JP2011049414A - Metallized film capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallized film capacitor having excellent safety preservation ability and an excellent withstand voltage at high temperatures. <P>SOLUTION: In a width direction of a metallized film, a first small segmented electrode part, a large segmented electrode part, a second small segmented electrode part, and an unsegmented electrode part 81 are arranged in order from the side of an insulating margin 72 to a Metallikon connection part 71. A plurality of small segmented electrodes 83 constituting the first small segmented electrode part are each connected to a large segmented electrode 84 by a fuse 93 formed between insulating slits 73 across the small segmented electrode 83 in a length direction. Further, a plurality of small segmented electrodes 85 constituting the second small segmented electrode part 85 are each connected to the large segmented electrode 84 and unsegmented electrode part 81 by fuses 94 and 95 formed between insulating slits 74 and 75 across the small segmented electrode 85 in a length direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metallized film capacitor used for smoothing and filtering inverter circuits for industrial equipment and automobiles.

  The conventional metallized film capacitor has a metallized near-metallized vapor deposition electrode 2 on the polypropylene film 1 shown in FIG. Film is being used. This metallized film capacitor has a self-healing function for recovering the insulation of the dielectric breakdown part due to scattering of the vapor deposition electrode around the dielectric breakdown part by the discharge energy at the time of dielectric breakdown of the polypropylene film. However, at high temperatures and high voltages, the number of dielectric breakdowns increases, so that the self-recovery function cannot be obtained sufficiently, and the capacitor may reach the short mode. For example, as shown in FIG. 13, in a metallized film capacitor in which a metallized film having a vapor-deposited metal film is laminated and wound on a dielectric (plastic film), the dielectric is shown at the x mark in the drawing. When the body breaks down and self-healing (spattering of the deposited metal) is insufficient, it is conducted with the deposited metal on the metallized film disposed under the metallized film via the broken dielectric part. Become.

  The smoothing capacitor of the inverter circuit is used at a high temperature and a high voltage, and has a strong demand for safety, and a metallized film in which the vapor deposition electrode is divided into a plurality of parts is employed (see, for example, Patent Documents 1 to 3). Examples of metallized films on which such divided electrodes are formed are shown in [FIG. 2-A] to [FIG. 2-C].

  In FIG. 2A, an insulating margin 12 is formed at the end of the metallized film facing the metallicon connection portion 10 in the width direction, and the divided electrode 7 is formed by the width direction insulating slit 5 and the longitudinal direction insulating slit 6. Is formed. These divided electrodes 7 are connected in parallel by a fuse 8. Further, the vapor deposition electrode in the vicinity of the metallicon has a configuration in which the metallicon connection portion 10 and the divided electrode 7 are separated by a longitudinal insulating slit 9, and the metallicon connection portion 10 and the divided electrode 7 are connected by a fuse 11.

  In FIG. 2B, an insulating margin 12a is formed at the end of the metallized film that faces the metallicon connecting portion 10a in the width direction, and a honeycomb-shaped divided electrode 7a is formed by the Y-shaped insulating slit 13a. . These divided electrodes 7a are connected in parallel by a fuse 8a.

  In FIG. 2C, an insulating margin 12b is formed at the end of the metallized film facing the metallicon connecting portion 10b in the width direction, and a honeycomb-shaped divided electrode 7b is formed by the Mueller-rear insulating slit 14a. ing. These divided electrodes 7b are connected in parallel by a fuse 8b.

  When a dielectric breakdown occurs in a metallized film capacitor using a metallized film having such divided electrodes, it has the above-described self-healing function. At the same time, even when a breakdown that exceeds the self-healing function of the metallized film capacitor occurs, current flows from the surrounding split electrode to the split electrode where the breakdown occurs, causing the vapor deposition electrode of the fuse part to scatter, causing breakdown. The generated divided electrode is separated from other divided electrodes to have a function of restoring insulation, and high safety is ensured.

  Furthermore, if the area of the divided electrode is reduced, the capacity reduction due to the fuse operation can be suppressed, and the life of the capacitor can be extended. However, if the material is too finely divided, the energy of the divided electrodes becomes small, and when a dielectric breakdown occurs, the fuse operation becomes difficult and the safety of the capacitor decreases. This phenomenon becomes more prominent as the temperature increases.

