capacitor

Abstract

A capacitor 1 comprises a capacitor element 10 that includes an element body 11 and an external electrode (first external electrode 12a) that is provided on the surface of the element body 11, a busbar (first busbar 20a) that is electrically connected to the external electrode (first external electrode 12a), a bottomed cylindrical exterior case 30 that has an opening 31 and accommodates the capacitor element 10 such that the busbar (first busbar 20a) protrudes from the opening 31 toward the outside, and a filler resin 40 that fills the exterior case 30 so as to bury the capacitor element 10. A through hole (first through hole 21aa) is provided in the busbar (first busbar 20a) at a portion that is between the capacitor element 10 and the opening 31. The through hole (first through hole 21aa) extends in a through direction DHaa that forms an angle of less than 45° with the opening plane 31s of the opening 31, and the entirety of the through hole (first through hole 21aa) is buried in the filler resin 40.

Description

capacitor

[0001] The present invention relates to a capacitor.

[0002] Patent Document 1 discloses a capacitor in which a capacitor element (1) is housed in a case (2) and filled with resin (3), and external connection terminals (6) (7) are led outward from the filled resin (3), and the external connection terminals (6) (7) are characterized in that they are provided with constricted portions (10) at the contact points with the resin surface and in the vicinity thereof, the constricted portions having a smaller cross-sectional area than other portions.

[0003] Patent Document 2 discloses an electrical component in which an electrical element (21) having a terminal (11) for connection to the outside of the case (31) attached thereto is housed in a case (31) so that the tip of the connection terminal (11) projects outside the case (31), and the case (31) is filled with resin (32), and a through hole (13) and a protrusion (14) extending from the inside of the case to the outside are provided near the boundary part of the connection terminal (11) from the inside to the outside of the case (31), and the resin (32) is filled so that each of the through hole (13) and the protrusion (14) is partially covered with the resin (32).

[0004] JP 2007-234708 A JP 2005-85880 A

[0005] As disclosed in Patent Documents 1 and 2, a known conventional capacitor is configured by housing a capacitor element electrically connected to a bus bar (lead terminal) inside an exterior case having an opening so that the bus bar protrudes from the opening toward the outside, and further filling the interior of the exterior case with a filling resin so as to embed the capacitor element.

[0006] However, in conventional capacitors, the following problems may occur because the capacitor element, bus bar, and filling resin have different thermal expansion coefficients.

[0007] In conventional capacitors, when the temperature of the operating environment changes, the capacitor element expands or contracts, which can apply stress to the busbar electrically connected to the capacitor element. In this case, in conventional capacitors, the busbar moves in a shearing direction relative to the filled resin surrounding the busbar, which can cause delamination between the busbar and the filled resin due to shear stress at the interface between the busbar and the filled resin, or the stress (pressure) from the busbar moving in the shearing direction can cause cracks in the filled resin.

[0008] For example, in conventional capacitors, when used in a high-temperature environment, as the capacitor element expands, the bus bar moves toward the opening of the outer case relative to the filled resin, which can cause shear stress at the interface between the bus bar and the filled resin, resulting in delamination between the bus bar and the filled resin, or stress (pressure) from the bus bar moving toward the opening of the outer case can cause cracks in the filled resin.

[0009] In response to the above problems, the capacitor described in Patent Document 1 is said to have a structure in which the filling resin that has entered the constricted portions of the external connection terminals strengthens the restriction of relative movement between the external connection terminals and the filling resin, thereby making it possible to prevent cracks from occurring in the portions of the external connection terminals that extend from the sealing resin even if the ambient temperature of the capacitor installation location changes. However, the capacitor described in Patent Document 1 still has room for improvement in terms of further preventing peeling between the external connection terminals and the filling resin, and cracks in the filling resin.

[0010] In addition, in the electrical component described in Patent Document 2, by providing a through hole in the connection terminal, it is possible to reduce the amount of expansion of the terminal in the width direction when a thermal shock is applied, and the through hole also divides the deformation area of ​​the resin due to the expansion of the terminal into multiple locations, making it possible to distribute the deformation, thereby preventing the occurrence of cracks and peeling of the resin. However, the electrical component described in Patent Document 2 leaves room for improvement in terms of further suppressing the occurrence of peeling between the connection terminal and the resin and the occurrence of cracks in the resin.

[0011] The present invention has been made to solve the above problems, and aims to provide a capacitor that can suppress the occurrence of peeling between the bus bar and the filling resin and the occurrence of cracks in the filling resin even when the temperature of the usage environment changes.

[0012] In a first aspect, the capacitor of the present invention comprises a capacitor element having an element body and external electrodes provided on a surface of the element body, a bus bar electrically connected to the external electrodes, a bottomed, cylindrical outer case having an opening and housing the capacitor element such that the bus bar protrudes outward from the opening, and a filling resin filled inside the outer case so as to embed the capacitor element, wherein a through hole is provided in a portion of the bus bar located between the capacitor element and the opening, the penetrating direction of the through hole forming an angle of less than 45° with respect to an opening plane of the opening, and the entire through hole is embedded in the filling resin.

[0013] In a second aspect, the capacitor of the present invention comprises a capacitor element having an element body and external electrodes provided on a surface of the element body, a bus bar electrically connected to the external electrodes, a bottomed, cylindrical outer case having an opening and housing the capacitor element such that the bus bar protrudes outward from the opening, and a filled resin filled inside the outer case so as to embed the capacitor element, wherein the bus bar has a through hole and a protruding portion protruding from a periphery of the through hole in a portion located between the capacitor element and the opening, the protruding portion having at least a tip end portion extending in a protruding direction that forms an angle of less than 45° with respect to an opening plane of the opening, and at least a portion of the through hole and the entire protruding portion are embedded in the filled resin.

[0014] According to the present invention, it is possible to provide a capacitor that can suppress the occurrence of peeling between the bus bar and the filling resin and the occurrence of cracks in the filling resin even when the temperature of the usage environment changes.

[0015] FIG. 1 is a schematic diagram showing a perspective view of an example of a capacitor according to embodiment 1 of the present invention. FIG. 2 is a schematic diagram showing an example of an exploded state of the capacitor shown in FIG. 1 (excluding the filled resin). FIG. 3 is a schematic diagram showing a perspective view of an example of a capacitor element shown in FIGS. 1 and 2. FIG. 4 is a schematic diagram showing an example of a cross-section of the capacitor element shown in FIG. 3 taken along line a1-a2. FIG. 5 is a schematic diagram showing a perspective view of the cross-section of the capacitor shown in FIG. 1. FIG. 6 is a schematic diagram showing a state in which the filled resin has been removed from the capacitor shown in FIG. 5. FIG. 7 is a schematic diagram showing a plan view of the cross-section of the capacitor shown in FIG. 6. FIG. 8 is a schematic diagram showing a perspective view of an example of a capacitor according to embodiment 2 of the present invention. FIG. 9 is a schematic diagram showing an example of an exploded state of the capacitor shown in FIG. 8 (excluding the filled resin). FIG. 10 is a schematic diagram showing a perspective view of the cross-section of the capacitor shown in FIG. 8. FIG. 11 is a schematic diagram showing a state in which the filled resin has been removed from the capacitor shown in FIG. 10. Fig. 12 is a schematic diagram showing a cross section of the capacitor shown in Fig. 11 in a plan view. Fig. 13 is a schematic diagram showing an oblique view of an example of a capacitor according to embodiment 3 of the present invention. Fig. 14 is a schematic diagram showing an example of an exploded state of the capacitor shown in Fig. 13 (excluding the filling resin). Fig. 15 is a schematic diagram showing a cross section of the capacitor shown in Fig. 13 in a perspective view. Fig. 16 is a schematic diagram showing a state in which the filling resin has been removed from the capacitor shown in Fig. 15. Fig. 17 is a schematic diagram showing a cross section of the capacitor shown in Fig. 16 in a plan view.

[0016] The capacitor of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0017] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From embodiment 2 onwards, descriptions of matters common to embodiment 1 will be omitted, and differences will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned one after the other for each embodiment.

[0018] In the following description, when there is no need to particularly distinguish between the embodiments, they will simply be referred to as "the capacitor of the present invention."

[0019] A film capacitor will be described below as an example of a capacitor element of the capacitor of the present invention, but the capacitor of the present invention can also be applied to capacitor elements other than film capacitors.

[0020] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0021] In this specification, unless otherwise specified, terms indicating the relationship between elements (e.g., "parallel," "perpendicular," etc.) and terms indicating the shape of elements not only mean the literal strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

[0022] In a first aspect, the capacitor of the present invention comprises a capacitor element having an element body and external electrodes provided on a surface of the element body, a bus bar electrically connected to the external electrodes, a bottomed, cylindrical outer case having an opening and housing the capacitor element such that the bus bar protrudes outward from the opening, and a filling resin filled inside the outer case so as to embed the capacitor element, wherein a through hole is provided in a portion of the bus bar located between the capacitor element and the opening, the penetrating direction of the through hole forming an angle of less than 45° with respect to an opening plane of the opening, and the entire through hole is embedded in the filling resin.

[0023] [First Embodiment] Hereinafter, an example of a first aspect of the capacitor of the present invention will be described as a capacitor of a first embodiment of the present invention.

[0024] Fig. 1 is a schematic perspective view of an example of a capacitor according to a first embodiment of the present invention, and Fig. 2 is a schematic view of an example of an exploded state of the capacitor shown in Fig. 1 (excluding the filled resin).

[0025] The capacitor 1 shown in FIGS. 1 and 2 includes a capacitor element 10, a first bus bar 20a, a second bus bar 20b, an outer case 30, and a filling resin 40.

[0026] In FIG. 1 and other figures, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to one another.

[0027] Fig. 3 is a schematic perspective view of an example of the capacitor element shown in Fig. 1 and Fig. 2. Fig. 4 is a schematic cross-sectional view of the capacitor element shown in Fig. 3 taken along line a1-a2.

[0028] The capacitor element 10 shown in FIGS. 3 and 4 has an element body 11, a first external electrode 12a, and a second external electrode 12b.

[0029] Body 11 is a wound body in which first metallized film 13 a and second metallized film 13 b are wound in a stacked state in first direction D1. In other words, capacitor element 10 is a wound-type film capacitor in which metallized films are wound in a stacked state.

[0030] The capacitor element 10 may be a laminated film capacitor (for example, rectangular parallelepiped) in which metallized films are laminated.

