JPH04165611A - Laminated film capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To perform a smoothing operation in a wide range and absorption of noise by a single element by providing two pairs of external electrodes made of independently metallized contact electrodes at four sides of a laminate. CONSTITUTION:Two pairs of metallized contact electrodes 2-5 are provided on four sides of a laminate, i.e., four surfaces of the laminate 1 for constituting the outer periphery of the laminate 1 in the laminating direction in a capacitor. In this case, in the laminate 1, plastic films 6 and deposited electrodes 7 are alternately laminated. The electrode 7 has one end margin 8 or discharging margin 9 of each section, and the electrodes 7 brought into adjacent contact through the thickness of the films 6 are so disposed that the margins 8 or 9 are positioned at the ends of opposite sides to each other. If the capacitor is considered from an input side, an equivalent circuit network becomes a distributed constant circuit network of the capacitor and a resistor to form a high frequency element filter. Thus, a smoothing operation in a wide range and absorption of noise can be performed by a single element.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laminated film 1 formed by laminating a metallized plastic film having a vapor-deposited electrode formed on at least one surface of the plastic film, a capacitor, and a manufacturing method thereof.

[Prior Art] Conventionally, as a means to remove or absorb high frequency noise, techniques have been adopted in which a capacitor or a plurality of capacitors are connected in parallel to a circuit, or a coil and a capacitor are combined to form an LC filter. ing.

As capacitors for such applications, conventionally used capacitors include film capacitors with protruding electrode structures, metallized film capacitors using metallized plastic films, and multilayer ceramic capacitors.

In addition to the following three types of capacitors, multilayer film capacitors made of metallized plastic films are superior in terms of miniaturization, so there is a demand for the development of -layers. Figures 14 and 15 are diagrams showing such a multilayer film capacitor, with Figure 14 being a perspective view and Figure 1
FIG. 5 is a perspective view for explaining the stacked state. In other words, a margin portion 2 is provided at one end of one side of the plastic film.
A pair of metallized plastic films 21-, each having a vapor-deposited electrode 22 formed thereon, are stacked so that their margin portions 21a are opposite to each other, and are laminated in this state to form a capacitor element 23. ing. Metallicon electrodes 24a are provided on both end surfaces of this capacitor element 23, and lead wires 24 are drawn out.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has the following drawbacks.

That is, in the conventional capacitor as described above, the self-inductance is not zero, and the effect of this on high-frequency noise cannot be ignored, and the impedance at high frequencies increases.

The factors of this inductance are the lead wire length and the capacitor internal electrode length. Of these, regarding the inductance component due to the lead wire length, the capacitor terminals are
The inductance caused by the lead wires is canceled out by using a so-called 4-terminal structure, or by using a chip structure, but there is a problem that the inductance component caused by the length of the internal electrode of the capacitor cannot be canceled. There remained a problem with high frequency noise absorption.

On the other hand, in the prior art, in order to compensate for such low high frequency noise absorbability, as described above, a plurality of capacitors are connected or an LC filter is formed. However, mounting a plurality of components in this manner goes against the demands for smaller, simpler, and more reliable equipment, and instead makes the equipment larger and more complex, reducing reliability.

The present invention was proposed to solve the problems of the prior art as described above, and its purpose is to use a single element,
An object of the present invention is to provide an excellent multilayer film capacitor and a method for manufacturing the same, which are capable of wide-range smoothing and noise absorption, and can contribute to miniaturization, simplification, and improved reliability of equipment.

[Means for Solving the Problems] A multilayer film capacitor according to the invention has a laminate in which plastic films and vapor-deposited electrodes formed on one surface of the plastic film are alternately stacked, and this laminate The vapor-deposited electrodes have non-evaporated parts on two adjacent end sides, and the vapor-deposited electrodes that are adjacent to each other across the thickness of the plastic film are arranged so that the non-evaporated parts face each other, and It is characterized by having two pairs of external electrodes consisting of separate and independent metallicon electrodes provided on the four sides of the laminate.

A method for manufacturing a multilayer film capacitor according to the invention of claim 2 is a method for manufacturing a multilayer film capacitor according to claim 1, in which one non-evaporated part of the evaporated electrode of the laminate is removed during evaporation, slitting, or winding. Sometimes oil
It is characterized in that it is provided by tape or laser processing, and the other non-evaporated part is provided by discharge treatment after lamination.

