JP3235610B2 - Method and apparatus for manufacturing multilayer film 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 method and an apparatus for manufacturing a multilayer film capacitor widely used in electronic equipment and electric equipment.

[0002]

2. Description of the Related Art In recent years, the miniaturization of electronic devices and electric devices and the accompanying high-density surface mounting of electronic components have been progressing, and the miniaturization and chip formation of multilayer film capacitors are also strongly required.

[0003] A conventional general method of manufacturing a laminated film capacitor includes two thin metallized films each having a single strip-shaped non-metallized portion (hereinafter referred to as a margin) formed thereon, and a large-sized film. There are a method of winding a cylinder to form a capacitor base material and a method of winding a wide metallized film having a plurality of margins formed on a flat plate to form a capacitor base material.

[0004] Among them, the latter method has a remarkably high productivity and is attracting attention as an excellent method for producing a multilayer film capacitor. In this manufacturing method, first, a wide metallized film having a plurality of margins formed thereon is wound into a flat plate (winding step), and then pressed between hot plates to form a plate-shaped capacitor base material. (Heat press step). Then, the plate-shaped capacitor base material is cut off from the flat plate, and cut into a plurality of square rod-shaped capacitor base materials (cutting step). After that, metal spraying is performed on both end surfaces of the square rod-shaped capacitor base material to extract electrodes (electrode extraction step), and cut and divided into individual capacitor elements (cutting step). Thereafter, lead wires are attached to both sprayed metal surfaces (lead attaching process) and exterior is applied (exterior process) to make the product. In the latest chip type products, appropriate A protective film is attached (protective film attaching step) to obtain a product.

Here, the heat press step in the conventional manufacturing method will be described with reference to the drawings. FIG.
It is an external view showing the wide metalized film wound up by the flat plate. In FIG. 4, 1 is a flat plate, and 2 is a wide-width metallized film wound on the flat plate 1. A plurality of margins 3 are formed continuously on the metallized surface of the wide metallized film 2 in the length direction while being influenced by the width direction of the film at every length corresponding to one circumference of the flat plate 1.

FIG. 5 is a cross-sectional view showing a heat press process. 4a and 4b are hot plates, and the flat plate 1 on which the wide metalized film 2 is wound is sandwiched between the hot plates 4a and 4b. The plate-shaped capacitor base material 5 is formed by pressing.

[0007]

However, as shown in FIG. 6, which shows a front view of the plate-shaped capacitor base material 5, the margin 3 is increased in the plate-shaped capacitor base material 5 which is heat-pressed by the conventional manufacturing method. In most cases, it was deformed like a bow in the longitudinal direction. The dimension L shown in FIG.
Is a representative value indicating the magnitude of the bow-like deformation of the margin.

The present inventors have found that this phenomenon is related to the fact that the flat plate 1 is heated by the hot plates 4a and 4b and thermally expanded at the time of heat pressing. The portions folded at the front and rear ends of the metallized film 2 are stretched together in the width direction, whereas the flat portions of the wide metallized film 2 are restrained from moving in the width direction by the hot plates 4a and 4b, and are not easily stretched. Clarified that it occurs.

[0009] Due to the resulting bow-like deformation of the margin, it has not been possible in the past to cut into a square rod-shaped capacitor base material unless the distance between the margins is sufficiently large. In particular, in the vicinity of both end portions of the plate-shaped capacitor base material, the bow-shaped deformation of the margin is very large and cannot be cut to a predetermined width, so that it has to be discarded. Therefore, there have been problems such as a reduction in the size of the multilayer film capacitor and an increase in cost.

The present invention has been made to solve the above problems by eliminating the bow-like deformation of the margin in the formed plate-shaped capacitor base material, thereby making it possible to reduce the distance between the margins and to provide a metallized film. An object of the present invention is to provide a small and inexpensive laminated film capacitor with reduced material loss.

[0011]

In order to achieve the above object, a method of manufacturing a multilayer film capacitor according to the present invention comprises the steps of: placing a flat plate wound with a wide metallized film having a plurality of margins in a constant temperature heating furnace; Or a step of forming a plate-shaped capacitor base material by heating the plate with a heater built in a flat plate and pressing the plate between the hot plates.

In order to achieve the above object, there is provided an apparatus for manufacturing a laminated film capacitor according to the present invention, comprising: a flat plate on which a wide metalized film provided with a plurality of strip-shaped non-metallized portions is wound; And a constant-temperature heating furnace for heating the flat plate, and a plate for pressing the flat plate in between. Instead of the constant temperature heating furnace, a heater for heating the plate itself may be built in the plate.

According to the present invention, the flat plate can be thermally expanded before being sandwiched between the hot plates. In that case,
Since any part of the wide metallized film is linked to the thermal expansion of the flat plate, if this state is maintained and sandwiched between the hot plates and pressed, the metallized film hardly moves in the width direction, and the plate-shaped capacitor mother It is also possible to eliminate the bow-like deformation of the margin in the material.

[0014]

(Embodiment 1) Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a heat press step in the first embodiment of the method for manufacturing a multilayer film capacitor of the present invention. In FIG. 1, 1 is a flat plate, 2 is a metallized film wound around the flat plate 1, and 4a and 4b are hot plates. The flat plate 1 on which the metallized film 2 has been wound is heated in advance in a large constant temperature heating furnace 6 and then heat pressed between hot plates 4a and 4b. Thus, a plate-shaped capacitor base material 5 is formed.

