JPS6027175B2 - Capacitor manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for stacking multiple layers of a composite film comprising a double-sided metallized plastic film having a metallized margin at the edges and a dielectric film coated on at least one side.

Multilayer capacitors, which have a structure in which a dielectric film is coated on one or both sides of a double-sided metallized plastic film and stacked in multiple layers, generally have a large capacitance ratio because the coating film can be thin. It is also a highly rational manufacturing method and is suitable for mass production. In other words, in place of the conventional wide film that was vapor-deposited (metallized) and dielectric-coated with a margin, each vapor-deposited strip was slit into narrow strips and wound around each individual capacitor. This method is replaced by a process in which the original film is wound and stacked in a flat or large circle in its wide width, and then cut into each strip and in a direction perpendicular to each strip.

The above manufacturing method is just an example and a general outline, and in reality, metallization, lead wire attachment, exterior packaging, etc. are also required, but when performing these steps, the layered films are bonded and integrated. There are enormous advantages to having a If the adhesion is weak, the laminated layers will not only shift or disintegrate, but also the cut surface will be jagged when cutting, and when metallizing, the end surface will be uneven, and the rapid charging and discharging will cause damage. In either case, it is difficult to obtain a capacitor with good characteristics because the contact may come off. In view of the above-mentioned drawbacks in manufacturing a multilayer capacitor, the present invention provides a method for manufacturing a multilayer capacitor with good adhesiveness.

Examples of double-sided coating will be described below in detail with reference to the drawings.

Even in the case of single-sided coating, the gist of the present invention does not change in any way. FIG. 1 shows the original film after plating and coating.

In the figure, 1 is a substrate film, 2 is a metal film (electrode) formed during vapor deposition, and 3 is a dielectric film formed by coating. This is done by coating with a ring machine or the like and then evaporating the solvent and drying it.
Next, by winding up this raw film onto a flat winding bobbin or a large diameter cylindrical bobbin, a multi-layered raw film is obtained. This laminated film needs to be bonded to each other as described above, and a method of pressing under heat is known as a bonding method. For example, if the coated dielectric film is polycarbonate, it can be bonded by heating it to around 140 qo, which is close to its softening point, and holding it under pressure for an appropriate period of time, but in reality, after holding it at a high temperature, 140℃
The temperature is heated back and forth, and then the temperature is lowered, but it takes a long time to raise and lower the temperature, and the temperature stays at a high temperature for a long time.Moreover, in this state, pressure must be continued, and the electrical weak points of the dielectric film are heated. occurs in large quantities, which tends to lead to a decrease in insulation resistance. In contrast, the present invention aims to obtain good adhesive properties by ultrasonically vibrating the pressure pick while applying pressure at room temperature or at a lower temperature than the above-mentioned method. Figure 2 shows the situation. In the figure, 4 is the laminated film, 5 is a coating portion, 6 is a coating margin portion, 7 is a pedestal, and 8 is a pressure jig, which is connected to an ultrasonic vibrator.

Although the figure shows a case in which the pressure jig 8 applies pressure only to the coated portion 5 and does not apply pressure to the margin portion 6, it is also possible to apply pressure over a wider area. However, if the margin part is also pressurized, wrinkles will easily occur on the cut surface if the center part is cut along the margin part, and if metallicon is applied, the electrical contact with the metal film may become weak. , it is better to limit it to the opposing parts of the metal film. In this bonding method using ultrasonic pressure bonding, the temperature (heat) required for bonding is applied using ultrasonic energy. Therefore, rapid heating and cooling is possible, and the temperature reaches the hatching point only for a few minutes while ultrasonic vibration is applied. Since the temperatures are close to each other, sufficient adhesive strength can be obtained without excessively damaging the dielectric film than in the case of conventional methods. Therefore, there is no decrease in insulation resistance, and the operability in subsequent steps can be made extremely satisfactory. FIG. 3 shows a cross-sectional view of the capacitor element before packaging, and 9 is a metallicon layer.

Lead wires are omitted. In addition, in these examples, the coating margin is provided on both sides along the edge, but it may be provided just along the edge on the opposite side from the metallization margin.
In this case, the gap through which metallicon can penetrate is halved.

In the present invention, it is appropriate that the pressing force be around 5k9/cm, the frequency of the ultrasonic wave should be 20 to 100 KHz, and the time should be several minutes.

According to the manufacturing method of the present invention as described above, the laminated film can be bonded without producing any electrically weak parts, that is, poor insulation parts in the exposed body film, and it can be easily handled during manufacturing, and at the same time, reliability can be improved. This makes it possible to manufacture multilayer capacitors with high performance.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a capacitor element to which the manufacturing method of the present invention is applied, FIG. 2 is a perspective view of an apparatus used to carry out the manufacturing method of the present invention, and FIG. 3 is a perspective view of the manufacturing method of the present invention. FIG. 2 is a cross-sectional view of a capacitor obtained by 1...Substrate film, 2...Metal film (electrode), 3.
...Dielectric film, 4...Laminated film, 5...
...Coating part, 6...Coating margin part,
7... cradle, 8... pressure pick up tool, 9...
...Metallicon layer. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A method for manufacturing a capacitor in which composite films are stacked in multiple layers, each of which is a double-sided metallized plastic film having a metallized margin at the end and a dielectric film coated on at least one side, the softening of the dielectric film. A method for manufacturing a capacitor, which comprises laminating the layers by applying ultrasonic vibrations while applying pressure to the laminated surfaces at a temperature 10° C. or more lower than the point. 2. The method of manufacturing a capacitor according to claim 1, wherein the surfaces to be pressurized are limited to opposing portions of the double-sided metal films, and the pressure is applied so as not to apply pressure to the metallized margin portion.