Film capacitors

Abstract

This film capacitor is fixed to a housing and comprises: a capacitor element having a stacked body of a dielectric film and an internal electrode, and end surface electrodes formed respectively on one end surface and the other end surface of the stacked body; a laminate film having a cover part that covers the capacitor element, and a flange part that extends from the outer edge of the cover part; terminal electrodes that are connected respectively to the end surface electrodes of the capacitor element inside of the laminate film and are exposed outside of the laminate film; and a fixing member for fixing to the housing and having a main part disposed along the capacitor element inside of the laminate film, and a fixing part that extends from the main part and is exposed outside of the laminate film.

Description

[Technical Field]

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

[0002] Capacitors that use a laminate film as an exterior material are known. For example, a surface-mounted capacitor described in Patent Document 1 has a capacitor element that is exteriorly covered with a laminate film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4354240 Summary of the Invention [Problem to be solved by the invention]

[0004] The surface mount capacitor of Patent Document 1 has a problem in that it is difficult to fix it to a housing.

[0005] The present invention provides a film capacitor that can be firmly fixed to a housing. [Means for solving the problem]

[0006] A film capacitor according to one aspect of the present invention comprises: A film capacitor fixed to a housing, a capacitor element having a wound or laminated body of a dielectric film and an internal electrode, and end electrodes formed on one end surface and the other end surface of the laminate; a laminate film having a covering portion that covers the capacitor element and a flange portion that extends from an outer edge of the covering portion; a terminal electrode connected to the end surface electrode of the capacitor element inside the laminate film and exposed to the outside of the laminate film; a fixing member for fixing the capacitor element to the housing, the fixing member having a main body portion disposed along the capacitor element inside the laminate film, and a fixing portion extending from the main body portion and exposed to the outside of the laminate film; Equipped with. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a film capacitor that can be firmly fixed to a housing. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a state in which the film capacitor according to the first embodiment is fixed to a housing; [Figure 2] FIG. 1 is a perspective view showing a film capacitor according to a first embodiment; [Figure 3] Exploded perspective view of the film capacitor in Figure 2 [Figure 4A] FIG. 3 is a perspective view showing a capacitor element of the film capacitor of FIG. 2. [Figure 4B] 4B is a perspective view of the capacitor element of FIG. 4B from a different angle. [Figure 5] A perspective view of the film capacitor in Figure 2, omitting the laminate film. [Figure 6] Plan view of the film capacitor in Figure 2 [Figure 7] Figure 1: AA cross section of the film capacitor [Figure 8] FIG. 1 is a cross-sectional view showing a film capacitor according to a first modification of the first embodiment; [Figure 9] FIG. 10 is a perspective view showing a fixing member of a film capacitor according to a second modification of the first embodiment; [Figure 10] FIG. 10 is a perspective view showing a power conversion device according to a second embodiment; [Figure 11] FIG. 11 is an exploded perspective view showing a film capacitor disposed in the power conversion device of FIG. 10. [Figure 12] BB cross section of the power converter shown in FIG. [Figure 13]Partial cross section of the film capacitor in Figure 11 [Figure 14] 10 is a perspective view of a film capacitor according to a third embodiment of the present invention; [Figure 15] Another view of the film capacitor in Figure 14 [Figure 16] An exploded perspective view of the film capacitor in Figure 15 [Figure 17] FIG. 10 is an exploded perspective view showing a film capacitor according to a first modification of the third embodiment; [Figure 18A] FIG. 18 is a perspective view showing a fixing member of the film capacitor of FIG. 17; [Figure 18B] 18B is a view of the fixing member of FIG. 18A from another angle. [Figure 19] FIG. 13 is a perspective view showing a film capacitor according to a second modification of the third embodiment; [Figure 20] Another view of the film capacitor in Figure 19 [Figure 21] An exploded perspective view of the film capacitor in Figure 20 [Figure 22] Diagram showing a capacitor bank containing six film capacitors [Figure 23] FIG. 10 is a perspective view showing a film capacitor according to a fourth embodiment. [Figure 24] A diagram of the film capacitor in Figure 23, omitting the laminate film [Figure 25] An exploded perspective view of the film capacitor in Figure 23 [Figure 26] FIG. 24 is a perspective view showing a power conversion device equipped with the film capacitor of FIG. 23. [Figure 27] FIG. 13 is a perspective view showing a power conversion device according to a first modification of the fourth embodiment; [Figure 28] FIG. 13 is a perspective view showing a power conversion device according to a second modification of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Background to the invention) In line with technological trends such as smaller, lighter, more heat-resistant, and higher power density of power conversion devices, capacitors used in power conversion devices are also required to be smaller, lighter, more heat-resistant, and have higher power density.

[0010] Mainly for the purpose of reducing size and weight, capacitors have been proposed in which a capacitor element made of a laminate of a dielectric and electrodes is covered with a laminate film. For example, Patent Document 1 discloses a surface-mounted capacitor that has lead-out leads and includes a capacitor element covered with a laminate film, and a fixing plate with external connection terminals.

[0011] In the case of capacitors with a laminate film exterior, such as the surface-mount capacitor described in Patent Document 1, the flexible laminate film makes it difficult to secure the capacitor to the housing of a power converter using the laminate film. Typical capacitors are housed in a plastic case filled with epoxy resin or the like. Unlike typical capacitors, capacitors with a laminate film exterior may experience mechanical or environmental loads, causing the laminate film to peel off and creating gaps between the capacitor element and the film. This can result in a decrease in the heat dissipation performance of capacitors with a laminate film exterior.

[0012] Therefore, the inventor(s) devised a film capacitor that can be firmly fixed to a housing by placing a member for fixing the capacitor to a housing, which is exteriorly covered with a laminate film, and arrived at the following invention.

[0013] A first embodiment of the present invention will be described below with reference to the accompanying drawings. In each drawing, each element is shown exaggerated for ease of explanation.

[0014] (Embodiment 1) [Overall configuration] Fig. 1 is a perspective view showing a state in which the film capacitor according to the first embodiment is fixed to a housing. Fig. 2 is a perspective view showing the film capacitor according to the first embodiment. Fig. 3 is an exploded perspective view of the film capacitor of Fig. 2. Note that the X, Y, and Z directions in the figure indicate the horizontal, vertical, and height directions of the film capacitor, respectively.

[0015] The film capacitor 100 is a capacitor fixed to a housing 10. As shown in FIGS. 1 to 3, the film capacitor 100 includes a capacitor element 20, a laminate film 30, terminal electrodes 40, and a fixing member 50. The housing 10 is, for example, the housing of a power conversion device such as an inverter that incorporates the film capacitor 100. The housing 10 may or may not have a cooling function.

[0016] <Capacitor element> FIG. 4A is a perspective view showing a capacitor element of the film capacitor of FIG. 2. FIG. 4B is a perspective view of the capacitor element of FIG. 4A viewed from a different angle. As shown in FIGS. 4A and 4B, capacitor element 20 is formed, for example, by a wound or laminated body of dielectric films and internal electrodes. Note that laminated bodies of dielectric films include those formed by winding dielectric films. As shown in FIG. 2, capacitor element 20 has a pair of end electrodes 21 formed on one end surface and the other end surface of the laminate. Terminal electrodes 40 are connected to one end electrode 21a and the other end electrode 21a, respectively.

[0017] In this embodiment, capacitor element 20 is a columnar capacitor element having an oval cross section. The dielectric film forming the capacitor element may be a plastic film such as polyethylene terephthalate, polypropylene, polyphenylene sulfide, or polyethylene naphthalate. The metal vapor deposition film formed on the surface of the plastic film as the internal electrode may be a metal such as aluminum or zinc.

[0018] In this embodiment, the semiconductor device has a side surface 22 that connects one end surface electrode 21a and the other end surface electrode 21b. The side surface 22 also has a pair of flat portions 22a facing each other and a pair of curved portions 22b connecting one of the flat portions 22a to the other of the flat portions 22a.

[0019] <Laminate film> Laminate film 30 is an exterior material that covers capacitor element 20 and improves the moisture resistance of capacitor element 20. As shown in FIGS. 1 to 3, laminate film 30 has a covering portion 31 that covers capacitor element 20 and a flange portion 32 that extends from the outer edge of covering portion 31.

[0020] The laminate films 30 are arranged to sandwich the capacitor element 20 from above and below. The flange portions 32 of the respective laminate films 30 are fused together to cover the capacitor element 20.

[0021] The laminate film 30 may be a film formed by laminating a resin film and aluminum foil. Specifically, an aluminum laminate film may be used in which aluminum foil is laminated between a heat-sealable resin film such as non-oriented polypropylene (CPP) and a strong resin film such as nylon or polyethylene terephthalate, with an adhesive or thermocompression bonding. The aluminum layer has excellent water vapor barrier properties, and covering the capacitor element 20 with an aluminum laminate film having an aluminum layer can improve the moisture resistance of the capacitor element 20. The laminate film 30 is not limited to an aluminum laminate film; any material with high adhesion between laminate films, water vapor barrier properties, strength, or durability can be used as the laminate film 30. Covering the capacitor element 20 with the laminate film 30 can improve the weather resistance of the capacitor element 20.

[0022] For example, capacitor element 20 can be covered with laminate film 30 by sandwiching capacitor element 20 between two films and bonding them by heat fusion. At this time, the film adheres closely to capacitor element 20 to form covering portion 31. In addition, a flange portion 32 is formed at the outer edge of covering portion 31, where two films are overlapped and bonded. Therefore, flange portion 32 is an adhesive portion or fused portion where films are overlapped and bonded or fused together.

[0023] In this embodiment, since capacitor element 20 is sandwiched between two films and heat-sealed, flange portions 32 are formed on all four sides of capacitor element 20. That is, flange portions 32 have four sides. In other words, when viewed from the height direction (Y direction), flange portions 32 are formed on all four sides of rectangular capacitor element 20, and are continuously connected to form a ring. Note that flange portions 32 do not necessarily have to be formed on all four sides of capacitor element 20.

[0024] Capacitor element 20 has a rectangular shape when viewed from the height direction (Y direction).

[0025] <Terminal electrode> The terminal electrode 40 is electrically connected to the end surface electrode 21 of the capacitor element 20 inside the laminate film 30. In this embodiment, the terminal electrode 40 is configured as a pair of terminal electrodes including one terminal electrode 40a connected to one end surface electrode 21a, and the other terminal electrode 40b connected to the other end surface electrode 21b. In addition, a portion of the terminal electrode 40 is exposed to the outside of the laminate film 30.

[0026] A sealant material 41 is preferably disposed on the terminal electrode 40 at the portion where it adheres to the laminate film 30 to improve adhesion, airtightness, and insulation. Even when a relatively thick terminal electrode 40 is used, no openings are formed between the laminate film 30 and the terminal electrode 40, improving moisture resistance. Furthermore, when the laminate film 30 includes a metal layer, the insulation between the terminal electrode 40 and the metal layer can be improved. For example, polypropylene containing an acid-modified resin can be used as the sealant material 41.

[0027] In this embodiment, the pair of terminal electrodes 40 are exposed from two opposing sides of the flange portion 32, respectively.

[0028] <Fixing material> The fixing member 50 is a member for fixing the film capacitor 100 to the housing 10. As shown in FIG. 3, the fixing member 50 has a main body portion 51 and a fixing portion 52. The main body portion 51 is a portion that is arranged along the capacitor element 20 inside the laminate film 30. The fixing portion 52 is a portion that extends from the main body portion 51 and is exposed to the outside of the laminate film 30, and is used for fixing to the housing 10. The fixing portion 52 can be fixed to the housing 10 with a fixing tool such as a screw using, for example, a hole 52a formed in the fixing portion 52 shown in FIG. 2.

[0029] In this embodiment, one fixing member 50 is disposed in the film capacitor 100. By configuring the fixing member 50 from a single member, the manufacturing cost of the film capacitor 100 can be reduced, and the manufacturing process of the film capacitor 100 can be simplified.

