JP6788492B2 - Solid electrolytic capacitors and their manufacturing methods - Google Patents

Description

The present invention relates to a solid electrolytic capacitor and a method for manufacturing the same.

In order to connect the anode terminal to the anode reed body, a solid electrolytic capacitor having a bottom electrode structure having a structure in which a part of the anode terminal is bent toward the anode lead body is known. In such a solid electrolytic capacitor, since the anode lead body and the anode terminal are connected by resistance welding, the anode terminal may fall from the bent portion due to the pressure applied during resistance welding. In addition, if the pressure applied during resistance welding is weakened so that the anode terminals do not fall, the anode terminals will not melt sufficiently, and poor connection may occur between the anode leads and the anode terminals. is there. Therefore, when connecting the anode lead body and the anode terminal, there is a technology to reinforce the anode terminal so that the anode terminal does not fall due to the pressure applied during resistance welding and prevent poor connection between the anode lead body and the anode terminal. It has been demanded.

Patent Document 1 discloses a technique for reinforcing a fuse in order to prevent deformation of the fuse in a solid electrolytic capacitor having a fuse.

Japanese Unexamined Patent Publication No. 2-106022

Patent Document 1 improves the strength of the fuse itself by providing the fuse with reinforcing ribs in order to prevent the fuse from being deformed. Therefore, since Patent Document 1 aims to prevent deformation of the member, it is possible to prevent the anode terminal from collapsing when connecting the anode lead body and the anode terminal, and the connection between the anode lead body and the anode terminal is poor. Cannot be reduced.

An object of the present invention is to provide a solid electrolytic capacitor and a method for manufacturing the same, which can prevent the anode terminal from collapsing and reduce the connection failure between the anode lead body and the anode terminal.

The solid electrolytic capacitor according to the first aspect of the present invention includes a rectangular anode made of a valve acting metal, a dielectric layer formed on the outer periphery of the anode, a solid electrolyte layer formed on the dielectric layer, and a solid electrolyte layer. A capacitor element including a cathode layer formed on the solid electrolyte layer, an anode lead body having at least a part protruding from one end of the capacitor element, and an anode terminal electrically connected to the anode lead body. A cathode terminal electrically connected to the cathode layer of the capacitor element and an exterior resin formed so as to cover the capacitor element are provided, and the anode terminal is an anode lead from the bottom surface of the mounting substrate. It has a bent portion bent toward the body, and at least one reinforcing rib is formed on the sharp angle side of the bent portion.

Further, in the solid electrolytic capacitor of the first aspect of the present invention, it is preferable that the reinforcing rib has a triangular pyramid shape.

Further, in the solid electrolytic capacitor of the first aspect of the present invention, it is preferable that the reinforcing rib is integrally molded with the anode terminal.

Further, in the solid electrolytic capacitor of the first aspect of the present invention, it is preferable that the thickness of the anode terminal is 150 μm or less and 80 μm or more, and the height of the bent portion is 500 μm or less and 200 μm or more.

In the method for producing a solid electrolytic capacitor according to a second aspect of the present invention, a rectangular anode made of a valve acting metal is formed, a dielectric layer is formed on the outer periphery of the anode, and a solid electrolyte is formed on the dielectric layer. A step of forming a capacitor element by forming a layer and forming a cathode layer on the solid electrolyte layer, a step of forming an anode lead body in which at least a part protrudes from one end of the capacitor element, and an anode terminal. It is formed, and the anode terminal is bent toward the anode lead body to form a bent portion, at least one reinforcing rib is formed on the sharp angle side of the bent portion, and the anode terminal is electrically attached to the anode lead body. And the step of forming a cathode terminal and electrically connecting the cathode terminal to the cathode layer of the capacitor element via a conductive adhesive layer, and forming an exterior resin so as to cover the capacitor element. Including the process of

Further, in the method for manufacturing a solid electrolytic capacitor according to the second aspect of the present invention, it is preferable to form the reinforcing ribs in a triangular pyramid shape.

Further, in the method for manufacturing a solid electrolytic capacitor according to the second aspect of the present invention, it is preferable that the reinforcing rib is integrally molded with the anode terminal.

Further, in the method for manufacturing a solid electrolytic capacitor according to the second aspect of the present invention, the thickness of the anode terminal is formed to be 150 μm or less and 80 μm or more, and the height of the bent portion is formed to be 500 μm or less and 200 μm or more. Is preferable.

