Capacitor module

Abstract

This invention provides a capacitor module that suppresses cracking of the sealing resin even when the capacitor element expands due to moisture absorption. [Solution] The capacitor module 1 comprises a capacitor element 10 having a first external electrode 12a and a second external electrode 12b, a first busbar 20 electrically connected to the first external electrode, a second busbar 30 electrically connected to the second external electrode, an insulator 40 sandwiched between the first busbar and the second busbar so as to form a laminated structure together with the first busbar and the second busbar, a case 50 in which the capacitor element is housed, and a sealing resin 60 filled inside the case so as to embed the capacitor element and allow the first busbar, the second busbar and the insulator to be drawn out from the inside to the outside. Inside the sealing resin, a first recess 71 is provided on the surface of the insulator on the first busbar side, which opens at the end of the insulator, and the sealing resin enters the first recess and makes contact with the insulator.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a capacitor including a capacitor element, a first bus bar and a second bus bar connected to electrodes at both ends of the capacitor element, a case housing the capacitor element, and a filling resin filled in the case. The first bus bar and the second bus bar each have a first overlapping portion and a second overlapping portion that overlap each other with an insulating plate interposed therebetween. The first overlapping portion, the second overlapping portion, and the insulating plate include a covered portion covered with the filling resin and an exposed portion exposed from the filling resin, and are formed so as to straddle the boundary between the covered portion and the exposed portion. The first overlapping portion, the second overlapping portion, and the insulating plate further include a through hole penetrating in the overlapping direction in which they overlap.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a capacitor module in which a capacitor element is housed inside a case and a sealing resin is filled inside the case so that the capacitor element is embedded, generally, a first busbar electrically connected to the first external electrode of the capacitor element and a second busbar electrically connected to the second external electrode of the capacitor element are drawn out from the inside to the outside of the sealing resin and electrically connected to the object to be connected, such as a circuit board or device. Furthermore, in order to ensure insulation between the first busbar and the second busbar (to prevent a short circuit between the first busbar and the second busbar), an insulator is sandwiched between the first busbar and the second busbar, and the insulator, along with the first busbar and the second busbar, is drawn out from the inside to the outside of the sealing resin.

[0005] However, with the capacitor module configuration described above, there is a risk that moisture may be introduced into the encapsulating resin during manufacturing, or that moisture may penetrate into the encapsulating resin from the outside during use. Moisture that thus becomes present inside the encapsulating resin may penetrate into the capacitor elements present inside the encapsulating resin. When moisture penetrates into the capacitor elements, the capacitor elements expand as they absorb the moisture, and the first busbar, second busbar, and insulator surrounding the capacitor elements are pressed against the encapsulating resin by the expanded capacitor elements, which may cause the encapsulating resin to crack (for example, develop a fissure). When the encapsulating resin cracks, moisture can more easily penetrate into the capacitor elements from the encapsulating resin itself, which may lead to a deterioration in the electrical characteristics of the capacitor elements and thus reduce the reliability of the capacitor module.

[0006] As mentioned above, even with the capacitor described in Patent Document 1, there is a risk that the filling resin (corresponding to the sealing resin) may crack due to moisture penetrating into the capacitor element located inside the filling resin.

[0007] The present invention was made to solve the above problems and aims to provide a capacitor module that can suppress cracking of the sealing resin even when the capacitor element expands due to moisture absorption. [Means for solving the problem]

[0008] The capacitor module of the present invention comprises a capacitor element having a first external electrode and a second external electrode; a first busbar electrically connected to the first external electrode; a second busbar electrically connected to the second external electrode; an insulator sandwiched between the first busbar and the second busbar so as to form a laminated structure together with the first busbar and the second busbar; a case in which the capacitor element is housed; and a sealing resin filled inside the case so as to embed the capacitor element and allow the first busbar, the second busbar, and the insulator to be drawn out from the inside to the outside, wherein, inside the sealing resin, a first recess is provided on the surface of the insulator on the first busbar side, opening at the end of the insulator, and the sealing resin enters the first recess and is in contact with the insulator. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a capacitor module that can suppress cracking of the sealing resin even when the capacitor element expands due to absorbing moisture. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic perspective view showing an example of the capacitor module of the present invention. [Figure 2] Figure 2 is a schematic perspective view showing an example of the capacitor module in Figure 1 with the sealing resin removed. [Figure 3] Figure 3 is a schematic perspective view showing an example of the capacitor module in Figure 1 with the sealing resin and case removed. [Figure 4] Figure 4 is a schematic perspective view showing an example of the capacitor element in Figure 3. [Figure 5] Figure 5 is a schematic cross-sectional view showing an example of a cross-section along the line a1-a2 of the capacitor element in Figure 4. [Figure 6] Figure 6 is a schematic cross-sectional view showing an example of a cross-section along the line A1-A2 of the capacitor module in Figure 1. [Figure 7] Figure 7 is a schematic cross-sectional view showing an example of a cross-section along the line B1-B2 of the capacitor module in Figure 1. [Figure 8] Figure 8 is a schematic perspective view showing an example of an insulator in Figures 6 and 7. [Figure 9] Figure 9 is a schematic cross-sectional view showing another example of the capacitor module of the present invention. [Figure 10] Figure 10 is a schematic perspective view showing an example of the insulator in Figure 9. [Modes for carrying out the invention]

[0011] The capacitor module of the present invention will be described below. However, the present invention is not limited to the configuration described below, and may be modified as appropriate without departing from the spirit of the invention. Furthermore, a combination of several of the preferred configurations described below also constitutes the present invention.

[0012] The drawings shown below are schematic representations, and their dimensions, aspect ratios, and scales may differ from those of the actual product.

[0013] In this specification, unless otherwise specified, terms describing relationships between elements (e.g., "parallel," "perpendicular," etc.) and terms describing the shape of elements mean not only the literal, exact form, but also a substantially equivalent range, such as a range with differences of a few percent.

[0014] [Capacitor Module] The capacitor module of the present invention includes a capacitor element having a first external electrode and a second external electrode, a first bus bar electrically connected to the first external electrode, a second bus bar electrically connected to the second external electrode, an insulator sandwiched between the first bus bar and the second bus bar so as to form a laminated structure together with the first bus bar and the second bus bar, a case in which the capacitor element is housed internally, a sealing resin filled inside the case such that the capacitor element is embedded and the first bus bar, the second bus bar, and the insulator are drawn out from the inside to the outside. Inside the sealing resin, a first recess that opens at an end of the insulator is provided on a surface of the insulator on the first bus bar side, and the sealing resin enters the first recess and contacts the insulator. This is the characteristic.

[0015] In a conventional capacitor module, when it is assumed that moisture enters the capacitor element existing inside the sealing resin by being brought in during manufacturing or by infiltrating from the outside to the inside of the sealing resin during use, the capacitor element swells by absorbing the moisture, and the first bus bar, the second bus bar, and the insulator existing around the capacitor element are pressed against the sealing resin by the swollen capacitor element, so there is a possibility that the sealing resin cracks (for example, gets fissures). For example, in a conventional capacitor module, a capacitor element that swells by absorbing moisture presses the insulator, and the pressed insulator presses the first bus bar and the second bus bar. Thus, due to the swelling of the capacitor element, the first bus bar, the second bus bar, and the insulator become more likely to move. Therefore, in a conventional capacitor module, the first bus bar, the second bus bar, and the insulator are more likely to be pressed against the sealing resin by the swollen capacitor element, so the sealing resin is more likely to crack. When the sealing resin cracks, moisture is more likely to enter the capacitor element from the sealing resin itself, so there is a possibility that the reliability of the capacitor module deteriorates, such as the electrical characteristics of the capacitor element degrading.

[0016] In contrast, in the capacitor module of the present invention, inside the encapsulating resin, on the surface of the insulator on the side of the first bus bar, a first recess that opens at the end of the insulator is provided. Further, in the capacitor module of the present invention, the encapsulating resin enters the first recess and contacts the insulator. Thereby, in the capacitor module of the present invention, the contact area between the insulator and the encapsulating resin is likely to increase. Therefore, combined with the anchor effect of the encapsulating resin, the insulator is likely to be fixed by the encapsulating resin that has entered the first recess. Therefore, in the capacitor module of the present invention, even if the capacitor element expands by absorbing moisture and the expanded capacitor element tries to push the insulator, it is difficult for the insulator to move. As a result, in the capacitor module of the present invention, it is difficult for a situation to occur in which the capacitor element that has expanded by absorbing moisture pushes the insulator and the pushed insulator pushes the first bus bar and the second bus bar. Therefore, in the capacitor module of the present invention, the first bus bar, the second bus bar, and the insulator are difficult to be pressed against the encapsulating resin by the expanded capacitor element, so the encapsulating resin is difficult to crack. As described above, in the capacitor module of the present invention, even if the capacitor element expands by absorbing moisture, it is possible to suppress cracking of the encapsulating resin, and as a result, it is possible to suppress a decrease in reliability.

[0017] Hereinafter, a specific example of the capacitor module of the present invention will be described.

[0018] FIG. 1 is a perspective view schematically showing an example of the capacitor module of the present invention. FIG. 2 is a perspective view schematically showing an example of a state in which the encapsulating resin is removed from the capacitor module in FIG. 1. FIG. 3 is a perspective view schematically showing an example of a state in which the encapsulating resin and the case are removed from the capacitor module in FIG. 1.

[0019] In FIG. 1 and the like, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other.

[0020] As shown in Figures 1, 2, and 3, the capacitor module 1 includes a capacitor element 10, a first busbar 20, a second busbar 30, an insulator 40, a case 50, and a sealing resin 60.

[0021] <Capacitor element> Figure 4 is a schematic perspective view showing an example of a capacitor element in Figure 3. Figure 5 is a schematic cross-sectional view showing an example of a cross-section along the line a1-a2 of the capacitor element in Figure 4.

[0022] As shown in Figures 4 and 5, the capacitor element 10 includes a base body 11, a first external electrode 12a, and a second external electrode 12b.

[0023] The base body 11 is a wound body in which a first metallized film 13a and a second metallized film 13b are stacked in a first direction D1 and wound together. In other words, the capacitor element 10 is a wound-type film capacitor in which metallized films are stacked and wound together.

[0024] The capacitor element 10 may also be a multilayer film capacitor (for example, in the shape of a rectangular parallelepiped) formed by stacking metallized films.

[0025] The base body 11 has a first end face 11a and a second end face 11b that are opposite to the second direction D2.

[0026] The base body 11 further has a side surface 11c that extends in the second direction D2 so as to connect the periphery of the first end surface 11a and the second end surface 11b.

[0027] In the capacitor element 10, from the viewpoint of reducing the height, it is preferable that the cross-sectional shape of the base body 11 is flattened when viewed in a cross-section perpendicular to the winding axis direction (second direction D2 in Figures 4 and 5). Specifically, it is preferable that the cross-sectional shape of the base body 11 is pressed into a flattened shape such as an ellipse or oblong, and that the thickness is smaller than when the cross-sectional shape of the base body 11 is a perfect circle.

[0028] Whether the base body 11 was pressed to have a flattened cross-sectional shape can be confirmed, for example, by checking whether there are press marks on the base body 11.

[0029] The capacitor element 10 may have a cylindrical winding shaft. The winding shaft is positioned on the central axis of the first metallized film 13a and the second metallized film 13b in the wound state, and serves as the winding shaft when winding the first metallized film 13a and the second metallized film 13b.

[0030] The first metallized film 13a comprises a first dielectric film 14a and a first metal layer 15a.

[0031] The first dielectric film 14a has a first main surface 14aa and a second main surface 14ab that are opposite to the first direction D1.

[0032] The first metal layer 15a is provided on the first main surface 14aa of the first dielectric film 14a. Specifically, the first metal layer 15a is provided on the first main surface 14aa of the first dielectric film 14a such that, in the second direction D2, it reaches one side edge of the first dielectric film 14a but does not reach the other side edge of the first dielectric film 14a.

[0033] The second metallized film 13b comprises a second dielectric film 14b and a second metal layer 15b.

[0034] The second dielectric film 14b has a first main surface 14ba and a second main surface 14bb that are opposite to the first direction D1.

[0035] The second metal layer 15b is provided on the first main surface 14ba of the second dielectric film 14b. Specifically, the second metal layer 15b is provided on the first main surface 14ba of the second dielectric film 14b such that, in the second direction D2, it does not reach one side edge of the second dielectric film 14b but reaches the other side edge of the second dielectric film 14b.

[0036] In the base body 11, the adjacent first metallized film 13a and second metallized film 13b are shifted in the second direction D2 such that the end of the first metal layer 15a that reaches the side edge of the first dielectric film 14a is exposed on the first end face 11a of the base body 11, and the end of the second metal layer 15b that reaches the side edge of the second dielectric film 14b is exposed on the second end face 11b of the base body 11. In other words, in the adjacent first metallized film 13a and second metallized film 13b, the first metallized film 13a protrudes toward the first external electrode 12a side relative to the second metallized film 13b. Also, in the adjacent first metallized film 13a and second metallized film 13b, the second metallized film 13b protrudes toward the second external electrode 12b side relative to the first metallized film 13a. In this state, the first metal layer 15a is connected to the first external electrode 12a but not to the second external electrode 12b. Also, the second metal layer 15b is connected to the second external electrode 12b but not to the first external electrode 12a.

[0037] In the base body 11, as described above, the adjacent first metallized film 13a and second metallized film 13b are shifted in the second direction D2. Therefore, in the adjacent first dielectric film 14a and second dielectric film 14b, the first dielectric film 14a, on which the first metal layer 15a is provided on the first main surface 14aa, protrudes toward the first external electrode 12a side relative to the second dielectric film 14b, on which the first metal layer 15a is not provided on the main surface. Also, in the adjacent first dielectric film 14a and second dielectric film 14b, the second dielectric film 14b, on which the second metal layer 15b is provided on the first main surface 14ba, protrudes toward the second external electrode 12b side relative to the first dielectric film 14a, on which the second metal layer 15b is not provided on the main surface.

[0038] Since the base body 11 is formed by winding the first metallized film 13a and the second metallized film 13b in a state where they are stacked in a first direction D1, it can be said that it contains the first dielectric film 14a, the first metal layer 15a, the second dielectric film 14b, and the second metal layer 15b in the first direction D1 in that order. Alternatively, the base body 11 can be said to be a wound body formed by winding the first dielectric film 14a, the first metal layer 15a, the second dielectric film 14b, and the second metal layer 15b in a state where they are stacked in the first direction D1 in that order.

[0039] In the base material 11, the first main surface 14aa of the first dielectric film 14a and the second main surface 14bb of the second dielectric film 14b face each other in the first direction D1, and the second main surface 14ab of the first dielectric film 14a and the first main surface 14ba of the second dielectric film 14b face each other in the first direction D1. Thus, in the base material 11, the first metallized film 13a and the second metallized film 13b are wound in a state where they are stacked in the first direction D1. In other words, in the base material 11, the first metallized film 13a is on the inside of the second metallized film 13b, specifically, the first metal layer 15a is on the inside of the first dielectric film 14a, and the second metal layer 15b is on the inside of the second dielectric film 14b, so the first metallized film 13a and the second metallized film 13b are wound in a state where they are stacked in the first direction D1. In other words, in the base body 11, the first metal layer 15a and the second metal layer 15b face each other with either the first dielectric film 14a or the second dielectric film 14b in between.

[0040] A fuse portion may be provided in the first metal layer 15a. The fuse portion provided in the first metal layer 15a is, for example, a portion that connects a divided electrode portion, which is a portion of the first metal layer 15a that is divided into multiple parts, with an electrode portion that is not facing the second metal layer 15b. Examples of electrode patterns for the first metal layer 15a provided with a fuse portion include the electrode patterns disclosed in Japanese Patent Application Publication No. 2004-363431 and Japanese Patent Application Publication No. Hei 5-251266.

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

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

[0043] In this specification, the main component means the component with the highest weight percentage, and preferably means a component with a weight percentage higher than 50% by weight.

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

[0045] In this specification, thermosetting resins mean resins that can be cured by heat, but this does not limit the curing method. Therefore, thermosetting resins include resins that can be cured by methods other than heat (e.g., light, electron beam, etc.), as long as they can be cured by heat. In addition, depending on the material, the reaction may be initiated by the reactivity of the material itself, and resins that proceed to cure without necessarily being subjected to external heat are also considered thermosetting resins. The same applies to photocurable resins; as long as they can be cured by light, they also include resins that can be cured by methods other than light (e.g., heat, etc.).

[0046] The curable resin is preferably composed of a cured product of a first organic material having hydroxyl groups (OH groups) and a second organic material having isocyanate groups (NCO groups). In this case, the curable resin is composed of a cured product having urethane bonds obtained by the reaction of the hydroxyl groups of the first organic material and the isocyanate groups of the second organic material.

[0047] The presence of urethane bonding in the first dielectric film 14a can be confirmed by analysis using Fourier transform infrared spectrophotometer (FT-IR).

[0048] When a curable resin is obtained by the reaction described above, 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 hydroxyl groups and isocyanate groups. In this case, the first dielectric film 14a may contain either one of hydroxyl groups and isocyanate groups, or both hydroxyl groups and isocyanate groups.

[0049] The presence of hydroxyl groups and / or isocyanate groups in the first dielectric film 14a can be confirmed by analysis using a Fourier transform infrared spectrophotometer (FT-IR).

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

[0051] Multiple types of organic materials may be used in combination as the first organic material.

[0052] Examples of the second organic material include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI), and aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). As the second organic material, at least one modified form of these polyisocyanates may be used, or a mixture of at least one of these polyisocyanates and its modified form may be used.

[0053] Multiple types of organic materials may be used in combination as the second organic material.

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

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

[0056] The first dielectric film 14a may further contain additives for adding various functions.

[0057] Examples of additives include leveling agents used to impart smoothness.

[0058] The additive preferably has a functional group that reacts with hydroxyl groups and / or isocyanate groups, 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 hydroxyl groups, epoxy groups, silanol groups, and carboxyl groups.

[0059] The second dielectric film 14b, like the first dielectric film 14a, may contain a thermosetting resin as its main component, a photocurable resin as its main component, or a thermoplastic resin as its main component. Furthermore, the second dielectric film 14b, like the first dielectric film 14a, may also contain additives.

[0060] The constituent materials of the first dielectric film 14a and the second dielectric film 14b may be different from each other, but it is preferable that they be the same.

[0061] The thickness of the first dielectric film 14a and the second dielectric film 14b is preferably 1 μm or more and 10 μm or less, and more preferably 3 μm or more and 5 μm or less.

[0062] The thicknesses of the first dielectric film 14a and the second dielectric film 14b may be different, but it is preferable that they be the same.

[0063] The thicknesses of the first dielectric film 14a and the second dielectric film 14b are measured using an optical film thickness gauge.

[0064] The first dielectric film 14a and the second dielectric film 14b are preferably each produced by forming a resin solution containing the resin material described above into a film, and then curing it by heat treatment.

[0065] Examples of constituent materials for the first metal layer 15a and the second metal layer 15b include metals such as aluminum, zinc, titanium, magnesium, tin, and nickel.

