening 19 may be closed by the sealing member 93 and the second opening 29 may be closed by the resin member 70.

[0063] (Seventh Embodiment) The capacitor 1 of the seventh embodiment in FIG. 15 will be described. In the seventh embodiment, the capacitor 1 includes a first covering member 91 and a second covering member 92 made of the same material as the film 30. The first covering member 91 is sized to cover the first opening 19. The second covering member 92 is sized to cover the second opening 29. The covering members 91 and 92 are provided on the bottom portions 11 and 21 so as to close the openings 19 and 29. As an example, the first covering member 91 is provided on the first outer surface 11B of the first bottom portion 11. The second covering member 92 is provided on the second outer surface 21B of the second bottom portion 21. According to this, it becomes easy to suppress moisture from coming into contact with the capacitor element 2. Note that the covering members 91 and 92 only need to be provided on the bottom portions 11 and 21, and the surfaces on which they are provided may be either the outer surfaces 11B and 21B or the inner surfaces 11A and 21A. They may be provided on both the outer surfaces 11B and 21B and the inner surfaces 11A and 21A.

[0064] (Eighth Embodiment) The capacitor 1 of the eighth embodiment shown in FIG. 16 will be described. In the eighth embodiment, with respect to the structure of the first embodiment, the resin member 70 is provided only in the first space 81 and the third space 83. A configuration in which the resin member 70 is not provided in the first space 81, the second space 82, and the third space 83 may be employed. Note that the resin member 70 does not have to be provided in all of the first space 81, the second space 82, and the third space 83.

[0065] (Ninth Embodiment) The capacitor 1 of the ninth embodiment shown in FIG. 17 will be described. In the tenth embodiment, with respect to the structure of the fifth embodiment, the resin member 70 is provided only in the first space 81 and the third space 83. Note that in the capacitor 1 of the tenth embodiment, the resin member 70 may not be provided in all of the first space 81, the second space 82, and the third space 83.

[0066] (Tenth Embodiment) The capacitor 1 of the tenth embodiment shown in FIG. 18 will be described. In the tenth embodiment, the first exposure hole 13 is closed by a sealing member 93 different from the resin member 70. This can also suppress the intrusion of moisture into the capacitor element 2.

[0067] (Other Embodiments) In the embodiments described so far, the form in which the capacitor element 2 is wrapped by a single continuous film 30 has been described. However, the film 30 is not limited to the configuration of being a single continuous film. It may have a plurality of films 30. The capacitor element 2 may be wrapped by a plurality of films 30. For example, having two films 30 and thermally welding the film end portion in one film and the film end portion in another film may also be a configuration for wrapping the capacitor element 2. The number of films 30 is not limited. Additionally, the film 30 may be composed of a film that shrinks with heat. In that case, the film 30 is also called a so-called shrink label. Even if a film 30 having the property of shrinking with heat is adopted, the above-described effects can be achieved.

[0068] (Disclosure of Technical Idea) This specification discloses a plurality of technical ideas described in a plurality of clauses listed below. Some clauses may be described in a multiple dependent form that alternatively quotes preceding clauses in subsequent clauses. Some clauses may be described in a multiple dependent form that quotes clauses in other multiple dependent forms. The clauses described in these multiple dependent forms define a plurality of technical ideas.

[0069] (Technical Idea 1) A capacitor element (2) having a first end face (4) with a first electrode (5), a second end face (6) with a second electrode (7), and a side face (3) extending between the first end face and the second end face; Outer shell members (10, 20) provided on the first end face and the second end face to suppress the permeation of moisture; A film (30) that covers the side face while overlapping with the outer shell member, has a weight per unit area lighter than that of the outer shell member, and suppresses the permeation of the moisture into the capacitor element together with the outer shell member. A capacitor comprising the same.

[0070] (Technical Idea 2) The capacitor according to Technical Idea 1, wherein there is 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.

[0071] (Technical Idea 3) The capacitor according to Technical Idea 1 or 2, further comprising a resin member (70) disposed between the outer shell member and the capacitor element.

[0072] (Technical Idea 4) The capacitor according to Technical Idea 3, wherein the resin member is further disposed between the film and the capacitor element.

