JPH06244066A - Manufacture of solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To enhance reliability and miniaturization in products by a method wherein, after the anode is connected with a plus external terminal, an oxide film layer and an organic solid electrolytic film layer are formed and a capacitor element is connected with both external terminals and then a die is resin- sealed via a resin tape, which is cut off in a predetermined length. CONSTITUTION:A plurality of rectangular parallelepiped aluminum anodes 30 are continuously connected with a plate-like conductive plate 34 constituting each plus external terminal 32 to form an anode continuous assembly 36. On the anode surface of this continuous assembly, an oxide film layer 42a and an organic solid electrolytic film layer 42b are formed. Further, a minus external terminal 48 is connected with a peak part of the anode 30 and also a conductive plate 34 is cut off to form a capacitor element 52. This capacitor element 52 is sealed with continuous resin 58 via a resin tape 56 in a recess 54a for receiving a die 54, thereafter the resin tape 56 is cut off for each capacitor element 52.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic capacitor, and more particularly to a method of manufacturing a solid electrolytic capacitor suitable for surface mounting on a printed circuit board or the like used in small electronic equipment.

[0002]

2. Description of the Related Art With the progress of miniaturization and portability of electronic devices, solid electrolytic capacitors used in these devices are required to be compact and easy to be surface-mounted. For this reason, at present, the conventional lead terminals are replaced with leadless ones.

As a method of manufacturing such a solid electrolytic capacitor, one having a structure as shown in FIG. 2 is known. That is, in FIG. 2 (A), the capacitor element 14 in which the internal terminals 12, 12 made of an aluminum rod anode are arranged so as to project is arranged so that the leading end portions of the internal terminals 12, 12 are held by the holding rods 16 for carrying frames. Welded to 18 20
Install by such means. In this case, although not shown, the capacitor element 14 has the internal terminals 12, 12
For each metal foil for positive and negative internal electrodes,
After being attached by ultrasonic welding or the like, the metal foil is wound around the internal terminals 12, 12 via a separator, and then this is subjected to chemical conversion and polymerization treatment in a treatment tank. That is, first, an oxide film layer is formed on the surface by immersing in a chemical conversion electrolytic solution for chemical conversion treatment, and then further immersing in a mixed solution of a monomer solution such as pyrrole and an oxidant solution to perform chemical polymerization. By the treatment, a solid electrolyte coating layer is further formed on the oxide coating layer.

Then, the capacitor element 14 is inserted into a resin case 22 which is arranged in a line so as to correspond to the capacitor element 14, and as shown in FIG.
It is resin-sealed with a potting resin 24 which is injected in advance. Next, in FIG. 2B, the resin case 22 is cut into a predetermined state along a cutting line 26, so that the resin sealing surface 24 is provided with the internal terminals 12, 12 as shown in FIG. 2C. Expose. Then, by connecting the external connection terminals 28, 28 made of an aluminum plate to the exposed internal terminals 12, 12 by means such as welding, a solid electrolytic capacitor is formed.

Therefore, since the solid electrolytic capacitor having such a structure is formed in a relatively small size and has a leadless structure, the ease of surface mounting can be improved.

[0006]

However, the above-mentioned conventional solid electrolytic capacitor still has a drawback to be improved as described below.

Therefore, first, the characteristics that the solid electrolytic capacitor should have will be briefly described. As described above, the solid electrolytic capacitor is formed by forming a capacitor element in advance and then sealing (packaging) the capacitor element with a resin. However, since the oxide and organic solid electrolyte coating layers formed on the capacitor element are vulnerable to mechanical stress, they must be protected from external stress during the manufacturing process. What happens is that if the coating layer is damaged, tan
This is because the electrical characteristics such as δ and leakage current are adversely affected. In addition, the formation area of the coating layer must be controlled accurately, which is also related to the deterioration of the electrical characteristics.

Next, the solid electrolytic capacitor thus manufactured is, of course, suitable for mass production,
In addition, it must achieve product reliability and miniaturization.

However, in the conventional method for manufacturing a solid electrolytic capacitor, the coating layer formed on (the internal terminal of) the capacitor element has a manufacturing process (a resin case cutting process) as is clear from the above description. In the connection process of external terminals), a considerable external stress is applied. Next, in the resin exterior of the capacitor element, each capacitor element must be sequentially resin-sealed, cut into a predetermined shape, and external terminals must be connected, but this process is not only complicated, There is a risk of impairing the hermeticity of the capacitor element and the connection strength of the external terminals, and the risk is increased with the miniaturization of products.

As described above, in the conventional manufacturing method,
The oxide coating layer and the organic solid electrolyte coating layer formed on the capacitor element often have a problem of being damaged. In addition, the manufacturing process, especially the external packaging process of the capacitor element is complicated and difficult, which is not suitable for mass production, and the reliability and downsizing of the product have not been sufficiently achieved.

Therefore, an object of the present invention is to provide a solid electrolytic capacitor which does not damage the oxide coating layer and the organic solid electrolyte coating layer, is suitable for mass production, and can improve the reliability and downsizing of the product. It is to provide a manufacturing method of.

