JPH05259003A - Solid electrolytic capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a small type and high capacitance solid electrolytic capacitor by a method wherein an anode member, where a solid electrolytic layer will be formed, is formed by a sheet of anode foil, and the anode foil is reinforced by a reinforcement member to separate a mechanical-strength ensured part from a capacity forming function part of the anode member. CONSTITUTION:Insulating plates 21 and 22, which will be used as the reinforcement member for anode foil 81 and 82, are formed larger than the anode foil 81 and 82. The above-mentioned insulating plates perform an additional function as the sheathing member of capacitor elements C1 and C2. Thus, the capacitor elements C1 and C2 are formed by the anode foil 81 and 82, and the rear side of the anode foil 81 and 82 is reinforced by the insulating plates 21 and 22 which are combindly used as sheathing members. As the sufficient electrostatic capacitance can be ensured by the use of the anode foil 81 and 82 and they are reinforced by the insulating plates 21 and 22, a solid electrolytic capacitor can be miniaturized, flattened, reduced in weight, and a large capacitance can also be accomplished. Also, the reliability of the capacitor can be improved, because a thick anode member is not formed by cutting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor using a solid electrolyte such as an organic conductive polymer in an electrolyte layer and a method for manufacturing the same.

[0002]

2. Description of the Related Art In this type of solid electrolytic capacitor, an anode body made of aluminum or the like is subjected to surface widening treatment by etching, a dielectric layer is formed on the surface by electrolytic treatment, and an organic layer is formed on the upper surface of the dielectric layer. A semiconductor element is grown to form a solid electrolyte layer to form a capacitor element, and the capacitor element is covered with an outer package, and an anode terminal is formed on the anode body side and a cathode terminal is formed on the solid electrolyte side, which is pulled out from the outer package. .

By the way, although this solid electrolytic capacitor can be miniaturized structurally, on the other hand, it is desired to form a sufficient practical capacitance. In addition, this type of solid electrolytic capacitor has been put to practical use for surface mounting because it is a hybrid integrated circuit, and has improved heat resistance against solder reflow and improved moisture resistance to prevent deterioration due to moisture in the air. Cannot be ignored.

Conventionally, in this solid electrolytic capacitor, a relatively thick aluminum plate or the like has been used for the anode body in the process of forming the solid electrolyte layer, which is a cause of hindering an increase in capacity per unit volume. The stress of cutting out, cutting, etc. in the manufacturing process of the anode body also causes the deterioration of the electrical characteristics of the anode body.

Therefore, it is an object of the present invention to provide a solid electrolytic capacitor which is miniaturized and has an increased electrostatic capacity, and a manufacturing method thereof.

[0006]

The solid electrolytic capacitor of the present invention comprises an anode foil (8) having a solid electrolyte layer (16) formed thereon.
1, 82 or 80), a reinforcing member (insulating plates 21, 22 or conductor plate 20) for installing the anode foil, an anode terminal (4) formed on the anode foil side, and on the solid electrolyte layer. It is composed of the formed cathode terminal (6) and an exterior member (exterior body 2) which partially includes the reinforcement member or is installed separately from the reinforcement member and covers the anode foil and the solid electrolyte layer. It is characterized by

In the solid electrolytic capacitor of the present invention, the anode foil (81, 82 or 80) is attached to the reinforcing member (insulating plate 21,
22 or a conductor plate 20), a step of forming a solid electrolyte layer (16) on the anode foil, a step of forming an anode terminal (4) on the anode foil, and a cathode terminal on the solid electrolyte layer. (6) is provided, and the step of including the reinforcing member as a part or provided separately from the reinforcing member and covering the anode foil and the solid electrolyte layer with an exterior member (exterior body 2). It is characterized by that.

[0008]

In this solid electrolytic capacitor, the anode member on which the solid electrolyte layer is to be formed is formed of the anode foil, and the anode foil is reinforced by the reinforcing member. That is, by separating the mechanical strength securing portion of the conventional anode member and the functional portion for capacity formation, it is not necessary to punch out the anode member, and downsizing and high capacity are realized. .

Further, in this method for producing a solid electrolytic capacitor, after fixing an anode foil as a capacity forming portion which has been subjected to etching treatment or chemical conversion treatment to a reinforcing member, a solid electrolyte layer is formed, and an anode foil is provided on the anode foil side. A cathode terminal is formed on the terminal and the solid electrolyte layer to form a capacitor element, and the capacitor element is provided with an exterior. By doing so, the formation of the solid electrolyte layer on the anode foil becomes good, which contributes to the improvement of the reliability of the solid electrolytic capacitor.

