JP7313976B2 - caseless film capacitor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caseless film capacitor in which a capacitance portion, which is the main portion of the capacitor, is covered with a molding resin without using an exterior case.

In the recent field of power devices using SiC or the like, high-frequency operation has become possible by reducing switching loss through high-speed switching operation. In this case, in order to improve the circuit characteristics, it is necessary to reduce the parasitic inductance of the circuit, which limits the switching speed. At the same time, there is a demand for capacitors with large capacity, high frequencies, and large currents.

JP-A-2019-4068 JP 2017-38065 A

Large-capacity, high-frequency, and large-current capacitors are connected to form, for example, a full-bridge inverter, but because the output voltage and output current fluctuate depending on the load conditions, the path (part) and magnitude of the current flowing through the capacitor also change (current input/output to/from the capacitor, output terminal current, circulating current between UV phases). Therefore, it is necessary to suppress the current density of each part of the capacitor according to the current conditions.

The terminal shape of the capacitor needs to be a thin plate electrode type that can be directly attached to the semiconductor device. In addition, countermeasures such as increasing the plate thickness of the electrodes are required to suppress heat generation.

In order to cope with low inductance and high frequency and high current at the same time, it is necessary to shorten the electrode length as much as possible and increase the cross-sectional area with a laminated structure of thin plate electrodes.

The present invention has been created in view of such circumstances, and it is an object of the present invention to realize low inductance and low loss (heat suppression) while increasing the size, capacity, and weight of a caseless film capacitor.

The present invention solves the above problems by taking the following measures.

A caseless film capacitor according to the present invention comprises:
A plurality of capacitor elements are arranged side by side in the horizontal direction and the vertical direction to form a capacitor element group in a state in which the electrode surfaces of the first polarity and the second polarity at both ends in the axial direction are positioned on the same plane, respectively;
The first polarity electrode surfaces of each of the plurality of capacitor elements are connected to each other via a first bridge electrode plate, and the second polarity electrode surfaces of each of the plurality of capacitor elements are connected to each other via a second bridge electrode plate,
The first rack electrode plate has an upper end portion connected to a first horizontally elongated terminal plate portion, and the second rack electrode plate has an upper end portion connected to a second horizontally elongated terminal plate portion,
At least one pair of capacitor units having a first lead terminal of a first polarity extending from an upper edge of the first horizontally elongated terminal plate portion and a second lead terminal of a second polarity extending from an upper edge of the second horizontally elongated terminal plate portion,
The pair of capacitor units are arranged in parallel with the axial directions of the respective capacitor elements,
In the pair of capacitor units, the first lead terminals having the same polarity are overlapped with each other, and the second lead terminals with the same polarity are overlapped with each other,
The whole is covered with mold resin except for the superimposed first and second lead terminals.

In the above configuration, the capacitor elements are arranged side by side in the entire caseless film capacitor in both the horizontal direction and the vertical direction perpendicular to the axial direction of the capacitor elements, and also in the axial direction.

The first lead-out terminal and the second lead-out terminal are overlapped by the number corresponding to the number of the capacitor units, and the terminal plate part relaying between the first lead-out terminal and the first rack electrode plate is made oblong to form the first oblong terminal plate part. That is, by increasing the cross-sectional area of the current input/output, it is possible to facilitate the flow of current, and by suppressing the current density, it is possible to reduce the inductance of the current line, thereby reducing loss and suppressing heat generation.

The caseless film capacitor of the present invention having the above configuration has the following preferred aspects and variations/modifications.

[1] a plurality of the first lead terminals are led out from a plurality of locations spaced apart from the upper edge of the first laterally elongated terminal plate portion, and a plurality of the second lead out terminals are led out from a plurality of locations spaced apart from the upper edge of the second laterally elongated terminal plate portion at predetermined intervals;
The first drawer terminal and the second drawer terminal are alternately arranged with their positions shifted in the longitudinal direction of the lateral terminal plate portion, the second drawer terminal is positioned between a pair of adjacent first drawer terminals, and the first drawer terminal is positioned between a pair of adjacent second drawer terminals.

Since the lead terminals of the first polarity and the second polarity are staggered and arranged alternately, the current input/output paths can be made uniform and current concentration can be prevented.

[2] The first vertical electrode plates may include a plurality of rows of first vertical electrode plates provided according to the number of rows of the capacitor elements arranged in the horizontal direction and connecting the electrode surfaces of the capacitor elements arranged in the vertical direction, and a first horizontal electrode plate connecting the plurality of rows of the first vertical electrode plates to each other in the horizontal direction.

The form of connection between the capacitor element group and the first vertical electrode plate is individual connection of the strip-shaped first vertical electrode plate to each capacitor element in one capacitor element row. Instead of connecting with a one -piece electrode plate that is deployed in a large area of the capacitors elements as a whole, the first vertical electrode plate, which is equivalent to multiple electrode plates developed in the large area, are connected in a unit, so the area increases due to large capacity. Even if it grows up, it is possible to improve the connection quality between the capacitor element (group) and the first electrode plate in a state in which deformation such as unevenness or wave of the electrode plate is suppressed. At the same time, weight reduction and cost reduction can be achieved.

In this case, as can be seen from the above-described configuration, the plurality of rows of the first vertical electrode plates are integrated via the first horizontally long terminal plate portions, so even if the thickness of each row of the first vertical electrode plates is extremely thin, the strength can be increased and the posture can be stabilized.

[3] The second vertical electrode plate has a plurality of rows of second vertical electrode plates that are provided according to the number of rows of the capacitor elements arranged in the horizontal direction and that connect the electrode surfaces of the capacitor elements that are arranged in the vertical direction, and a second horizontal electrode plate that connects the plurality of rows of the second vertical electrode plates to each other in the horizontal direction.

The form of connection between the capacitor element group and the second vertical electrode plate is individual connection of the strip-shaped second vertical electrode plate to each capacitor element in one capacitor element row. Instead of connecting with a single electrode plate that is deployed in a large area of the capacitors elements, it is a form that connects a second vertical electrode plate in a strip -shaped second vertical electrode plate equivalent to multiple electrode plates developed in its large area, so the area increases due to large capacity. Even if it grows up, it is possible to improve the connection quality between the capacitor element (group) and the second electrode plate in a state in which deformation such as unevenness or wave of the electrode plate is suppressed. At the same time, weight reduction and cost reduction can be achieved.

[4] Regarding the pair of inwardly facing electrode plates and the pair of outwardly facing electrode plates in the pair of capacitor units,
The upper end portion of the inward facing electrode plate has an extension portion extending upward from the uppermost capacitor element of the capacitor element group.
The horizontally elongated terminal plate portion connected to the upper end portion of the outer facing electrode plate includes a horizontal posture plate portion arranged in a horizontal posture along the top surface portion immediately above the top surface portion of the capacitor element group, and a rising plate portion bent upward from the inner end portion of the horizontal posture plate portion.
There is a mode in which the upper end portions of the outer facing electrode plates are connected to the horizontal posture plate portion.

Regarding the mode of connection of the horizontal terminal plate portion to the inwardly facing rack electrode plate, an upwardly extending portion is provided at the upper end portion of the inwardly facing rack electrode plate, and the horizontally long terminal plate portion is configured from the rising plate portion. In other words, it is possible to make the deployed attitude substantially straight from the electrode surface. In the case of a substantially straight deployed posture, the current path length is shorter than in the bent deployed posture, which also works favorably for low inductance and low loss (heat suppression).

[5] With regard to the polar relationship between the pair of inwardly facing electrode plates, the electrode plates may be of the same polarity or may be of different polarities.

In the case of inter-electrode plates of the same polarity, both may be N poles (negative electrodes) or both may be P poles (positive electrodes). In the case of cross-polarity electrode plates, the arrangement may be a combination of N poles and P poles (NP) or a combination of P poles and N poles (PN).

[6] The first lead terminal and the second lead terminal may be arranged at substantially the same height position in the vertical direction. According to this configuration, it is possible to reduce the volume of the caseless film capacitor (compactness) as compared with the case where the height must be different.

[7] There is a mode in which the overlapping position of the first lead terminals and the overlapping position of the second lead terminals are central positions of the entire axial width of the pair of capacitor units.

Due to the symmetrical arrangement, this favors the equalization of current flow. Further, in the configuration of the central position of [7], it is easy to make the structure of the horizontally elongated terminal plate portion extending from the plurality of lead terminals the same for the first polarity and the second polarity. When the number of parallel capacitor units is an even number, the central position of the full width in the axial direction of the parallel arranged capacitor units is the position where the adjacent electrode surfaces face each other inwardly.

[8] There is a mode in which at least one of the first electrode plate and the second electrode plate is formed as a single electrode plate in the form of a thin plate.

This configuration tends to increase the weight and cost as compared with the case of [3] above, but a relatively large area is secured as the cross-sectional area of the current path, and it is more advantageous in terms of low inductance and low loss (heat suppression).

If a cutout hole is formed in correspondence with the electrode surface of each capacitor element, and a small connecting protrusion is provided to protrude from the edge of the hole into the cutout hole, and the small connecting protrusion is electrically and mechanically connected to the electrode surface by soldering or the like, the connection can be made in a state that avoids the effects of deformation such as unevenness and waviness.

[9] With respect to at least one of the first and second electrode plates, which are thin plate-like and formed into a single electrode plate, there is a mode in which the entire electrode plate, the horizontally long terminal plate portion, and the lead-out terminal are formed of a single conductive plate.

The rack electrode plate, the horizontal terminal plate portion on the upper end side of the rack electrode plate, and the lead-out bus bar including the lead-out terminals protruding from the lone terminal plate portion (the rack electrode plate, the horizontally-long terminal plate portion, and the lead-out terminal as a whole) can be efficiently manufactured from a single conductive plate by sheet metal processing or press working.

According to the present invention, since a plurality of capacitor elements are arranged in parallel in each of the three-dimensional directions, it is possible to increase the capacity. Furthermore, the first lead terminal and the second lead terminal are overlapped for the number of units, and the terminal plate portion that relays between the lead terminal and the rack electrode plate is a horizontally long terminal plate portion, and the cross-sectional area for current input/output is increased.

FIG. 2 is a perspective view showing a first horizontally long terminal plate portion of a first polarity in a caseless film capacitor according to an embodiment of the present invention; FIG. 4 is a perspective view showing a state in which a plurality of vertical electrode plates are connected to the first horizontally long terminal plate portion according to the embodiment of the present invention; FIG. 3 is a perspective view showing a state in which the structure of FIG. 2 is attached to the capacitor element group in the embodiment of the present invention; 4 is a perspective view showing a state in which a first horizontal electrode plate of a first polarity is attached to the structure shown in FIG. 3 in the embodiment of the present invention; FIG. FIG. 5 is a perspective view showing a state in which a sheet-like insulating material is attached to the structure shown in FIG. 4 in the embodiment of the present invention; FIG. 4 is a perspective view showing a second horizontal terminal plate portion of a second polarity in the embodiment of the present invention; FIG. 7 is a perspective view showing a state in which a plurality of second vertical electrode plates of a second polarity are attached to the structure shown in FIG. 6 in the embodiment of the present invention; FIG. 8 is a perspective view showing a state in which the structure shown in FIG. 7 to which a sheet-like insulating material is attached is arranged to face the capacitor element group according to the embodiment of the present invention; FIG. 4 is a perspective view showing a state in which a structure in which a second lateral terminal plate portion and a plurality of rows of second vertical electrode plates are integrated in an embodiment of the present invention is brought into close contact with a group of capacitor elements and then connected. FIG. 10 is a perspective view showing a state in which a second horizontal electrode plate is attached to the structure shown in FIG. 9 in the embodiment of the present invention; FIG. 2 is a perspective view showing a state in which the first capacitor unit and the second capacitor unit are separated in the embodiment of the present invention; FIG. 2 is a perspective view showing a state in which the first capacitor unit and the second capacitor unit are butted and arranged side by side in the embodiment of the present invention; 1 is a perspective view showing the appearance of a finished caseless film capacitor in an embodiment of the present invention; FIG. 3A and 3B are enlarged front and rear views showing the structure of the main part (overlapping lead-out terminal part) in the embodiment of the present invention; FIG. 2 is an enlarged perspective view showing the structure of a main part (overlapping lead-out terminal part) in the embodiment of the present invention; FIG. 2 is an enlarged perspective view showing the structure of a main part (overlapping lead-out terminal part) in the embodiment of the present invention; FIG. 10 is a front view and rear view showing an enlarged structure of a main portion (overlapping lead-out terminal portion) in another embodiment of the present invention; A perspective view showing a first capacitor unit in still another embodiment of the present invention. FIG. 18 is a perspective view and an enlarged perspective view showing the internal structure (main parts of the capacitor) of the caseless film capacitor in the embodiment corresponding to FIG. 18 of the present invention; FIG. 18 is an enlarged front view of a main portion of the embodiment corresponding to FIG. 18 of the present invention;

Hereinafter, the embodiments of the caseless film capacitor of the present invention having the above configuration will be described in detail at the level of specific examples.

FIG. 13 shows the appearance of a finished caseless film capacitor. 8 is a molding resin as a protective material that covers almost the entire main portion of the capacitor except for the lead terminal portion. A plurality of first overlap lead terminal portions _5kP and a plurality of second overlap lead terminal portions _5kN are staggered in the longitudinal direction from the upper end surface of the mold resin 8. As shown in FIG.

FIG. 12 shows the main part of the capacitor covered with the molding resin 8 of FIG. This main part has a form in which a first capacitor unit 7 ₁ on the back side of the paper and a second capacitor unit 7 ₂ on the front side face each other.

FIG. 11 shows the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ separated. The first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ have the same basic structure.

FIG. 10 shows the appearance of the first capacitor unit 7 ₁ . 2 is a group of capacitor elements, 4 _N on the front _side is a second pole plate (grid), and 5 _N is a _second horizontal terminal plate portion _. The second vertical electrode plates 4 _N are configured in a vertical and horizontal grid of a plurality of columns of second vertical electrode plates 4a _N and a plurality of rows of second horizontal electrode plates 4b _N . Although not shown, a first bus bar (3 _P ) of the first polarity is arranged on the back side in a symmetrical manner with the second rack electrode plate 4 _N on the front side (details will be described later).

6 to 9 show the configuration of the second bus bar _3N arranged on the front side in FIG. 10 (inside between the pair of capacitor units in FIG. 12). 1 to 5 show the configuration of the first bus bar _3P arranged on the far side in FIG. 1 to 5 are different from those in FIGS. 10 to 13, and FIGS. 6 to 9 are the same as those in FIGS. They will be described in order below.

FIG. 1 shows the first oblong terminal plate portion _5P . This first horizontally long terminal plate portion 5 _P is also shown in FIGS. 2 to 5 and 8. FIG. The first horizontally elongated terminal plate portion _5P is formed by an upright plate portion _5aP and a horizontal _attitude plate portion _5bP bent and extended from the lower end _of the upright plate portion _5aP to form an angle having an L-shaped cross section. 5c _P1 is a terminal inclined portion, and 5c _P2 is a terminal vertical portion (details will be described later with reference to FIGS. 14 to 16).

FIG. 2 shows a state in which a plurality of first vertical electrode plates 4a _P of the first polarity are connected to the first horizontally elongated terminal plate portion 5 _P . The first vertical electrode plate _4aP has a strip shape, and the upper end portion thereof is bent horizontally. A plurality of rows of the first vertical electrode plates 4a _P are arranged parallel to each other, and are electrically and mechanically connected to the vertical surface of the first horizontally long terminal plate portion 5 _P at the horizontal bent portion of the upper end by spot welding or the like. Note that the first vertical electrode plate 4a _P may be configured by stacking two copper plates from the viewpoint of improving connectivity and increasing current paths to reduce heat generation.

FIG. 3 shows a state in which the structure of FIG. 2 is attached to the capacitor element group 2. As shown in FIG. 1 is a capacitor element, 1a _P is a first polarity electrode surface, 1a _N is a second polarity electrode surface, 2 is a capacitor element group, and 2a is a capacitor element row.

Capacitor element 1 has an oval cross section and is formed into a flat columnar body. Capacitor element group 2 is constructed by arranging a plurality of capacitor elements 1 not only in the horizontal direction but also in the vertical direction. In the capacitor element group 2, a plurality of capacitor elements 1 are arranged in parallel two-dimensionally in the vertical and horizontal directions, with the electrode surfaces 1a _P of the first polarity and the electrode surfaces 1a _N of the second polarity at both ends of the capacitor elements 1 in the axial direction being positioned on the same plane in the vertical direction. The plurality of capacitor elements 1 are arranged in parallel with each other in the same posture, with their axial directions oriented in the same direction (parallel to each other), and in a state where adjacent elements are in contact with each other. Capacitor element group 2 has an outer envelope surface of substantially rectangular parallelepiped shape in which the vertical and horizontal dimensions are larger than the depth dimension, which is relatively small. A plurality of the first vertical electrode plates 4a _P described in FIG.

In the illustrated example, the number of capacitor elements 1 constituting the capacitor element group 2 is 9 columns in the horizontal direction and 6 rows in the vertical direction, for a total of 54 pieces. However, this is just an example, and the number of columns and the number of rows may be any number.

A plurality of capacitor elements 1 arranged in parallel in the vertical direction constitute a capacitor element row 2a. A first vertical electrode plate 4a _P is electrically and mechanically connected to the entire first polarity electrode surface 1a _P of this one row of capacitor element rows 2a by soldering or the like.

A plurality of rows of first vertical electrode plates 4a _P in the first vertical electrode plate 4 _P ( FIG. 4 ) are connected to the first polarity electrode surface 1 a _P of the capacitor element group 2 . In this connection, the horizontal posture plate portion _5bP of the first laterally long terminal plate portion _5P is arranged in a horizontal posture along the uppermost surface portion of the envelope surface of the capacitor element group 2 directly above the uppermost surface portion.

FIG. 4 shows a state in which the first horizontal electrode plate 4b _P of the first polarity is attached to the structure shown in FIG. A plurality of rows _of first horizontal electrode plates 4b _{P that} are parallel to each other are electrically and mechanically connected to all of the first vertical electrode plates 4a _P in a plurality of columns by soldering _or the like. A first bus bar 3 _P is composed of the first rack electrode plate 4 _P having a grid-like structure and the first laterally elongated terminal plate portion 5 _P. The first bus bar 3 _P constitutes an external connection terminal structure drawn from the first polarity electrode surface 1 a _P of the capacitor element group 2 .

FIG. 5 shows a state in which a sheet-like insulating material 6 _P is attached to the structure shown in FIG. A sheet-like insulating material 6 _P covers both front and back surfaces of the rising plate portion 5a _P of the first lateral terminal plate portion 5 _P (the suffix "6 _P " does not indicate the first polarity). Regarding the insulating material 6 _P , the back surface side is covered almost continuously over the entire length, and the front surface side is covered with a non- _{continuous discontinuous covering with a space between the adjacent lead terminals 5c P and} 5c _P except for the portion corresponding to the first lead terminal 5c P. The sheet-shaped insulating material 6 _P has a back side portion and a front side portion that are connected in series. For example, the shape is such that a plurality of comb tooth portions of a comb are bent 180 degrees from the upper side of the drawing. The sheet-like insulating material 6 _P is in close contact with both the front surface and the back surface of the rising plate portion 5a _P without gaps.

FIG. 6 shows the second oblong terminal plate portion _5N . This second horizontally long terminal plate portion 5 _N is also shown in FIGS. 7 to 10. FIG. Unlike the first horizontally long terminal plate portion _5P shown in FIG. 1, the second horizontally long terminal plate portion _5N does not have a horizontal attitude plate portion, and is mainly formed of a rising plate portion _.

FIG. 7 shows a state in which a plurality of second vertical electrode plates 4a _N of the second polarity are connected to the second horizontally elongated terminal plate portion 5 _N . The second vertical electrode plate 4a _N has a strip shape, and its upper end is not bent horizontally and maintains a substantially straight vertical surface. A plurality of second vertical electrode plates 4a _N are prepared in the same number as the number of parallel capacitor elements 1, and are arranged in parallel in the vertical direction at predetermined intervals. A plurality of rows of the second vertical electrode plates _4aN are electrically and mechanically connected to the vertical surface of the second lateral terminal plate portion _5N at the vertical surface portion of the upper end by spot welding or the like.

When the upper end portion (vertical surface portion) of the second vertical electrode plate 4a _N is connected to the second horizontally long terminal plate portion _5N , the upper end portion (vertical surface portion) of the second vertical electrode plate _4aN has an extension portion 4a _1N that protrudes upward from the uppermost capacitor element 1 of the capacitor element group 2. The second horizontally elongated terminal plate portion _5N is connected to the second horizontally elongated terminal plate portion _5N through the extension portion _4a1N (see FIG. 14). In order to avoid complication of the drawing, FIG. 14 omits the insulating members 6 _N and 6 _P. As shown in FIG.

9 shows a state in which the structure of FIG. 7 is attached to the capacitor element group 2. FIG. The structure shown in FIG. 5 is turned clockwise by approximately 120 degrees, and the structure shown in FIG. In addition, FIG. 8 shows the state before attachment (separated state).

As shown in FIG. 9, a second vertical electrode plate 4a _N is electrically and mechanically connected by soldering or the like over the entire electrode surface 1a _N of the second polarity to one capacitor element row 2a.

In this connection, the plurality of first lead-out terminals 5c _P in the first laterally elongated terminal plate portion 5 _P and the plurality of second lead-out terminals 5c _N in the second laterally elongated terminal plate portion 5 _N are staggered in the longitudinal direction of the laterally elongated terminal plate portion, and the first lead-out terminals 5 c _P and the second lead-out terminals 5 c _N are arranged at substantially the same height position in the vertical direction. A second lead terminal 5cN is positioned between a pair of adjacent first lead terminals _5cP , _{5cP ,} and a first lead terminal _5cP is positioned between a pair of adjacent second lead terminals _5cN , _5cN .

FIG. 10 shows a state in which the second horizontal electrode plate 4b _N of the second polarity is attached to the structure shown in FIG. A plurality of rows _of second horizontal electrode plates 4b _N parallel to each other are electrically and mechanically connected to all of the plurality of columns _of the second vertical electrode plates 4a _N by soldering _or the like. A second bus bar _3N is composed of the second rack electrode plate _4N having a grid-like structure and the second oblong terminal plate portion _5N . The second bus bar 3 _N constitutes an external connection terminal structure drawn out from the second polarity electrode surface 1 a _N group of the capacitor element group 2 .

The second busbar _3N , which is formed by integrating the second rack electrode plate _4N and the second horizontally long terminal plate portion _5N , has a configuration in which almost the entirety thereof is developed within one plane. The vertical surface of the upper end portion of the second vertical electrode plate _4aN is electrically and mechanically connected to the vertical surface of the second lateral terminal plate portion _5N by spot welding or the like. A plurality of rows of second vertical electrode plates 4a _N are electrically and mechanically connected to the second polarity electrode surface 1a _N of the capacitor element group 2 by soldering or the like.

Regarding the arrangement posture of the second vertical electrode plates 4a _N in multiple rows and the second horizontally elongated terminal plate portions 5 _N to which the upper ends thereof are connected, these are arranged on the upwardly extending surface of the electrode surface 1a _N of the second polarity of the capacitor element group 2. That is, the second vertical electrode plate 4a _N and the second horizontally elongated terminal plate portion 5 _N are deployed in a vertical orientation extending substantially straight from the electrode surface 1a _N .

In addition, a second vertical electrode plate 4a _N is connected over the entire electrode surface 1a _N of the second polarity to one row of the capacitor element rows 2a, and such a connection is made for all the plural rows of the capacitor element rows 2a.

The sheet- _{like insulating material 6N covers} both front and back surfaces _{of the second horizontal terminal plate portion 5N whose main body is the rising plate portion (the suffix "6N" does not indicate the second polarity). 5P has a horizontal seat portion 6N1 inserted into a gap between} it and the horizontal posture plate portion _{5bP .}

The back side (left side) of FIG. 11 shows the structure of FIG. 10 to which the sheet-like insulating material _6N is attached. The first capacitor unit 7 ₁ is configured as described above.

As shown in FIG. 11, a second capacitor unit 7 ₂ having a similar structure faces the first capacitor unit 7 ₁ . In this face-to-face state of both capacitor units 7 ₁ and 7 ₂ , the group of components associated with the second polarity (see suffix “ _N ”) face inwards, and the group of components associated with the second polarity (see suffix “ _P ”) face outwards.

