JP6211255B2 - Metallized film capacitors - Google Patents

Description

  The present invention relates to a metallized film capacitor.

An example of the metallized film capacitor is described in Patent Document 1.
The metallized film capacitor described in Patent Document 1 (FIG. 1) is a metal in which metal vapor-deposited electrodes 12 and 15 are formed leaving margin portions 12a and 15c at one end in the width direction of dielectric films 11 and 14. Capacitor element 17 formed by stacking or winding so that the metallized films 13 and 16 are opposed to the metal vapor-deposited electrodes 12 and 15 via the dielectric films 11 and 14 and the margin portions 12a and 15c are located on the opposite side. And take-out electrodes 18 and 19 connected to both end faces of the capacitor element 17. The anode-side metal vapor deposition electrode 15 is mainly made of zinc or a zinc alloy, and the cathode-side metal vapor deposition electrode 12 is mainly made of aluminum.

However, the invention described in Patent Document 1 cannot be said to be sufficient for extending the capacitor life.
That is, in the invention described in Patent Document 1, zinc or an alloy of zinc is used as an anode material. However, since zinc or an alloy of zinc is inferior in self-healing performance compared with aluminum, a high voltage is applied in a high temperature atmosphere. When the load is applied, the safety performance of the metallized film on the anode side may be deteriorated.
In addition, zinc is more susceptible to oxidative degradation due to moisture than aluminum, and in a film capacitor in which the deposited metal film on the anode side is zinc, when a humidity resistance load test is performed in which a voltage is applied in a high-temperature, high-humidity atmosphere, There was a possibility that oxidation degradation of the deposited metal film on the anode side might occur due to the oxidation reaction.

JP 2009-277829 A

  The present invention has been made in view of the above-mentioned problems, and its purpose is excellent in self-healing performance, and deterioration of the safety performance of the metallized film on the anode side when a high voltage is applied in a high temperature atmosphere. An object of the present invention is to provide a metallized film capacitor that prevents and improves moisture resistance and prolongs the life of the capacitor.

According to a first aspect of the present invention, there is provided a metallized film capacitor in which a pair of metallized films are formed by superposing two metallized films on which a metal vapor-deposited electrode is formed leaving an insulation margin on a surface of a dielectric film. The metal vapor deposition electrode of one metallized film is opposed to the metal vapor deposition electrode of the other metallized film through the dielectric film, and the insulation margin is located on the opposite side in the film width direction. A metallized film capacitor comprising: a capacitor element formed by stacking or winding; and a metallicon electrode for electrode drawing connected to both end faces of the capacitor element, wherein the anode of the pair of metallized films is an anode. The metal vapor-deposited electrode formed on the metallized film on the side is mainly composed of aluminum, and the film resistance value is the gold on the cathode side. Smaller than the membrane resistance of the metallized electrodes formed on films, each metallized electrodes formed on the pair of metallized films, a capacitance forming part opposed to each other via the dielectric film, wherein A heavy edge portion that is provided at a connection portion with the metallicon electrode and has a film thickness that is thicker than that of the capacitance forming portion, and the thickness of the capacitance forming portion of the metal deposition electrode on the anode side is from the end of the edge portion side to the end portion of the insulation margin side is a continuously thinner so inclined shape of the pair of metal films, the said capacitance forming portion of the metal deposition electrode of the anode side end of the insulating margins side, the capacitor forming portion of the heavy edges portion are end portions of the heavy edges portion of the capacitance forming portion of the metal deposition electrode of the cathode side via the dielectric film Only the electrode surface faces the region that is the slope, the end of the insulating margin side of the capacitor forming portion of the metal deposition electrode of the cathode side, the metal deposition of the anode side through the dielectric film A metallized film capacitor, characterized by facing a boundary region between the heavy edge portion of the electrode and the capacitance forming portion .