[0010]

EXAMPLE FIGS. 1A and 1B show a first example of the solid electrolytic capacitor of the present invention. In this solid electrolytic capacitor, an outer casing 2 is formed with two insulating plates 21 and 22 forming a reinforcing member and an outer casing and a sealing resin 23 made of acryl or the like, and a capacitor element is enclosed therein. The strip-shaped anode terminal 4 and cathode terminal 6 drawn out from the sealing resin 23 side are bent and installed on the insulating plate 21 side so that surface connection is possible.

Inside the exterior body 2, thin anode foils 81 and 82 formed of an electrode material such as aluminum are installed, and the opposite surface side thereof is subjected to surface expansion treatment by etching treatment and chemical conversion treatment, respectively. Thus, the dielectric oxide film 10 is formed. In this case, the dielectric oxide film 10 is formed so as to avoid the portion where the internal terminal 12 on the anode side is installed.
The anode side internal terminals 12 are provided on the surfaces of the anode foils 81 and 82, respectively.
On the other hand, a solid electrolyte layer 16 made of a polymer film such as polypyrrole is formed on the dielectric oxide film 10 by providing an insulating space 14 by vapor phase polymerization, chemical polymerization or electrolytic polymerization. Then, the anode terminal 4 is sandwiched between the internal terminals 12 via the conductive adhesive 18, and the cathode terminal 6 is provided on the upper surface of each solid electrolyte layer 10 with the conductive adhesive 19 forming a conductor layer. It is sandwiched and fixed. Therefore, two capacitor elements C ₁ and C ₂ are formed on the front and back sides of the anode terminal 4 and the cathode terminal 6, and each capacitor element C ₁ and C ₂ is placed between the anode terminal 4 and the cathode terminal 6. It is connected in parallel.

The insulating plates 21 and 22 as reinforcing members for the anode foils 81 and 82 are formed larger than the anode foils 81 and 82, and also serve as exterior members for the capacitor elements C ₁ and C ₂ . A sealing resin 23 is filled in the space on the peripheral edge side of each of the insulating plates 21 and 22, and the capacitor elements C ₁ and C ₂ are covered with the insulating plates 21 and 22 and the sealing resin 23.

In this way, if the capacitor elements C ₁ and C ₂ are formed with the anode foils 81 and 82 and the backsides of the anode foils 81 and 82 are reinforced with the insulating plates 21 and 22 which also serve as exterior members, the anode foils are formed. Since the electrostatic capacity is sufficiently secured by using 81 and 82 and the reinforcement is performed by the insulating plates 21 and 22, miniaturization, flattening and weight reduction can be achieved, and high capacity can be achieved. You can Further, in the embodiment, since the front and back surfaces of the anode terminal 4 and the cathode terminal 6 form two capacitor elements C _1, C _2, the parallelization of both the static of the capacitor elements C _1, C ₂ The capacitance is C
If a and Cb, then the combined capacitance C is C = Ca + Cb
= 2Co (Ca = Cb = Co), so that the capacity can be increased and the volumetric efficiency can be improved.

Further, in this solid electrolytic capacitor, the outer package 2 is formed by the insulating plates 21 and 22 and the sealing resin 23, so that the outer structure of the solid electrolytic capacitor can be simplified.

Next, FIGS. 2 to 5 show a first embodiment of the method for manufacturing a solid electrolytic capacitor of the present invention.

As shown in FIG. 2A, the anode foils 81 and 82 are formed from a film-forming metal such as aluminum.
The anode foils 81 and 82 are subjected to surface enlargement treatment by etching treatment, and then the dielectric oxide film 10 is formed on the surface by chemical conversion treatment.

Next, as shown in FIG. 2B, the anode foils 81 and 82 are attached to the surfaces of the insulating plates 21 and 22 as reinforcing members. In this case, the insulating plates 21 and 22 are formed of a synthetic resin plate or the like having a similar shape to the anode foils 81 and 82 and having a larger area than the anode foils 81 and 82.

Next, as shown in FIG. 2C, the internal terminals 12 are fixed to the surfaces of the anode foils 81 and 82 by a fixing means such as welding. The internal terminal 12 has an anode foil 81,
It is formed of the same or other electrode material as 82.

Next, as shown in FIG. 2D and FIG. 3, solid electrolyte layers are formed on the surfaces of the anode foils 81 and 82 by providing an insulating space 14 from the internal terminals 12 on the surfaces of the anode foils 81 and 82. 16 is formed. That is, a polymer film such as polypyrrole is formed on the surface of the dielectric oxide film 10 by vapor phase polymerization, chemical polymerization or electrolytic polymerization.

Then, as shown in FIG. 4, the conductive adhesive 18 is interposed on the surface of the internal terminal 12 and the conductive adhesive 19 is applied to the surface of the solid electrolyte layer 16 of the anode terminal 4 and the anode foil 82.
The cathode terminal 6 is fixed to each other with the interposition of, and the other anode foil 82 is opposed, and the conductive adhesive 18 is interposed on the surface of the anode terminal 4 so that the internal terminal 12 on the anode terminal 81 side and the cathode terminal 6 side. The solid electrolyte layer 16 on the anode foil 81 side is fixed with the conductive adhesive 19 interposed therebetween, and the anode terminal 4 and the cathode terminal 6 are sandwiched by the two anode foils 81 and 82. As a result, two capacitor elements C ₁ and C ₂ are formed, and each capacitor element C ₁ and C ₂ is
The anode terminal 4 and the cathode terminal 6 are arranged in parallel. The anode terminal 4 and the cathode terminal 6 are formed of a conductor formed of the same electrode material as the anode foils 81 and 82 or a solderable conductor plate.

Next, as shown in FIG.
A sealing resin 23 is filled between the two insulating plates 21, 2
The space between the two is filled, and the anode terminal 4 and the cathode terminal 6 are pulled out from the sealing resin 23 portion. As shown by arrows A and B, each of the anode terminal 4 and the cathode terminal 6 should be bent along the surface of the sealing resin 23 forming the exterior body and the surface of the insulating plate 21 to be formed into external terminals capable of surface connection. Thus, the solid electrolytic capacitor shown in FIG. 1 is manufactured.

Next, FIG. 6 shows a second embodiment of the solid electrolytic capacitor of the present invention. In this solid electrolytic capacitor, an insulating frame 24 having a C-shaped cross section is used instead of the insulating plate 21 of the first embodiment, and the insulating frame 24 and the insulating plate 2 are used.
2 is joined and the opening side is filled with the sealing resin 23 to form the exterior member.

A capacitor element is formed inside the outer casing 2 by using the anode foil 80, as in the solid electrolytic capacitor of the first embodiment.
The difference is that a conductor plate 20 made of an electrode material is used as a reinforcing member. Therefore, the anode foil 80 is installed on the upper surface of the conductor plate 20 together with the internal terminals 12 with a constant insulation interval 14, and the surface of the anode foil 80 is expanded by etching and then dielectricized by chemical conversion treatment. The body oxide film 10 is formed. This dielectric oxide film 1
A solid electrolyte layer 16 made of a polymer film such as polypyrrole on the surface of No. 0 by gas phase polymerization, chemical polymerization or electrolytic polymerization
Are formed. The internal terminal 13 on the cathode side is fixed to the upper surface of the solid electrolyte layer 16 with a conductive adhesive 19 forming a conductor layer. Therefore, a single capacitor element is formed on the upper surface of the conductor plate 20.

In addition, the exterior body 2 includes an insulating plate 22 and an insulating frame 24.
And the sealing resin 23 is formed on the opening side.
And the internal terminals 12 and 13 are drawn out from the portion of the sealing resin 23, on which the anode terminal 4 and the cathode terminal 6 which are L-shaped external terminals are connected.

Even when the solid electrolytic capacitor is constructed by using one piece of the anode foil 80 as described above, the capacitance can be increased as well as the size reduction and the flattening.

Next, FIGS. 7 to 10 show a second embodiment of the method for manufacturing a solid electrolytic capacitor of the present invention.

As shown in FIG. 7A, the anode foil 80 is formed from a film-forming metal such as aluminum. The anode foil 80 is subjected to surface enlargement treatment by etching treatment, and then the dielectric oxide film 10 is formed on the surface thereof by chemical conversion treatment.

Next, as shown in FIG. 7B, the anode foil 80 is fixed to the surface of the conductor plate 20 as a reinforcing member by a fixing means such as welding and electrically connected. As the conductor plate 20, one larger than the anode foil 80 is used, and the internal terminal 12 is fixed to a position separated from the anode foil 80 by a fixing means such as welding and electrically connected. Then, the conductor plate 20
Is placed on the insulating plate 22 which is similar in shape to the conductor plate 20 and has a large area, with its peripheral portion exposed. That is, the insulating plate 22 forms a part of the exterior member together with the reinforcing member. Then, as the solid electrolyte layer 16, gas phase polymerization,
A polymer film such as polypyrrole is formed on the surface of the dielectric oxide film 10 by chemical polymerization or electrolytic polymerization.

Then, as shown in FIG. 7C, the internal terminal 13 on the cathode side is connected to the upper surface of the solid electrolyte layer 16 with a conductive adhesive 19.

Next, as shown in FIG. 8, an insulating frame 24 having a C-shaped cross section is installed on the upper surface side of the insulating plate 22, and both are integrally fixed by ultrasonic welding or an insulating adhesive.

Next, the sealing resin 23 is filled in the opening side of the outer package 2 which is integrated with the insulating plate 22 and the insulating frame 24, and the capacitor element is assembled with the internal terminals 12 and 13 partially pulled out. The inside of the outer package 2 is sealed. After the sealing resin 23 is hardened, the end portions of the exterior body 2 are cut off along with the internal terminals 12 and 13 or the internal terminals 12 and 13 at the portions indicated by arrows C and D.

Next, as shown in FIG. 10, an L-shaped anode terminal 4 and cathode terminal 6 are ultrasonically welded as external terminals to be connected to the internal terminals 12 and 13 exposed on the end face side of the outer package 2. The solid electrolytic capacitor shown in FIG. 6 can be obtained by connecting with a conductive adhesive.

According to such a manufacturing method, it is possible to easily manufacture a solid electrolytic capacitor having an increased electrostatic capacity as well as a reduced size and flatness.

In the solid electrolytic capacitor of the first embodiment and the method of manufacturing the same, the dielectric oxide film is selectively applied to the anode foil, and the anode is formed on the base metal of the anode foil on which the dielectric oxide film is not formed. Although the terminals or the internal terminals are connected by means such as welding, a dielectric oxide film may be formed on the entire surface of the anode foil, and the internal terminals on the anode side may be connected to the dielectric oxide film. It is not limited to the example structure.

[0035]

As described above, according to the fixed electrolytic capacitor of the present invention, since the capacitance is formed by using the anode foil, the electrostatic capacitance can be increased and the thick anode body as in the conventional case can be used. Reliability is improved because it is not cut out.

Further, according to the method for manufacturing a fixed electrolytic capacitor of the present invention, it is possible to manufacture a solid electrolytic capacitor having a small size and a high capacity by using the anode foil.

[Brief description of drawings]

FIG. 1 shows a first embodiment of a solid electrolytic capacitor of the present invention, (A) is a perspective view thereof, and (B) is a longitudinal sectional view thereof.

FIG. 2 is a first method of manufacturing a solid electrolytic capacitor according to the present invention.
It is a longitudinal section showing an example.

FIG. 3 is a perspective view showing one step of the method for manufacturing the solid electrolytic capacitor shown in FIG.

4 is a perspective view showing an exterior process in the method for manufacturing the solid electrolytic capacitor shown in FIG.

5 is a vertical cross-sectional view showing a processing step of terminals in the method of manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 6 shows a second embodiment of the solid electrolytic capacitor of the present invention, (A) is a perspective view thereof, and (B) is a longitudinal sectional view thereof.

FIG. 7: Second method of manufacturing solid electrolytic capacitor of the present invention
It is a longitudinal section showing an example.

8 is a perspective view showing an exterior process in the method for manufacturing the solid electrolytic capacitor shown in FIG.

9 is a vertical cross-sectional view showing a processing step of terminals in the method for manufacturing the solid electrolytic capacitor shown in FIG.

10 is a perspective view showing a step of connecting external terminals in the method of manufacturing the solid electrolytic capacitor shown in FIG.

[Explanation of symbols]

 2 Exterior body (exterior member) 4 Anode terminal 6 Cathode terminal 16 Solid electrolyte layer 20 Conductor plate (reinforcing member) 21, 22 Insulating plate (reinforcing member) 80, 81, 82 Anode foil

Claims (2)

[Claims] 1. An anode foil having a solid electrolyte layer formed thereon, a reinforcing member for installing the anode foil, an anode terminal formed on the anode foil side, and a cathode terminal formed on the solid electrolyte layer. A solid electrolytic capacitor, comprising: a part of the reinforcing member or installed separately from the reinforcing member to cover the anode foil and the solid electrolyte layer. 2. A step of fixing an anode foil to a reinforcing member, a step of forming a solid electrolyte layer on the anode foil, a step of forming an anode terminal on the anode foil, and a step of installing a cathode terminal on the solid electrolyte layer. And a step of including the reinforcing member as a part thereof or installed separately from the reinforcing member to cover the anode foil and the solid electrolyte layer with an exterior member, the solid electrolytic capacitor comprising: Manufacturing method.