Capacitor and manufacturing method of capacitor

Abstract

To provide a capacitor capable of easily releasing heat generated from a capacitor element to the outside.SOLUTION: A capacitor 1 includes: a capacitor element 2; and an exterior body 3 that has a storage part 310 storing the capacitor element 2. The storage part 310 is filled with gas. The gas contains at least one gas of helium and hydrogen.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates generally to a capacitor and a method for manufacturing a capacitor, and more particularly to a capacitor including a capacitor element and an exterior body, and a method for manufacturing a capacitor. [Background technology]

[0002] Patent Document 1 discloses a capacitor including a capacitor element having a first electrode on one end face and a second electrode on the other end face, and an exterior body covering the entire capacitor element. In this capacitor, the exterior body includes a first exterior body having a first end face facing the first electrode and covering the first electrode side of the capacitor element, and a second exterior body having a second end face facing the second electrode and covering the second electrode side of the capacitor element. The first exterior body and the second exterior body are joined together such that the inside of the exterior body is airtight, and a first bus bar is fixed to the first exterior body, and a second bus bar is fixed to the second exterior body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-32677 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the capacitor of Patent Document 1 has an airtight interior and is filled with atmospheric air, which causes a problem that heat generated by the capacitor element tends to accumulate within the first and second exterior housings of the capacitor.

[0005] An object of the present disclosure is to provide a capacitor that easily releases heat generated from a capacitor element to the outside, and a method for manufacturing a capacitor. [Means for solving the problem]

[0006] A capacitor according to an aspect of the present disclosure includes a capacitor element and an exterior body. The exterior body has a housing that houses the capacitor element. The housing is filled with a gas. The gas includes at least one of helium and hydrogen.

[0007] A method for manufacturing a capacitor according to an aspect of the present disclosure is a method for manufacturing a capacitor including a capacitor element and an exterior body having a housing portion for housing the capacitor element, the method including filling the housing portion of the exterior body with a gas, the gas being at least one of helium and hydrogen. Effect of the Invention

[0008] According to the present disclosure, heat generated from the capacitor element can be easily released to the outside. [Brief description of the drawings]

[0009] [Figure 1] Fig. 1A is a schematic perspective view showing an example of a capacitor according to an embodiment of the present disclosure, and Fig. 1B is a schematic exploded perspective view showing an example of an exterior body of the capacitor. [Diagram 2] Fig. 2A is a schematic perspective view showing an example of a process for producing a wound type capacitor element in the capacitor of the above embodiment, Fig. 2B is a schematic perspective view showing an example of a main body of a cylindrical capacitor element, and Fig. 2C is a perspective view showing an example of the above capacitor element. [Diagram 3] Fig. 3A is a schematic perspective view showing an example of a process for producing a stacked capacitor element in a capacitor, Fig. 3B is a schematic perspective view showing an example of a main body of a prismatic capacitor element, and Fig. 3C is a perspective view showing an example of the same capacitor element. [Figure 4] Fig. 4A is a schematic perspective view showing an example of a bus bar fixed by insert molding in the capacitor of the above embodiment, and Fig. 4B is a schematic perspective view showing an example of a state in which the bus bar is fixed to a capacitor element in the capacitor of the above embodiment. [Diagram 5] 5A and 5B are flow charts showing an example of a process flow for manufacturing a capacitor element in the capacitor according to the embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 1. Overview In the capacitor described in Patent Document 1, a capacitor element is placed inside an exterior body (including cases where multiple exterior bodies are combined to form a case) and the inside is sealed, thereby ensuring moisture resistance. Also, compared to cases where a gap between the capacitor and the exterior body is filled or sealed by filling the inside of the exterior body with resin, as in the case where a capacitor element is placed inside the exterior body, weight reduction and improvement in productivity can be expected.

[0011] However, according to the inventors' investigation, it was found that even if the inside of the exterior housing that houses the capacitor element is airtight, that is, the capacitor element is placed and sealed inside the exterior housing, it may be difficult for the heat generated from the capacitor element to be released to the outside of the capacitor inside the exterior housing. In this case, the capacitor element inside the capacitor may become hot, which may cause a malfunction in an electronic device or other device.

[0012] Therefore, the inventors conducted extensive research to develop a capacitor in which the capacitor element is not easily maintained at a high temperature and in which heat inside the capacitor can be easily released to the outside, and as a result, they developed the capacitor according to the present embodiment.

[0013] That is, the capacitor 1 according to this embodiment includes a capacitor element 2 and an exterior body 3. The exterior body 3 has a housing portion 310 that houses the capacitor element 2. The housing portion 310 in the exterior body 3 is filled with a gas. The gas includes at least one of helium and hydrogen. According to this embodiment, heat generated from the capacitor element 2 can be easily released to the outside.

[0014] The reason why capacitor 1 of this embodiment is able to efficiently dissipate heat generated from capacitor element 2 to the outside has not been made clear, but is generally presumed to be due to the following reasons.

[0015] In a conventional capacitor, a capacitor element is accommodated in a housing such as a case, and then the capacitor element is made airtight (sealed) inside the housing.

[0016] In the sealed state, the gap between the capacitor element in the case and the exterior body in the housing is preferably sealed or filled with, for example, resin, or if the gap is not sealed or filled with resin or the like, it is preferable that there is as little space as possible between the housing and the capacitor, because if there is a gap, water vapor or moisture in the air may penetrate, causing the capacitor element to deteriorate.

