JP2648200B2 - Manufacturing method of film capacitor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a capacitor used for an electronic device or an electric device, particularly, a film capacitor.

2. Description of the Related Art In recent years, efforts have been made to increase the number of functions and miniaturization of electronic devices and electric devices, and electronic components used in these devices are required to be smaller, higher performance, and lower cost. In order to cope with this, developments for miniaturization, chipping, high reliability, and cost reduction corresponding to these are actively performed. In order to reduce the size and chip of the film capacitor and improve its reliability, the structure of the electrode lead-out part and the external electrode is important, as well as the miniaturization and improvement of the capacitance-contributing part consisting of the dielectric and the electrode. Is an important task. In particular, the electrode lead portion occupies a large proportion in the volume of the entire capacitor, and it is necessary to connect the electrical characteristics of the capacitance contributing portion to the external electrode and to perform mechanical joining between the external electrode and the capacitance contributing portion. In terms of the overall configuration, miniaturization and improvement in reliability of the electrode lead-out section are the most important issues.

Hereinafter, the structure and manufacturing method of an electrode lead-out portion of a conventional film capacitor will be described with reference to the drawings.

FIGS. 10 (a) to 10 (c) show a winding method and a structure of a conventional wound film capacitor, and FIG. 10 (a) shows a typical example of a double-sided metallization in which metal is deposited on both sides. The perspective view which wound two films and a raw film is shown. In FIG. 10 (a), raw film 1 and double-sided metalized film 2
Means that the sheet is overlapped with two sheets in the range 6 and is wound by the core 3 as shown in FIG. 10 (b).

FIG. 10 (c) schematically shows the structure of this film capacitor. In FIG. 6 (c), the dimension indicated by 5 is a capacitance contributing portion, and the dimension indicated by 4 is a portion necessary for electrode extraction and does not contribute to the capacitance. This portion 4 is a capacitance contributing portion. Regardless of the size of the capacitor 5, it is required to be at least 0.5 mm or more, which is a large loss in manufacturing a small capacitor in which the size of the capacitor 5 is reduced to several mm. Further, in manufacturing the film capacitor shown in FIG. 3 (c), in order to reduce the dimension of the non-capacitance contributing portion 4, the meandering of the film at the time of winding is prevented and the amount of overlap of the two films is increased. It is necessary to control the precision to stably secure the interlayer gap of the film. Thus, the need for higher precision of the manufacturing equipment causes a problem of high cost and lower productivity.

11 (a) to 11 (c) show a winding method and structure of a wide laminated film capacitor for winding a wide film processed to form a plurality of rows of capacitors in the width direction of the film on a flat bobbin. FIG. 11 (a) shows a state in which the processed film, that is, the protective film 11 or the capacitor film 12, is wound around the flat bobbin 13. At this time, as shown in FIG. 11 (b), the protective film 11 is wound around the flat bobbin 13 before and after the capacitor film 12 is wound, and is formed so as to sandwich the capacitor film 12.

FIG. 11 (c) schematically shows the structure of the film capacitor. Here, a product having a size of 16 is obtained by being divided at the position indicated by the one-dot chain line 14, and this divided surface is an electrode extraction end surface. In FIG. 11 (c), the dimension indicated by 15 is a portion that does not contribute to the capacitance of the capacitor, and the non-capacitance contributing portion 15 is a gap for the sprayed metal between the films laminated on the electrode lead end face. In order to make the film, it is necessary to have a thickness greater than the thickness of a tool used for winding the film to form irregularities on the film, and conventionally, a minimum of 1 mm is required.
For this reason, as the size 16 of one product becomes smaller, the ratio of the loss due to the non-capacitance contributing portion 15 becomes larger, which hinders miniaturization. Another drawback is that the thickness of the product is larger than the total thickness of the film. In FIG. 11 (c), 17
Is a metal deposited, and 18 is a coating film.

Problems to be Solved by the Invention As described in the above two examples, in the conventional method for manufacturing a film capacitor, the ratio of the portions 4 and 15 that do not contribute to the capacitance to the whole is large, which is an obstacle to miniaturization of the product. In order to make the portions 4 and 15 that do not contribute to this capacity smaller,
It is indispensable to increase the precision of the manufacturing equipment, but it is technically difficult, and there is a problem in that the retention of characteristics is reduced due to poor winding precision, and the equipment cost is high.

Therefore, development of a method for manufacturing a film capacitor having a new connection portion between an internal electrode and an external electrode has been desired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method for manufacturing a small, highly reliable, and highly productive film capacitor.

Means for Solving the Problems In order to solve the above-mentioned problems, a method for manufacturing a film capacitor of the present invention comprises, at least a portion of the film capacitor body other than the electrode lead-out end face, and applying the outermost electrode to the dielectric removal reaction. The method includes a step of masking with a material having a lower reaction rate than the covering film and the dielectric film, and a step of selectively removing only the dielectric film on the electrode lead end face of the capacitor body. Further, in another method for manufacturing a film capacitor of the present invention, in order to further increase the productivity, instead of the masking step, a plurality of film capacitor bodies are stacked with the electrode drawing end faces in the same direction, and each film capacitor body is stacked. Are separated by a spacer made of a material having the same function as the masking material, and these are collectively put together by a frame-shaped jig which has two surfaces made of the same material and has the same function as the masking material and can be held under pressure. And a series of steps for maintaining the pressure under pressure so as to eliminate the gap between the spacer and the capacitor body.

According to the above manufacturing method, it is not necessary to previously form a gap in which the sprayed metal serving as the external electrode enters at the winding-out end face of the electrode of the film capacitor body, and the sprayed metal is formed before the external electrode is formed. By forming the intruding gap by a reaction for selectively removing only the dielectric film, the internal electrode and the external electrode can be connected with high reliability and with only a small occupied volume.

In addition, a plurality of film capacitor bodies are stacked with the electrode drawing end faces in the same direction, and the film capacitor bodies are separated from each other by a spacer made of a material having the same function as the masking material, instead of the masking step.
In addition, these are collectively put together and held by pressing with a frame-shaped jig having two surfaces made of a material having the same function as the masking material, and by pressing the electrode lead end surface,
A series of highly productive steps can be obtained.

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

First, an apparatus for performing a dielectric reaction will be described with reference to FIG. FIG. 1 is a schematic diagram showing that a laminated film capacitor element is masked according to the present invention and a dielectric removal reaction is performed. As shown in FIG. 1, a film capacitor body 21 sandwiched between masks 22 is disposed inside a vacuum vessel 23. The vacuum vessel 23 has a high-frequency electrode 24 to which a high-frequency power supply 25 is connected and a quartz window 26. The vacuum vessel 23, the high-frequency electrode 24, the high-frequency power supply 25, and the quartz window 26 constitute a device for performing a dielectric removal reaction.

Next, the configuration and mask of the capacitor body will be described with reference to FIGS. FIG. 2 (a), (b)
As shown in the figure, the film capacitor body 21 is made of a dielectric film 27.
A metallized film 28 as an electrode made of a vapor-deposited metal and a single-sided metallized film 31 provided with a metallized portion 29 extending in the longitudinal direction are used, and the position of the non-metallized portion 29 in the film width direction is set to the third position. 2 Another one-sided metallized film 31 symmetrical to the one shown in FIG. 2A is superposed on the one-sided metallized film 31 to form a pair, a plurality of such pairs are laminated, and a protective film comprising only a dielectric film is formed. A film capacitor body 21 is formed by adding 30. The mask 22 covers the outermost portion of the stack of the film capacitor body 21, and the mask 22 protects a portion that must not be removed or deteriorated during the dielectric removal reaction. The mask 22 is formed on a portion other than the electrode lead-out end face A of the film capacitor body 21 and the non-product surface, that is, the outermost portion of the film capacitor body 21, the protective film 30, the metallized film 28 and the dielectric film 27.
Cover the surface.

