Film capacitor, inverter and electric vehicle

Abstract

To provide a film capacitor excellent in reliability.SOLUTION: A film capacitor includes: a film capacitor element that has a first electrode and a second electrode; a first bus bar that has a first connection part and a first terminal part; a second bus bar that has a second connection part and a second terminal part; a box body that opens in one surface; a lid body; and a sealing member. The box body has a groove part in an opening end face, and the lid body has a first surface facing the box body and a second surface on the opposite side of the first surface, has a first through hole and a second through hole, and has a projection on the first surface. The first connection part is inserted into the first through hole to connect the first electrode and the first terminal part on the second surface to each other, and the second connection part is inserted into the second through hole to connect the second electrode and the second terminal part on the second surface to each other. The film capacitor element is suspended inside the box body, and the lid body is fitted to the groove part at the projection and fixed to the box body. The sealing member is located inside the groove part and on the second surface to seal the space between the box body and the lid body, first through hole, and second through hole.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a film capacitor, an inverter, and an electric vehicle. [Background technology]

[0002] There is known a film capacitor having a film capacitor element that uses a resin film as a dielectric. The film capacitor element includes a body portion made of a metallized film obtained by depositing a metal film made of aluminum, zinc or the like on one side of a resin film, and a pair of metal electrodes disposed on both end faces of the body portion.

[0003] In recent years, there has been a demand for improving the reliability of film capacitors. For example, Patent Document 1 discloses a film capacitor in which a film capacitor element is covered with an exterior member made of resin in order to improve the moisture resistance of the film capacitor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-22608 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional film capacitors, when moisture is generated from the resin that constitutes the exterior component, the metal film vapor-deposited on the dielectric film can be anodized, reducing the capacitance of the film capacitor, leaving room for improvement in terms of reliability, such as moisture resistance and durability. [Means for solving the problem]

[0006] The film capacitor of the present disclosure includes a film capacitor element having a first electrode and a second electrode; a first bus bar having a first connection portion connected to the first electrode and a first terminal portion for external connection; a second bus bar having a second connection portion connected to the second electrode and a second terminal portion for external connection; a box body having an opening on one side and housing the film capacitor element, the box body having a groove portion surrounding the opening on an end surface surrounding the opening; a lid for closing an opening of the box, the lid having a first surface facing the box and a second surface opposite to the first surface, a first through hole and a second through hole penetrating from the first surface to the second surface, and a protrusion portion on the first surface; A sealing member that seals the inside of the box, the first terminal portion and the second terminal portion are located on the second surface of the lid body, the first connection portion is inserted into the first through hole and connects the first electrode and the first terminal portion; the second connection portion is inserted into the second through hole and connects the second electrode and the second terminal portion; the film capacitor element is suspended within the box in a state in which the film capacitor element is connected to the first bus bar and the second bus bar; the lid body is fixed to the box body in a state in which the first connection portion and the second connection portion are inserted into the first through hole and the second through hole, respectively, and the protrusion portion is fitted into the groove portion; The sealing member is located inside the groove to seal between the box body and the lid body, and is also located on the second surface to seal the first through hole and the second through hole.

[0007] The inverter of the present disclosure includes a bridge circuit including a switching element and a capacitance section connected to the bridge circuit, the capacitance section including the above-mentioned film capacitor.

[0008] The electric vehicle of the present disclosure includes a power source, an inverter connected to the power source, a motor connected to the inverter, and wheels driven by the motor, the inverter being the inverter described above. Effect of the Invention

[0009] According to the film capacitor of the present disclosure, a film capacitor with excellent reliability can be provided. Furthermore, by including the above-mentioned film capacitor, the inverter and the electric vehicle of the present disclosure are also highly reliable. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an exploded perspective view showing a film capacitor according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a perspective view showing a film capacitor according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a diagram showing an example of a film capacitor element of a film capacitor according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2. [Diagram 5] 5 is an enlarged cross-sectional view showing a portion A in FIG. 4. [Figure 6] FIG. 11 is an enlarged cross-sectional view of a modified example of the film capacitor according to the embodiment of the present disclosure. [Figure 7] FIG. 2 is a diagram illustrating a configuration of an inverter according to an embodiment of the present disclosure. [Figure 8] 1 is a diagram illustrating a configuration of an electric vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of a film capacitor, an inverter, and an electric vehicle according to the present disclosure will be described with reference to the drawings. The drawings referred to below are schematic, and the dimensional ratios and the like shown in the drawings are not necessarily accurately depicted.

