Metalization film capacitor

Abstract

To enable efficient dissipation of heat generated in a capacitor element and reduction of equivalent series inductance (ESL) with a simple configuration.SOLUTION: A proximity portion 25 is provided on a first bus bar 2, and the proximity portion 25 is disposed closer to an inner surface (lower surface) of a case 5 than a main body portion 20 and an electrode connection portion 24. In addition, the electrode connection portion 24 of the first bus bar 2 is disposed at a position closer to an external connection terminal portion 22. Accordingly, heat generated by a capacitor element 10 can be dissipated via the proximity portion 25 disposed close to the inner surface of the case, and an increase in equivalent series inductance (ESL) can be suppressed.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a film capacitor including a capacitor element, a first bus bar, and a second bus bar. [Background technology]

[0002] Conventionally, a known film capacitor includes a capacitor element, one bus bar and the other bus bar having external connection terminals and electrically connected to one electrode and the other electrode of the capacitor element via electrode connection portions, and the capacitor element to which the one bus bar and the other bus bar are connected except for the external connection terminals is housed in a case and sealed with a filling resin that fills the case (see Patent Document 1). This type of capacitor is configured to dissipate heat generated by the capacitor element.

[0003] For example, in the capacitor described in Patent Document 1, the first bus bar, which is one of the bus bars connected to the first end surface electrodes of the six capacitor elements, has a configuration in which an electrode terminal portion, three first connection terminal portions, a second connection terminal portion, a relay terminal portion, and two support portions are integrated together. The second bus bar, which is the other of the bus bars connected to the second end surface electrodes of the six capacitor elements, also has a configuration in which an electrode terminal portion, three first connection terminal portions, a second connection terminal portion, a relay terminal portion, and two support portions are integrated together. Furthermore, the first bus bar has a buried portion that is buried in the filling resin at a front position and an exposed portion that is exposed from the filling resin, and is configured to dissipate heat generated by the capacitor elements to the outside by being exposed from the filling resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 241145 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the film capacitor described in Patent Document 1, two connection pins of the first bus bar are connected to each of the first end surface electrodes of the six capacitor elements, and the positions of six of these 12 connection pins are positioned further away from the exposed portions as viewed from the first connection terminal portion and second connection terminal portion that are connected to the external terminals, which may result in a deterioration of the equivalent series inductance (ESL).

[0006] The present invention has been made in view of the above problems, and has an object to provide a capacitor with a simple configuration that can efficiently dissipate heat generated by a capacitor element and reduce equivalent series inductance (ESL). [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 and a second bus bar having an external connection terminal portion and electrically connected to one electrode and the other electrode of the capacitor element via an electrode connection portion, respectively, and a part of the capacitor element to which the first bus bar and the second bus bar are connected, excluding the external connection terminal portion, housed in a case, and sealed by filling the case with a sealing resin, wherein at least one of the first bus bar and the second bus bar has an electrode connection portion that faces the inner surface of the case while being spaced apart, is connected to the electrode connection portion, and has a proximity portion that is closer to the inner surface of the case to which the electrode connection portion faces than the electrode connection portion.

[0008] According to this configuration, at least one of the first bus bar and the second bus bar has a proximity portion that is closer to the inner surface of the case than the electrode connection portion, so that heat generated by the capacitor element can be dissipated through the proximity portion that is closer to the inner surface of the case. The proximity portion may be in contact with the inner surface of the case. Furthermore, because the proximity portion is merely close to the inner surface of the case, it does not result in an increase in equivalent series inductance (ESL).

[0009] The proximity portion may be located at a position away from the external connection terminal with respect to the electrode connection portion of the bus bar. With this configuration, the electrode connection portion of the bus bar can be located closer to the external connection terminal, thereby suppressing an increase in equivalent series inductance (ESL).

[0010] The adjacent portion may be connected to the electrode connection portion via a bent portion formed between the adjacent portion and the electrode connection portion. Furthermore, the adjacent portion may be electrically connected to the electrode of the capacitor element and formed by increasing the thickness of a portion of the bus bar. In this way, the adjacent portion of the bus bar can be brought close to the inner surface of the case with a simple configuration.

[0011] Furthermore, it is preferable that the plurality of capacitor elements are arranged in a direction away from the external connection terminal portion, the first bus bar and the second bus bar have a plurality of electrode connection portions that are connected to the one electrode and the other electrode of the plurality of capacitor elements, respectively, at positions close to the external connection terminal portion, and the proximity portion is provided at a position away from the external connection terminal portion with respect to each of the plurality of electrode connection portions of the bus bar.

[0012] According to this configuration, when multiple capacitor elements are arranged in a direction away from the external connection terminal portion, the proximity portion of the bus bar is positioned at a position away from the external connection terminal with respect to each of the multiple electrode connection portions, and the multiple electrode connection portions are arranged at positions close to the external connection terminals, so that heat generated by the capacitor elements can be released through the proximity portion that is close to the inner surface of the case, and the equivalent series inductance (ESL) can be reduced. [Effects of the Invention]

[0013] According to the present invention, with a simple configuration, heat generated by a capacitor element can be efficiently dissipated and the equivalent series inductance (ESL) can be reduced. [Brief explanation of the drawings]

[0014] [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 without a sealing resin, as viewed from above. FIG. [Figure 3] FIG. 2 is a perspective view of the film capacitor without the case, as viewed from the bottom side. [Figure 4] FIG. 1 is a perspective view of a film capacitor without a sealing resin or a case, seen from above. [Figure 5] 5 is a perspective view of the film capacitor in the state shown in FIG. 4, as viewed from the bottom side. FIG. [Figure 6] 2 is a perspective view of the first and second bus bars and insulating members of the film capacitor of FIG. 1, as viewed from the bottom side. FIG. [Figure 7] 7 is a perspective view of the second bus bar of FIG. 6 as viewed from above. [Figure 8] 7 is a perspective view of the first bus bar of FIG. 6, as viewed from the bottom side. [Figure 9] FIG. 4 is a diagram showing the state of the first bus bar and the case. [Figure 10] 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 11] 11 is a perspective view of the film capacitor of FIG. 10 without a case, as viewed from the bottom side. FIG. [Figure 12] 11 is a perspective view of the film capacitor of FIG. 10 without a sealing resin and a case, as viewed from above. FIG. [Figure 13] 13 is a perspective view of the film capacitor in the state shown in FIG. 12, as viewed from the bottom side. FIG. [Figure 14] 11 is a perspective view of the first and second bus bars and insulating members of the film capacitor of FIG. 10, as viewed from the bottom side. [Figure 15] FIG. 4 is a diagram showing the state of the first bus bar and the case. [Figure 16] FIG. 10 is a perspective view of a film capacitor according to a third embodiment of the present invention, as viewed from the top side. [Figure 17]17 is a perspective view of the film capacitor of FIG. 16 without the case, as viewed from above. FIG. [Figure 18] FIG. 18 is a perspective view showing the film capacitor of FIG. 17 in a state where no sealing resin is present. [Figure 19] 19 is a perspective view of the film capacitor of FIG. 18 without a sealing resin, seen from a direction different from that of FIG. 18. FIG. [Figure 20] 19 is a perspective view of a first bus bar and a capacitor element of the film capacitor of FIG. 18. [Figure 21] 20 is a perspective view of a first bus bar, a second bus bar, and an insulating member of the film capacitor in the state shown in FIG. 19. [Figure 22] FIG. 4 is a diagram showing the state of the first bus bar and the case. [Figure 23] FIG. 10 is a diagram showing the state of the second bus bar and the case. DETAILED DESCRIPTION OF THE INVENTION

[0015] First Embodiment A first embodiment of a capacitor according to the present invention will be described with reference to FIGS. 1 to 9. In FIGS. 1 to 9, 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."

[0016] 1 to 5, the film capacitor 1 includes two capacitor elements 10, 10 arranged in the y-axis direction, a first bus bar 2, a second bus bar 3, an insulating member 4, a case 5, and a sealing resin 6. As shown in FIGS. 4 and 5, each of the two capacitor elements 10, 10 includes an element body 11, a first end surface electrode 12 formed by spraying a metal such as zinc on the lower surface of the element body 11 on the negative side of the z-axis, and a second end surface electrode 13 formed by spraying a metal such as zinc on the upper surface of the element body 11 on the positive side of the z-axis. The first end surface electrode 12 and the second end surface electrode 13 of the two capacitor elements 10, 10 correspond to the "first electrode" and the "second electrode" of the capacitor element in the present invention, respectively.

[0017] 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.

[0018] 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.

[0019] The first bus bar 2 and the second bus bar 3 are each made of a conductive material such as copper. As shown in FIG. 8 , the first bus bar 2 has a main body 20, a bent portion 21, and an external connection terminal portion 22. The main body 20 has a substantially rectangular shape in an xy-plane view. The bent portion 21 is bent upward (in the positive z-axis direction) by approximately 90 degrees from the left end of the main body 20 on the negative x-axis side, and has a substantially rectangular, flat plate-like outer shape in a yz-plane view. The external connection terminal portion 22 extends slightly upward (in the positive z-axis direction) from approximately the center of the upper end of the bent portion 21 on the positive z-axis side, and further extends substantially horizontally to the left (in the negative x-axis direction), and has an L-shape in a side view.

[0020] Here, the length of main body 20 in the x-axis direction is approximately the same as the length of capacitor element 10 in the x-axis direction, and the length of main body 20 in the y-axis direction is slightly shorter than twice the length of capacitor element 10 in the y-axis direction. E-shaped notches 23 are formed side by side in the y-axis direction near bent portion 21 of main body 20 at positions facing first end surface electrodes 12 of two capacitor elements 10, 10, respectively.

[0021] Each of these two cutouts 23 has two pin-shaped electrode connection portions 24 that are long in the x-axis direction formed by the cutout, and the two electrode connection portions 24, 24 of one cutout 23 are electrically connected to the first end surface electrode 12 of one capacitor element 10, while the two electrode connection portions 24, 24 of the other cutout 23 are electrically connected to the first end surface electrode 12 of the other capacitor element 10. These electrode connection portions 24 are arranged close enough to be soldered to the first end surface electrodes 12 of the two capacitor elements 10, 10, and correspond to the "electrode connection portions" in this invention.

[0022] Furthermore, a proximity portion 25 having a substantially rectangular shape in an xy-plane view is formed in the right half of the main body portion 20 of the first busbar 2 on the positive side of the x-axis, the proximity portion 25 being closer to the inner surface (lower surface) of the case 5 and farther from the first end surface electrode 12 than the electrode connection portion 24 ( FIG. 9 ). This proximity portion 25 is formed, for example, by punching and pressing a copper plate, so that a bent portion 26 that is bent diagonally downward and to the right is formed in the approximate center of the main body portion 20, and at the same time, the right half of the main body portion 20 is positioned lower (negative side of the z-axis) than the left half via the bent portion 26.

[0023] The main body portion 20, bent portion 21, external connection terminal portion 22, notch portion 23, electrode connection portion 24, bent portion 26 and adjacent portion 25 of the first bus bar 2 are simultaneously formed by punching and pressing.

[0024] Proximal portion 25 is connected to electrode connection portion 24, and by interposing bent portion 26 therebetween, proximal portion 25 is disposed closer to the inner surface (lower surface) of case 5 than main body portion 20, at a position farther from external connection terminal portion 22 than electrode connection portion 24. Here, proximal portion 25 may be disposed so as to contact the inner surface (lower surface) of case 5. When proximal portion 25 contacts the inner surface of case 5, proximal portion 25 is exposed from sealing resin 6 as shown in FIG. 3 .

[0025] As shown in Figure 7, the second busbar 3 has a flat main body portion 30 that is approximately rectangular in the x-y plane and is arranged close enough to the second end surface electrodes 13 of the two capacitor elements 10, 10 so that they can be soldered to each other, a flat bent portion 31 that is bent approximately 90° upward (in the positive direction of the z-axis) from the left end of the main body portion 30 on the negative side of the x-axis and has an outline that is approximately elongated and rectangular in the y-z plane, and an external connection terminal portion 32 that is formed by extending approximately horizontally to the left (in the negative direction of the x-axis) from approximately the center of the upper end of the bent portion 31 opposite the main body portion 30 side.

[0026] Here, the length of the main body 30 in the x-axis direction is sufficiently shorter than the length of the capacitor elements 10 in the x-axis direction, and the length of the main body 30 in the y-axis direction is slightly shorter than twice the length of the capacitor elements 10 in the y-axis direction. Two electrode connection portions 33 in the x-axis direction are formed at the right end of the main body 30 on the positive x-axis side, facing the second end surface electrodes 13 of the two capacitor elements 10, 10, respectively, with one pair of electrode connection portions 33 electrically connected to the second end surface electrode 13 of one capacitor element 10, and the other pair of electrode connection portions 33 electrically connected to the second end surface electrode 13 of the other capacitor element 10. The external connection terminal portion 32 extends slightly upward (in the positive z-axis direction) from approximately the center of the upper end portion on the positive z-axis side of the bent portion 31, and further extends approximately horizontally to the left (in the negative x-axis direction), and is L-shaped in side view.

[0027] The main body portion 30, the bent portion 31, the external connection terminal portion 32, and the electrode connection portion 33 of the second bus bar 3 are simultaneously formed by the punching press process.

[0028] As shown in Figure 6, the insulating member 4 has an L-shaped cross section in the xz 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, thereby providing insulation between the first bus bar 2 and the second bus bar 3.

[0029] 1 and 2, case 5 has an opening on its upper surface on the positive side of the z-axis and a space inside that forms a storage section, and can be made of various materials, such as organic materials such as resins and plastics such as polyphenylene sulfide (PPS) and polybutylene terephthalate (PBT), and inorganic materials such as ceramics. Case 5 corresponds to the "case" in this invention.

[0030] A portion of a capacitor unit (the capacitor elements, a portion of the first bus bar 2, a portion of the second bus bar 3, and a portion of the insulating member 4) having two capacitor elements 10, 10, the first and second bus bars 2, 3, and the insulating member 4 is accommodated in an accommodating portion within the case 5. Furthermore, a sealing resin 6 made of, for example, epoxy resin is filled in the accommodating portion of the case 5 accommodating the portion of the capacitor unit, thereby sealing the portion of the capacitor unit.

[0031] 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 injected into the case 5 in a liquid state through the opening of the case 5 and then curing. The sealing resin 6 corresponds to the "sealing resin" in this invention.

[0032] In this manner, when a portion of the capacitor unit is sealed with the sealing resin 6, as shown in FIG. 3, the proximity portion 25 of the first busbar 2 is exposed from the sealing resin 6 and comes into proximity (contact) with the lower surface on the negative side of the z-axis, which is the inner surface of the case 5, and therefore the heat generated by the two capacitor elements 10, 10 can be released through the proximity portion 25.

[0033] Furthermore, since the proximity portion 25 of the first busbar 2 is located farther from the external connection terminal portion 22 than the electrode connection portion 24 (since the electrode connection portion 24 is located closer to the external connection terminal portion 22 than the proximity portion 25), an increase in equivalent series inductance (ESL) is suppressed.