[0030] The fixing member 50 can be made of an organic material, for example, a composite material such as synthetic resin or FRP. Alternatively, the fixing member 50 may be made of an inorganic material such as metal. The fixing member 50 is made of a material and has a shape that has the mechanical strength required to fix the film capacitor 100 to the housing 10. The fixing member 50 may also be made of a material or have a shape that has desired thermal conductivity, electrical properties, etc.

[0031] The main body 51 of the fixing member 50 is brought into close contact with the side surface 22 of the capacitor element 20 by fusing the laminate films 30 together. The main body 51 may also be joined to the side surface 22 of the capacitor element 20 with an adhesive or the like.

[0032] Main body 51 is disposed along side surface 22 of capacitor element 20. Specifically, as shown in FIG. 3, main body 51 has a shape including flat portion 51a that is aligned with flat portion 22a and curved portion 51b that is aligned with curved portion 22b, and is disposed so as to be in contact with side surface 22 of capacitor element 20.

[0033] Fig. 5 is a perspective view, omitting the laminate film, of the film capacitor of Fig. 2. As shown in Fig. 5, flat portion 51a of main body 51 is arranged in contact with flat portion 22a of capacitor element 20, and curved portion 51b of main body 51 is arranged in contact with curved portion 22b of capacitor element 20.

[0034] Fig. 6 is a plan view of the film capacitor of Fig. 2. In this embodiment, the terminal electrodes 40 and the fixing portions 52 of the fixing member 50 are exposed from different sides of the flange portion 32. Specifically, as shown in Fig. 6, the two terminal electrodes 40 are exposed from opposing sides of the flange portion 32, and the two fixing portions 52 are exposed from opposing sides of the flange portion 32 different from the terminal electrodes 40.

[0035] Fig. 7 is a cross-sectional view taken along line AA of the film capacitor of Fig. 1. As shown in Fig. 7, the fixing portion 52 has an extension portion 54 extending from the main body portion 51 toward the housing 10, and a connection portion 55 extending from the extension portion 54 along the mounting surface 10a of the housing 10. The connection portion 55 extends outward from the extension portion 54.

[0036] The connection portion 55 can be fixed to the mounting surface 10a of the housing 10 using a fastener such as a screw, or can be fixed to the mounting surface 10a of the housing 10 with an adhesive or the like, or can be fixed to the mounting surface 10a of the housing 10 by a welding method.

[0037] In the present embodiment, the extension portion 54 includes a first extension portion 54a extending from the laminate film 30 and a second extension portion 54b bending from the first extension portion 54a and extending toward the housing 10. A connection portion 55 extends from the second extension portion 54b along the mounting surface 10a of the housing 10. By forming the fixing portion 52 in this shape, the film capacitor 100 can be placed on the mounting surface 10a of the housing 10, and the connection portion 55 can be brought into contact with the housing 10. This makes it easy to fix the film capacitor 100 to the housing 10.

[0038] 7, the height of the second extending portion 54b can be adjusted to fix the film capacitor 100 so that the flat portion 22a of the side surface 22 of the capacitor element 20 contacts the mounting surface 10a of the housing 10. For example, if the housing 10 has a cooling function, overheating of the film capacitor 100 can be prevented by bringing the side surface 22 of the capacitor element 20 into contact with the housing 10.

[0039] The film capacitor 100 can be manufactured, for example, by attaching a fixing member 50 to the capacitor element 20 shown in Figures 4A and 4B and covering it with a laminate film 30. The fixing member 50 can be attached to the capacitor element 20 by joining the main body 51 of the fixing member 50 to the side surface 22 of the capacitor element 20 with, for example, an adhesive or the like. The film capacitor 100 is completed by covering the capacitor element 20 with the fixing member 50 attached with the laminate film 30.

[0040] [effect] According to the above-described embodiment, the following effects can be achieved.

[0041] The film capacitor 100 is a film capacitor fixed to the housing 10 and includes a capacitor element 20, a laminate film 30, terminal electrodes 40, and a fixing member 50. The capacitor element 20 includes a laminate of a dielectric film and internal electrodes, and end electrodes 21 formed on one end surface and the other end surface of the laminate. The laminate film 30 includes a covering portion 31 that covers the capacitor element 20 and a flange portion 32 extending from the outer edge of the covering portion 31. The terminal electrodes 40 are connected to the end electrodes 21 of the capacitor element 20 inside the laminate film 30 and exposed outside the laminate film 30. The fixing member 50 is a member that fixes the film capacitor 100 to the housing 10. The fixing member 50 includes a main portion 51 that is arranged along the capacitor element 20 inside the laminate film 30, and a fixing portion 52 that extends from the main portion 51 and is exposed outside the laminate film 30.

[0042] With this configuration, the film capacitor 100 can be firmly fixed to the housing 10. Because the fixing portion of the fixing member 50 is disposed inside the laminate film 30, the fixing member 50 can be used to fix the film capacitor 100 to the housing 10. Therefore, the film capacitor 100 covered with the laminate film 30 can be firmly fixed to the housing 10 without using resin or the like. Furthermore, by exposing the fixing portion 52 of the fixing member 50 from the flange portion 32 of the laminate film 39, the film capacitor 100 can be easily fixed to the housing 10.

[0043] In the film capacitor 100, the main body 51 of the fixing member 50 is arranged along the side surface 22 of the capacitor element 20, and the capacitor element 20 can be fixed by pressing it against the housing 10. This allows the film capacitor 100 to be more firmly attached to the housing 10.

[0044] The flange portion 32 has a plurality of sides, and the terminal electrode 40 and the fixing portion 52 are exposed from different sides of the flange portion 32, respectively.

[0045] This configuration can suppress interference between the terminal electrodes 40 and the fixing member 50. It also makes effective use of the space in the housing 10. Furthermore, the film capacitor 100 can be mounted in a well-balanced manner on the housing 10 while suppressing interference with the terminal electrodes 40.