  Further, when the divided electrode area is reduced, the number of fuses is increased. However, since the fuse has a higher resistance than the divided electrode, it is reported that the heat generation of the capacitor increases (for example, patents). Reference 4). Such an increase in self-heating causes a decrease in withstand voltage performance and safety performance. Particularly in the center of the capacitor element, the temperature rises most due to self-heating, and the withstand voltage performance and the safety performance are deteriorated more than other portions.

  Therefore, in order to improve the above-described problems, a means has been devised in which divided electrode portions and electrodes that are not divided and have a large area (non-divided electrode portions) are collectively arranged (see, for example, Patent Document 5). In the metallized film capacitor described in Patent Document 5, a plurality of divided electrodes divided by slits are provided on the insulating margin side, and a non-divided electrode portion is provided on the terminal connection side (metallicon connection side). And the some division | segmentation electrode is comprised so that the area of a vapor deposition electrode may become small as it approaches an insulation margin.

Japanese Patent Laid-Open No. 08-250367 Japanese Patent Laid-Open No. 11-26281 JP-A-11-26280 JP 2003-338422 A JP 2005-12082 A

  By the way, capacitors used for smoothing an inverter circuit for automobiles are used at high temperatures, high frequencies, and high voltages, and miniaturization and high safety are required. For this reason, it is necessary to reduce the thickness of the dielectric film to reduce the size of the capacitor and to improve the withstand voltage performance and safety in the high temperature region.

  However, in the metallized film capacitor described in Patent Document 5, the divided electrode portions (small divided electrode portions) in which the divided electrodes having a relatively small electrode area are arranged in the longitudinal direction are gathered on the insulation margin side, while the terminal connection side Since the divided electrode portion (large divided electrode portion) and the non-divided electrode portion in which divided electrodes having a relatively large electrode area are arranged in the longitudinal direction are arranged, safety at high temperatures is always sufficiently ensured. The situation was not up. Specifically, when a dielectric breakdown occurs in the small divided electrode part, sufficient current does not flow from the divided electrode adjacent to the divided electrode constituting the small divided electrode part where the dielectric breakdown occurs, In particular, there is a possibility that the fuse cannot be operated at a high temperature.

  This invention is made | formed in view of the said subject, and it aims at providing the metallized film capacitor which has the favorable safety | security at high temperature and withstand voltage property.

  The present invention relates to a metallization in which a capacitor element is formed by winding or laminating a metallized film provided with a vapor deposition electrode on at least one surface of a dielectric film, and a metallicon for electrode drawing is connected to both end surfaces of the capacitor element. A film capacitor, in which a vapor deposition electrode is divided by insulating slits arranged at intervals in the longitudinal direction of the metallized film, a plurality of small divided electrodes formed along the longitudinal direction, and metallization A large-divided electrode part that forms a plurality of large-divided electrodes having a larger electrode area than the small-divided electrodes, which are divided by insulating slits arranged at intervals in the longitudinal direction of the film, along the longitudinal direction, and vapor deposition The electrode has a non-divided electrode portion that is continuous in the longitudinal direction, and the small divided electrode portion is neither the large divided electrode portion nor the non-divided electrode portion in the width direction of the metallized film. Each of the plurality of small divided electrodes is connected to the large divided electrode or the non-divided electrode portion by a fuse formed between insulating slits sandwiching the small divided electrode in the longitudinal direction. It is characterized by.

  According to the invention configured as described above, in the width direction of the metallized film, a plurality of large divided electrodes having a relatively large electrode area are formed by a plurality of small divided electrodes having a relatively small electrode area. Is disposed adjacent to either the large divided electrode portion or the non-divided electrode portion. Each of the plurality of small divided electrodes is connected to the large divided electrode or the non-divided electrode portion by a fuse. For this reason, the end portion of the small divided electrode is connected to either the large divided electrode or the non-divided electrode portion having an electrode area larger than that of the small divided electrode through the fuse, so that dielectric breakdown occurred in the small divided electrode. Even in such a case, sufficient current flows to operate the fuse from the large divided electrode or the non-divided electrode adjacent to the small divided electrode, and the fuse operates reliably (spraying the vapor deposition electrode of the fuse), thereby causing dielectric breakdown. The raised divided electrodes can be separated. In order to exert the above-described effects, the area of the second divided electrode that constitutes the large divided electrode portion should be twice or more than the area of the first divided electrode portion that constitutes the small divided electrode portion. preferable.

  Here, as the small divided electrode portion, two divided electrode portions of the first small divided electrode portion and the second small divided electrode portion are provided, and the first small divided electrode portion and the second small divided electrode portion in the width direction of the metallized film. It is preferable to arrange the large divided electrode portion adjacent to each other. According to this configuration, even when the plurality of small divided electrodes perform a fuse operation due to deterioration of the dielectric due to heat, voltage or the like in the first small divided electrode portion or the second small divided electrode portion, the current path is extremely large. Can be prevented from being disturbed. That is, when the non-divided electrode portion is disposed adjacently between the first small divided electrode portion and the second small divided electrode portion in the width direction of the metallized film, the vapor deposition electrode is divided into the non-divided electrode portion. Since there is no insulating slit, the current path may be extremely disturbed when a plurality of subdivided electrodes perform a fuse operation. As a result, the dielectric loss and equivalent series resistance of the capacitor may be extremely increased. On the other hand, the insulation formed in the large divided electrode portion by arranging the large divided electrode portion adjacently between the first small divided electrode portion and the second small divided electrode portion in the width direction of the metallized film. The slit restricts the current path and can prevent the current path from being extremely disturbed.

  Moreover, in the metallized film capacitor in which the capacitor element is formed by a pair of metallized films formed by superposing two metallized films, a large divided electrode portion and a non-divided electrode formed on one of the pair of metallized films It is preferable that all electrode surfaces of the part are configured to face the small divided electrode part formed on the other of the pair of metallized films. According to this configuration, even when a dielectric breakdown exceeding the self-healing function (self-healing function) of the metallized film occurs in the large divided electrode or the non-divided electrode part formed on one of the pair of metallized films, Sufficient current flows from the large divided electrode or the non-divided electrode portion having a larger electrode area than the small divided electrode adjacent to the small divided electrode formed on the other of the pair of metallized films. For this reason, the fuse formed at the end of the small divided electrode formed on the other of the pair of metallized films operates reliably (spraying the vapor deposition electrode of the fuse portion), and the large divided electrode or non-breaking dielectric breakdown occurs. The divided electrode portion can be separated from other divided electrodes. Thereby, even when a dielectric breakdown occurs in the large divided electrode or the non-divided electrode portion formed on one of the pair of metallized films, the insulation of the large divided electrode or the non-divided electrode portion can be recovered, and the capacitor The function as can be maintained.

  Further, it is preferable to dispose the non-divided electrode portion on the metallicon connection portion side of the metallized film. This is because, when a divided electrode part is arranged on the metallicon connection part side, when dielectric breakdown occurs in the divided electrode part, if a fuse connecting the divided electrode part and the non-divided electrode part operates, the divided electrode part Current path is completely cut off and may not function as a capacitor. On the other hand, by disposing the non-divided electrode part on the metallicon connection part side, even when dielectric breakdown occurs in the non-divided electrode (non-divided electrode formed on one of the pair of metallized films), the opposing metal By operating the fuse that connects the small divided electrode formed on the metalized film (the other metallized film of the pair of metalized films) and the non-divided electrode or the large divided electrode adjacent to the small divided electrode, An electrode region that functions as a capacitor can be left (a current path from the non-divided electrode can be secured).

  According to the present invention, it is possible to provide a metallized film capacitor having good safety and voltage resistance at high temperatures.

It is a figure which shows the laminated constitution of the metallized film currently used for the conventional metallized film capacitor. It is a top view which shows the conventional metallized film provided with the division | segmentation electrode, [FIG. 2-A] is a rectangular division | segmentation electrode, [FIG. 2-B] is a honeycomb-shaped division | segmentation formed by the Y-shaped insulation slit. Electrode, [FIG. 2-C] is a view showing a metallized film provided with a honeycomb-shaped divided electrode formed by Mueller-Rear type insulating slits. It is a figure which shows one Embodiment of the metallized film which comprises the metallized film capacitor of this invention. It is a figure which shows the internal structure of the metallized film capacitor of this invention. It is a conceptual diagram of the electric current path which flows through a vapor deposition electrode. It is a figure which shows the electric current path at the time of the dielectric breakdown in the non-dividing electrode position of the metallized film which comprises the metallized film capacitor of this invention. It is a figure which shows the electric current path at the time of the dielectric breakdown in the non-dividing electrode position of the metallized film which comprises the metallized film capacitor by a comparative example. It is a figure which shows the metallized film which comprises the metallized film capacitor of this invention. It is a figure which shows the metallized film concerning the comparative example 1. It is a figure which shows the deformation | transformation form of the metallized film which comprises the metallized film capacitor of this invention. It is a figure which shows the deformation | transformation form of the metallized film which comprises the metallized film capacitor of this invention. It is a figure which shows the deformation | transformation form of the metallized film which comprises the metallized film capacitor of this invention. It is a figure which shows an example of the laminated constitution of the conventional metallized film capacitor.

