JP3149523B2 - Solid electrolytic capacitors - Google Patents

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 for an electrolyte layer.

[0002]

2. Description of the Related Art In a solid electrolytic capacitor of this type, an anode body made of aluminum or the like is subjected to a surface enlargement process by etching, and a dielectric layer is formed on the surface thereof by an electrolytic process. A capacitor element is formed by growing a semiconductor layer to form a solid electrolyte layer, and the capacitor element is covered with an exterior body, and an anode terminal is formed on the anode body side, and a cathode terminal is formed on the solid electrolyte side, and pulled out from the exterior body. .

[0003]

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

Conventionally, in this solid electrolytic capacitor, a relatively thick aluminum plate or the like is used for the anode body in forming the solid electrolyte layer, which causes an increase in the capacity per unit volume. In addition, stresses such as cutting and cutting in the manufacturing process of the anode body affect the anode body and cause deterioration of electrical characteristics.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solid electrolytic capacitor which uses a metal foil for an anode and realizes miniaturization and high capacity.

[0006]

A solid electrolytic capacitor according to the present invention comprises a plurality of divided solid electrolytic capacitors each having a solid electrolyte layer (8) formed thereon.
Number of capacity forming parts (18), these capacity forming parts are linked in a chain
A connecting portion (20) for connecting, formed in a different direction from the capacitance forming portion;
Form internal terminals (6) provided in the anode foil (2), superimposing the capacitor forming portion by bending at the connecting portion of the anode foil
So, it binds with a conductive adhesive said solid electrolyte layer
And a capacitor element (4) formed of a sealing resin.
An exterior body (1) covering the capacitor element and the internal terminal
6) and connected to the internal terminal and arranged on the exterior body
And anodes terminal (12), is connected to the solid electrolyte layer
Is cathode terminal (14) disposed on the outer body and Bei the
And it said that there were pictures.

[0007] In addition, the solid electrolyte Conde capacitors of the present invention, before
The internal terminal is formed in the same direction as the capacitance forming portion.
And characterized by being bending from the capacitor forming portion and the different direction.

[0008]

In this solid electrolytic capacitor, the solid electrolyte layer
An anode foil is formed, and the anode foil is formed, for example, in a belt shape, and a plurality of capacitance forming portions are formed in a chain via a connecting portion . Therefore, a plurality of capacitance forming portions are folded at the connecting portion to form a stacked state, and the solid electrolyte layers formed on each of the capacitance forming portions are combined with a conductive adhesive to form one capacitor element. . Such a capacitor element is equivalent to connecting a plurality of capacitors corresponding to the number of stacked layers in units of the capacitance forming unit, and can achieve a reduction in size and an increase in capacitance.

In this solid electrolytic capacitor, internal terminals are formed on an anode foil which is a basic material of the capacitor element, and the internal terminals are directed in a direction different from that of the capacitance forming portion.
Since it is formed in the opposite direction, the molding process of the internal terminal and the electrical connection with the anode terminal as the external terminal can be performed in a portion separated from the capacitor forming portion, and the capacitor is formed in the capacitor forming portion. The spread of mechanical stress on the solid electrolyte layer can be minimized.

The anode foil may be one having internal terminals formed in the same direction as the capacitance forming portion. In this case, the internal terminals are formed at least before the formation of the solid electrolyte layer, preferably a dielectric oxide film. Before the formation, a material subjected to a bending process in an opposite direction as a different direction is used. By using such pre-processed anode foil,
Spread of mechanical stress on the dielectric oxide film and the solid electrolyte layer is suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 1 shows a first embodiment of the solid electrolytic capacitor of the present invention. This solid electrolytic capacitor has
A capacitor element 4 formed by folding an anode foil 2 made of aluminum foil or the like is provided. The capacitor element 4 has an anode-side internal terminal 6 formed by a part of the anode foil 2 and a capacitor element 4. The internal terminal 10 on the cathode side is connected to the solid electrolyte layer 8 formed by a connecting means such as a conductive adhesive. The solid electrolyte layer 8 formed on the anode foil 2 is formed by forming a dielectric oxide film 24 on the surface of the anode foil 2 by etching treatment and chemical conversion treatment, and then forming polypyrrole on the upper surface thereof by vapor phase polymerization, chemical polymerization or electrolytic polymerization. And the like. The anode terminal 1 is connected to the internal terminal 6.
2. A cathode terminal 14 is connected to the internal terminal 10, respectively. Capacitor element 4, internal terminal 6, internal terminal 1
0, a part of the anode terminal 12 and a part of the cathode terminal 14 are provided with an exterior body 16 formed of a sealing resin such as acrylic or epoxy.
It is covered with.

