JPH0272608A - Metallized film capacitor - Google Patents

Abstract

PURPOSE:To improve insulation property and voltage resistance property by forming an electrode at a part in the width direction, and folding the electrode in two outward and laying one on top of another in the condition of being inserted into each other, and surrounding the major part of the electrode with insulating film main body. CONSTITUTION:The great portion excepting the end face connecting with an electrode lead part 6 is surrounded by the insulating film main body 3 of a metallized film 1 on the facing side in the electrode 2 of the metallized film 1. And the electrode lead part 6 connected to the end face of each electrode 3 and the electrode 3 to become its opposite electrode are interrupted completely by the insulating film main body 2. Accordingly, the cause to bring about insulation faults and breakdown strength faults between the electrode lead part 6 and the electrode 3 to be used as the opposite electrode becomes zero even in the metallicon process. Hereby, excellent insulation property and voltage resistance property can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a metallized film capacitor using a metallized film, and particularly to a metallized film capacitor that contributes to improved characteristics.

[Prior Art] Generally, a metallized film capacitor is formed by overlapping and winding a pair of metallized films each having an electrode formed on one side of an insulating film body.

FIG. 3 shows an example of such a metallized film capacitor. In FIG. 3, 11 is a metallized film, 12 is an insulating film body, and 13 is an electrode formed on one side of this insulating film 12. be.

Here, the metallized film 11 is formed and arranged so as to provide a large creepage distance between the end surfaces of the electrodes 13 in order to enhance insulation and voltage resistance. Specifically, one edge in the width direction of the metallized film 11 is provided with a margin part 14 on which the electrode 13 is not formed, and the relationship between the two metallized films 11 is such that the respective margin parts 14 are in opposite positions to each other. , and are overlapped in a manner shifted in the width direction. That is,
As shown in FIG. 3, the creepage distance between the ends of the electrodes 13 of the pair of metallized films 11 can be increased by the sum of the width 1 of the margin portion 14 and the clearance dimension a2 of 0.

The elements stacked and wound in this manner are assembled by known means after electrode lead-out portions 15 are formed by applying metallization to both end faces.

By the way, in the above metallized film capacitor, the pair of metallized films 11 are shifted in the width direction,
The end face forming the electrode 13 is made to protrude and the end face forming the margin portion 4 is drawn inward. However, in this case, a slight gap 16 is created between the pair of metallized films 11, so the means for forming the electrode lead-out portion 15 is When metallization is applied as a metallization, fine metal powder enters the gap 16, causing poor insulation and withstand voltage between the electrode lead-out portion 15 of one electrode 13 and the electrode 13 serving as the counter electrode. Was.

Further, although the electrode forming end face 17 is provided with the electrode leading portion 15, the area of the electrode forming end face 17 that comes into contact with the electrode forming end face 15 is minute, so the strength of the metallicon may be weakened; the current capacity may not be large enough. It also had drawbacks such as:

[Problems to be Solved by the Invention] As described above, in conventional metallized film capacitors, fine metal powder enters the gap between the metallized films from both end faces of the element during metal contact, resulting in poor insulation and resistance. It has the drawback of generating voltage failures, and a solution to this problem has been required.

The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to eliminate the gap between the electrode lead-out portion of one electrode and the electrode serving as the counter electrode even during metal single-contact. This product has excellent insulation reliability without causing insulation defects or withstand voltage defects, and can significantly improve the withstand voltage value.
It is an object of the present invention to provide an excellent metallized film capacitor.

[Means for Solving the Problems] In the metallized film capacitor of the present invention, the range of the electrode formed on one side of the insulating film is slightly over half in the width direction of the film from the margin provided at one edge in the width direction of the film. A pair of metallized films provided with such electrodes are each folded in half in the width direction so that the electrode-forming end faces protrude from the folded part, and the opposite sides The structure is characterized by overlapping and winding the metallized film with the electrode forming surface inserted inside it.

U effect] In the present invention having the above configuration, most of the electrode formed on the metallized film, excluding the end surface connected to the electrode lead-out portion, is connected to the insulating film of the metallized film on the opposite side. Since it is surrounded by the main body, the electrode lead-out portion connected to the end face of each electrode and the electrode serving as the opposing electrode are completely cut off by the insulating film main body. Therefore, there is no possibility that poor insulation or withstand voltage will occur due to fine metal powder during metallization.

In addition, since the end face of the metallized film located on the inner surface of the bent part of the opposing metallized film serves as an intermediate margin, the absolute characteristics of withstand voltage are greatly improved, and at the same time, the impregnated type has improved corona generation voltage characteristics. It also has the advantage of

Furthermore, since the electrode forming end face located on the outer surface of the bent part has a rounded shape and has a large area in contact with the electrode lead-out part, there is an advantage that the strength of the metallicon can be improved and the current capacity can be increased.

Embodiment] Hereinafter, an embodiment of the metallized film capacitor of the present invention will be explained in detail with reference to FIGS. 1 and 2.

As shown in FIGS. 1 and 2, the pair of metallized films 1 are provided with a margin portion 7 at one edge in the width direction of one side of the insulating film body 2, and from this margin portion 7, half of the width of the film is The electrode 3 is formed by vapor-depositing a metal such as aluminum or zinc in an area slightly exceeding . Then, it is folded in half in the width direction so that the electrode-forming end surface 4 protrudes from the bending part 5 with the electrode 3 surface facing outward, and the electrode-forming surface is inserted inside the metallized film 1 on the side facing each other. Overlap in shape.

Then, a pair of metallized films 1 having such a configuration,
As shown in FIG. 1, metallicon is applied to both end surfaces of the obtained capacitor element by winding to form electrode lead-out portions 6.
Thereafter, the capacitor is assembled by known means and impregnated with an impregnating agent if necessary to obtain a finished capacitor.

In the metallized film capacitor of this embodiment having the above configuration, as is clear from FIG. is surrounded by the insulating film main body 2 of the metallized film 1 on the opposing side, and the electrode lead-out portion 6 connected to the end surface of each electrode 3 and the electrode 3 serving as the opposing electrode are as follows: It is completely blocked by the insulating film body 2. Therefore, even in the case of metallicon, there is no cause of poor insulation or withstand voltage between the electrode lead-out portion 6 and the electrode 3 serving as the counter electrode via metal particles, and excellent insulation properties and withstand voltage properties can be obtained. .

Furthermore, in this example, since the margin portion 7 is formed on the end face of the metallized film 1 located on the inner surface of the bent portion 5 of the opposing metallized film 1, it is possible to simply overlap the metallized films. Compared to the conventional technology, the absolute characteristics of withstand voltage are greatly improved, and at the same time, in the case of the impregnated type, since the margin portion 7 is impregnated with the impregnating agent, it can greatly contribute to improving the corona generation voltage.

Furthermore, since the electrode forming end surface 4 located on the outer surface of the bent portion 5 has a rounded shape and has a large area in contact with the electrode lead-out portion 6, there is an advantage that the strength of the metallicon can be improved and the current capacity can be increased.

The table on the next page shows a comparison of characteristics between the impregnated type metallized film capacitor according to the present invention shown in FIG. 1 and the impregnated type metallized film capacitor according to the prior art shown in FIG. 3. The number of samples is 30 for both the present invention and the conventional example, and the numerical values are average values.

(Leaving space below) As is clear from this table, in the conventional example, the insulation defect rate and withstand voltage defect rate were approximately 3 to 5% each, whereas in the present invention, both were zero, and withstand voltage failure rate was approximately 3 to 5%. The value is also more than twice that of the conventional one, which is a significant improvement in characteristics.

[Effects of the Invention] As explained above, in the present invention, metallized films in which electrodes are partially formed in the width direction are folded outward in half and inserted into each other so that the metallized film is stacked on top of the other.
Most of the electrode, excluding the end surface that connects to the electrode lead-out part, is surrounded by the insulating film body of the metallized film on the opposing side, and can be completely isolated from the electrode lead-out part of the opposing electrode, so even when metallized, one electrode It is possible to provide an excellent metallized film capacitor that can improve insulation properties and withstand voltage characteristics without causing poor insulation or withstand voltage between the electrode lead-out portion and the electrode serving as the counter electrode.

[Brief explanation of the drawing]

1 and 2 are views showing one embodiment of the metallized film capacitor of the present invention, in which FIG. 1 is a sectional view, FIG. 2 is a perspective view, and FIG. 3 is a conventional metallized film capacitor. FIG. 3 is a cross-sectional view showing the configuration. 1...Metalized film, 2...Insulating film body,
3... Electrode, 4... Electrode forming end surface, 5... Bent part, 6... Electrode lead-out part, 7... Margin part.

Claims (1)

[Claims] On one side of the insulating film body, a margin is provided at one edge in the width direction of the film, and an electrode is formed in a range slightly over half of the width of the film from this margin to form a pair of metallized electrodes. The pair of metallized films are each folded in half in the width direction with the electrode surface facing outward so that the electrode forming end surface protrudes from the folded part, and the metalized films on the opposite sides are folded in half. A metallized film capacitor characterized in that the elements are overlapped and wound in such a manner that the electrode forming surfaces are inserted, and electrode lead-out portions are provided on both end faces of the element formed by this winding.