JP2005109466A - Capacitor and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a group of capacitors in which capacity distribution is relatively limited. <P>SOLUTION: A method of manufacturing a capacitor in which an electric conductor on a surface of which a dielectric layer is formed is assumed to be one electrode, while a semiconductor layer formed by an energization technique is assumed to be other electrode, and in which a predetermined direct current is passed through all of a plurality of the electric conductors with the electric conductor serving as an anode to form semiconductor layers, as well as a capacitor provided by the method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a capacitor group having a relatively narrow capacitance distribution.

  Capacitors used in central processing unit (CPU) circuits used in personal computers, etc. have high capacity and low ESR (equivalent series) in order to suppress voltage fluctuations and reduce heat generation when passing through high ripple. Resistance) is required. In general, an aluminum solid electrolytic capacitor or a tantalum solid electrolytic capacitor is used.

  Solid electrolytic capacitors consist of an aluminum foil with fine pores in the surface layer and a sintered body of tantalum powder with fine pores inside as one electrode (conductor) formed on the surface of the electrode. It comprises a body layer and the other electrode (usually a semiconductor layer) provided on the dielectric layer.

  As a method for forming a semiconductor layer of a capacitor using the semiconductor layer as the other electrode, for example, Japanese Patent No. 1868722 (Patent Document 1), Japanese Patent No. 1985056 (Patent Document 2), Japanese Patent Application Laid-Open No. 2000-188239. (Patent Document 3), JP-A-3-18009 (Patent Document 4), JP-A-4-42912 (Patent Document 5) and JP-A-2-299213 (Patent Document 6). There is a method using an energization method.

  In Patent Documents 1 to 3, a conductor provided with a dielectric layer on the surface is dipped in a semiconductor layer forming solution, and the conductor side is an anode, and is constant between an external electrode (cathode) prepared in the semiconductor layer forming solution. In this method, a semiconductor layer is formed by applying a current and applying a current.

  Patent Document 4 is a method in which an external terminal is brought into contact with a semiconductor portion of a conductor having a dielectric layer and a semiconductor layer laminated on the surface to supply a current to further form a semiconductor layer in a semiconductor layer forming solution.

Patent Document 5 is a method of forming a semiconductor layer by supplying a current from the external terminal also serving as a capacitor cathode terminal, in which a conductor and a cathode conductor are formed in a foil-like wound body.
Moreover, in patent document 6, alternating current is supplied to a conductor and the semiconductor layer is formed.

Japanese Patent No. 1868722 Japanese Patent No. 1985056 JP 2000-188239 A JP-A-3-18009 JP-A-4-42912 JP-A-2-299213

  In the case of the method of forming a semiconductor layer by the energization method of applying a constant voltage described in Patent Documents 1 to 3, there was no problem when the semiconductor layer was formed on one conductor. When forming a semiconductor layer at the same time, each conductor is not necessarily homogeneous, and the semiconductor formation speed may vary depending on the conductor, so that not only the current value flowing through each conductor changes but also the total current Since the value also changes with time, there is a problem that the capacitance distribution of the finally produced capacitor group (proportional to the formation of the semiconductor, particularly proportional to the semiconductor mass) becomes considerably wide.

  In the case of the methods of Patent Documents 4 and 5, since a current is supplied from an external terminal, a semiconductor is formed from the outer layer of the conductor, and the formation of the outer layer inhibits the formation of the semiconductor inside the pores. . For this reason, not only the average value of the capacitance of the manufactured capacitor group is reduced, but also the distribution is considerably wide (in general, the value obtained by dividing the standard deviation of the capacitance by the average value of the capacitance is 15% or more). there were.

  In addition, when supplying current to a plurality of conductors simultaneously by the method of Patent Document 6, when one of the terminals to be fed is on the conductor side and the other terminal is an electrode plate in the semiconductor forming container, it is an alternating current. Therefore, there is a problem that a semiconductor layer is also formed on the electrode plate in the semiconductor forming container and eventually becomes short-circuited with the semiconductor on the conductor, resulting in a dangerous state. In addition, in order to avoid such a danger, when the distance between the plurality of conductors and the electrode plate in the semiconductor forming container is greatly separated, it is difficult to make the current distribution to each conductor uniform, and as a result, the semiconductor As a result, there was a problem that a large number of defective capacitors were formed, and as a result, the capacitance variation of the produced capacitor group was quite large (the value obtained by dividing the standard deviation of the capacitance by the average value of the capacitance was 15% or more). .

  As a result of diligent investigations to solve the above problems, the present inventors have made a plurality of conductors having a dielectric layer formed as anodes and energized a predetermined DC constant current all at once on the dielectric layer. It has been found that a group of capacitors having a narrow capacitance distribution can be manufactured relatively easily by forming a semiconductor layer on the substrate, and the present invention has been completed.

（式（１）及び（２）において，Ｒ¹〜Ｒ⁴は、各々独立して水素原子、炭素数１〜６のアルキル基または炭素数１〜６のアルコキシ基を表し、Ｘは酸素、イオウまたは窒素原子を表し、Ｒ⁵はＸが窒素原子のときのみ存在して水素原子または炭素数１〜６のアルキル基を表し、Ｒ¹とＲ²及びＲ³とＲ⁴は、互いに結合して環状になっていてもよい。）
で示される繰り返し単位を含む高分子にドーパントをドープした導電性高分子を主成分とした有機半導体から選択される少なくとも１種である前記４記載のコンデンサの製造方法。
６．一般式（１）で示される繰り返し単位を含む導電性高分子が、下記一般式（３）

（式中、Ｒ⁶及びＲ⁷は、各々独立して水素原子、炭素数１〜６の直鎖状もしくは分岐状の飽和もしくは不飽和のアルキル基、または該アルキル基が互いに任意の位置で結合して、２つの酸素原子を含む少なくとも１つ以上の５〜７員環の飽和炭化水素の環状構造を形成する置換基を表す。また、前記環状構造には置換されていてもよいビニレン結合を有するもの、置換されていてもよいフェニレン構造のものが含まれる。）
で示される構造単位を繰り返し単位として含む導電性高分子である前記５記載のコンデンサの製造方法。
７．導電性高分子が、ポリアニリン、ポリオキシフェニレン、ポリフェニレンサルファイド、ポリチオフェン、ポリフラン、ポリピロール、ポリメチルピロール、及びこれらの置換誘導体及び共重合体から選択される前記６記載のコンデンサの製造方法。
８．導電性高分子が、ポリ（３，４−エチレンジオキシチオフェン）である前記７記載のコンデンサの製造方法。
９．無機半導体が、二酸化モリブデン、二酸化タングステン、二酸化鉛、及び二酸化マンガンから選ばれる少なくとも１種の化合物である前記４に記載のコンデンサの製造方法。
１０．半導体の電導度が１０^-2〜１０³Ｓ／ｃｍの範囲である前記１記載のコンデンサの製造方法。
１１．前記１乃至１０のいずれかに記載の方法によって製造されたコンデンサ。
１２．前記１乃至１０のいずれかに記載の方法によって製造された、容量の標準偏差を容量の平均値で除した値が１０％以下であるコンデンサ群。
１３．前記１１または１２に記載のコンデンサを使用した電子回路。
１４．前記１１または１２に記載のコンデンサを使用した電子機器。 That is, the present invention provides the following capacitor manufacturing method and capacitor.
1. In a method of manufacturing a capacitor using a conductor having a dielectric layer formed on the surface as one electrode and a semiconductor layer formed by an energization method as the other electrode, the conductor is used as an anode, and a plurality of the conductors are batched. And forming a semiconductor layer by applying a predetermined constant DC current.
2. A metal frame having a plurality of metal substrates on which a plurality of conductor anodes having a dielectric layer formed on the surface are aligned and connected is prepared, and the semiconductor formation portion of the conductor is added to the semiconductor layer forming solution. The semiconductor layer is formed on the dielectric layer of the conductor by applying a constant DC current from a power supply terminal provided on the metallic frame to a cathode plate provided in the semiconductor layer formation container The manufacturing method of the capacitor | condenser described.
3. 3. The method for producing a capacitor according to 1 or 2, wherein the conductor is selected from a metal, an inorganic semiconductor, an organic semiconductor, a mixture of at least one of these, and a laminate in which a conductor is laminated on a surface layer thereof.
4). 2. The method for producing a capacitor as described in 1 above, wherein the semiconductor layer which is the other electrode formed by the energization method is at least one selected from an organic semiconductor layer and an inorganic semiconductor layer.
5). An organic semiconductor composed of a benzopyrroline tetramer and chloranil, an organic semiconductor mainly composed of tetrathiotetracene, an organic semiconductor mainly composed of tetracyanoquinodimethane, the following general formula (1) or (2)

(In Formula (1) and (2), R < ¹ > -R < ⁴ > represents a hydrogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group each independently, X is oxygen, sulfur, Or a nitrogen atom, R ⁵ is present only when X is a nitrogen atom and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² and R ³ and R ⁴ are bonded to each other. (It may be annular.)
5. The method for producing a capacitor as described in 4 above, which is at least one selected from organic semiconductors mainly composed of a conductive polymer obtained by doping a polymer containing a repeating unit represented by formula (1) with a dopant.
6). The conductive polymer containing the repeating unit represented by the general formula (1) is represented by the following general formula (3).

(Wherein R ⁶ and R ⁷ are each independently a hydrogen atom, a linear or branched saturated or unsaturated alkyl group having 1 to 6 carbon atoms, or the alkyl group is bonded to each other at an arbitrary position. And a substituent that forms a cyclic structure of at least one 5- to 7-membered saturated hydrocarbon containing two oxygen atoms, and a vinylene bond that may be substituted on the cyclic structure. And those having a phenylene structure which may be substituted.
6. The method for producing a capacitor as described in 5 above, wherein the capacitor is a conductive polymer containing a structural unit represented by
7). 7. The method for producing a capacitor as described in 6 above, wherein the conductive polymer is selected from polyaniline, polyoxyphenylene, polyphenylene sulfide, polythiophene, polyfuran, polypyrrole, polymethylpyrrole, and substituted derivatives and copolymers thereof.
8). 8. The method for producing a capacitor as described in 7 above, wherein the conductive polymer is poly (3,4-ethylenedioxythiophene).
9. 5. The method for producing a capacitor as described in 4 above, wherein the inorganic semiconductor is at least one compound selected from molybdenum dioxide, tungsten dioxide, lead dioxide, and manganese dioxide.
10. 2. The method for producing a capacitor as described in 1 above, wherein the electrical conductivity of the semiconductor is in the range of 10 ⁻² to 10 ³ S / cm.
11. 11. A capacitor manufactured by the method according to any one of 1 to 10 above.
12 A capacitor group manufactured by the method according to any one of 1 to 10 above, wherein a value obtained by dividing a standard deviation of capacitance by an average value of capacitance is 10% or less.
13. 13. An electronic circuit using the capacitor described in 11 or 12 above.
14 13. An electronic device using the capacitor described in 11 or 12 above.

A method for manufacturing a capacitor and one embodiment of the capacitor of the present invention will be described.
As an example of the conductor used in the present invention, a metal, an inorganic semiconductor, an organic semiconductor, carbon, a mixture of at least one of these, and a laminate in which a conductor is stacked on the surface layer thereof can be given.

  Examples of inorganic semiconductors include metal oxides such as lead dioxide, molybdenum dioxide, tungsten dioxide, niobium monoxide, tin dioxide, and zirconium monoxide. Examples thereof include conductive polymers such as copolymers, complexes of tetracyanoquinodimethane and tetrathiotetracene, and low-molecular complexes such as tetracyanoquinodimethane (TCNQ) salts. Moreover, as a laminated body which laminated | stacked the conductor on the surface layer, the laminated body which laminated | stacked the said conductor on paper, insulating polymer, glass, etc. is mentioned.

  When a metal is used as the conductor, a part of the metal may be used after being subjected to at least one treatment selected from carbonization, phosphation, boronation, nitridation, and sulfidation.

  The shape of the conductor is not particularly limited, and may be used as a foil shape, a plate shape, a rod shape, a shape obtained by forming the conductor itself into a powder shape, or sintering after forming. The conductor surface may be processed by etching or the like to have fine pores. When the conductor is powdered to form a molded body or a sintered shape after molding, fine pores should be provided in the interior after molding or sintering by appropriately selecting the pressure during molding. Can do. If the conductor is powdered to form a molded body or a sintered shape after molding, a part of the lead wire (or lead foil) prepared separately at the time of molding is molded together with the conductor, and the lead wire A portion outside the molding of the (or lead foil) can be used as a lead for the one electrode of the capacitor. Of course, it is also possible to connect the lead lead directly to the conductor.

The dielectric layer formed on the surface of the conductor according to the present invention is a dielectric mainly composed of at least one selected from metal oxides such as Ta ₂ O ₅ , Al ₂ O ₃ , TiO ₂ , and Nb ₂ O _5. Conventionally known dielectric layers in the field of body layers, ceramic capacitors and film capacitors can be mentioned. In the case of a dielectric layer mainly composed of at least one selected from the former metal oxides, the conductor having the metal element of the metal oxide is formed in an electrolytic solution containing a mineral acid or an organic acid. A capacitor obtained by forming the dielectric layer is an electrolytic capacitor having polarity. Examples of conventionally known dielectric layers for ceramic capacitors and film capacitors include the dielectric layers described in Japanese Patent Application Laid-Open Nos. 63-29919 and 63-34917 by the present applicant. . Further, a plurality of conventionally known dielectric layers may be used by laminating a dielectric layer mainly composed of at least one selected from metal oxides, ceramic capacitors, and film capacitors. Further, a dielectric layer in which at least one selected from metal oxides as a main component, a dielectric layer in which a conventionally known dielectric material is mixed with a ceramic capacitor, or a film capacitor may be used.

  On the other hand, the other electrode of the capacitor of the present invention includes at least one compound selected from an organic semiconductor and an inorganic semiconductor, but it is important to form the compound by an energization method described later.

  Specific examples of the organic semiconductor include an organic semiconductor composed of benzopyrroline tetramer and chloranil, an organic semiconductor mainly composed of tetrathiotetracene, an organic semiconductor mainly composed of tetracyanoquinodimethane, and the following general formula (1) Or the organic semiconductor which has as a main component the conductive polymer which doped the dopant to the polymer containing the repeating unit shown by (2) is mentioned.

In the formulas (1) and (2), R ^{1 to} R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and X is oxygen, sulfur or Represents a nitrogen atom, R ⁵ is present only when X is a nitrogen atom and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² and R ³ and R ⁴ are bonded to each other to form a ring It may be.

  Furthermore, in the present invention, the conductive polymer containing a repeating unit represented by the general formula (1) is preferably a conductive polymer containing a structural unit represented by the following general formula (3) as a repeating unit. Can be mentioned.

In the formula, R ⁶ and R ⁷ are each independently a hydrogen atom, a linear or branched saturated or unsaturated alkyl group having 1 to 6 carbon atoms, or the alkyl group is bonded to each other at an arbitrary position. And a substituent that forms a cyclic structure of at least one 5- to 7-membered saturated hydrocarbon containing two oxygen atoms. The cyclic structure includes those having a vinylene bond which may be substituted and those having a phenylene structure which may be substituted.

A conductive polymer containing such a chemical structure is charged and doped with a dopant. A dopant is not specifically limited, A well-known dopant can be used.
Examples of the polymer containing the repeating unit represented by the formulas (1) to (3) include polyaniline, polyoxyphenylene, polyphenylene sulfide, polythiophene, polyfuran, polypyrrole, polymethylpyrrole, and substituted derivatives and copolymers thereof. Etc. Of these, polypyrrole, polythiophene, and substituted derivatives thereof (for example, poly (3,4-ethylenedioxythiophene)) are preferable.

Specific examples of the inorganic semiconductor include at least one compound selected from molybdenum dioxide, tungsten dioxide, lead dioxide, manganese dioxide and the like.
When the organic semiconductor and the inorganic semiconductor have a conductivity in the range of 10 ⁻² to 10 ³ S / cm, the ESR value of the manufactured capacitor is preferably reduced.

  The semiconductor layer described above is formed by a pure chemical reaction (solution reaction, gas phase reaction and a combination thereof) without performing an energization operation, formed by an energization method, or a combination of these methods. In the present invention, the energization method is adopted at least once in the semiconductor layer forming step.

An example of a method for simultaneously forming a semiconductor layer on a plurality of conductors having a dielectric layer formed on the surface by the method of the present invention will be described.
A plurality of (for example, 10 to 1000, preferably 10 to 200) anode parts of conductors are aligned and connected at equal intervals and on the long metal plate. A metal frame in which a plurality of such long metal plates are arranged at equal intervals (for example, 10 to 500 sheets, preferably 10 to 200 sheets), a conductor semiconductor formation portion on the metal frame is separately provided. The substrate is soaked in the prepared semiconductor layer forming solution and a semiconductor layer forming reaction is performed for a predetermined time. In the present invention, the semiconductor layer is formed on the dielectric layer of the conductor by passing a predetermined direct current from the power supply terminal provided on the metallic frame toward the cathode plate provided in the semiconductor layer forming container. is important.

  By forming a semiconductor layer by energizing for a predetermined time with a predetermined DC constant current, the value obtained by dividing the standard deviation of the capacitance of the manufactured capacitor group by the average value of the capacitance is 10% or less, preferably 7% or less, more preferably It becomes possible to make it 5% or less. The energization amount supplied to each conductor is determined by energizing with a predetermined constant current, but the total energization current value is constant even if the energization amount fluctuates in some way for some conductors. As a result of the amount of current supplied to the conductor changing so as to cancel out the fluctuation, the amount of current supplied to each conductor is stabilized over the entire current supply time. If there is no side reaction, the mass of the semiconductor layer is given by the integral value of the total current and time, so the capacitance of the capacitor proportional to the mass of the semiconductor layer is stabilized, and the standard deviation of the capacitance of the fabricated capacitor group is It will be small. On the other hand, in the conventional method of forming a semiconductor layer by energizing for a predetermined time at a constant voltage, the current value supplied to each conductor is not stabilized over the entire energizing time, and the capacitor produced as a result The standard deviation of group capacity is unlikely to be small.

  In the present invention, the energization time and the predetermined current value vary depending on the type, size and density of the conductor used, the type and thickness of the formed dielectric layer, the type of semiconductor layer to be formed, etc. Determined by experiment. As one method of the preliminary experiment, it is possible to determine whether the predetermined constant current value is good or not by managing the mass of the semiconductor layer. For example, there can be mentioned a method in which energization time and semiconductor mass are plotted in advance at each constant current value, and the constant current value is selected when the semiconductor mass reaches a saturation value.

  Further, the initial voltage value during energization has a constant value determined by a predetermined constant current value. In the case of the dielectric layer formed by the chemical conversion described above, the initial voltage value may be equal to or higher than the chemical conversion voltage. When a semiconductor layer is formed by a conventional energization method, since it is basically set to be equal to or lower than the formation voltage, it is energized with a constant voltage that can always be conscious of the formation voltage, and is energized with a constant current as in the present method. The method could not be expected.

  The semiconductor layer forming solution includes a raw material that becomes a semiconductor when energized, and in some cases, the above-described dopants (for example, aryl sulfonic acid or salt, alkyl sulfonic acid or salt, various polymer sulfonic acids or salts, and each of the above substituents. At least one kind of known dopant such as a compound having a compound is dissolved, and a semiconductor layer is formed on the dielectric layer by energization. The temperature and pH of the semiconductor layer forming solution are determined under conditions that facilitate the formation of the semiconductor layer by preliminary experiments. The cathode plate provided in the semiconductor layer forming solution is used as an anti-cathode during energization, and an electrically conductive material, particularly a metal foil or plate is used. It is preferable to use a plurality of cathode plates electrically connected to at least one power feeding portion so that the plurality of conductors immersed in the semiconductor layer forming solution can be uniformly distributed. .

  In the present invention, in order to repair minute defects in the dielectric layer caused by the formation of the semiconductor layer after energization with a predetermined constant current, re-formation (when the dielectric layer is not formed by chemical conversion) This may be the first chemical conversion). Further, energization and re-forming with a predetermined constant current may be repeated a plurality of times, or the constant current value at the time of repetition may be changed. Normally, when stopping constant current energization, the above-mentioned metal frame is lifted from the semiconductor layer forming solution, washed and dried, and then entered into the re-formation process. After performing, you may put into a re-forming process. The reason is not clear, but the mass of the semiconductor layer may increase when the energization time is kept the same and the energization is stopped halfway and the cleaning and drying are repeated rather than continuing the constant current energization.

  The re-chemical conversion can be performed in the same manner as the above-described dielectric layer forming method. The re-forming voltage is usually performed below the forming voltage.

  In the present invention, the conductor layer is provided on the semiconductor layer formed by the above-described method or the like. The conductor layer can be formed, for example, by solidifying a conductive paste, plating, metal vapor deposition, attaching a heat-resistant conductive resin film, or the like. As the conductive paste, a silver paste, a copper paste, an aluminum paste, a carbon paste, a nickel paste, and the like are preferable, but these may be used alone or in combination of two or more. When using 2 or more types, they may be mixed or may be stacked as separate layers. After applying the conductive paste, it is left in the air or heated to solidify. The conductive paste layer is provided so that the thickness after solidification is in the range of about 0.1 to about 100 μm.

  The conductive paste is mainly composed of conductive powder such as resin and metal, and a solvent for dissolving the resin, a curing agent for the resin, or the like is added in some cases, but the solvent is scattered when solidified.

  As the resin, various known resins such as alkyd resin, acrylic resin, epoxy resin, phenol resin, imide resin, fluororesin, ester resin, imidoamide resin, amide resin, styrene resin are used. As the conductive powder, at least one of silver, copper, aluminum, gold, carbon, nickel, and an alloy powder mainly composed of these metals, a coat powder having these metals on the surface layer, or a mixed powder thereof is used. The

  The conductive powder is usually contained in an amount of 40 to 97% by mass. If it is less than 40% by mass, the conductivity of the produced conductive paste is small, and if it exceeds 97% by mass, the adhesion of the conductive paste becomes poor, which is not preferable. You may mix and use the conductive polymer and metal oxide powder which form the semiconductor layer mentioned above in the electrically conductive paste.

Examples of the plating include nickel plating, copper plating, silver plating, and aluminum plating. Examples of the deposited metal include aluminum, nickel, copper, and silver.
Specifically, for example, a carbon paste and a silver paste are sequentially laminated on an anode substrate on which a semiconductor layer is formed to form a conductor layer.

In this manner, a capacitor element in which the cathode portion is formed by stacking up to the conductor layer is manufactured.
The capacitor element of the present invention having the above-described configuration can be made into a capacitor product for various uses by, for example, an exterior such as a resin mold, a resin case, a metallic exterior case, a resin dipping, or an exterior with a laminate film. Among these, a chip-shaped capacitor with a resin mold is particularly preferable because it can be easily reduced in size and cost.

  As the type of resin used for the resin mold exterior, known resins used for sealing solid electrolytic capacitors such as epoxy resin, phenol resin, alkyd resin, etc. can be adopted. It is preferable because generation of sealing stress to the capacitor element that occurs at the time of stopping can be mitigated. A transfer machine is preferably used as a manufacturing machine for sealing the resin.

The capacitor thus fabricated may be subjected to an aging treatment in order to repair the deterioration of the thermal and / or physical dielectric layer during the formation of the conductor layer and the exterior. The aging method is performed by applying a predetermined voltage (usually within twice the rated voltage) to the capacitor. Aging time and temperature are determined in advance by experiment because optimum values vary depending on the type, capacity, and rated voltage of the capacitor. Usually, the time is from several minutes to several days, and the temperature is determined in consideration of thermal degradation of the voltage application jig. It is performed at 300 ° C. or lower. The aging atmosphere may be air or a gas such as Ar, N ₂ , or He. Moreover, although it may be performed under any conditions of reduced pressure, normal pressure, and increased pressure, stabilization of the dielectric layer may progress if the aging is performed while supplying water vapor or after supplying water vapor. One example of a method for supplying water vapor is a method for supplying water vapor by heat from a water reservoir placed in an aging furnace.

  As a voltage application method, it can be designed to flow an arbitrary current such as a direct current, an alternating current having an arbitrary waveform, an alternating current superimposed on the direct current, or a pulse current. It is also possible to stop the voltage application once during the aging and apply the voltage again.

