JP2003124067A - Solid electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolytic capacitor having excellent high-frequency response and mountability. SOLUTION: The solid electrolytic capacitor comprises a valve metal porous unit 7a isolated into a plurality by lateral and longitudinal grooves 9 provided on at least one surface of a conductive substance 7 as one electrode, a dielectric film 5 provided on the front surface of the unit 7a, a solid electrolytic layer 6 provided on the film 5, a connecting terminal 2 provided as the other electrode together with a current collector layer 8 on the layer 6, and a lead-out electrode 1 connected to the substance 7 of the one electrode via the layer 3 in the grooves 9 and exposed to the terminal 2 side of the other electrode.

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 which is used in various electronic devices and on which semiconductor parts can be directly mounted.

[0002]

2. Description of the Related Art As a conventional solid electrolytic capacitor, one side or an intermediate core portion in the thickness direction of a porous valve metal sheet body made of aluminum or tantalum is used as an electrode portion, and Forming a dielectric oxide film on the surface of the part, providing a solid electrolyte layer such as a functional polymer on the surface, a current collector layer on the surface of the solid electrolyte layer,
An electrode layer made of metal is provided on the current collector layer to form a capacitor element, the capacitor elements are laminated, and the electrode parts or electrode layers of each capacitor element are collectively connected to an external terminal, and the external terminal is exposed. The exterior is formed so as to perform.

[0003]

In the above-mentioned conventional solid electrolytic capacitor, a large capacity and an equivalent series resistance (hereinafter referred to as E
Although it can be lowered, it must be mounted on a circuit board via an external terminal like a general solid electrolytic capacitor. However, with the recent digitalization of circuits, high-frequency response of electronic parts is required, but in solid electrolytic capacitors that are surface-mounted with semiconductor parts on the above-mentioned circuit board, there are terminal lengths and wiring lengths. Therefore, there is a problem that the high frequency response is poor.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned conventional defects and provide a solid electrolytic capacitor which is capable of directly bump-connecting a semiconductor component and is excellent in high frequency response.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is to provide a valve metal porous portion separated into a plurality of vertical and horizontal grooves on at least one surface of a conductor. One of the electrodes, a dielectric coating on at least the surface of the valve metal porous portion, a solid electrolyte layer on the dielectric coating, and a connection terminal to be the other electrode together with the collector layer on the solid electrolyte layer. A solid electrolytic capacitor provided with a lead electrode connected to the conductor of one electrode through an insulating layer in the vertical and horizontal grooves and exposed on the connection terminal side of the other electrode. By arranging the electrode and the connection terminal which is the other electrode at a predetermined position on the same plane, the semiconductor component can be directly mounted, and a solid electrolytic capacitor excellent in high frequency response can be realized.

According to a second aspect of the present invention, at least one surface of the conductor is provided with a valve metal porous portion separated by a plurality of vertical or horizontal grooves to form one electrode, and at least one of the valve metal porous portions is provided. A dielectric film is provided on the surface, a solid electrolyte layer is formed on the dielectric film, and a connection terminal to be the other electrode together with the current collector layer is provided on the solid electrolyte layer, and an insulating layer is provided in the vertical or horizontal groove. A solid electrolytic capacitor provided with a lead-out electrode connected to the conductor of one electrode and exposed on the connection terminal side of the other electrode, which realizes a solid electrolytic capacitor excellent in productivity in addition to the function of claim 1. be able to.

The invention according to claim 3 is the solid electrolytic capacitor according to claim 1 or 2, wherein an aluminum foil having a porous portion formed on at least one surface by etching is used as one electrode. Therefore, it is possible to easily realize a large-capacity solid electrolytic capacitor excellent in high frequency response.

The invention according to claim 4 is the solid electrolytic capacitor according to claim 1 or 2, wherein a clad material of valve metal and copper is used as a conductor for one of the electrodes. In addition to the above action, a large-capacity solid electrolytic capacitor having excellent electrode connectivity can be obtained.

The invention according to claim 5 uses a metal foil as a conductor as one of the electrodes and a sintered body of valve metal powder as a porous portion of the valve metal. The solid electrolytic capacitor described in 1) can realize a solid electrolytic capacitor having a larger capacity.

The invention according to claim 6 is the solid electrolytic capacitor according to any one of claims 1 and 2, wherein the valve metal porous portion is provided with an organic dielectric film. In addition, it is possible to realize a solid electrolytic capacitor which is non-polar and has high reliability against bending stress.

The invention according to claim 7 is the solid electrolytic capacitor according to any one of claims 1 and 2, wherein a functional polymer is used as the solid electrolyte layer, which has a lower ESR.
A solid electrolytic capacitor having characteristics can be realized.

The invention according to claim 8 is the solid electrolytic capacitor according to any one of claims 1 and 2, wherein the extraction electrode is formed over the entire area of the vertical and horizontal grooves or over the entire vertical or horizontal area. A solid electrolytic capacitor having characteristics can be realized.

The invention according to claim 9 is the solid electrolytic capacitor according to any one of claims 1 and 2, wherein the extraction electrode is formed in a part of vertical and horizontal grooves or in a vertical or horizontal part. In addition to the effect of the eighth aspect, it is possible to realize a solid electrolytic capacitor excellent in absorption of mechanical stress.

According to a tenth aspect of the invention, there is provided the solid electrolytic capacitor according to the first aspect in which the extraction electrodes are formed at the intersections of the vertical and horizontal grooves, and a solid electrolytic capacitor having the same function as that of the ninth aspect is realized. You can

The eleventh aspect of the present invention is the solid electrolytic capacitor according to any one of the first and second aspects, in which the extraction electrode is formed of a through-hole electrode in a part of the vertical and horizontal grooves, and is a semiconductor component. It is possible to realize a solid electrolytic capacitor having excellent connectivity.

The invention according to claim 12 is the solid electrolytic capacitor according to any one of claims 1 and 2, wherein the width of the groove is formed in a taper shape that narrows from the surface portion toward the inside. It is possible to realize a solid electrolytic capacitor in which the film is easily formed and the reliability of the insulating film is excellent.

The invention according to claim 13 is the solid electrolytic capacitor according to any one of claims 1 and 2, wherein the width of the groove is formed in a taper shape widening from the surface portion toward the inside. It is possible to realize a solid electrolytic capacitor having a large capacity.

The fourteenth aspect of the present invention is the solid electrolytic capacitor according to any one of the first and second aspects, which uses an insulating resin material as the insulating layer, and realizes a solid electrolytic capacitor having high productivity. be able to.

According to a fifteenth aspect of the present invention, an insulating resin material containing an inorganic filler is used as the insulating layer.
Alternatively, the solid electrolytic capacitor according to any one of the aspects 1 and 2 can achieve a highly reliable solid electrolytic capacitor because an insulating layer having high heat resistance can be formed in addition to the effect of the fourteenth aspect.

According to a sixteenth aspect of the present invention, there is provided a solid electrolytic capacitor according to any one of the first and second aspects, in which an outer surface is formed on an outer peripheral surface, and a solid electrolytic capacitor having excellent reliability is realized. You can

The invention according to claim 17 is the solid electrolytic capacitor according to any one of claims 1 and 2, wherein a connection bump is provided on the connection terminal and the extraction electrode, which is a semiconductor component or a general electronic component. And the like can be directly mounted, and a solid electrolytic capacitor excellent in high frequency response can be realized.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The solid electrolytic capacitor of the present invention will be described below with reference to embodiments and drawings.

(Embodiment 1) Hereinafter, the first embodiment and FIGS. 1 to 7 will be referred to as claims 1, 3, 7, 10 and 12 to 1.
The invention described in 6 will be described.

1, 4, and 5 are plan views of the solid electrolytic capacitor according to the embodiment of the present invention, and FIGS. 2, 6, and 7.
Is a sectional view of a part thereof, and FIG. 3 is an enlarged view of the main part.

In the solid electrolytic capacitors shown in FIGS. 1 to 7, the valve metal porous portion 7a on one side of the aluminum foil which is the conductor 7 is used.
A plurality of grooves 9 are provided in the vertical and horizontal directions, and an insulating layer 3 is formed on the side walls of the grooves 9. The insulating layer 3 is provided in the vertical and horizontal grooves 9.
The extraction electrode 1 is formed by being connected to the aluminum foil which is the conductor 7 via the. The extraction electrode 1 is formed on the same surface side of the connection terminal 2.

On one side of the conductor 7, a dielectric coating 5 which is a layer of aluminum oxide is formed on the surface of the valve metal porous portion 7a divided into a plurality of vertical and horizontal grooves 9, and this dielectric coating 5 is formed. A solid electrolyte layer 6 of pyrrole, thiophene, or the like is provided on the above, and the connection terminal 2 is further formed on the solid electrolyte layer 6 via a current collector layer 8. The valve metal porous portion 7a formed on one surface of the conductor 7 can be formed by an etching process. In order to form the dielectric film 5 on the surface of the valve metal porous portion 7a, the aluminum which is the conductor 7 is used. It is obtained by oxidizing the foil with a chemical solution, and the capacity of the solid electrolytic capacitor can be increased. As the conductor 7, other than aluminum, a valve metal material such as tantalum or niobium can be used.

The dielectric film 5, the solid electrolyte layer 6, the current collector layer 8 and the connection terminal 2 are each divided by the groove 9 into individual capacitance terminals, and the extraction electrode 1, the dielectric film 5, and the solid electrolyte are separated. The layer 6, the current collector layer 8 and the connection terminal 2 are electrically insulated by the insulating layer 3. The outer peripheral portion of the capacitor element 10 is covered with the exterior 4.

The structure of another solid electrolytic capacitor shown in FIG. 4 is basically the same as that of the capacitor element 10 of FIG. 1, but the extraction electrode 1 is formed discontinuously in a part of vertical and horizontal grooves. By discontinuing the extraction electrode 1, the stress caused by the difference in thermal expansion coefficient between the electrode material forming the extraction electrode 1 and the insulating resin forming the insulating layer 3 can be relaxed. You can As a result, it is possible to obtain the extraction electrode structure that reduces the deterioration of the reliability of the electrical connection.

Another solid electrolytic capacitor shown in FIG. 5 has a structure in which the extraction electrode 1 is formed at the intersection of the vertical and horizontal grooves, and the extraction electrode 1 is designed to have a minimum necessary frequency. By arranging the extraction electrode 1 efficiently while maintaining the performance excellent in responsiveness, it is possible to realize further downsizing and increase productivity.

Next, the solid electrolytic capacitor element 10 of the present invention
In the case where the insulating layer 3 is formed by filling the insulating resin material by forming the groove 9 into a tapered shape in which the width of the groove 9 becomes narrower from the surface portion toward the inside as shown in FIG. In the above, the filling property and filling speed of the resin are increased, and a solid electrolytic capacitor excellent in productivity and reliability can be realized. Further, as shown in FIG. 7, the shape of the groove 9 of the capacitor element 10 is configured so that the width of the groove 9 becomes wider from the surface portion toward the inside, whereby the extraction electrode 1 is firmly held by the conductor 7. As a result, a solid electrolytic capacitor with improved reliability of electrical connection can be realized.

(Embodiment 2) The invention described in claims 2, 4, and 17 will be described with reference to Embodiment 2 of the present invention and FIGS.

FIG. 8 is a plan view of a solid electrolytic capacitor according to a second embodiment of the present invention, FIGS. 9 and 11 are partial sectional views thereof, and FIG. 10 is a perspective view thereof.

In the solid electrolytic capacitors of FIGS. 8 to 11, a valve metal material such as aluminum, tantalum, niobium and a clad material of copper can be used as the conductor 7, and as an example, the copper foil 12 and porous by etching. A description will be given using the clad material of the aluminum foil 11 thus prepared. Copper foil 1
As shown in FIG. 9, the clad material of 2 and the aluminum foil 11 is provided with a plurality of vertical or horizontal grooves 9 so as to cut the aluminum foil 11, and the insulating layer 3 is formed on the side wall of the groove. The extraction electrode 1 is formed in the plurality of grooves 9 provided vertically or horizontally and connected to the copper foil 8 via the insulating layer 3. The extraction electrode 1 is formed on the same surface side of the connection terminal 2.

On one surface of the aluminum foil 11, a dielectric coating 5 which is a layer of aluminum oxide, a solid electrolyte layer 6 on the dielectric coating 5, and a collector layer 8 on the connection terminal are provided. 2 is formed. The dielectric film 5, the solid electrolyte layer 6, the current collector layer 8 and the connection terminal 2 are each divided into individual capacitive elements by the groove 9, and the extraction electrode 1, the dielectric film 5, the solid electrolyte 6, and the current collector are separated. The body layer 8 and the connection terminal 2 are electrically insulated by the insulating layer 3.

Further, by constructing the solid electrolytic capacitor according to the second embodiment of the present invention, it is possible to easily realize a large capacity and a thin layer by using the entire aluminum foil 11 as the valve metal porous portion 7a. it can.
The outer peripheral portion of the capacitor element 10 is covered with the exterior 4. Here, the extraction electrode 1 forms the discontinuous extraction electrode 1 as shown in FIG. 8, but it is also possible to form the continuous extraction electrode 1 as in the first embodiment.

By configuring the solid electrolytic capacitor as described above, the area occupied by the groove 9 is reduced as compared with the structure described in the first embodiment, and as a result, a large capacity, low ESR and low ESL performance are obtained. It is possible to realize a solid electrolytic capacitor having. Further, by using the valve metal and the clad material of copper, the extraction electrode 1 can be directly formed on the copper foil 12 by using a plating technique or the like to form a connection, and the extraction electrode 1 can be electrically connected with a smaller interface resistance than aluminum. Since it is possible to use a conductive member, it is possible to form an electrode structure having excellent conductivity, and it is possible to collectively form the extraction electrode 1 by using a plating technique, which dramatically improves productivity. Can be increased. Furthermore, the strength of the fragile aluminum foil 11 can be reinforced, and when the solid electrolytic capacitor is mounted on the circuit board, the copper foil 12 can be used as the mounting surface, so that mounting on the board becomes easy.

The capacitor element 1 configured as described above
0 and the lead terminal of the semiconductor component can be connected by using a soldering technique, but a mounting form by bump connection has been widely put into practical use in order to realize higher density mounting.

Next, a structure for enabling this mounting mode will be described. 10 and 11 show the capacitor element 1.
0 is connected to the lead-out electrode 1 and the connection terminal 2 to electrically insulate the respective electrodes, and the connection bumps 14 are formed via a protective film 13 having a pattern design for enhancing long-term reliability.

By forming the connection bumps 14 by optimally designing the terminal pitch and the bump diameter, it becomes possible to directly connect the bumps to the semiconductor component, and the terminal pitch is finer than that of the semiconductor mounting of the lead terminals. Since the electrodes can be designed and the connection can be made with the shortest electrode length, low ESR and low ESL characteristics excellent in high frequency response can be realized. The connecting bumps 14 are optimally made of a low melting point metal solder alloy, gold, gold-tin alloy, or the like. Further, the connection bumps 14 can be configured in other embodiments. It goes without saying that the configuration described above can be applied to parts other than semiconductor parts.

(Embodiment 3) The invention according to claim 5 will be described with reference to Embodiment 3 of the present invention and FIGS. 1, 2, and 12. FIG. 12 is an enlarged view of a main part in the third embodiment of the present invention.

