JP6494988B2 - Metallized film for capacitor element and metallized film capacitor using the same - Google Patents

Description

  The present invention relates to a vapor deposition pattern of a metallized film for a capacitor element.

  In the technical field of metallized film capacitors used in hybrid vehicles (HV), electric vehicles (EV), fuel cell vehicles (FCV) and industrial machinery, the thickness of the dielectric film is reduced to reduce size, weight and cost. Is required to be thin. In order to reduce the thickness of the dielectric film, it is required to improve the withstand voltage performance. As a means for that, improvement of the vapor deposition pattern of the vapor deposition electrode formed on the dielectric film is performed along with the improvement of the material.

  The metallized film capacitor recovers the insulation of the dielectric breakdown part by the surrounding deposited metal scattering due to the dielectric breakdown of the metallized film (self-healing function (self-healing operation)). Since the surrounding vapor-deposited electrodes are scattered away, the progress of dielectric breakdown stops there and the insulation is restored. However, since the self-recovery function cannot be sufficiently obtained at high temperatures and high voltages where the number of dielectric breakdowns increases, the capacitor may fall into a short mode. In other words, in a metallized film capacitor in which a metallized film having a deposited metal film is laminated and wound on a dielectric film, if the deposited metal is insufficiently scattered, The two layers of deposited metal are electrically connected.

  Therefore, a security mechanism composed of a plurality of divided electrodes and fuses has been devised. When a split electrode is formed in a metallized film, current flows from the surrounding split electrode to the split electrode that caused the dielectric breakdown even if the breakdown exceeds the self-healing function of the metallized film, and the deposited metal of the fuse is removed. By the fuse operation to be scattered, it is possible to recover the insulation by separating the divided electrode that has caused the dielectric breakdown from the other divided electrodes, thereby ensuring high safety.

  By the way, as 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 it is subdivided too much, the energy of the divided electrodes becomes small, and when the dielectric breakdown occurs, the fuse operation becomes difficult and the safety of the capacitor is lowered. This phenomenon becomes more prominent as the temperature increases.

  Further, when the area of the divided electrode is reduced, the number of fuses increases. However, since the fuse has a higher resistance than the divided electrode, heat generation of the capacitor increases. Such an increase in self-heating causes a decrease in withstand voltage performance and safety performance. In particular, at the center of a capacitor element formed by winding or laminating a metallized film, the temperature rises rapidly due to self-heating, and the withstand voltage performance and the safety performance are deteriorated as compared with other portions.

  Therefore, a small area electrode array region developed in a relatively small area divided state along the dielectric film longitudinal direction (hereinafter simply referred to as “film longitudinal direction”) and a continuous state or a relatively large size along the film longitudinal direction. Means have been devised for centrally arranging large-area electrode array regions developed in an area-divided state (see, for example, Patent Document 1). In the metallized film for the capacitor element, a plurality of divided electrodes defined by insulating slits are provided on the insulating margin side, and a large area electrode array region is provided on the electrode lead-out portion (metallicon) side.

  Furthermore, as a set of the small area electrode array region and the large area electrode array region, this set is repeatedly arranged along the dielectric film width direction (hereinafter simply referred to as “film width direction”), and the small area electrode array A metallized film for a capacitor element has been developed in which each divided electrode in the row region is electrically connected in a state through a fuse by a metal vapor deposition film at the cut of the insulating slit to constitute the vapor deposition electrode.

  FIG. 6 shows a conventional example of a metallized film for a capacitor element that is strongly required to be safe because it is used at a high temperature and a high voltage. FIG. 7 is an enlarged plan view showing a part of the metallized film. 6 and 7, 1 is a metallized film, 2 is a dielectric film (shown with a part of the vapor deposition electrode removed), 3 is a vapor deposition electrode, 4 is an insulation slit (first insulation slit), 5B. Is a divided electrode, 6 is a fuse (first fuse), 7 is an electrode lead-out connection portion, and 8 is an insulation margin. A1 and A2 are large-area electrode array regions continuously developed along the film longitudinal direction X, and B1 and B2 are a plurality of divisions formed by insulating slits 4 arranged at predetermined intervals in the film longitudinal direction X. A small-area electrode array region having electrodes 5B, a set (A1, B1) of a large-area electrode array region A1 and a small-area electrode array region B1, and a set of a large-area electrode array region A2 and a small-area electrode array region B2. (A2, B2) are arranged along the film width direction Y. In this example, the repeated arrangement of the set of the large area electrode row region and the small area electrode row region is two rows. Large-area electrode array regions on both sides in the film width direction Y in a state where each divided electrode 5B of the small-area electrode array region B1 in the middle in the film width direction Y passes through the fuses 6 and 6 by the metal vapor deposition film at the cut of the insulating slit 4 It is electrically connected to A1 and A2. That is, the large area electrode array areas A1 and A2 are on both sides in the film width direction Y with respect to the small area electrode array area B1, and each divided electrode 5B is connected to the fuse 6 with respect to the large area electrode array areas A1 and A2 on both sides. , 6 are electrically connected. Further, the large-area electrode array on one side in the film width direction Y in a state where each divided electrode 5B of the small-area electrode array region B2 located at the end in the film width direction Y passes through the fuse 6 by the metal vapor deposition film at the cut of the insulating slit 4 It is electrically connected to the region A2. That is, the large area electrode array area A2 is only on one side in the film width direction Y with respect to the small area electrode array area B2, and each divided electrode 5B is connected to the large area electrode array area A2 on one side via the fuse 6. Electrically connected.

