JPS63249317A - Manufacture of metallized film capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to metallized film capacitors used in electronic and electrical equipment.

BACKGROUND OF THE INVENTION In recent years, chipping and miniaturization of electronic components have been progressing at a rapid pace due to advances in packaging technology. This wave of chipping and miniaturization is also hitting metallized film capacitors.

A metallized film capacitor is manufactured by winding or laminating a metallized film, and then applying metal spraying (in this case, evaporation of the base treatment) to both edges where opposing metallized electrodes (usually metal evaporated films) extend. metal spraying) or by applying conductive paint (hereinafter referred to as metal spraying). The contact condition between the metallized electrode and the sprayed metal is the most important factor that influences the capacitor characteristics. If this contact condition is poor, not only will the characteristics deteriorate, but if the metallized electrode and sprayed metal become separated, the capacitor function may even be lost, so sufficient electrical and mechanical strength is required. .

In recent years, metallized film capacitors have been made into chips.

In order to achieve miniaturization, a thin metallized film of about 1.6 μm to 4 μm is used. When these thin films are used, the thinness of the film reduces the gap through which the sprayed metal can penetrate, and the so-called stiffness of the film reduces the gap between the films that should otherwise exist due to deformation of the film itself. Due to the tendency of clogging or thermal shrinkage, the contact condition between the metallized electrode and the sprayed metal is much poorer than that of conventional thick films, and the dielectric loss tangent is low in wound capacitors. This causes the characteristics to deteriorate.

Furthermore, in the case of multilayer film capacitors in which each electrode has an independent structure, this contact between the layers is even more serious, and not only does the dielectric loss tangent characteristic deteriorate, but the vapor deposited electrode separates from the sprayed metal, causing static electricity. Another problem is that the capacitance is gradually decreasing.

The reason for this is that the sprayed metal does not fully penetrate the edges of the metallized film, resulting in very weak contact with the metalized electrode.

Conventionally, as a solution to this problem, as shown in FIG. A metallized film capacitor is proposed in which a composite film provided with a body is wound or laminated and then metal sprayed. The notch provided in the edge portion in the width direction is a means for ensuring a gap into which the sprayed metal enters and ensuring contact between the metallized electrode and the sprayed metal. 1 is a press mold, 2 is a vapor deposition electrode (
3 is a vapor deposition margin portion, 4 is a notch portion for securing a gap into which the sprayed metal enters, 5 is a plastic film which is a dielectric, and 6 is a metal sprayed end face. On the other hand, in the process of manufacturing the metallized film capacitor having the above structure, a press molding process is carried out for the purpose of stabilizing the capacitance accuracy or making the element dimensions uniform. This step is performed by applying pressure and temperature to physically and chemically deform the metallized film to bond the metallized film layers. To achieve this purpose, as shown in Figure 4, pressing is performed in the film lamination direction using a press die 1 to ensure adhesion between film layers, stabilize capacitance accuracy, and uniformize element dimensions. There is.

Problems to be Solved by the Invention However, the gaps between the notches provided at the edges in the width direction of the metallized film facilitate the penetration of the sprayed metal and ensure the contact between the metalized electrode and the sprayed metal. In the production of metallized film capacitors, the press forming process described above can ensure stable capacitance accuracy or uniform element dimensions, but the cutout part is used to ensure contact between the metalized electrode and the sprayed metal. The gap is deformed by the temperature and pressure during pressing, and as shown in FIG. 5, is almost lost, and furthermore, the state of loss in the gap 4 at the notch portion is not uniform.

In other words, it can be said that the metallized plastic film in contact with the edge 7 of the notch 4 of the metallized film capacitor bends and tucks in, causing the gap between the notch 4 to be lost. In this way, the contact state between the metallized canister and the sprayed metal becomes uncertain, and the dielectric loss tangent characteristics deteriorate.
There were problems such as a decrease in capacitance.

In view of the above problems, the present invention aims to manufacture a small metallized film capacitor that ensures surface contact between the metallized electrode and the sprayed metal, has stable dielectric loss tangent characteristics and capacitance, and has uniform element dimensions. The purpose is to provide a method.

Means for Solving the Problem In order to achieve the above object, the method for manufacturing a metallized film capacitor of the present invention provides a metallized film or a non-metallic film, or a dielectric film on at least one side of the metallized film in a press molding process. A process of repeatedly providing notches in the edge portion in the width direction of the composite film provided with the body, and press-molding (hereinafter referred to as partial press-molding) a portion including the opposing metallized electrodes, excluding the cut-out portions. It is set up.

Function: By providing this partial press molding process, it is possible to ensure adhesion between film layers, stabilize capacitance accuracy, and make device dimensions uniform. Without losing the gap created by repeatedly providing notches on the widthwise edge of the composite film provided with the body,
The sprayed metal enters the gap between the notches and ensures surface contact with the metallized electrode, thereby stabilizing the dielectric loss tangent characteristics.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a partial press molding process of a laminated metallized film capacitor in an embodiment of the present invention. 11 is a partial press molding die, 12 is a metal vapor deposition film, 13 is a vapor deposition margin, 14 is a notch, 16 is a plastic film, and 16 is a thermal sprayed end face.

The partial press molding step of the above metallized film capacitor manufacturing method will be explained below.

The stacked elements are placed between the upper and lower parts of the partial press molding die 11. Next, excluding the portion where the notches are repeatedly provided, the portion including the opposing vapor deposition electrodes is press-molded. When molding, apply at least pressure. The results will be explained with reference to FIG. FIG. 2 is a view of the end face seen from the thermal spraying end face 16 of FIG. 1. FIG. The gap between the notches 14 is at a temperature during pressing.

There is no influence from pressure or the like, and the notch portion 14 remains evenly formed.

According to this embodiment as described above, a portion where cutouts are repeatedly provided on the edge portion in the width direction of a metalized film, a non-metallic film, or a composite film in which a dielectric material is provided on at least one side of a metalized film is secured. This ensures that the sprayed metal enters the notch and ensures contact between the metallized electrode and the sprayed metal. Therefore, it is possible to stabilize dielectric loss tangent characteristics and capacitance accuracy.

Figures 3a and 3b show the capacitance accuracy and dielectric positive characteristics of the conventional capacitor and the capacitor obtained by the present invention. With conventional methods, the contact between the metallized electrode and the sprayed metal is uncertain and the dielectric properties vary, and there are some areas where contact cannot be achieved.
The capacitance accuracy shows a low value.

Effects of the Invention As described above, the present invention ensures adhesion between film layers, and also provides a metallized film, a non-metallic film, or a composite film in which a dielectric material is provided on at least one side of the metallized film at the edge portion in the width direction. A gap can be secured by the portion where the notches are repeatedly provided, and surface contact with the sprayed metal can be ensured. As described above, according to the manufacturing method of the present invention, it is possible to provide a metallized film capacitor with stable dielectric loss tangent and capacitance accuracy, as well as stable dimensional accuracy, and its practical effects are great.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a metallized film capacitor in an embodiment of the present invention during a partial press forming process, and Fig. 2 is a plane view of a sprayed end face after partial press forming of a metallized film capacitor in an embodiment of the present invention. Fig. 3 is a characteristic diagram for explaining the present invention in detail, Fig. 4 is a perspective view of a conventional metallized film capacitor in the press forming process, and Fig. 6 is a conventional press forming of a metallized film capacitor. FIG. 7 is a plan view of a later thermal sprayed end face. 11... Press mold, 12... Metal vapor deposition film, 13-... Vapor deposition margin part, 14...
Notch part, 16...Plastic film,
16...Thermal spraying end face. Name of agent: Patent attorney Toshio Nakao and one other person n-
“°7° is gold 1 ff; ---5 elephants tnfn Fig. 3

Claims (1)

[Claims] It is characterized by comprising the step of repeatedly forming notches on the edge of the metallized film or non-metalized film that is sprayed with metal on the end face, and pressing the portion containing the opposing metallized electrode, excluding the notch portion. A method for manufacturing a metallized film capacitor.