  FIG. 3 is a diagram showing an embodiment of a metallized film constituting the metallized film capacitor of the present invention. In the metallized film, one end part (electrode formation region) in the width direction of the metallized film (hereinafter simply referred to as “width direction”) constitutes a metallicon connection part 71 to which a metallicon for electrode extraction is connected, and the other end An insulating margin (a region where no vapor deposition electrode is formed at one end in the width direction of the metallized film) 72 is formed in the portion. Vapor deposition electrodes are formed on the film surface area other than the insulation margin 72 except for the insulation slits.

  On the insulating margin 72 side of the metallized film, a plurality of T-shaped insulating slits 73 are arranged at regular intervals in the longitudinal direction of the metallized film (hereinafter simply referred to as “longitudinal direction”). In addition, a plurality of T-shaped insulating slits are spaced apart from each other by a fixed interval that is wider than the interval between the insulating slits 73 (four times in this embodiment) on the metallicon connection side of the insulating slit 73 group arranged in the longitudinal direction. 74 are arranged in the longitudinal direction. Further, a plurality of T-characters are arranged on the metallicon connection portion side of the insulating slits 74 arranged in the longitudinal direction at a constant interval that is narrower than the interval between the insulating slits 74 (about one third in this embodiment). Insulating slits 75 are arranged in the longitudinal direction. A non-divided electrode portion 81 in which vapor deposition electrodes are continuous in the longitudinal direction is formed between the insulating slit 75 group arranged in the longitudinal direction and the metallicon connection portion 71. The slit widths of the insulating slits 73, 74, 75 are, for example, 0.2 mm.

  A plurality of small divided electrodes 83 in which the vapor deposition electrode is divided by the insulating slit 73 are formed, and the plurality of small divided electrodes 83 constitute a first small divided electrode portion. In addition, a plurality of large divided electrodes 84 in which the vapor deposition electrodes are divided by the insulating slits 74 are formed, and the plurality of large divided electrodes 84 constitute a large divided electrode portion. Furthermore, a plurality of small divided electrodes 85 in which the vapor deposition electrode is divided by the insulating slit 75 are formed, and the plurality of small divided electrodes 85 constitute a second small divided electrode portion. The electrode area of each of the plurality of large divided electrodes 84 is larger than the electrode area of each of the plurality of small divided electrodes 83 and the electrode area of each of the plurality of small divided electrodes 85. In this embodiment, the electrode area of the large divided electrode 84 is at least twice the electrode area of the small divided electrodes 83 and 85. A large divided electrode portion is disposed adjacent to the first small divided electrode portion and the second small divided electrode portion in the width direction.

  In this embodiment, as described above, the first small divided electrode portion, the large divided electrode portion, the second small divided electrode portion, and the non-divided electrode portion 81 are arranged in this order from the insulating margin 72 side to the metallicon connection portion 71 in the film width direction. Has been placed. That is, the small divided electrode portion (first and second small divided electrode portions) is disposed adjacent to either the large divided electrode portion or the non-divided electrode portion. Each of the plurality of small divided electrodes 83 is connected to the large divided electrode 84 by a fuse 93 formed between insulating slits 73 sandwiching the small divided electrode 83 in the longitudinal direction. Each of the plurality of small divided electrodes 85 is divided into a large divided electrode 84 and a non-divided electrode portion 81 by fuses 94 and 95 formed between insulating slits 74 and 75 sandwiching the small divided electrode 85 in the longitudinal direction, respectively. It is connected.

