Capacitor module

Abstract

A capacitor module 1 comprises: a plurality of capacitor elements 10 each having an element body 11, a first external electrode 12a provided on one end surface of the element body 11, and a second external electrode 12b provided on the other end surface facing the one end surface of the element body 11 in a first direction D1; and a plurality of connection terminals 20 electrically connected to the plurality of capacitor elements 10. The plurality of capacitor elements 10 include a first capacitor element 10a and a second capacitor element 10b which are adjacent to each other in the first direction D1 so that the first external electrodes 12a having the same polarity face each other apart from each other. The plurality of connection terminals 20 include: a first main connection terminal 21a that is electrically connected to the first external electrode 12a of the first capacitor element 10a and the second capacitor element 10b at a position separated from the first capacitor element 10a and the second capacitor element 10b; a first sub connection terminal 22a that is electrically connected to the first main connection terminal 21a at one end side, and that is electrically connected to the first external electrode 12a of the first capacitor element 10a at the other end side; and a second sub connection terminal 22b that is electrically connected to the first main connection terminal 21a at one end side, and that is electrically connected to the first external electrode 12a of the second capacitor element 10b at the other end side. A first through hole 31a is provided at the first main connection terminal 21a. A dimension P1 of the first through hole 31a in the first direction D1 is smaller than the maximum distance Q1 in the first direction D1 between a surface 22aa on a side opposite to the second sub connection terminal 22b in the first sub connection terminal 22a and a surface 22ba on a side opposite to the first sub connection terminal 22a in the second sub connection terminal 22b, and the first sub connection terminal 22a and the second sub connection terminal 22b pass through the first through hole 31a in a state in which one end of each are in contact with each other and the other ends are separated from each other.

Description

Capacitor Module

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

[0002] Patent Document 1 discloses a capacitor module comprising: a plurality of capacitors each having a first electrode and a second electrode facing each other, and a side surface connecting the first electrode and the second electrode and having a pair of flat portions facing each other and a pair of curved portions connecting one of the flat portions to the other, the capacitors being arranged in a row so that the flat portions face each other; at least one metal plate arranged somewhere between the flat portions of each of the adjacent capacitors and in contact with the first electrode of at least one of the adjacent capacitors; a first bus bar electrically connected to the at least one metal plate; and a second bus bar electrically connected to each of the second electrodes, wherein the first electrodes of the plurality of capacitors are each electrically connected to the at least one metal plate.

[0003] Patent Document 2 discloses a capacitor comprising a capacitor element, a first electrode plate connected to one electrode portion of the capacitor element via a first lead terminal, and a second electrode plate connected to the other electrode portion of the capacitor element via a second lead terminal, the first and second electrode plates being superimposed with a sheet-like insulator interposed between them, and the second electrode plate being positioned between the first electrode plate and the capacitor element, the second electrode plate having an opening through which the first lead terminal is inserted, the first electrode plate having a recess that is recessed into the opening and is used for connection to the first lead terminal, and a through hole that partially separates the recess from the other portion, the insulator having a plurality of slits that extend outward from a portion facing the recess, and the insulator located between the slits is folded toward the second electrode plate and is interposed between the recess and the inner peripheral edge of the opening.

[0004] International Publication No. 2021 / 241320 Japanese Patent Application Laid-Open No. 2015-15380

[0005] In a capacitor module provided with a plurality of capacitor elements, a combination of a plurality of connection terminals may be used to electrically connect the capacitor elements to each other.

[0006] For example, the capacitor module described in Patent Document 1 uses a combination of a metal plate connected to a first electrode of a capacitor and a first bus bar connected to the metal plate to electrically connect capacitors to each other, as shown in Figure 2 and other figures of Patent Document 1. However, in the capacitor module described in Patent Document 1, as shown in Figure 2 and other figures of Patent Document 1, the metal plate extends from one end to the other end of the capacitor, which means that the current path from the first electrode of the capacitor through the metal plate to the first bus bar is long, and this tends to increase the equivalent series inductance (ESL).

[0007] On the other hand, the capacitor described in Patent Document 2 uses a combination of lead terminals connected to the electrode portions of the capacitor elements and electrode plates connected to the lead terminals in order to electrically connect the capacitor elements to each other, as shown in Figure 1 and other figures of Patent Document 2. In the capacitor described in Patent Document 2, as shown in Figure 1 and other figures of Patent Document 2, the current path from the electrode portions of the capacitor elements through the lead terminals to the electrode plates is short, and therefore it is thought that the equivalent series inductance is less likely to become large compared to the capacitor module described in Patent Document 1.

[0008] On the other hand, in the capacitor described in Patent Document 2, as shown in FIG. 1 and other figures of Patent Document 2, the lead terminals are connected to the electrode plate by passing them through connection holes in the electrode plate. However, in the capacitor described in Patent Document 2, if the sizes of the lead terminals and the connection holes do not match precisely, the connection between the lead terminals and the electrode plate will be insufficient. Furthermore, in the capacitor described in Patent Document 2, in order to connect the lead terminals to the electrode plate, not only the sizes but also the positions of the lead terminals and the connection holes must be precisely matched. For example, in the capacitor described in Patent Document 2, even if the sizes of the lead terminals and the connection holes are correct, if they are misaligned, the lead wires cannot be passed through the connection holes.

[0009] As described above, in the capacitor described in Patent Document 2, when the capacitor elements are electrically connected to each other by the lead terminals and the electrode plates, there is room for improvement in terms of easily realizing the electrical connection between the lead terminals and the electrode plates.

[0010] In the capacitor module described in Patent Document 1, the metal plate and the first bus bar are connected by passing the bus bar contact portion of the metal plate through the hole in the first bus bar. Therefore, as with the capacitor described in Patent Document 2, there is room for improvement in terms of easily realizing electrical connection between the metal plate and the first bus bar.

[0011] The present invention has been made to solve the above problems, and aims to provide a capacitor module in which, when capacitor elements are electrically connected to each other by a plurality of connection terminals, electrical connection between the connection terminals can be easily achieved.

[0012] The capacitor module of the present invention comprises an element body, a plurality of capacitor elements each having a first external electrode provided on one end surface of the element body and a second external electrode provided on the other end surface opposite the one end surface of the element body in a first direction, and a plurality of connection terminals electrically connected to the plurality of capacitor elements, the plurality of capacitor elements including a first capacitor element and a second capacitor element adjacent in the first direction such that the first external electrodes of the first capacitor element and the second capacitor element are spaced apart and face each other, and the plurality of connection terminals include a first main connection terminal electrically connected to the first external electrodes of the first capacitor element and the second capacitor element at a position spaced apart from the first capacitor element and the second capacitor element, and a second main connection terminal electrically connected to the first main connection terminal at one end side. the first sub-connection terminal is electrically connected to the first external electrode of the first capacitor element at its other end, and a second sub-connection terminal is electrically connected to the first main connection terminal at its one end and electrically connected to the first external electrode of the second capacitor element at its other end, wherein the first main connection terminal is provided with a first through hole, the dimension of the first through hole in the first direction is smaller than the maximum distance in the first direction between a surface of the first sub-connection terminal opposite to the second sub-connection terminal and a surface of the second sub-connection terminal opposite to the first sub-connection terminal, and the first sub-connection terminal and the second sub-connection terminal pass through the first through hole with their one ends in contact and their other ends spaced apart.

