capacitor

Abstract

Provided is a capacitor in which the ability to dissipate heat from a capacitor element can be improved. A film capacitor comprising: a capacitor element; first and second bus bars connected to respective electrodes provided on opposite end surfaces of the capacitor element; a filling resin covering the entire capacitor element and a portion of the first and second bus bars; and a heat transfer member having electric insulating properties and a thermal conductivity higher than that of the filling resin, and connected to the first and second bus bars in the filling resin.

Description

[Technical Field]

[0001] The present invention relates to a capacitor. [Background technology]

[0002] Conventionally, there has been known a case-molded capacitor in which a bus bar is connected to each electrode provided on both end faces of a capacitor element, the capacitor element to which the bus bars are connected is housed in a case, and the case is filled with a filling resin (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-103777 Summary of the Invention [Problem to be solved by the invention]

[0004] When a current is applied to the capacitor, the capacitor element generates heat. In the capacitor having the above configuration, the capacitor element is embedded in the filled resin, so heat is not easily released from the capacitor element.

[0005] In recent years, hybrid vehicles and electric vehicles have become popular, and in these vehicles, a capacitor with the above configuration can be installed in an inverter device for driving an electric motor. In this case, a large current tends to flow from the power supply device to the inverter device, and therefore a large current tends to flow to the capacitor element, which tends to generate a large amount of heat.

[0006] Therefore, if heat dissipation from the capacitor element is insufficient as described above, there is a risk that the capacitor element may suffer from problems such as thermal damage.

[0007] In view of the above problem, an object of the present invention is to provide a capacitor that can improve heat dissipation from the capacitor element. [Means for solving the problem]

[0008] A principal aspect of the present invention relates to a capacitor. The capacitor according to this aspect includes a capacitor element, a first bus bar and a second bus bar connected to electrodes provided on both end faces of the capacitor element, a coating resin that covers the entire capacitor element and parts of the first and second bus bars, and a sheet-like heat transfer member that has insulating properties and a higher thermal conductivity than the coating resin and is connected to the first and second bus bars within the coating resin. The heat transfer member is not exposed from the coating resin. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a capacitor that can improve heat dissipation from the capacitor element.

[0010] The effects and significance of the present invention will become more apparent from the following description of the embodiments, however, the embodiments shown below are merely examples of how the present invention can be put into practice, and the present invention is not limited to the embodiments described below. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1(a) is a perspective view of a film capacitor according to an embodiment, and FIG. 1(b) is a side cross-sectional view of the film capacitor according to the embodiment from which a filling resin is omitted. [Figure 2] 2(a) and 2(b) are perspective views of the capacitor element unit according to the embodiment as viewed from above the front and from above the rear, respectively. [Figure 3] Figure 3(a) is a perspective view of a capacitor element unit according to an embodiment, as viewed from below the front, and Figure 3(b) is a perspective view of a capacitor element unit according to an embodiment, as viewed from below the front, with the heat transfer member removed. [Figure 4]4(a) and (b) are perspective views of a first bus bar as seen from above the front and above the rear, respectively, according to an embodiment, and FIG. 4(c) is a perspective view of a second bus bar as seen from above the front, according to an embodiment. [Figure 5] FIG. 5 is a perspective view of a case according to the embodiment. [Figure 6] FIG. 6(a) is a perspective view of a capacitor element unit according to a modified example, as viewed from below and the front, and FIG. 6(b) is a side cross-sectional view of a film capacitor according to a modified example, in which the filling resin is omitted. DETAILED DESCRIPTION OF THE INVENTION

[0012] A film capacitor 1, which is one embodiment of a capacitor of the present invention, will be described below with reference to the drawings. For convenience, the front-rear, left-right, and up-down directions are indicated in each drawing as appropriate. Note that the directions shown in the drawings indicate only relative directions of the film capacitor 1, and do not indicate absolute directions. For convenience of explanation, some components may be given names that correspond to the directions shown in the drawings, such as the "bottom portion" and the "front side portion."

[0013] FIG. 1(a) is a perspective view of the film capacitor 1, and FIG. 1(b) is a side cross-sectional view of the film capacitor 1 from which the filling resin 600 is omitted.

[0014] As shown in FIGS. 1(a) and 1(b), the film capacitor 1 includes three capacitor elements 100, a first bus bar 200, a second bus bar 300, a heat transfer member 400, a case 500, and a filled resin 600. The three capacitor elements 100, the first bus bar 200, and the second bus bar 300 are assembled together, and the heat transfer member 400 is connected to the first bus bar 200 and the second bus bar 300 to form a capacitor element unit 10. The capacitor element unit 10 is housed in the case 500, and the case 500 is filled with a filled resin 600, which serves as a coating resin. The filled resin 600 is a thermosetting resin, such as an epoxy resin. The three capacitor elements 100 and the heat transfer member 400, as well as portions of the first bus bar 200 and the second bus bar 300, are entirely covered by the filled resin 600 within the case 500, providing protection from moisture and impact.

[0015] 2(a) and 2(b) are perspective views of the capacitor element unit 10 as seen from above the front and from above the rear, respectively. Fig. 3(a) is a perspective view of the capacitor element unit 10 as seen from below the front, and Fig. 3(b) is a perspective view of the capacitor element unit 10 as seen from below the front with the heat transfer member 400 removed. Figs. 4(a) and 4(b) are perspective views of the first bus bar 200 as seen from above the front and from above the rear, respectively, and Fig. 4(c) is a perspective view of the second bus bar 300 as seen from above the front.

[0016] The three capacitor elements 100 are formed by stacking two metallized films, each consisting of a dielectric film with aluminum vapor-deposited on it, and then rolling or laminating the stacked metallized films and pressing them flat. Each capacitor element 100 has a shape similar to a flat, elongated cylinder. A first electrode 110 is formed on one end face 101 of each capacitor element 100 by spraying a metal such as zinc, and a second electrode 120 is formed on the other end face 102 by spraying a metal such as zinc.

[0017] Although capacitor element 100 of the present embodiment is formed from a metallized film in which aluminum is vapor-deposited on a dielectric film, it may also be formed from a metallized film in which other metals such as zinc or magnesium are vapor-deposited. Alternatively, capacitor element 100 may be formed from a metallized film in which multiple metals selected from these metals are vapor-deposited, or from a metallized film in which an alloy of these metals is vapor-deposited.

[0018] In the capacitor element unit 10, the three capacitor elements 100 are arranged in a line in the left-right direction, with one end face 101, i.e., the first electrode 110, facing rearward and the other end face 102, i.e., the second electrode 120, facing forward, and with their peripheral faces 103 adjacent to each other. A first bus bar 200 and a second bus bar 300 are electrically connected to the first electrodes 110 and second electrodes 120 of the three capacitor elements 100, respectively.

[0019] First bus bar 200 is formed by appropriately cutting out and bending a conductive material, for example, a copper plate, and has a configuration in which electrode terminal portion 210, intermediate portion 220, three first connection terminal portions 230, second connection terminal portion 240, three first extension portions 250, and two second extension portions 260 are integrated together. In this embodiment, first bus bar 200 is an N-pole bus bar.

[0020] The electrode terminal portion 210 is a rectangular plate with two notches cut out at the bottom in a predetermined shape, and contacts the first electrodes 110 of the three capacitor elements 100 so as to cover the first electrodes 110 from behind. The upper end of the electrode terminal portion 210 protrudes upward beyond the three first electrodes 110. A total of nine connection pins 211 are formed on the electrode terminal portion 210 at the left and right ends and in the two notched portions. Three corresponding connection pins 211 are joined to each first electrode 110 by a joining method such as soldering. Furthermore, two communication holes 212 are formed in the upper end of the electrode terminal portion 210 (the portion protruding beyond the first electrodes 110).

[0021] The intermediate portion 220 extends forward from the upper end (one end) of the electrode terminal portion 210 and is connected to three first connection terminal portions 230 and three second connection terminal portions 240. The intermediate portion 220 includes a first portion 221 that is a rectangular plate-like portion that is wider in the left-right direction than the electrode terminal portion 210, second portions 222 that are formed at three locations on the front end of the first portion 221 and have an inverted U-shaped bent shape, and a third portion 223 that rises from between the center and right-side second portions 222 at the front end of the first portion 221.

[0022] An upper surface 221a of the first portion 221 (the surface not facing the capacitor element 100) is a flat surface. The first portion 221 and the upper surface 221a function as a mounting portion and a mounting surface, respectively, on which the heat absorption member 2 (described later) is mounted. Hereinafter, the upper surface 221a of the first portion 221 will be referred to as the mounting surface 221a.

[0023] The intermediate portion 220, i.e., the first portion 221, is disposed along the upper portions of the peripheral surfaces 103 of the three capacitor elements 100, and covers the entire three capacitor elements 100 from above. A predetermined gap is provided between the first portion 221 and the peripheral surfaces 103 of the three capacitor elements 100.

[0024] Three (a plurality of) openings 224 are provided in the first portion 221 so as to be aligned in the left-right direction. Also, a protrusion 225 that protrudes downward is provided at the front edge of each opening 224 in the first portion 221. The tip of the protrusion 225 abuts against the peripheral surface 103 of the capacitor element 100.

[0025] The three first connection terminal portions 230 have a rectangular plate shape and extend forward from the tips of the three second portions 222 of the intermediate portion 220. The second connection terminal portion 240 has a semi-oval plate shape and extends forward from the tip of the third portion 223 of the intermediate portion 220. A circular mounting hole 241 is formed in the second connection terminal portion 240.

[0026] The three first extending portions 250 extend forward from the lower end (the end different from the one end) of the electrode terminal portion 210 and are close to the lower portions of the circumferential surfaces 103 of the three capacitor elements 100 so as to cover these portions from below. The central first extending portion 250 has a rectangular plate shape, and the two first extending portions 250 on the left and right have U-shaped plate shapes. The three first extending portions 250 extend to positions more than halfway from the first electrode 110 side of the circumferential surfaces 103 of the three capacitor elements 100.

[0027] The two second extending portions 260 extend downward from the left and right ends (one end) of the first portion 221 of the intermediate portion 220 and are close to the left and right portions of the peripheral surface 103 of the capacitor element 100 at the left and right ends so as to cover these portions from the left and right. The two second extending portions 260 have a rectangular plate shape. The two second extending portions 260 extend from the upper end side of the peripheral surface 103 of the capacitor element 100 at the left and right ends to a position more than halfway up.

[0028] A distance equal to or greater than the spatial distance (insulation distance) required for insulation is provided between each of the first extending portions 250 and second extending portions 260 and the second electrode 120 of the corresponding capacitor element 100. This ensures insulation between the first bus bar 200 and the second electrode 120.

[0029] In this embodiment, each of the first extending portions 250 and each of the second extending portions 260 contacts the peripheral surface 103 of the capacitor element 100. However, each of the first extending portions 250 and each of the second extending portions 260 may have a slight gap between them and the peripheral surface 103 of the capacitor element 100.

[0030] Second bus bar 300 is formed by appropriately cutting out and bending a conductive material, for example, a copper plate, and has a configuration in which electrode terminal portion 310, intermediate portion 320, three first connection terminal portions 330, and second connection terminal portion 340 are integrated together. In this embodiment, second bus bar 300 is a P-pole bus bar.

[0031] The electrode terminal portion 310 has a rectangular plate shape and contacts the second electrodes 120 of the three capacitor elements 100 so as to cover the second electrodes 120 from the front. A total of nine connection pins 311 are formed on the lower end of the electrode terminal portion 310. Three corresponding connection pins 311 are joined to each second electrode 120 by a joining method such as soldering.

[0032] The intermediate portion 320 extends obliquely upward and forward from the upper end of the electrode terminal portion 310, and is connected to three first connection terminal portions 330 and three second connection terminal portions 340. The intermediate portion 320 includes a first portion 321 that is a rectangular plate having the same width in the left-right direction as the electrode terminal portion 310, second portions 322 that are formed at three locations on the front end of the first portion 321 and have an inverted U-shaped bent shape, and a third portion 323 that rises from between the center and left-hand second portions 322 at the front end of the first portion 321.

[0033] The three first connection terminal portions 330 have a rectangular plate shape and extend forward from the tips of the three second portions 322 of the intermediate portion 320. The second connection terminal portion 340 has a semi-oval plate shape and extends forward from the tip of the third portion 323 of the intermediate portion 320. A circular mounting hole 341 is formed in the second connection terminal portion 340.

[0034] Heat transfer member 400 has a rectangular sheet shape, is bent into an L-shape, and is connected to first bus bar 200 and second bus bar 300 using a heat-resistant adhesive or the like. One end of heat transfer member 400 is connected to electrode terminal portion 310 of second bus bar 300 in a direction (up-down direction, front-rear direction) perpendicular to the arrangement direction (left-right direction) of the three capacitor elements 100, extends along electrode terminal portion 310 and peripheral surfaces 103 of the three capacitor elements 100, and the other end is connected to three first extending portions 250 of first bus bar 200. Heat transfer member 400 has a width in the arrangement direction (left-right direction) that is the same as the width of electrode terminal portion 310 and the width to both left and right ends of three first extending portions 250, and faces closely to all of the capacitor elements 100.

[0035] The heat transfer member 400 is an insulating member with high thermal conductivity, and is formed from, for example, a silicon-based material, and has insulating properties and a higher thermal conductivity than the filled resin 600. For example, the thermal conductivity of the filled resin 600 is about 0.4 to 0.5 W / m·K, whereas the thermal conductivity of the heat transfer member 400 is about 3.0 to 3.5 W / m·K.

[0036] In the capacitor element unit 10, each first connection terminal portion 330 of the second bus bar 300 is arranged next to each first connection terminal portion 230 of the first bus bar 200. The second connection terminal portion 240 of the first bus bar 200 is located between the right-end pair of first connection terminal portions 230, 330 and the central pair of first connection terminal portions 230, 330, and the second connection terminal portion 340 of the second bus bar 300 is located between the left-end pair of first connection terminal portions 230, 330 and the central pair of first connection terminal portions 230, 330.

[0037] The three second portions 222 of the intermediate portion 220 of the first bus bar 200 and the three second portions 322 of the intermediate portion 320 of the second bus bar 300 overlap with each other in the thickness direction, which is expected to reduce the ESL (equivalent series inductance) of the capacitor element unit 10.

[0038] An insulating sheet 700 is sandwiched between the three second portions 222 of the first bus bar 200 and the three second portions 322 of the second bus bar 300. The insulating sheet 700 extends to below the front sides of the first portions 221 of the intermediate portion 220 of the first bus bar 200. The insulating sheet 700 is formed from insulating paper or an insulating resin material such as acrylic or silicone. The insulating sheet 700 ensures insulation between the first bus bar 200 and the second bus bar 300, and insulation between the first bus bar 200 and the second electrodes 120 of the three capacitor elements 100.

[0039] FIG. 5 is a perspective view of the case 500.

[0040] Case 500 is made of resin, for example, polyphenylene sulfide (PPS), which is a thermoplastic resin. Case 500 is formed in a substantially rectangular box shape and has bottom surface 501, front side surface 502, rear side surface 503, left side surface 504, and right side surface 505 that rise from bottom surface 501, and is open at the top.

[0041] Cylindrical mounting bosses 510 are provided on the front and rear ends of the left side surface portion 504 and the right side surface portion 505. These mounting bosses 510 are used when fixing the film capacitor 1 to an installation portion of an external device. Two terminal blocks 520 are provided on the upper end of the front side surface portion 502. Installation surfaces 521, which are the upper surfaces of the terminal blocks 520, have shapes corresponding to the second connection terminal portions 240, 340 of the first bus bar 200 and the second bus bar 300. Cylindrical nuts 530 are attached to the installation surfaces 521.

[0042] When the film capacitor 1 is assembled, the capacitor element unit 10 is housed in the case 500, as shown in FIG. 1(b). The second connection terminal portion 240 of the first bus bar 200 is installed on the right terminal block 520, and the second connection terminal portion 340 of the second bus bar 300 is installed on the left terminal block 520. The mounting holes 241, 341 of each second connection terminal portion 240, 340 are fitted into the tip of a nut 530. The three second portions 222, 322 of the middle portions 220, 320 of the first bus bar 200 and the second bus bar 300 straddle the upper end of the front side surface portion 502 of the case 500. Most of the opening 500a of the case 500 is covered by the first portion 221 of the middle portion 220 of the first bus bar 200.

[0043] Within case 500, the three capacitor elements 100 have first electrodes 110 facing the inner wall surface of rear side surface 503 of case 500, and second electrodes 120 facing the inner wall surface of front side surface 502 of case 500. Furthermore, first extension portion 250 of first bus bar 200 and heat transfer member 400 are located between lower portions of circumferential surfaces 103 of the three capacitor elements 100 and bottom surface 501 of case 500, and are close to the inner wall surface of bottom surface 501. Furthermore, left and right second extension portions 260 of first bus bar 200 are close to the inner wall surfaces of left side surface 504 and right side surface 505 of case 500, respectively.

[0044] Filling resin 600 in a liquid state is injected into case 500 through three openings 224 provided in first portion 221 of intermediate portion 220 of first bus bar 200. In this embodiment, even if most of opening 500a of case 500 is blocked by first portion 221 of intermediate portion 220, filling resin 600 can be smoothly injected into case 500 using the three openings 224. In addition, electrode terminal portion 210 of first bus bar 200 is provided with two circulation holes 212, and injected filling resin 600 passes through these circulation holes 212, making it easier to spread between electrode terminal portion 210 and rear side surface portion 503.

[0045] 1(b) , the injection of the filled resin 600 is completed when the filled resin 600 is filled into the case 500 up to a position slightly below the first portion 221 of the middle section 220. The case 500 is heated, and the filled resin 600 in the case 500 hardens.

[0046] 1(a), the film capacitor 1 is completed. In the capacitor element unit 10, the three first connection terminal portions 230 and second connection terminal portions 240 of the first bus bar 200 and the three first connection terminal portions 330 and second connection terminal portions 340 of the second bus bar 300 are exposed from the filled resin 600 and positioned at the front of the case 500. Also, the first portion 221 and the mounting surface 221a of the intermediate portion 220 of the first bus bar 200 are exposed from the filled resin 600. Here, a fixed distance is maintained between the first portion 221 of the intermediate portion 220 and the three capacitor elements 100 by the three protrusions 225. Therefore, when the height position of the capacitor element unit 10 relative to the case 500 is determined so that the first portion 221 is exposed from the filled resin 600, the three capacitor elements 100 can be reliably embedded in the filled resin 600. Furthermore, in filled resin 600, first bus bar 200 and second bus bar 300 are connected via heat transfer member 400.

[0047] The film capacitor 1 can be mounted, for example, in an inverter device for driving an electric motor in an electric vehicle. The inverter device receives DC power from a power supply (battery). The inverter device includes an inverter circuit including an IGBT (Insulated Gate Bipolar Transistor), converts the DC power into three-phase AC power, and supplies it to the electric motor.

[0048] Corresponding external terminals (not shown) connected to a power supply device are connected to second connection terminal portions 240 of first bus bar 200 and second connection terminal portions 340 of second bus bar 300. At this time, second connection terminal portions 240, 340 and the external terminals are fixed to terminal block 520 by tightening bolts (not shown) to nuts 530. Corresponding external terminals (not shown) connected to an inverter circuit are connected to the three first connection terminal portions 230 of first bus bar 200 and the three first connection terminal portions 330 of second bus bar 300 by a connection method such as connector connection.

[0049] In order to enhance the heat dissipation effect of the film capacitor 1 installed in the inverter device, a cooling member 2 is attached to the attachment surface 221a of the middle portion 220 of the first bus bar 200 (see FIG. 1(b)). The cooling member 2 is used to forcibly cool the first bus bar 200 from the outside, and is made of a material with excellent thermal conductivity, such as aluminum, and is configured to have a flow path inside through which a refrigerant flows. The cooling member 2 may be a cooler that uses a Peltier element. Note that insulation is provided between the cooling member 2 and the attachment surface 221a.

[0050] When the inverter device operates and current is applied to the film capacitor 1, heat is generated in the three capacitor elements 100. Of the three capacitor elements 100, the central capacitor element 100 is more likely to reach a higher temperature due to the heat generated than the capacitor elements 100 at the left and right ends.

[0051] Heat emitted from the first electrodes 110 and peripheral surface 103 of the three capacitor elements 100 is conducted to the electrode terminal portion 210, the three first extending portions 250, and the two second extending portions 260 of the first bus bar 200. In the first bus bar 200, the cooling member 2 absorbs heat from the first portion 221 of the intermediate portion 220, and the first portion 221 is cooled to a low temperature. As a result, the heat conducted to the electrode terminal portion 210, the first extending portions 250, and the second extending portions 260 moves to the first portion 221 of the intermediate portion 220, and is released from the first portion 221 to the cooling member 2.

[0052] First portion 221 of intermediate section 220 is sized to cover all three capacitor elements 100. This increases the area of ​​first bus bar 200 cooled by cooling member 2, allowing for a greater amount of heat dissipation to cooling member 2.

[0053] Heat generated from the second electrodes 120 of the three capacitor elements 100 is transferred to the electrode terminals 310 of the second bus bar 300. The electrode terminals 310 are connected to the three first extensions 250 of the first bus bar 200 by the heat transfer member 400. The first bus bar 200 is forcibly cooled from the outside by the cooling member 2. Therefore, the heat transferred to the electrode terminals 310 travels through the heat transfer member 400 to the three first extensions 250, and then to the first portions 221 of the intermediate portion 220, from which the heat is released to the cooling member 2. At this time, the heat transfer member 400 has a width that faces all of the capacitor elements 100 in the direction (left-right direction) perpendicular to the direction in which the heat travels (up-down direction, front-rear direction). Therefore, the path for heat transfer is wide, and heat easily travels from the second bus bar 300 to the first bus bar 200.

[0054] In addition, the heat generated from the portion of the second electrode 120 of the three capacitor elements 100 that is not covered by the electrode terminal portion 310 but is covered by the heat transfer member 400, and the portion of the peripheral surface 103 that is not covered by the first extension portion 250 but is covered by the heat transfer member 400, is transferred directly to the heat transfer member 400 and moves to the three first extension portions 250, i.e., the first bus bar 200.

[0055] In this way, heat is dissipated from the three capacitor elements 100 to the outside via the first bus bar 200 and the second bus bar 300, and therefore these capacitor elements 100 are less likely to reach high temperatures when current is applied.

[0056] <Effects of the embodiment> As described above, according to this embodiment, the following effects are achieved.

[0057] Film capacitor 1 includes capacitor element 100, first bus bar 200 and second bus bar 300 connected to electrodes 110, 120 provided on both end faces of capacitor element 100, filled resin (coating resin) 600 covering the entire capacitor element 100 and parts of first bus bar 200 and second bus bar 300, and heat transfer member 400 having insulating properties and higher thermal conductivity than filled resin 600, and connected to first bus bar 200 and second bus bar 300 within filled resin 600. Furthermore, film capacitor 1 includes case 500 that houses capacitor element 100, and case 500 is filled with filled resin 600.