[0031] The element body 11 has a first end face 11a and a second end face 11b facing each other in the third direction D3.

[0032] The element body 11 has a side surface 11c extending in the third direction D3 so as to connect the peripheries of the first end surface 11a and the second end surface 11b.

[0033] From the viewpoint of reducing the height of capacitor element 10, element body 11 preferably has a flat cross-sectional shape when viewed in a cross section perpendicular to the winding axis direction (third direction D3 in FIGS. 3 and 4 ) of element body 11. Specifically, element body 11 is preferably pressed into a flattened shape such as an ellipse or oval, and has a smaller thickness than when the cross-sectional shape of element body 11 is a perfect circle.

[0034] Whether or not the element body has been pressed to have a flat cross-sectional shape can be confirmed, for example, by checking whether or not there are press marks on the element body.

[0035] Capacitor element 10 may have a cylindrical winding shaft that is disposed on the central axis of first metallized film 13 a and second metallized film 13 b in a wound state and serves as the winding shaft when winding first metallized film 13 a and second metallized film 13 b.

[0036] First metallized film 13a includes first dielectric film 14a and first metal layer 15a.

[0037] The first dielectric film 14a has a first main surface 14aa and a second main surface 14ab facing each other in the first direction D1.

[0038] The first metal layer 15a is provided on the first main surface 14aa of the first dielectric film 14a. Specifically, the first metal layer 15a is provided on the first main surface 14aa of the first dielectric film 14a so as to reach one side edge of the first dielectric film 14a in the third direction D3 but not reach the other side edge of the first dielectric film 14a.

[0039] Second metallized film 13b includes second dielectric film 14b and second metal layer 15b.

[0040] The second dielectric film 14b has a first main surface 14ba and a second main surface 14bb that face each other in the first direction D1.

[0041] The second metal layer 15b is provided on the first main surface 14ba of the second dielectric film 14b. Specifically, the second metal layer 15b is provided on the first main surface 14ba of the second dielectric film 14b so as not to reach one side edge of the second dielectric film 14b in the third direction D3 but to reach the other side edge of the second dielectric film 14b.

[0042] In element body 11, adjacent first metallized films 13a and second metallized films 13b are offset in third direction D3 so that the end of first metal layer 15a that reaches the side edge of first dielectric film 14a is exposed at first end face 11a of element body 11, and the end of second metal layer 15b that reaches the side edge of second dielectric film 14b is exposed at second end face 11b of element body 11. That is, in adjacent first metallized films 13a and second metallized films 13b, first metallized film 13a protrudes toward first external electrode 12a relative to second metallized film 13b. Also, in adjacent first metallized films 13a and second metallized films 13b, second metallized film 13b protrudes toward second external electrode 12b relative to first metallized film 13a. In this state, the first metal layer 15a is connected to the first external electrode 12a but is not connected to the second external electrode 12b, and the second metal layer 15b is connected to the second external electrode 12b but is not connected to the first external electrode 12a.

[0043] In the element body 11, the adjacent first metallized films 13a and second metallized films 13b are offset in the third direction D3 as described above, so that, among the adjacent first dielectric films 14a and second dielectric films 14b, the first dielectric film 14a having the first metal layer 15a on its first main surface 14aa protrudes toward the first external electrode 12a relative to the second dielectric film 14b having the first metal layer 15a not provided on its main surface. Furthermore, among the adjacent first dielectric films 14a and second dielectric films 14b, the second dielectric film 14b having the second metal layer 15b on its first main surface 14ba protrudes toward the second external electrode 12b relative to the first dielectric film 14a having the second metal layer 15b not provided on its main surface.

[0044] Since element body 11 is formed by winding first metallized film 13a and second metallized film 13b in a stacked state in first direction D1, it can be said that element body 11 includes first dielectric film 14a, first metal layer 15a, second dielectric film 14b, and second metal layer 15b in this order in first direction D1. It can also be said that element body 11 is a wound body formed by winding first dielectric film 14a, first metal layer 15a, second dielectric film 14b, and second metal layer 15b in this order in first direction D1.

[0045] In element body 11, first main surface 14aa of first dielectric film 14a and second main surface 14bb of second dielectric film 14b face each other in first direction D1, and second main surface 14ab of first dielectric film 14a and first main surface 14ba of second dielectric film 14b face each other in first direction D1. Thus, in element body 11, first metallized film 13a and second metallized film 13b are wound in a stacked state in first direction D1. In other words, in element body 11, first metallized film 13a and second metallized film 13b are wound in a stacked state in first direction D1 so that second metallized film 13b is on the inside of first metallized film 13a, specifically, so that first metal layer 15a is on the inside of first dielectric film 14a and second metal layer 15b is on the inside of second dielectric film 14b. That is, in the element body 11, the first metal layer 15a and the second metal layer 15b face each other with the first dielectric film 14a or the second dielectric film 14b sandwiched therebetween.

[0046] The first metal layer 15a may be provided with a fuse portion. The fuse portion provided in the first metal layer 15a is, for example, a portion that connects a divided electrode portion formed by dividing a portion of the first metal layer 15a that faces the second metal layer 15b into multiple portions with an electrode portion that does not face the second metal layer 15b. Examples of electrode patterns of the first metal layer 15a provided with a fuse portion include the electrode patterns disclosed in Japanese Patent Laid-Open Nos. 2004-363431 and 5-251266.

[0047] The second metal layer 15b may also be provided with a fuse portion, similar to the first metal layer 15a.

[0048] The first dielectric film 14a may contain a curable resin as a main component.

[0049] In this specification, the term "major component" means the component with the highest weight percentage, preferably a component with a weight percentage greater than 50% by weight.

[0050] The curable resin may be a thermosetting resin or a photocurable resin.

[0051] In this specification, thermosetting resin means a resin that can be cured by heat, but the curing method is not limited thereto. Therefore, thermosetting resins also include resins that can be cured by methods other than heat (e.g., light, electron beam, etc.) as long as they are resins that can be cured by heat. Furthermore, depending on the material, a reaction may be initiated due to the reactivity of the material itself, and resins that proceed to cure without necessarily being subjected to external heat or the like are also considered thermosetting resins. The same applies to photocurable resins; as long as they are resins that can be cured by light, they also include resins that can be cured by methods other than light (e.g., heat, etc.).

[0052] The curable resin is preferably a cured product of a first organic material having a hydroxyl group (OH group) and a second organic material having an isocyanate group (NCO group). In this case, the curable resin is a cured product having a urethane bond obtained by reacting the hydroxyl group of the first organic material with the isocyanate group of the second organic material.

[0053] The presence of urethane bonds in the dielectric film can be confirmed by analysis with a Fourier transform infrared spectrophotometer (FT-IR).

[0054] When the curable resin is obtained by the above-described reaction, uncured portions of the starting material may remain in the first dielectric film 14a. For example, the first dielectric film 14a may contain at least one of a hydroxyl group and an isocyanate group. In this case, the first dielectric film 14a may contain either a hydroxyl group or an isocyanate group, or may contain both a hydroxyl group and an isocyanate group.

[0055] The presence of hydroxyl groups and / or isocyanate groups in the dielectric film can be confirmed by FT-IR analysis.

[0056] Examples of the first organic material include phenoxy resin, polyvinyl acetoacetal resin, and polyvinyl butyral resin.

[0057] As the first organic material, a plurality of types of organic materials may be used in combination.

[0058] Examples of the second organic material include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI), and aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). As the second organic material, at least one modified product of these polyisocyanates may be used, or a mixture of at least one modified product of these polyisocyanates may be used.

[0059] As the second organic material, a plurality of types of organic materials may be used in combination.

[0060] The first dielectric film 14a may contain a thermoplastic resin as a main component.

[0061] Examples of the thermoplastic resin include polypropylene resin, polyethersulfone resin, polyetherimide resin, and polyarylate resin.

[0062] The first dielectric film 14a may contain additives to impart various functions.

[0063] The additives include, for example, a leveling agent for imparting smoothness.

[0064] The additive preferably has a functional group that reacts with a hydroxyl group and / or an isocyanate group and forms part of the crosslinked structure of the cured product. Examples of such additives include resins having at least one functional group selected from the group consisting of a hydroxyl group, an epoxy group, a silanol group, and a carboxyl group.

[0065] Like the first dielectric film 14a, the second dielectric film 14b may contain a thermosetting resin as a main component, a photocurable resin as a main component, or a thermoplastic resin as a main component, and like the first dielectric film 14a, the second dielectric film 14b may also contain an additive.

[0066] The first dielectric film 14a and the second dielectric film 14b may have different compositions, but preferably have the same composition.

[0067] The thickness of the first dielectric film 14a and the second dielectric film 14b is preferably 1 μm or more and 10 μm or less, and more preferably 3 μm or more and 5 μm or less.

[0068] The thicknesses of the first dielectric film 14a and the second dielectric film 14b may be different from each other, but are preferably the same.

[0069] The thickness of the dielectric film is measured using an optical film thickness gauge.

[0070] The first dielectric film 14a and the second dielectric film 14b are each preferably produced by forming a resin solution containing the resin material as described above into a film and then curing it by heat treatment.

[0071] Examples of materials that can be used to form the first metal layer 15a and the second metal layer 15b include metals such as aluminum, zinc, titanium, magnesium, tin, and nickel.

[0072] The first metal layer 15a and the second metal layer 15b may have different compositions, but preferably have the same composition.

[0073] The thickness of the first metal layer 15a and the second metal layer 15b is preferably 5 nm or more and 40 nm or less.

[0074] The thickness of the first metal layer 15a and the second metal layer 15b may be different from each other, but it is preferable that they are the same.

[0075] The thickness of the metal layer is measured by observing a cross section of the metallized film along the first direction using a transmission electron microscope (TEM).

[0076] The first metal layer 15a and the second metal layer 15b are preferably formed by depositing the metals described above on the major surfaces of the first dielectric film 14a and the second dielectric film 14b, respectively.

[0077] Although the above describes an embodiment in which element body 11 includes two metallized films, element body 11 may also include a single metallized film. For example, element body 11 may include a metallized film having first dielectric film 14a with first metal layer 15a provided on first main surface 14aa and second metal layer 15b provided on second main surface 14ab, and a second dielectric film 14b with no metal layer. Alternatively, element body 11 may include a metallized film having second dielectric film 14b with first metal layer 15a provided on second main surface 14bb and second metal layer 15b provided on first main surface 14ba, and a first dielectric film 14a with no metal layer.

[0078] The first external electrode 12a is provided on the surface of the element body 11. In the example shown in Figures 3 and 4, the first external electrode 12a is provided on the first end surface 11a of the element body 11. The first external electrode 12a is connected to the first metal layer 15a by contacting the end of the first metal layer 15a exposed at the first end surface 11a of the element body 11. On the other hand, the first external electrode 12a is not connected to the second metal layer 15b.

[0079] The second external electrode 12b is provided at a position spaced apart from the first external electrode 12a on the surface of the element body 11. In the example shown in Figures 3 and 4, the second external electrode 12b is provided on the second end face 11b of the element body 11. The second external electrode 12b is connected to the second metal layer 15b by contacting the end of the second metal layer 15b exposed at the second end face 11b of the element body 11. On the other hand, the second external electrode 12b is not connected to the first metal layer 15a.

[0080] Examples of materials that can be used to form the first external electrode 12a and the second external electrode 12b include metals such as zinc, aluminum, tin, and zinc-aluminum alloys.

[0081] The first external electrode 12a and the second external electrode 12b may have different compositions, but preferably have the same composition.

[0082] The first external electrode 12a and the second external electrode 12b are preferably formed by spraying the above-mentioned metal onto the first end surface 11a and the second end surface 11b of the element body 11, respectively.

[0083] 2, the first bus bar 20a is electrically connected to the first external electrode 12a. The first bus bar 20a may be connected to the first external electrode 12a via a joining member such as solder, or may be welded.

[0084] The first bus bar 20a has a first main surface 20aa and a second main surface 20ab that face each other in the thickness direction.

[0085] The first bus bar 20a preferably covers a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Fig. 2, the first bus bar 20a covers a side surface 11c of the body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided (in Fig. 2, they overlap in the first direction D1). In this case, the equivalent series inductance (ESL) of the capacitor 1 is likely to decrease.

[0086] The first bus bar 20a is preferably spaced apart from a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the examples shown in Figures 5, 6, and 7 described below, the first bus bar 20a is spaced apart from a side surface 11c of the element body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In this case, insulation between the element body 11 and the first bus bar 20a is more easily ensured.

[0087] When the first bus bar 20a is located away from a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided, it is preferable that a filling resin 40 be filled between the first bus bar 20a and that surface of the capacitor element 10.

[0088] 2, the second bus bar 20b is electrically connected to the second external electrode 12b. The second bus bar 20b may be connected to the second external electrode 12b via a joining member such as solder, or may be welded, for example.

[0089] The second bus bar 20b is electrically connected to the second external electrode 12b instead of the first external electrode 12a, and therefore has a polarity different from that of the first bus bar 20a, which is electrically connected to the first external electrode 12a.

[0090] The second bus bar 20b has a first main surface 20ba and a second main surface 20bb that face each other in the thickness direction.

[0091] The second bus bar 20b preferably covers a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Fig. 2, the second bus bar 20b covers a side surface 11c of the body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided (in Fig. 2, they overlap in the first direction D1). In this case, the equivalent series inductance of the capacitor 1 is likely to decrease.

[0092] The second bus bar 20b is preferably located away from a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the examples shown in Figures 5, 6, and 7 described below, the second bus bar 20b is located away from a side surface 11c of the element body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In this case, insulation between the element body 11 and the second bus bar 20b is more easily ensured.

[0093] When the second bus bar 20b is located away from a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided, it is preferable that a filling resin 40 is filled between the second bus bar 20b and that surface of the capacitor element 10.

[0094] The first bus bar 20a and the second bus bar 20b are preferably shaped like a plate. In this case, the first bus bar 20a and the second bus bar 20b may each have a shape that is partially bent.

[0095] The shapes of the first bus bar 20a and the second bus bar 20b may be the same as each other or may be different from each other.

[0096] Examples of materials for the first bus bar 20a and the second bus bar 20b include metals such as copper, oxygen-free copper, aluminum, and alloys containing at least one of these. Among these, copper or oxygen-free copper is preferred as the material for the first bus bar 20a and the second bus bar 20b. When the material for the first bus bar 20a and the second bus bar 20b is a copper-based material, examples of usable materials include oxygen-free copper (copper: 99.96 wt % or more), tough pitch copper (copper: 99.90 wt % or more), and phosphorus-deoxidized copper (copper: 99.90 wt % or more, phosphorus: 0.015 wt % or more, 0.040 wt % or less).

[0097] The constituent materials of the first bus bar 20a and the second bus bar 20b may be the same as or different from each other.

[0098] The thickness of the first bus bar 20a and the second bus bar 20b may be the same as or different from each other.

[0099] The first bus bar 20a and the second bus bar 20b may be partially overlapping and in close proximity to each other. In the example shown in Fig. 2, the first bus bar 20a and the second bus bar 20b are partially overlapping and in close proximity to each other at the second main surfaces 20ab and 20bb. In the example shown in Fig. 2, a gap of a predetermined distance is provided between the first bus bar 20a and the second bus bar 20b, specifically, between the second main surface 20ab of the first bus bar 20a and the second main surface 20bb of the second bus bar 20b.

[0100] When portions of the first bus bar 20a and the second bus bar 20b are closely overlapping with each other, specifically when a predetermined gap is provided between the first bus bar 20a and the second bus bar 20b, it is preferable that an insulating sheet (not shown) that forms a laminated structure together with the first bus bar 20a and the second bus bar 20b be sandwiched between the first bus bar 20a and the second bus bar 20b. Specifically, it is preferable that the laminated structure be formed by stacking the first bus bar 20a, the insulating sheet, and the second bus bar 20b in this order. In this case, the insulating sheet ensures insulation between the first bus bar 20a and the second bus bar 20b.

[0101] In this specification, the insulating sheet also includes forms such as insulating paper, insulating plate, and insulating film.

[0102] Examples of materials that can be used to form the insulating sheet include resins.

[0103] 1 and 2, the outer case 30 is a cylindrical shape with a bottom and an opening 31. Specifically, the outer case 30 is a cylindrical shape with a bottom and an opening 31 at one end in the first direction D1.

[0104] In the example shown in Figures 1 and 2, the outer case 30 has a bottom 32 facing the opening 31 in the first direction D1, and a side wall 33 extending from the bottom 32 toward the opening 31 in the first direction D1.

[0105] Capacitor element 10 is housed inside exterior case 30 such that first bus bar 20 a and second bus bar 20 b protrude from opening 31 to the outside.

[0106] It is preferable that capacitor element 10 is housed inside outer case 30 so as to be separated from the inner surface of outer case 30 .

[0107] The exterior case 30 may be, for example, a resin case or a metal case.

[0108] When the exterior case 30 is a resin case, examples of the resin that constitutes the resin case include liquid crystal polymer (LCP), polyphenylene sulfide resin, polybutylene terephthalate resin, etc. Among these, it is preferable that the resin case contains a liquid crystal polymer.

[0109] The liquid crystal polymer contained in the resin case may be, for example, a liquid crystal polymer having p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups in its skeleton. Liquid crystal polymers formed as polycondensates using various components other than p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups, such as phenol, phthalic acid, and ethylene terephthalate, may also be used. Liquid crystal polymers are also classified into types I, II, and III, but the material refers to the same material as the liquid crystal polymer formed from the above-mentioned components.

[0110] The resin case preferably further contains an inorganic filler in addition to the liquid crystal polymer.

[0111] The inorganic filler contained in the resin case can be a material having a higher strength than the liquid crystal polymer. The inorganic filler is preferably a material having a higher melting point than the liquid crystal polymer, and more preferably a material having a melting point of 680°C or higher.

[0112] The shape of the inorganic filler is not particularly limited, and examples thereof include a shape having a longitudinal direction, such as a fibrous or plate-like shape. As the inorganic filler having such a shape, multiple types of inorganic materials may be used in combination. It is preferable that the resin case contains at least one of a fibrous inorganic material and a plate-like inorganic material as the inorganic filler.

[0113] In this specification, a filler being fibrous means that the relationship between the longitudinal dimension in the longitudinal direction and the cross-sectional diameter in a cross section perpendicular to the longitudinal direction is longitudinal dimension / cross-sectional diameter ≧5 (i.e., the aspect ratio is 5:1 or more). Here, the cross-sectional diameter is the distance between the longest two points on the periphery of the cross section. If the cross-sectional diameter varies in the longitudinal direction, measurement is performed at the point where the cross-sectional diameter is largest.

[0114] In this specification, a filler being plate-shaped means that the relationship between the cross-sectional diameter of the face having the largest projected area and the maximum height in the direction perpendicular to this cross section is cross-sectional diameter / maximum height ≧3.

[0115] It is preferable that at least a portion of the inorganic filler has a portion in the side wall portion 33 that is oriented in a direction from the bottom portion 32 toward the opening portion 31 and a portion that is oriented in the outer circumferential direction of the side wall portion 33, and is dispersed inside the outer case 30.

[0116] The size of the inorganic filler is preferably 5 μm or more in diameter and 50 μm or more in length.

[0117] It is preferable that the inorganic filler be dispersed throughout the exterior case 30 without agglomerating.

[0118] Examples of inorganic fillers include inorganic materials such as fibrous glass filler, plate-like talc or mica, etc. Among these, it is preferable that the inorganic filler contains fibrous glass filler as a main component.

[0119] Even when the resin case contains another resin (for example, polyphenylene sulfide resin) instead of the liquid crystal polymer, it is preferable that the resin case further contains an inorganic filler as described above.

[0120] The resin case is manufactured by a method such as injection molding.

[0121] When the exterior case 30 is a metal case, examples of the metal constituting the metal case include simple metals such as aluminum, magnesium, iron, stainless steel, and copper, and alloys containing at least one of these simple metals. Of these, it is preferable that the metal case contains aluminum or an aluminum alloy.

[0122] The metal case is manufactured by a method such as impact molding.

[0123] 1 , the interior of the exterior case 30 is filled with the filling resin 40 so as to embed the capacitor element 10. When the interior of the exterior case 30 is filled with the filling resin 40 in this manner, the capacitor element 10 is held within the interior of the exterior case 30.

[0124] When capacitor element 10 is housed inside outer case 30 so as to be spaced apart from the inner surface of outer case 30, filling resin 40 is preferably filled between capacitor element 10 and outer case 30, specifically between the outer surface of capacitor element 10 and the inner surface of outer case 30. Furthermore, filling resin 40 is preferably filled inside outer case 30 in the region from opening 31 to capacitor element 10, in addition to between capacitor element 10 and outer case 30.