A method of manufacturing a multilayer film capacitor according to the invention of claim 3 is a method of manufacturing a multilayer film capacitor according to claim 1, in which a vapor-deposited electrode is provided on one surface of the plastic film so that one edge thereof has a non-evaporated portion. a step of laminating a plurality of pairs of the formed metallized plastic films so that the non-evaporated parts face each other and are shifted so that the electrode end surfaces are exposed to form a laminate, and forming a laminate at both ends of the laminate; forming first and second metallized electrodes to form a mother element; cutting the mother element to a predetermined length to form individual capacitor elements; a step of contacting a conductive electrode and applying a voltage between the first metallicon electrode and the conductive electrode to generate a predetermined discharge to form a non-evaporated portion on the first cut surface; A step of forming a third metallicon electrode on the first cut surface after the discharge treatment, and a step of contacting a conductive electrode with the second cut surface of the individual capacitor element and applying a voltage between the second metallicon electrode and the conductive electrode. a step of forming a non-deposited portion on the second cut surface by applying a predetermined discharge, and a step of forming a non-deposited portion on the second cut surface after the discharge treatment of the second cut surface;
The method is characterized by comprising a step of forming a metallicon electrode.

[Operations] The functions of the present invention having the above-described configuration are as follows.

First, in the multilayer film capacitor according to the structure of claim 1, when considered from the input end, the equivalent circuit network becomes a distributed constant network of capacitors and resistors to form a high frequency element filter. The voltage that appears between the electrodes gradually develops, and the frequency band higher than the resonant frequency found in ordinary two-terminal capacitors, that is, MHz.
Even in the band, there is no increase in the noise output voltage, and the noise output voltage attenuates as it is.

Furthermore, the equivalent circuit network has a smoothing effect even in the MHz band.

Next, the manufacturing methods of claims 2 and 3 are methods that apply the conventional manufacturing method of a laminated film capacitor using a metallized plastic film, and are excellent in practicality.

In particular, the manufacturing method of claim 3 can use a conventional general metallized plastic film, which is a one-sided margin film having a margin part (non-evaporated part) at one end, so there is no need to prepare a special film.

In addition, in this manufacturing method, both of the vapor-deposited counter electrodes are exposed on the cut surface, but the discharge with the electrode in contact with the cut surface is connected to one metallicon electrode to which voltage is applied. This occurs only at the evaporation electrode, and a margin portion (non-evaporation portion) is formed at the end of this evaporation electrode, and since no discharge occurs at the other evaporation electrode, the electrode end remains exposed.

This is the same on the first and second cutting planes,
As a result, the electrode ends of every other vapor-deposited electrode are exposed alternately on the cut surface, and no margin portion is formed at the opposite end. Therefore, by forming metallicon electrodes on the cut surfaces on both sides, the adjacent two
A capacitive layer can be obtained between two opposing pairs of metallicon electrodes, where the two metallicon electrodes have the same polarity. This method has excellent manufacturing efficiency because a large number of individual capacitors can be manufactured at one time using a mother element.

[Example] An example of the multilayer film capacitor and manufacturing method according to the present invention will be specifically described below with reference to FIGS. 1 to 8. In this case, Fig. 1 shows the completed capacitor, Figs. 2 and 3 show the cross section of the completed capacitor, Figs. 4 to 7 show the manufacturing process, and Fig. 8 shows the completed capacitor. FIG. 9 is a circuit diagram of a switching power supply.

First, as shown in FIG. 1, the capacitor of this example is
Two pairs of metallicon electrodes 2, 3 and 4, 5 are provided on four sides of the laminate 1, that is, on four surfaces in the stacking direction (vertical direction) constituting the outer peripheral surface of the laminate 1. In this case, the laminate 1
As shown in FIGS. 2 and 3, plastic films 6 and vapor-deposited electrodes 7 are alternately laminated.

The vapor-deposited electrodes 7 have a margin portion 8 or a discharge treatment margin portion 9 at one end of each cross section, and vapor-deposited electrodes 7 that are adjacent to each other with the thickness of the plus deck film 6 in between have a margin portion 8 or a discharge treatment margin portion 9 at one end of each cross section. The discharge treatment margin portions 9 are arranged so as to be located at opposite ends.