[0058] According to this configuration, by cooling first bus bar 200 from the outside, not only can heat transferred from capacitor element 100 to first bus bar 200 be efficiently released to the outside, but heat transferred to second bus bar 300 can also be transferred to first bus bar 200 through heat transfer member 400 and efficiently released to the outside. This improves heat dissipation from capacitor element 100 and prevents capacitor element 100 from becoming too hot when current is applied.

[0059] Furthermore, the film capacitor 1 is configured so that the heat transfer member 400 is present between the capacitor element 100 and the bottom surface 501 of the case 500 .

[0060] With this configuration, heat is less likely to build up between capacitor element 100 and bottom surface portion 501 of case 500.

[0061] Furthermore, in the film capacitor 1, the first bus bar 200 and the second bus bar 300 are configured to include electrode terminal portions 210, 310 that cover the electrodes 110, 120 and are connected to the electrodes 110, 120, first connection terminal portions 230, 330 and second connection terminal portions 240, 340 that are exposed from the filling resin 600 and to which external terminals are connected, and intermediate portions 220, 320 that extend from one end of the electrode terminal portions 210, 310 and are connected to the first connection terminal portions 230, 330 and second connection terminal portions 240, 340. The first bus bar 200 is provided with a first extending portion 250 that extends from an end different from the one end of the electrode terminal portion 210 and covers the circumferential surface 103 of the capacitor element 100, and the heat transfer member 400 is connected to the first extending portion 250 along the circumferential surface 103.

[0062] With this configuration, not only can heat generated from both electrodes 110, 120 of capacitor element 100 be dissipated to the outside through both electrode terminal portions 210, 310, but heat generated from circumferential surface 103 of capacitor element 100 can also be dissipated to the outside through first extension portion 250. Furthermore, heat generated from the portion of circumferential surface 103 that is not covered by first extension portion 250 in order to ensure an insulating distance from second electrode 120 can be received by heat transfer member 400 and transferred to first extension portion 250. This further improves heat dissipation from capacitor element 100.

[0063] Furthermore, the film capacitor 1 is configured such that a plurality of capacitor elements 100 are arranged side by side, and the heat transfer member 400 is connected to the first bus bar 200 and the second bus bar 300 in a direction perpendicular to the arrangement direction of the capacitor elements 100, and has a width in the arrangement direction that faces all of the capacitor elements 100.

[0064] According to this configuration, the width of the path along which heat travels in heat transfer member 400 is increased, and heat travels more easily from second bus bar 300 to first bus bar 200.

[0065] Furthermore, in the film capacitor 1, the first bus bar 200 includes a mounting surface 221a that is exposed from the filled resin 600 and on which the cooling member 2 is mounted.

[0066] According to this configuration, by attaching cooling member 2 to attachment surface 221a, first bus bar 200 can be cooled sufficiently.

[0067] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and application examples of the present invention can be modified in various ways in addition to the above-described embodiments.

[0068] For example, in the above embodiment, the heat transfer member 400 is connected between the three first extension portions 250 of the first bus bar 200 and the electrode terminal portion 310 of the second bus bar 300. However, as shown in FIG. 6( a), two heat transfer members 400 may be connected between the left and right second extension portions 260 of the first bus bar 200 and the electrode terminal portion 310 of the second bus bar 300. In this case, the two heat transfer members 400 are bent into an L shape and arranged close to the electrode terminal portion 310 and the peripheral surfaces 103 of the left and right capacitor elements 100. In this configuration, heat generated from the peripheral surface 103 of the capacitor element 100 can be released to the outside through the second extension portions 260. In addition, heat generated from the portion of the peripheral surface 103 that is not covered by the second extension portions 260 to ensure an insulating distance between the second electrode 120 and the second electrode 120 can be received by the heat transfer member 400 and transferred to the second extension portions 260. Furthermore, a heat transfer member having a shape that combines the heat transfer member 400 of the above embodiment and the heat transfer member 400 of Figure 6(a) may be connected to the three first extension portions 250 and two second extension portions 260 of the first bus bar 200 and the electrode terminal portions 310 of the second bus bar 300.

[0069] Furthermore, in the above embodiment, the first bus bar 200 is provided with three first extending portions 250 and two second extending portions 260. However, depending on the amount of heat dissipation required, the first bus bar 200 may be configured such that three first extending portions 250 are provided but two second extending portions 260 are not provided, a central first extending portion 250 and two second extending portions 260 are provided, a configuration in which three first extending portions 250 are not provided but two second extending portions 260 are provided, or a configuration in which neither the first extending portion 250 nor the second extending portions 260 are provided.

[0070] Furthermore, when the first extending portion 250 is not provided on the first bus bar 200, it is preferable that the heat transfer member 400 is connected between the electrode terminal portion 210 of the first bus bar 200 and the electrode terminal portion 310 of the second bus bar 300, as shown in Fig. 6(b). In this case, when the heat transfer member 400 comes into contact with the lower portions of the peripheral surfaces 103 of the three capacitor elements 100, the heat from the peripheral surfaces 103 may be easily transferred to the heat transfer member 400.

[0071] Furthermore, in the above embodiment, the left and right first extending portions 250 of the first bus bar 200 are configured to be U-shaped, so that the area covering the peripheral surface 103 of the capacitor element 100 is smaller than that of the central first extending portion 250, which is rectangular. However, if higher heat dissipation performance is required from the left and right first extending portions 250, such as when the left and right second extending portions 260 are no longer provided on the first bus bar 200, the left and right first extending portions 250 may be configured to be the same shape as the central first extending portion 250 so that the areas covering the peripheral surface 103 are the same. Furthermore, three first extending portions 250 may be connected to form one first extending portion.

[0072] Furthermore, in the above embodiment, the entire first portion 221 of the intermediate portion 220 of the first bus bar 200 is exposed from the filled resin 600. However, as long as at least the mounting surface (upper surface) 221a is exposed, the entire first portion 221 does not have to be exposed from the filled resin 600.

[0073] Furthermore, the configuration for forcibly cooling first bus bar 200 from the outside may be different from the configuration in which cooling member 2 is attached to attachment surface 221a exposed from filled resin 600. For example, in the case where first bus bar 200 is configured such that first portion 221 of intermediate portion 220 is not exposed from filled resin 600 and electrode terminal portion 210 is close to rear side surface 503 of case 500, a cooling member may be attached to the outer wall surface of rear side surface 503, and electrode terminal portion 210 may be cooled via rear side surface 503 by the cooling member.

[0074] Furthermore, in the above embodiment, first bus bar 200 and second bus bar 300 are provided with three first connection terminal portions 230, 330, but the number of first connection terminal portions 230, 330 may be changed as appropriate. Furthermore, first bus bar 200 and second bus bar 300 may be provided with one type of connection terminal portion instead of being provided with two types of connection terminal portions, first connection terminal portions 230, 330 and second connection terminal portions 240, 340.

[0075] Furthermore, in the above embodiment, first bus bar 200 is the N-pole bus bar, and second bus bar 300 is the P-pole bus bar. However, first bus bar 200 may be the P-pole bus bar, and second bus bar 300 may be the N-pole bus bar.

[0076] Furthermore, in the above embodiment, the film capacitor 1 is provided with three capacitor elements 100. However, the number of capacitor elements 100 can be changed as appropriate, including the case where it is one.

[0077] Furthermore, in the above embodiment, capacitor element 100 is formed by stacking two metallized films with aluminum vapor-deposited on a dielectric film and then rolling or laminating the stacked metallized films. However, capacitor element 100 may also be formed by stacking a metallized film with aluminum vapor-deposited on both sides of a dielectric film and an insulating film, and then rolling or laminating the resulting film.

[0078] Furthermore, in the above embodiment, the present invention is applied to film capacitor 1 in which capacitor element 100 is placed inside case 500 so that both electrodes 110, 120 face the side surfaces of case 500. However, the present invention can also be applied to a film capacitor in which the capacitor element is placed inside the case so that both electrodes face the bottom and opening surfaces of the case. Furthermore, the present invention can also be applied to a film capacitor in which the capacitor element is covered with a coating resin made of epoxy or the like and is not housed in a case, but the coating resin serves as an exterior body.

[0079] Furthermore, in the above embodiment, the film capacitor 1 is given as an example of the capacitor of the present invention. However, the present invention can also be applied to capacitors other than the film capacitor 1.

[0080] In addition, the embodiments of the present invention can be modified in various ways as appropriate within the scope of the technical ideas set forth in the claims.

[0081] In the description of the above embodiment, terms indicating directions such as "upward" and "downward" indicate relative directions that depend only on the relative positional relationship of the components, and do not indicate absolute directions such as vertical or horizontal. [Industrial Applicability]

[0082] The present invention is useful for capacitors used in various electronic devices, electrical devices, industrial devices, vehicle electrical equipment, and the like. [Explanation of symbols]

[0083] 1. Film capacitor (capacitor) 100 capacitor element 110 1st electrode (electrode) 120 Second electrode (electrode) 200 1st bus bar 210 Electrode terminal section 220 Middle section (first extension section) 221 Part 1 221a Mounting surface 230 First connection terminal portion (connection terminal portion) 240 Second connection terminal part (connection terminal part) 250 1st extension part (extension part) 260 Second extension part (extension part) 300 2nd bus bar 310 Electrode terminal section 320 Middle section 330 First connection terminal portion (connection terminal portion) 340 Second connection terminal part (connection terminal part) 400 Heat transfer material 500 cases 501 Bottom part 600 Filled resin (coated resin)

Claims

1. a capacitor element; a first bus bar and a second bus bar connected to electrodes provided on both end surfaces of the capacitor element, respectively; a coating resin that covers the entire capacitor element and parts of the first bus bar and the second bus bar; a sheet-like heat transfer member having insulating properties and a thermal conductivity higher than that of the coating resin, the sheet-like heat transfer member being connected to the first bus bar and the second bus bar within the coating resin; Equipped with The heat transfer member is not exposed from the coating resin. A capacitor characterized by:

2. 2. The capacitor according to claim 1, one end of the heat transfer member is connected to the second bus bar, extends along the circumferential surface of the capacitor element, and the other end is connected to the first bus bar; A capacitor characterized by:

3. 3. The capacitor according to claim 1, further comprising a case in which the capacitor element is housed; The coating resin is filled in the case. A capacitor characterized by:

4. 4. The capacitor according to claim 3, the heat transfer member is present between the capacitor element and the bottom surface of the case; A capacitor characterized by:

5. The capacitor according to any one of claims 1 to 4, The first bus bar and the second bus bar are an electrode terminal portion that covers the electrode and is connected to the electrode; a connection terminal portion exposed from the coating resin and to which an external terminal is connected; an intermediate portion extending from one end of the electrode terminal portion and connected to the connection terminal portion; the first bus bar is provided with an extension portion that extends from an end of the electrode terminal portion different from the one end or from one end of the intermediate portion and covers a peripheral surface of the capacitor element; The heat transfer member is connected to the extension portion along the circumferential surface. A capacitor characterized by:

6. The capacitor according to any one of claims 1 to 5, A plurality of the capacitor elements are arranged side by side, the heat transfer member is connected to the first bus bar and the second bus bar in a direction perpendicular to an arrangement direction of the capacitor elements, and has a width that faces all of the capacitor elements in the arrangement direction. A capacitor characterized by:

7. The capacitor according to any one of claims 1 to 6, the first bus bar includes a mounting surface exposed from the coating resin and on which a cooling member is mounted; A capacitor characterized by:

8. The capacitor according to any one of claims 1 to 7, the heat transfer member is connected to the first bus bar and the second bus bar without the coating resin therebetween; A capacitor characterized by:

9. A capacitor element; a first bus bar and a second bus bar connected to electrodes provided on both end surfaces of the capacitor element, respectively; a case in which the capacitor element is housed; a coating resin filled in the case and covering the entire capacitor element and parts of the first bus bar and the second bus bar; a sheet-like heat transfer member having insulating properties and a thermal conductivity higher than that of the coating resin, the sheet-like heat transfer member being connected to the first bus bar and the second bus bar within the coating resin; Equipped with the heat transfer member is disposed between the capacitor element and a bottom surface of the case. A capacitor characterized by:

10. A capacitor element; a first bus bar and a second bus bar connected to electrodes provided on both end surfaces of the capacitor element, respectively; a coating resin that covers the entire capacitor element and parts of the first bus bar and the second bus bar; a sheet-like heat transfer member having insulating properties and a thermal conductivity higher than that of the coating resin, the sheet-like heat transfer member being connected to the first bus bar and the second bus bar within the coating resin; Equipped with The first bus bar and the second bus bar are an electrode terminal portion that covers the electrode and is connected to the electrode; a connection terminal portion exposed from the coating resin and to which an external terminal is connected; an intermediate portion extending from one end of the electrode terminal portion and connected to the connection terminal portion; the first bus bar is provided with an extension portion that extends from an end of the electrode terminal portion different from the one end or from one end of the intermediate portion and covers a peripheral surface of the capacitor element; The heat transfer member is connected to the extension portion along the circumferential surface. A capacitor characterized by:

11. A plurality of capacitor elements arranged side by side; a first bus bar and a second bus bar connected to electrodes provided on both end surfaces of the capacitor element, respectively; a coating resin that covers the entire capacitor element and parts of the first bus bar and the second bus bar; a sheet-like heat transfer member having insulating properties and a thermal conductivity higher than that of the coating resin, the sheet-like heat transfer member being connected to the first bus bar and the second bus bar within the coating resin; Equipped with the heat transfer member is connected to the first bus bar and the second bus bar in a direction perpendicular to an arrangement direction of the capacitor elements, and has a width that faces all of the capacitor elements in the arrangement direction. A capacitor characterized by:

12. A capacitor element; a first bus bar and a second bus bar connected to electrodes provided on both end surfaces of the capacitor element, respectively; a coating resin that covers the entire capacitor element and parts of the first bus bar and the second bus bar; a sheet-like heat transfer member having insulating properties and a thermal conductivity higher than that of the coating resin, the sheet-like heat transfer member being connected to the first bus bar and the second bus bar within the coating resin; Equipped with the first bus bar includes a mounting surface exposed from the coating resin and on which a cooling member is mounted; A capacitor characterized by:

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