JP2012099712A - Metalization film capacitor and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metalization film capacitor which is manufactured under high processing efficiency and inexpensive method and is excellent in heat dissipation from a metal vapor-deposited film, i.e., a heat generation source, and a manufacturing method therefor.SOLUTION: A metalization film capacitor 10 includes: metal spray parts 7 formed on two electrode extraction surfaces of a metalization film columnar body 6 formed by winding metalization films 4; and external lead-out terminals 8 joined to the metal spray parts 7. The metalization film 4 includes a dielectric film 1 and a metal vapor-deposited film 2 formed on one side surface of the dielectric film 1. The metal vapor-deposited film 2 includes an insulated metal oxide 3 prepared by oxidizing the metal vapor-deposited film 2 at one edge area along the longer direction of the metal vapor-deposited film 2. One metal spray part 7 has the metal oxide 3 of the metal vapor-deposited film 2 closely brought into contact therewith, while the other metal spray part 7 has another edge part along the longer direction of the metal deposited film 2 closely brought into contact therewith.

Description

  The present invention relates to a coiled or laminated metallized film capacitor.

  A conventional metallized film capacitor, which is formed by winding a metallized film, has a metal sprayed part (or metallicon, metallicon electrode) formed on the two electrode extraction surfaces at both ends of the metallized film column. It is manufactured by soldering external lead terminals to these two metal sprayed portions. The laminated metallized film capacitor also has substantially the same structure as the wound type except that the metallized films are laminated to form a metallized film column.

  With reference to FIG. 5, the related structure of the conventional metallized film and two metal spraying parts is demonstrated. As shown in the figure, metal vapor deposition films k1 and k2 are respectively formed on one side of dielectric films f1 and f2 to form metallized films fa and fb, and these two metallized films fa and fb are laminated. Then, a set of metallized films f is formed, and the metallized film column body c is manufactured by winding the set of metallized films f. Here, the metal vapor deposition film k1 formed on one side surface of the dielectric film f1 constituting one metallized film fa has one end along the longitudinal direction in close contact with one metal sprayed portion d (one electrode). In order to be insulated from the other metal sprayed portion d (the other electrode), for example, a gap region (insulation margin region mg) of about 2 mm, that is, a non-deposition portion region is formed at the other end along the longitudinal direction. Is provided.

  On the other hand, the other metallized film fb constituting the set of metallized films f forms an insulating margin region mg on the side opposite to the one metallized film fa described above, and the metal sprayed part d (the other side of the other side) The metal vapor deposition films k1 and k2 of each of the pair of metallized films f are in close contact with the separate metal sprayed portions d and d, respectively. The metal lead film capacitor KC is formed by soldering the external lead terminal b to each of the two metal sprayed portions d. Patent Document 1 discloses a metallized film capacitor in which a set of two metallized films is wound and metal sprayed portions are formed at both ends thereof.

  In this way, in the conventional metallized film capacitor, each metal vapor deposition film constituting a set of two metallized films is in intimate contact with only one metal sprayed portion, so that the metal vapor deposition film as a heat source There is a problem that the heat radiation path from is only a path toward one of the metal sprayed portions, and sufficient heat dissipation is not obtained. In addition, when the polypropylene film generally applied as a dielectric film is illustrated, the heat conductivity is about 0.18 W / mK, for example, the heat conductivity at the time of forming a metal vapor deposition film from aluminum: 236 W / mK Since the heat conductivity is extremely low compared to the degree, heat dissipation from the dielectric film to the metal sprayed portion cannot be expected.

  With the recent miniaturization of metallized film capacitors, dielectric films with a high dielectric constant are often used, but the dielectric loss tangent of such dielectric films with a high dielectric constant becomes even larger. Therefore, the heat generation amount of the film itself is increased, and the heat generation density is further increased due to the downsizing of the capacitor itself, and the capacitor is further heated.

  In order to prevent the capacity reduction due to the temperature rise of the metallized film, the above-described insulation margin region of the metallized film is blocked with a potting resin material having a good thermal conductivity in order to prevent the heat dissipation problem. . However, the increase in the potting resin potting process during capacitor production reduces the manufacturing efficiency, and the use of a potting resin material with high thermal conductivity increases the material cost, which in turn increases the capacitor manufacturing cost. .

JP 2009-044040 A

  The present invention has been made in view of the above-described problems, and the potting resin material is not applied to the insulating margin region on the side of the metal vapor deposition film in order to enhance the heat dissipation, and under an efficient manufacturing method. It is an object of the present invention to provide a metallized film capacitor that is manufactured and has excellent heat dissipation, and a method for producing the metallized film capacitor.

  In order to achieve the above object, a metallized film capacitor according to the present invention has a metal sprayed portion formed on two electrode extraction surfaces of a metallized film column formed by winding or laminating a metallized film. A metallized film capacitor in which an external lead terminal is joined to a portion, wherein the metallized film is composed of a dielectric film and a metal vapor deposition film formed on one side surface thereof, and the metal vapor deposition film is in a longitudinal direction thereof. An insulating metal oxide formed by oxidizing the metal vapor deposition film is formed in one end region along the line, and the metal oxide of the metal vapor deposition film is in close contact with one of the two metal sprayed portions. The other end portion along the longitudinal direction of the metal vapor deposition film is in close contact with the other metal sprayed portion.

  The metallized film capacitor of the present invention eliminates the insulating margin region (gap region) provided on the side of the metal vapor deposition film constituting each of the pair of metallized films, and the entire surface of the dielectric film is made of metal. In addition to forming a vapor deposition film, one of the two ends of the metal vapor deposition film is oxidized to form an insulating metal oxide. It is possible to radiate heat to the thermal spraying part, thereby ensuring a heat radiating path from the metal vapor deposition film to the two metal thermal spraying parts and having excellent heat radiating performance.

  Here, the metallized film pillar is a laminate of two metallized films in which a metal vapor-deposited film made of aluminum or zinc is formed on the surface of a dielectric film made of polypropylene (PP) or polyphenylene sulfide (PPS). Both metallized films have the above metal oxides at the opposite ends, and each metal vapor deposition film and metal oxide are in contact with the metal sprayed parts (metallicon electrodes) on both sides. It is supposed to be. Furthermore, in the metal vapor deposition film, the end opposite to the metal oxide can be a so-called heavy edge that is thicker than other parts to ensure electrode contact. When the thickness is about 30 nm, the heavy edge can be adjusted to about 60 nm, which is twice that of the heavy edge.

  A metal sprayed portion made of zinc or the like is formed on the electrode take-out surfaces at both ends of the coiled or laminated metallized film column, and a part of the external lead terminal is soldered to the metal sprayed portion. This external lead terminal is made of a bar-like or plate-like bus bar or the like, and copper, aluminum, nickel, stainless steel or the like is applied as the material thereof.

  In addition, a resin body such as an epoxy resin, a silicone resin, or a urethane resin was molded into the case in a posture in which a metallized film column was disposed in a case made of aluminum or resin, and a molded resin body was formed. A metallized film capacitor may be used, and in this embodiment, both the waterproof and vibration-proof performance of the metallized film capacitor is improved by the molded resin body.

  Here, an embodiment in which the metal vapor deposition film is a vapor deposition layer made of aluminum or an alloy thereof and the metal oxide is made of alumina is preferable.

When aluminum is oxidized to form alumina, the electrical resistivity is greatly increased from 2.65 × 10 ⁻⁸ Ωm to 2 × 10 ¹³ Ωm to become an insulator, while the thermal conductivity is 236 W / mk. From 30 to 30 W / mk, which is only about 1/8, the degree of decrease in thermal conductivity is much lower than the degree of insulation.

  Alumina has a good thermal conductivity among insulating oxides, and since it is often used as a heat-dissipating filler, the heat-drawing effect through alumina can be sufficiently expected.

  Therefore, in the metallized film capacitor having the conventional structure, the aluminum vapor deposition is caused by the presence of the alumina formed by oxidizing the metal vapor deposition film of the aluminum material at the location where the gap as the insulation margin region is provided at the end of the metal vapor deposition film. Heat is dissipated from one end of the film to one metal sprayed portion, and heat is dissipated from alumina to the other metal sprayed portion, thereby greatly improving the heat dissipation performance.

  Further, the present invention extends to a method for manufacturing a metallized film capacitor. The method for manufacturing a metallized film capacitor includes forming a metal vapor-deposited film on one side surface of a dielectric film to provide an intermediate of the metallized film capacitor. A first step for producing, a second step for producing a metallized film by oxidizing one end region along the longitudinal direction of the metal vapor deposition film on the surface of the metallized film to form an insulating metal oxide, The two metallized films are laminated so that the end regions made of the metal oxides of the two metallized films are opposite to each other, and the two metallized films are wound or laminated to form a metallized film column. A third step of manufacturing a metallized film capacitor by manufacturing a body, forming a metal sprayed part on the two electrode extraction surfaces, and joining an external lead terminal to the metal sprayed part.

  According to this manufacturing method, after forming a metal vapor deposition film on the entire surface of the dielectric film, the end portion is oxidized to generate a metal oxide, so that the metal vapor deposition film is formed while securing an insulating margin region. Since the labor is eliminated and the insulation margin area is not closed with a potting resin material with good thermal conductivity, a metallized film capacitor with excellent heat dissipation can be manufactured without increasing the manufacturing cost. Can do.

  Also in this manufacturing method, an embodiment in which the metal vapor deposition film is a vapor deposition layer made of aluminum or an alloy thereof and the metal oxide is made of alumina is preferable.

  In this method mode, alumina is produced by applying an anodic oxidation method to an aluminum vapor deposition film. Specifically, after depositing an aluminum vapor deposition film on the surface of the dielectric film, the end is immersed in a dilute sulfuric acid or oxalic acid bath, and the treatment bath is electrolyzed with the aluminum vapor deposition film as an anode to electrolyze the aluminum. The end of the deposited film can be aluminized.

  As described above, since a metal oxide can be efficiently generated at the end of the aluminum vapor deposition film by a simple manufacturing method in which the end of the aluminum vapor deposition film is immersed in a treatment bath and electrolyzed, under a high production efficiency. Metalized film capacitors can be manufactured.

  As can be understood from the above description, according to the metallized film capacitor of the present invention and the manufacturing method thereof, the metal excellent in heat dissipation from the metal vapor-deposited film, which is a heat source, under a highly efficient and inexpensive manufacturing method. A film capacitor can be obtained.

(A) is the schematic diagram explaining the 1st, 2nd process of the manufacturing method of the metallized film capacitor of this invention, (b) is the schematic diagram which showed the metallized film manufactured at the 2nd process. It is. FIG. 6 is a schematic diagram for explaining a third step following FIG. 1. FIG. 3 is a schematic diagram for explaining a third step following FIG. 2. It is a figure which shows the equivalent circuit which comprises an alumina insulating layer. It is the longitudinal cross-sectional view explaining the conventional metallized film capacitor.

  Embodiments of the present invention will be described below with reference to the drawings. Although not shown in the figure, in a posture in which a metallized film column is disposed in a case made of aluminum or resin, an epoxy resin, a silicone resin, a urethane resin, or the like is molded in the case. It may be a metallized film capacitor in which a resin body is formed.

  FIG. 1a is a schematic diagram illustrating the first and second steps of the method for manufacturing a metallized film capacitor of the present invention, and FIG. 1b is a schematic diagram illustrating the metallized film manufactured in the second step. . FIG. 2 is a schematic diagram for explaining the third step following FIG. 1, and FIG. 3 is a schematic diagram for explaining the third step following FIG.

  FIG. 1a illustrates the first and second steps of the metallized film capacitor manufacturing method of the present invention in order (in the X direction). In the figure, the roll-rolled dielectric film 1 is unwound (Y1 direction), and the unwound dielectric film 1 is conveyed between the horizontal rollers R2 and R2 and passes through the vacuum deposition apparatus J. Aluminum is vapor-deposited on the surface of the film 1 (Y2 direction) to form a metallized film intermediate 4 ′ composed of the dielectric film 1 and the aluminum vapor-deposited film 2 (first step).

  Next, in order to form alumina at the end of the aluminum vapor deposition film 2 constituting the intermediate body 4 ′ of the metallized film, aluminum is placed in the dilute sulfuric acid bath constituting the anodizing apparatus YS with the intermediate body 4 ′ twisted. The end of the deposited aluminum film 2 is formed on the surface of the dielectric film 1 as shown in FIG. 1b by immersing the end of the deposited film 2 and electrolyzing the dilute sulfuric acid bath using the deposited aluminum film 2 as an anode. A metallized film 4 whose part is made of alumina 3 is manufactured, and this is roll-rolled R2 and wound (Y2 direction, second step).

  Here, the dielectric film 1 can be formed from polypropylene (PP), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), etc., and the metal vapor deposition film 2 is made of zinc, It can be formed by vapor-depositing copper or the like on the surface of the dielectric film, and an oxide such as copper may be formed at the end of the metal vapor-deposited film in the same manner as alumina.

  Further, the end of the metal vapor deposition film 2 opposite to the end where the alumina 3 is formed may be a so-called heavy edge that is thicker than other parts in order to ensure electrode contact. When the general part of the deposited film is about 30 nm, the heavy edge can be adjusted to about 60 nm, which is twice as much.

  When the two types of metallized films 4 in which the alumina 3 is formed on the left and right ends of the aluminum vapor deposition film 2 are manufactured by the above method, these are laminated as shown in FIG. By doing so, a metallized film column is manufactured.

  Next, as shown in FIG. 3, a metal sprayed portion 7 is formed by spraying aluminum, zinc, or the like on the electrode extraction surfaces at both ends of the manufactured metallized film column 6.

  An external lead terminal 8 made of copper, aluminum, nickel, stainless steel or the like and made of a rod-like or plate-like bus bar is connected to the metal sprayed portion 7 via a solder layer 9 to thereby form a metallized film capacitor. 10 is manufactured (third step).

  As is clear from the figure, in each metallized film 4, the end portion of the aluminum vapor deposition film 2 is in contact with one metal sprayed portion 7, and the alumina 3 on the other end side is in contact with the other metal sprayed portion 7. The two heat dissipation paths are formed from the aluminum vapor deposition film 2 that is in contact with the heat source (Z1 direction).

Here, when aluminum is oxidized to form alumina, the electrical resistivity is greatly increased from 2.65 × 10 ⁻⁸ Ωm to 2 × 10 ¹³ Ωm and becomes an insulator, while the thermal conductivity is It is only about 1/8, from 236 W / mk to 30 W / mk. That is, by producing alumina at the end of the aluminum deposited film, both insulation and good heat dissipation are guaranteed.

[Example of calculation showing insulation performance of alumina]
One calculation example showing the insulating properties of alumina by the present inventors will be shown below.

  As a calculation model, when the winding resistance is 200 m, the thickness of the aluminum deposited film is 25 nm, and the plane width of the alumina region is 1 mm, the insulation resistance value of alumina is calculated as follows, and the capacitor equivalent circuit shown in FIG. 4 is formed. Can do.

ここで、ρはアルミナの電気抵抗率（Ωｍ）、Ｌはアルミナ領域の幅（ｍ）、Ａはアルミナ領域の全長の端部面積（ｍ^２）である。

Here, ρ is the electrical resistivity (Ωm) of alumina, L is the width (m) of the alumina region, and A is the end area (m ² ) of the entire length of the alumina region.

According to the above calculation, the alumina insulating layer has an insulation resistance of 4.0 × 10 ¹⁵ Ω per side with respect to a set of metallized films composed of two metallized films.

  Taking the case where a 650 V DC current is passed through the capacitor, the leakage current of the alumina insulating layer is as follows in consideration of the equivalent circuit shown in FIG.

  From the above calculation result, it is calculated that the material has a practically sufficient insulating property.

  According to the method for producing a metallized film capacitor of the present invention and the metallized film capacitor formed thereby, the aluminum can be efficiently produced by a simple production method in which the end of the aluminum vapor deposited film is immersed in a treatment bath and electrolyzed. Alumina is generated at the end of the deposited film, and a heat radiation path from both ends of the metal deposited film that constitutes the metallized film to the two metal sprayed parts is guaranteed, providing excellent heat dissipation without increasing manufacturing costs. Metallized film capacitors can be manufactured.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Dielectric film, 2 ... Metal vapor deposition film (aluminum vapor deposition film), 3 ... Metal oxide (alumina), 4 ... Metallized film, 5 ... A set of metallized films, 6 ... Metallized film pillar, 7 ... Metal sprayed part (metallicon electrode), 8 ... external lead terminal (bus bar), 9 ... solder layer, 10 ... metallized film capacitor

Claims (4)

A metallized film capacitor in which a metal sprayed part is formed on two electrode extraction surfaces of a metallized film column formed by winding or laminating a metallized film, and an external lead terminal is joined to the metal sprayed part. And
The metallized film includes a dielectric film and a metal vapor deposition film formed on one side surface of the dielectric film, and the metal vapor deposition film is an insulating film formed by oxidizing the metal vapor deposition film in one end region along the longitudinal direction. The metal oxide of the metal vapor deposition film is in close contact with one of the two metal sprayed portions, and the other metal sprayed portion is in the other direction along the longitudinal direction of the metal vapor deposited film. A metallized film capacitor with close edges.   The metallized film capacitor according to claim 1, wherein the metal deposited film is a deposited layer made of aluminum or an alloy thereof, and the metal oxide is made of alumina. A first step of producing a metallized film intermediate by forming a metal vapor deposition film on one side of the dielectric film;
A second step of producing a metallized film by oxidizing one end region along the longitudinal direction of the metal vapor deposition film on the surface of the metallized film to form an insulating metal oxide;
The two metallized films are laminated so that the end regions made of the metal oxides of the two metallized films are opposite to each other, and the two metallized films are wound or laminated to form a metallized film column. A metallized film capacitor comprising a third step of manufacturing a metallized film capacitor by forming a metal sprayed part on the two electrode extraction surfaces and joining an external lead terminal to the metal sprayed part. Production method.   The method for producing a metallized film capacitor according to claim 3, wherein the metal vapor deposition film is a vapor deposition layer made of aluminum or an alloy thereof, and the metal oxide is made of alumina.

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