According to the first invention, the main component of the metal deposition electrode on the anode side among the metal deposition electrodes formed on the pair of metallized films in which the metal deposition electrode is formed leaving an insulation margin on the surface of the dielectric film. Is aluminum and its film resistance value is smaller than the film resistance value of the metal vapor deposition electrode formed on the metallized film on the cathode side. Even if it makes it, the electrostatic capacity of the metal vapor deposition electrode on the anode side can be sufficiently secured, and the time until most of the metal vapor deposition electrode on the anode side becomes an insulator can be extended. Further, an increase in tan δ can also be suppressed.

  Moreover, since the main component of the metal-deposited electrode material on the anode side is aluminum, a metallized film capacitor having improved capacitor life while maintaining the safety performance of the metallized film can be obtained.

  A metallized film capacitor according to a second invention is characterized in that each of the metal vapor deposition electrodes formed on the pair of metallized films is divided into a plurality of divided electrodes by insulating slits, leaving a fuse portion. To do.

  According to the second invention, the metal-deposited electrode on the anode side is divided into a plurality of divided electrodes by the insulating slit, leaving the fuse portion, so that the dielectric deteriorates due to voltage application in a high temperature and high humidity atmosphere. Even when dielectric breakdown occurs, insulation can be recovered by separating the divided electrodes, improving the withstand voltage performance and extending the capacitor life.

  Furthermore, both the anode side and the cathode side of the metal vapor-deposited electrode are divided into a plurality of divided electrodes by insulating slits, leaving a fuse portion, so the probability of insulation recovery when a high voltage is applied increases, and the safety performance Will improve.

According to the present invention, among the pair of metal vapor deposition electrodes, the main component of the metal vapor deposition electrode on the anode side is aluminum, and the film resistance value thereof is smaller than the film resistance value of the metal vapor deposition electrode on the cathode side, Even if a part of the metal deposition electrode on the anode side is insulated by an anodic oxidation reaction, the capacitance of the metal deposition electrode on the anode side can be sufficiently secured, and the majority of the metal deposition electrode on the anode side is insulated. Can be extended. Further, an increase in tan δ can also be suppressed.

  And since the main component of the metal vapor deposition electrode material by the side of anode was aluminum, it can be set as the metallized film capacitor which improved the capacitor lifetime, maintaining the safety | security performance of a metallized film.

It is a perspective view of the metallized film capacitor concerning the embodiment of the present invention. FIG. 2 is a perspective view of the capacitor element shown in FIG. 1. It is a fragmentary sectional view of the metallized film shown in FIG. It is explanatory drawing which shows an example of the pattern aspect of metal vapor deposition. It is a modification of the metallized film shown in FIG.

  Hereinafter, the metallized film capacitor 1 according to the embodiment of the present invention will be described with reference to FIGS.

(Configuration of metallized film capacitor)
As shown in FIG. 1, the metallized film capacitor 1 includes a capacitor element 2, a plastic case 3 that houses the capacitor element 2, and an epoxy resin 4 that seals the capacitor element 2 in the plastic case 3. ing.

  As shown in FIGS. 2 and 3, the capacitor element 2 was formed by metal spraying on two wound (a pair) of metallized films 5 and 6 and each end face of the metallized films 5 and 6. Metallicon electrodes 7 and 8 and lead wires 9 and 10 respectively connected to the metallicon electrodes 7 and 8 are provided.

As shown in FIG. 3, the metallized film 5 includes a dielectric film 11 and a metal vapor-deposited electrode 12 formed on the upper surface of the dielectric film 11 so that an insulation margin 13 remains. In addition, the metallized film 6 includes a dielectric film 21 and a metal vapor deposition electrode 22 formed on the upper surface of the dielectric film 21 so that an insulation margin 23 remains.
Each insulation margin 13, 23 extends in the length direction of the dielectric films 11, 21 at one end in the width direction of each dielectric film 11, 21.

