JP2003109864A - Electrode for high polymer solid electrolytic capacitor and electrode therefor using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for high polymer solid electrolytic capacitor capable of implementing a higher capacity capacitor. SOLUTION: The electrode for use in a high polymer solid electrolytic capacitor is stored and fixed in a closed space formed by an insulative resin, has a foil-shaped valve metal substrate having a plane which is rectangle in shape, and has a roughened surface formed with an insulative oxide film thereon, a valve metal substrate having a surface which is not roughened, and a foil- shaped conductive metal substrate. An end of the foil-shaped valve metal sustrate having a surface which is not roughened is bonded to an end of a notch portion of the foil-shaped valve metal substrate having a roughened surfaced formed with an insulative oxide film thereon such that both valve metals are electrically connected. An end of the foil-shaped conductive valve metal substrate is bonded to an end excluding the bonded option of the foil-shaped metal substrate having a surface which is not roughened such that both metals are electrically connected.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrode for a polymer solid electrolytic capacitor and a polymer solid electrolytic capacitor using the same.

[0002]

2. Description of the Related Art Electrolytic capacitors are made of aluminum, titanium, brass, nickel, which has an insulating oxide film forming ability.
A metal such as tantalum, a so-called valve metal, is used as an anode, the surface of the valve metal is anodized to form an insulating oxide film, and then an electrolyte layer that substantially functions as a cathode is formed. It is formed by providing a conductive layer such as silver as a cathode.

For example, an aluminum electrolytic capacitor uses a porous aluminum foil whose specific surface area is increased by etching as an anode.

On the other hand, due to the demand for smaller and thinner electronic equipment, further miniaturization and higher performance are required for electronic parts, and circuit boards are made more functional by thinning and multilayering. Is required.

Therefore, similar to the resistance function and the conductive pattern of the wiring board, the solid electrolytic capacitor is previously formed integrally with the board, and a plurality of solid electrolytic capacitors are formed by a circuit board formed on one board. It has been proposed to increase the density of electronic components and to reduce the thickness of circuit boards (Japanese Patent Laid-Open No. 2-52510 and Japanese Patent No. 2950587).
Issue).

In such an electric wiring board with a built-in solid electrolytic capacitor, a lead electrode for connecting the solid electrolytic capacitor to other electronic components to be mounted on the board is formed with an insulating oxide film serving as an anode. It is indispensable to connect to a foil-shaped valve metal substrate which has a function.

As such a lead electrode (lead-out electrode), there is a lead-wire-type lead-out electrode as disclosed in, for example, Japanese Patent Laid-Open No. 4-188815, and the above-mentioned publication forms an insulating oxide film. It is described that the aluminum foil is attached by crimping.

On the other hand, Japanese Patent No. 2950587 discloses that
Disclosed is an electrolytic capacitor in which a capacitor is manufactured by using a plate-shaped anode electrode as an electrode, and a printed circuit board having a desired wiring pattern is arranged on both surfaces of the capacitor element to be integrated with the capacitor element. As an aspect, it is shown that an anode terminal for extracting an anode made of a metal such as copper that can be soldered (soldered) is connected to a plate-like body by ultrasonic welding, laser welding, or the like.

In any case, in order to obtain a large capacitance, the solid electrolytic capacitor, particularly the polymer solid electrolytic capacitor, has a foil-shaped valve metal substrate with a rough surface so that the surface area of the valve metal substrate is large. A roughened foil obtained by cutting a foil-shaped valve metal substrate of a desired size out of a foil-shaped sheet of a valve metal such as aluminum that has been formed (widened) and on which an insulating oxide film such as aluminum oxide is formed. Form a solid polymer electrolyte layer that will become the cathode on the insulating oxide film of the valve metal, and then provide a conductor layer such as a carbon paste layer and a silver paste layer on the solid polymer electrolyte layer that will become the cathode. , The cathode lead electrode is formed, and the anode lead electrode made of a metal conductor such as copper is connected to the valve metal base so that the metals are electrically connected and joined. Done .

In such a case, a conductive polymer film is formed on the cut-out edge portion of the valve metal substrate during the anodizing treatment required to form an insulating oxide film, or by polymerizing a monomer in the electrode. When formed, the surface-expanded aluminum foil is in a porous state, so that each solution permeates to the joint with the lead electrode and contacts and reacts with the lead electrode material, causing a short circuit. . Such a phenomenon is not clearly indicated in JP-A-4-188815 that the aluminum foil on which the dielectric oxide film is formed is expanded, and the purpose of forming the resin layer on the lead attachment portion or the end surface of the anode foil. Although it does not prevent wicking, wicking cannot be prevented by forming a resin layer as shown here. Therefore, in the case of a two-electrode structure in which the lead electrode is made of a solderable metal such as copper, and the aluminum electrode foil having the expanded surface and the insulating oxide film is integrated with the lead electrode, the leakage current is reduced. There was a problem in that sufficient capacitor characteristics could not be obtained due to the increase in size and the short circuit at worst.

Further, the connection of the electrode for integrating the lead electrode and the aluminum electrode foil having the expanded surface and having the insulating oxide film formed thereon is partially described above, but the entire width of the electrode is welded or the like. It is carried out by means of. that time,
The surface-enlarged structure and the insulating oxide film on the aluminum electrode foil on which the end portions of the two electrodes are expanded and the insulating oxide film is formed on the surface of the aluminum electrode foil are not affected by the impact or the welding. There is a problem in that the function is significantly lost due to the pressure, and the function as a capacitor is substantially lost.

Therefore, the present inventor has made the surface roughened,
Electrical connection between the valve metal and the region near one end of the foil-shaped valve metal base whose surface is not roughened to the region near one end of the foil-shaped valve metal base on which the insulating oxide film is formed As described above, the joined and formed anode electrode has an insulating oxide film on the edge portion where the insulating oxide film is not formed on the foil-shaped valve metal substrate whose surface is roughened by anodic oxidation. Even if formed, the chemical conversion solution has an area near one end of the foil-shaped valve metal base whose surface is roughened and an area near one end of the foil-shaped valve metal base whose surface is not roughened. Of the foil-shaped valve metal base body whose surface is not roughened, and thus the area near one end of the roughened foil-shaped valve metal base body and the surface Insulating oxide film is formed on the joint with the area near one end of the foil-shaped valve metal substrate that is not roughened. Once formed, the current stops flowing, and anodization is completed, and an insulating oxide film can be formed on the edge portion of the foil-shaped valve metal substrate whose surface is roughened, as desired. Based on the knowledge that it will be possible, the lead electrode is made of a solderable metal such as copper, and this is integrated with a valve metal foil such as an unexpanded aluminum foil by means such as welding,
It has been proposed that the non-surface-expanded aluminum foil and the surface-expanded aluminum foil having an insulating oxide film be integrated into a three-electrode structure (Japanese Patent Application 2).
001-095055).

However, the anode electrode specifically proposed here is, for example, like the anode electrode 51 shown in FIG. 8, one end portion including all the sides of a rectangular aluminum foil 52 having a wide surface. Then, a rectangular non-surface-expanded aluminum foil 53 of the same width is joined by a welded joint portion 56, and further, a rectangular copper foil 54 of the same width is joined by a welded joint portion 55 thereto. This is a structure, and there is room for improvement in increasing the capacity of the capacitor.

By the way, Japanese Patent Laid-Open No. 6-53090 discloses a solid electrolytic capacitor which has both a leakage current characteristic and a capacitive characteristic by making a substantial capacity drawing portion large and making an anode portion of an internal element small. As a part of a square anode substrate made of valve metal having a dielectric oxide film layer on the surface of aluminum or the like having an alumina (aluminum oxide) film layer is used as an anode part, and the remaining part of the dielectric except for this anode part is In a solid electrolytic capacitor having a semiconductor layer on a surface of a body oxide film layer and a conductor layer formed thereon, the anode part is a right triangle including at least one corner of the quadrangle or a trapezoid including two right angles, and the rest is a pentagon. Alternatively, a trapezoidal shape is disclosed. Also,
It is described that the lead wire is attached to the anode part with respect to the capacitor element after the conductive layer is formed.In the example, the lead wire is placed on the anode part and spot-welded. Is listed. But,
In such a lead wire attaching method, if the aluminum foil having the alumina coating layer shown in the examples is mentioned,
Although it is necessary to connect the lead wire to the aluminum metal portion where the alumina coating layer does not exist, the aluminum foil has a thickness of about 100 μm as described in the examples of the above publications, and the presence of the alumina coating layer. If the lead wire is connected to a place where it does not exist, there is a problem that the strength of the connection portion cannot be sufficiently obtained. Specifically, it is extremely difficult to provide a lead wire on the edge portion where the alumina coating layer is not formed, and even if it is provided, the strength is not sufficient. Even if the alumina coating is peeled off by some means to expose the aluminum metal and connect the lead wire, the aluminum foil is extremely thin, and there is still a problem in strength. As a result, the impedance characteristics are deteriorated, and there is a problem that a solid electrolytic capacitor suitable for incorporation in a circuit board cannot be obtained.

Therefore, it is necessary to solve such a problem and increase the capacity of the capacitor.

[0016]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrode for a polymer solid electrolytic capacitor which can increase the capacity of the capacitor. Further, by using such an electrode, a large area can be used for mounting, the lead portion has sufficient strength, and a polymer solid electrolytic capacitor that can be mounted with high integration and high density is provided. That is.

[0017]

The above object is achieved by the present invention described below. (1) Stored in a closed space made of insulating resin,
An electrode used for a fixed polymer solid electrolytic capacitor, the planar shape of which is shorter than the entire length of one side of the rectangle at a corner where one side of the rectangle intersects with one side of the rectangle. A foil-shaped valve metal substrate having a shape in which a cutout having two sides of a length is formed, the surface of which is roughened, and an insulating oxide film is formed, and the surface of which is not roughened. A valve metal base and a foil-shaped conductive metal base, the surface of which is roughened and an insulating oxide film is formed on the end of the cutout portion of the foil-shaped valve metal base. Is joined so that the end portions of the foil-shaped valve metal substrate not roughened are electrically connected between the valve metals, and the surface of the foil-shaped valve metal substrate not roughened is Connect the ends of the foil-shaped conductive metal base to the ends excluding the joints so that the metals are electrically connected. To configured polymer solid electrolytic capacitor electrodes. (2) At least the insulating oxide film of the foil-shaped valve metal substrate on which the electrode for the polymer solid electrolytic capacitor of (1) above is used as an anode and whose surface is roughened to form an insulating oxide film, A solid polymer electrolyte capacitor in which a solid polymer electrolyte layer and a conductor layer are sequentially formed. (3) The polymer solid electrolytic capacitor according to (2) above, wherein the closed space formed of the insulating resin is formed of an insulating resin substrate. (4) The insulative resin substrate has a first insulative resin substrate and a second insulative resin substrate facing each other, and one surface of the first insulative resin substrate and the second insulating resin substrate. The polymer solid electrolytic capacitor as described in (3) above, which is integrally mounted between one surface of a conductive resin substrate. (5) The polymer solid electrolytic capacitor according to (4) above, wherein at least one wiring pattern is formed on the surface of the first insulating resin substrate and / or the second insulating resin substrate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The polymer solid electrolytic capacitor of the present invention is stored and fixed in a closed space formed of an insulating resin. Here, the closed space is a space surrounded by an insulating resin, and refers to, for example, an inner space of the housing, such as a hole for a through hole, part of
There may be a place communicating with the outside or a place made of a material different from the insulating resin, and such a case is also referred to as a closed space. The anode electrode of the present invention used in this polymer solid electrolytic capacitor has a roughened surface (enlarged surface) and a foil-shaped valve metal substrate having an insulating oxide film formed thereon, and a roughened surface. Not having a foil-shaped valve metal substrate and a foil-shaped conductive metal substrate, and a roughened valve metal substrate and a non-roughened surface so that the valve metals are electrically connected A valve metal base is joined at its ends, and a non-roughened valve metal base and a conductive metal base are joined at their ends so that the metals are electrically connected. There is something. In this case, the planar shape of the roughened valve metal substrate is a rectangular shape, and at a corner portion where one side of the rectangle intersects one side of the rectangle, two sides having a length shorter than the entire length of the one side of the rectangle are formed. Is formed with a notched portion having a groove, and the end of the notched portion is joined to the valve metal base body which is not roughened.

The non-roughened valve metal base body and the conductive metal base body are joined to each other as long as there is a single non-roughened valve metal base body.
The entire conductive metal substrate may be installed so as to overlap the non-roughened valve metal substrate.

According to the present invention, the notch has a form in which the joined body of the foil-shaped valve metal base and the foil-shaped conductive metal base whose surface is not roughened can be substantially accommodated. Compared with the prior art example as shown in FIG. 8, when the area of the plane of the anode electrode is made substantially the same, the surface is roughened and the area of the foil-shaped valve metal substrate on which the insulating oxide film is formed is increased ( 1.
It is possible to increase the capacity when a capacitor is configured.

Further, when the solid polymer electrolytic capacitor is housed and fixed in a closed space formed by an insulating resin substrate, preferably in a substrate built-in type, a foil-shaped conductive metal substrate is a lead electrode (lead electrode). Since it has a foil shape, it is advantageous for thinning and the lead portion has sufficient strength.

Further, a foil-shaped valve metal base whose surface is roughened and an insulating oxide film is formed with a foil-shaped valve metal base whose surface is not roughened and a conductive metal base are formed. Therefore, when the insulating oxide film is formed on the edge portion of the valve-shaped valve metal substrate whose surface is roughened by anodizing treatment, the chemical conversion solution is a foil whose surface is roughened. Of the foil-shaped non-roughened surface beyond the joint between the region near the one end of the valve-shaped metal base and the region near the one end of the foil-shaped valve metal base whose surface is not roughened A region near one end of a foil-shaped valve metal substrate whose surface is roughened without reaching the valve metal substrate and a region near one end of a foil-shaped valve metal substrate whose surface is not roughened When the insulating oxide film is formed on the joint, the current stops flowing and the anodic oxidation is completed. Becomes, also in such as during the polymerization process, without immersion observed up to the conductive metal substrate of the solution,
This can reduce short circuit and leakage current of the capacitor. Therefore, when the polymer solid electrolytic capacitor is built in the insulating resin substrate, a large area can be used for mounting, and high density and high density mounting can be achieved.

Furthermore, a polymer solid electrolytic capacitor is
Even if an insulating oxide film is formed over time on the surface of a foil-shaped valve metal substrate whose surface is not roughened after being embedded in a circuit board with a circuit formed on an insulating resin substrate, The foil-shaped valve metal substrate is not roughened, and a foil-shaped conductive metal is further bonded to the region in the vicinity of the other end of the foil-shaped valve metal substrate so that the foil-shaped conductive metal is electrically connected. By providing the metal with a contact with another electronic component mounted on the circuit board, a polymer solid electrolytic capacitor having desired impedance characteristics can be built in the circuit board. In Japanese Patent Laid-Open No. 6-53090, a right-angled triangular or trapezoidal anode portion is provided on a part of a foil-shaped valve metal substrate having a quadrangular insulating oxide film and a roughened surface. There is disclosed a solid electrolytic capacitor in which a semiconductor layer and a conductor layer are formed in conformity with the shape of the remaining portion of the trapezoidal or pentagonal rectangle. However, in the solid electrolytic capacitor of the above publication, a foil-shaped valve metal substrate having an insulating oxide film formed thereon and having a roughened surface is intercalated with a foil-shaped valve metal substrate having a non-roughened surface. The present invention does not form a quadrangle (rectangle) as a whole by being bonded to a conductive metal substrate, and the configuration is completely different from the present invention. Therefore, in the solid electrolytic capacitor of the above publication, it is necessary to connect a lead wire or the like to the edge portion of the valve metal substrate foil where the insulating oxide film does not exist or the insulating oxide film removed portion, and the strength of the lead portion is sufficient. There is a problem that cannot be obtained.

The following is a description with reference to the accompanying drawings.

FIG. 1 is a schematic plan view showing an example of the anode electrode of the polymer solid electrolytic capacitor of the present invention, and FIG.
It is a schematic sectional drawing along the AA line.

Here, aluminum is used as the valve metal having the ability to form an insulating oxide film.
As shown in FIG. 3, the anode electrode 1 of the polymer solid electrolytic capacitor has a roughened surface (enlarged surface) and a foil-shaped aluminum substrate 2 having an aluminum oxide film as an insulating oxide film formed on the surface. And a foil-shaped aluminum substrate 3 whose surface is not roughened, and a foil-shaped copper substrate 4 as a metal conductor forming a lead electrode.

At this time, the aluminum base 2 has a rectangular shape, and at one corner where one side of the rectangle intersects with one side,
This is a shape in which a triangular notch having two sides having a length shorter than the entire length of one side of a rectangle is formed, and the aluminum base 3 and the copper base 4 are joined together so as to fill the triangular notch. The aluminum base 2, the aluminum base 3, and the copper base 4 form a rectangle.

As shown in FIG. 1 and FIG. 2, the anode electrode 1 has a roughened surface and an aluminum oxide film is formed on the surface of the anode electrode 1 in the end region of the notch of the foil-shaped aluminum substrate 2. Is joined by ultrasonic welding to one end region of the foil-shaped aluminum base 3 whose surface is not roughened, so that the valve metals are electrically connected, and the surface is roughened. In the other end region of the foil-shaped aluminum base 3 which is not formed, the entire foil-shaped copper base 4 is joined and formed by ultrasonic welding so that the metals are electrically connected. ing. Here, the foil-shaped copper substrate 4
Although the whole is overlapped with the end of the foil-shaped aluminum base 3 whose surface is not roughened, the end regions of the copper base 4 may be overlapped with each other.

In forming the anode electrode, as shown in FIG. 3, first, a foil-shaped copper substrate 4 which is to be cut into a predetermined size to form a lead electrode and an aluminum foil sheet are cut into a predetermined size. The end regions of a predetermined area of the foil-shaped aluminum substrate 3 whose surface is not roughened and the entire foil-shaped copper substrate 4 are overlapped with each other.

Next, the end regions of the foil-shaped copper base 4 and the end regions of the foil-shaped aluminum base 3 which are superposed on each other are joined by ultrasonic welding to form a welded joint 5. To be done. Even when an aluminum oxide film is formed on the surface of the foil-shaped aluminum substrate 3,
By joining by ultrasonic welding, the aluminum oxide film is removed, and the entire foil-shaped copper base 4 and the end region of the foil-shaped aluminum base 3 are electrically connected to each other. To be joined. Here, it is assumed that the entire foil-shaped copper substrate 4 and the end region of the foil-shaped aluminum substrate 3 are bonded, but the present invention is not limited to this aspect, and the end region of the foil-shaped copper substrate 4 and the overlapping end regions of The area of the end region of the foil-shaped aluminum base 3 is determined so that the joint has a predetermined strength. Then, it is cut into a predetermined triangle.

Thereafter, as shown in FIG. 3, a foil-shaped aluminum substrate 2 having a predetermined size, the surface of which is roughened and an aluminum oxide film is formed on the surface, is cut out from the aluminum foil sheet, and further, Formed by cutting a predetermined triangular notch, and a foil-shaped aluminum base body 3 in which the surface of the joined body of the foil-shaped copper base body 4 and the foil-shaped aluminum base body 3 is not roughened, and a predetermined area, respectively. Are overlapped so that the end regions of the overlap. As described above, since the manufacturing by cutting is possible, the manufacturing is easy.

Next, the end portions of the foil-shaped aluminum base 2 having the surfaces that are superposed on each other are roughened and the aluminum oxide film is formed on the surfaces, and the foil-shaped aluminum whose surface is not roughened. The end regions of the base body 3 are joined by ultrasonic welding to form a weld joint 6 as shown in FIGS. 1 and 2. Bonding by ultrasonic welding removes the aluminum oxide film formed on the surface of the foil-shaped aluminum base 2, and the surface of the aluminum pure metal is rough so that the pure aluminum metals are electrically connected. The end region of the foil-like aluminum base 3 which is not surface-finished and the end region of the foil-like aluminum base 2 whose surface is roughened are joined. Here, the areas of the end regions of the foil-shaped aluminum base 3 and the end regions of the foil-shaped aluminum base 2 that overlap each other are determined so that the joint has a predetermined strength.

The thus-formed anode electrode 1 is obtained by cutting a foil-like aluminum substrate 2 having a roughened surface constituting a dielectric and having an aluminum oxide film formed on the surface, from an aluminum foil sheet. Therefore, the aluminum oxide film is not formed on the edge portion, and the edge of the foil-shaped aluminum substrate 2 having a roughened surface is used for use as the anode electrode of the polymer solid electrolytic capacitor. It is necessary to form an aluminum oxide film on the part by anodic oxidation.

FIG. 4 is a schematic diagram showing an anodizing method for forming an aluminum oxide film on the edge portion of a foil-shaped aluminum substrate 2 having a roughened surface.

As shown in FIG. 4, a foil-shaped aluminum substrate 2 having a roughened surface and a surface thereof are immersed in a chemical conversion solution 8 made of an aqueous solution of ammonium adipate contained in a stainless beaker 7. The anode electrode 1 is set so that a part of the non-roughened foil-shaped aluminum substrate 3 is immersed, and the voltage is adjusted so that the foil-shaped copper substrate 4 becomes positive and the stainless beaker 7 becomes negative. Is applied.

The working voltage can be appropriately determined according to the film thickness of the aluminum oxide film to be formed, and can be 10 nm.
When forming an aluminum oxide film having a film thickness of 1 to 1 μm, the voltage is usually set to several volts to 20 volts.

As a result, anodization is started, and the chemical conversion solution 8 rises due to the capillary phenomenon because the surface of the foil-shaped aluminum substrate 2 is roughened, but the surface of the foil-shaped aluminum substrate 3 is increased. Is not roughened, so that it cannot rise beyond the joint between the foil-shaped aluminum substrate 2 having a roughened surface and the foil-shaped aluminum substrate 3 having a roughened surface. Therefore, the formation solution 8 is surely prevented from coming into contact with the foil-shaped copper substrate 4 forming the lead electrode, and the surface including the edge portion is roughened. Further, the aluminum oxide film is formed only on the region of the foil-shaped aluminum base 3 which is joined to the foil-shaped aluminum base 2 whose surface is roughened and whose surface is not roughened.

The surface of the anode electrode 1 thus produced is roughened, and the entire surface of the foil-shaped aluminum substrate 2 on which the aluminum oxide film is formed is formed by a known method.
A cathode electrode is formed and a polymer solid electrolytic capacitor is obtained.

FIG. 5 is a schematic perspective view showing a polymer solid electrolytic capacitor with a part cut away for mainly explaining the layer structure and the like.

As shown in FIG. 5, the polymer solid electrolytic capacitor 10 includes a foil-shaped aluminum substrate 2 having a surface of an anode electrode 1 roughened and an aluminum oxide film (not shown) formed thereon. A cathode electrode 14 composed of a solid polymer electrolyte layer 11, a graphite paste layer 12 and a silver paste layer 13 is provided on the entire surface.

The solid polymer electrolyte layer 11 containing a conductive polymer compound is formed on the entire surface of the foil-shaped aluminum substrate 2 on which the surface of the anode electrode 1 is roughened and an aluminum oxide film is formed. The graphite paste layer 12 and the silver paste layer 13 are formed by oxidative polymerization or electrolytic oxidative polymerization, and are formed on the solid polymer electrolyte layer 11 by a screen printing method or a spray coating method.

The polymer solid electrolytic capacitor 10 thus manufactured is fixed between a pair of insulating resin substrates and is used by being built in the substrates.

FIG. 6 is a schematic sectional view of a substrate-incorporated polymer solid electrolytic capacitor when the polymer solid electrolytic capacitor is incorporated in an insulating resin substrate.

As shown in FIG. 6, the substrate built-in type polymer solid electrolytic capacitor 20 is provided with a first insulating resin substrate 21 and a second insulating resin substrate 22 which face each other, and has a first insulating property. The polymer solid electrolytic capacitor 10 is provided between the resin substrate 21 and the second insulating resin substrate 22.

A bank 23 having a height larger than the thickness of the solid polymer electrolytic capacitor 10 is formed on the first insulative resin substrate 21 along two sides facing each other. The molecular solid electrolytic capacitor 10 is positioned at a predetermined position on one surface of the first insulating resin substrate 21 between the banks 23, and is fixed by an adhesive 29.

As shown in the figure, the bank 23 is made of an insulating resin substrate made of the same material as the first insulating resin substrate 21 and the second insulating resin substrate 22, and a portion of a predetermined area is left on the peripheral portion thereof. To form a frame-shaped insulating resin substrate, and using the same adhesive material (prepreg) as the first insulating resin substrate 21 and the second insulating resin substrate 22 to form a frame. It is formed by fixing a strip-shaped insulating resin substrate to the first insulating resin substrate.

A wiring pattern 24 is formed on the other surface of the first insulating resin substrate 21, and a plurality of through holes 25A, 25B are formed in the first insulating resin substrate 21.

The polymer solid electrolytic capacitor 10 is positioned at a predetermined position on the first insulating resin substrate 21,
When fixed on the first insulating resin substrate 21 with the adhesive 29, the flat second insulating resin substrate is brought into contact with the bank 23 formed on the first insulating resin substrate 21. 22 is covered with the first insulating resin substrate 21 and the second insulating resin substrate 22 using the same adhesive (prepreg) as the first insulating resin substrate 21 and the second insulating resin substrate 21. The substrate 22 is adhered and fixed.

A wiring pattern 27 is formed on the upper surface of the second insulating resin substrate 22, and the second insulating resin substrate 22 is formed.
Also, a plurality of through holes 28A and 28B are formed.

When the first insulative resin substrate 21 and the second insulative resin substrate 22 are integrated, the respective through holes correspond in position. The resin 26 is injected, for example, so as to temporarily close the through holes 25A formed in the first insulating resin substrate 21 and the plurality of through holes 28A formed in the second insulating resin substrate 22,
It is then cured. After the resin 26 is hardened, the through holes 25A and 28A are processed so as to penetrate therethrough. The resin 26 functions as a reinforcing member for the element. As a result, the substrate-embedded polymer solid electrolytic capacitor 20 is obtained.

Further, electronic components 30 are mounted on the lower surface of the first insulating resin substrate 21 and the upper surface of the second insulating resin substrate 22, and their contacts are connected to the wiring pattern 2.
4 and 27 are electrically connected.

The first insulating resin substrate 21 and the second insulating resin substrate 22 are through holes at positions corresponding to the foil-shaped copper substrate 4 of the anode electrode 1 of the polymer solid polymer electrolytic capacitor 10, respectively. 28B, a through hole 25B is provided at a position corresponding to the cathode electrode 14, the copper substrate 4 forming the anode electrode 1 of the polymer solid electrolytic capacitor 10 via the through hole 28B, and the cathode electrode via the through hole 25B. 14 is configured to be visually confirmed.

Through the through holes 25A, 28A, 28B, the copper substrate 4 forming the anode electrode 1 of the solid polymer electrolytic capacitor 10 is connected to the wiring pattern 24 or the second wiring pattern 24 formed on the first insulating resin substrate 21. Insulating resin substrate 2
2 is electrically connected to the wiring pattern 27 formed in 2, and the cathode electrode 14 of the polymer solid electrolytic capacitor 10 is
The first insulating resin substrate 2 through the through hole 25B.
It is electrically connected to the wiring pattern 24 formed on No. 1 or the wiring pattern 27 formed on the second insulating resin substrate 22.

In FIG. 6, the first insulating resin substrate 2
The wiring pattern 24 formed in 1 and the foil-shaped copper substrate 4 forming the anode electrode 1 of the polymer solid electrolytic capacitor 10 are electrically connected by the solder 31 via the through hole 28B, and On the other hand, the wiring pattern 24 formed on the first insulating resin substrate 21 and the cathode electrode 14 of the polymer solid electrolytic capacitor 10 are connected to the through hole 2
An example in which they are electrically connected by the conductive resin 32 filled in 5B is shown.

Anode electrode 1 of polymer solid electrolytic capacitor
Is a foil-shaped aluminum base 2 having a roughened surface and an aluminum oxide film which is an insulating oxide film formed thereon, a foil-shaped aluminum base 3 having a non-roughened surface, and a metal conductor. As a foil-shaped copper substrate 4, the surface of which is roughened, and one end region of the foil-shaped aluminum substrate 2 having an aluminum oxide film formed on the surface, and the surface of which is not roughened The one end region of the aluminum base 3 is joined by ultrasonic welding so that the valve metals are electrically connected to each other, and the other end of the foil-like aluminum base 3 whose surface is not roughened. The partial region and one end region of the foil-shaped copper substrate 4 are joined by ultrasonic welding so that the metals are electrically connected to each other, and the surface is roughened. Anodizing on the edge of the substrate 2. Therefore, when the aluminum oxide film is formed, one of the entire foil-shaped aluminum substrate 2 whose surface is roughened and one of the foil-shaped aluminum substrate 3 whose surface is not roughened are formed in the chemical conversion solution 8. The anode electrode 1 is set so that the parts are immersed, and a voltage is applied so that the foil-shaped copper substrate 4 becomes positive and the stainless beaker 7 becomes negative.

As a result, the chemical conversion solution 8 rises due to the capillary phenomenon because the surface of the foil-shaped aluminum substrate 2 is roughened, but the surface of the foil-shaped aluminum substrate 3 is roughened. Since it does not exist, it does not rise beyond the joint between the foil-shaped aluminum substrate 2 whose surface is roughened and the foil-shaped aluminum substrate 3 whose surface is not roughened. The formation solution 8 is surely prevented from coming into contact with the foil-shaped copper substrate 4 constituting the above, and the surface including the edge portion is roughened. The aluminum oxide film is formed only on the region of the foil-shaped aluminum substrate 3 where the surface joined to the foil-shaped aluminum substrate 2 is not roughened.

Therefore, the electrical characteristics of the anode electrode 1 including the lead electrode made of the foil-shaped copper substrate 4 and the roughened surface of the foil-shaped aluminum substrate 2 covered with the aluminum oxide film are provided. It is possible to obtain an excellent polymer solid electrolytic capacitor 10, and the polymer solid electrolytic capacitor 10 thus obtained can be made sufficiently thin, so that it is suitable for being incorporated in a circuit board, and is desirable. 2 with a built-in polymer solid electrolytic capacitor
It is possible to create 0.

Further, the bank 23 is provided on the first insulating resin substrate 22, and the solid polymer electrolytic capacitor 1 is used to manufacture the substrate-embedded solid polymer electrolytic capacitor 20.
0 is contained in a closed space formed by the first insulating resin substrate 21, the bank 23 and the second insulating resin substrate 22, so that the second insulating resin substrate 22 is When the electrolytic capacitor 10 and the first insulating resin substrate 21 are integrated with each other, excessive pressure is not applied to the polymer solid electrolytic capacitor, and therefore, the aluminum oxide formed on the surface of the foil-shaped aluminum substrate 2 is prevented. It is possible to surely prevent the film from being broken and the aluminum acting as the anode and the solid polymer electrolyte layer 11 to come into contact with each other to cause a short circuit when the current is applied.

In the illustrated example, the wiring patterns 24, 2
Although 7 is formed on the surface opposite to the surface of the insulating resin substrate on which the polymer solid electrolytic capacitor 10 is installed, it may be formed on the same surface depending on the purpose and application.

FIG. 7 is a schematic plan view showing another example of the anode electrode of the polymer solid electrolytic capacitor of the present invention.

Aluminum is used as a valve metal capable of forming an insulating oxide film, and as shown in FIG.
The anode electrode 41 of the polymer solid electrolytic capacitor has a roughened surface (enlarged surface) and a foil-shaped aluminum base 42 on which an aluminum oxide film which is an insulating oxide film is formed, and a rough surface. It is provided with a foil-shaped aluminum substrate 43 which is not formed and a foil-shaped copper substrate 44 as a metal conductor which constitutes a lead electrode.

At this time, the aluminum base 42 has a rectangular shape, and has a rectangular notch having two sides each having a length shorter than the entire length of one side of the rectangle at one corner where the one side of the rectangle intersects. The aluminum base 43 and the copper base 44 are sequentially joined to one end of the cutout. In this case, since the edge portion 42e of the aluminum substrate 42 is electrolytically oxidized later, when the aluminum substrate 42 is immersed in the chemical conversion liquid, it is necessary to prevent the chemical conversion liquid from soaking up in the copper substrate 44. The whole of 44 is superposed on the end portion of the aluminum base body 43, but the overlapping portion is such that the horizontal plane is located above the edge portion 42e of the aluminum base body 42 when the horizontal plane of the chemical conversion liquid is used as a reference. Need to The same applies to the case where the end portions of the aluminum base 43 and the copper base 44 are overlapped with each other, and the copper base 4 including the overlapping portion is included.
4 needs to be located above the edge portion 42e.

Normally, it is soaked in the chemical conversion liquid as it is in the vertical relationship of FIG. 7, and therefore it is preferable to make it as shown in the drawing, but it is not necessarily limited to this depending on the dipping method.

Further, in FIG. 7, the joined body of the aluminum base body 43 and the copper base body 44 is joined to the other side of the cutout portion at a constant interval so as to be parallel to one side of the cutout portion of the aluminum base body 42. However, it is not limited to this as long as the aluminum base 42 and the copper base 44 do not come into direct contact with each other.

As shown in FIG. 7, the surface is roughened in one end region of the notch of the foil-shaped aluminum substrate 42 having the surface roughened and the aluminum oxide film formed on the surface. One end region of the non-foil-shaped aluminum base 43 is joined by ultrasonic welding so that the valve metals are electrically connected to each other, and the surface is not roughened. One end region of the foil-shaped copper base 44 is joined to the other end region of 43 by ultrasonic welding so that the metals are electrically connected to each other, and the two welded joints 45, 46 are joined. Are formed.

When forming the anode electrode of FIG.
It can be performed in the same manner as in the case of 2. Specifically, FIG.
In, a joined body of a foil-shaped copper base and a foil-shaped aluminum base whose foil-shaped surface is not roughened is formed and cut into a predetermined rectangular shape, and the foil-shaped surface is roughened. The same can be done except that the notch of the foil-shaped aluminum substrate having the aluminum oxide film formed on the surface is made into a square. Further, the aluminum oxide film on the edge portion can be formed in the same manner by setting the liquid surface of the chemical conversion liquid to a predetermined value.

Further, the polymer solid electrolytic capacitor can be manufactured in the same manner as in the case of FIGS. 1 and 2, and also in the case of the substrate built-in type.

According to the present invention, in a foil-shaped aluminum substrate whose surface is not roughened, an insulating property is provided over the entire circumference in the vicinity of a welded joint with the foil-shaped aluminum substrate whose surface is roughened. And a hydrophobic region may be formed.

Specifically, in the embodiment shown in FIGS. 1 and 2, the surface of the aluminum base 3 in the form of foil whose surface is not roughened is in the vicinity of the welded joint portion 6, and in the embodiment shown in FIG. A region having an insulating property and a hydrophobic property may be formed in the vicinity of the welded joint portion 46 of the non-planarized foil-shaped aluminum substrate 43 over the entire circumference.

The insulating and hydrophobic region may be formed by applying an amorphous fluororesin or the like to a foil-shaped aluminum substrate whose surface is not roughened, and is formed before anodization. If formed, it may be formed at any time.

As described above, the foil-shaped aluminum substrate whose surface in the vicinity of the welded joint is not roughened is formed with a region having an insulating property and a hydrophobic property over the entire circumference to form a foil-shaped aluminum substrate. In addition to the fact that the surface of the foil-like aluminum base material that is interposed between the copper base material and the copper base material is not roughened, the chemical conversion solution rises above the insulating and hydrophobic regions. Therefore, it is possible to more reliably prevent the chemical conversion solution from coming into contact with the foil-shaped copper substrate that constitutes the lead electrode, and the foil-shaped aluminum substrate whose surface including the edge portion is roughened. An aluminum oxide film can be formed only on the entire surface of 42. Therefore, the foil-shaped copper substrate that constitutes the lead electrode,
By providing a contact with another electronic component mounted on the circuit board, a polymer solid electrolytic capacitor having desired electrical characteristics can be built in the circuit board.

In addition, when the solid polymer electrolyte layer is formed by chemical oxidative bonding, a foil-like aluminum whose surface is not roughened along the aluminum oxide film roughened by the capillary phenomenon. The raw material monomer solution and the oxidizer solution that progress toward the substrate have an insulating property formed over the entire circumference of the foil-shaped aluminum substrate near the welded joint, and the progress is hindered by the hydrophobic region. Therefore, it is possible to reliably prevent the raw material monomer solution and the oxidant solution from traveling beyond the insulating and hydrophobic region and reaching the foil-shaped copper foil.

In the above, an example in which aluminum is used as the valve metal and copper is used as the conductive metal has been described, but these will be described in detail below.

In the present invention, the valve metal substrate is formed of a metal or alloy selected from the group consisting of metals having an insulating oxide film forming ability and alloys thereof. Preferred valve metals include one metal selected from the group consisting of aluminum, tantalum, titanium, niobium and zirconium, or an alloy of two or more metals, among which aluminum and tantalum are particularly preferred. The anode electrode is formed by processing these metals or alloys into a foil shape.

In the present invention, the material of the conductive metal is not particularly limited as long as it is a metal or alloy having conductivity, but preferably solder connection is possible, and particularly copper or brass. , Nickel, zinc and chromium are preferably selected from the group consisting of one kind of metal or an alloy of two or more kinds of metals. Among these, electrical characteristics, workability in the subsequent process, cost, etc. From the viewpoint of, copper is most preferably used.

In the present invention, the solid polymer electrolyte layer is
Contains a conductive polymer compound, preferably by chemical oxidative polymerization or electrolytic oxidative polymerization, the surface is roughened,
It is formed on a foil-shaped valve metal substrate on which an insulating oxide film is formed.

When the solid polymer electrolyte layer is formed by chemical oxidative polymerization, specifically, the surface of the solid polymer electrolyte layer is roughened as follows,
It is formed on a foil-shaped valve metal substrate on which an insulating oxide film is formed.

First, a solution containing 0.001 to 2.0 mol / liter of an oxidant is provided only on a foil-shaped valve metal substrate having a roughened surface and an insulating oxide film formed thereon, or further. Then, a solution containing a compound that gives a dopant species is uniformly applied by a method such as coating or spraying.

Then preferably at least 0.01
A solution containing the raw material monomer of the conductive polymer compound at a mol / liter or the raw material monomer of the conductive polymer compound itself is brought into direct contact with the insulating oxide film formed on the surface of the foil-shaped valve metal substrate. As a result, the raw material monomers are polymerized to synthesize the conductive polymer compound, and the solid polymer electrolyte layer made of the conductive polymer compound is formed on the insulating oxide film formed on the surface of the foil metal valve substrate. It is formed.

In the present invention, the conductive polymer compound contained in the solid polymer electrolyte layer is a substituted or unsubstituted π-conjugated heterocyclic compound, a conjugated aromatic compound and a heteroatom-containing conjugated aromatic compound. A compound selected from the group consisting of is preferably a raw material monomer, and among these, a substituted or unsubstituted π-conjugated heterocyclic compound is preferably a conductive polymer compound having a raw material monomer, and further, A conductive polymer compound selected from the group consisting of polyaniline, polypyrrole, polythiophene, polyfuran and derivatives thereof, particularly polyaniline, polypyrrole and polyethylenedioxythiophene are preferably used.

In the present invention, specific examples of the raw material monomer of the conductive polymer compound preferably used in the solid polymer electrolyte layer include unsubstituted aniline, alkylanilines, alkoxyanilines, haloanilines and o-phenylenediamine. 2,6-dialkylanilines,
2,5-dialkoxyanilines, 4,4′-diaminodiphenyl ether, pyrrole, 3-methylpyrrole,
3-ethylpyrrole, 3-propylpyrrole, thiophene, 3-methylthiophene, 3-ethylthiophene,
3,4-ethylenedioxythiophene etc. can be mentioned.

In the present invention, the oxidizing agent used in the chemical oxidative polymerization is not particularly limited, but examples thereof include halides such as iodine, bromine and bromine iodide, silicon pentafluoride and antimony pentafluoride. Metal halides such as silicon tetrafluoride, phosphorus pentachloride, phosphorus pentafluoride, aluminum chloride and molybdenum chloride, protonic acids such as sulfuric acid, nitric acid, fluorosulfuric acid, trifluoromethane sulfuric acid and chlorosulfuric acid, sulfur trioxide, nitrogen dioxide Oxygen compounds such as sodium persulfate, potassium persulfate, persulfates such as ammonium persulfate, hydrogen peroxide, potassium permanganate,
Peroxides such as peracetic acid, difluorosulfonyl peroxide are used as oxidants.

[0084] In the present invention, if necessary, as the compound providing dopant species to be added to the oxidizing agent, for _{example, LiPF 6, LiAsF 6, NaPF} 6, KPF 6,
Anions such as KAsF ₆ are hexafluoroline anion and hexafluoroarsenic anion, and cations are alkali metal cations such as lithium, sodium and potassium salts, LiBF ₄ , NaBF ₄ , NH ₄ BF ₄ , (C
_{H 3) 4 NBF 4, (} n-C 4 H 9) 4 NBF 4 tetrafluoride perborate salt compounds such as, p- toluenesulfonic acid, p- ethylbenzene sulfonic acid, p- hydroxybenzene sulfonic acid, dodecylbenzene sulfonic acid , Sulfonic acids such as methyl sulfonic acid, dodecyl sulfonic acid, benzene sulfonic acid, β-naphthalene sulfonic acid or derivatives thereof, sodium butyl naphthalene sulfonate, 2,6-
Salts of sulfonic acids such as sodium naphthalenedisulfonate, sodium toluenesulfonate, tetrabutylammonium toluenesulfonate and its derivatives, ferric chloride, ferric bromide, cupric chloride, cupric bromide and other metals Perhalogen acids such as halides, hydrochloric acid, hydrogen bromide, hydrogen iodide, sulfuric acid, phosphoric acid, nitric acid or their alkali metal salts, alkaline earth metal salts or ammonium salts, perchloric acid, sodium perchlorate or the like. Hydrohalic acids such as salts, inorganic acids or salts thereof, acetic acid, oxalic acid, formic acid, butyric acid, succinic acid, lactic acid, citric acid, phthalic acid, maleic acid, benzoic acid, salicylic acid, nicotinic acid and other mono- or dicarboxylic acids , Aromatic heterocyclic carboxylic acids, halogenated carboxylic acids such as trifluoroacetic acid and their Mention may be made of carboxylic acids such as.

In the present invention, the compound capable of providing these oxidizing agent and dopant species is used in the form of a suitable solution dissolved in water, an organic solvent or the like. The solvents may be used alone or in combination of two or more. The mixed solvent is also effective in increasing the solubility of the compound that provides the dopant species. As the mixed solvent, those having compatibility with each other and those having compatibility with the compound capable of providing the oxidizing agent and the dopant species are preferable. Specific examples of the solvent include organic amides, sulfur-containing compounds, esters, and alcohols.

On the other hand, when the solid polymer electrolyte layer is formed on the foil-shaped valve metal substrate having the surface roughened by the electrolytic oxidation polymerization and the insulating oxide film is formed, as is known in the art. The solid polymer electrolyte layer is formed by immersing the conductive underlayer as a working electrode, together with the counter electrode, in an electrolyte solution containing a raw material monomer of a conductive polymer compound and a supporting electrolyte and supplying an electric current. It

Specifically, first, a thin conductive underlayer is formed on a foil-shaped valve metal substrate having a roughened surface and an insulating oxide film formed thereon, preferably by chemical oxidative polymerization. It is formed. The thickness of the conductive underlayer is controlled by controlling the number of times of polymerization under constant polymerization conditions. The number of polymerizations is determined by the type of raw material monomer.

The conductive underlayer may be composed of any of metal, conductive metal oxide and conductive polymer compound, but is preferably composed of conductive polymer compound. As a raw material monomer for forming the conductive underlayer, a raw material monomer used for chemical oxidative polymerization can be used, and the conductive polymer compound contained in the conductive underlayer is a solid formed by chemical oxidative polymerization. It is the same as the conductive polymer compound contained in the polymer electrolyte layer.

When ethylenedioxythiophene or pyrrole is used as a raw material monomer for forming the conductive underlayer, the conductive polymer produced when the polymer solid electrolyte layer is formed only by chemical oxidative polymerization is used. 10% of the total amount
The conductive underlayer may be formed by converting the number of times of polymerization so that the conditions are such that about 30% (mass percentage) of the conductive polymer is generated.

After that, the conductive underlayer is used as a working electrode, together with the counter electrode, is immersed in an electrolytic solution containing a raw material monomer of the conductive polymer compound and a supporting electrolyte, and an electric current is supplied to the conductive underlayer. A solid polymer electrolyte layer is formed thereon.

If necessary, various additives can be added to the electrolytic solution in addition to the raw material monomer of the conductive polymer compound and the supporting electrolyte.

The conductive polymer compound that can be used in the solid polymer electrolyte layer is the same as the conductive polymer compound used in the conductive underlayer, that is, the conductive polymer compound used in the chemical oxidative polymerization. And a conductive polymer compound using a compound selected from the group consisting of a substituted or unsubstituted π-conjugated heterocyclic compound, a conjugated aromatic compound and a heteroatom-containing conjugated aromatic compound as a raw material monomer is preferable. Of these, conductive polymer compounds having a substituted or unsubstituted π-conjugated heterocyclic compound as a raw material monomer are preferable, and further selected from the group consisting of polyaniline, polypyrrole, polythiophene, polyfuran and derivatives thereof. Conductive polymer compounds, especially polyaniline, polypyrrole, and polyethylenedioxythiophene are preferred. Used well.

The supporting electrolyte is selected according to the monomer and the solvent to be combined. Specific examples of the supporting electrolyte include, for example, basic compounds such as sodium hydroxide, potassium hydroxide, ammonium hydroxide and carbonic acid. Sodium, sodium hydrogencarbonate, etc., acidic compounds include sulfuric acid, hydrochloric acid, nitric acid, hydrogen bromide, perchloric acid, trifluoroacetic acid, sulfonic acid, etc., and salts include sodium chloride, sodium bromide, iodide. Potassium, potassium chloride, potassium nitrate, sodium periodate, sodium perchlorate, lithium perchlorate, ammonium iodide,
Ammonium chloride, boron tetrafluoride compound, tetramethylammonium chloride, tetraethylammonium chloride, tetramethylammonium bromide,
Examples thereof include tetraethylammonium bromide, tetraethylammonium perchloride, tetrabutylammonium perchloride, tetramethylammonium, D-toluenesulfonic acid chloride, polydisalicylic acid triethylamine, and 10-camphorsulfonic acid sodium salt.

In the present invention, the dissolved concentration of the supporting electrolyte may be set so that a desired current density can be obtained.
Although not particularly limited, it is generally set within the range of 0.05 to 1.0 mol / liter.

In the present invention, the solvent used in the electrolytic oxidative polymerization is not particularly limited.
It can be appropriately selected from water, a protic solvent, an aprotic solvent or a mixed solvent in which two or more kinds of these solvents are mixed. As the mixed solvent, those having compatibility with each other and those having compatibility with the monomer and the supporting electrolyte can be preferably used.

Specific examples of the protic solvent used in the present invention include formic acid, acetic acid, propionic acid, methanol, ethanol, n-propanol, isopropanol, tert-butyl alcohol, methyl cellosolve,
Examples thereof include diethylamine and ethylenediamine.

Specific examples of the aprotic solvent include methylene chloride, 1,2-dichloroethane, carbon disulfide, acetonitrile, acetone, propylene carbonate, nitromethane, nitrobenzene, ethyl acetate, diethyl ether, tetrahydrofuran, dimethoxyethane, Dioxane, N, N-dimethylacetamide, N,
Examples thereof include N-dimethylformamide, pyridine, dimethyl sulfoxide and the like.

In the present invention, by electrolytic oxidative polymerization,
When forming the solid polymer electrolyte layer, any of a constant voltage method, a constant current method, and a potential sweep method may be used. Further, in the process of electrolytic oxidative polymerization, a constant voltage method and a constant current method may be combined to polymerize the conductive polymer compound. The current density is not particularly limited, but the maximum is 500 mA / cm ²
It is a degree.

In the present invention, at the time of chemical oxidative polymerization or electrolytic oxidative polymerization, the conductive polymer compound may be polymerized while being irradiated with ultrasonic waves as disclosed in JP-A-2000-100665. When the conductive polymer compound is polymerized while being irradiated with ultrasonic waves, it is possible to improve the film quality of the obtained solid polymer electrolyte layer.

In the present invention, the maximum thickness of the solid polymer electrolyte layer is not particularly limited as long as it can completely fill the irregularities on the surface of the anode electrode formed by etching or the like. Generally 5 to 1
It is about 00 μm.

In the present invention, the polymer solid electrolytic capacitor further comprises a conductor layer functioning as a cathode on the solid polymer electrolyte layer. As the conductor layer, a graphite paste layer and a silver paste layer are provided. The graphite paste layer and the silver paste layer can be provided,
It can be formed by a screen printing method, a spray coating method, or the like. Although the cathode of the polymer solid electrolytic capacitor can be formed only by the silver paste layer,
When the graphite paste layer is formed, silver migration can be prevented by using only the silver paste layer as compared with the case where the cathode of the polymer solid electrolytic capacitor is formed.

When forming the graphite paste layer and the silver paste layer as the cathode, a portion corresponding to the foil-shaped valve metal substrate on which the insulating oxide film is formed by roughening the surface with a metal mask or the like is used. The graphite paste layer and the silver paste layer are formed only on the portion corresponding to the foil-shaped valve metal substrate on which the insulating oxide film is formed by masking the removed portion and roughening the surface.

In the present invention, the material of the insulating resin substrate is not particularly limited, but as the resin, a phenol resin, a polyimide resin, an epoxy resin, a polyester resin or the like having good adhesiveness and solvent resistance can be used. it can.

In the present invention, as the resin or adhesive used between the insulating resin substrates for reinforcing the element, one having high thixotropy is preferable in view of workability and shape retention immediately after coating. Desirable, considering shrinkage and heat resistance after curing, epoxy resin or polyester resin,
Polyphenylene sulfide resin, silicone resin and the like are preferable.

When using a prepreg in an insulating resin substrate or a bank, the prepregs can be bonded to each other.

As the conductive adhesive, an adhesive material such as polyester resin, acrylic resin, epoxy resin or polyamide resin is used as a resin material, and a conductive material such as metal such as gold, silver, copper or palladium, or carbon. It can be used as a mixture of dispersed and mixed. The conductivity of the conductive adhesive is 100 S · cm or more (the upper limit is usually about 1000 S · cm).

[0107]

EXAMPLES Examples and comparative examples will be given below in order to further clarify the effects of the present invention.

Example 1 A polymer solid electrolytic capacitor having a solid polymer electrolyte layer was produced as follows.

As shown in FIG. 3, from the copper foil sheet,
A copper foil with a thickness of 60 μm cut out in a size of 2 mm × 28 mm and an aluminum foil sheet cut out in a size of 7 mm × 28 mm and a thickness of 70 μm without roughening treatment.
The aluminum foils of 1 are overlapped so that each one end area overlaps by 2 mm, and the overlapping portions of each one end area are joined by a 40 kHz-ultrasonic welding machine manufactured by Branson Business Headquarters of Japan Emerson Co., Ltd. At the same time, they were electrically connected to each other to form a joined body of a copper foil and an aluminum foil that had not been roughened.

Next, from this joined body, the length of three sides is 1
Triangles of 4 mm, 10 mm and 10 mm were cut out.

Next, a rectangular aluminum foil having a size of 18 mm × 20 mm was cut out from an aluminum foil sheet having a thickness of 100 μm and having an aluminum oxide film formed thereon and subjected to surface roughening treatment, and further, in this corner, Cut out a length of 5.8 mm from each of the two sides to form a triangular notch with three sides of 5.8 mm, 5.8 mm, and 8.2 mm, and the end area of this notch is A bonded product of a copper foil and a non-roughened aluminum foil so that the triangular bonded product cut out as described above overlaps the end region of the un-roughened aluminum foil by 3 mm. And the overlapped area of each end area is made by Branson Business Headquarters of Japan Emerson Co., Ltd.
kHz-Joined and electrically connected by an ultrasonic welding machine to form a joined body of copper foil, aluminum foil not roughened and aluminum foil roughened did. In this case, the total size is 1
It was trimmed to have a size of 8 mm x 20 mm.

Further, as shown in FIG. 4, an aluminum oxide film was formed in an aqueous solution of ammonium adipate adjusted to a pH of 6.0 at a concentration of 7% (mass percentage), and roughening treatment was performed. The joined body thus obtained was set in an aqueous solution of ammonium adipate so that the aluminum foil subjected to was completely immersed. On this occasion,
Part of the aluminum foil that has not been roughened,
Although immersed in an aqueous ammonium adipate solution, the copper foil was not contacted with the aqueous ammonium adipate solution.

The bonded body side was used as an anode and the formation current density was 50.
The surface of the aluminum foil dipped in the aqueous solution of ammonium adipate was oxidized under conditions of 100 to 100 mA / cm ² and a formation voltage of 23 V to form an aluminum oxide film, thereby preparing an anode electrode.

Then, the produced anode electrode was pulled up from an aqueous solution of ammonium adipate, and the solid polymer electrolyte layer made of polypyrrole was chemically oxidized and polymerized on the surface of the aluminum foil on which the anode electrode was roughened. Was formed.

Here, the solid polymer electrolyte layer made of polypyrrole was prepared by distilling and purifying 0.1 mol / liter of pyrrole monomer, 0.1 mol / liter of sodium alkylnaphthalenesulfonate and 0.05 mol / liter of sulfuric acid. The anode electrode was set so that only the aluminum foil on which the aluminum oxide film had been roughened and which had been subjected to the surface roughening treatment was immersed in the ethanol-water mixed solution cell containing iron (III), and the mixture was stirred for 30 minutes. Then, the chemical oxidative polymerization was allowed to proceed, and the same operation was repeated three times to produce the product. As a result, a solid polymer electrolyte layer having a maximum thickness of about 50 μm was formed.

Further, a carbon paste is applied to the surface of the solid polymer electrolyte layer thus obtained, and then a silver paste is applied to the surface of the carbon paste to form a cathode electrode. Was produced.

On the other hand, a copper foil having a thickness of 18 μm and having a thickness of 1 mm and having a size of 3 cm × 4 cm is attached on both sides.
A glass cloth-containing epoxy resin insulating substrate was prepared as follows.

In order to form an electric circuit on the copper foil surface,
The unnecessary portion of the copper foil was chemically etched to form a predetermined wiring pattern. However, all the copper foil on the surface of the substrate on which the polymer solid electrolytic capacitor was to be fixed was chemically etched and removed.

Further, at positions of the glass cloth-containing epoxy resin insulating substrate corresponding to the anode electrode and the cathode electrode of the polymer solid electrolytic capacitor to be incorporated, respectively,
3μm is formed by electroless plating on the through hole and the etched copper foil pattern.
Nickel plating is applied, and 0.08 on it
It was plated with μm gold.

Through holes for various electronic components to be mounted were further formed on the glass cloth-containing epoxy resin insulating substrate.

On the other hand, a substrate having a thickness of 100 μm and made of the same glass cloth-containing epoxy resin as the two substrates is 3 cm ×
The substrate was processed into a dimension of 4 cm, and the inner portion was removed by punching, leaving a region with a width of 3 mm around the processed substrate, to prepare a bank forming substrate.

Further, two epoxy prepregs having a thickness of 50 μm and made of the same glass cloth-containing epoxy resin as the two substrates were processed into a size of 3 cm × 4 cm, leaving a region of 3 mm width around the processed substrates. The inner part was removed by punching.

A bank-forming substrate, which had been punched and had its inner portion removed, and a surface of the glass cloth-containing epoxy resin insulating substrate from which one copper foil had been removed, were processed as described above to a thickness of 50 μm. Through one of the epoxy prepregs, and using a vacuum hot press machine under pressure and reduced pressure for 40 minutes,
Hold at 175 ° C to cure the epoxy prepreg,
The glass cloth-containing epoxy resin insulating substrate and the substrate from which the inner portion was removed were fixed to obtain an insulating resin substrate having a recess space.

On the surface of the two glass cloth-containing epoxy resin insulating substrates on which the other copper foil was removed, the anode electrode and the cathode electrode of the polymer solid electrolytic capacitor were formed in the through holes formed in the insulating resin substrate. The polymer solid electrolytic capacitor was fixed using a silicone adhesive so that the polymer solid electrolytic capacitor was located at the corresponding position.

Then, on a glass cloth-containing epoxy resin insulating substrate to which a polymer solid electrolytic capacitor was fixed,
A glass solid-containing epoxy resin insulating substrate having a recessed space formed on one surface, a polymer solid electrolytic capacitor is placed in the recessed space through the other epoxy prepreg having a thickness of 50 μm processed as described above. So as to be housed in the container.

The two insulative resin substrates thus adhered to each other were held at 175 ° C. for 40 minutes under pressure and reduced pressure using a vacuum hot press machine to cure the epoxy prepreg, and The glass cloth-containing epoxy resin insulating substrates were fixed together.

After cooling the glass cloth-containing epoxy resin insulating substrate, the glass cloth-containing epoxy resin insulating substrate is formed on the surface of the glass cloth-containing epoxy resin insulating substrate through the through holes formed in each of the glass cloth-containing epoxy resin insulating substrates. The wiring pattern and the lead electrode made of copper foil of the anode electrode of the built-in polymer solid electrolytic capacitor are electrically connected by solder, and the cathode electrode is electrically connected by using a conductive adhesive. Sample No. of polymer solid electrolytic capacitor with built-in substrate Got 1.