[0125] From the viewpoint of suppressing the penetration of moisture into capacitor element 10, it is preferable to appropriately select a resin with low moisture permeability as filling resin 40, such as epoxy resin, silicone resin, urethane resin, etc. Examples of the curing agent for epoxy resin include an amine curing agent, an imidazole curing agent, etc.

[0126] The above-mentioned resin alone may be used as the filling resin 40, but in order to improve strength, a resin to which a reinforcing agent has been added may also be used. Examples of the reinforcing agent include silica and alumina.

[0127] From the viewpoint of suppressing the penetration of moisture into capacitor element 10, it is preferable that the thickness of filling resin 40 at opening 31 is large. The thickness of filling resin 40 at opening 31 is preferably sufficiently large within the allowable range for the overall volume (physical size) of capacitor 1, and specifically, is preferably 2 mm or more, and more preferably 4 mm or more. In particular, it is preferable that capacitor element 10 is disposed closer to bottom 32 than to opening 31 inside exterior case 30, so that the thickness of filling resin 40 relative to capacitor element 10 is larger on the opening 31 side than on the bottom 32 side.

[0128] The thickness of the filled resin 40 is measured, for example, using a soft X-ray device if it is in a non-destructive state, and using a length measuring device such as a caliper if it is in a destructive state.

[0129] The relationship between the height of the outer case 30 and the height of the filling resin 40 in the first direction D1 is such that the thickness of the filling resin 40 at the opening 31 is as large as possible, and it may be up to a position inside the outer case 30, or it may be just about to the top, or it may overflow slightly due to surface tension.

[0130] Fig. 5 is a schematic perspective view of the cross section of the capacitor shown in Fig. 1. Fig. 6 is a schematic view of the capacitor shown in Fig. 5 with the filling resin removed. Fig. 7 is a schematic view of the cross section of the capacitor shown in Fig. 6 when viewed from above.

[0131] As shown in FIGS. 5, 6, and 7, first bus bar 20a has a first through-hole 21aa in a portion located between capacitor element 10 and opening 31.

[0132] The first through hole 21aa has a first end 21aaa located on the first main surface 20aa side of the first bus bar 20a, and a second end 21aab located on the second main surface 20ab side of the first bus bar 20a.

[0133] 7 , the penetration direction DHaa in which the first through hole 21aa extends (hereinafter also referred to as the penetration direction DHaa of the first through hole 21aa) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the penetration direction DHaa of the first through hole 21aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

[0134] The penetration direction DHaa of the first through hole 21aa is determined as the direction of a straight line connecting the center of gravity of the first end 21aaa of the first through hole 21aa in a plan view and the center of gravity of the second end 21aab of the first through hole 21aa in a plan view. For example, as shown in Fig. 2, if the planar shape of the first through hole 21aa (in Fig. 2, the planar shape when viewed from the third direction D3) is rectangular, the penetration direction DHaa of the first through hole 21aa is determined as the direction of a straight line connecting the intersection of the diagonals of the first end 21aaa (rectangle) of the first through hole 21aa in a plan view and the intersection of the diagonals of the second end 21aab (rectangle) of the first through hole 21aa in a plan view. The penetration directions of the other through holes are determined in a similar manner.

[0135] As shown in FIGS. 5 and 6, the first through-hole 21 aa is entirely filled with the filling resin 40 .

[0136] In capacitor 1, first through hole 21aa is entirely embedded in filled resin 40, and therefore first bus bar 20a is fixed by filled resin 40 that has entered first through hole 21aa. Furthermore, in capacitor 1, penetration direction DHaa of first through hole 21aa forms an angle of less than 45° with respect to opening surface 31s of opening 31. Therefore, movement of first bus bar 20a that shifts in the shear direction relative to filled resin 40 (particularly, toward opening surface 31s of opening 31 or away from opening surface 31s relative to filled resin 40) caused by expansion or contraction of capacitor element 10 when the temperature of the usage environment changes is suppressed by filled resin 40 that has entered first through hole 21aa. As a result, in capacitor 1, the occurrence of peeling between first bus bar 20a and filled resin 40 due to shear stress at the interface between first bus bar 20a and filled resin 40, and the occurrence of cracks in filled resin 40 due to stress (pressure) from first bus bar 20a moving in the shear direction are suppressed.

[0137] In contrast, if the angle that the penetration direction DHaa of the first through hole 21aa makes with respect to the opening surface 31s of the opening 31 is 45° or more, particularly approaching 90°, the filled resin 40 that has entered the first through hole 21aa is less likely to function to suppress the movement of the first bus bar 20a that shifts in the shear direction relative to the filled resin 40 (particularly, toward the opening surface 31s of the opening 31 or the opposite side from the opening surface 31s with respect to the filled resin 40). Therefore, if the penetration direction DHaa of the first through hole 21aa forms an angle of 45° or more with respect to the opening surface 31s of the opening 31, the movement of the first bus bar 20a that shifts in the shear direction relative to the filled resin 40 is less likely to be suppressed by the filled resin 40 that has entered the first through hole 21aa.

[0138] 1(a) and 1(b) of Patent Document 1, in the capacitor described in Patent Document 1, through holes 11 provided in the external connection terminals 6 (external connection terminals 7) are embedded in the resin 3. However, in the capacitor described in Patent Document 1, the penetration direction in which the through holes 11 extend is perpendicular to the opening surface of the opening of the case 2, and therefore it is difficult to suppress movement of the external connection terminals 6 (external connection terminals 7) that shifts in the shear direction relative to the resin 3 (particularly, toward or away from the opening surface of the opening of the case 2 relative to the resin 3) caused by expansion or contraction of the capacitor element 1 when the temperature of the usage environment changes.

[0139] 4 of Patent Document 2, the through-hole 13 provided in the connection terminal 11 is embedded in the resin 32. However, in the electrical component described in Patent Document 2, only a portion of the through-hole 13 is embedded in the resin 32, and therefore it is difficult to suppress movement of the connection terminal 11 that shifts in the shear direction relative to the resin 32 (particularly, toward or away from the opening surface of the opening of the case 31 relative to the resin 32) caused by expansion or contraction of the electric element 21 when the temperature of the usage environment changes.

[0140] For the above reasons, compared to, for example, the capacitor described in Patent Document 1 and the electrical component described in Patent Document 2, capacitor 1 has the advantageous effect of being able to suppress peeling between the bus bar and the filled resin and cracks in the filled resin even when the temperature of the usage environment changes.

[0141] In order to enhance the above-described effects of the capacitor 1, it is preferable that the penetration direction DHaa of the first through-hole 21aa be parallel to the opening surface 31s of the opening 31, as shown in FIG.

[0142] In the example shown in Fig. 7, the penetration direction DHaa of the first through hole 21aa is parallel to the third direction D3. Also, in the example shown in Fig. 7, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in Fig. 7, the penetration direction DHaa of the first through hole 21aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in Fig. 7, the penetration direction DHaa of the first through hole 21aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

[0143] The penetration direction DHaa of the first through-hole 21aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

[0144] The penetration direction DHaa of the first through hole 21aa may be parallel to the thickness direction of the first bus bar 20a (the third direction D3 in Figure 7) as long as it forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, or it may not be parallel to the thickness direction of the first bus bar 20a (it may be inclined with respect to the thickness direction of the first bus bar 20a).

[0145] When the penetration direction DHaa of the first through-hole 21aa is parallel to the thickness direction of the first bus bar 20a, the penetration direction DHaa is perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a.

[0146] If the penetration direction DHaa of the first through hole 21aa is not parallel to the thickness direction of the first bus bar 20a (if it is tilted relative to the thickness direction of the first bus bar 20a), it is not perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a (if it is tilted relative to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a).

[0147] As shown in FIG. 7 , the surface of the first bus bar 20 a on which the first through holes 21 aa (as well as the first through holes 21 ab described later) are provided is preferably perpendicular to the opening surface 31 s of the opening 31 .

[0148] In the example shown in FIG. 7 , the first main surface 20aa and the second main surface 20ab of the first bus bar 20a in which the first through hole 21aa is provided are perpendicular to the opening surface 31s of the opening 31.

[0149] Furthermore, as long as the penetration direction DHaa of the first through hole 21aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, the first main surface 20aa and the second main surface 20ab of the first bus bar 20a in which the first through hole 21aa is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

[0150] As shown in FIGS. 5, 6, and 7, first bus bar 20a is further provided with a first through hole 21ab in a portion located between capacitor element 10 and opening 31.

[0151] The first through hole 21ab has a first end 21aba located on the first main surface 20aa side of the first bus bar 20a, and a second end 21abb located on the second main surface 20ab side of the first bus bar 20a.

[0152] As shown in FIG. 7 , the penetration direction DHab in which the first through hole 21ab extends (hereinafter also referred to as the penetration direction DHab of the first through hole 21ab) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0153] As shown in FIGS. 5 and 6, the first through-hole 21 ab is entirely filled with the filling resin 40 .

[0154] In the capacitor 1, the penetration direction DHab of the first through hole 21ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire first through hole 21ab is embedded in the filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between the first bus bar 20a and the filled resin 40 and cracks in the filled resin 40 are suppressed.

[0155] The characteristics of the first through hole 21ab (for example, the through direction DHab of the first through hole 21ab) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0156] As shown in FIGS. 5, 6, and 7, second bus bar 20b has a second through hole 21ba in a portion located between capacitor element 10 and opening 31.

[0157] The second through hole 21ba has a first end 21baa located on the first main surface 20ba side of the second bus bar 20b, and a second end 21bab located on the second main surface 20bb side of the second bus bar 20b.

[0158] As shown in FIG. 7 , the penetration direction DHba in which the second through hole 21ba extends (hereinafter also referred to as the penetration direction DHba of the second through hole 21ba) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0159] As shown in FIGS. 5 and 6, the second through-hole 21 ba is entirely filled with the filling resin 40 .

[0160] In capacitor 1, the penetration direction DHba of second through hole 21ba forms an angle of less than 45° with respect to the opening surface 31s of opening 31, and the entire second through hole 21ba is embedded in filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between second bus bar 20b and filled resin 40 and cracks in filled resin 40 are suppressed.

