Film capacitor

Abstract

The present invention provides a film capacitor that allows for diversification of the outer casing used to enclose the capacitor element. [Solution] The film capacitor 1 comprises a capacitor element 2 having a dielectric film 20, a metal film 21 provided on the dielectric film 20, and an end electrode 22 electrically connected to the metal film 21; a base plate 3 having a first surface 31 on which the capacitor element 2 is arranged and a second surface 32 opposite to the first surface 31; an element connection portion 43 connected to the end electrode 22 and a terminal portion 44 connected to an external device, a bus bar 4 penetrating between the first surface 31 and the second surface 32, and a resin sealing portion 5 covering the capacitor element 2 and the bus bar 4 located on the first surface 31 side.

Description

Technical Field

[0001] The present disclosure generally relates to film capacitors, and more particularly to film capacitors having capacitor elements.

Background Art

[0002] Patent Document 1 discloses a film capacitor. In this film capacitor, the film capacitor element is encapsulated with an encapsulating resin composition.

[0003] The above encapsulating resin composition contains a thermosetting resin and an imidazole compound. Further, when the torque value of this encapsulating resin composition was measured over time using a lab plastomill under the conditions of a rotation speed of 30 rpm and a measurement temperature of 120°C, the time T1 during which the torque value was 2 times or less the minimum torque value was 15 seconds or more and 100 seconds or less, and the minimum torque value was 0.5 N·m or more and 5.0 N·m or less. Furthermore, the glass transition temperature of the cured product obtained by heating this encapsulating resin composition at 120°C for 4 hours is 150°C or more.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the film capacitor of Patent Document 1, after selecting the constituent components of the encapsulating resin composition, it is necessary to control the glass transition temperature of the cured product and the behavior of the torque change of the encapsulating resin composition measured under specific conditions using a torque lab plastomill. Thus, the encapsulating resin composition used in the film capacitor of Patent Document 1 is somewhat standardized.

[0006] Therefore, in Patent Document 1, it is difficult to manufacture film capacitors in which film capacitor elements are sealed with multiple types of outer casings having different physical properties (e.g., strength) depending on the application. Furthermore, even when using a single type of outer casing for one film capacitor, it is difficult to manufacture multiple types of film capacitors using outer casings with different physical properties in Patent Document 1. Thus, the sealing resin composition used in the film capacitors in Patent Document 1 lacks diversity.

[0007] The purpose of this disclosure is to provide a film capacitor that allows for diversification of the outer casing that encloses the capacitor element. [Means for solving the problem]

[0008] A film capacitor according to one aspect of the present disclosure comprises a capacitor element having a dielectric film, a metal film provided on the dielectric film, and an end electrode electrically connected to the metal film; a base plate having a first surface on which the capacitor element is arranged and a second surface opposite to the first surface; an element connection portion connected to the end electrode and a terminal portion connected to an external device, a bus bar penetrating between the first surface and the second surface, and a resin sealing portion covering the capacitor element and the bus bar located on the first surface side.

[0009] A film capacitor according to one aspect of the present disclosure comprises a capacitor element having a dielectric film, a metal film provided on the dielectric film, and an end electrode electrically connected to the metal film; a busbar having an element connection portion connected to the end electrode and a terminal portion connected to an external device; and a resin sealing portion covering the capacitor element and at least the portion of the busbar excluding the terminal portion. A gate mark is formed in the resin sealing portion so as to face the end electrode. [Effects of the Invention]

[0010] According to this disclosure, it is possible to diversify the casings that enclose the capacitor elements. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a perspective view showing a film capacitor according to the first embodiment. [Figure 2] Figure 2 is a cross-sectional view showing the same film capacitor. [Figure 3] Figure 3 is an exploded perspective view showing the same film capacitor (excluding the resin encapsulation). [Figure 4] Figure 4 is a perspective view showing the manufacturing process of the capacitor element used in the film capacitor described above. [Figure 5] Figure 5 is a cross-sectional view showing the manufacturing process of the film capacitor mentioned above. [Figure 6] Figure 6 is a perspective view showing a film capacitor according to the second embodiment. [Modes for carrying out the invention]

[0012] 1. Overview Patent Document 1 describes a film capacitor manufactured using a sealing resin composition specifically designed for low-temperature filling and curing properties in order to suppress the effects of heat on the film capacitor element. In this film capacitor, the film capacitor element is sealed with a sealing layer which is a cured product of the above-mentioned sealing resin composition.

