JPS6057691B2 - Solid electrolytic capacitor and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid electrolytic capacitor, and more particularly to an improved structure of a solid electrolytic capacitor in which a terminal cap is used as a terminal electrode, and a method for manufacturing the same.

BACKGROUND ART In-frame electrolytic capacitors having terminal electrodes formed as U-shaped metal terminal caps are conventionally known. A typical example thereof is the structure disclosed in Japanese Patent Laid-Open No. 15954/1983. Its features are shown in FIGS. 1 and 2 as perspective views and cross-sectional views, respectively.
A cathode of a capacitor element 2 having a protruding anode lead wire 1 is bonded to a U-shaped metal cap 4 with a conductive adhesive 3. The outer surface of the capacitor element 2 is coated with an insulating resin 5 by brushing or soaking. On the other hand, the metal cap 6 has a hole 7 in the center through which the lead wire 1 passes, and further has a non-conductive material 8 inside. This cap 6 is placed over the end of the capacitor element 2 and adhered by curing the material 8. The lead wire 1 and the hole 7 are welded together. However, in a capacitor having such a structure, the lead wire 1 must pass through the hole 7 of the cap 6, so the cap 4
and 6 were provided in separate processes, making manufacturing that much more troublesome.

This also makes it difficult to align the bottom surfaces of the caps 4 and 6 within the same plane with high precision. Furthermore, since there is a step between the insulating resin layer 5 on the outer surface and the bottom surfaces of the caps 4 and 6, unexpected external force is likely to be applied to this step, which may cause an accident such as the cap coming off. An object of the present invention is to provide a structure of a solid electrolytic capacitor that can be more reliably mounted on a circuit board and a method of manufacturing the same.

According to the present invention, there is obtained a solid electrolytic capacitor characterized in that the bottom surfaces of both caps and the bottom surface of the exterior resin are in the same plane.

Further, according to the present invention, there are the steps of: preparing a conductor frame having an opening on the bottom; fixing a capacitor element in the frame across the opening; and pouring an insulating resin into the frame. A method for manufacturing a solid electrolytic capacitor is obtained, which includes the steps of: cutting a frame and a resin along both sides of a capacitor element.

The present invention will be described below with reference to FIGS. 3 to 11.

FIG. 3 shows a metal frame 31 serving as the terminal electrode of the present invention, and the bottom surface has an opening 32 extending in the longitudinal direction. on the other hand,
The lead wires 1 of a plurality of capacitor elements 2 are welded to solderable metal wires 41 at regular intervals as shown in FIG.
Figure 5 (plan view) shows the capacitor element group obtained in this way.
6, and the cathode side of the capacitor element 2 and the cathode side 33 of the frame 31 are fixed together with a conductive adhesive 3, as shown in FIG. Frame 31
solder to the anode side 34 (welding may also be used). The capacitor structure connected in this way is placed in a box 61 having a flat bottom as shown in FIG. 6, and an insulating resin 71 is injected from the top. Thereafter, the resin 71 is cured by placing it in a constant temperature bath or the like, and the box 61 is removed. Next, XX in FIG. ．．
If you cut along Y-Y with a diamond cutter,
As shown in FIG. 7, a solid electrolytic capacitor having a structure in which the cathode terminal 33 and the anode terminal 34 are electrically separated is obtained. In the embodiments described above, the terminal structure is L-shaped. However, as shown in FIGS. 9 to 11, the terminal structure may include a U-shaped terminal 91 or an L-shaped modified terminal. 10
Various structures such as 1 are possible.

Regardless of the terminal structure, there are no steps on the bottom of the capacitor, and the terminal structure is extremely flat.
Application of extra external force can be avoided and mounting accuracy can also be improved. Also, looking at the side surface, a flat surface is formed by cutting, which has the advantage of being easy to pick up in automation during mounting. Moreover, since there is no step difference as shown in FIGS. 1 and 2 on the upper surface, means such as vacuum suction can be effectively used. Further, the shape of the capacitor element is not limited to the above embodiment.

In the above embodiment, the anode lead wire 1 was taken out from the center of the capacitor element 2, but as shown in FIG. If an element 82 is used, which has a structure in which a dielectric oxide film 8, a semiconductor layer 85, a graphite layer 86, and a conductive layer 87 are provided on the surface of an anode body 83, as is well known, the lead wire 81 is connected and protruded from the end. This has the advantage that the process of joining the anode side terminal to the anode side terminal can be carried out easily. Examples of finished products in this case are shown in FIGS. 13 and 14. Even without the metal wire 41, polarity can be determined based on the shape of the electrodes 101 and 34. It goes without saying that by changing the structure of the frame, the appearance shown in FIGS. 7, 9, and 10 without the metal wire 41 can be obtained. When the metal wire 41 is not exposed to the outside, FIG.
It is preferable to change the shapes of the anode and cathode as shown in FIG. 14 for the purpose of determining polarity, but of course a separate means for determining polarity may be provided. 13 and 14 using the element 82 shown in FIG. 12, for example, in the same way as the embodiment shown in FIG.
It goes without saying that you should do this (no longer needed). Note that the opening 32 provided in the frame 31 in the above embodiment is
It is clear that the number is not limited to one, but may be divided into multiple parts.

In other words, referring to FIG. 5, if the design is such that openings having an interval of X<15Y are arranged in the lower region of each capacitor element, the frame 3
This has the advantage of increasing the mechanical strength of 1, making it easier to work during the manufacturing process. Furthermore, if a flat plate is used instead of the box 61, a product similar to that of the embodiment can be obtained by simply forming walls at both ends of the frame 31.

Furthermore, instead of the box 61, it is also possible to seal the opening and both ends using heat-resistant adhesive tape such as masking tape. Capacitor element 2, anode lead wire and frame 31
It goes without saying that the method of connection with the above is not limited to the above embodiment. In particular, when the terminal structure is L-shaped, it is also possible to provide a hole on the anode terminal 34 side and pass the lead wire 1 through it, as in the conventional example, by considering the width of the frame 31. In this case, the metal wire 41 may be omitted. In addition, it is also conceivable to provide a notch in the anode terminal 34 or provide a tongue portion to obtain a strong bond. By making the metal wire 41 short for each capacitor element, it can be exposed to the outside of the product. Further, if the metal wire 41 is made of a magnetic material such as iron or nickel, and the frame 31 is made of a non-magnetic material, automatic polarity selection becomes easy. As described above, according to the present invention, the outer diameter dimension is accurately defined by the dimension of the frame 31, and the finished product is finally obtained by cutting, so that a solid product with high dimensional accuracy and little variation can be produced. We can provide mass-produced electrolytic capacitors.

[Brief Description of the Drawings] Figures 1 and 2 are a perspective view and a sectional view showing a conventional solid electrolytic capacitor, respectively, Figure 3 is a perspective view of an electrode frame used in the present invention, and Figure 4 is a perspective view of the present invention. FIG. 5 is a perspective view showing a capacitor element group in the middle of the manufacturing process; FIG. 5 is a plan view when the capacitor element group of the present invention is inserted into an electrode frame;
FIG. 6 is a perspective view showing a stage before injection of the exterior resin according to the present invention, FIGS. 7 and 8 are perspective views and cross-sectional views showing one embodiment of the solid electrolytic capacitor according to the present invention, and FIG.
10 and 11 are perspective views showing other embodiments of the present invention, FIG. 12 is a sectional view of another example of a capacitor element used in the present invention, and FIGS. FIG. 13A is an example in which the device shown in the figure is used.
1. FIG. 14A is a cross-sectional view, and FIG. 13B and FIG. 14B are respective perspective views. 1,81... Anode lead wire, 2,82...
Capacitor element, 3... Conductive adhesive, 4, 6
, 33, 34, 91, 101...metal terminal, 5
, 71... Insulating resin, 7... Hole, 8...
... Non-conductive material, 31 ... Metal frame, 32
...Opening, 41...Metal wire, 61...
··box.

Claims (1)

[Scope of Claims] 1. In a solid electrolytic capacitor having flat external electrodes at both ends of a capacitor element, the bottom surfaces of which are arranged in substantially the same plane, the bottom and side surfaces of an insulating material sheathing the capacitor element are A solid electrolytic capacitor, wherein the external electrode is formed substantially in the same plane as the bottom surface and the cut end surface. 2. preparing a conductor frame having an opening on the bottom;
The method includes fixing a capacitor element within the frame across the opening, flowing an insulating material into the frame, and cutting the frame and the insulating material along both sides of the capacitor element. A method for manufacturing a solid electrolytic capacitor, characterized by: