Capacitor module

Abstract

A capacitor module according to the present disclosure comprises: a capacitor element; a first bus bar having a first contact part and a first extension part; a second bus bar having a second contact part and a second extension part extending from the second contact part; a case accommodating the capacitor element and portions of the first bus bar and the second bus bar; and a sealing resin sealing the capacitor element and portions of the first bus bar and the second bus bar. The first extension part includes a first portion having a first surface and a second portion having a second surface, and the second extension part includes a third portion having a third surface and a fourth portion having a fourth surface. The first portion and the third portion are arranged such that the first surface and the third surface face each other inside the sealing resin, and the second portion and the fourth portion are arranged such that the second surface and the fourth surface face each other outside the sealing resin. The distance between the first surface and the third surface is greater than the distance between the second surface and the fourth surface.

Description

Capacitor module

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

[0002] A capacitor module in which a capacitor element is housed in a case and sealed with a sealing resin is known.

[0003] For example, Patent Document 1 discloses a case-molded capacitor including a capacitor element, an exterior case, a pair of bus bars, an insulating member, and a molding resin.

[0004] Japanese Patent Application Laid-Open No. 2020-167270

[0005] In the case-molded capacitor described in Patent Document 1, there is still room for improvement in suppressing cracks in the molding resin and improving moisture resistance.

[0006] The present disclosure provides a capacitor module capable of suppressing cracks in the sealing resin and improving moisture resistance.

[0007] A capacitor module according to an aspect of the present disclosure includes a capacitor element having a first electrode and a second electrode, a first bus bar having a first contact portion contacting the first electrode and a first extending portion extending from the first contact portion, a second bus bar having a second contact portion contacting the second electrode and a second extending portion extending from the second contact portion, a case housing the capacitor element and a part of the first bus bar and the second bus bar, and a sealing resin sealing the capacitor element and a part of the first bus bar and the second bus bar. The first extending portion includes a first portion having a first surface and a second portion having a second surface. The second extending portion includes a third portion having a third surface and a fourth portion having a fourth surface. The first portion and the third portion are arranged such that the first surface and the third surface face each other inside the sealing resin. The second portion and the fourth portion are arranged such that the second surface and the fourth surface face each other outside the sealing resin, and the distance between the first surface and the third surface is larger than the distance between the second surface and the fourth surface.

[0008] According to this disclosure, it is possible to provide a capacitor module that can suppress cracking of the sealing resin and improve moisture resistance.

[0009] Figure 1 shows a schematic perspective view of a capacitor module according to Embodiment 1 of the present disclosure. Figure 1 shows an exploded perspective view of a capacitor module. Figure 1 shows a perspective view of a capacitor element built into the capacitor module. Figure 4A shows a first busbar included in the capacitor module of Figure 1, viewed from the width direction (Y direction). Figure 5A shows a second busbar included in the capacitor module of Figure 1, viewed from the width direction (Y direction). Figure 1 shows a cross-sectional view of A-A. Figure 6 shows an enlarged view of R1 in the region of Embodiment 2. Figure 9 shows a perspective view with the case, sealing resin, and insulating paper of capacitor module 8 omitted. Figure 9 shows an enlarged view of region R2. Figure 9 shows a schematic partial cross-sectional view of a part of the first portion of the first extension. Figure 9 shows a schematic partial cross-sectional view of the first part according to a modified example of Embodiment 2. Figure 13 shows a schematic partial cross-sectional view of the first part according to a modified example of Embodiment 2. Figure 15 shows a perspective view of a capacitor module according to Embodiment 3. Figure 13 shows a perspective view with the case and sealing resin of the capacitor module omitted. Figure 13 shows a cross-sectional view between B and B. Figure 15 shows an enlarged view of region R3. Figure 13 shows a perspective view of the insulator.

[0010] (Background to this disclosure) In capacitor modules in which capacitor elements are housed in a case and sealed with sealing resin, it has been considered that the sealing resin can suppress the intrusion of moisture into the interior of the capacitor elements and thereby suppress the oxidation of electrodes, which is a cause of deterioration of the capacitor elements.

[0011] For example, Patent Document 1 discloses a case-molded capacitor in which an insulating plate is inserted between a pair of rising plate portions of a pair of busbars. Patent Document 1 also discloses that in the region where the pair of busbars are embedded in the molded resin, the pair of busbars and the insulating plate face each other with a minute gap in between.

[0012] However, if a small gap exists between the busbar and the insulating plate, the molding resin may not flow properly between the insulating plate and the busbar, potentially creating voids in the molding resin. In this case, the closer the voids in the molding resin are to the capacitor elements, the worse the moisture resistance of the case-molded capacitor becomes.

[0013] Furthermore, in capacitor modules, it is known that the capacitor elements expand and contract due to the heat cycle, which involves repeated cycles between high and low temperatures during capacitor use. In response to the expansion and contraction of the capacitor elements, stress is applied to the busbars connected to the capacitor elements, and shear stress is applied to the sealing resin. In particular, as in Patent Document 1, when a pair of busbars and an insulating plate face each other, the stress on the facing parts becomes greater, which can cause cracks to occur in the sealing resin. When cracks occur in the sealing resin, it can be an aesthetic problem for the capacitor module, and it can also reduce the moisture resistance of the capacitor module.

[0014] Therefore, the inventors investigated a capacitor module that suppresses cracking of the sealing resin and improves moisture resistance, and arrived at the following invention.

[0015] Embodiments of the present invention will be described below with reference to the attached drawings. Note that in each drawing, elements are exaggerated for the sake of clarity.

[0016] (Embodiment 1) [Overall Configuration] Figure 1 is a schematic perspective view of a capacitor module 1 according to Embodiment 1 of the present disclosure. Figure 2 is an exploded perspective view of Figure 1. In Figure 2, the sealing resin 50 is omitted. The X, Y, and Z directions in the figures represent the depth, width, and height directions of the capacitor module 1, respectively.

[0017] As shown in Figures 1 and 2, the capacitor module 1 comprises a capacitor element 10, a first busbar 20, a second busbar 30, a case 40, and a sealing resin 50.

[0018] In the capacitor module 1, the capacitor element 10 and parts of the first busbar 20 and the second busbar 30 are housed in a case 40 and sealed with sealing resin 50. Parts of the first busbar 20 and the second busbar 30 are exposed from the sealing resin 50 and function as external connection terminals 20a and 30a of the capacitor module 1.

[0019] In this embodiment, as shown in Figure 2, the capacitor module 1 includes four capacitor elements 10.

[0020] <Case> Case 40 is a case for housing components such as the capacitor element 10. As shown in Figure 1, case 40 has, for example, a roughly rectangular parallelepiped shape. Case 40 is also provided with an opening 41 and a bottom 42 on the opposite side of the opening 41. Therefore, case 40 is formed in a box shape with an opening 41. Case 40 houses the capacitor element 10 and a portion of the first busbar 20 and the second busbar 30.

[0021] Case 40 is formed from, for example, a synthetic resin such as polyphenylene sulfide (PPS resin) or polybutylene terephthalate (PBT resin).

[0022] <Sealing Resin> As shown in Figure 1, the sealing resin 50 is filled into the case 40 to seal the capacitor element 10 housed in the case 40 and a portion of the first busbar 20 and the second busbar 30. The sealing resin 50 is made of a thermosetting resin such as epoxy resin or urethane resin. A material with high fluidity and adhesion may be used as the material for the sealing resin 50.

[0023] <Capacitor Element> Figure 3 is a perspective view showing a capacitor element 10 built into the capacitor module 1 of Figure 1. As shown in Figure 3, the capacitor element 10 has a first electrode 11, a second electrode 12, and a side surface 13 connecting the first electrode 11 and the second electrode 12. The first electrode 11 and the second electrode 12 are provided on both end faces of the capacitor element 10.

[0024] In this embodiment, the capacitor element 10 is formed in a columnar shape with an oval end face. That is, the first electrode 11 and the second electrode 12 have an oval shape, and the capacitor element 10 is formed in a columnar shape.

[0025] The capacitor element 10 is a film capacitor composed of a laminate of dielectric films. More specifically, the capacitor element 10 is formed by stacking dielectric films, each having a metal vapor-deposited film on its surface, and then winding them. In this embodiment, the capacitor element 10 is formed into a columnar shape with an oval cross-section by pressing the wound dielectric film into a flattened shape.

[0026] As the dielectric film, for example, a dielectric film formed from a mixed resin solution containing phenoxy resin and MDI (diphenylmethane diisocyanate) can be used. Alternatively, a dielectric film formed from a mixed resin solution containing polyvinyl acetal (PVAA) and tolylene diisocyanate (TDI) may be used. By forming a dielectric film with such a mixed resin solution, the glass transition temperature of the dielectric film can be set to 120°C or higher, thereby improving the heat resistance of the capacitor module. As the metal vapor-deposited film formed on the surface of the dielectric film, for example, metals such as Al and Zn can be used.

[0027] A first electrode 11 is formed on one end face of the wound dielectric film, and a second electrode 12 is formed on the other end face. The first electrode 11 and the second electrode 12 can be formed, for example, by thermal spraying a conductive material containing a metal such as Al or Zn onto the end face of the wound dielectric film.

[0028] The capacitor element 10 is not limited to a film capacitor, but may be other types of capacitors such as ceramic capacitors or electrolytic capacitors.

[0029] As shown in Figure 2, in this embodiment, the first electrode 11 of each of the four capacitor elements 10 is positioned toward the opening 41 of the case 40. Therefore, the second electrode 12 of each of the four capacitor elements 10 is positioned toward the bottom 42 of the case 40.

[0030] <First Busbar> Figure 4A is a perspective view showing the first busbar 20 included in the capacitor module 1 of Figure 1. Figure 4B is a view of the first busbar 20 of Figure 4A from the width direction (Y direction).

[0031] The first busbar 20 is a component for electrically connecting the first electrodes 11 of the four capacitor elements 10 to the terminals of an external device (not shown).

[0032] The first busbar 20 is formed from a conductive material such as a plate-shaped metal. The first busbar 20 has a first contact portion 21 and a first extension portion 22.

[0033] As shown in Figure 2, the first contact portion 21 is the part that contacts the first electrode 11 of the capacitor element 10 and electrically connects the first electrode 11 and the first busbar 20. In this embodiment, the first contact portion 21 is formed in the shape of a plate that covers the four first electrodes 11 of the four capacitor elements 10. As shown in Figure 4A, the first contact portion 21 is provided with four through holes 21a at positions corresponding to each of the first electrodes 11 of the four capacitor elements 10. In addition, each of the four through holes 21a is provided with two protrusions 21b. The connection between the first contact portion 21 and the first electrode 11 is made, for example, by soldering at the portion of the protrusions 21b.