[0161] The characteristics of the second through hole 21ba (for example, the penetration direction DHba of the second through hole 21ba) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0162] As shown in FIG. 7 , the surface of the second bus bar 20 b on which the second through holes 21 ba (as well as the second through holes 21 bb described later) are provided is preferably perpendicular to the opening surface 31 s of the opening 31 .

[0163] In the example shown in FIG. 7 , the first main surface 20ba and the second main surface 20bb of the second bus bar 20b in which the second through hole 21ba is provided are perpendicular to the opening surface 31s of the opening 31.

[0164] Furthermore, as long as the penetration direction DHba of the second through hole 21ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, the first main surface 20ba and the second main surface 20bb of the second bus bar 20b in which the second through hole 21ba is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

[0165] As shown in FIGS. 5, 6, and 7, second bus bar 20b has a second through hole 21bb formed in a portion located between capacitor element 10 and opening 31.

[0166] The second through hole 21bb has a first end 21bba located on the first main surface 20ba side of the second bus bar 20b, and a second end 21bbb located on the second main surface 20bb side of the second bus bar 20b.

[0167] As shown in FIG. 7 , the penetration direction DHbb in which the second through hole 21bb extends (hereinafter also referred to as the penetration direction DHbb of the second through hole 21bb) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0168] As shown in FIGS. 5 and 6, the second through-hole 21 bb is entirely filled with the filling resin 40 .

[0169] In capacitor 1, the penetration direction DHbb of second through hole 21bb forms an angle of less than 45° with respect to the opening surface 31s of opening 31, and the entire second through hole 21bb is embedded in filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between second bus bar 20b and filled resin 40 and cracks in filled resin 40 are suppressed.

[0170] The characteristics of the second through hole 21bb (for example, the penetration direction DHbb of the second through hole 21bb) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0171] 2, 6, and 7, in the region where first bus bar 20a and second bus bar 20b overlap, at least a portion of first through hole 21aa and at least a portion of second through hole 21ba preferably overlap and communicate with each other. In this case, in capacitor 1, first bus bar 20a and second bus bar 20b are more firmly fixed by filled resin 40 that has entered first through hole 21aa and second through hole 21ba. Therefore, even if the temperature of the usage environment changes, peeling between first bus bar 20a and filled resin 40, peeling between second bus bar 20b and filled resin 40, and cracking of filled resin 40 are further suppressed.

[0172] In the examples shown in Figures 2, 6, and 7, in the area where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21aa and the entire second through hole 21ba overlap and communicate with each other, but the entire first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and the entire second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other.

[0173] 2, 6, and 7, in the region where the first bus bar 20a and the second bus bar 20b overlap, at least a portion of the first through hole 21ab and at least a portion of the second through hole 21bb preferably overlap and communicate with each other. In this case, in the capacitor 1, the first bus bar 20a and the second bus bar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21ab and the second through hole 21bb. This further reduces peeling between the first bus bar 20a and the filled resin 40, peeling between the second bus bar 20b and the filled resin 40, and cracks in the filled resin 40, even if the temperature of the usage environment changes.

[0174] In the examples shown in Figures 2, 6, and 7, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21ab and the entire second through hole 21bb overlap and communicate with each other, but the entire first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and the entire second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other.

[0175] The planar shapes of the first through hole 21aa, the first through hole 21ab, the second through hole 21ba, and the second through hole 21bb (in Figure 2, the planar shapes when viewed from the third direction D3) are not particularly limited, and examples include rectangular shapes such as a rectangle or a square, a circle, an ellipse, and shapes combining these.

[0176] The planar shapes of the first through hole 21aa, the first through hole 21ab, the second through hole 21ba, and the second through hole 21bb may be the same as one another, may be different from one another, or may be partially different from one another.

[0177] When the first through-hole 21aa and the second through-hole 21ba overlap and communicate with each other, it is preferable that the first through-hole 21aa and the second through-hole 21ba have the same planar shape.

[0178] When the first through-hole 21ab and the second through-hole 21bb overlap and communicate with each other, it is preferable that the first through-hole 21ab and the second through-hole 21bb have the same planar shape.

[0179] In the first aspect of the capacitor of the present invention, it is sufficient that the characteristic that "the direction in which the through hole extends forms an angle of less than 45° with respect to the opening plane of the opening, and the entire through hole is embedded in the filled resin" is satisfied for at least one through hole. For example, in capacitor 1, it is sufficient that the characteristic is satisfied for at least one through hole selected from the group consisting of first through hole 21aa, first through hole 21ab, second through hole 21ba, and second through hole 21bb.

[0180] In the first bus bar 20a, a through hole may be provided in the portion protruding outward from the opening 31 of the exterior case 30 as shown in FIG. 1, etc., or a through hole may not be provided.

[0181] In the second bus bar 20b, a through hole may be provided in the portion protruding outward from the opening 31 of the exterior case 30 as shown in FIG. 1, etc., or a through hole may not be provided.

[0182] If a through hole is provided in at least one of the first bus bar 20a and the second bus bar 20b in a portion that protrudes outward from the opening 31 of the outer case 30, it is preferable that the through hole be provided outside the filling resin 40 (not embedded in the filling resin 40).

[0183] The first aspect of the capacitor of the present invention is not limited to the above embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration of the capacitor, manufacturing conditions, etc.

[0184] For example, in the first embodiment of the capacitor of the present invention, the number of capacitor elements housed inside one exterior case is not particularly limited. That is, in the first embodiment of the capacitor of the present invention, one exterior case may house one capacitor element or multiple capacitor elements (two capacitor elements in the example shown in FIG. 1 etc.).

[0185] Furthermore, in the first aspect of the capacitor of the present invention, the number of through holes provided in a portion of one bus bar located between the capacitor element and the opening is not particularly limited. That is, in the first aspect of the capacitor of the present invention, one through hole may be provided in a portion of one bus bar located between the capacitor element and the opening, or multiple through holes (two in the example shown in FIG. 1 etc.) may be provided.

[0186] In a second aspect, the capacitor of the present invention comprises a capacitor element having an element body and external electrodes provided on a surface of the element body, a bus bar electrically connected to the external electrodes, a bottomed, cylindrical outer case having an opening and housing the capacitor element such that the bus bar protrudes outward from the opening, and a filled resin filled inside the outer case so as to embed the capacitor element, wherein the bus bar has a through hole and a protruding portion protruding from a periphery of the through hole in a portion located between the capacitor element and the opening, the protruding portion having at least a tip end portion extending in a protruding direction that forms an angle of less than 45° with respect to an opening plane of the opening, and at least a portion of the through hole and the entire protruding portion are embedded in the filled resin.

[0187] The second aspect of the capacitor of the present invention is similar to the first aspect of the capacitor of the present invention, except that "the bus bar has a through hole and a protruding portion protruding from the periphery of the through hole in a portion located between the capacitor element and the opening, the protruding direction in which at least the tip side portion of the protruding portion extends forms an angle of less than 45° with respect to the opening plane of the opening, and at least a portion of the through hole and the entirety of the protruding portion are embedded in the filling resin."

[0188] [Embodiment 2] Hereinafter, an example of the second aspect of the capacitor of the present invention will be described as a capacitor of embodiment 2 of the present invention.

[0189] In the capacitor according to the second embodiment of the present invention, the entire through-hole and the entire protrusion are embedded in the filling resin.

[0190] Fig. 8 is a schematic perspective view of an example of a capacitor according to embodiment 2 of the present invention. Fig. 9 is a schematic view of an example of an exploded state of the capacitor shown in Fig. 8 (excluding the filled resin).

[0191] The capacitor 2 shown in FIGS. 8 and 9 includes a capacitor element 10, a first bus bar 20a, a second bus bar 20b, an outer case 30, and a filling resin 40.

[0192] The features of each component of capacitor 2, namely, capacitor element 10, first bus bar 20a, second bus bar 20b, exterior case 30, and filled resin 40, are the same as those of each component described above in capacitor 1, except for the following points: In the example shown in Fig. 9, in the region where first bus bar 20a and second bus bar 20b overlap, a gap of a predetermined distance is provided between first bus bar 20a and second bus bar 20b, specifically, between second main surface 20ab of first bus bar 20a and second main surface 20bb of second bus bar 20b.

[0193] Fig. 10 is a schematic perspective view of the cross section of the capacitor shown in Fig. 8. Fig. 11 is a schematic view of the capacitor shown in Fig. 10 with the filling resin removed. Fig. 12 is a schematic view of the cross section of the capacitor shown in Fig. 11 as viewed from above.

[0194] As shown in Figures 10, 11, and 12, the first bus bar 20a has a first through hole 21aa and a first protrusion 25aa protruding from the periphery of the first through hole 21aa in the portion located between the capacitor element 10 and the opening 31.

[0195] 12 , the protruding direction DPaa in which at least the tip side portion of the first protruding portion 25aa extends (hereinafter also referred to as the protruding direction DPaa of the first protruding portion 25aa) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

[0196] The protrusion direction DPaa of the first protrusion 25aa is determined as the direction in which the tip portion of the first protrusion 25aa substantially extends along the path in which the first protrusion 25aa extends from its base (the side of the periphery of the first through hole 21aa) to its tip (the side opposite the periphery of the first through hole 21aa). For example, if the first protrusion 25aa extends from its base to its tip in a planar shape (a straight line when viewed in cross section), the protrusion direction DPaa of the first protrusion 25aa is determined as the direction in which the entire first protrusion 25aa, including its tip portion, extends. Furthermore, if the first protrusion 25aa extends from its base to its tip in a manner other than a planar shape (a manner other than a straight line when viewed in cross section), the protrusion direction DPaa of the first protrusion 25aa is determined as the direction in which the tip portion of the first protrusion 25aa extends. The protruding directions of the other protruding portions are determined in a similar manner.

[0197] As shown in FIGS. 10 and 11, the entire first through-hole 21 aa and the entire first protrusion 25 aa are embedded in the filling resin 40 .

[0198] In the capacitor 2, the first through-hole 21aa is entirely embedded in the filled resin 40, and therefore the first bus bar 20a is fixed by the filled resin 40 that has entered the first through-hole 21aa. In the capacitor 2, the first protruding portion 25aa is entirely embedded in the filled resin 40, and therefore the first bus bar 20a is fixed by the filled resin 40 that has bitten into the first protruding portion 25aa. Furthermore, in capacitor 2, because protrusion direction DPaa of first protrusion 25aa forms an angle of less than 45° with respect to opening surface 31s of opening 31, movement of first bus bar 20a in the shear direction relative to filled resin 40 (particularly toward opening surface 31s of opening 31 or the opposite side from opening surface 31s relative to filled resin 40) caused by expansion or contraction of capacitor element 10 when the temperature of the usage environment changes is suppressed by filled resin 40 that has entered first through-hole 21aa and further by filled resin 40 that has become embedded in first protrusion 25aa. As a result, in capacitor 2, peeling between first bus bar 20a and filled resin 40 caused by shear stress at the interface between first bus bar 20a and filled resin 40 and cracking in filled resin 40 caused by stress (pressure) from first bus bar 20a moving in the shear direction are suppressed.