[0017] In contrast, in the capacitor 1 of this embodiment, although there is a gap between the capacitor element 2 and the exterior body 3 in the internal space of the sealed exterior body 3, that is, the housing portion 310, this space is filled with a gas containing at least one of hydrogen and helium, which are gases. Since hydrogen and helium are gases with relatively high thermal conductivity, even if heat is generated from the capacitor element 2, heat transfer is likely to occur through the layer of gas filled in the housing portion 310, which is the internal space. For this reason, in the capacitor 1 of this embodiment, it is considered that the heat generated from the capacitor element 2 is likely to move toward the outside, which has a lower temperature. This makes it easy to release heat inside the capacitor 1 to the outside of the capacitor 1, that is, to the outside of the exterior body 3. As a result, it is possible to make it difficult for the capacitor element 2 and electronic components such as electronic devices equipped with the capacitor element 2 to deteriorate due to heat. For this reason, by filling the capacitor 1 with a specific gas, it is possible to extend the life of the capacitor 1 and devices equipped with the capacitor element 2.

[0018] 2.Details The capacitor 1 according to the present embodiment will be described in detail below with reference to the drawings. Each figure is a schematic diagram, and the size and thickness ratio of each component in each figure do not necessarily reflect the actual dimensional ratio. Also, the arrows indicating each direction in each figure are not intended to define the attitude and direction of the capacitor 1 during use, but are merely depicted to make the explanation easier to understand, and do not have any substance. The X-axis, Y-axis, and Z-axis are mutually orthogonal. In the following description, a view along the Y-axis may be referred to as a ZX plane view.

[0019] First, a preferred embodiment of the capacitor according to the present embodiment will be described.

[0020] [Capacitor] FIG. 1A shows an example of a capacitor 1 according to one embodiment of the present invention. The capacitor 1 shown in FIG. 1A includes a capacitor element 2 and an exterior body 3. The capacitor element 2 is accommodated in a housing portion 310 of the exterior body 3. That is, the exterior body 3 includes a housing portion 310 capable of housing the capacitor element 2. In the capacitor 1 of the present embodiment, the housing portion 310 of the exterior body 3 is filled with a gas. Specifically, in the capacitor 1 of the present embodiment, the inside of the exterior body 3 is sealed, but there is a not small gap between the exterior body 3 and the capacitor element 2 housed in the housing portion 310 inside the exterior body 3. The gap in the housing portion 310 is filled with a gas. In other words, in the present embodiment, the gas can be said to be a gas that fills the periphery of the capacitor element 2 in the housing portion 310 inside the exterior body 3.

[0021] <Gas> In this embodiment, as described above, the gas filled in the exterior body 3 is a gas containing at least one of hydrogen and helium. More preferably, the gas contains at least one of hydrogen and helium as a main component. In the present disclosure, the "main component" refers to a component that exhibits the highest volume fraction among the components that constitute the entire gas in a predetermined sealed space. Here, the case where at least one of hydrogen and helium is the "main component" refers to a case where only hydrogen exhibits the highest volume fraction, a case where only helium exhibits the highest volume fraction, and a case where a mixed gas of hydrogen and helium exhibits the highest volume fraction. The "highest volume fraction" refers to, for example, a gas volume that occupies 50 volume% or more of the total volume. In addition, the gas filled in the exterior body 3 may be only hydrogen, only helium, or only a mixed gas of hydrogen and helium. However, it is not intended to prevent a gas other than hydrogen and helium from being contained in the exterior body 3 at a ratio lower than the volume fraction of hydrogen, helium, or a mixed gas of hydrogen and helium.

[0022] When the ambient temperature is 0°C or 100°C, the thermal conductivity of hydrogen is higher than that of helium. Gases with lower thermal conductivity than helium include neon, ammonia, and oxygen, which have higher thermal conductivity than air. However, the gas filled inside the exterior body 3 is more effective in releasing heat generated from the capacitor element 2 to the outside when it is hydrogen, helium, or a mixture of hydrogen and helium. Although the thermal conductivity of gases tends to increase due to pressure, hydrogen and helium both have smaller molecular weights than other gas molecules (atoms), and are therefore less susceptible to the effects of pressure and therefore have higher thermal conductivity.

[0023] A capacitor provided in an electronic device such as a semiconductor device or an electronic component may reach a high temperature of about 100° C. during operation. Even in such a case, the capacitor 1 of this embodiment can efficiently dissipate heat generated from the capacitor element 2 to the outside of the capacitor 1.

[0024] In the capacitor 1, it can be confirmed, for example, as follows that the gap between the capacitor element 2 and the exterior body 3 inside the capacitor 1 is filled with gas (i.e., at least one of hydrogen and helium). For example, a syringe with a syringe needle attached is inserted into a part of the exterior body 3 of the capacitor 1 in a sealed state, a predetermined amount (e.g., 10 mL) is aspirated, and the aspirated gas is injected into a gas cell and analyzed by a thermal conductivity gas analyzer. The type of gas can be identified based on the obtained analysis result, and the presence or absence of hydrogen or helium can be confirmed. The content ratio can be determined from the ratio of the collected amount to the analyzed amount. Note that the method of confirming the gas is not limited to this, and any appropriate method can be adopted. For example, a detection sensor for the target gas is installed in the capacitor 1 in advance, and monitoring is performed from the beginning of filling to confirm the pressure change and the remaining amount change.

[0025] The gas may be filled into the exterior body 3 after the capacitor element 2 is placed in the exterior body 3 and then sealed, or the capacitor element 2 may be placed in the exterior body 3 while the gas is being filled and the exterior body is then sealed, or the capacitor element 2 may be placed in the exterior body 3 with the gas filled and then sealed. The method of filling the gas will be described in detail in the section "Method of manufacturing a capacitor" below.

[0026] Each part of the capacitor 1 will now be described in detail.

[0027] <Capacitor element> Capacitor element 2 includes a body 20 and an end electrode 25. In Fig. 1A, body 20 is shown as an example of a film capacitor made of a film and an electrode, and the following describes a case where capacitor element 2 is a film capacitor, but the capacitor element is not limited to this. As long as it does not impede the objectives of the present disclosure, the capacitor element may be, for example, an aluminum electrolytic capacitor, a ceramic capacitor, an electric double layer capacitor, or the like.

[0028] The main body 20 has a pair of electrodes 24 (a first electrode 241 and a second electrode 242), a dielectric film 22, and a pair of end faces 200 (a first end face 201 and a second end face 202) (see, for example, FIGS. 2A to 2C). In FIG. 2A, the first electrode 241 and the second electrode 242 are shown by a dot pattern.

[0029] The first electrode 241 may be any of a vapor deposition electrode, a metal foil electrode, and a plated electrode. Most of the first electrode 241 is present inside the main body 20. The first electrode 241 includes at least one metal selected from the group consisting of Al (aluminum), Zn (zinc), and Mg (magnesium). The thickness of the first electrode 241 is not particularly limited, but is, for example, 5 nm or more and 100 nm or less.

[0030] Similar to the first electrode 241, most of the second electrode 242 is present inside the main body 20. Inside the main body 20, the second electrode 242 faces the first electrode 241 via the dielectric film 22. Similar to the first electrode 241, the second electrode 242 also contains at least one metal selected from the group consisting of Al, Zn, and Mg. Similar to the first electrode 241, the thickness of the second electrode 242 is not particularly limited, and is, for example, not less than 5 nm and not more than 100 nm.

[0031] Of the pair of end faces 200, the first end face 201 is a face facing in the positive direction of the Y axis. A part of the first electrode 241 is exposed at the first end face 201. In the ZX plane view, the first electrode 241 has a spiral shape (see FIGS. 2A to 2C). However, the second electrode 242 is not exposed at the first end face 201.

[0032] The second end surface 202 is the surface opposite to the first end surface 201. In other words, the second end surface 202 is a surface facing in the negative direction of the Y axis. At the second end surface 202, a part of the second electrode 242 is exposed, and in the ZX plane view, the second electrode 242 also has a spiral shape like the first electrode 241. However, at the second end surface 202, the first electrode 241 is not exposed.

[0033] (Dielectric film) The dielectric film 22 is a film made of a dielectric material. In this embodiment, the dielectric film 22 includes a first dielectric film 221 and a second dielectric film 222. The dielectric film 22 is interposed between a first electrode 241 and a second electrode 242.

[0034] 2A, the dielectric film 22 has an elongated film shape, that is, the dielectric film 22 is a film having a thickness in the Z-axis direction, a width in the Y-axis direction, and extending in the X-axis direction.

[0035] In the dielectric film 22, the first electrode 241 is disposed on a surface of the first dielectric film 221 facing the positive direction of the Z axis. Specifically, as shown in FIG. 2A, the first electrode 241 is disposed on a portion of the surface facing the positive direction of the Z axis excluding the margin portion 23 (first margin portion 231). The margin portion 23 includes the first margin portion 231 and a second margin portion 232 described later. The margin portion 23 is a portion where the dielectric film 22 is exposed. The first margin portion 231 is present at an end portion in the positive direction of the Y axis. The first margin portion 231 is a portion having a narrow strip shape. That is, the first margin portion 231 is a portion that has a width in the Y axis direction and extends in the Y axis direction.

[0036] In the dielectric film 22, the second electrode 242 is disposed on the surface of the first dielectric film 221 facing the negative direction of the Z axis. The second electrode 242 faces the first electrode 241 via the dielectric film 22. Here, it can be said that the second electrode 242 is disposed on the surface of the second dielectric film 222 facing the positive direction of the Z axis. As shown in FIG. 2A, the second electrode 242 is disposed in a portion of the surface facing the positive direction of the Z axis excluding the margin portion 23 (the second margin portion 232). The second margin portion 232 exists at the end in the negative direction of the Y axis. The second margin portion 232 is a portion having a narrow strip shape. That is, the second margin portion 232 is a portion having a width in the Y axis direction and extending in the X axis direction.

[0037] The thickness of the dielectric film 22 is the distance between the first surface 2a and the second surface 2b in the Z-axis direction. The thickness of the dielectric film 22 is not particularly limited, but is, for example, not less than 1.0 μm and not more than 10.0 μm.

[0038] The material of the dielectric film 22 is not particularly limited, but may be at least one polymer selected from the group consisting of syndiotactic polystyrene (SPS), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PSS), and polystyrene (PS).

[0039] (Metallized film) 2A shows metallized film 21 that can form a film capacitor. Metallized film 21 includes dielectric film 22 described above and electrode 24 formed on the surface of dielectric film 22. In the film capacitor, metallized film 21 is wound around winding core C (see FIG. 2A).

[0040] Metallized film 21 has an elongated film shape. That is, metallized film 21 is a film that has a thickness in the Z-axis direction and a width in the Y-axis direction and extends in the Z-axis direction.

[0041] As described above, metallized film 21 is used for manufacturing a film capacitor. Metallized film 21 can be used as first metallized film 211 or second metallized film 212 by rotating it 180° in the ZX plan view. That is, metallized film 21 includes first metallized film 211 and second metallized film 212. Specifically, first metallized film 211 includes first dielectric film 221 and first electrode 241. Second metallized film 212 includes second dielectric film 222 and second electrode 242.

[0042] The thickness of metallized film 21 is not particularly limited, but is, for example, not less than 1.0 μm and not more than 10.0 μm.

[0043] (end face electrode) In this embodiment, the capacitor 1 has an end surface electrode 25 on the end surface 200 of the main body 20. The end surface electrode 25 includes a first end surface electrode 251 and a second end surface electrode 252 as a pair of end surface electrodes. The end surface electrodes 25 are formed on both ends of the rolled metallized film 21 in the axial C direction. Specifically, in this embodiment, as shown in FIG. 2C, a pair of end surface electrodes 25 (a first end surface electrode 251 and a second end surface electrode 252) are formed on a pair of end surfaces (a first end surface 201 and a second end surface 202) of the main body 20. The first end surface electrode 251 is connected to the first electrode 241, while the second end surface electrode 252 is connected to the second electrode 242. More specifically, the first end surface electrode 251 is connected to the first electrode 241 but is not connected to the second electrode 242. This is because the second margin portion 232 exists between the first end surface electrode 251 and the second electrode 242 (see FIG. 2A). The first end surface electrode 251 is disposed in the negative direction of the Y-axis. On the other hand, the second end surface electrode 252 is connected to the second electrode 242 but not connected to the first electrode 241. This is because the first margin portion 231 exists between the second end surface electrode 252 and the first electrode 241 (see FIG. 2A). The second end surface electrode 252 is disposed in the positive direction of the Y-axis. The capacitor 1 can be charged by applying a voltage between the first end surface electrode 251 and the second end surface electrode 252.

[0044] The material of the end electrode 25 is not particularly limited, but may be, for example, Zn (zinc), Sn (tin), or an alloy thereof. The thickness of the end electrode 25 is not particularly limited, but may be, for example, 0.5 mm or more and 1.5 mm or less. The method of producing the end electrode 30 is not particularly limited.

[0045] (others) Although the case where the capacitor element 2 is a wound type film capacitor has been described above with reference to Figs. 2A to 2C, the capacitor element 2 may be a laminated type film capacitor as shown in Figs. 3A to 3C. Figs. 3B and 3C show an example of a laminated type film capacitor. That is, in the capacitor element 2, first electrodes 241 and second electrodes 242 are alternately formed in one direction in the main body 20 with dielectric films 22 interposed therebetween. The capacitor element 2 has a rectangular parallelepiped shape.

[0046] In the case of a laminated film capacitor, of the pair of end faces 200, the first end face 201 is a face facing in the positive direction of the Y-axis. The first electrode 241 extends in the X-axis direction in the ZX plane view. The second electrode 242 also extends in the X-axis direction in the ZX plane view, similar to the first electrode 241. However, at the first end face 201, the second electrode 242 is not exposed. Furthermore, at the second end face 202, the first electrode 241 is not exposed.

[0047] A laminated film capacitor may also have end surface electrodes 25 on end surfaces 200 of main body 20. For example, as shown in Fig. 3C, capacitor element 2 is a laminated type, and end surface electrodes 25 are formed on both ends in the Y-axis direction of laminated metallized film 21.

[0048] <Exterior body> The exterior housing 3 has an accommodating portion 310. In the capacitor 1, the capacitor element 2 is accommodated in the accommodating portion 310. That is, the exterior housing 3 forms a case capable of holding the capacitor element 2 in the accommodating portion 310 therein. In the capacitor 1 of this embodiment, the exterior housing 3 has the accommodating portion 310, which is an internal space, inside, and the accommodating portion 310 can be filled with a gas.

[0049] The exterior body 3 may be any body that has a peripheral surface surrounding an internal space, can accommodate the capacitor element 2 in the internal space, and can seal the internal space. In FIG. 1A, the exterior body 3 includes a housing 31 and a cover portion 32.

[0050] The housing 31 is formed as a box-shaped body with an opening at the top side (the side in the positive direction of the Z axis) of the exterior body 3. For example, the housing 31 has a bottom surface 311 and a peripheral surface 312. The bottom surface 311 has a surface parallel to the XY plane, for example. The peripheral surface 312 is connected, for example, at the peripheral end of the bottom surface 311, and extends in the positive direction of the Z axis. It can also be said that the peripheral surface 312 constitutes a wall surface of the exterior body 3. As a result, the housing 31 has an internal space surrounded by the bottom surface 311 and the peripheral surface 312, and the surface opposite to the bottom surface 311 is open.

[0051] The cover unit 32 can seal the internal space by closing the opening of the housing 31. The cover unit 32 has, for example, a rounded rectangular shape that is approximately the same as or slightly larger than the area of ​​the opening of the housing 31. The cover unit 32 can be disposed, for example, so as to face the bottom surface 311 of the housing 31 and close the opening of the housing 31. This can seal the internal space within the exterior body 3.

[0052] As shown in Fig. 1B, in this embodiment, the cover portion 32 can have a through hole 33. The through hole 33 can be used to pull out an end of a bus bar 4 (described later) from inside the exterior body 3 to the outside. However, in the capacitor 1 of this embodiment, the exterior body 3 is in a sealed state, so the through hole 33 is blocked. For example, in Fig. 1B, the through hole 33 is blocked by a blocking member 34. The blocking member 34 may be a member having a shape that matches the dimensions of the through hole 33, or may be a cured product of an adhesive, or the like.