[0012]

In order to achieve the above-mentioned object, a method for producing a solid electrolytic capacitor according to the present invention comprises a plurality of etched rectangular parallelepiped aluminum anode bodies,
A step of forming an anode body continuous assembly by continuously connecting it to a flat conductive plate that constitutes each positive external terminal, and an oxide film layer and an organic solid electrolyte film layer on the surface of this continuous assembly. And a step of forming a capacitor element by connecting a negative external terminal on the top of each anode body of the continuous assembly and cutting the conductive plate, and the step of forming the capacitor element in a mold. The method is characterized in that it comprises a step of resin-sealing in the storage recess with a resin tape interposed therebetween, then removing the resin-sealed capacitor element together with the resin tape from the mold, and cutting the resin tape into individual capacitor elements.

[0013]

According to the present invention, first of all, the oxide coating layer and the organic solid electrolyte coating layer on (the anode body of) the capacitor element are connected continuously to the anode body by connecting the anode body to a conductive plate serving as an external terminal. Formed on the anode body of the body. Then, this anode body continuous assembly is formed into a capacitor element by connecting a minus external terminal to the anode body assembly and cutting the conductive plate. Next, the exterior of the capacitor element is formed by continuous resin encapsulation by resin-encapsulating the capacitor element, to which both positive and negative external terminals are connected in advance, with a resin tape interposed in the mold. This is completed by forming a non-stop capacitor element group, then removing this together with the resin tape from the mold, and cutting the resin tape.

That is, according to the present invention, the oxide coating layer and the organic solid electrolyte coating layer on the anode body are formed after connecting the anode body to the plus external terminal. On the other hand, as for the exterior of the capacitor element, after connecting both external terminals to the capacitor element, the capacitor element is continuously resin-sealed with a resin tape interposed in a mold, and then the resin tape is cut into predetermined pieces, It is completed in a batch process.

Therefore, according to the manufacturing method of the present invention, at least an excessive external stress is not applied to the coating layer. This is because the positive external terminal can be connected before forming the coating layer and the negative external terminal can be connected by an adhesive. On the other hand, the manufacturing method of the present invention is suitable for mass production because the exterior of the capacitor element can be batch-typed. Further, in the outer package, both external terminals form a part of the outer package to sufficiently secure the sealing property of the capacitor element and the connection strength of the external terminal, so that the reliability and downsizing of the product can be improved. .

[0016]

Embodiments of the method for manufacturing a solid electrolytic capacitor according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a manufacturing process comprising the method for manufacturing a solid electrolytic capacitor of the present invention.
First, in FIG. 1 (A), a plurality of etched rectangular parallelepiped aluminum anode bodies 30 are ultrasonically treated on a flat conductive plate 34 constituting each plus external terminal 32 [see FIG. 1 (D)]. The continuous assembly of anode bodies 36 is formed by continuously connecting them by welding or the like. The flat conductive plate 34 is formed of a copper plate having an inner side surface 34a clad with aluminum and an outer side surface 34b solder-plated and a width W set to a terminal width W [see (G) of FIG. 1]. To do.

Next, the anode body 3 of the continuous assembly 36
On the surface of No. 0, the oxide coating layer 42a and the organic solid electrolyte coating layer 42b are formed by the following process, for example. That is, in FIG. 1B, a through hole 38a that surrounds the anode body 30 is formed on the flat conductive plate 34 of the continuous assembly 36 in accordance with the interval L between the plurality of anode bodies 30. At the same time, a sealing jig 38 that is in close contact with the surface of the conductive plate 34 is attached while leaving the anode body 30 portion. And then, first,
The electrolytic solution 40a is injected into the through hole 38a of the sealing jig 38 and subjected to chemical conversion treatment to form an oxide film layer 42a on the surface of the anode body 30, and then further through the through hole 38a.
Then, a mixed solution 40b consisting of a monomer solution and an oxidizing agent solution is newly injected and chemically polymerized to form an organic solid electrolyte coating layer 42b on the surface of the oxide coating layer 42a of the anode body 30. In this case, the seal jig 38 has a silicone resin 44 interposed on the bottom surface thereof, and if necessary, after further applying a peel coat, the seal jig 38 cooperates with the pressing pin 46 to press and contact the conductive plate 34. Then, when the sealing jig 38 is removed, the silicone resin 44 is peeled off together with the sealing jig 38.

Therefore, according to the present invention including the above steps, in forming the coating layers 42a and 42b, the anode body 3 is formed.
Since 0 is seal-separated from other parts by the seal jig 38, liquid level management for the processing liquid is not required. Incidentally, in the past, since the above-mentioned formation of the coating layer was carried out in the processing tank, complicated and difficult liquid level management or other control was required.

Next, with respect to the continuous assembly 36 having the coating layers 42a and 42b formed thereon, as shown in FIG.
The minus external terminal 48 formed on the top of each anode body 30 is connected by a conductive adhesive 50 or the like, and the plus external terminal conductive plate 34 is cut in FIG. 1D (FIG. 1C). Of the cutting line 51] and forming the plus external terminal 32 to form the capacitor element 52.