That is, as shown in FIG. 2, in the cross section taken along the straight line A-A- connecting the pair of metallicon electrodes 4.5, the vapor deposited electrode 7 has a discharge treatment margin part 9 at the end on the side of one metallicon electrode 4. , and a vapor deposition electrode 7 having a discharge treatment margin portion 9 at the end on the other metallic electrode 5 side are arranged alternately. Similarly, as shown in FIG. 3, in the cross section taken by the straight line 13-B- connecting the pair of metallicon electrodes 2 and 3, a vapor deposited electrode 7 having a margin portion 8 at the end on the side of one metallicon electrode 2; The other metallic electrode 3
Vapor deposition electrodes 7 having margin portions 8 at the side ends are alternately arranged.

Furthermore, if we focus only on the vapor deposition electrode 7, for example, the uppermost vapor deposition electrode 7 in FIGS. 2 and 3 has a discharge treatment margin at the end on the metallicon electrode 4 side and the end on the metallicon electrode 3 side, respectively. The vapor deposition electrode 7 in the second stage from the top adjacent to this has a discharge treatment margin part 9 and a margin part 8 at the end on the metallicon electrode 5 side and the end on the metallicon electrode 2 side, respectively. It has a margin part 8. Then, as a pair of these two types of vapor deposition electrodes 7,
These are also arranged alternately for the third and subsequent stages.

That is, in the laminate 1 shown in FIGS. 1 to 3,
Each vapor deposition electrode 7 has a discharge treatment margin portion 9 and a margin portion 8 on two adjacent edges of the laminate 1, and adjacent vapor deposition electrodes 7 are separated from each other through the thickness of the plastic film 6. , the discharge treatment margin parts 9 and the margin parts 8 are arranged so as to face each other.

In addition, in FIGS. 2 and 3, 10 is the laminate II
- the lower protective film layer.

Next, a method for manufacturing a capacitor as shown in FIGS. 1 to 3 will be described.

First, as shown in FIG. 4, a long one-sided margin of 1.5 μm thickness and 8 mrn width is formed by providing a margin portion (non-deposited portion) 8 of 0°5 mm at one end of one side to form a vapor deposited electrode 7. A pair of films 11 are laminated to a thickness of 4.3 mm, and first and second metallicon electrodes 2 and 3 are provided on both end faces of this laminate.
was formed to complete the mother element. After that, this mother element was cut with a metal saw of φ1.25-0°5t and 68 teeth.
When cut into individual capacitor elements 12 with a width of 8.5 mm at 1000 rpm to 200 rpm, the cut surfaces 13 on both sides
] 4 was smooth and blackened, and it was confirmed that the ends of the vapor-deposited electrodes 7 were exposed at each cut surface 13 and 14. Figure 5 shows capacitor element 1 obtained in this way.
FIG.

Next, as shown in FIG.
Copper plate, phosphor bronze plate, or Be-Cu
A discharge brush 15 made of a (beryllium copper) plate is brought into contact with the first metallic electrode 2, and the first cut surface] 3
A negative voltage was applied to perform the discharge treatment. The applied voltage in this case is a direct current or pulsed voltage of 25 QVdc.

Ta. Then, the discharge brush] 5 was moved to continue the discharge treatment, and the discharge treatment was stopped when discharge no longer occurred.

Subsequently, as shown in FIG. 7, the discharge brush 15 is brought into contact with the second cut surface 4 of the capacitor element 12, and a positive electrode is applied to the second metallic contact electrode 3, and a negative electrode is applied to the second cut surface 14. A discharge treatment similar to that described above was performed by applying this voltage.

After that, on the cut surfaces 1.3.1.4 on both sides that were subjected to discharge treatment,
As shown in FIG. 1, a pair of third and fourth metallicon electrodes 4°5 are formed with a mask to prevent short circuit with the existing first and second metallicon electrodes 2.3, and four terminals are formed. A multilayer film capacitor with this structure was obtained.

In the multilayer film capacitor completed as described above, the first and second metallicon electrodes 2 and 3 formed before cutting are
When the capacitance between them was measured, it was found to be 2.degree. 2 .mu.F, and it was confirmed that the capacitance between the third and fourth metallicon electrodes 4.5 newly formed after discharge was also the same <2.degree. 2 .mu.F.

Furthermore, as shown in FIG. 1, when the completed capacitor was disassembled and the edges of the film were observed under a microscope, it was found that each one-sided margin film 11 had only one cut surface edge. , there was a discharge trace of about 0°1 mm (
A discharge treatment margin part) 9 is formed, and there is no discharge trace at the end of the other cut surface, and the vapor-deposited electrode 7 reaches the end of the cut surface and is connected to the third or fourth metallicon electrodes 4 and 5. It was confirmed that

That is, in the one-side margin film 11 shown in FIG.
A discharge trace is formed only at the end of the second cut surface 14, and there is no discharge trace at the end of the second cut surface 14, and the vapor deposition electrode 7 reaches the end of the cut surface and is connected to the fourth metallicon electrode 5. ing.

To explain in more detail, in the even-numbered one-sided margin film 11 from the top, discharge marks are formed only at the end of the second cut surface 14, and discharge marks are formed at the end of the first cut surface 13. The vapor deposition electrode 7 reaches the end of the cut surface and is connected to the third metallicon electrode 4. This is because in the discharge treatment by applying a voltage between the first metallicon electrode 2 and the first cut surface 13, the vapor deposition electrode 7 connected to the first metallicon electrode 2 (on the odd-numbered stage from -L) Vapor deposition electrode 7
), and the second metallicon electrode 3
In the discharge treatment by applying a voltage between the metallicon electrode 3 and the second cut surface 14, discharge occurred only at the vapor deposition electrodes 7 (even-numbered vapor deposition electrodes 7 from the top) connected to the second metallicon electrode 3. This is the result.

As a result of forming the discharge treatment margin portions 9 as described above, the vapor deposition electrodes 7 in odd-numbered stages from the top are
, are connected to the fourth metallicon electrodes 2 and 5, and the even-numbered evaporation electrodes 7 from the top are connected to the second and third metallicon electrodes 3.4.

The margin portion 8 of the one-side margin film 11 can be provided by oil tape or laser processing during vapor deposition, slitting, or winding.

Next, the operation of the multilayer film capacitor of this example completed as described above will be explained.

First, in a switching power supply circuit as shown in FIG. 9, the first metallicon electrode 2 of the capacitor element 12 is connected to the positive side of the input terminal, and the fourth metallicon electrode 5, which is common to this first metallicon electrode 2, is connected to the output terminal. Similarly, the third metallicon electrode 4 was connected to the negative side of the input side, and the second metallicon electrode 3 was connected to the negative side of the output side, respectively, as shown in Figs. 10 and 11. As shown in , it was confirmed that the noise voltage included in the output voltage of the capacitor of this example was significantly reduced compared to the noise voltage of the conventional capacitor.

That is, FIG. 10 is a diagram showing the noise voltage characteristics of the multilayer film capacitor of this example, and FIG. 11 is a diagram showing the noise voltage of a multilayer film capacitor (conventional example) with the same rating and the same capacity manufactured according to the conventional technology. It is clear from these drawings that the noise voltage of the multilayer film capacitor of this example is significantly reduced compared to the conventional example.

In addition, Figures 12 and 13 show the results of measuring frequency response using a spectrum analyzer.
FIG. 12 shows the characteristics of this embodiment, and FIG. 13 shows the characteristics of the conventional example. From FIGS. 12 and 13, it is clear that in high frequency bands, the amount of attenuation of the noise output voltage of this example is much larger than the amount of attenuation of the noise output voltage of the conventional example, which is small. .

It should be noted that the present invention is not limited to the above embodiments, and the materials used are not limited to a pair of metallized plastic films, for example, a double-sided metallized film with the same electrode structure and a plastic film. It is also possible to use a combination of films or a single film consisting of said double-sided metallized film coated with a plastic film layer.

[Effects of the Invention] As explained above, in the present invention, by connecting the external electrodes on two adjacent ends to the input end and the external electrodes on the other two ends to the output side, high frequency impedance can be reduced. Because it can be made small, a single element can perform a wide range of smoothing and noise absorption, making equipment smaller and simpler.
It is possible to provide an excellent multilayer film capacitor that can contribute to improved reliability.

Moreover, it can be easily manufactured using conventional film technology, has high manufacturing efficiency, and is excellent in economic efficiency.

