Film capacitor

Abstract

To reduce material and processing costs while improving fluidity of a sealing resin in a film capacitor in which a plurality of capacitor elements connected to a bus bar are sealed with the sealing resin.SOLUTION: The first bus bar 2 includes the extending portions 20b and 30b disposed between the side surface portions of the plurality of first capacitor elements 10A and the second capacitor elements 10B, and the connecting portions 23, 24, and 25 connected to the first end surface electrodes 12A and 12B of the first and second capacitor elements 10A and 10B, and the passageway 26 for the flow of the sealing resin before being cured is formed in the extending portion 20b. As a result, the uncured resins are caused to flow to both sides sandwiching the extension portion 20b via the passages 26 of the extension portion 20b. In addition, the first bus bars 2 are connected to the first end surface electrodes 10A and 10B by the connecting parts 232425 and without largely detouring around the outside of the plurality of capacitor elements 12A and 12B.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a film capacitor in which a plurality of capacitor elements connected to a bus bar are sealed with a sealing resin. [Background technology]

[0002] Conventionally, there is a film capacitor that includes a plurality of capacitor elements each having a pair of end electrodes and a side surface portion, a bus bar electrically connected to one of the end electrodes of the plurality of capacitor elements, and a sealing resin that seals the plurality of capacitor elements connected to the bus bar.

[0003] This type of film capacitor includes a capacitor in which the side surfaces of multiple capacitor elements are arranged facing each other, and a bus bar (second bus bar) connected to the other end surface electrodes of the multiple capacitor elements has a main body that is arranged vertically around each capacitor element to follow the side surface of one of the multiple capacitor elements that does not face the other capacitor elements, and an extension that extends horizontally from the main body to face one end surface electrodes of the multiple capacitor elements, the extension being arranged closely facing the bus bar (first bus bar) connected to one end surface electrodes of the multiple capacitor elements (see Patent Document 1). Another capacitor module includes a main body that is arranged between the side surfaces of the multiple capacitor elements, a metal plate having multiple electrode contact portions that are bent at right angles from the end of the main body in opposite directions and contact one end surface electrodes (first electrodes) of the multiple capacitor elements, a first bus bar that is formed separately from the metal plate and electrically connected to the metal plate, and a second bus bar that is electrically connected to the other end surface electrode (second electrode) (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-008579 [Patent Document 2] Patent No. 7452640 Summary of the Invention [Problem to be solved by the invention]

[0005] In the capacitor described in Patent Document 1, the bus bar (second bus bar) is shaped to make a large detour around the outside of the multiple capacitor elements, which increases the distance the bus bar must be routed and increases the material costs of the bus bar. Furthermore, the extension of the bus bar (second bus bar) extends from the main body to face one end electrodes of the multiple capacitor elements, and is positioned closely opposite the bus bar (first bus bar) connected to one end electrodes of the multiple capacitor elements. This means that the extension covers the top of the multiple capacitor elements, making it difficult for the resin to flow between the multiple capacitor elements when filling the sealing resin. This makes it take a long time to fill the sealing resin, resulting in reduced productivity.

[0006] Furthermore, in the film capacitor described in Patent Document 2 mentioned above, a metal plate is used in addition to the bus bar, and the main body of the metal plate is arranged between the side surfaces of the multiple capacitor elements, and multiple electrode connection portions are formed at the end of the main body of the metal plate so as to be bent at right angles in opposite directions to each other so as to contact one end surface electrode (first electrode) of the multiple capacitor elements, which results in an increase in material costs and processing costs (man-hours for bending).

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to reduce material and processing costs while improving the fluidity of the sealing resin in a film capacitor in which multiple capacitor elements connected to a bus bar are sealed with sealing resin. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the film capacitor of the present invention comprises a plurality of capacitor elements each having a pair of end electrodes and a side portion between the pair of end electrodes, a bus bar connected to the end electrodes of one of the plurality of capacitor elements, and a sealing resin that seals the plurality of capacitor elements connected to the bus bar, wherein the bus bar has a main body portion arranged between the side portions of the plurality of capacitor elements and a connection portion connected to one of the end electrodes, and a passage for the flow of the sealing resin before hardening is formed through the main body portion.

