JPS6356689B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metallized film capacitor, which is constructed by winding a metallized film on which electrodes are formed by vapor deposition or the like on the surface of a dielectric film.

Traditionally, in metallized film capacitors,
A metal electrode is formed on one or both sides of a dielectric film such as a polypropylene film, a polyester film, or a polycarbonate film by a vapor deposition method, a sputtering method, etc., and an insulating groove of about 0.5 mm to 5 mm is formed at the widthwise end of the dielectric film. A metallized film is obtained by providing and forming a margin portion (generally called a margin portion, hereinafter referred to as a margin portion).

Then, using such a metallized film,
To obtain a capacitor, two metallized films are overlapped and wound, and a metal material such as Zn, Sn, Cu, or Pb is sprayed on both end faces of the wound metallized film to form an electrode lead-out part. , connect lead wires to the electrode extensions by welding or the like to form a capacitor element, or stack metallized films one by one with the margins on the opposite side, and then use the above-mentioned wound type capacitor. Similarly, the electrodes are drawn out to form a capacitor element.

By the way, if we analyze and evaluate such wound type and laminated type capacitors in detail from the viewpoint of productivity, capacitor characteristics, etc., each type has its advantages and disadvantages.
In particular, the major difference in characteristics is that multilayer capacitors have a structure in which multiple small capacitance capacitors are connected in parallel, so even if a part of the metallized film breaks down due to some abnormality during use, Only one capacitor element loses its function, with little effect on other capacitor elements, resulting in only a slight reduction in capacitance. This means that it is a highly safe functional capacitor.

On the other hand, wound-type capacitors are currently mainstream because they can be easily manufactured using conventional general equipment, but some abnormality during use may cause part of the metallized film to break. When a phenomenon occurs, the capacitance change due to the destruction phenomenon is
Since the reduction is only proportional to the reduced area of the metallized film electrode, it is negligible at the initial stage, but since this type of wound capacitor is one capacitor as a whole, The damage gradually progresses without stopping, with the destroyed part of the body as the core.
Eventually, this will lead to smoke and ignition. Therefore, in this wound type capacitor, sufficient safety cannot be ensured unless some kind of safety device is added.

In view of the current situation, the present inventors have proceeded with the development of a capacitor that combines the high productivity of a wound type capacitor with the high safety of a laminated type capacitor. As a result, as shown in FIG. 1, the electrode 3 is divided into a plurality of rectangular islands in the length direction of the film, separate from the margin section 2 provided at the end of the dielectric film 1 in the width direction. A metallized film 5 is obtained by providing a margin portion 4 connected to the margin portion 2 as shown in FIG. If the capacitor element 7 is formed by overlapping and winding the metallized film 6 formed with the metallized film 6, the capacitor element 7 can be manufactured in the same manner as a wound type capacitor, and the electrode structure is the same as that of a laminated type capacitor. Because of this structure, even if a destructive phenomenon occurs in a part of the electrode 3, it does not spread to the entire electrode, and accidents such as smoke and ignition can be prevented.In other words, it has been found that it has a safety function. . In addition, in FIG. 1, 8 is a lead wire.

The present inventors also devised a method as shown in FIG. 2 as a method for obtaining the metallized film 5, which is an important part in such a capacitor with a safety function.

In FIG. 2, reference numeral 9 denotes a roller with conductive rubber disposed on its outer peripheral surface, and numeral 10 denotes a roller with an insulating outer peripheral surface provided with a band-shaped conductive part 11.
is provided so as to be in the same direction as the axial direction of the roller 10 and substantially perpendicular to the end surface of the metallized film 5. Also, this roller 9 and roller 10
A DC voltage is applied between the conductive portion 11 and the conductive portion 11 by a power source 12 . Further, the metallized film 5 is fed in the direction of the arrow with the electrode 3 in contact with the rollers 9 and 10.

As shown in FIG. 2, after forming the electrode 3 on the surface of the dielectric film 1, the film is fed with the electrode 3 in contact with rollers 9 and 10 to which a voltage is applied. The rollers 9 and 10 rotate in the direction of the arrow as the film moves. At this time, the conductive part 11 provided on the roller 10 comes into contact with the electrode 3 every time the roller 10 rotates once, and only then spark discharge occurs between the conductive part 11 and the electrode 3, and the electrode metal in that part is scattered and removed.
In other words, by simply feeding the film continuously,
A plurality of margin parts 4 having the same shape as the conductive parts 11 can be provided in the longitudinal direction of the film at intervals equal to the outer circumferential dimensions of the rollers 10 provided with the conductive parts 11.

