JP2649565B2 - Manufacturing method of low profile film capacitor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a lead-wired metallized film capacitor, particularly a capacitor having a small height and good solderability of a lead wire.

[Prior Art] A conventional lead wire drawing type metallized film capacitor is usually manufactured in the order of steps shown in FIG. 4th
In FIG. 1A, a lead wire 3 is welded to an element in which electrode portions 2 are formed on both end surfaces of a body 1 in which a metallized plastic film is wound or laminated by metal spraying. The fixing direction of the lead wire 3 is the direction of the uneven plane of the element body 1. Then, the release agent 4 is applied to the base of the lead wire 3.

Next, as shown in FIG. 4B, vacuum impregnation is performed in the low-viscosity epoxy resin 5. Since the mold release agent 4 does not adhere to the end of the lead wire 3, it is carefully supported so that the impregnating liquid does not adhere in this step. Further, an epoxy resin sheath 6 shown in FIG. At this time, the resin is cut at a fixed distance from the base end of the lead wire 3 in the semi-cured state, but at the time of full curing, resin dripping occurs at the base of the lead wire 3 as shown by l in the figure. Further, the release agent 4 remains.

[Problems to be solved by the invention]

The finished product manufactured by the above-mentioned normal manufacturing method has the following disadvantages when mounted on a printed circuit board. In the implementation,
The lead wire 3 is passed through a hole in the printed circuit board and soldered. At this time, as shown in FIG. 5 (a), when the capacitor is pressed down deeply until the sagging of the resin exterior 6 contacts the printed board, soldering is performed where the release agent 4 adheres. It is easy to have poor soldering. There is also a disadvantage that the height of the resin casing 6 is increased due to the sagging.
In order to avoid poor soldering, as shown in FIG. 5B, the lead wire 3 of the capacitor is usually not squeezed deeply, but is kinked and soldered at the tip of the lead wire 3 where there is no release agent. Therefore, the mounting height is further increased.

As explained above, when a capacitor is mounted,
There is a drawback that the component arrangement becomes tall, and it becomes difficult to increase the density when assembling a plurality of completed printed circuit boards. If you release the release agent as a finished product,
Although the solderability is good, the cost is high. Also at this time, an increase in height due to resin dripping cannot be avoided.

In view of the above circumstances, an object of the present invention is to provide a novel manufacturing method capable of obtaining a low-profile film capacitor exhibiting good solderability when mounted on a printed circuit board.

[Means for solving the problem]

In the present invention, after forming an electrode portion by spraying a high-melting metal on the flat end face of the flat body obtained by winding or laminating a metallized plastic film, a step of forming a local solder raised portion on the electrode portion, Next, a lead wire is fixed in a direction perpendicular to the uneven plane on the solder raised portion of the electrode portion of the element which has been subjected to a step of impregnating with a thermosetting resin, and then the element is looked at and covered with an insulating film. To do.

[Action]

In the present invention, after the electrode portion is formed on the element body, a solder raised portion is formed on the electrode portion. Then, after the resin impregnation, the lead wire is welded or soldered to the solder raised portion. In the conventional example, it is necessary to apply a release agent to the lead wire in order to prevent the impregnating agent from rising on the lead wire because the reverse order of welding the lead wire and then impregnating the resin is necessary. This has caused a problem when a capacitor is mounted on a printed circuit board as a finished product. In the present invention, no release agent is used.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an outline corresponding to the order of steps or a view for explaining steps. In this embodiment, a body 1 wound with a metallized plastic film is used. In FIG. 1 (a), electrode portions 2 formed by metal spraying on both ends of a body 1 are shown.
Approximately at the center, a solder raised portion 10 is formed. Next, as shown in FIG. 3B, vacuum impregnation of the element 11 formed as described above is performed. At this time, since the elements 11 have no lead wires, a large number of elements 11 can be impregnated simultaneously.

Next, as shown in FIG. 1C, the lead wire 3 is soldered or welded to the solder raised portion 10. Although a thin resin film is formed on the surface of the solder raised portion 10, it does not hinder the welding of the lead wire 3 at all. If the mounting direction of the lead wire 3 is perpendicular to the deviated plane of the element 11,
A tall capacitor can be obtained. Although reliability with respect to moisture can be obtained by impregnation with a resin, in order to ensure insulation of the electrode portion 2 and further improve reliability, as shown in FIG. Is housed in a tube (shrink tube) 12 made of a shrinkable material, and when heated, the shrink tube 12 closely covers the element 11.

〔The invention's effect〕

As shown in FIG. 2, the completed product manufactured in the above process can be pressed into the element 11 deep to the base end of the lead wire 3 and soldered when mounted on a printed circuit board. Since no release agent is attached to the lead wire 3, the solderability is good. Therefore, in combination with the fact that the lead wire 3 is fixed at right angles to the eccentric plane, it is possible to mount components with a short height.

In order to compare the conventional method with the method according to the present invention, 22
The dimensions of a standard product of μF, 35V are shown. The dimensions are A, H, L, P in Fig. 6.
A × H × L × P, and the conventional example is 10.5 × 20 × 26
× 22.5 (mm), in the present invention, 17.5 × 8.9 × 24 × 22.5
(Mm). The height H is equivalent to the height when the element is closely attached to the printed circuit board.
It is remarkably improved to 9mm. Moreover, in the conventional example, soldering cannot be performed in close contact with the printed circuit board, and soldering is performed near the end of the lead wire, so that the actual height of the capacitor is further increased.

With respect to the product of the present invention and the conventional product, the results of testing the solder wettability of the lead wire are shown in FIG. As can be seen, a significant improvement is obtained.

In addition, in the process, the resin impregnation can be performed without attaching a lead wire, and there are great advantages in mass production, such as omitting the exterior resin process.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention in the order of steps, FIG. 2 is a view showing a state in which a finished product according to the embodiment is mounted on a printed circuit board, and FIG. Diagram,
FIG. 4 is a view showing a conventional example, FIG. 5 is an explanatory view of a problem when a completed product according to the conventional example is mounted on a printed circuit board, FIG.
The figure shows the external dimensions. 1 ... body, 2 ... metal part, 3 ... lead wire, 10 ... solder raised part, 11 ... element, 12 ... shrink tube.

Claims (1)

(57) [Claims] 1. A step of forming an electrode portion by thermal spraying of a high melting point metal on an end face of a flat body obtained by winding or laminating a metallized plastic film, and then forming a local solder raised portion on the electrode portion. Then, after a step of impregnating with a thermosetting resin, a lead wire is fixed in a direction perpendicular to a flat surface on a solder raised portion of the electrode part of the element, and then the element is removed with an insulating film except for the lead wire. A method for manufacturing a low-profile film capacitor, characterized by being covered.