JP2000348975A - Chip-shaped solid-state electrolytic capacitor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a chip-shaped solid-state electrolytic capacitor, the size of which is reduced and the capacitance of which is increased by improving the element housing efficiency of the capacitor for a chip-shape solid-state electrolytic capacitor used for various kinds of electronic equipment, and a method for manufacturing the capacitor. SOLUTION: A chip-shaped solid-state electrolytic capacitor is constituted, in such a way that an anode terminal 6 bonded to an anode lead-out wire 2 of a capacitor element 1 which is covered with a coating resin 4 and a cathode terminal 7 bonded to a cathode layer are arranged, in such a way that the terminals 6 and 7 face opposite to each other. Therefore, the size of the capacitor can be reduced, and the capacitance of the capacitor can be increased, because the housing efficiency of the capacitor for the capacitor element 1 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type solid electrolytic capacitor used for various electronic devices and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, chip components have been rapidly increasing due to advances in light and thin electronic devices and surface-mounting technology. There is a demand for further miniaturization.

A conventional chip-type solid electrolytic capacitor of this type will be described below with reference to the drawings.

FIG. 4 is a sectional view showing the structure of a conventional chip-type tantalum solid electrolytic capacitor.
Reference numeral 1 denotes a capacitor element. The capacitor element 31 is formed by molding and sintering a tantalum metal powder serving as a valve metal into a porous body, and leads out an anode lead-out line 32 made of tantalum wire from the porous body. A dielectric oxide film layer is formed by anodic oxidation on a part of the lead wire 32 and the entire surface of the porous body, and an electrolyte layer such as manganese dioxide and a cathode layer 34 are formed on the surface thereof. The cathode layer 34 is formed by sequentially laminating a carbon layer and a silver paint layer by an immersion method. Reference numeral 33 denotes a Teflon plate attached to an anode lead wire 32. The Teflon plate 33 is used when the electrolyte layer is formed. It is an insulating plate for preventing manganese dioxide from creeping up and attaching to the anode lead-out line 32. 35
Is an anode terminal, which is connected to the anode lead wire 32 by welding, and is bent after forming an exterior resin 38 described later. Reference numeral 36 denotes a cathode terminal. The cathode terminal 36 is connected to the capacitor element 31 by a conductive adhesive 37, and is bent after forming the exterior resin 38. Reference numeral 38 denotes an exterior resin that covers the entire capacitor element 31 by molding.

[0005]

However, in the conventional chip type solid electrolytic capacitor configured as described above,
In the assembling process such as welding of the anode lead-out wire 32 derived from the capacitor element 31 and the anode terminal 35 and in the resin molding process, characteristic deterioration such as an increase in leakage current due to the application of mechanical and thermal stress and a defective rate. In addition, the space size of the welded portion and the size of the bent space including the connection lead-out portion between the capacitor element 31 and the cathode terminal 36 are large, so that the size and shape of the capacitor element 31 are structural dimensions. There were restrictions.

Further, since the effective use amount of the material of the anode terminal 35 and the cathode terminal 36 obtained by stamping the plate material is extremely low, there is a problem in terms of volumetric efficiency and economy of the capacitor.
In addition, there is a problem that appearance failure occurs in the bending step of the anode terminal 35 and the cathode terminal 36, and stress is applied to the capacitor element 31 to deteriorate the characteristics.

Further, since the exterior resin 38 is formed by transfer molding, a special molding die is required for each product size, which increases the cost. In addition, the exterior resin 38 is applied to the capacitor element 31 depending on the assembly state. On the other hand, there is also a problem that it is not always uniform.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. The present invention provides excellent electrical characteristics and yield, and enables mass production of small and large-capacity chip-type solid electrolytic capacitors at low cost. It is an object of the present invention to provide a chip-type solid electrolytic capacitor which can be used and a method for manufacturing the same.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an anode terminal joined to an anode lead wire of a capacitor element covered with an exterior resin and a cathode terminal joined to a cathode layer. It is configured to be arranged as described above.

According to the present invention, a small and large-capacity chip-type solid electrolytic capacitor can be obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a method of forming a sintered body by molding and sintering a powder of a valve action metal having an anode lead wire embedded so that one end is exposed. An oxide film layer, an electrolyte layer, a capacitor element formed by sequentially forming a cathode layer, an anode terminal joined to an anode lead wire of the capacitor element, a cathode terminal joined to the cathode layer of the capacitor element, A chip-type solid electrolytic capacitor made of an exterior resin covering the capacitor element and configured so that the anode terminal and the cathode terminal face each other,
By reducing the connection space between the anode terminal and the cathode terminal and eliminating the bending, there is an effect that the size and capacity can be increased.

