Electronic component, method for manufacturing electronic component, capacitor, and method for manufacturing capacitor

Abstract

An electronic component includes an electronic component element and a barrier film. The electronic component element has external electrodes at both ends. The barrier film covers at least a portion of the periphery of the electronic component element. The barrier film includes an insulating film and a clay layer, the insulating film having electrical insulating properties, and the clay layer containing clay.

Description

Technical Field

[0001] The present invention relates to an electronic component, a method for manufacturing an electronic component, a capacitor, and a method for manufacturing a capacitor. More specifically, it relates to an electronic component including an electronic component element and a barrier film, a method for manufacturing an electronic component, and a method for manufacturing a capacitor. Background Art

[0002] Patent Document 1 describes a case-molded capacitor. This case-molded capacitor comprises a capacitor element, lead terminals, a molded resin, and a case. The capacitor element is a wound film capacitor element housed in a case made of polyphenylene sulfide (PPS) resin. The molded resin fills the case, sealing the capacitor element. The lead terminals are electrically connected to the capacitor element and extend from the molded resin portion to the outside of the case.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-294788 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The case molded capacitor described in Patent Document 1 attempts to protect the capacitor element from humidity using molded resin and a case. However, to ensure moisture resistance, the case and molded resin must be thickened, requiring a large amount of resin and making miniaturization difficult.

[0008] An object of the present invention is to provide a method for manufacturing an electronic component that can be easily miniaturized, a capacitor, and a method for manufacturing a capacitor.

[0009] Means for solving problems

[0010] An electronic component according to one embodiment of the present invention includes an electronic component element and a barrier film. The electronic component element has external electrodes at both ends. The barrier film covers at least a portion of the periphery of the electronic component element. The barrier film includes an insulating film and a clay layer. The insulating film has electrical insulating properties. The clay layer contains clay.

[0011] Another embodiment of the present invention includes an electronic component element, an exterior resin layer, and a barrier film. The electronic component element has external electrodes at both ends. The exterior resin layer covers at least a portion of the electronic component element. The barrier film covers at least a portion of the periphery of the exterior resin layer. The barrier film includes an insulating film and a clay layer. The insulating film has electrical insulating properties. The clay layer contains clay.

[0012] In the capacitor according to one embodiment of the present invention, the electronic component element includes a capacitor element.

[0013] A method for manufacturing an electronic component according to one embodiment of the present invention comprises forming an electronic component element and wrapping a barrier film around at least a portion of the electronic component element. The barrier film comprises an insulating film and a clay layer. The insulating film has electrical insulating properties. The clay layer contains clay.

[0014] A capacitor manufacturing method according to one embodiment of the present invention comprises the steps of winding a metallized film to form a wound body, winding a barrier film around at least a portion of the wound body, and forming external electrodes by spraying a metal material onto both ends of the wound body on which the barrier film is wound. The barrier film comprises an insulating film and a clay layer formed on the insulating film. The insulating film has electrical insulating properties. The clay layer contains clay. When winding the barrier film, the clay layer is directed toward the wound body.

[0015] Effects of the Invention

[0016] According to the present invention, electronic components and capacitors have the following advantages: by including a clay layer that is less susceptible to moisture permeation than a resin layer of the same thickness, moisture resistance can be easily ensured without increasing the thickness of the molded resin and the case, and miniaturization is facilitated. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A is a cross-sectional view showing the electronic component according to the first embodiment. Figure 1 B is a cross-sectional view showing the electronic component according to the first embodiment. Figure 1 C is a cross-sectional view showing the electronic component according to the first embodiment. Figure 1 D is a cross-sectional view showing the electronic component according to the first embodiment.

[0018] Figure 2 A is a cross-sectional view showing an example of a barrier film used in the electronic component of the first embodiment. Figure 2 B is a schematic perspective view showing an example of mineral particles. Figure 2 C is a schematic cross-sectional view showing an example of a clay layer.

[0019] Figure 3 A is a cross-sectional view showing an example of external electrodes of the electronic component according to the first embodiment. Figure 3 B is a cross-sectional view showing another example of the external electrodes of the electronic component according to the first embodiment.

[0020] Figure 4 A is a process diagram (perspective view) of a method for manufacturing a wound-type capacitor element. Figure 4 B is a perspective view of the wound capacitor element.

[0021] Figure 5 This is a schematic cross-sectional view showing an example of a process for forming external electrodes.

[0022] Figure 6 A is a cross-sectional view showing an electronic component according to the second embodiment. Figure 6 B is a cross-sectional view showing the electronic component according to the third embodiment.

[0023] Figure 7 It is a cross-sectional view showing an electronic component of a comparative example. DETAILED DESCRIPTION

[0024] (Implementation Method 1)

[0025] (1) Summary

[0026] The electronic component 1 of this embodiment includes an electronic component element 2 and a barrier film 30 (see Figure 1 A) Electronic component element 2 has external electrodes 24 at both ends. Barrier film 30 covers at least a portion of the periphery of electronic component element 2. Barrier film 30 includes insulating film 33 and clay layer 31. Insulating film 33 has electrical insulating properties. Clay layer 31 contains clay.

[0027] With this structure, the electronic component 1 includes a clay layer 31 on the barrier film 30, which is less susceptible to moisture permeation than a resin layer of the same thickness. Specifically, the clay layer 31 has a labyrinthine structure, allowing less moisture per unit thickness than a resin layer alone. Consequently, the barrier film 30 with the clay layer 31 reduces moisture permeation compared to a resin layer without the clay layer 31. Consequently, the electronic component 1 utilizes the barrier film 30 to maintain moisture resistance while reducing the thickness of the exterior resin layer 4, facilitating miniaturization.

[0028] For example, when the electronic component is a film capacitor, the electronic component element is configured as a film capacitor element. The film capacitor element is produced, for example, by forming a very thin aluminum vapor-deposited electrode (20-30 nm thick) on a dielectric film. Next, two sheets of dielectric films with vapor-deposited electrodes are staggered and wound together. Finally, external electrodes are formed on both ends of the wound member by metallization.

[0029] The vapor-deposited electrodes in these film capacitor elements are extremely thin and have poor moisture resistance (resistance to moisture penetrating the film capacitor). Moisture can oxidize these electrodes, reducing their functionality as electrodes and degrading the film capacitor's properties. Therefore, film capacitor elements have traditionally been protected from moisture by being housed in a resin case and then filled with sealing resin within the case.

[0030] However, when using only epoxy resin for the resin case and sealing resin, the thickness of the resin case and sealing resin must be at least 2mm at the thinnest. Therefore, film capacitors using epoxy resin for the resin case and sealing resin are heavy and easily become very complicated to manufacture. Furthermore, when film capacitors are used in vehicles, their shape is customized and designed to vary with each vehicle model, making them difficult to reduce costs.

[0031] In addition, a technique of winding a film having an inorganic oxide (silicon oxide, or silicon oxide and aluminum oxide) layer around a capacitor element has been proposed. However, in recent years, demands for further preventing moisture absorption have increased, and conventional techniques are no longer able to cope with the situation.

[0032] On the other hand, the electronic component 1 of this embodiment includes a clay layer 31 containing clay on the barrier film 30 covering the electronic component element 2. This makes it easier to reduce the amount of moisture that passes through the barrier film 30 compared to a resin layer of the same thickness formed solely from resin. Consequently, less moisture reaches the electronic component element 2 from the outside of the electronic component 1, making it less likely that moisture will act on the electronic component element 2, and thus easily achieving an electronic component 1 with excellent moisture resistance. Furthermore, the clay layer 31 can be formed on the surface of the insulating film 33 by a simple method such as coating, which reduces the complexity of the manufacturing process of the electronic component 1 and facilitates cost reduction.

[0033] (2) Details

[0034] (2.1) Composition

[0035] Electronic components

[0036] like Figure 1 As shown in A, the electronic component 1 of this embodiment includes an electronic component element 2 and a barrier film 30. The electronic component element 2 is a component or part for enabling the electronic component 1 to perform its intended function. The electronic component element 2 has external electrodes 24 at both ends.

[0037] The barrier film 30 has the function of protecting the electronic component element 2. For example, the barrier film 30 has the function of protecting the electronic component element 2 from moisture. In addition, the barrier film 30 can have the function of protecting the electronic component element 2 from heat, light, electromagnetic waves, shock, chemicals, etc. The barrier film 30 covers at least a portion of the periphery of the electronic component element 2. For example, the barrier film 30 is formed in a manner that covers the entire electronic component element 2 except for the portion of the external electrode 24. The barrier film 30 can be provided in contact with the surface of the electronic component element 2. Figure 2 As shown in A, the barrier film 30 includes an insulating film 33 and a clay layer 31. The insulating film 33 has electrical insulating properties. The clay layer 31 contains clay.

[0038] The barrier film 30 is preferably arranged with the clay layer 31 facing the electronic component element 2. Specifically, the barrier film 30 preferably covers the electronic component element 2 so that the clay layer 31 is located on the inner side (on the electronic component element 2 side) when viewed from the insulating film 33. In the barrier film 30, the clay layer 31 has a higher adhesion to the electronic component element 2 than the insulating film 33. Therefore, by arranging the barrier film 30 with the clay layer 31 facing the electronic component element 2, the clay layer 31 and the electronic component element 2 are more closely adhered to each other, thereby reducing the intrusion of moisture into the electronic component element 2.

[0039] The barrier film 30 preferably covers the periphery of the external electrode 24. Figure 3 As shown in Figure A, the end 301 of the barrier film 30 in the width direction is preferably located around the external electrode 24 (outside the peripheral end 241). In this case, the peripheral end 241 of the external electrode 24 is preferably covered entirely by the end 301 of the barrier film 30 in the width direction. In this case, by covering the boundary between the element body 2a and the external electrode 24 with the barrier film 30, it is possible to suppress the intrusion of moisture from the boundary between the element body 2a and the external electrode 24. It should be noted that the element body 2a is a constituent element of the electronic component element 2, and the electronic component element 2 is formed by providing the external electrodes 24 at both ends of the element body 2a. In the case where the electronic component 1 is a film capacitor, the element body 2a is the portion composed of the metallized film other than the external electrode 24. In the case where the capacitor element 20 is a wound film capacitor element, the element body 2a is composed of the wound body 73.

[0040] In addition, the end surface of the barrier film 30 may also be covered by the external electrode 24. Figure 3 As shown in FIG. 2B , the peripheral end portion 241 of the external electrode 24 is preferably located outside the widthwise end surface of the barrier film 30. In this case, the peripheral end portion 241 of the external electrode 24 preferably covers the entire widthwise end surface of the barrier film 30. In this case, by covering the boundary between the element body 2a and the barrier film 30 with the external electrode 24, moisture intrusion from the boundary between the element body 2a and the barrier film 30 can be suppressed.

[0041] The electronic component 1 of this embodiment may further include an exterior resin layer 4 covering the electronic component element 2 and the barrier film 30. The exterior resin layer 4 protects the electronic component element 2 and the barrier film 30 from moisture. Furthermore, the exterior resin layer 4 may protect the electronic component element 2 and the barrier film 30 from heat, light, electromagnetic waves, shock, chemicals, and the like. The exterior resin layer 4 is formed from a housing (container) or a molded resin, or both.

[0042] The electronic component 1 of the present embodiment may further include a busbar 6. The busbar 6 is a terminal that electrically connects the electronic component 1 to a circuit substrate, etc. One end (base end) of the busbar 6 is electrically and mechanically connected to the external electrode 24 of the electronic component element 2. The other end (front end) of the busbar 6 is located outside the outer resin layer 4. The busbar 6 is made of, for example, copper or a copper alloy and is formed in a plate shape. The electronic component 1 of the present embodiment includes a pair of busbars 6, and the front end of each busbar 6 protrudes outward (for example, upward) from the same surface (for example, the upper surface) of the outer resin layer 4, but is not limited to such a shape and structure.

[0043] Hereinafter, a case where the electronic component 1 is a capacitor 10 will be described. The electronic component 1 as the capacitor 10 includes the capacitor element 20 as the electronic component element 2. That is, the electronic component element 2 in the capacitor 10 is the capacitor element 20.

[0044] <Capacitor Components>

[0045] Capacitor element 20 can use various capacitor elements depending on the type of capacitor 10. In this embodiment, capacitor 10 can be exemplified by film capacitors, ceramic capacitors, electrolytic capacitors, and the like. Among these, capacitor 10 is preferably a film capacitor, and among film capacitors, a capacitor using a wound capacitor element 20 is also preferred. In this case, barrier film 30 can be wound around capacitor element 20 using the same apparatus and steps as for producing wound capacitor element 20, making it easy to produce capacitor element 20 wound with barrier film 30. Note that capacitor element 20 may be a laminated film capacitor.

[0046] The capacitor element 20 has an external electrode 24 at both ends in the axial direction. The external electrode 24 is preferably formed by spraying a metal material. In addition, the external electrode 24 preferably contains 50% by weight or more of tin. Such an external electrode 24 is usually formed by spraying zinc, but the external electrode 24 formed by zinc tends to become porous, and moisture may penetrate from here. Therefore, in this embodiment, the tin content of the external electrode 24 is increased, thereby increasing the metal structure constituting the external electrode 24. It is not easy for moisture to pass through the external electrode 24, thereby reducing the penetration of moisture into the capacitor element 20. In addition, if the tin content of the external electrode 24 is increased, the metal structure constituting the external electrode 24 becomes dense, thereby improving the adhesion between the barrier film 30 and the external electrode 24, and further reducing the penetration of moisture into the capacitor element 20. The tin content of the external electrode 24 can be in the range of 50% by weight or more and 100% by weight or less.

[0047] Barrier film

[0048] The barrier film 30 has a function of protecting the capacitor element 20 from moisture. In addition, the barrier film 30 may have a function of protecting the capacitor element 20 from heat, light, electromagnetic waves, shock, chemicals, and the like.

[0049] like Figure 1 A and Figure 1 As shown in FIG. 3B , the barrier film 30 covers at least a portion of the periphery of the capacitor element 20. The periphery of the capacitor element 20 refers to the area around the axis of the capacitor element 20, with the opposing direction of a pair of external electrodes 24 as the axis. In the case where the capacitor element 20 is roughly cylindrical, the barrier film 30 is arranged in a manner opposite to the circumference of the capacitor element 20. Therefore, the barrier film 30 is formed to cover the entire capacitor element 20 except for the portion of the external electrodes 24. That is, the capacitor element 20 is almost entirely covered by the barrier film 30 and protected except for the portion of the external electrodes 24. As a result, it is not easy for moisture to penetrate into the capacitor element 20 from the entire periphery, and the moisture resistance of the capacitor 10 is improved. In particular, the peripheral surface (surface around the axis) of the capacitor element 20 is often larger than the end surface (axial surface), so it is preferred to set the barrier film 30 in a manner that surrounds at least the peripheral surface of the capacitor element 20. As described above, barrier film 30 is provided to cover at least a portion of the periphery of capacitor element 20 . Here, “at least a portion” preferably refers to, for example, 80% or more of the surface area of the outer surface of capacitor element 20 excluding external electrodes 24 .

[0050] The barrier film 30 is preferably arranged in multiple layers around the capacitor element 20. Specifically, multiple barrier films 30 are preferably arranged around the capacitor element 20 so as to overlap in the thickness direction. In this case, multiple clay layers 31 are stacked, improving the moisture resistance of the capacitor 10 compared to a single clay layer 31. Furthermore, even if defects such as pinholes exist in the clay layer 31, the defects can be covered by overlapping with other clay layers 31, minimizing the deterioration of the moisture resistance of the capacitor 10.

[0051] like Figure 2 As shown in Figure A, the barrier film 30 includes a clay layer 31 on one side (one surface) of an insulating film 33. The clay layer 31 is provided on the entire surface of the insulating film 33. It should be noted that the barrier film 30 may include the clay layer 31 on both surfaces of the insulating film 33. Furthermore, the barrier film 30 may include an adhesive layer between the insulating film 33 and the clay layer 31. Furthermore, the barrier film 30 may include an adhesive layer on the surface of the clay layer 31. Examples of the adhesive layer include a heat-sealed adhesive layer.

[0052] <Clay layer>

[0053] The barrier film 30 includes a clay layer 31 containing clay. Clay layer 31 comprises clay and is formed into a layer. In the present invention, clay refers to an aggregate of multiple mineral particles 311. Furthermore, the aggregate of multiple mineral particles 311 may contain a small amount of water. Mineral particles 311 include one or more selected from mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and nontronite. Among them, mineral particles 311 preferably include montmorillonite, a highly moisture-resistant clay material.

[0054] The crystal structure of montmorillonite is a single-layer structure consisting of an octahedral structure centered on Al (aluminum atom) and a tetrahedral structure centered on Si (silicon atom). Specifically, part of the trivalent Al is replaced by divalent Mg and Fe, resulting in a negative charge in the single layer. Therefore, Na is present in the crystal structure for charge compensation. + , Ca 2+ Furthermore, when montmorillonite is dispersed in water, the cationic portion hydrates and readily separates into single-layer units. Therefore, by dispersing montmorillonite in water, it readily separates into single layers. Consequently, montmorillonite readily becomes contained in the clay layer 31 in a separated single-layer state, readily forming a labyrinthine structure composed of mineral particles 311 in the clay layer 31.

[0055] The exchangeable cations between the layers of montmorillonite can be easily exchanged with other inorganic or organic cations. Therefore, it is possible to impart affinity with organic solvents and to insert various compounds between the layers. In addition, since there are hydroxyl groups on the crystal end faces, they can be modified using various silylating agents. Furthermore, if high moisture resistance of the clay layer 31 is to be obtained, it is preferred to hydrophobize the clay layer 31. For example, if the exchangeable cations (Na + If the clay layer 31 is hydrophobic, the exchangeable cations (e.g., Li, etc.) have a high affinity for water and are present between the layers, which is likely to hinder the hydrophobization of the clay layer 31. Therefore, it is considered to replace the exchangeable cations with Li and protons. For example, if montmorillonite is heat-treated, the ions will move to the interior and surface of the crystals, making it easier to hydrophobize the clay layer 31.

[0056] Figure 2 B is a schematic three-dimensional view of a mineral particle 311. In this embodiment, the mineral particle 311 is a plate-like or flake-like particle. That is, the mineral particle 311 is a particle having a thickness a that is smaller than the lateral width b. Here, the lateral width b is the dimension of the longest part of the mineral particle 311 when the mineral particle 311 is viewed from the front (from the front in the thickness direction). If the mineral particle 311 is, for example, a circular plate, the diameter is the lateral width b. The thickness a is the dimension in a direction perpendicular to the lateral width b and is the dimension between two opposing surfaces of the mineral particle 311.

