Capacitor module and electric power conversion device

Abstract

A capacitor module 1 comprises: a first capacitor unit 10 that includes at least one film capacitor 11; a second capacitor unit 20 that includes a substrate 21 and at least one layered ceramic capacitor 22 mounted on the substrate 21; a first conductor 30 that is electrically connected to a positive-electrode side of the first capacitor unit 10 and a positive-electrode side of the second capacitor unit 20, the first conductor 30 having a first terminal 31 on the side opposite from the first capacitor unit 10 and the second capacitor unit 20; a second conductor 40 that is electrically connected to a negative-electrode side of the first capacitor unit 10 and a negative-electrode side of the second capacitor unit 20, the second conductor 40 having a second terminal 41 on the side opposite from the first capacitor unit 10 and the second capacitor unit 20; a case 50 inside of which the first capacitor unit 10 is housed so that the first terminal 31 and the second terminal 41 are led out to the outside; and a filling resin 60 that fills the interior of the case 50 so that the first capacitor unit 10 is buried. The positive-electrode side of the first capacitor unit 10 is electrically connected to the first conductor 30 by a first connection portion 32, the negative-electrode side of the first capacitor unit 10 is electrically connected to the second conductor 40 by a second connection portion 42, the positive-electrode side of the second capacitor unit 20 is electrically connected to the first conductor 30 at a position between the first terminal 31 and the first connection portion 32, the negative-electrode side of the second capacitor unit 20 is electrically connected to the second conductor 40 at a position between the second terminal 41 and the second connection portion 42, and at least the substrate 21 of the second capacitor unit 20 is immobilized by the filling resin 60.

Description

Capacitor module and power conversion device

[0001] The present invention relates to a capacitor module and a power conversion device.

[0002] Patent Document 1 discloses a capacitor including a first capacitor element having a first electrode and a second electrode, a second capacitor element having a third electrode and a fourth electrode, a first bus bar having a first terminal, a first coupling portion, a first connecting piece, and a second connecting piece, a second bus bar having a second terminal, a second coupling portion, a third connecting piece, and a fourth connecting piece, and a first insulating member interposed between the first coupling portion and the second coupling portion, wherein one side of the first terminal, the first connecting piece, and the second connecting piece are each connected to the first coupling portion, and the side of the first connecting piece opposite to the side connected to the first coupling portion is connected to the first electrode, and the side of the second connecting piece opposite to the side connected to the first coupling portion is connected to the third electrode, and the second terminal, the third connecting piece, and the fourth connecting piece are each connected to the second coupling portion, and the side of the third connecting piece connected to the second coupling portion is connected to the the other end of the fourth connecting piece is connected to the second electrode, and the other end of the fourth connecting piece opposite the side connected to the second connecting portion is connected to the fourth electrode; the first capacitor element and the second capacitor element are arranged in parallel via the first bus bar and the second bus bar; and the first connecting portion and the second connecting portion are formed so that the sum (L1+L3) of a first electrical path length (L1) from the first terminal to the first connecting piece and a third electrical path length (L3) from the third connecting piece to the second terminal is equal to the sum (L2+L4) of a second electrical path length (L2) from the first terminal to the second connecting piece and a fourth electrical path length (L4) from the fourth connecting piece to the second terminal is equal (L1+L3=L2+L4), thereby providing equal-length wiring for the first capacitor element and the second capacitor element, and distributing current equally.

[0003] Patent Document 2 discloses a capacitor module for an inverter, which includes a plurality of substrates having a plurality of ceramic capacitors mounted on their upper surfaces, first and second power supply lands made of a conductive film formed on both surfaces for supplying power to the plurality of ceramic capacitors, and the first and second power supply lands on both surfaces being electrically connected to each other, a conductive spacer inserted between the plurality of substrates and electrically connecting the upper and lower first power supply lands to each other or the second power supply lands to each other, a fixing means for fixing the plurality of substrates in a stacked state via the conductive spacer, and a switching module fixed below the lowest substrate of the plurality of stacked substrates, and the fixing means for fixing the plurality of substrates to the switching module as well.

[0004] JP 2022-2339 A JP 2001-351829 A

[0005] In a power conversion apparatus (power conversion circuit) such as an inverter that is configured with a power module incorporating a power device such as an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field effect transistor (MOSFET) and a capacitor, reducing the inductance component in the loop path between the power module and the capacitor leads to a reduction in switching loss, noise, and the like that occurs in the power device.

[0006] A capacitor module in which a capacitor element is electrically connected to a pair of conductors such as a bus bar or a lead wire is sometimes used as a capacitor for a power conversion device. In this case, it is possible to reduce the inductance component in the loop path between the power module and the capacitor module by reducing the inductance component between the terminals of the capacitor module, i.e., the inductance component between the terminals of the pair of conductors. In other words, in order to realize a power conversion device with reduced switching loss, noise, etc., it is important to reduce the inductance component between the terminals of the capacitor module.

[0007] In contrast, Patent Document 1 discloses a capacitor module having a configuration in which a plurality of film capacitors (first capacitor element 11 and second capacitor element 12 in FIG. 2 ) are connected to a pair of bus bars (first bus bar 31 and second bus bar 32 in FIG. 2 ), as shown in FIG. 2 and other figures. However, in the capacitor module described in Patent Document 1, the volume of the film capacitor is large, so the loop path between the terminals of the capacitor module, i.e., the loop path between the terminals of the pair of bus bars (the loop path between first terminal 31 a and second terminal 32 a in FIG. 2 ), becomes long. Therefore, the capacitor module described in Patent Document 1 has limitations in reducing the inductance component between the terminals of the capacitor module.

[0008] Furthermore, Patent Document 2 discloses a capacitor module configured as shown in FIGS. 1 and 2, in which a plurality of substrates (substrates 4, 5, and 6 in FIGS. 1 and 2) each mounted with a plurality of multilayer ceramic capacitors (multilayer capacitor 7 in FIG. 2) are stacked via conductive spacers (conductive spacers 21 and 22 in FIG. 1) and fixed to a power module (switching module 3 in FIG. 2) with bolts (bolts 8 and 9 in FIG. 2). The capacitor module disclosed in Patent Document 2 uses multilayer ceramic capacitors, which generally have a smaller volume than film capacitors. This may result in a shorter circuit path between the terminals of the capacitor module compared to the capacitor module disclosed in Patent Document 1. However, the capacitor module disclosed in Patent Document 2 requires the use of conductive spacers, bolts, etc. to fix the substrates on which the multilayer ceramic capacitors are mounted, which increases costs and labor. Therefore, the capacitor module disclosed in Patent Document 2 has limitations in improving manufacturing efficiency.

[0009] The present invention has been made to solve the above problems, and aims to provide a capacitor module that can reduce the inductance component between terminals and improve manufacturing efficiency. Another aim of the present invention is to provide a power conversion device that can reduce the inductance component in the loop path between the power module and the capacitor module.

[0010] The capacitor module of the present invention includes a first capacitor section including at least one film capacitor, a substrate, and a second capacitor section including at least one multilayer ceramic capacitor mounted on the substrate, a first conductor electrically connected to the positive electrode side of the first capacitor section and the positive electrode side of the second capacitor section and having a first terminal on the side opposite the first capacitor section and the second capacitor section, a second conductor electrically connected to the negative electrode side of the first capacitor section and the negative electrode side of the second capacitor section and having a second terminal on the side opposite the first capacitor section and the second capacitor section, and a first capacitor conductor connected to the first capacitor section so that the first terminal and the second terminal are drawn out to the outside. and a filled resin filled inside the case so that the first capacitor unit is embedded, wherein the positive electrode side of the first capacitor unit is electrically connected to the first conductor at a first connection portion, the negative electrode side of the first capacitor unit is electrically connected to the second conductor at a second connection portion, the positive electrode side of the second capacitor unit is electrically connected to the first conductor at a position between the first terminal and the first connection portion, and the negative electrode side of the second capacitor unit is electrically connected to the second conductor at a position between the second terminal and the second connection portion, and at least the substrate of the second capacitor unit is fixed by the filled resin.

[0011] The power conversion device of the present invention is characterized by comprising: the capacitor module of the present invention; and a power module electrically connected to the first terminal and the second terminal of the capacitor module.

[0012] According to the present invention, it is possible to provide a capacitor module that can reduce the inductance component between terminals and improve manufacturing efficiency, and also to provide a power conversion device that can reduce the inductance component in the loop path between the power module and the capacitor module.

