JPH0362911A - Metallized film capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a dielectric loss tangent characteristic and accuracy of capacitance and to make it possible to achieve a compact configuration and mass production at low costs by forming an irregular surface so that a part of 90% or more of the surface is specified on the end surfaces of neighboring dielectrics at the end surface parts of specified electrode leads having the specified thickness. CONSTITUTION:A plurality of electrodes 2a and 2b whose thickness of the electrode resistor is within a range of 100-900Angstrom by vapor deposition or a method similar to the vapor deposition. The end surfaces of a film capacitor where the electrodes of the capacitor are led out are brought into contact with a gas at least containing a component having reacting property with an organic material which constitutes a dielectric. Parts 11a-11b on the side of the end surfaces for the electrode leads of the dielectric are chemically removed selectively. The vapor deposition electrodes are exposed from the end surfaces for the electrode leads. Neighboring dielectric layers are lapped by 90% or more at said end surfaces so as not to exceed 0.2mm, and irregularities are formed. In this way, the excellent connection between the vapor deposition electrodes having the thin film thickness required for obtaining a self- recovering property and the end surface electrodes can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to metallized film capacitors and methods of manufacturing the same.

BACKGROUND OF THE INVENTION In recent years, there has been a demand for smaller electronic components, and film capacitors are also desired to be smaller and have higher performance.

The most effective way to reduce the size of a film capacitor is to make the dielectric film thinner. Hereinafter, an example of a conventional metallized film capacitor will be described with reference to the drawings.

FIG. 6 is a sectional view showing the structure of a conventional metallized film capacitor element.

In FIG. 6, sla and rslb are metalized films, and 52a and s2b are metal vapor deposited films formed by vapor deposition or similar methods such as vapor sputtering, ion blating, etc. (hereinafter collectively referred to as vapor deposition). .

58a and 5Bb are non-metalized portions (referred to as margins).

) 67 is a film gap (called a wrap) provided for drawing out the electrode to the outside, 54a, 54bI
I'i is an end face electrode formed by metal spraying or the like on the end face of the electrode extension.

Conventionally, in order to ensure reliable connection between the deposited film and the end electrode, when the film is wound up, the film is alternately shifted in the width direction to form so-called wraps 57. This results in
A portion of the end face electrodes s4a, s4b formed by metal spraying or the like was inserted into the wrap and connected to the vapor deposited films 5ea, ssb.

Problems to be Solved by the Invention However, when the film is made thinner, the so-called stiffness of the film itself causes the wrap to become clogged during metal spraying, which prevents the connection between the deposited film and the end electrode. death! There was a problem. This resulted in deterioration of dielectric loss tangent characteristics and deterioration of capacitance accuracy.

In addition, for miniaturization, it is better to have a smaller lap, and currently it is said that the minimum size is about 0.2 mm, but with the above construction method, it is difficult to maintain the lap at a constant value below the above-mentioned size, and the yield is low. This has led to a decline in production costs and an increase in the cost of manufacturing equipment.

Furthermore, as the film becomes thinner, the dielectric breakdown limit decreases due to the increase in insulation defects, making it difficult to increase the rated voltage to the same level as before, so the voltage used must be reduced. Such measures were necessary.

Here, metallized film capacitors have self-healing properties, which means that the greater the resistance of the deposited film (that is, the thinner the deposited film is), the higher the self-healing ability is. It is possible to increase the voltage at the same level, but with conventional technology, if you try to maintain the same voltage using self-healing properties even if the thickness of the film is thinned, the thickness of the deposited film must be extremely thin. I had to.

On the other hand, if the thickness of the deposited film is made very thin, the connection between the deposited film and the end electrode becomes very weak, leading to deterioration of dielectric loss tangent characteristics and capacitance accuracy, making it unsuitable for practical use. The problem was that the number of components increased, leading to a decline in performance.

In order to solve this problem, in the conventional technique, as shown in FIG. 6, opposing portions 62a of vaporized M electrodes are used.

62b, the thickness of the deposited film is reduced, and the area 66 near the electrode extension part is
A and 66b solved this problem by increasing the thickness of the evaporated M film and partially changing the thickness of the evaporated film, but this method complicates the evaporation method and leads to higher costs. I had an issue.