  FIG. 4 is a diagram showing the internal structure of the metallized film capacitor of the present invention. Two metallized films formed as described above are overlapped and wound so that the metallicon connection part and the insulation margin face each other. The two metallized films are overlaid with the electrode forming surface on which the vapor deposition electrode is formed facing in the same direction. That is, the vapor deposition electrodes and the dielectric films are alternately arranged in the stacking direction so that the dielectric film is sandwiched between the vapor deposition electrodes. Then, after forming the wound metallized film into an oval shape, a metallicon for electrode drawing is formed at both ends (one end and the other end of the overlapped metallized film) to form a capacitor element 25. . Thereafter, a plurality of capacitor elements 25 are connected by the electrode plate 26 and the lead terminals 27 are connected. The connected capacitor element 25 is accommodated in a case 28, and a resin 29 is filled in the case 28 to obtain a metallized film capacitor.

  As described above, according to this embodiment, in the film width direction, the small divided electrode portion composed of a plurality of small divided electrodes 83 and 85 having a relatively small electrode area has a plurality of large divided portions having a relatively large electrode area. It is arranged adjacent to either the large-divided electrode portion or the non-divided electrode portion 81 composed of the electrode 84. Each of the plurality of small divided electrodes 83 is connected to the large divided electrode 84 by the fuse 93, and each of the plurality of small divided electrodes 85 is respectively connected to the large divided electrode 84 and the non-divided electrode portion 81 by the fuses 94 and 95. Connected. For this reason, the end portions of the small divided electrodes 83 and 85 are connected to either the large divided electrode 84 or the non-divided electrode portion 81 having an electrode area larger than that of the small divided electrodes 83 and 85 through a fuse. Even when dielectric breakdown occurs in the divided electrodes 83 and 85, a current sufficient to operate the fuse flows from the large divided electrode 84 or the non-divided electrode portion 81 adjacent to the small divided electrodes 83 and 85, and the fuse is surely secured. The divided electrodes that have caused the dielectric breakdown can be separated by operating (evaporating the vapor deposition electrode of the fuse portion).

  In addition, according to this embodiment, since the large divided electrode portion is disposed adjacently between the first small divided electrode portion and the second small divided electrode portion in the film width direction, the first small divided electrode portion Alternatively, it is possible to prevent the current path from being extremely disturbed even when, for example, a plurality of small divided electrodes 85 are subjected to a fuse operation due to deterioration of the dielectric due to heat or voltage in the second small divided electrode portion.

  FIG. 5 is a conceptual diagram of a current path flowing through the vapor deposition electrode. FIG. 4A shows a case where an undivided electrode portion is disposed adjacently between the first subdivided electrode portion and the second subdivided electrode portion in the film width direction, and FIG. Fig. 2 shows a case where a large divided electrode portion is disposed adjacently between the first small divided electrode portion and the second small divided electrode portion. In the case of FIG. 5A, since there is no insulating slit for dividing the vapor deposition electrode in the non-divided electrode portion, there is a possibility that the current path may be extremely disturbed when a fuse operation is performed over a plurality of small divided electrodes. is there. As a result, the dielectric loss and equivalent series resistance of the capacitor may be extremely increased. On the other hand, as shown in the same figure (b), by arrange | positioning a large divided electrode part adjacently between the 1st small divided electrode part and the 2nd small divided electrode part in the width direction of a metallized film. Insulating slits formed in the large-divided electrode portion can regulate the current path and prevent the current path from being extremely disturbed.

  Moreover, when forming a metallized film capacitor with a pair of metallized films formed by overlapping two metallized films, all of the large divided electrode part and the non-divided electrode part formed on one of the pair of metallized films The electrode surface is preferably configured to face the small divided electrode portion formed on the other of the pair of metallized films. According to this configuration, for example, as shown in FIG. 6, the self-healing function of the metallized film in the non-divided electrode portion formed on one of the pair of metallized films (the metallized film located on the upper layer side in the figure) Even when dielectric breakdown exceeding the (self-healing function) (dielectric breaks at the position of the x mark) occurs (when vapor deposition electrodes conduct between a pair of metallized films through the broken dielectric portion) A large divided electrode or a non-divided electrode having an electrode area larger than that of the small divided electrode adjacent to the small divided electrode formed on the other of the opposing metallized films (the metallized film located on the lower layer side in the figure) Current flows into the split electrode from the part. For this reason, the fuse formed at the end of the small divided electrode formed on the other of the pair of metallized films is operated reliably (the evaporated electrode of the fuse portion is scattered), and the non-divided electrode portion where the dielectric breakdown has occurred It can be separated from other divided electrodes. Thereby, even when a dielectric breakdown occurs in the non-divided electrode portion formed on one of the pair of metallized films, the insulation of the non-divided electrode portion can be recovered and the function as a capacitor can be maintained. it can.

  Furthermore, in the case where two metallized films are overlaid as described above, it is preferable to dispose the non-divided electrode part on the metallicon connection part side of the metallized film. This is because when a split electrode part is arranged on the metallicon connection part side (electrode lead side), if the dielectric breakdown occurs in the split electrode part (the dielectric breaks at the position of the x mark in the split electrode), the split When the fuse that connects the electrode part and the non-divided electrode is operated, the current path from the divided electrode part is completely cut off, and it may not function as a capacitor (FIG. 7). On the other hand, even if a dielectric breakdown occurs in the non-divided electrode part (non-divided electrode part formed on one of the pair of metallized films) by disposing the non-divided electrode part on the metallicon connection part side, A small divided electrode formed on the metallized film (the other metallized film of the pair of metallized films, the metallized film disposed on the lower layer side in FIG. 6) and the non-divided electrode adjacent to the small divided electrode By operating the fuse connecting the part or the large divided electrode, an electrode region functioning as a capacitor can be left.

<Example>
An example of the metallized film capacitor will be described below with reference to FIG. In FIG. 8, the longitudinal dimension 83a of the small divided electrode 83 constituting the first small divided electrode part is 4.0 mm, the longitudinal dimension 85a of the small divided electrode 85 constituting the second small divided electrode part is 5.0 mm, The longitudinal dimension 84a of the large divided electrode constituting the large divided electrode portion was set to 16.0 mm. On the other hand, the film width direction dimension 83b (from the boundary with the insulation margin 72 to the boundary between the insulation slit 73 and the large division electrode 84) of the first small division electrode portion is 12.5 mm, and the film width direction dimension 84b of the large division electrode 84 is. (Electrode dimension not including the insulating slit) is 9.0 mm, and the film width direction dimension 85b of the second small divided electrode part (the insulating slit 75 and the non-divided electrode part 81 are separated from the boundary between the large divided electrode 84 and the insulating slit 74). 12.5 mm) and the film width direction dimension 81b of the non-divided electrode portion 81 was 14.0 mm. The dimensions of the fuses 93, 94, and 95 were set to 0.2 mm. The dielectric used was a 2.5 μm polypropylene film, the non-metallicon vicinity vapor deposition electrode film resistance value was 10Ω / □, and the metallicon connection vapor deposition electrode film resistance value was 4Ω / □.

  Two metallized films formed as described above are wound so that the metallicon connection portion and the insulation margin face each other, and after forming into an oval shape, a metallicon is formed as an electrode lead at both ends to form a capacitor element. did. Further, as shown in FIG. 4, five capacitor elements 25 are connected by an electrode plate 26, lead terminals 27 are connected, housed in a case 28, filled with epoxy resin 29, cured, and 800 μF metallized film capacitor. Was made.

<Comparative example>
Next, examples of the metallized film capacitor according to the present invention will be described in comparison with comparative examples. The divided electrode dimensions, fuse width, and vapor deposition electrode film resistance value of the metalized film capacitor according to the present invention are as described above.

  Next, a comparative example of the metallized film capacitor will be described. FIG. 9 shows a metallized film according to Comparative Example 1. The comparative example 1 is different from the embodiment in that an undivided electrode portion is arranged in place of the large divided electrode between the first small divided electrode portion and the second small divided electrode portion. Other configurations and dimensions are the same as in the embodiment.

  The metallized film capacitor shown in FIG. The pitch of the insulating slit 5 that divides the metallized film dividing electrode 7 shown in FIG. 2-A in the film longitudinal direction is 10.0 mm, the pitch of the insulating slit 6 that divides in the film width direction is 18 mm, and the dividing electrode 7 is The width of the connected fuses 8 and 11 was 0.2 mm. The dielectric was a 2.5 μm polypropylene film, the non-metallicon vicinity deposited electrode film resistance was 10Ω / □, and the metallicon connection film resistance was 4Ω / □.