[0034] The first extension portion 22 extends from the first contact portion 21. The first extension portion 22 includes a first portion 23 extending from the first contact portion 21 in a direction intersecting the surface from which the first contact portion 21 extends, and a second portion 24 extending from the first portion 23. As shown in Figure 4B, the first portion 23 has a first surface 23a extending along the YZ plane and a fifth surface 23b opposite to the first surface 23a. The second portion 24 has a second surface 24a extending along the XY plane.

[0035] In this embodiment, as shown in Figure 4B, the first portion 23 is formed by bending near the end of the first contact portion 21, and the second portion 24 is formed by bending near the end of the first portion 23. As shown in Figure 2, the second portion 24 is the part of the first busbar 20 that is located outside the case 40. The second portion 24 is provided with an external connection terminal 20a.

[0036] In this embodiment, the first contact portion 21 and the first extension portion 22 are integrally formed, and the first extension portion 22 is a portion that bends and extends from the first contact portion 21. The first contact portion 21 and the first extension portion 22 may be formed from, for example, another member and electrically connected by welding or soldering.

[0037] <Second Busbar> Figure 5A is a perspective view showing the second busbar 30 included in the capacitor module 1 of Figure 1. Figure 5B is a view of the second busbar 30 of Figure 5A from the width direction (Y direction).

[0038] The second busbar 30 is a component for electrically connecting the second electrodes 12 of the four capacitor elements 10 to the terminals of an external device (not shown).

[0039] The second busbar 30 is formed from a conductive material such as a plate-shaped metal. The second busbar 30 has a second contact portion 31 and a second extension portion 32.

[0040] As shown in Figure 2, the second contact portion 31 is the part that contacts the second electrode 12 of the capacitor element 10 and electrically connects the second electrode 12 and the second busbar 30. In this embodiment, the second contact portion 31 is formed in the shape of a plate that covers the four second electrodes 12 of the four capacitor elements 10. As shown in Figure 5A, the second contact portion 31 is provided with four through holes 31a at positions corresponding to the second electrodes 12 of each of the four capacitor elements 10. In addition, each of the four through holes 31a is provided with two protrusions 31b. The connection between the second contact portion 31 and the second electrode 12 is made, for example, by soldering at the portion of the protrusions 31b.

[0041] The second extending portion 32 extends from the second contact portion 31. The second extending portion 32 includes a third portion 33 that extends from the second contact portion 31 in a direction intersecting the plane in which the second contact portion 31 extends, and a fourth portion 34 that extends from the third portion 33. As shown in FIG. 5B, the third portion 33 has a third surface 33a extending along the YZ plane and a sixth surface 33b on the side opposite to the third surface 33a. The fourth portion 34 has a fourth surface 34a extending along the XY plane.

[0042] In the present embodiment, as shown in FIG. 5B, the third portion 33 is formed by bending from near the end of the second contact portion 31, and the fourth portion 34 is formed by bending from near the end of the third portion 33. As shown in FIG. 2, the fourth portion 34 is a portion of the second bus bar 30 that is disposed outside the case 40. An external connection terminal 30a is provided on the fourth portion 34.

[0043] In the present embodiment, the second contact portion 31 and the second extending portion 32 are integrally formed, and the second extending portion 32 is a portion that extends by bending from the second contact portion 31. The second contact portion 31 and the second extending portion 32 may be formed of separate members and electrically connected by welding or soldering or the like, for example.

[0044] <Arrangement of the First Bus Bar and the Second Bus Bar> Referring to FIGS. 6 to 7, the arrangement of the first bus bar 20 and the second bus bar in the capacitor module 1 will be described. FIG. 6 is a cross-sectional view taken along line A-A of FIG. 1. FIG. 7 is an enlarged view of the region R1 in FIG. 7.

[0045] As shown in FIG. 6, the first bus bar 20 and the second bus bar 30 each have a portion sealed by the encapsulating resin 50 and a portion disposed outside the encapsulating resin 50. In the present embodiment, a part of the first contact portion 21 and the first extending portion 22 of the first bus bar 20 is sealed by the encapsulating resin 50. More specifically, at least a part of the first contact portion 21 and at least a part of the first portion 23 of the first extending portion 22 of the first bus bar 20 are sealed by the encapsulating resin 50. Similarly, in the present embodiment, a part of the second contact portion 31 and the second extending portion 32 of the second bus bar 30 is sealed by the encapsulating resin 50. More specifically, at least a part of the second contact portion 31 and at least a part of the third portion 33 of the second extending portion 32 of the second bus bar 30 are sealed by the encapsulating resin 50.

[0046] In the present embodiment, the first contact portion 21 of the first bus bar 20 is connected to the first electrode 11 of the capacitor element 10 and is disposed along a plane (XY plane) parallel to the bottom portion 42 of the case 40. The first portion 23 of the first extending portion 22 of the first bus bar 20 extends in a direction away from the first electrode 11 of the capacitor element 10 from the first contact portion 21 (+Z direction). The first surface 23a of the first portion 23 is disposed to face the side surface of the case 40. Further, in the present embodiment, as shown in FIG. 7, the first surface 23a of the first portion 23 is disposed inside the case 40 rather than the end portion facing the case 40 of the capacitor element 10 (side surface 13 in FIG. 7).

[0047] The second portion 24 of the first extending portion 22 of the first bus bar 20 extends along the XY plane from the first portion 23. In the present embodiment, the second portion 24 is disposed such that the second surface 24a faces the -Z direction.

[0048] In the present embodiment, the second contact portion 31 of the second bus bar 30 is connected to the second electrode 12 of the capacitor element 10 and is disposed along a plane (XY plane) parallel to the bottom portion 42 of the case 40. The third portion 33 of the second extending portion 32 of the second bus bar 30 extends in the +Z direction along the side surface 13 of the capacitor element 10 from the second contact portion 31. The third portion 33 is disposed such that the third surface 33a faces the side surface 13 of the capacitor element 10.

[0049] The fourth portion 34 of the second extension 32 of the second busbar 30 extends from the third portion 33 along the XY plane. In this embodiment, the fourth portion 34 is positioned such that its fourth surface 34a faces the +Z direction.

[0050] The first portion 23 of the first extension 22 and the third portion 33 of the second extension 32 are arranged such that the first surface 23a and the third surface 33a face each other. Therefore, the fifth surface 23b of the first portion 23 and the sixth surface 33b of the third portion 33 face opposite each other. Similarly, the second portion 24 of the first extension 22 and the fourth portion 34 of the second extension 32 are arranged such that the second surface 24a and the fourth surface 34a face each other.

[0051] Therefore, the first busbar 20 and the second busbar 30 are arranged so that their first extension portion 22 and second extension portion 32 overlap in the planar direction. More specifically, the first portion 23 of the first extension portion 22 and the third portion 33 of the second extension portion 32 overlap in the planar direction, and the second portion 24 of the first extension portion 22 and the fourth portion 34 of the second extension portion 32 overlap in the planar direction. In addition, insulating paper 60, as shown in Figure 2, is placed between the first extension portion 22 and the second extension portion 32 to prevent a short circuit between the first busbar 20 and the second busbar 30.

[0052] The first part 23 and the third part 33 are arranged facing each other via the sealing resin 50 in the direction (Z direction) from the bottom 42 of the case 40 toward the opening 41.

[0053] As shown in Figure 7, the distance d1 between the first surface 23a of the first part 23 and the third surface 33a of the third part 33 is greater than the distance d2 between the second surface 24a of the second part 24 and the fourth surface 34a of the fourth part 34.

[0054] Furthermore, in this embodiment, the distance d1 between the first surface 23a and the third surface 33a is greater than the distance d3 between the third surface 33a and the side surface 13 of the capacitor element 10. This is because the first surface 23a of the first portion 23 is positioned inside the case 40 by a distance d4 shown in Figure 7 from the side surface 13 of the capacitor element 10. By positioning the first surface 23a of the first portion 23 inside the case 40 from the side surface 13 of the capacitor element 10, the distance between the first portion 23 and the third portion 33 can be made larger.

[0055] Furthermore, in this embodiment, the distance d1 between the first surface 23a and the third surface 33a is smaller than the distance d5 between the surface 51 of the sealing resin exposed from the opening 41 and the capacitor element 10. In the example of Figure 7, the distance d5 represents the distance between the first electrode 11 of the capacitor element 10 and the surface 51 of the sealing resin 50.

[0056] When the capacitor module 1 is in use, the capacitor element 10 repeatedly expands and contracts in the direction from the first electrode 11 to the second electrode 12 (Z direction) due to the heat cycle. The first contact portion 21 of the first busbar 20 and the second contact portion 31 of the second busbar 30 are connected to the first electrode 11 and the second electrode 12 of the capacitor element, respectively. Therefore, as the capacitor element 10 expands and contracts, stress is applied to the first busbar 20 and the second busbar 30.

[0057] For example, when the capacitor element 10 expands, a stress is applied to the first busbar 20 in the +Z direction, and a stress is applied to the second busbar 30 in the -Z direction. Conversely, when the capacitor element 10 contracts, a stress is applied to the first busbar 20 in the -Z direction, and a stress is applied to the second busbar 30 in the +Z direction. Therefore, in particular, opposite stresses are applied to the overlapping portion of the first part 23 of the first busbar 20 and the third part 33 of the second busbar 30. This opposite stress causes shear stress to be applied to the sealing resin 50, making it prone to cracking.

[0058] By increasing the distance between the first portion 23 and the third portion 33, that is, by making distance d1 greater than distance d2, the shear stress on the sealing resin 50 can be reduced. This suppresses the occurrence of cracks in the sealing resin 50. Distances d1 and d2 can be adjusted, for example, by changing the position of the first portion 23 or the third portion 33 in the X direction. In this embodiment, as described above, the distance d1 is adjusted to be greater than distance d2 by positioning the first portion 23 inside the case 40 beyond the side surface 13 of the capacitor element 10.

[0059] The distance d1 between the first surface 23a and the third surface 33a is preferably determined based on the allowable inductance value in the capacitor module 1. The larger the distance d1 between the first surface 23a and the third surface 33a, that is, the further apart the first portion 23 and the third portion 33 are positioned, the greater the inductance of the capacitor module 1 tends to be. However, as described above, the closer the first portion 23 and the third portion 33 are, the more likely cracks are to occur in the sealing resin 50. For this reason, it is desirable to determine the distance d1 between the first surface 23a and the third surface 33a after considering the allowable inductance value and the allowable frequency of crack occurrence in the sealing resin 50.