Hereinafter, a difference between the first embodiment of the present invention and the conventional example will be described with reference to a specific example of the difference in the degree of the bow-like deformation of the margin. As a wide metallized film 2, a 300 mm wide metallized film in which a 51-line margin is formed by laser processing on a polyester film on which aluminum is deposited is wound on an aluminum flat plate 1 having a length of 300 mm and a width of 400 mm. Thereafter, this is put into a large constant temperature heating furnace 6 together with the iron heating plates 4a and 4b, and left for a while to be heated at a constant temperature.
After the difference between the temperature of the hot plate 4a and the temperature of the
a, 4b, and pressed. After that, the metallized film at the take-out corner was cut off to form a plate-shaped capacitor base material 5.

In this case, the maximum size L of the bow-like deformation of the margin in the plate-like capacitor base material 5 is 0.1.
mm or less. On the other hand, in the case where the conventional heat pressing was performed, the maximum value of L was 0.8 mm or more.

As is apparent from the above, the method of manufacturing the laminated film capacitor according to the present embodiment has an excellent effect in eliminating the bow-like deformation of the margin in the plate-shaped capacitor base material. It does not matter whether the temperature of the flat plate 1 or the temperature of the hot plates 4a, 4b is higher, and the temperature difference between them is important.

(Embodiment 2) FIG. 2 is a sectional view of a heat press step in a second embodiment of the method for manufacturing a laminated film capacitor of the present invention.

The difference from the embodiment of FIG. 1 is that instead of heating in a large constant-temperature heating furnace, a heater in which an insulated nichrome wire 7 is buried is embedded inside the flat plate 1, The point is that, after winding the wide metallized film 2, the flat plate 1 is heated from the inside by energizing the nichrome wire 7.

In a specific example, the temperature of the flat plate 1 and the hot plate 4 are controlled by such a heating method as in the first embodiment.
After the difference between the temperatures a and 4b became within 30 ° C., the sheet was pressed between the hot plates 4a and 4b to form a plate-shaped capacitor base material 5. Also in that case, the bow-shaped deformation of the margin in the plate-shaped capacitor base material was 0.1 mm or less at the maximum.

According to the present embodiment, by heating the flat plate 1 from the inside, it is possible to quickly and uniformly reach the required temperature, and it is possible to obtain an energy saving effect and obtain a multilayer film capacitor of stable quality. .

FIG. 3 is a front view of a plate-shaped capacitor base material obtained according to the above-described embodiment of the present invention. As shown in FIG. 3, in the plate-shaped capacitor base material 5, the respective margins 3 are arranged in parallel and linearly, so that such a plate-shaped capacitor base material 5 is used in a subsequent cutting process. It can be cut into the minimum width required for design to form a square rod-shaped capacitor base material.

In the first embodiment, the flat plate 1 is made of aluminum, and the hot plates 4a and 4b are made of iron. However, if the flat plate 1 has a required heat-resistant temperature, mechanical strength, and thermal physical properties, respectively. Other materials may be used. Also,
As a method of heating the flat plate 1, a constant temperature heating furnace is used in the first embodiment, and a heater made of a nichrome wire is used in the second embodiment. However, it is also possible to use a combination of these means. Needless to say.

In such a heat press process,
The temperature of the hot plate, the heat pressing conditions, the heating temperature and the time, etc. may be determined as appropriate according to the type of metallized film to be used or the required adhesive force between the metallized films.

[0025]

As described above, the production method according to the present invention provides:
After preheating a flat plate on which a wide metallized film provided with a plurality of margins is wound and pressing it between hot plates to form a plate-shaped capacitor base material, a plate-shaped capacitor base material is formed. By eliminating the bow-like deformation of the material, the distance between the margins can be reduced and the loss of the metallized film material can be reduced, so that a small and inexpensive laminated film capacitor can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat press step of a method for manufacturing a multilayer film capacitor according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a heat press step in a method for manufacturing a multilayer film capacitor according to a second embodiment.

FIG. 3 is a front view of a plate-shaped capacitor base material according to the embodiment of the present invention.

FIG. 4 is a perspective view of a wide-width metallized film wound on a flat plate according to the related art and the embodiment of the present invention.

FIG. 5 is a cross-sectional view of a heat press step in a conventional method for manufacturing a multilayer film capacitor.

FIG. 6 is a front view of a conventional plate-shaped capacitor base material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat plate 2 Metallized film 4a, 4b Hot plate 5 Plate-shaped capacitor base material 6 Constant temperature heating furnace 7 Nichrome wire

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Kuwata 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Satoshi Yokota 1006 Kadoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-79015 (JP, A) JP-A-55-150219 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01G 4/00-4/40 H01G 13/00-13/06

Claims (5)

(57) [Claims] 1. A flat plate on which a wide metallized film provided with a plurality of strip-shaped non-metallized portions is wound in a constant-temperature heating furnace, and then pressed between hot plates to form a plate. A method for manufacturing a multilayer film capacitor, comprising a step of forming a capacitor base material. 2. A flat plate on which a wide metallized film provided with a plurality of strip-shaped non-metallized portions is wound and heated by a heater built in the flat plate, and then pressed between hot plates. A method for manufacturing a laminated film capacitor, comprising a step of forming a plate-shaped capacitor base material. 3. The laminating die according to claim 1, wherein after the difference between the temperature of the flat plate and the temperature of the hot plate is within 30 ° C., the laminate is pressed between hot plates. Manufacturing method of film capacitor. 4. A flat plate around which a wide metallized film provided with a plurality of strip-shaped non-metallized portions is wound, a constant temperature heating furnace in which the flat plate is placed and which heats the flat plate, An apparatus for manufacturing a laminated film capacitor, comprising: 5. A flat plate around which a wide metallized film provided with a plurality of strip-shaped non-metallized portions is wound, a heater built in the flat plate and heating the flat plate itself, and An apparatus for manufacturing a multilayer film capacitor, comprising: