JP2020098834A - Low ESL conductor structure capacitor - Google Patents

Abstract

To provide a capacitor capable of lowering ESL in spite of having three terminals.SOLUTION: A capacitor comprises first and second capacitor elements 2, 3 and first to third conductors 4 to 6. The third conductor 6 has two body parts. One of the body parts, a first body part 61, is overlapped with a body part 41 of the first conductor 4 in a state in which their upper ends are trued up. A base end part 62b of an external connection terminal 62 of the third conductor 6 and a base end part 42b of an external connection terminal 42 of the first conductor 4 face each other. The other of the body parts, a second body part 71, is overlapped with a body part 51 of the second conductor 5 in a state in which their upper ends are trued up. A base end part 62c of the external connection terminal 62 of the third conductor 6 and a base end part 52b of an external connection terminal 52 of the second conductor 5 face each other. The first body part 61 and the second body part 71 share the external connection terminal 62. Between the first body part 61 and the second body part 71 is provided a work space S1 for connecting the shared external connection terminal 62 with an external apparatus.SELECTED DRAWING: Figure 2

Description

The present invention relates to a capacitor having a reduced ESL (equivalent series inductance).

It has been conventionally performed, for example, as disclosed in Patent Document 1, to reduce the ESL by stacking conductors having different polarities (having parallel plate shapes). Further, in Patent Documents 2 and 3, when pulling out the two terminals (P terminal, N terminal) to the outside of the case, a parallel plate shape is formed to the limit to achieve low ESL, and the tips of the terminals are left and right so as to be separated from each other. It is disclosed that it is opened to form a flush surface to facilitate attachment to an external device. Patent Document 4 discloses a capacitor which is provided with three terminals (P terminal, C terminal, N terminal) and has a low ESL.

JP-A-9-260180 JP, 2011-054616, A JP 2012-152104 A JP, 2017-050335, A

By the way, since the terminal (external connection terminal) is a portion where the current is concentrated, it is preferable to make the terminals as close to each other as in Patent Documents 2 and 3 in order to reduce the ESL.

However, it is difficult to apply this configuration to a three-terminal capacitor. That is, in the case of three terminals, since the number of terminals is an odd number, when the terminals are brought close to each other in a one-to-one relationship, the terminals are left over. It is conceivable to bring the three terminals close together, but in this case, the terminals on both sides can be opened left and right, but the terminal in the center cannot be opened (bent to the left or right).

In addition, depending on where the capacitor is installed, the connection between the external device and the terminal may be behind the capacitor itself or the external device. In particular, the central terminal tends to become a shadow because the terminals are located on both sides. In this case, in order to secure a space for the connection work, it is necessary to extend the terminal or interpose a separate member, which increases the connection distance to the external device and causes an increase in ESL.

Therefore, an object of the present invention is to provide a capacitor that has three terminals and can achieve low ESL.

The capacitor of the present invention includes a first capacitor element 2, a second capacitor element 3, a first conductor 4 connected to one electrode 2a of the first capacitor element 2, and one electrode 3a of the second capacitor element 3. A second conductor 5 connected to the second capacitor 5 and a third conductor 6 connected to the other electrode 2b of the first capacitor element 2 and the other electrode 3b of the second capacitor element 3, The conductors 4, 5 and 6 are narrower than the body portions 41, 51, 61 and 71 and are connected to the capacitor element 2 (or 3) and are connected to external devices. Provided with external connection terminals 42, 52, 62, respectively, the third conductor 6 has two body portions 61, 71, and the first body portion 61 on one side is the body portion of the first conductor 4. 41 with the upper end aligned, and the external connection terminal 62 of the third conductor 6 and the base end portions 62b, 42b of the external connection terminal 42 of the first conductor 4 face each other and the second end on the other side. The main body portion 71 is overlapped with the main body portion 51 of the second conductor 5 with its upper end aligned, and the external connection terminal 62 of the third conductor 6 and the base end portion 62c of the external connection terminal 52 of the second conductor 5, 52b are opposed to each other, the first body portion 61 and the second body portion 71 share the external connection terminal 62, and are shared between the first body portion 61 and the second body portion 71. Further, a work space S1 for connecting the external connection terminal 62 and an external device is provided.

Further, the body portions 41, 51, 61, 71 are divided into a plurality of legs to form leg portions 41a, 51a, 61a, 71a, and between the leg portions (41a, 41a, 51a, 51a, 61a, 61a, It is preferable that a work space S2 for connecting the external device and the external connection terminals 42 and 52 is provided between (71a, 71a).

In the capacitor of the present invention, since the main body portions having different polarities are overlapped with each other, the effect of reducing ESL can be obtained. In particular, since the base end portions of the external connection terminals where current concentrates are opposed to each other, the effect of reducing ESL is high. Further, since a work space for connecting the shared external connection terminal and the external device is provided between the first main body portion and the second main body portion of the third conductor, the external connection terminal for connection is provided. It is possible to achieve low ESL without the need to extend.

In addition, even if the main body is divided into a plurality of legs and a working space for connecting the outside and the external connection terminal is provided between the legs, the external connection terminal can be connected for connection. There is no need to extend it, and further lower ESL can be achieved.

It is an exploded perspective view showing a capacitor concerning one embodiment of this invention. It is a perspective view showing the state where a capacitor element and a conductor were connected. It is sectional drawing of a capacitor. It is a bottom view of a capacitor It is a schematic circuit diagram of a capacitor.

Next, one embodiment of the capacitor of the present invention will be described in detail with reference to the drawings. The capacitor 1 of the present invention is a snubber capacitor used for charging an external device having three terminals (P terminal, C terminal, N terminal) such as a three-level inverter, as shown in FIGS. First capacitor element 2, second capacitor element 3, first conductor 4 connected to one electrode 2a of first capacitor element 2, and one electrode 3a of second capacitor element 3 The second conductor 5, the third conductor 6 connected to the other electrode 2b of the first capacitor element 2 and the other electrode 3b of the second capacitor element 3, each capacitor element 2, 3 and each conductor 4, 5, A case 8 for housing 6 and a resin 9 filled in the case 8 are provided. Hereinafter, each component will be described, but the concept of “upper and lower” in the description is at the time of manufacturing, more specifically, at the time of resin filling, and does not necessarily specify the upper and lower sides during use.

The first capacitor element 2 is a film capacitor formed by winding a metallized film in which a metal is vapor-deposited on the surface of an insulating film, and as shown in FIG. The electrodes 2a and 2b are formed respectively. The capacitor element 2 has a flat shape when viewed in the axial direction, specifically, a substantially track shape (a shape in which two parallel lines are connected to each other by a semicircle), and a flat portion 2c and a curved surface are formed on the outer circumference in the axial direction. 2d.

The second capacitor element 3 is similar to the first capacitor element 2. Therefore, the same subscripts are attached and detailed description is omitted.

The first conductor 4 faces the flat portion 2c of the first capacitor element 2 and is connected to the first capacitor element 2, and the main body portion 41 is narrower than the main body portion 41 and is used for connection to an external device. And an external connection terminal 42.

As shown in FIG. 1, the main body part 41 has a rectangular flat plate provided with a rectangular cutout from the lower end side so that the upper end side is connected but the lower end side is separated, that is, the lower side is It is bifurcated and has a shape including two leg portions 41a and 41a and a body portion 41b connecting the upper ends of the leg portions 41a and 41a. It should be noted that this shape can be said to be an inverted U-shape or an inverted U-shape. The width W1 between the leg portions 41a, 41a is, for example, 20 to 30 mm. Then, from each of the leg portions 41a, 41a, a connection piece 41c used for connection with the first capacitor element 2 is provided so as to project in the horizontal direction.

Further, as shown in FIG. 3, the lower portion of the main body portion 41 is buried in the resin 9, and the upper portion thereof is pulled out of the resin. When the portion buried in the resin is the buried portion 43 and the portion pulled out of the resin is the lead-out portion 44, the horizontal width of the lead-out portion 44 is equal to or larger than the width of the buried portion 43. ing. That is, the buried portion 43 is formed on the lower side of the leg portion 41a, but the width of the leg portion 41a in the vertical direction does not change in the horizontal direction. Therefore, the buried portion 43 and the drawer portion 44 have the same width between the leg portions 41a, and When reaching the portion 41b, the width of the lead-out portion 44 is larger than that of the buried portion 43. However, it is not always necessary that the leg portions 41a have the same width in the vertical direction, and the leg portions 41a may be widened on the side of the lead-out portion 44, for example. The horizontal width of the leg portion 41a is preferably equal to or larger than the horizontal width of the first capacitor element 2.

The external connection terminal 42 extends from the upper end of the lead portion 44. Further, it is extended from the center of the main body portion 41 so as to be located between the leg portions 41a, 41a in a plan view. The external connection terminal 42 is bent horizontally from the base end. The bending direction is the side on which the connection piece 41c is provided. A connection hole 42a for use in connection with an external device is provided near the tip.

The second conductor 5 is different from the first conductor 4 in that it is connected to the second capacitor element 3, but has the same shape as the first conductor 4 as shown in FIG. Therefore, the same subscripts are attached and detailed description is omitted. The second conductor 5 is back-to-back with the first conductor 4 (the connecting pieces 41c, 51c and the external connecting terminals 42, 52 are facing each other outwardly) with the third conductor 6 positioned therebetween. Will be placed).

The third conductor 6 is provided with two body portions 61 and 71, and the external connection terminal 62 is shared by the two body portions 61 and 71. Therefore, the third conductor 6 is different from the first conductor 4 and the second conductor 5. Is different. When one body is the first body 61 and the other body is the second body 71, the first body 61 and the second body 71 are arranged to face each other with a gap. There is. The width W2 of the gap is, for example, 20 to 25 mm. The upper ends are connected by one external connection terminal 62. Further, connection pieces 61c and 71c are respectively extended from the lower ends of the leg portions 61a and 71a so as to be connected to the lower electrodes 2b and 3b of the first and second capacitor elements 2 and 3, respectively. The extending direction is the side opposite to the external connection portion 62. Since other configurations are similar to those of the first electrode plate, the same subscripts are given and detailed description thereof is omitted.

Each of the conductors 4, 5 and 6 is bilaterally symmetrical with respect to the central axis passing through the center in the width direction. The third conductor 6 is also symmetrical with respect to the central axis passing through the center in the depth direction. Such conductors 4, 5 and 6 are formed by appropriately punching or bending a metal plate (flat metal) such as a copper plate or an aluminum plate.

In the capacitor 1 of the present invention, as the case 8, the first case 81 accommodating the leg portions 41a, 51a, 61a, 71a on one side of each of the conductors 4, 5, 6 and the leg portions 41a, 51a, 61a on the other side. , 71a are used as the second case 82. Each of the first and second cases 81 and 82 has a substantially cubic shape and has an open top surface, and has a storage space capable of storing the capacitor elements 2 and 3 and the leg portions 41a, 51a, 61a and 71a therein. I have it. The first and second cases 81 and 82 are arranged with a space therebetween. The width W3 of this interval is, for example, 15 to 20 mm. The resin 9 filled in the case 8 is, for example, an epoxy resin. However, the present invention is not limited to this, and various known resins such as urethane resin can be used.

Next, the manufacturing process of the capacitor 1 of the present invention will be described. First, the first capacitor element 2 is connected between the first conductor 4 and the third conductor 6. Specifically, the first capacitor element 2 is arranged so that the electrodes 2a and 2b are oriented vertically, and the flat portion 2c is arranged along the leg portion 41a of the first conductor 4 so that the upper electrode 2a of the first capacitor element 2 is formed. Is connected to the connection piece 41c of the first conductor 4, and the connection piece 61c of the first body portion 61 of the third conductor 6 is connected to the lower electrode 2b. At this time, the upper ends of the main body portions 41 and 61 (drawing portions 44 and 64) are aligned, and the base end portion 42b of the external connection terminal 42 of the first conductor 4 and the first main body of the external connection terminal 62 of the third conductor 6 are arranged. The main body portion 41 of the first conductor 4 and the first main body portion 61 of the third conductor 6 are superposed with an insulating layer (air layer) interposed therebetween so that the base end portion 62b on the side of the portion 61 faces each other ( Parallel plate shape). As a result, one capacitor unit U1 including the first capacitor element 2 and the first and third conductors 4 and 6 is formed (see FIG. 2).

Further, the second capacitor element 3 is connected between the second conductor 5 and the third conductor 6. Specifically, the second capacitor element 3 is arranged so that the electrodes 3a and 3b are oriented vertically, and the flat portion 3c is arranged along the leg portion 51a of the second conductor 5 so that the upper electrode 3a of the second capacitor element 3 is formed. Is connected to the connection piece 51c of the second conductor 5, and the lower electrode 3b is connected to the connection piece 71c of the second body portion 71 of the third conductor 6. At this time, the upper ends of the main body portions 51 and 71 (lead-out portions 54 and 64) are aligned, and the base end portion 52b of the external connection terminal 52 of the second conductor 5 and the second main body of the external connection terminal 62 of the third conductor 6 are arranged. The main body portion 51 of the second conductor 5 and the second main body portion 71 of the third conductor 6 are overlapped with each other with the insulating layer (air layer) interposed therebetween such that the base end portion 62c on the side of the portion 71 faces each other ( Parallel plate shape). As a result, another capacitor unit U2 including the second capacitor element 3 and the second and third conductors 5 and 6 is formed separately from the capacitor unit U1 (see FIG. 2). Further, the external connection terminals 42, 52, 62 of the conductors 4, 5, 6 are aligned in a straight line, and their upper surfaces are flush with each other. Since these capacitor units U1 and U2 are connected by the external connection terminal 62 of the third conductor 6, the capacitor as a whole constitutes the circuit shown in FIG.

Subsequently, the leg portions 41a, 51a, 61a, 71a of one of the conductors 4, 5, 6 and the first and second capacitor elements 2, 3 connected to the leg portions 41a, 51a, 61a, 71a are connected. It is housed in the first case 81. In addition, the other leg portion 41a, 51a, 61a, 71a of each conductor 4, 5, 6 and the first and second capacitor elements 2, 3 connected to this leg portion 41a, 51a, 61a, 71a It is housed in two cases 82. Then, the case 8 is filled with the resin 9 and the first and second capacitor elements 2 and 3 are resin-molded to complete the manufacture of the capacitor 1.

When the capacitor 1 having the above-described configuration is put into an external device having three terminals, for example, the first conductor 4 is connected to the P terminal, the second conductor 5 is connected to the N terminal, and the third conductor 6 is connected to the C terminal. .. At this time, since there is a gap between the first body portion 61 and the second body portion 71 of the third conductor 6, this gap can be used as a work space S1 for connection work (see FIG. 4). ). Further, since the body portions 41, 51, 61, 71 of the conductors 4, 5, 6 are bifurcated, the first and second cases 81, 82 can be provided separately, and the leg portions (41a , 41a, 51a, 51a, 61a, 61a, 71a, 71a), and more specifically, the first and second cases 81, 82 between the P and N terminals of the external device and the external connection terminal 42. , 52 can be used as a work space S2 for connection. Therefore, even though the external connection terminals 42, 52, and 62 are located in the outer frame of the capacitor 1 formed by connecting the outer peripheries of the first and second cases 81 and 82, the external connection terminals are connected to each other. Further, it is not necessary to extend the external connection terminals 42, 52, 62, and the ESL can be reduced. The capacitor 1 and the external device are connected by screwing.

Further, in the capacitor 1 of the present invention, the main body portions 41, 51, 61, 71 are drawn out of the resin while maintaining the width thereof (or widened), so that the external connection terminals 42, 52 are correspondingly. , 62 can be shortened, and the effect of reducing ESL can be obtained. In addition, the base end portions (42b and 62b, 52b and 62c) of the external connection terminals 42, 52 and 62 are opposed to each other, in other words, the conductors are overlapped to the limit (to the limit), The effect of reducing the ESL can be greatly obtained as compared with the case where the external connection terminals (base ends) are provided so as to be offset from each other. In addition, in the case of a capacitor in which the conductors are overlapped only in the case and the external connection terminals are displaced from each other and pulled out of the resin, the inductance is 8 nH, but in the capacitor 1 of the present invention, it is 3.2 nH, which is significantly large. A reduction effect was recognized.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, in the above embodiment, one capacitor element 2 (or 3) is connected to each of the left and right legs 41a, 51a, 61a, 71a, but the same number is used between the left and right legs 41a, 51a, 61a, 71a. If so, a plurality of capacitor elements 2 and 3 may be connected. In this case, it is preferable that the external connection terminals 42, 52, and 62 are connected symmetrically with respect to the center. Further, the number of legs is not limited to two and may be three or more. Further, in the above-described embodiment, two capacitor elements 2 (or 3) are connected to one capacitor unit U1 and U2, respectively, but if the number of capacitor units U1 and U2 is the same, one or three or more. The capacitor element may be connected. That is, if the number of capacitor elements is equal between the first and second capacitor elements 2 and 3, the number of the first capacitor elements 2 and the second capacitor elements 3 may be one or three or more.

The first and second capacitor elements 2 and 3 are not limited to film capacitors, and various capacitor elements such as ceramic capacitors may be used. When using a capacitor element that does not require resin molding, the case 8 and the resin 9 may be omitted. Regarding the shape of the capacitor element, various shapes such as a columnar shape and a prismatic shape can be adopted.

An insulating paper or an insulating plate may be used as the insulating layer between the conductors 4, 5, and 6. Further, it is not always necessary to use two cases 8. For example, if one case is used and a hole penetrating in the vertical direction is provided at a position overlapping the external connection terminals 42, 52, and 62 in plan view, the work spaces S1 and S2 are formed, and the external connection terminals 42 are formed. , 52, 62 and an external device can be connected. A case may be provided for each of the capacitor elements 2 and 3.

The width W2 between the first main body portion 61 and the second main body portion 71 of the third conductor 6 may be any distance as long as connection work can be performed, and can be appropriately changed according to the size of the screw fastening device. The same applies to the width W3 between the first case and the second case.

Reference Signs List 1 capacitor 2 first capacitor element 2a one electrode 2b other electrode 2c flat portion 2d curved surface 3 second capacitor element 3a one electrode 3b other electrode 3c flat portion 3d curved surface portion 4 first conductor 41 main body portion 41a leg portion 41b Body part 41c Connection piece 42 External connection terminal 42a Connection hole 42b Base end part 43 Buried part 44 Draw-out part 5 Second conductor 51 Main body part 51a Leg part 51b Body part 51c Connection piece 52 External connection terminal 52a Connection hole 52b Base end part 53 Buried portion 54 Drawer portion 6 Third conductor 61 First body portion 61a Leg portion 61b Body portion 61c Connection piece 62 External connection terminal 62a Connection hole 62b Base end portion 62c on the side of the first main body portion Base end on the side of the second main body portion Part 63 Buried part 64 Draw-out part 71 Second body part 71a Leg part 71b Body part 71c Connection piece 8 Case 81 First case 82 Second case 9 Resin S1 For connecting external connection terminal of third conductor and external device Work space S2 Work spaces U1 and U2 for connecting external connection terminals of the first and second conductors to an external device Capacitor unit W1 Gap width between legs W2 Gap between first main body and second main body Width W3 Gap width between cases

Claims (2)

A first capacitor element,
A second capacitor element,
A first conductor connected to one electrode of the first capacitor element;
A second conductor connected to one electrode of the second capacitor element;
A capacitor comprising a third conductor connected to the other electrode of the first capacitor element and the other electrode of the second capacitor element,
Each conductor has a main body connected to the capacitor element, and an external connection terminal narrower than the main body and used for connection with an external device,
The third conductor has two main body parts, and the first main body part on one side is overlapped with the main body part of the first conductor in a state where the upper ends thereof are aligned with each other to form an external connection terminal of the third conductor and the first conductor. Of the external connection terminal are opposed to each other, and the second main body on the other side is overlapped with the main body of the second conductor in a state where the upper end is aligned with the external connection terminal of the third conductor. The base end portions of the external connection terminals of the two conductors face each other,
The first body portion and the second body portion share the external connection terminal,
A capacitor provided with a work space for connecting a shared external connection terminal and an external device between the first main body and the second main body. The capacitor according to claim 1, wherein each main body portion is divided into a plurality of legs to form a leg portion, and a work space for connecting an external device and an external connection terminal is provided between the leg portions.

Images