[0060] [Effects] According to the above-described embodiment, the following effects can be achieved.

[0061] The capacitor module 1 comprises a capacitor element 10, a first busbar 20, a second busbar 30, a case 40, and a sealing resin 50. The capacitor element 10 has a first electrode 11 and a second electrode 12. The first busbar 20 has a first contact portion 21 that contacts the first electrode 11 and a first extension portion 22 that extends from the first contact portion 21. The second busbar 30 has a second contact portion 31 that contacts the second electrode 12 and a second extension portion 32 that extends from the second contact portion 31. The case 40 houses the capacitor element 10 and parts of the first busbar 20 and the second busbar 30. The sealing resin 50 seals the capacitor element 10 and parts of the first busbar 20 and the second busbar 30. The first extension portion 22 includes a first part 23 having a first surface 23a and a second part 24 having a second surface 24a. The first part 23 and the third part 33 are arranged inside the sealing resin 50 such that the first surface 23a and the third surface 33a face each other. The second part 24 and the fourth part 34 are arranged outside the sealing resin 50 such that the second surface 24a and the fourth surface 34a face each other. The distance d1 between the first surface 23a and the third surface 33a is greater than the distance d2 between the second surface 24a and the fourth surface 34a.

[0062] This configuration makes it possible to provide a capacitor module that can suppress cracking of the sealing resin and improve moisture resistance. At least a portion of the first portion 23 and the third portion 33 are arranged inside the sealing resin 50. Therefore, the smaller the distance between the first portion 23 and the third portion 33, the greater the shear stress applied to the sealing resin 50 when the capacitor element 10 expands and contracts. Accordingly, by increasing the distance between the first portion 23 and the third portion 33, the shear stress applied to the sealing resin 50 can be reduced, the occurrence of cracks in the sealing resin 50 can be suppressed, and the moisture resistance of the capacitor module 1 can be improved.

[0063] The case 40 has an opening 41 and a bottom 42 opposite to the opening 41. The first electrode 11 is positioned toward the opening 41 of the case 40. The second electrode 12 is positioned toward the bottom 42 of the case 40. The first extension 22 and the second extension 32 are positioned facing each other via the sealing resin 50 in the direction from the bottom 42 toward the opening 41.

[0064] This configuration suppresses cracking of the sealing resin 50 and improves the moisture resistance of the capacitor module 1.

[0065] The second extension portion 32 extends from the bottom portion 42 toward the opening 41 along the side surface 13 of the capacitor element 10. The distance d1 between the first surface 23a and the third surface 33a is greater than the distance d3 between the second extension portion 32 and the side surface 13.

[0066] This configuration makes it possible to more reliably secure the distance d1 between the first surface 23a and the third surface 33a, thereby suppressing cracks in the sealing resin 50 and improving the moisture resistance of the capacitor module 1.

[0067] The distance d1 between the first surface 23a and the third surface 33a is smaller than the distance d5 between the surface of the sealing resin 50 exposed from the opening 41 and the capacitor element 10.

[0068] This configuration suppresses cracking of the sealing resin 50 and improves the moisture resistance of the capacitor module 1.

[0069] An insulating paper 60 is placed between the first extended portion 22 and the second extended portion 32.

[0070] This configuration makes it possible to suppress short circuits between the first busbar 20 and the second busbar 30.

[0071] [Modification] In the above-described embodiment, an example was given in which the capacitor module 1 includes four capacitor elements 10, but the invention is not limited to this. The capacitor module 1 may include one or more capacitor elements 10.

[0072] Furthermore, although the above-described embodiment described an example in which the distance d1 between the first surface 23a and the third surface 333a is greater than the distance d2 between the second surface 24a and the fourth surface 34a, the embodiment is not limited to this. The distance d1 between the first surface 23a and the third surface 33a may be greater than, for example, the minimum distance between the second surface 24a and the fourth surface 334a. Alternatively, the distance d1 between the first surface 23a and the third surface 33a may be greater than the thickness of the first busbar 20 or the second busbar 30.

[0073] (Embodiment 2) Figure 8 is a perspective view showing a capacitor module 2 according to Embodiment 2. Figure 9 is a perspective view of the capacitor module 2 of Figure 8 with the case 40, sealing resin 50, and insulating paper 60 omitted. Figure 10 is an enlarged view of region R2 in Figure 9. As shown in Figures 8 to 10, Embodiment 2 differs from Embodiment 1 in that the end face 123c of the first portion 123 of the first extension 122 and the end face 133c of the third portion 133 of the second extension 132 are chamfered. The other configurations of the capacitor module 2 are the same as in Embodiment 1, so their description is omitted.

[0074] As shown in Figures 8 to 10, in this embodiment, the end face of the portion defining the contour of the first bus bar 20 is chamfered. Similarly, the end face of the portion defining the contour of the second bus bar 30 is also chamfered. Chamfering includes R-chamfering, which processes the corners of the end face into an R shape, and C-chamfering, which forms a 45-degree face at the corners of the end face.

[0075] Figure 11 is a schematic partial cross-sectional view showing a part of the first portion 123 of the first extension 122 in Figure 9. As shown in Figure 11, in this embodiment, the corners of the end face 123c of the first portion 123 are machined so that the corners of the end face 123c of the first portion 123 have a rounded shape.

[0076] The first portion 123 and the third portion 133 are positioned, at least in part, inside the sealing resin 50. Therefore, when the expansion and contraction of the capacitor element 10 increases stress on the first portion 123 and the third portion 133, the shear stress on the sealing resin 50 also increases. By chamfering the corners of the first portion 123 and the third portion 133, the shear stress on the sealing resin 50 can be distributed, and cracks in the sealing resin 50 can be suppressed.

[0077] [Effects] According to the above-described embodiment, the following effects can be achieved.

[0078] The end faces 123c and 133c in the direction along the surface of the sealing resin 50 exposed from the openings 41 of the first portion 23 and the third portion 33 are chamfered.

[0079] This configuration reduces the shear stress on the sealing resin 50, suppressing the occurrence of cracks and improving the moisture resistance of the capacitor module 2.

[0080] [Modified Version] Figures 12A to 12B are schematic partial cross-sectional views showing the first parts 223 and 323 according to a modified version of Embodiment 2.

[0081] As shown in Figure 12A, the entire end face 223c of the first portion 223 may be processed to have a rounded R shape. Also, as shown in Figure 12B, the corners of the end face 323c of the first portion 323 may be chamfered.

[0082] In the above-described embodiment, an example was explained in which the distance between the first surface 23a and the third surface 33a is greater than the distance between the second surface and the fourth surface, similar to Embodiment 1, but the embodiment is not limited to this. When the end faces of the first portion 23 and the third portion 33 are chamfered, the distance between the first surface 23a and the third surface 33a may be the same as the distance between the second surface and the fourth surface. By chamfering the end faces of the first portion 23 and the third portion 33, a stress distribution effect can be achieved. Therefore, even if the distance between the first surface 23a and the third surface 33a is small, the occurrence of cracks in the sealing resin 50 can be suppressed, and the moisture resistance of the capacitor module 2 can be improved.

[0083] (Embodiment 3) Figure 13 is a perspective view showing a capacitor module 3 according to Embodiment 3. Figure 14 is a perspective view of the capacitor module 3 in Figure 13 with the case 40 and sealing resin 50 omitted. Figure 15 is a cross-sectional view taken along line B-B in Figure 13. Figure 16 is an enlarged view of region R3 in Figure 15. Figure 17 is a perspective view showing the insulator 61 in Figure 13. As shown in Figures 13 to 17, Embodiment 3 differs from Embodiment 2 in that, instead of insulating paper, an insulator 61 is placed at the ends of the first portion 23 of the first extension portion 22 and the third portion 33 of the second extension portion 32. The other configurations of the capacitor module 3 are the same as in Embodiment 2, so their description is omitted.

[0084] As shown in Figures 13 to 16, in the capacitor module 3, the first busbar 20 and the second busbar 30 are insulated by an insulator 61. In this embodiment, the first busbar 20 and the second busbar 30 are insulated by inserting a part of the insulator 61 between the first part 23 and the third part 33.

[0085] The insulator 61 is positioned at the ends of the first portion 23 and the third portion 33 in the direction along the XY plane. In this embodiment, as shown in Figures 15 and 16, two insulators 61 are positioned at both ends of the first portion 23 and the third portion 33, but the insulator 61 only needs to be positioned at at least one of the ends of the first portion 23 and the third portion 33.

[0086] As shown in Figures 16 and 17, the insulator 61 is formed in the shape of a three-prong fork, including a first insulating portion 62, a second insulating portion 63, a third insulating portion 64, and a fourth insulating portion 65. The first insulating portion 62 of the insulator 61 is positioned between the first surface 23a of the first portion 23 and the third surface 33a of the third portion 33, maintaining a predetermined distance between the first portion 23 and the third portion 33. The second insulating portion 63 of the insulator 61 is positioned along the end faces at the ends of the first portion 23 and the third portion 33, restricting the movement of the insulator 61 in the Y direction. The third insulating portion 64 of the insulator 61 extends from the second insulating portion 63 along the fifth surface 23b of the first portion 23. The fourth insulating portion 65 of the insulator 61 extends from the second insulating portion 63 along the sixth surface 33b of the third portion 33. The first insulating portion 62, the second insulating portion 63, the third insulating portion 64, and the fourth insulating portion 65 of the insulator 61 are formed integrally.

[0087] Because the insulator 61 is formed in a three-pronged fork shape, it is easy to insert the insulator 61 between the first portion 23 and the third portion 33, and the distance between the first portion 23 and the third portion 33 can be appropriately maintained. In addition, because it is formed in a three-pronged fork shape, it is possible to prevent the insulator 61 from falling out from between the first portion 23 and the third portion 33.

[0088] As shown in Figure 17, if the periphery of the second insulating portion 63 is formed with a rounded shape, stress can be distributed, and thus the occurrence of cracks in the sealing resin 50 can be suppressed more efficiently.

[0089] By placing the insulator 61, the stress applied to the sealing resin 50 from the first portion 23 and the third portion 33 can be absorbed by the insulator 61. This suppresses the occurrence of cracks in the sealing resin 50. Furthermore, even if cracks occur in the sealing resin 50 starting from the first portion 23 and the third portion, the presence of the insulator 61 prevents the cracks from progressing beyond the insulator 61.

