Film capacitor

Abstract

The present invention provides a film capacitor that can reduce ESL while ensuring good insulation performance between a pair of opposing end electrodes of a capacitor element arranged so that the opposing end electrodes have different polarities. [Solution] The film capacitor 1 comprises a plurality of capacitor elements 2, a case 3 that houses them, and a sealing resin 5 that is filled inside the case and seals the capacitor elements 2. Each capacitor element has end electrodes 22 on both end faces, and busbars 23 are connected to the end electrodes. The plurality of capacitor elements are housed in the case 3 with at least two capacitor elements having opposing end electrodes 22, and the opposing pair of end electrodes 22, 22 having different polarities. An insulating member 4, which is formed separately from the case, is interposed between the pair of end electrodes 22, 22.

Description

Technical Field

[0001] This invention relates to a film capacitor having a plurality of capacitor elements.

Background Art

[0002] For example, as one of the capacitors having high withstand voltage and low loss electrical characteristics, such as a capacitor used in relation to an electric vehicle motor, a film capacitor having a plurality of capacitor elements is used.

[0003] As such a film capacitor, Patent Document 1 discloses a structure in which a plurality of capacitor elements coated with an exterior material are arranged such that the end face electrodes of adjacent capacitor elements face each other through the exterior material.

[0004] According to this film capacitor, the distance between the opposing capacitor elements can be reduced. When a pair of opposing end face electrodes are used with different polarities, the equivalent series inductance (hereinafter also referred to as ESL) can be reduced, and sufficient insulation can be ensured between the opposing capacitor elements.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the film capacitor described in Patent Document 1, adjacent capacitor elements face each other through the exterior material that coats each capacitor element. Therefore, the distance between the opposing capacitor elements is approximately twice the thickness of the exterior material, and there is a limit to the effect of reducing the ESL when a pair of opposing end face electrodes are used with different polarities.

[0007] Furthermore, reducing the thickness of the outer covering material to further reduce ESL leads to the problem of decreased insulation between opposing capacitor elements. While this decrease in insulation can be suppressed by forming the outer covering material from a highly insulating material, forming the entire outer covering material covering each capacitor element from a highly insulating material introduces a new problem: increased cost.

[0008] Thus, the film capacitor described in Patent Document 1 had the problem that it was difficult to sufficiently reduce ESL while ensuring good insulation performance between opposing capacitor elements.

[0009] The object of this invention is to provide a film capacitor that can sufficiently reduce ESL while ensuring good insulation performance between capacitor elements arranged such that a pair of opposing end electrodes have different polarities. [Means for solving the problem]

[0010] The above objectives will be achieved by the following means: [1] A film capacitor comprising a plurality of capacitor elements, a case housing the plurality of capacitor elements, and a sealing resin that fills the inside of the case and seals the plurality of capacitor elements, Each of the multiple capacitor elements has end electrodes on both ends, and busbars are connected to the end electrodes. Multiple capacitor elements are housed in a case, with at least two capacitor elements having opposing end electrodes, and each pair of opposing end electrodes having different polarities. A feature is that an insulating member, formed separately from the case, is interposed between the pair of end face electrodes.

[0011] According to this invention, since a pair of end-face electrodes connected to busbars with different polarities face each other with an insulating member in between, ESL can be reduced by canceling out the magnetic flux. Furthermore, since the insulating member is formed separately from the case, the thickness, material, shape, etc. of the insulating member can be designed independently of the case, increasing the design flexibility of the insulating member. For this reason, the thickness of the insulating member can be made thinner regardless of the thickness of the case, or a material with high insulating performance can be used only in the parts of the case that require insulation, rather than the entire case.

[0012] Furthermore, because the case and insulating material can be manufactured separately, the production of the case and insulating material becomes easier. [2] The CTI value of the insulating material is greater than the CTI value of the case. Note that CTI is an abbreviation for Comparative Tracking Index.

[0013] This invention facilitates the design of creepage insulation between opposing capacitor elements. [3] The thickness of the insulating material is thinner than the thickness of the case.

[0014] According to this invention, the distance between a pair of opposing end-face electrodes to which the busbar is connected can be reduced, thereby significantly reducing ESL (End-Side Level). [4] The insulating material has through holes or notches formed in it.

[0015] According to this invention, the sealing resin flows smoothly through the through holes or notches inside the case, so that the entire case can be uniformly filled with the sealing resin. [5] The insulating member has protrusions.

[0016] According to this invention, by contacting or fitting the busbar to the protrusion of the insulating member, the busbar can be precisely positioned and arranged, thereby enabling precise creepage insulation design. [6] When two or more capacitor elements arranged side by side in the facing direction of a pair of end face electrodes are used as a set of capacitor element units, a plurality of sets of capacitor element units are arranged side by side in a direction orthogonal to the facing direction, and in the plurality of sets of capacitor element units, an insulating member is interposed between all pairs of end face electrodes.

[0017] According to this invention, the same effect as described in [1] above can be obtained. [7] The insulating member is one continuous insulating member that crosses between a pair of end face electrodes present in at least two sets of capacitor element units.

[0018] According to this invention, the number of insulating members can be reduced, and cost reduction can be achieved.

Effect of the Invention

[0019] While ensuring good insulation performance between capacitor elements arranged such that a pair of opposing end face electrodes have different polarities, sufficient reduction of ESL can be achieved.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view of a film capacitor according to a first embodiment of this invention. [Figure 2] It is a perspective view of the film capacitor shown in FIG. 1 before filling with the encapsulating resin. [Figure 3] It is a perspective view of the state where the case is removed in FIG. 2. [Figure 4] It is a perspective view of the state where an insulating member is attached to the case. [Figure 5] It is a perspective view of the state where the case and the insulating member are separated. [Figure 6] It is a cross-sectional view when FIG. 2 is cut along line VI-VI. [Figure 7] It is a perspective view of a film capacitor according to a second embodiment of this invention. [Figure 8] It is a perspective view of the film capacitor shown in FIG. 7 before filling with the encapsulating resin. [Figure 9] Figure 8 is a perspective view with the case removed. [Figure 10] This is a perspective view of the case with the insulating material attached. [Figure 11] This is a perspective view showing the case and insulating material separated. [Modes for carrying out the invention]

[0021] Hereinafter, embodiments of this invention will be described based on the drawings. [First Embodiment] Figure 1 is a perspective view of a film capacitor 1 according to the first embodiment of this invention, Figure 2 is a perspective view of the film capacitor shown in Figure 1 before the sealing resin is filled in, and Figure 3 is a perspective view of the state in Figure 2 with the case 3 removed.

[0022] As shown in Figures 1 to 3, the film capacitor 1 according to the first embodiment comprises a plurality of capacitor elements 2 (two in this embodiment) and a case 3 that houses these capacitor elements 2. Each capacitor element 2 has end face electrodes 22 on both end faces, and bus bars 23 are connected to each end face electrode 22. The film capacitor 1 further comprises an insulating member 4 interposed between each capacitor element 2, 2, and each capacitor element 2, insulating member 4, and bus bars 23 are sealed by a sealing resin 5 filled inside the case 3, except for a portion of the insulating member 4 and bus bars 23. (Capacitor element) The capacitor element 2 is formed by winding together two metallized films, each having aluminum deposited on a dielectric film. In addition, each capacitor element 2 has end electrodes 22 formed on both end faces perpendicular to the winding direction by applying a metallizing treatment such as spraying zinc onto them.

[0023] Furthermore, as shown in the perspective view of Figure 3, busbars 23 made of a conductive material are attached to each end face electrode 22 of the capacitor element 2 in a conductive state by soldering or welding.

[0024] In this embodiment, each busbar 23 is formed in a roughly H shape, consisting of a large rectangular base 231, two terminals 232 extending upward at both ends of the base 231 in the longitudinal direction, and two hanging pieces 233 extending downward at both ends of the base 231 in the longitudinal direction. The hanging pieces 233 are joined to each end face electrode 22 by soldering or the like. The two terminals 232 function for connecting to external devices, etc. The shape of the busbar 23 and the shape of the terminals 232 are not limited. (Case and insulating material) Figure 4 shows the case 3 with the insulating member 4 attached, and Figure 5 shows the case 3 and insulating member 4 separated.

[0025] Case 3 is a rectangular box shape with an open top, and houses the two capacitor elements 2 described above in its internal hollow section. The material of Case 3 is not particularly limited, but insulating resin is one example. The shape of Case 3 is also not particularly limited; any box shape with an opening and capable of housing the capacitor elements is acceptable.

[0026] As shown in Figures 4 and 5, when the vertical direction of the case is the x-direction, the horizontal direction is the y-direction, and the height direction is the z-direction, the two capacitor elements 2 are housed in the case 3 with their respective end electrodes 22 facing in the x-direction. In other words, in the x-direction, the end electrodes 22 of the two capacitor elements 2 are facing each other, and the opposing pair of end electrodes 22, 22 are arranged to have different polarities. Consequently, the busbars 23, 23 connected to the opposing pair of end electrodes 22, 22 are also facing each other.

[0027] An insulating member 4 is interposed between a pair of opposing end face electrodes 22, 22. This insulating member 4 has a main body 41 whose size corresponds to the size of the cross-section parallel to the yz plane of the case 3, and two projections 42 are formed on the upper edge of the main body 41, projecting upward at a distance from each other. These projections 42 correspond to the two terminals 232 of the busbar 23 attached to the end face electrodes 22 of the capacitor element 2, and are formed to be larger than the size of each terminal 232.

[0028] In case 3, a series of ribs 31 are formed in the central part in the x-direction, projecting outward along the outer circumferential surface of case 3. Specifically, the ribs 31 extend in the z-direction on the side surface 32 parallel to the xz-plane of case 3, and in the y-direction on the bottom surface 33, as shown in the cross-sectional view of Figure 6. Inside these ribs 31, grooves 34 are formed along the ribs 31, opening to the inner surface of the case. The insulating member 4 is attached to case 3 with its side edges and bottom edges fitted into these grooves 34.

[0029] The ribs 31 may be formed as bulges on the inner surface of the case 3. Alternatively, instead of forming the ribs 31, a groove may be formed on the inner surface of the case 3 by reducing its thickness, and the partition 4 may be fitted into this groove; the form of the fitting structure is not limited. The insulating member 4 may also be attached to the case 3 without relying on a fitting structure. Furthermore, the insulating member 4 does not need to be integrally fixed to the case 3 at the stage of attachment to the case 3; ultimately, the insulating member 4 and the case 3 are integrally fixed via the sealing resin 5 by filling the case 3 with sealing resin as described later.

[0030] On both sides of the insulating member 4 in the thickness direction, upward-facing U-shaped positioning ridges 43 are formed parallel to the upper edge, at the lower center of the upper edge of the main body 41. Each capacitor element 2 housed in the case 3 is positioned within the case 3 by the ridges 43 fitting into the upper edge of the base 231 of the bus bar 23 and the corner between the terminal 232 and the base 231. Furthermore, the presence of the ridges 43 increases the creepage distance between the bus bars 23, 23 (a pair of opposing end face electrodes 22, 22) of opposing capacitor elements 2, 2, thus contributing to improved insulation performance. The ridges 43 can be of any shape as long as they can position the bus bar 23. However, the ridges 43 do not have to be present.

[0031] Furthermore, through holes 44 are formed at the upper ends of both ends of the main body 41 of the insulating member 4 in the y-direction, and notches 45 are also formed at the lower ends. As will be described later, these through holes 44 and notches 45 ensure the fluidity of the sealing resin when the liquid sealing resin is filled into the case 3, and are formed in a position within the case 3 where they do not overlap with the end face electrodes 22 when the end face electrodes 22 are projected onto the insulating member 4 in the x-direction. The shape and number of the through holes 44 and notches 45 can be arbitrarily set. Also, only one of the through holes 44 or notches 45 may be present.

[0032] Furthermore, when the two capacitor elements 2 are housed in the case 3, the surface of the busbar 23 of each capacitor element 2 facing the insulating member 4 is in contact with the insulating member 4, as shown in Figure 6. In this state, the two capacitor elements 2 face each other with the insulating member 4 in between, and the surfaces of the two terminals 232 of the busbar 23 of each capacitor element 2 are in contact with the respective protrusions 42 of the insulating member 4, so that the entire busbar 23 is positioned within a range smaller than the shape of the insulating member 4. This ensures creepage distance between the opposing pair of busbars 23, 23 of the capacitor elements 2, 2, and thus ensures insulation performance. Note that the busbar 23 of each capacitor element 2 and the insulating member 4 may be in close proximity without being in contact.

[0033] In this embodiment, since the insulating member 4 is formed separately from the case 3, the degree of design freedom regarding the material, thickness, shape, etc. of the insulating member 4 is increased compared to the case where the insulating member 4 and the case 3 are formed integrally. Therefore, the insulating member 4 can be optimally designed from the viewpoint of ensuring good insulation performance between the opposing busbars 23,23 of the capacitor elements 2,2 and the pair of end face electrodes 22,22 to which the busbars 23,23 are connected, and reducing ESL.

[0034] Specifically, in this embodiment, the thickness of the insulating member 4 is formed to be thinner than the thickness of the case 3. Therefore, the distance between the opposing pair of busbars 23,23 of the capacitor elements 2,2 and the pair of end electrodes 22,22 to which the busbars 23,23 are connected can be reduced, and when the film capacitor 1 is used such that the opposing pair of end electrodes 22,22 have different polarities, it becomes possible to reduce the ESL due to the magnetic flux cancellation effect.

[0035] Furthermore, in this embodiment, the insulating member 4 is made of a material such as resin with a CTI (comparative tracking index) value greater than that of case 3, that is, a material with higher insulating performance than that of case 3. The CTI value is determined by the tracking resistance evaluation method specified in IEC60112 and JIS C 2134.

[0036] In this way, a material with high insulating performance can be used only in the parts of Case 3 that require insulation, rather than the entire case 3. This makes it easier to design creepage insulation between the opposing pair of busbars 23, 23 of the capacitor elements 2, 2. In other words, it becomes possible to ensure insulation performance between the pair of busbars 23, 23 with a small creepage distance, and this, combined with the ability to reduce the thickness of the insulating material 4, contributes to the overall miniaturization of the film capacitor 1.

[0037] Furthermore, because the insulating member 4 is separate from the case 3, it is possible to realize shapes for the insulating member 4 that would not be possible if it were manufactured together with the case 3, making it easier to form the aforementioned protrusions 43 and the through holes 44 and notches 45 for ensuring the fluidity of the sealing resin. Moreover, since the case 3 and the insulating member 4 can be manufactured separately, the manufacturing of the case 3 and the insulating member 4 is also simplified. (Sealing with sealing resin) As shown in Figure 1, each capacitor element 2 is sealed with sealing resin 5, except for the upper part of the projection 42 of the insulating member 4 and the upper part of the terminal 232 of the busbar 23. The upper part of the projection 42 of the insulating member 4 and the upper part of the terminal 232 of the busbar 23 are exposed upward from the sealing resin 5. An external device, for example, can be connected to the exposed terminal 232 of the busbar 23.

[0038] Sealing with the sealing resin 5 is performed by filling the case 3, in which the insulating member 4 is set and the capacitor element 2 is housed, with liquid sealing resin and allowing it to harden. For example, epoxy resin can be used as the type of sealing resin 5. The amount of sealing resin 5 filled is sufficient to cover approximately the entire inside of the case 3.

[0039] When the liquid sealing resin is filled, it passes through the insulating member 4 in the thickness direction via the through holes 44 and notches 45 formed in the insulating member 4, and flows smoothly inside the case 3. Therefore, regardless of the filling position of the sealing resin 5 inside the case 3, the sealing resin 5 can be filled uniformly and easily throughout the case 3. (modified version) The embodiments shown in Figures 1 to 6 illustrate a case where the end face electrodes 22 of two capacitor elements 2 face each other in the x-direction, and the opposing pair of end face electrodes 22, 22 have different polarities. However, the number of capacitor elements 2 arranged in the x-direction is not limited to two; three or more capacitor elements 2 may be arranged so that adjacent end face electrodes 22 face each other, and the opposing pair of end face electrodes 22, 22 have different polarities. In this case as well, an insulating member 4, formed separately from the case 3, is interposed between all opposing pairs of end face electrodes 22, 22. In short, it is sufficient that at least two of the multiple capacitor elements 2 have their end face electrodes 22 facing each other, and that an insulating member 4, formed separately from the case 3, is interposed between the opposing pairs of end face electrodes 22, 22. [Second Embodiment] Figure 7 is a perspective view of a film capacitor 6 according to a second embodiment of the present invention, Figure 8 is a perspective view of the film capacitor shown in Figure 7 before the sealing resin is filled in, and Figure 9 is a perspective view of the state in Figure 8 with the case 9 removed.

[0040] As shown in Figures 7 to 9, the film capacitor 6 according to the second embodiment, like the first embodiment, is housed in a case 9 with the end face electrodes 72 of two capacitor elements 7 facing each other in the x-direction.

[0041] Furthermore, when these two capacitor elements 7 are considered as the first capacitor element unit 81, a second capacitor element unit 82, having the same configuration as the first capacitor element unit 81, is arranged in the y-direction, that is, in a direction perpendicular to the direction of the opposing pair of end face electrodes 72, 72 of the capacitor elements 7, 7 in the first capacitor element unit 81 (opposing direction). Therefore, case 9 has a larger shape in the y-direction compared to case 3 used in the first embodiment. (Capacitor element) The capacitor element 7 is identical in configuration to the capacitor element 2 in the first embodiment, except for the configuration of the busbar 73. That is, the capacitor element 7 is provided with end electrodes 72 on both end faces, and a busbar 73 made of a conductive material is attached to each end electrode 72. The busbar 73 will be described later.

[0042] As shown in Figure 9, for the busbars 73 connected to each end face electrode 72 of each capacitor element 7, adjacent busbars in the y-direction of the first and second capacitor element units 81 and 82 are made up of a single common busbar 73. Therefore, two capacitor elements 7 that share a common busbar 73 are used in an electrically parallel connection state.

[0043] Each busbar 73 has a rectangular base 731 that extends in the y-direction with a length that spans the case 9. The busbar 73 further has two first terminals 732 extending upward from the base 731 on the first capacitor element unit 81 side, and two hanging pieces 733 extending downward from the base 731. The busbar 73 further has two second terminals 734 extending upward from the base 731 on the second capacitor element unit 82 side, and two hanging pieces 735 extending downward from the base 731. In the regions corresponding to the first and second capacitor element units 81 and 82, the hanging pieces 733 and 735 are joined to the respective end face electrodes 72 by soldering or the like. The first terminals 732 and second terminals 734 formed on the busbar 73 correspond to terminals 232 in the first embodiment.

[0044] In addition, separate and independent busbars may be used for each pair of adjacent capacitor elements 7 in the y-direction, similar to the first embodiment. (Cases and dividers) Figure 10 shows the case 9 with the insulating member 10 attached, and Figure 11 shows the case 9 and insulating member 10 separated.

[0045] In the first and second capacitor element units 81 and 82, an insulating member 10, formed separately from the case 9, is interposed between each capacitor element 7, 7. In this second embodiment, the insulating member 10 is a single continuous insulating member that traverses the y-direction between a pair of opposing end face electrodes 72, 72 of each capacitor element 7, 7 in each capacitor element unit 81 and 82. Similar to the first embodiment, a continuous rib 91 is formed along the side surface 92 and bottom surface 93 of the case 9 in the x-direction center of the case 9, and the insulating member 10 is attached to the case 9 with its outer circumference fitted into a groove 94 formed in the rib 91.

[0046] The insulating member 10 has a main body 101 whose size corresponds to the size of the cross-section parallel to the yz plane of the case 10. In the region on the side of the first capacitor element unit 81, two first projections 102 are formed on the upper edge of the main body 101, projecting upward at a distance from each other. Similarly, in the region on the side of the second capacitor element unit 82, two second projections 103 are formed on the upper edge of the main body 101, projecting upward at a distance from each other. These first projections 102 and second projections 103 correspond to the two first terminals 732 and two second terminals 734 of the busbar 73 of each capacitor element 7, and are formed to be larger than the size of each terminal 732, 734.

[0047] On both sides of the insulating member 10 in the thickness direction, a first positioning protrusion 104 is formed in the region between the two first protrusions 102, at a position below the upper edge of the main body 101, and parallel to the upper edge. Similarly, a second positioning protrusion 105 is formed in the region between the two second protrusions 103, at a position below the upper edge of the main body 101, and parallel to the upper edge. Furthermore, a third positioning protrusion 106 is formed in the region between the first protrusion 102 and the second protrusion 103, at a position below the upper edge of the main body 101, and parallel to the upper edge.

[0048] Each capacitor element 7 of the first capacitor element unit 81 is positioned within the case 9 by having the first protrusion 104 fitted into the upper edge between the first terminals 732, 732 of the busbar 73 and into the corner portion between the first terminal 732 and the base 731. Similarly, each capacitor element 7 of the second capacitor element unit 82 is positioned within the case 9 by having the second protrusion 105 fitted into the upper edge between the second terminals 734, 734 of the busbar 73 and into the corner portion between the second terminal 734 and the base 731. Furthermore, the third protrusion 106 is fitted into the upper edge between the first terminal 732 and the second terminal 734 of the busbar 73 and into the corner portion between these terminals and the base 731, thereby positioning it. Also, as in the first embodiment, the first to third protrusions 104 to 106 contribute to improving insulation performance.

[0049] Furthermore, through holes 107 are formed at the upper ends of both ends of the main body 101 of the insulating member 10 in the y-direction, and notches 108 are also formed at the lower ends. These through holes 107 and notches 108 have the function of ensuring the fluidity of the resin when filling the sealing resin into the case 9.

[0050] Furthermore, when each capacitor element 7 is housed in the case 9, the surface of the busbar 73 facing the insulating member 10 is in contact with or close to the insulating member 10. In this state, in each of the first and second capacitor element units 81 and 82, two capacitor elements 7 face each other with the insulating member 10 in between. The surfaces of the first terminal 732 and the second terminal 734 of the busbar 73 are in contact with or close to the first projection 102 and the second projection 103 of the insulating member 10, respectively, and the entire busbar 73 is positioned within a range smaller than the shape of the insulating member 10. This ensures a creepage distance between the end face electrodes 72, 72 of the opposing capacitors 7, 7, thereby ensuring insulation performance.

[0051] Furthermore, the fact that each capacitor element 7 is sealed with sealing resin 11, and that the upper parts of the first projection 102 and the second projection 103 of the insulating member 10 and the upper parts of the first terminal 732 and the second terminal 734 of the busbar 73 are exposed upward from the sealing resin 11, is also the same as in the first embodiment.

[0052] Note that the insulating member 10 may not be a single insulating member, but rather separate insulating members may be used for each capacitor element unit 81, 82.

[0053] In the film capacitor 6 according to the second embodiment, similar to the film capacitor 1 according to the first embodiment, the insulating member 10 is formed separately from the case 9. Therefore, compared to the case where the insulating member 10 and the case 9 are formed integrally, the degree of design freedom regarding the material, thickness, shape, etc., of the insulating member 10 is increased. As a result, it is possible to design an optimal insulating member from the viewpoint of ensuring good insulation performance between the opposing pair of end face electrodes 72, 72 of the capacitor elements 7, 7 and reducing ESL. The thickness of the insulating member 10 is formed to be thinner than the thickness of the case 9. As a result, the distance between the opposing pair of end face electrodes 72, 72 of the capacitor elements 7, 7 can be reduced, and ESL can be reduced by the magnetic flux cancellation effect. In addition, a material with a CTI value greater than that of the case 9 is used as the insulating member 10.

[0054] In addition, the insulating member 10 is a single continuous insulating member that crosses the pair of end face electrodes 72, 72 present in the first capacitor element unit 81 and the second capacitor element unit 82. Therefore, compared to the case where separate insulating members are used for each capacitor element unit 81 and 82, the number of insulating members 10 can be reduced, resulting in cost reduction, and the handling of the insulating member 10 and assembly into the case 9 can be simplified. (Modified version of the second embodiment) In the embodiments shown in Figures 7 to 11, a case is shown where two sets of capacitor element units, a first capacitor element unit 81 and a second capacitor element unit 82, are arranged in the y direction. However, three or more sets of capacitor element units may be arranged in the y direction. In this case, a single common busbar 73 may be used as the busbar 73 for the capacitor elements 7 in the y direction, or separate, independent busbars 73 may be used for each capacitor element unit. Furthermore, as the insulating member 10, a single continuous insulating member may be used that traverses the y direction between the opposing pair of end face electrodes 72, 72 of the capacitor elements 7, 7 of each capacitor element unit 81, 82, or independent insulating members may be used for each capacitor element unit 81, 82.

[0055] Furthermore, in each capacitor element unit 81, 82, the number of capacitor elements 7 arranged in the x-direction is not limited to two; three or more capacitor elements 7 may be arranged in the x-direction. Also, the number of capacitor elements 7 arranged in the x-direction in each capacitor element unit 81, 82 is not the same; they may differ for each capacitor element unit 81, 82.

[0056] Furthermore, each capacitor element unit 81, 82 may be arranged in the z direction. In this case, a single common busbar 73 may be used as the busbar 73 for the capacitor elements 7 in the z direction, or separate, independent busbars 73 may be used for each capacitor element unit. Also, as the insulating member 10, a single continuous insulating member may be used that longitudinally intersects in the z direction between the opposing pair of end face electrodes 72, 72 of the capacitor elements 7, 7 of each capacitor element unit 81, 82, or independent insulating members may be used for each capacitor element unit 81, 82. [Explanation of symbols]

[0057] 1.6 Film Capacitors 2.7 Capacitor element 3, 9 cases 4, 10 Insulating material 5, 11 Sealing resin 22, 72 end electrode 23, 73 Bus Bar 231, 731 base 232 terminal, 732 1st terminal, 734 2nd terminal 31, 91 ribs 34, 94 grooves 41, 101 Main body of insulating material 43 Protrusions, 104-106 1st-3rd Protrusions 44, 107 through holes 45, 108 notches

Claims

1. A film capacitor comprising a plurality of capacitor elements, a case housing the plurality of capacitor elements, and a sealing resin filling the inside of the case to seal the plurality of capacitor elements, Each of the aforementioned plurality of capacitor elements has end electrodes on both end faces, and busbars are connected to the end electrodes. The plurality of capacitor elements are housed in the case in such a state that at least two of the capacitor elements have opposing end electrodes, and the opposing pair of end electrodes have different polarities. A film capacitor characterized in that an insulating member, formed separately from the case, is interposed between the pair of end face electrodes.

2. The film capacitor according to claim 1, wherein the CTI value of the insulating member is greater than the CTI value of the case.

3. The film capacitor according to claim 1, wherein the thickness of the insulating member is thinner than the thickness of the case.

4. The film capacitor according to claim 1, wherein the insulating member has through holes or notches formed therein.

5. The insulating member is a film capacitor according to claim 1, having a protrusion.

6. When two or more capacitor elements arranged side by side in the opposing direction of the pair of end face electrodes constitute a set of capacitor element units, multiple sets of capacitor element units are arranged side by side in a direction perpendicular to the opposing direction, The film capacitor according to any one of claims 1 to 5, wherein the insulating member is interposed between all of the pair of end face electrodes in the plurality of capacitor element units.

7. The film capacitor according to claim 6, wherein the insulating member is a single continuous insulating member that spans between the pair of end face electrodes present in at least two sets of capacitor element units.

Images