In view of the above-mentioned problems with the conventional methods, the present invention has been developed to ensure that even if the film is made thinner, the necessary connection between the evaporated electrode in the casing and the end face electrode is sufficiently secured without lowering the rated voltage. The present invention aims to provide a film capacitor that does not cause deterioration in characteristics or capacitance accuracy, is small in size, and can be mass-produced at low cost, and a method for manufacturing the same.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention forms a plurality of electrodes with a film thickness in the range of 100 to 900 wafers by vapor deposition or a method similar to evaporation, and forms a plurality of electrodes with a thickness in the range of 100 to 900 wafers. The end surface to be removed is brought into contact with a gas containing at least a component reactive with the organic material constituting the dielectric material, and the portion of the dielectric material on the side of the electrode extension end surface is chemically and selectively removed.

The evaporated electrode is exposed from the end face where the electrode is to be drawn out, and the adjacent dielectric layers are lapped within the end face within a range of not less than 90 mm and not more than 0.2 mm to form irregularities.

By using a thin film, it is possible to form unevenness by wrapping adjacent dielectric layers in a range of 90% or more but not exceeding 0.2fl on the end face, so that the vapor deposited electrode and the end face electrode can be overlapped. The necessary connections are sufficiently secured to prevent deterioration of dielectric loss tangent characteristics and capacitance accuracy, and a good connection between the thin evaporated electrode and the end electrode, which is necessary to obtain self-healing properties, is obtained. Therefore, it is possible to manufacture small metallized film capacitors with good mass productivity and at low cost with the same rated voltage of 11 as before without partially changing the thickness of the deposited film.

EXAMPLES Hereinafter, the metallized film capacitor of the present invention and its manufacturing method will be explained based on examples.

FIG. 1 is a sectional view of the metallized film capacitor in this example.

In the figure, 1a and 1b are single-sided metalized films, and ? 1
ii2a and 2b are dielectric films made of organic materials (
Hereinafter referred to as film. ) are formed on each of 3a and 3b by a vacuum evaporation method. 4a, +b are end face electrodes formed by metal spraying, a part 6 of which is 't'Ff, pole 2
It is inserted between a, 2b and the films 3a*3b, or at least one of the parts between the films 3a and 3b. A portion 6 of the end face mold 1i4a#4b is
By being inserted between the layers as described above, the laminate of the single-sided metallized films 1a and 1b and the end surface electrodes 4a and +b
The adhesion with is very strong.

esa and eb are protruding parts of the electrode i2a#2b, respectively, which are formed by selectively removing the electrode extension end surface side portions of the films 3a and 3b, as described later, and the surface of the electrode 12at2b and the end surface electrode. 4a, 4
Since it is connected with b, very good contact can be obtained.

Hereinafter, a specific example thereof will be explained using FIG. 2.

A poly-ethylene terephthalate film 3 a p 3 b with a thickness of 2 μm is used as a dielectric material, and aluminum is vacuum-deposited to form electrodes 2 a and 2 b with a thickness of 300 mm, thereby producing single-sided metallized films 1 a and 1 b. did. and,
This single-sided metallized film 1a.

A plurality of non-metalized portions 7a extending in the length direction of the film were provided on 1b by a masking method.

These single-sided metallized films 1a and 1b are stacked with the non-metalized portion 8 shifted, wound onto a flat bobbin 8 as shown in FIG. 2A, and pressed while heating.
The bobbin 8 was cut and separated to obtain a laminate 9 having a plurality of capacitor elements as shown in FIG. 2B.

This laminate 9 was cut using a sharp knife, such as a razor, at the electrode extension end faces A and A/ of each capacitor element to obtain a capacitor element 10 shown in FIG. 2C. By this cutting, the electrode extension end face 1 of the capacitor element 10 is
1a, 11b include films 3a, 3b and electrodes 2a, 2.
A large number of gaps 12 were formed between the films 3a and 3b or between the films 3a and 3b.

The electrode end faces 11a, 11b and the gap 12 of the capacitor element 10 obtained in this manner are reacted with highly reactive GANU obtained by ionizing oxygen using a high-frequency electric field to form a film electrode end face side portion. , a portion of the surface of the film 3a3b exposed in the gap was selectively removed. The removal width of the film electrode extension end face side portion is 0.05 fl from the original electrode extension end faces 11a and 11b.
And so.

By selectively removing the films 3a, sb, the electrodes 2a, 2
b has a protruding shape as shown by numerals 13a and 13b in the second drawing. Thereafter, zinc was sprayed onto the electrode lead-out end faces 11a and 11b using a metal spraying method to form end face electrodes 4a and 4b, thereby obtaining a capacitor base material 71.

The capacitor base material 71 thus obtained was cut using a rotating blade 72 as shown in FIG. 3 to obtain a capacitor element 73.

When the capacitor element thus obtained is cut and observed, an end surface electrode 4a can be seen as shown in FIG.

A part of 4b is electrodes 2a, 2b and film 3a.

3b or between the films 3a and sb, a large number of them were inserted in a part of the end surface of the lE rod drawn out.

However, they did not reach the opposing electrodes at 1.

As Comparative Example A, aluminum was vacuum-deposited on the same polyethylene terephthalate film with a thickness of 2 μm to form an electrode with a thickness of 2000 μm to produce a single-sided metallized film, which was subjected to the same process as in the example. A capacitor element was obtained.

As Comparative Example B, on the same polyethylene terephthalate film with a thickness of 2 μm, aluminum was vacuum-deposited to form a 300-μm-thick electric kettle to produce a single-sided metallized film, and the wrap was Q, 2. ml and roll it up,
After pressing while heating, zinc was sprayed onto the exposed end faces of each electrode layer using a metal spraying method to form end face electrodes and obtain capacitor elements.

When the thus obtained capacitor element of Comparative Example B was cut and observed, it was found that many portions of the poles at the end surfaces were inserted into the wrap of the film, as shown in FIG. However, they did not reach the opposing electrodes.

The capacitor of the present invention obtained as described above and the capacitors of Comparative Examples A and B were
FIG. 4 shows the capacitance change rate, dielectric loss tangent characteristics, and insulation resistance values when V, 125 V, and 150 V were applied for 60 seconds.

As shown in FIG. 4, the metallized film capacitor of the present invention maintains the capacitance change rate, dielectric loss tangent characteristic, and insulation resistance value at a good value of 1 at a higher voltage than the comparative example.

This indicates that the metallized film capacitor of the present invention has good self-healing properties.

Further, the capacitor of the present invention and the capacitors of Comparative Examples A and B were subjected to a high temperature load reliability test.

The test temperature was 86°C and the load voltage was 100V. The results are shown in FIG.

As shown in FIG. 5, the capacitance change rate, dielectric loss tangent characteristic, and insulation resistance value of the metallized film capacitor of the present invention have been maintained for a long time compared to the comparative example.

In Comparative Example A, the insulation resistance value decreased, and in Comparative Example B, the capacitance change rate was large and the dielectric loss tangent characteristics were deteriorated.

The above results show that the film capacitor of the present invention can maintain good characteristics even at high operating voltages.

In addition, the film capacitor of the present invention can have smaller external dimensions because the amount of unevenness on the end face of the electrode extension can be smaller than that of ordinary wrap, and manufacturing does not require special methods such as partially changing the thickness of the deposited film. There is no cost increase and mass production is high.

In this example, polyethylene terephthalate was used as the dielectric, aluminum was vacuum-deposited as the electrode, and zinc was sprayed as the end electrode. , electrode
The method for forming the electrode button and the end surface electrode is not limited to this, and materials used in ordinary film capacitors and methods for forming the electrode button and the end surface electrode can be used.

Furthermore, the structure of the capacitor is not limited to the laminated type shown in this embodiment, and it is of course possible to obtain the same hardening as described above with a wound type as well.

Furthermore, the structure of the film is not limited to the single-sided metallized film shown in this example, and a double-sided metalized film or a composite film in which a dielectric material is formed on at least one side of the metallized film may be used as described above. The same effect can be obtained.

The method for selectively removing the film is not limited to this example, and for example, a gas with increased reactivity by activating fluorine or hydrogen can be used.

Effects of the Invention As described above, the present invention forms a plurality of electrodes with an electrode resistor film thickness in the range of 100 to 900 by vapor deposition or a method similar to vapor deposition, and the end face of the film capacitor from which the electrodes are to be drawn is dielectrically coated. chemically and selectively removing the electrode extension end surface side portion of the dielectric by bringing it into contact with a gas containing at least a component reactive with the organic material constituting the body;
The vaporized M electrode is exposed from the end surface where the electrode is to be drawn out, and the adjacent dielectric layer is 0.0.
By forming unevenness by lapping within a range not exceeding 2 mm, it is possible to create a good bond between the thin evaporated electrode and the end electrode, which is necessary to obtain self-healing properties, without partially changing the thickness of the evaporated film. This makes it possible to provide a compact, highly reliable film capacitor with a high operating voltage rating and with good mass production efficiency.

[Brief explanation of drawings]

Figure 1 is a sectional view of one embodiment of the film capacitor according to the present invention, Figure 2 is a diagram for explaining the manufacturing method thereof, and Figure (8) is a winding system using a flat bobbin. A perspective view showing the process. Figure (B) is a sectional view of the laminate separated from the flat bobbin. Figure 0 is a cross-sectional view of the laminate separated from the flat bobbin. 3 is a cross-sectional view showing a state in which the end face side portion is selectively removed, FIG. 3 is a perspective view showing the process of cutting the capacitor base material to obtain a capacitor element, and FIG. 4 is a DC voltage diagram for capacitors of the present invention and a comparative example. Characteristic diagram showing the results when applying
The figure also shows the results of the high temperature load test at 0t! J = figure,
FIG. 6 is a sectional view of a conventional film capacitor, and FIG. 7 is a sectional view showing an example of a conventional film capacitor in which the thickness of the deposited film is partially changed. 1a, 1b... Single-sided metallized film, 2a, 2
b... Electrode, 3a, 3b... Dielectric film (film), 4a, 4b... End electrode, 5.
...Part of the end electrode, ea, eb...
-Protruding parts of electrodes 2a and 2b.

Claims (11)

[Claims] (1) A plurality of electrodes having a film thickness in the range of 100 Å to 900 Å, a dielectric material made of at least one layer of organic material disposed between the electrodes, and a dielectric material provided on each electrode extension end face and alternately connected to the electrodes. and an end face electrode, the end faces of adjacent dielectrics in the electrode lead-out end face portion are uneven surfaces, and the amount of the unevenness is not more than 0.2 mm and covers 90% or more of the electrode lead-out end face. A metallized film capacitor featuring: (2) At least a portion of the end face electrode has an uneven dielectric layer of at least 5 μm or more on the electrode extension end face;
2. The metallized film capacitor according to claim 1, wherein the metallized film capacitor is interposed between a dielectric layer and an electrode layer. (3) An end face of the dielectric in a laminate or a wound product in which a plurality of electrodes having a thickness in the range of 100 Å to 900 Å are formed and the dielectric consists of at least one layer of organic material arranged between the electrodes. forming an end electrode after chemically selectively removing a portion of the dielectric on the side of the electrode extension end surface by contacting the electrode extension end face with the aligned electrode extension end face with a gas containing at least a component reactive with the organic material; A method for manufacturing a metallized film capacitor, characterized by: (4) The method for manufacturing a metallized film capacitor according to claim 3, characterized in that the portion of the dielectric material on the side of the electrode extension end surface is chemically and selectively removed using plasma containing at least oxygen. (5) The electrode extension end surface side portion of the dielectric is chemically and selectively removed using plasma containing oxygen-containing gas added with at least one of CF_4, SF_6, and N_2O. A method of manufacturing metallized film capacitors. (6) The method for manufacturing a metallized film capacitor according to claim 3, characterized in that the portion of the dielectric on the side of the electrode extension end face is chemically and selectively removed using oxygen radicals extracted from plasma containing at least oxygen. (7) The method of manufacturing a metallized film capacitor according to claim 3, characterized in that the portion of the dielectric material on the side of the electrode extension end surface is chemically and selectively removed using a gas containing at least ozone. (8) The method for manufacturing a metallized film capacitor according to claim 3, characterized in that the portion of the dielectric on the side of the electrode extension end face is chemically and selectively removed with a gas containing at least ozone and N_2O added thereto. . (9) The method for manufacturing a metallized film capacitor according to claim 7 or 8, wherein ultraviolet rays are irradiated when selectively removing the electrode extension end face side portion of the dielectric material chemically. (10) A step of winding or laminating a wide single-sided metalized film having an electrode layer with a film thickness in the range of 100 Å to 900 Å and having a plurality of capacitor elements, and a wound product obtained in the above step. Alternatively, the step of cutting the laminate at the end face portion of the electrode lead-out side, and the step of bringing the end face of the lead-out electrode into contact with a gas containing at least a component reactive with the organic material constituting the film to chemically cut the end face side portion of the electrode lead-out face of the film. 1. A method for manufacturing a metallized film capacitor, the method comprising the steps of: selectively removing the capacitor; and forming an end electrode on the end surface side portion of the electrode extension. (11) A wide double-sided metallized film having an electrode layer with a film thickness in the range of 100 Å to 900 Å and a plurality of capacitor elements and a wide laminated film are alternately wound or laminated. a step of cutting the rolled product or laminate obtained in the step at the end face portion of the electrode extension, and contacting the end face of the electrode extension with a gas containing at least a component reactive with the organic material constituting the film. A method for manufacturing a metallized film capacitor, comprising the steps of: chemically selectively removing a portion of the film on the side of the electrode extension end face; and forming an end face electrode on the side portion of the electrode extension end face.