JP2023176482A - Solid electrolytic capacitor and method for manufacturing the same - Google Patents

Abstract

To provide a solid electrolytic capacitor with an excellent heat resistance formed of a capacitor element with an excellent shape stability of an insulation layer.SOLUTION: The solid electrolytic capacitor includes a capacitor element having an anode part, a cathode part, and an intermediate part. The anode part, the cathode part, and the intermediate part are arranged along one anode body. The anode part has a first part of the anode body. The intermediate part has a first insulation layer formed by filling a first insulation resin into a hole of a second part of the anode body and a second insulation layer including a second insulation resin covering the first insulation layer. The cathod part has a third part of the anode body, a solid electrolytic layer covering a third dielectric oxide coating layer, a cathod extraction layer covering the solid electrolytic layer. A glass transit temperature T1 of the first insulation resin is higher than a glass transit temperature T2 of the second insulation resin. The first and second insulation resins have a thioether structure.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a solid electrolytic capacitor and a method of manufacturing the same.

Solid electrolytic capacitors have low equivalent series resistance (ESR) and excellent frequency characteristics, so they are installed in various electronic devices. Capacitor elements used in solid electrolytic capacitors include a foil containing a valve metal such as titanium, tantalum, aluminum, niobium, etc. as an anode body. For example, a capacitor element is known in which a single anode body having an oxide film formed on its surface is divided into an anode portion and a cathode portion. In such a capacitor element, a solid electrolyte layer and a cathode extraction layer are formed on the surface of the anode body on the cathode side.

Here, in order to reliably electrically insulate the anode part and the cathode part, Patent Documents 1 and 2 describe that an intermediate part containing an insulating material is disposed between the anode part and the cathode part. ing.

International Publication No. 2021/085350 Japanese Patent Application Publication No. 2020-178098

In the method described in Patent Document 1 or 2, when forming the intermediate portion, an insulating material is provided between the anode portion and the cathode portion, and the insulating material is thermoset at 100° C. or higher. However, with such a method, it is difficult to control the shape of the insulating material. For example, the anode body of Patent Document 1 has a core region and a porous region arranged around the core region, and when forming the intermediate region, an insulating material is applied to fill the pores of the porous region. Give. In addition, in Cited Document 2, the intermediate portion is similarly formed.

However, when heating is performed after applying the insulating material, the viscosity of the insulating material decreases in a temperature range where a curing reaction of the insulating material starts or a temperature range where a solvent or low molecular weight component in the insulating material evaporates. Therefore, in the method of Patent Document 1 or 2, the insulating material tends to spread not only in the depth direction of the region forming the intermediate portion (for example, in the thickness direction of the porous region) but also in the width direction. As a result, the porous region in the desired region cannot be sufficiently filled with the insulating material, and the impregnation rate of the insulating material tends to be lower than the desired value, particularly near the interface between the core region and the porous region.

When the impregnation rate of the insulating material in the intermediate portion is low, oxygen that has entered from the anode portion tends to reach the cathode portion side through the porous region of the intermediate portion, and the movement of oxygen cannot be sufficiently suppressed by the intermediate portion. Then, on the cathode side, the solid electrolyte layer may be oxidized and deteriorated, resulting in a decrease in heat resistance reliability.

The present disclosure has been made to solve the conventional problems. Specifically, the objective is to provide a solid electrolytic capacitor with excellent heat resistance, which includes a capacitor element with an insulating layer having excellent shape stability.

In order to solve the above problems, a solid electrolytic capacitor of the present disclosure includes a capacitor element including an anode part, a cathode part, and an intermediate part interposed between these parts, the anode part, the intermediate part, and The cathode section is arranged along one anode body having a porous region on the main surface side and a dielectric oxide film layer formed on the surface of the porous region, and the anode section The intermediate portion includes a first insulating layer in which the porous region of the second portion of the anode body and the pores of the dielectric oxide film layer are filled with a first insulating resin; a second insulating layer containing a second insulating resin that covers the first insulating layer, and the cathode part includes a third part of the anode body and the dielectric oxide layer of the third part. a solid electrolyte layer covering the solid electrolyte layer; and a cathode extraction layer covering the solid electrolyte layer, the glass transition temperature T ₁ of the first insulating resin is higher than the glass transition temperature T ₂ of the second insulating resin, and the first The insulating resin and the second insulating resin are solid electrolytic capacitors containing a thioether structure.

The present disclosure is a method for manufacturing a solid electrolytic capacitor including a capacitor element including an pole part, a cathode part, and an intermediate part interposed between these parts, and the method includes preparing an anode body having a porous region on the surface. a dielectric oxide layer forming step of forming a dielectric oxide layer on the surface of the porous region; and a position corresponding to the intermediate portion of the anode body with the dielectric oxide layer formed on the surface. a first insulating layer forming step of filling the porous region and the pores of the dielectric oxide layer with an insulating resin and curing it to form a first insulating layer; a second insulating layer forming step of arranging and curing an insulating resin to form a second insulating layer; and forming a solid electrolyte layer on the dielectric oxide film layer at a position corresponding to the cathode part of the anode body. , a cathode part forming step of further forming a cathode extraction layer on the solid electrolyte layer, wherein the glass transition temperature _T1 of the resin included in the first insulating layer is the glass transition temperature of the resin included in the second insulating layer. The present invention further provides a method for manufacturing a solid electrolytic capacitor, wherein the temperature is higher than _T2 , and the resin included in the first insulating layer and the resin included in the second insulating layer include a thioether structure.

According to the present disclosure, a solid electrolytic capacitor having an insulating layer of a capacitor element having excellent shape stability and excellent heat resistance is provided.

1 is a cross-sectional view schematically showing a capacitor element of a solid electrolytic capacitor according to an embodiment of the present disclosure. 1 is a cross-sectional view schematically showing a solid electrolytic capacitor according to an embodiment of the present disclosure. 1 is a flowchart illustrating a method for manufacturing a solid electrolytic capacitor according to an embodiment of the present disclosure.