However, in the case of such a method, the structure is complex, and the conductive rubber used is severely damaged, requiring frequent replacement of the conductive rubber.
There was a problem with poor productivity.

The present invention aims to solve these drawbacks and to make it possible to easily obtain a metallized film. The method for manufacturing the metallized film capacitor of the present invention will be explained below with reference to FIGS. 3 and 4.
This will be explained using the drawings of the figures.

FIG. 3 shows a state in which a manufacturing method according to an embodiment of the present invention is being carried out, and in FIG.
The same parts as in Figure 2 are given the same numbers.

13 is a conductive bobbin;
In this process, a dielectric film 1 having margin portions 2 at its widthwise ends and electrodes 3 formed thereon is wound up such that the electrodes 3 are in contact with the bobbin 13.

As shown in FIG. 3, an electrode 3 is formed on the surface of the dielectric film 1, and a conductive bobbin 13 is attached so that a part of the electrode 3 is in contact with the conductive bobbin 13.
After being wound up, the dielectric film 1 is fed with the electrode 3 in contact with the outer peripheral surface of the roller 10, so that the roller 10 rotates in the direction of the arrow in accordance with the movement of the dielectric film 1. At this time, roller 10
The conductive part 11 provided in the roller 10 contacts the electrode 3 every time the roller 10 rotates once, and only then the conductive part 11
A spark discharge occurs between the electrode 3 and the electrode 3, and the electrode metal in that area is scattered and removed. That is, by simply feeding the dielectric film 1 continuously, the conductive portion 1
The margin portions 4 having the same shape as the conductive portions 11 can be formed at intervals equal to the outer circumferential dimensions of the rollers 10 provided with the margin portions 1 .

Here, since the contact area between the conductive bobbin 13 and the electrode 3 is large, no spark discharge occurs. However, as the dielectric film 1 is fed in the direction of the arrow, the conductive bobbin 9 and roller 10
Since the electrode between the electrode and the conductive part 11 becomes shorter and the resistance of the electrode decreases, the margin part formation state may become unstable. In such a case, the power supply 12 may be provided with a control circuit that controls the current as the resistance of the circuit decreases.

Further, the conductive portion 11 provided on the roller 10 does not need to be provided at right angles to the end surface of the dielectric film 1 as in the above embodiment, but may be provided at an angle as shown in FIG. If the margin part 4
can be formed diagonally.

As is clear from the above description, in the present invention, a metallized film having a margin portion that divides the electrode into a plurality of pieces in the length direction of the film can be obtained simply by continuously feeding the film. A metallized film capacitor with safety functions can be obtained with high productivity without significantly changing the manufacturing process of conventional wound capacitors. Further, metallized films can be obtained with high productivity without the hassle of replacing conductive rubber.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main parts of a metallized film capacitor obtained by the present invention, and FIG. 2 is a perspective view showing the main steps in a method for manufacturing a metallized film capacitor previously developed by the present inventors. Third
4 and 4 are perspective views showing an embodiment of the main steps in the method for manufacturing a metallized film capacitor according to the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Dielectric film, 2, 4... Margin part, 7... Capacitor element, 10... Roller, 1
1... Conductive part, 12... Power supply, 13... Bobbin.

Claims (1)

[Claims] 1 After forming electrodes on the surface of the dielectric film,
The electrode is wound around a conductive bobbin so that the electrode is in contact with the bobbin, and then the electrode is brought into contact with the outer peripheral surface of a roller that has a strip-shaped conductive part on the insulating outer peripheral surface in the same direction as the axial direction. The dielectric film is fed while being pulled out from the bobbin in a state where the dielectric film is drawn out from the bobbin, and a voltage is applied between the bobbin and the conductive part of the roller to remove a part of the electrode by spark discharge. constitutes,
1. A method for manufacturing a metallized film capacitor, which comprises subsequently winding the metallized film to form a capacitor element.