[0046] The fixing portions 52 of the fixing member 50 are exposed from two opposing sides of the flange portion 32, respectively.

[0047] With this configuration, the film capacitor 100 can be more firmly fixed to the housing 10. Furthermore, by placing the film capacitor 100 on the housing 10, the fixing portion 52 can be disposed on top of the housing 10. This improves the efficiency of the work involved in attaching the film capacitor 100 to the housing 10.

[0048] The capacitor element 20 has a side surface 22 to which the end surface electrodes 21 are connected, and the main body 51 of the fixing member 50 is disposed along the side surface 22 of the capacitor element 20 .

[0049] With this configuration, the film capacitor 100 can be more firmly fixed to the housing 10. Since the main body 51 does not straddle the end surface electrodes 21, the effect of the fixing member 50 on the electrical characteristics of the film capacitor 100 can be reduced.

[0050] The side surface 22 of the capacitor element 20 has a pair of flat portions 22a facing each other and a pair of curved portions 22b connecting one of the flat portions 22a to the other of the flat portions 22a. The fixing member 50 is disposed along both the flat portions 22a and the curved portions 22b.

[0051] With this configuration, the fixing member 50 can be tightly attached to the side surface 22 of the capacitor element 20. Therefore, the film capacitor 100 can be fixed to the housing 10 more firmly.

[0052] The fixing portion 52 of the fixing member 50 has an extension portion 54 extending from the main body portion 51 toward the housing 10, and a connection portion 55 extending from the extension portion 54 along the mounting surface 10a of the housing 10 and connected to the housing 10.

[0053] With this configuration, the distance between the film capacitor 100 and the housing 10 can be changed by changing the length of the extension portion 54, so that the film capacitor 100 can be positioned in a way that is suitable for the surrounding thermal environment.

[0054] The extension portion 54 includes a first extension portion 54a extending from the laminate film 30, and a second extension portion 54b bending from the first extension portion 54a and extending toward the housing 10.

[0055] With this configuration, by placing the film capacitor 100 in the housing 10, the connecting portion 55 can be brought into contact with the housing 10. Therefore, the film capacitor 100 can be easily fixed to the housing 10.

[0056] [Variations] In the above-described embodiment, an example has been described in which the connection portions 55 are formed to extend toward the outside of the film capacitor 100, but the present invention is not limited to this. The connection portions 55 may be formed to extend toward the inside of the film capacitor 100. By having the connection portions 55 extend toward the inside, the mounting area of the film capacitor 100 can be reduced.

[0057] In the above-described embodiment, the fixing portion 52 has the extending portion 54 and the connecting portion 55, but the present invention is not limited to this. The fixing portion 52 may have a shape that extends from the flange portion 32 without bending.

[0058] In the above-described embodiment, the film capacitor 100 includes one fixing member 50. However, the present invention is not limited to this. The fixing member 50 may be divided into two or more members.

[0059] FIG. 8 is a cross-sectional view showing a film capacitor according to Modification 1 of Embodiment 1. As shown in FIG. 8, one flat portion 22a of capacitor element 20 and mounting surface 10a of housing 10 do not need to be in contact with each other. By adjusting the height of second extension portion 64b of fixing portion 62 of fixing member 60, the distance between one flat portion 22a of capacitor element 20 and mounting surface 10a of housing 10 can be adjusted. In this case, a mounting state suited to the surrounding thermal environment can be achieved. Furthermore, the space between flat portion 22a of capacitor element 20 and housing 10 can be used effectively, for example, to place another component or other structure therein.

[0060] Fig. 9 is a perspective view showing a fixing member for a film capacitor according to Modification 2 of Embodiment 1. As shown in Fig. 9, a positioning protrusion 75a for positioning the film capacitor in the housing may be formed on a connection portion 75 of fixing member 70. Also, a hole 72a formed in fixing portion 72 may be used as a positioning hole.

[0061] Similar to the fixing member 50 of the first embodiment, the fixing member 70 has a main body portion 71 and a fixing portion 72. The fixing portion 72 has an extending portion 74 and a connecting portion 75.

[0062] For example, the film capacitor can be easily positioned in the housing by inserting the positioning protrusion 75a into a positioning hole (not shown) formed in the housing 10. Furthermore, the film capacitor can be easily positioned in the housing by inserting the positioning protrusion (not shown) formed in the housing 10 into the positioning hole 72a provided in the connection portion 75.

[0063] (Embodiment 2) A power conversion device 1 and a film capacitor 200 according to a second embodiment of the present invention will be described. In the second embodiment, differences from the first embodiment will be mainly described. In the second embodiment, the same or equivalent configurations as those in the first embodiment will be denoted by the same reference numerals. Furthermore, in the second embodiment, descriptions that overlap with those in the first embodiment will be omitted.

[0064] Fig. 10 is a perspective view showing a power converter according to a second embodiment. Fig. 11 is an exploded perspective view showing a film capacitor arranged in the power converter of Fig. 10. In the second embodiment, the shape and arrangement of terminal electrodes 240 differ from those in the first embodiment. In the second embodiment, a power converter 1 equipped with a film capacitor 200 will be described.

[0065] As shown in FIG. 10, the power conversion device 1 includes a power module 2, a film capacitor 200, and a housing 210.

[0066] The power module 2 is a module that converts DC current and AC current to control frequency and voltage. The power module 2 has a plurality of terminal electrodes 3, each of which is connected to a terminal electrode 240 of the capacitor element 220. By connecting the terminal electrode 240 of the capacitor element 220 to the terminal electrode 3 of the power module 2, the capacitor element 220 and the power module 2 are electrically connected.

[0067] As shown in FIG. 11 , in the capacitor element 220, the end surface electrode 221 includes a first end surface electrode 221a formed on one end surface and a second end surface electrode 221b formed on the other end surface. The terminal electrode 240 includes two first terminal electrodes 240a electrically connected to the first end surface electrode 221a and one second terminal electrode 240b electrically connected to the second end surface electrode 221b. One end of the second terminal electrode 240b is connected to the second end surface electrode 221b, penetrates the interior of the capacitor element 220, and is exposed from the first end surface electrode 221a. The portion of the second terminal electrode 240b that penetrates the interior of the capacitor element 220 is coated with an insulating coating. Configuring the capacitor element 220 in this manner contributes to a low ESL.

[0068] 10 includes two first terminal electrodes 3a connected to two first terminal electrodes 240a of the capacitor element 220, and one second terminal electrode 3b connected to one second terminal electrode 240b of the capacitor element 220. The power module 2 also has a third terminal electrode 4 connected to an external device.

[0069] 12 is a BB cross-sectional view of the power converter of FIG. 10. As shown in FIG. 12, the second terminal electrode 240b of the capacitor element 220 and the second terminal electrode 3b of the power module 2 are connected to each other while overlapping in the height direction (Z direction). In this embodiment, after the power module 2 is placed in the housing 210, the film capacitor 200 is placed on the housing 210 from above (Z direction), so that the second terminal electrode 240b of the capacitor element 220 can be overlapped with the second terminal electrode 3b of the power module 2. The first terminal electrode 3a of the power module 2 and the first terminal electrode 240a of the capacitor element 220 also overlap in the height direction. By placing the film capacitor 200 in the housing 210, the fixing member 50 is placed on the housing 210, and further, the terminal electrode 240 of the capacitor element 220 is placed on the terminal electrode 3 of the power module 6. In other words, by placing the film capacitor 200 in the housing 210, it is possible to place the film capacitor 200 in the housing 210 and connect it to the terminal electrode 3 of the power module 6.

[0070] Fig. 13 is a partial cross-sectional view of the film capacitor of Fig. 11. Fig. 13 shows the film capacitor 200 in a state before it is placed on the housing 210. For the sake of explanation, Fig. 13 also shows the housing 210. As shown in Fig. 13, the terminal electrode 240 of the capacitor element 220 has a base portion 242 extending from the end surface electrode 221 along the flange portion 32, and an offset portion 243 inclined from the base portion 242 toward the housing 210. The offset portion 243 is inclined toward the housing 210 from a direction along the mounting surface 210a of the housing 210. In other words, one end portion 243a and the other end portion 243b of the offset portion 243 are positioned at different heights (Z direction) from each other.

[0071] Because the terminal electrodes 240 have the offset portions 243, when the film capacitor 200 is placed in the housing 210, the terminal electrodes 240 of the film capacitor 200 can be brought into contact with the terminal electrodes 3 of the power module 2 without any gaps. This allows the terminal electrodes to be connected to each other using a connection method that requires high dimensional accuracy, such as laser welding. Furthermore, because the dimensional accuracy of the terminal electrodes 240 can be relaxed, it is possible to simplify the manufacturing process of the power conversion device and reduce manufacturing costs.

[0072] Both the first terminal electrode 240a and the second terminal electrode 240b of the film capacitor 200 may include the base portion 242 and the offset portion 243, or either one of them may include the base portion 242 and the offset portion 243.

[0073] [effect] According to the above-described embodiment, the following effects can be achieved.

[0074] The power conversion device 1 includes a power module 2, a film capacitor 200, and a housing 210. The film capacitor 200 is electrically connected to the power module 2. The housing 210 accommodates the power module 2 and the film capacitor 200.

[0075] With this configuration, the film capacitor 200 can be firmly fixed to the housing 210, which contributes to improving the heat resistance and reliability of the power conversion device 1.

[0076] In the film capacitor 200 , the terminal electrode 240 has a base portion 242 that extends from the end surface electrode 221 toward the flange portion 32 , and an offset portion 243 that is inclined from the base portion 242 toward the housing 210 .

[0077] With this configuration, when the film capacitor 200 is placed in the housing 210, the terminal electrodes 240 of the film capacitor 200 can be brought into contact with the terminal electrodes 3 of the power module 2 without any gaps. This allows the use of connection techniques that require high dimensional accuracy, such as laser welding. Furthermore, the requirement for dimensional accuracy of the terminal electrodes 240 of the film capacitor 200 can be relaxed, which simplifies the manufacturing process and reduces manufacturing costs.

[0078] In the above-described embodiment, an example in which the offset portion 243 is inclined toward the housing 210 has been described, but the present invention is not limited to this. For example, the offset portion 243 may be inclined in a direction away from the housing 210. In this case, by placing the film capacitor 200 in the housing 210 and then placing an external device such as the power module 2 from above, the terminal electrodes 240 of the film capacitor 200 and the terminal electrodes 3 of the power module 2 can be brought into contact with each other without any gaps.

[0079] (Embodiment 3) A film capacitor 300 according to a third embodiment of the present invention will be described. In the third embodiment, differences from the first embodiment will be mainly described. In the third embodiment, the same or equivalent configurations as those in the first embodiment will be denoted by the same reference numerals. Furthermore, in the third embodiment, descriptions that overlap with those in the first embodiment will be omitted.

[0080] Fig. 14 is a perspective view of a film capacitor according to embodiment 3. Fig. 15 is a view of the film capacitor of Fig. 14 seen from a different angle. Fig. 16 is an exploded perspective view of the film capacitor of Fig. 15. In embodiment 3, as shown in Figs. 14 to 16, the shape of fixing member 350 and the shape of terminal electrode 340 differ from those of embodiment 1.

[0081] 14 to 16, the film capacitor 300 has a fixing member 350 formed such that one end surface electrode 321 of the capacitor element 320 faces the mounting surface of the housing 310. In other words, a connecting portion 355 of a fixing portion 352 of the fixing member 350 is disposed so as to extend in a direction along one end surface electrode 321 (first end surface electrode 321a). An extending portion 354 of the fixing portion 352 extends in the height direction (Z direction) from the connecting portion 355 and is connected to the main body portion 351.

[0082] In the first and second embodiments, the capacitor element is placed horizontally relative to the housing, whereas in the third embodiment, capacitor element 320 is placed vertically relative to housing 310 as shown in FIG.