[0057] In this embodiment, the mineral particles 311 have a high aspect ratio. That is, the aspect ratio defined by lateral width b / thickness a is high. The aspect ratio is obtained by measuring the thickness a and lateral width b of the mineral particles 311. The thickness a is measured, for example, by a transmission electron microscope (TEM), but the thickness of a single layer of mineral particles 311 is roughly uniform in each type, so there is no need to measure a large number of mineral particles 311. For example, in the case of montmorillonite, the thickness a is about 1 nm. The lateral width b is measured, for example, by an atomic force microscope (AFM). Observe the flat part of the mineral particle 311 and estimate the longest dimension as the lateral width b.

[0058] Figure 2 C represents a schematic cross-sectional view of clay layer 31. Clay layer 31 contains mineral particles 311 and binder 312. Specifically, clay layer 311 may consist of mineral particles 311 and binder 312, or it may contain mineral particles 311, binder 312, and other additives. Binder 312 comprises one or more selected from polypropylene, polyethylene sulfide, polyimide, polyamide, polyethylene terephthalate, epoxy resin, fluororesin, polyester resin, polyurethane resin, acrylic resin, phenoxy resin, polyacetal, and polyvinyl alcohol. Alternatively, binder 312 may be a binder resin that can be used as a varnish for a coating or slurry. Considering the ease of forming clay layer 31 and its adhesion to mineral particles 311, binder 312 is preferably polyamide, polyimide, polyurethane resin, epoxy resin, or phenoxy resin. Alternatively, a curing agent (crosslinking agent) suitable for the above resins may be used. In this case, the binder 312 is formed of a cross-linked resin, and the moisture resistance of the clay layer 31 may be improved.

[0059] The clay layer 31 is formed by dispersing a plurality of mineral particles 311 in a binder 312. The mineral particles 311 are dispersed in a state where their thickness direction is roughly consistent with the thickness direction of the clay layer 31. There are gaps between the plurality of mineral particles 311 adjacent to each other in the thickness direction, and the binder 312 is filled in the gaps. In addition, there are gaps between the plurality of mineral particles 311 adjacent to each other in a direction perpendicular to the thickness direction, and the binder 312 is filled in the gaps. In this way, the clay layer 31 has a maze-like structure (maze structure) in which the plurality of mineral particles 311 serve as passages. That is, in the clay layer 31, the plurality of mineral particles 311 are dispersed in a state where their thickness direction is consistent with the thickness direction of the clay layer 31 and they are roughly randomly positioned in the width direction, so that zigzag passages are formed between adjacent mineral particles 311. Therefore, when water W passes through the clay layer 31 in the thickness direction, it cannot move in a straight line, but must move in a zigzag manner between the adjacent mineral particles 311 (refer to Figure 2C (dashed line). Therefore, compared to a resin layer without mineral particles (a layer consisting solely of a binder), clay layer 31 is less susceptible to moisture W from passing through it. Even with a reduced thickness of barrier film 30, the moisture resistance of capacitor 10 can be maintained. For example, even if clay layer 31 is a few to several dozen μm thick, capacitor 10 can be obtained that has moisture resistance comparable to that of a 2 mm thick resin layer composed solely of epoxy resin. Consequently, capacitor 10 of this embodiment can sometimes achieve moisture resistance 1,000 times greater than that of a barrier film consisting solely of resin.

[0060] The theoretical formula of the labyrinth structure of the clay layer 31 is represented by the following formula (1).

[0061] P / P0=(1-Φ) / (1+0.5AΦ)…(1)

[0062] In the above formula (1), "P / P0" represents relative transmittance, "Φ" represents the volume fraction of the mineral particles 311 in the clay layer 31, and A represents the aspect ratio of the mineral particles 311.

[0063] The smaller the value of "P / PO" of the clay layer 31, the less likely it is for water to pass through it, and the larger the value of "P / P0", the easier it is for water to pass through it. Therefore, in formula (1), the larger the value of Φ, the less likely it is for water to pass through the clay layer 31, and the smaller the value of Φ, the easier it is for water to pass through the clay layer 31. In addition, in formula (1), the larger the value of A, the less likely it is for water to pass through the clay layer 31, and the smaller the value of A, the easier it is for water to pass through the clay layer 31. Therefore, in order to improve the moisture resistance of the capacitor 10 and to obtain a barrier film 30 that is less likely to allow water to pass through, it is preferable to increase the volume fraction of the mineral particles 311 in the clay layer 31, and it is also preferable to increase the content of mineral particles 311 with a high aspect ratio.

[0064] The aspect ratio of mineral particles 311 is preferably 20 or greater. To obtain a clay layer 31 that is less susceptible to moisture permeation, it is preferable to use mineral particles 311 with a higher aspect ratio. However, considering other properties of the clay layer 31, such as its strength, adhesion, and ease of formation, the aspect ratio is preferably within the above range. The aspect ratio of mineral particles 311 is more preferably 100 or greater, and even more preferably 150 or greater. It should be noted that the upper limit of the aspect ratio of mineral particles 311 is not specifically set and is appropriately determined based on factors such as the dispersibility of the mineral particles 311 in the clay layer 31.

[0065] Alternatively, mineral particles 311 may be combined with materials having a high aspect ratio and materials having a low aspect ratio. In this case, the low aspect ratio materials (mineral particles with smaller diameters) can easily enter between the high aspect ratio materials, thereby increasing the filling rate of mineral particles 311 in clay layer 31. When using both high aspect ratio materials and low aspect ratio materials, it is preferred that the high aspect ratio materials account for at least half of the total amount of mineral particles 311 contained in clay layer 31.

[0066] The content of mineral particles 311 in the clay layer 31 is preferably 50% by mass or greater relative to the total amount. For example, when the clay layer 31 is composed of mineral particles 311 and a binder 312, the content of mineral particles 311 is preferably 50% by mass or greater and 95% by mass or less relative to the total amount of the clay layer 31, and the content of binder 312 is preferably 5% by mass or greater and 50% by mass or less relative to the total amount of the clay layer 31. This facilitates obtaining a clay layer 31 that is less susceptible to moisture permeation while maintaining the desired properties of the clay layer 31, such as strength, adhesion, and ease of formation.

[0067] The thickness of the clay layer 31 is preferably 0.5 μm to 5 μm. A thicker clay layer 31 is preferred to reduce water permeation through the clay layer 31. However, considering the strength, adhesion, and ease of formation of the clay layer 31, the thickness is preferably within the above range. The thickness of the clay layer 31 is more preferably 1.0 μm to 3 μm.

[0068] Note that the clay layer 31 has low not only moisture permeability but also gas permeability, and thus the barrier film 30 can easily ensure gas barrier properties.

[0069] <Insulating Film>

[0070] The barrier film 30 includes an insulating film 33. The insulating film 33 is an electrically insulating film. The insulating film 33 functions as a base material supporting the clay layer 31. This prevents the clay layer 31 from being damaged. Furthermore, the clay layer 31 is easier to handle, making it easier to position the clay layer 31 around the capacitor element 20.

[0071] The insulating film 33 is preferably flexible. Furthermore, the insulating film 33 is preferably a film made of a resin. Examples of the resin film include films made of synthetic resins such as polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyamide (nylon (registered trademark)). The thickness of the insulating film 33 is appropriately set in consideration of electrical insulation and flexibility, and is preferably several tens of μm, and more preferably not less than 10 μm and not more than 30 μm.

[0072] <Production of Barrier Film>

[0073] The barrier film 30 is made by forming a clay layer 31 on the surface of an insulating film 33. The clay layer 31 is formed by supplying a treatment liquid containing mineral particles 311 and a binder 312 onto the surface of the insulating film 33 and drying the treatment liquid on the surface of the insulating film 33. In the treatment liquid, the mineral particles 311 and the binder 312 are dispersed in a solvent. The solvent can be water, an organic solvent, or a mixture thereof. Water is preferably used for ease of handling, such as waste liquid disposal.

[0074] When supplying the treatment liquid to the surface of the insulating film 33, a coating method such as brushing or spraying or an immersion method such as dipping can be used. In this case, even if there are irregularities on the surface of the insulating film 33, the treatment liquid can be supplied accordingly, and the clay layer 31 can be easily formed. When drying the treatment liquid, natural drying or heat drying can be used.

[0075] According to the manufacturing method described above, even a thin film (several to tens of μm) can be installed with a clay layer (clay layer) 31 that exhibits high moisture resistance. Even if the thickness of the outer resin layer 4 is reduced, the moisture resistance of the barrier film 30 can be ensured. Moreover, the thinner the thickness of the outer resin layer 4, the smaller and lighter the capacitor 10 can be.

[0076] <Exterior resin layer>

[0077] The outer resin layer 4 covers at least a portion of the capacitor element 20 and the barrier film 30. The outer resin layer 4 preferably covers the entire capacitor element 20 and the barrier film 30. In this case, the entire capacitor element 20 and the barrier film 30 are sealed by the outer resin layer 4. The clay layer 31 is laminated with the outer resin layer 4. That is, the clay layer 31 and the outer resin layer 4 are arranged opposite each other in the thickness direction of the barrier film 30. The thickness of the outer resin layer 4 is preferably greater than that of the clay layer 31. This allows the thin and easily cracked clay layer 31 to be easily protected by the outer resin layer 4. The thickness of the outer resin layer 4 is preferably 1 mm to 6 mm. This reduces the moisture permeability of the outer resin layer 4, in addition to the clay layer 31, thereby improving the moisture resistance of the capacitor 10. The thickness of the outer resin layer 4 is more preferably 1 mm to 4.5 mm, and even more preferably 1 mm to 3 mm.

[0078] Examples of the resin contained in the exterior resin layer 4 include epoxy resins, unsaturated polyester resins, and polyimide resins. However, epoxy resins are preferred in consideration of moldability when covering the capacitor element 20. Furthermore, the exterior resin layer 4 may be formed solely of a resin, but may also be formed of a composite material containing a resin and a filler. In this case, for example, silica or the like may be used as the filler, and the filler content relative to the total amount of the exterior resin layer 4 may be set to 1% by mass or more and 99% by mass or less.

[0079] (2.2) Manufacturing method

[0080] The method for manufacturing an electronic component 1 according to this embodiment includes the steps of forming an electronic component element 2 and wrapping a barrier film 30 around at least a portion of the periphery of the electronic component element 2. If the electronic component 1 is a capacitor 10, the method for manufacturing the capacitor 10 includes the steps of forming a capacitor element 20 and wrapping a barrier film 30 around at least a portion of the periphery of the capacitor element 20. The method for manufacturing the electronic component 1 or capacitor 10 according to this embodiment may further include the step of covering the capacitor element 20 with an exterior resin layer 4.

[0081] The production of wound capacitor element 20 includes the steps of winding metallized films 71 and 72 to form wound body 73; winding barrier film 30 around at least a portion of wound body 73; and forming external electrodes 24 by thermally spraying a metal material onto both ends of wound body 73 wound with barrier film 30. Specifically, wound capacitor element 20 can be produced as follows.

[0082] First, prepare the first metallized film 71 and the second metallized film 72 (see Figure 4 A) The first metallized film 71 includes a first dielectric film 701 and a first conductive layer 711. The first dielectric film 701 is a long strip. The first conductive layer 711 is formed on one side of the first dielectric film 701, except for a first edge portion 721. The first edge portion 721 is the exposed portion of the first dielectric film 701 and is formed along one long side of the first dielectric film 701 into a strip thinner than the first conductive layer 711.

[0083] The second metallized film 72 is formed in the same manner as the first metallized film 71. Specifically, the second metallized film 72 includes a second dielectric film 702 and a second conductive layer 712. The second dielectric film 702 is a long strip having the same width as the first dielectric film 701. The second conductive layer 712 is formed on one side of the second dielectric film 702, except for a second edge portion 722. The second edge portion 722 is the exposed portion of the second dielectric film 702 and is formed along one long side of the second dielectric film 702 in a strip shape thinner than the second conductive layer 712.

[0084] The first dielectric film 701 and the second dielectric film 702 are formed of, for example, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, or polystyrene. The first conductive layer 711 and the second conductive layer 712 are formed by a method such as evaporation or sputtering. The first conductive layer 711 and the second conductive layer 712 are formed of, for example, aluminum, zinc, or magnesium.

[0085] Then, if Figure 4As shown in A, the two long sides of the first metallized film 71 and the second metallized film 72 are aligned and overlapped. At this time, the first dielectric film 701 or the second dielectric film 702 is interposed between the first conductive layer 711 and the second conductive layer 712. Furthermore, the long side formed with the first edge portion 721 is opposite to the long side formed with the second edge portion 722. By winding the first metallized film 71 and the second metallized film 72 in an overlapping state in this way, a cylindrical winding body 73 can be obtained. Next, the barrier film 30 is wound around the outer periphery of the winding body 73, thereby covering the winding body 73 with the barrier film 30. At this time, the barrier film 30 can be wound only once (1 roll) or multiple times. Next, the side surfaces of the winding body 73 are pressed from both sides to process the winding body 73 into an oblong cross-section (refer to Figure 4 B) By flattening in this way, space can be saved. In this way, the element body 2a formed by the wound body 73 can be covered with the barrier film 30.

[0086] Next, a first external electrode 21 and a second external electrode 22 are formed as external electrodes 24 at both ends of the wound body 73 by metal spraying (metallikon), thereby obtaining a wound capacitor element 20. The first external electrode 21 is electrically connected to the first conductive layer 711 (first internal electrode). The second external electrode 22 is electrically connected to the second conductive layer 712 (second internal electrode). The first conductive layer 711 and the second conductive layer 712 constitute a pair of internal electrodes. The first external electrode 21 and the second external electrode 22 can be formed of a metal material containing, for example, 50% by weight or more of tin. The metal material may contain, for example, zinc as a metal other than tin.

[0087] Metal spraying Figure 5 It should be noted that Figure 5 The figure shows a state where a roll 73 wound with the barrier film 30 is divided into four equal parts along the axis. First, the end face 302 of the barrier film 30 is aligned with the end face 730 of the roll 73. Next, particles of molten metal material 25 are sprayed onto the end face 302 of the barrier film 30 and the end face 730 of the roll 73, depositing them on the end faces 302 and 730. After the molten metal material 25 has accumulated to a predetermined thickness, it solidifies due to heat dissipation, forming the first and second external electrodes 21 and 22. Furthermore, by winding the two sets of metallized films 71 and 72 with an offset state, a fine gap is created at the end face 730 of the roll 73. The metal material 25 enters this gap, bringing it into contact with the first and second conductive layers 711 and 712 of the first and second metallized films 71 and 72, respectively.

[0088] It should be noted that the first external electrode 21 and the second external electrode 22 may each be formed of a plurality of layers. In this case, any one layer may be formed of a metal material containing 50% by weight or more of tin.

[0089] Then, if Figure 4 As shown in FIG. 2B , the first bus bar 61 is electrically connected to the first external electrode 21, and the second bus bar 62 is electrically connected to the second external electrode 22. Examples of such connection methods include soldering, resistance welding, and ultrasonic welding. The first bus bar 61 and the second bus bar 62 are formed into a plate shape, for example, from copper or a copper alloy.

[0090] Next, a process of forming an outer resin layer 4 is performed. In the process of forming the outer resin layer 4, the capacitor element 20 connected to the bus bar 6 is sealed with a resin to form the outer resin layer 4. As the resin, epoxy resin, unsaturated polyester resin, polyimide resin, urethane resin, silicone resin, etc. can be exemplified. As the forming method when covering the capacitor element 20, transfer molding, compression molding, lamination molding, etc. can be exemplified. In addition, the capacitor element 20 can also be housed and sealed in a housing having the outer resin layer 4. The outer resin layer 4 is formed to cover the entire capacitor element 20 except for the connection portion of the capacitor element 20 with the bus bar 6. The front end portion of the bus bar 6 is located on the outside of the outer resin layer 4 (on the side opposite to the capacitor element 20).

[0091] In this embodiment, barrier film 30 is wound around wound body 73 after the metallized films 71 and 72 are wound, streamlining the process and simplifying the process. Furthermore, after the metallization process, if it is necessary to remove metal shavings adhering to areas other than the areas where external electrodes 24 are formed (e.g., around capacitor element 20), insulating film 33 of barrier film 30 is wound around capacitor element 20 so that it is positioned outermost, making it easier to remove metal shavings adhering to insulating film 33. It should be noted that such metal shaving removal is performed by scrubbing or polishing.

[0092] (3) Modification

[0093] Embodiment 1 is merely one of various embodiments of the present invention. Embodiment 1 can be modified in various ways according to design, etc., as long as the purpose of the present invention can be achieved.

[0094] While the above description describes the case where the electronic component is a capacitor, the present invention is not limited thereto. The present invention can also be applied to electronic components other than capacitors, including passive or active components. Passive or active components other than capacitors may include passive or active elements corresponding to the type of electronic component, respectively, in place of capacitor elements.

[0095] In the above description, the case where the barrier film 30 covers the wound body 73 before forming the first external electrode 21 and the second external electrode 22 by metallization has been described. However, the present invention is not limited thereto. The wound body 73 may be covered with the barrier film 30 after forming the first external electrode 21 and the second external electrode 22. In particular, Figure 3 As shown in A, when the first external electrode 21 and the second external electrode 22 are covered with the barrier film 30, the winding body 73 and the first external electrode 21 and the second external electrode 22 can also be covered with the barrier film 30 after the first external electrode 21 and the second external electrode 22 are formed on the winding body 73.

[0096] In addition, if Figure 3 As shown in Figure A, even when the barrier film 30 is used to cover the periphery of the first and second external electrodes 21, 22, the barrier film 30 can be applied to the wound body 73 before the first and second external electrodes 21, 22 are formed. In this case, the width of the barrier film 30 is 1 to 2 mm greater than the width of the metallized films 71, 72 forming the wound body 73, and the end 301 of the barrier film 30 is made to protrude beyond the axial end surface 730 of the wound body 73. Then, within the space enclosed by the end 301 of the barrier film 30, the first and second external electrodes 21, 22 are formed on the axial end surface 730 of the wound body 73 by metallization.

[0097] (Implementation Method 2)

[0098] The electronic component 1 of the present embodiment is different from the electronic component 1 of the first embodiment in the position of the barrier film 30 .

[0099] Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

[0100] The configuration described in the second embodiment can be applied in combination with the configuration described in the first embodiment (including modifications) as appropriate.

[0101] Electronic component 1 of this embodiment, similarly to Embodiment 1, includes: electronic component element 2 having external electrodes 24 at both ends; exterior resin layer 4 covering at least a portion of electronic component element 2; and barrier film 30 covering at least a portion of the periphery of the exterior resin layer. Barrier film 30, similarly to the above, includes insulating film 33 having electrical insulating properties and clay layer 31 containing clay.

[0102] Figure 6A shows a capacitor 10 as the electronic component 1 of this embodiment. Capacitor 10 includes a barrier film 30 and an exterior resin layer 4. However, the barrier film 30 is provided so as to cover the periphery of the exterior resin layer 4 without contacting the surface of the capacitor element 20. In this case, the exterior resin layer 4 is located between the capacitor element 20 and the barrier film 30. Therefore, the exterior resin layer 4 is located closer to the electronic component element 2 (capacitor element 20) than the barrier film 30. The barrier film 30 is in contact with the surface of the exterior resin layer 4.

[0103] In capacitor 10 of this embodiment, capacitor element 20 is also covered by barrier film 30 via exterior resin layer 4 . Barrier film 30 prevents moisture from reaching capacitor element 20 , thereby reducing moisture absorption by capacitor element 20 and improving moisture resistance of capacitor 10 .

[0104] (Implementation 3)

[0105] The electronic component 1 of the present embodiment is different from the electronic component 1 of the first or second embodiment in the position of the barrier film 30 .

[0106] Hereinafter, the same configurations as those in Embodiment 1 or 2 are denoted by common reference numerals and description thereof will be appropriately omitted.

[0107] The configuration described in the third embodiment can be applied in combination with the configuration described in the first or second embodiment (including modified examples) as appropriate.

[0108] Figure 6 B shows a capacitor 10 as the electronic component 1 of this embodiment. This capacitor 10, in the configuration of Embodiment 1, further includes another barrier film 30 on the surface of the exterior resin layer 4. Alternatively, the capacitor 10 of this embodiment, in the configuration of Embodiment 2, further includes another barrier film 30 on the surface of the capacitor element 20. Specifically, the barrier film 30 includes a first barrier film 30a disposed in contact with the surface of the capacitor element 20, and a second barrier film 30b disposed in contact with the surface of the exterior resin layer 4. Therefore, the exterior resin layer 4 is provided between the first barrier film 30a and the second barrier film 30b.

[0109] In the capacitor 10 of this embodiment, the capacitor element 20 is covered by the first barrier film 30a, the second barrier film 30b, and the outer resin layer 4. The two barrier films 30 make it difficult for moisture to reach the capacitor element 20, further reducing the moisture absorption of the capacitor element 20 and improving the moisture resistance of the capacitor 10.

[0110] (Performance Comparison)

[0111] The moisture resistance performance of capacitors 10 according to Embodiments 1, 2, and 3 and the comparative example was compared.

[0112] Regarding moisture resistance, a voltage of 750 V was applied to capacitors 10 according to Embodiments 1, 2, 3, and the comparative example in a high-temperature, high-humidity atmosphere at 85°C and 85% humidity, and the change in capacitance of each capacitor 10 was measured. The moisture resistance of capacitors 10 was compared when the rate of capacitance change exceeded -5%.

[0113] The capacitor 10 of embodiments 1, 2, and 3 has a barrier film 30. The insulating film 33 of the barrier film 30 is a film made of polyethylene naphthalate with a thickness of 12 μm, and the clay layer 31 is formed to have a thickness of 1 μm. The clay layer 31 contains montmorillonite as clay and nylon as a binder. The outer resin layer 4 uses epoxy resin. The external electrode 24 is formed of 100% by weight of tin. The bus bar 6 uses a copper bus bar. It should be noted that the comparative example is a capacitor that does not have a barrier film in embodiments 1, 2, and 3. That is, as Figure 7 As shown, capacitor element 20 is sealed by exterior resin layer 4 but is not covered by barrier film 30. External electrode 24 is formed of 100% by weight zinc.

[0114] Then, the moisture resistance of Embodiments 1, 2, and 3 was evaluated by relative evaluation of the time that the rate of change of capacitance exceeded -5% when the time that the rate of change of capacitance exceeded -5% was set to 1. The result was that the evaluation result of the capacitor 10 of Embodiment 1 was 1.8 times the evaluation result of the comparative example, which was good. That is, the time that the rate of change of capacitance exceeded -5% of the capacitor 10 of Embodiment 1 was extended to 1.8 times compared with the capacitor 10 of the comparative example. Similarly, the evaluation result of the capacitor 10 of Embodiment 2 was 2.2 times the evaluation result of the comparative example, which was good, and the evaluation result of the capacitor 10 of Embodiment 3 was 2.6 times the evaluation result of the comparative example, which was good.

[0115] Capacitors 10 equipped with barrier films 30 in this manner have improved moisture resistance compared to capacitors 10 without barrier films 30. Furthermore, the more barrier films 30 are used, the higher the moisture resistance of capacitor 10. Furthermore, capacitors 10 have improved moisture resistance when barrier films 30 are arranged on the outside of exterior resin layer 4, compared to when they are arranged on the inside.

[0116] (Summarize)

[0117] The electronic component (1), the capacitor (10), the method for manufacturing the electronic component (1), and the method for manufacturing the capacitor (10) of this embodiment have the following aspects.

[0118] An electronic component (1) of a first embodiment includes an electronic component element (2) and a barrier film (30). The electronic component element (2) has external electrodes (24) at both ends. The barrier film (30) covers at least a portion of the periphery of the electronic component element (2). The barrier film (30) includes an insulating film (33) having electrical insulating properties and a clay layer (31) containing clay.

[0119] According to this method, there is an advantage that, by providing a clay layer (31) through which water hardly passes, moisture resistance can be easily ensured without increasing the thickness of the molded resin and the housing, and miniaturization is facilitated.

[0120] According to the second embodiment, in the electronic component (1) of the first embodiment, the barrier film (30) is arranged so that the clay layer (31) faces the electronic component element (2).

[0121] According to this method, there is an advantage that the clay layer (31) having better adhesion than the insulating film (33) can be closely adhered to the electronic component element (2), and the infiltration of moisture into the electronic component element (2) is easily reduced.

[0122] According to a third aspect, in the electronic component (1) of the first or second aspect, a barrier film (30) covers the periphery of the external electrode (24).

[0123] According to this method, there is an advantage that the boundary of the external electrode (24) of the electronic component element (2) is covered with the barrier film (30), and it is easy to reduce the intrusion of moisture from the boundary of the external electrode (24).

[0124] A fourth aspect is the electronic component (1) according to any one of the first to third aspects, wherein the external electrode (24) is formed by sputtering and contains 50% by weight or more of tin.

[0125] According to this method, the following advantages are achieved: compared with the case where the external electrode (24) is formed of zinc, it is easy to form an external electrode (24) in which metal particles are densely arranged, and it is easy to reduce the intrusion of moisture from the external electrode (24). In addition, the adhesion between the barrier film (30) and the external electrode (24) is also improved, and it is easy to reduce the intrusion of moisture.

