Film capacitor and manufacturing method thereof
The film capacitor design addresses the challenge of heat generation by using a stacked unit structure with increased electrode thickness through opposing contact, and a manufacturing method that minimizes heat exposure, resulting in reduced heat generation and improved reliability.
Patent Information
- Application Number
- JP2023151515
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-09-19
- Publication Date
- 2025-04-01
AI Technical Summary
Existing film capacitors face challenges in reducing heat generation during current supply, as increasing the thickness of the metal film to reduce heat generation leads to longer deposition times and potential damage to the dielectric film due to heat from vapor deposition.
The film capacitor design includes a plurality of stacked units with specific metallized films and electrodes, where each unit consists of a first, second, third, and fourth metallized film, allowing for increased electrode thickness through opposing contact, and the manufacturing method involves forming electrodes on dielectric films by evaporation, reducing the need for multiple depositions and subsequent heat exposure.
This design effectively reduces heat generation during power supply while minimizing damage to the dielectric films from heat exposure during the manufacturing process, resulting in a more efficient and reliable film capacitor.
Smart Images
Figure 2025043916000001_ABST
Abstract
Description
[Technical field]
[0001] The present disclosure relates generally to a film capacitor and a manufacturing method thereof, and more particularly to a film capacitor that utilizes a film as a dielectric and a manufacturing method thereof. [Background technology]
[0002] Patent Document 1 discloses a method for manufacturing a film capacitor element. In this method, first, a main body is prepared. The main body is formed by winding or laminating a metallized film. The metallized film has a dielectric film and a metal film. The metal film is formed by vapor deposition on a first surface of the dielectric film. The main body has a first end face and a second end face. The second end face is the surface opposite to the first end face.
[0003] Next, a metal is sprayed onto each of the first end surface and the second end surface using an inert gas to form a metallikon electrode.
[0004] In the manner described above, the film capacitor element of Patent Document 1 is manufactured. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] Patent Publication No. 2023-046075 Summary of the Invention [Problem to be solved by the invention]
[0006] However, the film capacitor element of Patent Document 1 has a problem in that it is difficult to reduce heat generation during current flow. For example, it seems that heat generation during current flow can be reduced by increasing the thickness of the metal film of the metallized film. However, if the thickness of the metal film is increased by vapor deposition, the vapor deposition takes longer, and damage to the dielectric film due to heat can become greater. Therefore, in the film capacitor element of Patent Document 1, it is difficult to reduce heat generation during current flow while reducing damage to the dielectric film due to the heat of vapor deposition.
[0007] An object of the present disclosure is to provide a film capacitor capable of reducing heat generation when energized, and a method for manufacturing the same. [Means for solving the problem]
[0008] A film capacitor according to an embodiment of the present disclosure includes a plurality of laminate units, a first end surface electrode connected to the plurality of laminate units, and a second end surface electrode facing the first end surface electrode and connected to the plurality of laminate units. Each of the plurality of laminate units includes a first metallized film, a second metallized film, a third metallized film, and a fourth metallized film, in this order. The first metallized film includes a first dielectric film having a first surface and a first back surface opposite the first surface, and a first electrode formed on the first surface and connected to the first end surface electrode. The second metallized film includes a second dielectric film having a second surface facing the first metallized film and a second back surface opposite the second surface, and a second electrode formed on the second back surface and connected to the second end surface electrode. The third metallized film includes a third dielectric film having a third surface facing the second metallized film and a third back surface opposite the third surface, a third electrode formed on the third surface, in opposing contact with the second electrode and connected to the second edge electrode. The fourth metallized film includes a fourth dielectric film having a fourth surface facing the third metallized film and a fourth back surface opposite the fourth surface, and a fourth electrode formed on the fourth back surface, in opposing contact with a first electrode in another stack unit and connected to the first edge electrode.
[0009] A method for manufacturing a film capacitor according to an embodiment of the present disclosure is a method for manufacturing the film capacitor. The first metallized film is manufactured by forming the first electrode on the first dielectric film by vapor deposition. The second metallized film is manufactured by forming the second electrode on the second dielectric film by vapor deposition. The third metallized film is manufactured by forming the third electrode on the third dielectric film by vapor deposition. The fourth electrode is manufactured by forming the fourth dielectric film by vapor deposition. The first metallized film, the second metallized film, the third metallized film, and the fourth metallized film are stacked in this order to form a laminate unit. A plurality of the laminate units are stacked so that the first metallized film and the fourth metallized film overlap. The first end surface electrode connected to the first electrode and the fourth electrode, and the second end surface electrode connected to the second electrode and the third electrode are formed by metal spraying. Effect of the Invention
[0010] According to the present disclosure, heat generation during energization can be reduced. [Brief description of the drawings]
[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a film capacitor according to a first embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing the above-mentioned film capacitor in a more realistic form. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing a lamination unit in the film capacitor. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a laminate unit in the film capacitor in a more realistic form. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing, in an exaggerated manner, metal particles constituting the first and second end surface electrodes in the film capacitor. [Figure 6]FIG. 6 is a schematic cross-sectional view showing, in an exaggerated manner, metal particles constituting the first and second end surface electrodes in the film capacitor according to the second embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view showing, in an exaggerated manner, metal particles constituting first and second end surface electrodes in a film capacitor for comparison with the film capacitor according to the first and second embodiments. [Figure 8] Fig. 8A is a schematic perspective view showing a process for manufacturing a wound type capacitor element body, Fig. 8B is a schematic perspective view showing a wound type capacitor element body, and Fig. 8C is a schematic perspective view showing a wound type film capacitor. [Figure 9] Fig. 9A is a schematic perspective view showing a process for manufacturing a multilayer capacitor element body, Fig. 9B is a schematic perspective view showing a multilayer capacitor element body, and Fig. 9C is a schematic perspective view showing a multilayer film capacitor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] 1. Overview 8C shows an example of the film capacitor 1 according to this embodiment. This film capacitor 1 is a wound type film capacitor 1, and can be manufactured as follows.
[0013] First, first to fourth metallized films 31 to 34 are manufactured. That is, first electrode 51 is formed on first dielectric film 41 by vapor deposition to manufacture first metallized film 31 (see FIGS. 1 to 4). Second metallized film 32, third metallized film 33, and fourth metallized film 34 are manufactured in the same manner.
[0014] Next, as shown in Fig. 8A, first metallized film 31, second metallized film 32, third metallized film 33, and fourth metallized film 34 are stacked in this order to form laminate unit 10. Then, this laminate unit 10 is wound around winding axis C to stack a plurality of laminate units 10. As a result, in two adjacent laminate units 10, the first metallized film 31 in one laminate unit 10b overlaps with the fourth metallized film 34 in the other laminate unit 10a, as shown in Figs. 1 and 2. In this manner, a cylindrical capacitor element body 100 is obtained.
[0015] Next, as shown in Fig. 8B, the cylindrical capacitor element body 100 is pressed in a direction perpendicular to the first direction D1 to obtain a flattened cylindrical capacitor element body 100. Then, a first end surface electrode 21 is formed on a first end surface 101 by metal spraying. Similarly, a second end surface electrode 22 is formed on a second end surface 102 by metal spraying. In this manner, a wound-type film capacitor 1 as shown in Fig. 8C is obtained.
[0016] In the film capacitor 1 according to the present embodiment, the first electrode 51 and the fourth electrode 54 face each other and are in contact with each other as shown in Fig. 2, so that the thickness of the electrodes can be increased. Similarly, the second electrode 52 and the third electrode 53 face each other and are in contact with each other, so that the thickness of the electrodes can be increased.
[0017] Therefore, the film capacitor 1 according to this embodiment can reduce heat generation during electrical conduction.
[0018] Furthermore, in the manufacturing method of film capacitor 1 according to the present embodiment, in manufacturing first metallized film 31, first electrode 51 is formed by vapor deposition only on one side (first surface 41a) of first dielectric film 41. The same is true for manufacturing second to fourth metallized films 32 to 34. In this way, vapor deposition is performed only once for one dielectric film, and it is not necessary to take time for each vapor deposition. This is because the thickness of the electrodes is increased by facing first electrode 51 and fourth electrode 54 in contact with each other and by facing second electrode 52 and third electrode 53 in contact with each other, as described above.
[0019] Therefore, according to the manufacturing method of the film capacitor 1 of this embodiment, when the first to fourth electrodes 51 to 54 are formed on the first to fourth dielectric films 41 to 44, respectively, by vapor deposition, damage to the first to fourth dielectric films 41 to 44 caused by the heat of vapor deposition can be reduced.
[0020] 2.Details (1) First embodiment Hereinafter, a film capacitor 1 according to a first embodiment will be described with reference to Fig. 1 to Fig. 5. Each figure is a schematic view, and the ratio of sizes and thicknesses of each component in each figure does not necessarily reflect the actual dimensional ratio.
[0021] The arrows indicating the directions in each figure are not intended to define the directions when the film capacitor 1 is used, but are merely depicted to facilitate understanding of the description and have no substance. The first direction D1, the second direction D2, and the third direction D3 are mutually perpendicular. In this embodiment, the first direction D1 is the left-right direction (width direction), the second direction D2 is the front-rear direction, and the third direction D3 is the up-down direction (thickness direction). In particular, the first direction D1 is the direction connecting the first end surface electrode 21 and the second end surface electrode 22, and may also be referred to as the reference direction D1. The same applies to the second embodiment described below.
[0022] The film capacitor 1 according to this embodiment includes a plurality of laminate units 10, a first end surface electrode 21, and a second end surface electrode 22. Each of the components will be described below.
[0023] <Multiple stacking units> The multiple laminate units 10 are stacked in a third direction D3 (vertical direction). In the case of a wound-type film capacitor 1, the multiple laminate units 10 are stacked in the radial direction of an imaginary circle centered on a winding shaft C (see FIG. 8A).
[0024] Each of the multiple laminate units 10 includes a first metallized film 31, a second metallized film 32, a third metallized film 33, and a fourth metallized film 34 in this order. In Fig. 1 and Fig. 3, the first metallized film 31, the second metallized film 32, the third metallized film 33, and the fourth metallized film 34 are shown separated from each other for ease of understanding. However, in each laminate unit 10, a more realistic shape is shown in Fig. 4 in which the first metallized film 31 and the second metallized film 32 are in contact with each other, the second metallized film 32 and the third metallized film 33 are in contact with each other, and the third metallized film 33 and the fourth metallized film 34 are in contact with each other, rather than the shape shown in Fig. 3. Furthermore, as shown in Figure 2, in two adjacent laminate units 10a, 10b, it is more realistic that the fourth metallized film 34 of one laminate unit 10a is in contact with the first metallized film 31 of the other laminate unit 10b than as shown in Figure 1.
[0025] <First metallized film> First metallized film 31 has a certain width in a first direction D1, extends in a second direction D2, and has a thickness in a third direction D3. First metallized film 31 includes a first dielectric film 41 and a first electrode 51.
[0026] [First dielectric film] The first dielectric film 41 is a film made of a dielectric material. The dielectric material is not particularly limited, but examples thereof include polypropylene (PP) and polyethylene terephthalate (PET).
[0027] The first dielectric film 41 has a constant width in a first direction D1, extends in a second direction D2, and has a constant thickness in a third direction D3.
[0028] The first dielectric film 41 has a first surface 41a and a first back surface 41b. The first surface 41a is the upper surface. The first back surface 41b is the surface opposite to the first surface 41a. In other words, the first back surface 41b is the lower surface. The thickness of the first dielectric film 41 is the distance between the first surface 41a and the first back surface 41b, and is not particularly limited, but is, for example, not less than 1.0 μm and not more than 10.0 μm.
[0029] [1st electrode] The first electrode 51 may be any of a vapor deposition electrode, a metal foil electrode, and a plated electrode. The material of the first electrode 51 is not particularly limited, but may be, for example, aluminum (Al), magnesium (Mg), or an alloy thereof. The thickness of the first electrode 51 is not particularly limited, but may be, for example, 5 nm or more and 100 nm or less.
[0030] The first electrode 51 is formed on the first surface 41a of the first dielectric film 41. Specifically, the first electrode 51 is formed in a solid shape on the first surface 41a of the first dielectric film 41 except for a first margin portion 61.
[0031] The first margin portion 61 is present at an end portion on one side (left side) in the first direction D1 on the first surface 41a of the first dielectric film 41. The first margin portion 61 is a narrow strip-shaped portion (see FIGS. 8A and 9A). That is, the first margin portion 61 is a portion that has a width in the first direction D1 and extends in the second direction D2. As such, the first electrode 51 is not present in the first margin portion 61, and therefore the first electrode 51 is not in contact with the second end surface electrode 22. On the other hand, the first electrode 51 is connected to the first end surface electrode 21.
[0032] <Second metallized film> Second metallized film 32 has a width in first direction D1, extends in second direction D2, and has a thickness in third direction D3. The width and thickness of second metallized film 32 are approximately equal to the width and thickness of first metallized film 31. Second metallized film 32 includes second dielectric film 42 and second electrode 52.
[0033] [Second dielectric film] The second dielectric film 42 is also a film made of a dielectric material similar to that of the first dielectric film 41. The dimensions of the second dielectric film 42 are similar to those of the first dielectric film 41.
[0034] The second dielectric film 42 has a second surface 42a and a second back surface 42b. The second surface 42a is the upper surface. The second surface 42a faces the first metallized film 31. Specifically, the second surface 42a faces and contacts the first back surface 41b of the first dielectric film 41 (see FIGS. 2 and 4). The second back surface 42b is the surface opposite to the second surface 42a. In other words, the second back surface 42b is the lower surface.
[0035] Here, the first dielectric film 41 is shifted toward the first end surface electrode 21 with respect to the second dielectric film 42 along the reference direction D1. Thus, on the other side (right side) of the reference direction D1, the right end surface of the first dielectric film 41 and the right end surface of the second dielectric film 42 are not on the same plane. That is, as shown in Fig. 5, the right end surface of the first dielectric film 41 exists on a plane α1, and the right end surface of the second dielectric film 42 exists on a plane β1. The planes α1 and β1 are imaginary planes that are perpendicular to the reference direction D1 and parallel to each other.
[0036] On the other hand, the second dielectric film 42 is arranged shifted toward the second end surface electrode 22 with respect to the first dielectric film 41. Thus, on one side (left side) of the reference direction D1, the left end surface of the first dielectric film 41 and the left end surface of the second dielectric film 42 are not on the same plane. That is, as shown in FIG. 5, the left end surface of the first dielectric film 41 is on a plane α2, and the left end surface of the second dielectric film 42 is on a plane β2. The planes α2 and β2 are imaginary planes that are perpendicular to the reference direction D1 and parallel to each other. In FIG. 5, the metal particles 201 constituting the first end surface electrode 21 and the metal particles 202 constituting the second end surface electrode 22 are exaggerated. The same is true in FIG. 6 and FIG. 7. Furthermore, in FIG. 5 to FIG. 7, the first metallized film 31, the second metallized film 32, the third metallized film 33, and the fourth metallized film 34 are illustrated apart from each other to make the explanation easier to understand.
[0037] [Second electrode] The second electrode 52 may be any one of a vapor deposition electrode, a metal foil electrode, and a plated electrode, similar to the first electrode 51. The material of the second electrode 52 is the same as the material of the first electrode 51. The thickness of the second electrode 52 is the same as the thickness of the first electrode 51.
[0038] The second electrode 52 is formed on the second back surface 42b of the second dielectric film 42. Specifically, the second electrode 52 is formed in a solid shape on the second back surface 42b of the second dielectric film 42 except for the second margin portion 62.
[0039] The second margin portion 62 is present at the end portion on the other side (right side) in the first direction D1 on the second back surface 42b of the second dielectric film 42. The second margin portion 62 is a narrow strip-shaped portion. That is, the second margin portion 62 is a portion that has a width in the first direction D1 and extends in the second direction D2. As such, the second electrode 52 is not present in the second margin portion 62, and therefore the second electrode 52 is not in contact with the first end surface electrode 21. On the other hand, the second electrode 52 is connected to the second end surface electrode 22.
[0040] <Third metallized film> Third metallized film 33 has a width in first direction D1, extends in second direction D2, and has a thickness in third direction D3. The width and thickness of third metallized film 33 are approximately equal to the width and thickness of first metallized film 31. Third metallized film 33 includes third dielectric film 43 and third electrode 53.
[0041] [Third dielectric film] The third dielectric film 43 is also a film made of a dielectric material similar to that of the first dielectric film 41. The dimensions of the third dielectric film 43 are similar to those of the first dielectric film 41.
[0042] Third dielectric film 43 has third surface 43a and third back surface 43b. Third surface 43a is the upper surface. Third surface 43a faces second metallized film 32. Third back surface 43b is the surface opposite to third surface 43a. In other words, third back surface 43b is the lower surface.
[0043] [Third electrode] The third electrode 53 may be any one of a vapor deposition electrode, a metal foil electrode, and a plated electrode, similar to the first electrode 51. The material of the third electrode 53 is the same as the material of the first electrode 51. The thickness of the third electrode 53 is the same as the thickness of the first electrode 51.
[0044] The third electrode 53 is formed on the third surface 43a of the third dielectric film 43. Specifically, the third electrode 53 is formed in a solid shape on the third surface 43a of the third dielectric film 43 except for the third margin portion 63.
[0045] The third margin portion 63 is present at the end portion on the other side (right side) in the first direction D1 on the third surface 43a of the third dielectric film 43. The third margin portion 63 is a narrow strip-shaped portion (see FIGS. 8A and 9A). That is, the third margin portion 63 is a portion that has a width in the first direction D1 and extends in the second direction D2. As such, the third electrode 53 is not present in the third margin portion 63, and therefore the third electrode 53 is not in contact with the first end surface electrode 21. On the other hand, the third electrode 53 is connected to the second end surface electrode 22.
[0046] 1 and 3, the third electrode 53 is illustrated apart from the second electrode 52, but in reality, the third electrode 53 faces and contacts the second electrode 52 as shown in Figures 2 and 4. That is, the third electrode 53 is electrically connected to the second electrode 52.
[0047] <Fourth metallized film> Fourth metallized film 34 has a width in first direction D1, extends in second direction D2, and has a thickness in third direction D3. The width and thickness of fourth metallized film 34 are approximately equal to the width and thickness of first metallized film 31. Fourth metallized film 34 includes fourth dielectric film 44 and fourth electrode 54.
[0048] [Fourth dielectric film] The fourth dielectric film 44 is also a film made of a dielectric material similar to that of the first dielectric film 41. The dimensions of the fourth dielectric film 44 are similar to those of the first dielectric film 41.
[0049] Fourth dielectric film 44 has fourth surface 44a and fourth back surface 44b. Fourth surface 44a is the upper surface. Fourth surface 44a faces third metallized film 33. Specifically, fourth surface 44a faces and contacts third back surface 43b of third dielectric film 43 (see FIGS. 2 and 4). Fourth back surface 44b is the surface opposite to fourth surface 44a. In other words, fourth back surface 44b is the lower surface.
[0050] Here, the third dielectric film 43 is shifted toward the second end surface electrode 22 with respect to the fourth dielectric film 44 along the reference direction D1. Thus, on one side (the left side) of the reference direction D1, the left end surface of the third dielectric film 43 and the left end surface of the fourth dielectric film 44 are not on the same plane. That is, as shown in Fig. 5, the left end surface of the third dielectric film 43 exists on the plane β2, and the left end surface of the fourth dielectric film 44 exists on the plane α2.
[0051] On the other hand, the fourth dielectric film 44 is disposed offset toward the first end surface electrode 21 with respect to the third dielectric film 43. Thus, on the other side (right side) of the reference direction D1, the right end surface of the third dielectric film 43 and the right end surface of the fourth dielectric film 44 are not on the same plane. That is, as shown in Fig. 5, the right end surface of the third dielectric film 43 exists on the plane β1, and the right end surface of the fourth dielectric film 44 exists on the plane α1.
[0052] [4th electrode] The fourth electrode 54 may be any one of a vapor deposition electrode, a metal foil electrode, and a plated electrode, similar to the first electrode 51. The material of the fourth electrode 54 is the same as the material of the first electrode 51. The thickness of the fourth electrode 54 is the same as the thickness of the first electrode 51.
[0053] The fourth electrode 54 is formed on the fourth back surface 44b of the fourth dielectric film 44. Specifically, the fourth electrode 54 is formed in a solid shape on the fourth back surface 44b of the fourth dielectric film 44 except for the fourth margin portion 64.
[0054] The fourth margin portion 64 is present at an end on one side (left side) in the first direction D1 on the fourth back surface 44b of the fourth dielectric film 44. The fourth margin portion 64 is a narrow strip-shaped portion. That is, the fourth margin portion 64 is a portion that has a width in the first direction D1 and extends in the second direction D2. As such, the fourth electrode 54 is not present in the fourth margin portion 64, and therefore the fourth electrode 54 is not in contact with the second end surface electrode 22. On the other hand, the fourth electrode 54 is connected to the first end surface electrode 21.
[0055] 1, the fourth electrode 54 in one laminate unit 10a of two adjacent laminate units 10a, 10b is shown separated from the first electrode 51 in the other laminate unit 10b, but in reality, the fourth electrode 54 faces and contacts the first electrode 51 in another laminate unit 10, as shown in FIG. 2. In other words, the fourth electrode 54 is electrically connected to the first electrode 51.
[0056] <First end electrode> The first end surface electrode 21 is connected to the multiple laminate units 10. Specifically, the first end surface electrode 21 is electrically connected to the first electrodes 51 and the fourth electrodes 54 in the multiple laminate units 10. However, the first end surface electrode 21 is not connected to the second electrodes 52 and the third electrodes 53 in the multiple laminate units 10.
[0057] The material of the first end surface electrode 21 is not particularly limited, but may be, for example, zinc (Zn), tin (Sn), or an alloy thereof. The thickness of the first end surface electrode 21 (the distance along the first direction D1) is not particularly limited, but may be, for example, 0.5 mm or more and 1.5 mm or less.
[0058] The method for forming the first end surface electrode 21 is not particularly limited, but examples thereof include metal spraying. When the first end surface electrode 21 is formed by metal spraying, the first end surface electrode 21 is composed of countless metal particles 201 (see FIGS. 5 to 7). The average particle diameter (D50) of the metal particles 201 is not particularly limited, but is, for example, 1 μm or more and 100 μm or less.
[0059] <Second end electrode> The second end surface electrode 22 is connected to the multiple laminate units 10. Specifically, the second end surface electrode 22 is electrically connected to the second electrodes 52 and the third electrodes 53 in the multiple laminate units 10. However, the second end surface electrode 22 is not connected to the first electrodes 51 and the fourth electrodes 54 in the multiple laminate units 10. In this manner, the second end surface electrode 22 faces the first end surface electrode 21 along the first direction D1, with the multiple laminate units 10 interposed therebetween.
[0060] The material, thickness and formation method of the second end surface electrode 22 are the same as the material, thickness and formation method of the first end surface electrode 21. When the second end surface electrode 22 is formed by metal spraying, the second end surface electrode 22 is composed of countless metal particles 202 (see FIGS. 5 to 7). The average particle diameter (D50) of the metal particles 202 is the same as the average particle diameter (D50) of the metal particles 201 that constitute the first end surface electrode 21.
[0061] <Manufacturing method of film capacitors> Next, a method for manufacturing the film capacitor 1 according to this embodiment will be described separately for the wound film capacitor 1 and the stacked film capacitor 1.
[0062] <Wound film capacitor> A method for manufacturing the wound film capacitor 1 will be described with reference to Figures 8A to 8C. In Figure 8A, the first electrode 51, the third electrode 53, and the fourth electrode 54 are indicated by dot hatching.
[0063] First, first electrode 51 is formed on first dielectric film 41 by vapor deposition to produce first metallized film 31. Second metallized film 32, third metallized film 33, and fourth metallized film 34 are produced in a similar manner. Note that first metallized film 31 can be substituted for second metallized film 32, third metallized film 33, and fourth metallized film 34 by inverting first metallized film 31 upside down and / or left to right.
[0064] Next, as shown in FIG. 8A, the first metallized film 31, the second metallized film 32, the third metallized film 33, and the fourth metallized film 34 are stacked in this order to form a laminate unit 10. Then, the laminate unit 10 is wound around a winding axis C to stack a plurality of laminate units 10. As a result, in two adjacent laminate units 10, the first metallized film 31 in one laminate unit 10b and the fourth metallized film 34 in the other laminate unit 10a are stacked as shown in FIG. 1 and FIG. 2. In this manner, a cylindrical capacitor element body 100 is obtained. When the first metallized film 31, the second metallized film 32, the third metallized film 33, and the fourth metallized film 34 are stacked, they are slightly shifted in the first direction D1 (left-right direction) as shown in FIG. 5 to FIG. 7.
[0065] Next, as shown in FIG. 8B, the cylindrical capacitor element body 100 is pressed in a direction perpendicular to the first direction D1 to obtain a flattened cylindrical capacitor element body 100. The flattened cylindrical capacitor element body 100 has a first end face 101, a second end face 102, and a peripheral face 103. The first end face 101 is on the right side. The first electrode 51 and the fourth electrode 54 are exposed at the first end face 101. The second end face 102 is on the left side. The second electrode 52 and the third electrode 53 are exposed at the second end face 102. The peripheral face 103 is a face that connects the outer periphery of the first end face 101 and the outer periphery of the second end face 102, and is covered with a known electrical insulating material.
[0066] Then, the first end surface electrode 21 is formed on the first end surface 101 by metal spraying. As a result, the first end surface electrode 21 is connected to the first electrode 51 and the fourth electrode 54. Similarly, the second end surface electrode 22 is formed on the second end surface 102 by metal spraying. As a result, the second end surface electrode 22 is connected to the second electrode 52 and the third electrode 53. In this manner, a wound-type film capacitor 1 as shown in FIG. 8C is obtained.
[0067] <Stacked film capacitor> A method for manufacturing the multilayer film capacitor 1 will be described with reference to Figures 9A to 9C. In Figure 9A, the first electrode 51 and the third electrode 53 are indicated by dot hatching.