Next, a method for manufacturing a film capacitor will be described in detail with reference to FIGS. First, the manufacturing process from the wide winding process to the slit process will be described with reference to FIG. As shown in FIG. 3, a single-sided metallized film 31 partially metallized and processed to form a plurality of rows of capacitors in the film width direction is wound by a flat bobbin 32. Next, it is heat-pressed by a hot plate 33 to form a one-sided metallized film 31.
Are adhered to each other. Then, it is cut on the flat bobbin 32 by a cutting tool and separated into bobbins to form two front and back capacitor element plates 34. Further, the capacitor element plate 34 is divided into slits by a blade according to a predetermined dimension along the longitudinal direction of the film at the time of winding. The film capacitor manufactured by these series of steps is the film capacitor body 21 shown in FIG. The protective film 30 of the capacitor body 21 may be wound on the flat bobbin 32 in advance, or may be wound on the outside of the single-sided metallized film 31 before the heat press step.

Next, FIG. 1 shows a step of selectively removing the portion of the leading end face A of the dielectric film 27. Vacuum container capable of holding under reduced pressure
A high frequency is applied to the film capacitor body 21 disposed in 23 by a high-frequency electrode 24, and a portion of the electrode lead end face A of the dielectric film 27 in the film capacitor body 21 is selectively removed by oxygen plasma treatment. You. As a result of this oxygen plasma treatment, the portion of the film capacitor element body 21 on the electrode lead end face side is chemically and selectively removed in a range narrower than the dimension 20 in FIG. 2, and as shown schematically in FIG. Metallized film as electrode of metallized film 31
28 is exposed on the end face, and irregularities are formed on the end faces of the dielectric film 27 and the protective film 30 at the end face of the electrode lead, and the unevenness is 0.1 mm or less and 90% or more of the thickness of the end face of the electrode lead. Can be formed in parts.

In FIG. 4, the portion indicated by the dimension range 35 is the removal amount of the dielectric film 27 and the protective film 30 on the electrode extraction end face A side, which is about 50 to 100 μm in this embodiment. In the present embodiment, the dimension range 38 in which the unevenness caused by the natural variation of the removal amount of the dielectric film 27 and the protective film 30 is about
10 to 20 μm. In this embodiment, the dimension of the portion 36 that does not contribute to the capacitance on the electrode extraction end face A side is 300 μm, and can be implemented with a size sufficiently smaller than the dimension of the capacitance contributing portion 37.

As shown in FIG. 4, the mask 22 allows the gas used for the dielectric removal reaction to pass through the protective film 30, the non-metallized portion 29 of the one-sided metallized film 31, and the defective portion generated in the metallized film 28. The portion of the dielectric film 27 that is exposed from is shielded from contact. If the mask is not provided as described above, the dielectric film portion exposed without being metallized on the protective film or the one-sided metallized film is also selectively removed by the oxygen plasma treatment. as,
If the amount of film removal of the electrode extraction end face is 50 to 100 μm, the amount of selective removal of the exposed protective film and the dielectric film is also increased, so that the exposed portion becomes a defective portion subjected to oxygen plasma treatment, The product may be damaged due to insulation deterioration or the like. Therefore, the material of the mask 22 to be used is a metal or an inorganic material which is hardly oxidized by oxygen plasma, or a material having a lower reaction rate to oxygen plasma than the dielectric film 27 and the protective film 30 is used. The former can be reused, and the latter undergoes a partial removal action during the oxygen plasma treatment. However, by discarding after a predetermined process, an inexpensive material can be used.

Next, steps from completion of the oxygen plasma treatment to completion of the capacitor element will be described with reference to FIG. As shown in FIG. 5, in the metallicon process, a metal is sprayed by the thermal spraying device 39 on the uneven surface from which the electrode drawing end face A side of the dielectric film 27 and the protective film 30 has been selectively removed, and the thermal spray penetrated into the uneven surface. The metallized film 28 in FIG.
Electrical connection is made between the two, and the sprayed metal 40 is etched into the uneven surface to form an external electrode with sufficient adhesive force on the film capacitor body 21.

If necessary, a part of the external electrode is cut and formed in the electrode surface cutting step, and then the film capacitor body 21 is cut into small pieces of a predetermined size by a cutting tool 42 to form a capacitor element 41 having a predetermined capacitance characteristic. Can be

As shown in FIG. 5, in the metallikon step, a plurality of film capacitor bodies 21 are stacked in a frame jig 44 via a spacer 43 and processed. The spacer 43 may also serve as the mask 22.

As described above, according to the present embodiment, it is possible to obtain a film capacitor having a small area occupied by the non-capacitance contributing portion 36, high reliability, and high productivity, having a connection structure between an internal electrode and an external electrode.

Embodiment 2 Next, another embodiment of the present invention will be described with reference to FIGS. 6 (a) and 6 (b).

FIG. 6 (a) is a perspective view after masking a film capacitor showing another embodiment of the present invention, and FIG.
FIG. 6 is a sectional view taken along line VI-VI of FIG. As shown in FIG. 6B, a metallized film is formed on one surface of a dielectric film 51 made of an organic material.
On one end side of the single-sided metallized film 52 on which 58 is deposited, a non-metallized portion 53 where no metal is formed is provided over a range 59, and the non-metallized portion 53 is provided on the opposite side in the width direction of the film. A single-sided metallized film 52 is wound around an inner mask 54 also serving as a core in a state where the two films are stacked without shifting each other in the width direction, and an outer periphery is formed by an outer mask 56 which can be tightened in a circumferential direction by screws 55. Covered. A protective film 57 made of an organic material is interposed between the one-sided metallized film 52 and each of the masks 54 and 56, and the protective film 57 is provided.
Thus, the inner and outer peripheral surfaces of the single-sided metalized film 52 are protected. The material of the inner and outer masks 54 and 56 can be selected from those having a lower reaction speed than the protective film 57 and the dielectric film 51 with respect to the dielectric removal reaction, but in the present embodiment, the inner mask 54 is The outer mask 56 is made of an aluminum alloy, and the outer mask 56 is made of a stainless alloy.

Next, a manufacturing method after the winding and masking steps of this embodiment will be described. As shown in FIG. 6A, the masks 54, 5
Film capacitor body 50 masked by 6
Is subjected to oxygen plasma treatment in the same manner as shown in FIG. 1 of the first embodiment to selectively remove the dielectric film (the dielectric film 51 and the protective film 57) on the end surface on the electrode lead-out side. The amount of dielectric film removed is the same as in the first embodiment. Next, with the masking as described above, an external electrode is sprayed on the end face of the electrode lead, and thereafter, the film capacitor body 50 is formed.
After heat aging the masks 54 and 56, the outer mask 5
6 is removed, and the film capacitor body 50 is radially cut at a predetermined width to obtain a single film capacitor having a predetermined capacity. At this time, both masks of the film capacitor body 50
The fastening parts 54 and 56 are not used as products because the dielectric of the product is partially destroyed by the oxygen plasma gas.

According to the second embodiment, an inexpensive winding device allows
There is no need to control the displacement of the metallized film in the film width direction with high precision, and a simple winding method in which the single-sided metallized film 52 is stacked with the same width and wound can be applied, and a small amount of laminated capacitors can be produced at a high yield. And the product characteristics can be provided in the same manner as in the first embodiment, and the practical effect is great.

In this embodiment, two single-sided vapor-deposited films are stacked on the film capacitor body, but a combination of a double-sided vapor-deposited film and a raw film may be used.

Third Embodiment The third embodiment of the present invention will be described with reference to the drawings.

FIG. 7 is a perspective view showing a state in which the wound film capacitor body is masked. As shown in FIGS. 8 (a) to (c), the wound film capacitor body is
Two sheets of a double-sided metallized film 62 having a metallized film 71 and a partially non-metallized portion 68 and a raw film 63 made of a dielectric material are wound around a core 64, and this is shown in FIG. like,
The entire periphery of the capacitor body 65 except the electrode lead-out end face A is masked by a mask 69. Here, the structure of the film capacitor body 65 is
As shown in FIG. 8 (b), in the longitudinal direction of the film, a protective film tube 67 composed of only the raw film 63 is provided in a range 60A, 60B before and after the capacity forming part 66 in which the double-sided metallized film 62 is disposed. And the structure in the film width direction is the eighth
As shown in FIG. 8C, the width of the raw film 63 and the width of the double-sided metallized film 62 are the same, and the non-metallized portion 68 having the dimension range 61 is provided on the double-sided metallized film 62 on the opposite side in the film width direction. Have. The material of the mask 69 is such that the raw film 63 and the dielectric film 70 of the double-sided metallized film 62 respond to the dielectric film removing reaction.
Although it is possible to select from those having a lower reaction speed, in this embodiment, a metal foil film with an adhesive is used.

Next, a manufacturing method after the winding and masking steps of the third embodiment will be described. The masked film capacitor element body 65 shown in FIG. 7 is subjected to oxygen plasma treatment in the same manner as in the first embodiment shown in FIG. 1, and the dielectric film (the dielectric film 70 and Raw film
63) is selectively removed. The dielectric film removal amount is the first
This is the same as the embodiment. Next, while masked,
An external electrode is sprayed on the electrode extraction end face A, and thereafter the film is thermally used, and then the external mask 69 is peeled off to obtain a single film capacitor element having a predetermined capacity.

According to the third embodiment, it is not necessary to control the displacement of the double-sided metallized film 62 and the raw film 63 in the film width direction with high precision by using the conventional inexpensive winding device. A simple winding method in which 62 is overlapped and wound with the same width, or a method in which a wide film is wound while being slit, can be used, and as shown in FIG. A small wound film capacitor can be manufactured with high productivity, the product characteristics are the same as in the first embodiment, and the practical effect is great.

In this embodiment, the film capacitor body is formed by laminating the double-sided metallized film 62 and the raw film 63, but it may be wound with two single-sided metallized films.

Embodiment 4 Next, an embodiment of the present invention described in claim 2 will be described.
As shown in FIGS. 9A and 9B, a plurality of laminated film capacitor bodies 81 are stacked with the electrode lead-out surface A in the same direction, and a mask 82 as a spacer is provided between the film capacitor bodies 81. The film capacitor body 81 and the mask 82 are sandwiched between two parallel surfaces 84 and 85 of a frame jig 83, and the film capacitor body 81 and the mask 82 are pressed by a pressure screw 86. Is held. As shown in FIG. 9 (c) in an enlarged manner, the laminated film capacitor body 81 is the same as that shown in FIG. 2, and the mask 82 is made of a material having a lower reaction speed than the dielectric material for the dielectric film removing reaction. Is formed. In this embodiment, the mask
82 was a 0.1 mm thick stainless steel plate. The laminated film capacitor body 81 and the mask 82 are sandwiched between two parallel surfaces 84 and 85 of the frame jig 83, and the tightening screws 86 are tightened with a predetermined torque, so that the film capacitor body 81 and the mask 82 are masked. 82 contact surfaces are in close contact. In this embodiment, the contact is made by a surface pressure of 0.1 kg / cm ² or more. After the laminated film capacitor body 81 and the mask 82 are brought into close contact with each other by the frame-shaped jig 83, an apparatus for performing a dielectric removal reaction as shown in FIG. Removed. The laminated film capacitor body from which the dielectric has been removed becomes a capacitor element through a metallikon process and a cutting process in the same manner as in the first embodiment.

According to the present embodiment, the laminated film capacitor body 81 and the mask 82 are pressed and adhered to each other with the frame jig 83, so that a recyclable metal material or an inorganic material such as a ceramic is used as the mask material. However, as long as there are no pores and the reaction speed is slower than that of a dielectric, even a material such as an inexpensive organic material sheet can be easily used by adhesion by pressing, and a large number of laminated film capacitors can be used at the same time. Because it can be held in the removal reactor,
The effects of improving productivity and reducing manufacturing costs are practically significant.

In the fourth embodiment, the wide laminated film capacitor manufactured by the steps shown in FIGS. 3 to 5 has been described, but the winding as shown in FIG. 6 described in the second embodiment is performed. In the production of multilayer film capacitors
The multilayer film capacitor body and the mask as shown in FIG. 6 (b) are wound into a multi-layered donut shape by using a pressing method with two surfaces of the inner mask 54 and the outer mask 56 shown in FIG. By doing so, the same effect as in the fourth embodiment can be obtained.