[0090] The insulator 61 can be formed from an insulating material such as synthetic resin. Furthermore, it is desirable that the insulator 61 be made from a resin with lower hardness than the sealing resin 50. By forming the insulator 61 from a resin with lower hardness than the sealing resin 50, the stress from the first portion 23 and the third portion 33 can be absorbed by the insulator 61, thereby suppressing the occurrence of cracks in the sealing resin 50.

[0091] [Effects] According to the above-described embodiment, the following effects can be achieved.

[0092] An insulator 61 is positioned at least one end in a direction along the surface of the sealing resin 50 exposed from the openings 41 of the first portion 23 and the third portion 33. The insulator 61 includes a first insulating portion 62 positioned between the first surface 23a and the third surface 33a, and a second insulating portion 63 positioned along the end faces 23c, 33c of at least one end of the first portion 23 and the third portion 33. The first insulating portion 62 and the second insulating portion 63 are integrally formed.

[0093] With this configuration, the distance between the first busbar 20 and the second busbar 30, particularly the distance between the first portion 23 and the third portion 33, can be kept constant, thereby distributing the stress on the sealing resin 50 and suppressing the occurrence of cracks.

[0094] The insulator 61 includes a third insulating portion 64 extending from the second insulating portion 63 along the fifth surface 23b, and a fourth insulating portion 65 extending from the second insulating portion 63 along the sixth surface 33b. The first insulating portion 62, the second insulating portion 63, the third insulating portion 64, and the fourth insulating portion 65 are integrally formed.

[0095] This configuration allows for easy placement of the insulator 61 and further prevents the insulator 61 from falling off.

[0096] The insulator 61 is made of resin, and the hardness of the resin constituting the insulator 61 is lower than the hardness of the sealing resin 50.

[0097] This configuration allows for the absorption of stress on the sealing resin 50, thereby suppressing the occurrence of cracks in the sealing resin 50.

[0098] In the embodiments described above, an example was given in which the insulator 61 is formed in a three-pronged fork shape, but the invention is not limited to this. The insulator 61 may be formed in a T-shape, for example, having a first insulating portion 62 and a second insulating portion 63.

[0099] (Outline of Embodiments) (1) The capacitor module of the present disclosure comprises a capacitor element having a first electrode and a second electrode, a first busbar having a first contact portion that contacts the first electrode and a first extension portion that extends from the first contact portion, a second busbar having a second contact portion that contacts the second electrode and a second extension portion that extends from the second contact portion, a case housing the capacitor element and a part of the first busbar and the second busbar, and a part of the first busbar and the second busbar. The device comprises a sealing resin for sealing the first extended portion, the first extended portion includes a first part having a first surface and a second part having a second surface, the second extended portion includes a third part having a third surface and a fourth part having a fourth surface, the first and third parts are arranged so that the first and third surfaces face each other inside the sealing resin, and the second and fourth parts are arranged so that the second and fourth surfaces face each other outside the sealing resin, and the distance between the first and third surfaces is greater than the distance between the second and fourth surfaces.

[0100] (2) In the capacitor module of (1), the case has an opening and a bottom opposite to the opening, the first electrode is positioned toward the opening of the case, the second electrode is positioned toward the bottom of the case, and the first and third parts may be positioned facing each other via a sealing resin in the direction from the bottom toward the opening.

[0101] (3) In the capacitor module of (2), the second extension extends from the bottom toward the opening along the side surface of the capacitor element, and the distance between the first surface and the third surface may be greater than the distance between the second extension and the side surface.

[0102] (4) In any one of the capacitor modules from (1) to (3), the distance between the first surface and the third surface may be greater than the minimum distance between the second surface and the fourth surface.

[0103] (5) In any one of the capacitor modules from (1) to (4), the distance between the first surface and the third surface may be greater than the thickness of the first busbar or the second busbar.

[0104] (6) In any one of the capacitor modules of (1) to (5), the case has an opening, and the distance between the first surface and the third surface may be smaller than the distance between the surface of the sealing resin exposed from the opening and the capacitor element.

[0105] (7) In any one of the capacitor modules from (1) to (6), insulating paper may be placed between the first extended portion and the second extended portion.

[0106] (8) In any one capacitor module of (1) to (6), the case has an opening, and an insulator is disposed at at least one end in a direction along the surface of the sealing resin exposed from the openings of the first and third portions, the insulator includes a first insulating portion disposed between the first and third surfaces, and a second insulating portion disposed along the end face of the at least one end of the first and third portions, the first insulating portion and the second insulating portion may be integrally formed.

[0107] (9) In the capacitor module of (8), the first portion includes a fifth surface located opposite to the first surface, the third portion includes a sixth surface located opposite to the third surface, and the insulator includes a third insulating portion extending from the second insulating portion along the fifth surface and a fourth insulating portion extending from the second insulating portion along the sixth surface, and the first insulating portion, the second insulating portion, the third insulating portion and the fourth insulating portion may be formed integrally.

[0108] In the capacitor module of (10), (8), or (9), the insulator is made of resin, and the hardness of the resin constituting the insulator may be lower than the hardness of the sealing resin.

