JP3155323B2 - Method of manufacturing film capacitor and method of manufacturing metallized film for capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallized film capacitor and a metallized film for manufacturing the same.

[0002]

2. Description of the Related Art This type of metallized film capacitor is usually manufactured through the following steps. First, as shown in FIG. 5, a metal such as aluminum or zinc is formed on the upper surface of a long dielectric film substrate 4 having a constant width, except for a non-deposition portion 4A for margin having a constant width along one side edge. Forming a vapor-deposited film 3 and forming a first metallized film 1
And

Next, similarly to the metallized film 1, a second metallized film 2 in which a metal vapor-deposited film 5 is formed on the upper surface of a dielectric film substrate 6 except for a non-vapor-deposited portion 6A for margin is formed. Non-evaporation parts 4A, 6A for margin
Are located on opposite sides of each other, and the non-evaporated portions 4A and 6A are overlapped with the first metallized film such that they are located inside the edge of the other film.

Further, after this laminated film (1 + 2) is wound in a cylindrical shape, electrodes 8 such as zinc and solder are formed on both ends of the cylindrical body 7 by a spraying method or the like as shown in FIG. A lead wire 9 is connected to each of the electrodes 8, and the entire product is covered with an exterior 10, thereby completing the product.

Incidentally, in an AC circuit for electric equipment or the like, a security device may be provided in order to prevent damage to the device and a fire accident due to an abnormality in the capacitor, and this type of security device generally operates due to an abnormal current. Electric fuses, thermal fuses using a rise in temperature, pressure fuses using deformation of a lid of a capacitor case, and the like are used.

However, each of the above fuses has a drawback that the response speed is not sufficient, and a certain time is required until the fuses operate. It has also been proposed to incorporate the above-mentioned fuse function inside the capacitor. However, the strength of the capacitor case is restricted, which makes it difficult to design the capacitor. It has to be provided as a device, and there is a disadvantage that the cost is high.

Therefore, recently, measures have been taken to improve the above-mentioned drawbacks by providing a fuse function to the metallized film for a capacitor itself. FIG. 7 shows an example of such a metallized film with a fuse. This metallized film is used as one of the metallized films 1 (or 2) in FIG. 5 described above, and the non-evaporated portion 11 for division extending in the width direction is provided on the metal evaporated film 3 (or 5). The formed metal deposition film 3 is divided into a number of rectangular portions 3A.

In order to form such a non-evaporated portion 11,
After spraying oil on the corresponding portion of the film substrate 4,
A method of locally stopping deposition by performing deposition, a method of removing a deposited film by laser light, and the like are possible.

When the metallized film shown in FIG. 7 is used, when a short circuit occurs between the metal deposition films 3 and 5, the junction P1 between the rectangular portion 3A including the short-circuited portion and the electrode 8 generates heat and is disconnected as a fuse. Then, the current supply to the short-circuit portion is stopped.

However, in the above fuse structure,
It is difficult to accurately adjust the contact resistance between the rectangular portion 3A and the electrode 8, and there is a disadvantage that the fuse action tends to vary.

FIG. 8 shows a metallized film in which the above disadvantages are improved. In this film, a non-deposited fuse extending in the longitudinal direction of the film is provided at a predetermined distance from an edge of the film opposite to the non-deposited portion 4 for margin. The portion 12 is formed intermittently, and the dividing non-deposited portion 11 extending from the fuse non-deposited portion 12 to the margin non-deposited portion 4 is formed. The non-deposited portion 12 for fuses manufactured so far has its longitudinal end formed in a U-shape as shown in FIG. 9, and the fuse portion 13 has a rectangular shape.

In this example, the gap between the non-deposited portions 12 for fuses serves as the fuse portion 13, and the metal deposited films 3, 5 are formed.
Is short-circuited, the rectangular portion 3A including the short-circuited portion
The fuse portion 13 connected to the fuse 13 generates heat and is disconnected, and the current supply to the short-circuit portion is stopped. According to this example, the fuse unit 1
By setting the width of 3 appropriately, there is an advantage that the amount of current flowing until the fuse portion 13 is disconnected can be freely set.

[0013]

However, the present inventors have conducted various security tests on the fuse action of FIG. 9, and as a result, it has been confirmed that the fuse action still varies. When the cause was examined in detail, it was found that the cause was due to the shape of the fuse portion 13.

That is, since the fuse section 13 has a rectangular shape with a constant width, when an excess current flows, first, the entire area of the fuse section 13 generates heat (hatched portion in FIG. 9), and the metal of the heat generating portion evaporates. Evaporation starts selectively from the easy part. Then, once evaporation occurs, heat is concentrated on the narrowed portion, and the fuse portion 13 is cut off at once. In this process, the influence of a slight thickness error or a slight width error of the fuse portion 13 is enlarged, and a shift at the start of evaporation is caused. This leads to instability of the fuse action.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a film capacitor and a metallized film for the capacitor which can obtain a stable fuse action.

[0016]

SUMMARY OF THE INVENTION In order to solve the above problems, the production of a metallized film for a capacitor according to the present invention is provided.
Method, the upper surface of the long plastic film substrate with a constant width, and forming a metal evaporated film except the non-deposition portion for margin constant width along the side edges of the other hand, the fill
While running the base material, the metal vapor-deposited film is condensed in a circle at a position away from the other side edge of the film by a certain distance.
Laser beam intermittently,
Evaporates the metal deposition film and extends in the longitudinal direction of the film base
And both end edges are convex toward the adjacent fuse portion.
Forming a non-deposited portion for a fuse formed in a semicircular shape intermittently, thereby forming a fuse portion having a fixed width in a gap between the non-deposited portions for a fuse, and forming a film on the metal-deposited film. Forming a non-deposition portion for region division extending at least from the non-deposition portion for fuse to the non-deposition portion for margin extending in the width direction of the base material.

[0017] The metal evaporated film is aluminum, zinc, copper or may be formed by one or more metals selected from these alloys. Further, the film substrate may be selected from polyethylene terephthalate, polypropylene, polystyrene, polycarbonate, polytetrafluoroethylene, and polyethylene.

On the other hand, production of the film capacitor of the present invention
The method is to use a long plastic film base material with a fixed width.
On top, a non-steaming margin for a fixed width along one side edge
Forming a metal deposition film excluding the attachment portion,
While running the base material, the film
Focus at a certain distance from the other side edge of
Laser beam intermittently,
Evaporates the metal deposition film and extends in the longitudinal direction of the film base
And both end edges are convex toward the adjacent fuse portion.
The non-evaporated part for the fuse formed in a semicircular shape is intermittently formed.
By forming, between these non-deposited parts for fuses
Forming a fixed width fuse portion in each gap;
The metal deposited film extends in the width direction of the film base
Both reach from non-deposited part for fuse to non-deposited part for margin
To form a non-deposited area for
A step of obtaining a film, and forming the capacitor-producing film as a first film, on the upper surface of a plastic film substrate having the same width and the same length as the film substrate of the first film, with one side edge thereof. A second film on which a metal vapor-deposited film is formed except for a non-deposited portion for margin having a constant width along the second film, wherein the non-deposited portion for margin of the second film corresponds to the non-deposited portion for fuse of the first film, and The laminated film is superimposed on the first film so that the non-deposited portion for margin of one film corresponds to the metal deposited film of the second film.
And obtaining a wound the laminate film into a cylindrical shape, a step of connecting each of the electrodes to the each metal deposition film by connecting each electrode to both ends of the cylindrical body
It is characterized by having .

[0019]

According to the manufacturing method of preparation and the metallized film for a capacitor film capacitor the present invention, since the width of the central portion shape of the fuse part is narrower shape than both end portions, an excessive current flows relative The central part of the fuse part, which has a high electrical resistance, generates heat intensively, and evaporation starts from this central part without fail. Therefore, the influence of a slight thickness error or a slight dimensional error of the fuse portion on the critical current value at which the fuse portion is disconnected is small, the variation of the critical current value is small, and a stable fuse action can be obtained.

[0020]

Next, embodiments of the film capacitor and the metallized film for the capacitor according to the present invention will be described in detail. FIGS. 1 and 2 show an embodiment of a metallized film. Reference numeral 4 denotes a long plastic film base material having a constant width, and reference numeral 3 denotes a metal vapor-deposited film 3 formed on the upper surface of the film base material 4. is there.

The metal deposition film 3 is separated from the margin non-deposition portion 4A extending in the longitudinal direction of the film at a constant width along one side edge of the film substrate 4 by a predetermined distance from the other side edge of the film substrate 4. The non-deposited portion 20 for fuses extending intermittently in the longitudinal direction of the film at the position where the fuse is formed, and the non-deposited portion 11 for region division extending from the non-deposited portion 20 for fuses to reach the non-deposited portion 4A for margin extending in the film width direction. It is formed over the entire upper surface of the film substrate 4 except for the upper surface.

The plastic used as the material of the film substrate 4 is not limited, but preferably, one or two or more selected from polyethylene terephthalate, polypropylene, polystyrene, polycarbonate, polytetrafluoroethylene, and polyethylene are laminated. The thickness is set as required.

The metal deposition film 3 is preferably formed of one or more metals selected from aluminum, zinc, copper and alloys thereof, and the thickness is appropriately set as required. You. If the metal deposition film 3 is made of the metal, the production cost is relatively low, and good capacitor performance and good fuse performance can be obtained.

The main feature of this embodiment is that the both ends 20A in the longitudinal direction of the film of the non-deposited portion 20 for the fuse are formed in a semicircular shape, so that the width W2 at the center of the fuse portion 21 is reduced at both ends. The point is that it is smaller than the width at the part. That is, the radii of curvature R of these two end edges 20A are の of the width W1 of the non-deposited portion 20 for fuse. The value of the width W1 is not limited, but is generally set to 0.
The center width W2 of the fuse portion 21 is preferably about 0.1 to 2.0 mm.

However, the present invention is not limited to the illustrated example, and both end edges 20A in the longitudinal direction of the film of the non-deposited fuse portion 20 may be formed in an elliptical shape or a triangular shape. That is, it is only necessary that the width of the central portion of the fuse portion 21 be smaller than the width of both end portions.

Also, in the drawing, one of the non-deposition portions 20 for fuses is shown.
The non-evaporated portions 11 for region division are formed every other region, and two fuse portions 21 are formed for each of the rectangular portions 3A. However, the present invention is not limited to this. May be changed arbitrarily.

In order to produce the metallized film as described above, for example, the non-deposited portions 20 of the film substrate 4
A method of spraying oil on the portion corresponding to 11 and then performing evaporation on portions other than the non-evaporation portion for margin 4A to locally stop the evaporation is possible, but the non-evaporation portion can be more precisely formed. Laser light may be used for the formation.

A manufacturing method using a laser beam is performed, for example, as follows. While continuously running the uncut and wide film base material 4 in a vacuum container, the non-evaporation part 4 for the margin is used.
After the metal-deposited film 3 is formed on the portion excluding the portion A, the portions of the metal-deposited film 3 where the respective non-deposited portions 11 and 20 are to be formed have a diameter equal to the width of the non-deposited portions 11 and 20 by a laser beam irradiation device. Each of the circularly focused laser beams is irradiated (see reference numeral 22 in FIG. 2).

As a result, the metal deposition film 3 at the irradiated location evaporates, exposing the film substrate 4. Next, the wide film substrate 4 is cut into a plurality of strips by slitting,
What is necessary is just to wind each and to make a metallized film.

Next, an embodiment of a film capacitor using the metallized film will be described. FIG. 3 is a cross-sectional view showing one example thereof, wherein reference numeral 1 denotes the above-described metallized film (first film), and reference numeral 2 denotes a second film.