According to a second aspect of the present invention, in the first aspect, a ring-shaped Teflon plate having a hole through which an anode lead wire exposed from the capacitor element is inserted is joined to the capacitor element. This has the effect of preventing manganese dioxide from creeping up and adhering to the anode lead wire when forming the electrolyte layer of the capacitor element.

According to a third aspect of the present invention, in the first or second aspect, the anode terminal and the cathode terminal are formed of a nickel plate having a surface plated with solder. In addition to the effect of the invention described in 1, the present invention has an effect that it can be produced at low cost.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the connection between the anode terminal and the anode lead wire is welding, and the connection between the cathode terminal and the cathode layer is conductive. With the configuration performed with the adhesive, it has an effect that stable production can be easily performed.

According to a fifth aspect of the present invention, there is provided an anode body formed by molding and sintering a powder of a valve action metal having an anode lead wire embedded so that one end is exposed, and a dielectric oxide film layer, an electrolyte layer, A capacitor element formed by sequentially forming a cathode layer, a convex silver rivet joined to the cathode layer so as to project in a direction opposite to the anode lead-out line of the capacitor element, and a tip of the silver rivet And a bottomed case made of an insulating resin containing a capacitor element with a hole exposed at the tip of the anode lead-out wire and housing the capacitor element, a sealing resin filled in the case, A lid made of an insulating resin whose opening is closed, and with the anode lead wire and silver rivet exposed from the case closed by this lid, respectively, in a state in which they are independent from the outer surface of the case and the lid in a state where they are connected to the silver rivet. cap Has been constructed by the pair of electrode members made of solder plating layer formed, by covering accommodating the capacitor element in a bottomed case,
Exposure from the exterior surface due to displacement of the capacitor element can be easily prevented, the volume of the capacitor element can be increased to the full internal dimensions of the bottomed case, the capacitance of the chip type solid electrolytic capacitor can be increased, This has the function of increasing the capacity.

According to a sixth aspect of the present invention, in the invention according to the fifth aspect, a ring-shaped Teflon plate having a hole through which an anode lead wire exposed from the capacitor element is inserted is joined to the capacitor element. In addition, when the electrolyte layer of the capacitor element is formed, the manganese dioxide can be prevented from creeping up and adhering to the anode lead wire.

According to a seventh aspect of the present invention, in the invention according to any one of the first to fourth aspects, one end of the anode lead-out line is opposite to the exposed surface of the anode lead-out line of the capacitor element in which one end is exposed. The surface is bonded on the cathode terminal using a conductive adhesive, and then a rectangular tubular frame formed so as to surround the capacitor element is placed on the cathode terminal, and then in the frame. A chip-type solid electrolytic capacitor in which a thermosetting type exterior resin is injected until the entire capacitor element is covered and the exterior resin is cured, and then the frame is removed and an anode terminal is joined to the anode lead-out line. Which has an effect that a chip-type solid electrolytic capacitor having a small size and a large capacity can be obtained by a simple method.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view showing the structure of a chip type tantalum solid electrolytic capacitor as a chip type solid electrolytic capacitor according to a first embodiment of the present invention. Is a capacitor element made of a porous body by molding and sintering a tantalum metal powder as a valve metal, and a dielectric oxide film layer, an electrolyte layer, and a cathode layer (not shown) are provided on the outer surface of the capacitor element 1. Is formed by a known method.

Reference numeral 2 denotes an anode lead wire made of a tantalum wire embedded in the capacitor element 1. Reference numeral 3 denotes a Teflon plate which is inserted into the anode lead wire 2 and joined to the capacitor element 1. When forming the layers,
It is provided in order to prevent manganese dioxide from creeping up and adhering to the anode lead wire 2.

Reference numeral 4 denotes an exterior resin made of a thermosetting epoxy resin covering the capacitor element 1, 5 denotes a conductive adhesive, 6 denotes a nickel plate having a surface plated with solder, and Positively joined anode terminals,
7 is made of a nickel plate whose surface is plated with solder,
The cathode terminal is electrically connected to the cathode layer of the capacitor element 1 via the conductive adhesive 5.

Next, a method of manufacturing the chip type tantalum solid electrolytic capacitor according to the present embodiment having the above-described configuration will be described with reference to FIGS. 2 (a) to 2 (e).

First, as shown in FIG. 2A, a Teflon plate 3 is mounted on a sintered body made of tantalum metal powder in which an anode lead wire 2 is embedded so that one end is exposed, and a dielectric oxide (not shown) is attached. The capacitor element 1 is manufactured by sequentially laminating a film layer, an electrolyte layer, and a cathode layer.

Next, as shown in FIG. 2 (b), a conductive adhesive 5 (not shown) is applied to the cathode terminal 7 made of a solder-plated nickel plate having a thickness of 0.1 mm. The capacitor element 1 is placed thereon, and the conductive adhesive 5 is cured in a thermostat at 180 ° C. for 60 minutes.

Next, as shown in FIG. 2C, a rectangular cylindrical frame 8 having an inner diameter formed by 0.1 to 0.2 mm larger than the external dimensions of the capacitor element 1 is mounted on the capacitor element 1. It is arranged so as to surround it, and the exterior resin 4 made of a liquid thermosetting epoxy resin is injected into the frame 8 until the capacitor element 1 is covered. Subsequently, in this state, the exterior resin 4 is cured using a thermostat at 150 ° C. for 60 minutes, and then the frame 8 is removed.

Subsequently, the exterior resin 4 is shaved so as to cut out the anode lead wire 2 so that the anode lead wire 2 having a predetermined length protrudes from the exterior resin 4.

Next, as shown in FIG. 2D, an anode terminal 6 made of a nickel plate having a thickness of 0.1 mm and having a hole into which the anode lead-out wire 2 is fitted and which is plated with solder.
Is placed so that the anode lead-out wire 2 fits into the hole, and the anode lead-out wire 2 and the anode terminal 6 are joined through this hole by means such as resistance welding or laser welding.

Next, as shown in FIG. 2 (e), unnecessary portions of the anode terminal 6 and the cathode terminal 7 are cut and removed, and processed into the same outer dimensions as the capacitor element 1 covered with the exterior resin 4. By doing so, a chip type tantalum solid electrolytic capacitor is obtained.

As described above, according to the present embodiment, a small and large-capacity chip-type tantalum solid electrolytic capacitor can be efficiently produced by a simple method.

(Embodiment 2) FIGS. 3A and 3B are plan views showing the configuration of a chip type tantalum solid electrolytic capacitor as a chip type solid electrolytic capacitor according to a second embodiment of the present invention. It is a front sectional view,
Reference numeral 11 denotes a capacitor element.
Is formed on a surface of a porous tantalum anode body 12 formed by molding and sintering a tantalum powder made of a valve metal in which an anode lead wire 17 is embedded so that one end is exposed, and a dielectric oxide film 13 is formed by a known method. An electrolyte layer 14 and a carbon layer 15 are sequentially formed, and then a cathode layer 16 is formed on the surface of the carbon layer 15 with silver paint.

The capacitor element 11 configured as described above
A thermosetting conductive adhesive 18 is applied in a direction opposite to the above-mentioned anode lead-out wire 17 to temporarily connect and fix a convex silver rivet 19, and then put into an electric furnace to form a thermosetting conductive rivet. The adhesive 18 is cured to fix the cathode layer 16 and the convex silver rivet 19.

In this manner, the capacitor element 11 with the silver rivet 19 connected thereto is cut while leaving the required portion of the anode lead wire 17, and then the tip of the silver rivet 19 and the tip of the anode lead wire 17 are cut. Are housed in a bottomed case 20 made of an insulating resin having a hole exposed to the outside.

Thereafter, the case 20 is filled with a thermosetting exterior resin 22 and charged into an electric furnace to cure the exterior resin 22 and seal the inside of the case 20.
The upper lid 21 made of insulating resin is fitted so as to cover the opening of the “0”.

Thereafter, the case 2 closed with the upper lid 21
Anode lead wire 17 and silver rivet 19 exposed from 0
The anode terminal part and the cathode terminal part are formed by forming a solder plating layer 23 in a cap shape independently facing the outer surface of the case 20 and the upper lid 21 in a state where they are electrically connected to each other to form a chip type tantalum solid electrolyte. It is a capacitor.