[0109] (11) The capacitor module of the present disclosure comprises a capacitor element having a first electrode and a second electrode; a first busbar having a first contact portion that contacts the first electrode and a first extension portion that extends from the first contact portion; a second busbar having a second contact portion that contacts the second electrode and a second extension portion that extends from the second contact portion; a case having an opening and housing the capacitor element and a part of the first busbar and the second busbar; and a sealing resin that seals the capacitor element and a part of the first busbar and the second busbar, wherein the first extension portion includes a first portion having a first surface and a second portion having a second surface, and the second extension portion includes a third portion having a third surface and a fourth portion having a fourth surface, and the first portion and the third portion are arranged so that the first surface and the third surface face each other inside the sealing resin, and the end faces in the direction along the surface of the sealing resin that are exposed from the openings of the first portion and the third portion are chamfered.

[0110] This disclosure is useful for capacitor modules used in various electronic devices, electrical equipment, industrial equipment, vehicle equipment, etc.

[0111] 1, 2, 3 capacitor module 10 capacitor element 11 first electrode 12 second electrode 20 first bus bar 21 first contact portion 22, 122 first extension portion 23, 123, 223, 323 first portion 23a first surface 23b fifth surface 23c, 123c, 223c, 323c end surface 24 second portion 24a Second surface 30 Second bus bar 31 Second contact portion 31a Through hole 31b Projection 32, 132 Second extension portion 33, 133, 233, 333 Third portion 33a Third surface 33b Sixth surface 33c, 133c, 233c, 333c End surface 34 Fourth portion 34a Fourth surface 40 Case 41 Opening 42 Bottom 50 60 Sealing resin 61 Insulating paper 62 Insulator 62 First insulating part 63 Second insulating part 64 Third insulating part 65 Fourth insulating part

Claims

A capacitor element having a first electrode and a second electrode, A first busbar having a first contact portion that contacts the first electrode and a first extension portion that extends from the first contact portion, A second busbar having a second contact portion that contacts the second electrode and a second extending portion that extends from the second contact portion, A case housing the capacitor element and a part of the first busbar and the second busbar, The capacitor element and a sealing resin that seals a portion of the first busbar and the second busbar, Equipped with, The first extension includes a first portion having a first surface and a second portion having a second surface. The second extension includes a third portion having a third surface and a fourth portion having a fourth surface. The first portion and the third portion are arranged inside the sealing resin such that the first surface and the third surface face each other. The second portion and the fourth portion are arranged so that the second surface and the fourth surface face each other outside the sealing resin. The distance between the first surface and the third surface is greater than the distance between the second surface and the fourth surface. Capacitor module. 　 The case has an opening and a bottom opposite to the opening, The first electrode is positioned toward the opening of the case, The second electrode is positioned toward the bottom of the case, The first and third portions are arranged facing each other via the sealing resin in a direction from the bottom toward the opening. The capacitor module according to claim 1. 　 The second extension extends along the side surface of the capacitor element from the bottom toward the opening, The distance between the first surface and the third surface is greater than the distance between the second extension and the side surface. The capacitor module according to claim 2. 　 The distance between the first surface and the third surface is greater than the minimum distance between the second surface and the fourth surface. A capacitor module according to any one of claims 1 to 3. 　 The distance between the first surface and the third surface is greater than the thickness of the first busbar or the second busbar. A capacitor module according to any one of claims 1 to 4. 　 The case has an opening, The distance between the first surface and the third surface is smaller than the distance between the surface of the sealing resin exposed from the opening and the capacitor element. A capacitor module according to any one of claims 1 to 5. 　 An insulating paper is placed between the first extended portion and the second extended portion. A capacitor module according to any one of claims 1 to 6. 　 The case has an opening, An insulator is provided at at least one end in the direction along the surface of the sealing resin that is exposed from the openings of the first and third portions, The insulator includes a first insulating portion disposed between the first surface and the third surface, and a second insulating portion disposed along the end face of at least one end of the first portion and the third portion. The first insulating portion and the second insulating portion are formed integrally. A capacitor module according to any one of claims 1 to 6. 　 The first part includes a fifth surface located on the opposite side of the first surface, The third portion includes a sixth surface located on the opposite side of the third surface, The insulator includes a third insulating portion extending from the second insulating portion along the fifth surface, and a fourth insulating portion extending from the second insulating portion along the sixth surface. The first insulating portion, the second insulating portion, the third insulating portion, and the fourth insulating portion are integrally formed. The capacitor module according to claim 8. 　 The insulator is formed of resin, The hardness of the resin constituting the insulator is lower than the hardness of the sealing resin. The capacitor module according to claim 8 or 9. 　 A capacitor element having a first electrode and a second electrode, A first busbar having a first contact portion that contacts the first electrode and a first extension portion that extends from the first contact portion, A second busbar having a second contact portion that contacts the second electrode and a second extending portion that extends from the second contact portion, A case having an opening, which houses the capacitor element and a portion of the first busbar and the second busbar, The capacitor element and a sealing resin that seals a portion of the first busbar and the second busbar, Equipped with, The first extension includes a first portion having a first surface and a second portion having a second surface. The second extension includes a third portion having a third surface and a fourth portion having a fourth surface. The first portion and the third portion are arranged inside the sealing resin such that the first surface and the third surface face each other. The end faces of the first and third portions in the direction along the surface of the sealing resin that are exposed from the openings are chamfered. Capacitor module.

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