JPH05205973A - Manufacture of surface-mounting plastic film capacitor - Google Patents

Abstract

PURPOSE:To enable a surface-mounting plastic film capacitor to be enhanced in mass-productivity by a method wherein plastic film capacitor elements are housed in a case in a line, an outer electrode is provided to both the sides of the case, resin is filled into the case and hardened, and then the case is divided into separate film capacitors. CONSTITUTION:Plastic film capacitor elements 1 provided with metal sprayed parts 11 and 12 respectively are prepared, and a resin case 2, whose widthwise inner dimension L2 is larger than L1 or the length of the film capacitor 1 and on whose lengthwise side faces 21 and 22 through-holes 23 and 24 are provided at a regular interval, is provided. The plastic film capacitor elements 1 are housed in the case 2 in a line, and metal is sprayed on the side faces 21 and 22 to form outer electrodes 3 and 4. Then, resin 5 is filled into the case 2 and hardened, furthermore the faces of the outer electrodes 3 and 4 are plated with solder or soldered, and then the case 2 is divided into capacitor elements 1. By this setup, an automated manufacturing method excellent in mass- productivity can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a surface mounting plastic film capacitor having a structure suitable for surface mounting on a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, in order to surface mount a plastic film capacitor in which a metallized plastic film is wound or laminated, as shown in FIG. 3A, a metallized plastic film is wound or laminated. The capacitor element 70 having metal sprayed on both ends of the object is inserted between the terminals 72 and 73 of the lead frame 71, and the metal sprayed portions (metallikon) 70a and 70b and the terminals 72 and 7 are inserted.
3 is welded, then molded with a thermosetting resin as shown in FIG. 3 (b) to form an exterior 74, and then the terminals 72, 73 are separated from the lead frame 21 as shown in FIG. 3 (c). The terminals 72 and 73 are formed by bending along the surface of the exterior 74. FIG. 4 is a side sectional view showing the structure of the surface mount plastic film capacitor thus manufactured.

[0003]

However, the above-mentioned conventional method of surface mounting the plastic film capacitor has the following drawbacks.

Inserting the capacitor element 70 between the terminals 72 and 73 of the lead frame 71 and the terminals 72 and 73.
And metal sprayed parts 70a, 70 on both ends of the capacitor element 70
The welding work with b is difficult and the product yield is poor.

Since the exterior 74 is formed by resin molding, it is disadvantageous in mass productivity and economical efficiency, and the cost is high.

Therefore, in order to solve the above-mentioned drawbacks, the applicant of the present invention has proposed a novel method for manufacturing a plastic film capacitor for surface mounting in the patent application of Japanese Patent Application No. 3-237305.

According to the present invention, a plurality of plastic film capacitor elements having metal sprayed portions at both ends are arranged and housed in a case made of resin, and a molten resin is injected into the case to cure the plastic film. The case is polished until the metal sprayed surface of the capacitor element is exposed, external electrodes are formed on the polished surface by metal spraying or conductive paste, and solder plating or soldering is applied to the external electrode surface, and the plastic film capacitor The element was cut into individual pieces to manufacture a surface mount plastic film capacitor. As a result, a method of manufacturing a plastic film capacitor for surface mounting which is excellent in automation and mass productivity can be provided.

However, this invention also has the following drawbacks. Polishing a resin case is a time-consuming process and reduces its productivity.

Polishing the resin produces a large amount of dust and deteriorates the working environment.

The present invention has been made in view of the above points, and an object thereof is to provide a method of manufacturing a plastic film capacitor for surface mounting, which is excellent in automation and mass productivity and can be manufactured without polishing. To do.

[0011]

In order to solve the above problems, according to the present invention, a surface mount plastic film capacitor is manufactured by the following steps. A plastic film capacitor element obtained by winding or laminating a metallized plastic film and subjecting the opposite end surfaces to metal spraying, has an inner dimension in the width direction larger than a dimension between the metal sprayed end surfaces of the plastic film capacitor element. In a long case having a large predetermined size and having through holes formed on both side surfaces in the width direction at regular intervals, a plurality of holes are formed so that the centers of the through holes are substantially located at the center of the metal sprayed surface of the plastic film capacitor element. The step of arranging the individual pieces, the step of forming external electrodes by performing metal spraying on both sides of the case so as to electrically connect to the metal sprayed part of the plastic film capacitor element through the through holes, and melting in the case The step of injecting and hardening the resin, the soldering or solder plating on the external electrodes, and then the plastic film condensation Process to avoid cutting the element individually.

[0012]

The plastic film capacitor for surface mounting is manufactured by the above process, which is suitable for automation and mass productivity. Further, since there is no polishing step in the above steps, the productivity is improved and the situation that the working environment is not deteriorated by a large amount of dust does not occur.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 (a) to 1 (e) are views for explaining a manufacturing process of a surface mount plastic film capacitor according to the present invention. 1 (a), (b),
1E is a perspective view, and FIGS. 1C and 1D are cross-sectional views in the width direction.

That is, first, as shown in FIG. 1A, a metallized plastic film is wound or laminated, and an epoxy resin is impregnated into the metallized plastic film, and the opposite end surfaces are metal-sprayed to form a metal sprayed portion 11. A plastic film capacitor element 1 formed by forming 12 is prepared.

Next, as shown in FIG. 1B, the inner dimension L2 in the width direction is a predetermined dimension (0.1 mm to 0.1 mm) from the dimension L1 between the end faces of the metal sprayed parts 11, 12 of the plastic film capacitor element 1. About 0.2 mm) and through holes 23 are formed on both side surfaces 21 and 22 in the width direction at regular intervals.
A long resin case 2 provided with 24 is prepared. The case 2 is preferably made of a resin material having a heat distortion temperature of 180 ° C. or higher. For example, epoxy resin, phenol resin, PPS resin, or the like is used.

Then, as shown in FIG. 1B, a plurality of the plastic film capacitor elements 1 are arranged and housed in the case 2. At this time, the centers of the end faces of the metal sprayed parts 11, 12 of each plastic film capacitor element 1 are made to be substantially located at the centers of the through holes 23, 24 of the case 2.

Next, as shown in FIG. 2C, the outer surfaces of both side surfaces 21 and 22 of the case 2 are sprayed by metal spraying to form the external electrodes 3, 3.
4 is formed. As a result, the external electrodes 3, 4 and the metal sprayed parts 11, 1 of the plastic film capacitor element 1 are
2 is electrically connected through the through holes 23 and 24. Since the sprayed metal does not easily adhere to both side surfaces 21 and 22 of the case 2 as it is, it is necessary to roughen the surface in advance before spraying the metal. For example, as shown in the cross-sectional shape in FIG. 2, this roughening is performed by needle-punching or blasting a wedge-shaped fine groove with a width of 0.05 mm to 0.1 mm and a depth of 0.15 mm to 0.2 mm to obtain a density of 500 to It performed to form at 700 / cm ^2.

The through holes 23, 24 must be formed smaller than the area of the end faces of the metal sprayed parts 11, 12 of the plastic film capacitor element 1. This is because metal is not introduced (sprayed) into the case 2 through the through holes 23 and 24 when the side surfaces 21 and 22 of the case 2 are sprayed with metal. However, the through hole 2
When the electrodes 3 and 24 are circular, the external electrodes 3 and 4 and the metal sprayed portion 1
The diameter is 1φ to ensure the electrical connection between 1 and 12.
The above is preferable.

Next, as shown in FIG. 3D, a liquid resin 5 is injected into the case 2 to seal the plastic film capacitor element 1 and then the resin 5 is cured. A thermosetting epoxy resin or the like is used as the resin 5.

After solder plating or soldering is performed on the surfaces of the external electrodes 3 and 4, as shown in FIG.
The individual plastic film capacitor element 1 is cut together with the case 2 and the like covering it to manufacture the surface mounting plastic film capacitor 6.

[0021]

As described in detail above, according to the method of manufacturing the surface mount plastic film capacitor of the present invention, the following excellent effects are obtained. Multiple plastic film capacitor elements are arranged and housed in the case, external electrodes are formed on both sides of the case, and the resin is injected into the case, cured, and individually cut into pieces. Is excellent in

Since the production can be performed without using polishing, the productivity is improved and the situation that the working environment is not deteriorated by a large amount of dust does not occur.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a manufacturing process of a plastic film capacitor for surface mounting according to the present invention.

FIG. 2 is a diagram showing a cross-sectional shape of a roughened surface.

FIG. 3 is a view for explaining a manufacturing process of a conventional surface-mount plastic film capacitor.

FIG. 4 is a side sectional view showing a structure of a conventional surface mount plastic film capacitor.

[Explanation of symbols]

 1 Plastic Film Capacitor Element 11, 12 Metal Sprayed Part 2 Case 23, 24 Through Hole 3,4 External Electrode 5 Resin

Claims (1)

[Claims] 1. A plastic film capacitor element formed by winding or laminating a metallized plastic film and subjecting opposite end surfaces to metal spraying, wherein the inner dimension in the width direction is the metal sprayed end surface of the plastic film capacitor element. In a long case having a predetermined size larger than the space therebetween and having through holes formed on both side surfaces at regular intervals, the center of the through holes is located substantially at the center of the metal sprayed surface of the plastic film capacitor element. A step of arranging a plurality of pieces, and a step of performing metal spraying to form external electrodes on both side surfaces of the case so as to be electrically connected to the metal sprayed part of the plastic film capacitor element through a through hole, A step of injecting a molten resin into the case and hardening it, and a step of soldering or solder-plating the external electrodes, and then the plastic foil A method of manufacturing a plastic film capacitor for surface mounting, comprising a step of individually cutting the film capacitor element.