Film capacitor

Abstract

To improve the moisture resistance of a film capacitor while efficiently radiating the heat of a capacitor element.SOLUTION: In the vertical film capacitor in which first end-face electrode 12 of capacitor element 10 is disposed parallel to the opening face of the case, the entire surface of main body 20 including all of the plurality of electrode connecting parts of first bus bar 2 is covered with metal plate 7, the entire surface of first end-face electrode 12 of capacitor element 10 is covered with metal plate 7, and the other main face (z-axis positive side face) of metal plate 7 is exposed from the sealing resin.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a film capacitor including a capacitor element, a first bus bar, a second bus bar, and a sealing resin that seals the capacitor element and the first and second bus bars. [Background technology]

[0002] Conventionally, a film capacitor has been known that includes a capacitor element, a first bus bar having an electrode connection portion electrically connected to one end surface electrode of the capacitor element, a second bus bar having an electrode connection portion electrically connected to the other end surface electrode of the capacitor element, and a sealing resin that seals the capacitor element and the first and second bus bars while leaving portions of the first and second bus bars housed in a case exposed (see Patent Document 1).

[0003] This type of capacitor is configured to dissipate heat generated by the capacitor element. For example, the capacitor disclosed in Patent Document 1 includes a heat dissipation member including a first heat sink disposed along the substrate portion of the first electrode plate and a second heat sink disposed along the substrate portion of the second electrode plate. The substrate portions of the first and second electrode plates are electrically connected to the two electrode surfaces of the capacitor element by soldering via connecting pieces. The main bodies of the first and second heat sinks are provided with openings at positions overlapping the connecting pieces to expose the connecting pieces, and the connecting pieces can be soldered to the electrode surfaces through the openings. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-173788 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the capacitor described in Patent Document 1, although the first and second heat sinks arranged along the first and second electrode plates provide good heat dissipation in the electrode direction of the capacitor element, the connection pieces where the first and second electrode plates are soldered are exposed through the openings in the first and second heat sinks. As a result, external moisture can penetrate the soldered parts through the sealing resin and the thinner parts of the sealing resin, causing the capacitor element to absorb moisture and potentially reducing the moisture resistance of the capacitor.

[0006] The present invention has been made in view of the above-mentioned problems, and has an object to improve the moisture resistance of a film capacitor while efficiently dissipating heat generated by a capacitor element. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the film capacitor of the present invention comprises a capacitor element, a first bus bar having an electrode connection portion electrically connected to one end surface electrode of the capacitor element, a second bus bar having an electrode connection portion electrically connected to the other end surface electrode of the capacitor element, and a sealing resin that seals the capacitor element and the first and second bus bars while portions of the first and second bus bars are exposed, characterized in that the first bus bar has a plurality of electrode connection portions, and all of the plurality of electrode connection portions are covered with a metal member.

[0008] With this configuration, since all of the electrode connection portions of the first bus bar are covered with the metal member, heat generated by the capacitor element can be efficiently released to the outside via the metal member, improving the heat dissipation performance of the film capacitor. Also, moisture can be prevented from entering the capacitor from the outside, improving the moisture resistance of the film capacitor.

[0009] Preferably, the metal member is made of a metal plate, and the electrode connection portions of the first bus bar are covered by one main surface of the metal plate, and the other main surface of the metal plate is exposed from the sealing resin. With this configuration, heat generated by the capacitor element can be efficiently dissipated to the outside via the metal plate (the other main surface) exposed from the sealing resin.

[0010] Preferably, the metal member is the second bus bar, which not only improves both the heat dissipation and moisture resistance of the film capacitor but also reduces material costs because a separate metal member is not used.

[0011] The capacitor element may further include a case that houses a portion of the capacitor element connected to the first bus bar and the second bus bar and is filled with the sealing resin, the case having an opening, and one end surface electrode of the capacitor element is disposed parallel to the opening of the case. With this configuration, a vertically-mounted film capacitor with excellent heat dissipation and moisture resistance can be provided.

[0012] Preferably, the capacitor elements are arranged in a plurality of rows so that the one end surface electrodes are located on the same plane, and the metal member has an area sufficient to cover all of the electrode connection portions of the first bus bars. With this configuration, even a film capacitor including a plurality of capacitor elements can have improved heat dissipation and moisture resistance.

[0013] Furthermore, the metal member may have an injection port for the sealing resin formed in a location facing the dead space between the plurality of capacitor elements, which allows the sealing resin to be injected smoothly. [Effects of the Invention]

[0014] According to the present invention, it is possible to improve the moisture resistance of the film capacitor while efficiently dissipating heat generated by the capacitor element. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view of a film capacitor according to a first embodiment of the present invention, as viewed from the top surface side. [Figure 2] 2 is a perspective view of the film capacitor of FIG. 1, viewed from above, without a case and metal members. FIG. [Figure 3] 3 is a perspective view of the film capacitor of FIG. 2 without a sealing resin, as viewed from above. FIG. [Figure 4] FIG. 4 is a perspective view of the film capacitor of FIG. 3 as viewed from the bottom side. [Figure 5] FIG. 4 is a side view of the film capacitor of FIG. 3. [Figure 6] FIG. 2 is a perspective view of the metal member of the film capacitor of FIG. 1 as seen from above; [Figure 7] FIG. 10 is a perspective view of a film capacitor according to a second embodiment of the present invention, as viewed from the top side. [Figure 8] 8 is a perspective view of a metal member of the film capacitor of FIG. 7, seen from above. [Figure 9] FIG. 10 is a perspective view of the film capacitor according to the third embodiment of the present invention, viewed from above, without a case and sealing resin. [Figure 10] FIG. 10 is a side view of the film capacitor of FIG. [Figure 11] 10 is a perspective view of the first and second bus bars and insulating members of the film capacitor of FIG. 9, viewed from above. [Figure 12] 12 is a perspective view of a first bus bar of the film capacitor of FIG. 11, as viewed from above. FIG. [Figure 13] 12 is a perspective view of the second bus bar of the film capacitor of FIG. 11, as viewed from the bottom side. FIG. [Figure 14] 12 is a perspective view of the insulating member of the film capacitor of FIG. 11 as viewed from above. FIG. [Figure 15] FIG. 10 is a perspective view of a film capacitor according to a fourth embodiment of the present invention, as viewed from the top side. [Figure 16] FIG. 16 is a side view of the film capacitor of FIG. 15 without a case and a sealing resin. [Figure 17] FIG. 17 is a perspective view of the film capacitor of FIG. 16 as viewed from the top side. [Figure 18] 16 is a perspective view of a plurality of capacitor elements of the film capacitor of FIG. 15, viewed from the top side. FIG. [Figure 19] 16 is a perspective view of a first bus bar of the film capacitor of FIG. 15, as viewed from above. FIG. [Figure 20] 16 is a perspective view of the second bus bar of the film capacitor of FIG. 15, as viewed from above. FIG. [Figure 21] FIG. 21 is a perspective view of the second bus bar of FIG. 20 as viewed from the bottom side. [Figure 22] 16 is a perspective view of the insulating member of the film capacitor of FIG. 15, viewed from above. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] First Embodiment A first embodiment of the film capacitor according to the present invention will be described in detail.

[0017] The configuration of a film capacitor 1 according to a first embodiment will be described with reference to FIGS. 1 to 6. In FIGS. 1 to 6, the x-axis, y-axis, and z-axis are illustrated so that they are aligned in the same direction. Hereinafter, the positive and negative x-axis sides will be referred to as the right and left, the positive and negative y-axis sides as the rear and front, and the positive and negative z-axis sides as the top and bottom. Hereinafter, a planar view of the film capacitor 1 viewed from the positive (top) or negative (bottom) side of the z-axis to the negative (bottom) or positive (top) side of the z-axis will be referred to as an "xy planar view," a planar view of the film capacitor 1 viewed from the positive (top) or negative (bottom) side of the y-axis to the negative (front) or positive (rear) side of the y-axis will be referred to as an "xz planar view," and a planar view of the negative (left) or positive (right) side of the x-axis from the positive (right) or negative (left) side of the x-axis will be referred to as a "yz planar view."

[0018] As shown in Figures 1 to 6, the film capacitor 1 includes a capacitor element 10 whose end surface electrodes are arranged parallel to the xy plane, a first bus bar 2, a second bus bar 3, an insulating member 4, a case 5, a sealing resin 6, and a metal plate 7 covering the upper surface of the first bus bar 2 on the positive side of the z axis.

[0019] Capacitor element 10 is configured to include element body 11, first end surface electrode 12 formed by spraying a metal such as zinc on the upper surface of element body 11 on the positive side of the z axis, and second end surface electrode 13 formed by spraying a metal such as zinc on the lower surface of element body 11 on the negative side of the z axis. Here, first end surface electrode 12 and second end surface electrode 13 of capacitor element 10 correspond to the "one end surface electrode" and "the other end surface electrode" of the capacitor element in the present invention, respectively.

[0020] The element body 11 is formed by stacking two metallized films, each having aluminum vapor-deposited on a dielectric film, rolling or laminating the stacked metallized films, and pressing them into a flat shape. The element body 11 is not limited to the above-described configuration, which is formed from a metallized film having aluminum vapor-deposited on a dielectric film. For example, the element body 11 may be formed from a metallized film having other metals vapor-deposited thereon, such as zinc or magnesium, or from a metallized film having multiple of these metals vapor-deposited thereon, or from a metallized film having an alloy of these metals vapor-deposited thereon.

[0021] The first end surface electrode 12 is used as a P-pole side, and the second end surface electrode 13 is used as an N-pole side. Alternatively, the first end surface electrode 12 may be used as an N-pole side, and the second end surface electrode 13 may be used as a P-pole side.

[0022] The first bus bar 2 and the second bus bar 3 are each made of a conductive material such as copper. As shown in FIGS. 3 to 5 , the first bus bar 2 is disposed opposite the first end surface electrode 12 of the capacitor element 10 and includes a main body portion 20, a bent portion 21, and an external connection terminal portion 22. The main body portion 20 has a substantially rectangular flat plate shape in the x-y plane view. The bent portion 21 is bent upward (in the positive z-axis direction) by approximately 90 degrees from the left end portion of the main body portion 20 on the negative x-axis side, and has a thin, elongated, substantially rectangular flat plate shape in the y-z plane view. The external connection terminal portion 22 is formed by bending the upper end portion of the bent portion 21 on the positive z-axis side substantially horizontally to the right (in the positive x-axis direction), and has a thin, elongated, substantially rectangular flat plate shape in the x-y plane view.