[0013] However, generally, it is difficult to increase the strength of the sealing layer when molding at low temperatures. Therefore, it is also difficult to directly attach the sealing layer to external equipment by means of fastening or other means. On the other hand, if a sealing resin composition with a high molding temperature is used to increase the strength of the sealing layer, the thermal effect on the film capacitor element cannot be ignored.

[0014] Therefore, the present inventor conducted intensive research and development to manufacture a film capacitor in which a film capacitor element is sealed with a plurality of types of exterior bodies having different physical properties (such as strength, etc.) according to the application. As a result, the following film capacitor 1 was developed.

[0015] That is, as shown in FIG. 1, the film capacitor 1 according to the present embodiment includes a capacitor element 2, a base plate 3, a bus bar 4, and a resin sealing portion 5.

[0016] The capacitor element 2 has a dielectric film 20, a metal film 21 provided on the dielectric film 20, and an end face electrode 22 electrically connected to the metal film 21 (see FIG. 4).

[0017] The base plate 3 has a first surface 31 on which the capacitor element 2 is disposed and a second surface 32 opposite to the first surface 31 (see FIGS. 2 and 3).

[0018] The bus bar 4 has an element connection portion 43 connected to the end face electrode 22 and a terminal portion 44 connected to an external device, and penetrates between the first surface 31 and the second surface 32 (see FIGS. 1 to 3).

[0019] The resin sealing portion 5 covers the capacitor element 2 and the bus bar 4 existing on the first surface 31 side (see FIG. 1).

[0020] As shown in FIGS. 1 and 2, for one film capacitor 1, two types of exterior bodies are used. That is, the two types of exterior bodies are the base plate 3 and the resin sealing portion 5. The base plate 3 and the resin sealing portion 5 do not necessarily have the same physical properties. The physical properties of the base plate 3 and the physical properties of the resin sealing portion 5 may be changed according to the application.

[0021] Therefore, it is possible to diversify the exterior bodies for sealing the capacitor element 2.

[0022] 2. Details The film capacitor 1 according to the first and second embodiments will be described below with reference to Figures 1 to 6. Each figure is a schematic representation, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios.

[0023] The arrows in each diagram indicating the vertical, horizontal, and front-to-back directions are not intended to specify the direction in which film capacitor 1 should be used, but are merely there to make the explanation easier to understand and do not represent any actual physical direction. Viewing along the vertical direction is called a "plan view," viewing along the horizontal direction is called a "side view," and viewing along the front-to-back direction is called a "front view."

[0024] (1) First Embodiment Hereinafter, a film capacitor 1 according to the first embodiment will be described with reference to Figures 1 to 5. As shown in Figure 1, the film capacitor 1 comprises a capacitor element 2, a base plate 3, a bus bar 4, and a resin encapsulation portion 5. In the first embodiment, the film capacitor 1 comprises one capacitor element 2 and two bus bars 4, but the number of capacitor elements 2 and the number of bus bars 4 are not particularly limited.

[0025] <Capacitor element> Examples of capacitor element 2 include wound film capacitor elements and multilayer film capacitor elements. In the first embodiment, the case in which capacitor element 2 is a wound film capacitor element will be described, but capacitor element 2 may also be a multilayer film capacitor element.

[0026] As shown in Figures 2 and 3, the capacitor element 2 has an element body 23 and an end face electrode 22.

[0027] ≪Element Body≫ The shape of the element body 23 is not particularly limited, but in the first embodiment, the element body 23 is rectangular in plan view, flattened circular in side view, and rectangular in front view. The element body 23 has a dielectric film 20 and a metal film 21 (see Figure 4). Thus, the capacitor element 2 has a dielectric film 20 and a metal film 21. The manufacturing process of the capacitor element 2 will be explained in the section on <Method of Manufacturing a Film Capacitor>.

[0028] [Dielectric film] The material of the dielectric film 20 is not particularly limited, but examples include polypropylene (PP) and polyethylene terephthalate (PET).