[0009] With this configuration, the passage for the flow of the uncured sealing resin is formed in the body portion disposed between the side surfaces of the plurality of capacitor elements, allowing the uncured resin to flow to both sides of the body portion via the passage. Furthermore, the bus bar does not have to make a large detour around the outside of the plurality of capacitor elements, and the simple configuration in which it is connected to one of the end surface electrodes by the connecting portion reduces material and processing costs.

[0010] Furthermore, of the plurality of capacitor elements arranged on both sides of the main body portion of the busbar, at least two may be arranged on one side of the main body portion and at least one may be arranged on the other side of the main body portion, and the passage may be located between the two capacitor elements on the one side of the main body portion.

[0011] According to this configuration, the passage is located between at least two capacitor elements arranged on one side of the main body of the bus bar, so that the resin before hardening can also flow between these two capacitor elements.

[0012] The passage may be formed at a position adjacent to the connection portion connected to the one end surface electrode of the capacitor element arranged on the other side of the main body.

[0013] The capacitor element on one side of the main body and the capacitor element on the other side of the main body may have different uses and functions, and the passage may be located in a lower part of the main body.

[0014] It is also preferable that the passage and the connection portion connected to the capacitor element on the other side of the main body portion are formed by processing at the same time.

[0015] This configuration simplifies the process of forming the connection parts and passages, and does not increase material costs as in conventional film capacitors in which the bus bar is shaped to make a large detour around the outside of multiple capacitor elements, nor does it increase processing costs (man-hours for bending) as in conventional film capacitors in which multiple electrode connection parts are processed into a shape that bends in opposite directions. [Effects of the Invention]

[0016] The present invention can reduce material and processing costs while improving the fluidity of the sealing resin in a film capacitor in which a plurality of capacitor elements connected to a bus bar are sealed with sealing resin. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view of a film capacitor according to a first embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view of the film capacitor of FIG. 1 without a case and a sealing resin. [Figure 3] FIG. 3 is a perspective view of the film capacitor of FIG. 2 as seen from below. [Figure 4] FIG. 2 is a perspective view of a first bus bar of the film capacitor of FIG. [Figure 5] 5 is a perspective view of the first bus bar of FIG. 4, seen from a different direction. [Figure 6] FIG. 2 is a perspective view of a second bus bar of the film capacitor of FIG. [Figure 7] FIG. 2 is a perspective view of an insulating member of the film capacitor of FIG. [Figure 8] FIG. 10 is a perspective view of the film capacitor according to the second embodiment of the present invention in a state where the case and sealing resin are not present. [Figure 9]9 is a perspective view of some of the components of the film capacitor of FIG. 8, viewed from another direction. [Figure 10] FIG. 9 is a perspective view of a first bus bar of the film capacitor of FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0018] First Embodiment A first embodiment of a film capacitor according to the present invention will be described in detail with reference to FIGS. 1 to 7. In FIGS. 1 to 7, 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 ...right) or negative (left) side of the x-axis to the negative (left) or positive (right) side of the x-axis will be referred to as a "yz planar view."

[0019] As shown in Figures 1 to 7, the film capacitor 1 includes a plurality of first capacitor elements 10A whose end surface electrodes are arranged parallel to the xy plane, one second capacitor element 10B, a first bus bar 2, a second bus bar 3, an insulating member 4, a case 5, and a sealing resin 6.

[0020] The first capacitor elements 10A are used, for example, for smoothing purposes, and as shown in Figures 2 and 3, a total of six of them are arranged in two rows and three columns in the x-axis and y-axis directions. Each first capacitor element 10A includes an element main body 11A, a first end surface electrode 12A formed by spraying a metal such as zinc on the lower surface of the element main body 11A on the negative side of the z-axis, and a second end surface electrode 13A formed by spraying a metal such as zinc on the upper surface of the element main body 11A on the positive side of the z-axis.

