JP4435381B2 - Dry metallized film capacitor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry metallized film capacitor using a metallized film.
[0002]
[Prior art]
As shown in FIG. 7, a conventional dry metallized film capacitor is formed by winding a pair of metallized films 8 (FIG. 4), winding a plastic film such as a polypropylene film as the subsequent film 7, and forming zinc on the winding end surface. In order to cut off the influence of the capacitor element 1 formed by spraying a metal such as the electrode lead part 5, the external terminal 6 connected to the electrode lead part 5 of the capacitor element 1, and the atmosphere. The outer periphery of the side surface is covered with an adhesive tape 3 of a polyethylene terephthalate film, and an insulating resin 4 such as an epoxy resin is filled in the space between the adhesive tape and both electrode lead portions of the capacitor element.
[0003]
[Problems to be solved by the invention]
In the conventional dry metallized film capacitor, as described above, a polypropylene film or the like is wound as a subsequent film of the capacitor element, and the outer periphery of the side surface is covered with an adhesive tape such as a polyethylene terephthalate film. During or during use, there has been a problem that the characteristics of the capacitor deteriorate due to the influence of an atmosphere such as water vapor or oxygen that permeates through these films.
[0004]
[Means for Solving the Problems]
The present invention has been made to solve the above problems, and a capacitor element is wound with a film having a metal oxide layer having a barrier property against water vapor or air, or a plastic film is wound. A film having the metal oxide layer is wound thereon, and a dry metallized film capacitor having excellent environmental resistance due to its barrier effect is provided.
[0005]
That is, a capacitor element 1 in which a pair of metallized films 8 are overlapped and wound, and a metal oxide layer wound around the capacitor element 1 and made of oxide of alumina, zinc oxide, or zinc / aluminum mixture. and coated film 2, and the electrode lead portions 5 formed respectively on the winding end faces of both films 2, the external terminal 6 connected to the electrode lead-out portion 5, the outer peripheral portion of the capacitor element 1 turned film 2 winding A dry metallized film capacitor comprising: an adhesive tape 3 wound a plurality of times; and an insulating resin 4 filled and cured between the adhesive tape 3 and both electrode lead portions 5 .
[0006]
The dry metallized film capacitor further includes a plastic film 7 wound between the outer peripheral portion of the capacitor element 1 and the film 2 coated with the metal oxide layer .
[0007]
Furthermore, a dry metallized film capacitor is characterized in that the film substrate coated with the metal oxide layer is a polyethylene terephthalate film, a polyethylene film, a polypropylene film, or a polyphenylene sulfide film.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
A film 2 having a metal oxide layer is wound around a capacitor element 1 in which a pair of metallized films 8 are wound in layers, an electrode lead portion 5 is formed on the winding end surface, and external terminals 6 are connected to the electrode lead portion 5. Connecting.
Alternatively, the plastic film 7 is wound around the capacitor element 1 in which the pair of metallized films 8 are wound in layers, the electrode lead portion 5 is formed on the winding end surface, and the external terminal 6 is connected to the electrode lead portion 5; A film 2 having a metal oxide layer is coated on the outer periphery of the plastic film 7.
As the film having the metal oxide layer, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, or a polyphenylene sulfide film coated with an oxide of alumina, zinc oxide, or zinc / aluminum mixture is used.
By winding the film having the metal oxide layer on the latter film, it is possible to prevent moisture and air from entering from the surface layer portion of the capacitor element due to the barrier effect of the metal oxide, and to stabilize the quality. Can be planned.
[0009]
【Example】
[Example 1]
FIG. 1 is a drawing showing an embodiment of a dry metallized film capacitor of the present invention, (a) is a longitudinal sectional view, (b) is a side view, and FIG. 2 is a perspective view of the capacitor element constituting FIG. FIG. 4 is a development view of the metallized film constituting the capacitor element.
Examples of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following examples.
The dry metallized film capacitor shown in FIG. 1 is formed by winding a pair of metallized films 8 shown in FIG. 4 and winding a film 2 having a barrier metal oxide layer as shown in FIG. The electrode lead part 5 is formed by spraying a metal such as zinc or solder on the winding end face, and the capacitor element 1 is formed by connecting the external terminal 6 to the electrode lead part 5 by welding or soldering. Yes.
Then, the outer peripheral portion of the side surface of the capacitor element 1 is wound a plurality of times with an adhesive tape 3 made of a polyethylene terephthalate film, and an epoxy resin or the like is cured between the adhesive tape 3 and the electrode lead portions 5 of the capacitor element 1. The conductive insulating resin 4 is injected, filled, and cured to obtain a dry metalized film capacitor.
[0010]
In this example, after a pair of aluminum-deposited metallized polypropylene films having a thickness of 5 μm and a width of 100 mm were wound and wound, a polyethylene terephthalate film having a thickness of 12 μm and a width of 101 mm was coated with alumina as a film having a metal oxide layer. A capacitor element is formed by winding the wound film 10 times, and the outer periphery of the side surface of the capacitor element is wound three times with an adhesive tape made of a polyethylene terephthalate film having a thickness of 50 μm, and an epoxy resin is injected, filled, and cured. , 66 μF × 1125 VDC dry metallized film capacitor. Further, as a comparative capacitor, a dry metallized film capacitor was produced by winding the latter film 10 times with a conventionally used polypropylene film having a thickness of 25 μm and a width of 100 mm.
Each of the prepared samples is 10 units.
[0011]
For each of these five dry metallized film capacitors, a 1125V DC voltage was applied in an environment of a temperature of 40 ° C. and a relative humidity of 90 to 95%, a humidity resistance load test, an ambient temperature of 60 ° C., an applied voltage of 1350 VDC (rated) A life test was conducted with a voltage of 1.2) and an application time of 1500 hours.
The results are shown in FIGS. 5 and 6, respectively.
[0012]
From the test results, the following was found.
In the moisture resistance load test, the dry metallized film capacitor of the present invention is stable in capacity with almost 0.1% decrease in capacity after about 1500 hours, whereas in the conventional example, the capacity is about 1. It has decreased by 2%.
In the life test, the dry metallized film capacitor of the present invention has a capacity reduction of about 8% after 1500 hours, while the capacity of the conventional example is greatly reduced by about 33%.
[0013]
This is because the dry metallized film capacitor of the present invention has a film having a barrier metal oxide layer wound around the latter film of the capacitor element, so that the barrier effect penetrates from the surface layer portion of the capacitor element. This is because water vapor and air are blocked, and deterioration of the metallized film constituting the element is suppressed, so that the capacity reduction is reduced.
[0014]
[Example 2]
FIG. 3 is a drawing of a dry metallized film capacitor according to another embodiment of the present invention. FIG. 3 (a) is a longitudinal sectional view, and FIG. 3 (b) is a side view. The description is omitted. The difference from the above-described embodiment is the configuration of the latter film 7 of the capacitor element 1, in which a pair of metallized films 8 shown in FIG. The capacitor element 1 is formed by winding the outer peripheral surface of the capacitor element 1 a plurality of times with a film 2 having a metal oxide layer, and further winding the outer peripheral surface of the side surface with an adhesive tape 3 made of a polyethylene terephthalate film. ing.
[0015]
In this example, a pair of aluminum vapor-deposited metallized polypropylene films having a thickness of 5 μm and a width of 100 mm are stacked and wound, and a conventionally used polypropylene film having a thickness of 25 μm and a width of 100 mm is wound 10 times as a subsequent film. A capacitor element is formed, a polyethylene terephthalate film having a thickness of 12 μm and a width of 101 mm, coated with barrier alumina on the outer peripheral portion of the capacitor element, is wound three times, and the outer peripheral portion of the side surface is polyethylene terephthalate having a thickness of 50 μm Surrounded three times with an adhesive tape made of a film or the like, injected with epoxy resin, filled and then cured to produce 10 66 μF × 1125 VDC dry metallized film capacitors.
[0016]
For each of these five dry metallized film capacitors, together with the sample of Example 1, under a temperature of 40 ° C. and a relative humidity of 90 to 95%, a DC voltage of 1125 V was applied and a humidity resistance load test was performed. A life test was conducted at 60 ° C., an applied voltage of 1350 VDC (rated voltage × 1.2), and an application time of 1500 hours.
The results are shown in FIGS. 5 and 6, respectively.
[0017]
From the test results, the following was found.
In the moisture resistance load test, the dry metallized film capacitor of the present invention is stable in capacity with almost 0.2% decrease in capacity after about 1500 hours, whereas in the conventional example, the capacity is about 1. It has decreased by 2%.
In the life test, the dry metallized film capacitor of the present invention has a capacity reduction of about 9% after 1500 hours, while the capacity of the conventional example is greatly reduced by about 33%.
[0018]
As a result of the above test, the alumina coating film having a barrier property is wound as the back film of the capacitor element, or the normal coating film is wound and then the alumina coating film is wound around the outer periphery of the side surface. As a result, water vapor and air that permeate through the film of the surface layer portion of the capacitor element are blocked, capacity reduction is suppressed, and quality stabilization can be achieved.
