JP2017191823A - Metalized film capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain superior total evaluation of a metallized film capacitor by making a metallized film thin and also reducing the size of the metallized film capacitor compact while letting the metallized film capacitor have higher voltage resistance, safety, heating characteristics, and moisture resistance.SOLUTION: A metalized film capacitor comprises a capacitor element having metal electrodes 3p, 3n formed at both axial ends by superposing metallized films, and an anode-side and a cathode-side external lead-out terminal connected to the respective metal electrodes of the capacitor element. A first metallized film F1 has a first electrode pattern P1 having its metal vapor-deposited electrode 2p divided and interconnected through a fuse part 2p, and is connected to the anode-side external lead-out terminal. A second metallized film F2 has a second electrode pattern having its metal vapor-deposited electrode 2n left continuous in a non-division state or divided to larger area than the first metallized film F1, and also has a larger film resistance value than the first metallized film F1, and is connected to the cathode-side external lead-out terminal.SELECTED DRAWING: Figure 1

Description

  The present invention provides a capacitor element in which a pair of metallized films on which a metal vapor-deposited electrode is formed on a dielectric film are superimposed, and a metal electrode is formed on each of one end and the other end in the axial direction, and the capacitor element The present invention relates to a metallized film capacitor comprising an anode side and a cathode side external lead terminal connected to each of the metal electrodes.

  Recently, when a capacitor is downsized, it is strongly required to reduce the thickness of the dielectric film (thinning). In this case, while reducing the thickness of the dielectric film, both the withstand voltage performance and the safety performance (self-healing) of the capacitor must be equal to or better than those of the conventional film thickness capacitor. That is, from the viewpoint of the same thickness, it is desired to further increase the withstand voltage compared to the conventional case.

The main approach for realizing high withstand voltage of capacitors is as follows:
(1) Increase in dielectric strength of dielectric film materials (2) Increase in voltage resistance of capacitor elements by optimization of vapor deposition specifications (deposition pattern / deposition film resistance) can be mentioned.

  In the present application, the dielectric strength of the capacitor is increased while using a conventional dielectric film material. That is, the withstand voltage of the capacitor is increased by the approach (2). Here, the optimization of the vapor deposition film resistance value of (2) specifically indicates an increase in the film resistance of the vapor deposition film resistance, and the voltage resistance of the capacitor element is increased by increasing the film resistance of the vapor deposition film resistance value. It is self-evident that

  However, increasing the deposited film resistance value is accompanied by an increase in the equivalent series resistance (ESR) of the capacitor element. Since the heat generation temperature of the capacitor element may increase when a ripple current is applied, a simple increase in film resistance of the deposited film resistance value does not easily solve the problem.

  The metal electrodes respectively formed at one end and the other end in the axial direction of the capacitor element are respectively connected to the external lead terminal on the anode side and the external lead terminal on the cathode side. The metal vapor deposition electrode connected to the external lead terminal on the anode side becomes an anode electrode film, and the metal vapor deposition electrode connected to the external lead terminal on the cathode side becomes a cathode electrode film.

  Here, in the moisture resistance load test, there is a problem of electrode disappearance due to an anodic oxidation reaction (oxidation of the anode electrode film) that occurs when a voltage is applied in a high temperature and high humidity atmosphere.

  In other words, the above-mentioned film resistance increase of the deposited film resistance is intended to be realized by reducing the thickness of the deposited metal. However, if the thickness of the deposited film exceeds a certain limit, the electrode disappearance due to the anodic oxidation reaction is rather conventional. Another problem arises that it occurs in a shorter time, leading to deterioration of moisture resistance.

  The above is a problem regarding the withstand voltage performance, but there is another safety problem.

  In metallized film capacitors for applications that require sufficiently high safety (for example, HV, industrial equipment, railway vehicles, etc.), a segmented electrode that is generally accompanied by a fuse part mechanism (security mechanism) is used as the electrode pattern of the metal deposition electrode. A pattern is used. A number of deposition patterns with a security mechanism have been developed so far, but roughly divided into the following three types.

  (1) A type in which a pair of patterns in which a divided electrode is formed on the entire surface of one dielectric film is a pair (see, for example, Patent Document 1).