[0068] First metallized film 31, second metallized film 32, third metallized film 33 and fourth metallized film 34 are manufactured as described above.
[0069] Next, as shown in FIG. 9A, the first metallized film 31, the second metallized film 32, the third metallized film 33, and the fourth metallized film 34 are stacked in this order to form a laminate unit 10. Then, a plurality of laminate units 10 are stacked in the third direction D3 (vertical direction). In this case, in two adjacent laminate units 10, the first metallized film 31 in one laminate unit 10b and the fourth metallized film 34 in the other laminate unit 10a are stacked. In this manner, a rectangular parallelepiped capacitor element body 100 is obtained. When the first metallized film 31, the second metallized film 32, the third metallized film 33, and the fourth metallized film 34 are stacked, they are slightly shifted in the first direction D1 (horizontal direction) as shown in FIGS. 5 to 7.
[0070] Similar to the above-described flat cylindrical capacitor element body 100, the rectangular parallelepiped capacitor element body 100 has a first end face 101, a second end face 102, and a peripheral surface 103. The peripheral surface 103 is covered with a known electrical insulating material.
[0071] Then, a first end surface electrode 21 is formed on the first end surface 101 by metal spraying. As a result, the first end surface electrode 21 is connected to the first electrode 51 and the fourth electrode 54. Similarly, a second end surface electrode 22 is formed on the second end surface 102 by metal spraying. As a result, the second end surface electrode 22 is connected to the second electrode 52 and the third electrode 53. In this manner, a stacked film capacitor 1 as shown in FIG. 9C is obtained.
[0072] <Action and effect> The film capacitor 1 according to this embodiment is charged by applying a voltage between the first end surface electrode 21 and the second end surface electrode 22. Also, it is discharged through the first end surface electrode 21 and the second end surface electrode 22.
[0073] 2, in the film capacitor 1 according to this embodiment, the first electrode 51 and the fourth electrode 54 are in opposing contact with each other. Therefore, the thickness of the electrode formed by the opposing contact of the first electrode 51 and the fourth electrode 54 is greater than the thickness of the first electrode 51 alone and the thickness of the fourth electrode 54 alone. In other words, the electrical resistance of the electrode formed by the opposing contact of the first electrode 51 and the fourth electrode 54 is lower than the electrical resistance of the first electrode 51 alone and the electrical resistance of the fourth electrode 54 alone.
[0074] On the other hand, in the film capacitor 1 according to the present embodiment, the second electrode 52 and the third electrode 53 are in opposing contact with each other. Therefore, the thickness of the electrode formed by the opposing contact of the second electrode 52 and the third electrode 53 is greater than the thickness of the second electrode 52 alone and the thickness of the third electrode 53 alone. In other words, the electrical resistance of the electrode formed by the opposing contact of the second electrode 52 and the third electrode 53 is lower than the electrical resistance of the second electrode 52 alone and the electrical resistance of the third electrode 53 alone.
[0075] Therefore, the film capacitor 1 according to this embodiment can reduce heat generation during electrical conduction.
[0076] 1 to 4, in this embodiment, the first electrode 51 and the fourth electrode 54 are not in contact with the second end surface electrode 22. On the other hand, the second electrode 52 and the third electrode 53 are not in contact with the first end surface electrode 21. This makes it possible to suppress the occurrence of short circuits.
[0077] In this embodiment, as shown in FIG. 5, the first dielectric film 41 is shifted toward the first end surface electrode 21 with respect to the second dielectric film 42 along the reference direction D1. Furthermore, the third dielectric film 43 is shifted toward the second end surface electrode 22 with respect to the fourth dielectric film 44. By shifting the left and right end surfaces of the first to fourth dielectric films 41 to 44 in this manner, recessed portions can be regularly formed on the first end surface 101 of the capacitor element body 100, and recessed portions can also be regularly formed on the second end surface 102. Depending on the thicknesses of the first to fourth dielectric films 41 to 44 and the particle diameters of the metal particles 201 and 202, the metal particles 201 and 202 are likely to be embedded in the recessed portions. Therefore, the first metallized film 31 and the fourth metallized film 34 can be firmly connected to the first end surface electrode 21. In addition, second metallized film 32 and third metallized film 33 can be firmly connected to second end surface electrode 22.
[0078] In contrast, in the film capacitor 1 shown in Fig. 7, the left and right end faces of the first to fourth dielectric films 41 to 44 are shifted in a manner opposite to that shown in Fig. 5. In Fig. 5, both the first electrode 51 and the fourth electrode 54 are closer to the first end electrode 21, and both the second electrode 52 and the third electrode 53 are closer to the second end electrode 22. Therefore, from the viewpoint of the reliability of the electrical connection, the configuration shown in Fig. 5 is more preferable than the configuration shown in Fig. 7.
[0079] Furthermore, in the method for manufacturing film capacitor 1 according to the present embodiment, in manufacturing first metallized film 31, first electrode 51 is formed by vapor deposition only on one side (first surface 41a) of first dielectric film 41. The same is true for manufacturing second to fourth metallized films 32 to . In this way, vapor deposition is performed only once for one dielectric film, and vapor deposition is not performed two or more times. There is no need to spend a lot of time even on a single vapor deposition.
[0080] Therefore, according to the manufacturing method of the film capacitor 1 of this embodiment, when the first to fourth electrodes 51 to 54 are formed on the first to fourth dielectric films 41 to 44, respectively, by vapor deposition, damage to the first to fourth dielectric films 41 to 44 caused by the heat of vapor deposition can be reduced.
[0081] (2) Second embodiment Next, a film capacitor 1 according to a second embodiment will be described with reference to Fig. 6. In the second embodiment, components similar to those in the first embodiment are denoted by the same reference numerals as in the first embodiment, and detailed description thereof may be omitted.
[0082] In this embodiment, as shown in Fig. 6, the second dielectric film 42 is shifted toward the first end surface electrode 21 with respect to the third dielectric film 43 along the reference direction D1. Thus, on the other side (right side) of the reference direction D1, the right end surface of the second dielectric film 42 and the right end surface of the third dielectric film 43 are not on the same plane. That is, as shown in Fig. 6, the right end surface of the second dielectric film 42 exists on a plane β1, and the right end surface of the third dielectric film 43 exists on a plane γ1. The planes β1 and γ1 are imaginary planes that are perpendicular to the reference direction D1 and parallel to each other.
[0083] On the other hand, the third dielectric film 43 is disposed offset toward the second end surface electrode 22 with respect to the second dielectric film 42. Thus, on one side (left side) of the reference direction D1, the left end surface of the second dielectric film 42 and the left end surface of the third dielectric film 43 are not on the same plane. That is, as shown in Fig. 6, the left end surface of the second dielectric film 42 exists on plane β2, and the left end surface of the third dielectric film 43 exists on plane γ2. Plane β2 and plane γ2 are imaginary planes that are perpendicular to reference direction D1 and parallel to each other.
[0084] <Action and effect> The second embodiment also has the same effect as the first embodiment. Furthermore, in this embodiment, as shown in FIG. 6, the second dielectric film 42 is shifted toward the first end surface electrode 21 with respect to the third dielectric film 43 along the reference direction D1. By shifting the left and right end surfaces of the second and third dielectric films 42-43 in this way, the number of depth stages of the recessed portions formed on the first end surface 101 and the second end surface 102 of the capacitor element body 100 can be increased more than that shown in FIG. 5. That is, in FIG. 5, the depth of the recessed portion corresponds to the distance between the plane α1 and the plane β1, and the distance between the plane β2 and the plane α2. That is, the depth stage of the recessed portion is only one stage. In contrast, in FIG. 6, the depth of the recessed portion corresponds to the distance between the plane α1 and the plane β1, the distance between the plane α1 and the plane γ1, the distance between the plane γ2 and the plane β2, and the distance between the plane γ2 and the plane α2. That is, the depth stage of the recessed portion is two stages. Therefore, metal particles 201, 202 formed by metal spraying are more likely to fit into the recessed areas in Fig. 6 compared to Fig. 5. This allows for more solid connection between first metallized film 31 and fourth metallized film 34 and first end electrode 21. Also, more solid connection between second metallized film 32 and third metallized film 33 and second end electrode 22 can be achieved.
[0085] 3. Aspects As is apparent from the above embodiment, the present disclosure includes the following aspects. In the following, reference symbols are given in parentheses only to clarify the correspondence with the embodiment.
[0086] The first aspect is a film capacitor (1) comprising a plurality of laminate units (10), a first end surface electrode (21) connected to the plurality of laminate units (10), and a second end surface electrode (22) facing the first end surface electrode (21) and connected to the plurality of laminate units (10). Each of the plurality of laminate units (10) includes a first metallized film (31), a second metallized film (32), a third metallized film (33), and a fourth metallized film (34), in this order. The first metallized film (31) includes a first dielectric film (41) having a first surface (41a) and a first back surface (41b) opposite the first surface (41a), and a first electrode (51) formed on the first surface (41a) and connected to the first end surface electrode (21). The second metallized film (32) includes a second dielectric film (42) having a second surface (42a) facing the first metallized film (31) and a second back surface (42b) opposite the second surface (42a), and a second electrode (52) formed on the second back surface (42b) and connected to the second end electrode (22). The third metallized film (33) includes a third dielectric film (43) having a third surface (43a) facing the second metallized film (32) and a third back surface (43b) opposite the third surface (43a), and a third electrode (53) formed on the third surface (43a), in opposing contact with the second electrode (52), and connected to the second end electrode (22). The fourth metallized film (34) includes a fourth dielectric film (44) having a fourth surface (44a) facing the third metallized film (33) and a fourth back surface (44b) opposite the fourth surface (44a), and a fourth electrode (54) formed on the fourth back surface (44b), facing and in contact with a first electrode (51) in another laminate unit (10), and connected to the first end electrode (21).
[0087] According to this aspect, heat generation during energization can be reduced.
[0088] The second aspect is a film capacitor (1) based on the first aspect. In the second aspect, the first electrode (51) and the fourth electrode (54) are not in contact with the second end surface electrode (22). The second electrode (52) and the third electrode (53) are not in contact with the first end surface electrode (21).
[0089] According to this aspect, the occurrence of a short circuit can be suppressed.
[0090] A third aspect is a film capacitor (1) based on the first or second aspect. In the third aspect, the first dielectric film (41) is shifted toward the first end surface electrode (21) relative to the second dielectric film (42) along a reference direction (D1) connecting the first end surface electrode (21) and the second end surface electrode (22). The third dielectric film (43) is shifted toward the second end surface electrode (22) relative to the fourth dielectric film (44) along the reference direction (D1).
[0091] According to this embodiment, the first metallized film (31) and the fourth metallized film (34) can be firmly connected to the first end surface electrode (21). The second metallized film (32) and the third metallized film (33) can be firmly connected to the second end surface electrode (22).
[0092] The fourth aspect is the film capacitor (1) based on the third aspect. In the fourth aspect, the second dielectric film (42) is shifted toward the first end surface electrode (21) side relative to the third dielectric film (43) along the reference direction (D1).
[0093] According to this embodiment, the first metallized film (31) and the fourth metallized film (34) can be more firmly connected to the first end electrode (21). The second metallized film (32) and the third metallized film (33) can be more firmly connected to the second end electrode (22).
[0094] A fifth aspect is a method for manufacturing a film capacitor (1), which is a method for manufacturing a film capacitor (1) based on any one of the first to fourth aspects. The first electrode (51) is formed on the first dielectric film (41) by vapor deposition to manufacture the first metallized film (31). The second electrode (52) is formed on the second dielectric film (42) by vapor deposition to manufacture the second metallized film (32). The third electrode (53) is formed on the third dielectric film (43) by vapor deposition to manufacture the third metallized film (33). The fourth electrode (54) is formed on the fourth dielectric film (44) by vapor deposition to manufacture the fourth metallized film (34). The first metallized film (31), the second metallized film (32), the third metallized film (33), and the fourth metallized film (34) are stacked in this order to form a stacking unit (10). A plurality of the laminate units (10) are stacked so that the first metallized film (31) and the fourth metallized film (34) overlap each other. The first end surface electrode (21) connected to the first electrode (51) and the fourth electrode (54), and the second end surface electrode (22) connected to the second electrode (52) and the third electrode (53) are formed by metal spraying.
[0095] According to this embodiment, when the first to fourth electrodes (51 to 54) are formed on the first to fourth dielectric films (41 to 44), respectively, by vapor deposition, damage to the first to fourth dielectric films (41 to 44) caused by heat of vapor deposition can be reduced. [Explanation of symbols]
[0096] 1. Film capacitor 10 Stacking Units 10a Stacking unit 10b Stacking unit 21 1st end electrode 22 2nd end electrode 31 First metallized film 32 Second metallized film 33 Third Metallized Film 34 4th metallized film 41 First dielectric film 41a 1st surface 41b 1st back side 42 Second dielectric film 42a 2nd surface 42b 2nd back side 43 Third Dielectric Film 43a 3rd surface 43b 3rd back 44 4th Dielectric Film 44a 4th surface 44b 4th back 51 1st electrode 52 2nd electrode 53 3rd electrode 54 4th electrode D1 Reference direction
Claims
1. a first end surface electrode connected to the plurality of laminate units; and a second end surface electrode facing the first end surface electrode and connected to the plurality of laminate units; each of the plurality of stacking units includes a first metallized film, a second metallized film, a third metallized film, and a fourth metallized film, in this order; the first metallized film includes a first dielectric film having a first surface and a first back surface opposite the first surface, and a first electrode formed on the first surface and connected to the first end electrode; the second metallized film includes a second dielectric film having a second surface facing the first metallized film and a second back surface opposite the second surface, and a second electrode formed on the second back surface and connected to the second edge electrode, the third metallized film includes a third dielectric film having a third surface facing the second metallized film and a third back surface opposite the third surface, and a third electrode formed on the third surface, in opposing contact with the second electrode, and connected to the second end electrode; the fourth metallized film includes a fourth dielectric film having a fourth surface facing the third metallized film and a fourth back surface opposite the fourth surface, and a fourth electrode formed on the fourth back surface, facing and in contact with a first electrode in another stacking unit, and connected to the first end electrode; Film capacitor.
2. the first electrode and the fourth electrode are not in contact with the second end surface electrode, the second electrode and the third electrode are not in contact with the first end surface electrode; The film capacitor according to claim 1 .
3. the first dielectric film is shifted toward the first end surface electrode with respect to the second dielectric film along a reference direction connecting the first end surface electrode and the second end surface electrode, the third dielectric film is shifted toward the second end surface electrode side with respect to the fourth dielectric film along the reference direction; The film capacitor according to claim 1 .
4. the second dielectric film is shifted toward the first end surface electrode with respect to the third dielectric film along the reference direction; The film capacitor according to claim 3 .
5. A method for producing the film capacitor according to claim 1, comprising the steps of: forming the first electrode on the first dielectric film by vapor deposition to produce the first metallized film; forming the second electrode on the second dielectric film by vapor deposition to produce the second metallized film; forming the third electrode on the third dielectric film by vapor deposition to produce the third metallized film; forming the fourth electrode on the fourth dielectric film by vapor deposition to produce the fourth metallized film; forming a laminate unit by stacking the first metallized film, the second metallized film, the third metallized film, and the fourth metallized film in this order; stacking a plurality of the lamination units so that the first metallized film and the fourth metallized film overlap each other; the first end surface electrode connected to the first electrode and the fourth electrode, and the second end surface electrode connected to the second electrode and the third electrode are formed by metal spraying; A method for manufacturing a film capacitor.
Citation Information
Patent Citations
Method for manufacturing film capacitor element
JP2023046075A