[0053] The shape of the housing 31 is not limited to the above and may be a cylindrical shape, etc. The shape of the cover part 32 is also not limited to the above as long as it can be combined with the housing 31 to seal the internal space.

[0054] Furthermore, in the above description, the exterior body 3 is configured with the housing 31 and the cover part 32 as separate bodies, but the housing 31 and the cover part 32 may be configured as a single body. Also, if the exterior body 3 is configured to be hermetically sealed, it may be configured such that, for example, the opening of one housing 31 is overlapped with the opening of the other housing 31 to close the opening and create a hermetically sealed state.

[0055] Furthermore, the exterior body 3 may be provided with a valve insertion hole (not shown) for installing a valve connecting the inside and outside. In this case, by opening and closing the valve, for example, in a closed state, it becomes easier to maintain the sealed state of the exterior body 3, and for example, in an open state, it becomes possible to analyze the internal gas and refill the gas. Therefore, even if the remaining gas amount in the capacitor 1 becomes low, the capacitor 1 can be easily regenerated by refilling it with gas.

[0056] The material for producing the exterior body 3 is not particularly limited, but it can be produced from, for example, polyphenylene sulfide.

[0057] <Busbar> 1A and 1B, the capacitor 1 further includes a bus bar 4. The bus bar 4 is a plate-shaped conductive member. In the present embodiment, the bus bar 4 includes a first bus bar 41 and a second bus bar 42.

[0058] Bus bar 4 is used, for example, for electrically connecting to an external circuit, power source, etc. Bus bar 4 is connected to end electrode 25 of capacitor element 2, and is drawn out to the outside of exterior body 3 (see FIG. 1A, etc.). Specifically, bus bar 4 penetrates a part of exterior body 3 and is drawn out so as to protrude from housing portion 310 of exterior body 3 toward the outside of exterior body 3. In this case, capacitor 1 can be more easily applied to electronic devices, electronic components, etc., such as semiconductor devices.

[0059] It is preferable that the portion where the bus bar 4 penetrates the exterior body 3, for example the through hole 33, be blocked with an adhesive. In this case, the through hole 33 in the exterior body 3 can be blocked. This can prevent the gas filled inside the exterior body 3 from leaking through the through hole to the outside of the exterior body 3. Furthermore, the sealed state of the exterior body 3 can be maintained more stably.

[0060] The material of the busbar 4 is not particularly limited, but the busbar 4 may be made of, for example, a steel plate. The busbar 4 contains, for example, Cu and / or Al.

[0061] 1A, 4A, and 4B, the first busbar 41 has a first protruding piece 411, a first flat portion 412, and a first leg piece 413. The second busbar 42, like the first busbar 41, has a second protruding piece 421, a second flat portion 422, and a second leg piece 423.

[0062] The first protruding piece 411 extends in the positive direction of the Z axis. In the capacitor 1, the first protruding piece 411 protrudes beyond the cover portion 32 of the exterior body 3 and protrudes to the outside of the exterior body 3. More specifically, the tip side of the first protruding piece 411 penetrates the through hole 33 of the cover portion 32 and protrudes to the outside of the exterior body 3. The first flat portion 412 has a surface that is approximately parallel to the flat surface of the main body portion 20 of the capacitor element 2, one end portion is connected to the first protruding piece 411, and an end portion different from the one end portion is connected to the first leg piece 413. The first flat portion 412 may be disposed in contact with the capacitor element 2. The first leg piece 413 is connected to the first end surface electrode 251 and is connected to the first flat portion 412. The first protruding piece 411, the first flat portion 412, and the first leg piece 413 are integrally formed.

[0063] The second protruding piece 421 extends in the positive direction of the Z axis. In the capacitor 1, the second protruding piece 421 protrudes beyond the cover portion 32 of the exterior body 3 and protrudes to the outside of the exterior body 3. More specifically, the tip side of the second protruding piece 421 penetrates the through hole 33 of the cover portion 32 and protrudes to the outside of the exterior body 3. The second flat portion 422 has a surface that is approximately parallel to the flat surface of the main body portion 20 of the capacitor element 2, one end portion is connected to the second protruding piece 421, and an end portion different from the one end portion is connected to the second leg piece 423. The second flat portion 422 may be disposed in contact with the capacitor element 2. The second leg piece 423 is connected to the second end surface electrode 252 and is connected to the second flat portion 422. The second protruding piece 421, the second flat portion 422, and the second leg piece 423 are integrally formed.

[0064] The shape of busbar 4 is not limited to the above, and may have a portion connected to end electrode 25 and a portion drawn out to the outside of exterior body 3. For example, busbar 4 may have a piece other than the leg pieces (first leg piece 413 and second leg piece 423), the tip side of the piece being connected to end electrode 25, and the side of the piece opposite to the portion (tip side) connected to end electrode 25 protruding out to the outside of exterior body 3. In other words, the above-mentioned first planar portion 412 and second planar portion 422 may not be formed.

[0065] In this manner, the first bus bar 41 is connected to the first end surface electrode 251. The first bus bar 41 is not connected to the second end surface electrode 252. The first bus bar 41 protrudes in the positive direction of the Z axis. On the other hand, the second bus bar 42 is connected to the second end surface electrode 252. The second bus bar 42 is not connected to the first end surface electrode 251. Second bus bar 42 protrudes in the same direction as first bus bar 41.

[0066] In the capacitor 1, the bus bar 4 is preferably fixed to the exterior body 3 by insert molding. In this case, the bus bar 4 can be easily installed compared to connecting the bus bar 4 to the capacitor element 2 and then sealing the exterior body 3, and therefore workability can be improved. Here, in the present disclosure, insert molding is a molding method in which a material for producing the exterior body 3 (e.g., a molding resin) and a material constituting the bus bar 4 (e.g., a metal plate-shaped member) are integrally molded. Specifically, as shown in FIG. 4A, the bus bar 4 can be fixed to the exterior body 3 (cover portion 32) by previously arranging a member constituting the bus bar 4 in a mold for forming the cover portion 32 of the exterior body 3, pouring a molding resin into the mold, and appropriately curing it. Note that this is not limited to the above, and the bus bar 4 may be arranged in the exterior body 3 and sealed in a state attached to the capacitor element 2, for example, as shown in FIG. 4B.

[0067] In the above, the first bus bar 41 and the second bus bar 42 protrude in the same direction, but this is not limited to the above, and the first bus bar 41 and the second bus bar 42 may protrude in different directions or orientations.

[0068] (others) In the capacitor 1 of this embodiment, the internal space, i.e., the housing portion 310 does not need to be filled with resin. In other words, the gap between the capacitor element 2 and the exterior body 3 in the housing portion 310 does not need to be sealed. This is because the gap between the capacitor element 2 housed in the housing portion 310 of the exterior body 3 and the housing portion 310 is filled with gas as described above. Therefore, when filling the gap by filling the housing portion inside the exterior body with resin as in the conventional method, a work process for filling the resin is required in manufacturing the capacitor, which causes a problem of a long lead time. However, according to the capacitor 1 of this embodiment, such a work process can be simplified. In addition, according to the capacitor 1 of this embodiment, the weight of the capacitor 1 can be reduced compared to when filling the resin.

[0069] [Capacitor manufacturing method] Next, a method for manufacturing the capacitor according to this embodiment will be described using an example in which the capacitor element 2 is a film capacitor. However, the manufacturing method is not limited to the following as long as it does not impair the configuration of the present disclosure and the effects based on the configuration.

[0070] <Manufacturing of capacitor elements> As described above, the production of capacitor element 2 includes the element body forming step, the pressing step, and the end electrode forming step (see FIG. 5A).

[0071] First, materials are prepared for producing capacitor element 2. Specifically, metallized film 21 and, if necessary, appropriate materials are prepared.

[0072] For example, as shown in Fig. 2A, capacitor element 2 is first formed by stacking two elongated metallized films 21 (first metallized film 211 and second metallized film 212) and winding them around axis C to form a cylindrical wound body (main body 20) (element main body formation process). When main body 20 of capacitor element 2 is a film capacitor, metallized film 21 may be formed by an appropriate method. The metallized film can be formed, for example, as follows.

[0073] The metallized film 21 is formed by forming an electrode 24 on the surface of the dielectric film 22. Specifically, the electrode 24 can be formed on the surface of the dielectric film 22 by, for example, evaporating or sputtering a metal material onto the dielectric film 22. The method of forming the electrode on the surface of the dielectric film 22 is not limited to the above. For example, the electrode 24 may be produced by overlapping a thin metal film on the surface of the dielectric film 22 and pressing it together. The preferred materials for producing the dielectric film 22 and the electrode 24 are as described above.

[0074] In this manner, metallized film 21 is produced. The produced metallized film 21 may be long, or the long metallized film 21 may be wound in a roll. In this embodiment, metallized film 21 is wound in a roll (see FIG. 2A). When metallized film 21 is wound in a roll, for example, storage, processing, and the like are easy, and workability is excellent. Furthermore, metallized film 21 may be cut to an appropriate size while still in the roll, for example, to facilitate appropriate processing.

[0075] In the element body forming step, a plurality of metallized films 21 (first metallized film 211 and second metallized film 212 in FIG. 2A) are prepared, and as shown in FIG. 2A, first metallized film 211 and second metallized film 212 are stacked with their two long sides aligned. At this time, first dielectric film 221 or second dielectric film 222 is interposed between first electrode 241 and second electrode 242. Furthermore, the long side on which first margin portion 231 is formed and the long side on which second margin portion 232 is formed are reversed. In this way, first metallized film 211 and second metallized film 212 are stacked and wound around axis C, thereby obtaining cylindrical body portion 20. First electrode 241 and second electrode 242 constitute a pair of electrodes 24 as electrodes inside the capacitor. The wound cylindrical body portion 20 can be removed from axis C and stored.

[0076] Next, the side surface of the cylindrical main body 20 shown in FIG. 2A is pressed and flattened, thereby obtaining a flattened cylindrical main body 20 (pressing step; see FIG. 2B).

[0077] In the pressurizing step, the cylindrical main body portion 20 is pressed in a direction perpendicular to the longitudinal direction of the axis C.

[0078] Specifically, the side surface of the main body 20 is flattened by pressing it along one direction perpendicular to the longitudinal direction of the axis C (for example, the negative direction of the Z axis) (see FIG. 2B). The cross-sectional shape of the main body 20 is an ellipse. By flattening it in this way, the space required for the capacitor 1 can be reduced.

[0079] In this manner, a flat body portion 20 is obtained. Inside the body portion 20, a pair of electrodes 24 (first electrode 241 and second electrode 242) face each other via the dielectric film 22 (first dielectric film 221 or second dielectric film 222).