  Two metallized films shown in the above comparative examples 1 and 2 are wound so that the metallicon connection portion and the insulation margin face each other, and formed into an oval mold, and then metallicons are formed as electrode leads at both ends to form a capacitor element. It was. Further, as shown in FIG. 4, five capacitor elements 25 are connected by an electrode plate 26 and connected to a lead terminal 27, housed in a case 28, filled and cured with an epoxy resin 29, and an 800 μF metallized film. A capacitor was made.

  Samples were prepared for Examples and Comparative Examples 1 and 2, and a durability test (temperature 110 ° C., 750 VDC, applied for 1000 hours) was performed. After the test, the capacitance change rate of the sample was measured. The test results are shown in Table 1.

  From the test results in Table 1, in Example and Comparative Example 1, no short circuit occurred at the end of the test, whereas in Comparative Example 2, a short circuit occurred during the test. This is because when the dielectric breakdown occurs in the dielectric polypropylene film in the metallized film according to the example and the comparative example 1, the current sufficient to scatter and separate the fuse is transferred from the large divided electrode or the non-divided electrode portion to the small divided electrode. Flows in. As a result, it is possible to separate the divided electrodes that have caused dielectric breakdown, and avoid the occurrence of a short circuit. On the other hand, when the dielectric breakdown occurs in the metallized film according to Comparative Example 2, it is considered that the current connected to the divided electrodes does not flow enough to scatter and separate the fuses and the short mode is reached. It is done.

  Subsequently, for Examples and Comparative Example 1 in which good safety performance was obtained, the dielectric loss tangent was measured when the capacitance was changed by about −70 to −80% with respect to the initial value, and the change with respect to the initial value was measured. Rate was evaluated. The results are shown in Table 2. In order to change the capacitance, 1500 VDC was applied to the sample for 5 minutes at an ambient temperature of 120 ° C.

  As is clear from the test results in Table 2, with respect to the rate of change of the dielectric loss tangent, the example is a negative value, while the comparative example 1 is a positive value and is greatly increased. This is a result of Comparative Example 1 in which a plurality of small divided electrodes perform a fuse operation due to dielectric breakdown and the current path is disturbed. On the other hand, the Example has the following advantageous effects over Comparative Example 1. That is, at the end of the life of the capacitor and excessive use conditions, the dielectric loss tangent may increase significantly with respect to the initial value (the resistance component of the capacitor increases). In this case, the self-heating of the capacitor increases, which may cause deterioration of the withstand voltage performance and the safety performance. Therefore, in the embodiment in which the rate of change of the dielectric loss tangent does not remarkably increase, the possibility of causing deterioration of the withstand voltage performance and the safety performance can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the four-stage configuration in which 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 the film width direction is not limited thereto. It is good also as a 3 step | paragraph structure which has arrange | positioned the non-dividing electrode part, the small dividing electrode part, and the large dividing electrode part in the film width direction. Further, at least a non-divided electrode portion, a small divided electrode portion, and a large divided electrode portion are provided, and the small divided electrode portion is disposed adjacent to either the large divided electrode portion or the non-divided electrode portion in the film width direction. As long as the electrode portions are arranged in five or more stages.

  10-12 is a figure which shows the deformation | transformation form of the metallized film which comprises the metallized film capacitor of this invention. In the metallized film shown in FIG. 10, the first subdivided electrode portion, the first non-divided electrode portion, the second non-divided electrode portion, the second subdivided electrode portion, from the insulation margin side to the metallicon connection portion in the film width direction, They are arranged in the order of the large divided electrode portions. In the metallized film shown in FIG. 11, in the film width direction from the insulation margin side to the metallicon connection portion, the first small divided electrode portion, the first large divided electrode portion, the second large divided electrode portion, the second small divided electrode portion, The non-divided electrode portions are arranged in this order. In the metallized film shown in FIG. 12, the first small divided electrode portion, the large divided electrode portion, the first non-divided electrode portion, the second small divided electrode portion, the second small electrode portion, the large divided electrode portion, from the insulation margin side to the metallicon connection portion in the film width direction. The non-divided electrode portions are arranged in this order. According to this configuration, even when dielectric breakdown occurs in the small divided electrode, sufficient current flows to operate the fuse from the large divided electrode or the non-divided electrode adjacent to the small divided electrode, so that the fuse is reliably It is possible to separate the divided electrodes that have caused the dielectric breakdown by operating (spraying the vapor deposition electrodes of the fuse portion).

  Moreover, in the said embodiment, although the electrode area of each of several subdivided electrodes arranged in the film longitudinal direction is made the same, you may make it different. Similarly, although the electrode areas of the large divided electrodes arranged in the film longitudinal direction are the same, they may be different. In short, the electrode area of the large divided electrode adjacent to the small divided electrode should be larger than the electrode area of the small divided electrode. Even in this case, the electrode area of the large divided electrode is preferably at least twice the electrode area of the adjacent small divided electrode.

  In addition, when two metallized films are overlapped, the metallized films having the same electrode pattern may be overlapped, or the metallized films having different electrode patterns may be overlapped. Even in this case, the metallized film so that all of the large divided electrode part and the non-divided electrode part formed on one of the pair of metallized films are opposed to the small divided electrode part formed on the other of the pair of metallized films. Are preferably overlapped. Thereby, even when a dielectric breakdown occurs in the large divided electrode and the non-divided electrode portion formed on one of the pair of metallized films, the insulation of the large divided electrode or the non-divided electrode portion can be recovered, and the capacitor The function as can be maintained.

DESCRIPTION OF SYMBOLS 1 ... Polypropylene film 2 ... Metallicon vicinity vapor deposition electrode 3 ... Non-metallicon vicinity vapor deposition electrode 4 ... Insulation margin 5 ... Width direction insulation slit 6 ... Longitudinal direction insulation slit 7, 7a, 7b ... Divided electrode 8, 8a, 8b ... Fuse 9 ... Longitudinal insulating slit 10 near the metallicon ... Metallicon connection 11 ... Fuses 12, 12a, 12b near the metallicon ... Insulation margins 13, 13a ... Y-shaped insulating slits 14, 14a ... Mueller-Rear insulating slit 25 ... Capacitor element 26 ... Electrode plate 27 ... Lead terminal 28 ... Case 29 ... Epoxy resin 73, 74, 75 ... Insulating slit 81 ... Non-divided electrode 83, 85 ... Small divided electrode 84 ... Large divided electrode 93, 94, 95 ... Fuse 83a ... Small divided electrode 83 Film longitudinal dimension 84a ... Film longitudinal dimension of the large divided electrode 84 5a ... Film longitudinal direction dimension 81b of the small divided electrode 85 ... Film width direction dimension 83b of the non-divided electrode part 81 ... Film width direction dimension 84b of the small divided electrode part 83 ... Film width direction dimension 85b of the large divided electrode part 84 ... Small Dimension of the divided electrode 85 in the film width direction

Claims (4)

In a metallized film capacitor in which a metallized film provided with an evaporation electrode on at least one surface of a dielectric film is wound or laminated to form a capacitor element, and metallicons for electrode drawing are connected to both end surfaces of the capacitor element.
A subdivided electrode part that forms a plurality of subdivided electrodes along the longitudinal direction in which the vapor deposition electrode is divided by insulating slits arranged at intervals in the longitudinal direction of the metallized film;
Large division that forms a plurality of large divided electrodes along the longitudinal direction in which the vapor deposition electrode is divided by insulating slits arranged at intervals in the longitudinal direction of the metallized film and has a larger electrode area than the small divided electrodes An electrode part;
The vapor deposition electrode comprises a non-divided electrode portion continuous in the longitudinal direction,
In the width direction of the metallized film, the small divided electrode portion is disposed adjacent to either the large divided electrode portion or the non-divided electrode portion,
Each of the plurality of small divided electrodes is connected to the large divided electrode or the non-divided electrode portion by a fuse formed between insulating slits sandwiching the small divided electrode in the longitudinal direction. Film capacitor. As the small divided electrode portion, there are two divided electrode portions, a first small divided electrode portion and a second small divided electrode portion,
2. The metallized film capacitor according to claim 1, wherein the large divided electrode portion is disposed adjacently between the first small divided electrode portion and the second small divided electrode portion in the width direction of the metallized film. The metallized film capacitor according to claim 1 or 2, wherein the capacitor element is formed by a pair of metallized films formed by superposing the two metallized films.
A metal in which all electrode surfaces of the large divided electrode portion and the non-divided electrode portion formed on one of the pair of metallized films are opposed to the small divided electrode portion formed on the other of the pair of metallized films. Film capacitor. The metallized film capacitor according to claim 3, wherein the non-divided electrode part is disposed on the metallized connection part side of the metallized film.

Images