  The deposited electrode 3 having a pattern having two sets (A1, B1) and (A2, B2) of the set of the large area electrode array region and the small area electrode array region as described above is formed on the dielectric film 2. And such a vapor deposition electrode 3 is formed in at least one side of the dielectric film 2, and the metallized film 1 is comprised by this.

  In the metallized film 1 shown in FIGS. 6 and 7, an electrode lead connection portion 7 to which an electrode lead portion (metallicon) is connected is formed at one end edge in the film width direction Y, and an insulating margin 8 is provided at the other end edge. Is formed. The insulating slits 4 arranged at a constant pitch along the film longitudinal direction X on the insulating margin 8 side of the metallized film 1 are formed in a Y shape, and the base end portion of the Y-shaped insulating slit 4 is an insulating margin 8. It is connected to the. In the middle of the film width direction Y, the insulating slits 4 arranged in parallel with the arrangement direction of the Y-shaped insulating slits 4 at the same pitch as the Y-shaped insulating slits 4 are formed in a Mueller-Rear shape. ing. The so-called Müller-Rear shape is a shape having inward arrow blades at both ends of a line segment of a predetermined length. The small-area electrode array region B1 has a plurality of divided electrodes 5B in which vapor-deposited electrode films are divided and formed by Mueller-Rear-shaped insulating slits 4. The small area electrode array region B2 has a plurality of divided electrodes 5B in which vapor-deposited electrode films are dividedly formed by Y-shaped insulating slits 4.

  In addition, a large area electrode array area A1 in which vapor deposition electrode films are continuous in the film longitudinal direction X is adjacently disposed on the electrode lead-out connection portion 7 side of the small area electrode array area B1, and an insulation margin of the small area electrode array area B1. On the 8th side (between the small area electrode array area B1 and the small area electrode array area B2), the large area electrode array area A2 is disposed adjacently.

  The divided electrodes 5B in the small area electrode array region B1 are connected to the large area electrode array region A1 via the fuse 6 on the electrode lead-out connection portion 7 side, and are connected to the large area electrode array region via the fuse 6 on the insulating margin 8 side. Connected to A2. The divided electrodes 5B in the small area electrode array region B2 are connected to the large area electrode array region A2 via the fuse 6 on the electrode lead-out connection portion 7 side.

  The metallized film 1 having such a configuration is wound or laminated to form a metallized film multilayer body (columnar body having an oval cross section), and electrode lead portions (metallicons) are formed on both end faces of the metallized film multilayer body. Connected to form a metalized film capacitor element (see, for example, Patent Document 2).

  In the metallized film 1 for a capacitor element having such a configuration, for example, when dielectric breakdown occurs in the divided electrode 5B in the small area electrode array region B1, the large area electrode array regions A1 and A2 are connected via the fuses 6 and 6 on both sides. A large current flows into the divided electrode 5B where the dielectric breakdown has occurred. As a result, the fuses 6 and 6 on both sides operate (vapor deposition metal scatters), and the divided electrode 5B that has caused the dielectric breakdown is separated from the large-area electrode array regions A1 and A2. Therefore, according to this metallized film 1 for a capacitor element, high safety can be ensured.

JP 2005-12082 A JP 2010-182848 A

  In the metallized film for a capacitor element, the withstand voltage performance is improved by reducing the area of the divided electrodes. As one of the methods, when a set of a large area electrode array region and a small area electrode array area as shown in Patent Document 2 is used as a partition unit, and the entire electrode surface is composed of a plurality of partition units, the partition unit is a film. There is a structure in which multiple columns are arranged in the width direction. That is, it is a pattern in which a set of large area electrode array regions and small area electrode array regions is alternately repeated in the width direction. In order to reduce the area of the divided electrodes in order to improve the withstand voltage performance, it is considered to increase the number of repetitions of the set of the large area electrode row region and the small area electrode row region in the film width direction. FIG. 8 is a plan view showing the structure of a metallized film proposed as an improvement in the conventional example shown in FIG. The number of sets of large area electrode array areas and small area electrode array areas is doubled from 2 sets to 4 sets, and the number of arrays of split electrodes along the film longitudinal direction X is also doubled. The area is getting smaller.

  As described above, since two fuses are associated with each divided electrode, in the improved pattern of the conventional example shown in FIG. 8, in the film width direction Y, the large-area electrode array region and the small-area electrode array region Each time the number of sets is increased by 1, the number of fuses (per unit row) increases by two. As shown in the figure, when the number of sets is increased from 2 sets to 4 sets, the number of fuses is increased by 4 from 2 · 2-1 = 3 to 2 · 4−1 = 7 in the film width direction. In general, when the number of sets is n, the number of fuses is (2n-1) in the film width direction. Further, in the film longitudinal direction X, when the number of divisions of the divided electrodes is doubled, the number of fuses is also doubled. As the number of fuses increases, there is a problem that the equivalent series resistance (ESR) of the capacitor increases.

  In addition, when the number of divisions in the film width direction is doubled, the number of insulating slits is also doubled, and the effective electrode area is reduced, so that there is a problem that miniaturization of the metallized film capacitor is hindered. Particularly, in the case of a metallized film capacitor for high voltage, since the insulating slit width is large, the effective electrode area is further reduced.

  The present invention was created in view of such circumstances, and with regard to a metallized film for a capacitor element, withstand voltage performance and safety performance while suppressing an increase in equivalent series resistance (ESR) and a decrease in effective electrode area. It aims to improve.

  The present invention solves the above problems by taking the following measures.

The metallized film for a capacitor element according to the present invention is:
A small area electrode array region developed in a relatively small area division state along the dielectric film longitudinal direction and a large area electrode array region developed in a continuous state or a relative large area division state along the dielectric film longitudinal direction Are repeatedly arranged along the dielectric film width direction,
In addition, in a state where each divided electrode of the small area electrode array region is interposed with the first fuse by the metal vapor deposition film at the cut of the first insulating slit, the large area electrode array region is on both sides of the small area electrode array region. In a certain state, the large-area electrode array region on both sides, and in the state where the large-area electrode array region is only on one side of the small-area electrode array region, Are connected to each other to form a vapor deposition electrode,
This vapor deposition electrode is formed on at least one side of the dielectric film,
In each divided electrode in the small area electrode array region, a second insulating slit and a second fuse are further arranged in the middle in the dielectric film width direction so that each divided electrode is formed into a pair of subdivided small electrodes. The pair of subdivided small electrodes in the dielectric film width direction are electrically connected via the second fuse ,
Furthermore, in the small area electrode array region sandwiched between the large area electrode array regions on both sides, the first fuse and the second fuse have the second fuse in relation to the size relationship of the fuse width. The fuse width is set to be equal to or smaller than the fuse width of the first fuse .

Here, the area of each divided electrode (small-area divided electrode) constituting the small-area electrode row region is smaller than the area of each divided electrode (large-area divided electrode) constituting the large-area electrode row region, By increasing the area ratio between the two, as will be described later, when dielectric breakdown occurs in a small-area divided electrode, the current flowing into the small-area divided electrode through the fuse increases, and the fuse operates reliably (the fuse is The vapor deposition electrode which comprises can be scattered). As a result, it is possible to recover the insulation by separating the small-area divided electrode from which the dielectric breakdown has occurred from other electrodes.

  The “first insulating slit” in the above configuration corresponds to the “insulating slit” in comparison with the conventional example, and the “first fuse” corresponds to the “fuse” in comparison with the conventional example. In the present invention, the terms “second insulating slit” and “second fuse” are used as new components, and are described as “first insulating slit” and “first fuse” in order to distinguish them from these. doing.

  In the metallized film for a capacitor element of the present invention configured as described above, in order to reduce the area of the divided electrode, the divided electrode itself partitioned by the first insulating slit is newly added to the inside thereof. A pair of subdivided small electrodes is made by providing an insulating slit and a second fuse. The area of each subdivided small electrode is about one half of the area of the original divided electrode, and a reduction in area is realized. That is, when the dielectric breakdown occurs, the area of the electrode that is divided and invalidated due to the scattering of the deposited metal is reduced, so that the decrease in the capacitance is suppressed and the withstand voltage performance is improved.

  When a breakdown occurs in a subdivided small electrode, a fuse that allows current to flow from an electrode region adjacent to the subdivided small electrode is the first fuse at the boundary with the adjacent large area electrode array region. And a second fuse at the boundary with another adjacent subdivided small electrode.

