JPH0621235U - Surface mount film capacitor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a film capacitor for surface mounting, which is excellent in automation and mass productivity, and in which the sprayed metal does not enter the case. A film capacitor element 1 in which metallized plastic films are wound or laminated and metal spraying is applied to opposite end surfaces thereof to provide metal sprayed portions 11 and 12, and an inner dimension L2 in the width direction is a film capacitor element 1 The case 2 is provided with a predetermined size larger than the size L1 between the end faces of the metal sprayed parts 11, 12. The film capacitor element 1 is housed in the case 2, and the resin 5 is injected and cured in the case 2. Grooves 25 and 26 are formed on both side surfaces 21 and 22 of the case 2 to form metal sprayed parts 11 and 12 of the film capacitor element 1.
The outer electrodes 3 and 4 are provided on both side surfaces 21 and 22 of the case 2 by metal spraying. This external electrode 3,
4 is a film capacitor element 1 through the grooves 25 and 26.
Are electrically connected to the metal sprayed parts 11, 12. Then, a solder layer is provided thereon.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a surface-mounting film capacitor having a structure suitable for mounting on a printed circuit board or the like, and more particularly to a surface-mounting film capacitor whose external electrodes can be easily and surely pulled out.

[0002]

[Prior art]

 Conventionally, in order to manufacture a film capacitor for surface mounting, a capacitor element having metal sprayed parts on both ends is inserted between the terminals of the lead frame, the metal sprayed parts and the terminals are welded, and the outer periphery is molded with resin. After molding, the terminals were separated from the lead frame.

However, when the surface mounting film capacitor is manufactured in this manner, it is difficult to insert the capacitor element between the terminals of the lead frame and the welding operation between the terminals and the metal sprayed portion, and the product There was a problem that the yield was poor.

In order to solve the above-mentioned drawbacks, the applicant of the present application has proposed a novel method for manufacturing a surface mounting film capacitor in the description and drawings of Japanese Patent Application No. 4-37303.

FIG. 4 is a diagram showing a manufacturing process of the surface mount film capacitor. In order to manufacture a surface mount film capacitor as shown in the figure, first, as shown in (a) of the figure, a film capacitor element in which metallized plastic film is wound or laminated and metal sprayed on both ends A plurality of 70 are prepared.

Next, as shown in FIG. 2B, a case 80 having through holes 81 and 82 provided on both side surfaces 85 and 86 thereof at regular intervals is prepared, and the film capacitor element 70 is housed therein. At this time, the centers of the through holes 81, 82 of the case 80 are positioned at the centers of the metal sprayed parts 71, 72 of the film capacitor element 70.

Then, as shown in the cross section of FIG. 1C, the outer electrodes 83 and 84 are formed by performing metal spraying on both side surfaces of the case 80. At this time, the external electrodes 83, 84 are electrically connected to the metal sprayed parts 71, 72 of the film capacitor element 70 through the through holes 81, 82.

After the molten resin 90 is injected and cured in the case 80 and soldering or solder plating is performed on the external electrodes 83 and 84, as shown in the cross section of FIG. As shown in (e), the film capacitor element 70 is individually cut to complete the surface-mounting film capacitor 75. As a result, the surface mount film capacitor 75 having excellent automation and mass productivity can be provided.

[0009]

[Problems to be solved by the device]

 However, the above invention also has the following problems. That is, it is desirable that the through holes 81 and 82 of the case 80 have a diameter of 1φ or more in order to secure electrical contact, but if the thickness of the film capacitor element 70 is 2.5 mm or less, the 1φ through holes. In 81 and 82, when the metal is sprayed, the sprayed metal may enter the inside of the case 80 through the through holes 81 and 82, and electrical conduction may occur between the two metal sprayed parts 71 and 72.

If the molten resin can be injected into the case 80 in advance before the metal spraying, such a problem does not occur. However, if the molten resin is injected into the case 80 before the metal spraying, the molten resin can be injected. Leaks out through the through holes 81 and 82 of the case 80. Therefore, the molten resin cannot be injected before the metal spraying, and the above problems cannot be solved.

The present invention has been made in view of the above-mentioned points, and an object thereof is to provide a surface-mounting film capacitor which is excellent in automation and mass productivity and in which a sprayed metal does not enter the case. It is in.

[0012]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a surface mount film capacitor according to the present invention is a film capacitor element formed by winding or laminating a metallized plastic film and subjecting its opposite end faces to metal spraying, and a widthwise inner part. The film capacitor element comprises a case whose size is larger than the dimension between the metal sprayed end faces of the film capacitor element by a predetermined dimension, the film capacitor element is housed in the case, and a resin is poured and cured in the case. Grooves are formed on both sides of the case to expose the metal sprayed end faces of the film capacitor element, and the both sides of the case are metal-sprayed through the grooves to form the film capacitor element. An external electrode electrically connected to the metal sprayed portion was provided, and a solder layer was further provided on the external electrode.

[0013]

[Action]

 Since the case can be filled with resin before the groove is processed, the sprayed metal for forming the external electrodes can be prevented from entering the case, and the electrical conduction between the metal sprayed parts of the film capacitor element can be prevented. It will not occur.

[0014]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 (a) to 1 (i) are views for explaining a manufacturing process of a surface mount film capacitor according to the present invention. 1 (a), (b), (g), and (i) are perspective views, FIGS. 1 (c) and 1 (d) are cross-sectional views, FIG. 1 (e) is a side view, and FIG. (H) is a plan view.

First, as shown in FIG. 1A, a metallized plastic film is wound or laminated, and the opposite end faces are subjected to metal spraying to form metal sprayed parts 11 and 12. A film capacitor element 1 which is obtained by impregnating the above with an epoxy resin is prepared.

Next, as shown in FIG. 1B, the inner dimension L2 in the width direction is smaller than the dimension L1 between the end faces of the metal sprayed parts 11, 12 of the film capacitor element 1 by a predetermined dimension (0.1 mm to Prepare a large, long resin case 2. It is desirable that the resin material forming the case 2 has 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 film capacitor elements 1 are accommodated in the case 2 in an aligned manner.

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

Next, as shown in FIG. 3D, the upper surfaces of the case 2 and the resin 5 are polished to be flat.

Next, as shown in FIG. 2E, both side surfaces 21 and 22 of the case 2 are cut by rotary blades 61 and 62, and as shown in FIGS. Grooves 25 and 26 reaching both metal sprayed parts 11 and 12 of the capacitor element 1 are formed.

Next, as shown in FIG. 1H, the outer electrodes 3 and 4 are formed by performing metal spraying on the entire side surfaces 21 and 22 of the case 2. At this time, since the case 5 is filled with the resin 5, there is no possibility that the sprayed metal will enter the case 2.

As a result, the external electrodes 3 and 4 are electrically connected to the metal sprayed parts 11 and 12 of the film capacitor element 1 through the grooves 25 and 26. Since the sprayed metal does not adhere to both side surfaces 21 and 22 of the case 2 as they are, it is desirable to roughen the surface before spraying the metal. This roughening is performed, for example, as shown in the cross-sectional shape of FIG. It is formed by forming 700 pieces / cm ² .

Next, after solder plating or soldering is performed on the surfaces of the external electrodes 3 and 4 shown in FIG. 3H, the individual film capacitor elements 1 are mounted as shown in FIG. Then, the surface mount film capacitor 6 is manufactured by cutting it together with the case 2 and so on.

FIG. 3 is a diagram showing the numbers of occurrences of conduction defects in the surface mounting film capacitor 6 according to the present invention and the conventional surface mounting film capacitor 75 shown in FIG. As shown in the figure, in the present invention, it can be seen that no conduction failure occurs due to penetration of the sprayed metal.

In the above-described embodiment, the rows of grooves 21 and 22 of the case 2 are formed in several rows in the vertical direction, but instead, one groove may be formed in the horizontal direction.

[0026]

[Effect of device]

 As described in detail above, according to the surface mount film capacitor of the present invention, the internal film capacitor element and the external electrode can be electrically connected with a simple structure in which a groove is formed in the case. Therefore, it is easy to manufacture, and since the case can be filled with resin before the grooves are formed in the case, the sprayed metal for forming the external electrodes can be prevented from entering the case, and the film capacitor can be prevented. The excellent effect that electrical conduction between the metal sprayed parts of the element is prevented occurs.

[Brief description of drawings]

FIG. 1 is a view for explaining a manufacturing process of a surface mount film capacitor according to the present invention.

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

FIG. 3 is a surface mount film capacitor 6 according to the present invention.
FIG. 5 is a diagram showing the number of defective conduction caused by penetration of a sprayed metal into the surface mount film capacitor 75 shown in FIG. 4.

FIG. 4 is a diagram showing a manufacturing process of the surface mount film capacitor disclosed in the patent application of Japanese Patent Application No. 4-37303 filed previously.

[Explanation of symbols]

 1 Film Capacitor Element 11, 12 Metal Sprayed Part 2 Case 21, 22 Both Sides 25, 26 Groove 3,4 External Electrode 5 Resin 6 Surface Mount Film Capacitor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H01G 4/32 305 A 8019-5E

Claims (1)

[Scope of utility model registration request] 1. A film capacitor element formed by winding or laminating a metallized plastic film and subjecting the opposite end faces to metal spraying, and an inner dimension in the width direction between the metal sprayed end faces of the film capacitor element. A case larger in size by a predetermined size than that of the film capacitor element, the film capacitor element is housed in the case, resin is injected into the case and cured, and grooves are formed on both side surfaces of the case to form the film capacitor element. The metal sprayed end faces of are exposed, and external electrodes electrically connected to the metal sprayed portions of the film capacitor element through the grooves by metal spraying are provided on both side surfaces of the case. A film capacitor for surface mounting, comprising a solder layer.