[0199] For the above reasons, similar to capacitor 1, capacitor 2 has the advantageous effect of being able to suppress peeling between the bus bar and the filled resin and cracking of the filled resin even when the temperature of the usage environment changes, compared to, for example, the capacitor described in Patent Document 1 and the electrical component described in Patent Document 2.

[0200] In order to enhance the above-described effects of the capacitor 2, it is preferable that the protruding direction DPaa of the first protruding portion 25aa is parallel to the opening surface 31s of the opening 31, as shown in FIG.

[0201] In the example shown in Fig. 12, the protruding direction DPaa of the first protruding portion 25aa is parallel to the third direction D3. Also, in the example shown in Fig. 12, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in Fig. 12, the protruding direction DPaa of the first protruding portion 25aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in Fig. 12, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

[0202] The protruding direction DPaa of the first protruding portion 25aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

[0203] 12 , from the viewpoint of enhancing the above-described effects of the capacitor 2, the penetration direction DHaa of the first through hole 21aa preferably forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the penetration direction DHaa of the first through hole 21aa preferably forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

[0204] In order to enhance the above-described effects of the capacitor 2, it is more preferable that the penetration direction DHaa of the first through-hole 21aa is parallel to the opening surface 31s of the opening 31, as shown in FIG.

[0205] In the example shown in Fig. 12, the penetration direction DHaa of the first through hole 21aa is parallel to the third direction D3. Also, in the example shown in Fig. 12, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in Fig. 12, the penetration direction DHaa of the first through hole 21aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in Fig. 12, the penetration direction DHaa of the first through hole 21aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

[0206] The penetration direction DHaa of the first through-hole 21aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

[0207] The penetration direction DHaa of the first through hole 21aa may be parallel to the thickness direction of the first bus bar 20a (in Figure 12, the third direction D3), or it may not be parallel to the thickness direction of the first bus bar 20a (it may be inclined with respect to the thickness direction of the first bus bar 20a).

[0208] When the penetration direction DHaa of the first through-hole 21aa is parallel to the thickness direction of the first bus bar 20a, the penetration direction DHaa is perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a.

[0209] If the penetration direction DHaa of the first through hole 21aa is not parallel to the thickness direction of the first bus bar 20a (if it is tilted relative to the thickness direction of the first bus bar 20a), it is not perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a (if it is tilted relative to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a).

[0210] As shown in FIG. 12 , the surface of the first bus bar 20 a on which the first through holes 21 aa (as well as the first through holes 21 ab described later) are provided is preferably perpendicular to the opening surface 31 s of the opening 31 .

[0211] In the example shown in FIG. 12 , the first main surface 20aa and the second main surface 20ab of the first bus bar 20a in which the first through hole 21aa is provided are perpendicular to the opening surface 31s of the opening 31.

[0212] The first main surface 20aa and the second main surface 20ab of the first bus bar 20a in which the first through-hole 21aa is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

[0213] As shown in Figures 10, 11, and 12, the first bus bar 20a further has a first through hole 21ab and a first protrusion 25ab protruding from the periphery of the first through hole 21ab in the portion located between the capacitor element 10 and the opening 31.

[0214] As shown in Figure 12, the protrusion direction DPab in which at least the tip side portion of the first protrusion 25ab extends (hereinafter also referred to as the protrusion direction DPab of the first protrusion 25ab) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0215] As shown in FIGS. 10 and 11, the entire first through-hole 21ab and the entire first protrusion 25ab are embedded in the filling resin 40.

[0216] In the capacitor 2, the protrusion direction DPab of the first protrusion 25ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire first through hole 21ab and the entire first protrusion 25ab are embedded in the filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between the first busbar 20a and the filled resin 40 and cracks in the filled resin 40 are suppressed.

[0217] The characteristics of the first through hole 21ab (for example, the through direction DHab of the first through hole 21ab) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0218] The characteristics of the first protrusion 25ab (for example, the protrusion direction DPab of the first protrusion 25ab) are similar to the characteristics of the first protrusion 25aa, including the points described above.

[0219] As shown in Figures 10, 11, and 12, the second bus bar 20b has a second through hole 21ba and a second protrusion 25ba protruding from the periphery of the second through hole 21ba in the portion located between the capacitor element 10 and the opening 31.

[0220] As shown in Figure 12, the protrusion direction DPba in which at least the tip side portion of the second protrusion 25ba extends (hereinafter also referred to as the protrusion direction DPba of the second protrusion 25ba) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0221] As shown in FIGS. 10 and 11, the entire second through-hole 21 ba and the entire second protrusion 25 ba are embedded in the filling resin 40 .

[0222] In capacitor 2, the protrusion direction DPba of the second protrusion 25ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire second through hole 21ba and the entire second protrusion 25ba are embedded in the filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between the second busbar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

[0223] The characteristics of the second through hole 21ba (for example, the penetration direction DHba of the second through hole 21ba) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0224] The characteristics of the second protrusion 25ba (for example, the protrusion direction DPba of the second protrusion 25ba) are similar to the characteristics of the first protrusion 25aa, including the points described above.

[0225] As shown in FIG. 12 , the surface of the second bus bar 20 b on which the second through holes 21 ba (as well as the second through holes 21 bb described later) are provided is preferably perpendicular to the opening surface 31 s of the opening 31 .

[0226] In the example shown in FIG. 12 , the first main surface 20ba and the second main surface 20bb of the second bus bar 20b in which the second through hole 21ba is provided are perpendicular to the opening surface 31s of the opening 31.

[0227] The first main surface 20ba and the second main surface 20bb of the second bus bar 20b in which the second through hole 21ba is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

[0228] As shown in Figures 10, 11, and 12, the second bus bar 20b further has a second through hole 21bb and a second protrusion 25bb protruding from the periphery of the second through hole 21bb in the portion located between the capacitor element 10 and the opening 31.

[0229] As shown in Figure 12, the protrusion direction DPbb in which at least the tip side portion of the second protrusion 25bb extends (hereinafter also referred to as the protrusion direction DPbb of the second protrusion 25bb) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0230] As shown in FIGS. 10 and 11, the entire second through-hole 21 bb and the entire second protrusion 25 bb are embedded in the filling resin 40 .

[0231] In capacitor 2, the protrusion direction DPbb of the second protrusion 25bb forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire second through hole 21bb and the entire second protrusion 25bb are embedded in the filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

[0232] The characteristics of the second through hole 21bb (for example, the penetration direction DHbb of the second through hole 21bb) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0233] The characteristics of the second protrusion 25bb (for example, the protrusion direction DPbb of the second protrusion 25bb) are similar to the characteristics of the first protrusion 25aa, including the points described above.

[0234] 9, 11, and 12, in the region where the first bus bar 20a and the second bus bar 20b overlap, at least a portion of the first through hole 21aa and at least a portion of the second through hole 21ba preferably overlap and communicate with each other. In this case, in the capacitor 2, the first bus bar 20a and the second bus bar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21aa and the second through hole 21ba. This further reduces peeling between the first bus bar 20a and the filled resin 40, peeling between the second bus bar 20b and the filled resin 40, and cracks in the filled resin 40, even if the temperature of the usage environment changes.

[0235] In the examples shown in Figures 9, 11, and 12, in the area where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21aa and the entire second through hole 21ba overlap and communicate with each other, but the entire first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and the entire second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other.

[0236] 9, 11, and 12, in the region where the first bus bar 20a and the second bus bar 20b overlap, at least a portion of the first through hole 21ab and at least a portion of the second through hole 21bb preferably overlap and communicate with each other. In this case, in the capacitor 2, the first bus bar 20a and the second bus bar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21ab and the second through hole 21bb. This further reduces peeling between the first bus bar 20a and the filled resin 40, peeling between the second bus bar 20b and the filled resin 40, and cracks in the filled resin 40, even if the temperature of the usage environment changes.

[0237] In the examples shown in Figures 9, 11, and 12, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21ab and the entire second through hole 21bb overlap and communicate with each other, but the entire first through hole 21ab and a portion of the second through hole 21bb may overlap and communicate with each other, or a portion of the first through hole 21ab and the entire second through hole 21bb may overlap and communicate with each other, or a portion of the first through hole 21ab and a portion of the second through hole 21bb may overlap and communicate with each other.

[0238] 9, 11, and 12, first protrusion 25aa and second protrusion 25ba preferably extend in opposite directions toward their respective tips. In this case, in capacitor 2, first bus bar 20a and second bus bar 20b are more firmly fixed by filled resin 40 that is embedded in first protrusion 25aa and second protrusion 25ba. This further reduces peeling between first bus bar 20a and filled resin 40, peeling between second bus bar 20b and filled resin 40, and cracking of filled resin 40, even when the temperature of the usage environment changes.

[0239] 9, 11, and 12, first protrusion 25ab and second protrusion 25bb preferably extend in opposite directions toward their respective tips. In this case, in capacitor 2, first bus bar 20a and second bus bar 20b are more firmly fixed by filled resin 40 that is embedded in first protrusion 25ab and second protrusion 25bb. This further reduces peeling between first bus bar 20a and filled resin 40, peeling between second bus bar 20b and filled resin 40, and cracking of filled resin 40, even when the temperature of the usage environment changes.

[0240] At least one of the first protrusions 25aa and 25ab is preferably integrated with the first bus bar 20a, i.e., at least one of the first protrusions 25aa and 25ab preferably constitutes a part of the first bus bar 20a.

[0241] In this specification, two elements being integrated means that there is no interface between the elements, for example, it means that the boundary between the elements cannot be discerned.

[0242] At least one of the first protrusions 25aa and 25ab does not have to be integrated with the first bus bar 20a. For example, at least one of the first protrusions 25aa and 25ab may be a separate member independent of the first bus bar 20a and joined or adhered to the first bus bar 20a.

[0243] At least one of the second protrusions 25ba and 25bb is preferably integrated with the second bus bar 20b, i.e., at least one of the second protrusions 25ba and 25bb preferably constitutes a part of the second bus bar 20b.

[0244] At least one of the second protrusions 25ba and 25bb does not have to be integrated with the second bus bar 20b. For example, at least one of the second protrusions 25ba and 25bb may be a separate member independent of the second bus bar 20b and joined or adhered to the second bus bar 20b.

[0245] The planar shapes of the first protrusion 25aa, the first protrusion 25ab, the second protrusion 25ba, and the second protrusion 25bb (in FIG. 9, the planar shapes when viewed from the first direction D1) are not particularly limited, and examples include rectangular shapes such as a rectangle or a square, a circle, an ellipse, and shapes that are a combination of these.

[0246] The planar shapes of the first protruding portion 25aa, the first protruding portion 25ab, the second protruding portion 25ba, and the second protruding portion 25bb may be the same as one another, may be different from one another, or may be partially different from one another.

[0247] [Embodiment 3] Hereinafter, another example of the capacitor according to the second aspect of the present invention will be described as a capacitor according to embodiment 3 of the present invention.

[0248] In the capacitor of the third embodiment of the present invention, unlike the capacitor of the second embodiment of the present invention, a part of the through-hole and the entire protrusion are embedded in the filling resin.

[0249] Except for the above points, the capacitor of the third embodiment of the present invention is similar to the capacitor of the second embodiment of the present invention.

[0250] Fig. 13 is a schematic perspective view of an example of a capacitor according to embodiment 3 of the present invention. Fig. 14 is a schematic view of an example of an exploded state of the capacitor shown in Fig. 13 (excluding the filled resin).

[0251] The capacitor 3 shown in FIGS. 13 and 14 includes a capacitor element 10, a first bus bar 20a, a second bus bar 20b, an outer case 30, and a filling resin 40.

[0252] The features of each component of capacitor 3, namely, capacitor element 10, first bus bar 20a, second bus bar 20b, exterior case 30, and filled resin 40, are the same as those of each component described above in capacitor 1, except for the following points: In the example shown in Figures 13 and 14, in the region where first bus bar 20a and second bus bar 20b overlap, a gap of a predetermined distance is provided between first bus bar 20a and second bus bar 20b, specifically, between second main surface 20ab of first bus bar 20a and second main surface 20bb of second bus bar 20b.

[0253] Fig. 15 is a schematic perspective view of the cross section of the capacitor shown in Fig. 13. Fig. 16 is a schematic view of the capacitor shown in Fig. 15 with the filling resin removed. Fig. 17 is a schematic view of the cross section of the capacitor shown in Fig. 16 when viewed from above.

[0254] As shown in Figures 15, 16, and 17, the portion of the first bus bar 20a located between the capacitor element 10 and the opening 31 is provided with a first through hole 21aa and a first protrusion 25aa protruding from the periphery of the first through hole 21aa.

[0255] 17 , the protruding direction DPaa of the first protruding portion 25aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

[0256] As shown in FIGS. 15 and 16, a portion of the first through-hole 21 aa and the entire first protrusion 25 aa are embedded in the filling resin 40 .

[0257] In capacitor 3, because a portion of first through hole 21aa is embedded in filled resin 40, the length of the interface between first bus bar 20a and filled resin 40 is shorter than in capacitor 2, thereby reducing stress caused by the difference in thermal expansion coefficient between first bus bar 20a and filled resin 40. As a result, in capacitor 3, the occurrence of peeling between first bus bar 20a and filled resin 40 and the occurrence of cracks in filled resin 40 are suppressed compared to capacitor 2.

[0258] In the electrical component described in Patent Document 2, as shown in FIG. 4 of Patent Document 2, only a portion of the through hole 13 is embedded in the resin 32, but no protruding portion is provided that protrudes from the periphery of the through hole 13 and is entirely embedded in the resin 32. Therefore, movement of the connection terminal 11 that shifts in the shear direction relative to the resin 32 (particularly, toward or away from the opening surface of the opening of the case 31 relative to the resin 32) caused by expansion or contraction of the electrical element 21 when the temperature of the usage environment changes is not easily suppressed.

[0259] For the above reasons, Capacitor 3, like Capacitor 1 and Capacitor 2, has the advantageous effect of being able to suppress peeling between the bus bar and the filled resin and cracking of the filled resin even when the temperature of the usage environment changes, compared to, for example, the capacitor described in Patent Document 1 and the electrical component described in Patent Document 2.

[0260] In order to enhance the above-described effects of the capacitor 3, it is preferable that the protruding direction DPaa of the first protruding portion 25aa is parallel to the opening surface 31s of the opening 31, as shown in FIG.

[0261] In the example shown in Fig. 17, the protruding direction DPaa of the first protruding portion 25aa is parallel to the third direction D3. Also, in the example shown in Fig. 17, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in Fig. 17, the protruding direction DPaa of the first protruding portion 25aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in Fig. 17, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

[0262] The protruding direction DPaa of the first protruding portion 25aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

[0263] 17 , from the viewpoint of enhancing the above-described effects of the capacitor 3, the penetration direction DHaa of the first through hole 21aa preferably forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the penetration direction DHaa of the first through hole 21aa preferably forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

[0264] In order to enhance the above-described effects of the capacitor 3, it is more preferable that the penetration direction DHaa of the first through-hole 21aa is parallel to the opening surface 31s of the opening 31, as shown in FIG.

[0265] In the example shown in Fig. 17, the penetration direction DHaa of the first through hole 21aa is parallel to the third direction D3. Also, in the example shown in Fig. 17, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in Fig. 17, the penetration direction DHaa of the first through hole 21aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in Fig. 17, the penetration direction DHaa of the first through hole 21aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

[0266] The penetration direction DHaa of the first through-hole 21aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

[0267] The penetration direction DHaa of the first through hole 21aa may be parallel to the thickness direction of the first bus bar 20a (in Figure 17, the third direction D3), or it may not be parallel to the thickness direction of the first bus bar 20a (it may be inclined with respect to the thickness direction of the first bus bar 20a).

[0268] When the penetration direction DHaa of the first through-hole 21aa is parallel to the thickness direction of the first bus bar 20a, the penetration direction DHaa is perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a.

[0269] If the penetration direction DHaa of the first through hole 21aa is not parallel to the thickness direction of the first bus bar 20a (if it is tilted relative to the thickness direction of the first bus bar 20a), it is not perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a (if it is tilted relative to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a).

[0270] As shown in FIG. 17 , the surface of the first bus bar 20 a on which the first through holes 21 aa (as well as the first through holes 21 ab described later) are provided is preferably perpendicular to the opening surface 31 s of the opening 31 .

[0271] In the example shown in FIG. 17 , the first main surface 20aa and the second main surface 20ab of the first bus bar 20a in which the first through hole 21aa is provided are perpendicular to the opening surface 31s of the opening 31.

[0272] The first main surface 20aa and the second main surface 20ab of the first bus bar 20a in which the first through-hole 21aa is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

[0273] As shown in Figures 15, 16, and 17, the first bus bar 20a further has a first through hole 21ab and a first protrusion 25ab protruding from the periphery of the first through hole 21ab in the portion located between the capacitor element 10 and the opening 31.

[0274] As shown in FIG. 17, the protruding direction DPab of the first protruding portion 25ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0275] As shown in FIGS. 15 and 16, a portion of the first through-hole 21ab and the entire first protrusion 25ab are embedded in the filling resin 40.

[0276] In the capacitor 3, the protrusion direction DPab of the first protrusion 25ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and a portion of the first through hole 21ab and the entire first protrusion 25ab are embedded in the filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between the first busbar 20a and the filled resin 40 and cracks in the filled resin 40 are suppressed.

[0277] The characteristics of the first through hole 21ab (for example, the through direction DHab of the first through hole 21ab) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0278] The characteristics of the first protrusion 25ab (for example, the protrusion direction DPab of the first protrusion 25ab) are similar to the characteristics of the first protrusion 25aa, including the points described above.

[0279] As shown in Figures 15, 16, and 17, the second bus bar 20b has a second through hole 21ba and a second protrusion 25ba protruding from the periphery of the second through hole 21ba in the portion located between the capacitor element 10 and the opening 31.

[0280] As shown in FIG. 17 , the protruding direction DPba of the second protruding portion 25ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0281] As shown in FIGS. 15 and 16 , a portion of the second through-hole 21 ba and the entire second protrusion 25 ba are embedded in the filling resin 40 .

[0282] In capacitor 3, the protrusion direction DPba of the second protrusion 25ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and a portion of the second through hole 21ba and the entire second protrusion 25ba are embedded in the filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between the second busbar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

[0283] The characteristics of the second through hole 21ba (for example, the penetration direction DHba of the second through hole 21ba) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0284] The characteristics of the second protrusion 25ba (for example, the protrusion direction DPba of the second protrusion 25ba) are similar to the characteristics of the first protrusion 25aa, including the points described above.

[0285] As shown in FIG. 17 , the surface of the second bus bar 20 b on which the second through holes 21 ba (as well as the second through holes 21 bb described later) are provided is preferably perpendicular to the opening surface 31 s of the opening 31 .

[0286] In the example shown in FIG. 17 , the first main surface 20ba and the second main surface 20bb of the second bus bar 20b in which the second through hole 21ba is provided are perpendicular to the opening surface 31s of the opening 31.

[0287] The first main surface 20ba and the second main surface 20bb of the second bus bar 20b in which the second through hole 21ba is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

[0288] As shown in Figures 15, 16, and 17, the second bus bar 20b further has a second through hole 21bb and a second protrusion 25bb protruding from the periphery of the second through hole 21bb in the portion located between the capacitor element 10 and the opening 31.

[0289] As shown in FIG. 17 , the protruding direction DPbb of the second protruding portion 25bb forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

[0290] As shown in FIGS. 15 and 16 , a portion of the second through-hole 21 bb and the entire second protrusion 25 bb are embedded in the filling resin 40 .

[0291] In capacitor 3, the protrusion direction DPbb of the second protrusion 25bb forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and a portion of the second through hole 21bb and the entire second protrusion 25bb are embedded in the filled resin 40. Therefore, similar to the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

[0292] The characteristics of the second through hole 21bb (for example, the penetration direction DHbb of the second through hole 21bb) are similar to the characteristics of the first through hole 21aa, including the points described above.