[0066] The constituent materials of the first metal layer 15a and the second metal layer 15b may be different from each other, but it is preferable that they be the same.

[0067] The thickness of the first metal layer 15a and the second metal layer 15b is preferably 5 nm or more and 40 nm or less.

[0068] The thicknesses of the first metal layer 15a and the second metal layer 15b may be different, but it is preferable that they be the same.

[0069] The thicknesses of the first metal layer 15a and the second metal layer 15b are measured by observing the cross-sections of the first metallized film 13a and the second metallized film 13b along the first direction D1 using a transmission electron microscope (TEM).

[0070] The first metal layer 15a and the second metal layer 15b are preferably formed by depositing the above-described metal onto the main surfaces of the first dielectric film 14a and the second dielectric film 14b, respectively.

[0071] Although the above describes an embodiment in which the base body 11 includes two metallized films, the base body 11 may include only one metallized film. For example, the base body 11 may include a metallized film having a first dielectric film 14a in which a first metal layer 15a is provided on a first main surface 14aa and a second metal layer 15b is provided on a second main surface 14ab, and a second dielectric film 14b without a metal layer. Alternatively, the base body 11 may include a metallized film having a second dielectric film 14b in which a first metal layer 15a is provided on a second main surface 14bb and a second metal layer 15b is provided on a first main surface 14ba, and a first dielectric film 14a without a metal layer.

[0072] The first external electrode 12a is provided on the surface of the base body 11. In the example shown in Figures 4 and 5, the first external electrode 12a is provided on the first end face 11a of the base body 11. The first external electrode 12a is connected to the first metal layer 15a by contacting the end of the first metal layer 15a exposed on the first end face 11a of the base body 11. On the other hand, the first external electrode 12a is not connected to the second metal layer 15b.

[0073] The second external electrode 12b is provided on the surface of the base body 11 at a position away from the first external electrode 12a. In the example shown in Figures 4 and 5, the second external electrode 12b is provided on the second end face 11b of the base body 11. The second external electrode 12b is connected to the second metal layer 15b by contacting the end of the second metal layer 15b exposed on the second end face 11b of the base body 11. On the other hand, the second external electrode 12b is not connected to the first metal layer 15a.

[0074] The first external electrode 12a and the second external electrode 12b have opposite polarities. For example, the first external electrode 12a may be the positive electrode (P pole) and the second external electrode 12b may be the negative electrode (N pole), or the first external electrode 12a may be the negative electrode (N pole) and the second external electrode 12b may be the positive electrode (P pole).

[0075] Examples of materials that make up the first external electrode 12a and the second external electrode 12b include metals such as zinc, aluminum, tin, and zinc-aluminum alloys.

[0076] The constituent materials of the first external electrode 12a and the second external electrode 12b may be different from each other, but it is preferable that they be the same.

[0077] The first external electrode 12a and the second external electrode 12b are preferably formed by thermal spraying the above-described metal onto the first end face 11a and the second end face 11b of the base body 11, respectively.

[0078] The above configuration is merely one example of a capacitor element 10. In other words, the capacitor element 10 is not limited to the above configuration.

[0079] In the above example, the capacitor element 10 is shown to be a film capacitor, but the capacitor element 10 may be a capacitor element other than a film capacitor.

[0080] The number of capacitor elements 10 in the capacitor module 1 is not particularly limited. In other words, the capacitor module 1 only needs to have at least one capacitor element 10, and specifically, it may have one capacitor element 10 or it may have multiple capacitor elements 10.

[0081] If the capacitor module 1 has multiple capacitor elements 10, the configurations of the multiple capacitor elements 10 may be the same as each other, different from each other, or partially different.

[0082] When the capacitor module 1 has multiple capacitor elements 10, the arrangement of the multiple capacitor elements 10 when housed inside the case 50 is not particularly limited. For example, the multiple capacitor elements 10 may be arranged in one row or in multiple rows when housed inside the case 50. When the multiple capacitor elements 10 are arranged in multiple rows, the multiple capacitor elements 10 may be arranged in multiple rows in one direction or in multiple directions.

[0083] <First bus bar> The first busbar 20 is electrically connected to the first external electrode 12a. The first busbar 20 may be connected to the first external electrode 12a by, for example, welding or by a joining member such as solder. As a result, the first external electrode 12a is electrically drawn out through the first busbar 20. For example, if the first external electrode 12a is the positive electrode, the first busbar 20 becomes the lead conductor for the positive electrode.

[0084] The first busbar 20 has a first terminal 21 located outside the sealing resin 60. The first terminal 21 is located on the side of the first busbar 20 opposite to the capacitor element 10, rather than on the side of the first busbar 20 opposite to the capacitor element 10. The first terminal 21 is electrically connected to an object to be connected (not shown), such as a substrate or device, by, for example, laser welding.

[0085] The number of first terminals 21 on the first busbar 20 is not particularly limited. That is, the first busbar 20 may have one first terminal 21 or may have multiple first terminals 21.

[0086] The first busbar 20 may be bent inside the sealing resin 60. In the examples shown in Figures 1, 2, and 3, the first busbar 20 has a first type portion 20a that extends inside the sealing resin 60 in a direction along the side surface 11c of the element 11 on which the first external electrode 12a and the second external electrode 12b are not provided on the surface of the capacitor element 10, and a second type portion 20b that extends from the inside to the outside of the sealing resin 60 relative to the first type portion 20a. The first type portion 20a and the second type portion 20b extend in directions that intersect each other, and in this case, in directions perpendicular to each other. In other words, the first busbar 20 is bent inside the sealing resin 60 at the connection point between the first type portion 20a and the second type portion 20b. Note that although the first busbar 20 is bent at the first type portion 20a (see Figure 6 described later), it does not have to be bent at the first type portion 20a.

[0087] The first bus bar 20 does not need to be bent inside the sealing resin 60.

[0088] Examples of materials that can be used to construct the first busbar 20 include metals such as copper, oxygen-free copper, aluminum, and alloys containing at least one of these. In particular, the constituent material of the first busbar 20 is preferably copper or oxygen-free copper. When the constituent material of the first busbar 20 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).

[0089] <Second bus bar> The second busbar 30 is electrically connected to the second external electrode 12b. The second busbar 30 may be connected to the second external electrode 12b by, for example, welding or by a joining member such as solder. As a result, the second external electrode 12b is electrically drawn out through the second busbar 30. For example, if the second external electrode 12b is the negative electrode, the second busbar 30 becomes the lead conductor for the negative electrode.

[0090] The second busbar 30 has a second terminal 31 located outside the sealing resin 60. The second terminal 31 is located on the side of the second busbar 30 opposite to the capacitor element 10, rather than on the side of the second busbar 30 opposite to the capacitor element 10. The second terminal 31 is electrically connected to an object to be connected, such as a substrate or device, by laser welding, for example.

[0091] The number of second terminals 31 in the second busbar 30 is not particularly limited. That is, the second busbar 30 may have one second terminal 31 or may have multiple second terminals 31.

[0092] The second busbar 30 does not need to be bent inside the sealing resin 60. In the examples shown in Figures 1, 2, and 3, the second busbar 30 has a third type portion 30a that extends from the inside to the outside of the sealing resin 60. The third type portion 30a is not bent inside the sealing resin 60.

[0093] The second busbar 30 may be bent inside the sealing resin 60.

[0094] Examples of materials that can be used to construct the second busbar 30 include metals such as copper, oxygen-free copper, aluminum, and alloys containing at least one of these. In particular, it is preferable that the constituent material of the second busbar 30 be copper or oxygen-free copper. When the constituent material of the second busbar 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).

[0095] The constituent material of the second busbar 30 may be the same as the constituent material of the first busbar 20, or it may be different from the constituent material of the first busbar 20.

[0096] The thickness of the second busbar 30 may be the same as the thickness of the first busbar 20, or it may be different from the thickness of the first busbar 20.

[0097] <insulator> The insulator 40 is sandwiched between the first busbar 20 and the second busbar 30 so as to form a laminated structure together with the first busbar 20 and the second busbar 30. Specifically, the first busbar 20, the insulator 40, and the second busbar 30 are stacked in order to form a laminated structure. In such a laminated structure, the creepage distance between the first busbar 20 and the second busbar 30 is ensured by the insulator 40, thereby ensuring insulation between the first busbar 20 and the second busbar 30 (short circuits between the first busbar 20 and the second busbar 30 are prevented).

[0098] Examples of materials that make up the insulator 40 include resin.

[0099] The insulator 40 may include, for example, a super engineering plastic as the resin. In this case, the insulating properties of the insulator 40 tend to improve.

[0100] If the insulator 40 contains a super engineering plastic, the super engineering plastic is preferably a polyphenylene sulfide resin. In this case, the tracking resistance of the insulator 40 is more easily improved, and thus the insulating properties of the insulator 40 are more easily improved.

[0101] The thickness of the insulator 40 may be the same as the thickness of the first busbar 20 and the second busbar 30, or it may be different from the thickness of the first busbar 20 and the second busbar 30.

[0102] The insulator 40 is preferably in the form of a plate. In other words, the insulator 40 is preferably an insulating plate.

[0103] In this specification, the term "insulating board" also includes forms such as insulating paper, insulating sheets, and insulating films.

[0104] It is preferable that the insulator 40 is bent together with the first busbar 20 and the second busbar 30. In the example shown in Figure 1, the insulator 40 is bent in an L-shape together with the first busbar 20 and the second busbar 30 on the side opposite to the capacitor element 10. When the first busbar 20, the second busbar 30, and the insulator 40 are bent in this way, the creepage distance between the first busbar 20 and the second busbar 30 is more easily secured, making it easier to ensure insulation between the first busbar 20 and the second busbar 30 (making it easier to prevent short circuits between the first busbar 20 and the second busbar 30). Furthermore, when the first busbar 20, the second busbar 30, and the insulator 40 are bent, the electromagnetic fields generated by the first busbar 20 and the second busbar 30 tend to cancel each other out, making it easier to reduce the equivalent series inductance (ESL) between the first busbar 20 and the second busbar 30.

[0105] <Case> The capacitor element 10 is housed inside the case 50.

[0106] It is preferable that the capacitor element 10 is housed inside the case 50 so as to be separated from the inner surface of the case 50.

[0107] The case 50 may be a bottomed cylindrical shape with an opening 51. In the example shown in Figure 1, the case 50 is a bottomed cylindrical shape with an opening 51 at one end in the first direction D1.

[0108] If the case 50 is a bottomed cylindrical shape with an opening 51, it may have a bottom portion 52 facing the opening 51 and a side wall portion 53 extending from the bottom portion 52 toward the opening 51. In the example shown in Figure 1, the case 50 has a bottom portion 52 facing the opening 51 in a first direction D1, and a side wall portion 53 extending from the bottom portion 52 toward the opening 51 in the first direction D1.

[0109] The shape of case 50 may be other than the shape described above.

[0110] Examples of case 50 include resin cases, metal cases, and so on.

[0111] If case 50 is a resin case, examples of resins that make up the resin case include liquid crystal polymer, polyphenylene sulfide resin, polybutylene terephthalate resin, etc. Among these, it is preferable that the resin case contains liquid crystal polymer.

[0112] As for the liquid crystal polymer contained in the resin case, for example, a liquid crystal polymer having p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups in its backbone can be used. In addition to p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups, liquid crystal polymers formed by polycondensation using various components such as phenol, phthalic acid, and ethylene terephthalate can also be used. Furthermore, when classifying liquid crystal polymers, there are classification methods such as Type I, Type II, and Type III, but in terms of materials, these refer to the same materials as the liquid crystal polymers formed from the above-mentioned components.

[0113] The resin case preferably contains an inorganic filler in addition to the liquid crystal polymer.

[0114] As the inorganic filler included in the resin case, a material with higher strength than the liquid crystal polymer can be used. Preferably, the inorganic filler is a material with a higher melting point than the liquid crystal polymer, and more preferably a material with a melting point of 680°C or higher.

[0115] The form of the inorganic filler is not particularly limited, and examples include forms having a longitudinal direction, such as fibrous or plate-like shapes. Multiple types of inorganic materials may be used in combination as such inorganic fillers. Preferably, the resin case contains at least one of a fibrous inorganic material and a plate-like inorganic material as the inorganic filler.

[0116] In this specification, a filler is described as fibrous if the relationship between the longitudinal dimension in the longitudinal direction and the cross-sectional diameter in a section perpendicular to the longitudinal direction is such that longitudinal dimension / cross-sectional diameter ≥ 5 (i.e., an aspect ratio of 5:1 or greater). Here, the cross-sectional diameter is defined as the distance between the two longest points on the outer circumference of the cross-section. If the cross-sectional diameter differs in the longitudinal direction, the measurement is taken at the point where the cross-sectional diameter is maximum.

[0117] In this specification, a filler is described as being in the form of a plate, meaning that in the filler, the relationship between the cross-sectional diameter of the surface with the largest projected area and the maximum height in the direction perpendicular to this cross-section is such that the cross-sectional diameter / maximum height ≥ 3.

[0118] Preferably, the inorganic filler has at least a portion of it that is oriented in the direction from the bottom 52 side toward the opening 51 side on the side wall portion 53 of the case 50, and a portion that is oriented toward the outer circumference of the side wall portion 53, and is dispersed inside the case 50.

[0119] The inorganic filler material is preferably 5 μm or larger in diameter and 50 μm or larger in length.

[0120] It is preferable that the inorganic filler is dispersed throughout the case 50 without agglomerating.

[0121] Examples of inorganic fillers include fibrous glass fillers, plate-shaped talc, or mica. Among these, it is preferable that the inorganic filler primarily contains fibrous glass fillers.

[0122] 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 the inorganic filler described above.

[0123] The resin case is manufactured by methods such as injection molding and 3D printing (three-dimensional modeling).

[0124] If case 50 is a metal case, examples of metals that make up the metal case include elemental metals such as aluminum, magnesium, iron, stainless steel, and copper, as well as alloys containing at least one of these elemental metals. In particular, it is preferable that the metal case contains aluminum or an aluminum alloy.

[0125] The metal case is manufactured by methods such as impact molding and 3D printing (three-dimensional molding).

[0126] <Sealing resin> The sealing resin 60 is filled inside the case 50 so that the capacitor element 10 is embedded within it. This fixes the capacitor element 10 in place within the case 50 using the sealing resin 60.

[0127] The sealing resin 60 is filled inside the case 50 so that the first busbar 20, the second busbar 30, and the insulator 40 are drawn out from the inside to the outside. In the example shown in Figure 1, the first busbar 20, the second busbar 30, and the insulator 40 are drawn out from the inside to the outside of the sealing resin 60 and also from the inside to the outside of the case 50. The first busbar 20 and the second busbar 30 (specifically, the first terminal 21 and the second terminal 31) drawn out in this way are electrically connected to an object to be connected, such as a substrate or device, by laser welding, for example, with insulation between them ensured by the insulator 40.

[0128] In the example shown in Figure 1, the first terminal 21 and the second terminal 31 are misaligned when viewed from the direction in which the first busbar 20 and the second busbar 30 protrude from the sealing resin 60 (first direction D1 in Figure 1) (they are misaligned in the third direction D3 in Figure 1), but the first terminal 21 and the second terminal 31 do not have to be misaligned (they may overlap).

[0129] If the capacitor element 10 is housed inside the case 50 so as to be separated from the inner surface of the case 50, it is preferable that the sealing resin 60 is filled between the capacitor element 10 and the case 50, specifically between the outer surface of the capacitor element 10 and the inner surface of the case 50. Furthermore, it is preferable that the sealing resin 60 is filled not only between the capacitor element 10 and the case 50, but also in the area extending from the opening 51 of the case 50 to the capacitor element 10.

[0130] From the viewpoint of suppressing the intrusion of moisture from the sealing resin 60 itself into the capacitor element 10, it is preferable that the thickness of the sealing resin 60 at the opening 51 of the case 50 is large. The thickness of the sealing resin 60 at the opening 51 of the case 50 is preferably sufficiently large within the allowable range of the overall volume (size) of the capacitor element 10 and the case 50, specifically preferably 2 mm or more, and more preferably 4 mm or more. Furthermore, it is preferable to position the capacitor element 10 on the bottom 52 side rather than the opening 51 side within the case 50 so that the thickness of the sealing resin 60 over the capacitor element 10 is larger on the opening 51 side than on the bottom 52 side.

[0131] The thickness of the sealing resin 60 is measured, for example, using a soft X-ray device in a non-destructive state, and using a length measuring device such as a caliper in a destructive state.

[0132] In the first direction D1, the relationship between the height of the case 50 and the height of the sealing resin 60 is such that the thickness of the sealing resin 60 at the opening 51 of the case 50 is as large as possible, and it may extend to the inside of the case 50, or it may fill it to the brim, or it may slightly overflow due to surface tension.

[0133] As the sealing resin 60, it is preferable to appropriately select a resin with low moisture permeability from the viewpoint of suppressing the penetration of moisture from the sealing resin 60 itself into the capacitor element 10. Examples include epoxy resin, silicone resin, and urethane resin. Examples of curing agents for epoxy resin include amine curing agents and imidazole curing agents.

[0134] As the sealing resin 60, only the resin described above may be used, but a resin to which a reinforcing agent has been added may also be used for the purpose of improving strength. Examples of reinforcing agents include silica and alumina.

[0135] The following describes the characteristics of the capacitor module 1, specifically the form of the insulator 40 and the sealing resin 60. In addition to Figures 1, 2, and 3, Figures 6, 7, and 8 below will also be referenced in the following description.

[0136] Figure 6 is a schematic cross-sectional view showing an example of a cross-section along the line A1-A2 of the capacitor module in Figure 1. Figure 7 is a schematic cross-sectional view showing an example of a cross-section along the line B1-B2 of the capacitor module in Figure 1. Figure 8 is a schematic perspective view showing an example of an insulator in Figures 6 and 7.

[0137] As shown in Figures 6 and 7, in the capacitor module 1, a first recess 71 is provided on the surface of the insulator 40 on the first busbar 20 side inside the sealing resin 60, opening at the end of the insulator 40. Furthermore, as shown in Figures 6 and 7, in the capacitor module 1, the sealing resin 60 is in contact with the insulator 40 while penetrating into the first recess 71. As a result, the contact area between the insulator 40 and the sealing resin 60 is increased in the capacitor module 1, and combined with the anchoring effect of the sealing resin 60, the insulator 40 is more easily fixed by the sealing resin 60 that has penetrated into the first recess 71. Therefore, in the capacitor module 1, even if the capacitor element 10 expands due to absorbing moisture and tries to push the insulator 40, the insulator 40 becomes less likely to move. Consequently, in the capacitor module 1, the situation in which the capacitor element 10 expands due to absorbing moisture and pushes the insulator 40, and the pushed insulator 40 pushes the first busbar 20 and the second busbar 30, becomes less likely. Therefore, in the capacitor module 1, the first busbar 20, the second busbar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, thus making the sealing resin 60 less likely to crack. As a result, in the capacitor module 1, even if the capacitor element 10 expands due to absorbing moisture, it is possible to suppress cracking of the sealing resin 60, and consequently, it is possible to suppress a decrease in reliability.

[0138] Furthermore, in the capacitor module 1, as described above, the insulator 40 is more easily fixed by the sealing resin 60 that has entered the first recess 71. Therefore, even if the capacitor element 10, which has expanded due to absorbing moisture, tries to push against the first bus bar 20, the second bus bar 30, and the insulator 40, the gap between the first bus bar 20 and the insulator 40, and the gap between the second bus bar 30 and the insulator 40, will not easily become larger. As a result, in the capacitor module 1, it is less likely that moisture will penetrate into the capacitor element 10 inside the sealing resin 60 from areas outside the sealing resin 60, such as the boundary between the first bus bar 20 and the insulator 40, and the boundary between the second bus bar 30 and the insulator 40. Consequently, the capacitor module 1 can improve moisture resistance, which is related to reliability.

[0139] Furthermore, in the capacitor module 1, as described above, the insulator 40 is more easily fixed by the sealing resin 60 that has entered the first recess 71. Therefore, even if the capacitor element 10, which has expanded due to absorbing moisture, tries to push against the first bus bar 20, the second bus bar 30, and the insulator 40, the relative positions of the first bus bar 20, the second bus bar 30, and the insulator 40 are less likely to change, and consequently, the first bus bar 20 and the second bus bar 30 are less likely to separate from each other. Thus, in the capacitor module 1, it is possible to suppress the increase in equivalent series inductance (ESL) between the first bus bar 20 and the second bus bar 30.

[0140] Furthermore, in the capacitor module 1, when the first busbar 20 and the second busbar 30 are electrically connected to an object to be connected, such as a substrate or device, and especially when the first busbar 20 and the second busbar 30 are laser-welded to the object to be connected, it is desirable to have high positional accuracy of the first busbar 20 and the second busbar 30 relative to the object to be connected, for reasons such as facilitating the connection of the first busbar 20 and the second busbar 30 to the object to be connected. In contrast, in the capacitor module 1, as described above, even if the capacitor element 10 expands due to absorbing moisture, the positional relationship between the first busbar 20 and the second busbar 30 is less likely to change, making it possible to have high positional accuracy of the first busbar 20 and the second busbar 30 relative to the object to be connected.

[0141] Furthermore, if a super engineering plastic, more preferably a polyphenylene sulfide resin, is used as the insulator 40 to improve its insulating properties, there is a possibility that the adhesion between the insulator 40 and the sealing resin 60 will decrease. Even in this case, as described above, because the sealing resin 60 enters the first recess 71 and is in contact with the insulator 40, the contact area between the insulator 40 and the sealing resin 60 tends to increase, thus suppressing the decrease in adhesion between the insulator 40 and the sealing resin 60.

[0142] The surface of the insulator 40 on the first busbar 20 side only needs to be a surface that can be substantially described as being located on the first busbar 20 side among the opposing surfaces of the insulator 40. Specifically, the surface of the insulator 40 on the first busbar 20 side includes not only the first opposing surface facing the first busbar 20, but also a first non-opposing surface that does not face the first busbar 20 but is on the same plane as the first opposing surface (connected to the first opposing surface). In the example shown in Figure 6, the first recess 71 is provided on the first opposing surface of the insulator 40 that is located on the first busbar 20 side and faces the first busbar 20.

[0143] As the sealing resin 60 enters the first recess 71 and comes into contact with the insulator 40, it is sufficient that it is in contact with the inner wall surface of the first recess 71.

[0144] Preferably, the sealing resin 60 penetrates into the first recess 71 and further contacts the first busbar 20. In the example shown in Figure 6, the sealing resin 60 penetrates into the portion of the first part 40a of the insulator 40 within the first recess 71, thereby contacting the first busbar 20. When the sealing resin 60 is in contact with the first busbar 20 in addition to the insulator 40, the first busbar 20 and the insulator 40 are more easily fixed integrally by the sealing resin 60. Therefore, even if the capacitor element 10, which has expanded due to absorbing moisture, tries to press against the first busbar 20, the second busbar 30, and the insulator 40, the first busbar 20 and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, making the sealing resin 60 much less likely to crack.

[0145] The sealing resin 60 is preferably filled inside the first recess 71, and more preferably filled in the region surrounded by the first busbar 20 and the first recess 71. In this case, it is easier to realize a configuration in which the sealing resin 60 penetrates into the first recess 71 while being in contact with the first busbar 20 and the insulator 40.

[0146] The insulator 40 may be bent inside the sealing resin 60. In the example shown in Figure 6, the insulator 40 has a first portion 40a that extends inside the sealing resin 60 in a direction along the side surface 11c of the element 11 on which the first external electrode 12a and the second external electrode 12b are not provided on the surface of the capacitor element 10, and a second portion 40b that extends from the inside to the outside of the sealing resin 60 relative to the first portion 40a. The first portion 40a and the second portion 40b extend in directions that intersect each other, and in this case, in directions perpendicular to each other. In other words, the insulator 40 is bent inside the sealing resin 60 at the connection point between the first portion 40a and the second portion 40b.

[0147] The insulator 40 does not need to be bent inside the sealing resin 60.

[0148] The location of the first recess 71 provided in the insulator 40 is not particularly limited, as long as it is a location within the sealing resin 60 that can be opened at the end of the insulator 40, thereby allowing the sealing resin 60 to enter. For example, the first recess 71 may be provided in at least one of the first portion 40a and the second portion 40b of the insulator 40. In other words, the first recess 71 may be provided in the insulator 40 only in the first portion 40a, only in the second portion 40b, or in both the first portion 40a and the second portion 40b.

[0149] The first recess 71 only needs to be located inside the sealing resin 60 in some part. In other words, the entire first recess 71 may be located inside the sealing resin 60, or only a part of it may be located inside the sealing resin 60 (a part of it may be exposed from the sealing resin 60). From the viewpoint of increasing the amount of sealing resin 60 that enters the first recess 71 and more firmly fixing the insulator 40 with the sealing resin 60 that enters the first recess 71, it is preferable that the entire first recess 71 is located inside the sealing resin 60.

[0150] The shape of the first recess 71 provided in the insulator 40 is not particularly limited as long as it is a shape that can be opened at the end of the insulator 40 inside the sealing resin 60, thereby allowing the sealing resin 60 to enter. For example, the planar shape of the first recess 71 (in Figure 8, the planar shape when viewed from the first direction D1) may be a shape in which the width is constant from one end to the other, a tapered shape in which the width decreases from one end to the other, or a tapered shape in which the width increases from one end to the other. The planar shape of the first recess 71 may be a shape in which the outer edge is composed of a straight line, a shape in which the outer edge is composed of a curve, or a shape in which the outer edge is composed of both a straight line and a curve. Furthermore, for example, the cross-sectional shape of the first recess 71 (in Figure 8, the cross-sectional shape when viewed along the first direction D1 and the third direction D3 (corresponding to Figure 7)) may be a shape in which the width (diameter) is constant from the insulator 40 side toward the opposite side of the insulator 40, or a tapered shape in which the width (diameter) decreases from the insulator 40 side toward the opposite side of the insulator 40, or a tapered shape in which the width (diameter) increases from the insulator 40 side toward the opposite side of the insulator 40. The cross-sectional shape of the first recess 71 may be a shape in which the outer edge is composed of a straight line, or a shape in which the outer edge is composed of a curve, or a shape in which the outer edge is composed of both a straight line and a curve.

[0151] The first recess 71 may or may not extend in any direction (for example, it may be provided locally at the end of the insulator 40).

[0152] If the first recess 71 extends, the first recess 71 will constitute a channel into which the sealing resin 60 enters. Furthermore, if the first recess 71 extends so as to face the first bus bar 20, the region enclosed by the first bus bar 20 and the first recess 71 will constitute a channel into which the sealing resin 60 enters.

[0153] If the first recess 71 extends, it may extend in one direction or it may bend along the way and extend in multiple directions.

[0154] The number of first recesses 71 provided in the insulator 40 is not particularly limited. In other words, the insulator 40 may have one first recess 71 or may have multiple first recesses 71.

[0155] If the insulator 40 is provided with a plurality of first recesses 71, the shapes (including the planar shape and cross-sectional shape) of the plurality of first recesses 71 may be the same as each other, may be different from each other, or may be different in part.

[0156] If the insulator 40 is provided with a plurality of first recesses 71, and the plurality of first recesses 71 extend in the same direction, the directions in which the plurality of first recesses 71 extend may be the same, different from each other, or partially different.

[0157] When the insulator 40 is provided with a plurality of first recesses 71, the arrangement of the plurality of first recesses 71 is not particularly limited. For example, the plurality of first recesses 71 may be arranged regularly or irregularly.

[0158] Preferably, the first recess 71 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Figure 6, the first recess 71 extends in a second direction D2 parallel to the side surface 11c of the element 11 where the first external electrode 12a and the second external electrode 12b are not provided, in the first portion 40a of the insulator 40.

[0159] On the other hand, when the capacitor element 10 expands due to the absorption of moisture, the capacitor element 10 is more likely to expand on the surface side where the first external electrode 12a and the second external electrode 12b are not provided than on the surface side where the first external electrode 12a and the second external electrode 12b are provided. In the example shown in Figure 6, the capacitor element 10 is more likely to expand on the side surface 11c of the base body 11 than on the first end surface 11a and the second end surface 11b of the base body 11. In other words, in the example shown in Figure 6, the capacitor element 10 is more likely to expand in the first direction D1 and the third direction D3, which the side surface 11c of the base body 11 faces, than in the second direction D2, which the first end surface 11a and the second end surface 11b of the base body 11 face. Thus, in the example shown in Figure 6, etc., if the capacitor element 10 is prone to expanding on the side surface 11c of the main body 11, in this case, if the capacitor element 10 is prone to expanding in the first direction D1, then the expanded capacitor element 10 will exert a force that tries to push up the insulator 40, and furthermore, the insulator 40 will exert a force that tries to push up the first busbar 20, both of which are applied in the first direction D1.

[0160] In contrast, in the example shown in Figure 6, etc., if a first recess 71 extending in the second direction D2 is provided in the insulator 40, the sealing resin 60 will enter the first recess 71 and come into contact with the insulator 40 along the second direction D2, which is perpendicular to the first direction D1, where the expanding capacitor element 10 exerts a force to push up the insulator 40, and furthermore, the insulator 40 exerts a force to push up the first busbar 20. As a result, the movement of the insulator 40 pushed up in the first direction D1 by the expanding capacitor element 10 is more easily suppressed by the sealing resin 60 that enters the first recess 71 along the second direction D2, which is perpendicular to the first direction D1, and fixes the insulator 40. As a result, even if the capacitor element 10 tends to expand on the side 11c of the base body 11, even if the capacitor element 10 tends to expand in the first direction D1, the first bus bar 20, the second bus bar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, making the sealing resin 60 very less likely to crack.

[0161] If the first recess 71 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, then the direction in which the first recess 71 extends should be a direction that can be substantially said to be along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. Preferably, the direction in which the first recess 71 extends is parallel to the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, but it does not have to be strictly parallel.

[0162] If the first recess 71 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, the first recess 71 may extend in the second direction D2, as shown in Figure 6, etc., or in the third direction D3, or in both directions D2 and D3. In any case, the first recess 71 may extend in a straight line, in a curved line, or in a shape that is a combination of a straight line and a curve.

[0163] It is preferable that, within the sealing resin 60, a second recess 72 is provided on the surface of the insulator 40 on the second busbar 30 side, which opens at the end of the insulator 40. Furthermore, it is preferable that the sealing resin 60 is in contact with the insulator 40 while penetrating into the second recess 72. In this case, the insulator 40 is more easily fixed not only by the sealing resin 60 that has penetrated into the first recess 71, but also by the sealing resin 60 that has penetrated into the second recess 72. Therefore, even if the capacitor element 10 expands by absorbing moisture and tries to push the insulator 40, the insulator 40 becomes less likely to move. As a result, it becomes less likely that the capacitor element 10, which has expanded by absorbing moisture, will push the insulator 40, and that the pushed insulator 40 will push the first busbar 20 and the second busbar 30. Consequently, the first busbar 20, the second busbar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, making the sealing resin 60 less likely to crack.

[0164] The surface of the insulator 40 on the second busbar 30 side only needs to be a surface that can be substantially described as being located on the second busbar 30 side among the opposing surfaces of the insulator 40. Specifically, the surface of the insulator 40 on the second busbar 30 side includes not only the second opposing surface that faces the second busbar 30, but also the second non-opposing surface that does not face the second busbar 30 but is on the same plane as the second opposing surface (connected to the second opposing surface). In the example shown in Figure 6, the second recess 72 is provided on the second non-opposing surface of the insulator 40 that is located on the second busbar 30 side but does not face the second busbar 30.

[0165] As the sealing resin 60 enters the second recess 72 and comes into contact with the insulator 40, it is sufficient that it is in contact with the inner wall surface of the second recess 72.

[0166] The location of the second recess 72 provided in the insulator 40 is not particularly limited, as long as it is a location within the sealing resin 60 that can be opened at the end of the insulator 40, thereby allowing the sealing resin 60 to enter. For example, the second recess 72 may be provided in at least one of the first portion 40a and the second portion 40b of the insulator 40. In other words, the second recess 72 may be provided only in the first portion 40a of the insulator 40, or only in the second portion 40b, or in both the first portion 40a and the second portion 40b.

[0167] The second recess 72 only needs to be located inside the sealing resin 60 in some part. In other words, the entire second recess 72 may be located inside the sealing resin 60, or only a part of it may be located inside the sealing resin 60 (or a part of it may be exposed from the sealing resin 60). From the viewpoint of increasing the amount of sealing resin 60 that enters the second recess 72 and more firmly fixing the insulator 40 with the sealing resin 60 that enters the second recess 72, it is preferable that the entire second recess 72 is located inside the sealing resin 60.

[0168] When the insulator 40 is provided with a first recess 71 and a second recess 72, the second recess 72 may or may not overlap the first recess 71 via the insulator 40. In the example shown in Figure 6, the second recess 72 may or may not overlap the first recess 71 in the first direction D1 via the insulator 40. In the latter case, the second recess 72 may be offset from the first recess 71 in the third direction D3.

[0169] The shape of the second recess 72 provided in the insulator 40 is not particularly limited as long as it is a shape that can be opened at the end of the insulator 40 inside the sealing resin 60, thereby allowing the sealing resin 60 to enter. For example, the planar shape of the second recess 72 (in Figure 8, the planar shape when viewed from the first direction D1) may be a shape in which the width is constant from one end to the other, a tapered shape in which the width decreases from one end to the other, or a tapered shape in which the width increases from one end to the other. The planar shape of the second recess 72 may be a shape in which the outer edge is composed of a straight line, a shape in which the outer edge is composed of a curve, or a shape in which the outer edge is composed of both a straight line and a curve. Furthermore, for example, the cross-sectional shape of the second recess 72 (in Figure 8, the cross-sectional shape when viewed along the first direction D1 and the third direction D3 (corresponding to Figure 7)) may be a shape in which the width (diameter) is constant from the insulator 40 side toward the opposite side of the insulator 40, or a tapered shape in which the width (diameter) decreases from the insulator 40 side toward the opposite side of the insulator 40, or a tapered shape in which the width (diameter) increases from the insulator 40 side toward the opposite side of the insulator 40. The cross-sectional shape of the second recess 72 may be a shape in which the outer edge is composed of a straight line, or a shape in which the outer edge is composed of a curve, or a shape in which the outer edge is composed of both a straight line and a curve.

[0170] The second recess 72 may or may not extend in any direction (for example, it may be provided locally at the end of the insulator 40).

[0171] If the second recess 72 extends, the second recess 72 will constitute a channel into which the sealing resin 60 enters. Furthermore, if the second recess 72 extends so as to face the second bus bar 30, the area enclosed by the second bus bar 30 and the second recess 72 will constitute a channel into which the sealing resin 60 enters.

[0172] If the second recess 72 extends, it may extend in one direction or it may bend along the way and extend in multiple directions.

[0173] The number of second recesses 72 provided in the insulator 40 is not particularly limited. In other words, the insulator 40 may have one second recess 72, or it may have multiple second recesses 72.

[0174] If the insulator 40 is provided with a plurality of second recesses 72, the shapes of the plurality of second recesses 72 (including the planar shape and cross-sectional shape) may be the same as each other, may be different from each other, or may be different in part.

[0175] If the insulator 40 is provided with a plurality of second recesses 72, and the plurality of second recesses 72 extend in the same direction, the directions in which the plurality of second recesses 72 extend may be the same, different from each other, or partially different.

[0176] When the insulator 40 is provided with a plurality of second recesses 72, the arrangement of the plurality of second recesses 72 is not particularly limited. For example, the plurality of second recesses 72 may be arranged regularly or irregularly.

[0177] Preferably, the second recess 72 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Figure 6, the second recess 72 extends in a second direction D2 parallel to the side surface 11c of the element 11 where the first external electrode 12a and the second external electrode 12b are not provided, in the first portion 40a of the insulator 40.

[0178] In the example shown in Figure 6, etc., if a second recess 72 extending in the second direction D2 is provided in the insulator 40, the sealing resin 60 will enter the second recess 72 and come into contact with the insulator 40 along the second direction D2, which is perpendicular to the first direction D1, in response to the force applied in the first direction D1 by the expanded capacitor element 10 that tries to push up the insulator 40. As a result, the movement of the insulator 40 pushed up in the first direction D1 by the expanded capacitor element 10 is more easily suppressed by the sealing resin 60 that enters the second recess 72 along the second direction D2, which is perpendicular to the first direction D1, and fixes the insulator 40. As a result, even if the capacitor element 10 tends to expand on the side 11c of the base body 11, even if the capacitor element 10 tends to expand in the first direction D1, the first bus bar 20, the second bus bar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, making the sealing resin 60 very less likely to crack.

[0179] If the second recess 72 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, then the direction in which the second recess 72 extends should be a direction that can be substantially said to be along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. Preferably, the direction in which the second recess 72 extends is parallel to the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, but it does not have to be strictly parallel.

[0180] If the second recess 72 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, the second recess 72 may extend in the second direction D2, as shown in Figure 6, etc., or in the third direction D3, or in both directions D2 and D3. In any case, the second recess 72 may extend in a straight line, in a curved line, or in a shape that is a combination of a straight line and a curve.

[0181] Figure 9 is a schematic cross-sectional view showing another example of the capacitor module of the present invention. Figure 10 is a schematic perspective view showing an example of the insulator in Figure 9.

[0182] As shown in the capacitor module 2 in Figure 9, it is preferable that the first recess 71 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, and further extends in a direction intersecting the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Figure 9, the first recess 71 extends in a second direction D2 parallel to the side surface 11c of the body 11 on which the capacitor element 10 is not provided, in the first portion 40a of the insulator 40. In addition, in the example shown in Figure 9, the first recess 71 further extends in a first direction D1 perpendicular to the side surface 11c of the body 11 on which the capacitor element 10 is not provided, in the second portion 40b of the insulator 40. In other words, in the example shown in Figure 9, the first recess 71 extends continuously from the second direction D2 to the first direction D1 across the first portion 40a to the second portion 40b of the insulator 40.

[0183] As shown in Figure 9, it is preferable that the second recess 72 extends in a direction along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, and further extends in a direction intersecting the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Figure 9, the second recess 72 extends in a second direction D2 parallel to the side surface 11c of the body 11 on which the capacitor element 10 is not provided, in the first portion 40a of the insulator 40. In addition, in the example shown in Figure 9, the second recess 72 further extends in a first direction D1 perpendicular to the side surface 11c of the body 11 on which the capacitor element 10 is not provided, in the second portion 40b of the insulator 40. In other words, in the example shown in Figure 9, the second recess 72 extends continuously from the second direction D2 to the first direction D1 across the first portion 40a to the second portion 40b of the insulator 40.

[0184] Preferably, the sealing resin 60 penetrates into the second recess 72 and further contacts the second busbar 30. In the example shown in Figure 9, the sealing resin 60 penetrates into the portion of the second part 40b of the insulator 40 within the second recess 72, thereby contacting the second busbar 30. When the sealing resin 60 is in contact with the second busbar 30 in addition to the insulator 40, the second busbar 30 and the insulator 40 are more easily fixed integrally by the sealing resin 60. Therefore, even if the capacitor element 10, which has expanded due to absorbing moisture, tries to press against the first busbar 20, the second busbar 30, and the insulator 40, the second busbar 30 and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, making the sealing resin 60 much less likely to crack.

[0185] The sealing resin 60 is preferably filled inside the second recess 72, and more preferably filled in the area surrounded by the second busbar 30 and the second recess 72. In this case, it is easier to realize an embodiment in which the sealing resin 60 penetrates into the second recess 72 while being in contact with the second busbar 30 and the insulator 40.

[0186] As described above, in capacitor module 2, compared to capacitor module 1, the first recess 71 and second recess 72 into which the sealing resin 60 enters are longer, which increases the contact area between the insulator 40 and the sealing resin 60, making it easier for the insulator 40 to be more firmly fixed by the sealing resin 60. Therefore, in capacitor module 2, even if the capacitor element 10 expands due to absorbing moisture and tries to push the insulator 40, the insulator 40 will be less likely to move compared to capacitor module 1. As a result, in capacitor module 2, compared to capacitor module 1, the situation in which the expanded capacitor element 10 pushes the insulator 40 and the pushed insulator 40 pushes the first bus bar 20 and the second bus bar 30 is less likely to occur. Consequently, in capacitor module 2, compared to capacitor module 1, the first bus bar 20, the second bus bar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, making the sealing resin 60 less likely to crack. As described above, in capacitor module 2, even if the capacitor element 10 expands due to absorbing moisture, cracking of the sealing resin 60 can be suppressed more effectively compared to capacitor module 1, and consequently, the decrease in reliability can be suppressed more effectively.

[0187] Furthermore, in capacitor module 2, as described above, the insulator 40 is more firmly fixed by the sealing resin 60 compared to capacitor module 1. Therefore, even if the capacitor element 10, which has expanded due to absorbing moisture, tries to push against the first bus bar 20, the second bus bar 30, and the insulator 40, the gap between the first bus bar 20 and the insulator 40, and the gap between the second bus bar 30 and the insulator 40, will not become as large compared to capacitor module 1. As a result, in capacitor module 2, compared to capacitor module 1, it is less likely that moisture will penetrate into the capacitor element 10 inside the sealing resin 60 from areas outside the sealing resin 60, such as the boundary between the first bus bar 20 and the insulator 40, and the boundary between the second bus bar 30 and the insulator 40. Consequently, capacitor module 2 can achieve improved moisture resistance, which is related to reliability, compared to capacitor module 1.

[0188] Furthermore, as described above, in capacitor module 2, compared to capacitor module 1, the insulator 40 is more firmly fixed by the sealing resin 60. Therefore, even if the capacitor element 10, which has expanded due to absorbing moisture, tries to push against the first bus bar 20, the second bus bar 30, and the insulator 40, the relative positions of the first bus bar 20, the second bus bar 30, and the insulator 40 are less likely to change compared to capacitor module 1, and consequently, the first bus bar 20 and the second bus bar 30 are less likely to separate from each other. Thus, in capacitor module 2, compared to capacitor module 1, it is possible to further suppress the increase in equivalent series inductance (ESL) between the first bus bar 20 and the second bus bar 30.

[0189] Furthermore, in capacitor module 2, even if the capacitor element 10 expands due to absorbing moisture, the relative position of the first busbar 20 and the second busbar 30 is less likely to change compared to capacitor module 1, as described above. Therefore, it is possible to achieve higher positional accuracy of the first busbar 20 and the second busbar 30 with respect to the object to which they are connected.

[0190] Furthermore, in capacitor module 2, as described above, the insulator 40 is more easily fixed more firmly by the sealing resin 60 compared to capacitor module 1. Therefore, even when a super engineering plastic, more preferably polyphenylene sulfide resin, is used as the insulator 40, the contact area between the insulator 40 and the sealing resin 60 tends to increase, which in turn helps to further suppress the decrease in adhesion between the insulator 40 and the sealing resin 60.

[0191] In the example shown in Figure 10, the first recess 71 extends continuously from the first portion 40a to the second portion 40b of the insulator 40. In this case, when manufacturing the insulator 40 by a molding method using a mold, the insulator 40 can be easily removed from the mold even if the first recess 71 is provided in the insulator 40.

[0192] The first recess 71 does not have to extend continuously from the first portion 40a to the second portion 40b of the insulator 40. Specifically, the first recess 71 may extend independently in the first portion 40a and the second portion 40b of the insulator 40, such that the first recess 71 extending in the first portion 40a of the insulator 40 and the first recess 71 extending in the second portion 40b of the insulator 40 are not connected to each other. For example, a first recess 71 extending in the second direction D2 in the first portion 40a of the insulator 40 and a first recess 71 extending in the third direction D3 in the second portion 40b of the insulator 40 may coexist. Also, for example, a first recess 71 extending in the third direction D3 in the first portion 40a of the insulator 40 and a first recess 71 extending in the third direction D3 in the second portion 40b of the insulator 40 may coexist.

[0193] The above describes two embodiments: one in which the first recess 71 is provided only in the first portion 40a of the insulator 40 (capacitor module 1), and another in which the first recess 71 is provided in both the first portion 40a and the second portion 40b of the insulator 40 (capacitor module 2). However, the first recess 71 may also be provided only in the second portion 40b of the insulator 40. In other words, the first recess 71 may be provided in at least one of the first portion 40a and the second portion 40b of the insulator 40.

[0194] In the example shown in Figure 10, the second recess 72 extends continuously from the first portion 40a to the second portion 40b of the insulator 40. In this case, when manufacturing the insulator 40 by a molding method using a mold, the insulator 40 can be easily removed from the mold even if the second recess 72 is provided in the insulator 40.

[0195] The second recess 72 does not have to extend continuously from the first portion 40a to the second portion 40b of the insulator 40. Specifically, the second recess 72 may extend independently in the first portion 40a and the second portion 40b of the insulator 40, such that the second recess 72 extending in the first portion 40a of the insulator 40 and the second recess 72 extending in the second portion 40b of the insulator 40 are not connected to each other. For example, a second recess 72 extending in the second direction D2 in the first portion 40a of the insulator 40 and a second recess 72 extending in the third direction D3 in the second portion 40b of the insulator 40 may coexist. Also, for example, a second recess 72 extending in the third direction D3 in the first portion 40a of the insulator 40 and a second recess 72 extending in the third direction D3 in the second portion 40b of the insulator 40 may coexist.

[0196] The above describes two embodiments: one in which the second recess 72 is provided only in the first portion 40a of the insulator 40 (capacitor module 1), and another in which the second recess 72 is provided in both the first portion 40a and the second portion 40b of the insulator 40 (capacitor module 2). However, the second recess 72 may be provided only in the second portion 40b of the insulator 40. In other words, the second recess 72 may be provided in at least one of the first portion 40a and the second portion 40b of the insulator 40.

[0197] The following describes a configuration example in which moisture intrusion into the capacitor element 10 located inside the sealing resin 60 is considered to have a significant impact. Even with the following configuration example, the capacitor module 1, etc., can suppress cracking of the sealing resin 60 caused by the expansion of the capacitor element 10 due to moisture absorption.

[0198] (Configuration Example 1) Within the encapsulating resin 60, at least one selected from the group consisting of the first busbar 20, the second busbar 30, and the insulator 40 may face the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Figure 6, etc., within the encapsulating resin 60, the first busbar 20 and the insulator 40 of the first busbar 20, the second busbar 30, and the insulator 40 face the side surface 11c of the element 11 where the first external electrode 12a and the second external electrode 12b are not provided.

[0199] On the other hand, if the capacitor element 10 expands due to absorbing moisture, as described above, the capacitor element 10 tends to expand on the side 11c of the base body 11 where the first external electrode 12a and the second external electrode 12b are not provided (in the first direction D1 in Figure 6, etc.). When the capacitor element 10 tends to expand on the side 11c of the base body 11 (in the first direction D1 in Figure 6, etc.), the first busbar 20, the second busbar 30, and the insulator 40 that face the side 11c of the base body 11 (the first busbar 20 and the insulator 40 in Figure 6, etc.) tend to be pressed against the sealing resin 60 by the expanded capacitor element 10, which may result in the sealing resin 60 becoming more prone to cracking.

[0200] Even in the above-described case, as mentioned above, because the sealing resin 60 enters the first recess 71 and is in contact with the insulator 40, and more preferably because the sealing resin 60 enters the first recess 71 and the second recess 72 and is in contact with the insulator 40, the first busbar 20, the second busbar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, thus making the sealing resin 60 less likely to crack.

[0201] In this configuration example, if at least one of the first busbar 20 and the second busbar 30 faces the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided, the equivalent series inductance (ESL) of the capacitor module 1 tends to decrease.

[0202] In this configuration example, at least one selected from the group consisting of the first busbar 20, the second busbar 30, and the insulator 40 may or may not be in contact with the surface of the capacitor element 10 that does not have the first external electrode 12a and the second external electrode 12b, when facing the surface of the capacitor element 10 that does not have the first external electrode 12a and the second external electrode 12b. For example, the insulator 40 may or may not be in contact with the surface of the capacitor element 10 that does not have the first external electrode 12a and the second external electrode 12b.

[0203] (Configuration example 2) Within the encapsulating resin 60, the first busbar 20 may extend longer than the second busbar 30 along the surface of the capacitor element 10 where the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in Figure 6, the first busbar 20 extends longer than the second busbar 30 along the side surface 11c of the body 11 where the first external electrode 12a and the second external electrode 12b are not provided on the surface of the capacitor element 10.

[0204] On the other hand, if the capacitor element 10 expands due to absorbing moisture, as described above, the capacitor element 10 is more likely to expand on the side 11c of the base body 11 where the first external electrode 12a and the second external electrode 12b are not provided (in the first direction D1 in Figure 6, etc.). When the capacitor element 10 is more likely to expand on the side 11c of the base body 11 (in the first direction D1 in Figure 6, etc.), the first busbar 20, which extends along the side 11c of the base body 11, is more likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, and as a result, there is a possibility that the sealing resin 60 will be more likely to crack over a wide area.

[0205] Even in the above-described case, as mentioned above, because the sealing resin 60 enters the first recess 71 and is in contact with the insulator 40, and more preferably because the sealing resin 60 enters the first recess 71 and the second recess 72 and is in contact with the insulator 40, the first bus bar 20, and by extension the first bus bar 20, the second bus bar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, thus making the sealing resin 60 less likely to crack.

[0206] (Configuration Example 3) The surface of the capacitor element 10 that does not have the first external electrode 12a and the second external electrode 12b may face the opening 51 of the case 50. In the example shown in Figure 6, the side surface 11c of the body 11 that does not have the first external electrode 12a and the second external electrode 12b faces the opening 51 of the case 50.

[0207] On the other hand, when the capacitor element 10 expands due to absorbing moisture, as described above, the capacitor element 10 tends to expand on the side 11c of the base body 11 where the first external electrode 12a and the second external electrode 12b are not provided (in the first direction D1 in Figure 6, etc.). Also, inside the case 50, the sealing resin 60 is often filled more in the region between the capacitor element 10 and the opening 51 than in other regions. Therefore, as described above, when the capacitor element 10 tends to expand on the side 11c of the base body 11 facing the opening 51 of the case 50 (in the first direction D1 in Figure 6, etc.), the area of ​​the sealing resin 60 that is pressed against the first busbar 20, the second busbar 30, and the insulator 40 (the first busbar 20 and the insulator 40 in Figure 6, etc.) by the expanded capacitor element 10 becomes larger, and as a result, there is a possibility that the sealing resin 60 will become more prone to cracking over a wide area.

[0208] Even in the above-described case, as mentioned above, because the sealing resin 60 enters the first recess 71 and is in contact with the insulator 40, and more preferably because the sealing resin 60 enters the first recess 71 and the second recess 72 and is in contact with the insulator 40, the first busbar 20, the second busbar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, thus making the sealing resin 60 less likely to crack.

[0209] (Configuration example 4) If there are multiple capacitor elements 10, the multiple capacitor elements 10 may be arranged along the bottom 52 of the case 50. Furthermore, the first bus bar 20 and the second bus bar 30 may extend across the multiple capacitor elements 10.

[0210] In this case, moisture that seeps in from areas outside the sealing resin 60, such as the boundary between the first busbar 20 and the insulator 40, and the boundary between the second busbar 30 and the insulator 40, can easily travel along the first busbar 20 and the second busbar 30 and penetrate into the multiple capacitor elements 10 located inside the sealing resin 60. When the multiple capacitor elements 10 expand due to absorbing moisture, the area of ​​the sealing resin 60 that is pressed against the first busbar 20, the second busbar 30, and the insulator 40 by the expanded multiple capacitor elements 10 becomes larger, potentially making the sealing resin 60 more prone to cracking over a wide area.

[0211] Even in the above-described case, as mentioned above, because the sealing resin 60 enters the first recess 71 and is in contact with the insulator 40, and more preferably because the sealing resin 60 enters the first recess 71 and the second recess 72 and is in contact with the insulator 40, the first busbar 20, the second busbar 30, and the insulator 40 are less likely to be pressed against the sealing resin 60 by the expanded capacitor element 10, thus making the sealing resin 60 less likely to crack.

[0212] Although configuration examples 1 to 4 have been described individually above, multiple configuration examples may be combined. Even in this case, the capacitor module 1, etc., makes it possible to suppress cracking of the sealing resin 60 caused by the expansion of the capacitor element 10 due to moisture absorption.

[0213] The capacitor module of the present invention is not limited to the above-described form, and various applications and modifications can be made within the scope of the present invention regarding the configuration, manufacturing conditions, etc., of the capacitor module.

[0214] The capacitor module of the present invention is useful for automotive applications, such as inverters, chargers, DC-DC converters, etc., installed in electric vehicles.

[0215] The capacitor module of the present invention can be applied not only to automotive applications but also to various fields such as power electronics. [Explanation of Symbols]

[0216] 1, 2 Capacitor Modules 10 Capacitor element 11 Base Body 11a First end face of the base body 11b Second end face of the base body 11c Side view of the base body 12a 1st external electrode 12b 2nd external electrode 13a First Metallized Film 13b Second Metallized Film 14a First dielectric film 14aa First main surface of the first dielectric film 14ab Second main surface of the first dielectric film 14b Second Dielectric Film 14ba First main surface of the second dielectric film 14bb Second main surface of the second dielectric film 15a 1st metal layer 15b 2nd metal layer 20 First Bus Bar 20a Class 1 part 20b Type 2 part 21 1st terminal 30 Second Bus Bar 30a Type 3 part 31 2nd terminal 40 Insulator 40a Part 1 40b Part 2 50 cases 51 Opening 52 Bottom 53 Side wall section 60 Sealing resin 71 First recess 72 Second recess D1 1st direction D2 2nd direction D3 Third direction

Claims

1. A capacitor element having a first external electrode and a second external electrode, A first busbar electrically connected to the first external electrode, A second busbar electrically connected to the second external electrode, An insulator sandwiched between the first busbar and the second busbar so as to form a laminated structure together with the first busbar and the second busbar, A case in which the aforementioned capacitor element is housed, The capacitor element is embedded in the case, and the case is filled with a sealing resin such that the first busbar, the second busbar, and the insulator are drawn out from the inside to the outside. Inside the sealing resin, the surface of the insulator on the first busbar side is provided with a first recess that opens at the end of the insulator. A capacitor module characterized in that the sealing resin is in contact with the insulator while being inserted into the first recess.

2. The capacitor module according to claim 1, wherein the sealing resin is in contact with the first busbar while being inserted into the first recess.

3. The capacitor module according to claim 1 or 2, wherein the first recess extends in a direction along the surface of the capacitor element where the first external electrode and the second external electrode are not provided.

4. The capacitor module according to claim 3, wherein the first recess further extends in a direction intersecting the surface of the capacitor element where the first external electrode and the second external electrode are not provided.

5. Within the sealing resin, a second recess is provided on the surface of the insulator on the second busbar side, which is open at the end of the insulator. The capacitor module according to any one of claims 1 to 4, wherein the sealing resin is in contact with the insulator while being inserted into the second recess.

6. The capacitor module according to claim 5, wherein the sealing resin enters into the second recess and further contacts the second busbar.

7. The capacitor module according to claim 5 or 6, wherein the second recess extends in a direction along the surface of the capacitor element where the first external electrode and the second external electrode are not provided.

8. The capacitor module according to claim 7, wherein the second recess further extends in a direction intersecting the surface of the capacitor element where the first external electrode and the second external electrode are not provided.

9. A capacitor module according to any one of claims 1 to 8, wherein, inside the sealing resin, at least one selected from the group consisting of the first busbar, the second busbar, and the insulator faces the surface of the capacitor element where the first external electrode and the second external electrode are not provided.

10. The capacitor module according to claim 9, wherein, within the sealing resin, the first busbar extends longer than the second busbar along the surface of the capacitor element where the first external electrode and the second external electrode are not provided.

11. The capacitor module according to any one of claims 1 to 10, wherein the case is a bottomed cylindrical shape with an opening, and has a bottom facing the opening and a side wall extending from the bottom toward the opening.

12. The capacitor module according to claim 11, wherein the surface of the capacitor element on which the first external electrode and the second external electrode are not provided faces the opening of the case.

13. Multiple capacitor elements are arranged along the bottom of the case, The capacitor module according to claim 11 or 12, wherein the first busbar and the second busbar extend across a plurality of capacitor elements.

14. The capacitor module according to any one of claims 1 to 13, wherein the insulator comprises a super engineering plastic.

15. The capacitor module according to claim 14, wherein the super engineering plastic is a polyphenylene sulfide resin.

16. The capacitor module according to any one of claims 1 to 15, wherein the capacitor element is a film capacitor.

Images