The solid electrolytic capacitor of the present invention has the same basic structure as that of the first embodiment described with reference to FIGS. 1 and 2, and the detailed description of the same components will be omitted. In particular, as shown in FIG. 12, the structure characterized by the present invention uses a metal such as a valve metal foil as the conductor 7 which is one electrode, and a sintered body layer 15 of the valve metal powder as the valve metal porous portion. Then, the surface of the sintered body layer 15 is anodized to form the dielectric film 5, and the solid electrolyte layer 6 and the current collector layer 8 formed on the dielectric film 5 are interposed. The solid electrolytic capacitor connected to the connection terminal 2 has such a structure that not only has an excellent high-frequency response but also has a thin sheet shape and a large capacity. it can. As a result, it is effectively embedded in the circuit board and miniaturized in the circuit.

(Embodiment 4) The invention according to claim 6 will be described with reference to Embodiment 4 of the present invention and FIGS. The solid electrolytic capacitor of the present invention has substantially the same basic configuration as that of the first embodiment, and detailed description of the same components will be omitted.

A particular feature of the structure of the present invention is that the dielectric coating 5 is formed of an organic dielectric coating instead of the metal oxide dielectric coating 5 formed by anodic oxidation. The organic dielectric coating 5 is formed on the surface of the valve metal porous portion 7a formed on one surface of the conductor 7 by dipping it in a solution containing acrylic resin, electrodeposition, and electrodeposition. be able to. After that, the connection terminals 2 are formed on the organic dielectric coating 5 via the solid electrolyte layer 6 and the current collector layer 8 to obtain a solid electrolytic capacitor having the organic dielectric coating 5.

By using the solid electrolytic capacitor having such a structure, the dielectric film 5 becomes nonpolar and the direction of electrode extraction is lost, so that it is mounted on a circuit board or combined with various electronic parts to form a composite part. Sometimes the degree of freedom in design is improved. Further, when an oxide film formed by anodic oxidation is used as the dielectric film 5, the oxide film is destroyed by external stress, for example, external stress, and a short circuit defect occurs. For this reason, it was difficult to use it in a stressed portion such as a flexible substrate, but the solid electrolytic capacitor of the present invention is highly flexible and can be mounted on a circuit or substrate where bending stress is applied.

(Embodiment 5) The invention according to claim 11 will be described with reference to Embodiment 5 of the present invention and FIGS. 13 is a plan view of a solid electrolytic capacitor according to a fifth embodiment of the present invention, and FIG. 14 is a partial sectional view thereof.

The solid electrolytic capacitor of the present invention has the same basic structure as that of the first embodiment, and detailed description of the parts having the same structure will be omitted. In particular, the structure of the present invention is characterized in that the extraction electrode 1 is provided with a through hole in a part of the insulating layer 3 filled in the vertical and horizontal grooves 9, and the through hole is connected to the conductor 7 of one electrode. That is, the through-hole electrode 16 for exposing on the connection terminal 2 side is formed.

By forming the through-hole electrode 16, the extraction electrode 1 can be formed at a desired position with a minimum area, so that short circuit failure, disconnection failure due to bending stress, etc. can be reduced. Further, since the through-hole electrode 16 can be formed in accordance with the terminal pitch of the semiconductor component, it is possible to directly form the connection bump 12 on the through-hole electrode 16 and a solid electrolytic capacitor excellent in high frequency response and productivity can be obtained. Can be realized.

[0048]

As described above, according to the structure of the solid electrolytic capacitor of the present invention, very low ESR and ESL characteristics can be obtained, and it becomes possible to directly mount a semiconductor component or other electronic component, and a high frequency response is obtained. A solid electrolytic capacitor having excellent properties can be manufactured easily and efficiently.

[Brief description of drawings]

FIG. 1 is a plan view of a solid electrolytic capacitor according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is an enlarged view of the main part.

FIG. 4 is a plan view of the same.

FIG. 5 is a plan view of the same.

FIG. 6 is a sectional view of the same.