[Solid electrolytic capacitor]
(overall structure)
The overall configuration of a solid electrolytic capacitor according to an embodiment of the present disclosure will be described. The solid electrolytic capacitor according to this embodiment includes a capacitor element including an anode part, a cathode part, and an intermediate part interposed between these parts. The anode portion, intermediate portion, and cathode portion of the capacitor element are arranged along one anode body having a porous region on the main surface side and a dielectric oxide film layer formed on the surface of the porous region. They are arranged in this order. The anode portion is comprised of the first portion of the anode body. The intermediate portion includes a second portion adjacent to the first portion of the anode body, and a first insulating resin in which the porous region of the second portion of the anode body and the pores of the dielectric oxide film layer are filled with a first insulating resin. a second insulating layer containing a second insulating resin and covering the first insulating layer. The cathode part includes a third part other than the first part and the second part of the anode body and adjacent to the second part, a solid electrolyte layer covering the dielectric oxide film layer of the third part, and the solid electrolyte. and a cathode extraction layer covering the layer.

Here, the first insulating resin and the second insulating resin disposed in the intermediate portion each include a thioether structure. Such a first resin and a second resin can be obtained by reacting a mixture containing an epoxy compound and a thiol compound. The mixture containing the epoxy compound and the thiol compound has an appropriate viscosity before curing, and can be filled into the porous region of the anode body or the dielectric oxide layer without using a solvent. Therefore, 90% or more of the plurality of pores existing in the porous region of the anode body in the intermediate portion can be filled with the first insulating resin. Moreover, when the first insulating resin and the second insulating resin contain a thioether structure, it becomes easier to keep the elastic modulus of the first insulating resin and the second insulating resin within a desired range.

Furthermore, in this embodiment, the glass transition temperature T ₁ of the first insulating resin disposed in the porous region of the intermediate portion and the pores of the dielectric oxide layer is the same as that of the second insulating resin also disposed in the intermediate portion. Higher than the glass transition temperature _T2 . Such a second insulating resin can be obtained even if the mixture is cured only by UV irradiation without heat treatment. On the other hand, the first insulating resin can be obtained by subjecting the mixture to heat treatment in addition to UV irradiation. In addition, many of the pores existing in the porous region of the anode body in the intermediate part are submicron-sized, and when the pores are filled with the first insulating resin and compounded, the molecular movement of the first insulating resin is suppressed. Therefore, the glass transition temperature of the first insulating resin is higher than that of the second insulating resin existing in a bulk state. This increases the heat resistance of the capacitor element, and the first insulating layer is less likely to deform even when heat is applied to the capacitor element. As a result, oxygen that has entered the solid electrolytic capacitor is suppressed from diffusing from the anode side to the cathode side via the intermediate portion. Therefore, deterioration of the solid electrolyte layer in the cathode portion is suppressed, and heat resistance reliability is improved.

Furthermore, the intermediate portion of the capacitor element of this embodiment includes, in addition to the first insulating layer, a second insulating layer that covers the first insulating layer. Therefore, the anode part and the cathode part are reliably insulated.

Note that, in view of the purpose of the present disclosure, when the capacitor element has a flat plate shape, it is preferable that the first insulating layer and the second insulating layer are disposed on both sides of the capacitor element.

In this specification, the direction connecting the anode portion, the intermediate portion, and the cathode portion of the capacitor element is referred to as the first direction. Further, the end of the capacitor element on the anode side in the first direction is called a first end, and the end on the cathode side is called a second end. The boundary between the anode part and the intermediate part, and the boundary between the intermediate part and the cathode part are defined by a cross section (hereinafter referred to as "first cross section") obtained by cutting the main surface of the capacitor element parallel to the first direction. ”) can be determined. The boundary between the anode part and the intermediate part is a plane of the first cross section that passes through a point closest to the first end of the first insulating resin filled in the porous region. On the other hand, the boundary between the intermediate portion and the cathode portion is a plane passing through the end of the first cross section that is closest to the first end of the solid electrolyte layer on the main surface of the capacitor element. Note that the intermediate portion is a region between the boundary between the anode portion and the intermediate portion determined as described above and the boundary between the intermediate portion and the cathode portion.

Hereinafter, a capacitor element in a solid electrolytic capacitor will be specifically explained with reference to the drawings. However, this embodiment is not limited to this.

FIG. 1 is a cross-sectional view schematically showing a capacitor element according to this embodiment. Note that in the drawings, in order to clarify the shape or characteristics of each component of the electrolytic capacitor, these dimensions are shown relative to each other, and are not necessarily drawn to the same scale.

FIG. 1 shows main surfaces 110X and 110Y of the capacitor element cut in parallel to a first direction connecting the first end _110T1 on the anode side of the capacitor element 110 and the second end _110T2 on the cathode side. FIG.

Capacitor element 110 has, for example, a flat plate shape. The capacitor element 110 has an anode part 110a, an intermediate part 110b, and a cathode part 110c, which are arranged in this order in the first direction along one anode body 11. The anode body 11 includes a core region 11Y, a porous region 11X disposed on both sides of the core region 11Y, and a dielectric oxide film layer (first dielectric oxide film layer) disposed on the surface of the porous region 11X. 12a, a second dielectric oxide layer 12b, and a third dielectric oxide layer 12c).

The anode portion 110a includes a first portion 11a that is a part of the anode body 11. That is, the anode portion 110a includes a core region 11Y, porous regions 11X disposed on both sides of the core region 11Y, and a first dielectric oxide film layer 12a covering the surface of the porous region 11X.

Intermediate portion 110b includes second portion 11b of anode body 11. However, in the intermediate portion 110b, the porous region 11X of the anode body 11 and the pores of the second dielectric oxide film layer 12b are filled with the first insulating resin. In this specification, a region in which the pores of the porous region 11X and the second dielectric oxide film layer 12b are filled with the first insulating resin is referred to as a first insulating layer 21. The intermediate portion 110b includes a first insulating layer 21 and a second insulating layer 22 containing a second insulating resin disposed on the first insulating layer 21. In other words, the intermediate portion 110b includes a core region 11Y, a first insulating layer 21 disposed in the core region 11Y, and a second insulating layer 22 covering the first insulating layer 21.

The cathode section 110c includes a third portion 11c of the anode body 11, a solid electrolyte layer 13 covering the third portion 11c, and a cathode extraction layer 14 covering the solid electrolyte layer 13. That is, a core region 11Y, a porous region 11X arranged on both sides of the core region 11Y, a third dielectric oxide layer 12c covering the surface of the porous region 11X, and a third dielectric oxide layer 12c. 12c, and a cathode extraction layer 14 that covers the solid electrolyte layer 13.

As described above, in the intermediate portion 110b of the capacitor element 110, the first insulating resin is disposed within the plurality of pores in the porous region 11X and the second dielectric oxide layer 12b. As a result, the pores in the porous region 11X and the second dielectric oxide film layer 12b are sufficiently closed, and oxygen is prevented from diffusing from the anode section 110a side to the cathode section 110c side. By having the second insulating layer 22 covering the first insulating layer 21, the insulation properties of the intermediate portion 110b are further enhanced.

(Anode part)
The anode portion 110a of the capacitor element 110 includes the first portion 11a of the anode body 11, as described above. The anode body 11 is obtained by subjecting a foil containing a valve metal (metal foil) to roughening treatment and chemical conversion treatment, for example, by electrolytic etching. Specifically, the porous region 11X is formed by roughening the foil or the like. At this time, the area that has not been subjected to the surface roughening process becomes the core area 11Y. Then, a dielectric oxide film layer (first dielectric oxide film layer 12a in the anode portion 110a) is formed by further subjecting the foil after the surface roughening treatment to a chemical conversion treatment. The porous region 11X, the core region 11Y, and the first dielectric oxide layer 12a can be distinguished from the first cross section of the capacitor element 110.

Examples of the valve metal include titanium, tantalum, aluminum, and niobium. The valve metal may be an alloy or an intermetallic compound. The thickness of the anode body 11 varies depending on the purpose of use, but is generally about 40 to 150 μm. The size and shape of the anode body 11 vary depending on the application, but if it is a flat plate, it is preferably rectangular with a width of about 1 to 50 mm and a length of about 1 to 50 mm; A rectangular shape of approximately 2 to 20 mm is more preferred.

The thickness of the porous region 11X in the anode body 11 is not particularly limited. From the viewpoint of capacitance, the thickness of the porous region 11X arranged on one main surface side of the anode body 11 is preferably 20% or more of the thickness of the foil before roughening. On the other hand, from the viewpoint of strength, the thickness of the porous region 11X disposed on the one main surface side is preferably 40% or less of the thickness of the foil before roughening. The thickness of the porous region 11X in the anode portion 110a is determined from the boundary between the first dielectric oxide film layer 12a and the porous region 11X to the boundary between the porous region 11X and the core region 11Y in the first cross section of the capacitor element 110. This is the average value when measuring the distance to 3 points.

On the other hand, the dielectric oxide film layer (first dielectric oxide film layer 12a) is a layer formed along the main surface (surface) of the anode body 11, and is formed along the inner wall of the hole in the porous region. It is a layer. Therefore, the dielectric oxide film layer also has a plurality of fine holes.

The dielectric oxide film layer may be formed on the entire surface of the anode body 11, or may be formed only on a part of the surface. The dielectric oxide film layer is formed by, for example, anodic oxidation of the surface of the porous region 11X. As such, the dielectric oxide layer may include an oxide of a valve metal. For example, if aluminum is used as the valve metal, the dielectric oxide layer may include aluminum oxide. However, the dielectric oxide film layer is not limited to this, and any layer that functions as a dielectric may be used.

(middle part)
The intermediate portion 110b includes a core region 11Y of the anode body 11, a first insulating layer 21 in which the porous region 11X of the anode body 11 and the second dielectric oxide film layer 12b are filled with a first insulating resin, and the first It has a second insulating layer 22 that covers the insulating layer 21 and includes a second insulating resin. Note that the core region 11Y, porous region 11X, and dielectric oxide film layer (also referred to as "second dielectric oxide film layer 12b" in the intermediate part 110b) of the anode body 11 are included in the above-mentioned anode part 110a. Since the configuration is the same as that of the configuration, a detailed explanation will be omitted here.

The first insulating layer 21 is a layer in which a first insulating resin is placed in a plurality of pores in the porous region 11X and the second dielectric oxide layer 12b. When looking at the first cross section of the capacitor element 110, the arrangement ratio of the first insulating resin to the plurality of pores in the porous region 11X and the second dielectric oxide film layer 12b, that is, the filling rate of the first insulating resin is 90% or more is preferable. If it is less than 90%, oxygen entering from the anode part 110a side may reach the cathode part 110c side through the porous region 11X inside the anode body 11. Therefore, the solid electrolyte layer 13 of the cathode portion 110c may be oxidized and deteriorated, resulting in a decrease in heat resistance reliability. On the other hand, when the filling rate is 90% or more, oxygen diffusion is suppressed regardless of the temperature, so that heat resistance reliability is improved.

The filling rate can be confirmed by observing the first cross section of the middle part of the capacitor element 110 using a scanning electron microscope (SEM), and determining the area of the plurality of pores in the porous region 11X and the filling rate of the pores from the observation photograph. Calculate the area of the insulating resin. Then, it is determined from these ratios [(area of insulating resin/area of pores)×100)].

Further, the second insulating layer 22 is a layer containing a second insulating resin and is disposed to cover the first insulating layer 21 . The second insulating layer 22 is formed by, for example, filling the porous region 11X with a precursor of the first insulating resin and curing it to form the first insulating layer 21. It may be a layer using a precursor of the first insulating resin that protrudes without being filled into the coating layer 12b. However, as a curing reaction, the second insulating resin may be cured only by UV irradiation without heat treatment, whereas the first insulating resin may be cured by heat treatment in addition to UV irradiation. It is preferable that By changing the curing conditions in this way, the glass transition temperature T ₁ of the first insulating resin can be made higher than the glass transition temperature T ₂ of the second insulating resin. The glass transition temperature T ₁ of the first insulating resin is preferably 145° C. or higher, and T ₁ is preferably higher than T ₂ by 10° C. or higher. When the difference in glass transition temperature between the first insulating resin and the second insulating resin is 10° C. or more, the heat resistance stability of the intermediate portion 110b is improved.

To confirm the glass transition temperature, the first insulating resin or the second insulating resin was measured using a differential scanning calorimeter (DSC7000 manufactured by Hitachi High-Technology) in temperature modulation DSC mode at a heating rate of 5° C./min and an applied frequency of 0.02 Hz. Determined by measurement conditions. More specifically, the glass transition temperature is measured with the first insulating resin filled in the porous region 11X and the second dielectric oxide film layer 12b. On the other hand, for the second insulating resin, a precursor of the second insulating resin is applied onto an arbitrary substrate (for example, a plate-shaped member made of silicone rubber), and the second insulating resin is formed under the same conditions as when forming the second insulating layer 22. A cured sample is prepared, and the glass transition temperature of the sample is measured.