  Here, the film width direction of dielectric films 11 and 21 (hereinafter simply referred to as the width direction) is the direction in which metallicon electrodes 7 and 8 face each other. The length direction of the dielectric films 11 and 21 (hereinafter simply referred to as the length direction) is the winding direction of the dielectric films 11 and 21.

  The capacitor element 2 is formed such that the metal vapor deposition electrodes 12 and 22 of the two metallized films 5 and 6 are opposed to each other with the dielectric films 11 and 21 therebetween, and each of the metallized films 5 and 6 has an insulation margin. 13 and 23 are wound in a state of being overlapped so as to be located on opposite sides in the width direction.

  Next, the dielectric films 11 and 21 and the metal vapor deposition electrodes 12 and 22 constituting the metallized films 5 and 6 will be described in detail.

As shown in FIG. 3, the dielectric film 11 is a film connected to the metallicon electrode 7, and is made of, for example, polypropylene. The thickness of the dielectric film 11 is, for example, 2.8 μm.
On the other hand, the dielectric film 21 is a film connected to the metallicon electrode 8 and is made of, for example, polypropylene. The thickness of the dielectric film 21 is, for example, 2.8 μm, like the dielectric film 11.
The material and thickness of the dielectric films 11 and 21 are not limited to this.

The metal vapor deposition electrode 12 has a capacitance forming portion 14 (electrode facing portion) and a heavy edge portion 15. The capacitance forming portion 14 has a uniform film thickness t1, and the film resistance value in the capacitance forming portion 14 is about 12Ω / □.
Aluminum is used as the material of the capacitance forming portion 14. The film thickness t1 of the capacitor forming portion 14 may not be uniform, and the capacitor forming portion 14 may be configured to continuously decrease in the width direction, for example.

The heavy edge portion 15 is provided at an end portion of the metal vapor deposition electrode 12 on the side of the metallicon electrode 7 (that is, a connection portion with the metallicon electrode 7), and is thicker than the capacitance forming portion 14 (that is, film resistance). Low value).
An alloy of aluminum and zinc is used for the heavy edge portion 15. Further, the film resistance value at the heavy edge portion 15 is about 5Ω / □.
In FIG. 3, the slope is a gentle slope from the heavy edge portion 15 to the capacitance forming portion 14, but it is also possible to make a standing upright portion by masking the heavy edge portion.

  The metal vapor deposition electrode 12 is made of substantially aluminum as a whole, although the heavy edge portion 15 contains zinc. That is, it can be said that the main component of the metal deposition electrode 12 is aluminum. The proportion of aluminum in the entire metal of the metal vapor deposition electrode 12 is not particularly limited, but is, for example, 60% or more.

  The metal vapor deposition electrode 12 configured as described above is connected to the anode side electrode via the metallicon electrode 7 and the lead wire 9. That is, the metal vapor deposition electrode 12 (metallized film 5) is an anode side electrode.

On the other hand, the metal vapor deposition electrode 22 has a capacitance forming portion 24 and a heavy edge portion 25. The capacitance forming portion 24 has a uniform film thickness t2, and the film resistance value in the capacitance forming portion 24 is about 20Ω / □. Aluminum is used as the material of the capacitance forming portion 24.
The film thickness t2 of the capacitor forming portion 24 may not be uniform, and the capacitor forming portion 24 may be configured to continuously decrease in the width direction, for example.

  The heavy edge portion 25 is provided at the end of the metal vapor deposition electrode 22 on the side of the metallicon electrode 8 (that is, the connection portion with the metallicon electrode 8), and is thicker than the capacitance forming portion 24 (that is, film resistance). Low value). Similar to the heavy edge portion 15, an alloy of aluminum and zinc is used for the heavy edge portion 25. The film resistance value at the heavy edge portion 25 is about 5Ω / □.

  The metal vapor deposition electrode 22 configured as described above is connected to the cathode side electrode via the metallicon electrode 8 and the lead wire 10. That is, the metal vapor deposition electrode 22 (metallized film 6) is a cathode side electrode.

  In the present embodiment, the heavy edge portions 15 and 25 are made of an alloy of aluminum and zinc, but the material may be aluminum alone. Moreover, the heavy edge parts 15 and 25 do not need to be provided in any one or both.

Here, the film thickness (average film thickness) of the metal vapor deposition electrode 12 (anode-side metal vapor deposition electrode) is formed to be larger than the film thickness (average film thickness) of the metal vapor deposition electrode 22 (cathode-side metal vapor deposition electrode). The film resistance value of the metal vapor deposition electrode 12 (anode-side metal vapor deposition electrode) is smaller than the film resistance value of the metal vapor deposition electrode 22 (the cathode-side metal vapor deposition electrode).
The film thickness of the metal vapor deposition electrode 12 referred to in the present application means the film thickness t1 of the capacitance forming portion 14, and the film thickness of the metal vapor deposition electrode 22 means the film thickness t2 of the capacitance forming portion 24.
In addition, an average film thickness is the average value calculated | required by measuring the film thickness of the several point of the capacity | capacitance formation parts 14 and 24 of the metal vapor deposition electrodes 12 and 22. FIG. The film thickness (film resistance) is measured by the four-probe method. If the film thickness is uniform, measure two or more points in the film width direction. If the film thickness is not uniform, the film moves in the film width direction. Measure three or more points near both ends.

Next, the aspect of metal vapor deposition formed on the metal vapor deposition electrodes 12 and 22 will be described with reference to FIG.
Since the metal vapor deposition mode is the same for both the metal vapor deposition electrodes 12 and 22, only the metal vapor deposition mode formed on the metal vapor deposition electrode 12 will be described below, and the metal vapor deposition mode formed on the metal vapor deposition electrode 22 will be described. I'll omit that explanation.

As shown in FIG. 4, an insulating slit 31 that divides the metal vapor deposition electrode 12 into a plurality of parts is formed in the metal vapor deposition electrode 12.
The insulating slit 31 is a portion where metal deposition is not performed. Specifically, the insulating slit 31 is a slit having a Y shape or a combination of two Y shapes in opposite directions (the shape is not limited to this). Absent). The metal vapor deposition electrode 12 is divided into a plurality of divided electrodes 32 by combining a plurality of insulating slits 31 of the shape.

Adjacent divided electrodes 32 are connected by a fuse portion 33. That is, the insulating slit 31 divides the metal vapor deposition electrode 12 into a plurality of parts, leaving the fuse portion 33.
The fuse portion 33 is a portion that functions as a fuse when insulation breakdown cannot occur due to self-healing performance when dielectric breakdown occurs.

  In addition, although the metal vapor deposition aspect of the metal vapor deposition electrode 12 and the metal vapor deposition electrode 22 was made the same, you may differ. For example, insulating slits having different shapes may be formed between the metal vapor deposition electrode 12 and the metal vapor deposition electrode 22.

(Modification of metallized film)
Next, a modified example of the metallized film 5 will be described with reference to FIG.
A metallized film 50 (anode-side metallized film) shown in FIG. 5 is a metallized film in which the shape of the metal deposition electrode is different from that of the metallized film 5 (anode-side metallized film) shown in FIG. . 5 that are the same as those shown in FIG. 3 are denoted by the same reference numerals.

As shown in FIG. 5, in the metallized film 50, the thickness of the capacitance forming portion 54 (electrode facing portion) formed on the metal deposition electrode 52 is changed from the end portion 54a on the heavy edge portion 15 side to the insulating margin 13 side. It is made into the smooth inclination shape so that it may become thin continuously toward the edge part 54b.
The film thickness at the end 54 a on the heavy edge 15 side is the same as the film thickness on the heavy edge 15, and the film thickness at the end 54 b on the insulating margin 13 side is, for example, the film of the capacitor forming unit 24. It is the same as the thickness t2 (see FIG. 3).