[0013] According to the present invention, it is possible to provide a capacitor module in which, when capacitor elements are electrically connected to each other by a plurality of connection terminals, the electrical connection between the connection terminals can be easily realized.

[0014] 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 the capacitor module shown in FIG. 1 in an exploded state. FIG. 3 is a schematic cross-sectional view showing an example of a cross-section of the capacitor module shown in FIG. 1 taken along line A1-A2. FIG. 4 is a schematic perspective view showing an example of a capacitor element shown in FIGS. 1, 2, and 3. FIG. 5 is a schematic cross-sectional view showing an example of a cross-section of the capacitor element shown in FIG. 4 taken along line B1-B2. FIG. 6 is a schematic cross-sectional view showing another example of a capacitor module according to the first embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing an example of a capacitor module according to a second embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing an example of a capacitor module according to a third embodiment of the present invention.

[0015] 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.

[0016] 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.

[0017] 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."

[0018] 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.

[0019] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0020] 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.

[0021] The capacitor module of the present invention comprises an element body, a plurality of capacitor elements each having a first external electrode provided on one end surface of the element body and a second external electrode provided on the other end surface opposite the one end surface of the element body in a first direction, and a plurality of connection terminals electrically connected to the plurality of capacitor elements, the plurality of capacitor elements including a first capacitor element and a second capacitor element adjacent in the first direction such that the first external electrodes of the first capacitor element and the second capacitor element are spaced apart and face each other, and the plurality of connection terminals include a first main connection terminal electrically connected to the first external electrodes of the first capacitor element and the second capacitor element at a position spaced apart from the first capacitor element and the second capacitor element, and a second main connection terminal electrically connected to the first main connection terminal at one end side. the first sub-connection terminal is electrically connected to the first external electrode of the first capacitor element at its other end, and a second sub-connection terminal is electrically connected to the first main connection terminal at its one end and electrically connected to the first external electrode of the second capacitor element at its other end, wherein the first main connection terminal is provided with a first through hole, the dimension of the first through hole in the first direction is smaller than the maximum distance in the first direction between a surface of the first sub-connection terminal opposite to the second sub-connection terminal and a surface of the second sub-connection terminal opposite to the first sub-connection terminal, and the first sub-connection terminal and the second sub-connection terminal pass through the first through hole with their one ends in contact and their other ends spaced apart.

[0022] [Embodiment 1] In the capacitor module of embodiment 1 of the present invention, when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal increases as one moves from one end to the other end.

[0023] 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 an exploded state of the capacitor module shown in Fig. 1. Fig. 3 is a schematic cross-sectional view showing an example of a cross-section of the capacitor module shown in Fig. 1 taken along line A1-A2.

[0024] The capacitor module 1 shown in FIGS. 1, 2, and 3 has a plurality of capacitor elements 10 and a plurality of connection terminals 20.

[0025] In FIG. 1 and other figures, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to one another.

[0026] Fig. 4 is a schematic perspective view showing an example of the capacitor element shown in Fig. 1, Fig. 2, and Fig. 3. Fig. 5 is a schematic cross-sectional view showing an example of a cross section of the capacitor element shown in Fig. 4 taken along line B1-B2.

[0027] The capacitor element 10 shown in FIGS. 4 and 5 has an element body 11, a first external electrode 12a, and a second external electrode 12b.

[0028] 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 second direction D2. In other words, capacitor element 10 is a wound-type film capacitor in which metallized films are wound in a stacked state.

[0029] The capacitor element 10 may be a laminated film capacitor (for example, rectangular parallelepiped) in which metallized films are laminated.

[0030] From the viewpoint of reducing the height of capacitor element 10, it is preferable that element body 11 has a flat cross-sectional shape when viewed in a cross section perpendicular to the winding axis direction (first direction D1 in FIGS. 4 and 5 ) of element body 11. Specifically, it is preferable that element body 11 be pressed into a flattened shape such as an ellipse or oval, and that the cross-sectional shape of element body 11 be a shape that is thinner than when the cross-sectional shape of element body 11 is a perfect circle.

[0031] 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.

[0032] 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.

[0033] First metallized film 13a includes first dielectric film 14a and first metal layer 15a.

[0034] The first dielectric film 14a has a first main surface 14aa and a second main surface 14ab facing each other in the second direction D2.

[0035] 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 first direction D1 but not to reach the other side edge of the first dielectric film 14a.

[0036] Second metallized film 13b includes second dielectric film 14b and second metal layer 15b.

[0037] The second dielectric film 14b has a first main surface 14ba and a second main surface 14bb that face each other in the second direction D2.

[0038] 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 first direction D1 but to reach the other side edge of the second dielectric film 14b.

[0039] In element body 11, adjacent first metallized films 13a and second metallized films 13b are offset in first direction D1 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 first direction D1 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.

[0040] In the element body 11, the adjacent first metallized films 13a and second metallized films 13b are misaligned in the first direction D1 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.

[0041] Since element body 11 is formed by winding first metallized film 13a and second metallized film 13b in a stacked state in second direction D2, 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 second direction D2. 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 second direction D2.

[0042] 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 second direction D2, and second main surface 14ab of first dielectric film 14a and first main surface 14ba of second dielectric film 14b face each other in second direction D2. Thus, in element body 11, first metallized film 13a and second metallized film 13b are wound in a stacked state in second direction D2. In other words, in element body 11, first metallized film 13a and second metallized film 13b are wound in a stacked state in second direction D2 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.

[0043] 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.

[0044] The second metal layer 15b may also be provided with a fuse portion, similar to the first metal layer 15a.

[0045] The first dielectric film 14a may contain a curable resin as a main component.

[0046] 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.

[0047] The curable resin may be a thermosetting resin or a photocurable resin.

[0048] 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.).

[0049] 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.

[0050] The presence of urethane bonds in the dielectric film can be confirmed by analysis with a Fourier transform infrared spectrophotometer (FT-IR).

[0051] 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.

[0052] The presence of hydroxyl groups and / or isocyanate groups in the dielectric film can be confirmed by FT-IR analysis.

[0053] Examples of the first organic material include phenoxy resin, polyvinyl acetoacetal resin, and polyvinyl butyral resin.

[0054] As the first organic material, a plurality of types of organic materials may be used in combination.

[0055] 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.

[0056] As the second organic material, a plurality of types of organic materials may be used in combination.

[0057] The first dielectric film 14a may contain a thermoplastic resin as a main component.

[0058] Examples of the thermoplastic resin include polypropylene resin, polyethersulfone resin, polyetherimide resin, and polyarylate resin.

[0059] The first dielectric film 14a may contain additives to impart various functions.

[0060] The additives include, for example, a leveling agent for imparting smoothness.

[0061] 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.

[0062] 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.

[0063] The first dielectric film 14a and the second dielectric film 14b may have different compositions, but preferably have the same composition.

[0064] 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.

[0065] 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.

[0066] The thickness of the dielectric film is measured using an optical film thickness gauge.

[0067] 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.

[0068] 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.

[0069] The first metal layer 15a and the second metal layer 15b may have different compositions, but preferably have the same composition.

[0070] 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.

[0071] 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.

[0072] The thickness of the metal layer is measured by observing a cross section of the metallized film along the second direction using a transmission electron microscope (TEM).

[0073] 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.

[0074] 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.

[0075] The first external electrode 12a is provided on one end surface of the element body 11. Specifically, 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.

[0076] The second external electrode 12b is provided on the other end face that faces in the first direction D1 from the one end face of the element body 11. Specifically, the second external electrode 12b is connected to the second metal layer 15b by contacting the end of the second metal layer 15b that is 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.

[0077] Examples of materials for the first external electrode 12a and the second external electrode 12b include metals such as zinc, aluminum, tin, and zinc-aluminum alloys.

[0078] The first external electrode 12a and the second external electrode 12b may have different compositions, but preferably have the same composition.

[0079] 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.

[0080] 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.

[0081] As shown in FIGS. 1 and 2, the plurality of capacitor elements 10 include a first capacitor element 10a and a second capacitor element 10b.

[0082] The first capacitor element 10a and the second capacitor element 10b are adjacent to each other in the first direction D1 such that the first external electrodes 12a having the same polarity (positive or negative) face each other at a distance.

[0083] The number of the plurality of capacitor elements 10 is not particularly limited as long as it is two or more including the first capacitor element 10a and the second capacitor element 10b.

[0084] The following describes a manner in which the plurality of connection terminals 20 are connected to the first capacitor element 10a and the second capacitor element 10b that are adjacent in the first direction D1 so that the first external electrodes 12a face each other at a distance.

[0085] The plurality of connection terminals 20 are electrically connected to the plurality of capacitor elements 10 .

[0086] The plurality of connection terminals 20 are used as terminals for electrically connecting the plurality of capacitor elements 10 to an object to be mounted, for example, when the capacitor module 1 is mounted on the object to be mounted.

[0087] As shown in FIGS. 1 and 2, the plurality of connection terminals 20 include a first main connection terminal 21a, a first sub-connection terminal 22a, and a second sub-connection terminal 22b.

[0088] The first main connection terminal 21a extends in the first direction D1.

[0089] The first main connection terminal 21a is electrically connected to the first external electrodes 12a of the first capacitor element 10a and the second capacitor element 10b at a position away from the first capacitor element 10a and the second capacitor element 10b (in Figure 1, a position away in the second direction D2).

[0090] The first main connection terminal 21a preferably has a plate-like shape, in which case the first main connection terminal 21a is also called a bus bar.

[0091] When viewed from the first direction D1, the first main connection terminal 21a may be L-shaped (or inverted L-shaped) as shown in Figures 1 and 2, with a portion extending in the second direction D2 and a portion extending in the third direction D3 connected at their tips, or it may have some other shape.

[0092] The first main connection terminal 21a is provided with a first through hole 31a. Specifically, the first through hole 31a penetrates the first main connection terminal 21a in the second direction D2.

[0093] The planar shape of the first through hole 31a when viewed from the second direction D2 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.

[0094] The cross-sectional shape of the first through hole 31a when viewed in a cross section along the second direction D2 is not particularly limited, and may be a shape in which the dimension P1 (see Figure 3) of the first through hole 31a in the first direction D1 is constant toward the first capacitor element 10a and the second capacitor element 10b, or a shape in which the dimension P1 of the first through hole 31a in the first direction D1 is not constant.

[0095] If the cross-sectional shape of the first through hole 31a when viewed along the second direction D2 is such that the dimension P1 of the first through hole 31a in the first direction D1 is not constant toward the first capacitor element 10a and the second capacitor element 10b, for example, the cross-sectional shape of the first through hole 31a when viewed along the second direction D2 may be such that the dimension P1 of the first through hole 31a in the first direction D1 becomes smaller as it approaches the first capacitor element 10a and the second capacitor element 10b, or may be such that the dimension P1 of the first through hole 31a in the first direction D1 becomes larger as it approaches the first capacitor element 10a and the second capacitor element 10b.

[0096] As shown in Figure 3, the dimension P1 of the first through hole 31a in the first direction D1 is smaller than the maximum distance Q1 in the first direction D1 between the surface 22aa of the first sub-connection terminal 22a opposite the second sub-connection terminal 22b and the surface 22ba of the second sub-connection terminal 22b opposite the first sub-connection terminal 22a.

[0097] Furthermore, if the cross-sectional shape of the first through hole 31a when viewed along the second direction D2 is such that the dimension P1 of the first through hole 31a in the first direction D1 is not constant toward the first capacitor element 10a and the second capacitor element 10b, it is preferable that the maximum value of the dimension P1 of the first through hole 31a in the first direction D1 is smaller than the maximum distance Q1 in the first direction D1 between the surface 22aa of the first sub-connection terminal 22a opposite the second sub-connection terminal 22b and the surface 22ba of the second sub-connection terminal 22b opposite the first sub-connection terminal 22a.

[0098] The dimension of the first through hole 31a in the third direction D3 is not particularly limited as long as it is larger than the dimensions of the first sub-connection terminal 22a and the second sub-connection terminal 22b in the third direction D3.

[0099] 3, the first sub-connection terminal 22a is electrically connected at one end to the first main connection terminal 21a and at the other end to the first external electrode 12a of the first capacitor element 10a. In other words, the first main connection terminal 21a is electrically connected to the first external electrode 12a of the first capacitor element 10a via the first sub-connection terminal 22a. In other words, the first main connection terminal 21a is located more electrically distant from the first external electrode 12a of the first capacitor element 10a than the first sub-connection terminal 22a.

[0100] It is preferable that one end of the first sub-connection terminal 22a contacts the first main connection terminal 21a.

[0101] The first sub-connection terminal 22a may be connected at one end to the first main connection terminal 21a via a joining member such as solder, or may be welded.

[0102] The first sub-connection terminal 22a preferably contacts the first outer electrode 12a of the first capacitor element 10a at the other end side.

[0103] The first sub-connection terminal 22a may be connected at the other end to the first external electrode 12a of the first capacitor element 10a via a joining member such as solder, or may be welded.

[0104] When connecting the first capacitor element 10a and the connection terminal 20, by making the connection terminal 20 a separate combination of the first main connection terminal 21a and the first sub-connection terminal 22a as described above, it becomes easier to connect the first capacitor element 10a and the connection terminal 20 compared to when the first main connection terminal 21a and the first sub-connection terminal 22a are not a separate combination.

[0105] 3, the second sub-connection terminal 22b is electrically connected at one end to the first main connection terminal 21a and at the other end to the first external electrode 12a of the second capacitor element 10b. In other words, the first main connection terminal 21a is electrically connected to the first external electrode 12a of the second capacitor element 10b via the second sub-connection terminal 22b. In other words, the first main connection terminal 21a is located more electrically distant from the first external electrode 12a of the second capacitor element 10b than the second sub-connection terminal 22b.

[0106] It is preferable that one end of the second sub-connection terminal 22b contacts the first main connection terminal 21a.

[0107] The second sub-connection terminal 22b may be connected at one end to the first main connection terminal 21a via a joining member such as solder, or may be welded.

[0108] The second sub-connection terminal 22b preferably contacts the first outer electrode 12a of the second capacitor element 10b at the other end side.

[0109] The second sub-connection terminal 22b may be connected at the other end to the first external electrode 12a of the second capacitor element 10b via a joining member such as solder, or may be welded.

[0110] When connecting the second capacitor element 10b and the connection terminal 20, by making the connection terminal 20 a separate combination of the first main connection terminal 21a and the second sub-connection terminal 22b as described above, it becomes easier to connect the second capacitor element 10b and the connection terminal 20 compared to when the first main connection terminal 21a and the second sub-connection terminal 22b are not a separate combination.

[0111] The first sub-connection terminal 22a and the second sub-connection terminal 22b are preferably shaped like a plate, in which case the first sub-connection terminal 22a and the second sub-connection terminal 22b are also called bus bars.

[0112] The first sub-connection terminal 22a and the second sub-connection terminal 22b may have a rod-like (linear) shape. In this case, the first sub-connection terminal 22a and the second sub-connection terminal 22b are also called lead terminals.

[0113] The thickness of the first sub-connection terminal 22a and the second sub-connection terminal 22b may be the same as or different from each other.

[0114] The dimensions of the first sub-connection terminal 22a and the second sub-connection terminal 22b in the extension direction may be the same as or different from each other.

[0115] Examples of materials for the first main connection terminal 21 a, the first sub-connection terminal 22 a, and the second sub-connection terminal 22 b 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 main connection terminal 21 a, the first sub-connection terminal 22 a, and the second sub-connection terminal 22 b. When the first main connection terminal 21 a, the first sub-connection terminal 22 a, and the second sub-connection terminal 22 b are made of 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).

[0116] The constituent materials of the first main connection terminal 21a, the first sub-connection terminal 22a, and the second sub-connection terminal 22b may be the same as or different from one another, or may be partially different from one another.

[0117] The thicknesses of the first main connection terminal 21a, the first sub-connection terminal 22a, and the second sub-connection terminal 22b may be the same as each other, may be different from each other, or may be partially different from each other.

[0118] 3, the first sub-connection terminal 22a and the second sub-connection terminal 22b pass through the first through hole 31a with one ends thereof in contact with each other and the other ends thereof spaced apart. With the first sub-connection terminal 22a and the second sub-connection terminal 22b passing through the first through hole 31a, one end of each of the first sub-connection terminals 22a and the second sub-connection terminals 22b is located on the opposite side of the first through hole 31a from the first capacitor element 10a and the second capacitor element 10b, and the other end of each of the first sub-connection terminals 22a and the second sub-connection terminals 22b is located on the first capacitor element 10a and the second capacitor element 10b side of the first through hole 31a.

[0119] In the capacitor module 1, the first sub-connection terminal 22a and the second sub-connection terminal 22b are in a state in which one end thereof is in contact with each other and the other end thereof is separated from each other, so that the first sub-connection terminal 22a and the second sub-connection terminal 22b can easily pass through the first through hole 31a on the one end side.

[0120] One end of the first sub-connection terminal 22a and one end of the second sub-connection terminal 22b may be joined by welding or the like, or may simply be in contact with each other without being joined.

[0121] As described above, in the capacitor module 1, the dimension P1 of the first through hole 31a in the first direction D1 is smaller than the maximum distance Q1 in the first direction D1 between the surface 22aa of the first sub-connection terminal 22a opposite the second sub-connection terminal 22b and the surface 22ba of the second sub-connection terminal 22b opposite the first sub-connection terminal 22a. Therefore, in the capacitor module 1, when the first sub-connection terminal 22a and the second sub-connection terminal 22b pass through the first through hole 31a, the first sub-connection terminal 22a and the second sub-connection terminal 22b are electrically connected to the first main connection terminal 21a, specifically, to the periphery of the first through hole 31a, at positions between one end and the other end, as shown in FIG. 3. Therefore, in the capacitor module 1, the first main connection terminal 21a can be electrically connected to the first sub-connection terminal 22a and the second sub-connection terminal 22b at a position away from the first capacitor element 10a and the second capacitor element 10b, as shown in FIG.

[0122] In the capacitor module 1, the first main connection terminal 21a is electrically connected to the first sub-connection terminal 22a and the second sub-connection terminal 22b, so that the first capacitor element 10a and the second capacitor element 10b are electrically connected via the first main connection terminal 21a, the first sub-connection terminal 22a, and the second sub-connection terminal 22b.

[0123] In the capacitor module 1, when the first main connection terminal 21a is electrically connected to the first sub-connection terminal 22a and the second sub-connection terminal 22b, as long as one end of each of the first sub-connection terminal 22a and the second sub-connection terminal 22b passes through the first through hole 31a, it is not necessary to strictly match the size of the first through hole 31a (e.g., the dimension in the first direction D1) with the size of the first sub-connection terminal 22a and the second sub-connection terminal 22b (e.g., the dimension in the first direction D1). Therefore, in the capacitor module 1, when processing to provide the first through hole 31a in the first main connection terminal 21a, restrictions on the size of the first through hole 31a are alleviated compared to conventional capacitor modules (e.g., the capacitor module described in Patent Document 1 and the capacitor described in Patent Document 2).

[0124] As described above, in the capacitor module 1, when the first capacitor element 10a and the second capacitor element 10b are electrically connected by the first main connection terminal 21a, the first sub-connection terminal 22a, and the second sub-connection terminal 22b, electrical connection of the first main connection terminal 21a, the first sub-connection terminal 22a, and the second sub-connection terminal 22b can be easily achieved.

[0125] Here, consider a conventional capacitor module in which two through holes are provided in the first main connection terminal, and the first sub-connection terminal and the second sub-connection terminal pass through the two through holes separately in a parallel state with a gap between them.

[0126] In conventional capacitor modules, when the distance between the first capacitor element and the second capacitor element is reduced, the distance between the first sub-connection terminal and the second sub-connection terminal is reduced, and therefore the distance between the through hole through which the first sub-connection terminal passes and the through hole through which the second sub-connection terminal passes is reduced. However, it is difficult to process the first main connection terminal to provide a through hole with a small distance. As such, in conventional capacitor modules, because it is difficult to process the first main connection terminal to provide a through hole with a small distance, there is a limit to how small the distance between the first capacitor element and the second capacitor element can be.

[0127] Furthermore, in conventional capacitor modules, for example, when forming through holes in the first main connection terminal, if the spacing between the through holes is too small, the through holes will connect to each other. In conventional capacitor modules, if the through holes in the first main connection terminal connect to each other, a through hole will exist in the gap between the first sub-connection terminal and the second sub-connection terminal, creating a path through the through hole from the side opposite the first and second capacitor elements to the first capacitor elements and the second capacitor elements. Therefore, in conventional capacitor modules, for example, when soldering the first main connection terminal to the first sub-connection terminal and the second sub-connection terminal on the side opposite the first and second capacitor elements, solder is likely to leak through the through hole to the first and second capacitor elements. Therefore, in conventional capacitor modules, various components are likely to be connected at undesired locations, such as when the main connection terminal and the first external electrode are connected via solder.

[0128] In contrast, in the capacitor module 1, it is sufficient to provide the first main connection terminal 21a with a single first through hole 31a through which the first sub-connection terminal 22a and the second sub-connection terminal 22b pass together, and there is no need to provide two through holes through which the first sub-connection terminal 22a and the second sub-connection terminal 22b pass separately. Therefore, in the capacitor module 1, the process of providing a through hole in the first main connection terminal 21a is simplified. Furthermore, in the capacitor module 1, even if an attempt is made to reduce the distance between the first capacitor element 10a and the second capacitor element 10b, there is no need to perform the difficult process of providing a through hole with a small distance in the first main connection terminal 21a. Therefore, in the capacitor module 1, it is possible to reduce the distance between the first capacitor element 10a and the second capacitor element 10b. In the capacitor module 1, even if the distance between the first capacitor element 10a and the second capacitor element 10b is small, the above-mentioned configuration makes it possible for the first main connection terminal 21a to be electrically connected to the first sub-connection terminal 22a and the second sub-connection terminal 22b.

[0129] Furthermore, in the capacitor module 1, the first sub-connection terminal 22a and the second sub-connection terminal 22b are electrically connected to the first main connection terminal 21a by passing through the first through hole 31a with one end of each terminal in contact with each other, so it is possible to prevent a path from passing through the first through hole 31a from the side opposite the first capacitor element 10a and the second capacitor element 10b toward the first capacitor element 10a and the second capacitor element 10b. Therefore, in the capacitor module 1, even if the first main connection terminal 21a is soldered to the first sub-connection terminal 22a and the second sub-connection terminal 22b on the side opposite the first capacitor element 10a and the second capacitor element 10b, for example, the solder is less likely to leak through the first through hole 31a toward the first capacitor element 10a and the second capacitor element 10b. Therefore, in the capacitor module 1, it is less likely that various components will be connected at locations other than the desired locations, for example, that the first main connection terminal 21a and the first external electrode 12a will be connected via solder rather than via the first sub-connection terminal 22a and the second sub-connection terminal 22b.

[0130] Furthermore, in the capacitor module 1, it is sufficient to provide the first main connection terminal 21a with a single first through hole 31a through which the first sub-connection terminal 22a and the second sub-connection terminal 22b pass together, and the size of the first through hole 31a (e.g., the dimension in the first direction D1) can be made small to the extent that one end of each of the first sub-connection terminal 22a and the second sub-connection terminal 22b passes through. In the capacitor module 1, if the size of the first through hole 31a is small, for example, less preheating is required when soldering the first main connection terminal 21a to the first sub-connection terminal 22a and the second sub-connection terminal 22b, and therefore damage caused by heat during soldering is less likely to extend to the multiple capacitor elements 10, particularly the first capacitor element 10a and the second capacitor element 10b.

[0131] Furthermore, in the capacitor module 1, the first capacitor element 10a and the second capacitor element 10b are adjacent to each other in the first direction D1 so that the first external electrodes 12a having the same polarity are spaced apart and facing each other. This also means that the current path from the first external electrodes 12a of the first capacitor element 10a and the second capacitor element 10b through the first sub-connection terminal 22a and the second sub-connection terminal 22b to the first main connection terminal 21a is short, making it difficult for the equivalent series inductance to become large.

[0132] The arrangement of the first sub-connection terminal 22 a and the second sub-connection terminal 22 b may be such that one ends are in contact with each other and the other ends are spaced apart, and therefore the arrangement of the first sub-connection terminal 22 a and the second sub-connection terminal 22 b does not include an arrangement in which the first sub-connection terminal 22 a and the second sub-connection terminal 22 b are in contact entirely from one end to the other end, or an arrangement in which the first sub-connection terminal 22 a and the second sub-connection terminal 22 b are spaced apart entirely from one end to the other end.

[0133] In the example shown in Figure 3, when the first sub-connection terminal 22a and the second sub-connection terminal 22b are viewed as a single unit, the distance in the first direction D1 between the first sub-connection terminal 22a and the second sub-connection terminal 22b increases as one moves from one end to the other end.

[0134] In the example shown in FIG. 3, the first sub-connection terminal 22a and the second sub-connection terminal 22b each extend linearly.

[0135] The first sub-connection terminal 22a and the second sub-connection terminal 22b may be arranged in a manner other than the example shown in FIG.

[0136] FIG. 6 is a cross-sectional view showing another example of the capacitor module according to the first embodiment of the present invention.

[0137] 6 shows a cross section taken at a position corresponding to that of FIG.

[0138] In the capacitor module 1' shown in Figure 6, as in the capacitor module 1 shown in Figure 3, when the first sub-connection terminal 22a and the second sub-connection terminal 22b are viewed as an integrated unit, the distance in the first direction D1 between the first sub-connection terminal 22a and the second sub-connection terminal 22b increases as one moves from one end to the other end.

[0139] In the example shown in FIG. 6, the first sub-connection terminal 22a and the second sub-connection terminal 22b each extend in a curved shape.

[0140] In the example shown in Figure 6, compared to the example shown in Figure 3, the first sub-connection terminal 22a and the second sub-connection terminal 22b are curved so as to move closer to each other in the first direction D1, but they may also be curved so as to move away from each other in the first direction D1.

[0141] 1 and 2, in the capacitor module 1, first capacitor elements 10a and second capacitor elements 10b may be arranged alternately in the first direction D1 as the multiple capacitor elements 10. In other words, in the capacitor module 1, a unit formed by arranging the first capacitor element 10a and the second capacitor element 10b in the first direction D1 may be used as a constituent unit, and multiple such units may be arranged in the first direction D1.

[0142] As shown in Figures 1 and 2, when the first capacitor elements 10a and the second capacitor elements 10b are arranged alternately in the first direction D1, the first capacitor elements 10a and the second capacitor elements 10b are adjacent to each other in the first direction D1 so that the second external electrodes 12b having the same polarity (different polarity from the first external electrodes 12a) face each other at a distance.

[0143] The following describes a manner in which the multiple connection terminals 20 are connected to the first capacitor element 10a and the second capacitor element 10b that are adjacent in the first direction D1 so that the second external electrodes 12b face each other at a distance from each other.

[0144] As shown in Figures 1 and 2, the multiple connection terminals 20 may further include, in addition to the first main connection terminal 21a, the first sub-connection terminal 22a, and the second sub-connection terminal 22b, a second main connection terminal 21b, a third sub-connection terminal 22c, and a fourth sub-connection terminal 22d.

[0145] 1 and 2, the second main connection terminal 21b extends in the first direction D1 so as to be parallel to the first main connection terminal 21a and spaced apart from the first main connection terminal 21a in the third direction D3.

[0146] The second main connection terminal 21b is electrically connected to the second external electrodes 12b of the first capacitor element 10a and the second capacitor element 10b at a position away from the first capacitor element 10a and the second capacitor element 10b (in Figure 1, a position away in the second direction D2).

[0147] When viewed from the first direction D1, the second main connection terminal 21b may be L-shaped (or inverted L-shaped) as shown in Figures 1 and 2, with a portion extending in the second direction D2 and a portion extending in the third direction D3 connected at their tips, or it may have some other shape.

[0148] When viewed from the first direction D1, the second main connection terminal 21b may have a shape that is line-symmetrical to the first main connection terminal 21a, as shown in Figures 1 and 2, or may have a shape that is not line-symmetrical to the first main connection terminal 21a.

[0149] In FIG. 2, the first main connection terminal 21a and the second main connection terminal 21b are shown separated in the third direction D3 compared to FIG. 1 so as to make the overall picture easier to understand.

[0150] The second main connection terminal 21b is provided with a second through hole 31b. Specifically, the second through hole 31b penetrates the second main connection terminal 21b in the second direction D2.

[0151] The dimension of the second through hole 31b in the first direction D1 is smaller than the maximum distance in the first direction D1 between the surface of the third sub-connection terminal 22c opposite the fourth sub-connection terminal 22d and the surface of the fourth sub-connection terminal 22d opposite the third sub-connection terminal 22c.

[0152] Furthermore, if the cross-sectional shape of the second through hole 31b when viewed along the second direction D2 is such that the dimension of the second through hole 31b in the first direction D1 is not constant toward the first capacitor element 10a and the second capacitor element 10b, it is preferable that the maximum value of the dimension of the second through hole 31b in the first direction D1 is smaller than the maximum distance in the first direction D1 between the surface of the third sub-connection terminal 22c opposite the fourth sub-connection terminal 22d and the surface of the fourth sub-connection terminal 22d opposite the third sub-connection terminal 22c.

[0153] The third sub-connection terminal 22c is electrically connected at one end to the second main connection terminal 21b and at the other end to the second external electrode 12b of the first capacitor element 10a. In other words, the second main connection terminal 21b is electrically connected to the second external electrode 12b of the first capacitor element 10a via the third sub-connection terminal 22c. In other words, the second main connection terminal 21b is located more electrically distant from the second external electrode 12b of the first capacitor element 10a than the third sub-connection terminal 22c.

[0154] The fourth sub-connection terminal 22d is electrically connected at one end to the second main connection terminal 21b and at the other end to the second external electrode 12b of the second capacitor element 10b. In other words, the second main connection terminal 21b is electrically connected to the second external electrode 12b of the second capacitor element 10b via the fourth sub-connection terminal 22d. In other words, the second main connection terminal 21b is located more electrically distant from the second external electrode 12b of the second capacitor element 10b than the fourth sub-connection terminal 22d is.

[0155] The third sub-connection terminal 22c and the fourth sub-connection terminal 22d pass through the second through hole 31b with one ends thereof in contact with each other and the other ends thereof spaced apart. With the third sub-connection terminal 22c and the fourth sub-connection terminal 22d passing through the second through hole 31b, one end of each of the third sub-connection terminal 22c and the fourth sub-connection terminal 22d is located on the opposite side of the second through hole 31b from the first capacitor element 10a and the second capacitor element 10b, and the other end of each of the third sub-connection terminal 22c and the fourth sub-connection terminal 22d is located on the first capacitor element 10a and the second capacitor element 10b side of the second through hole 31b.

[0156] In the capacitor module 1, the third sub-connection terminal 22c and the fourth sub-connection terminal 22d are in a state in which one ends are in contact with each other and the other ends are separated from each other, making it easier for the third sub-connection terminal 22c and the fourth sub-connection terminal 22d to pass through the second through hole 31b on the one end side.

[0157] As described above, in the capacitor module 1, the dimension of the second through hole 31b in the first direction D1 is smaller than the maximum distance in the first direction D1 between the surface of the third sub-connection terminal 22c opposite the fourth sub-connection terminal 22d and the surface of the fourth sub-connection terminal 22d opposite the third sub-connection terminal 22c. Therefore, in the capacitor module 1, when the third sub-connection terminal 22c and the fourth sub-connection terminal 22d pass through the second through hole 31b, the third sub-connection terminal 22c and the fourth sub-connection terminal 22d are electrically connected to the second main connection terminal 21b, specifically, to the periphery of the second through hole 31b, at positions between one end and the other end. Therefore, in the capacitor module 1, the second main connection terminal 21b can be electrically connected to the third sub-connection terminal 22c and the fourth sub-connection terminal 22d at a position away from the first capacitor element 10a and the second capacitor element 10b.

[0158] In the capacitor module 1, the second main connection terminal 21b is electrically connected to the third sub-connection terminal 22c and the fourth sub-connection terminal 22d, so that the first capacitor element 10a and the second capacitor element 10b are electrically connected via the second main connection terminal 21b, the third sub-connection terminal 22c, and the fourth sub-connection terminal 22d.

[0159] In the capacitor module 1, electrical connection between the first main connection terminal 21a, the first sub-connection terminal 22a, and the second sub-connection terminal 22b can be easily achieved, as can electrical connection between the second main connection terminal 21b, the third sub-connection terminal 22c, and the fourth sub-connection terminal 22d.

[0160] In the capacitor module 1, even if the distance between the first capacitor element 10a and the second capacitor element 10b is small, the second main connection terminal 21b can be electrically connected to the third sub-connection terminal 22c and the fourth sub-connection terminal 22d.

[0161] Furthermore, in the capacitor module 1, for example, even if the second main connection terminal 21b is soldered to the third sub-connection terminal 22c and the fourth sub-connection terminal 22d on the side opposite to the first capacitor element 10a and the second capacitor element 10b, the solder is less likely to leak through the second through-hole 31b toward the first capacitor element 10a and the second capacitor element 10b. Therefore, in the capacitor module 1, it is less likely that various components will be connected at locations other than the desired locations, for example, that the second main connection terminal 21b and the second external electrode 12b will be connected via solder instead of via the third sub-connection terminal 22c and the fourth sub-connection terminal 22d.

[0162] Furthermore, in the capacitor module 1, the size of the second through hole 31b (e.g., the dimension in the first direction D1) can be made small to the extent that one end side of each of the third sub-connection terminal 22c and the fourth sub-connection terminal 22d can pass through. In the capacitor module 1, if the size of the second through hole 31b is small, for example, less preheating is required when soldering the second main connection terminal 21b to the third sub-connection terminal 22c and the fourth sub-connection terminal 22d, and therefore damage caused by heat during soldering is less likely to extend to the multiple capacitor elements 10, particularly the first capacitor element 10a and the second capacitor element 10b.

[0163] Furthermore, in the capacitor module 1, the first capacitor element 10a and the second capacitor element 10b are adjacent to each other in the first direction D1 so that the second external electrodes 12b having the same polarity are spaced apart and facing each other. This also means that the current path from the second external electrodes 12b of the first capacitor element 10a and the second capacitor element 10b through the third sub-connection terminal 22c and the fourth sub-connection terminal 22d to the second main connection terminal 21b is short, making it difficult for the equivalent series inductance to become large.

[0164] Other features of the second main connection terminal 21b are similar to those of the first main connection terminal 21a.

[0165] Other features of the second through hole 31b are similar to those of the first through hole 31a.

[0166] Other features of the third sub-connection terminal 22c and the fourth sub-connection terminal 22d are similar to those of the first sub-connection terminal 22a and the second sub-connection terminal 22b.

[0167] The arrangement of the third sub-connection terminal 22c and the fourth sub-connection terminal 22d may be the same as that shown in FIG. 3 or FIG.

[0168] The capacitor module 1 may further include an exterior case in which a plurality of capacitor elements 10 are housed.

[0169] 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.

[0170] 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 second direction D2. Specifically, the outer case may have a bottom facing the opening in the second direction D2 and a sidewall extending from the bottom toward the opening in the second direction D2.

[0171] Examples of the exterior case include a resin case and a metal case.

[0172] 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.

[0173] 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.

[0174] The resin case preferably further contains an inorganic filler in addition to the liquid crystal polymer.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] The size of the inorganic filler is preferably 5 μm or more in diameter and 50 μm or more in length.

[0180] It is preferable that the inorganic filler be dispersed throughout the outer case without agglomerating.

[0181] 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.

[0182] 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.

[0183] The resin case is manufactured by a method such as injection molding.

[0184] 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.

[0185] The metal case is manufactured by a method such as impact molding.

[0186] In the capacitor module 1, one possible method for increasing the overall capacitance of the plurality of capacitor elements 10 is to arrange a large number of the plurality of capacitor elements 10. For example, when the plurality of capacitor elements 10 are housed inside an exterior case, one possible way to arrange a large number of the plurality of capacitor elements 10 within the interior space of the exterior case is to reduce the spacing between adjacent capacitor elements 10. In contrast, in the capacitor module 1, as described above, it is possible to reduce the spacing between adjacent capacitor elements 10, and therefore it is possible to increase the overall capacitance of the plurality of capacitor elements 10 even when the plurality of capacitor elements 10 are housed inside the exterior case.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] The relationship between the height of the outer case and the height of the filled resin in the second direction D2 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 on the inside of the outer case, or it may be just about to the top, or it may overflow slightly due to surface tension.

[0194] At least a portion of each of the first main connection terminal 21a and the second main connection terminal 21b may protrude from the filled resin.

[0195] At least a portion of each of the first sub-connection terminal 22a, the second sub-connection terminal 22b, the third sub-connection terminal 22c, and the fourth sub-connection terminal 22d may be embedded in the filling resin.

[0196] [Embodiment 2] In the capacitor module of embodiment 2 of the present invention, when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, there are, from one end to the other end, a first region where the surface of the first sub-connection terminal facing the second sub-connection terminal and the surface of the second sub-connection terminal facing the first sub-connection terminal are in contact, and a second region where the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal is constant.

[0197] In the capacitor module of the second embodiment of the present invention, when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, the first region and the second region are continuously connected.

[0198] Except for the above points, the capacitor module of the second embodiment of the present invention is similar to the capacitor module of the first embodiment of the present invention.

[0199] FIG. 7 is a cross-sectional view showing an example of a capacitor module according to a second embodiment of the present invention.

[0200] 7 shows a cross section taken at a position corresponding to that of FIG.

[0201] In the capacitor module 2 shown in Figure 7, when the first sub-connection terminal 22a and the second sub-connection terminal 22b are viewed as an integrated unit, a first region R1 and a second region R2 exist in that order from one end to the other end.

[0202] In the first region R1, a surface 22ab of the first sub-connection terminal 22a facing the second sub-connection terminal 22b and a surface 22bb of the second sub-connection terminal 22b facing the first sub-connection terminal 22a are in contact with each other.

[0203] In the second region R2, the distance between the first sub-connection terminal 22a and the second sub-connection terminal 22b in the first direction D1 is constant.

[0204] In the capacitor module 2, when the first sub-connection terminal 22a and the second sub-connection terminal 22b are viewed as an integrated unit, the first region R1 and the second region R2 are continuously connected.

[0205] When the first sub-connection terminal 22 a and the second sub-connection terminal 22 b are viewed as an integrated unit, the ratio of the dimension of each of the first region R1 and the second region R2 in the second direction D2 to the dimension of the entire region in the second direction D2 is not particularly limited. Specifically, the dimensions of the first region R1 and the second region R2 in the second direction D2 may be the same as or different from each other. When the dimensions of the first region R1 and the second region R2 in the second direction D2 are different from each other, the dimension of the first region R1 in the second direction D2 may be larger than or smaller than the dimension of the second region R2 in the second direction D2.

[0206] Figure 7 shows an example of the arrangement of the first sub-connection terminal 22a and the second sub-connection terminal 22b, but the arrangement of the third sub-connection terminal 22c and the fourth sub-connection terminal 22d (see Figure 1) may also be the same as Figure 7.

[0207] [Embodiment 3] In the capacitor module of embodiment 3 of the present invention, similar to the capacitor module of embodiment 2 of the present invention, when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, there are, in order from one end to the other end, a first region where the surface of the first sub-connection terminal facing the second sub-connection terminal and the surface of the second sub-connection terminal facing the first sub-connection terminal are in contact, and a second region where the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal is constant.

[0208] In the capacitor module of embodiment 3 of the present invention, unlike the capacitor module of embodiment 2 of the present invention, when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, a third region is further present that continuously connects the first region and the second region, in which the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal increases as the distance moves from the first region side toward the second region side.

[0209] FIG. 8 is a cross-sectional view showing an example of a capacitor module according to a third embodiment of the present invention.

[0210] 8 shows a cross section at a position corresponding to that in FIG.

[0211] In the capacitor module 3 shown in Figure 8, when the first sub-connection terminal 22a and the second sub-connection terminal 22b are viewed as an integrated unit, in addition to the first region R1 and the second region R2, a third region R3 also exists, continuously connecting the first region R1 and the second region R2.

[0212] In the third region R3, the distance in the first direction D1 between the first sub-connection terminal 22a and the second sub-connection terminal 22b increases from the first region R1 side toward the second region R2 side.

[0213] 8, the first sub-connection terminal 22a and the second sub-connection terminal 22b each extend linearly in the third region R3, but they may also extend curved. When the first sub-connection terminal 22a and the second sub-connection terminal 22b each extend curved in the third region R3, the first sub-connection terminal 22a and the second sub-connection terminal 22b may be curved so as to approach each other in the first direction D1, or so as to move away from each other in the first direction D1, compared to the example shown in FIG.