[0126] The fifth embodiment is the electronic component (1) according to any one of the first to fourth embodiments, further comprising an exterior resin layer (4) covering the electronic component element (2) and the barrier film (30).

[0127] According to this method, there are the following advantages: it is easy to further reduce the moisture absorption of the electronic component element (2) through the outer resin layer (4); in addition, the strength of the electronic component element (2) can be ensured by the outer resin layer (4), and the electronic component element (2) can be protected.

[0128] The sixth aspect is the electronic component (1) according to the fifth aspect, further comprising another barrier film (30) covering at least a portion of the exterior resin layer (4).

[0129] According to this embodiment, there is an advantage that the barrier film (30) provided outside the exterior resin layer (4) can further reduce the intrusion of water, thereby improving the moisture resistance.

[0130] The electronic component (1) of the seventh embodiment comprises an electronic component element (2), an outer resin layer (4), and a barrier film (30). The electronic component element (2) has external electrodes (24) at both ends. The outer resin layer (4) covers at least a portion of the electronic component element (2). The barrier film (30) covers at least a portion of the periphery of the outer resin layer (4). The barrier film (30) comprises an insulating film (33) and a clay layer (31), wherein the insulating film (33) has electrical insulating properties and the clay layer (31) contains clay.

[0131] According to this method, there is an advantage that, by providing a clay layer (31) that is difficult for water to pass through, moisture resistance can be easily ensured without increasing the thickness of the exterior resin layer (4), and miniaturization is facilitated.

[0132] An eighth aspect is the electronic component (1) according to any one of the first to seventh aspects, wherein the external electrode (24) has a plurality of layers, and at least one of the plurality of layers contains 50% by weight or more of tin.

[0133] According to this embodiment, compared with the case where the external electrode (24) is formed of zinc, it is easier to form the external electrode (24) having a layer where metal particles are densely arranged, and it is easier to reduce the intrusion of moisture from the external electrode (24).

[0134] In the capacitor (10) of the eighth embodiment, the electronic component element (2) according to any one of the first to seventh embodiments includes a capacitor element (20).

[0135] According to this method, there is an advantage that, by providing a clay layer (31) through which water does not easily pass, moisture resistance can be easily ensured without increasing the thickness of the molded resin and the case, and the capacitor can be easily miniaturized.

[0136] A ninth embodiment of the present invention provides a method for manufacturing an electronic component (1) comprising the steps of forming an electronic component element (2) and winding a barrier film (30) around at least a portion of the electronic component element (2). The barrier film (30) comprises an insulating film (33) having electrical insulating properties and a clay layer (31) containing clay.

[0137] According to this method, there is an advantage that, by providing a clay layer (31) through which moisture does not easily pass, moisture resistance can be easily ensured without increasing the thickness of the molded resin and the housing, and miniaturized electronic components (1) can be easily manufactured.

[0138] The manufacturing method of the capacitor (10) of the tenth embodiment comprises: a step of winding metallized films (71, 72) to form a wound body (73); a step of winding a barrier film (30) around at least a portion of the wound body (73); and a step of forming external electrodes (24) by spraying a metal material on both ends of the wound body (73) after winding the barrier film (30). The barrier film (30) includes an insulating film (33) and a clay layer (31), the insulating film having electrical insulation properties, and the clay layer containing clay and formed on the insulating film (33). When winding the barrier film (30), the barrier film (30) is wound so that the clay layer (31) faces the wound body (73).

[0139] This method has the following advantages: by providing a clay layer (31) that is difficult for moisture to pass through, moisture resistance can be easily ensured without increasing the thickness of the molded resin and the housing, making it easy to manufacture a miniaturized capacitor. In addition, since the barrier film (30) is wound around the wound body (73) after the step of winding the metallized films (71, 72), the process is rational and simplified.

[0140] The eleventh aspect is the method for manufacturing a capacitor (10) according to the tenth aspect, wherein the metal material contains 50% by weight or more of tin.

[0141] According to this method, the following advantages are achieved: compared with the case where the external electrode (24) is formed of zinc, it is easy to form an external electrode (24) in which metal particles are densely arranged, and it is easy to reduce the intrusion of moisture from the external electrode (24). In addition, the adhesion between the barrier film (30) and the external electrode (24) is also improved, and it is easy to reduce the intrusion of moisture.

[0142] Description of Reference Numerals

[0143] 1 Electronic components

[0144] 10 Capacitors

[0145] 2 Electronic components

[0146] 20 capacitor elements

[0147] 24 External electrodes

[0148] 71, 72 Metallized film

[0149] 30 Barrier Film

[0150] 31 Clay layer

[0151] 33 Insulation film

[0152] 4. External resin layer.

Claims

1. A film capacitor comprising: A wound capacitor element having an element body as a wound body, a barrier film covering the peripheral surface of the element body, and external electrodes respectively arranged on both end surfaces of the element body; an outer resin layer covering the capacitor element, The barrier film comprises an insulating film and a clay layer, wherein the insulating film has electrical insulation properties and the clay layer contains clay. The clay layer is in contact with the peripheral surface of the element body, The insulating film is in contact with the exterior resin layer.

2. The film capacitor according to claim 1, wherein The external electrode covers the end surface of the barrier film.

3. The film capacitor according to claim 1, wherein The barrier film covers the periphery of the external electrode.

4. The film capacitor according to any one of claims 1 to 3, wherein The external electrodes are formed by sputtering and contain 50 wt % or more of tin.

5. The film capacitor according to any one of claims 1 to 3, wherein The external electrode includes a plurality of layers, and at least one of the plurality of layers contains 50 wt % or more of tin.

6. A method for manufacturing a film capacitor, comprising the following steps: a step of forming an element body as a wound body; forming a capacitor element having a barrier film wound around the peripheral surface of the element body; and a step of covering the capacitor element with an outer resin layer, The barrier film comprises an insulating film and a clay layer, wherein the insulating film has electrical insulation properties and the clay layer contains clay. The clay layer is in contact with the peripheral surface of the element body, The insulating film is in contact with the exterior resin layer.

7. The method for manufacturing a film capacitor according to claim 6, wherein: The step of forming the element body includes the step of winding the metallized film to form a wound body. The step of forming the capacitor element includes: winding the barrier film around the circumference of the element body; and forming external electrodes by thermally spraying a metal material on both ends of the element body around which the barrier film is wound.

8. The method for manufacturing a film capacitor according to claim 7, wherein: The metal material contains 50 wt % or more of tin.

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