Finally, the capacitor element 52
1E, in FIG.
In FIG. 1, the continuous resin-sealed capacitor element 52 group is formed by sealing the resin 58 with the resin tape 56 interposed therebetween. Then, in FIG. Mold 54 with 56
1 by removing the resin tape 56 along the cutting line 60 for each capacitor element 52 (therefore, in this case, it is not necessary to apply a release agent into the mold 54). A solid electrolytic capacitor 62 as shown in (G) is formed. At the time of cutting the resin tape 56, a part 56a (a part that abuts on the bottom of the storage recess 54a) remains on the capacitor element 52, and a plus and / or minus mark 56b is attached thereto. Thus, the polarities of the external terminals 32 and 48 of the capacitor element 52 can be displayed.

As described above, according to the present invention, the oxide coating layer and the organic solid electrolyte coating layer on the anode body are formed after the anode body is connected to the plus external terminal. On the other hand, as for the exterior of the capacitor element, after connecting both external terminals to the capacitor element, the capacitor element is continuously resin-sealed with a resin tape interposed in a mold, and then the resin tape is cut into predetermined pieces, It is completed in a batch process.

Therefore, according to the manufacturing method of the present invention, at least an excessive external stress is not applied to the coating layer. This is because the positive external terminal can be connected before forming the coating layer and the negative external terminal can be connected by an adhesive. On the other hand, the manufacturing method of the present invention is suitable for mass production because the exterior of the capacitor element can be batch-typed. Further, in the outer package, both external terminals form a part of the outer package to sufficiently secure the sealing property of the capacitor element and the connection strength of the external terminal, so that the reliability and downsizing of the product can be improved. .

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and many design changes can be made without departing from the spirit thereof.

[0025]

As described above, according to the present invention,
First, the oxide film layer and the organic solid electrolyte film layer on (the anode body of) the capacitor element are formed on the anode body of the anode body continuous assembly, in which the anode body is connected to the positive conductive plate serving as an external terminal. To be done. And this anode body continuous assembly is
On the other hand, a negative external terminal is connected and the conductive plate is cut to form a capacitor element. Next, the exterior of the capacitor element is formed by continuous resin encapsulation by resin-encapsulating the capacitor element, to which both positive and negative external terminals are connected in advance, with a resin tape interposed in the mold. This is completed by forming a non-stop capacitor element group, then removing this together with the resin tape from the mold, and cutting the resin tape. That is, according to the present invention, the oxide coating layer and the organic solid electrolyte coating layer on the anode body are formed after connecting the anode body to the plus external terminal. On the other hand, as for the exterior of the capacitor element, after connecting both external terminals to the capacitor element, the capacitor element is continuously resin-sealed with a resin tape interposed in a mold, and then the resin tape is cut into predetermined pieces, It is completed in a batch process.

Therefore, according to the manufacturing method of the present invention, at least an excessive external stress is not applied to the coating layer (that is, the coating layer is not damaged). This is because the positive external terminal can be connected before forming the coating layer and the negative external terminal can be connected by an adhesive. On the other hand, the manufacturing method of the present invention is suitable for mass production because the exterior of the capacitor element can be batch-typed. Further, in the outer package, both external terminals form a part of the outer package to sufficiently secure the sealing property of the capacitor element and the connection strength of the external terminal, so that the reliability and downsizing of the product can be improved. .

[Brief description of drawings]

1A to 1G are process explanatory views showing an embodiment of a process for manufacturing a solid electrolytic capacitor according to the present invention.

FIG. 2A to FIG. 2C are process explanatory views showing a manufacturing process of a conventional solid electrolytic capacitor.

[Explanation of symbols]

 30 rectangular parallelepiped aluminum anode body 32 plus external terminal 34 flat conductive plate 36 anode body continuous assembly 38 sealing jig 38a through hole 40a electrolyte solution 40b mixed solution 42a oxide coating layer 42b organic solid electrolyte coating layer 44 silicon resin 46 pressing pin 48 Minus external terminal 50 Conductive adhesive 52 Capacitor element 54 Mold 54a Storage recess 56 Resin tape 56a Part of resin tape 56b Mark 58 Resin 60 Cutting line 62 Solid electrolytic capacitor

Claims (1)

[Claims] 1. A step of forming a continuous assembly of anode bodies by continuously connecting a plurality of etched rectangular parallelepiped aluminum anode bodies on a flat conductive plate which constitutes each plus external terminal thereof, and Forming an oxide coating layer and an organic solid electrolyte coating layer on the surface of the continuous assembly, and connecting a negative external terminal to the top of each anode body of the continuous assembly, and cutting the conductive plate. And the step of forming a capacitor element with a resin tape in the housing recess of the mold with a resin tape interposed therebetween, and then the resin-sealed capacitor element is removed from the mold together with the resin tape. A method of manufacturing a solid electrolytic capacitor, comprising a step of cutting each capacitor element.