In such a solid electrolytic capacitor, the anode foil 2 is folded to enlarge the surface on which the capacitance is formed per unit volume, so that the capacitance can be increased and the size can be reduced. In addition, since the exterior body 16 can form the capacitor element 4 and a part of its terminal with a sealing resin in a single step, it contributes to a reduction in manufacturing cost.

Next, a method of manufacturing the solid electrolytic capacitor will be described with reference to FIGS. As shown in FIG. 2 (A), the anode foil 2 is formed of a band-shaped aluminum foil, and a plurality of rectangular capacity forming portions 18 are formed in a chain with a connecting portion 20 interposed therebetween. The internal terminal 6 protruding in the opposite direction to the portion 18 is integrally punched. The connecting portion 20 is connected to each of the capacitance forming portions 1.
In addition to having a function of holding the elements 8 in a chain, they form a bent portion when the respective capacitance forming parts 18 are overlapped. Therefore, in order to prevent the stress at the time of bending from spreading to the capacitance forming portion 18, a notch portion 22 having a V-shaped cross section is formed in the center of each connecting portion 20 in the width direction thereof. Then, the anode forming portion 18 of the anode foil 2 is subjected to a surface enlargement process by etching, and a dielectric oxide film 24 is formed thereon by a chemical conversion process.

Next, as shown in FIG. 2B and FIG. 4, the dielectric oxide film 2
A solid electrolyte layer 8 made of a polymer film such as polypyrrole is formed on the substrate 4 by gas phase polymerization, chemical polymerization or electrolytic polymerization.

Next, as shown in FIGS. 2C and 2D, the anode foils 2 are alternately bent at the notches 22 so as to form peaks or valleys, and the respective capacitance forming portions 18 are folded in a staggered manner. At the same time, one capacitor element 4 is formed by bonding the solid electrolyte layers 8 with a conductive adhesive 26. That is, in the capacitor element 4, the solid electrolyte layer 8
The conductive adhesive 26 interposed therebetween or provided on the surface forms a conductor layer, which together with the solid electrolyte layer 8 forms a substantial cathode.

Next, as shown in FIG. 3E, an internal terminal 10 is connected to the solid electrolyte layer 8 side of the capacitor element 4. The connection of the internal terminals 10 may be performed simultaneously with the step of folding the anode foil 2 and the step of bonding the solid electrolyte layer 8. Further, the internal terminals 10 may be connected so as to be sandwiched between the solid electrolyte layers 8 of the respective capacitance forming portions 18. Then, an anode terminal 12 and a cathode terminal 14 as external terminals are connected to the internal terminals 6 and 10, respectively.

Next, as shown in FIG. 3F, on the outer surface of the capacitor element 4 to which the anode terminal 12 and the cathode terminal 14 are connected, the internal terminals 6, 10 and the anode terminal 12 and the cathode terminal 14 are connected. The exterior body 16 is formed by a sealing resin including the connection portions of the above, and the capacitor element 4 is sealed by the exterior body 16. After this sealing, the anode terminal 12 and the cathode terminal 14 projecting from the outer surface of the outer package 16 are bent from the side surface to the bottom surface of the outer package 16,
The solid electrolytic capacitor shown in FIG. 1 is obtained.

According to such a manufacturing method, the solid electrolytic capacitor shown in FIG. 1 can be easily and efficiently manufactured, and the method of folding the anode foil 2 is adopted. In addition to the miniaturization and flattening of the capacitor element 4, the size of the capacitance forming surface is increased, and a small-sized and high-capacity solid electrolytic capacitor can be manufactured.
In particular, in this embodiment, since the internal terminals 6 are formed in the direction opposite to the capacity forming portion 18, the forming process of the internal terminals 6 can be performed at a portion separated from the capacity forming portion 18, and the machine accompanying the forming process can be used. Thus, it is possible to suppress the spread of the natural stress to the solid electrolyte layer in the capacity forming section 18, thereby improving the electrical characteristics such as the suppression of the leakage current and the like, thereby improving the reliability of the product.

FIG. 5 shows a second embodiment of the solid electrolytic capacitor of the present invention. In the first embodiment, the exterior body 1
6 is made of a sealing resin, but in the second embodiment, the exterior body 1 is made up of an exterior case 28 made of an insulating synthetic resin and a sealing resin 30 filled in the exterior case 28.
6. In this case, since the capacitor element 4 is inserted into the outer case 28 and the capacitor element 4 is connected to the anode terminal 12, the internal terminal 6 is processed into a C-shaped cross section for convenience of connection, and the internal terminal 6 is connected on the cathode side. A cathode terminal 14 also serving as 10 is provided. The cathode terminal 14 has a C-shaped internal terminal portion 11 which is homed, and is electrically connected to the solid electrolyte layer 8 of the capacitor element 4 with a conductive adhesive 26 via the internal terminal portion 11. Even with such a solid electrolytic capacitor, it is possible to reduce the size and increase the capacity of the solid electrolytic capacitor as in the above-described embodiment.

Next, a method of manufacturing this solid electrolytic capacitor will be described with reference to FIG. 6. As shown in FIG. 6A, after the capacitor element 4 is formed and the internal Terminal 6 is bent into a C-shape, and capacitor element 4
The L-shaped anode terminal 12 is electrically connected to the connecting portion 32 formed in parallel with the fixing member 32 by a fixing means such as a conductive adhesive. In addition, the capacitor element 4 has C
The internal terminal portion 11 of the cathode terminal 14 having a letter shape is electrically connected by the same fixing means as the anode side.

As described above, the anode terminal 12 and the cathode terminal 14
The capacitor element 4 to which is connected as shown in FIG. 6B is installed inside an exterior case 28 made of a synthetic resin in advance. Then, a sealing resin 30 is injected into the opening of the outer case 28 in a desired manner with the dispenser 34, and the sealing resin 30 is filled up to the opening of the outer case 28 as shown in FIG.

Next, FIGS. 7 to 9 show a third embodiment of the solid electrolytic capacitor of the present invention. In the first embodiment, the internal terminals 6 are formed on the edge opposite to the capacitance forming portion 18. However, as shown in FIG. It is. In this case, the internal terminal 6 may be assigned to one of the capacitance forming portions 18.

Next, as shown in FIG. 7B and FIG. 8, the internal terminal 6 is folded back from the root thereof to the side opposite to the capacitor forming section 18 to form the capacitor in the same manner as in the first embodiment. It protrudes to the opposite side from the part 18. The bending process of the internal terminal 6 is performed before the formation of the solid electrolyte layer 8,
It is possible to prevent mechanical stress from spreading to the solid electrolyte layer 8.

After processing the internal terminals 6 in this manner, the anode foil 2 is folded, and the solid electrolyte layer 8 formed in the capacitance forming portion 18 is joined with the conductive adhesive 26 to form the capacitor element 4. Thereafter, the internal terminal 6 is homed into a C shape, and the internal terminal 6 is connected to the anode terminal 12 and the solid electrolyte layer 8 is connected to the cathode terminal 14.

Then, as shown in FIG. 9, after inserting the capacitor element 4 into the outer case 28,
To complete the solid electrolytic capacitor. According to this embodiment, effects similar to those of the above embodiment can be expected.

[0027]

As described above, according to the fixed electrolytic capacitor of the present invention, a plurality of capacitors formed on the anode foil are formed.
Since multiple capacitors are used to form the capacitor,
In addition to increasing the capacitance, the use of an anode foil reduces the size and suppresses leakage current. Can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a solid electrolytic capacitor of the present invention.

FIG. 2 is a diagram illustrating a method of manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 3 is a diagram showing a method of manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 4 is a sectional view taken along line GG of FIG. 2 (B).

FIG. 5 is a longitudinal sectional view showing a second embodiment of the solid electrolytic capacitor of the present invention.

6 is a diagram illustrating a method of manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 7 is a diagram showing a method of manufacturing a solid electrolytic capacitor according to a third embodiment of the present invention.

8 is a side view showing an internal terminal side of the solid electrolytic capacitor shown in FIG.

FIG. 9 is a longitudinal sectional view showing a third embodiment of the solid electrolytic capacitor of the present invention.

[Explanation of symbols]

 2 Anode foil 4 Capacitor element 6 Internal terminal 8 Solid electrolyte layer 10 Internal terminal 12 Anode terminal 14 Cathode terminal 18 Capacitor forming part 20 Connecting part

Claims (2)

(57) [Claims] 1. A composite having a solid electrolyte layer formed by partitioning
Number of capacity forming parts, connecting these capacity forming parts in a chain
Connecting part, internal terminal formed in a different direction from the capacitance forming part
With the anode foil, superposing the capacitor forming portion by bending at the connecting portion of the anode foil, the solid electrolyte layer and a capacitor element formed by bonding with a conductive adhesive, the capacitor is formed by the sealing resin Element and the interior
An exterior member covering the terminal, an anode terminal which is disposed on the outer body is connected to the internal terminal being arranged to be connected to the solid electrolyte layer on the outer body
The solid electrolytic capacitor comprising: the cathode terminals, a. 2. The internal terminal is the same as the capacitor forming section.
The solid electrolytic capacitor according to claim 1, characterized by being bending one formed in a direction in different directions the capacitor forming portion.