The end 54a on the heavy edge 15 side means a portion including the end on the heavy edge 15 side of the capacitance forming portion 54, and the end 54b on the insulating margin 13 side means the portion of the capacitance forming portion 54. Of these, the portion including the end on the insulating margin 13 side is meant.
Therefore, the film thickness of the capacitor forming portion 54 does not need to be continuously reduced from the end on the heavy edge portion 15 side to the end on the insulating margin 13 side, and the film thickness does not decrease in at least one of the both end portions. A straight portion may be provided. For example, in this modification, as shown in FIG. 5, a straight portion L is provided at the end portion 54b.

  The capacitor forming portion 54 is made of an electrode material mainly composed of aluminum, for example, aluminum alone or an alloy of aluminum and zinc.

  In the metallized film 50 formed as described above, since the film thickness of the capacitance forming part 54 is continuously reduced, the upper surface of the metal vapor deposition electrode 52 of the metallized film 50 and the cathode above the upper surface. The gap between the metallized film (not shown) on the side and the dielectric film (gap caused by the heavy edge portion) can be reduced, and the capacitor life can be improved.

(Example)
As shown in Table 1 below, of the pair of metal vapor deposition electrodes, the main component of the metal vapor deposition electrode on the anode side is aluminum, the film resistance is as follows, and both the anode side and the cathode side are divided electrodes (FIG. 4). The following sample,
Example 1 (FIG. 3) Anode side (uniform film thickness): 10Ω / □, cathode side: 20Ω / □
Example 2 (FIG. 5) Anode side (film thickness gradient): 7 to 15Ω / □, cathode side: 20Ω / □
Comparative example: anode side (uniform film thickness): 20Ω / □, cathode side: 20Ω / □
A metallized film capacitor with a rating of 600V-200 μF was prepared and subjected to a moisture resistance load test for 2000 hours at 85 ° C. and 85% RH. The results are shown in Table 1 (average number of samples n = 10).

  As apparent from Table 1 above, in Examples 1 and 2, where the anode side of the pair of metal vapor deposition electrodes has a low film resistance (large film thickness), both the anode side and the cathode side have a high film resistance (the same film thickness). Compared with Comparative Example 1), it was possible to suppress a decrease in capacitance of the metal deposition electrode on the anode side, and to suppress an increase in tan δ.

Further, the metal deposition electrode on the anode side includes a capacitance forming portion and a heavy edge portion that is provided at a connection portion between the metallicon electrode and is thicker than the capacitance forming portion.
The thickness of the capacitor forming portion is such that the end portion on the heavy edge portion side is the thickest, and the end portion on the heavy edge portion side is continuously inclined from the end portion on the insulation margin side to the end portion on the insulation margin side. In the case of Example 2, the gap between the film layers can be reduced, and the life characteristics can be further improved.

(effect)
The metallized film capacitor according to the present invention includes a metal-deposited electrode on the anode side among the metal-deposited electrodes formed on a pair of metallized films in which a metal-deposited electrode is formed leaving an insulation margin on the surface of the dielectric film. Since the main component is aluminum and the film resistance value is smaller than the film resistance value of the metal vapor deposition electrode formed on the metallized film on the cathode side, a part of the metal vapor deposition electrode on the anode side is subjected to anodic oxidation reaction. Even if the insulator is used, the capacitance of the anode-side metal deposition electrode can be sufficiently secured, and the time until the majority of the anode-side metal deposition electrode becomes an insulator can be extended.

  Moreover, since the main component of the metal-deposited electrode material on the anode side is aluminum, a metallized film capacitor having improved capacitor life while maintaining the safety performance of the metallized film can be obtained.

  In addition, the anode-side metal vapor deposition electrode is divided into a plurality of divided electrodes by insulating slits, leaving the fuse portion, so that the dielectric is applied by applying voltage in a high-temperature, high-humidity atmosphere. Even when deterioration occurs and dielectric breakdown occurs, insulation can be recovered by separating the divided electrodes, thereby improving the withstand voltage performance and extending the life of the capacitor.

  Furthermore, both the anode side and the cathode side of the metal vapor-deposited electrode are divided into a plurality of divided electrodes by insulating slits, leaving a fuse portion, so the probability of insulation recovery when a high voltage is applied increases, and the safety performance Will improve.

  Further, the film thickness of the capacitor forming portion has a smooth slope so that the end on the heavy edge portion side is the thickest and continuously decreases from the end portion on the heavy edge portion side toward the end portion on the insulation margin side. By adopting the shape, the gap between the film layers can be reduced, and the life characteristics can be improved.

  Moreover, the insulating slit which divides | segments a metal vapor deposition electrode into plurality, leaving a fuse part is formed in both of a pair of metal vapor deposition electrodes. Therefore, when the insulation cannot be recovered due to the self-healing performance, the fuse portion is evaporated and scattered. As a result, the region including the insulation defect portion is insulated, and the safety performance of the metallized film can be further improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

  In the present embodiment, the capacitor element is formed by winding two metallized films, but a capacitor element may be formed by laminating a plurality of metallized films.

DESCRIPTION OF SYMBOLS 1 Metallized film capacitor 2 Capacitor element 3 Plastic case 4 Epoxy resin 5, 6 Metallized film 7, 8 Metallicon electrode 9, 10, Lead wire 11, 21 Dielectric film 12 Metal vapor deposition electrode (metal vapor deposition electrode on the anode side)
13, 23 Insulation margin 14 Capacitance forming portion 15 Heavy edge portion 22 Metal vapor deposition electrode (metal vapor deposition electrode on the cathode side)
31 Insulating slit 32 Split electrode 33 Fuse part 54a, 54b End part

Claims (2)

Two metallized films on which a metal vapor-deposited electrode is formed leaving an insulation margin on the surface of the dielectric film are overlapped to form a pair of metallized films, and the metal of one metallized film of the pair of metallized films A capacitor element formed by laminating or winding the vapor deposition electrode so that the dielectric film is opposed to the metal vapor deposition electrode of the other metallized film through the dielectric film, and the insulation margin is located on the opposite side in the film width direction;
A metallized electrode for electrode extraction connected to both end faces of the capacitor element, and a metallized film capacitor,
Among the pair of metallized films, the metal vapor deposition electrode formed on the metallized film on the anode side is mainly composed of aluminum, and the film resistance value is the metal vapor deposited on the metallized film on the cathode side. Smaller than the membrane resistance of the electrode,
Each of the metal vapor deposition electrodes formed on the pair of metallized films is provided at a connection portion between the capacitance forming portion and the metallicon electrode facing each other through the dielectric film, and the film thickness is the capacitance formation portion. With a heavy edge part, which is thicker than
The film thickness of the capacitance forming portion of the metal vapor deposition electrode on the anode side is inclined so as to be continuously thin from the end on the heavy edge portion side to the end portion on the insulation margin side,
The capacitor formed of the metal end of the insulation margin side of the capacitor forming part of the deposition electrode, the metal deposition electrode of the cathode side via the dielectric film out of the anode side of said pair of metallized film Insulation of the capacitance forming portion of the metal vapor deposition electrode on the cathode side , facing the region of the heavy edge portion side of the portion facing the region where the electrode surface is inclined from the heavy edge portion to the capacitance forming portion The metallized film capacitor characterized in that a margin side end faces a boundary region between the heavy edge part and the capacitance forming part of the metal deposition electrode on the anode side through the dielectric film.   2. The metallized film capacitor according to claim 1, wherein each of the metal vapor deposition electrodes formed on the pair of metallized films is divided into a plurality of divided electrodes by insulating slits, leaving a fuse portion.

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