[0021] The second capacitor element 10B is used, for example, in a noise removal filter and is arranged next to the six first capacitor elements 10A on the negative side of the y-axis. The second capacitor element 10B has a smaller volume than the first capacitor element 10A and, like the first capacitor element 10A, includes an element body 11B, a first end surface electrode 12B formed by spraying a metal such as zinc on the lower surface of the element body 11B on the negative side of the z-axis, and a second end surface electrode 13B formed by spraying a metal such as zinc on the upper surface of the element body 11B on the positive side of the z-axis. Here, the peripheral surfaces of the element body portions 11A and 11B of the first and second capacitor elements 10A and 10B correspond to the "side surface" in this invention.

[0022] The first and second end surface electrodes 12A and 13A of the first capacitor element 10A and the first and second end surface electrodes 12B and 13B of the second capacitor element 10B correspond to a "pair of end surface electrodes" of the capacitor element in the present invention. The first end surface electrodes 12A and 12B correspond to a "one end surface electrode" of the capacitor element in the present invention.

[0023] The element bodies 11A and 11B are formed by overlapping and rolling or laminating two metallized films, each of which is formed by depositing aluminum on a dielectric film, and then pressing them into a flat shape. The first capacitor element 10A and the second capacitor element 10B each have a flat shape in which the length in the x-axis direction is longer than the y-axis direction. The element bodies 11A and 11B are not limited to the above-described configuration. For example, they may be formed from a metallized film deposited with other metals, such as zinc or magnesium, or a combination of these metals or an alloy of these metals.

[0024] The first end surface electrode 12A and the second end surface electrode 13A of the first capacitor element 10A are used as the P pole and the N pole, respectively. Alternatively, the first end surface electrode 12A may be used as the N pole and the second end surface electrode 13A may be used as the P pole. The first end surface electrode 12B of the second capacitor element 10B has an N polarity, but the second end surface electrode 13B has a polarity different from the P pole and N pole (for example, a ground polarity) and is used to pass noise removed by a filter circuit (not shown) to the ground.

[0025] The first bus bar 2 and the second bus bar 3 are each formed by stamping a conductive material such as copper. As shown in FIGS. 2 to 5 , the first bus bar 2 has a bus bar main body 20 having an L-shape in a y-z plane view, and external connection terminal portions 21. The bus bar main body 20 has a base portion 20a having a substantially rectangular, flat plate shape in a x-y plane view, and an extension portion 20b having a substantially rectangular, flat plate shape in a x-z plane view, which is integrally formed at the front end of the base portion 20a on the negative side of the y-axis and extends upward (in the positive direction of the z-axis). The extension portion 20b is disposed between the first capacitor element 10A and the second capacitor element 10B. The external connection terminal portions 21 are integrally formed at three locations on the upper end of the extension portion 20b on the positive side of the z-axis of the bus bar main body 20, extending slightly upward, and each external connection terminal portion 21 has a substantially L-shape in a x-z plane view. Here, the extension portion 20b corresponds to the "main body portion" in this invention.

[0026] Here, the length of base 20a in the x-axis direction is approximately the same as or slightly longer than twice the length of first capacitor element 10A in the x-axis direction, and the length of base 20a in the y-axis direction is shorter than three times but slightly longer than twice the length of first capacitor element 10A in the y-axis direction. A total of eight approximately U-shaped cutouts 22 are formed in base 20a at positions facing first end surface electrodes 12A of four first capacitor elements 10A, respectively.

[0027] Each of these eight notches 22 has a pin-shaped connecting portion 23 that is long in the y-axis direction, and two connecting portions 23 per element are soldered to the first end surface electrodes 12A of the four first capacitor elements 10A to electrically connect them.

[0028] In addition, four pin-shaped connection portions 24 that are long in the y-axis direction are formed at the rear end of the base 20a of the busbar body 20 on the positive side of the y-axis, and two of the connection portions 24 are soldered and electrically connected to the first end surface electrodes 12A of the two first capacitor elements 10A lined up on the positive side of the y-axis.

[0029] Furthermore, a connection portion 25 extending forward in the negative y-axis direction is formed at approximately the center of the front end of base 20a of busbar body 20 on the negative y-axis side, and is soldered and electrically connected to first end surface electrode 12B of second capacitor element 10B. The tip of connection portion 25 is formed in a pointed pin shape. Here, these connection portions 23, 24, and 25 correspond to the "connection portion" in this invention.

[0030] The first busbar 2 is formed by punching a conductive material such as copper. In this process, the lower end of the extension portion 20b of the busbar body 20 on the negative side of the z-axis is cut out to form a connection portion 25, and at the same time, a rectangular passage 26 is formed that passes horizontally through the extension portion 20b. This passage 26 is located between the two first capacitor elements 10A that are lined up on the positive side of the y-axis of the extension portion 20b of the first busbar 2.

[0031] Furthermore, a through-hole 27 for the flow of uncured resin used for sealing resin 6 is provided approximately at the center of base 20a of busbar body 20, and uncured resin for sealing resin 6 filled in case 5 flows evenly between first capacitor elements 10A, etc., via passage 26 and through-hole 27. Note that first busbar 2 corresponds to the "busbar" in this invention.

[0032] As shown in FIGS. 2 and 6 , the second busbar 3 has a busbar main body 30 that is L-shaped in the y-z plane and external connection terminal portions 31. The busbar main body 30 has a base portion 30a that is substantially rectangular and flat in the x-y plane, and an extension portion 30b that is substantially rectangular and flat in the x-z plane and integrally formed with the front end of the base portion 30a on the negative side of the y-axis, extending upward (in the positive direction of the z-axis). The external connection terminal portions 31 are formed at three locations on the upper end of the extension portion 30b on the positive side of the z-axis of the busbar main body 30, extending slightly upward. Each external connection terminal portion 31 has a substantially L-shape in the x-z plane. The external connection terminal portions 21, 31 are formed so that the external connection terminal portions 31 of the second busbar 3 and the external connection terminal portions 21 of the first busbar 2 are alternately arranged in the y-axis direction when the first and second busbars 2, 3 are connected to the first capacitor element 10A.

[0033] Here, the length of base 30a in the x-axis direction is approximately the same as or slightly longer than twice the length of first capacitor element 10A in the x-axis direction, and the length of base 30a in the y-axis direction is more than twice but slightly shorter than three times the length of first capacitor element 10A in the y-axis direction. Twelve approximately U-shaped cutouts 32 are formed in base 30a of busbar body 30 at positions facing second end surface electrodes 13A of six first capacitor elements 10A, respectively.

[0034] Each of these 12 notches 32 has a pin-shaped connecting portion 33 that is long in the y-axis direction, and two connecting portions 33 are soldered and electrically connected to the second end surface electrode 13A of one first capacitor element 10A.

[0035] In addition, three through holes 34 are formed in a row on a line in the y-axis direction that passes through approximately the center of the base 30a of the busbar body 30 in the x-axis direction, from the front end on the negative side of the y-axis to the rear end on the positive side, and through these through holes 34, the uncured resin for the sealing resin 6 flows evenly downward from the top surface of the base 30a of the second busbar 3.

[0036] 7, the insulating member 4 has a first insulating portion 4a in the shape of a rectangular flat plate with multiple recessed notches cut out at the top end thereof in the x-z plane, and a second insulating portion 4b in the shape of a long, thin flat plate bent along the top end face having the notched portions of the first insulating portion 4a and the right end face on the positive side of the x-axis, the surface of the first insulating portion 4a being parallel to the x-y plane. The insulating member 4 is disposed between the extension portion 20b of the first bus bar 2 and the extension portion 30b of the second bus bar 3, thereby insulating the first bus bar 2 from the second bus bar 3.

[0037] Meanwhile, second capacitor element 10B is used as a noise removal filter, which has a different application function from first capacitor element 10A, which is used as a smoothing capacitor. As shown in Figures 2 and 3, first end surface electrode 12B on the underside of second capacitor element 10B is placed on connection portion 25 of first bus bar 2, and the tip of connection portion 25 is soldered to first end surface electrode 12B for electrical connection, and the tip of connection terminal 8, which is connected to an external circuit (e.g., a filter circuit) not shown, is soldered to second end surface electrode 13B for electrical connection.

[0038] As shown in Figure 1, the case 5 has an opening on the upper surface on the positive side of the z-axis and a storage section inside, 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.

[0039] Then, a portion of a capacitor unit (capacitor elements 10A and 10B, a portion of first bus bar 2, a portion of second bus bar 3, a portion of insulating member 4, and a portion of connection terminal 8) having six first capacitor elements 10A, six second capacitor elements 10B, the first and second bus bars 2 and 3, and the insulating member 4 is accommodated in the accommodation portion within case 5. Furthermore, a liquid resin for sealing resin 6 made of, for example, epoxy resin is filled into the accommodation portion of case 5 that accommodates the portion of the capacitor unit, thereby sealing the portion of the capacitor unit.

[0040] Various insulating materials used as sealing resins for electronic components can be used instead of epoxy resin as the sealing resin 6. The sealing resin 6 is filled in a liquid state into the case 5 from the opening, and then hardens.

[0041] At this time, when liquid resin is filled from the opening surface of the case 5, the unhardened resin flows evenly through the through hole 34 of the second bus bar 3, the passage 26 and through hole 27 of the first bus bar 2, between the first and second bus bars 2, 3 and each first capacitor element 10A, between the first bus bar 2 and the second capacitor element 10B, and between the first capacitor elements 10A, particularly on both sides of the extension portion 20b in the y-axis direction.

[0042] Therefore, according to the first embodiment described above, the material costs do not increase as in conventional film capacitors in which the bus bar is shaped to make a large detour around the outside of multiple capacitor elements, and the processing costs (number of bending steps) do not increase as in conventional film capacitors in which multiple electrode connection portions are processed to bend in opposite directions, so that the first bus bar 2 with a simple configuration can be electrically connected to multiple first capacitor elements 10A and second capacitor elements 10B, and by forming a passage 26 in the extension portion 20b of the first bus bar 2, pre-hardened resin can be made to flow on both sides in the y-axis direction, sandwiching the extension portion (main body portion) 20b of the first bus bar 2.

[0043] Furthermore, since the passage 26 is located between the side portions of the two first capacitor elements 10A that are lined up on the positive side of the y-axis of the extension portion 20b of the first busbar 2, the resin before hardening can also flow between these two first capacitor elements 10A.

[0044] Furthermore, when forming the passage 26 at the bottom of the extension portion 20b of the first busbar 2, the connection portion 25 connected to the second capacitor element 10B on the other side of the extension portion 20b and the passage 26 are processed and formed simultaneously in a single process, thereby simplifying the process of forming the connection portion 25 and the passage 26.

[0045] Second Embodiment A second embodiment of the film capacitor according to the present invention will be described in detail with reference to Figures 8 to 10. Differences from the first embodiment will be described below, and will also be described with reference to Figures 1 to 7. Note that in these figures, the x-axis, y-axis, and z-axis are illustrated so that they are in the same direction, just like the x-axis, y-axis, and z-axis in Figures 1 to 7.

[0046] In the film capacitor 1 of the second embodiment, the orientation of the second capacitor element 10B is different from that of the first embodiment, and the shape of the connection portion of the first bus bar 2 for connecting to the first end surface electrode 12B of this second capacitor element 10B is different from that of the first embodiment.

[0047] 8 to 10 , the first and second end electrodes 12B, 13B of the second capacitor element 10B are arranged parallel to the yz plane, and the connection portion 25a, which is formed in the first bus bar 2 simultaneously with the passage 26a, does not have a pointed tip as in the first embodiment. The lower end of a pin-shaped conductor 9a extending in the z-axis direction is fixed in a hole formed in the tip of the connection portion 25a, and this conductor 9a is welded to the first end electrode 12B of the second capacitor element 10B. Furthermore, a pin-shaped conductor 9b extending in the z-axis direction is also fixed to the tip of the connection terminal 8, which is connected to an external circuit (not shown), and is welded to the second end electrode 13B of the second capacitor element 10B. In this case, the conductor 9a, together with the connection portion 25a, constitutes the “connection portion” of the present invention.

[0048] At this time, as in the first embodiment, a portion of a capacitor unit having six first capacitor elements 10A, six second capacitor elements 10B, the first and second bus bars 2, 3, and an insulating member 4 (capacitor elements 10A, 10B, a portion of the first bus bar 2, a portion of the second bus bar 3, a portion of the insulating member 4, and a portion of the connection terminal 8) is accommodated in the accommodation portion within the case 5, and when liquid resin for the sealing resin 6 is filled into the accommodation portion of the case 5, the unhardened resin flows evenly through the through hole 34 of the second bus bar 3, the passage 26a and through hole 27 of the first bus bar 2, between the first and second bus bars 2, 3 and each first capacitor element 10A, between the first bus bar 2 and the second capacitor element 10B, and between the first capacitor elements 10A themselves.

[0049] According to the second embodiment, it is possible to obtain the same effects as those of the first embodiment.

[0050] The present invention is not limited to the above-described configuration, and various design modifications can be made within the scope of the claims.

[0051] For example, in the above embodiment, the film capacitor 1 has been described as having a case 5, but the present invention can be similarly implemented in a so-called caseless type. Also, the present invention can be similarly implemented in a case where there is only one first capacitor element 10A instead of the six as described above.

[0052] Furthermore, as described above, the positions at which the passages 26, 26a are formed in the extending portion 20b of the first busbar 2 are not limited to the lower end on the negative side of the z-axis of the extending portion 20b. Furthermore, the connecting portions 25, 25a and the passages 26, 26a are not necessarily formed at the same time.

[0053] Furthermore, the functions and applications of the first and second capacitor elements 10A and 10B are not limited to the smoothing and noise removal filters described above.

[0054] Furthermore, in the above embodiment, the first capacitor element 10A and the second capacitor element 10B have different uses and functions, but they may have the same uses and functions.

[0055] Furthermore, the number of second capacitor elements 10B is not limited to one as described above, but may be two or more, in which case two or more connection portions may be formed on the bus bar (first bus bar 2).

[0056] The present invention is widely applicable to film capacitors that include a plurality of capacitor elements each having a pair of end electrodes and a side portion between the pair of end electrodes, a bus bar connected to one of the end electrodes of the plurality of capacitor elements, and a sealing resin that seals the plurality of capacitor elements connected to the bus bar. [Explanation of symbols]

[0057] 1...Film capacitor 2...1st bus bar 3...Second bus bar 6...Sealing resin 12A, 12B...First end surface electrode (one end surface electrode) 13A, 13B…Second end electrode 20b...Extension part (main body part) 23, 24, 25, 25a...Connections 26,26a…Aisle

Claims

1. a plurality of capacitor elements each having a pair of end electrodes and a side surface portion between the pair of end electrodes; a bus bar connected to one of the end surface electrodes of the plurality of capacitor elements; a sealing resin that seals the plurality of capacitor elements connected to the bus bar; Equipped with the bus bar has a main body portion disposed between the side surface portions of the plurality of capacitor elements and a connection portion connected to the one end surface electrode, A film capacitor characterized in that a passage for the flow of the sealing resin before hardening is formed in the main body portion.

2. of the plurality of capacitor elements arranged on both sides of the body portion of the bus bar, at least two are arranged on one side of the body portion and at least one is arranged on the other side of the body portion, The passage is located between two capacitor elements on the one side of the body.

2. The film capacitor according to claim 1.

3. The film capacitor according to claim 2, characterized in that the passage is formed at a position adjacent to the connection portion connected to one end surface electrode of the capacitor element arranged on the other side of the main body portion.

4. the capacitor element on one side of the main body portion and the capacitor element on the other side of the main body portion have different uses and functions; The passage is located at the bottom of the main body.

4. The film capacitor according to claim 3.

5. 5. The film capacitor according to claim 4, wherein the passage and the connection portion connected to the capacitor element on the other side of the main body are formed by simultaneous processing.

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