The second film 2 is formed on the upper surface of a plastic film substrate 6 having the same width and the same length as the film substrate 4 except for a marginal non-evaporated portion 6A having a constant width along one side edge. The first metal deposition film 5 is formed.
It does not have the non-deposited portion for fuse and the non-deposited portion for margin like the film 1. Normally, the margin non-deposition portion 6A is set to have the same width as the margin non-deposition portion 4A.
The values do not necessarily have to be the same, and the values may be slightly changed.

According to the film capacitor and the metallized film for a capacitor having the above-described structure, the fuse portion 21 has a drum-like shape in which the width at the center is narrower than that at both ends, so that when an excessive current flows, the electric resistance is relatively reduced. The central portion of the high fuse portion 21 generates heat intensively, and this central portion evaporates quickly. Therefore, the fuse portion 21
The influence of a slight thickness error or a slight dimensional error of the fuse portion 21 on the critical current value at which the wire breaks is small.
The variation of the critical current value is small, and a stable fuse action can be obtained.

[0033]

[Experimental Example] Next, the effect of the present invention will be demonstrated with an experimental example. Using a film made of polyethylene terephthalate having a thickness of 4.8 μm, a film for producing a capacitor of the present invention as shown in FIG. 1 (experimental example) and a conventional film for producing a capacitor as shown in FIG. 8 (comparative example) were produced. did.

The common dimensions of the experimental example and the comparative example are as follows. Film width: 30 mm Width of non-deposited portion 4A for margin: 1.5 mm Non-deposited portion 20 for fuse and non-deposited portion 11 for area division
Width: 0.5mm deposited metal: aluminum deposited amount: The sheet resistance 3.5 ohms / cm ² Experiment, while both ends of the fuse non deposition unit 20 to the semi-circular curvature radius 0.5 mm, compared In the example, only a rectangular point is different.

Film capacitors were prepared in exactly the same manner using the films obtained in the experimental examples and the comparative examples, and the obtained capacitors were subjected to JIS-C
A security test specified in 4908 was performed. This security test was performed by connecting the circuit shown in FIG. 4 to the capacitor Cx while keeping the capacitor in a constant temperature bath capable of forcibly cooling to ± 3 ° C. while maintaining the temperature constant, and performing the following procedure.

The switch S is set to the open position, and a voltage 1.3 times the rated voltage having a waveform close to a 50 Hz sine wave is applied to the capacitor Cx. The switch S is switched to the terminal b and the discharging capacitor C
A DC voltage seven times the rated voltage of the capacitor Cx is applied to o. The capacity of Co is twice the capacity of Cx. When the discharging capacitor Co is charged, the switch S is switched to the terminal a, and the electric charge of Co is discharged to Cx to which an AC voltage 1.3 times the rated voltage is applied. After the discharge, the switch S is returned to the terminal b again, and the same operation is repeated thereafter. The discharge frequency at this time is once every 15 seconds. The current value is recorded by an AC ammeter, and when the AC current flowing through Cx becomes almost 0, the test is terminated and the number of cycles is recorded. Table 1 shows the results of the security test.

[0037]

[Table 1]

As is clear from Table 1, the cycle number was in the range of 476 to 593 in the ten capacitors manufactured using the film of the experimental example, while the cycle number was in the range of 205 to 981 in the film of the comparative example. The values fluctuated greatly.

[0039]

As described in the foregoing, according to the manufacturing method and the film production method of the capacitor metallized film capacitor in accordance with the present invention, the shape of the fuse part is the width of the center portion becomes narrower shape than both end portions from the central portion of the high fuse portion relatively electrical resistance and excess current flows to generate heat intensive, certainly evaporation starts from the central portion. Therefore, the influence of a slight thickness error or a slight dimensional error of the fuse portion on the critical current value at which the fuse portion is disconnected is small, the variation of the critical current value is small, and a stable fuse action can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a film for manufacturing a capacitor according to the present invention.

FIG. 2 is an enlarged view of a fuse portion of the film for manufacturing a capacitor.

FIG. 3 is a sectional view of a main part of a capacitor using the film for manufacturing a capacitor.

FIG. 4 is a circuit diagram showing a circuit used for a security test.

FIG. 5 is a sectional view of a main part of a conventional film capacitor.

FIG. 6 is a plan view of a conventional film capacitor.

FIG. 7 is a plan view of a conventional film for manufacturing a capacitor.

FIG. 8 is a plan view of a conventional film for manufacturing a capacitor.

FIG. 9 is an enlarged view of a fuse portion of a conventional film for manufacturing a capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film for capacitor manufacture (1st film) 2 2nd film 3,5 Metal deposition film 3A Dividing part 3B Electrode connection part 4,6 Film base 4A, 6A Non-deposition part for margin 11 Non-deposition part for area division 20 Fuse Non-evaporation part 20A Both ends of fuse part 21 Fuse part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-22514 (JP, A) JP-A-58-66318 (JP, A) JP-A-62-18703 (JP, A) JP-A-4- 123414 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01G 4/00-4/40 H01G 13/00-13/06

Claims (4)

(57) [Claims] A step of forming a metal vapor-deposited film on the upper surface of a long plastic film base material having a constant width except for a non-deposition portion for margin having a constant width along one side edge thereof; While running the material, the metal deposition film
At a certain distance from the other side edge of the film ,
By intermittently irradiating circularly focused laser light
The metal deposition film at the irradiated location is evaporated to extend in the longitudinal direction of the film substrate, and both end edges thereof are directed to the adjacent fuse portion.
By forming the non-deposited portion for fuse formed in a semicircular shape that becomes convex in a continuous manner, a fuse portion having a fixed width is formed in a gap between these non-deposited portions for fuse .
And that step, the metal evaporated film, extending in the width direction of the film substrate, this comprising the step of forming at least a non-deposition portion area divided from the non-deposition portion fuse reaches the non-deposition portion for margin <br Production of metallized film for capacitors, characterized by
Construction method . 2. The method according to claim 1, wherein the metal deposition film is made of aluminum, zinc,
One or more selected from copper or their alloys
2. The method according to claim 1, wherein the metal is formed from the above metal.
Production method of metallized film for capacitors. 3. The film base material is polyethylene.
Terephthalate, polypropylene, polystyrene, poly
Carbonate, polytetrafluoroethylene, polyethylene?
Use one or more plastics selected from
The condensation according to claim 1 or 2, wherein
Manufacturing method of metallized film for sa. 4. A long plastic film having a constant width.
A fixed width margin along one side edge of the top surface of the substrate
Forming a metal deposition film except for the non-deposition part for, While running the film substrate, the metal deposition film
At a certain distance from the other side edge of the film,
By intermittently irradiating circularly focused laser light
Evaporates the metal deposition film on the irradiated area
Extends in the hand direction with both edges facing the adjacent fuse section.
Non-deposited part for fuse formed in semicircular shape
By forming the fuses intermittently,
Between the wearing parts Form a fixed width fuse section in each gap
Process, The metal deposition film extends in the width direction of the film base,
At least from non-deposited part for fuse to non-deposited part for margin
Forming a non-evaporated part for dividing the
Obtaining a film; The film for producing a capacitor is referred to as a first film.
On the other hand, the first film has the same width and the same
On the top of a long plastic film substrate,
Except for the non-deposited part for margin with a fixed width along the side edge,
The second film having the film formed thereon is bonded to the second film.
The non-deposited portion for the resin is the non-deposited portion for the fuse of the first film.
Non-evaporated part for the margin of the first film, corresponding to the attachment part
Correspond to the metal-deposited film of the second film.
A step of obtaining a laminated film by superimposing on the film, The laminated film is wound into a cylindrical shape, and both ends of the cylindrical body are wound.
These electrodes are connected to the
Connecting to each of the metal deposition films.
A method for manufacturing a film capacitor, comprising: