JP2021190664A - Manufacturing method of film capacitor - Google Patents

Abstract

To provide a manufacturing method of a film capacitor, in which a generation of a short circuit is suppressed.SOLUTION: Firstly, a structure is prepared which contains a lamination body containing a first metal film and a second metal film, a first outer electrode formed on a first end surface of the lamination body, and a second outer electrode formed on a second end surface on the side opposite to the first end surface. Here, the first and second metal films comprise: a dielectric film having a contractible part; a metal film formed on a main surface of the dielectric film. The first and second metal films include: a margin area on which no metal film is formed; and an electrode region on which the metal film is formed. The contractible part is positioned in the electrode region, and is extended in a band shape in a direction parallel to first sides of the first and second metal films. Secondary, the contractible part is contracted. Then, the film capacitor is manufactured.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a film capacitor.

As shown in FIG. 9, the film capacitor 300 usually includes a first metallized film 310 including a first metal film 311 and a first metal film 315 formed on the surface thereof, and a second dielectric. A laminate 350 in which a plurality of second metallized films 320 having a film 321 and a second metal film 325 formed on the surface thereof are alternately laminated, and a first metal film 315 connected to the first metal film 315. It includes an external electrode 360 and a second external electrode 370 connected to the second metal film 325.

The first external electrode 360 and the second external electrode 370 are formed by spraying a metal onto the end face of the laminated body 350. When the first external electrode 360 is in close proximity to or in contact with the second metal film 325, a short circuit occurs between the first external electrode 360 and the second metal film 325, and the function of the film capacitor 300 is impaired. Similarly, when the second external electrode 370 is in close proximity to or in contact with the first metal film 315, a short circuit occurs between the second external electrode 370 and the first metal film 315, and the function of the film capacitor 300 is impaired. .. In order to avoid this, as described in Patent Document 1, the first metallized film 310 and the second metallized film 320 do not have the first metal film 315 and the second metal film 325 formed. The margin regions 317 and 327 are provided, respectively, and the first metallized film 310 and the second metallized film 320 are laminated so as to be offset from each other.

JP-A-2015-170695

However, the size of the margin regions 317 and 327 and / or the offset amount of the first metallized film 310 and the second metallized film 320 at the time of laminating may deviate from the design values, or the first external electrode 360 and Due to variations in the shooting conditions for forming the second external electrode 370, the first external electrode 360 and the second metal film 325, and / or the second external electrode 370 and the first metal film Short circuits may occur due to contact of the 315 or insufficient distance between the two.

Therefore, an object of the present invention is to provide a method for manufacturing a film capacitor in which the occurrence of a short circuit is suppressed.

According to the first aspect of the present invention
(A) A laminate containing a first metallized film and a second metallized film, a first external electrode formed on the first end face of the laminate, and a second opposite side of the first end face. A step of preparing a structure, including a second external electrode, formed on the end face of the
Here, the first metallized film includes a first dielectric film having a shrinkable portion and a first metal film formed on the main surface of the first dielectric film.
In the first metallized film, a margin region in which the first metal film was not formed and a margin region in which the first metal film was not formed, extending in a band shape along the first side of the first metallized film, and a first metal film were formed. Has an electrode area and
The shrinkable portion of the first dielectric film is located in the electrode region of the first metallized film and extends in a band shape in a direction parallel to the first side of the first metallized film.
The distance from the first side of the first metallized film to the shrinkable portion of the first dielectric film is parallel to the first side of the first metallized film, from the second side to the first dielectric film. Less than the distance to the shrinkable part of
The second metallized film comprises a second dielectric film having a shrinkable portion and a second metal film formed on the main surface of the second dielectric film.
In the second metallized film, a margin region in which the second metal film was not formed and a second metal film were formed, extending in a band shape along the first side of the second metallized film. Has an electrode area and
The shrinkable portion of the second dielectric film is located in the electrode region of the second metallized film and extends in a band shape in a direction parallel to the first side of the second metallized film.
The distance from the first side of the second metallized film to the shrinkable portion of the second dielectric film is parallel to the first side of the second metallized film, from the second side to the second dielectric film. Less than the distance to the shrinkable part of
In the laminated body, the first metallized film and the second metallized film are laminated or laminated and wound.
The first external electrode is electrically connected to the first metal film and is
The second external electrode is electrically connected to the second metal film and is
(B) The step of contracting the contractable portion and
A method for manufacturing a film capacitor including the above is provided.

According to the manufacturing method of the present invention, a film capacitor in which the occurrence of a short circuit is suppressed can be manufactured.

FIG. 1 is a flowchart of the manufacturing method of the embodiment. FIG. 2 is a schematic perspective view for explaining a step of preparing a first metallized film. FIG. 3 is a schematic perspective view for explaining a step of preparing a first metallized film. FIG. 4 is a schematic perspective view for explaining a step of preparing a first metallized film. FIG. 5 is a schematic perspective view for explaining a step of preparing a second metallized film. FIG. 6 is a schematic cross-sectional view for explaining a step of laminating or laminating and winding a first metallized film and a second metallized film. FIG. 7 is a schematic cross-sectional view for explaining a step of spraying a metal. FIG. 8 is a schematic cross-sectional view for explaining a step of contracting the contractable portion. FIG. 9 is a diagram conceptually showing a cross section of a conventional film capacitor.

As shown in FIG. 1, a method for manufacturing a film capacitor includes a step S1 for preparing a first metallized film, a step S2 for preparing a second metallized film, a first metallized film, and a second. It includes a step S3 of laminating or laminating and winding a metallized film, a step S4 of spraying a metal, and a step S5 of shrinking a shrinkable portion. Hereinafter, each step will be described. In the following description, the thickness direction of the first dielectric film 11 and the second dielectric film 21 is the Z axis, the axis orthogonal to the Z axis is the X axis, and the axes orthogonal to the Z axis and the X axis are defined. Set the Cartesian coordinates for the Y axis. Further, step S1 for preparing the first metallized film, step S2 for preparing the second metallized film, and step S3 for laminating or laminating or winding the first metallized film and the second metallized film. The step S4 of spraying the metal does not have to be performed by itself. A structure including a laminate of a first metallized film and a second metallized film, a first external electrode, and a second external electrode, which can be obtained by these steps, is obtained from the outside. You may.

(1) Step S1 for preparing the first metallized film
First, a dielectric film is prepared. The dielectric film may have a thickness of, for example, 1-5 μm. The dielectric film is made of a dielectric material such as polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), polypropylene (PP), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polystyrene (PS), and polycarbonate (PC). It is formed.

The prepared dielectric film is stretched. The stretching may be uniaxial stretching or biaxial stretching. In the case of uniaxial stretching, it may be stretched in the X-axis direction. Thereby, a stretched dielectric film 1 (see FIG. 2) is obtained. The stretching does not have to be performed by itself, and the previously stretched dielectric film 1 may be obtained. The dielectric film 1 has a first side 12 and a second side 14 parallel to the Y axis.

Next, as shown in FIG. 3, the portion of the stretched dielectric film 1 other than the strip-shaped portion 13 extending in the Y-axis direction is annealed to shrink the dielectric film 1, and the first dielectric is used. Obtain film 11. For example, by rolling the thermal roller 91 on the surface of the dielectric film 1 in the Y-axis direction, a portion other than the strip-shaped portion 13 of the dielectric film 1 can be annealed. The band-shaped portion 13 that is not annealed does not shrink. This band-shaped portion 13 can be shrunk by heating in a later step, and is therefore referred to as a shrinkable portion 13. The distance D1 from the contractable portion 13 to the first side 12 is smaller than the distance D2 from the contractible portion 13 to the second side 14.

As shown in FIG. 4, the first metal film 15 is formed on the main surface of the first dielectric film 11 to obtain the first metallized film 10. The first metallized film 10 has a margin region 17 in which the first metal film 15 is not formed, and an electrode region 19 in which the first metal film 15 is formed. The margin region 17 extends in a band shape along the first side 12. Further, the contractible portion 13 is located in the electrode region 19. The width (length in the X-axis direction) of the margin region 17 may be appropriately set according to the voltage applied to the film capacitor manufactured by the manufacturing method according to the embodiment, and for example, 100 V, 200 V, etc. for the film capacitor. When a voltage of 400V, 500V, or 800V is applied, the width of the margin region 17 may be 0.1 mm or more, 0.4 mm or more, 1 mm or more, 1.3 mm or more, 2.4 mm or more, respectively.

The first metal film 15 may have a thickness of, for example, 10 to 100 nm. The first metal film 15 may be, for example, a film of aluminum (Al) or zinc (Zn). The first metal film 15 can be formed by any thin film forming method such as a vapor deposition method, a sputtering method, and an ion plating method. Further, the margin region 17 and the electrode region 19 may be formed by any patterning method.

As described above, the first metallization including the first dielectric film 11 having the shrinkable portion 13 and the first metal film 15 formed on the main surface of the first dielectric film 11. Film 10 is obtained.

Instead of partially annealing the stretched dielectric film 1, it is also possible to form the first dielectric film 11 having the shrinkable portion 13 by partially containing a filler in the dielectric film. .. The first dielectric film 11 formed by partially containing a filler does not contain a filler in the shrinkable portion 13, but contains a filler in other portions. The shrinkable portion 13 containing no filler can be heat-shrinked in a later step, but the portion containing the filler is less likely to be heat-shrinked.

(2) Step S2 for preparing the second metallized film
Since the second metallized film 20 (FIG. 5) is manufactured in the same manner as the first metallized film 10 described above, detailed description thereof will be omitted.

Similar to the first metallized film 10, the second metallized film 20 was formed on the main surface of the second dielectric film 21 having the shrinkable portion 23 and the second dielectric film 21. A second metal film 25 is provided. The second metallized film 20 has a margin region 27 in which the second metal film 25 is not formed and a second metal extending in a band shape along the first side 22 of the second metallized film 20. It has an electrode region 29 on which the film 25 is formed. The shrinkable portion 23 of the second dielectric film 21 is located in the electrode region 29 and extends in a band shape in a direction parallel to the first side 22 of the second metallized film 20. The distance D3 from the first side 22 of the second metallized film 20 to the shrinkable portion 23 is smaller than the distance D4 from the second side 24 of the second metallized film 20 to the shrinkable portion 23.

(3) Laminating or laminating and winding step S3
As shown in FIG. 6, the first metallized film 10 and the second metallized film 20 are laminated or laminated to form a laminated body 50. A plurality of first metallized films 10 and a plurality of second metallized films 20 may be alternately laminated to form a laminated body 50. Alternatively, at least one long first metallized film 10 and at least one long second metallized film 20 are laminated, and the laminated body (winding body) 50 is wound by winding the laminated body (winding body) 50. May be formed. In either case, the second side 14 of the first metallized film 10 and the first side 22 of the second metallized film 20 are located on the first end face 51 of the laminated body 50, and the first metallization The first metallized film 10 and the second metallized film so that the first side 12 of the film 10 and the second side 24 of the second metallized film 20 are located on the second end face 53 of the laminated body 50. 20 are laminated. The second end face 53 is an end face opposite to the first end face 51, and both the first end face 51 and the second end face 53 may be perpendicular to the X axis. Further, the first side 22 of the second metallized film 20 is located inside the laminated body 50 with respect to the second side 14 of the first metallized film 10, and the first side of the first metallized film 10 is located. The first metallised film 10 and the second metallised film 20 are offset from each other in the X-axis direction so that 12 is located inside the laminate 50 with respect to the second side 24 of the second metallised film 20. To. In addition, in order to insulate and protect the first metal film 15 or the second metal film 25 (in FIG. 6, the first metal film 15), another dielectric film 2 may be laminated as the uppermost layer. The dielectric film 2 may or may not have a shrinkable portion.

(4) Step S4 for spraying metal
Metal is sprayed onto each of the first end face 51 and the second end face 53 of the laminate 50. As a result, as shown in FIG. 7, the first external electrode 60 is formed on the first end surface 51, and the second external electrode 70 is formed on the second end surface 53. The first external electrode 60 is electrically connected to the first metal film 15. The second external electrode 70 is electrically connected to the second metal film 25. In this way, the laminate 50 including the first metallized film 10 and the second metallized film 20, the first external electrode 60 formed on the first end surface 51 of the laminate 50, and the first end surface 51. A structure 100 including a second external electrode 70 formed on a second end face 53 on the opposite side is obtained.

As described above, the first metallized film 10 is provided with a margin region 17 in which the first metal film 15 is not formed along the first side 12, and the second metallized film 20 is provided with a margin region 17. A margin region 27 in which the second metal film 25 is not formed is provided along the first side 22. Further, the first side 22 of the second metallized film 20 is located inside the laminated body 50 with respect to the second side 14 of the first metallized film 10, and the first side 12 of the first metallized film 10 is located. Is located inside the laminate 50 with respect to the second side 24 of the second metallized film 20. As a result, it is suppressed that the first metal film 15 is electrically connected to the second external electrode 70 and that the second metal film 25 is electrically connected to the first external electrode 60. To. However, due to factors such as a deviation in the offset amount between the first metallized film 10 and the second metallized film 20 in the laminated body 50 and variations in the spraying conditions, the first metal film 15 and the second external electrode 70 The distance between and / or the distance between the second metal film 25 and the first external electrode 60 may be insufficient. In this case, when a voltage is applied to the manufactured film capacitor, a short circuit occurs between the first metal film 15 and the second external electrode 70, or between the second metal film 25 and the first external electrode 60. May occur. In order to avoid this, the subsequent step S5 of contracting the contractible portion is performed.

(5) Step S5 to contract the contractable part
As shown in FIG. 8, the shrinkable portion 13 of the first dielectric film 11 and the shrinkable portion 23 of the second dielectric film 21 are contracted in the X-axis direction to obtain a film capacitor 200. For example, by heating the structure 100, the contractable portions 13 and 23 can be contracted. As the contractible portions 13 and 23 contract, the first metal film 15 and the second metal film 25 also contract. As a result, the distance between the first metal film 15 and the second external electrode 70 and the distance between the second metal film 25 and the first external electrode 60 increase. Therefore, it is possible to suppress the occurrence of a short circuit between the first metal film 15 and the second external electrode 70, and between the second metal film 25 and the first external electrode 60.

The amount of shrinkage of the contractable portions 13 and 23 in the X-axis direction may be appropriately set according to the voltage applied to the film capacitor 200 so as to suppress the occurrence of a short circuit. For example, 100 V to the film capacitor 200. When voltages of 200V, 400V, 500V, and 800V are applied, the shrinkage amount may be 0.1 mm or more, 0.4 mm or more, 1 mm or more, 1.3 mm or more, and 2.4 mm or more, respectively.

The shrinkable portions 13 and 23 may be shrunk after the structure 100 produced in step S4 is immersed in the liquid resin for sealing. In this case, the shrinkable portions 13 may be shrunk by heating to cure the sealing resin. , 23 may be contracted.

In the first metallized film 10 and the second metallized film 20, since the shrinkable portions 13 and 23 are located in the electrode regions 19 and 29, even if the shrinkable portions 13 and 23 shrink, the margin region The sizes of 17 and 27 are maintained. Therefore, good insulation between the first metal film 15 and the second metal film 25 can be maintained, and it is possible to suppress the occurrence of a short circuit between the first metal film 15 and the second metal film 25. can do.

In the first metallized film 10, the distance D1 from the first side 12 to the shrinkable portion 13 is smaller than the distance D2 from the second side 14 to the shrinkable portion 13 (see FIG. 3), so that the shrinkable portion When 13 is contracted, the first side 12 retracts without changing the position of the second side 14. Therefore, the distance between the first metal film 15 and the second external electrode 70 can be increased while maintaining the electrical connection between the first metal film 15 and the first external electrode 60. Similarly, in the second metallized film 20, the distance D3 from the first side 22 to the shrinkable portion 23 is smaller than the distance D4 from the second side 24 to the shrinkable portion 23 (see FIG. 4). When the contractable portion 23 is contracted, the first side 22 retracts without changing the position of the second side 24. Therefore, the distance between the second metal film 25 and the first external electrode 60 can be increased while maintaining the electrical connection between the second metal film 25 and the second external electrode 70.

10 1st metallized film, 11 1st dielectric film, 12 1st side, 13 shrinkable part, 14 2nd side, 15 1st metal film, 17 margin area, 19 electrode area, 20 second Metallic film, 21 2nd dielectric film, 22 1st side, 23 shrinkable part, 24 2nd side, 25 2nd metal film, 27 margin area, 29 electrode area, 50 laminated body, 51 first End face, 53 second end face, 60 first external electrode, 70 second external electrode, 100 structure, 200 film capacitor

Claims (1)

(A) A laminate containing a first metallized film and a second metallized film, a first external electrode formed on the first end face of the laminate, and a second opposite side of the first end face. A step of preparing a structure, including a second external electrode, formed on the end face of the
Here, the first metallized film includes a first dielectric film having a shrinkable portion and a first metal film formed on the main surface of the first dielectric film.
In the first metallized film, a margin region in which the first metal film was not formed and a margin region in which the first metal film was not formed, extending in a band shape along the first side of the first metallized film, and a first metal film were formed. Has an electrode area and
The shrinkable portion of the first dielectric film is located in the electrode region of the first metallized film and extends in a band shape in a direction parallel to the first side of the first metallized film.
The distance from the first side of the first metallized film to the shrinkable portion of the first dielectric film is parallel to the first side of the first metallized film, from the second side to the first dielectric film. Less than the distance to the shrinkable part of
The second metallized film comprises a second dielectric film having a shrinkable portion and a second metal film formed on the main surface of the second dielectric film.
In the second metallized film, a margin region in which the second metal film was not formed and a second metal film were formed, extending in a band shape along the first side of the second metallized film. Has an electrode area and
The shrinkable portion of the second dielectric film is located in the electrode region of the second metallized film and extends in a band shape in a direction parallel to the first side of the second metallized film.
The distance from the first side of the second metallized film to the shrinkable portion of the second dielectric film is parallel to the first side of the second metallized film, from the second side to the second dielectric film. Less than the distance to the shrinkable part of
In the laminated body, the first metallized film and the second metallized film are laminated or laminated and wound.
The first external electrode is electrically connected to the first metal film and is
The second external electrode is electrically connected to the second metal film and is
(B) The step of contracting the contractable portion and
How to make a film capacitor, including.

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