JPH0555082A - Manufacture of surface mounting plastic film capacitor - Google Patents

Abstract

PURPOSE:To manufacture a surface mounting plastic film capacitor adapted for mass production and economy by winding or a metallized plastic film, pouring liquidlike resin in a case to form an outer electrode, and individually cutting and dividing capacitor elements. CONSTITUTION:A plurality of capacitor elements 1 in which metallized plastic films are wound or laminated and metal flame-sprayed parts 1a, 1b are provided on opposed end faces, are aligned to be disposed in a long resin case 2 having a lateral inner size L2 larger by a predetermined size than a size L1 between the frame-sprayed end faces, and liquidlike resin 3 is poured in the case. After the resin is cured, the lateral end faces of the case 2 are polished until the flame-sprayed end faces 1a, 1b of the capacitors 1 are exposed, and outer electrodes are formed of metal flame-sprayed surface of conductive paste on the exposed end faces 1a, 1b and the resin surface. The outer electrodes are solder-plated or soldered, and the capacitors 1 are individually cut and divided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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 mount a plastic film capacitor in which a metallized plastic film is wound or laminated, for surface mounting, as shown in FIG. 3A, both ends of the metalized plastic film are wound or laminated. After inserting the metal sprayed capacitor element 20 between the terminals 22 and 23 of the lead frame 21 and welding the metal sprayed parts (metallikon) 20a and 20b to the terminals 22 and 23, as shown in FIG. 3 (b). As shown in FIG. 3C, the terminals 22 and 23 are separated from the lead frame 21, and the terminals 22 and 23 are formed along the surface of the outer casing 24 after being molded with a thermosetting resin as shown in FIG. It is bent and formed. Note that FIG. 4 is a partial cross-sectional side view showing the structure of the surface mount plastic film capacitor thus manufactured.

[0003]

However, the above-described conventional method of surface-mounting the plastic film capacitor has the following drawbacks. (1) It is difficult to insert the capacitor element 20 between the terminals 22 and 23 of the lead frame 21 and to weld the metal sprayed portions 20a and 20b at both ends of the terminals 22 and 23 to the product yield. bad. (2) Since the exterior is formed by resin molding (molding), it is disadvantageous in mass productivity and economical efficiency, resulting in high cost.

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 suitable for mass productivity and economy.

[0005]

According to the present invention for solving the above problems, a surface mount plastic film capacitor is manufactured by the following steps. A long case in which a plastic film capacitor element obtained by winding or laminating metallized plastic films and subjecting opposite end faces to metal spraying has a predetermined inner dimension in the width direction larger than a dimension between the end faces subjected to metal spraying. A step of arranging a plurality of pieces in alignment with each other and injecting the liquid resin into the case,
The widthwise end face of the case is ground until the metal sprayed surface of the plastic film capacitor element is exposed, and external electrodes are formed on the exposed metal sprayed surface, the case end surface and the injection resin end surface by the metal sprayed surface or conductive paste. Step, a step of subjecting the external electrode surface to solder plating or soldering, and thereafter cutting the plastic film capacitor element into individual pieces.

[0006]

Since the plastic film capacitor for surface mounting is manufactured by the above steps, the external extraction electrode can be formed by a relatively easy and inexpensive method using a metal sprayed surface or a conductive paste. Further, the exterior is filled with resin in the case and completed by curing, which is suitable for automation and mass productivity.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1A to 1H are views for explaining a manufacturing process of the surface mount plastic film capacitor according to the present invention.

First, as shown in FIG. 1 (a), a metallized plastic film is wound or laminated, impregnated with epoxy resin, and the opposite end faces are sprayed with metal to form metal sprayed portions 1a and 1b. A plastic film capacitor element 1 to be prepared is prepared.

Next, as shown in FIG. 1B, the inner dimension L2 in the width direction is a predetermined dimension (0.1 mm to A large long resin case 2 is prepared, and a plurality of the plastic film capacitor elements 1 are arranged and arranged in the resin case 2. It is desirable that the resin material of the case 2 has a heat distortion temperature of 180 ° C. or higher. For example, an epoxy resin, a phenol resin, a PPS resin, or the like is used.

Next, as shown in FIG. 1C, a molten resin material 3 is poured into the resin case 2 and the resin 3 is cured. As the injection resin material 3, a thermosetting epoxy resin or the like is used. After the injected resin is cured, the resin and the upper surface of the resin case 2 are provided with a predetermined dimension L3 (0.2 mm to 0.2 mm) from the plastic film capacitor element 1 as shown in FIG.
3 mm) and leave it for polishing. Next, as shown in FIG. 1E, the width direction end surface of the resin case 2 and the resin material 3 are connected to the metal sprayed parts 1 at both ends of the plastic film capacitor element 1.
Polish until a and 1b are exposed.

Since the sprayed metal does not adhere to the surface of the resin material 3 in the state where the metal sprayed portions 1a and 1b on both ends of the plastic film capacitor element 1 are exposed by the above-mentioned polishing, the sprayed metal does not adhere to the surface as shown in FIG. After the end surface is roughened 4 as shown in f), metal spraying is performed to external electrode portions 5a, 5
b is formed. This roughening is, for example, as shown in the sectional shape of FIG. 2, a width of 0.05 mm to 0.1 mm and a depth of 0.15 m.
Wedge-shaped fine grooves of about m to 0.2 mm are formed with a density of 500 to 700 / cm ² by needle punching or a cutter blade. The formation of the external electrode portions 5a and 5b is not limited to metal spraying, and may be formed by applying a conductive paste such as silver.

Solder plating or soldering is applied to the surfaces of the external electrode portions 5a and 5b, and then, as shown in FIG. 1 (h),
For each individual plastic film capacitor element, separate it with resin case 2 and resin material 3 covering it,
The surface mount plastic film capacitor 6 is used.

[0013]

As described above, according to the present invention, the external extraction electrode can be formed relatively easily as a metal sprayed surface or a conductive paste, and the exterior is filled with resin in the case and completed by curing. It is possible to provide a method for manufacturing a plastic film capacitor for surface mounting, which is excellent in automation and mass productivity.

[Brief description of drawings]

1A to 1H are views for explaining a manufacturing process of a surface mount plastic film capacitor according to the present invention.

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

FIG. 3A to FIG. 3C are views for explaining a manufacturing process of a conventional surface mount plastic film capacitor.

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

[Explanation of symbols]

 1 plastic film capacitor element 2 resin case 3 resin material 4 roughening 5a, 5b external electrode section 6 plastic film capacitor for surface mounting

Claims (1)

[Claims] 1. A plastic film capacitor element obtained by winding or laminating a metallized plastic film and subjecting opposite end faces to metal spraying, wherein an inner dimension in a width direction is a predetermined dimension from a dimension between the end faces subjected to the metal spraying. A step of arranging a plurality of pieces in a large elongated case and injecting a molten resin into the case; and, after the molten resin is cured, the widthwise end face of the case is sprayed with metal of the plastic film capacitor element. Polishing until the surface is exposed, a step of forming an external electrode with a metal sprayed surface or a conductive paste on the exposed metal sprayed surface, the case end surface and the injection resin end surface, and subjecting the external electrode surface to solder plating or soldering, Thereafter, the plastic film capacitor for surface mounting is characterized by the step of individually cutting the plastic film capacitor element. Method of manufacturing a capacitor.