Sample No. 1 of the polymer solid electrolytic capacitor with a built-in substrate manufactured in this way. The electrical characteristics of No. 1 were evaluated using an impedance analyzer 4294A manufactured by Agilent Technologies.

As a result, the electrostatic capacity at 120 Hz is 224.
μF, ESR (equivalent series resistance) at 100kHz is 2
It was 3 mΩ. The leakage current (5 minutes value) when a voltage of 10 V was applied at room temperature was 0.15 μA.

Further, the sample No. of the polymer solid electrolytic capacitor with a built-in substrate was used. 1 under the constant temperature condition of 125 ° C,
When left for 1000 hours and evaluated for electrical characteristics in exactly the same manner, the electrostatic capacity at 120 Hz is 2
It was 20 μF and the ESR at 100 kHz was 25 mΩ. Furthermore, the leakage current (5 minutes value) when a voltage of 10 V was applied at room temperature was 0.20 μA.

Comparative Example 1 In Example 1, the entire joined body of the copper foil, the aluminum foil not subjected to the surface roughening treatment and the aluminum foil on which the aluminum oxide film was formed and which was subjected to the surface roughening treatment was used. The size is the same as in Example 1, and the copper foil sheet (2
0 mm × 3 mm) and an aluminum foil sheet (20 mm × 8 mm) that has not been roughened are joined in a strip shape with an overlap of 3 mm as shown in FIG. 8 and are not roughened. An aluminum foil sheet and an aluminum foil sheet (20 mm x 13 mm) on which an aluminum oxide film has been formed and which has been subjected to a surface-roughening treatment are joined with an overlap of 3 mm. Sample No. of capacitor 2 was produced. When the characteristics were examined in the same manner as in Example 1, the electrostatic capacity was 144 μF and the ESR was
Is 25 mΩ, the leakage current is 0.14 μA, the capacitance after standing is 143 μF, the ESR is 25 mΩ, the leakage current is
It was 0.15 μA.

It was found that the capacity of Example 1 can be made larger than that of Comparative Example 1 by using the anode electrode having the same overall size as that of Comparative Example 1.

Example 2 In the same manner as in Example 1, except that the anode electrode was as shown in FIG. Got 3.

In this case, copper foil (3 mm × 60 mm size, 6 mm
(0 μm thickness) and an aluminum foil (13 mm × 60 mm size, 70 μm thickness) which has not been subjected to a surface roughening treatment were joined in the same manner as in Example 1 and then cut out into a size of 13 mm × 6 mm. . However, in this case, the copper foil had its end portions overlapped with the aluminum foil not subjected to the surface roughening treatment, and the overlap was 3 mm.

Also, an aluminum oxide film is formed,
Roughened aluminum foil (100 μm
The thickness was 18 mm × 20 mm, and 5 mm × 7 mm cutouts were used.

After joining (overlapping 3 mm), between the aluminum foil on which the aluminum oxide film has been formed and which has been subjected to the surface-roughening treatment and the aluminum foil which has not been subjected to the surface-roughening treatment. As shown in FIG. 7, a gap of about 1 mm is provided.

This substrate built-in type solid electrolytic capacitor No.
When the characteristics of No. 3 were examined in the same manner as in Example 1, the electrostatic capacity was 210 μF, the ESR was 20 mΩ, the leakage current was 0.21 μA, and the electrostatic capacity after leaving was 208 μF,
The ESR was 19 mΩ and the leakage current was 0.24 μA.

The anode electrode of this one, including the protrusion,
Compared to the dimension value of the anode electrode of Comparative Example 1 of 18 mm × 20 mm,
Although a protrusion of 5 mm x 6 mm is generated, it is excellent in terms of increasing the capacity. Further, the protrusion has a size that can be sufficiently absorbed when the substrate is built in.

[0139]

According to the present invention, since the area of the insulating oxide film of the anode electrode can be increased, the capacity of the capacitor can be increased. When this polymer solid electrolytic capacitor is used by incorporating it in a substrate, a large area can be used for mounting, the strength of the lead portion is sufficient, and high integration and high density mounting can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an example of an anode electrode of a polymer solid electrolytic capacitor of the present invention.

FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG.

FIG. 3 is a schematic configuration diagram showing a method for manufacturing an anode electrode of the polymer solid electrolytic capacitor of FIG.

FIG. 4 is a schematic configuration diagram showing an anodizing method for forming an aluminum oxide film on an edge portion of a foil-shaped aluminum substrate having a roughened surface.

FIG. 5 is a schematic perspective view mainly showing a polymer solid electrolytic capacitor with a part cut away for explaining a layer structure and the like.

FIG. 6 is a schematic cross-sectional view when the polymer solid electrolytic capacitor of the present invention is of a substrate built-in type.

FIG. 7 is a schematic plan view showing another example of the anode electrode of the polymer solid electrolytic capacitor of the present invention.

FIG. 8 is a schematic plan view showing an example of an anode electrode of a comparative polymer solid electrolytic capacitor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Anode electrode 2 A foil-shaped aluminum substrate with a roughened surface and an oxide film formed on it 3 A foil-shaped aluminum substrate with a surface not roughened 4 A foil-shaped copper substrate 5 A welded joint 6 A welded joint 7 Stainless Beaker 8 Chemical Solution 10 Polymer Solid Electrolytic Capacitor 11 Solid Polymer Electrolyte Layer 12 Graphite Paste Layer 13 Silver Paste Layer 14 Cathode Electrode 20 Substrate Embedded Polymer Solid Electrolytic Capacitor 21 First Insulating Resin Substrate 22 Second Insulating Resin Substrate 23 First Insulating Resin Substrate Bank 24 Wiring Pattern 25 Through Hole 26 Resin 27 Wiring Pattern 28 Through Hole 29 Adhesive 30 Electronic Component 31 Solder 32 Conductive Resin 41 Anode Electrode 42 Surface Roughened , A foil-shaped aluminum substrate 43 on which an oxide film is formed, and a foil-shaped aluminum substrate whose surface is not roughened Aluminum base 53 foil-shaped copper base 45 welded joint 46 welded joint 51 anode electrode 52 surface-roughened foil-shaped aluminum base 53 having an oxide film formed thereon surface non-roughened foil-shaped Aluminum base 54 Foil-shaped copper base 55 Weld joint 56 Weld joint

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Noriyoshi Nanba             1-13-1, Nihonbashi, Chuo-ku, Tokyo             -In DC Inc.

Claims (5)

[Claims] 1. An electrode for use in a solid polymer electrolytic capacitor, which is housed and fixed in a closed space formed of an insulating resin, the planar shape of which is one side of a rectangle in a rectangular shape. It has a shape in which a notch having two sides having a length shorter than the total length of one side of a rectangle is formed at one corner where one side intersects, and the surface is roughened to form an insulating oxide film. It has a formed foil-shaped valve metal substrate, a valve metal substrate whose surface is not roughened, and a foil-shaped conductive metal substrate, where the surface is roughened and an insulating oxide film is formed. The end portion of the foil-shaped valve metal substrate whose surface is not roughened is joined to the end portion of the cutout portion of the formed foil-shaped valve metal substrate so that the valve metals are electrically connected. Then, the foil-shaped valve metal substrate whose surface is not roughened is provided at the end portion excluding the joint portion with the foil-shaped valve metal substrate. Conductive end portions of the metal substrate, bonded to configured polymer solid electrolytic capacitor electrodes as intermetallic are electrically connected. 2. The electrode for polymer solid electrolytic capacitor according to claim 1 is used as an anode, the surface is roughened, and an insulating oxide film is formed on the insulating oxide film of a foil-shaped valve metal substrate. A polymer solid electrolytic capacitor in which at least a solid polymer electrolyte layer and a conductor layer are sequentially formed. 3. The closed space formed of the insulating resin,
The polymer solid electrolytic capacitor according to claim 2, which is formed of an insulating resin substrate. 4. The insulative resin substrate has a first insulative resin substrate and a second insulative resin substrate facing each other, and one surface of the first insulative resin substrate and the second insulative resin substrate. 4. The polymer solid electrolytic capacitor according to claim 3, wherein the polymer resin is integrally attached between one surface of the insulating resin substrate of. 5. The polymer solid electrolytic capacitor according to claim 4, wherein at least one wiring pattern is formed on the surface of the first insulating resin substrate and / or the second insulating resin substrate.