Metallized film capacitor

Abstract

To provide a metallized film capacitor having a split electrode section made up of multiple split electrodes, capable of exhibiting stable self-healing and safety functions in the event of insulation breakdown.SOLUTION: Two adjacent first small divided electrodes 4a are electrically connected to each other by fuse portions H1 and H2 that they share at their vertices, and the fuse portions H1 and H2 are electrically connected to the large electrode portion, i.e., a non-divided electrode portion 6. Furthermore, two adjacent first small divided electrodes 4a are electrically connected to each other by fuse portions H3 and H4 and fuse portions H5 and H6 that they share at their vertices, and the fuse portions H3 and H4 and fuse portions H5 and H6 are electrically connected to the large divided electrode 51 of the large divided electrode portion 5, i.e., the large electrode portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metallized film capacitor in which a vapor-deposited metal electrode formed on the film surface of a dielectric film has a divided electrode portion consisting of multiple divided electrodes divided in the longitudinal direction of the dielectric film by non-vapor-deposited insulating slits. [Background technology]

[0002] With the recent spread of electric vehicles, metallized film capacitors, which have metal vapor deposition electrodes formed on the surface of a dielectric film, are being used for smoothing and filtering in inverter circuits for automobiles, as well as in inverter circuits for industrial equipment.

[0003] A feature of this type of metallized film capacitor is that, in the event of a breakdown, the discharge energy causes the vapor-deposited metal around the breakdown area to scatter, restoring the insulation in the area. To extend the life and improve safety of metallized film capacitors, the vapor-deposited metal electrode is divided by non-vapor-deposited slits to form multiple segmented electrodes, which are connected by a vapor-deposited metal fuse. In the event of a breakdown, the fuse blows, restoring the insulation and providing safety.

[0004] An example of this type of metallized film capacitor is described in Patent Document 1. The metallized film capacitor described in Patent Document 1 has a vapor-deposited metal layer formed on a dielectric film, with multiple polygonal segmented electrodes subdivided by multiple non-vapor-deposited slits, and each segmented electrode is connected by a fuse portion made of vapor-deposited metal. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-143170 Summary of the Invention [Problem to be solved by the invention]

[0006] In this type of metallized film capacitor, when dielectric breakdown occurs, charge moves from the surrounding area to the dielectric breakdown area, and the resulting current energy exerts the self-healing function described above, thereby enabling the capacitor to have a long life.

[0007] However, the metallized film capacitor described in Patent Document 1 has a configuration in which multiple identically shaped split electrodes are arranged on one side of the dielectric film in the width direction. This results in the split electrodes being too densely packed in a specific area, complicating the charge transfer path (inflow current path) and reducing the area of ​​each split electrode. This makes it difficult to supply sufficient short-circuit current energy to the breakdown point, potentially preventing stable self-healing and safety functions in the event of breakdown.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a metallized film capacitor having a split electrode portion consisting of multiple split electrodes, which is capable of exhibiting stable self-healing and safety functions in the event of insulation breakdown. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the metallized film capacitor of the present invention is characterized in that a metal vapor deposition electrode formed on the film surface of a dielectric film is divided into split electrode sections consisting of multiple split electrodes divided in the longitudinal direction of the dielectric film by non-vapor-deposited insulating slits, and large electrode sections having an electrode area larger than that of the split electrodes, the split electrode sections and the large electrode sections are arranged alternately in the width direction of the dielectric film, the multiple split electrodes each have a polygonal shape, and two split electrodes adjacent in the longitudinal direction of the multiple split electrodes share a fuse section so that they are electrically connected to each other at their vertices, and the fuse section is electrically connected to the large electrode section.