[0080] Next, end electrodes 25 (first end electrode 251 and second end electrode 252) are formed by spraying metal onto end faces 200 (201, 202) on both sides of main body 20. This completes capacitor element 2 (end electrode forming step).

[0081] In the end surface electrode forming step, it is preferable to form the end surface electrodes 25 on the end surfaces 200 (201, 202) of the main body portion 20 after the above-mentioned pressing step.

[0082] In forming the end electrodes 25, for example, a metal spraying method (also called metallicon) is used to spray a metal material onto the end faces 200 (201, 202) on both sides of the flat main body 20 to form the end electrodes 25 (first end electrode 251 and second end electrode 252). The metal material to be sprayed is not particularly limited, but at least one material selected from the group consisting of Zn (zinc), Sn (tin), and alloys thereof may be used. It is preferable to use a material with a low melting point as the metal material to be sprayed. In this case, when forming the end electrodes 25 by metallicon, defects of the main body 20 due to heat are unlikely to occur. The material of the end electrodes 25 preferably has a melting point of 700°C or less, and more preferably has a melting point of 450°C or less.

[0083] As a result, first edge electrode 251 is electrically connected to first electrode 241 of first metallized film 211. Additionally, second edge electrode 252 is electrically connected to second electrode 242 of second metallized film 212. In this manner, capacitor element 2 including body portion 20 and edge electrode 25 is produced.

[0084] The production of the capacitor element 2 may include an aging process. In the aging process, a heat treatment is performed on the body 20 on which the end electrodes 25 are formed. That is, in the aging process, a pair of end electrodes 25 is formed on the end faces 200 of the body 20, and then the element having the body 20 and the end electrodes 25 (i.e., the capacitor element 2) is heated.

[0085] More specifically, the capacitor element 2 is placed in an appropriate heating device and heated under appropriate heating conditions. The heating conditions can be adjusted appropriately taking into consideration the type of dielectric film 22, the shape required for the capacitor 1, and removal of moisture that may be contained in the capacitor 1. One example of the heating conditions is a heating temperature of, for example, 80°C or higher and 300°C or lower, and a heating time of, for example, 30 minutes to 24 hours. It is more preferable that the heating temperature in the aging process is 100°C or higher and 150°C or lower. However, the heating conditions are not limited to those described above.

[0086] Although the manufacturing of the capacitor element 2 has been described above, a step of performing an appropriate treatment may be included between each step as long as it does not impede the objective of the present disclosure. Also, a step of performing an appropriate treatment may be included after the aging step. For example, the manufacturing of the capacitor 1 may include a step of cooling the capacitor element 2 (capacitor 1).

[0087] <Capacitor manufacturing> The following describes capacitor 1 including bus bar 4. A method for manufacturing capacitor 1 of this embodiment includes a bus bar attachment step, a gas filling step, and an element sealing step, as shown in Fig. 5B, for example.

[0088] <<First embodiment>> (Busbar installation process) A capacitor element 2 and an exterior body 3 having an accommodation portion 310 are prepared. If necessary, a bus bar 4 is prepared. The capacitor element 2 is placed in the accommodation portion 310 of the exterior body 3, and then one end portion of the pair of bus bars 4 (first leg piece 413 and second leg piece 423 in FIGS. 1A, 1B, 4A, and 4B) is brought into contact with and fixed to end surface electrodes 25 (first end surface electrode 251 and second end surface electrode 252) on both end surfaces 200 (201, 202) of the capacitor element 2, respectively. This electrically connects the pair of bus bars 4 and the pair of end surface electrodes 25.

[0089] When the exterior body 3 includes a housing 31 and a cover portion 32, the capacitor element 2 is placed in the internal space of the housing 31, and then the pair of bus bars 4 are fixed to the pair of end surface electrodes 25. Then, the cover portion 32 is placed over the exterior body 3 so that the first protruding piece 411 and the second protruding piece 421 of the bus bar 4 protrude to the outside of the exterior body 3. At this time, the first protruding piece 411 and the second protruding piece 421 of the bus bar 4 are pulled out through the through hole 33 of the cover portion 32.

[0090] The bus bar 4 may be fixed to the exterior body 3 in advance by insert molding. In other words, when the bus bar 4 and the exterior body 3 are integrally formed, for example, when the cover portion 32 of the exterior body 3 and the bus bar 4 are integrally formed as shown in Fig. 4A, the above process is not necessary. Also, as shown in Fig. 4B, after the bus bar 4 is fixed to the capacitor element 2, the capacitor element 2 to which the bus bar 4 is fixed may be placed in the accommodation portion 310 of the exterior body 3, and then the cover portion 32 may be placed thereon.

[0091] (Gas filling process) Next, the inside of the exterior body 3, i.e., the storage section 310, is filled with gas. As described above, the gas is at least one of hydrogen and helium. Specifically, the capacitor element 2 (including the case where the bus bar 4 is fixed) is placed on the exterior body 3 in a space filled with gas, for example, in a chamber, and left to stand for a predetermined time, thereby filling the storage section 310 with gas.

[0092] Alternatively, the gas may be filled in the chamber by placing exterior body 3 in the gas-filled state, filling accommodation portion 310 with gas, and then placing capacitor element 2 therein.

[0093] (Element sealing process) Next, in a state where the storage section 310 of the exterior body 3 is filled with gas, the exterior body 3 is sealed. Specifically, in a state where the storage section 310 is filled with gas, the opening of the housing 31 is covered with the cover section 32 to seal the exterior body 3. If the through hole 33 of the cover section 32 is not blocked, the through hole 33 may be blocked with the blocking member 34 after the cover section 32 is placed on the housing 31. The through hole 33 may also be blocked by filling the gap between the bus bar 4 and the through hole 33 with an adhesive. Of course, the through hole 33 of the cover section 32 may be blocked in advance to cover the opening of the housing 31.

[0094] As a result, a capacitor 1 is obtained in which the inside of the sealed exterior body 3 is filled with gas.

[0095] <<Second embodiment>> In the second embodiment, the gas filling method in the gas filling step is different from that in the first embodiment. That is, in the second embodiment, in the gas filling step, the capacitor element 2 is placed in the storage section 310 of the exterior body 3 while blowing gas into the storage section 310, and the opening of the housing 31 is covered with the cover part 32 while maintaining the blowing of gas. This results in a capacitor 1 in which the inside of the sealed exterior body 3 is filled with gas. In this case, the amount of gas used can be reduced compared to the first embodiment. Note that in the second embodiment, when the bus bar 4 is fixed to the exterior body 3 by insert molding, the capacitor element 2 may be placed in the housing 31, and then the cover part 32 and the bus bar 4 may be covered in a state where they are integrated, and the gas may be blown into the storage section 310 with a small gap between the housing 31 and the cover part 32.

[0096] <<Third embodiment>> The third embodiment differs from the first and second embodiments in that an element sealing step is performed before the gas filling step. Specifically, in the third embodiment, the capacitor element 2 (including the case where the bus bar 4 is fixed) is placed in the exterior body 3, and the housing 31 is covered with the cover part 32 to create a sealed state. In this state, the storage section 310 in the exterior body 3 is generally filled with air or the like. Therefore, for example, a valve that communicates the inside and the outside is installed in a part of the exterior body 3, and the air inside is sucked from the valve by a suction device. The suction device can be an appropriate pump or the like. As a result, the storage section 310 of the exterior body 3 is put into a vacuum state. Next, the valve is closed once, the suction device is removed from the valve, a pipe for introducing gas is connected, the valve is opened, and the storage section 310 is filled with gas. The amount of gas filled can be confirmed by installing, for example, a pressure meter. As a result, a capacitor 1 in which the inside of the sealed exterior body 3 is filled with gas is obtained.

[0097] Although the steps of manufacturing the capacitor 1 have been described above using examples, this is not intended to limit the method of manufacturing the capacitor 1 of the present disclosure. For example, the capacitor 1 may be manufactured by including steps other than those described above, or may be manufactured in an order other than the order of the steps described above.

[0098] 3. Aspects As is apparent from the above embodiment, the present disclosure includes the following aspects. In the following, reference symbols are given in parentheses only to clarify the correspondence with the embodiment.

[0099] A capacitor (1) according to a first aspect includes a capacitor element (2) and an exterior body (3). The exterior body (3) has a housing (310) that houses the capacitor element. The housing (310) is filled with a gas. The gas includes at least one of helium and hydrogen.

[0100] According to this embodiment, heat generated from the capacitor element (2) can be easily dissipated from inside the capacitor (1) to the outside.

[0101] The capacitor (1) according to the second aspect is the same as the capacitor (1) according to the first aspect, and further includes a bus bar (4). The capacitor element (2) has an end surface electrode (25). The bus bar (4) is connected to the end surface electrode (25) and is extended to the outside of the exterior body (3).

[0102] According to this embodiment, the capacitor (1) can be easily used in electronic devices such as semiconductor devices, electronic components, and the like.

[0103] The capacitor (1) according to the third aspect is the second aspect, wherein a portion where the bus bar (4) penetrates from the inside to the outside of the exterior body (3) is sealed with an adhesive.

[0104] According to this embodiment, the gas filled in the exterior body (3) can be made less likely to leak to the outside of the exterior body (3). Also, the sealed state of the exterior body (3) can be maintained more stably.

[0105] The capacitor (1) of a fourth aspect is the capacitor of the second or third aspect, in which the bus bar (4) is fixed to the exterior body (3) by insert molding.

[0106] According to this embodiment, the bus bar (4) can be easily installed, which makes it easy to improve workability.

[0107] A fifth aspect of the present invention relates to a method for manufacturing a capacitor (1) including a capacitor element (2) and an exterior body (3) having a housing (310) for housing the capacitor element (2). The method for manufacturing the capacitor (1) includes a step of filling the housing (310) with a gas. The gas is at least one of helium and hydrogen.

[0108] According to this embodiment, a capacitor (1) can be manufactured that allows heat generated from the capacitor element (2) to easily escape from the inside of the capacitor (1) to the outside. [Explanation of symbols]

[0109] 1 Capacitor 2. Capacitor elements 25 End electrode 3 Exterior body 310 Storage unit 4 Busbars

Claims

1. A capacitor element; an exterior body having a housing portion that houses the capacitor element; The container is filled with a gas, The gas includes at least one gas selected from the group consisting of helium and hydrogen. Capacitor.

2. A bus bar is further provided, The capacitor element has end electrodes, the bus bar is connected to the end surface electrode and is extended to the outside of the exterior body; The capacitor of claim 1 .

3. A portion where the bus bar penetrates from the inside to the outside of the exterior body is sealed with an adhesive. The capacitor of claim 2.

4. The bus bar is fixed to the exterior body by insert molding. The capacitor according to claim 2 or 3.

5. A method for manufacturing a capacitor including a capacitor element and an exterior body having a housing portion that houses the capacitor element, Filling the storage section with a gas, The gas is at least one of helium and hydrogen. How a capacitor is manufactured.

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