FIG. 7 is a sectional view of the same.

FIG. 8 is a plan view of the same.

FIG. 9 is a sectional view of the same.

FIG. 10 is a perspective view of the same.

FIG. 11 is a sectional view of the same.

FIG. 12 is an enlarged sectional view of the same.

FIG. 13 is a plan view of the same.

FIG. 14 is a sectional view of the same.

[Explanation of symbols]

1 Extraction electrode 2 connection terminals 3 insulating layers 4 exterior 5 Dielectric coating 6 Solid electrolyte layer 7 conductor 7a Valve metal porous part 8 Current collector layer 9 grooves 10 Capacitor element 11 Aluminum foil 12 Copper foil 13 Protective film 14 connection bump 15 Sintered body layer 16 Through-hole electrode

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuo Fujii             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Ryo Kimura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (17)

[Claims] 1. A valve metal porous portion divided into a plurality of vertical and horizontal grooves on at least one surface of a conductor to form one electrode, and a dielectric coating on at least the surface of the valve metal porous portion, and this dielectric. A solid electrolyte layer on the coating, a connection terminal to be the other electrode together with the collector layer on the solid electrolyte layer is provided, and the other is connected to the conductor of one electrode through an insulating layer in the vertical and horizontal grooves. Solid electrolytic capacitor provided with an extraction electrode exposed on the connection terminal side of the electrode. 2. A valve metal porous portion divided into a plurality of vertical or horizontal grooves on at least one surface of a conductor to form one electrode, and at least the surface of the valve metal porous portion has a dielectric coating, A solid electrolyte layer on the dielectric film, a connection terminal to be the other electrode together with the current collector layer on the solid electrolyte layer, the conductor of one electrode through the insulating layer in the vertical or horizontal groove Solid electrolytic capacitor provided with a lead-out electrode connected to the other end and exposed on the connection terminal side of the other electrode. 3. The solid electrolytic capacitor according to claim 1, wherein an aluminum foil having a porous portion formed on at least one surface by etching is used as one electrode. 4. The solid electrolytic capacitor according to claim 2, wherein a valve metal and a copper clad material are used as a conductor for one of the electrodes. 5. The solid electrolytic capacitor according to claim 1, wherein a metal foil is used as a conductor as one of the electrodes, and a sintered body of valve metal powder is used as a valve metal porous portion. 6. The solid electrolytic capacitor according to claim 1, wherein an organic dielectric film is provided on the valve metal porous portion. 7. The solid electrolytic capacitor according to claim 1, wherein a functional polymer is used as the solid electrolyte layer. 8. The solid electrolytic capacitor according to claim 1, wherein the extraction electrode is formed over the entire area of the vertical and horizontal grooves or over the entire area of the vertical and horizontal directions. 9. The solid electrolytic capacitor according to claim 1, wherein the extraction electrode is formed in a part of vertical and horizontal grooves or in a vertical or horizontal part. 10. The solid electrolytic capacitor according to claim 1, wherein the extraction electrode is formed at an intersection of vertical and horizontal grooves. 11. The solid electrolytic capacitor according to claim 1, wherein the extraction electrode is formed of a through-hole electrode in a part of vertical and horizontal grooves. 12. The solid electrolytic capacitor according to claim 1, wherein the width of the groove is formed in a taper shape that becomes narrower from the surface portion toward the inside. 13. The solid electrolytic capacitor according to claim 1, wherein the groove is formed in a taper shape in which the width increases from the surface portion toward the inside. 14. The solid electrolytic capacitor according to claim 1, wherein an insulating resin material is used as the insulating layer. 15. The solid electrolytic capacitor according to claim 1, wherein an insulating resin material containing an inorganic filler is used as the insulating layer. 16. The solid electrolytic capacitor according to claim 1, wherein an outer surface is formed on the outer peripheral surface. 17. The solid electrolytic capacitor according to claim 1, wherein a connection bump is provided on the connection terminal and the extraction electrode.