[0083] In this embodiment, fixing member 350 includes first fixing member 350a and second fixing member 350b. First fixing member 350a and second fixing member 350b can sandwich and support side surface 322 of capacitor element 320, so that film capacitor 300 can be stably fixed to the housing.

[0084] The terminal electrodes 340 include two first terminal electrodes 340a electrically connected to the first end surface electrode 321a of the capacitor element 320, and one second terminal electrode 340b electrically connected to the second end surface electrode 321b. One end of the second terminal electrode 340b is connected to the second end surface electrode 321b, penetrates the inside of the capacitor element 320, and is exposed from the first end surface electrode 321a. The portion of the second terminal electrode 340b that penetrates the inside of the capacitor element 320 is coated with an insulating coating.

[0085] The tip portion of terminal electrode 340 extends along the plane on which connecting portion 355 of fixing member 350 extends. Therefore, terminal electrode 340 and connecting portion 355 of fixing member 350 are arranged on the same plane.

[0086] [effect] According to the above-described embodiment, the following effects can be achieved.

[0087] Connection portion 355 of fixing member 350 is disposed so as to extend in a direction along one end surface electrode 321. With this configuration, film capacitor 300 can be disposed with end surface electrode 321 of capacitor element 320 facing the housing, thereby reducing the mounting area.

[0088] The fixing member 350 includes a first fixing member 350a and a second fixing member 350b. Each of the fixing members 350a and 350b includes a main body 351 and a fixing portion 352 including an extension portion 354 and a connection portion 355. The first fixing member 350a and the second fixing member 350b have the same shape. The first fixing member 350a and the second fixing member 350b can sandwich and support the side surface 322 of the capacitor element 320. This allows the film capacitor 300 to be stably fixed to the housing 310.

[0089] [Variations] Fig. 17 is an exploded perspective view showing a film capacitor according to Modification 1 of Embodiment 3. Fig. 18A is a perspective view showing a fixing member of the film capacitor of Fig. 17. Fig. 18B is a view of the fixing member of Fig. 18A viewed from a different angle. In film capacitor 300A of Modification 1, the shape of fixing member 356 differs from that of film capacitor 300 of Embodiment 3.

[0090] 17 to 18B, in film capacitor 300A of modification 1, fixing member 356 is configured as one fixing member including two extension portions 357 and two connection portions 358. Two extension portions 357 are connected by main body portion 359 to configure one fixing member 356.

[0091] With this configuration, the side surface 322 of the capacitor element 320 can be surrounded and held by one fixing member 356. This allows the film capacitor 300A to be stably fixed to the housing.

[0092] Fig. 19 is a perspective view showing a film capacitor according to Modification 2 of Embodiment 3. Fig. 20 is a view of the film capacitor of Fig. 19 viewed from a different angle. Fig. 21 is an exploded perspective view of the film capacitor of Fig. 20. In film capacitor 400 of Modification 2, the shape of terminal electrode 440 of capacitor element 420 and the shape of fixing member 450 differ from those of film capacitor 300 of Embodiment 3.

[0093] 19 to 21, in the film capacitor 400, the two fixing portions 452 of the fixing member 450 are exposed from the same side of the flange portion 32 of the laminate film 30. On the other hand, the two terminal electrodes 440 of the capacitor element 420 are exposed from opposing sides of the flange portion 32 of the laminate film 30.

[0094] The fixing member 450 has a main body portion 451 arranged along the side surface 422 of the capacitor element 420 and a fixing portion 452 extending from the main body portion 451. The main body portion 451 has a first portion 451a that contacts one curved portion 422b of the capacitor element 420, a second portion 451b that contacts the flat portion 422a, and a third portion 451c that contacts the other curved portion 422b. The fixing portion 452 extends from the third portion 451c of the main body portion 451. Two fixing members 450 having the same shape are arranged in the film capacitor 400 of the second modification. As shown in FIG. 18 , the connecting portions 455 of the respective fixing members 450 are arranged to extend in opposite directions. By extending the connecting portions 455 in opposite directions, stability can be improved when the film capacitor 400 is placed in the housing 410.

[0095] Capacitor element 420 has two terminal electrodes 440 respectively connected to two end surface electrodes 421. Each terminal electrode 440 includes a first portion 440a exposed from end surface electrode 421 to the outside of flange portion 32 and extending toward the housing, and a second portion 440b extending along the surface on which connection portion 455 of fixing member 450 extends.

[0096] With this configuration, film capacitor 400 can be placed in housing 410 so that curved portion 422b of capacitor element 420 faces housing 410. This makes it possible to reduce the mounting area.

[0097] 22 is a diagram showing a capacitor bank including six film capacitors. In capacitor bank 400A, the six film capacitors 400 are connected in parallel and arranged in a housing 410. By connecting multiple film capacitors 400 in parallel and arranging them in one housing 410, it is possible to provide a capacitor bank 400A with a desired capacitance.

[0098] (Fourth embodiment) A power conversion device 5 and a film capacitor 500 according to a fourth embodiment of the present invention will be described. In the fourth embodiment, differences from the second embodiment will be mainly described. In the fourth embodiment, the same or equivalent configurations as those in the second embodiment will be denoted by the same reference numerals. Furthermore, in the fourth embodiment, descriptions that overlap with those in the second embodiment will be omitted.

[0099] FIG. 23 is a perspective view showing a film capacitor according to a fourth embodiment. FIG. 24 is a view of the film capacitor of FIG. 23 with the laminate film omitted. FIG. 25 is an exploded perspective view of the film capacitor of FIG. 23. FIG. 26 is a perspective view showing a power converter equipped with the film capacitor of FIG. 23. As shown in FIGS. 23 to 25, the fourth embodiment differs from the second embodiment in that a film capacitor 500 includes a Y capacitor 560. Furthermore, the fourth embodiment differs from the second embodiment in that a power module 6 is arranged between a housing 510 and the film capacitor 500 in the power converter 5, as shown in FIG. 26.

[0100] 23 to 25, film capacitor 500 includes Y capacitor 560 that connects end surface electrode 521 of capacitor element 520 and fixing member 550. In this embodiment, fixing member 550 is made of a conductive material. Therefore, fixing member 550 functions as a ground terminal. By providing the Y capacitor, common mode noise can be removed.

[0101] In the present embodiment, Y capacitor 560 includes a first Y capacitor 560a connected to first end surface electrode 521a of capacitor element 520, and a second Y capacitor 560b connected to second end surface electrode 521b of capacitor element 520. Y capacitor 560 is arranged in main body portion 551 of fixing member 550, but Y capacitor 560 does not necessarily have to be arranged in main body portion 551, and may be arranged in fixing portion 552.

[0102] Alternatively, instead of the Y capacitor, a sheet-like dielectric may be placed between capacitor element 520 and fixing member 550 , and a Y capacitor capacitance may be formed between fixing member 550 and end surface electrode 521 .

[0103] 26, the power converter 5 of the fourth embodiment includes a power module 6, a film capacitor 500, and a housing 510. The power module 6 is disposed between the film capacitor 500 and the housing 510.

[0104] The power module 6 has a terminal electrode 7 connected to the terminal electrode 540 of the capacitor element 520. More specifically, the power module 6 has two first terminal electrodes 7a connected to the two first terminal electrodes 540a of the capacitor element 520 and one second terminal electrode 7b connected to one second terminal electrode 540b. The power module 6 also has a third terminal electrode 8 connected to an external device.

[0105] In this embodiment, a film capacitor 500 is arranged on top of a power module 6 so as to cover the power module 6 arranged in a housing 510. When the film capacitor 500 is arranged on the power module 6, the terminal electrodes 7 of the power module 6 and the terminal electrodes 540 of the film capacitor 500 are formed so that they come into contact with each other.

[0106] By adjusting the Z-direction length of the extension portion 554 of the fixing member 550 of the film capacitor 500 according to the size or height of the power module 6, the terminal electrode 540 of the film capacitor 500 can be easily brought into contact with the terminal electrode 7 of the power module 6.

[0107] [effect] According to the above-described embodiment, the following effects can be achieved.

[0108] In the film capacitor 500, the fixing member 550 is made of a conductive material. With this configuration, the fixing member 550 can be used as a connection terminal.

[0109] The film capacitor 500 further includes a Y capacitor 560 that connects the end surface electrode 521 and the fixing member 550, and the fixing member 550 functions as a ground terminal. With this configuration, the Y capacitor can be integrated into the film capacitor 500, thereby achieving a miniaturized device. Furthermore, the mounting cost can be reduced. In addition, the fixing member 550 can be used as a ground terminal.

[0110] In the power conversion device 5, the power module 6 is disposed between the film capacitor 500 and the housing 510. With such a configuration, the mounting area can be reduced, which contributes to making the power conversion device 5 smaller and lighter.

[0111] [Variations] Fig. 27 is a perspective view showing a power converter according to a first modification of the fourth embodiment. As shown in Fig. 27, in a power converter 5A, a power module 6 is arranged on each of an upper surface 510a and a lower surface 510b of a housing 510. A film capacitor 500 is connected to each power module 6. In this manner, the power modules 6 and the film capacitors 500 may be arranged on both sides of the housing 510 so as to sandwich the housing 510 therebetween.

[0112] Such a configuration contributes to increasing the power density and reducing the size of the power conversion device.

[0113] Fig. 28 is a perspective view showing a power converter according to Modification 2 of Embodiment 4. As shown in Fig. 28, three power modules 6 may be arranged in a row on an upper surface 510a of a housing 510, and three film capacitors 500 may be connected to each power module 6.

[0114] (Outline of the embodiment) (1) A film capacitor fixed to a housing, comprising: a capacitor element having a laminate of a dielectric film and an internal electrode and end electrodes formed on one end surface and the other end surface of the laminate; a laminate film having a covering portion that covers the capacitor element and a flange portion extending from the outer edge of the covering portion; terminal electrodes connected to the end electrodes of the capacitor element inside the laminate film and exposed to the outside of the laminate film; and a fixing member that is a member for fixing to the housing, having a main body portion that is arranged along the capacitor element inside the laminate film and a fixing portion that extends from the main body portion and is exposed to the outside of the laminate film.

[0115] With this configuration, the film capacitor can be firmly fixed to the housing.

[0116] (2) In the film capacitor described in (1), the terminal electrodes and the fixing portion may be exposed from the flange portion.

[0117] With this configuration, the capacitor element can be easily covered with the laminate film.

[0118] (3) In the film capacitor described in (2), the flange portion may have a plurality of sides, and the terminal electrode and the fixing portion may be exposed from different sides of the flange portion.

[0119] This configuration can suppress interference between the terminal electrodes and the fixing member, and also makes effective use of the space in the housing.

[0120] (4) In the film capacitor described in (3), the fixing portion of the fixing member may be exposed from two opposing sides of the flange portion.

[0121] With this configuration, the film capacitor can be more firmly fixed to the housing.

[0122] (5) In the film capacitor described in any one of (1) to (4), the capacitor element may have a side surface to which the end surface electrodes are connected, and the main body portion of the fixing member may be arranged along the side surface of the capacitor element.

[0123] This configuration allows the film capacitor to be more firmly fixed to the housing. In addition, because the main body of the fixing member does not straddle the end electrodes, the impact of the fixing member on the electrical characteristics of the film capacitor can be reduced.

[0124] (6) In the film capacitor described in (5), the side surface of the capacitor element has a pair of flat portions facing each other and a pair of curved portions connecting one of the flat portions to the other of the flat portions, and the fixing member may be arranged along both the flat portions and the curved portions.

[0125] With this configuration, the fixing member can be brought into close contact with the side surface of the capacitor element, so that the film capacitor can be more firmly fixed to the housing.

[0126] (7) In the film capacitor described in any one of (1) to (6), the fixing portion of the fixing member may have an extension portion extending from the main body portion toward the housing, and a connection portion extending from the extension portion along the mounting surface of the housing and connected to the housing.

[0127] With this configuration, the distance between the film capacitor and the housing can be changed by changing the length of the extension portion, thereby realizing a mounting state suited to the surrounding thermal environment.

[0128] (8) In the film capacitor described in (7), the extension portion may include a first extension portion extending from the laminate film and a second extension portion bending from the first extension portion and extending toward the housing.

[0129] With this configuration, the connecting portion can be brought into contact with the housing simply by placing the film capacitor in the housing, so the film capacitor can be fixed to the housing in a simpler process.

[0130] (9) In the film capacitor according to (7) or (8), the connecting portion may be formed with a positioning protrusion or a positioning hole for positioning the film capacitor in the housing.

[0131] This configuration makes it easy to position the film capacitor in the housing, and allows the film capacitor to be fixed to the housing through a simple process.

[0132] (10) In the film capacitor described in any one of (1) to (9), the terminal electrode may have a base portion extending from the end surface electrode along the flange portion, and an offset portion inclined from the base portion toward the housing or away from the housing.

[0133] This configuration allows the terminal electrodes of the capacitor to be in contact with the terminal electrodes of the external device without any gaps when the film capacitor is fixed to the housing. This makes it possible to use joining methods that require high dimensional accuracy, such as laser welding. Since the dimensional accuracy requirements for the terminal electrodes can be relaxed, it is possible to simplify the manufacturing process and reduce manufacturing costs.

[0134] (11) In the film capacitor according to any one of (1) to (10), the fixing member may be made of a conductive material.

[0135] With this configuration, the fixing member can also be used as a connection terminal.

[0136] (12) The film capacitor according to (11) may further include a Y capacitor connecting the end surface electrode and the fixing member, and the fixing member may function as a ground terminal.

[0137] This configuration allows the Y capacitor to be integrated into the film capacitor, resulting in a smaller size, reduced manufacturing costs for mounting the Y capacitor, and the fixing member can function as a ground terminal.

[0138] (13) A power module, a film capacitor according to any one of (1) to (11) electrically connected to the power module, and a housing in which the power module and the film capacitor are disposed.

[0139] With this configuration, the film capacitor can be firmly fixed to the housing, which contributes to improving the heat resistance and reliability of the power conversion device.

[0140] (14) In the power converter according to (13), the power module may be disposed between the film capacitor and the housing.

[0141] Such a configuration allows the mounting area to be reduced, which contributes to making the power conversion device smaller and lighter. [Industrial Applicability]

[0142] The present invention is useful for film capacitors used in various electronic devices, electrical devices, industrial devices, vehicle devices, etc. [Explanation of symbols]

[0143] 1, 5, 5A, 5B Power Converter 2, 6 Power Module 10, 210, 410, 510 enclosure 10a, 210a mounting surface 20, 220, 320, 420, 520 capacitor elements 21, 221, 321, 421, 521 end electrode 22, 322, 422 sides 22a, 422a flat part 22b, 422b curved section 30 Laminating Film 31 Covering part 32 Flange 40, 240, 340, 440, 540 terminal electrode 242 Base 243 Offset section 50, 60, 70, 350, 450, 550 Fixing member 51, 71, 351, 359, 451, 551 Main body 52, 62, 72, 352, 452, 552 Fixed part 54, 74, 354, 357, 554 extension part 54a 1st extension section 54b, 64b 2nd extension section 55, 75, 355, 358, 455 Connections 100, 200, 300, 300A, 400, 500 Film Capacitors 560 Y capacitor 560a First Y Capacitor 560b Second Y Capacitor

Claims

1. A film capacitor fixed to a housing, a capacitor element having a laminate of a dielectric film and an internal electrode, and end electrodes formed on one end surface and the other end surface of the laminate; a laminate film having a covering portion that covers the capacitor element and a flange portion that extends from an outer edge of the covering portion; a terminal electrode connected to the end surface electrode of the capacitor element inside the laminate film and exposed to the outside of the laminate film; a fixing member for fixing the capacitor element to the housing, the fixing member having a main body portion disposed along the capacitor element inside the laminate film, and a fixing portion extending from the main body portion and exposed to the outside of the laminate film; Equipped with Film capacitor.

2. the terminal electrode and the fixing portion are exposed from the flange portion; The film capacitor according to claim 1 .

3. the flange portion has a plurality of sides, and the terminal electrode and the fixing portion are exposed from different sides of the flange portion, respectively. The film capacitor according to claim 2 .

4. The fixing portion of the fixing member is exposed from two opposing sides of the flange portion, The film capacitor according to claim 3 .

5. the capacitor element has a side surface to which the end surface electrodes are connected, and the main body of the fixing member is disposed along the side surface of the capacitor element. The film capacitor according to claim 1 .

6. the side surfaces of the capacitor element have a pair of flat portions facing each other and a pair of curved portions connecting one of the flat portions to the other of the flat portions, The fixing member is disposed along both the flat portion and the curved portion. The film capacitor according to claim 5 .

7. The fixing portion of the fixing member has an extension portion that extends from the main body portion toward the housing, and a connection portion that extends from the extension portion along a mounting surface of the housing and is connected to the housing. The film capacitor according to claim 1 .

8. The extension portion includes a first extension portion extending from the laminate film and a second extension portion bending from the first extension portion and extending toward the housing. The film capacitor according to claim 7.

9. The connection portion has a positioning protrusion or a positioning hole formed therein for positioning the film capacitor in the housing. The film capacitor according to claim 7.

10. The terminal electrode has a base portion extending from the end surface electrode along the flange portion, and an offset portion inclined from the base portion toward the housing or in a direction away from the housing. The film capacitor according to claim 1 .

11. the fixing member is formed of a conductive material; The film capacitor according to claim 1 .

12. a Y capacitor connecting the end surface electrode and the fixing member, The fixing member functions as a ground terminal. The film capacitor according to claim 11.

13. A power module; The film capacitor according to claim 1 , which is electrically connected to the power module; a housing in which the power module and the film capacitor are disposed; Equipped with Power conversion device.

14. the power module is disposed between the film capacitor and the housing. The power converter according to claim 13.

Images