The first lead terminal 5c _P and the second lead terminal 5c _N will be described below.

FIG. 15 is an enlarged view of the main part of FIG. 12 as viewed from the front side, and corresponds to FIG. 14(a). FIG. 16 is an enlarged view of the main part of FIG. 12 viewed from the back side, and corresponds to FIG. 14(b). “7 ₁ ” located on the left side of FIG. 14(a) corresponds to “7 1 ” located on the right side of FIG. 14(b), and “7 ₂ ” located on the right side of FIG. 14(a) corresponds to “ _{7 2 ”} located on the left side of FIG. 14(b) (mirror image relationship).

A plurality of tongue-like first lead-out terminals _5cP further extend upward from a plurality of positions spaced apart from the upper edge of _the rising plate portion _5aP of the first lateral terminal plate portion 5P. Similarly, a plurality of tongue-shaped second lead-out terminals 5c _N extend further upward from a plurality of locations spaced apart from the upper edge of the second horizontally long terminal plate portion 5 _N , the main body of which is a rising plate portion. The number of first lead terminals _5cP and the number of second lead terminals _5cN are the same, and the intervals between the first lead terminals _5cP and the intervals between the second lead terminals _5cN are the same.

One capacitor unit 7 is configured with the above configuration. Here, the above description of the capacitor unit 7 is organized.

A plurality of capacitor elements 1 are arranged vertically and horizontally to form a capacitor element group 2 . A first bus bar 3 _{P bent in a crank shape with respect to the first polarity electrode surface 1 a P of} the capacitor element group 2 and a planar second bus bar 3 _N are electrically and mechanically connected.

Each of the crank-shaped first busbars _3P is composed of a first horizontally elongated terminal plate portion _5P , a first vertical electrode plate _4aP , and a first horizontal electrode plate _4bP . The first vertical electrode plate 4a _P and the first horizontal electrode plate 4b _P are connected in a grid pattern. In the first vertical electrode plate _4P , the upper end portion of the first vertical electrode plate _4aP is connected to the first horizontally long terminal plate portion _5P . A first vertical electrode plate 4a _P is connected to the electrode surface 1a _P . Horizontal posture plate portion 5b _P in first oblong terminal plate portion 5 _P is arranged in a horizontal posture along the top surface portion of capacitor element group 2 right above the top surface portion. A sheet-like insulating material 6 _P is coated on both the front and back surfaces of the rising plate portion 5a _P of the first laterally long terminal plate portion 5 _P .

Each of the planar second bus bars 3 _N is composed of a second horizontally elongated terminal plate portion 5 _N , a second vertical electrode plate 4a _N , and a second horizontal electrode plate 4b _N . The second vertical electrode plates 4a _N and the second horizontal electrode plates 4b _N are connected in a grid pattern. In the second vertical electrode plate _4N , the upper end portion of the second vertical electrode plate _4aN is connected to the second oblong terminal plate portion _5N . A second vertical electrode plate 4a _N is connected to the electrode surface 1a _N . A sheet-like insulating material _6N is coated on both front and back surfaces of the second horizontally long terminal plate portion _5N whose main body is a rising plate portion.
This sheet-like insulating material 6 _N also extends to the gap between the uppermost surface of the capacitor element group 2 and the horizontal posture plate portion 5b _P of the first laterally long terminal plate portion 5 _P .

The plurality of first lead-out terminals _5cP and the plurality of second lead-out terminals _5cN are arranged at the same height and staggered in the lateral direction. A second lead terminal 5cN is positioned between a pair of adjacent first lead terminals _5cP , _{5cP ,} and a first lead terminal _5cP is positioned between a pair of adjacent second lead terminals _5cN , _5cN .

The caseless film capacitor of this embodiment includes at least one pair of capacitor units 7 configured as described above. Here, an embodiment in which two capacitor units 7 are used to form a pair of caseless film capacitors will be described. The two capacitor units 7 are referred to as a first capacitor unit 7 ₁ and a second capacitor unit 7 ₂ . Note that the terms "first" and "second" before "capacitor unit" do not define polarities (first polarity, second polarity), unlike others.

As shown in FIGS. 10 to 16, the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ are arranged side by side in a state in which the second horizontally long terminal plate portion 5 _N of the first capacitor unit 7 ₁ and the second horizontally long terminal plate portion 5 _N in the second capacitor unit 7 ₂ face each other directly, and in a state of facing each other in which the second grid-like electrode plate 4 _N and the grid-like second electrode plate 4 _N directly face each other. Regarding the relationship between the axial direction of the plurality of capacitor elements 1 in the first capacitor unit 7 ₁ and the axial direction of the plurality of capacitor elements 1 in the second capacitor unit 7 ₂ , the arrangement relationship is such that when one axial direction is extended, the other axial direction coincides with the extension line.

In the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ , the first lead terminal 5c _{P of the first capacitor unit 7 1 and the first lead terminal 5 c P of the} second capacitor unit 7 ₂ are overlapped, and the second lead terminal 5 c _N of the first capacitor unit 7 ₁ and the second lead terminal 5 c _N of the second capacitor unit 7 ₂ are overlapped. That is, the first lead-out terminals 5c _P and 5c _P having the same polarity are overlapped with each other, and the second lead-out terminals 5c _N and 5c _N with the same polarity are overlapped with each other. Here, the overlapping of the lead terminals means that they are in close contact with each other without gaps and are integrated as an electrical conductor.

The overlapping position of the first lead terminals 5c _P and 5c _P and the overlapping position of the second lead terminals 5 c _N and 5 c _N are the central positions of the axial full width of the pair of capacitor units 7 ₁ and 7 ₁ arranged side by side (see FIG. 14 in particular).

The overlapping positions of the first lead-out terminals 5c _P and 5c _P and the overlapping positions of the second lead-out terminals 5c _N and 5c _N are the positions in which the adjacent vertical/horizontal electrode plates (second polarity vertical/horizontal electrode plates (4a _N , 4b _N )-(4a _N , 4b _N ) of the pair of capacitor units 7 ₁ and 7 ₁ ) face each other (particularly in FIG. 14).

A spacer (not shown) is attached to the first horizontal electrode plate 4b _P of the first capacitor unit 7 ₁ in order to stabilize the mutual positional relationship between the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ facing each other. By bringing this spacer into contact with the second horizontal electrode plate 4b _N of the second capacitor unit 7 ₂ on the other side, the vertical axis of the first capacitor unit 7 ₁ and the vertical axis of the second capacitor unit 7 ₂ are precisely parallel.

Although the explanation will be back and forth, the first lead-out terminals 5c _P and 5c _P are bent so that the facing gaps between the two capacitor units 7 ₁ and 7 ₂ are the same from the top end to the bottom end when the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ face each other in a parallel state. That is, as shown in FIGS. 14 to 16, there are terminal inclined portions 5c _P1 and _{5c P1} bent obliquely upward and inward from the root portions of the first lead terminals 5c _P and 5c _{P ,} and terminal vertical portions 5c _P2 and 5c _P2 bent vertically upward. The second lead terminals 5c _N and 5c _N are similarly bent. That is, the second lead-out terminals 5c _N and 5c _N have inclined terminal portions 5c _N1 and 5c _{N1 that are bent obliquely upward and inward from the root portions of the second lead-out terminals 5c N and 5c N, and terminal vertical portions 5c N2 and 5c N2 that are} further bent vertically upward.

The terminal vertical portions 5c _P2 and 5c _{P2 of} the first polarity are superimposed on _each other at the _extreme end (uppermost end) to form the first superimposed lead-out terminal portion 5k _P of the first polarity. Then, the first overlapped drawer terminal portion 5k _P and the second overlapping terminal portion 5k _n are arranged in a different position on one straight line, and the second -layered drawer terminals are located between the first pair of first -layered drawer terminals, and the second -layered drawer terminal 5k _n between the 5K _P , and the adjacent second stacking is located. The first overlapping drawer terminal 5k _{P is located between the drawer terminal portion 5k n and} 5K _{n .}

A hanging jig (hanger) for resin molding is attached to the rows of the first and second superimposed lead terminal portions 5k _P and 5k _N . The attachment is by sandwiching (sandwiching).

two capacitor units 7₁, 7₂facing each other and the hanging jig set is housed in a molding die with an upper opening, and the hanging jig is supported by the molding die. A spacer (not shown) is attached to the molded product in advance so as to abut on the inner peripheral surface of the molding die to properly maintain the posture of the molded product. A mold resin 8 such as an epoxy resin is poured into a molding die, and after the resin is solidified, the mold is released and taken out to obtain a caseless film capacitor. In the caseless film capacitor, the superimposed first lead-out terminal 5c_P.. . and the second lead-out terminal 5c_N.The whole is covered with mold resin 8 except for . In addition, the sheet-like insulating material 6_P., 6_N.part of is exposed to the outside.

In the caseless film capacitor of the above embodiment, a plurality of capacitor element groups 2, which are aggregates of capacitor elements 1, are arranged in parallel both in the horizontal direction and in the vertical direction, and first and second bus bars _3P and _3N are connected to both _electrode surfaces 1aP and _1aN of the first and second polarities of the capacitor element group 2, respectively, to form a capacitor unit 7. In the capacitor unit 7, which is a basic unit of a capacitor, a plurality of capacitor element groups 2, which are aggregates of the capacitor elements 1, are arranged side by side both in the horizontal direction and the vertical direction. Furthermore, first and second capacitor units 7 ₁ and 7 ₂ are prepared as such a capacitor unit 7, and a plurality of these capacitor units 7 ₁ and 7 ₂ are arranged side by side in a butted state to construct the capacitance part of a caseless film capacitor. As a result of all of the above, it is possible to provide a capacitor with a sufficiently large capacitance compared to a capacitor that is simply arranged side by side (a plurality of capacitors are arranged side by side in a three-dimensional direction).

Of the plurality of capacitor elements 1 that constitute the capacitor element group 2, _one row of the plurality of _capacitor elements 1 arranged in the vertical direction constitutes a capacitor element row 2a.

As a modification of the above embodiment, it is possible to arrange the first lead terminal 5c _P and the second lead terminal 5c _N in one capacitor unit 7 without shifting their positions in the longitudinal direction of the lateral terminal plate portions 5 _P and 5 _N (the present invention broadly includes this aspect). In this case, if the first lead-out terminal 5c _P and the second lead-out terminal 5c _N are at the same height position, their overlapping positions will overlap, causing a short circuit. Therefore, in order to avoid a short-circuit state, it is necessary to shift the height position between the overlapping position of the first lead terminal _5cP and the overlapping position of the second lead terminal _5cN .

In contrast to this modification, in the above embodiment, the positions of the lead terminals 5c _P and 5c _N are shifted and arranged alternately for the first polarity and the second polarity, so that the overlapping positions of the lead terminals 5c _P and 5c _N for the first polarity and the second polarity can be made substantially at the same height. This makes it possible to reduce the volume of the capacitor.

In the above embodiment, the number of capacitor units 7 is two (an even number), "7 ₁ " and "7 ₂ ". As shown in FIGS. 11, 12 and 14, the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ have a symmetrical structure. As is clear from the figure, in both the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ , the first bus bar 3 _P has a crank shape (vertical line + horizontal line + vertical line), and the crank shape is symmetrical. That is, the overall shapes of the horizontal attitude plate portion 5b _P and the rising plate portion 5a _P of the first laterally long terminal plate portion 5 _{P , as well as the terminal inclined portion 5c P1 and} the terminal vertical portion 5c _P2 of the lead-out terminal 5c P, are symmetrical to each other. The second bus bar 3 _N is not crank- _shaped but one- _plane along the vertical direction.

As a result, the overlap position of the first lead terminals 5c _P and the overlap position of the second lead terminals 5 c _N are at the central position of the axial full width of the two capacitor units 7 ₁ and 7 ₂ arranged side by side, which is advantageous in equalizing the current flow. In addition, regarding the structure of the horizontally long terminal plate portions 5 _P and 5 _N from which the plurality of lead terminals 5 c _P and 5 c _N are extended, the structures of the first polarity and the second polarity can be the same or substantially the same.

The overlapping position of the second lead-out terminals 5c _N and 5c _N is the facing position of the adjacent vertical and horizontal electrode plates (4a _N and 4b _N ) and (4a _N and 4b _N ) in the two capacitor units 7 ₁ and 7 ₂ arranged in parallel.