  When the divided electrodes are subdivided to form a pair of subdivided small electrodes, the second fuse is not formed between the obtained pair of subdivided small electrodes, and both subdivided small electrodes are completely divided. If so, the current flowing into each subdivided small electrode is reduced, making it difficult for the fuse operation to occur at the time of dielectric breakdown, leading to a reduction in safety. Therefore, a second fuse is provided between the adjacent subdivided small electrodes, and current flows from the adjacent subdivided small electrode through the second fuse in the event of dielectric breakdown due to the presence of the second fuse. This makes it easy to cause a fuse operation. Current flows from the large area electrode array region through the first fuse to the subdivided small electrode that has caused breakdown, and current flows from the adjacent subdivided small electrode through the second fuse. To do. Insulation can be recovered by separating the subdivided small electrodes of dielectric breakdown in both the first fuse portion and the second fuse portion.

  Also, as a measure to double the number of split type electrodes, the split electrode is divided into two (subdivided) inside itself, so the number of fuses to be increased should be only one per split electrode. Is possible. This can be halved compared to the increase in at least two fuses in the case of the conventional example in which the number of sets of the large area electrode array area and the small area electrode array area is doubled. Since the increase in the number of fuses can be suppressed in this manner, an increase in equivalent series resistance (ESR) can be suppressed and a temperature rise can be suppressed.

  Further, as a countermeasure for doubling the number of division type electrodes, the division electrode is divided into two (subdivided) inside itself, so that the number of insulating slits to be increased is only one per division electrode. It is possible. This can be reduced by a factor of four compared to an increase of at least four insulating slits in the case of the improvement of the conventional example in which the number of sets of the large area electrode array region and the small area electrode array region is doubled. As described above, since it is possible to suppress an increase in the number of insulating slits and, in turn, an increase in the area of the insulating slits, it is possible to suppress a decrease in the effective electrode area and to promote downsizing of the capacitor element.

In addition, in the configuration described above, the first fuse and the second fuse are set so that the fuse width of the second fuse is equal to or less than the fuse width of the first fuse. Yes.
In this way, by the configuration in which the fuse width of the first fuse facing the large area electrode array region having a large capacity is increased and the fuse width of the second fuse facing the adjacent subdivided small electrode having a small capacity is reduced, It is possible to ensure both the operation of separating the dielectric subdivided small electrodes from the large-area electrode array region and the operation of separating from the adjacent subdivided small electrodes.
By the above synergy, according to the present invention, with respect to the metallized film for the capacitor element, the increase of the equivalent series resistance (ESR) and the decrease of the effective electrode area are suppressed, and the withstand voltage performance and the safety performance are improved. Is possible.

As a preferable aspect in the above configuration , the second insulating slit is formed so as to extend in the longitudinal direction of the dielectric film, and the second insulating slit is cut at the center in the longitudinal direction of the dielectric film of each divided electrode. And the second fuse is formed by a metal vapor deposition film at the cut.

  Furthermore, as another preferred embodiment, the vapor deposition electrode is made of aluminum, zinc, or an alloy thereof, and the electrode thickness of the electrode lead-out connecting portion is configured to be thicker than the electrode thickness in other regions. is there. If comprised in this way, the connection reliability of an electrode drawer connection part and an electrode drawer part will become high.

  Furthermore, the metallized film capacitor according to the present invention is a metallized film capacitor in which two metallized films for any of the capacitor elements described above are overlapped to form a pair of metallized films. All of the large area electrode array regions in one metallized film are configured to face the subdivided small electrodes in the other metallized film.

According to the present invention, with respect to the metallized film for the capacitor element, each divided electrode in the small area electrode array region is divided inside itself to form a pair of subdivided small electrodes, and then both are connected to the second fuse. Since the fuse width of the second fuse is set to be equal to or smaller than the fuse width of the first fuse in the small area electrode array region, the increase in equivalent series resistance (ESR) and the effective electrode area are reduced . It is possible to improve the withstand voltage performance and the safety performance while suppressing the decrease.

The top view and sectional drawing which show the structure of the metallized film for capacitor | condenser elements in the Example of this invention The top view which expands and shows a part of metallized film in the Example of this invention. The top view which shows the metallized film of the two sheets overlaid in the Example of this invention The perspective view of the capacitor | condenser element using the metallized film concerning the Example of this invention The top view which shows the structure of the metallized film for capacitor elements in another Example of this invention. The top view which shows the structure of the metallized film for capacitor elements in a prior art example The top view which expands and shows a part of metallized film in a prior art example The top view which shows the structure of the metallized film proposed as an improvement plan in a prior art example

  Hereinafter, the embodiment of the metallized film for a capacitor element of the present invention having the above-described configuration will be described in detail at the level of specific examples.

  1A is a plan view showing the structure of a metallized film for a capacitor element in an embodiment of the present invention, FIG. 1B is a cross-sectional view thereof, and FIG. 2 is an enlarged view of a part of the metallized film. It is a top view. Although the present embodiment naturally has a new configuration different from the improvement plan of the conventional example shown in FIG. 8, for the convenience of explanation, a configuration that follows the improvement plan of the conventional example will be described, and then a configuration unique to the present embodiment. (In other words, the second insulating slit indicated by reference numeral 4b and the second fuse indicated by reference numeral 6b, which are new components, will be referred to only in the latter half of the description).

  1 and 2, 1 is a metallized film, 2 is a dielectric film (showing a state where a part of the vapor deposition electrode is peeled off), 3 is a vapor deposition electrode made of metal such as aluminum, zinc or an alloy thereof, 4 Is a first insulating slit, 5B is a divided electrode, 5b is a subdivided small electrode, 6 is a first fuse, 7 is an electrode lead-out connection portion, 8 is an insulation margin, and A1 to A4 constitute a part of the vapor deposition electrode 3 The large-area electrode array regions B1 to B4 are small-area electrode array regions constituting the remaining part of the vapor deposition electrode 3. The metallized film 1 is obtained by patterning a vapor deposition electrode 3 on the surface of a dielectric film 2. The vapor deposition electrode 3 is composed of a set (A1, B1), (A2, B2), (A3, B3), (A4, B4) of four rows of large area electrode rows and small area electrode rows. . A1 is the first large-area electrode array region, B1 is the first small-area electrode array region, and these are a set of the first large-area electrode array region / small-area electrode array region (A1, B1) Configure. A2 is the second large-area electrode array region, B2 is the second small-area electrode array region, and these are a set of the second large-area electrode array region / small-area electrode array region (A2, B2) Configure. A3 is the third large-area electrode array region, B3 is the third small-area electrode array region, and these are a set of the third-area large-area electrode array region / small-area electrode array region (A3, B3) Configure. A4 is the fourth large-area electrode array region, B4 is the fourth small-area electrode array region, and these are a set of the fourth-area large-area electrode array region / small-area electrode array region (A4, B4) Configure. In this example, the repeated arrangement of the set of the large area electrode row region and the small area electrode row region is four rows.

  The second, third, and fourth large area electrode array regions A2, A3, and A4 have the same configuration. The first large-area electrode array region A1 includes an electrode lead-out connection portion 7 for connecting a metal spray electrode (metallicon) at one end edge in the film width direction Y of the metallized film 1. This electrode lead-out connection portion 7 is a region that is continuously developed along the film longitudinal direction X at one end edge in the film width direction Y of the dielectric film 2 (the conductive film elongated in the lateral direction outside the broken line in FIG. 1). Body region), which is integrally connected to the first large-area electrode array region A1. As shown in FIG. 1B, the electrode lead-out connecting portion 7 has a thicker electrode than the other region of the vapor deposition electrode 3. For this reason, the connection reliability between the electrode lead-out connecting portion 7 and the electrode lead-out portion (metallicon) is high. This thick electrode lead-out connection portion 7 is called a heavy edge portion, and the other thin region of the vapor deposition electrode 3 is called an active portion.

  The first, second, and third small-area electrode column regions B1, B2, and B3 have the same configuration. In these three small area electrode array regions B1, B2, B3, the first insulating slit 4 is formed in a so-called Mueller-Rear shape. That is, the first insulating slit 4 has a shape having inward arrow blades at both ends of a line segment having a predetermined length. In the fourth small-area electrode array region B4, the first insulating slit 4 is formed in a Y shape (a shape in which an inward arrow blade on one end side is missing in the Mueller-Rear shape). The fourth small-area electrode array region B4 has the first insulating slit 4 connected to the insulating margin 8 at the other edge in the film width direction Y of the metallized film 1. The insulation margin 8 is an insulating region that is elongated in the lateral direction and is continuously developed in the film longitudinal direction X at the other edge in the film width direction Y of the dielectric film 2. Other configurations are the same as those in the first to third rows. In FIG. 2, the third and fourth rows of small area electrode row regions B3 and B4 and the fourth row of large area electrode row region A4 are shown enlarged, but the first row and second row of small area electrode row regions A4 are shown. The pattern of the column regions B1 and B2 is the same as that of the third small-area electrode column region B3.

  The large area electrode array region Ai (i = 1, 2, 3, 4) is a region continuously developed along the film longitudinal direction X. The small-area electrode array region Bi (i = 1, 2, 3, 4) has a Mueller-Riya or Y-shape arranged in the film longitudinal direction X at a predetermined interval as in the conventional improvement plan as its basic configuration. This is a region having a plurality of divided electrodes 5B divided and formed by the first insulating slit 4. Each of the divided electrodes 5B has an elongated hexagonal shape or an elongated pentagonal shape (here, as a new configuration, the second insulating slit 4b to be formed in the middle portion in the film width direction Y is touched). Absent). A set of large area electrode array regions and small area electrode array regions (Ai, Bi) is repeatedly arranged along the film width direction Y. In the first to third small-area electrode row regions B1 to B3, each divided electrode 5B as a basic configuration is formed of a metal vapor deposition film at the cut of the first insulating slit 4 on both sides in the film width direction Y. Are electrically connected to the large-area electrode array regions Ai and Ai + 1 on both sides in a state through the first fuses 6 and 6. In the fourth area of the small-area electrode array region B4, each divided electrode 5B as the basic configuration has a first fuse 6 formed of a metal vapor deposition film at the cut of the first insulating slit 4 on one side in the film width direction Y. In this state, it is electrically connected to the large area electrode array region A4 on one side.

  And the vapor deposition electrode 3 which consists of 4 sets of the above large area electrode row area | regions and the small area electrode row area | regions as mentioned above is formed in the at least single side | surface of the dielectric film 2, and the metallized film 1 is comprised.

  The description of the configuration so far corresponds to the same configuration as the improvement of the conventional example shown in FIG. 8, but the present invention further adopts the following configuration. Hereinafter, a new configuration (second insulating slit 4b and second fuse 6b) in the present embodiment will be described.

  That is, each small-area electrode array region Bi (i = 1, 2, 3) is based on a plurality of divided electrodes 5B partitioned in the film longitudinal direction X by the first insulating slit 4 corresponding to the improvement plan of the conventional example. In the divided electrode 5B, the second insulating slit 4b and the second fuse 6b made of the metal vapor deposition film are further arranged in the middle in the film width direction Y, and each divided electrode 5B is arranged in the film width direction Y. A pair of subdivided small electrodes 5b, 5b divided into two, and a pair of subdivided small electrodes 5b, 5b in the film width direction Y are electrically connected via a second fuse 6b. It has become. The second insulating slit 4b is formed so as to extend in the film longitudinal direction X. The second insulating slit 4b has a cut at the center in the film longitudinal direction X of each divided electrode 5B, and is formed by a metal vapor deposition film at the cut. A second fuse 6b is formed. The second insulating slit 4 b protrudes short on both sides along the film longitudinal direction X at the center of a predetermined length of a line segment that forms the main body of the first insulating slit 4.

  As for the fuse width relationship between the first fuse 6 and the second fuse 6b, the fuse width W2 of the second fuse 6b is set to be equal to or smaller than the fuse width W1 of the first fuse 6 (W2 ≦ W1). In order to ensure the operation of separating the subdivided small electrode 5b that has caused dielectric breakdown from the large-area electrode array region Ai and the operation of disconnecting from the adjacent subdivided small electrode 5b, the fuse of the second fuse 6b is used. The width W2 is preferably smaller than the fuse width W1 of the first fuse 6 (W2 <W1), and the ratio of the fuse width W2 to the fuse width W1 is more preferably set to less than 0.7-1.

  Prepare two sheets of metallized film 1 composed of vapor deposition electrode 3 formed on dielectric film 2 as described above, and invert metallized films 1 and 1 of both sheets 180 ° as shown in FIG. In this state, the upper and lower layers are overlapped so that the electrode lead-out portion 7 of one metallized film does not overlap the vapor deposition electrode of the other metallized film. The fourth row of small area electrode array region B4 of the lower metallized film 1 faces the first large area electrode array region A1 along the side edge of the upper layer metallized film 1 immediately below. The electrode lead-out connection portion 7 faces the insulation margin 8. The second, third, and fourth large-area electrode array regions A2, A3, and A4 in the upper metallized film 1 are the third, second, and first arrays in the lower metallized film 1, respectively. Opposite the small area electrode array regions B3, B2, B1. In addition, the first, second, and third small-area electrode row regions B1, B2, and B3 in the upper metallized film 1 are the fourth, third, and second rows in the lower metallized film 1, respectively. Opposite the large-area electrode array regions A4, A3, and A2. The first large-area electrode array region A1 on the side edge of the lower metallized film 1 is directly below the fourth small-area electrode array region B4 of the upper metallized film 1. The insulation margin 8 faces the electrode lead connection 7. In short, the small area electrode array region in one metallized film faces the large area electrode array region in the other metallized film.

  Here, if the large area electrode array region in one metallized film and the large area electrode array region in the other metallized film face each other, there is a risk of short-circuit failure, so the large area electrode array region in one metallized film It is preferable that all face the small area electrode array region (a pair of subdivided small electrodes) in the other metallized film. From the viewpoint of avoiding the large area electrode array region in one metallized film and the large area electrode array region in the other metallized film facing each other, all of the large area electrode array regions in one metallized film May be opposed to the subdivided small electrode (one of a pair of subdivided small electrodes) in the other metallized film.

  In the state where the upper metallized film 1 and the lower metallized film 1 are overlapped as described above, as shown in FIG. 10 is wound and flattened into a long and narrow oval shape by a press as shown in the figure (the flatness ratio is 0.7 or more) to obtain a metallized film multilayer body 11. Furthermore, electrode lead portions (metallicons) 12 and 12 are formed by metal spraying at both ends in the axial direction of the metallized film multilayer body 11 to obtain a highly flattened metallized film capacitor element C. The electrode lead portions 12 and 12 are electrically connected to electrode lead connection portions 7 and 7 on both axial sides.

  In addition, there is also a type of capacitor element in which two layers of short metallized films 1 and 1 are stacked instead of winding the two long metallized films 1 and 1 as described above.

  As described above, in this embodiment, when the area of the divided electrode 5B is reduced, the divided electrode 5B itself partitioned by the first insulating slit 4 itself has a second insulating slit 4b and a second By providing the fuse 6b, a pair of subdivided small electrodes 5b and 5b are formed. The area of each subdivided small electrode 5b is about one half of the area of the original divided electrode 5B, and the area reduction is realized. As a result, when the dielectric breakdown of the subdivided small electrode 5b occurs, the electrode area that is divided and invalidated due to the scattering of the deposited metal is reduced as compared with the case of the original divided electrode 5B. Is suppressed, and the withstand voltage performance is improved.

  In addition, when doubling the number of split-type electrodes, it is divided into two (subdivided) inside the basic split electrode 5B itself, so that only one per split electrode 5B is provided for the increase of the second fuse 6b. The second fuse 6b can be increased. That is, the number of fuses can be reduced by half compared to an increase in at least two fuses in the conventional improvement plan (FIG. 8) in which the number of sets of large area electrode row areas and small area electrode row areas is doubled. Since the increase in the number of fuses can be suppressed in this way, an increase in equivalent series resistance (ESR) can be suppressed and a temperature rise can be suppressed.

  Further, when doubling the number of divided type electrodes, the number of second insulating slits 4b is increased per one divided electrode 5B because it is divided into two (subdivided) inside the basic divided electrode 5B itself. Only one is required. That is, the number of sets of large-area electrode array regions / small-area electrode array regions can be reduced by a factor of four compared to the increase in at least four insulating slits in the case of the improvement plan of the conventional example (FIG. 8). As a result, an increase in the number of the second insulating slits 4b and an increase in the area of the second insulating slits 4b are suppressed. That is, it is possible to suppress the reduction of the effective electrode area and to promote the miniaturization of the capacitor element.

  In the above-described embodiment, the fuse width W2 of the second fuse 6b is set to be equal to or smaller than the fuse width W1 of the first fuse 6, thereby further providing the following advantages.

  When a breakdown occurs in a certain subdivided small electrode 5b, a fuse that allows current to flow from an electrode region adjacent to the subdivided small electrode 5b is adjacent to the large area electrode array region Ai (i = 1, 2). ..)) And the second fuse 6b at the boundary between the adjacent subdivided small electrode 5b. When the divided electrode 5B is subdivided to form the subdivided small electrodes 5b, 5b, the second fuse 6b is not formed between the obtained pair of subdivided small electrodes 5b, 5b, and both subdivided small electrodes 5b are formed. Assuming that the electrodes 5b and 5b are completely divided, the energy of the individual subdivided small electrodes 5b is reduced due to the area reduction, and it becomes difficult for the fuse operation to occur at the time of dielectric breakdown, leading to a reduction in safety. To do. This phenomenon appears more prominently at higher temperatures. Therefore, in order to receive energy from the adjacent subdivided small electrodes 5b to easily cause a fuse operation, a cut is made in the second insulating slit 4b between the adjacent subdivided small electrodes 5b and 5b, and the second insulating slit 4b is used as the second insulating slit 4b. Fuse 6b. A current flows from the large-area electrode array region Ai (i = 1, 2,...) Through the first fuse 6 to the subdivided small electrode 5b that has caused breakdown, and the adjacent subdivided small electrode Current flows from 5b through the second fuse 6b. Insulation is recovered by cutting off the dielectric breakdown sub-electrode 5b in both the first fuse 6 and the second fuse 6b. Here, the fuse width W1 of the first fuse 6 facing the large area electrode array region Ai (i = 1, 2,...) Having a large capacity is increased, and the second width facing the adjacent subdivided small electrode 5b having a small capacity. Since the fuse width W2 of the fuse 6b is reduced, the operation for separating the dielectric breakdown sub-electrode 5b from the large-area electrode array region Ai (i = 1, 2,...) And the operation for separating the adjacent sub-segment sub-electrode 5b are performed. It is possible to ensure both.

  The configuration of the large area electrode array region Ai (i = 1, 2,...) May be configured as shown in FIG. That is, along the film longitudinal direction X, it is divided into a plurality of divided electrodes 5A in a relatively large area divided state with a pitch larger than the pitch of the divided electrodes 5B in the small area electrode array region Bi (i = 1, 2,...). Has been. Specifically, the second, third and fourth large-area electrode array regions A2, A3 and A4 are partitioned in the film longitudinal direction X by linear insulating slits 4c extending in the film width direction Y. The pitch of the linear insulating slits 4c is larger than the pitch of the first insulating slits 4 in the small area electrode array region Bi. Here, as an example, 6 pitches of the divided electrodes 5B correspond to 1 pitch of divided electrodes 5A. The linear insulating slit 4c is formed as an extension of the central line of the first insulating slit 4 (not limited to this). The arrangement of the linear insulating slits 4c is shifted by 3 pitches of the divided electrodes 5B in the second row and the third row, and also by 3 pitches of the divided electrodes 5B in the third row and the fourth row. It's off. As a result, the second and fourth columns are in phase. The arrangement of the linear insulating slits 4c is not limited to this. The first large-area electrode array region A1 is a continuous region in the film longitudinal direction X, as in the previous example.

  The area of the divided electrode 5A may be other than the above, and the minimum area may be larger than the area of one subdivided small electrode 5b, and more preferably the total area of the pair of subdivided small electrodes 5b and 5b. Bigger is better.

  In summary, with respect to the metallized film for the capacitor element, each divided electrode 5B in the small-area electrode array region Bi (i = 1, 2,...) Is divided inside itself, and a pair of subdivided small electrodes 5b, 5b is obtained. Since both are connected via the second fuse 6b, the withstand voltage performance and the safety performance are improved while suppressing an increase in equivalent series resistance (ESR) and a decrease in effective electrode area. Can be made.

  INDUSTRIAL APPLICATION This invention is useful as a technique which suppresses the increase in equivalent series resistance (ESR) and the reduction | decrease of an effective electrode area, regarding improving the withstand voltage performance and safety | security performance regarding the metallized film for capacitor elements.

DESCRIPTION OF SYMBOLS 1 Metallized film 2 Dielectric film 3 Vapor deposition electrode 4 1st insulation slit 4b 2nd insulation slit 5B Divided electrode 5b Subdivided small electrode 6 1st fuse 6b 2nd fuse 7 Electrode extraction connection part 8 Insulation margin Ai (I = 1, 2,...) Large area electrode array region Bi (i = 1, 2,...) Small area electrode array region X Dielectric film longitudinal direction Y Dielectric film width direction

Claims (4)

A small area electrode array region developed in a relatively small area division state along the dielectric film longitudinal direction and a large area electrode array region developed in a continuous state or a relative large area division state along the dielectric film longitudinal direction Are repeatedly arranged along the dielectric film width direction,
In addition, in a state where each divided electrode of the small area electrode array region is interposed with the first fuse by the metal vapor deposition film at the cut of the first insulating slit, the large area electrode array region is on both sides of the small area electrode array region. In a certain state, the large-area electrode array region on both sides, and in the state where the large-area electrode array region is only on one side of the small-area electrode array region, Are connected to each other to form a vapor deposition electrode,
This vapor deposition electrode is formed on at least one side of the dielectric film,
In each divided electrode in the small area electrode array region, a second insulating slit and a second fuse are further arranged in the middle in the dielectric film width direction so that each divided electrode is formed into a pair of subdivided small electrodes. The pair of subdivided small electrodes in the dielectric film width direction are electrically connected via the second fuse ,
Furthermore, in the small area electrode array region sandwiched between the large area electrode array regions on both sides, the first fuse and the second fuse have the second fuse in relation to the size relationship of the fuse width. A metallized film for a capacitor element, wherein the fuse width is set to be equal to or smaller than the fuse width of the first fuse . The second insulating slit is formed so as to extend in the longitudinal direction of the dielectric film, and the second insulating slit has a cut at the center of the divided film in the longitudinal direction of the dielectric film, and the metal vapor deposition film at the cut The metallized film for a capacitor element according to claim 1, wherein the second fuse is formed by: 3. The capacitor element according to claim 1 , wherein the vapor deposition electrode is made of aluminum, zinc, or an alloy thereof, and the electrode thickness of the electrode lead-out connection portion is thicker than the electrode thickness in the other region . Metallized film. In a metallized film capacitor in which two metallized films for a capacitor element according to any one of claims 1 to 3 are overlapped to form a pair of metallized films,
The metallized film capacitor characterized in that all of the large area electrode array regions in one metallized film of the pair of metallized films are opposed to the subdivided small electrodes in the other metallized film .

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