As described above, the chip-type solid electrolytic capacitor of the present invention comprises the bottomed case 20 and the capacitor element 11.
To accommodate the capacitor element 11
There is no exposure of the capacitor element 11 from the exterior resin 22 due to the displacement, so that the capacity of the capacitor element 11 can be increased to the full capacity in the case 20 and the capacitance of the chip-type solid electrolytic capacitor can be increased. Can be achieved.

[0036]

As described above, in the chip type solid electrolytic capacitor according to the present invention, the anode terminal joined to the anode lead-out line of the capacitor element covered with the exterior resin and the cathode terminal joined to the cathode layer face each other. With this configuration, it is possible to provide a small-sized and large-capacity chip-type solid electrolytic capacitor having a high storage efficiency of the capacitor element and a method of manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a chip-type solid electrolytic capacitor according to a first embodiment of the present invention.

FIGS. 2A to 2E are manufacturing process charts showing a manufacturing method of the same chip type tantalum solid electrolytic capacitor.

FIG. 3 (a) is a plan view showing the configuration of a chip-type tantalum solid electrolytic capacitor according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a configuration of a conventional chip-type tantalum solid electrolytic capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Capacitor element 2, 17 Anode lead-out line 3 Teflon board 4, 22 Outer resin 5, 18 Conductive adhesive 6 Anode terminal 7 Cathode terminal 8 Frame 12 Anode 13 Dielectric oxide film 14 Electrolyte layer 15 Carbon layer 16 Cathode layer 19 Silver rivet 20 Case 21 Top lid 23 Solder plating layer

Claims (7)

[Claims] A dielectric oxide film layer, an electrolyte layer, and a cathode layer are sequentially formed on an anode body formed by molding and sintering a powder of a valve action metal having an anode lead wire embedded so that one end is exposed. The capacitor element thus constituted, an anode terminal joined to an anode lead wire of the capacitor element, a cathode terminal joined to a cathode layer of the capacitor element, and an exterior resin covering the capacitor element, wherein the anode terminal A chip-type solid electrolytic capacitor configured so that the and the cathode terminal face each other. 2. The chip type solid electrolytic capacitor according to claim 1, wherein a ring-shaped Teflon plate having a hole through which an anode lead-out line exposed from the capacitor element is inserted is connected to the capacitor element. 3. The anode terminal and the cathode terminal are made of a nickel plate having a surface plated with solder.
2. The chip-type solid electrolytic capacitor according to item 1. 4. The welding of the anode terminal and the anode lead wire is performed by welding,
The chip type solid electrolytic capacitor according to any one of claims 1 to 3, wherein the cathode terminal and the cathode layer are joined with a conductive adhesive. 5. A dielectric oxide film layer, an electrolyte layer, and a cathode layer are sequentially formed on an anode body formed by molding and sintering a powder made of a valve metal in which an anode lead wire is embedded so that one end is exposed. The configured capacitor element, a convex silver rivet joined on the cathode layer so as to protrude in a direction opposite to the anode lead-out line of the capacitor element, and a tip part of the silver rivet and the anode lead-out line A bottomed case made of insulating resin that houses a capacitor element with a hole whose tip is exposed to the outside, a sealing resin filled in this case, and an insulating material that covers the opening of the case. A lid made of a resin, and a solder formed in a cap shape independently facing the outer surfaces of the case and the lid in a state of being electrically connected to the anode lead wire and the silver rivet exposed from the case closed by the lid. plating A chip-type solid electrolytic capacitor constituted by a pair of electrode portions composed of layers. 6. The chip-type solid electrolytic capacitor according to claim 5, wherein a ring-shaped Teflon plate having a hole through which an anode lead wire exposed from the capacitor element is inserted is connected to the capacitor element. 7. A surface of the capacitor element in which one end of the anode lead-out line is exposed, and a surface opposite to the exposed surface of the anode lead-out line are joined to the cathode terminal using a conductive adhesive, and then the capacitor element is surrounded. A rectangular cylindrical frame formed so as to be placed on the cathode terminal, and then a thermosetting type exterior resin is injected into the frame until the entire capacitor element is covered, and the exterior resin is cured. The method for manufacturing a solid electrolytic capacitor according to any one of claims 1 to 4, wherein after removing the frame, an anode terminal is joined to the anode lead wire.