  (2) A type in which two dielectric films and non-divided electrodes are laid out in a single dielectric film to form a pair (see, for example, Patent Document 2).

  (3) A type in which the entire surface of one dielectric film is a divided electrode and the entire surface of the other dielectric film is a non-divided electrode to form two pairs (for example, see Patent Document 3).

  In the above, the film resistance values of the two opposing electrode patterns are often the same.

  By the way, the fuse unit mechanism is a necessary element for ensuring safety. However, since the fuse unit has a higher resistance than the electrode unit, the fuse unit mechanism has a heat generation temperature of the capacitor element. Leading to a rise.

  In summary, increasing the voltage resistance of a capacitor is contradictory to the deterioration of heat generation characteristics and moisture resistance from the viewpoint of ensuring safety. That is, there is a trade-off relationship between increasing the withstand voltage, ensuring safety, improving heat generation characteristics, and improving moisture resistance.

  The following three examples can be cited as examples of improving the vapor deposition pattern and the vapor deposition film resistance value, but none of them satisfy the four characteristics of withstand voltage performance, safety, heat generation characteristics, and moisture resistance performance.

  (1) As a problem of anodic oxidation, there is one in which the film resistance value differs between the first metallized film and the second metallized film. That is, a film having a difference in height between the film resistance values of two films to achieve both moisture resistance and safety is known (for example, see Patent Document 4). In this technique, the film resistance value of the metal vapor deposition electrode of the first metallized film is different from the film resistance value of the metal vapor deposition electrode of the second metallized film. In other words, the film resistance value of the metal deposition electrode on the anode side is set smaller than the film resistance value of the metal deposition electrode on the cathode side. If the material of the metal vapor deposition electrode is the same on the anode side and the cathode side, the magnitude of the film resistance value is determined by the magnitude of the film thickness. That is, the larger the film thickness, the smaller the film resistance value. That the film resistance value of the metal vapor deposition electrode on the anode side is smaller means that the film thickness of the metal vapor deposition electrode is larger. The anode-side metal vapor deposition electrode having a large film thickness has a slow anodic oxidation progress, and the improvement in moisture resistance is recognized.

  (2) In an internal series type, a film resistance value is provided with a height difference so that it can withstand the use of a large current (see, for example, Patent Document 5). In this technique, a first electrode pattern composed of divided electrodes (island electrodes) is formed on a first metallized film, and a second electrode having a large area in a non-divided state is formed on a second metallized film. A pattern is formed. In the first metallized film, the split electrode on one end side in the film width direction is connected to the anode side, and the split electrode on the other end side is connected to the cathode side. Capacitance is formed between the second electrode pattern (large area) on the low potential side and the divided electrode on the anode side, and the same second electrode pattern is set on the high potential side with the divided electrode on the cathode side. Capacitance is also formed between them, and both capacitances are connected in series (internal series type). The film resistance value of the first electrode pattern (the anode side and the cathode side) is set smaller than the film resistance value of the second electrode pattern. The contact failure between the metal electrode and the split electrode at the axial end of the capacitor element is detected, and the contact failure is detected by the lack of the capacitance. Thus, it can withstand the use of a large current.

  (3) There is known one in which one is a divided electrode and the other is a safety electrode, and a difference in height is provided in the membrane resistance value to achieve both safety and reduced heat generation (see, for example, Patent Document 6). In this technique, both the first metallized film and the second metallized film are composed of two metallized film elements (4, 4) (the reference numerals in parentheses are those described in the patent literature). These two metallized film elements have different electrode patterns from each other. One metallized film element has a metal vapor deposition electrode pattern formed by a set of a plurality of island-shaped divided electrode portions (6a), and the other metallized film element has a metal vapor deposition electrode pattern linear. It is formed of a set of safety electrode portions (9a, 9b). These two metallized film elements are superposed to form one metallized film. The linear safety electrode portions (9a, 9b) are arranged so as to cross the divided electrode portions (6a), and both are in contact with each other to form one metal vapor deposition electrode. The metallized film on the anode side and the metallized film on the cathode side are similarly configured. With this configuration, both the first metallized film and the second metallized film can make the film resistance value of the safety electrode part different from the film resistance value of the divided electrode part. That is, it is possible to easily make the film resistance values of the divided electrode portion and the safety electrode portion different from each other.