[0012] Fig. 1 is an exploded perspective view showing a film capacitor according to an embodiment of the present disclosure, Fig. 2 is a perspective view showing a film capacitor according to an embodiment of the present disclosure, Fig. 3 is a view showing an example of a film capacitor element of the film capacitor according to an embodiment of the present disclosure, Fig. 4 is a cross-sectional view taken along the line IV-IV in Fig. 2, Fig. 5 is an enlarged cross-sectional view showing an enlarged A portion in Fig. 4, and Fig. 6 is an enlarged cross-sectional view of a modified example of the film capacitor according to an embodiment of the present disclosure. In Figs. 1 and 2, the sealing member is omitted. The enlarged cross-sectional view shown in Fig. 6 corresponds to the enlarged cross-sectional view shown in Fig. 5.

[0013] The film capacitor 1 of this embodiment includes a film capacitor element 2, a first bus bar 3, a second bus bar 4, a box body 5, a cover body 6, and a sealing member .

[0014] The film capacitor element 2 includes a body 20, a first electrode 21a, and a second electrode 21b. The body 20 has a first end surface 20a and a second end surface 20b. The first electrode 21a is located on the first end surface 20a, and the second electrode 21b is located on the second end surface 20b. In the following description, the first electrode 21a and the second electrode 21b may be collectively referred to as metallikon electrodes 21.

[0015] As shown in FIG. 3, the main body 20 may be a wound body formed by overlapping and winding a metallized film (also referred to as a first metallized film) 22a and a metallized film (also referred to as a second metallized film) 22b. The first metallized film 22a has a dielectric film (also referred to as a first dielectric film) 23a and a metal film (also referred to as a first metal film) 24a arranged on a first surface 23aa of the first dielectric film 23a. The first metal film 24a is connected to a first electrode 21a located on a first end surface 20a of the main body 20. The second metallized film 22b has a dielectric film (also referred to as a second dielectric film) 23b and a metal film (also referred to as a second metal film) 24b arranged on a first surface 23ba of the second dielectric film 23b. The second metal film 24b is connected to a second electrode 21b located on a second end surface 20b of the main body 20.

[0016] For ease of understanding, in Fig. 3, metallized films 22a, 22b are drawn out and the thickness of the drawn out metallized films 22a, 22b is drawn to increase toward the front. In Fig. 3, the width direction of metallized films 22a, 22b is shown as the first direction (X direction), the length direction is shown as the second direction (Y direction), and the thickness direction is shown as the third direction (Z direction). Metallized films 22a, 22b are overlapped in the Z direction. First end surface 20a and second end surface 20b are located at both ends of main body 20 in the X direction. In film capacitor element 2 shown in Fig. 3, the X direction coincides with the axial direction of winding.

[0017] First metallized film 22a and second metallized film 22b are wound with a slight misalignment in the X direction, as shown in Fig. 3. When a potential difference exists between first metal film 24a and second metal film 24b, a capacitance is generated in an effective area where first metal film 24a and second metal film 24b overlap with first dielectric film 23a or second dielectric film 23b sandwiched therebetween.

[0018] Main body 20 is not limited to the roll shown in FIG. 3, but may be a laminate formed by alternately stacking first metallized films 22a and second metallized films 22b.

[0019] The dielectric films 23a and 23b are made of an insulating resin material, and may be, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyarylate (PAR), polyphenylene ether (PPE), polyetherimide (PEI), cycloolefin polymer, or the like.

[0020] The metal films 24a and 24b are made of a metal material, which may be, for example, aluminum, zinc, or an alloy containing aluminum, zinc, or the like as a main component.

[0021] Metallikon electrode 21 is made of a metal material. The metal material used for metallikon electrode 21 may be, for example, zinc (Zn), aluminum (Al), tin (Sn), a tin-zinc (Sn-Zn) alloy, copper (Cu), brass (Cu-Zn alloy), nickel (Ni), or the like.

[0022] The first bus bar 3 includes a first connection portion 31 and a first terminal portion 32. The first connection portion 31 is connected to the first electrode 21a of the film capacitor element 2. The first terminal portion 32 is a terminal portion for external connection. As shown in FIGS. 1 and 2, the first terminal portion 32 may have a plurality of terminals 32a, 32b. The plurality of terminals 32a, 32b may be used for connection to different external devices.

[0023] The second bus bar 4 includes a second connection portion 41 and a second terminal portion 42. The second connection portion 41 is connected to the second electrode 21b of the film capacitor element 2. The second terminal portion 42 is a terminal portion for external connection. As shown in FIGS. 1 and 2, the second terminal portion 42 may have a plurality of terminals 42a, 42b. The plurality of terminals 42a, 42b may be used for connection to different external devices.

[0024] The first busbar 3 and the second busbar 4 are made of a metal material. The metal material used for the first busbar 3 and the second busbar 4 may be, for example, copper, aluminum, or an alloy mainly composed of copper, aluminum, or the like. The first connection portion 31, the first terminal portion 32, the second connection portion 41, and the second terminal portion 42 may be produced, for example, by bending or folding a single metal plate punched into a predetermined shape at predetermined positions.

[0025] The box 5 accommodates the film capacitor element 2. As shown in FIG. 1, the box 5 has one open side. A groove 52 is formed in an end face 5a surrounding the opening 51. When viewed from a direction perpendicular to the bottom face 5b of the box 5, the groove 52 surrounds the entire periphery of the opening 51. The groove 52 surrounds the entire periphery of the opening 51. The depth d (see FIG. 5) of the groove 52 from the end face 5a may be, for example, about 1 mm to 5 mm, about 2 mm to 4 mm, or about 3 mm.

[0026] The box 5 is made of, for example, a resin material, a metal material, etc. The resin material used for the box 5 may be, for example, a thermoplastic resin such as polyphenylene sulfide (PPS), polyamide-imide (PAI), polyether ether ketone (PEEK), etc., or a thermosetting resin such as a phenol resin, an epoxy resin, etc. The metal material used for the box 5 may be, for example, iron including stainless steel, aluminum, magnesium, copper, titanium, an aluminum alloy, a magnesium alloy, a copper alloy, a titanium alloy, etc.

[0027] FIG. 1 shows box 5 in the shape of a rectangular parallelepiped with one open side, but box 5 may also be in the shape of, for example, a square prism, a cylinder, an elliptical cylinder, or the like with one open side (top surface).

[0028] As shown in FIG. 6, the groove 52 may include a groove 52a surrounding the opening 51 and a groove 52b located outside the groove 52a and surrounding the groove 52a.

[0029] The lid 6 is a substantially plate-like member that closes the opening of the box 5. The lid 6 has a first surface 6a facing the box 5 and a second surface 6b opposite to the first surface 6a. The lid 6 has a first through hole 61 and a second through hole 62 that penetrate in the thickness direction from the first surface 6a to the second surface 6b. As shown in FIGS. 1, 4, and 5, the lid 6 has a protrusion 63 formed on the first surface 6a. The protrusion 63 fits into the groove 52 of the box 5. The protrusion 63 may surround the entire periphery of the opening 51 when viewed from a direction perpendicular to the bottom surface 5b of the box 5. The protrusion 63 may have a height h (see FIG. 5) from the base end 63a of the protrusion 63, for example, of about 1 mm to 5 mm, about 2 mm to 4 mm, or about 3 mm.

[0030] The lid 6 may be made of, for example, a resin material, a metal material, etc. The resin material used for the lid 6 may be, for example, a thermoplastic resin such as polyphenylene sulfide (PPS), polyamide-imide (PAI), polyether ether ketone (PEEK), etc., or a thermosetting resin such as a phenol resin, an epoxy resin, etc. The metal material used for the lid 6 may be, for example, iron including stainless steel, aluminum, magnesium, copper, titanium, an aluminum alloy, a magnesium alloy, a copper alloy, a titanium alloy, etc.

[0031] The first terminal portion 32 of the first bus bar 3 is located on the second surface 6b. The first connection portion 31 of the first bus bar 3 is inserted into the first through hole 61 and connects the first electrode 21a and the first terminal portion 32.

