JPH09134854A - Manufacture of solid electrolytic capacitor and anode body for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the dielectric loss tangent value (tan δ) of a solid electrolytic capacitor by using a sintered molded body obtained by sintering a columnar molded body of the powder of a metal performing valve action. SOLUTION: A molded body 1 is manufactured by using powder prepared by mixing a granular or fibrous solid acrylic resin in the powder 3 of a valve action metal. When the molded body 1 is manufactured in such a way, the space in the body 1 after a binder is decomposed and scattered becomes larger as compared with the case where a liquid binder is used. A solid organic binder, concretely, a solid PVA, PVB, etc., can be used in place of the solid acrylic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solid electrolytic capacitor and an anode body for a solid electrolytic capacitor, and more particularly to a sintered anode body formed by molding and sintering a powder of a valve metal, a dielectric oxide film, The present invention relates to a method for manufacturing a solid electrolytic capacitor having a structure in which a solid electrolyte layer and a cathode conductor layer are formed, and an anode body of the solid electrolytic capacitor.

[0002]

2. Description of the Related Art A manufacturing process of a solid electrolytic capacitor of this type will be described with reference to a tantalum solid electrolytic capacitor using tantalum as a valve metal. First, metal tantalum powder is filled in a die and pressed by a punch to form a columnar body such as a prism or a cylinder. At this time, the tantalum wire is embedded in advance in the tantalum powder filled in the die so that the tantalum wire to be the anode lead wire can be pulled out in the axial direction from one end surface of the pillar after molding.

Next, the formed compact is sintered at high temperature and high vacuum to obtain a sintered compact. Then, a tantalum oxide film as a dielectric layer, a manganese dioxide layer as a solid electrolyte layer, and a cathode conductor layer are sequentially formed on the surface of this sintered compact to obtain a capacitor element.

After that, an external anode terminal and an external cathode terminal for connection with an external circuit are connected to the tantalum wire or the cathode conductor layer, respectively. Finally, the capacitor is completed by sealing and enclosing with an insulating resin layer or a metal case, if necessary.

By the way, in the above-mentioned manufacturing process of the tantalum compact, the flowability of the powder when filling the die with the metal tantalum powder becomes a problem. That is, if the tantalum powder alone is used for molding, problems such as the tantalum powder not all entering the die, the die being easily worn, and the punch not coming off from the die occur. Therefore, it is common practice to add an inorganic binder liquid or an organic binder liquid to the metal tantalum powder in advance and granulate the granulated tantalum powder into a columnar body.

In addition to the above-mentioned general granulation method, several granulation methods have been devised. For example, Japanese Patent Application Laid-Open
Japanese Patent No. 4701 discloses a method of granulating tantalum fine powder using a granulating machine such as spray drying using polyvinyl alcohol (PVA), polyvinyl butyral (PVB) or camphor as a binder.
Further, in Japanese Patent Laid-Open No. 65502/1993, a fluidized bed granulator is used, an inorganic binder liquid such as water is used in the first half of the manufacturing process, and PVA, PVB, methylcellulose, carboxymethylcellulose are used in the latter half. A method of granulating tantalum powder in two steps using an organic binder solution is disclosed.

In connection with the present invention, all of the conventional methods for producing a solid electrolytic capacitor described above are characterized in that a liquid binder is used as a binder for granulating the valve action metal powder. .

Further, in Japanese Unexamined Patent Publication No. 5-283264, sintering is performed by using a carbon material sintered body using a carbon material fiber having a diameter of 2 to 30 μm and a length of 0.1 to 10 mm as a solid fiber binder. An invention of an electrode composed of a sheet and a carbonaceous lead integrated with the sintered sheet is disclosed.

Further, as an anode body of a solid electrolytic capacitor, Japanese Patent Laid-Open No. 5-275293 discloses a valve action metal powder having an average diameter of 0.1 to 5 μm, and the size of pores is controlled by a valve. A method for producing an anode body having a size of the working metal powder of 0.05 to 5 times has been proposed.

[0010]

In the above-mentioned conventional method for manufacturing a solid electrolytic capacitor, when granulating to improve the flowability of the valve action metal powder, a binder dissolved in an organic solvent or the like is used as a liquid or It is added to the valve metal as an atomized form. As a result, the dielectric loss tangent value (tan
There is a problem that δ) increases. The description is given below.

FIG. 12 shows a sectional view of a molded body molded by the conventional technique. In FIG. 12, a part is schematically enlarged and shown. In the molded body according to the conventional technique shown in FIG. 12, since a liquid (or atomized) binder liquid is used during granulation prior to molding, a binder layer is formed on the surface of the valve action metal powder 3 after granulation. 5 is formed. This binder layer 5
Is much thinner than the particle size of the valve action metal powder 3. After that, when the granulated valve action metal powder 3 is molded,
As shown in FIG. 12, the valve action metal powders 3 are in contact with each other via the binder layer 5 covering the surfaces thereof, but as described above, the binder layer 5 has the size of the valve action metal powders 3. Is extremely thin against. Therefore, in actuality, it can be said that the valve action metal powder 3 is packed in the molded body with almost no gap. In FIG. 12, 2 is an anode lead wire.

The binder layer 5 is dispersed and scattered by heating or the like during the subsequent sintering, but the space formed by this becomes very narrow. That is, in the sintered compact after sintering, the valve action metal powders 3 are intimately bonded to each other, and thereafter, in the solid electrolyte forming step following the dielectric oxide film formation, the solid electrolyte mother liquor (for example, , Manganese nitrate solution) is so narrow that it penetrates into the molded body. For example, this state can be expressed as a state in which the surface of the sintered compact is likely to be clogged when the solid electrolyte is formed.

As described above, in the conventional solid electrolytic capacitor, the impregnation property when impregnating the solid electrolyte mother liquor into the molded body is not good due to the clogging of the molded body. In other words, the solid electrolyte mother liquor is not sufficiently filled in the pores,
The solid electrolyte layer formed on the dielectric oxide film is extremely thin in the depths of the thin and narrow pores. as a result,
When constructed as a capacitor, the current path between the positive and negative electrodes is thin and thin, so the resistance increases and the dielectric loss tangent value (t
an δ) increases. The clogging of such a molded body becomes worse as the valve action metal powder 3 becomes finer, but in recent years, the particle size of the valve action metal powder 3 is very small in order to promote the miniaturization and large capacity of the capacitor. Therefore, elimination of clogging of molded articles and improvement of tan δ have become very important issues.

In the prior art disclosed in Japanese Patent Laid-Open No. 5-283264, a solid fibrous binder is used. The purpose of using this solid fibrous binder is to provide an electrode 6 having sufficient strength as shown in FIG. This is to obtain a sintered body and to increase the bonding strength between the electrode plate 7 and the carbonaceous lead 8. Therefore, when a solid electrolytic capacitor is manufactured by using the electrode 6, there is a drawback that the pores inside the electrode 6 become narrow and tan δ when constructed as a solid electrolytic capacitor increases.

An object of the present invention is to provide a method for producing a solid electrolytic capacitor using a sintered compact obtained by compacting a powder of valve metal into a column and sintering it. It is to provide a solid electrolytic capacitor manufacturing method and a solid electrolytic capacitor anode body that can be improved.

[0016]

In order to achieve the above object, a method of manufacturing a solid electrolytic capacitor according to the present invention comprises a step of forming a valve-acting metal powder as a main raw material into a columnar molded body, A step of sequentially forming a dielectric oxide film, a solid electrolyte layer and a cathode conductor layer on a sintered compact obtained by sintering the compact, and further comprising the step of molding the valve-acting metal in the step of compacting the compact. The present invention is characterized in that a molded body is molded using a powder in which a particulate or fibrous solid acrylic resin is mixed as the powder.

The particulate solid acrylic resin has an average particle size in the range of 1 to 100 μm, and its proportion in the total mixed powder is in the range of 3 to 10 wt%. The average shape of the fibrous solid acrylic resin is a shape having a diameter of 5 to 50 μm and a length of 50 μm to 5 mm, and the proportion of the whole mixed powder is 3 to 10 wt%.
Is in the range.

Further, in the method for producing a solid electrolytic capacitor according to the present invention, solid polyvinyl alcohol or solid polyvinyl butyral is used as a solid organic binder in the form of particles or fibers instead of the solid acrylic resin in the form of particles or fibers. It is characterized by using either one.

Further, the anode body of the solid electrolytic capacitor according to the present invention is produced by molding valve-acting metal powder as a main raw material into a columnar molded body and sintering the molded body. And the pores contained in the sintered compact are in the range of 5 to 200 μm, and the voids occupy 0.5 to 50% of the volume of the sintered compact. And

[0020]

In the anode body of the solid electrolytic capacitor of the present invention, the pores contained in the sintered compact are in the range of 5 to 200 μm, and the pores occupy 0.5 to 50% of the volume of the sintered compact. It is a thing. Therefore, the anode body of the solid electrolytic capacitor according to the present invention, when forming the solid electrolyte layer after forming the dielectric oxide film through the sintering process, a path for the solid electrolyte mother liquor to permeate the inside of the sintered compact. Has been expanded. Therefore, the solid electrolytic mother liquor is sufficiently permeated into the sintered compact, so that the solid electrolyte layer formed on the dielectric oxide film becomes thicker and the resistance value is smaller, resulting in a lower dielectric loss tangent value when constructed as a capacitor. Become.

[0021]

Next, an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 shows a tantalum compact according to a first embodiment of the present invention (after pressure molding of tantalum powder,
It is sectional drawing which shows the state (before sintering), and one part of FIG. 1 is expanded typically and shown in figure. Further, FIG. 1 corresponds to FIG. 12 showing a schematic enlarged cross section of a tantalum compact according to a conventional technique.

In FIG. 1, in a molded body 1 according to the first embodiment of the present invention, particles 4 of a solid binder are interposed between tantalum (valve action metal) powders 3. As will be described later, the solid binder particles 4 have an average particle size in the range of 1 to 100 μm, and have the same size as the particle size of the tantalum powder 3.

The binder particles 4 described above are decomposed and scattered by heating in a sintering process or the like in a subsequent process. The space after the scattering serves as a path (intrusion path) through which the electrolyte mother liquor when forming the solid electrolyte after sintering penetrates into the molded body. The size of the invasion path is determined by the size of the average particle size of the binder particles 4 and is sufficiently large for the tantalum powder 3, and the binder layer in the molded body according to the conventional technique (see FIG. 12). It is incomparably larger than the intrusion path formed by No. 5.
That is, the impregnation property of the electrolyte mother liquor into the sintered compact 1 in Embodiment 1 is much better than the impregnation property in the compact according to the conventional technique. As a result, the current path between the positive electrode and the negative electrode when constructed as a capacitor is thicker and thicker than that of a conventional capacitor, and therefore has a low resistance value, which brings about good tan δ characteristics.

The present inventor manufactured the tantalum solid electrolytic capacitor according to the first embodiment as follows. First, particulate acrylic solid resin as binder particles 4 is added to tantalum powder 3 having a CV value of 40,000 CV / g. Next, a tantalum wire having a diameter of 0.5 mm, which is to be the anode lead wire 2, is erected in the mixed tantalum powder and pressure-molded to produce a molded body 1. The formed body 1 is formed into a cylindrical shape having a diameter of 6.0 mm and a length of 7.90 mm.

Next, the formed compact 1 is sintered in a high temperature and high vacuum atmosphere to obtain a tantalum sintered compact. Furthermore,
This molded body is formed in a phosphoric acid solution to form a tantalum oxide film, and a manganese dioxide layer as a solid electrolyte layer, a carbon layer as a cathode conductor layer, and a silver paste layer are sequentially formed on the tantalum solid electrolytic layer. Get the capacitor element.

In the capacitor element thus obtained, the CV value of the raw tantalum powder, the average particle size of the binder particles and the addition rate thereof (the ratio of the binder particles in the mixed tantalum powder consisting of the raw tantalum powder and the solid binder particles) Is shown in Table 1.

[0028]

[Table 1]

In Table 1, Level 1 is a capacitor element using a compact made of only raw tantalum powder without binder particles. Level 8 is a capacitor element using a molded body according to the related art in which a liquid binder is added to the raw material tantalum powder.

The present inventor investigated the following four items in the state of powder, compact, sintered compact or capacitor element against the levels shown in Table 1. Mixed powder (composed of raw tantalum powder and binder)
Flowability (FIG. 3) Strength of molded body (FIG. 4) Cross-sectional state of sintered molded body (FIGS. 5 to 7) tan δ as a capacitor (FIG. 8)

In FIG. 3, the vertical axis represents the flowability of the mixed powder, and the horizontal axis represents the level of the powder to be measured. Flowability is indicated by the time required for 50 g of powder stored in the container to flow vertically down an hourglass-shaped tube of constant diameter. From FIG.
The powder does not flow only with the raw tantalum powder (level 1). The flowability of the mixed powder with the solid binder particles added is
When the binder particle size is about 50 μm or more, it tends to be saturated, but it rapidly deteriorates between 100 μm (level 6) and 150 μm (level 7). From comparison between Level 4 and Level 5, it can be seen that if the binder particle size is the same, the larger the binder addition rate, the better the flowability.

Next, in FIG. 4, the vertical axis represents the strength of the molded product, and the horizontal axis represents the level of the measured molded product. The strength is indicated by a force when a molded body is deformed by gradually applying a force to the cylindrical molded body on two surfaces parallel to the anode lead wire 2. From FIG. 4, it can be seen that, if the addition rate of the binder particles is the same, the larger the binder particle size, the higher the strength of the molded body. The strength of the molded body (level 1) using only the raw material tantalum powder is lower than any other level. In addition, the strength of any of the molded bodies containing the solid binder particles is higher than that of the molded body using the conventional liquid binder (Level 8).

FIG. 5 to FIG. 7 show images observed by an optical microscope of the cross section of the sintered compact when the compact is sintered to form a sintered compact. Referring to FIGS. 5 to 7, a sintered compact formed only of the raw material tantalum powder (Level 1: FIG. 5A) and a conventional sintered compact using a liquid binder (Level 8: FIG. 7).
In (b)), no pores are seen on the surface and inside of the sintered compact, whereas in the sintered compacts containing solid binder particles (FIGS. 5 (b) to 7 (a)), the surface and inside are not formed. Voids are observed to be formed in the.

Next, t when constructed as a capacitor
FIG. 8 shows the relationship between an δ and the level of the tantalum mixed powder. In FIG. 8, the tan δ of the capacitor to which the solid binder particles are added is lower than the capacitor using the liquid binder (level 8) at any level, and is almost equal to the tan δ of the capacitor using only the raw tantalum powder (level 1). is there. In addition, in a capacitor to which binder particles are added, if the addition ratio is constant, the binder particles will be 0.
Between 8 μm (level 2) and 50 μm (level 4), tan δ tends to decrease as the particle size increases. On the other hand, when the binder particle size is 50 μm or more, conversely, tan δ also tends to increase as the binder particle size increases.
Further, from the comparison between Level 4 and Level 5, it can be seen that, if the binder particle size is the same, the larger the binder addition rate, the larger tan δ.

From the results of the investigations described above, when the particle size of the solid binder particles exceeds 100 μm, the flowability of the mixed powder deteriorates sharply, while when it is 0.8 μm or less, the mechanical strength of the molded body is not so high. Since it will be the same as or smaller than that of the capacitor manufactured by
It is preferably 100 μm or less. On the other hand, regarding the addition rate of the solid binder particles, if the content is higher than 10% (level 5), the strength of the compact may be lowered and tan δ may be deteriorated, and if it is lower than 3% (level 4), the flowability of the mixed powder may be decreased. 3% or more, 10%
It is desirable that: That is, when the solid tantalum oxide film of the manganese dioxide layer is used as the solid binder particles 4, when the raw material tantalum powder is mixed with an acrylic solid resin having an average particle diameter of 1 to 100 μm in an addition ratio of 3 to 10%. The coatability is improved, and a tantalum solid electrolytic capacitor having a small tan δ can be provided.

In the first embodiment, the solid binder particles 4 shown in FIGS. 5 to 7 are spherical, but the solid binder particles 4 are angular or flat. You may.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
It is sectional drawing which shows the tantalum compact which concerns on, and has expanded one part and shown typically. The binder particles 4 of the molded body 1 in Embodiment 1 shown in FIG. 1 have an average particle size of 1 to 1.
The binder particles 4 of the molded body 1 in the second embodiment shown in FIG.
The fiber is characterized by having a diameter of 5 to 50 μm and a length of 50 μm to 5 mm.

The fibrous binder particles 4 according to the second embodiment are decomposed and scattered by heating in the sintering process which is a post process. Then, the space after the scattering serves as a path (intrusion path) through which the electrolyte mother liquor when the solid electrolyte is formed after sintering penetrates into the sintered compact 1, but the binder particles 4 according to the second embodiment are fibrous. Because of the long shape, the entry route of the electrolyte mother liquor is longer than that of the first embodiment. As a result, the tan δ characteristic is better than that of the first embodiment.

A list of the CV value of the raw material tantalum powder, the diameter and the length of the binder particles 4 in the second embodiment is shown in the table below.
It is shown in Table 2.

[0040]

[Table 2]

The present inventor of the second embodiment also has
The following two items were investigated in the state of powder and capacitor element with respect to the level shown in. Mixed powder (composed of raw tantalum powder and binder)
Flowability (Fig. 9) tan δ as a capacitor (Fig. 10)

In Table 2, Level 11 is a capacitor element using a molded body in the prior art in which a liquid binder is added to the raw tantalum powder, and Level 2
Are capacitor elements using the particulate solid binder particles according to the second embodiment shown in Table 1.

In FIG. 9, the vertical axis represents the flowability of the mixed powder, and the horizontal axis represents the level of the powder to be measured. In FIG. 9, the flowability deteriorates as the length of the fibrous binder increases, and the powder does not flow at 8000 μm (level 15). Further, when the diameter of the fibrous binder becomes extremely thin, the flowability deteriorates, and at 1 μm (level 19), the powder does not flow, while on the other hand, the diameter of the fibrous binder becomes thicker and becomes 75 μm (level 1).
Even in the case of 7), the flowability deteriorates.

Next, t when constructed as a capacitor
FIG. 10 shows the relationship between an δ and the level of the tantalum mixed powder. In FIG. 10, when the diameter of the fibrous binder is extremely thin, the effect of reducing tan δ is lost, and at 1 μm (level 19), the tan δ is almost the same as that of the conventional liquid binder (level 11).

From the investigation results described above, if the diameter of the fibrous binder particles is smaller than 5 μm, the flowability is deteriorated and the effect of reducing tan δ is lost, and if it exceeds 50 μm, the flowability is deteriorated. The diameter of the fibrous binder particles is preferably in the range of 5 to 50 μm. On the other hand, the length of the fibrous binder particles is 5000 μm
When it exceeds (5 mm), the flowability is deteriorated, and when the length of the fibrous binder particles is smaller than 50 μm, it becomes a particulate binder. Therefore, the length of the fibrous binder particles is 50 μm or more. It is desirable to be in the range of 5 mm. As the shape of the fibrous binder particles,
Thread-like or rod-like shapes are possible.

The hole diameter and the volume ratio of each capacitor element manufactured according to the first and second embodiments were confirmed, and typical ones are shown in Table 3.

[0047]

[Table 3]

The inventor investigated tan δ of the capacitor element against the levels shown in Table 3.

In FIG. 11, the vertical axis represents the dielectric loss tangent value, and the horizontal axis represents the level of the powder to be measured. In FIG. 11, first, focusing on the hole diameter, when the hole ratio is 10%, the dielectric loss tangent value can be reduced when the hole diameter is 5 or 10%, but when the hole diameter is 2.5 μm, the dielectric loss tangent value is much smaller than that of the conventional example. Only a slight improvement.

On the other hand, focusing on the hole ratio, the hole diameter is 5 to 5.
When the ratio of 200 μm increases, the dielectric loss tangent value decreases, but when it exceeds 50%, the decrease is not recognized. Moreover, when the ratio is decreased, the dielectric loss tangent value is increased.

From the above-described investigation results, when the pore diameter of the sintered compact is smaller than 5 μm, the dielectric loss tangent value becomes large, and when the pore diameter exceeds 200 μm, the surface area of the sintered compact becomes small. It is preferably in the range of 5 to 200 μm. On the other hand, when the ratio of voids is less than 0.5%, the dielectric loss tangent value increases, and when the ratio of voids exceeds 50%, there is no effect of reducing the dielectric loss tangent value, but the surface area of the sintered compact decreases. , The ratio of holes is 0.5
It is desirable to be 50%.

The particulate solid binder particles shown in Table 1 and the fibrous solid binder particles shown in Table 2 were combined and mixed with the raw material tantalum powder.
A molded body may be manufactured.

In the first and second embodiments, the case where tantalum is used as the valve action metal powder and the acrylic solid resin is used as the solid binder particles has been described, but the present invention is not limited thereto. Since the operation and effect of the present invention are obtained in correlation with the particle size of the valve metal powder and the particle size of the solid binder particles, a valve metal powder such as aluminum is used as the valve metal powder. You may use. Further, as the solid binder particles, the same effects as those in the first and second embodiments can be obtained even when particles of an organic binder such as PVA and PVB which are well known in the related art are used. Further, a functional polymer such as polypyrrole or polyaniline may be used as the solid electrolyte layer.

[0054]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, when a solid electrolytic capacitor using a sintered compact obtained by compacting and sintering a valve action metal powder is used, a valve action is performed in the forming step of the compact. A molded body is manufactured using a powder obtained by mixing a metal powder with a particulate or fibrous solid acrylic resin.

As a result, according to the present invention, the impregnating property with which the electrolyte mother liquor impregnates the sintered compact during the formation of the solid electrolyte,
It is possible to improve the coverage of the solid electrolyte with respect to the dielectric film by lowering it than that in the molded body according to the prior art, and to reduce its resistance value. Therefore, the dielectric loss tangent value (tan δ) of the capacitor can be improved.

The above-mentioned particulate acrylic resin has an average particle size in the range of 1 to 100 μm, and its proportion in the whole mixed powder is in the range of 3 to 10 wt%, or the above fibrous acrylic resin has an average particle size thereof. Shape is 5-50μ in diameter
m, the length is in the range of 50 μm to 5 mm, and the above-mentioned effects can be remarkably exhibited by setting the ratio in the whole mixed powder in the range of 3 to 10 wt%.

Further, by using either solid polyvinyl alcohol or solid polyvinyl butyral as the above-mentioned particulate or fibrous organic binder, the above-mentioned effects can be similarly obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a tantalum compact according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a tantalum compact according to Embodiment 2 of the present invention.

FIG. 3 is a diagram showing a comparison of the flowability of powder for producing a molded body in Embodiment 1 of the present invention.

FIG. 4 is a diagram showing the strengths of the molded bodies in comparison with each other in Embodiment 1 of the present invention.

FIG. 5 is a photograph showing a cross section of a sintered compact according to Embodiment 1 of the present invention in comparison with optical microscope images.

FIG. 6 is a photograph showing a cross section of a sintered compact according to Embodiment 1 of the present invention in comparison with optical microscope images.

FIG. 7 is a photograph showing a cross section of a sintered compact according to Embodiment 1 of the present invention in comparison with optical microscope images.

FIG. 8 is a diagram showing a comparison of tan δ of tantalum solid electrolytic capacitors according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a comparison of the flowability of powder for producing a molded body in Embodiment 2 of the present invention.

FIG. 10 is a diagram showing a comparison of tan δ of tantalum solid electrolytic capacitors according to a second embodiment of the present invention.

FIG. 11 is a diagram showing a comparison of tan δ of the tantalum solid electrolytic capacitors according to the first embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a conventional tantalum compact.

FIG. 13 is a perspective view showing an electrode disclosed in JP-A-5-283264.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molded body 2 Anode lead wire 3 Valve metal powder 4 Binder particle 5 Binder layer 6 Electrode 7 Electrode plate 8 Carbonaceous lead

Claims (5)

[Claims] 1. A method of manufacturing a solid electrolytic capacitor, comprising a forming step of a formed body and a cathode layer forming step, wherein the forming step of the formed body uses a powder of a valve metal as a main raw material and forms a columnar formed body. The cathode layer forming step is a step of sequentially forming a dielectric oxide film, a solid electrolyte layer and a cathode conductor layer on a sintered molded body obtained by sintering the molded body. A method for producing a solid electrolytic capacitor, characterized in that, in the step of forming a body, a formed body is formed by using a powder obtained by mixing a powder of the valve metal with a solid acrylic resin in the form of particles or fibers. 2. The average particle size of the particulate solid acrylic resin is in the range of 1 to 100 μm, and the proportion of the whole mixed powder is in the range of 3 to 10 wt%. Manufacturing method of solid electrolytic capacitor. 3. The average shape of the fibrous solid acrylic resin is in the range of 5 to 50 μm in diameter and 50 μm to 5 mm in length, and the proportion of the whole mixed powder is 3 to 10 μm.
It is in the range of wt%, The manufacturing method of the solid electrolytic capacitor of Claim 1 characterized by the above-mentioned. 4. A solid polyvinyl alcohol or a solid polyvinyl butyral is used as the solid organic binder in the form of particles or fibers instead of the solid acrylic resin in the form of particles or fibers. A method for producing the solid electrolytic capacitor described. 5. A solid electrolytic capacitor anode body obtained by molding a powder of valve metal as a main raw material into a columnar molded body and sintering the molded body, which is included in the sintered molded body. The solid electrolytic capacitor anode body, wherein the pores are in the range of 5 to 200 μm, and the pores occupy 0.5 to 50% of the volume of the sintered compact.