From the viewpoint of heat resistance reliability, the glass transition temperature of the first insulating resin is more preferably 150° C. or higher. The glass transition temperature of the second insulating resin is preferably 135° C. or higher. The glass transition point is determined under the measurement conditions of a differential scanning calorimeter (DSC7000, manufactured by Hitachi High-Technology) in temperature modulation DSC mode, heating rate of 5° C./min, and application frequency of 0.02 Hz. When the glass transition temperature of the first insulating resin is 150° C. or higher and the glass transition temperature of the second insulating resin is 135° C. or higher, thermal decomposition is difficult to occur even if exposed to a high temperature environment for a long time. In addition, insulation properties can be maintained for a long period of time, and heat resistance reliability tends to be high.

It is desirable that the elastic modulus of the first insulating resin at 25° C. is 0.1 GPa or more. The elastic modulus is a value measured by dynamic mechanical analysis (DMA) under measurement conditions of a heating rate of 5° C./min and a frequency of 10 Hz. When the elastic modulus at 25° C. is 0.1 GPa or more, peeling is unlikely to occur at the interface between each pore of the porous region 11X and the first insulating resin even if exposed to a high temperature environment for a long time. Therefore, insulation can be maintained for a long period of time, and heat resistance reliability tends to be high. The elastic modulus of the first insulating resin can be determined by applying a precursor of the first insulating resin onto an arbitrary substrate (for example, a plate-shaped member made of silicone rubber) and applying the precursor under the same conditions as when forming the first insulating layer 21. A sample is prepared by curing the sample, and the elastic modulus of the sample is measured.

It is desirable that the second insulating resin has an elastic modulus of 1.0 MPa or more at 25°C. The elastic modulus is a value measured by dynamic mechanical analysis (DMA) under measurement conditions of a heating rate of 5° C./min and a frequency of 10 Hz. When the elastic modulus at 25° C. is 1.0 MPa or more, peeling is unlikely to occur at the interface between the first insulating layer and the second insulating layer even if exposed to a high temperature environment for a long time. Therefore, insulation can be maintained for a long period of time, and heat resistance reliability tends to be high. The elastic modulus of the second insulating resin can be determined by applying a precursor of the second insulating resin onto an arbitrary substrate (for example, a plate-shaped member made of silicone rubber) and applying the precursor under the same conditions as when forming the second insulating layer 22. A sample is prepared by curing the sample, and the elastic modulus of the sample is measured.

The oxygen permeability coefficients of the first insulating resin and the second insulating resin are preferably 1.0×10 ⁻¹¹ cc·cm/(cm ² ·sec·cmHg) or less. The oxygen permeability coefficient is a value measured by an electrolytic sensor method according to JIS K7176-1. When the oxygen permeability coefficient of the insulating resin is 1.0×10 ⁻¹¹ cc·cm/(cm ² ·sec·cmHg) or less, oxygen entering from the anode portion 110a passes through the porous region 11X inside the anode body 11. It is possible to sufficiently suppress the movement of the liquid to the cathode portion 110c side.

The thickness of the second insulating layer 22 is usually preferably 1 μm or more and 50 μm or less, more preferably 1 μm or more and 20 μm or less. When the thickness of the second insulating layer 22 is within this range, the insulation properties of the intermediate portion 110b are more likely to be improved.

As described above, the first insulating resin included in the first insulating layer 21 and the second insulating resin included in the second insulating layer 22 are preferably resins containing a thioether structure in which an epoxy group reacts with a thiol group. Such a resin can be obtained by curing a mixture containing an epoxy compound containing an epoxy group and a thiol compound containing a thiol group. For example, these curing may be accelerated by a photobase generator.

Here, in order to improve the heat resistance reliability of the solid electrolytic capacitor 100, even if the first insulating resin present in each pore of the porous region 11X is exposed to a high temperature environment for a long time, the valve action metal It is required that peeling does not easily occur at the interface between (the porous region 11X) and the first insulating resin, and that the insulation properties of the solid electrolytic capacitor 100 do not deteriorate due to thermal decomposition of the first insulating resin. Furthermore, the second insulating resin present in the second insulating layer 22 also peels off at the interface between the second insulating layer 22 (second insulating resin) and the first insulating layer 21 when exposed to a high temperature environment for a long time. It is required that the insulation properties of the solid electrolytic capacitor 100 do not deteriorate due to thermal decomposition of the second insulating resin.

Generally, resins obtained only from epoxy compounds have excellent heat resistance but are brittle. Therefore, when an epoxy compound is reacted with a thiol compound and crosslinked, a thioether structure is formed and flexibility is developed. Therefore, the first insulating resin including the structure has excellent heat resistance and is difficult to peel off at the interface with the pores.

Furthermore, if it is attempted to fill the pores in the porous region 11X with only an epoxy compound, heat treatment at 150° C. or higher is required during curing. On the other hand, when a thiol compound is combined with an epoxy compound, curing at low temperatures becomes possible. Furthermore, when a photobase generator or the like is further combined, photocuring at room temperature becomes possible. Therefore, in this embodiment, after applying (filling) the mixture of the epoxy compound and the thiol compound into the plurality of pores in the porous region 11 can be started. In other words, by using resins (first insulating resin and second insulating resin) containing a thioether structure in which an epoxy group reacts with a thiol group, the shape stability of the first insulating layer 21 and the second insulating layer 22 is improved. .

Here, the epoxy compound may be any compound having one or more epoxy groups in the molecule, but compounds having two or more epoxy groups are more preferable from the viewpoint of easily increasing the crosslinking density. Specific examples of epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, etc. Among these, bisphenol A type epoxy compounds are preferred.

The thiol-based compound may be any compound having one or more thiol groups in the molecule, but compounds having two or more thiol groups are more preferable from the viewpoint of easily increasing the crosslink density. Preferred examples of the thiol compounds include tetrafunctional thiols having a glycoluril skeleton as a parent skeleton and tetrafunctional thiols having a pentaerythritol skeleton. Further, the amount of the thiol compound when forming the first insulating resin or the second insulating resin is preferably 50 to 200 parts by weight, and preferably 70 to 100 parts by weight based on 100 parts by weight of the epoxy compound. It is more preferable that

Further, the photobase generator that can be combined with the above compound can be a known photobase generator, such as carboxylates, salts containing borate anions, quaternary ammonium salts, and carbamates. Among these, o-nitrobenzyl type photobase generator, (8E)-8-ethylidene-4-methoxy-5,6,7,8tetrahydronaphthalene-1-carboxylic acid 1,8-diazabicyclo[5,4,0 ] Undec-7-ene, 1,2-disopropyl-3-[bis(dimethylamino)methylene]guanidium 2-(3-benzoylphenyl)propinate, 1,2-dicyclohexyl-4,4,5,5-tetramethyl Diguadium n-butyltriphenylborate, (2-(9-oxoxanthen-2-yl)propionic acid 1,5,7-triazabicyclo[4,4,0]dec-5-ene)), bis (dimethylamino)methylidene]amino}-N-cyclohexyl(cyclohexylamino)methaniminium tetrakis(3-fluorophenyl)borate is preferred. Further, the amount of the photobase generator when forming the first insulating layer 21 and the second insulating layer 22 is preferably 1.0 to 15 parts by mass based on 100 parts by mass of the epoxy compound. More preferably, the amount is 3.5 to 15 parts by mass.

Here, the ratio of the length of the intermediate portion 110b in the first direction to the length of the cathode portion 110c in the first direction (length of the intermediate portion 110b/length of the cathode portion 110c) is 0.04 or more and 0.04 or more. Desirably 1 or less. For example, if the length of the cathode portion 110c in the first direction is 5.5 mm, the length of the intermediate portion 110b in the first direction is preferably 0.20 mm to 0.55 mm. When the above ratio is 0.04 or more, insulation properties and oxygen barrier properties become good, and heat resistance reliability tends to increase. Further, when the ratio is 0.1 or less, the capacitance, which is a basic characteristic of a capacitor, is hardly affected.

(Cathode part)
As described above, the cathode section 110c includes the third portion 11c of the anode body 11, the solid electrolyte layer 13 covering the third portion 11c, and the cathode extraction layer 14 covering the solid electrolyte layer 13. Since the anode body 11 is the same as the anode body 11 included in the above-described anode portion 110a, detailed description thereof will be omitted here.

The solid electrolyte layer 13 may be formed to cover at least a portion of the third dielectric oxide film layer 12c of the anode body 11, and may be formed to cover the entire surface of the dielectric oxide film layer 12c. Good too. The solid electrolyte layer 13 is made of a conductive polymer material such as polypyrrole, polythiophene, polyfuran, polyaniline, or the like.

The cathode extraction layer 14 may be formed to cover at least a portion of the solid electrolyte layer 13, and may be formed to cover the entire surface of the solid electrolyte layer 13. The cathode extraction layer 14 is, for example, a carbon layer and a metal (eg, silver) paste layer formed on the surface of the carbon layer, which are sequentially laminated. Note that the configuration of the cathode extraction layer 14 is not limited to this, and may be any configuration as long as it has a current collecting function.

(solid electrolytic capacitor)
FIG. 2 is a cross-sectional view schematically showing an electrolytic capacitor according to one embodiment. The solid electrolytic capacitor 100 of this embodiment includes a capacitor element 110 of one or more layers, an anode lead terminal 120A joined to the anode part 110a of the capacitor element 110, a cathode lead terminal 120B joined to the cathode part 110c, and a capacitor element 110 having one or more layers. A sealing resin 130 that seals the element 110 is provided.

The solid electrolytic capacitor 100 may include a plurality of capacitor elements 110, and when it includes a plurality of capacitor elements 110, these are stacked. The number of laminated layers of capacitor element 110 is not particularly limited, and is, for example, 2 or more and 10 or less. The anode parts 110a of the stacked capacitor elements 110 are joined together by welding, caulking, etc., and are electrically connected.

Further, an anode lead terminal 120A is connected to the anode portion 110a of the capacitor element 110. The anode portion 110a and the anode lead terminal 120A may be joined by laser welding or the like, or may be joined by resistance welding or the like.

Furthermore, the cathode portions 110c of the stacked capacitor elements 110 are also electrically connected to each other. A cathode lead terminal 120B is connected to the cathode portion 110c of the capacitor element 110. The cathode lead terminal 120B is joined to the cathode portion 110c via, for example, a conductive adhesive or solder. The conductive adhesive can be, for example, a mixture of a curable resin and carbon particles or metal particles.

Further, the capacitor element 110 joined to each of the lead terminals 120A and 120B is sealed with a sealing resin 130 so that at least a portion of the anode lead terminal 120A and the cathode lead terminal 120B are exposed. Examples of the sealing resin include phenol resin, urea resin, melamine resin, and epoxy resin.

[Method for manufacturing solid electrolytic capacitors]
The solid electrolytic capacitor according to this embodiment can be manufactured by the following method.

As shown in the flowchart of FIG. 3, the method for manufacturing a solid electrolytic capacitor of this embodiment includes a preparation step of preparing an anode body having a porous region, and forming a dielectric oxide film layer on the surface of the porous region. a dielectric oxide film layer forming step, and an insulating resin is applied to the porous region and the pores of the dielectric oxide film layer at a position corresponding to the intermediate portion of the anode body having the dielectric oxide film layer formed on the surface. a first insulating layer forming step of filling and forming a first insulating layer; and a second insulating layer forming step of arranging an insulating resin to cover the first insulating layer and forming a second insulating layer covering the first insulating layer. and a cathode part forming step of forming a solid electrolyte layer on the dielectric oxide film layer at a position corresponding to the cathode part of the anode body, and further forming a cathode extraction layer on the solid electrolyte layer. After forming a capacitor element by this method, a lead terminal connecting step and a sealing step may be performed as necessary. Note that in the solid electrolytic capacitor obtained by the above manufacturing method, the glass transition temperature T ₁ of the resin included in the first insulating layer is higher than the glass transition temperature T ₂ of the resin included in the second insulating layer. As a method for making the glass transition temperature _T1 of the resin contained in the first insulating layer higher than the glass transition temperature _T2 of the resin contained in the second insulating layer, there are methods such as changing the curing conditions of each resin, or At the time of formation, photocuring and thermal curing may be used in combination, or a generator may be used to accelerate the curing reaction. As the generator, a photobase generator may be used alone, but a photobase generator and a radical type generator may be used in combination. However, this embodiment is not limited to this.

(Preparation process)
In this step, an anode body having a porous region is prepared. For example, a commercially available anode body may be prepared. On the other hand, at least one main surface of the metal foil containing the valve metal may be roughened to prepare an anode body having a porous region. Examples of methods for roughening the metal foil include electrolytic etching, but the conditions are not particularly limited and are appropriately set depending on the depth of the porous region, the type of valve metal, etc.