[0019]
As a film having a barrier metal oxide layer, a film obtained by vapor-depositing alumina (aluminum oxide) on a polyethylene terephthalate film called an alumina coating film was used in the above embodiment, but the material is limited to this. Instead, zinc oxide or zinc / aluminum mixture oxide can be used as the metal oxide, and the plastic film is equivalent to polyethylene terephthalate film, polyethylene film, polypropylene film, polyphenylene sulfide film, etc. The effect of can be obtained.
[0020]
In the above embodiment, a pair of metallized films are rolled and wound, and a film having a metal oxide layer is wound as a subsequent film. The metallized film deposited metal may be scattered and wound by an electrical process called burn-off, and a film having the metal oxide layer may be wound around the outer periphery of the side surface as a subsequent film.
Moreover, you may give the coating for thermal bonding or ultrasonic bonding to the any one surface side of the film which has the said metal oxide layer.
[0021]
Furthermore, although aluminum was used as the vapor deposition metal of the metallized film constituting the capacitor element, it is not limited to this, and other metals such as zinc and zinc / aluminum mixtures may be used, and a polypropylene film as a dielectric. However, the present invention is not limited to this, and a polyethylene terephthalate film, a polyethylene film, a polyphenylene sulfide film, or the like may be used.
And as a pair of metallized films, both vapor deposition surfaces used metallized films with a security mechanism of split electrodes. However, both vapor deposition surfaces of a pair of metallized films are solid vapor deposition, or one of them is a metal consisting of split electrodes, etc. There is no problem even if a modified film is used.
[0022]
In the above embodiment, the outer peripheral portion of the side surface of the capacitor element is wound with an adhesive tape a plurality of times, and an insulating resin made of a thermosetting resin such as an epoxy resin is provided between the adhesive tape and both electrode lead portions of the capacitor element. A capacitor element is formed by winding a film having a barrier metal oxide layer as a post-coating film, which is cured after injection, filling, and is accommodated in a rectangular resin case made of polybutylene terephthalate, etc. Even if a thermosetting resin such as a resin is injected, filled and cured to form a dry metallized film capacitor, the same effect can be obtained.
[0023]
【The invention's effect】
The dry metallized film capacitor of the present invention is formed by winding a film having a barrier metal oxide layer as a subsequent film of a capacitor element, or a side peripheral portion of a capacitor element wound with a normal latter film By winding the film having the metal oxide layer on the surface, water vapor and air entering from the film on the surface layer portion of the capacitor element are blocked, and deterioration of the metallized film constituting the element is suppressed, so that the capacity is reduced. It can be suppressed and the quality can be further stabilized, and its value is extremely large industrially and practically.
[Brief description of the drawings]
FIG. 1 is a drawing showing one embodiment of a dry metallized film capacitor of the present invention, in which (a) is a longitudinal sectional view and (b) is a side view.
2 is a perspective view of a capacitor element constituting FIG. 1. FIG.
FIG. 3 is a drawing of a dry metallized film capacitor according to another embodiment of the present invention, in which (a) is a longitudinal sectional view and (b) is a side view.
FIG. 4 is a development view of a pair of metallized films constituting the capacitor element of the present invention.
FIG. 5 is a diagram showing the results of a moisture resistance load test.
FIG. 6 is a view showing a high-temperature life test result.
FIG. 7 is a longitudinal sectional view of a conventional dry metallized film capacitor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Film which has a metal oxide layer (back winding film)
3 Adhesive Tape 4 Insulating Resin 5 Electrode Lead 6 External Terminal 7 Plastic Film (Rolling Film)
8 Metallized film

Claims (3)

A capacitor element in which a pair of metallized films are stacked and wound ;
A film wound around the capacitor element and coated with a metal oxide layer made of oxide of alumina, zinc oxide, or zinc / aluminum mixture ;
An electrode lead portion formed respectively on both winding end faces of the film ;
And an external terminal connected to the electrode lead-out portion,
An adhesive tape wound a plurality of times on the outer periphery of the capacitor element wound with the film;
An insulating resin filled and cured between the adhesive tape and the electrode lead-out portions;
Dry metallized film capacitor, characterized in that it comprises a. The dry metallized film capacitor according to claim 1, further comprising a plastic film wound between an outer peripheral portion of the capacitor element and a film coated with the metal oxide layer . The dry metallized film capacitor according to claim 1 or 2, wherein the film substrate coated with the metal oxide layer is a polyethylene terephthalate film, a polyethylene film, a polypropylene film, or a polyphenylene sulfide film.

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