Film capacitor, and metallized film

Abstract

To provide a film capacitor capable of maintaining overall functionality thereof even when an insulation breakdown occurs that exceeds the limit of the self-restoration function by improving the self-restoration function.SOLUTION: A film capacitor 1 includes: a dielectric film 2 that has a first plane 2a and a second plane 2b, opposite the first plane 2a; a first electrode 31 placed on the first plane 2a; and a second electrode 32 that is placed on the second plane 2b opposite to the first electrode 31 via the dielectric film 2. The first electrode 31 includes two adjacent first small electrodes 61 and a first fuse 71 connecting the two adjacent first small electrodes 61. Each of the two adjacent first small electrodes 61 is constituted of a metal oxide layer 8 and a metal layer 9 in contact with the metal oxide layer 8. The first fuse 71 is made up of only the metal layer 9.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to film capacitors and metallized films, and more particularly to film capacitors and metallized films comprising a dielectric film. [Background technology]

[0002] Patent Document 1 discloses a film capacitor. This film capacitor is manufactured by winding or laminating a film material for film capacitors. The film for film capacitors has a two-layer structure in which a polypropylene film is vapor-deposited with an inorganic dielectric of a predetermined thickness. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-004743 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the film capacitor of Patent Document 1, it is thought that the electrodes are formed by simply depositing a metal solidly on an inorganic dielectric, which poses a problem in that, in the event of dielectric breakdown exceeding the limit of the self-healing function, it is difficult for the film capacitor as a whole to maintain its functionality.

[0005] The object of the present disclosure is to provide a film capacitor and a metallized film that have improved self-healing function and can maintain the function of the film capacitor as a whole even if insulation breakdown occurs that exceeds the limit of the self-healing function. [Means for solving the problem]

[0006] A film capacitor according to one embodiment of the present disclosure includes a dielectric film having a first surface and a second surface opposite the first surface, a first electrode disposed on the first surface, and a second electrode disposed on the second surface and facing the first electrode via the dielectric film. The first electrode includes two adjacent first small electrodes and a first fuse connecting the two adjacent first small electrodes. Each of the two adjacent first small electrodes is composed of a metal oxide layer and a metal layer in contact with the metal oxide layer. The first fuse is composed only of a metal layer.

[0007] A film capacitor according to one embodiment of the present disclosure includes a dielectric film having a first surface and a second surface opposite the first surface, a first electrode disposed on the first surface, and a second electrode disposed on the second surface and facing the first electrode via the dielectric film. The first electrode includes a first divided electrode, a first undivided electrode adjacent to the first divided electrode in a first direction, and a plurality of first fuses. The first divided electrode includes a plurality of first small electrodes aligned in the first direction and a second direction perpendicular to the first direction. Each of the plurality of first fuses connects two first small electrodes adjacent to each other in the first direction. Each of the two first small electrodes adjacent to each other in the first direction is composed of a metal oxide layer and a metal layer in contact with the metal oxide layer. Each of the plurality of first fuses is composed only of a metal layer.

[0008] A metallized film according to one embodiment of the present disclosure includes a dielectric film and an electrode disposed on one side of the dielectric film. The electrode includes two adjacent small electrodes and a fuse connecting the two adjacent small electrodes. Each of the two adjacent small electrodes is composed of a metal oxide layer in contact with the one side of the dielectric film and a metal layer in contact with the metal oxide layer. The fuse is composed only of the metal layer in contact with the one side of the dielectric film. [Effects of the Invention]

[0009] According to the present disclosure, the self-healing function is improved, and even if a dielectric breakdown occurs that exceeds the limit of the self-healing function, the function of the film capacitor as a whole can be maintained. [Brief explanation of the drawings]

[0010] [Figure 1] Fig. 1A is a schematic enlarged cross-sectional view showing a main part of a film capacitor according to a first embodiment, and Fig. 1B is a schematic enlarged plan view showing a main part of the film capacitor. [Figure 2] FIG. 2 is a diagram illustrating the film capacitor. [Figure 3] 3A and 3B are schematic perspective views showing an example of a manufacturing process of the film capacitor. [Figure 4] 4A and 4B are schematic cross-sectional views showing a main part of the film capacitor according to the first embodiment and a main part of a film capacitor according to a modification of the first embodiment, respectively. [Figure 5] FIG. 5 is a diagram illustrating a film capacitor according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] 1. Overview 3B shows an example of the film capacitor 1 according to this embodiment. The film capacitor 1 has, for example, a flattened cylindrical shape.

[0012] The above-described film capacitor 1 is manufactured, for example, as shown in Fig. 3A. First, two elongated metallized films 10 (first metallized film 11 and second metallized film 12) are stacked and wound around winding axis C to form cylindrical element body 100.

[0013] Here, first metallized film 11 includes dielectric film 2 (first dielectric film 21) and electrode 3 (first electrode 31). First electrode 31 is disposed on one surface 2a of first dielectric film 21. While first electrode 31 is illustrated simply in FIG. 3A, in detail, first electrode 31 includes a plurality of small electrodes 6 (first small electrodes 61) and fuse 7 (first fuse 71), as shown in FIG. 2. Fuse 7 connects two adjacent small electrodes 6. Second metallized film 12 can be regarded as a mirror image of first metallized film 11. Second dielectric film 22, second electrode 32, and second small electrode 62 correspond to first dielectric film 21, first electrode 31, and first small electrode 61, respectively.

[0014] After forming the cylindrical element body 100, pressure is applied to the side surfaces of the element body 100 to obtain a flattened cylindrical element body 100. A first end surface electrode 3a and a second end surface electrode 3b are formed by spraying metal onto both bottom surfaces (end surfaces) of the element body 100, thereby obtaining a film capacitor 1 as shown in FIG.

[0015] Inside the film capacitor 1, the first electrode 31 and the second electrode 32 face each other via the dielectric film 2. A first end surface electrode 3a and a second end surface electrode 3b are present at both ends of the film capacitor 1. The first end surface electrode 3a is connected to the first electrode 31 (see FIG. 4A). Meanwhile, the second end surface electrode 3b is connected to the second electrode 32 (see FIG. 4A). The film capacitor 1 can be charged by applying a voltage between the first end surface electrode 3a and the second end surface electrode 3b.

[0016] 1A, each of two adjacent small electrodes 6 is composed of a metal oxide layer 8 and a metal layer 9. The metal layer 9 is in contact with the metal oxide layer 8. In this way, compared to forming the metal layer 9 directly on the dielectric film 2, forming the metal layer 9 on the dielectric film 2 via the metal oxide layer 8 makes it easier for the metal particles to come into close contact with each other, making the metal layer 9 more dense and reducing the electrical resistance. This can improve the self-healing function of the small electrodes 6.

[0017] On the other hand, the fuse 7 is composed only of the metal layer 9. In this way, forming the metal layer 9 directly on the dielectric film 2 prevents the metal layer 9 from becoming densified, and the electrical resistance of the fuse 7 becomes higher than the electrical resistance of the small electrodes 6. In other words, the sensitivity of the fuse 7 becomes higher. This makes the fuse 7 more likely to blow if a dielectric breakdown occurs that exceeds the limit of the self-healing function.

[0018] Therefore, according to this embodiment, the self-healing function is improved, and even if a dielectric breakdown occurs that exceeds the limit of the self-healing function, the function of the film capacitor 1 as a whole can be maintained.

[0019] 2.Details (1) First embodiment A film capacitor 1 according to a first embodiment will be described below with reference to Figures 1 to 4A. Each figure is a schematic diagram, and the ratios of the sizes and thicknesses of the components in each figure do not necessarily reflect the actual dimensional ratios.

[0020] The arrows indicating the directions in each figure are merely there to facilitate understanding of the explanation and are not intended to define the directions when the film capacitor 1 is in use. The first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other.

[0021] The first direction D1 is the short-side direction (width direction) of the dielectric film 2, and may be referred to as the "left-right direction." One side of the first direction D1 means "left," and the other side of the first direction D1 means "right."

[0022] The second direction D2 is the longitudinal direction of the dielectric film 2 and may be referred to as the "front-to-back direction." One side of the second direction D2 means "front," and the other side of the second direction D2 means "rear." However, in the wound-type film capacitor 1 shown in Figures 3A and 3B, the second direction D2 may be the circumferential direction of an imaginary circle centered on the winding shaft C.

[0023] The third direction D3 is the thickness direction of the dielectric film 2 and may be referred to as the "up-down direction." One side of the third direction D3 means "up," and the other side of the third direction D3 means "down." A view along the third direction D3 may be referred to as a "planar view." However, in the wound-type film capacitor 1 shown in Figures 3A and 3B, the third direction D3 may be the radial direction of an imaginary circle centered on the winding shaft C.

[0024] <Film capacitor> Fig. 2 is an explanatory diagram showing the film capacitor 1 according to the first embodiment. Specifically, to facilitate understanding of the following description, Fig. 2 illustrates two metallized films 10 (first metallized film 11 and second metallized film 12) that are not wound but are stacked with a shift in the front-to-back direction.

[0025] As shown in Fig. 2, the film capacitor 1 includes a dielectric film 2, a first electrode 31, and a second electrode 32. The film capacitor 1 may further include a first end surface electrode 3a and a second end surface electrode 3b (see Fig. 3B). Note that the first end surface electrode 3a and the second end surface electrode 3b are not shown in Fig. 2.

[0026] The dielectric film 2, the first electrode 31, the second electrode 32, the first end surface electrode 3a, and the second end surface electrode 3b will be described below in order.

[0027] <Dielectric film> The dielectric film 2 is a film made of a dielectric material, and is not particularly limited to such a dielectric material, but examples thereof include polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polycarbonate (PC), and polystyrene (PS).

[0028] The dielectric film 2 is in the form of an elongated film. That is, the dielectric film 2 is a film having a width in the left-right direction, extending in the front-rear direction, and having a thickness in the up-down direction.

[0029] The dielectric film 2 has a first surface 2a and a second surface 2b (see FIGS. 1A and 4A). The first surface 2a is the upper surface. The second surface 2b is the surface opposite to the first surface 2a. In other words, the second surface 2b is the lower surface.

[0030] The thickness of the dielectric film 2 is the distance between the first surface 2a and the second surface 2b. The thickness of the dielectric film 2 is not particularly limited, but is, for example, 1.0 μm or more and 10.0 μm or less.

[0031] In the first embodiment, the dielectric film 2 includes a first dielectric film 21 and a second dielectric film 22. The first dielectric film 21 and the second dielectric film 22 have approximately the same shape and size. As shown in FIG. 2 , the first dielectric film 21 and the second dielectric film 22 are misaligned in the left-right direction. Specifically, the left edge of the first dielectric film 21 is located to the left of the left edge of the second dielectric film 22. On the other hand, the right edge of the second dielectric film 22 is located to the right of the right edge of the first dielectric film 21.

[0032] First dielectric film 21 forms a part of first metallized film 11, and second dielectric film 22 forms a part of second metallized film 12.

[0033] ≪First electrode≫ The first electrode 31 is disposed on the first surface 2a of the dielectric film 2 (the first dielectric film 21 in the first embodiment). Specifically, as shown in Fig. 2, the first electrode 31 is disposed on the first surface 2a except for the first margin portion 201.

[0034] The first margin portion 201 is present at the right end portion on the first surface 2a of the first dielectric film 21. The first margin portion 201 is a narrow strip-shaped portion. That is, the first margin portion 201 has a width in the left-right direction and extends in the front-rear direction.

[0035] First electrode 31 has first divided electrode 41, first undivided electrode 51, and a plurality of first fuses 71. First electrode 31 forms a part of first metallized film 11.

[0036] [First divided electrode] The first divided electrode 41 occupies approximately the right half of the first surface 2a of the dielectric film 2 (first dielectric film 21 in the first embodiment). The first divided electrode 41 is located between the first margin portion 201 and the first undivided electrode 51. The first divided electrode 41 includes a plurality of first small electrodes 61. In this manner, the first divided electrode 41 is divided into a plurality of first small electrodes 61.

[0037] The multiple first small electrodes 61 are arranged in a matrix. That is, the multiple first small electrodes 61 are lined up in a first direction D1 (left-right direction) and a second direction D2 (front-back direction). In Fig. 2, four first small electrodes 61 are lined up in the left-right direction. The number of first small electrodes 61 lined up in the left-right direction is not particularly limited as long as there is more than one. Note that Fig. 3A is a simplified illustration, and therefore the number of first small electrodes 61 lined up in the left-right direction is two.

[0038] Each of the first small electrodes 61 has a rectangular shape of approximately the same size. In each first small electrode 61, two opposing sides (left and right sides) in the left-right direction extend in the front-rear direction, and two opposing sides (front and rear sides) in the front-rear direction extend in the left-right direction. The shape of the small electrodes 61 is not particularly limited.

[0039] In the first embodiment, each of the plurality of first small electrodes 61 is made up of a metal oxide layer 8 and a metal layer 9, as shown in FIG. 1A.

[0040] The metal oxide layer 8 is in direct contact with the first surface 2a of the dielectric film 2 (first dielectric film 21 in the first embodiment). The metal oxide constituting the metal oxide layer 8 is not particularly limited, but examples thereof include aluminum oxide, silicon oxide, zirconium oxide, titanium oxide, barium oxide, calcium oxide, and copper oxide. Of these, aluminum oxide (Al2O3, etc.) is preferable. The thickness of the metal oxide layer 8 is not particularly limited, but is, for example, 3 nm or more and 50 nm or less.

[0041] The metal layer 9 is in direct contact with the metal oxide layer 8. That is, in a plan view, the metal layer 9 of the first small electrode 61 overlaps the metal oxide layer 8. The metal layer 9 of the first small electrode 61 is not in direct contact with the first surface 2a of the dielectric film 2 (first dielectric film 21 in the first embodiment). Thus, in the first small electrode 61, the metal oxide layer 8 is interposed between the metal layer 9 and the dielectric film 2. The metal constituting the metal layer 9 is not particularly limited, but examples thereof include aluminum (Al), gold (Au), magnesium (Mg), zinc (Zn), tin (Sn), nickel (Ni), chromium (Cr), iron (Fe), copper (Cu), titanium (Ti), and alloys thereof. The thickness of the metal layer 9 is not particularly limited, but is 3 nm or more and 100 nm or less.

[0042] [First non-divided electrode] As shown in FIG. 2, the first undivided electrode 51 occupies approximately half of the left side of the first surface 2a of the dielectric film 2 (first dielectric film 21 in the first embodiment). As such, the first undivided electrode 51 is adjacent to the first divided electrode 41 in the first direction D1 (left-right direction). The first undivided electrode 51 has a solid shape extending in the front-rear direction. As such, the first undivided electrode 51 is not divided.

[0043] 4A, the first undivided electrode 51 is composed of a metal oxide layer 8 and a metal layer 9. The metal oxide layer 8 and metal layer 9 of the first undivided electrode 51 are similar to the metal oxide layer 8 and metal layer 9 of the first small electrode 61, respectively.

[0044] [First fuse] The first fuse 71 is a part that melts when an excessive current flows and breaks the circuit. As shown in Fig. 1B, the first fuse 71 connects two first small electrodes 61 that are adjacent to each other in the first direction D1 (left-right direction) among the multiple first small electrodes 61.

[0045] 1A, the first fuse 71 is composed only of a metal layer 9. That is, the metal layer 9 of the first fuse 71 is in direct contact with the first surface 2a of the dielectric film 2 (the first dielectric film 21 in the first embodiment). The metal layer 9 of the first fuse 71 is connected to the metal layers 9 of the left and right first small electrodes 61.

[0046] 2, the first fuse 71 connects the first small electrode 61 and the first undivided electrode 51. The first small electrode 61 directly connected to the first undivided electrode 51 by the first fuse 71 is the first small electrode 61 adjacent to the first undivided electrode 51 in the first direction D1 (left-right direction) among the multiple first small electrodes 61. In the first embodiment, the first small electrode 61 directly connected to the first undivided electrode 51 by the first fuse 71 is the first small electrode 61 located at the left end of the four first small electrodes 61 lined up in the left-right direction.

[0047] ≪Second electrode≫ The second electrode 32 is disposed on the second surface 2b of the dielectric film 2 (first dielectric film 21 in this embodiment) (see FIG. 4A). The second electrode 32 faces the first electrode 31 with the dielectric film 2 interposed therebetween.

[0048] However, it can also be said that the second electrode 32 is disposed on the first surface 2a of the second dielectric film 22 (see FIGS. 2 and 4A). Therefore, hereinafter, unless otherwise specified, a description will be given of the case where the second electrode 32 is disposed on the first surface 2a of the second dielectric film 22. As shown in FIG. 2, the second electrode 32 is disposed on the first surface 2a of the second dielectric film 22 excluding the second margin portion 202.

[0049] The second margin portion 202 is present at the left end portion on the first surface 2a of the second dielectric film 22. The second margin portion 202 is a narrow strip-shaped portion. That is, the second margin portion 202 has a width in the left-right direction and extends in the front-rear direction.

[0050] Second electrode 32 includes second divided electrode 42, second undivided electrode 52, and a plurality of first fuses 71. Second electrode 32 forms a part of second metallized film 12.

[0051] [Second split electrode] The second divided electrode 42 occupies approximately half of the left side of the first surface 2a of the dielectric film 2 (the second dielectric film 22 in the first embodiment). The second divided electrode 42 is located between the second margin portion 202 and the second undivided electrode 52. The second divided electrode 42 includes a plurality of second small electrodes 62. In this manner, the second divided electrode 42 is divided into a plurality of second small electrodes 62.

[0052] The multiple second small electrodes 62 are arranged in a matrix. That is, the multiple second small electrodes 62 are lined up in a first direction D1 (left-right direction) and a second direction D2 (front-back direction). In the first embodiment, four second small electrodes 62 are lined up in the left-right direction. The number of second small electrodes 62 lined up in the left-right direction is not particularly limited as long as it is plural. In the first embodiment, the second small electrodes 62 have approximately the same shape and size as the first small electrodes 61, but this is not particularly limited.

[0053] The second divided electrode 42 generally faces the first undivided electrode 51 via the dielectric film 2. More specifically, the majority of the multiple second small electrodes 62 face the first undivided electrode 51 via the dielectric film 2.

[0054] A portion of the second divided electrode 42 faces the first divided electrode 41 via the dielectric film 2. Specifically, the second small electrode 62 adjacent to the second undivided electrode 52 faces the first small electrode 61 adjacent to the first undivided electrode 51 via the dielectric film 2.

[0055] In the first embodiment, each of the plurality of second small electrodes 62 is made up of a metal oxide layer 8 and a metal layer 9.

[0056] 4A, the metal oxide layer 8 constituting the second small electrode 62 is in direct contact with the first surface 2a of the second dielectric film 22, but is not in direct contact with the second surface 2b of the first dielectric film 21. The metal oxide constituting the metal oxide layer 8 of the second small electrode 62 and the thickness of the metal oxide layer 8 are similar to the metal oxide constituting the metal oxide layer 8 of the first small electrode 61 and the thickness of the metal oxide layer 8.

[0057] 4A , the metal layer 9 is in direct contact with the metal oxide layer 8. That is, in a plan view, the metal layer 9 of the second small electrode 62 overlaps the metal oxide layer 8. The metal layer 9 of the second small electrode 62 is not in direct contact with the first surface 2 a of the second dielectric film 22, but is in direct contact with the second surface 2 b of the first dielectric film 21. Thus, in the second small electrode 62, the metal oxide layer 8 is interposed between the metal layer 9 and the dielectric film 2 (second dielectric film 22). The metal constituting the metal layer 9 of the second small electrode 62 and the thickness of the metal layer 9 are similar to the metal constituting the metal layer 9 of the first small electrode 61 and the thickness of the metal layer 9.

[0058] Although not shown in FIG. 4A, the metal layer 9 of the first small electrode 61 is in direct contact with the second surface 2b of the second dielectric film 22.

[0059] [Second non-divided electrode] As shown in Fig. 2, the second undivided electrode 52 occupies approximately half of the right side of the first surface 2a of the dielectric film 2 (the second dielectric film 22 in the first embodiment). As such, the second undivided electrode 52 is adjacent to the second divided electrode 42 in the first direction D1 (left-right direction). The second undivided electrode 52 has a solid shape extending in the front-rear direction. As such, the second undivided electrode 52 is not divided.

[0060] The second undivided electrode 52 faces the first divided electrode 41 via the dielectric film 2. More specifically, the second undivided electrode 52 faces the plurality of first small electrodes 61 included in the first divided electrode 41 via the dielectric film 2. However, the second undivided electrode 52 does not face the first undivided electrode 51 via the dielectric film 2.

[0061] [First fuse] The first fuse 71 included in the second electrode 32 is a part that melts and breaks the circuit when an excessive current flows, similar to the first fuse 71 included in the first electrode 31. As shown in Fig. 2, the first fuse 71 of the second electrode 32 connects two second small electrodes 62 that are adjacent to each other in the first direction D1 (left-right direction) among the multiple second small electrodes 62.

[0062] Like the first fuse 71 of the first electrode 31, the first fuse 71 of the second electrode 32 is also composed of only a metal layer 9. However, in the first embodiment, the metal layer 9 of the first fuse 71 of the second electrode 32 is in direct contact with the first surface 2a of the second dielectric film 22. The metal layer 9 of the first fuse 71 of the second electrode 32 is connected to the metal layers 9 of the second small electrodes 62 on the left and right sides.

[0063] 2, the first fuse 71 of the second electrode 32 connects the second small electrode 62 and the second undivided electrode 52. The second small electrode 62 directly connected to the second undivided electrode 52 by the first fuse 71 of the second electrode 32 is the second small electrode 62 adjacent to the second undivided electrode 52 in the first direction D1 (left-right direction) among the multiple second small electrodes 62. In the first embodiment, the second small electrode 62 directly connected to the second undivided electrode 52 by the first fuse 71 of the second electrode 32 is the second small electrode 62 located at the right end of the four second small electrodes 62 lined up in the left-right direction.

[0064] ≪First end electrode≫ 3B and 4A, the first end surface electrode 3a is disposed on the left side of the film capacitor 1. The first end surface electrode 3a is connected to the first electrode 31. Specifically, the first end surface electrode 3a is connected to a first undivided electrode 51 included in the first electrode 31. The first end surface electrode 3a is not connected to the second electrode 32. This is because a second margin portion 202 exists between the first end surface electrode 3a and the second electrode 32.

[0065] The material of the first end surface electrode 3a is not particularly limited, but examples thereof include zinc (Zn), tin (Sn), and alloys thereof. The thickness of the first end surface electrode 3a is not particularly limited, but examples thereof are 0.5 mm to 1.5 mm. The method of forming the first end surface electrode 3a is not particularly limited, but examples thereof include metal spraying.

[0066] ≪Second end electrode≫ 3B and 4A, the second end surface electrode 3b is disposed on the right side of the film capacitor 1. The second end surface electrode 3b is connected to the second electrode 32. Specifically, the second end surface electrode 3b is connected to the second undivided electrode 52 included in the second electrode 32. The second end surface electrode 3b is not connected to the first electrode 31. This is because a first margin portion 201 exists between the second end surface electrode 3b and the first electrode 31.

[0067] The material, thickness and forming method of the second end surface electrode 3b are the same as those of the first end surface electrode 3a.

[0068] <Metallized film> Next, a description will be given of metallized film 10 according to the first embodiment. Metallized film 10 is suitable for use in manufacturing film capacitor 1 described above.

[0069] Metallized film 10 includes dielectric film 2 and electrode 3 (see FIGS. 2 and 3A). Here, metallized film 10 is a collective term for first metallized film 11 and second metallized film 12. First metallized film 11 and second metallized film 12 are in a reversed left-right relationship (see FIG. 2). Therefore, by reversing first metallized film 11 left-right, second metallized film 12 can be substituted for first metallized film 11.

[0070] <Dielectric film> Dielectric film 2 is a general term for first dielectric film 21 and second dielectric film 22. As described above, first dielectric film 21 forms a part of first metallized film 11, and second dielectric film 22 forms a part of second metallized film 12.

[0071] ≪Electrode≫ Electrode 3 is disposed on one surface 2a of dielectric film 2. Here, electrode 3 is a collective term for first electrode 31 and second electrode 32. Therefore, for first metallized film 11, first electrode 31 is disposed on first dielectric film 21. On the other hand, for second metallized film 12, second electrode 32 is disposed on second dielectric film 22.

[0072] The electrode 3 includes two adjacent small electrodes 6 and a fuse 7 (first fuse 71). Here, the small electrodes 6 are a collective term for the first small electrodes 61 and the second small electrodes 62.

[0073] Each of two adjacent small electrodes 6 is composed of a metal oxide layer 8 and a metal layer 9 .

[0074] The metal oxide layer 8 is in direct contact with one surface 2a of the dielectric film 2. The metal oxide constituting the metal oxide layer 8 and the thickness of the metal oxide layer 8 are as described above.

[0075] The metal layer 9 is in direct contact with the metal oxide layer 8. Thus, in the small electrode 6, the metal oxide layer 8 is interposed between the metal layer 9 and the dielectric film 2. The metals constituting the metal layer 9 and the thickness of the metal layer 9 are as described above.

[0076] 〔fuse〕 The fuse 7 (first fuse 71) connects two adjacent small electrodes 6. The fuse 7 is composed only of a metal layer 9. The metal layer 9 is in direct contact with one surface 2a of the dielectric film 2.

[0077] <Metallized film manufacturing method> Next, an example of a method for manufacturing metallized film 10 according to the first embodiment will be described.

[0078] First, masking is applied to areas of the dielectric film 2 where the metal oxide layer 8 is not to be formed. For example, oil is applied or transferred to the areas where the metal oxide layer 8 is not to be formed to mask the areas. The oil is not particularly limited, but examples thereof include silicone oil, fluorine oil, paraffin oil, ester oil, and vegetable oil.

[0079] Next, a metal oxide layer 8 is formed by depositing a metal oxide on the dielectric film 2 that has been masked as described above.

[0080] Next, oil is applied or transferred to the dielectric film 2 on which the metal oxide layer 8 is formed, to mask areas where the electrodes 3 (small electrodes 6, undivided electrodes 5, fuses 7) are not to be formed.

[0081] Then, metal is vapor-deposited onto the dielectric film 2 that has been masked as described above to form the metal layer 9. At this time, the metal particles adhering to the metal oxide layer 8 are more likely to come into close contact with each other than the metal particles adhering to the dielectric film 2.

[0082] In this manner, metallized film 10 having the layer structure shown in FIG. 1A is obtained.

[0083] <Action and effect> 1A, each of two adjacent small electrodes 6 is composed of a metal oxide layer 8 and a metal layer 9. The metal layer 9 is in contact with the metal oxide layer 8. As described above, compared to forming the metal layer 9 directly on the dielectric film 2, forming the metal layer 9 on the dielectric film 2 via the metal oxide layer 8 makes it easier for the metal particles to come into close contact with each other, making the metal layer 9 more dense and reducing the electrical resistance. This can improve the self-healing function of the small electrodes 6.

[0084] Furthermore, as shown in FIG. 4A, the undivided electrode 5 is also composed of a metal oxide layer 8 and a metal layer 9, similar to the small electrode 6, and therefore the self-healing function of the undivided electrode 5 can also be improved.

[0085] On the other hand, the fuse 7 is composed only of the metal layer 9. In this way, forming the metal layer 9 directly on the dielectric film 2 prevents the metal layer 9 from becoming densified, and the electrical resistance of the fuse 7 becomes higher than the electrical resistance of the small electrode 6 and the non-split electrode 5. In other words, the sensitivity of the fuse 7 becomes higher. This makes the fuse 7 more likely to blow if a dielectric breakdown occurs that exceeds the limit of the self-healing function.

[0086] Therefore, according to the first embodiment, the self-healing function is improved, and even if a dielectric breakdown occurs that exceeds the limit of the self-healing function, the function of the film capacitor 1 as a whole can be maintained.

[0087] (2) Second embodiment <Film capacitor> Next, a film capacitor 1 according to a second embodiment will be described with reference to FIG. 5. In the second embodiment, components similar to those in the first embodiment are given the same reference numerals as in the first embodiment, and detailed descriptions thereof may be omitted. Components in the second embodiment that are not specifically mentioned are similar to those in the first embodiment. Note that the first end surface electrode 3a and the second end surface electrode 3b are not shown in FIG. 5.

[0088] The second embodiment differs from the first embodiment in that each of the first electrode 31 and the second electrode 32 further includes a plurality of second fuses 72.

[0089] 〔fuse〕 5, the second fuse 72 of the first electrode 31 connects two of the multiple first small electrodes 61 that are adjacent to each other in the second direction D2 (front-rear direction). On the other hand, the second fuse 72 of the second electrode 32 connects two of the multiple second small electrodes 62 that are adjacent to each other in the second direction D2.

[0090] Like the first fuse 71, the second fuse 72 is also composed of only a metal layer 9. However, in the second embodiment, the metal layer 9 of the second fuse 72 of the first electrode 31 is in direct contact with the first surface 2a of the first dielectric film 21, and the metal layer 9 of the second fuse 72 of the first electrode 31 is connected to the metal layers 9 of the front and rear first small electrodes 61. On the other hand, the metal layer 9 of the second fuse 72 of the second electrode 32 is in direct contact with the first surface 2a of the second dielectric film 22, and the metal layer 9 of the second fuse 72 of the second electrode 32 is connected to the metal layers 9 of the front and rear second small electrodes 62.

[0091] In this way, the second fuse 72 is generally similar to the first fuse 71, except for its orientation.

[0092] <Metallized film> Metallized film 10 according to the second embodiment is generally similar to metallized film 10 according to the first embodiment, except that electrode 3 further includes second fuse 72.

[0093] <Action and effect> The second embodiment has the same effects as the first embodiment. Furthermore, according to the second embodiment, it is possible to suppress an excessive decrease in the capacitance of the film capacitor 1 in the event of a dielectric breakdown for the following reasons.

[0094] For example, consider the case in which breakdown occurs in the area of ​​one first small electrode 61 surrounded by dashed-dotted line X1 in Figure 2. In this case, the first fuses 71 on both the left and right sides of the first small electrode 61 surrounded by dashed-dotted line X1 may blow. This would isolate the three first small electrodes 61 surrounded by dashed-dotted line Y1. This could result in a decrease in capacitance equivalent to these three first small electrodes 61.

[0095] In contrast, in the second embodiment, as shown in Fig. 5, second fuses 72 are present in front and behind each first small electrode 61. Therefore, even if dielectric breakdown occurs in the portion of one first small electrode 61 surrounded by the dashed-dotted line X2, causing the first fuses 71 on the left and right of this first small electrode 61 and the second fuses 72 on the front and rear of this first small electrode 61 to blow, isolation of the three first small electrodes 61 surrounded by the dashed-dotted line Y2 is suppressed. This is because each of these three first small electrodes 61 is connected to the first small electrode 61 adjacent to it in the front-rear direction by the second fuse 72. As a result, the capacitance is reduced only by an amount corresponding to one first small electrode 61 surrounded by the dashed-dotted line X2.

[0096] Therefore, according to the second embodiment, it is possible to prevent the capacitance of the film capacitor 1 from decreasing excessively when a dielectric breakdown occurs.

[0097] 3. Variations Fig. 4B shows a film capacitor 1 according to a modified example. This film capacitor 1 differs from the film capacitor 1 shown in Fig. 4A in the following points.

[0098] That is, film capacitor 1 shown in Fig. 4A is manufactured using two metallized films 10 (first metallized film 11 and second metallized film 12). In Fig. 4A, an electrode 3 is disposed on one side of each of two metallized films 10.

[0099] In contrast, the film capacitor 1 shown in Figure 4B is manufactured using one metallized film 10 (first metallized film 11) and one dielectric film 2 (second dielectric film 22). In Figure 4B, electrodes 3 are disposed on both sides of one metallized film 10. That is, a metal oxide layer 8 and a metal layer 9 are formed in this order on a first surface 2a of the first dielectric film, and a metal oxide layer 8 and a metal layer 9 are formed in this order on a second surface 2b of the first dielectric film.

[0100] The performance of the film capacitor 1 shown in FIG. 4B is almost the same as the performance of the film capacitor 1 shown in FIG. 4A.

[0101] Other variations are as follows:

[0102] In the first and second embodiments, the film capacitor 1 is a wound type, but the film capacitor 1 may also be a laminated type.

[0103] 1A, 4A, and 4B show a step between the small electrode 6 and the fuse 7 on the surface of the electrode 3, but this step does not have to exist. In other words, the entire surface of the electrode 3 may be flat.

[0104] 4. Aspects As is clear from the above-described embodiments and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiments.

[0105] The first aspect is a film capacitor (1) comprising a dielectric film (2) having a first surface (2a) and a second surface (2b) opposite the first surface (2a), a first electrode (31) disposed on the first surface (2a), and a second electrode (32) disposed on the second surface (2b) and facing the first electrode (31) via the dielectric film (2). The first electrode (31) includes two adjacent first small electrodes (61) and a first fuse (71) connecting the two adjacent first small electrodes (61). Each of the two adjacent first small electrodes (61) is composed of a metal oxide layer (8) and a metal layer (9) in contact with the metal oxide layer (8). The first fuse (71) is composed only of the metal layer (9).

[0106] According to this embodiment, the self-healing function is improved, and even if a dielectric breakdown occurs that exceeds the limit of the self-healing function, the function of the film capacitor (1) as a whole can be maintained.

[0107] The second aspect is a film capacitor (1) based on the first aspect. In the second aspect, the second electrode (32) includes two adjacent second small electrodes (62) and a first fuse (71) connecting the two adjacent second small electrodes (62). Each of the two adjacent second small electrodes (62) is composed of a metal oxide layer (8) and a metal layer (9) in contact with the metal oxide layer (8). The first fuse (71) is composed of only the metal layer (9).

[0108] According to this embodiment, the self-healing function is further improved, and even if a dielectric breakdown occurs that exceeds the limit of the self-healing function, the function of the film capacitor (1) as a whole can be further maintained.

[0109] A third aspect is a film capacitor (1) comprising: a dielectric film (2) having a first surface (2a) and a second surface (2b) opposite the first surface (2a); a first electrode (31) disposed on the first surface (2a); and a second electrode (32) disposed on the second surface (2b) and facing the first electrode (31) via the dielectric film (2). The first electrode (31) has a first divided electrode (41), a first undivided electrode (51) adjacent to the first divided electrode (41) in a first direction (D1), and a plurality of first fuses (71). The first divided electrode (41) includes a plurality of first small electrodes (61) aligned in the first direction (D1) and a second direction (D2) perpendicular to the first direction (D1). Each of the plurality of first fuses (71) connects two first small electrodes (61) adjacent to each other in the first direction (D1) among the plurality of first small electrodes (61). Each of the two first small electrodes (61) adjacent to each other in the first direction (D1) is composed of a metal oxide layer (8) and a metal layer (9) in contact with the metal oxide layer (8). Each of the plurality of first fuses (71) is composed of only a metal layer (9).

[0110] According to this embodiment, the self-healing function is improved, and even if a dielectric breakdown occurs that exceeds the limit of the self-healing function, the function of the film capacitor (1) as a whole can be maintained.

[0111] A fourth aspect is a film capacitor (1) based on the third aspect. In the fourth aspect, the first electrode (31) further includes a plurality of first fuses (71) connecting the first undivided electrode (51) to a plurality of first small electrodes (61) adjacent to the first undivided electrode (51) in the first direction (D1) among the plurality of first small electrodes (61). The first undivided electrode (51) is composed of a metal oxide layer (8) and a metal layer (9) in contact with the metal oxide layer (8). Each of the plurality of first fuses (71) is composed only of a metal layer (9).

[0112] According to this embodiment, the sensitivity of the first fuse (71) connecting the first small electrode (61) and the first undivided electrode (51) can be increased.

[0113] A fifth aspect is a film capacitor (1) based on the third or fourth aspect. In the fifth aspect, the first electrode (31) further includes a plurality of second fuses (72) that connect two first small electrodes (61) adjacent to each other in the second direction (D2) among the plurality of first small electrodes (61). Each of the plurality of second fuses (72) is formed only by a metal layer (9).

[0114] According to this embodiment, it is possible to prevent the capacitance of the film capacitor (1) from decreasing excessively in the event of a dielectric breakdown.

[0115] A sixth aspect is a metallized film (10) comprising a dielectric film (2) and an electrode (3) disposed on one side (2a) of the dielectric film (2). The electrode (3) includes two adjacent small electrodes (6) and a fuse (7) connecting the two adjacent small electrodes (6). Each of the two adjacent small electrodes (6) is composed of a metal oxide layer (8) in contact with the one side (2a) of the dielectric film (2) and a metal layer (9) in contact with the metal oxide layer (8). The fuse (7) is composed only of the metal layer (9) in contact with the one side (2a) of the dielectric film (2).

[0116] According to this embodiment, the self-healing function is improved, and even if a dielectric breakdown occurs that exceeds the limit of the self-healing function, the function of the film capacitor (1) as a whole can be maintained. [Explanation of symbols]

[0117] 1. Film capacitor 2. Dielectric film 2a 1st page 2b 2nd side 3 electrodes 31 1st electrode 32 2nd electrode 41 1st divided electrode 51 1st undivided electrode 6 small electrodes 61 1st small electrode 62 2nd small electrode 7. Fuse 71 First Fuse 72 Second Fuse 8 Metal Oxide Layer 9 metal layer 10 Metallized film

Claims

1. a dielectric film having a first surface and a second surface opposite to the first surface; a first electrode disposed on the first surface; and a second electrode disposed on the second surface and facing the first electrode with the dielectric film interposed therebetween; the first electrode includes two adjacent first small electrodes and a first fuse connecting the two adjacent first small electrodes; each of the two adjacent first small electrodes is composed of a metal oxide layer and a metal layer in contact with the metal oxide layer; the first fuse is composed of only a metal layer; Film capacitor.

2. the second electrode includes two adjacent second small electrodes and a first fuse connecting the two adjacent second small electrodes; each of the two adjacent second small electrodes is composed of a metal oxide layer and a metal layer in contact with the metal oxide layer; the first fuse is composed of only a metal layer; The film capacitor according to claim 1 .

3. a dielectric film having a first surface and a second surface opposite to the first surface; a first electrode disposed on the first surface; and a second electrode disposed on the second surface and facing the first electrode with the dielectric film interposed therebetween; the first electrode includes a first divided electrode, a first undivided electrode adjacent to the first divided electrode in a first direction, and a plurality of first fuses; the first divided electrode includes a plurality of first small electrodes arranged in the first direction and a second direction perpendicular to the first direction, each of the plurality of first fuses connects two first small electrodes adjacent to each other in the first direction among the plurality of first small electrodes; each of the two first small electrodes adjacent to each other in the first direction is composed of a metal oxide layer and a metal layer in contact with the metal oxide layer; each of the plurality of first fuses is formed only from a metal layer; Film capacitor.

4. the first electrode further includes a plurality of first fuses that connect the first undivided electrode to a plurality of first small electrodes that are adjacent to the first undivided electrode in the first direction, among the plurality of first small electrodes; the first undivided electrode is composed of a metal oxide layer and a metal layer in contact with the metal oxide layer, each of the plurality of first fuses is formed only from a metal layer; The film capacitor according to claim 3 .

5. the first electrode further includes a plurality of second fuses connecting two first small electrodes adjacent to each other in the second direction among the plurality of first small electrodes, each of the plurality of second fuses is formed only from a metal layer; The film capacitor according to claim 3 .

6. a dielectric film and an electrode disposed on one surface of the dielectric film; the electrodes include two adjacent small electrodes and a fuse connecting the two adjacent small electrodes; each of the two adjacent small electrodes is composed of a metal oxide layer in contact with one surface of the dielectric film and a metal layer in contact with the metal oxide layer; the fuse is composed only of a metal layer in contact with the one side of the dielectric film; Metallized film.

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