[0010] With this configuration, the split electrode portions and the large electrode portions are arranged alternately in the width direction of the dielectric film, so that when a breakdown occurs, a large amount of current energy can be supplied to the breakdown portion from the large electrode portion with a large electrode area. Furthermore, two adjacent split electrodes are electrically connected to each other at their vertices by a shared fuse portion, and this fuse portion is electrically connected to the large electrode portion. Therefore, even if the fuse portion operates (melts), the inflow current path can be prevented from being disrupted. As a result, the fuse portion located at the portion where the current flows into the breakdown portion can be more reliably melted, thereby providing stable self-healing and safety functions in the event of a breakdown.

[0011] Furthermore, when the divided electrode portion is a small divided electrode portion consisting of a plurality of small divided electrodes, the large electrode portion is divided by non-evaporated insulating slits and includes a large divided electrode portion consisting of a plurality of large divided electrodes having larger electrode areas than the small divided electrodes, and two small divided electrodes adjacent to each other in the longitudinal direction among the plurality of small divided electrodes may share a first fuse portion so as to be electrically connected to each other at their vertices, and the first fuse portion may be electrically connected to the large divided electrode.

[0012] According to this configuration, a large amount of current energy can be supplied from the large divided electrode portion to the insulation breakdown portion, so that the first fuse portion located at the point where the current flows into the insulation breakdown portion can be blown, and insulation can be restored by blowing the first fuse portion in the event of insulation breakdown.

[0013] In addition, it is preferable that the electrode area ratio of the large divided electrodes to the small divided electrodes is 2 or more, so that sufficient current energy can be supplied to the breakdown portion from the large divided electrodes of the large divided electrode portion at the time of dielectric breakdown, and the fuse portion located at the portion where current flows into the breakdown portion can be more reliably melted.

[0014] Furthermore, when the divided electrode portion is a small divided electrode portion consisting of a plurality of small divided electrodes, the large electrode portion may include a non-divided electrode portion in which a metal vapor-deposited electrode is not divided in the longitudinal direction of the dielectric film by a non-vapor-deposited insulating slit, and two small divided electrodes adjacent in the longitudinal direction among the plurality of small divided electrodes may share a second fuse portion so that they are electrically connected to each other at their vertices, and the second fuse portion may be electrically connected to the non-divided electrode portion.

[0015] According to this configuration, current energy can be supplied from the non-split electrode portion to the insulation breakdown portion, so that the second fuse portion located at the point where the current flows into the insulation breakdown portion can be blown, and insulation can be restored by blowing the second fuse portion in the event of insulation breakdown.

[0016] The divided electrode portion may include a first small-divided electrode portion consisting of a plurality of first small-divided electrodes and a second small-divided electrode portion consisting of a plurality of second small-divided electrodes, the non-divided electrode portion being electrically connected to an extraction electrode which is connected to an external electrode, and the non-divided electrode portion, the first small-divided electrode portion, the large-divided electrode portion, and the second small-divided electrode portion being arranged in this order in the width direction of the dielectric film.

[0017] According to this configuration, the non-divided electrode portion, first small divided electrode portion, large divided electrode portion, and second small divided electrode portion are arranged in this order in the width direction of the dielectric film. Therefore, when fuse operation occurs across multiple first small divided electrodes of the first small divided electrode portion located on the non-divided electrode portion side, the current path of the current flowing from the non-divided electrode portion to the second small divided electrode portion can be regulated by the insulating slit formed in the large divided electrode portion between the first small divided electrode portion and the second small divided electrode portion, and the current can flow along a stable current path from the non-divided electrode portion to the second small divided electrode of the second small divided electrode portion. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a metallized film capacitor that can exhibit stable self-healing and safety functions in the event of dielectric breakdown. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing a metallized film in which a vapor-deposited metal electrode is formed on a dielectric film constituting a metallized film capacitor according to one embodiment of the present invention. [Figure 2] 2A, 2B, and 2C are cross-sectional views taken along line XX, line YY, and line ZZ in FIG. 1, respectively. [Figure 3] FIG. 2 is an enlarged view of the circled portion A in FIG. [Figure 4] FIG. 2 is an enlarged view of the circled portion B in FIG. [Figure 5] FIG. 2 is an enlarged view of the circled portion C in FIG. [Figure 6] FIG. 2 is an enlarged view of the circled portion D in FIG. [Figure 7] FIG. 2 is an enlarged view of the circled portion E in FIG. [Figure 8] FIG. 2 is an enlarged view of the circled portion F in FIG. [Figure 9] 2 is a diagram showing the state in which the metallized films of FIG. 1 are superimposed; DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of a metallized film capacitor according to the present invention will be described in detail with reference to FIGS.

