Capacitor module

Abstract

A capacitor module 1 comprises: a capacitor element 10 having an element body 11, a first external electrode 12a provided on a surface of the element body 11, and a second external electrode 12b provided at a position separated from the first external electrode 12a on the surface of the element body 11; a first bus bar 20a electrically connected to the first external electrode 12a; a second bus bar 20b electrically connected to the second external electrode 12b; and an insulation sheet 30 which is sandwiched between the first bus bar 20a and the second bus bar 20b and forms a laminated structure together with the first bus bar 20a and the second bus bar 20b. The first bus bar 20a has a first through-hole 21aa, and the insulation sheet 30 has a first projection part 31aa projecting on the first bus bar 20a side. The first projection part 31aa is locked in the first through-hole 21aa.

Description

Capacitor Module

[0001] The present invention relates to a capacitor module.

[0002] Patent Document 1 discloses a battery pack comprising an outer case, a circuit board and battery cells, and an insulating material between the circuit board and the battery cells, the insulating material having notches extending from holes through which leads extending from the circuit board are inserted to the outer edge, the notches being shaped in two or more different directions, the leads inserted through the holes being bent in a direction different from the direction of the part where the holes and the notches are connected, and the insulating material being sandwiched and fixed between the bent parts of the leads and the circuit board.

[0003] JP 2009-54391 A

[0004] In a capacitor module provided with capacitor elements, positive and negative bus bars electrically connected to the capacitor elements may be used as connection terminals for electrically drawing out the capacitor elements. In such a capacitor module provided with positive and negative bus bars, if the spacing between the bus bars is small, particularly if there is a risk of the bus bars coming into contact with each other, an insulating sheet (including insulating paper) may be sandwiched between the bus bars to prevent a short circuit between the bus bars.

[0005] When an insulating sheet is sandwiched between bus bars during assembly of a capacitor module, the insulating sheet is typically fixed to the bus bars using fixing members such as tape, adhesive, a dedicated jig, etc. However, when an attempt is made to fix an insulating sheet to a bus bar using fixing members during assembly of a capacitor module, the cost of preparing the fixing members and the effort required to install the fixing members are high, which may reduce the manufacturing efficiency of the capacitor module.

[0006] Meanwhile, Patent Document 1, which is in the field of battery packs rather than capacitor modules, describes a technique for fixing insulating paper between a circuit board and a battery cell by passing leads connected between the circuit board and the battery cell through holes in the insulating paper, as shown in FIG. 1 of Patent Document 1. However, the technique described in Patent Document 1 requires costs for preparing leads and labor for installing the leads to fix the insulating paper, which may reduce the manufacturing efficiency of battery packs. Furthermore, the technique described in Patent Document 1 is difficult to apply to products that do not use leads, such as capacitor modules equipped with bus bars as described above.

[0007] As described above, the conventional method for fixing an insulating sheet leaves room for improvement in terms of preventing a decrease in manufacturing efficiency when fixing an insulating sheet.

[0008] The present invention has been made to solve the above problems, and has an object to provide a capacitor module that can suppress a decrease in manufacturing efficiency when fixing an insulating sheet.

[0009] A capacitor module of the present invention comprises a capacitor element having a base body, a first external electrode provided on a surface of the base body, and a second external electrode provided on the surface of the base body at a position spaced apart from the first external electrode, a first bus bar electrically connected to the first external electrode, a second bus bar electrically connected to the second external electrode, and an insulating sheet sandwiched between the first bus bar and the second bus bar and forming a laminated structure together with the first bus bar and the second bus bar, wherein the first bus bar has a first through hole, and the insulating sheet has a first protrusion protruding toward the first bus bar, and the first protrusion is engaged with the first through hole.

[0010] According to the present invention, it is possible to provide a capacitor module that can suppress a decrease in manufacturing efficiency when fixing an insulating sheet.

[0011] FIG. 1 is a schematic perspective view showing an example of a capacitor module according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view showing an example of a capacitor element shown in FIG. 1. FIG. 3 is a schematic cross-sectional view showing an example of a cross-section of the capacitor element shown in FIG. 2 taken along line a1-a2. FIG. 4 is a schematic perspective view showing an enlarged view of a portion of the capacitor module shown in FIG. 1. FIG. 5 is a schematic cross-sectional view showing an example of a cross-section of the capacitor module shown in FIG. 4 taken along line b1-b2. FIG. 6 is a schematic perspective view showing an enlarged view of another portion of the capacitor module shown in FIG. 1. FIG. 7 is a schematic cross-sectional view showing an example of a cross-section of the capacitor module shown in FIG. 6 taken along line c1-c2. FIG. 8 is a schematic perspective view showing an enlarged view of a portion of an example of a capacitor module according to a second embodiment of the present invention. FIG. 9 is a schematic cross-sectional view showing an example of a cross-section of the capacitor module shown in FIG. 8 taken along line d1-d2. FIG. 10 is a schematic perspective view showing an enlarged view of a portion of an example of a capacitor module according to a third embodiment of the present invention. Fig. 11 is a cross-sectional schematic diagram showing an example of a cross section along line e1-e2 of the capacitor module shown in Fig. 10. Fig. 12 is a perspective schematic diagram showing an enlarged portion of an example of a capacitor module according to embodiment 4 of the present invention. Fig. 13 is a cross-sectional schematic diagram showing an example of a cross section along line f1-f2 of the capacitor module shown in Fig. 12.

[0012] The capacitor module of the present invention will be described below. Note that the present invention is not limited to the following configuration and may be modified as appropriate without departing from the spirit of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0013] 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.

[0014] In the following description, when no particular distinction is made between the embodiments, they will simply be referred to as "the capacitor module of the present invention."

[0015] In the following, a film capacitor will be shown as an example of a capacitor element of the capacitor module of the present invention, but the capacitor module of the present invention can also be applied to capacitor elements other than film capacitors.

[0016] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0017] 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.

[0018] A capacitor module of the present invention comprises a capacitor element having a base body, a first external electrode provided on a surface of the base body, and a second external electrode provided on the surface of the base body at a position spaced apart from the first external electrode, a first bus bar electrically connected to the first external electrode, a second bus bar electrically connected to the second external electrode, and an insulating sheet sandwiched between the first bus bar and the second bus bar and forming a laminated structure together with the first bus bar and the second bus bar, wherein the first bus bar has a first through hole, and the insulating sheet has a first protrusion protruding toward the first bus bar, and the first protrusion is engaged with the first through hole.

[0019] First Embodiment In a capacitor module according to a first embodiment of the present invention, the first protrusion is tongue-shaped.

[0020] FIG. 1 is a schematic perspective view showing an example of a capacitor module according to a first embodiment of the present invention.

[0021] The capacitor module 1 shown in FIG. 1 includes a plurality of capacitor elements 10 , a first bus bar 20 a , a second bus bar 20 b , and an insulating sheet 30 .

[0022] In FIG. 1 and other figures, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to one another.

[0023] Fig. 2 is a schematic perspective view showing an example of the capacitor element shown in Fig. 1. Fig. 3 is a schematic cross-sectional view showing an example of a cross section of the capacitor element shown in Fig. 2 taken along line a1-a2.

[0024] The capacitor element 10 shown in FIGS. 2 and 3 has an element body 11, a first external electrode 12a, and a second external electrode 12b.

[0025] 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.

[0026] The capacitor element 10 may be a laminated film capacitor (for example, rectangular parallelepiped) in which metallized films are laminated.

[0027] 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. 2 and 3 ) 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.

[0028] 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.

[0029] 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.

[0030] First metallized film 13a includes first dielectric film 14a and first metal layer 15a.

[0031] 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.

[0032] 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.

[0033] Second metallized film 13b includes second dielectric film 14b and second metal layer 15b.

[0034] 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.

[0035] 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.

[0036] 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 one end surface 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 the other end surface opposite in third direction D3 to one end surface 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] The second metal layer 15b may also be provided with a fuse portion, similar to the first metal layer 15a.

[0042] The first dielectric film 14a may contain a curable resin as a main component.

[0043] 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.

[0044] The curable resin may be a thermosetting resin or a photocurable resin.

[0045] 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.).

[0046] 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.

[0047] The presence of urethane bonds in the dielectric film can be confirmed by analysis with a Fourier transform infrared spectrophotometer (FT-IR).

[0048] 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.

[0049] The presence of hydroxyl groups and / or isocyanate groups in the dielectric film can be confirmed by FT-IR analysis.

[0050] Examples of the first organic material include phenoxy resin, polyvinyl acetoacetal resin, and polyvinyl butyral resin.

[0051] As the first organic material, a plurality of types of organic materials may be used in combination.

[0052] 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.

[0053] As the second organic material, a plurality of types of organic materials may be used in combination.

[0054] The first dielectric film 14a may contain a thermoplastic resin as a main component.

[0055] Examples of the thermoplastic resin include polypropylene resin, polyethersulfone resin, polyetherimide resin, and polyarylate resin.

[0056] The first dielectric film 14a may contain additives to impart various functions.

[0057] The additives include, for example, a leveling agent for imparting smoothness.

[0058] 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.

[0059] 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.

[0060] The first dielectric film 14a and the second dielectric film 14b may have different compositions, but preferably have the same composition.

[0061] 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.

[0062] 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.

[0063] The thickness of the dielectric film is measured using an optical film thickness gauge.

[0064] 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.

[0065] 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.

[0066] The first metal layer 15a and the second metal layer 15b may have different compositions, but preferably have the same composition.

[0067] 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.

[0068] 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.

[0069] 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).

[0070] 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.

[0071] 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.

[0072] The first external electrode 12a is provided on the surface of the element body 11. In the example shown in Figures 2 and 3, the first external electrode 12a is provided on one end surface 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 on one end surface of the element body 11. On the other hand, the first external electrode 12a is not connected to the second metal layer 15b.

[0073] 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 2 and 3, the second external electrode 12b is provided on the other end face of the element body 11 that faces the one end face in the third direction D3. The second external electrode 12b is connected to the second metal layer 15b by contacting the end of the second metal layer 15b exposed on the other end face of the element body 11. On the other hand, the second external electrode 12b is not connected to the first metal layer 15a.

[0074] 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.

[0075] The first external electrode 12a and the second external electrode 12b may have different compositions, but preferably have the same composition.

[0076] The first external electrode 12a and the second external electrode 12b are preferably formed by spraying the above-mentioned metal onto one end surface and the other end surface of the element body 11, respectively.

[0077] As described above, each of the capacitor elements 10 has the element body 11, the first external electrode 12a, and the second external electrode 12b.

[0078] There is no particular limitation on the number of the plurality of capacitor elements 10. For example, the number of the plurality of capacitor elements 10 may be three as shown in FIG. 1 , may be two, or may be four or more.

[0079] The number of capacitor elements 10 is not limited to a plurality, and may be only one.

[0080] 1, 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.

[0081] The first bus bar 20a preferably has a plate-like shape.

[0082] Examples of materials for the first bus bar 20a 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. When the material for the first bus bar 20a is a copper-based material, examples of materials that can be used include oxygen-free copper (copper: 99.96% by weight or more), tough pitch copper (copper: 99.90% by weight or more), and phosphorus-deoxidized copper (copper: 99.90% by weight or more, phosphorus: 0.015% by weight or more, 0.040% by weight or less).

[0083] 1, 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.

[0084] 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.

[0085] The second bus bar 20b preferably has a plate-like shape.

[0086] Examples of materials for 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 second bus bar 20b. When the second bus bar 20b is made of a copper-based material, examples of materials that can be used include oxygen-free copper (copper: 99.96% by weight or more), tough pitch copper (copper: 99.90% by weight or more), and phosphorus-deoxidized copper (copper: 99.90% by weight or more, phosphorus: 0.015% by weight or more, 0.040% by weight or less).

[0087] The material of the second bus bar 20b may be the same as the material of the first bus bar 20a, or may be different from the material of the first bus bar 20a.

[0088] The thickness of the first bus bar 20a and the second bus bar 20b may be the same as or different from each other.

[0089] 1 , the insulating sheet 30 is sandwiched between the first bus bar 20 a and the second bus bar 20 b, and forms a layered structure together with the first bus bar 20 a and the second bus bar 20 b. Specifically, the first bus bar 20 a, the insulating sheet 30, and the second bus bar 20 b are stacked in order to form the layered structure. In this layered structure, the insulating sheet 30 ensures the insulation of the first bus bar 20 a and the second bus bar 20 b.

[0090] The insulating sheet 30 has a first sheet surface 30a located on the first bus bar 20a side, and a second sheet surface 30b located on the opposite side to the first bus bar 20a.

[0091] In this specification, the sheet also includes forms such as paper, board, and film.

[0092] Examples of materials that can be used for the insulating sheet 30 include resin. When the insulating sheet 30 is made of resin, the insulating sheet 30 may be a resin member that has been pre-formed into a predetermined shape. For example, the insulating sheet 30 may be a resin member that has been pre-formed so that at least one of the first sheet surface 30a and the second sheet surface 30b has a shape other than a flat shape (for example, a curved shape, a convex shape, etc.).

[0093] The thickness of the insulating sheet 30 is preferably smaller than the thickness of the first bus bar 20a and the second bus bar 20b at least in positions other than the respective protruding portions described below.

[0094] The thickness of the insulating sheet 30 may be the same as the thickness of the first bus bar 20a and the second bus bar 20b, or may be greater than the thickness of the first bus bar 20a and the second bus bar 20b, at least at positions other than the respective protrusions described below.

[0095] The insulating sheet 30 may be made up of one layer or multiple layers.

[0096] As long as the insulating sheet 30 is located at a position sandwiched between the first bus bar 20a and the second bus bar 20b, it may extend from the position sandwiched between the first bus bar 20a and the second bus bar 20b to a position not sandwiched between the first bus bar 20a and the second bus bar 20b.

[0097] As long as the first bus bar 20a and the second bus bar 20b overlap each other at least in the laminated structure, they do not have to overlap each other in areas other than the laminated structure. In other words, it is sufficient that at least a portion of the first bus bar 20a and at least a portion of the second bus bar 20b overlap each other.

[0098] From the above, it is sufficient that at least a portion of the first bus bar 20a, at least a portion of the insulating sheet 30, and at least a portion of the second bus bar 20b are stacked in order to form a laminated structure.

[0099] In the above-described laminated structure, the first bus bar 20a, the insulating sheet 30, and the second bus bar 20b preferably extend parallel to one another.

[0100] In the capacitor module 1, the insulating sheet 30 is fixed to the first bus bar 20a. An example of how the insulating sheet 30 is fixed to the first bus bar 20a will be described below.

[0101] Fig. 4 is a schematic perspective view showing an enlarged portion of the capacitor module shown in Fig. 1. Fig. 5 is a schematic cross-sectional view showing an example of a cross section of the capacitor module shown in Fig. 4 taken along line b1-b2.

[0102] 1, 4, and 5, the first bus bar 20a has a first through hole 21aa. In the examples shown in Fig. 1, 4, and 5, the first through hole 21aa penetrates the first bus bar 20a in the third direction D3.

[0103] As shown in FIGS. 1, 4, and 5, the insulating sheet 30 has a first protruding portion 31aa that protrudes toward the first bus bar 20a.

[0104] 1, 4, and 5, the first protrusion 31aa has a tongue shape. Specifically, the first protrusion 31aa has a tongue shape that extends toward the first bus bar 20a. In the example shown in FIGS. 1, 4, and 5, the first protrusion 31aa is formed by bending a portion of the insulating sheet 30 toward the first bus bar 20a while separating it from the surrounding area to form the tongue shape.

[0105] 1, 4, and 5, the first protrusion 31aa is engaged with the first through-hole 21aa. In the example shown in Fig. 1, 4, and 5, the tip side of the first protrusion 31aa passes through the first through-hole 21aa and becomes caught on the periphery of the first through-hole 21aa, thereby being engaged with the first through-hole 21aa.

[0106] 1, 4, and 5, with the tip end side of the first protrusion 31aa passing through the first through hole 21aa, the second seat surface 30b side faces the first bus bar 20a side, and the first seat surface 30a side faces the opposite side from the first bus bar 20a. Also, in the example shown in Fig. 1, 4, and 5, with the tip end side of the first protrusion 31aa passing through the first through hole 21aa, the second seat surface 30b side is in contact with the periphery of the first through hole 21aa.

[0107] As shown in Fig. 4, the first protrusion 31aa preferably has the same width as the first through hole 21aa. In the example shown in Fig. 4, the first protrusion 31aa has the same dimension in the first direction D1 as the first through hole 21aa. In this case, the first protrusion 31aa is more likely to be firmly locked in the first through hole 21aa.

[0108] The first protrusion 31aa may have a width smaller than that of the first through-hole 21aa.

[0109] In the capacitor module 1, the first protrusion may be engaged with the first through hole at a location other than the location where the first protrusion 31aa is engaged with the first through hole 21aa, as described below.

[0110] Fig. 6 is an enlarged perspective view showing another part of the capacitor module shown in Fig. 1. Fig. 7 is a cross-sectional view showing an example of a cross section of the capacitor module shown in Fig. 6 taken along line c1-c2.

[0111] 1, 6, and 7, the first bus bar 20a has a first through hole 21ab at a position spaced apart from the first through hole 21aa. In the examples shown in Fig. 1, 6, and 7, the first through hole 21ab penetrates the first bus bar 20a in the second direction D2.

[0112] As shown in FIGS. 1, 6, and 7, the insulating sheet 30 has a first protruding portion 31ab that protrudes toward the first bus bar 20a at a position spaced apart from the first protruding portion 31aa.

[0113] 1, 6, and 7, the first protrusion 31ab is tongue-shaped. Specifically, the first protrusion 31ab is tongue-shaped and extends toward the first bus bar 20a. In the example shown in FIGS. 1, 6, and 7, the first protrusion 31ab is formed by bending the end of the insulating sheet 30 toward the first bus bar 20a while the end protrudes in a tongue-like shape.

[0114] 1, 6, and 7, the first protrusion 31ab is engaged with the first through-hole 21ab. In the example shown in Fig. 1, 6, and 7, the tip side of the first protrusion 31ab passes through the first through-hole 21ab and gets caught on the periphery of the first through-hole 21ab, thereby being engaged with the first through-hole 21ab.

[0115] 1, 6, and 7, with the tip end side of the first protrusion 31ab passing through the first through hole 21ab, the second seat surface 30b side faces the first bus bar 20a side, and the first seat surface 30a side faces the opposite side from the first bus bar 20a. Also, in the example shown in Fig. 1, 6, and 7, with the tip end side of the first protrusion 31ab passing through the first through hole 21ab, the second seat surface 30b side is in contact with the periphery of the first through hole 21ab.

[0116] As shown in Fig. 6, the first protrusion 31ab preferably has the same width as the first through hole 21ab. In the example shown in Fig. 6, the first protrusion 31ab has the same dimension in the first direction D1 as the first through hole 21ab. In this case, the first protrusion 31ab is more likely to be firmly locked in the first through hole 21ab.

[0117] The first protrusion 31ab may have a width smaller than that of the first through-hole 21ab.

[0118] In the capacitor module 1, the points at which the first protrusion is engaged with the first through hole may be other points other than the point at which the first protrusion 31aa is engaged with the first through hole 21aa and the point at which the first protrusion 31ab is engaged with the first through hole 21ab, as follows:

[0119] 1, the first bus bar 20a has a first through hole 21ac at a position away from the first through hole 21aa and the first through hole 21ab. In the example shown in FIG. 1, the first through hole 21ac penetrates the first bus bar 20a in the second direction D2.

[0120] As shown in FIG. 1, the insulating sheet 30 has a first protruding portion 31ac that protrudes toward the first bus bar 20a at a position spaced apart from the first protruding portions 31aa and 31ab.

[0121] 1, the first protrusion 31ac has a tongue shape. Specifically, the first protrusion 31ac has a tongue shape that extends toward the first bus bar 20a. In the example shown in FIG. 1, the first protrusion 31ac is formed by bending an end of the insulating sheet 30 toward the first bus bar 20a while the end protrudes in a tongue shape.

[0122] As shown in Fig. 1, the first protrusion 31ac is engaged with the first through-hole 21ac. In the example shown in Fig. 1, the tip side of the first protrusion 31ac passes through the first through-hole 21ac and is caught on the periphery of the first through-hole 21ac, thereby being engaged with the first through-hole 21ac.

[0123] 1, with the tip end side of the first protrusion 31ac passing through the first through hole 21ac, the second seat surface 30b side faces the first bus bar 20a side, and the first seat surface 30a side faces the opposite side from the first bus bar 20a. In the example shown in FIG. 1, with the tip end side of the first protrusion 31ac passing through the first through hole 21ac, the second seat surface 30b side is in contact with the periphery of the first through hole 21ac.

[0124] It is preferable that the first protrusion 31ac has the same width as the first through-hole 21ac, in which case the first protrusion 31ac can be more easily and firmly locked in the first through-hole 21ac.

[0125] The first protrusion 31ac may have a width smaller than that of the first through-hole 21ac.

[0126] An enlarged perspective view showing the portion where the first protrusion 31ac is locked in the first through-hole 21ac and its cross-sectional view are omitted here because they are similar to FIGS. 6 and 7.

[0127] The planar shapes of the first through holes 21aa, 21ab, and 21ac are not particularly limited, and examples thereof include rectangles such as rectangles and squares, circles, ellipses, and shapes that are combinations of these.

[0128] The planar shapes of the first through-hole 21aa, the first through-hole 21ab, and the first through-hole 21ac may be the same as or different from one another.

[0129] The planar shapes of the first protrusion 31aa, the first protrusion 31ab, and the first protrusion 31ac are not particularly limited, and examples thereof include rectangles such as rectangles and squares, semicircles, semi-ellipses, and shapes that are combinations of these.

[0130] The planar shapes of the first protruding portion 31aa, the first protruding portion 31ab, and the first protruding portion 31ac may be the same as or different from one another.

[0131] As described above, in the capacitor module 1, the first protrusions (e.g., first protrusions 31aa) are engaged with the first through-holes (e.g., first through-holes 21aa), thereby fixing the insulating sheet 30 to the first bus bar 20a. Thus, unlike conventional capacitor modules, the capacitor module 1 does not require the use of fixing members such as tape, adhesive, or a dedicated jig to fix the insulating sheet 30 to the first bus bar 20a. Therefore, compared to conventional capacitor modules, the capacitor module 1 reduces the cost, effort, and the like required to fix the insulating sheet 30 to the first bus bar 20a. Therefore, the capacitor module 1 makes it possible to realize a capacitor module that can suppress a decrease in manufacturing efficiency when fixing the insulating sheet 30 to the first bus bar 20a.

[0132] 1, the first protrusion (e.g., first protrusion 31aa) is preferably engaged with the first through hole (e.g., first through hole 21aa) at a position where it does not overlap with the second bus bar 20b. In other words, the first through hole and the first protrusion are preferably provided at a position where they do not overlap with the second bus bar 20b.

[0133] When the first protrusion is engaged in the first through hole at a position where it does not overlap the second bus bar 20b, a longer creepage distance is ensured between the first bus bar 20a and the second bus bar 20b compared to when the first protrusion is engaged in the first through hole at a position where it overlaps the second bus bar 20b, thereby more reliably preventing a short circuit between the first bus bar 20a and the second bus bar 20b.

[0134] In the capacitor module 1, it is sufficient that there is at least one position where the first protrusion is engaged with the first through hole. For example, in the capacitor module 1, the positions where the first protrusion is engaged with the first through hole may include at least one of the positions where the first protrusion 31aa is engaged with the first through hole 21aa, the positions where the first protrusion 31ab is engaged with the first through hole 21ab, and the positions where the first protrusion 31ac is engaged with the first through hole 21ac. Furthermore, in the capacitor module 1, the positions where the first protrusion is engaged with the first through hole may include at least one of the positions where the first protrusion 31aa is engaged with the first through hole 21aa, the positions where the first protrusion 31ab is engaged with the first through hole 21ab, and the positions where the first protrusion 31ac is engaged with the first through hole 21ac, and may further include at least one other engaging position. Alternatively, in the capacitor module 1, the points at which the first protrusion is engaged with the first through hole may not include the points at which the first protrusion 31aa is engaged with the first through hole 21aa, the points at which the first protrusion 31ab is engaged with the first through hole 21ab, and the points at which the first protrusion 31ac is engaged with the first through hole 21ac, but may include at least one other engaging point.

[0135] In the capacitor module 1, the insulating sheet 30 is preferably fixed to the second bus bar 20b in addition to the first bus bar 20a. An example of how the insulating sheet 30 is fixed to the second bus bar 20b will be described below.

[0136] As shown in Fig. 1, the second bus bar 20b is preferably provided with a second through hole 21ba. In the example shown in Fig. 1, the second through hole 21ba penetrates the second bus bar 20b in the third direction D3.

[0137] As shown in FIG. 1, the insulating sheet 30 preferably has a second protruding portion 31ba that protrudes toward the second bus bar 20b.

[0138] As shown in Fig. 1, the second protrusion 31ba is preferably tongue-shaped. Specifically, the second protrusion 31ba is preferably tongue-shaped and extends toward the second bus bar 20b. In the example shown in Fig. 1, the second protrusion 31ba is formed by bending a portion of the insulating sheet 30 toward the second bus bar 20b while separating it from the surrounding area to form the tongue shape.

[0139] As shown in Fig. 1, the second protrusion 31ba is preferably engaged with the second through-hole 21ba. In the example shown in Fig. 1, the tip side of the second protrusion 31ba passes through the second through-hole 21ba and is caught on the periphery of the second through-hole 21ba, thereby being engaged with the second through-hole 21ba.

[0140] 1, with the tip end side of the second protrusion 31ba passing through the second through hole 21ba, the first seat surface 30a side faces the second bus bar 20b side, and the second seat surface 30b side faces the opposite side from the second bus bar 20b. In the example shown in FIG. 1, with the tip end side of the second protrusion 31ba passing through the second through hole 21ba, the first seat surface 30a side is in contact with the periphery of the second through hole 21ba.

[0141] Note that the enlarged oblique view showing the area where the second protrusion 31ba is engaged with the second through hole 21ba and its cross-sectional view are omitted here, as they are similar to Figures 4 and 5 except that the object to which the insulating sheet 30 is fixed has changed from the first bus bar 20a to the second bus bar 20b.

[0142] The planar shape of the second through-hole 21ba is not particularly limited, and examples thereof include a rectangle such as a rectangle or a square, a circle, an ellipse, and a shape that is a combination of these.

[0143] The planar shape of the second through hole 21ba may be the same as the planar shape of the first through hole 21aa, the first through hole 21ab, and the first through hole 21ac, or may be different from the planar shape of the first through hole 21aa, the first through hole 21ab, and the first through hole 21ac.

[0144] The planar shape of the second protrusion 31ba is not particularly limited, and examples thereof include a rectangle such as a rectangle or a square, a semicircle, a semiellipse, and a combination thereof.

[0145] The planar shape of the second protrusion 31ba may be the same as the planar shape of the first protrusion 31aa, the first protrusion 31ab, and the first protrusion 31ac, or may be different from the planar shape of the first protrusion 31aa, the first protrusion 31ab, and the first protrusion 31ac.

[0146] As described above, in the capacitor module 1, it is preferable that the insulating sheet 30 is fixed to the second bus bar 20b by engaging the second protrusion (e.g., second protrusion 31ba) with the second through-hole (e.g., second through-hole 21ba). In this case, unlike conventional capacitor modules, the capacitor module 1 does not require the use of fixing members such as tape, adhesive, or a dedicated jig to fix the insulating sheet 30 to the second bus bar 20b. Therefore, compared to conventional capacitor modules, the capacitor module 1 reduces the cost, effort, and the like required to fix the insulating sheet 30 to the second bus bar 20b. Therefore, the capacitor module 1 can realize a capacitor module that can suppress a decrease in manufacturing efficiency when fixing the insulating sheet 30 to the second bus bar 20b.

[0147] 1, the second protrusion (e.g., second protrusion 31ba) is preferably engaged with the second through-hole (e.g., second through-hole 21ba) at a position where it does not overlap with the first bus bar 20a. In other words, the second through-hole and the second protrusion are preferably provided at a position where they do not overlap with the first bus bar 20a.

[0148] When the second protrusion is engaged in the second through hole at a position where it does not overlap the first bus bar 20a, a longer creepage distance is ensured between the first bus bar 20a and the second bus bar 20b compared to when the second protrusion is engaged in the second through hole at a position where it overlaps the first bus bar 20a, thereby more reliably preventing a short circuit between the first bus bar 20a and the second bus bar 20b.

[0149] In the capacitor module 1, it is preferable that there is at least one location where the second protrusion is engaged with the second through hole. For example, in the capacitor module 1, the location where the second protrusion is engaged with the second through hole may be only the location where the second protrusion 31ba is engaged with the second through hole 21ba. Alternatively, in the capacitor module 1, the location where the second protrusion is engaged with the second through hole may be the location where the second protrusion 31ba is engaged with the second through hole 21ba, and at least one other location may be present. Alternatively, in the capacitor module 1, the location where the second protrusion is engaged with the second through hole may not be the location where the second protrusion 31ba is engaged with the second through hole 21ba, but may be at least one other location.

[0150] Note that the capacitor module 1 does not necessarily have to have a location where the second protrusion is engaged with the second through-hole. That is, the capacitor module 1 does not necessarily have to have a second through-hole in the second bus bar 20b, and the insulating sheet 30 does not necessarily have to have a second protrusion.

[0151] The capacitor module 1 may further include an exterior case in which a plurality of capacitor elements 10 are housed.

[0152] The plurality of capacitor elements 10 are preferably housed inside the outer case so as to be spaced apart from the inner surface of the outer case.

[0153] The outer case may be, for example, a cylindrical case with a bottom and an opening. In this case, the outer case may be a cylindrical case with a bottom and an opening at one end in the third direction D3. Specifically, the outer case may have a bottom facing the opening in the third direction D3 and a sidewall extending from the bottom toward the opening in the third direction D3.

[0154] Examples of the exterior case include a resin case and a metal case.

[0155] When the exterior case 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.

[0156] 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.

[0157] The resin case preferably further contains an inorganic filler in addition to the liquid crystal polymer.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] The size of the inorganic filler is preferably 5 μm or more in diameter and 50 μm or more in length.

[0163] It is preferable that the inorganic filler be dispersed throughout the outer case without agglomerating.

[0164] 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.

[0165] 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.

[0166] The resin case is manufactured by a method such as injection molding.

[0167] When the exterior case 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.

[0168] The metal case is manufactured by a method such as impact molding.

[0169] The capacitor module 1 may further include a filling resin filled inside the exterior case so as to embed the plurality of capacitor elements 10. When the exterior case is filled with the filling resin in this manner, the plurality of capacitor elements 10 are held inside the exterior case.

[0170] When the plurality of capacitor elements 10 are housed inside the outer case so as to be spaced apart from the inner surface of the outer case, the filling resin is preferably filled between the plurality of capacitor elements 10 and the outer case, more specifically, between the outer surfaces of the plurality of capacitor elements 10 and the inner surface of the outer case. Furthermore, the filling resin is preferably filled inside the outer case not only between the plurality of capacitor elements 10 and the outer case, but also in the region from the opening of the outer case to the plurality of capacitor elements 10.

[0171] As the filling resin, it is preferable to appropriately select a resin with low moisture permeability from the viewpoint of suppressing the penetration of moisture into capacitor element 10, and examples thereof include epoxy resin, silicone resin, urethane resin, etc. Examples of the curing agent for the epoxy resin include an amine curing agent, an imidazole curing agent, etc.

[0172] The filler resin may be the above-mentioned resin alone, or may be a resin to which a reinforcing agent such as silica or alumina has been added for the purpose of improving strength.

[0173] From the viewpoint of preventing moisture from penetrating into capacitor elements 10, it is preferable that the thickness of the filling resin at the opening of the outer case be large. The thickness of the filling resin at the opening of the outer case is preferably sufficiently large within the allowable range for the volume (physical size) of the entire capacitor module 1, and specifically, is preferably 2 mm or more, and more preferably 4 mm or more. In particular, it is preferable that the thickness of the filling resin for the plurality of capacitor elements 10 be larger on the opening side of the outer case than on the bottom side by arranging the plurality of capacitor elements 10 closer to the bottom side than the opening side of the outer case inside the outer case.

[0174] The thickness of the filled resin 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 vernier caliper if it is in a destructive state.

[0175] The relationship between the height of the outer case and the height of the filled resin in the third direction D3 is such that the thickness of the filled resin at the opening of the outer case is as large as possible, and it may be up to a position inside the outer case, or it may be just about to the top, or it may overflow slightly due to surface tension.

[0176] It is preferable that a portion of each of the first bus bar 20a and the second bus bar 20b, particularly the portion of each of the first bus bar 20a and the second bus bar 20b opposite to the capacitor element 10, protrude from the filled resin.

[0177] In conventional capacitor modules, if the insulating sheet is not fixed to the bus bar or is not sufficiently fixed to the bus bar, when the capacitor element is housed inside the outer casing and then the interior of the outer casing is filled with a filling resin to embed the capacitor element, the insulating sheet may become misaligned with respect to the bus bar due to pressure from the filling resin. For example, in the manufacturing process of conventional capacitor modules, the insulating sheet may be temporarily fixed to the bus bar using a fixing member such as tape, adhesive, or a dedicated jig before filling the interior of the outer casing with a filling resin to embed the capacitor element. However, simply temporarily fixing the insulating sheet to the bus bar using the above-mentioned fixing member does not sufficiently fix the insulating sheet to the bus bar. Therefore, when filling the interior of the outer casing with a filling resin to embed the capacitor element, the insulating sheet may become misaligned with respect to the bus bar due to pressure from the filling resin.

[0178] In contrast, in the capacitor module 1, the first protrusions (e.g., first protrusions 31aa) are engaged with the first through-holes (e.g., first through-holes 21aa), thereby fixing the insulating sheet 30 to the first bus bar 20a. Furthermore, in the capacitor module 1, the leading ends of the first protrusions pass through the first through-holes and become caught on the peripheries of the first through-holes, thereby engaging the first protrusions with the first through-holes. This makes it difficult for the insulating sheet 30 to shift relative to the first bus bar 20a in a direction perpendicular to the direction in which the first protrusions extend, that is, in the example shown in FIG. 1 , in the first direction D1. Therefore, in the capacitor module 1, even if pressure is applied to the insulating sheet 30 from the filling resin when a plurality of capacitor elements 10 are housed inside the exterior case and the interior of the exterior case is filled with filling resin so as to embed the plurality of capacitor elements 10, the position of the insulating sheet 30 relative to the first bus bar 20a is difficult to shift, particularly in the first direction D1.

[0179] Similarly, in capacitor module 1, when the second protrusion (e.g., second protrusion 31ba) is engaged with the second through-hole (e.g., second through-hole 21ba), insulating sheet 30 is less likely to shift relative to second bus bar 20b in a direction perpendicular to the direction in which the second protrusion extends, that is, in the example shown in Fig. 1 . Therefore, in capacitor module 1, when a plurality of capacitor elements 10 are housed inside the exterior case and then a filling resin is filled inside the exterior case so as to embed the plurality of capacitor elements 10, even if pressure is applied to insulating sheet 30 from the filling resin, the position of insulating sheet 30 relative to second bus bar 20b is less likely to shift, particularly in first direction D1.

[0180] Second Embodiment In a capacitor module according to a second embodiment of the present invention, the first protrusion is tongue-shaped, similar to the capacitor module according to the first embodiment of the present invention.

[0181] In the capacitor module of the second embodiment of the present invention, unlike the capacitor module of the first embodiment of the present invention, the first protrusion is bent at its tip end.

[0182] Fig. 8 is a schematic perspective view showing an enlarged portion of an example of a capacitor module according to embodiment 2 of the present invention. Fig. 9 is a schematic cross-sectional view showing an example of a cross section along line d1-d2 of the capacitor module shown in Fig. 8.

[0183] The overall image of an example of the capacitor module according to the second embodiment of the present invention is the same as the example of the capacitor module according to the first embodiment of the present invention (see Fig. 1 ) described above, except for at least the shape of the first protrusion. In addition, Fig. 8 shows an enlarged view of the example of the capacitor module according to the second embodiment of the present invention at a position corresponding to Fig. 6 in the example of the capacitor module according to the first embodiment of the present invention.

[0184] 8 and 9, the tip side of the first protrusion 31ab is bent. In the example shown in Fig. 8 and 9, the tip side of the first protrusion 31ab is bent so that it passes through the first through hole 21ab and approaches the first bus bar 20a. This makes it easier for the tip side of the first protrusion 31ab to pass through the first through hole 21ab and get caught on the periphery of the first through hole 21ab.

[0185] As shown in Fig. 8, the first protrusion 31ab preferably has a wide portion 32ab at its tip end that is wider than the other portions of the first protrusion 31ab. In the example shown in Fig. 8, the wide portion 32ab located at the tip end of the first protrusion 31ab has a dimension in the first direction D1 that is larger than the other portions of the first protrusion 31ab.

[0186] As shown in Fig. 8, the wide portion 32ab of the first protrusion 31ab is preferably wider than the first through hole 21ab. In the example shown in Fig. 8, the wide portion 32ab of the first protrusion 31ab is larger in dimension in the first direction D1 than the first through hole 21ab. This makes it easier for the wide portion 32ab of the first protrusion 31ab to catch on the periphery of the first through hole 21ab when the tip side of the first protrusion 31ab passes through the first through hole 21ab. As a result, the first protrusion 31ab is more likely to be firmly locked in the first through hole 21ab.

[0187] [Embodiment 3] In a capacitor module according to embodiment 3 of the present invention, unlike the capacitor modules according to embodiments 1 and 2 of the present invention, the first protrusions are convex.

[0188] In the capacitor module of embodiment 3 of the present invention, the insulating sheet has a first sheet surface located on the first bus bar side and a second sheet surface located on the opposite side from the first bus bar, and the first sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion, and the second sheet surface of the insulating sheet is not convex toward the first bus bar side at the position of the first protrusion.

[0189] Fig. 10 is a schematic perspective view showing an enlarged portion of an example of a capacitor module according to embodiment 3 of the present invention. Fig. 11 is a schematic cross-sectional view showing an example of a cross section along line e1-e2 of the capacitor module shown in Fig. 10.

[0190] The overall image of an example of the capacitor module according to the third embodiment of the present invention is the same as the example of the capacitor module according to the first embodiment of the present invention (see Fig. 1 ) described above, except for at least the shape of the first protrusion. In addition, Fig. 10 shows an enlarged view of the example of the capacitor module according to the third embodiment of the present invention at a position corresponding to Fig. 6 in the example of the capacitor module according to the first embodiment of the present invention.

[0191] In the capacitor module 3 shown in Figures 10 and 11, the first protrusion 31ab has a convex shape. In the example shown in Figures 10 and 11, the first protrusion 31ab has a convex shape (e.g., a protrusion shape) that rises toward the first bus bar 20a. In the example shown in Figures 10 and 11, the first protrusion 31ab has a convex shape as follows.

[0192] 10 and 11 , the insulating sheet 30 has a first sheet surface 30a located on the first bus bar 20a side and a second sheet surface 30b located on the opposite side from the first bus bar 20a. In the example shown in Fig. 10 and 11 , the first sheet surface 30a and the second sheet surface 30b of the insulating sheet 30 face each other in the second direction D2.

[0193] As shown in FIG. 11, the first sheet surface 30a of the insulating sheet 30 is convex toward the first bus bar 20a at the position of the first protrusion 31ab.

[0194] 11, the second sheet surface 30b of the insulating sheet 30 is not convex toward the first bus bar 20a at the position of the first protrusion 31ab. In the example shown in FIG. 11, the second sheet surface 30b of the insulating sheet 30 is flat at the position of the first protrusion 31ab.

[0195] As described above, in the capacitor module 3, the first protrusion 31ab is configured to have a convex shape because the first sheet surface 30a and the second sheet surface 30b of the insulating sheet 30 have the above-described shapes at the position of the first protrusion 31ab. In the example shown in Fig. 11, the insulating sheet 30 is thicker at the position of the first protrusion 31ab than at other positions.

[0196] 11 , it is preferable that the first sheet surface 30a of the insulating sheet 30 protrudes at the position of the first protruding portion 31ab beyond the side of the first bus bar 20a opposite to the insulating sheet 30. In this case, the first protruding portion 31ab is more likely to be firmly locked into the first through hole 21ab.

[0197] As shown in FIG. 11, the insulating sheet 30 preferably has a thickness greater than that of the first bus bar 20a at the position of the first protruding portion 31ab.

[0198] 10 and 11, the first protrusion 31ab preferably contacts at least a portion of the inner wall surface of the first through hole 21ab. It is particularly preferable that the first protrusion 31ab contacts the entire inner wall surface of the first through hole 21ab. In these cases, the first protrusion 31ab is more likely to be firmly locked in the first through hole 21ab.

[0199] The first protrusion 31ab in the capacitor module 3 is formed by, for example, when the insulating sheet 30 is made of one layer, making the layer thicker at the position where the first protrusion 31ab is desired, or when the insulating sheet 30 is made of multiple layers, increasing the number of layers and making the layer thicker at the position where the first protrusion 31ab is desired.

[0200] [Fourth Embodiment] In a capacitor module according to a fourth embodiment of the present invention, the first protrusions are convex, similar to the capacitor module according to the third embodiment of the present invention.

[0201] In the capacitor module of embodiment 4 of the present invention, unlike the capacitor module of embodiment 3 of the present invention, the insulating sheet has a first sheet surface located on the first bus bar side and a second sheet surface located on the opposite side from the first bus bar, and the first sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion, and the second sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion.

[0202] Fig. 12 is a schematic perspective view showing an enlarged portion of an example of a capacitor module according to embodiment 4 of the present invention. Fig. 13 is a schematic cross-sectional view showing an example of a cross section along line f1-f2 of the capacitor module shown in Fig. 12.

[0203] The overall image of an example of the capacitor module according to embodiment 4 of the present invention is similar to the example of the capacitor module according to embodiment 1 of the present invention described above (see Fig. 1 ), except for at least the shape of the first protrusion. In addition, Fig. 12 shows an enlarged view of the example of the capacitor module according to embodiment 4 of the present invention at a position corresponding to Fig. 6 in the example of the capacitor module according to embodiment 1 of the present invention.

[0204] In the capacitor module 4 shown in Fig. 12 and Fig. 13, the first protrusion 31ab has a convex shape. In the example shown in Fig. 12 and Fig. 13, the first protrusion 31ab has a convex shape (e.g., an embossed shape) that protrudes toward the first bus bar 20a. In the example shown in Fig. 12 and Fig. 13, the first protrusion 31ab has a convex shape as follows.

[0205] 12 and 13, the insulating sheet 30 has a first sheet surface 30a located on the first bus bar 20a side and a second sheet surface 30b located on the opposite side from the first bus bar 20a. In the example shown in Fig. 12 and 13, the first sheet surface 30a and the second sheet surface 30b of the insulating sheet 30 face each other in the second direction D2.