[0023] Here, the length of the main body 20 in the y-axis direction is approximately the same as the length of the capacitor element 10 in the y-axis direction, and the length of the main body 20 in the x-axis direction is slightly shorter than the length of the capacitor element 10 in the x-axis direction, and almost the entire surface of the first end surface electrode 12 of the capacitor element 10 is covered by the main body 20 except for the right end portion of the first end surface electrode 12 on the positive side of the x-axis.

[0024] Two E-shaped notches 23 are formed side by side in the y-axis direction at a position near the bent portion 21 of the main body 20, and pin-shaped electrode connection portions 24 are formed in these two notches 23 in the x-axis direction by the notches, and the electrode connection portions 24 are electrically connected by soldering to the first end surface electrode 12 of the capacitor element 10. These electrode connection portions 24 correspond to the "electrode connection portion" in this invention.

[0025] The main body portion 20, the bent portion 21, the external connection terminal portion 22, and the electrode connection portion 24 of the first bus bar 2 are simultaneously formed by punching and pressing.

[0026] As shown in FIGS. 3 to 5 , the second bus bar 3 is disposed opposite the second end surface electrode 13 of the capacitor element 10 and includes a main body portion 30, a bent portion 31, and an external connection terminal portion 32. The main body portion 30 has a generally rectangular flat plate shape in the xy plane view. The bent portion 31 is bent upward (in the positive z-axis direction) by approximately 90 degrees from the left end portion of the main body portion 30 on the negative x-axis side, and has a generally elongated rectangular flat plate shape in the yz plane view. The external connection terminal portion 32 is formed by bending the upper end portion of the bent portion 31 on the positive z-axis side approximately horizontally to the left (in the negative x-axis direction), and has a generally elongated rectangular flat plate shape in the xy plane view.

[0027] Here, similar to the main body portion 20 of the first busbar 2, the length of the main body portion 30 of the second busbar 3 in the y-axis direction is approximately the same as the length of the capacitor element 10 in the y-axis direction, and the length of the main body portion 30 in the x-axis direction is slightly shorter than the length of the capacitor element 10 in the x-axis direction, and the second end surface electrode 13 of the capacitor element 10 is covered by the main body portion 30 except for the right end portion on the positive side of the x-axis of the second end surface electrode 13.

[0028] Two E-shaped notches 33 are formed side by side in the y-axis direction at a position near the bent portion 31 of the main body portion 30, and these two notches 33 have pin-shaped electrode connection portions 34 formed in the x-axis direction by the notches, and the electrode connection portions 34 are electrically connected to the second end surface electrode 13 of the capacitor element 10 by soldering.

[0029] As with the first bus bar 2, the main body portion 30, the bent portion 31, the external connection terminal portion 32, and the electrode connection portion 34 of the second bus bar 3 are simultaneously formed by punching and pressing.

[0030] As shown in Figures 3 and 4, the insulating member 4 has a flat, approximately rectangular shape when viewed in the yz plane, and is arranged between the bent portion 21 of the first bus bar 2 and the bent portion 31 of the second bus bar 3, providing insulation between the first bus bar 2 and the second bus bar 3, as well as insulation between the second bus bar 3 and the first end surface electrode 12 of the capacitor element 10.

[0031] 1, the case 5 is formed in the shape of a rectangular parallelepiped housing, has an opening on the upper surface on the positive side of the z-axis, has a space inside that serves as a storage section, and can be formed from various materials, for example, organic materials such as resins and plastics such as polyphenylene sulfide (PPS) and polybutylene terephthalate (PBT), and inorganic materials such as ceramics. The case 5 corresponds to the "case" in this invention.

[0032] A portion of a capacitor unit having capacitor element 10, first and second bus bars 2 and 3, and insulating member 4 (capacitor element 10, a portion of first bus bar 2, a portion of second bus bar 3, and a portion of insulating member 4) is housed in a housing portion within case 5. Furthermore, liquid sealing resin 6 made of, for example, epoxy resin is poured into the housing portion of case 5 housing part of the capacitor unit, thereby sealing part of the capacitor unit. Note that reference numeral 51 in FIG. 1 denotes attachment portions for attaching film capacitor 1 to an external device, etc., and these are provided at multiple locations (four locations in FIG. 1) on the outer surface of case 5.

[0033] This sealing resin 6 is not limited to epoxy resin, and various insulating materials used as sealing resins for electronic components can be used. The sealing resin 6 is formed by being poured into the case 5 in a liquid state from the opening side of the case 5 and then curing. The sealing resin 6 corresponds to the "sealing resin" in this invention.

[0034] Meanwhile, the metal plate 7 is made of aluminum, for example, and the lengths of the metal plate 7 in the x-axis direction and the y-axis direction are longer than the lengths of the capacitor element 10 in the x-axis direction and the y-axis direction, respectively. The metal plate 7 is formed in a rectangular shape in an xy-plane view with an area larger than that of the main body 20 of the first bus bar 2. As a result, as shown in Fig. 5 , the right end (x-axis positive side) of the first end surface electrode 12 of the capacitor element 10, which was not completely covered by the main body 20 of the first bus bar 2, is also completely covered by the metal plate 7. When viewed from above, which is the z-axis positive side, the entire first end surface electrode 12 of the capacitor element 10, including the soldered portions of the two electrode connection portions 24 of the first bus bar 2, is covered and hidden by the metal plate 7.