According to the present invention, it is possible to obtain a solid electrolytic capacitor and a method for manufacturing the same, which can prevent the anode terminal from collapsing and reduce the connection failure between the anode lead body and the anode terminal.

It is a schematic diagram which shows the cross section of the solid electrolytic capacitor which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows an example of the reinforcing rib which concerns on 1st Embodiment of this invention, (a) is the perspective view of the reinforcing rib, (b) is the sectional view of the reinforcing rib. It is a schematic diagram which shows the modification of the reinforcing rib which concerns on 1st Embodiment of this invention, (a) is the perspective view of the reinforcing rib, (b) is the sectional view of the reinforcing rib. It is a schematic diagram which shows the cross section of the solid electrolytic capacitor which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the reinforcing rib which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the flow of manufacturing of the solid electrolytic capacitor which concerns on embodiment of this invention.

Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings. In addition, in order to avoid complication due to repeated explanations, the same or corresponding parts are designated by the same reference numerals in the respective drawings, and the description thereof will be omitted as appropriate.

[First Embodiment]
The solid electrolytic capacitor 100 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic view showing a cross section of the solid electrolytic capacitor 100.

Here, as shown in FIG. 1, a Cartesian coordinate system (x, y, z) is used. In the state shown in FIG. 1, in the Cartesian coordinate system (x, y, z), the x-axis direction is the left-right direction (width direction), the y-axis direction is the front-back direction (depth direction), and the z-axis direction is It is in the vertical direction (height direction).

The solid electrolytic capacitor 100 is a rectangular parallelepiped solid electrolytic capacitor having six surfaces: an upper surface 100a, a lower surface 100b, a left surface 100c, a right surface 100d, a front surface (not shown), and a rear surface (not shown). The solid electrolytic capacitor 100 includes a capacitor element 1, an anode lead body 2, an anode terminal 3, a reinforcing rib 3A, a cathode terminal 4, a conductive adhesive layer 5, and an exterior resin 6.

The capacitor element 1 is a rectangular parallelepiped capacitor element having six surfaces: an upper surface 1a, a lower surface 1b, a left surface 1c, a right surface 1d, a front surface (not shown), and a rear surface (not shown). Further, the capacitor element 1 includes an anode body 1A, a dielectric layer 1B, a solid electrolyte layer 1C, and a cathode layer 1D. The shape of the capacitor element 1 according to the first embodiment is an example, and does not limit the shape of the capacitor element 1 of the present invention.

The anode body 1A is formed of a valve acting metal and has a rectangular parallelepiped shape having six surfaces. Examples of the valve acting metal include tantalum, niobium, titanium, and aluminum.

The dielectric layer 1B is an oxide film formed on the five surfaces of the anode body 1A excluding the left surface 1c. The dielectric layer 1B can be formed from, for example, Ta ₂ O ₅ (tantalum pentoxide).

The solid electrolyte layer 1C is an electrolyte formed on the dielectric layer 1B. The solid electrolyte layer 1C is made of MnO ₂ (manganese dioxide) formed by, for example, immersing in manganese nitrate and then thermally decomposing it. The solid electrolyte layer 1C may be formed of, for example, polythiophene or polypyrrole instead of MnO ₂ .

The cathode layer 1D is a cathode formed on the solid electrolyte layer 1C. The cathode layer 1D is formed of a molten material containing, for example, graphite and Ag (silver).

In the first embodiment, the configuration of the capacitor element 1 is not limited to the above, and may be formed by using other known techniques and materials.

The anode lead body 2 is formed of the same valve acting metal as the anode body 1A of the capacitor element 1, and at least a part thereof is led out from the central portion of the left surface 1c of the capacitor element 1 toward the left.

The anode terminal 3 is formed on the left side of the lower surface 100b of the solid electrolytic capacitor 100, and is connected to the anode portion of a mounting substrate (not shown) connected to the lower surface 100b. Further, as shown in FIG. 1, the anode terminal 3 has a shape that is bent up by approximately 90 ° toward the anode lead body 2, and has a bent portion 3a and a bent portion 3b. Here, on the acute-angled side of the bent portion 3a, a reinforcing rib 3A for reinforcing the bent portion 3b is formed.

The bent portion 3a is a portion that bends the anode terminal 3 toward the anode lead body 2 in order to electrically connect the anode terminal 3 to the anode lead body 2. The bent-up portion 3b is a portion in which the anode terminal 3 is bent in order to electrically connect the anode terminal 3 and the anode lead body 2. That is, at the anode terminal 3, the bent portion 3b is electrically connected to the anode lead body 2. The anode lead body 2 and the bent portion 3b are connected by, for example, resistance welding. In this case, the anode lead body 2 and the bending-raising portion 3b are subjected to a current while pressurizing the anode lead body 2 and the bending-raising portion 3b in contact with each other to partially melt the bending-raising portion 3b. You can connect by.

The reinforcing rib 3A will be described with reference to FIG. FIG. 2A is a perspective view showing an example of the reinforcing rib 3A according to the first embodiment, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. ..

Here, as shown in FIGS. 2 (a) and 2 (b), a Cartesian coordinate system (x, y, z) is used. In the state illustrated in FIGS. 2A and 2B, in the Cartesian coordinate system (x, y, z), the x-axis direction is the left-right direction (width direction), and the y-axis direction is the front-back direction (depth). Direction), and the z-axis direction is the vertical direction (height direction).

The reinforcing rib 3A is provided on the acute-angled side of the bent portion 3a along the bent portion 3b with the bent portion 3a as a base point. The shape of such a reinforcing rib 3A is not particularly limited, but as shown in FIGS. 2A and 2B, for example, the reinforcing rib 3A is formed along the bent portion 3b with the bent portion 3a as a base point. It is a convex part formed up to the end. Such a reinforcing rib 3A can be formed by, for example, rib-out processing when the anode terminal 3 is bent to form the bent portion 3b. Further, the number of reinforcing ribs 3A provided in the bent portion 3a is not limited, and N reinforcing ribs 3A (N is an integer of 2 or more) may be formed.

Further, the reinforcing rib 3A may be provided not only on the bent portion 3b but also on the left portion with the bent portion 3a as a base point. 3A and 3B are schematic views showing a modified example of the reinforcing rib 3A, FIG. 3A is a perspective view, and FIG. 3B is a sectional view taken along line BB in FIG. 3A. Is. Here, as shown in FIGS. 3 (a) and 3 (b), a Cartesian coordinate system (x, y, z) is used. In the state shown in FIGS. 3 (a) and 3 (b), in the Cartesian coordinate system (x, y, z), the x-axis direction is the left-right direction (width direction), and the y-axis direction is the front-back direction (depth). Direction), and the z-axis direction is the vertical direction (height direction).

As shown in FIGS. 3 (a) and 3 (b), the reinforcing rib 3A is provided on the acute-angled side of the bent portion 3a and partly along the bent portion 3b with the bent portion 3a as a base point. , A part is provided along the left direction with the bent portion 3a as a base point. That is, the reinforcing rib 3A does not need to be provided from the bent portion 3a as a base point over the end portion of the bent raised portion 3b, and may be provided at least a part of the bent raised portion 3b.

The method of forming the reinforcing rib 3A is not limited to the ribbing process. The reinforcing rib 3A may be formed, for example, by welding a member made of the same material as the anode terminal 3 and previously processed into a predetermined shape to the bent portion 3b.

By forming the reinforcing rib 3A along the bent portion 3b on the acute angle side of the bent portion 3a, the mechanical strength of the bent portion 3a can be improved. As a result, it is possible to prevent the bent portion 3b from being distorted or falling due to the pressure when the anode lead body 2 and the anode terminal 3 are resistance welded. As a result, sufficient pressure can be applied between the anode lead body 2 and the anode terminal 3 during resistance welding, so that poor connection between the anode lead body 2 and the anode terminal 3 is reduced. Further, in the first embodiment, it is not necessary to form the anode terminal 3 thickly in order to prevent the bent portion 3b from being distorted or tilted, and the thickness of the anode terminal 3 can be made thinner. Therefore, the first embodiment is superior to the related technology from the viewpoint of cost. Further, by making the thickness of the anode terminal 3 thinner, the contact area between the anode terminal 3 and the anode lead body 2 becomes smaller, the pressure at the time of resistance welding can be increased, and resistance welding or the like can be reliably performed. Welding current can also be suppressed. Further, by forming the anode terminal 3 thinly, the capacitor element 1 can be formed larger. Thereby, in the first embodiment, it is possible to manufacture a solid electrolytic capacitor having a larger capacity while being small in size. Here, the thickness of the anode terminal 3 is preferably 150 μm or less and 80 μm or more, and the height of the bent portion 3b is preferably 500 μm or less and 200 μm or more.

See FIG. 1 again. The cathode terminal 4 is formed in the lower right portion of the solid electrolytic capacitor 100, and is connected to a cathode portion of a set substrate (not shown) for the solid electrolytic capacitor 100. Further, a conductive adhesive layer 5 for electrically connecting to the cathode layer 1D of the capacitor element 1 is formed on the upper surface of the cathode terminal 4. Here, the conductive adhesive layer 5 is not particularly limited, but is made of, for example, a conductive adhesive.

The exterior resin 6 is formed so as to cover the outer periphery of the capacitor element 1. As the exterior resin 6, for example, a transfer mold resin, a liquid epoxy resin, and a liquid crystal polymer can be used.

[Second Embodiment]
The solid electrolytic capacitor 100A according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic view showing a cross section of the solid electrolytic capacitor 100A.

The solid electrolytic capacitor 100A is a rectangular parallelepiped solid electrolytic capacitor having six surfaces: an upper surface 100a, a lower surface 100b, a left surface 100c, a right surface 100d, a front surface (not shown), and a rear surface (not shown). The solid electrolytic capacitor 100A includes a capacitor element 1, an anode lead body 2, an anode terminal 3, a reinforcing rib 3B, a cathode terminal 4, a conductive adhesive layer 5, and an exterior resin 6. The solid electrolytic capacitor 100A has a different shape of the reinforcing ribs as compared with the solid electrolytic capacitor 100 according to the first embodiment. Specifically, as will be described later, the reinforcing rib 3B has a triangular pyramid shape.

The reinforcing rib 3B will be described with reference to FIG. FIG. 5 is a perspective view showing the reinforcing rib 3B according to the second embodiment.

Here, as shown in FIG. 5, a Cartesian coordinate system (x, y, z) is used. In the state shown in FIG. 2, in the Cartesian coordinate system (x, y, z), the x-axis direction is the left-right direction (width direction), the y-axis direction is the front-back direction (depth direction), and the z-axis direction is up and down. The direction (height direction).

The reinforcing rib 3B has the shape of a triangular pyramid formed on the anode terminal 3 in the left direction and the upward direction with the bent portion 3a as a base point. Since such a reinforcing rib 3B has an effect like a support rod for preventing an object from falling over, it is more effective in preventing distortion and falling of the bent portion 3b. Further, the number of reinforcing ribs 3B formed is not limited, and N reinforcing ribs 3B (N is an integer of 2 or more) may be formed on the acute angle side of the bent portion 3a. The reinforcing rib 3B can be formed, for example, by ribbing the anode terminal 3. In this case, the reinforcing rib 3B and the anode terminal 3 are integrally formed. The method of forming the reinforcing rib 3B is not limited to the ribbing process, and for example, the reinforcing rib 3B processed into a predetermined shape with the same material as the anode terminal 3 is welded to the acute angle side of the bent portion 3a. May be formed with. The solid electrolytic capacitor 100A has the same other configurations as the solid electrolytic capacitor 100 according to the first embodiment, and thus the description thereof will be omitted.

[Production method]
Next, an example of the method for manufacturing the solid electrolytic capacitor 100 according to the first embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing the flow of the manufacturing method of the solid electrolytic capacitor 100 according to the first embodiment.

First, an anode body 1A having a predetermined shape is formed from tantalum powder on the outer periphery of the anode lead body 2 made of tantalum wire by a press machine (step S101). Here, in FIG. 1, the anode lead body 2 is led out from the central portion of the left surface 1c of the capacitor element 1 toward the left. Then, the anode body 1A is sintered under the conditions of high vacuum and high temperature (step S102).

Next, in the sintered anode body 1A, a dielectric layer containing Ta ₂ O ₅ on the surface corresponding to the five surfaces of the upper surface 1a, the lower surface 1b, the right surface 1d, the front surface (not shown), and the rear surface (not shown). Form 1B. Then, it is thermally decomposed with manganese nitrate on the upper surface of the dielectric layer 1B to form the solid electrolyte layer 1C made of manganese dioxide. Further, the capacitor element 1 is obtained by forming the cathode layer 1D containing graphite and Ag (silver) on the upper surface of the solid electrolyte layer 1C (step S103).

Next, the anode terminal 3 is formed (step S104). Specifically, the rectangular plate is bent 90 ° toward the anode lead body 2 to form a bent portion 3a and a bent raised portion 3b connected to the anode lead body 2, and ribbing is performed. The anode terminal 3 is formed by integrally molding the applied reinforcing rib 3A into the bent portion 3b of the anode terminal 3.