  The divided electrode part increases the film thickness to reduce the film resistance value to suppress heat generation during energization, while the safety electrode part reduces the film thickness to increase the film resistance value to ensure safety. Has improved.

Japanese Patent Laid-Open No. 11-26281 JP 2005-12082 A JP 2004-200508 A JP 2014-49711 A Japanese Unexamined Patent Publication No. 7-57955 JP 2011-29555 A

  In the technique of the above-mentioned Patent Document 4, the film resistance value of the metal deposition electrode on the anode side is made smaller than the film resistance value of the metal deposition electrode on the cathode side. This is the same on the cathode side, and both are divided electrode patterns. In the sense that the film resistance value of the metal deposition electrode on the cathode side is relatively large, the metal deposition electrode pattern is effective in increasing the withstand voltage during normal energization, but the pattern of the metal deposition electrode is the first metallized film and the second metallization. Since the film is the same, in order to exert a predetermined effect in a security mechanism composed of a plurality of divided electrodes and fuse portions, both metallized films have a larger number of divided electrode portions and therefore the number of fuse portions than a certain level. There is a need to.

  However, with such a configuration, increasing the film resistance value to increase the withstand voltage during normal energization as described above causes an increase in the heat generation temperature of the capacitor element and causes deterioration in moisture resistance performance. Become.

  In the technique of Patent Document 5, although there is a concept of increasing the film resistance value to promote heat generation suppression and improving the safety performance, the relationship between increasing the film resistance value and the polarity of the anode / cathode The relationship with the electrode property and the electrode pattern has not been studied. As a result, it is difficult to solve the problem of deterioration of moisture resistance performance associated with anodization.

  In the technique of Patent Document 6, both the first metallized film and the second metallized film have a complicated form in which two vapor deposition electrode elements having different electrode patterns are overlapped. Although one vapor deposition electrode element and the other vapor deposition electrode element have different film resistance values, both the vapor deposition electrode elements are present in the same metallized film, and the first metallized film and the second metallized film. Thus, the membrane resistance values are considered to be equal to each other. In short, there is no mention of adopting a special configuration regarding the difference in film resistance between the two metallized films and the correlation between the polarity of the anode and the cathode and the electrode pattern.

  The present invention has been created in view of such circumstances, and with respect to a metallized film capacitor, while satisfying high voltage resistance, safety, heat generation characteristics and moisture resistance, the metallized film is thinned and thus metallized film. The objective is to achieve a compact capacitor and to achieve excellent overall evaluation.

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

The metallized film capacitor according to the present invention is:
Capacitor element in which a metal vapor-deposited electrode is formed on a dielectric film, and the first metallized film and the second metallized film are superposed and a metal electrode is formed at one end and the other end in the axial direction. A metallized film capacitor comprising anode-side and cathode-side external lead terminals connected to the respective metal electrodes of the capacitor element,
The first metallized film has a first electrode pattern in which the metal vapor deposition electrodes are divided and connected to each other via a fuse portion, and is connected to the external lead terminal on the anode side,
On the other hand, the second metallized film has a second electrode pattern in a non-divided state in which the metal vapor deposition electrode is continuous or in a state of being divided in a larger area than the metal vapor deposition electrode of the first metallized film. And the film resistance value is larger than the film resistance value of the metal vapor deposition electrode of the first metallized film and is connected to the external lead terminal on the cathode side.

  In other words, the electrode pattern of the first metallized film is such that the metal vapor deposition electrode is a divided electrode having a large number of divisions and a small area, has a small membrane resistance value, and is on the anode side. In the electrode pattern of the second metallized film, the metal vapor deposition electrode is composed of a divided electrode with a small number of divisions or a non-divided electrode with a division number of zero, and has a large membrane resistance value, and the cathode side It has become. In other words, the second electrode pattern is in an undivided continuous state or divided into a plurality of areas, but each area is larger than the area of the divided electrodes of the first electrode pattern.

  The metallized film capacitor of the present invention having the above configuration exhibits the following action.