[0214] When the first sub-connection terminal 22a and the second sub-connection terminal 22b are viewed as an integrated unit, the ratio of the dimension of each of the first region R1, the second region R2, and the third region R3 in the second direction D2 to the dimension of the entire region in the second direction D2 is not particularly limited. Specifically, the dimensions of the first region R1, the second region R2, and the third region R3 in the second direction D2 may be the same as one another, may be different from one another, or may be partially different from one another. When the dimensions of the first region R1, the second region R2, and the third region R3 in the second direction D2 are different from one another or partially different from one another, the order of the magnitude relationship of the dimensions of each region in the second direction D2 is not particularly limited. For example, among the dimensions of the first region R1, the second region R2, and the third region R3 in the second direction D2, the dimension of the first region R1 in the second direction D2 may be the largest, the dimension of the second region R2 in the second direction D2 may be the largest, or the dimension of the third region R3 in the second direction D2 may be the largest. Also, among the dimensions of the first region R1, the second region R2, and the third region R3 in the second direction D2, the dimension of the first region R1 in the second direction D2 may be the smallest, the dimension of the second region R2 in the second direction D2 may be the smallest, or the dimension of the third region R3 in the second direction D2 may be the smallest.

[0215] In the example shown in Figure 8, the first main connection terminal 21a is electrically connected to the first sub-connection terminal 22a and the second sub-connection terminal 22b in the first region R1, but may also be electrically connected in the third region R3.

[0216] Figure 8 shows an example of the arrangement of the first sub-connection terminal 22a and the second sub-connection terminal 22b, but the arrangement of the third sub-connection terminal 22c and the fourth sub-connection terminal 22d (see Figure 1) may also be the same as Figure 8.

[0217] The capacitor module of the present invention is useful for power conversion devices such as motor drive inverters mounted on electric vehicles, for example.

[0218] The present specification discloses the following:

[0219] <1> A capacitor element includes an element body, a plurality of capacitor elements each having a first external electrode provided on one end surface of the element body and a second external electrode provided on another end surface opposing the one end surface of the element body in a first direction, and a plurality of connection terminals electrically connected to the plurality of capacitor elements, wherein the plurality of capacitor elements include a first capacitor element and a second capacitor element adjacent in the first direction such that the first external electrodes of the first capacitor element and the second capacitor element are spaced apart and face each other, and the plurality of connection terminals include a first main connection terminal electrically connected to the first external electrodes of the first capacitor element and the second capacitor element at a position spaced apart from the first capacitor element and the second capacitor element, a first sub-connection terminal electrically connected to the first main connection terminal at one end side and electrically connected to the first external electrode of the first capacitor element at the other end side, and a second sub-connection terminal electrically connected to the first main connection terminal at one end side and electrically connected to the first external electrode of the second capacitor element at the other end side, A capacitor module characterized in that the first main connection terminal has a first through hole, the dimension of the first through hole in the first direction is smaller than the maximum distance in the first direction between a surface of the first sub-connection terminal opposite the second sub-connection terminal and a surface of the second sub-connection terminal opposite the first sub-connection terminal, and the first sub-connection terminal and the second sub-connection terminal pass through the first through hole with their one ends in contact and their other ends spaced apart.

[0220] <2> A capacitor module described in <1>, wherein, when the first sub-connection terminal and the second sub-connection terminal are viewed as a single unit, the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal increases from the one end toward the other end.

[0221] <3> The capacitor module according to <2>, wherein the first sub-connection terminal and the second sub-connection terminal each extend linearly.

[0222] <4> The capacitor module according to <2>, wherein the first sub-connection terminal and the second sub-connection terminal each extend in a curved shape.

[0223] <5> A capacitor module described in <1>, in which, when the first sub-connection terminal and the second sub-connection terminal are viewed as a single unit, there are, in order from the one end to the other end, a first region where the surface of the first sub-connection terminal facing the second sub-connection terminal and the surface of the second sub-connection terminal facing the first sub-connection terminal are in contact, and a second region where the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal is constant.

[0224] <6> The capacitor module according to <5>, wherein when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, the first region and the second region are continuously connected.

[0225] <7> A capacitor module described in <5>, in which, when the first sub-connection terminal and the second sub-connection terminal are viewed as a single unit, a third region is further present so as to continuously connect the first region and the second region, in which the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal increases as the distance moves from the first region side toward the second region side.

[0226] 1, 1', 2, 3 Capacitor module 10 Capacitor element 10a First capacitor element 10b Second capacitor element 11 Element 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 20 Connection terminal 21a First main connection terminal 21b Second main connection terminal 22a First sub-connection terminal 22aa Surface of first sub-connection terminal opposite to second sub-connection terminal 22ab Surface of first sub-connection terminal on the second sub-connection terminal side 22b Second sub-connection terminal 22ba 22bb: Surface of the second sub-connecting terminal opposite to the first sub-connecting terminal 22c: Third sub-connecting terminal 22d: Fourth sub-connecting terminal 31a: First through hole 31b: Second through hole D1: First direction D2: Second direction D3: Third direction P1: Dimension of the first through hole in the first direction Q1: Maximum distance in the first direction between the surface of the first sub-connecting terminal opposite to the second sub-connecting terminal and the surface of the second sub-connecting terminal opposite to the first sub-connecting terminal R1: First region R2: Second region R3: Third region

Claims

1. A capacitor device comprising: an element body; a plurality of capacitor elements, each of which has a first external electrode provided on one end face of the element body and a second external electrode provided on the other end face opposing the one end face of the element body in a first direction; and a plurality of connection terminals electrically connected to the plurality of capacitor elements, wherein the plurality of capacitor elements include a first capacitor element and a second capacitor element adjacent to each other in the first direction such that the first external electrodes having the same polarity are spaced apart and facing each other, wherein the plurality of connection terminals include a first main connection terminal electrically connected to the first external electrodes of the first capacitor element and the second capacitor element at a position spaced apart from the first capacitor element and the second capacitor element, a first sub-connection terminal electrically connected to the first main connection terminal at one end side and electrically connected to the first external electrode of the first capacitor element at the other end side, and a second sub-connection terminal electrically connected to the first main connection terminal at one end side and electrically connected to the first external electrode of the second capacitor element at the other end side, wherein the first main connection terminal is provided with a first through hole, A capacitor module characterized in that a dimension of the first through hole in the first direction is smaller than a maximum distance in the first direction between a surface of the first sub-connecting terminal opposite the second sub-connecting terminal and a surface of the second sub-connecting terminal opposite the first sub-connecting terminal, and the first sub-connecting terminal and the second sub-connecting terminal pass through the first through hole with their one ends in contact with each other and their other ends separated from each other.

2. A capacitor module as described in claim 1, wherein when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal increases from the one end toward the other end.

3. The capacitor module according to claim 2, wherein the first sub-connection terminal and the second sub-connection terminal each extend linearly.

4. The capacitor module according to claim 2, wherein the first sub-connection terminal and the second sub-connection terminal each extend in a curved shape.

5. A capacitor module as described in claim 1, wherein when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, there are, in order from the one end toward the other end, a first region where a surface of the first sub-connection terminal facing the second sub-connection terminal and a surface of the second sub-connection terminal facing the first sub-connection terminal are in contact, and a second region in which the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal is constant.

6. The capacitor module according to claim 5, wherein, when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, the first region and the second region are continuously connected.

7. A capacitor module as described in claim 5, further comprising a third region in which, when the first sub-connection terminal and the second sub-connection terminal are viewed as an integrated unit, the distance in the first direction between the first sub-connection terminal and the second sub-connection terminal increases going from the first region side toward the second region side, the third region further existing so as to continuously connect between the first region and the second region.

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