[0073] (Technical Idea 5) a first conductive member (40) provided on the first electrode; and a second conductive member (50) provided on the second electrode, wherein the outer shell member includes exposure holes (13, 213, 223) that expose the conductive members (40, 50) extending from the first electrode and the second electrode; the capacitor according to Technical Idea 3 or 4, wherein the exposure holes are closed by the resin member or a sealing member (93) different from the resin member.

[0074] (Technical Idea 6) wherein the outer shell member includes openings (19, 29) that expose the first electrode and the second electrode; the capacitor according to Technical Idea 5, wherein the openings are closed by the resin member or the sealing member.

[0075] (Technical Idea 7) wherein the outer shell member is insulating; wherein the film exposes a metal member (30D) from end faces of film end portions (31, 32) that overlap the outer shell member; the capacitor according to Technical Idea 5 or 6, wherein the outer shell member includes walls (16, 26) located between the first conductive member and the metal member and between the second conductive member and the metal member at a position closer to the film end portion than the exposure holes.

[0076] (Technical Idea 8) the capacitor according to any one of Technical Ideas 1 to 7, wherein the film includes a recess (35) that is recessed toward the capacitor element between the outer shell members.

[0077] (Technical Idea 9) the capacitor according to any one of Technical Ideas 1 to 8, further including coating members (91, 92) that suppress water permeation at the first end face and the second end face together with the outer shell member on an inner surface (11A, 21A) or an outer surface (11B, 21B) of the outer shell member.

[0078] (Technical Idea 10) An outer shell member (10, 20) is provided on a first end face (4) of a capacitor element (2) having a first electrode (5) and on a second end face (6) of the capacitor element having a second electrode (7). A method for manufacturing a capacitor, in which a side face (3) of the capacitor element that connects the first end face and the second end face is wrapped from the outside of the outer shell member with a film (30) having a weight per unit area lighter than that of the outer shell member.

Explanation of Signs

[0079] 2 capacitor element, 3 side face, 4 first end face, 5 first electrode, 6 second end face, 7 second electrode, 10 outer shell member, 11A inner face, 11B outer face, 13, 213, 223 exposed hole, 16 wall, 19 opening, 20 outer shell member, 21A inner face, 21B outer face 26 wall, 29 opening, 30 film, 30D metal member, 31, 32 film end portion, 35 recess, 40 first conductive member, 50 second conductive member, 70 resin member, 91, 92 covering member, 93 sealing member.

Claims

1. A capacitor element (2) having a first end face (4) with a first electrode (5), a second end face (6) with a second electrode (7), and a side face (3) extending between the first end face and the second end face, a first outer shell member (10) provided on the first end face for suppressing permeation of moisture, a second outer shell member (20) provided on the second end face for suppressing permeation of moisture, a film (30) covering the side face while overlapping with the first outer shell member and the second outer shell member, having a weight per unit area lighter than that of the first outer shell member and the second outer shell member, and suppressing permeation of the moisture to the capacitor element together with the first outer shell member and the second outer shell member, a resin member (70) disposed between the first outer shell member and the second outer shell member and the capacitor element, and further between the film and the capacitor element, a first conductive member (40) provided on the first electrode, a second conductive member (50) provided on the second electrode, and the first outer shell member includes a first opening (19) overlapping a position where the first electrode and the first conductive member are welded, the second outer shell member includes a second opening (29) overlapping a position where the second electrode and the second conductive member are welded, the first opening and the second opening are closed by the resin member or a sealing member (93) different from the resin member, the first conductive member is insert-molded in the first outer shell member, a capacitor in which the second conductive member is insert-molded in the second outer shell member.

2. The capacitor according to claim 1, wherein there is an adhesive portion between a portion of the first outer shell member and the second outer shell member overlapping with the film and a portion of the film overlapping with the first outer shell member and the second outer shell member.

3. The capacitor according to claim 1, wherein the film includes a concave portion (35) recessed toward the capacitor element between the first outer shell member and the second outer shell member.

4. The capacitor according to claim 1, further comprising coating members (91, 92) on the inner surfaces (11A, 21A) or outer surfaces (11B, 21B) of the first outer shell member and the second outer shell member for suppressing moisture permeation at the first end face and the second end face together with the first outer shell member and the second outer shell member.

Images