JP3237181B2 - 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. .

Incidentally, this solid electrolytic capacitor can be miniaturized structurally, but on the other hand, it is desired to form a practically sufficient capacitance. In addition, this type of solid electrolytic capacitor has been put into practical use for surface mounting due to the development of a hybrid integrated circuit, and its heat resistance against solder reflow and moisture resistance to prevent deterioration due to moisture in the air have been improved. Can not 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.

It is an object of the present invention to provide a flattened solid electrolytic capacitor using a metal foil for the anode.

[0006]

The solid electrolytic capacitor of the present invention comprises an anode foil (4) on which a solid electrolyte layer (10) is formed, and a reinforcing member (insulating plate 2,
A conductor plate 24), an anode terminal (6) installed on the reinforcing member and connected to the anode foil, a cathode terminal (14) connected on the solid electrolyte layer, the anode foil, the reinforcing member And an exterior member (outer body 16, outer case 18) for covering the solid electrolyte layer.

[0007]

In this solid electrolytic capacitor, an anode member on which a solid electrolyte layer is to be formed is formed of an anode foil, and the anode foil is reinforced with a reinforcing member. In other words, by separating the mechanical strength securing portion of the conventional anode member from the functional portion for forming the capacity, it is not necessary to punch out the anode member, and flattening and high capacity are realized. .

In this method for manufacturing a solid electrolytic capacitor, a mechanically soft anode foil is fixed to a reinforcing member, and then the anode foil is subjected to an etching process or a chemical conversion process to form a solid electrolyte layer as a capacity forming portion. The capacitor element is formed by forming an anode terminal on the anode foil side and a cathode terminal on the solid electrolyte layer, and the capacitor element is provided with an exterior. By doing so, the formation of the solid electrolyte layer on the anode foil is improved, which contributes to the improvement of the reliability of the solid electrolytic capacitor.

[0009]

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, and FIG. 2 shows a method of manufacturing the same.
As shown in FIG. 1, the solid electrolytic capacitor is provided with an insulating plate 2 as a reinforcing member, and the insulating plate 2 is formed of an acrylic plate. An anode foil 4 is provided on the outer surface of the insulating plate 2, and a part of the anode foil 2 is extended and electrically connected to the surface of the anode terminal 6 fixed so as to be embedded in the insulating plate 2. ing. On the surface of the anode foil 4, a dielectric oxide film 8 is formed by an etching process and a chemical conversion process. On the upper surface of the dielectric oxide film 8, a solid electrolyte layer 10 made of a polymer film such as polypyrrole is formed by gas phase polymerization, chemical polymerization or electrolytic polymerization,
One capacitor element 12 is formed. A cathode terminal 14 is fixed and electrically connected to the upper surface of the solid electrolyte layer 10 of the capacitor element 12 by a conductive adhesive or other fixing means.

The capacitor element 12 is covered with an exterior body 16 formed with a sealing resin. In this embodiment, the exterior body 16 is formed into a flat rectangular parallelepiped. On the exterior body 16, the anode terminal 6 and the cathode terminal 14 protruding from the side surface are bent from the side surface to the bottom surface by homing to be processed as external terminals.

FIG. 2 shows a method of manufacturing this solid electrolytic capacitor.
As shown in FIG. 2A, after a strip-shaped anode terminal 6 is fixed on the upper surface of a flat insulating plate 2 formed of an insulating material, an anode made of aluminum foil or the like is fixed. The foil 4 is fixed in such a manner as to be wound on the insulating plate 2. In this case, a part of the anode foil 4 is extended and fixed to the upper surface of the anode terminal 6 and is electrically connected. Also,
The anode foil 4 is fixed to the surface of the insulating plate 2 with an adhesive or the like. After the surface of the anode foil 4 is enlarged by etching, it is subjected to a chemical conversion treatment to form a dielectric oxide film 8, on which a polymer such as polypyrrole is formed by gas phase polymerization, chemical polymerization or electrolytic polymerization. A solid electrolyte layer 10 composed of a film is generated.

Next, as shown in FIG. 2B, a strip-shaped cathode terminal 14 is fixed to the upper surface of the solid electrolyte layer 10 with a conductive adhesive and is electrically connected thereto. In this case, the cathode terminal 14 is drawn out on the side opposite to the anode terminal 6 to form the capacitor element 12.

Next, as shown in FIG. 2C, an outer package 16 is formed on the capacitor element 12 with a sealing resin, and the outer surface of the capacitor element 12 is sealed. The anode terminal 6 and the cathode terminal 14 are pulled out. Then, each of the anode terminal 6 and the cathode terminal 14 is subjected to homing processing from the side surface to the bottom surface of the exterior body 16 to form external terminals for surface connection, thereby obtaining a chip-type solid electrolytic capacitor.

In such a solid electrolytic capacitor, the insulating plate 2 is provided on the back side of the anode foil 4 to reinforce it.
Moreover, since the anode foil 4 is made of a capacity forming material, a sufficient capacitance is ensured, and its reinforcement is performed by the insulating plate 2, so that the size, flattening, and weight reduction can be achieved, and high capacity can be achieved. Can be achieved.

FIG. 3 shows a second embodiment of the solid electrolytic capacitor of the present invention. In the solid electrolytic capacitor of this embodiment, an anode foil 4 is provided on the surface of an insulating plate 2 as a reinforcing member, and a dielectric oxide film 8 and a solid electrolyte layer 10 are provided on the surface to form a capacitor element 12. This is similar to the first embodiment. The anode terminal 6 and the cathode terminal 14 are integrally formed on the side wall surface of a rectangular parallelepiped outer case 18, and the capacitor element 12 is installed therein, and the anode foil 4 and the anode terminal 6 are electrically conductive. The solid electrolyte layer 10 and the cathode terminal 14 are similarly electrically connected with the conductive adhesive 22 while being electrically connected with the adhesive 20. And the outer case 18
Is filled with a sealing resin 23 to seal the capacitor element 12 inside the outer case 18. According to such an embodiment, the same operation and effect as the above embodiment can be expected.

FIG. 4 shows a method of manufacturing this solid electrolytic capacitor.
Referring to FIG. 4A, as shown in FIG. 4A, the anode foil 4 is wound so that the insulating plate 2 is wound around the front and back surfaces of the insulating plate 2.
After the surface of the anode foil 4 is subjected to an etching treatment as shown in FIG. 4A, a dielectric oxide film 8 is formed, and a solid electrolyte layer 10 is formed thereon to form a capacitor. The element 12 is formed.

As shown in FIG. 5, the outer case 18 in which the capacitor element 12 is to be sealed is formed of an insulating plate of acrylic or the like.
The anode terminal 6 and the cathode terminal 14 having a character shape are formed by insert molding or the like. Of course, a window may be formed in a part of the outer case 18 and the anode terminal 6 and the cathode terminal 14 may be fixed to the part by an adhesive or a mechanical fitting.

Then, the capacitor element 12 is installed inside the outer case 18, and in this case, the anode foil 4 side and the anode terminal 6, and the solid electrolyte layer 10 and the cathode terminal 14 are connected with conductive adhesives 20, 22, respectively. I do. After such electrical connection, the inside of the outer case 18 is filled with the sealing resin 23 to form a solid electrolytic capacitor as shown in FIG.

Next, FIG. 6 shows a third embodiment of the solid electrolytic capacitor of the present invention. In the first and second embodiments, the insulating plate 2 is used as the reinforcing member. However, in the third embodiment, the conductor plate 24 such as an aluminum plate is used. On the surface of the conductor plate 24, an anode foil 4 bent in a wave shape for increasing the surface area is provided, and its end is fixed to the surface of the conductor plate 24 and electrically connected thereto. On the surface of the anode foil 4, after a surface enlargement process by an etching process and formation of a dielectric oxide film 8 by a chemical conversion process, a solid electrolyte layer 10 is formed to form a capacitor element 12.

A strip-shaped anode terminal 6 is connected to the conductor plate 24, and a strip-shaped cathode terminal 14 is connected on the solid electrolyte layer 10 of the anode foil 4 with a conductive adhesive 26. Then, the capacitor element 12 is covered and sealed with an exterior body 16 formed with a sealing resin such as acrylic, and the anode terminal 6 and the cathode terminal 14 drawn out from the end surface side.
Are formed as external terminals by homing along the end surface and bottom surface of the exterior body 16 forming a rectangular parallelepiped.

If such a conductive plate 24 is used as a reinforcing member and the bent anode foil 4 is provided on the surface thereof, the solid electrolytic capacitor can be reduced in size, flattened, and increased in capacity by increasing its surface area. it can.

[0023]

As described above, according to the fixed electrolytic capacitor of the present invention, since the capacitance is formed by using the anode foil, the capacitance can be increased, and the size and the size can be reduced by using the anode foil. A solid electrolytic capacitor with a high capacity can be realized, and the reliability can be improved because a thick anode body is not cut out as in the conventional case.

[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 longitudinal sectional view showing a method of manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the solid electrolytic capacitor of the present invention.

FIG. 4 is a side view showing a method for manufacturing the solid electrolytic capacitor shown in FIG.

5 is a perspective view showing an outer case provided with an anode terminal and a cathode terminal used in the method for manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 6 is a longitudinal sectional view showing a third embodiment of the solid electrolytic capacitor of the present invention.

[Explanation of symbols]

 2 Insulating plate (reinforcing member) 4 Anode foil 6 Anode terminal 10 Solid electrolyte layer 12 Capacitor element 14 Cathode terminal 16 Outer body (outer member) 18 Outer case (outer member) 24 Conductor plate (reinforcing member)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01G 9/04 H01G 9/012

Claims (1)

(57) [Claims] An anode foil on which a solid electrolyte layer is formed; a reinforcing member for installing the anode foil; an anode terminal provided on the reinforcing member and connected to the anode foil; A solid electrolytic capacitor comprising: a connected cathode terminal; and an exterior member that covers the anode foil, the reinforcing member, and the solid electrolyte layer.