Advantageous Effects of the Invention As described above, according to the present invention, at least a part of the film capacitor body other than the electrode lead-out end face is made of a dielectric film by the protective film covering the dielectric film of the film capacitor body and the outermost electrode. By covering the film removal reaction with a material having a low reaction rate and contacting an organic material and a reactive gas to selectively remove the dielectric film on the electrode lead-out side end face of the film capacitor body, the non-capacitance contributing portion is removed. Occupies a small area, has high reliability, and has high productivity, and can obtain a film capacitor having a connection structure between an internal electrode and an external electrode.

In addition, a plurality of film capacitor elements are stacked via a spacer that has a slower response time than the film covering the outermost of the dielectric film and the electrode to the dielectric removal reaction, and the dielectric film is selectively removed in this state. By doing so, a large number of film capacitors can be processed at the same time, and productivity can be improved and manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a manufacturing apparatus for performing a dielectric removal reaction by masking a film capacitor body in a method for manufacturing a film capacitor according to an embodiment of the present invention. FIGS. FIG. 3 is a perspective view showing the structure of a capacitor body and a mask in the method for manufacturing the same film capacitor, FIG. 3 is a schematic view showing a wide winding process to a slitting process of the method for manufacturing the same film capacitor, and FIG. FIG. 5 is a cross-sectional view schematically showing a state of a film capacitor body subjected to a dielectric removal reaction in a method of manufacturing a capacitor, and FIG. FIG. 6 is a schematic perspective view showing a film capacitor element and a method for manufacturing the film capacitor according to a second embodiment of the present invention. FIG. 7 is a perspective view and a sectional view showing the structure of a mask, and FIG. 7 is an external view after a masking step of the film capacitor in the method for manufacturing a film capacitor according to the third embodiment of the present invention, and FIGS. 8 (a) to 8 (c). FIGS. 9 (a) to 9 (c) are perspective views, side views and schematic sectional views showing a winding method and a structure of a film capacitor body and a mask in the method of manufacturing the film capacitor. FIGS. 9 (a) to 9 (c) show a fourth embodiment of the present invention. FIG. 9A is a front view showing a state in which the laminated film capacitor body and the mask are held under pressure by a frame-shaped jig having two parallel surfaces in the method for manufacturing a film capacitor of FIG. 10 (a) to 10 (c) are perspective views, side views and schematic sectional views showing a conventional method for manufacturing a film capacitor, and FIG. 11 (a).
(C) is a perspective view, a side view, and a schematic cross-sectional view illustrating a method of manufacturing another conventional film capacitor. 21,50,65,81 …… Film capacitor body, 22,54,56,6
9,82 …… Mask (spacer), 27,51,70 …… Dielectric film,
28,58,71… Metallized film (electrode), 29,53,68… Non-metallized part, 30,57,67… Protective film, 63… Raw film, 83
...... frame-shaped jig.

Claims (2)

(57) [Claims] 1. A film capacitor element comprising: a plurality of electrodes; a dielectric film made of an organic material disposed between the electrodes; and a film made of an organic material covering at least one outermost surface of the electrodes. Masking at least a portion other than the electrode lead end face with a material having a lower reaction rate with respect to the film covering the outermost surface of the electrode and the dielectric film than the dielectric film, and an electrode lead end face of the capacitor body. And selectively removing the dielectric film. 2. A film capacitor element comprising a plurality of electrodes, a dielectric film made of an organic material disposed between the electrodes, and a film made of an organic material covering at least one outermost surface of the electrodes. , The electrode extraction end faces are in the same direction, and a plurality of them are stacked.
The film covering the outermost part of the electrode and the dielectric film are separated by a spacer made of a material having a lower reaction rate to the dielectric removal reaction than the dielectric film, and the film capacitor body and the spacer are collectively similar to the spacer. A step of sandwiching with a frame-shaped jig having two surfaces made of functional material and capable of holding under pressure, and holding under pressure so as to eliminate a gap between the spacer and the film capacitor body; Selectively removing the dielectric film on the electrode lead-out surface.