[0032] The second terminal portion 42 of the second bus bar 4 is located on the second surface 6b. The second connection portion 41 of the second bus bar 4 is inserted into the second through hole 62 and connects the second electrode 21b and the second terminal portion 42.

[0033] The film capacitor element 2 is suspended within the box body 5 in a state where it is connected to the first bus bar 3 and the second bus bar 4. The film capacitor element 2 is fixed within the box body 5 in a state where it is not in contact with the box body 5 and the lid body 6.

[0034] The sealing member 7 is located inside the groove 52 and seals the gap between the box 5 and the lid 6. The sealing member 7 is also located on the second surface 6b of the lid 6 and seals the first through hole 61 and the second through hole 62. The sealing member 7 may be located only in an area covering the opening of the first through hole 61 and an area covering the opening of the second through hole 62 on the second surface 6b, or may be located over substantially the entire area of ​​the second surface 6b. The sealing member 7 may be filled in a recess formed on the second surface 6b of the lid 6, as shown in FIG. 4.

[0035] The sealing member 7 is made of, for example, a resin material, etc. The resin material used for the sealing member 7 may be, for example, an epoxy resin, an acrylic resin, etc.

[0036] In the film capacitor 1, the film capacitor element 2 is not sealed with resin, and the sealing member 7 seals between the box body 5 and the lid body 6, as well as the first through hole 61 and the second through hole 62. This reduces the possibility that the metal films 24a and 24b are anodized by moisture generated from the resin or moisture entering from the outside, reducing the capacitance of the film capacitor element 2. As a result, the capacitance of the film capacitor 1 can be maintained for a long period of time. In addition, in the film capacitor 1, the lid body 6 is fixed to the box body 5 in a state in which the protruding portion 63 is fitted into the groove portion 52 and the sealing member 7 is positioned in the groove portion 52. This makes it possible to lengthen the path length of the intrusion path (path via the sealing member 7) of moisture from the outside. As a result, the capacitance of the film capacitor 1 can be effectively maintained for a long period of time. In this way, according to the film capacitor 1 of this embodiment, it is possible to provide a film capacitor with excellent reliability.

[0037] In the film capacitor 1, the film capacitor element 2 is not sealed with resin. Therefore, even if a short circuit occurs at an insulation defect portion of the dielectric films 23a, 23b and the self-healing function of the film capacitor 1 is exerted, the gas generated from the dielectric films 23a, 23b and the metal films 24a, 24b by the short circuit energy can be released to the outside of the film capacitor element 2. As a result, the risk of the film capacitor element 2 being damaged by the gas pressure at the time of the short circuit can be reduced. In turn, it is possible to provide a film capacitor with excellent reliability.

[0038] As shown in Fig. 1, the film capacitor 1 may include a plurality of film capacitor elements 2. The first bus bar 3 may have a plurality of first connection portions 31 and one first terminal portion 32. The second bus bar 4 may have a plurality of second connection portions 41 and one second terminal portion 42. The plurality of first connection portions 31 may connect the plurality of first electrodes 21a of the plurality of film capacitor elements 2 to the first terminal portion 32, respectively. The plurality of second connection portions 41 may connect the plurality of second electrodes 21b of the plurality of film capacitor elements 2 to the second terminal portion 42, respectively.

[0039] The box 5 (i.e., the space defined by the box 5 and the lid 6) may be filled with dry air or an inert gas. This effectively suppresses the anodization of the metal films 24a and 24b, and effectively reduces the risk of a decrease in the capacitance of the film capacitor element 2. As a result, a film capacitor with higher reliability can be obtained. The dry air may have a relative humidity of, for example, about 10% or less, or about 5% or less at room temperature (e.g., 20°C). The inert gas may be, for example, nitrogen (N2), argon (Ar), neon (Ne), krypton (Kr), xenon (Xe), carbon dioxide (CO2), or the like.

[0040] The sealing member 7 may be made of a resin material with low moisture permeability. This makes it possible to effectively prevent moisture from entering from the outside. As a result, a film capacitor with excellent reliability can be obtained. The sealing member 7 has a moisture permeability of, for example, 10 g / m 2 / day or less, and 5g / m 2 / day or less, and 3g / m 2 / day or less may be acceptable.

[0041] The protrusions 63 formed on the first surface 6a of the cover 6 may surround the entire periphery of the opening 51 when viewed from a direction perpendicular to the bottom surface 5b of the box 5. This makes it possible to lengthen the path length of the intrusion path of moisture from the outside all around the periphery of the opening 51. As a result, the capacitance of the film capacitor 1 can be effectively maintained for a long period of time, resulting in a film capacitor with excellent reliability.

[0042] 6, when the groove 52 includes a plurality of grooves 52a and 52b, the protrusion 63 may include a protrusion 63b surrounding the opening 51 and a protrusion 63c located outside the protrusion 63b and surrounding the protrusion 63b. The protrusion 63b may be fitted into the groove 52a, and the protrusion 63c may be fitted into the groove 52b. This can increase the path length of the intrusion path of moisture from the outside around the entire circumference of the opening 51. As a result, the capacitance of the film capacitor 1 can be more effectively maintained for a long period of time, resulting in a film capacitor with excellent reliability.

[0043] When viewed from a direction perpendicular to the bottom surface 5b of the box body 5, the film capacitor 1 may have the first terminal portion 32 of the first bus bar 3 and the second terminal portion 42 of the second bus bar 4 overlapped. By arranging the first terminal portion 32 and the second terminal portion 42 overlapping each other, mutual inductance occurs between the first bus bar 3 and the second bus bar 4, and the equivalent series inductance can be reduced. As a result, when the film capacitor 1 is used in a power conversion component, it is possible to reduce an overshoot of the switching voltage. When the first terminal portion 32 and the second terminal portion 42 are overlapped, an insulating member 8 may be located between the first terminal portion 32 and the second terminal portion 42 as shown in Figs. 1 and 4. This makes it possible to suppress a short circuit between the first terminal portion 32 and the second terminal portion 42. The second connection portion 41 may be drawn upward through a hole formed in the first terminal portion 32 and the insulating member 8 and connected to the second terminal portion 42, as shown in Figs. 1 and 2, for example. The insulating member 8 is made of, for example, a resin material, insulating paper, or the like. The resin material used for the insulating member 8 may be, for example, polyethylene terephthalate, phenol resin, epoxy resin, etc. The insulating paper used for the insulating member 8 may be, for example, Nomex (registered trademark) paper, etc.

[0044] Next, an inverter according to an embodiment of the present disclosure will be described. Fig. 7 is a diagram showing a configuration of an inverter according to an embodiment of the present disclosure. Fig. 7 shows an example of an inverter that generates a three-phase AC for driving a motor.

[0045] The inverter 100 of this embodiment includes a bridge circuit 131 and a capacitance unit 133. The bridge circuit 131 may include a switching element such as an insulated gate bipolar transistor (IGBT). The capacitance unit 133 is disposed between input terminals of the bridge circuit 131 to stabilize the voltage. The capacitance unit 133 includes a film capacitor 1.

[0046] 7, the inverter 100 is connected to a boost circuit 135 that boosts the voltage of a DC power supply. The bridge circuit 131 is connected to a motor generator M that serves as a drive source. The inverter 100 has a capacitance section 133 that includes a film capacitor 1 that can maintain a capacitance for a long period of time, so that the voltage and current input to the inverter 100 can be smoothed for a long period of time.

[0047] Next, an electric vehicle according to an embodiment of the present disclosure will be described. Fig. 8 is a diagram showing a configuration of an electric vehicle according to an embodiment of the present disclosure. Fig. 8 shows a hybrid electric vehicle (HEV) as an example of the electric vehicle.

[0048] The electric vehicle 200 of this embodiment includes a drive motor 241, an engine 243, a transmission 245, an inverter 100, a power source (battery) 249, front wheels 251a, and rear wheels 251b.

[0049] The electric vehicle 200 includes a drive motor 241 and an engine 243 as drive sources. The output of the drive source is transmitted to a pair of left and right front wheels 251a via a transmission 245. A power source 249 is connected to the drive motor 241 via an inverter 100.

[0050] The electric vehicle 200 is provided with a vehicle ECU 253 that performs overall control of the entire electric vehicle 200. A drive signal from the electric vehicle 200 is input to the vehicle ECU 253. The drive signal from the electric vehicle 200 is a signal generated when a driver or the like operates an ignition key 255, an accelerator pedal, a brake, or the like. Based on the drive signal from the electric vehicle 200, the vehicle ECU 253 outputs an instruction signal to the engine ECU 257, the power source 249, the inverter 100 as a load, and the like. The engine ECU 257 controls the rotation speed of the engine 243 in response to the instruction signal, and drives the electric vehicle 200.

[0051] Since the electric vehicle 200 includes the inverter 100 to which the film capacitor 1 is applied as the capacitance portion 133, the switching noise generated in the inverter 100 and the like can be reduced for a long period of time.

[0052] The inverter 100 can be applied to power conversion components not only in hybrid vehicles but also in electric vehicles (EVs), electric bicycles, generators, solar cells, and the like.

[0053] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible without departing from the gist of the present disclosure. [Explanation of symbols]

[0054] 1. Film capacitor 2. Film capacitor elements 3 No. 1 bus bar 4 No. 2 bus bar 5 box body 5a End face 5b Bottom 6 Lid 6a 1st page 6b 2nd side 7 Sealing member 20 Main body 20a 1st end face 20b 2nd end face 21 Metallicon Electrode 21a 1st electrode 21b 2nd electrode 22a Metallized film (first metallized film) 22b Metallized film (second metallized film) 23a Dielectric film (first dielectric film) 23aa 1st page 23b Dielectric film (second dielectric film) 23ba front page 24a Metal film (first metal film) 24b Metal film (second metal film) 31 First connection part 32 1st terminal section 32a, 32b terminals 35 Boost circuit 41 Second connection part 42 2nd terminal section 42a Terminal 51 Aperture 52,52a,52b Groove 61 First through hole 62 Second Through Hole 63,63b,63c Projection part 63a proximal end 100 Inverter 131 Bridge Circuit 133 Capacity part 200 Electric Vehicles 241 Driving motor 243 Engine 245 Transmission 249 Power supply 251a front wheel 251b rear wheel 253 Vehicle ECU 255 Ignition Key 257 Engine ECU M Motor Generator

Claims

1. a film capacitor element having a first electrode and a second electrode; a first bus bar having a first connection portion connected to the first electrode and a first terminal portion for external connection; a second bus bar having a second connection portion connected to the second electrode and a second terminal portion for external connection; an insulating member located between the first terminal portion and the second terminal portion; a box body having an opening on one side and housing the film capacitor element, the box body having a groove portion surrounding the opening on an end surface surrounding the opening; a lid for closing an opening of the box, the lid having a first surface facing the box and a second surface opposite to the first surface, a first through hole and a second through hole penetrating from the first surface to the second surface, and a protrusion portion on the first surface; A sealing member that seals the inside of the box, the first terminal portion and the second terminal portion are located on the second surface of the lid body, the first connection portion is inserted into the first through hole and connects the first electrode and the first terminal portion; the second connection portion is inserted into the second through hole and drawn upward through a hole formed in the first terminal portion and the insulating member to connect the second electrode and the second terminal portion; the film capacitor element is suspended within the box in a state in which the film capacitor element is connected to the first bus bar and the second bus bar, the lid body is fixed to the box body in a state in which the first connection portion and the second connection portion are inserted into the first through hole and the second through hole, respectively, and the protrusion portion is fitted into the groove portion, the sealing member is located inside the groove portion and seals the gap between the box body and the lid body, and is located on the second surface and seals the first through hole and the second through hole. Film capacitor.

2. The film capacitor according to claim 1 , wherein the box is filled with dry air or an inert gas.

3. The film capacitor according to claim 1 , wherein the sealing member is made of a resin having low moisture permeability.

4. The film capacitor according to claim 1 , wherein the protrusion surrounds an opening of the box body in a plan view.

5. The protrusion has a height from a base end of 3 mm or more, The film capacitor according to claim 1 , wherein the depth of the groove from the end face is greater than the height of the protrusion.

6. A bridge circuit including a switching element and a capacitance unit connected to the bridge circuit, The capacitance section includes the film capacitor according to any one of claims 1 to 5. An inverter.

7. A vehicle driving system comprising: a power source; an inverter connected to the power source; a motor connected to the inverter; and wheels driven by the motor; The inverter according to claim 6, wherein the inverter is an inverter for an electric vehicle.

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