[Brief explanation of the drawing]

1 to 9 are diagrams showing an embodiment of the laminated film capacitor and manufacturing method according to the present invention. FIG. 1 is a perspective view showing a completed capacitor, and FIG.
3 is a sectional view taken along line B-B'' of FIG. 6 is a perspective view showing a state in which individual capacitor elements are formed by
Fig. 7 and Fig. 7 are schematic perspective views showing different discharge states during the manufacturing process, Fig. 8 is a perspective view showing the internal electrodes of the completed capacitor, and Fig. 9 shows the capacitor shown in Fig. 1 connected to a switching power supply. It is a circuit diagram showing a state. FIG. 10 is a noise voltage characteristic diagram of the capacitor shown in FIG. 1, FIG. 11 is a noise voltage characteristic diagram of the capacitor according to the prior art, and FIG. 12 is a frequency response curve diagram of the capacitor shown in FIG.
FIG. 13 is a frequency response curve diagram of a capacitor according to the prior art. FIG. 14 is a perspective view showing a conventional laminated film capacitor, and FIG. 15 is a perspective view showing a metallized plastic film constituting the capacitor shown in FIG. DESCRIPTION OF SYMBOLS 1... Laminated body, 2... 1st metallicon electrode, 3...
...Second metallicon electrode, 4...Third metallicon electrode, 5...Fourth metallicon electrode, 6...Plastic film, 7... Vapor deposition electrode, 8...Margin part, 9 . . . Discharge treatment margin portion, 10 . . . Protective film layer. DESCRIPTION OF SYMBOLS 11... One side margin film, 12... Capacitor element, 13... First cut surface, 14... Second cut surface, 15... Discharge brush. 21...Metalized plastic film, 21a...
Margin portion, 22... Vapor deposition electrode, 23... Capacitor element, 24... Lead wire, 24a... Metallicon electrode.

Claims (3)

[Claims] (1) It has a laminate in which a plastic film and a vapor deposited electrode formed on one surface of the plastic film are alternately laminated, and the vapor deposited electrode of this laminate has a non-vapor deposited part on two adjacent edges. In addition, the vapor-deposited electrodes that are adjacent to each other through the thickness of the plastic film are arranged so that the non-deposited parts face each other, and further, the metallicon electrodes that are adjacent to each other across the thickness of the plastic film are arranged such that the non-deposited parts face each other, and the metal electrodes that are adjacent to each other through the thickness of the plastic film are Naru 2
A multilayer film capacitor characterized by having a pair of external electrodes. (2) It has a laminate in which plastic films and vapor-deposited electrodes formed on one surface of the plastic film are alternately laminated, and the vapor-deposited electrodes of this laminate have non-vapor-deposited parts on two adjacent edges. , and the vapor-deposited electrodes that are adjacent to each other across the thickness of the plastic film are arranged such that the non-deposited parts face each other, and furthermore, it consists of separate and independent metallicon electrodes provided on the four sides of this laminate. A method for manufacturing a laminated film capacitor characterized by having two pairs of external electrodes, the non-vaporized part of one of the vapor-deposited electrodes of the laminated body being coated with oil tape or laser during vapor deposition, slitting, or winding. A method for manufacturing a multilayer film capacitor, characterized in that the non-evaporated portion is provided by processing, and the other non-deposited portion is provided by discharge treatment after lamination. (3) It has a laminate in which plastic films and vapor-deposited electrodes formed on one surface of the plastic film are alternately laminated, and the vapor-deposited electrodes of this laminate have non-vapor-deposited parts on two adjacent edges. , and the vapor-deposited electrodes that are adjacent to each other across the thickness of the plastic film are arranged such that the non-deposited parts face each other, and furthermore, it consists of separate and independent metallicon electrodes provided on the four sides of this laminate. A method for manufacturing a laminated film capacitor characterized by having two pairs of external electrodes, comprising: a pair of metallized electrodes formed on one surface of a plastic film with vapor-deposited electrodes having a non-deposited portion on one edge thereof; A step of stacking a plurality of pairs of plastic films so that the non-evaporated parts face each other and are shifted so that the electrode end faces are exposed to form a laminate, and a step of forming a laminate with first and second metallized resin on both ends of the laminate. forming an electrode to form a mother element; cutting the mother element to a predetermined length to form individual capacitor elements; and contacting a conductive electrode to a first cut surface of the individual capacitor element; A step of applying a voltage between the metallicon electrode and the conductive electrode to generate a predetermined discharge to form a non-deposited part on the first cut surface, forming a third metallicon electrode, and contacting a conductive electrode with the second cut surface of the individual capacitor element, and applying a voltage between the second metallicon electrode and the conductive electrode to generate a predetermined discharge. let me,
forming a non-evaporated portion on the second cut surface;
A method for manufacturing a multilayer film capacitor, comprising the step of: forming a fourth metallicon electrode on the second cut surface after discharging the cut surface.