(Dielectric oxide film layer formation process)
In this step, a dielectric oxide film layer is formed on the surface of the anode body prepared in the above-mentioned preparation step. The method of forming the dielectric oxide film layer is not particularly limited. The dielectric oxide film layer can be formed by, for example, subjecting the anode body to a chemical conversion treatment. In the case of chemical conversion treatment, for example, the above-described anode body can be immersed in a chemical conversion liquid such as an ammonium adipate solution and then heat treated. Alternatively, the dielectric oxide film layer may be formed by immersing the anode body in a chemical solution and applying a voltage.

Note that the dielectric oxide film layer may be formed on the entire surface of the porous region, or may be formed only on a portion of the surface.

(First insulation layer formation step)
In this step, an insulating resin is filled in the porous region and the pores in the dielectric oxide film layer at a position corresponding to the middle part of the anode body with the dielectric oxide film layer formed on the surface, and the first insulating layer is formed. Form.

As a method for filling the pores with an insulating resin, a mixture containing an epoxy compound and a thiol compound is applied onto the porous area and the dielectric oxide film layer by various printing methods, coating with a dispenser, transfer method, etc. A method may be mentioned in which a sufficient amount is applied and impregnated, and then these are reacted and cured. Although the above curing may be thermal curing, it is more preferable to perform curing by light irradiation because the first insulating resin can be cured before it spreads outward from the position corresponding to the intermediate portion. When performing light irradiation and heating, it is preferable to perform the light irradiation first and then perform the heating. Further, the irradiated light can be, for example, ultraviolet light.

Note that the mixture may contain a solvent in order to sufficiently impregnate the porous region and the pores of the dielectric oxide layer with the mixture.

(Second insulating layer forming step)
After the first insulating layer forming step, an insulating resin is placed and cured to cover the surface of the first insulating layer to form a second insulating layer. Like the first insulating layer, the second insulating layer can also be formed by a printing method, a method using a dispenser, a transfer method, etc. For example, the second insulating layer is formed so as to cover the surface of the first insulating layer by applying the same mixture as in the formation of the first insulating layer to the intermediate portion and curing it by light irradiation. After the light irradiation, heating may be further performed.

(Cathode part formation process)
In this step, a solid electrolyte layer and a cathode extraction layer are formed on the surface of the dielectric oxide film layer at a position corresponding to the cathode portion. The solid electrolyte layer can be formed by chemically polymerizing or electrolytically polymerizing raw material monomers or oligomers in the presence of an anode body. The solid electrolyte layer may be formed by applying a solution in which a conductive polymer is dissolved or a dispersion in which a conductive polymer is dispersed to the dielectric oxide layer. The method for applying the dispersion liquid is not particularly limited, and may be the same as known methods.

Next, a cathode extraction layer is formed by sequentially applying, for example, carbon paste and silver paste to the surface of the solid electrolyte layer. The method of applying carbon paste or silver paste is not particularly limited, and may be the same as known methods.

(Lead terminal connection process)
In the lead terminal connecting step, an anode lead terminal is electrically connected to the anode body, and a cathode lead terminal is electrically connected to the cathode extraction layer. The anode body and the anode lead terminal are electrically connected, for example, by welding them together. Further, the electrical connection between the cathode extraction layer and the cathode lead terminal is performed, for example, by adhering the cathode extraction layer and the cathode lead terminal via a conductive adhesive.

(Sealing process)
A portion of the capacitor element and lead terminals may be sealed with a sealing resin. Sealing is performed using molding techniques such as injection molding, insert molding, and compression molding. For example, using a predetermined mold, a composition containing a curable resin or a thermoplastic resin is filled to cover the capacitor element and one end of the lead terminal, and then heated or the like is performed.

EXAMPLES Hereinafter, the present invention will be specifically explained based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

下記一般式で表される、ｏ－ニトロベンジル型光塩基発生剤

（４）反応性希釈剤
ＥＰ－４０８８Ｓ：ジシクロペンタジエン型エポキシ、ＡＤＥＫＡ社製、エポキシ基当量１７０
（５）増感剤
２－プロピルチオキサントン、東京化成社製 (Preparation of raw materials)
The following compounds were prepared as materials for the insulating layer.
(1) Epoxy compound jER828: Bisphenol A type epoxy compound, manufactured by Mitsubishi Chemical Corporation, epoxy group equivalent: 190
BATG: Tetrafunctional epoxy compound, manufactured by Showa Denko, epoxy group equivalent 128
VG3101L: trifunctional epoxy compound, manufactured by Printec, epoxy group equivalent 210
(2) Thiol compound MTPE1: pentaerythritol skeleton tetrafunctional thiol, manufactured by Showa Denko, thiol group equivalent: 136
C3TS-G: Tetrafunctional thiol with glycoluril skeleton as the parent skeleton, manufactured by Shikoku Kasei Co., Ltd., thiol group equivalent: 110
(3) Photobase generator WPBG-345: Borate type photobase generator represented by the following formula, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

o-nitrobenzyl type photobase generator represented by the following general formula

(4) Reactive diluent EP-4088S: dicyclopentadiene type epoxy, manufactured by ADEKA, epoxy group equivalent 170
(5) Sensitizer 2-propylthioxanthone, manufactured by Tokyo Kasei Co., Ltd.

(Example 1)
(1) Preparation of anode body An anode body having porous regions on both main surfaces was prepared by electrolytically etching an aluminum foil having a thickness of 115 μm. The thickness of the porous region formed on each main surface of the anode body was 40 μm. Further, the length of the anode body in the first direction was 6.5 cm.

(2) Formation of dielectric oxide film layer The above anode body was subjected to chemical conversion treatment to form a dielectric oxide film layer covering both main surfaces thereof.

(3) Formation of first insulating layer 3.61 parts by mass of epoxy compound "BATG", 0.59 parts by mass of epoxy compound "VG3101L", and 0.20 parts by mass of reactive diluent "EP-4088S" are mixed. did. To increase solubility, the mixture was heated in a constant temperature bath at 50 to 65° C. for 10 minutes, and then cooled to room temperature. Thereafter, 3.54 parts by mass of a thiol compound "C3TS-G" and 0.15 parts by mass of a photobase generator were further added, and the mixed solution was sufficiently kneaded using a planetary kneader. Subsequently, the liquid mixture was linearly applied to a region corresponding to the longitudinally intermediate portion of the anode body using a dispenser. Immediately after coating, a UV irradiator was used to irradiate ultraviolet light (integrated light amount: 10,000 mJ/cm ² ), and heat treatment was performed at 100°C for 15 minutes to form a first insulating resin in which the plurality of pores in the porous region were filled with the first insulating resin. 1 insulating layer was formed.

(4) Formation of the second insulating layer During the formation of the first insulating layer (3) above, the mixed liquid that did not fit into the pores of the porous region and the dielectric oxide layer and remained on the anode body was coated. Immediately thereafter, it was irradiated with ultraviolet rays (integrated light amount 30,000 mJ/cm ² ) using an ultraviolet irradiator, and was cured by heat treatment at 100° C. for 15 minutes to form a second insulating layer.

(5) Formation of solid electrolyte layer An aniline aqueous solution containing aniline and sulfuric acid was prepared. A tape-shaped electrode was pasted on the second insulating layer described above. Subsequently, a region of the anode body corresponding to the cathode portion and the counter electrode were immersed in an aniline aqueous solution, and electrolytic polymerization was performed at a current density of 10 mA/cm ² for 20 minutes. As a result, a solid electrolyte layer was formed in the cathode section.

(6) Formation of cathode extraction layer Carbon paste and silver paste were sequentially applied onto the solid electrolyte layer and dried. Thereby, a cathode extraction layer was formed and a capacitor element was obtained.

(Examples 2 to 4, Comparative Example 1)
As shown in Table 1, a capacitor element was produced in the same manner as in Example 1, except that the raw material blending ratio of the insulating resin was changed.

(Comparative example 2)
When forming the first insulating layer and the second insulating layer in step (3) above, do not perform thermal curing, but after irradiating with ultraviolet light (integrated light amount 30,000 mJ/cm ² ), leave at room temperature for 1 hour to cure. Ta. Thereafter, a capacitor element was produced in the same manner as in Example 1.

(evaluation)
・Heat resistance of insulating resin: Glass transition temperature The glass transition temperature of the first insulating resin and the second insulating resin was measured using a differential scanning calorimeter (DSC7000 manufactured by Hitachi High-Technology) in temperature modulation DSC mode at a heating rate of 5°C/min. The measurement was performed under the measurement conditions of an applied frequency of 0.02 Hz. The glass transition temperature of the first insulating resin was measured in a state in which the porous region and the second dielectric oxide film layer were filled with the first insulating resin. On the other hand, for the second insulating resin, a sample was prepared by applying the mixture used in (3) above onto a plate-shaped member made of silicone rubber and curing it under the same conditions as when forming the second insulating layer. Then, the glass transition temperature of the sample was measured. When the glass transition temperature T ₁ of the first insulating resin was higher than the glass transition temperature T ₂ of the second insulating resin, it was marked as “〇”, and in other cases, it was marked as “×”.

・Followability of insulating resin to aluminum foil: Storage modulus The storage modulus of the first insulating resin and second insulating resin was measured by dynamic mechanical analysis (DMA) at a heating rate of 5°C/min and a frequency of 10 Hz. Measured under the following measurement conditions. The elastic modulus of the first insulating resin is determined by applying the mixture used in (3) above to a thickness of 100 μm on a plate-shaped member made of silicone rubber, and using an ultraviolet irradiator with a wavelength of 365 nm to obtain an integrated light amount of 10,000 mJ/ Cured in cm ² . Then, a liquid sample up to a thickness of 50 μm from the surface was taken out, cured at 100° C. for 15 minutes, and its storage modulus was measured. Regarding the second insulating resin, a plate-like member made of silicone rubber was prepared under the same curing conditions as in (4) above, and its storage modulus was measured. When the elastic modulus of the first insulating resin at 25° C. was 0.1 GPa or more, it was marked “○”, and when it was less than 0.1 GPa, it was marked “x”. Moreover, when the elastic modulus of the second insulating resin at 25° C. was 1.0 MPa or more, it was marked as “○”, and when it was less than 1.0 MPa, it was marked as “x”.

- Oxygen barrier property of insulating resin: Oxygen permeability coefficient As a method for preparing a test piece, a coating film with a diameter of 40 mm and a thickness of 10 μm was prepared. The curing method at this time was the same as the above procedure (3) for both the first insulating resin and the second insulating resin. The oxygen permeability coefficients of the first insulating resin and the second insulating resin produced by these procedures were measured by an electrolytic sensor method according to JIS K7176-1. If the oxygen permeability coefficient is 1.0×10 ^-11 cc・cm/(cm ²・sec・cmHg) or less, mark “〇”, 1.0×10 ⁻¹¹ cc・cm/(cm ²・sec・cmHg) If it is larger, it is marked as "×".

- Evaluation of heat resistance reliability of capacitor element The capacitance of the capacitor element obtained above was measured before and after the heat treatment, and the rate of change was calculated. Heating was performed at 145° C. for 250 hours. The rate of change was determined by {(capacitance before heat treatment−capacitance after heat treatment)/capacitance before heat treatment}. If the rate of change was 40% or less, it was marked "○", and if it was greater than 40%, it was marked "x".

-Resin filling property of intermediate portion of capacitor element In addition, the filling rate of the first insulating resin of the capacitor element obtained as described above was measured. Specifically, the first cross section of the capacitor element was observed using SEM. Then, from the observation photograph, the area of the plurality of pores in the intermediate porous region and the area of the first insulating resin were determined, and the ratio of these [(area of the first insulating resin/area of the pores) x 100 )] was determined as the filling rate. When the filling rate was 90% or more, it was marked "○", and when it was less than 90%, it was marked "x".

- Overall Judgment All of the above evaluations were judged as "○", and the overall judgment was judged as "〇". If any of the four judgments had an "x", it was determined as an overall judgment of "x".

Regarding the heat resistance reliability of the insulating resin, Examples 1 to 4 and Comparative Example 1 were all evaluated as ○, whereas Comparative Example 2 was evaluated as ×. In Comparative Example 2, heat treatment after light irradiation was not performed when forming the first insulating layer and the second insulating layer, so it is thought that the crosslinking density of the first insulating resin and the second Zetsuen resin as a cured product was low. Furthermore, since the molecular bonding force between the first insulating resin and the metal on the surface of the submicron-sized pores existing in the porous region of the anode body is small, T ₁ of the first insulating resin is larger than T ₁ of the second insulating resin. It is considered that the value was not reached. From this, it became clear that T ₁ of the first insulating resin is preferably larger than T ₂ of the second insulating resin.

Regarding the elastic modulus of the first insulating resin at 25° C., Examples 1 to 4 were all evaluated as ○, whereas Comparative Examples 1 and 2 were evaluated as ×. This is considered to be because, in Comparative Example 1, the first insulating resin and the second insulating resin did not contain a thioether structure. On the other hand, in Comparative Example 2, since no heat treatment was performed after light irradiation, the crosslinking density as a cured product was low, and it is thought that the elastic modulus of the first insulating resin at 25° C. was less than 0.1 GPa. In addition, when these materials are exposed to a high-temperature environment for a long time in a heat resistance reliability test, the adhesive strength at the interface between each pore in the porous region and the first insulating resin decreases, making it impossible to maintain insulation properties. It is thought that there was no such thing. As a result, it is thought that the oxygen that entered from the anode part could not be sufficiently suppressed from moving to the cathode part through the porous region inside the anode body, and the capacitance change rate also deteriorated. From this, it became clear that the elastic modulus of the first insulating resin at 25° C. is preferably 0.1 GPa or more.

Regarding the oxygen barrier properties of the first insulating resin and the second insulating resin, Examples 1 to 4 were all evaluated as ○, whereas Comparative Examples 1 to 2 were evaluated as ×. It is believed that in Comparative Examples 1 and 2, the crosslinking density as a cured product was low, and the oxygen permeability coefficient was 1.0×10 ⁻¹¹ cc·cm/(cm ² ·sec·cmHg) or more. As a result, in heat resistance reliability tests, it was not possible to sufficiently suppress oxygen that entered from the anode part from the beginning of the test and moved to the cathode part through the porous region inside the anode body, and the rate of capacitance change also worsened. It is thought that he did. From this, it has become clear that the oxygen permeability coefficients of the first insulating resin and the second insulating resin are preferably 1.0×10 ⁻¹¹ cc·cm/(cm ² ·sec·cmHg) or less.

Further, regarding the resin filling rate, Examples 1 to 4 and Comparative Example 2 were all evaluated as ○, whereas Comparative Example 1 was evaluated as ×. This is because the first insulating resin of Comparative Example 1 does not contain a thioether structure, so heat treatment at 100°C for 15 minutes after light irradiation has poor reactivity, and the mixed liquid spreads on the surface of the intermediate part, causing the first insulating resin to It is thought that the resin filling rate became small because the shape of the insulating layer could not be controlled. As a result, in heat resistance reliability tests, it was not possible to sufficiently suppress oxygen that entered from the anode part from the beginning of the test and moved to the cathode part through the porous region inside the anode body, and the rate of capacitance change also worsened. It is thought that he did. For this reason, the filling rate of the first insulating resin is preferably 90% or more.

Since the solid electrolytic capacitor of the present disclosure has excellent heat resistance and reliability, it can be used for various purposes.

11 Anode body 11X Porous region 11Y Core region 11a First portion 11b Second portion 11c Third portion 12a First dielectric oxide layer 12b Second dielectric oxide layer 12c Third dielectric oxide layer 13 Solid electrolyte layer 14 Cathode extraction layer 21 First insulating layer 22 Second insulating layer 100 Electrolytic capacitor 110 Capacitor element 110a Anode part 110b Intermediate part 110c Cathode part 110T1 First end part 110T2 Second end part 110X, 110Y Main surface 120A Anode lead terminal 120B Cathode Lead terminal 130 Sealing resin

Claims (7)

A capacitor element comprising an anode part, a cathode part, and an intermediate part interposed between these parts,
The anode portion, the intermediate portion, and the cathode portion are arranged along one anode body having a porous region on the main surface side and a dielectric oxide film layer formed on the surface of the porous region. ,
The anode portion includes a first portion of the anode body,
The intermediate portion covers a first insulating layer in which the porous region of the second portion of the anode body and the pores of the dielectric oxide layer are filled with a first insulating resin, and the first insulating layer. a second insulating layer containing a second insulating resin;
The cathode part includes a third part of the anode body, a solid electrolyte layer covering the dielectric oxide film layer of the third part, and a cathode extraction layer covering the solid electrolyte layer,
The glass transition temperature _T1 of the first insulating resin is higher than the glass transition temperature _T2 of the second insulating resin,
the first insulating resin and the second insulating resin include a thioether structure;
Solid electrolytic capacitor. The elastic modulus of the first insulating resin at 25° C. is 0.1 GPa or more,
The solid electrolytic capacitor according to claim 1. The elastic modulus of the second insulating resin at 25° C. is 1.0 MPa or more,
The solid electrolytic capacitor according to claim 1. The oxygen permeability coefficients of the first insulating resin and the second insulating resin are 1.0×10 ⁻¹¹ cc·cm/(cm ² ·sec·cmHg) or less;
The solid electrolytic capacitor according to claim 1. In the first insulating layer, a filling rate of the first insulating resin with respect to the plurality of pores is 90% or more;
The solid electrolytic capacitor according to claim 1. The ratio of the length of the intermediate portion to the length of the cathode portion in a direction connecting the anode portion, the intermediate portion, and the cathode portion is 0.04 or more and 0.1 or less;
The solid electrolytic capacitor according to any one of claims 1 to 5. A method for manufacturing a solid electrolytic capacitor including a capacitor element including an anode part, a cathode part, and an intermediate part interposed therebetween,
a preparation step of preparing an anode body having a porous region on the surface;
a dielectric oxide layer forming step of forming a dielectric oxide layer on the surface of the porous region;
The porous region and the pores of the dielectric oxide film layer at a position corresponding to the intermediate portion of the anode body having the dielectric oxide film layer formed on the surface thereof are filled with an insulating resin and cured. a first insulating layer forming step of forming an insulating layer;
a second insulating layer forming step of arranging and curing an insulating resin to cover the first insulating layer to form a second insulating layer;
a cathode part forming step of forming a solid electrolyte layer on the dielectric oxide film layer at a position corresponding to the cathode part of the anode body, and further forming a cathode extraction layer on the solid electrolyte layer;
Equipped with
The glass transition temperature _T1 of the resin included in the first insulating layer is higher than the glass transition temperature _T2 of the resin included in the second insulating layer,
The resin included in the first insulating layer and the resin included in the second insulating layer include a thioether structure,
Method of manufacturing solid electrolytic capacitors.

Images