  In the second metallized film, since the film resistance value is large, it is possible to achieve a higher withstand voltage during normal energization than in the case where the film resistance value is small. In addition, in the second metallized film, the number of fuse portions having a large energization resistance value compared to the film-shaped electrode portion is small, if any, so that the film-shaped electrode as described above. Even if the film resistance value of the part is increased (even if the film resistance is increased), the heat generation of the capacitor element can be suppressed.

  And in the 1st metallized film, while making the membrane resistance value of the divided electrode of a small area small, while suppressing the heat_generation | fever at the time of normal electricity supply, security performance is increased by increasing the number of fuse parts. It becomes possible to make it excellent. Furthermore, in the metal vapor deposition electrode of the first metallized film, the film resistance value is reduced, so that the electrode disappearance due to the anodic oxidation reaction is prevented and the heat generation suppression during normal energization is coupled with excellent moisture resistance performance. It becomes possible to make things.

  Through the above synergies, it is possible to reduce the thickness of the metallized film and hence the size of the metallized film capacitor while satisfying high voltage resistance, safety, heat generation characteristics, and moisture resistance.

In the metallized film capacitor of the present invention having the above configuration,
[1] Regarding the film thickness of the first and second electrode patterns, the film thickness of the first electrode pattern is greater than the film thickness of the second electrode pattern, whereby the second electrode There is an aspect in which the film resistance value of the pattern is made larger than the film resistance value of the first electrode pattern.

  [2] Further, there is an aspect in which the first and second electrode patterns are made of the same material.

  With this configuration, the film resistance value can be easily adjusted.

  According to the present invention, it is possible to reduce the thickness of the metallized film and thus reduce the size of the metallized film capacitor while satisfying high voltage resistance, safety, heat generation characteristics, and moisture resistance.

FIG. 2A is a development view of a first metallized film showing the configuration of a metallized film capacitor in an embodiment of the present invention, and shows a structure of superposition by winding the first and second metallized films. Sectional view (b) FIG. 2A is a development view of a second metallized film showing the configuration of a metallized film capacitor in an example of the present invention, and shows a structure of superposition by winding the first and second metallized films. Sectional view (b) (reprinted from FIG. 1 (b)) The perspective view which shows the external appearance of the metallized film capacitor in the Example of this invention

  Hereinafter, the embodiment of the metallized film capacitor of the present invention described above will be described in detail at the level of specific examples.

  1 to 3 relate to a metallized film capacitor according to an embodiment of the present invention, FIG. 1 (a) is a development view of a first metallized film in the capacitor, and FIG. Sectional drawing which shows the structure of the superposition by winding of two metallized films, Fig.2 (a) is a development view of the second metallized film, Fig.2 (b) is a reprint of Fig.1 (b), FIG. 3 is a perspective view showing the appearance of the metallized film capacitor. In these drawings, for the convenience of distinguishing the anode side and the cathode side on the sign, “p” is added to the anode side after the numerical value of the sign, and the cathode side is shown. “N” is added to the symbol.

  1 to 3, reference numeral 1 denotes a dielectric film such as polypropylene (PP) (shown with a part of a metal vapor-deposited electrode removed), 2p and 2n denote metal vapor-deposited electrodes on the anode side and the cathode side, and F1 and F2 Are first and second metallized films, 3p and 3n are metal electrodes on the anode and cathode sides, 4 is a capacitor element, and 5p and 5n are external lead terminals on the anode and cathode sides.

  As shown in the development view of FIG. 1, a metal deposition electrode 2p on the anode side is formed with a predetermined pattern (described later) on one surface (upper surface) of the dielectric film 1 to form a first metallized film F1. . Further, as shown in the development view of FIG. 2, a metal deposition electrode 2n on the cathode side is similarly formed on one surface (upper surface) of the dielectric film 1 with another predetermined pattern (described later) to form a second metallized film F2. Is configured.

  As shown in FIGS. 1 (b) and 2 (b), the first and second pair of metallized films F1 and F2 are wound together (stacked) in a superimposed state and are shown in FIG. Thus, the capacitor element 4 is formed by deforming into a columnar body having an oval cross section, and forming anode-side and cathode-side metal electrodes 3p, 3n at both ends in the axial direction (same as the film width direction Y). . The metal electrodes 3p and 3n at both ends in the axial direction Y of the capacitor element 4 having a flat columnar body are formed as metal spray electrodes (metallicons) by spraying metal fine particles. An outer film 6 for protecting the dielectric film is wound around the outermost layer of the capacitor element 4 a plurality of times.

The electrode lead-out connection 2p ₃ in the anode-side metal vapor deposition electrode 2p is connected to the anode-side metal electrode 3p, and the electrode lead-out connection 2n ₃ in the cathode-side metal vapor deposition electrode 2n is connected to the cathode-side metal electrode 3n. Is connected.

  1 and 2, the anode-side and cathode-side metal electrodes 3p and 3n indicated by broken lines only indicate their arrangement positions, and do not represent actual shapes. The shape is a flat oval shape as shown in FIG. In FIG. 1B and FIG. 2B, two layers are extracted from the cross-sectional state in which the first and second pairs of metallized films F1 and F2 are overlapped. Yes. There are four layers of dielectric film 1 shown in white, two layers of metal deposition electrode 2p on the anode side shown in black, and two layers of metal deposition electrode 2n on the cathode side. The overlapping state of the metal vapor deposition electrodes alternates between the anode side, the cathode side, the anode side, and the cathode side. Needless to say, the dielectric film 1 is sandwiched between the metal deposition electrode 2p on the anode side and the metal deposition electrode 2n on the cathode side to form a capacitance.

  The metal electrode 3p on the anode side connected to the metal vapor deposition electrode 2p in the first metallized film F1 among the metal electrodes 3p and 3n at both ends in the axial direction is connected to the external lead terminal 5p on the anode side as shown in FIG. Has been. Further, the metal electrode 3n connected to the cathode-side metal vapor deposition electrode 2n in the second metallized film F2 is connected to the cathode-side metal vapor deposition electrode 5n as shown in FIG. That is, the metal vapor deposition electrode 2p in the first metallized film F1 is configured as an anode, and the metal vapor deposition electrode 2n in the second metallized film F2 is configured as a cathode.

  Next, the first electrode pattern P1 that is the pattern of the metal deposition electrode 2p on the anode side and the second electrode pattern P2 that is the pattern of the metal deposition electrode 2n on the cathode side will be described. The electrode pattern of the metal deposition electrode 2p on the anode side in the first metallized film F1 and the metal deposition electrode 2n on the cathode side in the second metallized film F2 are different from each other.

That is, as shown in FIG. 1A, the metal-deposited electrode 2p on the anode side of the first metallized film F1 has a smaller area than the electrode pattern (second electrode pattern P2) of the second metallized film F2. Are formed in a state of a first electrode pattern P1 having a large number of divided electrodes 2p ₁ divided by ₁ and a fuse portion 2p ₂ connecting adjacent divided electrodes 2p ₁ and 2p ₁ to each other. In addition, an electrode lead-out connection portion 2p _{3 for} connecting the anode-side metal deposition electrode 2p and the anode-side metal electrode 3p in a relay manner is formed at one end edge in the film width direction Y. The electrode lead-out connecting portion 2p ₃ is an elongated strip-like region outside the two-dot chain line.

The individual divided electrodes 2p ₁ in the first electrode pattern P1 will be described in more detail as follows. The individual divided electrodes 2p ₁ have a hexagonal shape (shown in black), and are arranged so that a large number of divided electrodes 2p ₁ develop in a honeycomb shape. One hexagonal divided electrode 2p ₁ is an insulation formed in a Y shape (one piece is equally opened by 120 °) in which three straight slits shown by white background are joined at each end. It is formed by being surrounded by three partial slits 2p _4. Surrounding are two of them that are 120 ° apart from each other.

There are two types of patterns in the three divided electrodes 2p ₁ , 2p ₁ , 2p ₁ that are adjacent to each other in a triangular shape. One is a pattern in which all three linear slits are coupled at the center of the three divided electrodes. The other is a pattern in which all three linear slits are separated at the center of the three divided electrodes. The remote center portion is formed of a metal vapor deposition electrode, and serves as a fuse portion 2p ₂ that connects three divided electrodes 2p ₁ , 2p ₁ , 2p ₁ adjacent to each other in a triangular shape. Therefore, all of the hexagonal divided electrodes 2p ₁ in the first electrode pattern P1 are integrally and continuously connected to each other via the fuse portion 2p _2, and the electrode lead-out connecting portion 2p ₃ that extends linearly at the edge is also used. Connected continuously.

On the other hand, as shown in FIG. 2A, in the metal deposition electrode 2n on the cathode side of the second metallized film F2, the metal deposition electrode formed over almost the entire surface of the dielectric film 1 remains continuous. It is formed on the second electrode pattern P2 in a non-divided state (a solid state spreading on one surface without a gap). The second electrode pattern P2 is a pattern in a state of being divided by an area larger than the electrode pattern (first electrode pattern P1) of the first metallized film F1 and connected to each other via a fuse portion. Also good. In addition, on the other edge in the film width direction Y, a cathode-side electrode lead-out connecting portion 2n ₃ that connects the cathode-side metal deposition electrode 2n and the cathode-side metal electrode 3n in a relay manner is formed. The electrode lead-out connecting portion 2n ₃ is an elongated strip-like region outside the two-dot chain line.

In the first metallized film F1, an insulation margin 2p ′ indicated by a white background in which no metal vapor deposition electrode is present is formed at the edge along the film longitudinal direction X opposite to the electrode lead-out connection portion 2p _{3 in the} film width direction Y. Is formed. Similarly, in the second metallized film F2, insulating margin indicated in the absence white metal deposition electrode edge along the longitudinal direction of the film X on the opposite side to the electrode lead connecting portions 2n ₃ in the film width direction Y 2n 'is formed.

As shown in FIG. 1B and FIG. 2B, all of the anode-side electrode lead-out connecting portions 2p ₃ including the first and third layers from the top are the anode-side metal electrode 3p. It is connected to the. Similarly, the cathode-side electrode lead-out connection portions 2n ₃ of the even-numbered phases starting with the second layer and the fourth layer are all connected to the cathode-side metal electrode 3n.

As described above, in the present invention,
(1) Differentiating the first electrode pattern P1 in the first metallized film F1 and the second electrode pattern P2 in the second metallized film F2 (one is a metal vapor-deposited electrode divided into a fuse part) Connected through the other, the other is a non-divided state in which the metal vapor deposition electrode remains continuous or a state divided by a larger area than the one metallized film),
(2) In addition to the one metal vapor deposition electrode as an anode and the other metal vapor deposition electrode as a cathode,
(3) The film resistance value of the first electrode pattern P1 and the film resistance value of the second electrode pattern P2 are made different (the film resistance value of the second metallized film F2 on the large area side is changed to the first value). Greater resistance (high resistance) than the membrane resistance value of the metallized film F1),
The combination of these three conditions is a feature. Hereinafter, the difference in the film resistance value of (3) will be described.

  Regarding the film resistance value of the metal vapor deposition electrode, the first electrode pattern P1 and the second electrode pattern P2 have a clear magnitude relationship. That is, the film resistance value in the first electrode pattern P1 is set to be smaller than the film resistance value in the second electrode pattern P2.

  There is no particular question about the technique used to distinguish between large and small membrane resistance values. In the case where the material of the metal vapor deposition electrode is the same (for example, both are made of aluminum), it is only necessary to give a difference in the film thickness. That is, the film thickness of the metal vapor deposition electrode 2p in the first electrode pattern P1 is made thicker, and the film thickness of the metal vapor deposition electrode 2n in the second electrode pattern P2 is made thinner. It should be noted that a difference in the film resistance value is made by changing the material (such as a combination of aluminum and zinc or a combination of aluminum and zinc) or by adjusting the combination of the material and the film thickness. May be.

  Incidentally, the film resistance value of the first electrode pattern P1 is preferably 10Ω / □ to 20Ω / □, and the film resistance value of the second electrode pattern P2 is preferably 20Ω / □ to 30Ω / □. Regarding the difference between the two film resistance values, when the film resistance value of the first electrode pattern P1 is 10Ω / □, the difference between the two film resistance values is 10Ω / □ to 20Ω / □ (second electrode pattern P2 The film resistance value is preferably set to 20Ω / □ to 30Ω / □, and more preferably set to around 15Ω / □ (the film resistance value of the second electrode pattern P2 is around 25Ω / □). This is because if the difference between the two film resistance values is too small, the voltage resistance deteriorates, and if the difference between the two film resistance values is too large, the safety and heat generation characteristics deteriorate. On the other hand, when the film resistance value of the second electrode pattern P2 is set to 20Ω / □, the difference in film resistance value between the two is 1Ω / □ to 10Ω / □ (the film resistance value of the first electrode pattern P1 is set to 10Ω / □). ~ 19Ω / □), preferably around 5Ω / □ (the film resistance value of the first electrode pattern P1 is set around 15Ω / □). This is because if the difference between the two film resistance values is too small, safety / heat generation characteristics and moisture resistance deteriorate, and if the difference between the two film resistance values is too large, the voltage resistance deteriorates.

Anyway, in a preferred embodiment of the present invention, the first metal films F1 is a first electrode pattern P1 that metal deposition electrode 2p is made from the split electrodes 2p ₁ small area with a large number number of divisions Yes, the membrane resistance value is small, and it is on the anode side. And the 2nd metallized film F2 is the 2nd electrode pattern P2 in which the metal vapor deposition electrode 2n consists of a non-divided electrode with a division number of zero and a large area, or a divided electrode with a small number of divisions and a large area. The resistance value is large and the cathode side. In other words, the second electrode pattern P2 is an undivided continuous state or divided into a plurality of areas, but each area is larger than the area of the divided electrodes of the first electrode pattern P1.

  Next, advantages of the metallized film capacitor configured as described above will be described.

  When the metallized film is thinned, in order to increase the withstand voltage when the capacitor is normally energized, the first electrode pattern P1 in the small area division state does not increase the film resistance value, but is not divided. In the second electrode pattern P2 in a large area state in which the individual areas are larger than the area of the divided electrodes of the first electrode pattern P1 although being divided into a continuous state or a plurality of areas, the film resistance value thereof is By increasing the voltage, the withstand voltage is increased during normal energization compared to the case where the membrane resistance value is small.

  Since the number of fuse portions having a large conduction resistance value compared to the film-like electrode portion in the second metallized film F2 is small even if it is not the second electrode pattern P2, as described above. Even if the film resistance value of the film-like electrode portion is increased (even if the film resistance is increased), the heat generation of the capacitor element 4 can be suppressed.

In addition, in order to suppress heat generation during normal energization in the first electrode pattern P1, heat generation during normal energization is suppressed by reducing the film resistance value of the small-area divided electrode. Making the divided electrode into a small area leads to an increase in the number of the fuse portions 2p ₂ and can improve the safety performance.

  Further, in the metal vapor deposition electrode 2p of the first electrode pattern P1, the polarity is used as an anode, but the metal vapor deposition electrode 2p on the anode side has a small film resistance value, and its thickness is inversely large. Moisture resistance can also be improved in conjunction with the suppression of heat generation during normal energization due to the small film resistance value described above while slowing the anodization progress rate.

  Through the above synergies, the metallized film can be made thinner and the metallized film capacitor can be made smaller and excellent overall evaluation while satisfying high voltage resistance / safety, heat generation characteristics and moisture resistance. .

  Table 1 shows the test results of the prototype compared with the two conventional examples.

ここで、テストの条件は次のとおりとなっている。

Here, the test conditions are as follows.

Element specifications: capacity 100 μF, rated 1650 VDC (dielectric film 7 μm, 100 mm width)
Withstand voltage: Life test: 75 ° C., 2100 VDC, change in capacitance of capacitor element after elapse of 1000 hrs (average value of the number of samples N = 5)
Safety: Number of short-circuit occurrences in life test Heat generation characteristics: Ripple energization test: Element center temperature rise under conditions of 15 Arms, 5 kHz, 25 ° C. (average value of N = 5)
Moisture resistance: Moisture resistance load test: 85 ° C., 85% R.D. H. , 1650VDC, change in capacitance of capacitor element after 2000 hrs (N = 5 average value)
The upper part of the deposited film in Table 1 shows the electrode pattern shape, and the lower part shows the film resistance value. In Conventional Example 1, both the anode side and the cathode side have a honeycomb electrode pattern and a membrane resistance value of 10Ω / □. In Conventional Example 2, the electrode pattern is a honeycomb shape on both the anode side and the cathode side, and the membrane resistance value is 20Ω / □. In the example, the electrode pattern on the anode side has a honeycomb shape and the membrane resistance value is 10Ω / □, while the electrode pattern on the cathode side is an undivided electrode and the membrane resistance value is 20Ω / □.

  As is apparent from the results of Table 1, Conventional Example 1 satisfies safety, heat generation characteristics, and moisture resistance, but does not satisfy voltage resistance (high voltage resistance cannot be achieved). On the other hand, Conventional Example 2 satisfies the voltage resistance (high voltage resistance can be achieved), but does not satisfy safety, heat generation characteristics, and moisture resistance. On the other hand, according to the embodiment, all of the voltage resistance, safety, heat generation characteristics and moisture resistance can be satisfied.

In the above, the first electrode pattern P1 is the shape of the divided electrodes 2p ₁ is a hexagon which constitutes it, the shape of the divided electrodes 2p ₁ is can adopt any shape other than a hexagon It is.

In addition, the second electrode pattern P2 is a non-divided state (solid) that remains continuous, but other than this, the area is sufficiently larger than the area of the divided electrode 2p1 in the _first electrode pattern P1. It is good also as a pattern divided | segmented in this state. In this case, the divided electrodes having a large area may be connected to each other via a fuse portion, or may be isolated from each other. For example, the metal vapor-deposited electrode may be divided into a plurality of parts such as two or three in the film width direction Y, and the dividing line may be a strip-shaped large area divided electrode that is linear along the film longitudinal direction X. Alternatively, may be a divided electrode of larger area in the shape similar to the shape of the divided electrodes 2p ₁ of the first electrode pattern P1, further its shape can be adopted any. For example, the first electrode pattern P1 is formed in a honeycomb shape in which hexagonal divided electrodes having a small area are spread, and the second electrode pattern P2 is formed in a honeycomb shape in which hexagonal divided electrodes having a larger area are spread. is there.

  Note that the first and second pair of metallized films F1 and F2 may be stacked in addition to the above winding.

  The present invention relates to a metallized film capacitor, in order to promote the reduction of the thickness of the metallized film and the miniaturization of the metallized film capacitor, without any conflict between high voltage resistance, safety, heat generation characteristics and moisture resistance. It is useful as a technique for satisfying.

DESCRIPTION OF SYMBOLS 1 Dielectric film 2p Metal deposition electrode on the anode side 2n Metal deposition electrode on the cathode side 2p ₂ Fuse part 3p Metal electrode on the anode side 3n Metal electrode on the cathode side 4 Capacitor element 5p External lead terminal on the anode side 5n Cathode side external lead Terminal F1 First metallized film F2 Second metallized film P1 First electrode pattern P2 Second electrode pattern

Claims (3)

Capacitor element in which a metal vapor-deposited electrode is formed on a dielectric film, and the first metallized film and the second metallized film are superposed and a metal electrode is formed at one end and the other end in the axial direction. A metallized film capacitor comprising anode-side and cathode-side external lead terminals connected to the respective metal electrodes of the capacitor element,
The first metallized film has a first electrode pattern in which the metal vapor deposition electrodes are divided and connected to each other via a fuse portion, and is connected to the external lead terminal on the anode side,
On the other hand, the second metallized film has a second electrode pattern in a non-divided state in which the metal vapor deposition electrode is continuous or in a state of being divided in a larger area than the metal vapor deposition electrode of the first metallized film. The metallized film capacitor has a film resistance value greater than that of the metal vapor deposition electrode of the first metallized film and is connected to the external lead terminal on the cathode side.   Regarding the film thickness of the first and second electrode patterns, the film thickness of the first electrode pattern is greater than the film thickness of the second electrode pattern. The metallized film capacitor according to claim 1, wherein a resistance value is larger than a film resistance value of the first electrode pattern.   The metalized film capacitor according to claim 2, wherein the first and second electrode patterns are made of the same material.

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