[0034] Therefore, according to the first embodiment described above, the first busbar 2 has a proximity portion 25, which is closer to the inner surface (lower surface) of the case 5 than the main body portion 20 and the electrode connection portion 24, and therefore the heat generated by the capacitor element 10 can be effectively released via the proximity portion 25 which is closer to the inner surface (lower surface) of the case 5.

[0035] Furthermore, since the electrode connection portion 24 of the first bus bar 2 is disposed at a position closer to the external connection terminal portion 22, an increase in equivalent series inductance (ESL) can be suppressed.

[0036] Furthermore, the first bus bar 2 and the second bus bar 3 can be easily formed in a single processing step by punching and pressing a copper plate or the like.

[0037] Second Embodiment A second embodiment of the capacitor according to the present invention will be described in detail with reference to FIGS.

[0038] The configuration of a film capacitor 1a, which is a capacitor according to a second embodiment, will be described with reference to Figures 10 to 15. 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 9.

[0039] The film capacitor 1a in the second embodiment differs from the first embodiment in that, whereas in the first embodiment, two capacitor elements 10, 10 are arranged in the y-axis direction, in the second embodiment, another set of two capacitor elements 10, 10 of the first embodiment is arranged in the x-axis direction, resulting in an arrangement of capacitor elements 10 in two rows and two columns on the xy plane. The configuration of the film capacitor 1a in the second embodiment will be described in detail below. Note that in Figures 10 to 15, the same reference numerals as in Figures 1 to 9 indicate the same or corresponding parts.

[0040] As shown in Figures 10 to 15, the film capacitor 1a of the second embodiment includes a total of four capacitor elements 10 arranged in a 2x2 matrix along the x-axis and y-axis directions, with the x-axis as the longitudinal direction, a first bus bar 2a, a second bus bar 3a, an insulating member 4a, a case 5a, and a sealing resin 6a. The case 5a and the sealing resin 6a are made of the same material as the case 5 and the sealing resin 6 of the first embodiment. The case 5a has an opening on its upper surface on the positive side of the z-axis and has a space inside that forms a housing. The sealing resin 6a is formed by being poured in liquid form into the case 5a through the opening of the case 5a and then curing.

[0041] The first bus bar 2a and the second bus bar 3a are formed of a conductive material such as copper, similar to the first bus bar 2 and the second bus bar 3 of the first embodiment. As shown in FIG. 14 , the first bus bar 2a has a main body 20a, a bent portion 21a, and an external connection terminal portion 22a. The main body 20a has a generally rectangular shape that is long in the x-axis direction in an xy-plane view. The bent portion 21a is bent approximately 90° upward (in the z-axis positive direction) from the left end of the main body 20a on the negative side of the x-axis, and has a generally rectangular, flat plate shape in a yz-plane view. The external connection terminal portion 22a extends slightly upward (in the z-axis positive direction) from approximately the center of the upper end of the bent portion 21a on the positive side of the z-axis, and further extends generally horizontally to the left (in the x-axis negative direction), and has an L-shape in a side view.

[0042] Furthermore, the length of main body 20a in the x-axis direction is approximately twice the length of one capacitor element 10 in the x-axis direction, and the length of main body 20a in the y-axis direction is slightly shorter than twice the length of one capacitor element 10 in the y-axis direction. Two E-shaped notches 23a1 are formed side by side in the y-axis direction at positions near bent portion 21a of main body 20a and facing each of first end surface electrodes 12 of two capacitor elements 10 on the negative side of the x-axis close to bent portion 21a, and two E-shaped notches 23a2 are formed side by side in the y-axis direction at positions far from bent portion 21a of main body 20a and facing each of first end surface electrodes 12 of two capacitor elements 10 on the positive side of the x-axis far from bent portion 21a, for a total of four E-shaped notches 23a1, 23a2.

[0043] Each of the four cutouts 23a1, 23a2 has two pin-shaped electrode connection portions 24a1, 24a2 formed therein. The electrode connection portion 24a1 of each of the two cutouts 23a1 on the negative side of the x-axis, closer to the bent portion 21a, is electrically connected to the first end surface electrodes 12 of two capacitor elements 10 aligned in the y-axis direction and closer to the bent portion 21a. The electrode connection portion 24a2 of each of the cutouts 23a2 on the positive side of the x-axis, farther from the bent portion 21a, is electrically connected to the first end surface electrodes 12 of two capacitor elements 10 aligned in the y-axis direction and farther from the bent portion 21a. These electrode connection portions 24a1, 24a2 are arranged close enough to be soldered to the first end surface electrodes 12 of the four capacitor elements 10, and correspond to the "electrode connection portion" in this invention.

[0044] Furthermore, a proximity portion 25a1 having an approximately rectangular shape in the xy plane is formed between two notches 23a1 on the negative side (left side) of the x-axis near the bent portion 21a of the main body portion 20a of the first bus bar 2a and two notches 23a2 on the far positive side (right side) of the x-axis, and a proximity portion 25a2 having an approximately rectangular shape in the xy plane is formed at the right end portion on the positive side of the x-axis of the main body portion 20a of the first bus bar 2a.

[0045] At this time, for example, by stamping and pressing a copper plate, bent portion 26a1 bent diagonally downward and rightward and bent portion 26a2 bent diagonally upward and rightward are formed, and proximal portion 25a1 is formed between notch 23a1 on the negative side of the x-axis near bent portion 21a of main body portion 20a and notch 23a2 on the positive side of the x-axis farther from bent portion 21a, via bent portions 26a1 and 26a2. Furthermore, by stamping and pressing, bent portion 26a3 bent diagonally downward and rightward is formed at the right end of main body portion 20a, and another proximal portion 25a2 is formed at the right end of main body portion 20a via bent portion 26a3. These proximal portions 25a1 and 25a2 are connected to electrode connecting portions 24a1 and 24a2.

[0046] Proximal portions 25a1 and 25a2 are formed so that a portion of main body 20a slightly to the left of the center (negative x-axis side) and a portion to the right of main body 20a on the positive x-axis side are positioned lower (negative z-axis direction) than the other portions, and these distal portions 25a1 and 25a2 are positioned closer to the lower surface (bottom surface) on the negative z-axis side, which is the inner surface of case 5a, than electrode connection portion 24a. Proximal portions 25a1 and 25a2 may be positioned so as to contact the inner surface (bottom surface) of case 5a. When proximal portions 25a1 and 25a2 contact the inner surface of case 5a, proximal portions 25a1 and 25a2 are exposed from sealing resin 6 as shown in FIG. 11 .

[0047] The main body 20a, bent portion 21a, external connection terminal portion 22a, notches 23a1 and 23a2, electrode connection portions 24a1 and 24a2, bent portions 26a1, 26a2 and 26a3, and adjacent portions 25a1 and 25a2 of the first bus bar 2a are simultaneously formed by punching and pressing.

[0048] As shown in FIG. 14 , the second bus bar 3a has a main body portion 30a, a bent portion 31a, and an external connection terminal portion 32a. The main body portion 30a is disposed close enough to the second end surface electrodes 13 of the four capacitor elements 10 so that the main body portion 30a can be soldered to each of them, and has a substantially rectangular shape in the x-y plane. The bent portion 31a is formed by bending the left end portion of the main body portion 30a on the negative x-axis side upward by approximately 90 degrees (in the positive z-axis direction), and has an elongated, substantially rectangular shape in the y-z plane. The external connection terminal portion 32a extends slightly upward (in the positive z-axis direction) from approximately the center of the upper end portion on the positive z-axis side of the bent portion 31a, and further extends substantially horizontally to the left (in the negative x-axis direction), and has an L-shape in a side view.

[0049] Here, the length of main body 30a in the x-axis direction is sufficiently shorter than twice the length of one capacitor element 10 in the x-axis direction, and the length of main body 30a in the y-axis direction is slightly shorter than twice the length of one capacitor element 10 in the y-axis direction. Two E-shaped notches 33a are formed side by side in the y-axis direction at positions facing the second end electrodes 13 of two capacitor elements 10 on the negative side of the x-axis (left side) near bent portion 31a in the approximate center of main body 30a, and two pin-shaped electrode connectors 34a1 elongated in the x-axis direction are formed in each of these notches 33a. Furthermore, two pin-shaped electrode connectors 34a2 elongated in the x-axis direction are formed at the right end of main body 30a on the positive side of the x-axis, far from bent portion 31a, at positions facing the second end electrodes 13 of two capacitor elements 10 on the positive side of the x-axis (right side).

[0050] Each pair of electrode connection portions 34a1 closest to bent portion 31a is electrically connected to the second end surface electrodes 13 of the two capacitor elements 10 on the negative side of the x-axis and closest to bent portion 31a. Each pair of electrode connection portions 34a2 far from bent portion 31a is electrically connected to the second end surface electrodes 13 of the two capacitor elements 10 on the positive side of the x-axis and far from bent portion 31a.

[0051] By punching and pressing, the main body portion 30a, bent portion 31a, external connection terminal portion 32a, notch portion 33a, and electrode connection portions 34a1 and 34a2 of second bus bar 3a are simultaneously formed.

[0052] As shown in FIG. 14, the insulating member 4a has an L-shaped cross section in the xz plane and is arranged between the bent portion 21a of the first bus bar 2a and the bent portion 31a of the second bus bar 3a, thereby insulating the first bus bar 2a from the second bus bar 3a.

[0053] Case 5a corresponds to the "case" in the present invention, and a portion of a capacitor unit (capacitor elements, a portion of first bus bar 2a, a portion of second bus bar 3a, and a portion of insulating member 4a) having four capacitor elements 10, first and second bus bars 2a and 3a, and insulating member 4a is accommodated in an accommodating portion within case 5a. Furthermore, sealing resin 6a made of, for example, epoxy resin, which corresponds to the "sealing resin" in the present invention, is filled in the accommodating portion of case 5a accommodating the portion of the capacitor unit, sealing the portion of the capacitor unit.

[0054] In this manner, when a portion of the capacitor unit is sealed with the sealing resin 6a, as shown in FIG. 11, the proximity portions 25a1 and 25a2 of the first busbar 2a are exposed from the sealing resin 6a and come into proximity (contact) with the lower surface on the negative side of the z-axis, which is the inner surface of the case 5a, and therefore the heat generated by the four capacitor elements 10 can be released through the proximity portions 25a1 and 25a2.

[0055] Furthermore, since the proximity portion 25a1 of the first busbar 2a is located farther from the external connection terminal portion 22a than the electrode connection portion 24a1, and the proximity portion 25a2 of the first busbar 2a is located farther from the external connection terminal portion 22a than the electrode connection portion 24a2, an increase in equivalent series inductance (ESL) is suppressed.

[0056] Therefore, according to the second embodiment described above, in a film capacitor 1a having capacitor elements 10 arranged in two rows and two columns, heat generated by the capacitor elements 10 can be released through the proximity portions 25a1 and 25a2 that are close to the inner surface (bottom surface) of the case 5a, as in the first embodiment. Moreover, because the electrode connection portions 24a1 and 24a2 of the first bus bars 2a connected to the capacitor elements 10 are positioned closer to the external connection terminal portions 22a, an increase in equivalent series inductance (ESL) can be suppressed. Furthermore, the first bus bars 2a and the second bus bars 3a can each be easily formed in a single processing step by punching and pressing a copper plate or the like.

[0057] <Third embodiment> A third embodiment of the capacitor according to the present invention will be described in detail with reference to FIGS.

[0058] The structure of a film capacitor 1b, which is a capacitor according to the third embodiment, will be described with reference to Figures 16 to 23. 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 9. The film capacitor 1b according to the third embodiment differs from the first embodiment in the following points.

[0059] In the first embodiment, the first and second end electrodes 12, 13 of the capacitor element 10 are parallel to the opening of the case 5, i.e., a so-called vertical installation type. The two capacitor elements 10 are arranged in the y-axis direction so that the long and short dimensions of the first and second end electrodes 12, 13 are aligned along the x-axis and y-axis, respectively. In contrast, in the third embodiment, the first and second end electrodes 12, 13 of the capacitor element 10 are aligned horizontally, i.e., perpendicular to the opening of the case, and the two capacitor elements 10 are arranged in the y-axis direction so that the long and short dimensions of the first and second end electrodes 12, 13 are aligned along the y-axis. The configuration of the film capacitor 1b in the third embodiment will be described in detail below. Note that in FIGS. 16 to 23, the same reference numerals as those in FIGS. 1 to 9 indicate the same or corresponding components.

[0060] 16 to 23, the film capacitor 1b of the third embodiment includes two capacitor elements 10, a first bus bar 2b, a second bus bar 3b, an insulating member 4b, a case 5b, and a sealing resin 6b, all arranged in the y-axis direction. The case 5b and the sealing resin 6b are made of the same material as the case 5 and the sealing resin 6 of the first embodiment, and the case 5b has an opening on its upper surface on the positive side of the z-axis and a space therein that forms a housing. The sealing resin 6b is formed by being poured into the case 5b in a liquid state through the opening of the case 5b and then curing.

[0061] The first bus bar 2b and the second bus bar 3b are formed of a conductive material such as copper, similar to the first bus bar 2 and the second bus bar 3 of the first embodiment. As shown in FIGS. 18, 20, and 22, the first bus bar 2b has a main body portion 20b and an external connection terminal portion 21b. The main body portion 20b has a generally rectangular flat plate shape that is long in the y-axis direction in a y-z plan view. The external connection terminal portion 21b extends slightly upward (in the positive z-axis direction) from approximately the center of the upper end portion on the positive z-axis side of the main body portion 20b and further extends generally horizontally to the left (in the negative x-axis direction), and has an L-shape in a side view.

[0062] Furthermore, the length of main body 20b in the y-axis direction is approximately twice the long dimension of one capacitor element 10 in the y-axis direction, and the length in the z-axis direction is slightly longer than the short dimension of one capacitor element 10 in the z-axis direction. Four U-shaped notches 22b are formed side by side in the y-axis direction at approximately the center of main body 20b in the z-axis direction, at positions facing the upper ends of first end surface electrodes 12 of two capacitor elements 10 on the positive side in the z-axis.

[0063] Furthermore, each of these four notches 22b has one pin-shaped electrode connection portion 23b formed in the z-axis direction by the notch, and the electrode connection portion 23b of each of the two notches 22b on the negative side of the y-axis is electrically connected to the first end surface electrode 12 of one capacitor element 10, and the electrode connection portion 23b of each of the two notches 22b on the positive side of the y-axis is electrically connected to the first end surface electrode 12 of the other capacitor element 10. These electrode connection portions 23b are arranged close enough to be soldered to the first end surface electrodes 12 of the two capacitor elements 10, and correspond to the "electrode connection portion" in this invention.

[0064] Furthermore, in the lower half of the main body 20b of the first busbar 2b on the negative side of the z-axis, a proximal portion 25b that is approximately rectangular when viewed in the yz plane is formed via a bent portion 24b that bends diagonally downward to the left, and this proximal portion 25b is electrically connected to the electrode connection portion 23b.

[0065] Proximate portion 25b is disposed closer to the inner surface (the left inner surface on the negative side of the x-axis) of case 5a than electrode connection portion 23b (FIG. 22). Proximate portion 25b may be disposed so as to contact the inner surface (the left inner surface) of case 5b. In this case, proximate portion 25b of first busbar 2b is exposed from sealing resin 6b as shown in FIG. 17.

[0066] Here, for example, by punching and pressing a copper plate, the main body portion 20b, external connection terminal portion 21b, cutout portion 22b, electrode connection portion 23b, bent portion 24b bent diagonally downward to the left, and adjacent portion 25b of the first bus bar 2b are simultaneously formed.

[0067] As shown in FIGS. 18, 19, 21, and 23, the second bus bar 3b has a main body portion 30b, a first bent portion 31b, a second bent portion 32b, and an external connection terminal portion 33b. The main body portion 30b has a generally rectangular shape in the xy plane. The first bent portion 31b is formed by bending the upper end portion of the main body portion 30b on the z-axis positive side to the left (in the x-axis negative direction) by approximately 90 degrees, and has a generally rectangular flat plate shape in the xy plane. The second bent portion 32b is formed by bending the upper end portion of the first bent portion 31b on the x-axis negative side (left end) upward by approximately 90 degrees (in the x-axis positive direction), and has a generally rectangular flat plate shape that is longer and narrower than the first bent portion 31b in the yz plane. The external connection terminal portion 33b extends slightly upward (in the positive direction of the z-axis) from approximately the center of the upper end portion on the positive side of the z-axis of the second bent portion 32b, and then extends approximately horizontally to the left (in the negative direction of the x-axis), and has an L-shape when viewed from the side.

[0068] Furthermore, the length of main body 30b in the y-axis direction is approximately twice the length of one capacitor element 10 in the y-axis direction, and the length of main body 30b in the z-axis direction is approximately the same as the length of one capacitor element 10 in the z-axis direction. Four U-shaped cutouts 34b are formed side by side in the y-axis direction at approximately the center of main body 30b in the z-axis direction, at positions facing the upper ends of second end surface electrodes 13 of two capacitor elements 10 on the positive side in the z-axis.

[0069] Furthermore, each of these four notches 34b has one pin-shaped electrode connection portion 35b formed in the z-axis direction by the notch, and the electrode connection portion 35b of each of the two notches 34b on the negative side of the y-axis is electrically connected to the second end surface electrode 13 of one capacitor element 10, and the electrode connection portion 35b of each of the two notches 34b on the positive side of the y-axis is electrically connected to the second end surface electrode 13 of the other capacitor element 10. These electrode connection portions 35b are arranged close enough to be soldered to the second end surface electrodes 13 of the two capacitor elements 10, and correspond to the "electrode connection portion" in this invention.

[0070] Furthermore, in the lower half of the main body portion 30b of the second busbar 3b on the negative side of the z-axis, a proximal portion 37b that is approximately rectangular when viewed in the yz plane is formed via a bent portion 36b that bends diagonally downward to the right, and this proximal portion 37b is connected to the electrode connection portion 35b.

[0071] The proximity portion 37b is disposed closer to the inner surface (the right inner surface on the positive side of the x-axis) of the case 5b than the electrode connection portion 35b. The proximity portion 37b may be disposed so as to contact the inner surface (the right inner surface) of the case 5b. In this case, the proximity portion 37b of the second busbar 3b is exposed from the sealing resin 6b.

[0072] The main body portion 30b, external connection terminal portion 33b, notch portion 34b, electrode connection portion 35b, bent portion 36b and adjacent portion 37b of second bus bar 3b are simultaneously formed by, for example, punching and pressing a copper plate.

[0073] As shown in Figures 19 and 21, the insulating member 4b has a flat plate portion that is approximately rectangular when viewed in the yz plane and is elongated in the y-axis direction, and two bent portions in which the upper and lower ends of the flat plate portion on the positive side of the z-axis are bent to the left (negative direction of the x-axis) and the lower end of the flat plate portion on the negative side of the z-axis is bent to the right (positive direction of the x-axis).The insulating member 4b is arranged between the main body portion 20b of the first bus bar 2b and the first and second bent portions 32b1, 32b of the second bus bar 3b, and provides insulation between the first bus bar 2b and the second bus bar 3b.

[0074] Case 5b corresponds to the "case" in the present invention, and a portion of a capacitor unit having two capacitor elements 10, first and second bus bars 2b and 3b, and insulating member 4b (the capacitor elements, a portion of first bus bar 2b, a portion of second bus bar 3b, and a portion of insulating member 4b) is accommodated in an accommodating portion within case 5b. Furthermore, sealing resin 6b made of, for example, epoxy resin, which corresponds to the "sealing resin" in the present invention, is filled in the accommodating portion of case 5b accommodating the portion of the capacitor unit, sealing the portion of the capacitor unit.

[0075] In this way, when a portion of the capacitor unit is sealed with the sealing resin 6b, the proximity portion 25b of the first bus bar 2b and the proximity portion 37b of the second bus bar 3b are exposed from the sealing resin 6b and come into proximity (contact) with the inner surface (left inner surface and right inner surface) of the case 5b, and therefore the heat generated by the two capacitor elements 10 can be efficiently released through these proximity portions 25b, 37b.

[0076] Furthermore, since the proximity portion 25b of the first busbar 2b and the proximity portion 37b of the second busbar 3b are located farther from the external connection terminal portion 21b of the first busbar 2b and the external connection terminal portion 33b of the second busbar 3b than the electrode connection portion 23b of the first busbar 2b and the electrode connection portion 35b of the second busbar 3b, respectively, an increase in equivalent series inductance (ESL) is suppressed.

[0077] Therefore, according to the third embodiment described above, in a so-called horizontally placed film capacitor 1b, heat generated by the capacitor element 10 can be dissipated through the proximity portion 25b of the first bus bar 2b and the proximity portion 37b of the second bus bar 3b, which are located close to the inner surfaces (left and right inner surfaces) of the case 5b, as in the first embodiment. Furthermore, the electrode connection portion 23b of the first bus bar 2b and the electrode connection portion 35b of the second bus bar 3b, which are connected to the capacitor element 10, are positioned closer to the external connection terminal portions 22b and 33b of the first and second bus bars 2b and 3b, respectively, thereby suppressing an increase in equivalent series inductance (ESL). Furthermore, the first bus bar 2b and the second bus bar 3b can each be easily formed in a single processing step by punching and pressing a copper plate or the like.

[0078] The present invention is not limited to the above-described configuration, and various design modifications can be made within the scope of the claims.

[0079] For example, in the first and third embodiments described above, the proximity portions 25, 25b, 37b are configured to be connected via bent portions 26, 24b, 36b formed between the electrode connection portions 24, 23b, 35b, but the proximity portions may also be configured to be electrically connected to the end face electrodes of the capacitor element 10 and to be formed by increasing the thickness of a portion of the bus bar.

[0080] Moreover, the adjacent portions 25a1 and 25a2 of the first bus bar 2a in the second embodiment may also be formed by thickening the corresponding portions of the main body portion 20a.

[0081] In the second embodiment, the first bus bar 2a is provided with two adjacent portions 25a1 and 25a2, but the first bus bar 2a may have only one adjacent portion.

[0082] Furthermore, when arranging n capacitor elements 10 in the x-axis direction and m capacitor elements 10 in the y-axis direction, as in the second embodiment in which the capacitor elements 10 are arranged in two rows and two columns in the xy plane, up to n proximity portions may be formed in the first bus bar in the x-axis direction, as in the second embodiment, and the first end surface electrodes 12 of each capacitor element 10 may be connected to the electrode connection portions.

[0083] Furthermore, in the above-described third embodiment, the case where proximity portions 25b, 37b are provided on both the first bus bar 2b and the second bus bar 3b has been described, but a configuration in which a proximity portion is provided on only one of the bus bars may also be used.

[0084] The present invention is widely applicable to film capacitors that include a capacitor element, first and second bus bars having external connection terminal portions and electrically connected to one electrode and the other electrode of the capacitor element via electrode connection portions, respectively, and a portion of the capacitor element to which the first and second bus bars are connected, excluding the external connection terminal portions, housed in a case, and sealed by filling the case with sealing resin. [Explanation of symbols]

[0085] 1, 1a, 1b...Film capacitor 2, 2a, 2b ... 1st bus bar 3, 3a, 3b ... 2nd bus bar 5, 5a, 5b...case 6,6a,6b…Sealing resin 21b, 22, 22a, 33b ... External connection terminals 24, 24a, 23b, 35b ... Electrode connection parts 24b,36b...bending part 25, 25a1, 25a2, 25b, 37b ... adjacent area 26,26a1,26a2,26a3...bending part

Claims

1. a capacitor element; a first bus bar and a second bus bar having external connection terminals electrically connected to one electrode and the other electrode of the capacitor element via electrode connection portions, respectively; and a part of the capacitor element connected to the first bus bar and the second bus bar, excluding the external connection terminals, housed in a case, and sealed by filling the case with a sealing resin, At least one of the first bus bar and the second bus bar has an electrode connection portion that faces the inner surface of the case while being spaced apart from the inner surface of the case, is connected to the electrode connection portion, and has a proximity portion that is closer to the inner surface of the case that the electrode connection portion faces than the electrode connection portion.

2. The film capacitor according to claim 1 , wherein the proximity portion is provided at a position away from the external connection terminal portion with respect to the electrode connection portion of the bus bar.

3. 3. The film capacitor according to claim 1, wherein the adjacent portion is connected to the electrode connection portion via a bent portion formed between the adjacent portion and the electrode connection portion.

4. 3. The film capacitor according to claim 1, wherein the adjacent portion is electrically connected to an electrode of the capacitor element and is formed by increasing the thickness of a portion of the bus bar.

5. A plurality of the capacitor elements are arranged in a direction away from the external connection terminal portion, the first bus bar and the second bus bar have a plurality of electrode connection portions connected to the one electrodes and the other electrodes of the plurality of capacitor elements, respectively, at positions close to the external connection terminal portions; The proximity portion is provided at a position away from the external connection terminal portion with respect to each of the plurality of electrode connection portions of the bus bar.

2. The film capacitor according to claim 1.

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