[0206] As shown in FIG. 13, the first sheet surface 30a of the insulating sheet 30 is convex toward the first bus bar 20a at the position of the first protrusion 31ab.

[0207] As shown in FIG. 13, the second sheet surface 30b of the insulating sheet 30 is convex toward the first bus bar 20a at the position of the first protrusion 31ab.

[0208] As described above, in the capacitor module 4, the first protrusion 31ab is configured to have a convex shape because the first sheet surface 30a and the second sheet surface 30b of the insulating sheet 30 have the above-described shapes at the position of the first protrusion 31ab. In the example shown in Fig. 13, the insulating sheet 30 has the same thickness at the position of the first protrusion 31ab as at other positions.

[0209] 13, it is preferable that the first sheet surface 30a of the insulating sheet 30 protrudes at the position of the first protruding portion 31ab beyond the side of the first bus bar 20a opposite to the insulating sheet 30. In this case, the first protruding portion 31ab is more likely to be firmly locked into the first through hole 21ab.

[0210] 12 and 13, the first protrusion 31ab preferably contacts at least a portion of the inner wall surface of the first through hole 21ab. It is particularly preferable that the first protrusion 31ab contacts the entire inner wall surface of the first through hole 21ab. In these cases, the first protrusion 31ab is more likely to be firmly locked in the first through hole 21ab.

[0211] The first protrusions 31ab of the capacitor module 4 are formed by, for example, embossing the insulating sheet 30 or the like.

[0212] [Other embodiments] In the capacitor module of the present invention, embodiments 2 to 4 show a first protrusion shape different from that of embodiment 1, but when the insulating sheet has a second protrusion as in embodiment 1, the second protrusion may have a shape similar to that of embodiments 2 to 4 in addition to the shape of embodiment 1.

[0213] The capacitor module of the present invention is useful for power conversion devices such as motor drive inverters mounted on electric vehicles, for example.

[0214] The present specification discloses the following:

[0215] <1> A capacitor module comprising: a capacitor element having a base body, a first external electrode provided on a surface of the base body, and a second external electrode provided on the surface of the base body at a position spaced apart from the first external electrode; a first bus bar electrically connected to the first external electrode; a second bus bar electrically connected to the second external electrode; and an insulating sheet sandwiched between the first bus bar and the second bus bar and forming a laminated structure together with the first bus bar and the second bus bar, wherein the first bus bar has a first through hole, and the insulating sheet has a first protrusion protruding toward the first bus bar, and the first protrusion is engaged in the first through hole.

[0216] <2> The capacitor module according to <1>, wherein the first protrusion is tongue-shaped.

[0217] <3> The capacitor module according to <2>, wherein the first protrusion has a bent tip end.

[0218] <4> The capacitor module according to <2> or <3>, wherein the first protrusion has a wide portion on the tip side that is wider than other portions.

[0219] <5> The capacitor module according to <4>, wherein the wide portion of the first protrusion is wider than the first through hole.

[0220] <6> The capacitor module according to <1>, wherein the first protrusion is convex.

[0221] <7> The capacitor module according to <6>, wherein the insulating sheet has a first sheet surface located on the first bus bar side and a second sheet surface located on the opposite side from the first bus bar, the first sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion, and the second sheet surface of the insulating sheet is not convex toward the first bus bar side at the position of the first protrusion.

[0222] <8> The capacitor module according to <6>, wherein the insulating sheet has a first sheet surface located on the first bus bar side and a second sheet surface located on the opposite side from the first bus bar, the first sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion, and the second sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion.

[0223] <9> The capacitor module according to any one of <1> to <8>, wherein the first protrusion is engaged with the first through hole at a position where it does not overlap the second bus bar.

[0224] <10> The capacitor module according to any one of <1> to <9>, wherein the second bus bar is provided with a second through hole, the insulating sheet further has a second protruding portion protruding toward the second bus bar, and the second protruding portion is engaged with the second through hole.

[0225] 1, 2, 3, 4 Capacitor module 10 Capacitor element 11 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 20b Second bus bar 21aa, 21ab, 21ac First through hole 21ba Second through hole 30 Insulating sheet 30a First sheet surface of insulating sheet 30b Second sheet surface of insulating sheet 31aa, 31ab, 31ac First protrusion 31ba Second protrusion 32ab Wide portion of first protrusion D1 First direction D2 Second direction D3 Third direction

Claims

1. A capacitor module comprising: a capacitor element having a base body, a first external electrode provided on a surface of the base body, and a second external electrode provided on the surface of the base body at a position spaced from the first external electrode; a first bus bar electrically connected to the first external electrode; a second bus bar electrically connected to the second external electrode; and an insulating sheet sandwiched between the first bus bar and the second bus bar and forming a laminated structure together with the first bus bar and the second bus bar, wherein the first bus bar has a first through hole, and the insulating sheet has a first protrusion protruding toward the first bus bar, and the first protrusion is engaged with the first through hole.

2. The capacitor module according to claim 1, wherein the first protrusion is tongue-shaped.

3. The capacitor module according to claim 2, wherein the first protrusion has a bent tip end.

4. A capacitor module according to claim 2 or 3, wherein the first protrusion has a wide portion on the tip side that is wider than other portions.

5. The capacitor module according to claim 4, wherein the wide portion of the first protrusion is wider than the first through hole.

6. The capacitor module according to claim 1, wherein the first protrusion is convex.

7. The capacitor module described in claim 6, wherein the insulating sheet has a first sheet surface located on the first bus bar side and a second sheet surface located on the opposite side to the first bus bar, the first sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion, and the second sheet surface of the insulating sheet is not convex toward the first bus bar side at the position of the first protrusion.

8. The capacitor module described in claim 6, wherein the insulating sheet has a first sheet surface located on the first bus bar side and a second sheet surface located opposite the first bus bar, the first sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion, and the second sheet surface of the insulating sheet is convex toward the first bus bar side at the position of the first protrusion.

9. A capacitor module according to any one of claims 1 to 8, wherein the first protrusion is engaged with the first through hole at a position not overlapping with the second bus bar.

10. A capacitor module as described in any one of claims 1 to 9, wherein the second bus bar is provided with a second through hole, the insulating sheet further has a second protrusion protruding toward the second bus bar, and the second protrusion is engaged with the second through hole.

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