[0021] Figure 1 shows a metallized film 10 in which a metal vapor deposition electrode is formed on a dielectric film 1 constituting the metallized film capacitor of this embodiment, and this metallized film 10 has an insulating margin 2 provided at one end in the width direction of the dielectric film 1 made of a plastic film, and a metal vapor deposition electrode formed by vapor-depositing metal on the surface of the dielectric film 1 excluding this insulating margin 2.

[0022] Dielectric film 1 can be made of a plastic film such as polypropylene, polyethylene terephthalate, polyethylene naphthalate, or polystyrene. Aluminum is preferably used as the metal for the metal deposition electrode, and metallized film 10 can be formed by depositing other metals such as zinc or magnesium, in addition to aluminum, onto dielectric film 1. Metallized film 10 can also be formed by depositing multiple of these metals, or an alloy of these metals, onto dielectric film 1.

[0023] Furthermore, as shown in Figure 1, the metal vapor deposition electrode formed by vapor deposition has multiple vertical line-shaped and multiple diagonal line-shaped non-vapor-deposited insulating slits 3 of different lengths across the width of the dielectric film 1, and the metal vapor deposition electrode is divided into divided electrode sections (corresponding to the "divided electrode sections" in this invention) 4 consisting of multiple divided electrodes divided in the longitudinal direction of the dielectric film 1 by the insulating slits 3, large divided electrode sections (corresponding to the "large electrode sections" in this invention) 5 divided in the longitudinal direction of the dielectric film 1, and a non-divided electrode section (corresponding to the "large electrode sections" in this invention) 6 that is not divided in the longitudinal direction of the dielectric film 1 by the insulating slits 3.

[0024] Here, a connection portion 7 is provided at the end in the width direction of the non-divided electrode portion 6 (the side opposite to the first small divided electrode portion 41 side) to connect to an extraction electrode (not shown in FIG. 1) for connection to an external electrode (not shown in FIG. 1). The insulating slit 3 is formed with a slit width of, for example, 0.05 to 0.6 mm, and its end is rounded.

[0025] The divided electrode section 4 is divided into a first small divided electrode section 41 consisting of a plurality of first small divided electrodes 4a having a polygonal shape arranged in the longitudinal direction of the dielectric film 1, and a second small divided electrode section 42 consisting of a plurality of second small divided electrodes 4b having a polygonal shape arranged in the longitudinal direction of the dielectric film 1. Between the first small divided electrode section 41 and the second small divided electrode section 42, a large divided electrode section 5 is arranged in the longitudinal direction of the dielectric film 1. The large divided electrode section 5 is composed of a plurality of large divided electrodes 51 having a polygonal shape and a larger electrode area than the first small divided electrodes 4a and the second small divided electrodes 4b.

[0026] The first small divided electrodes 4a are formed into an isosceles trapezoid shape by insulating slits 3, and adjacent first small divided electrodes 4a are arranged so that two parallel sides of the isosceles trapezoid that have the same length are shared by the insulating slits 3 extending in the width direction. The second small divided electrodes 4b are formed into a trapezoid shape by insulating slits 3, and adjacent second small divided electrodes 4b are arranged so that two parallel sides of the trapezoid that have the same length are shared by the insulating slits 3 extending in the width direction.

[0027] Furthermore, the large divided electrodes 51 are formed in the shape of a regular hexagon stretched in the width direction of the dielectric film 1 by the insulating slits 3, and adjacent large divided electrodes 51 are arranged so that the longest side of the hexagon is common to each other via the insulating slits 3 extending in the width direction. The large divided electrode 51, which has the largest electrode area, is formed to be approximately twice the area of ​​the first small divided electrode 4a, which also has the largest electrode area.

[0028] As shown in FIG. 1, the non-divided electrode portion 6, the first small divided electrode portion 41, the large divided electrode portion 5, and the second small divided electrode portion 42 are arranged in this order in the width direction of the dielectric film 1, and the second small divided electrode portion 42, which is made up of the second small divided electrode 4b having the smallest area, is located on the insulating margin 2 side.

[0029] As shown in Figure 3, which is an enlargement of the circled area A in Figure 1, and Figure 4, which is an enlargement of the circled area B in Figure 1, the non-divided electrode portion 6 side of the first small divided electrode 4a adjacent to the first small divided electrode portion 41 share fuse portions (corresponding to the "second fuse portion" in this invention) H1 and H2 made of evaporated metal for the metal evaporated electrode so that they are electrically connected to each other at their vertices, and these fuse portions H1 and H2 are electrically connected to the non-divided electrode portion 6.

[0030] 5, which is an enlargement of the circled area C in FIG. 1, and FIG. 6, which is an enlargement of the circled area D in FIG. 1, the large divided electrode portions 5 of the first small divided electrodes 4a adjacent to the first small divided electrode portion 41 share fuse portions (corresponding to the "first fuse portion" in this invention) H3 and H4 made of evaporated metal for the metal evaporated electrode so as to be electrically connected to each other at their vertices, and the fuse portion H3 is electrically connected to two adjacent large divided electrodes 51, and the fuse portion H4 is electrically connected to one large divided electrode 51.

[0031] Furthermore, as shown in Figure 7, which is an enlargement of the circled area E in Figure 1, and Figure 8, which is an enlargement of the circled area F in Figure 1, the large divided electrode portion 5 sides of the adjacent second small divided electrodes 4b of the second small divided electrode portion 42 share fuse portions (corresponding to the "first fuse portion" in this invention) H5 and H6 made of evaporated metal for the metal evaporated electrode so as to be electrically connected to each other at their vertices, and the fuse portion H5 is electrically connected to two adjacent large divided electrodes 51, and the fuse portion H6 is electrically connected to one large divided electrode 51.

[0032] The cross sections taken along lines XX, YY, and ZZ in FIG. 1 are shown in FIGS. 2(a), (b), and (c), respectively.

[0033] In this configuration, the undivided electrode portion 6 or the large divided electrode 51 with a large electrode area can store a large amount of energy, so that in the event of a breakdown, a short-circuit current from the undivided electrode portion 6 or the large divided electrode 51 flows into the first small divided electrode 4a and / or the second small divided electrode 4b, reliably melting the fuse portion H1 to H6 located at the current inflow portion and separating the electrode where the breakdown occurred. Meanwhile, the remaining electrodes adjacent to the separated electrode at their vertices but not separated can maintain connection with each other, thereby suppressing a decrease in capacity.

[0034] For example, if breakdown occurs in any of the small divided electrodes 4a, short-circuit currents from the adjacent undivided electrode portion 6 (and the opposing undivided electrode portion 6) and the large divided electrode 51 with a large electrode area flow into the small divided electrode 4a where breakdown has occurred, thereby reliably separating the small divided electrode 4a. On the other hand, the connection between the first small divided electrodes 4a whose vertices are adjacent to the small divided electrode 4a is maintained via the undivided electrode portion 6 and the large divided electrode 51, thereby suppressing a decrease in capacitance.

[0035] Incidentally, a metallized film capacitor is formed by stacking two metallized films 10, each having a divided electrode portion 4, a large divided electrode portion 5, and a non-divided electrode portion 6, one on top of the other and winding them together, as shown in Figure 1. When stacking two metallized films 10, it is desirable to stack them so that the insulating margins 2 of the first metallized film 10 and the second metallized film 10 are positioned opposite each other in the width direction, as shown in Figure 9, and to form the divided electrode portion 4, large divided electrode portion 5, and non-divided electrode portion 6 so that the non-divided electrode portions 6 do not overlap each other (in other words, the non-divided electrode portion 6 on one film side overlaps only the divided electrode portions 4, 5 on the opposing film side).

[0036] Because the non-divided electrode portions 6 do not overlap each other, when, for example, a breakdown (dielectric breakdown at the position marked with an X in Figure 9) occurs in the non-divided electrode portion 6 of the upper metallized film 10, current flows into the large divided electrode 51 or non-divided electrode portion 6 of the lower metallized film 10, which has a larger electrode area and is adjacent to the first small divided electrode 4a, which has a smaller electrode area and is located directly below the breakdown portion of the opposing lower metallized film 10. All of the fuse portions H1 to H4 located at the current flow-in point melt, and the first small divided electrode 4a (the shaded portion in Figure 9) located directly below the breakdown portion of the lower metallized film 10, which faces the breakdown portion of the non-divided electrode portion 6 of the upper metallized film 10, can be reliably separated from the other divided electrodes, thereby restoring the insulation of the non-divided electrode portion 6 and maintaining its function as a capacitor.

[0037] As described above, in the embodiment described above, two adjacent first small divided electrodes 4a are electrically connected to each other by fuse portions H1 and H2 shared at their vertices, and the fuse portions H1 and H2 are electrically connected to the non-divided electrode portion 6, which is a large electrode portion. Also, two adjacent first small divided electrodes 4a are electrically connected to each other by fuse portions H3 and H4 shared at their vertices, and the fuse portions H3 and H4 are electrically connected to the large divided electrode 51 of the large divided electrode portion 5, which is a large electrode portion. Furthermore, two adjacent second small divided electrodes 4b are electrically connected to each other by fuse portions H5 and H6 shared at their vertices, and the fuse portions H5 and H6 are electrically connected to the large divided electrode 51 of the large divided electrode portion 5, which is a large electrode portion.

[0038] Therefore, since the non-divided electrode portion 6 or the large divided electrode 51 with a large electrode area can store a large amount of energy, when a breakdown occurs, current from the non-divided electrode portion 6 or the large divided electrode 51 flows into the first small divided electrode 4a and / or the second small divided electrode 4b, and the fuse portion located at the current flow-in portion among the fuse portions H1 to H6 is reliably melted to separate the electrode where the breakdown has occurred. At the same time, the connection between electrodes whose vertices are adjacent to the separated electrode can be maintained, thereby suppressing a decrease in capacity, and a metallized film capacitor can be provided that can exhibit stable self-healing and safety functions in the event of a breakdown.

[0039] Furthermore, since the electrode area of ​​the large divided electrode 51 is more than twice that of the first small divided electrode 4a, sufficient current energy can be supplied from the large divided electrode portion 5 to the breakdown portion in the event of a breakdown, and the fuse portion located at the point where the current flows into the breakdown portion can be reliably melted.

[0040] Furthermore, since the non-divided electrode portion 6, the first small-divided electrode portion 41, the large-divided electrode portion 5 and the second small-divided electrode portion 42 are arranged in this order in the width direction of the dielectric film 1, when fuse operation occurs across multiple first small-divided electrodes 4a of the first small-divided electrode portion 41 located on the non-divided electrode portion 6 side, the current path of the current flowing from the non-divided electrode portion 6 to the second small-divided electrode portion 42 can be regulated by the insulating slit 3 formed in the large-divided electrode portion 5 between the first small-divided electrode portion 41 and the second small-divided electrode portion 42, and the current can flow along a stable current path from the non-divided electrode portion 6 to the second small-divided electrode 4b of the second small-divided electrode portion 42.

[0041] The present invention is not limited to the above-described configuration, and various design modifications can be made within the scope of the claims.

[0042] For example, in the above embodiment, the metal vapor deposition electrode is described as being divided into a first small divided electrode portion 41, a large divided electrode portion 5, a second small divided electrode portion 42, and a non-divided electrode portion 6, but instead of the non-divided electrode portion 6, a large divided electrode portion consisting of multiple large divided electrodes larger than the large divided electrode 51 may be provided.

[0043] In addition, in the above-described embodiment, the first and second small divided electrodes 4a, 4b are formed in an isosceles trapezoidal shape and a trapezoidal shape, and the large divided electrode 51 is formed in a hexagonal shape, but the electrode shapes are not limited to these and may be any polygonal shape.

[0044] The present invention is widely applicable to metallized film capacitors in which a metal vapor-deposited electrode formed on the film surface of a dielectric film has a split electrode portion consisting of multiple split electrodes divided in the longitudinal direction of the dielectric film by non-vapor-deposited insulating slits. [Explanation of symbols]

[0045] 1...Dielectric film 3...insulation slit 4...Divided electrode section 41...First subdivided electrode section 42...Second subdivided electrode section 4a...First small divided electrode 4b...Second small divided electrode 5...Large divided electrode section 51...Large division electrode 6...Non-divided electrode section H1, H2 ... fuse section (second fuse section) H3, H4, H5, H6 ... fuse section (first fuse section) 7...Connection

Claims

1. a metal vapor deposition electrode formed on a film surface of a dielectric film is divided into a divided electrode portion consisting of a plurality of divided electrodes divided in the longitudinal direction of the dielectric film by non-vapor deposition insulating slits, and a large electrode portion having an electrode area larger than that of the divided electrodes; the divided electrode portions and the large electrode portions are alternately arranged in the width direction of the dielectric film, each of the plurality of segmented electrodes has a polygonal shape; A metallized film capacitor characterized in that two adjacent split electrodes of the plurality of split electrodes in the longitudinal direction share a fuse portion so as to be electrically connected to each other at their vertices, and the fuse portion is electrically connected to the large electrode portion.

2. When the divided electrode portion is a small divided electrode portion consisting of a plurality of small divided electrodes, the large electrode portion includes a large divided electrode portion composed of a plurality of large divided electrodes divided by non-evaporated insulating slits and having an electrode area larger than that of the small divided electrodes; 2. The metallized film capacitor according to claim 1, wherein two adjacent small divided electrodes among the plurality of small divided electrodes in the longitudinal direction share a first fuse portion so as to be electrically connected to each other at their vertices, and the first fuse portion is electrically connected to the large divided electrode.

3. 3. The metallized film capacitor according to claim 2, wherein the ratio of the area of ​​the large divided electrodes to the area of ​​the small divided electrodes is 2 or more.

4. When the divided electrode portion is a small divided electrode portion consisting of a plurality of small divided electrodes, the large electrode portion includes a non-divided electrode portion in which a vapor-deposited metal electrode is not divided in the longitudinal direction of the dielectric film by a non-vapor-deposited insulating slit; The metallized film capacitor according to claim 2 or 3, characterized in that two adjacent small divided electrodes among the plurality of small divided electrodes in the longitudinal direction share a second fuse portion so as to be electrically connected to each other at their vertices, and the second fuse portion is electrically connected to the non-divided electrode portion.

5. The divided electrode portion includes a first divided electrode portion consisting of a plurality of first divided electrodes and a second divided electrode portion consisting of a plurality of second divided electrodes, the non-divided electrode portion is electrically connected to an extraction electrode that is connected to an external electrode, 5. The metallized film capacitor according to claim 4, wherein the non-divided electrode portion, the first small divided electrode portion, the large divided electrode portion, and the second small divided electrode portion are arranged in this order in the width direction of the dielectric film.

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