Next, the cathode terminal 4 is formed (step S105). The cathode terminal 4 can be formed by a known method.

Next, the anode terminal 3 and the anode lead body 2 are connected, and the cathode terminal 4 and the capacitor element 1 are connected (step S106). Specifically, the anode terminal 3 and the anode lead body 2 are connected by resistance welding the bent portion 3b and the anode lead body 2. In order to connect the cathode terminal 4 and the capacitor element 1, first, a conductive adhesive layer 5 made of a conductive adhesive is applied to the upper surface of the cathode terminal 4. Then, the capacitor element 1 is mounted on the conductive adhesive layer 5, and the conductive adhesive layer 5 is dried and cured to connect the capacitor element 1 and the cathode terminal 4.

Next, the capacitor element 1 is sealed by thermoforming using a transfer mold resin as the exterior resin 6 (step S107).

Finally, the solid electrolytic capacitor 100 was obtained by cutting the excess portion of the exterior resin 6 with a dicing saw so as to have a predetermined size (step S108). By forming the reinforcing rib 3B instead of the reinforcing rib 3A in step S104, the solid electrolytic capacitor 100A according to the second embodiment can be obtained.

Although the present invention has been described above based on the embodiments and examples, the present invention is not limited to the embodiments and examples. The configuration and details of the present invention can be modified in various ways that can be understood by those skilled in the art within the scope of the present invention described in the claims.

1 ... Capacitor element 1A ... Anode body 1B ... Dielectric layer 1C ... Solid electrolyte layer 1D ... Cathode layer 2 ... Anode lead body 3 ... Anode terminal 3a ... Bending Part 3b ・ ・ ・ Bending part 3A, 3B ・ ・ ・ Reinforcing rib 4 ・ ・ ・ Cathode terminal 5 ・ ・ ・ Conductive adhesive layer 6 ・ ・ ・ Exterior resin 100, 100A ・ ・ ・ Solid electrolytic capacitor

Claims (4)

Includes a rectangular anode made of a valve acting metal, a dielectric layer formed on the outer periphery of the anode, a solid electrolyte layer formed on the dielectric layer, and a cathode layer formed on the solid electrolyte layer. With a capacitor element
An anode lead body in which at least a part protrudes from one end of the capacitor element,
An anode terminal electrically connected to the anode reed body and
A cathode terminal electrically connected to the cathode layer of the capacitor element,
An exterior resin formed so as to cover the capacitor element is provided.
The anode terminal is
The connection part connected to the mounting board and
A bent portion bent from the connecting portion toward the anode reed body,
It has a bent portion having a constant thickness extending from the bent portion toward the anode lead body.
At least one reinforcing rib is formed between both side ends of the bent portion so as to project from the bent portion to an acute angle side along the bent portion.
The reinforcing rib is a solid electrolytic capacitor that is a convex portion and is integrally molded with the anode terminal. The thickness of the anode terminal, 150 [mu] m or less, at 80μm or more, the bent-up portion of the height 500μm or less, the solid electrolytic capacitor according to claim 1 is 200μm or more. A rectangular anode body made of a valve acting metal is formed, a dielectric layer is formed on the outer periphery of the anode body, a solid electrolyte layer is formed on the dielectric layer, and a cathode layer is formed on the solid electrolyte layer. The process of forming a capacitor element by
A step of forming an anode lead body in which at least a part protrudes from one end of the capacitor element, and
By bending the conductor plate toward the anode lead body to form a bent portion, the connecting portion connected to the mounting substrate and the bent portion extending toward the anode lead body and having a constant thickness are bent. The process of forming the anode terminal connected via the part and
The step of electrically connecting the anode terminal to the anode lead body and
A step of forming a cathode terminal and electrically connecting the cathode terminal to the cathode layer of the capacitor element via a conductive adhesive layer.
Including a step of forming an exterior resin so as to cover the capacitor element.
In the step of forming the anode terminal, at least one reinforcing rib projecting from the bent portion as a base point to an acute angle side along the bent portion is formed as a convex portion between both side ends of the bent portion, and the anode is formed. A method for manufacturing a solid electrolytic capacitor that is integrally molded with a terminal. The method for manufacturing a solid electrolytic capacitor according to claim 3 , wherein the thickness of the anode terminal is formed to be 150 μm or less and 80 μm or more, and the height of the bent portion is formed to be 500 μm or less and 200 μm or more.

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