[0029] In the first embodiment, the dielectric film 20 includes a first dielectric film 201 and a second dielectric film 202 (see Figure 4).

[0030] [Metal film] The metal film 21 is provided on the dielectric film 20 (see Figure 4). The metal film 21 is formed, for example, by vapor deposition. The material of the metal film 21 is not particularly limited, but examples include aluminum (Al), magnesium (Mg), and alloys thereof.

[0031] In the first embodiment, the metal film 21 includes a first metal film 211 and a second metal film 212. Inside the element body 23, the first metal film 211 and the second metal film 212 face each other via a dielectric film 20.

[0032] A portion of the first metal film 211 is exposed on the left side of the element body 23, but the first metal film 211 is not exposed on the right side of the element body 23. On the other hand, a portion of the second metal film 212 is exposed on the right side of the element body 23, but the second metal film 212 is not exposed on the left side of the element body 23.

[0033] ≪End surface electrode≫ The end electrodes 22 are provided on both the left and right end faces of the element body 23 (see Figure 2). The end electrodes 22 are formed, for example, by metal spraying (metallicon). The metal to be sprayed is not particularly limited, but examples include zinc (Zn), tin (Sn), and alloys thereof. In this way, the end electrodes 22 are electrically connected to the metal film 21.

[0034] In the first embodiment, the end face electrode 22 includes a first end face electrode 221 and a second end face electrode 222. The first end face electrode 221 is provided on the left end face of the element body 23. The first end face electrode 221 is electrically connected to the first metal film 211 but not to the second metal film 212. On the other hand, the second end face electrode 222 is provided on the right end face of the element body 23. The second end face electrode 222 is electrically connected to the second metal film 212 but not to the first metal film 211.

[0035] <Base plate> In the first embodiment, the base plate 3 is included in the outer casing. The base plate 3 is plate-shaped. In plan view, the base plate 3 is larger than the capacitor element 2. The base plate 3 mainly covers the lower surface of the outer surface of the capacitor element 2.

[0036] The material of the base plate 3 is not particularly limited, but examples include polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), epoxy resin (EP), etc.

[0037] The base plate 3 has a first surface 31 and a second surface 32. The base plate 3 may further have a mounting portion 35 (see Figure 1).

[0038] ≪Side 1≫ In the first embodiment, the first surface 31 is the upper surface of the base plate 3. The first surface 31 includes an installation surface 311 and a groove 312 (see Figure 3). Thus, in the first embodiment, the entire first surface 31 is not flat, but the entire first surface 31 may be flat.

[0039] [Installation surface] The mounting surface 311 is the surface facing the capacitor element 2. The capacitor element 2 is placed on the mounting surface 311. In this case, the mounting surface 311 may be in direct contact with the capacitor element 2, but in the first embodiment, the mounting surface 311 is not in direct contact with the capacitor element 2 due to the protrusion 332 described later.

[0040] The mounting surface 311 has a rectangular shape in plan view. In plan view, the size of the mounting surface 311 is approximately the same as the size of the capacitor element 2. In this way, the capacitor element 2 is arranged on the first surface 31.

[0041] The mounting surface 311 is provided with multiple (three in the first embodiment) protrusions 332. The protrusions 332 project upward and extend in the front-to-back direction. The multiple protrusions 332 are spaced apart in the left-to-right direction. The mounting surface 311 and the protrusions 332 form a surface with irregularities 33. In this way, the surface with irregularities 33 is provided on the first surface 31 in the portion facing the capacitor element 2. When the capacitor element 2 is placed on the mounting surface 311, the capacitor element 2 rests on the protrusions 332 and is elevated above the mounting surface 311. In other words, a gap 34 is formed between the capacitor element 2 and the mounting surface 311 (see Figure 5).

[0042] [Mizobe] The groove 312 is recessed downwards and is provided to surround the installation surface 311 (see Figure 3). Thus, in a plan view, the groove 312 forms a frame shape. A portion of the resin sealing portion 5 is filled into the groove 312 (see Figure 2).

[0043] ≪Second side≫ The second surface 32 is the surface opposite to the first surface 31. In other words, the second surface 32 is the bottom surface of the base plate 3. In the first embodiment, the entire second surface 32 is not flat, but the entire second surface 32 may be flat.

[0044] ≪Mounting part≫ The mounting portion 35 is used to attach the film capacitor 1 to external equipment (not shown, the same applies hereinafter). In the first embodiment, two mounting portions 35 protrude laterally. Specifically, one mounting portion 35 protrudes to the left, and the other mounting portion 35 protrudes to the right. The number and orientation of the mounting portions 35 on the base plate 3 are not particularly limited. External equipment is not particularly limited, but examples include components that make up an inverter.

[0045] The structure of the mounting portion 35 is not particularly limited, but in the first embodiment, a collar 9 is embedded in the mounting portion 35. The collar 9 is a cylindrical metal ring. The collar 9 of the mounting portion 35 penetrates in the vertical direction. The collar 9 is used for fastening to external equipment, etc.

[0046] <Bus bar> The busbar 4 is a conductive member used to electrically connect the capacitor element 2 to external equipment. The busbar 4 is formed by cutting a metal plate into a predetermined shape and bending it as appropriate. The metal plate is not particularly limited, but examples include copper plates and aluminum plates.

[0047] As shown in Figure 3, the busbar 4 is integrated with the base plate 3. In other words, the busbar 4 is insert-molded together with the base plate 3.

[0048] The shape of the busbar 4 is not particularly limited, but in the first embodiment, the busbar 4 has an element connection portion 43, a terminal portion 44, and a connecting portion 45. Hereinafter, the two busbars 4 will be referred to as the first busbar 41 and the second busbar 42. When it is necessary to distinguish between the first busbar 41 and the second busbar 42, the components of the first busbar 41 are represented by adding "a" to the reference numeral of the components of the busbar 4, and the components of the second busbar 42 are represented by adding "b" to the reference numeral of the components of the busbar 4.

[0049] As shown in Figures 2 and 3, the busbar 4 penetrates between the first surface 31 and the second surface 32 of the base plate 3.

[0050] ≪Element connection section≫ The element connection portion 43 protrudes upward from the first surface 31 of the base plate 3. Specifically, the element connection portion 43 protrudes upward from the mounting surface 311. That is, in a plan view, the element connection portion 43 is located inside the frame-shaped groove portion 312.

[0051] As shown in Figure 2, the element connection portion 43 is connected to the end face electrode 22. Specifically, the element connection portion 43a is connected to the first end face electrode 221, while the element connection portion 43b is connected to the second end face electrode 222. The element connection portion 43 is connected to the end face electrode 22 by, for example, a solder joint 8 (see Figure 1).

[0052] ≪Terminal section≫ The terminal portion 44 is connected to an external device. The terminal portion 44 protrudes downward from the second surface 32 of the base plate 3. In the first embodiment, the terminal portion 44 has a through hole 440. The through hole 440 penetrates in the front-to-back direction. The through hole 440 is used for connection to an external device, etc. The direction in which the through hole 440 penetrates is not particularly limited.

[0053] ≪Connection part≫ The connecting portion 45 is the part that connects the element connection portion 43 and the terminal portion 44. In other words, the connecting portion 45 is the part of the busbar 4 other than the element connection portion 43 and the terminal portion 44. In the first embodiment, the connecting portion 45 extends in the front-rear direction. The connecting portion 45 may extend in directions other than the front-rear direction.

[0054] In the first embodiment, as shown in Figure 2, the element connection portion 43a protrudes upward from the left end of the connecting portion 45a. The terminal portion 44a protrudes downward from the front end of the connecting portion 45a. On the other hand, the element connection portion 43b protrudes upward from the right end of the connecting portion 45b. The terminal portion 44b protrudes downward from the front end of the connecting portion 45b.

[0055] In the first embodiment, at least the portion of the busbar 4 other than the element connection portion 43 and the terminal portion 44 is embedded in the base plate 3. That is, at least the connecting portion 45 of the busbar 4 is embedded in the base plate 3. In other words, as shown in Figure 2, the connecting portion 45 is embedded between the first surface 31 and the second surface 32 of the base plate 3. It is sufficient that at least the connecting portion 45 is embedded in the base plate 3, so for example, a part of the element connection portion 43 and a part of the terminal portion 44 may be embedded in the base plate 3.

[0056] <Resin sealing part> In the first embodiment, the resin encapsulation portion 5 is included in the outer casing. The resin encapsulation portion 5 covers the capacitor element 2 and the busbar 4 (in this case, the element connection portion 43) located on the first surface 31 side of the base plate 3. In this way, the resin encapsulation portion 5 covers the outer surface of the capacitor element 2, mainly all surfaces except the bottom surface.

[0057] As shown in Figure 1, the lower part of the resin-sealed portion 5 is bonded to the base plate 3 and is therefore not exposed to the outside. Thus, the portion of the resin-sealed portion 5 other than the lower part is exposed. In this way, in the first embodiment, the resin-sealed portion 5 located on the first surface 31 of the base plate 3 is exposed to the outside.

[0058] The resin encapsulation portion 5 is, for example, a cured product of a curable resin and has electrical insulating properties. The curable resin is not particularly limited, but examples include unsaturated polyester (UP), phenolic resin (PF), epoxy resin (EP), urea resin (UF), melamine resin (MF), etc. Preferably, the resin encapsulation portion 5 contains unsaturated polyester.

[0059] In the first embodiment, the resin-sealed portion 5 is formed by injection molding. Furthermore, the resin-sealed portion 5 is formed at a temperature of 120°C or lower. Injection molding will be explained in the section on "Method for Manufacturing Film Capacitors".

[0060] In the first embodiment, a gate mark 50 (the portion enclosed by dashed lines in Figure 1) is formed in the resin-sealed portion 5 so as to face the end electrode 22. The gate mark 50 is a trace in the resin-sealed portion 5 corresponding to the position of the gate 611 (injection port) of the injection mold 6 when the resin-sealed portion 5 is formed by injection molding (see Figure 5). The gate mark 50 is either protruding or recessed. In a side view, the size of the gate mark 50 is not particularly limited.

[0061] The strength of the resin-sealed portion 5 may be the same as or different from the strength of the base plate 3. For example, the strength of the resin-sealed portion 5 may be less than the strength of the base plate 3. Strength refers to the stress that causes an object (in the first embodiment, the resin-sealed portion 5 and the base plate 3) to break when stress is applied to it.

[0062] <Manufacturing method for film capacitors> Next, a method for manufacturing the film capacitor 1 according to the first embodiment will be described.

[0063] First, the capacitor element 2 is manufactured. Specifically, as shown in Figure 4, a cylindrical wound body 25 is formed by overlapping a long first metallized film 241 and a second metallized film 242 and winding them around an axis C.

[0064] Here, the first metallized film 241 is provided with a first metal film 211 (shown as a dot pattern in Figure 4) on the first dielectric film 201. However, the first metal film 211 is not provided on the first margin portion 261 of the first dielectric film 201. On the other hand, the second metallized film 242 is provided with a second metal film 212 (shown as a dot pattern in Figure 4) on the second dielectric film 202. However, the second metal film 212 is not provided on the second margin portion 262 of the second dielectric film 202. Note that the patterns of the first metal film 211 and the second metal film 212 are not particularly limited.

[0065] Next, the wound body 25 is flattened by applying pressure in a direction perpendicular to the axis C, resulting in an element body 23 that has a flattened circular shape when viewed from the side. Then, a pair of end face electrodes 22 are formed by thermal spraying metal onto the left and right end faces of the element body 23. This gives rise to the capacitor element 2.

[0066] On the other hand, as shown in Figure 3, a base plate 3 with the busbar 4 insert-molded is prepared. Then, the capacitor element 2 is placed on the first surface 31 of the base plate 3. Specifically, the capacitor element 2 is placed on the mounting surface 311 via the protrusion 332. After that, the element connection part 43 and the end face electrode 22 are connected, for example, by soldering. Welding or the like may be used instead of soldering.

[0067] Next, as shown in Figure 5, the resin encapsulation part 5 is formed by injection molding using an injection molding die 6. The injection molding die 6 has, for example, a first mold 61 (cavity mold) and a second mold 62 (core mold).

[0068] Type 1 61 is a fixed type and has a cavity 60, a gate 611, and a runner 610. On the other hand, Type 2 62 is a movable type.

[0069] During the mold clamping process, the cavity 60 primarily houses the capacitor element 2. The gap 34 formed between the capacitor element 2 and the mounting surface 311 communicates with the cavity 60. Furthermore, the groove 312 of the base plate 3 faces the cavity 60.

[0070] The gate 611 is in communication with the cavity 60. During the mold clamping process, the gate 611 faces the end face electrode 22 (in this case, the second end face electrode 222) of the capacitor element 2.

[0071] Runner 610 is in communication with gate 611. Runner 610 is connected to an injection device (not shown, the same applies hereafter).

[0072] Then, after the mold clamping process, the process moves to the injection process. That is, molten resin (plasticized curable resin) is fed from the injection device to the runner 610 and filled into the cavity 60 through the gate 611. The molding temperature at this time is not particularly limited, but is preferably 120°C or lower.

[0073] Here, the molten resin immediately after being injected from the gate 611 first contacts the end electrode 22 (in this case, the second end electrode 222), and then flows around the cavity 60, filling it while contacting other parts. After that, the injection mold 6 is cooled appropriately, and then the mold opening process begins. As a result, the film capacitor 1 shown in Figure 1 is removed from the injection mold 6.

[0074] <Effects and Effects> In the first embodiment, as shown in Figures 1 and 2, two types of casings are used for one film capacitor 1. These two types of casings are the base plate 3 and the resin encapsulation part 5. The base plate 3 and the resin encapsulation part 5 do not need to have the same physical properties. Depending on the application, the physical properties of the base plate 3 and the resin encapsulation part 5 may be changed.

[0075] Therefore, according to the first embodiment, it is possible to diversify the type of outer casing that encloses the capacitor element 2.

[0076] Furthermore, in the first embodiment, the resin-encapsulated portion 5 is exposed except for the lower part. In this way, the film capacitor 1 becomes close to a so-called caseless capacitor, and at least by not using a case, it can be made lighter.

[0077] Furthermore, in the first embodiment, the first surface 31 of the base plate 3 is provided with irregularities 33 in the portion facing the capacitor element 2. Therefore, regardless of the surface condition of the capacitor element 2, specifically whether the lower surface of the capacitor element 2 is smooth or not, a gap 34 can be secured between the capacitor element 2 and the first surface 31 (in this case, the mounting surface 311) through which molten resin flows to form the resin sealing portion 5. Moreover, when the gap 34 is filled with molten resin and the resin sealing portion 5 is formed, an anchoring effect is obtained. In other words, the adhesion force between the capacitor element 2 and the base plate 3 is improved.

[0078] Furthermore, in the first embodiment, since at least the connecting portion 45 of the busbar 4 is embedded in the base plate 3, the contact force between the base plate 3 and the busbar 4 is improved. In addition, it is possible to suppress the intrusion of outside air into the capacitor element 2 through the space between the base plate 3 and the busbar 4.

[0079] In the first embodiment, the gate mark 50 is formed on the resin sealing portion 5 so as to face the end electrode 22. This means that, during injection molding, the molten resin immediately after being injected from the gate 611 first comes into contact with the end electrode 22. In this way, the molten resin immediately after being injected from the gate 611 does not immediately come into contact with the element body 23, thus reducing heat and pressure damage to the element body 23. In other words, by forming the gate mark 50 on the resin sealing portion 5 so as to face the end electrode 22 rather than the element body 23, it becomes possible to use a curable resin with a higher molding temperature. This means that the range of selectable types of curable resins for forming the resin sealing portion 5 can be broadened. This allows for changes in the physical properties of the resin sealing portion 5. On the other hand, since the base plate 3 is formed before injection molding, the range of selectable materials is even wider than that for the resin sealing portion 5. Therefore, further diversification of the outer casing that seals the capacitor element 2 can be achieved.

[0080] Furthermore, in the first embodiment, injection molding is employed, making it easier to form the resin-sealed portion 5 compared to other molding methods.

[0081] Furthermore, in the first embodiment, since the resin sealing portion 5 contains unsaturated polyester, the airtightness of the resin sealing portion 5 can be improved compared to the case where unsaturated polyester is not included.

[0082] Furthermore, in the first embodiment, since the resin-sealed portion 5 is formed at a temperature of 120°C or lower, the capacitor element 2 is less susceptible to thermal damage.

[0083] (2) Second Embodiment Next, the film capacitor 1 according to the second embodiment will be described with reference to Figure 6. In the second embodiment, components similar to those in the first embodiment are given the same reference numerals as in the first embodiment, and detailed descriptions may be omitted. The following description will focus on the differences from the first embodiment.

[0084] The second embodiment differs from the first embodiment in that the film capacitor 1 does not have a base plate 3. In other words, in the second embodiment, a single type of outer casing (in this case, a resin encapsulation part 5) is used for one film capacitor 1.

[0085] In the second embodiment, the resin encapsulation portion 5 covers the capacitor element 2 and at least the portion of the busbar 4 excluding the terminal portion 44. That is, the resin encapsulation portion 5 covers the capacitor element 2 and the element connection portion 43 and the connecting portion 45 of the busbar 4. It is sufficient that at least the terminal portion 44 is not covered by the resin encapsulation portion 5, so for example, the connecting portion 45 does not need to be covered by the resin encapsulation portion 5.

[0086] In the second embodiment, similar to the first embodiment, a gate mark 50 is formed in the resin-sealed portion 5 so as to face the end face electrode 22.

[0087] <Effects and Effects> The second embodiment also produces the same effects and advantages as the first embodiment.

[0088] In the second embodiment, as shown in Figure 6, a single type of casing is used for one film capacitor 1. That is, the single type of casing is the resin encapsulation part 5.

[0089] Here, in the second embodiment as well, the gate mark 50 is formed in the resin sealing portion 5 so as to face the end electrode 22. As described in the <Effects and Effects> section of the first embodiment, if the gate mark 50 is formed in the resin sealing portion 5 so as to face the end electrode 22 rather than the element body 23, it becomes possible to use a curable resin with a higher molding temperature. This makes it possible to change the physical properties of the resin sealing portion 5. In other words, when using a single type of casing for one film capacitor, it becomes possible to easily manufacture multiple types of film capacitors 1 using casings with different physical properties. Thus, according to the second embodiment, it is possible to diversify the casings that seal the capacitor element 2.

[0090] 3. Variant The film capacitor 1 according to the second embodiment does not have a mounting portion 35, but it may have a mounting portion 35 integrated with the resin encapsulation portion 5.

[0091] 4. Appearance As will be apparent from the above embodiments and modifications, this disclosure includes the following aspects. In the following, reference numerals are enclosed in parentheses solely to indicate their correspondence with the embodiments.

[0092] The first embodiment is a film capacitor (1) comprising: a capacitor element (2) having a dielectric film (20), a metal film (21) provided on the dielectric film (20), and an end electrode (22) electrically connected to the metal film (21); a base plate (3) having a first surface (31) on which the capacitor element (2) is arranged and a second surface (32) opposite to the first surface (31); an element connection portion (43) connected to the end electrode (22), a terminal portion (44) connected to an external device, a bus bar (4) penetrating between the first surface (31) and the second surface (32); and a resin sealing portion (5) covering the capacitor element (2) and the bus bar (4) located on the first surface (31) side.

[0093] According to this embodiment, it is possible to diversify the outer casing that encloses the capacitor element (2).

[0094] The second embodiment is a film capacitor (1) based on the first embodiment. In the second embodiment, the resin encapsulation portion (5) present on the first surface (31) is exposed to the outside.

[0095] According to this embodiment, the film capacitor (1) becomes similar to a so-called caseless capacitor, and at least by not using a case, it can be made lighter.

[0096] A third embodiment is a film capacitor (1) based on the first or second embodiment. In the third embodiment, the first surface (31) is provided with irregularities (33) in the portion facing the capacitor element (2).

[0097] According to this embodiment, regardless of the surface condition of the capacitor element (2), a gap (34) can be secured between the capacitor element (2) and the first surface (31) through which liquid resin flows to form a resin sealing portion (5). Furthermore, when the gap (34) is filled with liquid resin to form the resin sealing portion (5), an anchoring effect is obtained. In other words, the adhesion force between the capacitor element (2) and the base plate (3) is improved.

[0098] The fourth embodiment is a film capacitor (1) based on any one of the first to third embodiments. In the fourth embodiment, at least the portion of the busbar (4) other than the element connection portion (43) and the terminal portion (44) is embedded in the base plate (3).

[0099] According to this embodiment, the adhesion between the base plate (3) and the bus bar (4) is improved, and it is possible to suppress outside air from entering the capacitor element (2) through the gap between the base plate (3) and the bus bar (4).

[0100] The fifth embodiment is a film capacitor (1) based on any one of the first to fourth embodiments. In the fifth embodiment, a gate mark (50) is formed in the resin sealing portion (5) so as to face the end electrode (22).

[0101] According to this embodiment, it is possible to further diversify the outer casing that encloses the capacitor element (2).

[0102] A sixth embodiment is a film capacitor (1) comprising: a capacitor element (2) having a dielectric film (20), a metal film (21) provided on the dielectric film (20), and an end electrode (22) electrically connected to the metal film (21); a busbar (4) having an element connection portion (43) connected to the end electrode (22) and a terminal portion (44) connected to an external device; and a resin sealing portion (5) covering the capacitor element (2) and at least the portion of the busbar (4) excluding the terminal portion (44). A gate mark (50) is formed in the resin sealing portion (5) so as to face the end electrode (22).

[0103] According to this embodiment, it is possible to diversify the outer casing that encloses the capacitor element (2).

[0104] The seventh embodiment is a film capacitor (1) based on any one of the first to sixth embodiments. In the seventh embodiment, the resin encapsulation portion (5) is formed by injection molding.

[0105] According to this embodiment, it is easier to form the resin-sealed portion (5) compared to other molding methods.

[0106] The eighth embodiment is a film capacitor (1) based on any one of the first to seventh embodiments. In the eighth embodiment, the resin encapsulation portion (5) contains unsaturated polyester.

[0107] According to this embodiment, the airtightness of the resin-sealed portion (5) can be improved compared to the case where the resin-sealed portion (5) does not contain unsaturated polyester.

[0108] The ninth embodiment is a film capacitor (1) based on any one of the first to eighth embodiments. In the ninth embodiment, the resin encapsulation portion (5) is formed at a temperature of 120°C or lower.

[0109] According to this embodiment, the capacitor element (2) becomes less susceptible to damage due to heat. [Explanation of symbols]

[0110] 1 Film Capacitor 2 Capacitor elements 20 Dielectric film 21 Metal film 22 End electrode 3 Base plate 31 Page 1 32 Side 2 33 Unevenness 4 bus bars 43 Element connection section 44 Terminal section 5 Resin sealing part 50 Gate remains

Claims

1. A capacitor element having a dielectric film, a metal film provided on the dielectric film, and an end electrode electrically connected to the metal film, A base plate having a first surface on which the capacitor elements are arranged, and a second surface opposite to the first surface, It has an element connection portion connected to the end face electrode and a terminal portion connected to an external device, and a busbar that penetrates between the first surface and the second surface, The system comprises a resin sealing portion that covers the capacitor element and the busbar located on the first surface side, Film capacitor.

2. The resin sealing portion present on the first surface is exposed to the outside. The film capacitor according to claim 1.

3. On the first surface, irregularities are provided in the portion facing the capacitor element. The film capacitor according to claim 1.

4. At least the portion of the busbar other than the element connection portion and the terminal portion is embedded in the base plate. The film capacitor according to claim 1.

5. A gate mark is formed in the resin sealing portion so as to be opposite to the end face electrode. The film capacitor according to claim 1.

6. A capacitor element having a dielectric film, a metal film provided on the dielectric film, and an end electrode electrically connected to the metal film, A busbar having an element connection portion connected to the end face electrode and a terminal portion connected to an external device, The capacitor element and the busbar, with a resin sealing portion covering at least the portion of the busbar excluding the terminal portion, A gate mark is formed in the resin sealing portion so as to be opposite to the end face electrode. Film capacitor.

7. The resin sealing portion is formed by injection molding. A film capacitor according to claim 1 or 6.

8. The resin sealing portion contains unsaturated polyester, A film capacitor according to claim 1 or 6.

9. The resin-sealed portion is formed at a temperature of 120°C or lower. A film capacitor according to claim 1 or 6.

Images