[0013] FIG. 1 is a perspective view schematically illustrating an example of a capacitor module of the present invention. FIG. 2 is a perspective view schematically illustrating the capacitor module of FIG. 1 with the filling resin removed. FIG. 3 is a perspective view schematically illustrating the capacitor module of FIG. 1 with the filling resin and case removed. FIG. 4 is a plan view schematically illustrating the structure of FIG. 3 as viewed from a first direction. FIG. 5 is a side view schematically illustrating the structure of FIG. 3 as viewed from a second direction. FIG. 6 is a perspective view schematically illustrating a film capacitor constituting the first capacitor section of FIG. 3. FIG. 7 is a cross-sectional view schematically illustrating an example of a cross section of the film capacitor of FIG. 6 taken along line a1-a2. FIG. 8 is a perspective view schematically illustrating a portion of the second capacitor section of FIG. 3. FIG. 9 is a circuit diagram illustrating the circuit of the capacitor module of FIG. 1. FIG. 10 is a perspective view schematically illustrating another example of a capacitor module of the present invention. FIG. 11 is a perspective view schematically illustrating an example of a power conversion device of the present invention. FIG. 12 is a circuit diagram illustrating the circuit of the power conversion device of FIG. 11.

[0014] The capacitor module of the present invention and the power conversion device of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate without departing from the spirit of the present invention. Furthermore, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0015] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0016] 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.

[0017] [Capacitor Module] A capacitor module of the present invention includes a first capacitor section including at least one film capacitor, a substrate, and a second capacitor section including at least one multilayer ceramic capacitor mounted on the substrate, a first conductor electrically connected to the positive electrode side of the first capacitor section and the positive electrode side of the second capacitor section and having a first terminal on the side opposite to the first capacitor section and the second capacitor section, a second conductor electrically connected to the negative electrode side of the first capacitor section and the negative electrode side of the second capacitor section and having a second terminal on the side opposite to the first capacitor section and the second capacitor section, and a capacitor conductor connected to the first capacitor section so that the first terminal and the second terminal are drawn out to the outside. and a filled resin filled inside the case so that the first capacitor unit is embedded, wherein the positive electrode side of the first capacitor unit is electrically connected to the first conductor at a first connection portion, the negative electrode side of the first capacitor unit is electrically connected to the second conductor at a second connection portion, the positive electrode side of the second capacitor unit is electrically connected to the first conductor at a position between the first terminal and the first connection portion, and the negative electrode side of the second capacitor unit is electrically connected to the second conductor at a position between the second terminal and the second connection portion, and at least the substrate of the second capacitor unit is fixed by the filled resin.

[0018] In the capacitor module of the present invention, the positive electrode side of the first capacitor unit is electrically connected to the first conductor at the first connection portion, and the negative electrode side of the first capacitor unit is electrically connected to the second conductor at the second connection portion. Furthermore, in the capacitor module of the present invention, the positive electrode side of the second capacitor unit is electrically connected to the first conductor at a position between the first terminal and the first connection portion, and the negative electrode side of the second capacitor unit is electrically connected to the second conductor at a position between the second terminal and the second connection portion. As described above, in the capacitor module of the present invention, the positive electrode side of the first capacitor unit and the positive electrode side of the second capacitor unit are electrically connected to the first conductor in order toward the first terminal, and the negative electrode side of the first capacitor unit and the negative electrode side of the second capacitor unit are electrically connected to the second conductor in order toward the second terminal. In other words, in the capacitor module of the present invention, the second capacitor unit is connected in parallel with the first capacitor unit at positions on the first terminal and second terminal sides of the first capacitor unit. Therefore, in the capacitor module of the present invention, the loop path between the terminals of the capacitor module, i.e., the loop path between the first terminal and the second terminal, is shortened via the second capacitor section, specifically, a multilayer ceramic capacitor, which generally has a smaller volume than a film capacitor. Therefore, in the capacitor module of the present invention, it is possible to reduce the inductance component between the terminals of the capacitor module, i.e., the inductance component between the first terminal and the second terminal.

[0019] Furthermore, in the capacitor module of the present invention, at least the substrate of the second capacitor section is fixed with a filling resin. Thus, in the capacitor module of the present invention, the filling resin is used not only to embed the first capacitor section but also to secure the second capacitor section. In other words, when manufacturing the capacitor module of the present invention, the filling resin used to embed the first capacitor section is used to secure the second capacitor section. This eliminates the need for special components such as conductive spacers and bolts, as in the capacitor module described in Patent Document 2, thereby reducing costs and labor. Therefore, the capacitor module of the present invention can improve manufacturing efficiency when securing the second capacitor section.

[0020] As described above, the capacitor module of the present invention can reduce the inductance component between terminals and improve manufacturing efficiency.

[0021] A specific example of the capacitor module of the present invention will be described below.

[0022] Fig. 1 is a perspective view schematically showing an example of a capacitor module of the present invention. Fig. 2 is a perspective view schematically showing the capacitor module in Fig. 1 with the filling resin removed. Fig. 3 is a perspective view schematically showing the capacitor module in Fig. 1 with the filling resin and case removed. Fig. 4 is a plan view schematically showing the structure in Fig. 3 as viewed from a first direction. Fig. 5 is a side view schematically showing the structure in Fig. 3 as viewed from a second direction.

[0023] As shown in Figures 1, 2, 3, 4, and 5, the capacitor module 1 has a first capacitor section 10, a second capacitor section 20, a first conductor 30, a second conductor 40, a case 50, and a filling resin 60.

[0024] In FIG. 1 and other figures, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to one another.

[0025] Each component of the capacitor module 1 will be described below.

[0026] <First Capacitor Section> The first capacitor section 10 includes at least one film capacitor 11 .

[0027] There is no particular limitation on the number of film capacitors 11 in the first capacitor section 10. In other words, the first capacitor section 10 is required to include at least one film capacitor 11, and specifically, the first capacitor section 10 may include one film capacitor 11 or may include multiple film capacitors 11 as shown in FIG.

[0028] When the first capacitor section 10 includes a plurality of film capacitors 11, the configurations of the plurality of film capacitors 11 may be the same as each other, may be different from each other, or may be partially different from each other.

[0029] When the first capacitor section 10 includes a plurality of film capacitors 11, there is no particular limitation on the arrangement of the plurality of film capacitors 11 when housed inside the case 50 described below. For example, the plurality of film capacitors 11 may be arranged in a single row or in multiple rows when housed inside the case 50 described below. When the plurality of film capacitors 11 are arranged in multiple rows, the plurality of film capacitors 11 may be arranged in multiple rows in one direction or in multiple directions.

[0030] Fig. 6 is a perspective view schematically showing a film capacitor constituting the first capacitor portion in Fig. 3. Fig. 7 is a cross-sectional view schematically showing an example of a cross section of the film capacitor taken along line a1-a2 in Fig. 6.

[0031] As shown in FIGS. 6 and 7, the film capacitor 11 has an element body 12, a first external electrode 13a, and a second external electrode 13b.

[0032] Body 12 is a wound body formed by winding first metallized film 14 a and second metallized film 14 b in a stacked state in third direction D3. That is, film capacitor 11 is a wound-type film capacitor formed by winding metallized films in a stacked state.

[0033] The film capacitor 11 may be a laminated film capacitor (for example, rectangular parallelepiped) formed by laminating metallized films.

[0034] The element body 12 has a first end face 12a and a second end face 12b facing each other in the first direction D1.

[0035] The element body 12 further has a side surface 12c extending in the first direction D1 so as to connect the peripheries of the first end surface 12a and the second end surface 12b.

[0036] From the viewpoint of achieving a low profile, it is preferable that film capacitor 11 have a flat cross-sectional shape when viewed in a cross section perpendicular to the winding axis direction (first direction D1 in FIGS. 6 and 7 ) of element body 12. Specifically, it is preferable that element body 12 be pressed into a flat shape such as an ellipse or oval, and that the cross-sectional shape of element body 12 be a shape that is thinner than when the cross-sectional shape of element body 12 is a perfect circle.

[0037] Whether or not the element body 12 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 12 .

[0038] Film capacitor 11 may have a cylindrical winding shaft that is disposed on the central axis of first metallized film 14 a and second metallized film 14 b in a wound state and serves as the winding shaft when winding first metallized film 14 a and second metallized film 14 b.

[0039] First metallized film 14a includes first dielectric film 15a and first metal layer 16a.

[0040] The first dielectric film 15a has a first main surface 15aa and a second main surface 15ab facing each other in the third direction D3.

[0041] The first metal layer 16a is provided on the first main surface 15aa of the first dielectric film 15a. Specifically, the first metal layer 16a is provided on the first main surface 15aa of the first dielectric film 15a so as to reach one side edge of the first dielectric film 15a in the first direction D1 but not to reach the other side edge of the first dielectric film 15a.

[0042] Second metallized film 14b includes second dielectric film 15b and second metal layer 16b.

[0043] The second dielectric film 15b has a first main surface 15ba and a second main surface 15bb facing each other in the third direction D3.

[0044] The second metal layer 16b is provided on the first main surface 15ba of the second dielectric film 15b. Specifically, the second metal layer 16b is provided on the first main surface 15ba of the second dielectric film 15b so as not to reach one side edge of the second dielectric film 15b in the first direction D1 but to reach the other side edge of the second dielectric film 15b.

[0045] In the element body 12, adjacent first metallized films 14a and second metallized films 14b are offset in the first direction D1 so that the end of the first metal layer 16a that reaches the side edge of the first dielectric film 15a is exposed at the first end face 12a of the element body 12, and the end of the second metal layer 16b that reaches the side edge of the second dielectric film 15b is exposed at the second end face 12b of the element body 12. That is, in adjacent first metallized films 14a and second metallized films 14b, the first metallized film 14a protrudes toward the first external electrode 13a relative to the second metallized film 14b. Also, in adjacent first metallized films 14a and second metallized films 14b, the second metallized film 14b protrudes toward the second external electrode 13b relative to the first metallized film 14a. In this state, the first metal layer 16a is connected to the first external electrode 13a but is not connected to the second external electrode 13b, and the second metal layer 16b is connected to the second external electrode 13b but is not connected to the first external electrode 13a.

[0046] In the element body 12, the adjacent first metallized films 14a and second metallized films 14b are misaligned in the first direction D1 as described above, so that, among the adjacent first dielectric films 15a and second dielectric films 15b, the first dielectric film 15a having the first metal layer 16a on its first main surface 15aa protrudes toward the first external electrode 13a relative to the second dielectric film 15b having the first metal layer 16a not provided on its main surface. Furthermore, among the adjacent first dielectric films 15a and second dielectric films 15b, the second dielectric film 15b having the second metal layer 16b on its first main surface 15ba protrudes toward the second external electrode 13b relative to the first dielectric film 15a having the second metal layer 16b not provided on its main surface.

[0047] Since element body 12 is formed by winding first metallized film 14a and second metallized film 14b in a stacked state in third direction D3, it can be said that element body 12 includes first dielectric film 15a, first metal layer 16a, second dielectric film 15b, and second metal layer 16b in this order in third direction D3. It can also be said that element body 12 is a wound body formed by winding first dielectric film 15a, first metal layer 16a, second dielectric film 15b, and second metal layer 16b in this order in third direction D3.

[0048] In element body 12, first main surface 15aa of first dielectric film 15a and second main surface 15bb of second dielectric film 15b face each other in third direction D3, and second main surface 15ab of first dielectric film 15a and first main surface 15ba of second dielectric film 15b face each other in third direction D3. Thus, in element body 12, first metallized film 14a and second metallized film 14b are wound in a stacked state in third direction D3. In other words, in element body 12, first metallized film 14a and second metallized film 14b are wound in a stacked state in third direction D3 so that second metallized film 14b is on the inside of first metallized film 14a, specifically, so that first metal layer 16a is on the inside of first dielectric film 15a and second metal layer 16b is on the inside of second dielectric film 15b. That is, in the element body 12, the first metal layer 16a and the second metal layer 16b face each other with the first dielectric film 15a or the second dielectric film 15b sandwiched therebetween.

[0049] The first metal layer 16a may be provided with a fuse portion. The fuse portion provided in the first metal layer 16a is, for example, a portion that connects a divided electrode portion formed by dividing a portion of the first metal layer 16a that faces the second metal layer 16b into multiple portions with an electrode portion that does not face the second metal layer 16b. Examples of electrode patterns of the first metal layer 16a that are provided with a fuse portion include the electrode patterns disclosed in Japanese Patent Laid-Open Nos. 2004-363431 and 5-251266.

[0050] The second metal layer 16b may also be provided with a fuse portion, similar to the first metal layer 16a.

[0051] The first dielectric film 15a may contain a curable resin as a main component.

[0052] 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.

[0053] The curable resin may be a thermosetting resin or a photocurable resin.

[0054] 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.).

[0055] 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.

[0056] The presence of urethane bonds in the dielectric film can be confirmed by analysis using a Fourier transform infrared spectroscopy (FT-IR).

[0057] When the curable resin is obtained by the above-described reaction, uncured portions of the starting material may remain in the first dielectric film 15a. For example, the first dielectric film 15a may contain at least one of a hydroxyl group and an isocyanate group. In this case, the first dielectric film 15a may contain either a hydroxyl group or an isocyanate group, or may contain both a hydroxyl group and an isocyanate group.

[0058] The presence of hydroxyl groups and / or isocyanate groups in the dielectric film can be confirmed by analysis with a Fourier transform infrared spectrophotometer (FT-IR).

[0059] Examples of the first organic material include phenoxy resin, polyvinyl acetoacetal resin, and polyvinyl butyral resin.

[0060] As the first organic material, a plurality of types of organic materials may be used in combination.

[0061] 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.

[0062] As the second organic material, a plurality of types of organic materials may be used in combination.

[0063] The first dielectric film 15a may contain a thermoplastic resin as a main component.

[0064] Examples of the thermoplastic resin include polypropylene resin, polyethersulfone resin, polyetherimide resin, and polyarylate resin.

[0065] The first dielectric film 15a may further contain additives to impart various functions.

[0066] The additives include, for example, a leveling agent for imparting smoothness.

[0067] 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.

[0068] Like the first dielectric film 15a, the second dielectric film 15b 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 15a, the second dielectric film 15b may further contain an additive.

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

[0070] The thickness of the first dielectric film 15a and the second dielectric film 15b is preferably 1 μm or more and 10 μm or less, and more preferably 3 μm or more and 5 μm or less.

[0071] The thicknesses of the first dielectric film 15a and the second dielectric film 15b may be different from each other, but are preferably the same.

[0072] The thickness of the dielectric film is measured using an optical film thickness gauge.

[0073] The first dielectric film 15a and the second dielectric film 15b 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.

[0074] Examples of materials that can be used to form the first metal layer 16a and the second metal layer 16b include metals such as aluminum, zinc, titanium, magnesium, tin, and nickel.

[0075] The first metal layer 16a and the second metal layer 16b may have different compositions, but preferably have the same composition.

[0076] The thickness of the first metal layer 16a and the second metal layer 16b is preferably 5 nm or more and 40 nm or less.

[0077] The thickness of the first metal layer 16a and the second metal layer 16b may be different from each other, but it is preferable that they are the same.

[0078] The thickness of the metal layer is measured by observing a cross section of the metallized film taken along the third direction using a transmission electron microscope (TEM).

[0079] The first metal layer 16a and the second metal layer 16b are preferably formed by depositing the metals described above on the major surfaces of the first dielectric film 15a and the second dielectric film 15b, respectively.

[0080] Although the above describes an embodiment in which element body 12 includes two metallized films, element body 12 may also include a single metallized film. For example, element body 12 may include a metallized film having first dielectric film 15a with first metal layer 16a provided on first main surface 15aa and second metal layer 16b provided on second main surface 15ab, and second dielectric film 15b with no metal layer. Alternatively, element body 12 may include a metallized film having second dielectric film 15b with first metal layer 16a provided on second main surface 15bb and second metal layer 16b provided on first main surface 15ba, and first dielectric film 15a with no metal layer.

[0081] The first external electrode 13a is provided on the surface of the element body 12. In the example shown in Figures 6 and 7, the first external electrode 13a is provided on the first end surface 12a of the element body 12. The first external electrode 13a is connected to the first metal layer 16a by contacting the end of the first metal layer 16a exposed at the first end surface 12a of the element body 12. On the other hand, the first external electrode 13a is not connected to the second metal layer 16b.

[0082] The second external electrode 13b is provided at a position spaced apart from the first external electrode 13a on the surface of the element body 12. In the example shown in Figures 6 and 7, the second external electrode 13b is provided on the second end surface 12b of the element body 12. The second external electrode 13b is connected to the second metal layer 16b by contacting the end of the second metal layer 16b exposed at the second end surface 12b of the element body 12. On the other hand, the second external electrode 13b is not connected to the first metal layer 16a.

[0083] The first external electrode 13a and the second external electrode 13b have different polarities. For example, the first external electrode 13a is a positive electrode (P electrode) and the second external electrode 13b is a negative electrode (N electrode). In this case, the first external electrode 13a constitutes the positive electrode of the first capacitor section 10, and the second external electrode 13b constitutes the negative electrode of the first capacitor section 10.

[0084] Examples of materials for the first external electrode 13a and the second external electrode 13b include metals such as zinc, aluminum, tin, and zinc-aluminum alloys.

[0085] The first external electrode 13a and the second external electrode 13b may have different compositions, but preferably have the same composition.

[0086] The first external electrode 13a and the second external electrode 13b are preferably formed by spraying the above-mentioned metal onto the first end surface 12a and the second end surface 12b of the element body 12, respectively.

[0087] The above configuration is merely an example of the film capacitor 11. In other words, the film capacitor 11 is not limited to the above configuration.

[0088] <Second Capacitor Section> The second capacitor section 20 includes a substrate 21 and at least one multilayer ceramic capacitor 22 mounted on the substrate 21 .

[0089] FIG. 8 is a perspective view schematically showing a part of the second capacitor portion in FIG.

[0090] The substrate 21 has a first main surface 21 a and a second main surface 21 b that face each other in the first direction D1. Specifically, of the two main surfaces of the substrate 21, the first main surface 21 a of the substrate 21 is on the film capacitor 11 side, and the second main surface 21 b of the substrate 21 is on the multilayer ceramic capacitor 22 side.

[0091] The substrate 21 is, for example, a printed wiring board (PWB) on which wiring is provided. In this case, the second capacitor section 20 in a state in which at least one multilayer ceramic capacitor 22 is mounted on the substrate 21 becomes a printed circuit board (PCB).

[0092] The substrate 21 may be a substrate on which no wiring is provided.

[0093] The multilayer ceramic capacitor 22 has an element portion 23, a first external terminal 26a, and a second external terminal 26b.

[0094] The element portion 23 has an element body 24, a first external electrode 25a, and a second external electrode 25b.

[0095] The element body 24 is formed by alternately stacking dielectric ceramic layers (not shown) and internal electrode layers (not shown) in the first direction D1.

[0096] The dielectric ceramic layers extend along a second direction D2 and a third direction D3.

[0097] The dielectric ceramic layer may be made of, for example, BaTiO ３ , CaTiO ３ , SrTiO ３ , CaZrO ３ Examples of the dielectric ceramic material include a dielectric ceramic material containing, as a main component, a perovskite-type compound such as a Mn compound, an Fe compound, a Cr compound, a Co compound, or a Ni compound. In addition to the main component, the dielectric ceramic material may contain, for example, a Mn compound, an Fe compound, a Cr compound, a Co compound, or a Ni compound.

[0098] The internal electrode layers extend in a flat plate shape along the dielectric ceramic layers.

[0099] A pair of internal electrode layers adjacent in the first direction D1 face each other in the first direction D1 via a dielectric ceramic layer, and are extended to different end faces of a pair of end faces of the element body 24 facing in the second direction D2.

[0100] Examples of materials constituting the internal electrode layers include electrode materials containing metals such as Ni, Cu, Ag, Pd, Ag-Pd alloys, Au, etc. In addition to the above-mentioned metals, the electrode materials may also contain ceramic materials called co-materials, such as the dielectric ceramic material constituting the dielectric ceramic layers.

[0101] The first external electrode 25a is provided on one end surface of the element body 24. As a result, the first external electrode 25a is connected to the internal electrode layer drawn out to one end surface of the element body 24.

[0102] The second external electrode 25b is provided on the other end surface of the element body 24. As a result, the second external electrode 25b is connected to the internal electrode layer drawn out to the other end surface of the element body 24.

[0103] Each of the first external electrode 25a and the second external electrode 25b preferably has, in order from the element body 24 side, a base electrode layer and a plated electrode layer.

[0104] The base electrode layer is preferably in contact with the element body 24 .

[0105] Examples of materials for the base electrode layer include metals such as Cu, Ni, Ag, Pd, Ag-Pd alloys, and Au.

[0106] The base electrode layer may be made up of a single layer or multiple layers.

[0107] Examples of materials for the plating electrode layer include metals such as Ni, Sn, Cu, Ag, Pd, Ag-Pd alloys, and Au.

[0108] The plating electrode layer may be made up of a single layer or multiple layers.

[0109] When the plated electrode layer is made up of a plurality of layers, the plated electrode layer preferably has, in order from the base electrode layer side, a Ni-plated electrode layer and a Sn-plated electrode layer.

[0110] The first external terminal 26a is provided on the first external electrode 25a. This connects the first external terminal 26a to the first external electrode 25a. The first external terminal 26a may be welded to the first external electrode 25a, or may be connected to the first external electrode 25a via a joining member such as solder, a conductive adhesive, or a conductive paste.

[0111] The second external terminal 26b is provided on the second external electrode 25b. This connects the second external terminal 26b to the second external electrode 25b. The second external terminal 26b may be welded to the second external electrode 25b, or may be connected to the second external electrode 25b via a joining member such as solder, a conductive adhesive, or a conductive paste.

[0112] The first external terminal 26a (first external electrode 25a) and the second external terminal 26b (second external electrode 25b) have mutually different polarities. For example, the first external terminal 26a (first external electrode 25a) is a positive electrode (P electrode), and the second external terminal 26b (second external electrode 25b) is a negative electrode (N electrode). In this case, the first external terminal 26a (first external electrode 25a) constitutes the positive electrode of the second capacitor section 20, and the second external terminal 26b (second external electrode 25b) constitutes the negative electrode of the second capacitor section 20.

[0113] The first external terminal 26 a and the second external terminal 26 b protrude toward the substrate 21 beyond the surface of the element portion 23 that faces the substrate 21, and are in contact with the substrate 21. As a result, with the multilayer ceramic capacitor 22 mounted on the substrate 21, the element portion 23 is in a floating state above the substrate 21.

[0114] There is no particular limitation on the number of element portions 23 in the multilayer ceramic capacitor 22. That is, the multilayer ceramic capacitor 22 may include one element portion 23 as shown in Fig. 8 or the like, or may include a plurality of element portions 23 like the multilayer ceramic capacitor (ceramic electronic component) with external terminals disclosed in Japanese Patent Laid-Open Publication No. 2000-235932.

[0115] When the multilayer ceramic capacitor 22 includes a plurality of element portions 23, for example, the plurality of element portions 23 are stacked in a first direction D1, and each of the first external electrodes 25 a is commonly connected to one first external terminal 26 a, and further, each of the second external electrodes 25 b is commonly connected to one second external terminal 26 b.

[0116] The above configuration is merely one example of the multilayer ceramic capacitor 22. In other words, the multilayer ceramic capacitor 22 is not limited to the above configuration.

[0117] There is no particular limitation on the number of multilayer ceramic capacitors 22 in the second capacitor section 20. In other words, the second capacitor section 20 is required to have at least one multilayer ceramic capacitor 22, and specifically, the second capacitor section 20 may include one multilayer ceramic capacitor 22 or may include a plurality of multilayer ceramic capacitors 22 as shown in FIG.

[0118] When the second capacitor section 20 includes a plurality of multilayer ceramic capacitors 22, the configurations of the plurality of multilayer ceramic capacitors 22 may be the same as each other, may be different from each other, or may be partially different from each other.

[0119] When the second capacitor section 20 includes a plurality of multilayer ceramic capacitors 22, there is no particular limitation on the arrangement of the plurality of multilayer ceramic capacitors 22 when mounted on the substrate 21. For example, the plurality of multilayer ceramic capacitors 22 may be arranged in a single row or in multiple rows when mounted on the substrate 21. When the plurality of multilayer ceramic capacitors 22 are arranged in multiple rows, the plurality of multilayer ceramic capacitors 22 may be arranged in multiple rows in one direction or in multiple directions.

[0120] There is no particular limitation on the number of second capacitor sections 20 in the capacitor module 1. In other words, the capacitor module 1 is required to have at least one second capacitor section 20, and specifically, the capacitor module 1 may have one second capacitor section 20, or may have multiple second capacitor sections 20 as shown in Fig. 1 etc.

[0121] <First Conductor> The first conductor 30 is electrically connected to the positive electrode side of the first capacitor section 10 and the positive electrode side of the second capacitor section 20. For example, this is as follows.

[0122] The first conductor 30 is electrically connected to the first external electrode 13a of the film capacitor 11, which constitutes the positive electrode of the first capacitor section 10. The first conductor 30 may be connected to the first external electrode 13a by, for example, welding or via a joining member such as solder.

[0123] The first conductor 30 is electrically connected to a first external terminal 26 a (first external electrode 25 a ) of the multilayer ceramic capacitor 22 that constitutes the positive electrode of the second capacitor section 20 .

[0124] When the substrate 21 is a printed wiring board provided with wiring, the first conductor 30 may be electrically connected to the first external terminal 26 a (first external electrode 25 a) of the multilayer ceramic capacitor 22 via the wiring of the substrate 21. In this case, the first branch portion 33 of the first conductor 30 may penetrate the substrate 21 from the first main surface 21 a on the film capacitor 11 side toward the second main surface 21 b on the multilayer ceramic capacitor 22 side (see FIGS. 4 and 5 ), and then be connected to the wiring provided on the second main surface 21 b of the substrate 21 via a joining member such as solder, thereby being electrically connected to the first external terminal 26 a (first external electrode 25 a) of the multilayer ceramic capacitor 22 via the wiring of the substrate 21.

[0125] Alternatively, if the substrate 21 is a substrate without wiring, the first conductor 30 may be electrically connected to the first external terminal 26a (first external electrode 25a) of the multilayer ceramic capacitor 22 without wiring. In this case, the first branch portion 33 of the first conductor 30 may penetrate from the first main surface 21a to the second main surface 21b of the substrate 21 (see FIGS. 4 and 5 ), and then extend further onto the second main surface 21b of the substrate 21, thereby being electrically connected to the first external terminal 26a (first external electrode 25a) of the multilayer ceramic capacitor 22.

[0126] As a result, the positive electrode of the first capacitor section 10 (here, the first external electrode 13a) and the positive electrode of the second capacitor section 20 (here, the first external terminal 26a (first external electrode 25a)) are electrically drawn out via the first conductor 30. In other words, the first conductor 30 is a drawing conductor for the positive electrode.

[0127] The first conductor 30 has a first terminal 31 on the side opposite to the first capacitor section 10 and the second capacitor section 20 .

[0128] There is no particular limitation on the number of first terminals 31 in the first conductor 30. That is, the first conductor 30 may have one first terminal 31, or may have a plurality of first terminals 31 as shown in FIG.

[0129] The position of the first terminal 31 that is drawn out to the outside of the case 50 (described later) is not particularly limited.

[0130] 1 and other examples, the first conductor 30 has four first terminals 31. Of these first terminals 31, for example, three first terminals 31 protruding in the third direction D3 are electrically connected to a power module, which will be described later.

[0131] Examples of the first conductor 30 include a bus bar (for example, plate-shaped), a lead wire (for example, rod-shaped), and the like.

[0132] The first conductor 30 may or may not be bent.

[0133] Examples of materials for the first conductors 30 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 conductors 30. When the material for the first conductors 30 is a copper-based material, examples of materials that can be used include oxygen-free copper (copper: 99.96% by weight or more), tough pitch copper (copper: 99.90% by weight or more), and phosphorus-deoxidized copper (copper: 99.90% by weight or more, phosphorus: 0.015% by weight or more, 0.040% by weight or less).

[0134] <Second Conductor> The second conductor 40 is electrically connected to the negative electrode side of the first capacitor section 10 and the negative electrode side of the second capacitor section 20. For example, this is as follows.

[0135] The second conductor 40 is electrically connected to the second external electrode 13b of the film capacitor 11, which constitutes the negative electrode of the first capacitor section 10. The second conductor 40 may be connected to the second external electrode 13b by, for example, welding or via a joining member such as solder.

[0136] The second conductor 40 is electrically connected to the second external terminal 26 b (second external electrode 25 b ) of the multilayer ceramic capacitor 22 that constitutes the negative electrode of the second capacitor section 20 .

[0137] When the substrate 21 is a printed wiring board provided with wiring, the second conductor 40 may be electrically connected to the second external terminal 26b (second external electrode 25b) of the multilayer ceramic capacitor 22 via the wiring of the substrate 21. In this case, the second branch portion 43 of the second conductor 40 may extend toward the substrate 21 and be in contact with the second main surface 21b of the substrate 21 (see FIGS. 4 and 5 ), and then be connected to the wiring provided on the second main surface 21b of the substrate 21 via a joining member such as solder, thereby being electrically connected to the second external terminal 26b (second external electrode 25b) of the multilayer ceramic capacitor 22 via the wiring of the substrate 21.

[0138] Alternatively, if the substrate 21 is a substrate without wiring, the second conductor 40 may be electrically connected to the second external terminal 26b (second external electrode 25b) of the multilayer ceramic capacitor 22 without wiring. In this case, the second branch portion 43 of the second conductor 40 may extend toward the substrate 21 and contact the second main surface 21b of the substrate 21 (see FIGS. 4 and 5 ), and then extend further on the second main surface 21b of the substrate 21, thereby being electrically connected to the second external terminal 26b (second external electrode 25b) of the multilayer ceramic capacitor 22.

[0139] As a result, the negative electrode of the first capacitor section 10 (here, the second external electrode 13b) and the negative electrode of the second capacitor section 20 (here, the second external terminal 26b (second external electrode 25b)) are electrically drawn out via the second conductor 40. In other words, the second conductor 40 is a drawing conductor for the negative electrode.

[0140] The second conductor 40 has a second terminal 41 on the opposite side to the first capacitor section 10 and the second capacitor section 20 .

[0141] There is no particular limitation on the number of second terminals 41 in the second conductor 40. That is, the second conductor 40 may have one second terminal 41, or may have a plurality of second terminals 41 as shown in FIG.

[0142] The position of the second terminal 41 that is drawn out to the outside of the case 50 (described later) is not particularly limited.

[0143] 1 and other examples, the second conductor 40 has four second terminals 41. Of these second terminals 41, for example, three second terminals 41 protruding in the third direction D3 are electrically connected to a power module, which will be described later.

[0144] Examples of the second conductor 40 include a bus bar (for example, plate-shaped), a lead wire (for example, rod-shaped), and the like.

[0145] The second conductor 40 may or may not be bent.

[0146] Examples of materials for the second conductors 40 include metals such as copper, oxygen-free copper, aluminum, and alloys containing at least one of these. Among these, copper or oxygen-free copper is preferred as the material for the second conductors 40. When the material for the second conductors 40 is a copper-based material, examples of materials that can be used include oxygen-free copper (copper: 99.96% by weight or more), tough pitch copper (copper: 99.90% by weight or more), and phosphorus-deoxidized copper (copper: 99.90% by weight or more, phosphorus: 0.015% by weight or more, 0.040% by weight or less).

[0147] The constituent material of the second conductors 40 may be the same as the constituent material of the first conductors 30 , or may be different from the constituent material of the first conductors 30 .

[0148] The thickness of the second conductors 40 may be the same as the thickness of the first conductors 30 or may be different from the thickness of the first conductors 30 .

[0149] <Case> The first capacitor section 10 is housed inside the case 50 such that the first terminal 31 and the second terminal 41 are drawn to the outside. As a result, the positive electrode of the first capacitor section 10 and the positive electrode of the second capacitor section 20 are electrically drawn to the outside of the case 50 via the first conductor 30 (first terminal 31), and the negative electrode of the first capacitor section 10 and the negative electrode of the second capacitor section 20 are electrically drawn to the outside of the case 50 via the second conductor 40 (second terminal 41).

[0150] It is preferable that the first capacitor section 10 is housed inside the case 50 so as to be separated from the inner surface of the case 50 .

[0151] The shape of the case 50 is not particularly limited.

[0152] 1 and the like, the case 50 is a cylindrical shape with a bottom and an opening 51. Specifically, the case 50 is a cylindrical shape with a bottom and an opening 51 at one end in the first direction D1.

[0153] In the example shown in Figure 1, etc., the case 50 has a bottom 52 facing the opening 51 in the first direction D1, and side wall portions 53 (in Figure 1, etc., it includes four side wall portions 53) extending from the bottom 52 toward the opening 51 in the first direction D1.

[0154] The case 50 may be, for example, a resin case or a metal case.

[0155] When the case 50 is a resin case, examples of the resin that constitutes the resin case include a liquid crystal polymer, a polyphenylene sulfide resin, a polybutylene terephthalate resin, etc. Among these, it is preferable that the resin case contains a liquid crystal polymer.

[0156] The liquid crystal polymer contained in the resin case may be, for example, a liquid crystal polymer having p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups in its skeleton. Liquid crystal polymers formed as polycondensates using various components other than p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups, such as phenol, phthalic acid, and ethylene terephthalate, may also be used. Liquid crystal polymers are also classified into types I, II, and III, but the material refers to the same material as the liquid crystal polymer formed from the above-mentioned components.

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

[0158] The inorganic filler contained in the resin case can be a material having a higher strength than the liquid crystal polymer, preferably a material having a higher melting point than the liquid crystal polymer, more preferably a material having a melting point of 680°C or higher.

[0159] The shape of the inorganic filler is not particularly limited, and examples thereof include a shape having a longitudinal direction, such as a fibrous or plate-like shape. As the inorganic filler having such a shape, multiple types of inorganic materials may be used in combination. It is preferable that the resin case contains at least one of a fibrous inorganic material and a plate-like inorganic material as the inorganic filler.

[0160] In this specification, a filler being fibrous means that the relationship between the longitudinal dimension in the longitudinal direction and the cross-sectional diameter in a cross section perpendicular to the longitudinal direction is longitudinal dimension / cross-sectional diameter ≧5 (i.e., the aspect ratio is 5:1 or more). Here, the cross-sectional diameter is the distance between the longest two points on the periphery of the cross section. If the cross-sectional diameter varies in the longitudinal direction, measurement is performed at the point where the cross-sectional diameter is largest.

[0161] In this specification, a filler being plate-shaped means that the relationship between the cross-sectional diameter of the face having the largest projected area and the maximum height in the direction perpendicular to this cross section is cross-sectional diameter / maximum height ≧ 3.

[0162] It is preferable that at least a portion of the inorganic filler has a portion oriented in a direction from the bottom 52 side toward the opening 51 side in the side wall portion 53 of the case 50, and a portion oriented in the outer circumferential direction of the side wall portion 53, and is dispersed inside the case 50.

[0163] The inorganic filler preferably has a diameter of 5 μm or more and a length of 50 μm or more.

[0164] It is preferable that the inorganic filler be dispersed throughout the case 50 without agglomerating.

[0165] 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.

[0166] 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.

[0167] The resin case is manufactured by a method such as injection molding or 3D printing (three-dimensional modeling).

[0168] When case 50 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.

[0169] The metal case is manufactured by a method such as impact molding or 3D printing (three-dimensional modeling).

[0170] <Filled Resin> Filled resin 60 is filled inside case 50 so that first capacitor section 10 is embedded. As a result, first capacitor section 10 is fixed inside case 50 by filled resin 60. Furthermore, filled resin 60 prevents moisture from penetrating first capacitor section 10, and as a result, deterioration of first capacitor section 10 is suppressed.

[0171] When first capacitor portion 10 is housed inside case 50 so as to be spaced apart from the inner surface of case 50, it is preferable that filling resin 60 be filled between first capacitor portion 10 and case 50, specifically between the outer surface of film capacitor 11 and the inner surface of case 50. Furthermore, it is preferable that filling resin 60 be filled inside case 50 not only between first capacitor portion 10 and case 50, but also in the region from opening 51 of case 50 to first capacitor portion 10.

[0172] From the viewpoint of suppressing the infiltration of moisture into the first capacitor portion 10, it is preferable that the thickness of the filled resin 60 at the opening 51 of the case 50 is large. The thickness of the filled resin 60 at the opening 51 of the case 50 is preferably sufficiently large within the allowable range for the overall volume (physical size) of the first capacitor portion 10 and the case 50, and specifically, is preferably 2 mm or more, and more preferably 4 mm or more. In particular, it is preferable that the first capacitor portion 10 is disposed closer to the bottom 52 than to the opening 51 inside the case 50, so that the thickness of the filled resin 60 relative to the first capacitor portion 10 is greater on the opening 51 side than on the bottom 52 side.

[0173] The filling resin 60 may be filled inside the case 50 so that a portion of the first conductor 30 is buried while the first terminal 31 is exposed. In this case, the first conductor 30 is fixed inside the case 50 by the filling resin 60.

[0174] The filling resin 60 may be filled inside the case 50 so that a portion of the second conductor 40 is buried while the second terminal 41 is exposed. In this case, the second conductor 40 is fixed inside the case 50 by the filling resin 60.

[0175] The thickness of the filled resin 60 is measured, for example, using a soft X-ray device if it is in a non-destructive state, and using a length measuring device such as a caliper if it is in a destructive state.

[0176] The relationship between the height of the case 50 and the height of the filling resin 60 in the first direction D1 is such that the thickness of the filling resin 60 at the opening 51 of the case 50 is as large as possible, and it may be up to a position inside the case 50, or it may be just about filled to the brim, or it may overflow slightly due to surface tension.

[0177] From the viewpoint of suppressing the penetration of moisture into the first capacitor portion 10, it is preferable to appropriately select a resin with low moisture permeability as the filling resin 60, such as an epoxy resin, a silicone resin, or a urethane resin. Examples of the hardener for the epoxy resin include an amine hardener and an imidazole hardener.

[0178] The above-mentioned resin alone may be used as the filling resin 60, but in order to improve strength, a resin to which a reinforcing agent has been added may also be used. Examples of the reinforcing agent include silica and alumina.

[0179] The following describes the connection mode of the first capacitor section 10, the second capacitor section 20, the first conductor 30, and the second conductor 40, which is a feature of the capacitor module 1, with reference to the circuit of the capacitor module 1.

[0180] 1 , each of the three second capacitor sections 20 is electrically connected to the first conductor 30 and the second conductor 40, thereby configuring three sets (three-phase) of circuits including separate second capacitor sections 20. Below, of the three sets (three-phase) of circuits, one set (one-phase) of circuits including one second capacitor section 20 will be described, but the same applies to the other two sets (two-phase) of circuits.

[0181] FIG. 9 is a circuit diagram showing the circuit of the capacitor module in FIG.

[0182] As shown in Fig. 9 , in the capacitor module 1, the positive electrode side (upper side in Fig. 9 ) of the first capacitor section 10 is electrically connected to the first conductor 30 via a first connection portion 32, and the negative electrode side (lower side in Fig. 9 ) of the first capacitor section 10 is electrically connected to the second conductor 40 via a second connection portion 42. Here, the first connection portion 32 is the connection portion between the first conductor 30 and the positive electrode side (upper side in Fig. 9 ) of the film capacitor 11 that is located closest to the first terminal 31 (leftmost side in Fig. 9 ) among all the film capacitors 11 that make up the first capacitor section 10. The second connection portion 42 is the connection portion between the second conductor 40 and the negative electrode side (lower side in Fig. 9 ) of the film capacitor 11 that is located closest to the first terminal 31 (leftmost side in Fig. 9 ) among all the film capacitors 11 that make up the first capacitor section 10.

[0183] Furthermore, as shown in Figure 9, in the capacitor module 1, the positive side (upper side in Figure 9) of the second capacitor section 20 is electrically connected to the first conductor 30 at a position between the first terminal 31 and the first connection portion 32, and the negative side (lower side in Figure 9) of the second capacitor section 20 is electrically connected to the second conductor 40 at a position between the second terminal 41 and the second connection portion 42.

[0184] As described above, in the capacitor module 1, the positive electrode side of the first capacitor section 10 and the positive electrode side of the second capacitor section 20 are electrically connected in sequence to the first conductor 30 toward the first terminal 31, and the negative electrode side of the first capacitor section 10 and the negative electrode side of the second capacitor section 20 are electrically connected in sequence to the second conductor 40 toward the second terminal 41. That is, in the capacitor module 1, the second capacitor section 20 is connected in parallel with the first capacitor section 10 at a position closer to the first terminal 31 and the second terminal 41 than the first capacitor section 10. Therefore, in the capacitor module 1, the loop path between the terminals of the capacitor module 1, i.e., the loop path between the first terminal 31 and the second terminal 41, is shortened via the second capacitor section 20, specifically, the multilayer ceramic capacitor 22, which generally has a smaller volume than the film capacitor 11. As a result, in the capacitor module 1, the inductance component between the terminals of the capacitor module 1, i.e., the inductance component between the first terminal 31 and the second terminal 41, mainly depends on the path that exists outside the first capacitor section 10, i.e., the inductance component L of the path that loops around the first terminal 31, the second capacitor section 20, and the second terminal 41. Therefore, in the capacitor module 1, it is possible to reduce the inductance component between the first terminal 31 and the second terminal 41 compared to a configuration in which the second capacitor section 20 is not provided in the capacitor module 1.

[0185] In the capacitor module 1, the first capacitor section 10 preferably includes a plurality of film capacitors 11 connected in parallel with each other. In this case, the first capacitor section 10 can be easily increased in capacitance.

[0186] In the example shown in FIG. 9, all of the film capacitors 11 that make up the first capacitor section 10 are connected in parallel with one another.

[0187] The first capacitor section 10 may include a plurality of film capacitors 11 connected in series with each other.

[0188] In the capacitor module 1, the second capacitor section 20 preferably includes a plurality of multilayer ceramic capacitors 22 connected in series with each other. In this case, even if a short circuit occurs in one of the multilayer ceramic capacitors 22, the function of the second capacitor section 20 is maintained by the other multilayer ceramic capacitors 22 connected in series to the first multilayer ceramic capacitor 22 and not short-circuited.

[0189] In the capacitor module 1, the second capacitor section 20 preferably includes a plurality of multilayer ceramic capacitors 22 connected in parallel with each other. In this case, the second capacitor section 20 can be easily increased in capacitance.

[0190] In the example shown in FIG. 9, as a particularly preferred embodiment, the four multilayer ceramic capacitors 22 constituting the first group P1 are connected in parallel with each other, the four multilayer ceramic capacitors 22 constituting the second group P2 are connected in parallel with each other, and the first group P1 and the second group P2 are connected in series with each other.

[0191] The manner in which the second capacitor section 20 is fixed, which is another feature of the capacitor module 1, will be described below.

[0192] As shown in FIG. 1 , in the capacitor module 1, at least the substrate 21 of the second capacitor section 20 is fixed with the filling resin 60. That is, in the capacitor module 1, at least the substrate 21 of the second capacitor section 20 is in contact with the filling resin 60. As such, in the capacitor module 1, the filling resin 60 is used not only to embed the first capacitor section 10 but also to secure the second capacitor section 20. That is, when manufacturing the capacitor module 1, the filling resin 60 for embedding the first capacitor section 10 is used to secure the second capacitor section 20. This eliminates the need for special components such as conductive spacers and bolts, as in the capacitor module described in Patent Document 2, thereby reducing costs and labor. Therefore, the capacitor module 1 can improve manufacturing efficiency when securing the second capacitor section 20.

[0193] In the capacitor module 1, it is preferable that at least a portion of the multilayer ceramic capacitor 22 is exposed from the filling resin 60. If the multilayer ceramic capacitor 22 is embedded in the filling resin 60 without being exposed from the filling resin 60, when the resin constituting the filling resin 60 is filled into the interior of the case 50 so as to embed the multilayer ceramic capacitor 22 during the manufacturing process and then cured, internal stress is generated in the resin, which may damage the multilayer ceramic capacitor 22 (the element portion 23 in the example shown in FIG. 8 ). In contrast, when at least a portion of the multilayer ceramic capacitor 22 is exposed from the filling resin 60, stress is less likely to be applied to the multilayer ceramic capacitor 22 from the filling resin 60 when the resin constituting the filling resin 60 hardens, compared to when the multilayer ceramic capacitor 22 is embedded in the filling resin 60, and the multilayer ceramic capacitor 22 is less likely to be damaged.

[0194] When there are multiple multilayer ceramic capacitors 22, it is preferable that at least a portion of at least one of the multilayer ceramic capacitors 22 is exposed from the filling resin 60, and it is particularly preferable that at least a portion of all of the multilayer ceramic capacitors 22 is exposed from the filling resin 60.

[0195] In the capacitor module 1, when at least a portion of the multilayer ceramic capacitor 22 is exposed from the filling resin 60, it is preferable that the filling resin 60 is not in contact with the multilayer ceramic capacitor 22. In this case, when the resin constituting the filling resin 60 hardens, stress is not applied to the multilayer ceramic capacitor 22 from the filling resin 60, and therefore the multilayer ceramic capacitor 22 is not damaged.

[0196] When there are multiple multilayer ceramic capacitors 22, it is preferable that the filling resin 60 is not in contact with at least one of the multilayer ceramic capacitors 22, and it is particularly preferable that the filling resin 60 is not in contact with all of the multilayer ceramic capacitors 22.

[0197] The positional relationship between the multilayer ceramic capacitor 22 and the filling resin 60 may be other than that shown in FIG.

[0198] FIG. 10 is a perspective view schematically showing another example of the capacitor module of the present invention.

[0199] 10 , when at least a portion of the multilayer ceramic capacitor 22 is exposed from the filling resin 60, the filling resin 60 may be in contact with the multilayer ceramic capacitor 22. In this case, as shown in Fig. 8 , if the multilayer ceramic capacitor 22 has an element portion 23, a first external terminal 26 a, and a second external terminal 26 b, and the element portion 23 is configured to be floating above the substrate 21 by the first external terminal 26 a and the second external terminal 26 b, even if the filling resin 60 is in contact with the first external terminal 26 a and the second external terminal 26 b, which are part of the multilayer ceramic capacitor 22, stress is unlikely to be applied to the element portion 23 from the filling resin 60 when the resin constituting the filling resin 60 hardens. This makes the element portion 23 less likely to be damaged, and as a result, the multilayer ceramic capacitor 22 less likely to be damaged. When the multilayer ceramic capacitor 22 has the configuration shown in Figure 8, it is of course preferable that the entire element portion 23 is not in contact with the filling resin 60, but if only the surface of the element portion 23 facing the substrate 21 is in contact with the filling resin 60, the element portion 23 is less likely to be damaged when the resin that makes up the filling resin 60 hardens.

[0200] When a plurality of multilayer ceramic capacitors 22 are present, the filling resin 60 may be in contact with at least one of the multilayer ceramic capacitors 22 .

[0201] The multilayer ceramic capacitor 22 may be embedded in the filling resin 60. When a plurality of multilayer ceramic capacitors 22 are present, at least one of the multilayer ceramic capacitors 22 may be embedded in the filling resin 60.

[0202] The capacitor module of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration of the capacitor module, manufacturing conditions, etc.

[0203] The capacitor module of the present invention is useful for in-vehicle applications, such as inverters, chargers, and DC-DC converters mounted on electric vehicles.

[0204] The capacitor module of the present invention is applicable not only to in-vehicle applications but also to various fields such as power electronics.

[0205] [Power Converter] The power converter of the present invention is characterized by comprising: the capacitor module of the present invention; and a power module electrically connected to the first terminal and the second terminal of the capacitor module.

[0206] As described above, in the power conversion device of the present invention, the capacitor module of the present invention can reduce the inductance component between the first terminal and the second terminal of the capacitor module. Therefore, in the power conversion device of the present invention, the capacitor module of the present invention, which can reduce the inductance component between the first terminal and the second terminal, can reduce the inductance component in the loop path between the capacitor module and the power module electrically connected to the first terminal and the second terminal of the capacitor module. Therefore, in the power conversion device of the present invention, it is possible to reduce switching loss, noise, etc. generated in the power device built into the power module.

[0207] A specific example of the power conversion device of the present invention will be described below.

[0208] In the following, as an example of the power conversion device of the present invention, a power conversion device having the capacitor module 1 will be described. The same applies to a power conversion device having a capacitor module other than the capacitor module 1 (for example, the capacitor module 2).

[0209] FIG. 11 is a perspective view schematically showing an example of a power conversion device of the present invention.

[0210] As shown in FIG. 11 , the power conversion device 100 includes a capacitor module 1 and a power module 110 .

[0211] Each component of the power conversion device 100 will be described below.

[0212] <Capacitor Module> The capacitor module 1 has the configuration described above with reference to FIG. 1 and the like.

[0213] A first through hole 31a may be provided in the first terminal 31 of the capacitor module 1. A second through hole 41a may be provided in the second terminal 41 of the capacitor module 1. The first through hole 31a and the second through hole 41a are used to insert a connecting member 120 (described later) when electrically connecting the power module 110 to the first terminal 31 and the second terminal 41, as described later.

[0214] <Power Module> The power module 110 is electrically connected to the first terminal 31 and the second terminal 41 of the capacitor module 1 .

[0215] In the example shown in Figure 11, the power module 110 is electrically connected to the first terminal 31 and the second terminal 41 of the capacitor module 1 via a connecting member 120 inserted into the first through hole 31a and the second through hole 41a.

[0216] Examples of the connecting member 120 include a screw, a bolt, etc. When the connecting member 120 is a screw or a bolt, the first terminal 31 and the second terminal 41 of the capacitor module 1 are fastened to the power module 110 by the connecting member 120.

[0217] The power module 110 may be connected to the first terminal 31 and the second terminal 41 of the capacitor module 1 by, for example, laser welding, instead of by the connecting member 120 .

[0218] 11 , the power module 110 is electrically connected to three of the four first terminals 31 of the capacitor module 1 that protrude in the third direction D3, and is also electrically connected to three of the four second terminals 41 of the capacitor module 1 that protrude in the third direction D3. In this case, DC is input to one first terminal 31 that protrudes in the second direction D2 and one second terminal 41 that protrudes in the second direction D2, passes through the first capacitor section 10 (film capacitor 11), etc., and is then converted to AC by the power module 110.

[0219] The power module 110 includes a built-in power device such as an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET).

[0220] FIG. 12 is a circuit diagram showing the circuit of the power conversion device in FIG.

[0221] In the circuit of the power conversion device 100 shown in FIG. 12 , compared to the circuit of the capacitor module 1 shown in FIG. 9 , the power module 110 is electrically connected to the first terminal 31 and the second terminal 41 of the capacitor module 1. As described above, the capacitor module 1 is capable of reducing the inductance component between the first terminal 31 and the second terminal 41. Therefore, in the power conversion device 100, the capacitor module 1 capable of reducing the inductance component between the first terminal 31 and the second terminal 41 can reduce the inductance component in the loop path between the capacitor module 1 and the power module 110 electrically connected to the first terminal 31 and the second terminal 41 of the capacitor module 1. Specifically, in the power conversion device 100, the inductance component in the loop path between the power module 110 and the capacitor module 1 mainly depends on the inductance component L of the path that loops through the power module 110 (positive electrode side), the first terminal 31 of the capacitor module 1, the second capacitor section 20 of the capacitor module 1, the second terminal 41 of the capacitor module 1, and the power module 110 (negative electrode side). As described above, in the power conversion device 100, it is possible to reduce switching loss, noise, and the like that occur in the power devices built into the power module 110.

[0222] The power conversion device of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration, manufacturing conditions, etc. of the power conversion device.

[0223] The power conversion device of the present invention is useful for in-vehicle applications, such as inverters and DC-DC converters mounted on electric vehicles.

[0224] The power conversion device of the present invention is applicable not only to in-vehicle applications but also to various fields such as power electronics.

[0225] The present specification discloses the following:

[0226] <1> A capacitor assembly comprising: a first capacitor section including at least one film capacitor; a second capacitor section including a substrate and at least one multilayer ceramic capacitor mounted on the substrate; a first conductor electrically connected to a positive electrode side of the first capacitor section and a positive electrode side of the second capacitor section, and having a first terminal on a side opposite to the first capacitor section and the second capacitor section; a second conductor electrically connected to a negative electrode side of the first capacitor section and a negative electrode side of the second capacitor section, and having a second terminal on a side opposite to the first capacitor section and the second capacitor section; a case in which the first capacitor section is housed such that the first terminal and the second terminal are extended to the outside; and a filling resin filled inside the case so that the first capacitor section is embedded, wherein the positive electrode side of the first capacitor section is electrically connected to the first conductor at a first connection portion, and the negative electrode side of the first capacitor section is electrically connected to the second conductor at a second connection portion, a positive electrode side of the second capacitor unit electrically connected to the first conductor at a position between the first terminal and the first connection portion, a negative electrode side of the second capacitor unit electrically connected to the second conductor at a position between the second terminal and the second connection portion, and at least the substrate of the second capacitor unit is fixed with the filling resin.

[0227] <2> The capacitor module according to <1>, wherein at least a portion of the multilayer ceramic capacitor is exposed from the filling resin.

[0228] <3> The capacitor module according to <2>, wherein the filling resin is not in contact with the multilayer ceramic capacitor.

[0229] <4> The capacitor module according to <2>, wherein the filling resin is in contact with the multilayer ceramic capacitor.

[0230] <5> The capacitor module according to any one of <1> to <4>, wherein the first capacitor section includes a plurality of the film capacitors connected in parallel to each other.

[0231] <6> The capacitor module according to any one of <1> to <5>, wherein the second capacitor section includes a plurality of the multilayer ceramic capacitors connected in series with each other.

[0232] <7> The capacitor module according to any one of <1> to <6>, wherein the second capacitor section includes a plurality of the multilayer ceramic capacitors connected in parallel to each other.

[0233] <8> A power conversion device comprising: the capacitor module according to any one of <1> to <7>; and a power module electrically connected to the first terminal and the second terminal of the capacitor module.

[0234] REFERENCE SIGNS LIST 1, 2 Capacitor module 10 First capacitor section 11 Film capacitor 12 Element body 12a First end face of element body 12b Second end face of element body 12c Side face of element body 13a First external electrode 13b Second external electrode 14a First metallized film 14b Second metallized film 15a First dielectric film 15aa First main surface of first dielectric film 15ab Second main surface of first dielectric film 15b Second dielectric film 15ba First main surface of second dielectric film 15bb Second main surface of second dielectric film 16a First metal layer 16b Second metal layer 20 Second capacitor section 21 Substrate 21a First main surface of substrate 21b Second main surface of substrate 22 Multilayer ceramic capacitor 23 Element section 24 Element body 25a First external electrode 25b Second external electrode 26a First external terminal 26b Second external terminal 30 First conductor 31 First terminal 31a First through hole 32 First connection portion 33 First branch portion 40 Second conductor 41 Second terminal 41a Second through hole 42 Second connection portion 43 Second branch portion 50 Case 51 Opening 52 Bottom 53 Side wall 60 Filled resin 100 Power conversion device 110 Power module 120 Connection member D1 First direction D2 Second direction D3 Third direction L Inductance component P1 First group P2 Second group

Claims

1. A capacitor comprising: a first capacitor section including at least one film capacitor; a second capacitor section including a substrate and at least one multilayer ceramic capacitor mounted on the substrate; a first conductor electrically connected to the positive electrode side of the first capacitor section and the positive electrode side of the second capacitor section and having a first terminal on the side opposite the first capacitor section and the second capacitor section; a second conductor electrically connected to the negative electrode side of the first capacitor section and the negative electrode side of the second capacitor section and having a second terminal on the side opposite the first capacitor section and the second capacitor section; a case in which the first capacitor section is housed so that the first terminal and the second terminal are extended to the outside; and a filling resin filled inside the case so that the first capacitor section is embedded, wherein the positive electrode side of the first capacitor section is electrically connected to the first conductor at a first connection portion, and the negative electrode side of the first capacitor section is electrically connected to the second conductor at a second connection portion, a positive electrode side of the second capacitor unit electrically connected to the first conductor at a position between the first terminal and the first connection portion; a negative electrode side of the second capacitor unit electrically connected to the second conductor at a position between the second terminal and the second connection portion; and at least the substrate of the second capacitor unit is fixed with the filling resin.

2. The capacitor module according to claim 1, wherein at least a portion of said multilayer ceramic capacitor is exposed from said filling resin.

3. The capacitor module according to claim 2, wherein the filling resin is not in contact with the multilayer ceramic capacitor.

4. The capacitor module according to claim 2, wherein the filling resin is in contact with the multilayer ceramic capacitor.

5. A capacitor module according to any one of claims 1 to 4, wherein the first capacitor section includes a plurality of the film capacitors connected in parallel with each other.

6. The capacitor module according to any one of claims 1 to 5, wherein the second capacitor section includes a plurality of the multilayer ceramic capacitors connected in series with each other.

7. The capacitor module according to any one of claims 1 to 6, wherein the second capacitor section includes a plurality of the multilayer ceramic capacitors connected in parallel with each other.

8. A power conversion device comprising: a capacitor module according to any one of claims 1 to 7; and a power module electrically connected to the first terminal and the second terminal of the capacitor module.

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