In one capacitor unit 7, the second laterally elongated terminal plate portion _5N from which the second lead-out terminals _5cN extend and the plurality of rows of vertical electrode plates _4aN are arranged on the upwardly extending surface of the electrode surface _1aN of the second polarity. This stipulates the arrangement orientation of the vertically elongated electrode plates 4a _N and the horizontal terminal plate portions 5 _N to which the upper end portions are connected so that they are positioned on a plane extending upward from the electrode surface 1a _N . That is, the vertical electrode plate 4a _N and the laterally elongated terminal plate portion 5 _N are deployed in a substantially straight posture from the electrode surface 1a _N . Since it is deployed almost straight, the current path length is shorter than when it is deployed in a bent position, which is more advantageous for reducing inductance and loss (heat suppression).

Although a pair of capacitor units 7 is used in the above embodiment, the present invention is not limited to this, and may include a case of two or more pairs.

FIG. 17 shows another embodiment relating to the arrangement of the polarities in the axial direction of the capacitor elements 1 in the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ . As in FIG. 14, FIG. 17 also omits the insulating members 6 _N and 6 _P to avoid complication of the drawing. Fig. 17(a) is an enlarged view of the main part seen from the front side like Fig. 14(a), and Fig. 17(b) is an enlarged view of the main part seen from the back side like Fig. 14(b). In this embodiment, FIGS. 17(a) and 17(b) are exactly the same as figures. However, regarding the signs, "P" and "N" are interchanged between (a) and (b).

In the embodiments (FIGS. 1 to 16) described so far, the polarities of the capacitor elements 1 in the first capacitor unit 7 ₁ are arranged in the axial direction from left to right (PN), and the polarities of the capacitor elements 1 in the second capacitor unit 7 ₂ are arranged (NP). This is the reverse arrangement with respect to the arrangement (PN) of the first capacitor unit 7 ₁ .

In the case of FIG. 14, the boundary between the first capacitor unit 7 ₁ and the second capacitor unit 7 ₂ is represented by the symbol "=", and the overall polarity arrangement is
(PN) = (NP)
(See FIG. 14). This is a symmetrical pattern around the boundary.

On the other hand, in the case of the embodiment shown in FIG. 17, the polar arrangement is a parallel-moving repetitive pattern. In short,
(PN) = (PN)
and In this embodiment, the arrangement (PN) of the second capacitor unit 7 ₂ is the same as the arrangement (PN) of the first capacitor unit 7 ₁ .

In FIG. 17A, of the two capacitor elements 1, 1 aligned in the axial direction, the polarity arrangement of the electrode surfaces of the capacitor element 1 belonging to the first capacitor unit 7 ₁ on the _left side is such that the electrode surface 1a _P with the first polarity (P _pole ) is on the left side and the electrode surface 1a N with the second polarity (N pole) is on the right side. is the electrode surface 1a _{N of} .

Along with this arrangement, the first horizontally long terminal plate portion 5 _P has an L-shaped cross section in the first capacitor unit _{7 1 ,} while the second capacitor unit 7 ₂ has a form that rises straight in the vertical direction at the central boundary (the main portion is only the rising plate portion). The second capacitor unit ₇₂ has an L-shaped cross section, which is different from the _embodiment shown in FIG.

That is, regarding the distance from the center line, in the first capacitor unit 7 ₁ , the first horizontally long terminal plate portion 5 _P is more distant than the second horizontally long terminal plate portion 5 _N , whereas in the second capacitor unit 7 ₂ , the second horizontally long terminal plate portion 5 _N is more distant than the first horizontally long terminal plate portion 5 _P , and the symmetry recognized in the case of FIG. 14 is lost. On the other hand, as a result of facing different poles at the central boundary, it is possible to reduce the mutual inductance due to the magnetic field canceling effect.

In the case of the parallel displacement type repeating pattern in FIG. 17 represented by (PN)=(PN) above, the second capacitor unit 7 ₂ may have the same structure as the first capacitor unit 7 ₁ . In other words, one of them should be turned around the vertical axis by 180 degrees to face the other capacitor unit.

As a modification of the embodiment of FIG. 14 in which the polarity arrangement is a symmetrical pattern (PN)=(NP), a symmetrical pattern of (NP)=(PN) in which the P pole and the N pole are interchanged may be used.

FIGS. 18 to 20 show an embodiment of a caseless film capacitor in which the first and second busbars are constructed from a single electrode plate.

The first bus bar 3 _P has a first horizontally long terminal plate portion 5 _P from which a plurality of first lead-out terminals 5 c _P extend, and is configured with a first rack electrode plate 4 _P that connects the first horizontally long terminal plate portion 5 _P. Each of the plurality of first lead-out terminals _5cP in the first bus bar _3P has a terminal inclined portion _5cP1 and a terminal vertical portion _5cP2 . The first horizontally elongated terminal plate portion 5 _P of the first bus bar 3 _P has a raised plate portion 5 a _P and a horizontal posture plate portion 5 b _P , and is configured in an angle with an L-shaped cross section. The first bus bar _3P having such a configuration is entirely composed of a single conductive plate.

Similarly, the second bus bar 3 _N has a second horizontally long terminal plate portion 5 _N from which a plurality of second lead terminals 5 c _N extend, and is configured with a second bridge electrode plate 4 _N connecting the second horizontally long terminal plate portion 5 _N. Each of the plurality of second lead-out terminals _5cN of the second bus bar _3N has a terminal inclined portion _5cN1 and a terminal vertical portion _5cN2 . The second horizontally long terminal plate portion _5N of the second busbar _3N is integrally formed vertically with respect to the second rack electrode plate _4N . The second bus bar _3N having such a configuration is entirely composed of a single conductive plate.

Since both the first bus bar 3 _P and the second bus bar 3 _N are produced by sheet metal working or press working based on a single thin flat conductive plate, efficient production is possible. The first and second electrode plates 4 _{P and} 4 _N connected to the capacitor element group 2 in contact with each other are not combined in a grid pattern _, but rather are electrode plates _with a _{relatively wide area that extend in a continuous manner as a whole. Small connection projecting pieces 4d P and 4d N are} provided to extend inside the hole.

Two sets of the cutout hole 4c _P and the small connecting projection 4d _P and two sets of the cutout hole 4c _N and the small connecting projection 4d _N are provided for each capacitor element 1, and the small connecting projections 4d _P and 4d _N are electrically and mechanically connected to the electrode surfaces 1a _P and 1a _N of the capacitor element 1 by soldering or the like.

In the case of this embodiment, even if the rack electrode plates 4 _P and 4 _N are single and have a large area, they are locally connected to the electrode surfaces 1a _P and 1a _N by the small connecting projections 4d _P and 4d _N protruding in the cutout holes 4c _P and 4c _N. Therefore, it is expected that the influence of deformation such as unevenness and waviness can be mitigated to ensure a predetermined connection quality. A relatively large cross-sectional area of the current path is ensured because of the one-piece structure, which is advantageous in terms of low inductance and low loss (heat suppression).

INDUSTRIAL APPLICABILITY The present invention is useful as a technology for realizing high-quality inflow and outflow of current, low inductance, and low loss (heat suppression) while increasing the size, capacity, and weight of a caseless film capacitor.

1 Capacitor Element 1a _P First Polarity Electrode Surface 1a _N Second Polarity Electrode Surface 2 Capacitor Element Group 2a Capacitor Element Row 4a _P First Vertical Electrode Plate 4a _N Second Polarity Vertical Electrode Plate _{4b P} First Polarity Horizontal Electrode Plate 4b _N Second Polarity Horizontal Electrode Plate 4a _1N Extension 5 _P First Horizontal Terminal Plate 5 _N Second Horizontal Terminal Plate 5a _P Rise Plate portion 5b _P Horizontal posture plate portion 5c P First lead terminal 5c _N Second lead terminal 7 ₁ Capacitor unit 7 ₂ Second capacitor unit 8 Mold resin

Claims (10)

A plurality of capacitor elements are arranged side by side in the horizontal direction and the vertical direction to form a capacitor element group in a state in which the electrode surfaces of the first polarity and the second polarity at both ends in the axial direction are positioned on the same plane, respectively;
The first polarity electrode surfaces of each of the plurality of capacitor elements are connected to each other via a first bridge electrode plate, and the second polarity electrode surfaces of each of the plurality of capacitor elements are connected to each other via a second bridge electrode plate,
The first rack electrode plate has an upper end portion connected to a first horizontally elongated terminal plate portion, and the second rack electrode plate has an upper end portion connected to a second horizontally elongated terminal plate portion,
At least one pair of capacitor units having a first lead terminal of a first polarity extending from an upper edge of the first horizontally elongated terminal plate portion and a second lead terminal of a second polarity extending from an upper edge of the second horizontally elongated terminal plate portion,
The pair of capacitor units are arranged in parallel with the axial directions of the respective capacitor elements,
In the pair of capacitor units, the first lead terminals having the same polarity are overlapped with each other, and the second lead terminals with the same polarity are overlapped with each other,
Regarding the pair of inwardly facing rack electrode plates and the pair of outwardly facing rack electrode plates in the pair of capacitor units,
The pair of inwardly facing rack electrode plates has an extension portion extending upward from the uppermost capacitor element of the capacitor element group, and the laterally long terminal plate portion connected to the upper end portion of the pair of inwardly facing rack electrode plates is composed of a rising plate portion connected in a state of extending above the extension portion,
The horizontally elongated terminal plate portion connected to the upper end portions of the pair of outer electrode plates facing each other is composed of a horizontal posture plate portion arranged in a horizontal posture along the top surface portion immediately above the top surface portion of the capacitor element group, and a rising plate portion bent upward from the inner end portion of the horizontal posture plate portion,
A caseless film capacitor, wherein the entire capacitor element group is covered with a mold resin. 2. The caseless film capacitor according to claim 1 , wherein said pair of inwardly facing electrode plates are electrode plates of the same polarity. 2. The caseless film capacitor according to claim 1 , wherein said pair of inwardly facing accumulator electrodes are accumulator electrode plates of opposite polarities. A plurality of the first lead terminals are led out from a plurality of positions spaced apart from the upper edge of the first laterally long terminal plate portion, and a plurality of the second lead terminals are led out from a plurality of positions spaced from the upper end edge of the second laterally long terminal plate portion at predetermined intervals,
The caseless film capacitor according to any one of claims 1 to 3, wherein the first lead terminals and the second lead terminals are arranged in a staggered manner with their positions shifted in the longitudinal direction of each of the laterally long terminal plate portions, the second lead terminal being positioned between a pair of adjacent first lead terminals, and the first lead terminal being positioned between a pair of adjacent second lead terminals. 5. The caseless film capacitor according to any one of claims 1 to 4, wherein the first vertical electrode plate has a plurality of rows of first vertical electrode plates that are provided according to the number of rows of the capacitor elements arranged in the horizontal direction and connect the electrode surfaces of the capacitor elements arranged in the vertical direction, and a first horizontal electrode plate that connects the plurality of rows of the first vertical electrode plates to each other in the horizontal direction. The caseless film capacitor according to any one of claims 1 to 5 , wherein the second vertical electrode plates have a plurality of rows of second vertical electrode plates that are provided according to the number of rows of the capacitor elements arranged in the horizontal direction and connect the electrode surfaces of the capacitor elements arranged in the vertical direction, and a second horizontal electrode plate that connects the plurality of rows of the second vertical electrode plates to each other in the horizontal direction. 7. The caseless film capacitor according to claim 1, wherein said first lead terminal and said second lead terminal are arranged at substantially the same height position in said longitudinal direction. 8. The caseless film capacitor according to any one of claims 1 to 7 , wherein the overlapping position of the first lead terminals and the overlapping position of the second lead terminals are central positions of the entire axial width of the pair of capacitor units. 9. The caseless film capacitor according to any one of claims 1 to 8 , wherein at least one of the first electrode plate and the second electrode plate is a thin plate and is configured as a single electrode plate. 10. The caseless film capacitor according to claim 9 , wherein, with respect to at least one of the first and second electrode plates, which are thin plate-shaped and are configured as a single electrode plate, the electrode plate, the horizontally long terminal plate portion, and the lead terminal are all formed of a single conductive plate.

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