[0293] The characteristics of the second protrusion 25bb (for example, the protrusion direction DPbb of the second protrusion 25bb) are similar to the characteristics of the first protrusion 25aa, including the points described above.

[0294] 13 , 14 , 15 , 16 , and 17 , in the region where the first bus bar 20 a and the second bus bar 20 b overlap, at least a portion of the first through hole 21 aa and at least a portion of the second through hole 21 ba preferably overlap and communicate with each other. In this case, in the capacitor 3, the first bus bar 20 a and the second bus bar 20 b are more firmly fixed by the filled resin 40 that has entered the first through hole 21 aa and the second through hole 21 ba. This further reduces peeling between the first bus bar 20 a and the filled resin 40, peeling between the second bus bar 20 b and the filled resin 40, and cracks in the filled resin 40, even if the temperature of the usage environment changes.

[0295] In the examples shown in Figures 13, 14, 15, 16, and 17, in the area where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21aa and the entire second through hole 21ba overlap and communicate with each other, but the entire first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and the entire second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other.

[0296] 13 , 14 , 15 , 16 , and 17 , in the region where the first bus bar 20 a and the second bus bar 20 b overlap, it is preferable that at least a portion of the first through hole 21 ab and at least a portion of the second through hole 21 bb overlap and communicate with each other. In this case, in the capacitor 3, the first bus bar 20 a and the second bus bar 20 b are more firmly fixed by the filled resin 40 that has entered the first through hole 21 ab and the second through hole 21 bb. This further reduces peeling between the first bus bar 20 a and the filled resin 40, peeling between the second bus bar 20 b and the filled resin 40, and cracks in the filled resin 40, even if the temperature of the usage environment changes.

[0297] In the examples shown in Figures 13, 14, 15, 16, and 17, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21ab and the entire second through hole 21bb overlap and communicate with each other, but the entire first through hole 21ab and a portion of the second through hole 21bb may overlap and communicate with each other, or a portion of the first through hole 21ab and the entire second through hole 21bb may overlap and communicate with each other, or a portion of the first through hole 21ab and a portion of the second through hole 21bb may overlap and communicate with each other.

[0298] In the second aspect of the capacitor of the present invention, it is sufficient that the characteristic that "the protrusion direction in which at least the tip portion of the protrusion extends forms an angle of less than 45° with respect to the opening plane of the opening, and at least a portion of the through hole and the entire protrusion are embedded in the filled resin" is satisfied for at least one combination of a through hole and a protrusion. For example, in Capacitor 2 and Capacitor 3, the characteristic is satisfied for at least one combination of a through hole and a protrusion selected from the group consisting of the combination of first through hole 21aa and first protrusion 25aa, the combination of first through hole 21ab and first protrusion 25ab, the combination of second through hole 21ba and second protrusion 25ba, and the combination of second through hole 21bb and second protrusion 25bb.

[0299] The second aspect of the capacitor of the present invention is not limited to the above embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration of the capacitor, manufacturing conditions, etc.

[0300] For example, in the second embodiment of the capacitor of the present invention, the number of capacitor elements housed inside one exterior case is not particularly limited. That is, in the second embodiment of the capacitor of the present invention, one exterior case may house one capacitor element or multiple capacitor elements (two capacitor elements in the examples shown in Figures 8 and 13, etc.).

[0301] Furthermore, in the second aspect of the capacitor of the present invention, the number of through holes and protrusions provided in the portion of one bus bar located between the capacitor element and the opening is not particularly limited. That is, in the second aspect of the capacitor of the present invention, the portion of one bus bar located between the capacitor element and the opening may have one through hole and one protrusion, or may have a plurality of through holes and a plurality of protrusions (two of each in the examples shown in Figures 8 and 13).

[0302] The capacitor of the present invention is useful for power conversion devices such as motor drive inverters mounted on electric vehicles.

[0303] The present specification discloses the following:

[0304] <1> A capacitor comprising: a capacitor element having an element body and external electrodes provided on a surface of the element body; a bus bar electrically connected to the external electrodes; a cylindrical outer case with a bottom and an opening, the outer case containing the capacitor element such that the bus bar protrudes outward from the opening; and a filled resin filled inside the outer case so as to embed the capacitor element, wherein the bus bar has a through hole in a portion located between the capacitor element and the opening, the penetrating direction of the through hole forming an angle of less than 45° with respect to an opening plane of the opening, and the entire through hole is embedded in the filled resin.

[0305] <2> The capacitor according to <1>, wherein the penetration direction is parallel to the opening surface of the opening.

[0306] <3> The capacitor according to <1> or <2>, wherein a surface of the bus bar in which the through holes are provided is perpendicular to the opening surface of the opening.

[0307] <4> The capacitor according to any one of <1> to <3>, wherein the external electrodes include a first external electrode and a second external electrode, the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode, the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar, and in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other.

[0308] <5> A capacitor comprising: a capacitor element having an element body and external electrodes provided on a surface of the element body; a bus bar electrically connected to the external electrodes; a cylindrical exterior case having an opening and a bottom, the capacitor element housed inside the exterior case such that the bus bar protrudes outward from the opening; and a filled resin filled inside the exterior case so as to embed the capacitor element, wherein the bus bar has a through hole and a protruding portion protruding from a periphery of the through hole in a portion located between the capacitor element and the opening, the protruding portion having at least a tip end portion extending in a protruding direction that forms an angle of less than 45° with respect to an opening plane of the opening, and at least a portion of the through hole and the entire protruding portion are embedded in the filled resin.

[0309] <6> The capacitor according to <5>, wherein the entire through hole and the entire protrusion are embedded in the filling resin.

[0310] <7> The capacitor according to <5>, wherein a portion of the through hole and the entire protrusion are embedded in the filling resin.

[0311] <8> The capacitor according to any one of <5> to <7>, wherein the protruding direction is parallel to the opening surface of the opening.

[0312] <9> The capacitor according to any one of <5> to <8>, wherein the through hole extends in a direction that forms an angle of less than 45° with respect to the opening plane of the opening.

[0313] <10> The capacitor according to <9>, wherein the penetration direction is parallel to the opening surface of the opening.

[0314] <11> The capacitor according to any one of <5> to <10>, wherein a surface of the bus bar on which the through holes are provided is perpendicular to the opening surface of the opening.

[0315] <12> The capacitor according to any one of <5> to <11>, wherein the external electrodes include a first external electrode and a second external electrode, the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode, the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar, and in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other.

[0316] <13> The capacitor according to any one of <1> to <12>, wherein the capacitor element is a film capacitor.

[0317] 1, 2, 3 Capacitor 10 Capacitor element 11 Body 11a First end face of body 11b Second end face of body 11c Side face of body 12a First external electrode 12b Second external electrode 13a First metallized film 13b Second metallized film 14a First dielectric film 14aa First main surface of first dielectric film 14ab Second main surface of first dielectric film 14b Second dielectric film 14ba First main surface of second dielectric film 14bb Second main surface of second dielectric film 15a First metal layer 15b Second metal layer 20a First bus bar 20aa First main surface of first bus bar 20ab Second main surface of first bus bar 20b Second bus bar 20ba First main surface of second bus bar 20bb Second main surface of second bus bar 21aa, 21ab First through hole 21aaa, 21aba First end of first through hole 21aab, 21abb Second end of first through hole 21ba, 21bb Second through hole 21baa, 21bba First end of second through hole 21bab, 21bbb Second end of second through hole 25aa, 25ab First protrusion 25ba, 25bb Second protrusion 30 Outer case 31 Opening 31s Opening surface of opening 32 Bottom 33 Side wall 40 Filled resin D1 First direction D2 Second direction D3 Third direction DHaa, DHab Penetration direction in which first through hole extends DHba, DHbb Penetration direction in which second through hole extends DPaa, DPab Protrusion direction in which at least the tip side portion of first protrusion extends DPba, DPbb: Projection direction in which at least the tip side portion of the second projecting portion extends

Claims

1. A capacitor comprising: a capacitor element having an element body and an external electrode provided on a surface of the element body; a bus bar electrically connected to the external electrode; a bottomed, cylindrical exterior case having an opening and containing the capacitor element such that the bus bar protrudes from the opening to the outside; and filled resin with which the interior of the exterior case is filled so as to embed the capacitor element, wherein a through hole is provided in a portion of the bus bar located between the capacitor element and the opening, the penetrating direction of the through hole forms an angle of less than 45° with respect to the opening plane of the opening, and the entire through hole is embedded in the filled resin.

2. The capacitor of claim 1, wherein the penetration direction is parallel to the opening surface of the opening.

3. The capacitor according to claim 1 or 2, wherein a surface of the bus bar in which the through hole is provided is perpendicular to the opening surface of the opening.

4. The capacitor according to any one of claims 1 to 3, wherein the external electrodes include a first external electrode and a second external electrode, the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode, the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar, and in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other.

5. A capacitor comprising: a capacitor element having an element body and an external electrode provided on a surface of the element body; a bus bar electrically connected to the external electrode; a bottomed, cylindrical exterior case having an opening and containing the capacitor element such that the bus bar protrudes from the opening to the outside; and filled resin with which the interior of the exterior case is filled so as to embed the capacitor element, wherein a through hole and a protruding portion protruding from the periphery of the through hole are provided in a portion of the bus bar located between the capacitor element and the opening, the protruding direction of at least a tip side portion of the protruding portion forms an angle of less than 45° with respect to the opening plane of the opening, and at least a portion of the through hole and the entirety of the protruding portion are embedded in the filled resin.

6. The capacitor according to claim 5, wherein the entire through hole and the entire protrusion are embedded in the filling resin.

7. The capacitor according to claim 5, wherein a portion of said through hole and said entire protrusion are embedded in said filling resin.

8. A capacitor according to any one of claims 5 to 7, wherein the protruding direction is parallel to the opening surface of the opening.

9. The capacitor according to any one of claims 5 to 8, wherein the direction in which the through hole extends forms an angle of less than 45° with respect to the opening plane of the opening.

10. The capacitor of claim 9, wherein the penetration direction is parallel to the opening surface of the opening.

11. The capacitor according to any one of claims 5 to 10, wherein a surface of the bus bar in which the through hole is provided is perpendicular to the opening surface of the opening.

12. The capacitor according to any one of claims 5 to 11, wherein the external electrodes include a first external electrode and a second external electrode, the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode, the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar, and in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other.

13. The capacitor according to any one of claims 1 to 12, wherein the capacitor element is a film capacitor.

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