[0035] 1 and 5, the metal plate 7 is arranged such that the lower surface on the negative side of the z-axis, which is one of the main surfaces of the metal plate 7, faces the upper surface on the positive side of the z-axis of the main body 20 of the first bus bar 2 in a thermally conductive manner, and the upper surface on the positive side of the z-axis, which is the other main surface of the metal plate 7, is exposed from the sealing resin 6. Note that the lower surface of the metal plate 7 may be in contact with the upper surface of the main body 20 of the first bus bar 2. Here, the metal plate 7 corresponds to the "metal member" in this invention.

[0036] Positioning ridges 52 extending in the z-axis direction and protruding inward from case 5 are formed approximately at the center of the front wall of case 5 on the negative side of the y-axis and approximately at the center of the rear wall on the positive side of the y-axis, while concave notches 71 are formed in metal plate 7 at two locations facing both ridges 52 of case 5, at approximately the center of the front end on the negative side of the y-axis and approximately the center of the rear end on the positive side of the y-axis. Then, as shown in FIG. 1 , when metal plate 7 is placed on main body 20 of first bus bar 2 housed in case 5 after injection of sealing resin 6, metal plate 7 is positioned by fitting ridges 52 of case 5 into notches 71 of metal plate 7, and metal plate 7 is placed on main body 20 of first bus bar 2 housed in case 5 without misalignment.

[0037] Therefore, according to the first embodiment, in a vertically-mounted film capacitor 1 in which the first end surface electrode 12 of the capacitor element 10 is arranged parallel to the opening surface of the case 5, the metal plate 7 covers all of the soldered portions of the two electrode connection portions 24 of the first bus bar 2, and the metal plate 7 can cover the entire surface of the first end surface electrode 12 of the capacitor element 10, including the right end portion on the positive side of the x-axis of the first end surface electrode 12, which was not completely covered by the main body portion 20 of the first bus bar 2. As the other main surface (the surface on the positive side of the z-axis) of the metal plate 7 is exposed from the sealing resin 6, it becomes possible to efficiently release heat from the capacitor element 10 to the outside via the metal plate 7, thereby improving the heat dissipation performance of the film capacitor 1.

[0038] Furthermore, since the two electrode connection portions 24 of the first busbar 2 are covered with the metal plate 7, it is possible to prevent external moisture from entering through areas where the sealing resin 6 is thin, regardless of the thickness of the sealing resin 6, thereby improving the moisture resistance of the film capacitor 1.

[0039] Furthermore, since the protrusions 52 of the case 5 are inserted into the notches 71 formed in the metal plate 7 to position it, it is possible to prevent the metal plate 7 from shifting position when it is placed on the main body 20 of the first busbar 2 of the metal plate 7.

[0040] Second Embodiment A second embodiment of the film capacitor according to the present invention will be described in detail.

[0041] The configuration of a film capacitor 1a according to a second embodiment will be described with reference to Figures 7 and 8. In these figures, the x-axis, y-axis, and z-axis are illustrated so that they are in the same direction, similar to the x-axis, y-axis, and z-axis in Figures 1 to 6.

[0042] The film capacitor 1a according to the second embodiment differs from the first embodiment in that, instead of the metal plate 7 having a rectangular shape in the xy plane in the first embodiment, a metal plate 7a having a hexagonal shape in the xy plane with two opposing corners removed and smaller than the metal plate 7 is disposed on the upper surface of the main body of the first bus bar 2a, as shown in Figures 7 and 8. The first and second bus bars 2a and 3a, the insulating member 4a, the case 5a, and the sealing resin 6a have the same configurations and compositions as the first and second bus bars 2 and 3, the insulating member 4, the case 5, and the sealing resin 6 in the first embodiment, respectively. In Figure 7, reference numerals 51a denote multiple attachment portions for attachment to external devices, etc., similar to the attachment portion 51 of the case 5 shown in Figure 1.

[0043] In this case, the metal plate 7a does not cover two opposing corners of the main body 20 of the first busbar 2, but the metal plate 7a has an area large enough to cover all of the two electrode connection portions 24 provided on the main body 20. As shown in Fig. 8, similar to the first embodiment, positioning notches 71a are formed at the front end of the metal plate 7a on the negative side of the y-axis and at the rear end of the metal plate 7a on the positive side of the y-axis.

[0044] Therefore, according to the second embodiment, in addition to being able to obtain the same effects as the first embodiment described above, the material cost can be reduced because the metal plate 7a is smaller than that of the first embodiment.

[0045] <Third embodiment> A third embodiment of the film capacitor according to the present invention will be described in detail.

[0046] The configuration of a film capacitor 1b according to the third embodiment will be described with reference to Figures 9 to 14. In these figures, the x-axis, y-axis, and z-axis are illustrated so that they are in the same direction, similar to the x-axis, y-axis, and z-axis in Figures 1 to 6.

[0047] Film capacitor 1b in the third embodiment has the same appearance as film capacitor 1 in the first embodiment shown in Fig. 1, but the shapes of first bus bar 2b and second bus bar 3b are different from those in the first embodiment. Here, in the third embodiment, the case and sealing resin are not shown in Figs. 9 and 10, but have the same configurations as case 5 and sealing resin 6 in the first embodiment.

[0048] Film capacitor 1b includes capacitor element 10, in which first and second end surface electrodes 12, 13 are arranged parallel to the xy plane, first bus bar 2b, second bus bar 3b, insulating member 4b, a case, sealing resin, and metal plate 7b. Metal plate 7b has the same configuration as metal plate 7 in the first embodiment, and has notches 71b similar to notch 71 at approximately the center of its front end on the negative side of the y axis and at approximately the center of its rear end on the positive side of the y axis.

[0049] 12, the first bus bar 2b has a main body portion 20b, a bent portion 21b, and an external connection terminal portion 22b. The main body portion 20b has a generally rectangular flat plate shape in the xy plane view, the bent portion 21b is bent upward (in the z-axis positive direction) by approximately 90 degrees from the left end portion on the x-axis negative side of the main body portion 20b, and has a generally elongated rectangular flat plate shape in the yz plane view, and the external connection terminal portion 22b is bent approximately horizontally from the upper end portion on the z-axis positive side of the bent portion 21b to the left (in the x-axis negative direction), and has a generally elongated rectangular flat plate shape in the xy plane view.

[0050] The length of the main body portion 20b in the y-axis direction is approximately the same as the length of the capacitor element 10 in the y-axis direction, and the length of the main body portion 20b in the x-axis direction is slightly shorter than the length of the capacitor element 10 in the x-axis direction, so that the main body portion 20b covers almost the entire first end surface electrode 12 of the capacitor element 10 except for the right end portion on the positive side of the x-axis.

[0051] 12, two E-shaped notches 23b are formed side by side in the y-axis direction in the main body 20b at positions facing the first end surface electrode 12 of the capacitor element 10. Pin-shaped electrode connection portions 24b are formed in each of the notches 23b by the notch and in the x-axis direction. The two electrode connection portions 24b are formed in positions visible through an opening in a second busbar 3b and an opening in an insulating member 4b, which will be described later, and these two electrode connection portions 24b are electrically connected to the first end surface electrode 12 of the capacitor element 10 by soldering. These two electrode connection portions 24b correspond to the "electrode connection portions" in this invention.

[0052] As shown in FIG. 13 , the second bus bar 3b has a main body portion 30b, a first bent portion 31b1, a second bent portion 31b2, a third bent portion 31b3, and an external connection terminal portion 32b. The main body portion 30b has a generally rectangular flat plate shape in an xy-plane view. The length of the main body portion 30b in the y-axis direction is approximately the same as the length of the capacitor element 10 in the y-axis direction, the length of the main body portion 30b in the x-axis direction is slightly longer than the length of the capacitor element 10 in the x-axis direction, and the main body portion 30b has an area covering the entire first end surface electrode 12 of the capacitor element 10. The first bent portion 31b1 is bent approximately 90° downward (in the z-axis negative direction) from the right end portion of the main body portion 30b on the x-axis positive side, and has an elongated, generally rectangular flat plate shape in a yz-plane view. Here, the length of the first bent portion 31b1 in the z-axis direction is formed to be approximately the same as or slightly longer than the thickness of the capacitor element 10 in the z-axis direction.

[0053] The second bent portion 31b2 is bent approximately 90° to the left (x-axis negative direction) from the lower end on the z-axis negative side of the first bent portion 31b1, and is approximately parallel to the main body portion 30b and has a substantially rectangular flat plate shape in the xy plane, with approximately the same size as the main body portion 30b. The third bent portion 31b3 is bent approximately 90° upward (z-axis positive direction) from the left end on the x-axis negative side of the main body portion 30b, and has a thin, elongated, substantially rectangular flat plate shape in the yz plane. The external connection terminal portion 32b is formed by bending approximately horizontally to the right (x-axis positive direction) from the upper end on the z-axis positive side of the third bent portion 31b3, and has a thin, elongated, substantially rectangular flat plate shape in the xy plane.

[0054] 13, two E-shaped notches 33b are formed side by side in the y-axis direction at the left end of second bent portion 31b2 on the negative side of the x-axis. Pin-shaped electrode connection portions 34b are formed in these notches 33b in the x-axis direction by the notches, and electrode connection portions 34b are electrically connected to second end surface electrode 13 of capacitor element 10 by soldering.

[0055] Furthermore, a rectangular opening 35b is formed at a position on the negative side of the x-axis and closer to the positive side of the y-axis of the main body 30b, at a position where the two electrode connection portions 24b of the main body 20 of the first bus bar 2b soldered to the first end surface electrode 12 of the capacitor element 10 can be seen. Note that the first and second bus bars 2b, 3b are formed by punching press processing, similar to the first and second bus bars 2, 3 of the first embodiment.

[0056] 14, the insulating member 4b has a main body portion 40b in the form of a substantially rectangular plate in the xy-plane view, a bent portion 41b in the form of a substantially rectangular plate in the yz-plane view, which is formed by bending the left end of the main body portion 40b on the negative side of the x-axis upward (in the positive z-axis direction) by approximately 90 degrees, and a second bent portion 42b in the form of a substantially rectangular plate in the yz-plane view, which is formed by bending the right end of the main body portion 40b on the positive x-axis side downward (in the negative z-axis direction) by approximately 90 degrees. The insulating member 4b is disposed between the first bus bar 2b and the second bus bar 3b to electrically insulate the first bus bar 2b from the second bus bar 3b.

[0057] The main body 40b of the insulating member 4b has substantially the same rectangular shape as the main body 30b of the second bus bar 3b, and the area of ​​the insulating member 4b is larger than that of the main body 30b of the second bus bar 3b so that both ends in the y-axis direction protrude, and the insulating member 4b is formed slightly smaller than the metal plate 7b. Furthermore, a rectangular opening 43b is formed in the main body 40b at a position facing the opening 35b of the main body 30b of the second bus bar 3b, and the two electrode connection portions 24b of the main body 20 of the first bus bar 2b, which are soldered to the first end surface electrode 12 of the capacitor element 10, can be seen through both openings 35b, 43b.

[0058] Furthermore, concave notches 44b into which the two protrusions of the case fit are formed in two locations on main body 40b of insulating member 4b: approximately at the center of the front end on the negative side of the y-axis and approximately at the center of the rear end on the positive side of the y-axis. When part of a capacitor unit having capacitor element 10, first and second bus bars 2b, 3b, and insulating member 4b (capacitor element 10, part of first bus bar 2b, part of second bus bar 3b, and part of insulating member 4b) is accommodated in the accommodation portion within the case, the protrusions of the case are inserted into notches 44b of insulating member 4b, thereby providing the positioning function of notches 71b of metal plate 7b, and the capacitor unit can be accommodated in the case without misalignment.

[0059] In this way, metal plate 7b can cover and conceal the entire first end surface electrode 12 of capacitor element 10, including two electrode connection portions 24b soldered to first end surface electrode 12 of capacitor element 10. Therefore, according to the third embodiment, it is possible to obtain the same effects as those of the first embodiment described above.

[0060] Furthermore, by overlapping the first bus bar 2b and the second bus bar 3b, heat generated by the second bus bar 3b can be dissipated from the metal plate 7b via the first bus bar 2b, and the ESL (equivalent series inductance) can be reduced.

[0061] <Fourth embodiment> A fourth embodiment of the film capacitor according to the present invention will be described in detail.

[0062] The configuration of a film capacitor 1c according to the fourth embodiment will be described with reference to Figures 15 to 22. In these figures, the x-axis, y-axis, and z-axis are illustrated so that they are in the same direction, similar to the x-axis, y-axis, and z-axis in Figures 1 to 6.

[0063] The film capacitor 1c of the fourth embodiment differs from the first embodiment in that it includes four capacitor elements 10 but does not include a metal member such as the metal plate 7. Furthermore, as it includes four capacitor elements 10, the configurations of the first and second bus bars electrically connected to the first and second end surface electrodes 12, 13 of each capacitor element 10 differ from those of the first embodiment. The differences between the fourth embodiment and the first embodiment will be described below.

[0064] A film capacitor 1c of the fourth embodiment includes four capacitor elements 10, a first bus bar 2c, a second bus bar 3c, an insulating member 4c, a case 5c, and a sealing resin 6c.

[0065] As shown in FIG. 18, four capacitor elements 10 are arranged in a matrix of two rows and two columns in the x-axis and y-axis directions so that the first and second end surface electrodes 12, 13 of each capacitor element are parallel to the xy plane.

[0066] 19, the first bus bar 2c has a main body portion 20c, a bent portion 21c, and an external connection terminal portion 22c. The main body portion 20c has a generally rectangular flat plate shape in the xy plane view, the bent portion 21c is bent upward (in the z-axis positive direction) by approximately 90 degrees from the left end portion on the x-axis negative side of the main body portion 20c, and has a generally elongated rectangular flat plate shape in the yz plane view, and the external connection terminal portion 22c is bent approximately horizontally from the upper end portion on the z-axis positive side of the bent portion 21c to the left (in the x-axis negative direction), and has a generally elongated rectangular flat plate shape in the xy plane view.

[0067] The length of the main body portion 20c in the y-axis direction is approximately the same as the total length in the y-axis direction of the two capacitor elements 10 aligned in the y-axis direction, and the length of the main body portion 20c in the x-axis direction is slightly shorter than the total length in the x-axis direction of the two capacitor elements 10 aligned in the x-axis direction, so that the main body portion 20c covers almost the entire surface of the first end surface electrodes 12 of the four capacitor elements 10 except for the right ends on the positive x-axis side of the first end surface electrodes 12 of the two capacitor elements 10 on the right side (positive x-axis side).

[0068] 19, E-shaped notches 23c are formed in the main body 20c at two locations facing the first end surface electrodes 12 for each capacitor element 10, with four notches 23c arranged in two rows in the y-axis direction for a total of eight notches 23c. Pin-shaped electrode connectors 24c are formed in each of these notches 23c in the x-axis direction through the notches, and are soldered to the first end surface electrodes 12 of each capacitor element 10. A circular hole 25c is formed in approximately the center of the main body 20c. These electrode connectors 24c correspond to the "electrode connectors" of the present invention.

[0069] As shown in FIG. 20 , the second bus bar 3c has a main body portion 30c, a first bent portion 31c1, a second bent portion 31c2, a third bent portion 31c3, and an external connection terminal portion 32c. The main body portion 30c has a generally rectangular flat plate shape in the x-y plane view. The lengths in the x-axis direction and the y-axis direction are generally the same as the total lengths in the x-axis direction and the y-axis direction of the capacitor elements 10 arranged in pairs. The main body portion 30c has an area sufficient to cover all of the first end surface electrodes 12 of the four capacitor elements 10. The first bent portion 31c1 is bent downward (in the z-axis negative direction) by approximately 90 degrees from the right end portion on the x-axis positive side of the main body portion 30c, and has a generally rectangular flat plate shape in the y-z plane view. The length in the z-axis direction of the first bent portion 31c1 is generally the same as or slightly longer than the thickness in the z-axis direction of the capacitor element 10.

[0070] The second bent portion 31c2 is bent approximately 90° to the left (x-axis negative direction) from the lower end on the z-axis negative side of the first bent portion 31c1, and is approximately parallel to the main body portion 30c and has a substantially rectangular flat plate shape in the xy plane, with approximately the same size as the main body portion 30c. The third bent portion 31c3 is bent approximately 90° upward (z-axis positive direction) from the left end on the x-axis negative side of the main body portion 30c, and has a thin, elongated, substantially rectangular flat plate shape in the yz plane. The external connection terminal portion 32c is formed by bending approximately horizontally to the right (x-axis positive direction) from the upper end on the z-axis positive side of the third bent portion 31c3, and has a thin, elongated, substantially rectangular flat plate shape in the xy plane.

[0071] 21 , similar to the main body 20c of the first bus bar 2c, the second bent portion 31c2 of the second bus bar 3c has E-shaped notches 33c formed in the y-axis direction at two locations facing the second end surface electrodes 13 for each capacitor element 10, with a total of eight notches 33c arranged in two rows of four in the y-axis direction. Pin-shaped electrode connectors 34c are formed in each of these notches 33c in the x-axis direction by the notches, and the pin-shaped electrode connectors 34c are soldered to the second end surface electrodes 13 of each capacitor element 10.

[0072] 20 and 21, circular holes 35c and 36c are formed in the approximate centers of the main body 30c and the second bent portion 31c2 of the second bus bar 3c. The circular holes 25c of the main body 20c of the first bus bar 2c and the circular holes 35c and 36c of the second bus bar 3c are positioned to overlap in an xy-plane view and are formed in the dead space in the middle of the four capacitor elements 10, serving as an injection port for the liquid resin for the sealing resin 6c, making it easy to inject the liquid resin into the case 5c. The first and second bus bars 2c and 3c are formed by punching and pressing, similar to the first and second bus bars 2 and 3 of the first embodiment.

[0073] 22, the insulating member 4c has a main body 40c having a generally rectangular, flat plate shape in the xy-plane view, a bent portion 41c having an elongated, generally rectangular, flat plate shape in the yz-plane view, which is formed by bending the left end of the main body 40c on the negative side of the x-axis upward (in the positive z-axis direction) by approximately 90 degrees, and a second bent portion 42c having an elongated, generally rectangular, flat plate shape in the yz-plane view, which is formed by bending the right end of the main body 40c on the positive x-axis side downward (in the negative z-axis direction) by approximately 90 degrees. The insulating member 4c is disposed between the first bus bar 2c and the second bus bar 3c to electrically insulate the first bus bar 2c from the second bus bar 3c.

[0074] The main body 40c of the insulating member 4c has substantially the same rectangular shape as the main body 30c of the second bus bar 3c, and the area of ​​the insulating member 4c is larger than that of the main body 30c of the second bus bar 3c so that both ends in the y-axis direction extend beyond the main body 30c of the second bus bar 3c. Furthermore, a circular hole 43c, smaller than the circular hole 35c, is formed in the main body 40c at a position substantially in the center of the main body 40c that overlaps with the circular hole 35c of the main body 30c of the second bus bar 3c. Similar to the circular hole 35c, this circular hole 43c serves as an injection port for the liquid resin for the sealing resin 6c. Furthermore, concave notches 44c, into which the two protrusions of the case 5c fit, are formed in two locations on the main body 40c of the insulating member 4c: substantially at the center of the front end on the negative side of the y-axis and substantially at the center of the rear end on the positive side of the y-axis.

[0075] When a portion of a capacitor unit having capacitor element 10, first and second bus bars 2c and 3c, and insulating member 4c (capacitor element 10, a portion of first bus bar 2c, a portion of second bus bar 3c, and a portion of insulating member 4c) is accommodated in an accommodating portion within case 5c, a positioning function is achieved by inserting protrusions of case 5c into notches 44c of insulating member 4c, so that the capacitor unit can be accommodated in case 5c without being misaligned. Note that in Figure 15, 51c denotes multiple (four) attachment portions for attaching to external devices, etc., similar to attachment portion 51 of case 5 shown in Figure 1.

[0076] As such, although the film capacitor 1c of the fourth embodiment does not have a metal plate 7 like the first embodiment, the main body portion 30c of the second busbar 3c can completely cover and conceal the first end surface electrodes 12 of the four capacitor elements 10, including the eight electrode connection portions 24c soldered to the first end surface electrodes 12 of the four capacitor elements 10, and therefore the main body portion 30c of the second busbar 3c functions as the "metal member" of the present invention.

[0077] Therefore, according to the fourth embodiment described above, in a vertically-mounted film capacitor 1c in which the first end surface electrodes 12 of the four capacitor elements 10 are arranged parallel to the opening surface of the case 5c, the main body 30c of the second bus bar 3c covers all of the soldered portions of the eight electrode connection portions 24c of the first bus bar 2c and can completely conceal the first end surface electrodes 12 of the four capacitor elements 10, thereby achieving the same effects as the first embodiment described above. Furthermore, since no metal members are provided, material costs can be reduced compared to when metal members are provided.

[0078] Furthermore, circular holes 25c, 35c, 36c, and 43c are formed in the main body 20c of the first bus bar 2c, the main body 30c and second bent portion 31c2 of the second bus bar 3c, and the main body 40c of the insulating member 4c, respectively, at positions that overlap when viewed in the xy plane and in the dead space in the middle of the four capacitor elements 10. This allows the liquid resin for the sealing resin 6c to be smoothly injected into the case 5c through these circular holes 25c, 35c, 36c, and 43c, and allows the liquid resin for the sealing resin 6c to penetrate into the case 5c.

[0079] The present invention is not limited to the above-described configuration, and various design modifications can be made within the scope of the claims. For example, the present invention can be implemented in the same manner even if the first to fourth embodiments described above are of a caseless type that does not have the cases 5, 5a, and 5c.

[0080] In the first and second embodiments described above, two or an even number of six or more capacitor elements 10 may be provided, or an odd number such as three may be provided and arranged in a row.

[0081] Furthermore, in the above-described first to third embodiments, the metal member is described as being a metal plate 7 made of aluminum, but the metal member is not limited to metal plates 7, 7a, and 7b, and the material may also be a metal other than aluminum.

[0082] In the third embodiment, the metal plate 7b may not be provided, and the second bus bar 3b may be used as a metal member in place of the metal plate 7b, thereby reducing material costs.

[0083] In the fourth embodiment, a metal member such as a metal plate 7 may be provided so as to overlap the main body portion 30c of the second bus bar 3c and cover the first end surface electrodes 12 of all four capacitor elements 10.

[0084] Furthermore, in the fourth embodiment, a case where four capacitor elements 10 are provided is described, but an even number of capacitor elements 10, such as two or six or more, or an odd number such as three arranged in a row may also be provided, and the present invention can be implemented in the same way to obtain the same effects.

[0085] The present invention is widely applicable to film capacitors comprising a capacitor element, a first bus bar having an electrode connection portion electrically connected to one end surface electrode of the capacitor element, a second bus bar having an electrode connection portion electrically connected to the other end surface electrode of the capacitor element, and a sealing resin that seals the capacitor element and the first and second bus bars while leaving portions of the first and second bus bars exposed. [Explanation of symbols]

[0086] 1, 1a, 1b, 1c...Film capacitors 2, 2a, 2b, 2c ... 1st bus bar 3, 3a, 3b, 3c ... 2nd bus bar 5, 5a, 5c...case 6,6a,6c…Sealing resin 7, 7a, 7b ... Metal plate (metal member) 10...Capacitor element 12...First end electrode 13...Second end electrode 21b, 22, 22a, 33b ... External connection terminals 24, 24b, 24c ... Electrode connection parts 24b,36b...bending part 25c, 35c, 36c, 43c...Circular hole (inlet)

Claims

1. A film capacitor comprising: a capacitor element; a first bus bar having an electrode connection portion electrically connected to one end surface electrode of the capacitor element; a second bus bar having an electrode connection portion electrically connected to the other end surface electrode of the capacitor element; and a sealing resin that seals the capacitor element and the first and second bus bars in a state where portions of the first and second bus bars are exposed, The film capacitor is characterized in that the first bus bar has a plurality of electrode connection portions, and all of the plurality of electrode connection portions are covered with a metal member.

2. The film capacitor according to claim 1, characterized in that the metal member is made of a metal plate, and the plurality of electrode connection portions of the first bus bar are covered by one main surface of the metal plate, and the other main surface of the metal plate is exposed from the sealing resin.

3. The film capacitor according to claim 1 , wherein the metal member is the second bus bar.

4. a case that houses a portion of the capacitor element to which the first bus bar and the second bus bar are connected and is filled with the sealing resin, The case has an opening, 2. The film capacitor according to claim 1, wherein one end surface electrode of the capacitor element is disposed parallel to the opening surface of the case.

5. a plurality of the capacitor elements are arranged such that the one end surface electrodes are positioned on the same plane; 5. The film capacitor according to claim 1, wherein the metal member has an area that covers the entire electrode connection portion of the first bus bar.

6. 6. The film capacitor according to claim 5, wherein the metal member has an injection port for the sealing resin formed in a location facing a dead space between the plurality of capacitor elements.

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