The capacitor manufactured in the present invention can be preferably used for a circuit that requires a high-capacity and low-ESR capacitor such as a central processing circuit and a power supply circuit, and these circuits are used in personal computers, servers, cameras, games, and the like. It can be used for various digital devices such as a computer, a DVD, an AV device, and a mobile phone, and electronic devices such as various power sources.
Since the capacitor manufactured according to the present invention has high capacity, little variation, and good ESR performance, the use of this makes it possible to obtain an electronic circuit and an electronic device with high reliability and no variation in quality.

  The present invention is produced by a capacitor manufacturing method and a manufacturing method thereof, characterized in that a semiconductor layer is formed by energizing a predetermined DC constant current in a batch with a plurality of the conductors as an anode. According to the present invention, a capacitor group having a relatively narrow capacitance distribution can be obtained.

  Hereinafter, specific examples of the present invention will be described in more detail, but the present invention is not limited to the following examples.

Example 1:
1. Installing multiple conductors on a metal frame Conducting a tantalum sintered body (size 4.5 x 3.3 x 1 mm, mass 81 mg, lead wire 0.29 mmφ on the surface of 7 mm) with a CV of 100,000 µF · V / g Used as a body. A polytetrafluoroethylene washer was attached to the lead wire to prevent the solution from splashing when the semiconductor layer was formed later. The lead wires of the 32 sintered bodies were aligned and equidistantly arranged at equal intervals, leaving 30 mm on the left and right on a stainless steel long metal plate having a length of 250 mm, a width of 20 mm, and a thickness of 2 mm. Twenty such long metal plates were arranged in parallel at intervals of 5 mm, and arranged on a metal frame so as to be electrically connected at 15 mm on the left and right sides of the long metal plate. As described above, 640 sintered bodies are arranged on the metal frame at equal intervals, and each sintered body is electrically connected to a power supply terminal provided on the metal frame through a lead wire.

2. Capacitor production A sintered body and a part of the lead wire enter the chemical conversion tank in a chemical conversion tank (Ta side plates are attached to the four sides and five sides) containing a 1% phosphoric acid solution prepared separately. The metal frame is disposed at 8 ° C. for 8 hours at 80 ° C. and 9 V, and the dielectric layer is mainly composed of tantalum pentoxide on the inner pore surface and outer surface of the sintered body and part of the lead wire. Formed. After pulling up from the chemical conversion tank, washing with water and drying, adjust the metal frame, and the tank containing 3% 3,4-ethylenedioxythiophene alcohol solution and 13% anthraquinone-2-sulfonic acid aqueous solution containing 1.5% ammonium persulfate dissolved A large number of point-like microcontacts mainly composed of ethylenedioxypolymer are deposited on the dielectric layer by repeating the immersion 7 times so that only the sintered body part is immersed in the bath containing A large number of electrical microdefects were produced in the dielectric layer. After washing with water and drying, a semiconductor layer forming container containing 3,4-ethylenedioxythiophene (used as an aqueous solution in which the monomer is less than the saturation concentration), anthraquinone-2-sulfonic acid dissolved water, and 20% ethylene glycol electrolyte The metal frame is adjusted and installed so that only the sintered body part is immersed in (the 5 side has a Ta plate affixed), and the semiconductor layer is formed with the feeding terminal provided on the metallic frame as the anode A constant current of 25 mA was applied for 2 hours using the Ta plate in the container as a cathode. After the metallic frame is pulled up, washed with water, washed with alcohol, and dried, the metallic frame is placed so that the sintered body and a part of the lead wire are immersed in the above-mentioned chemical conversion tank, and a minute LC (leakage current) of the dielectric layer is installed. ) Was re-formed (80 ° C., 30 minutes, 7 V) to repair the defects. After being pulled up, washed with water and dried, the energization and re-formation were repeated 20 times (the last 19th and 20th constant current values were 45 mA), then washed with water, washed with alcohol and dried, and the semiconductor layer as the cathode was formed. Formed. Subsequently, the sintered body part is immersed and dried sequentially in a carbon paste tank, a silver paste tank of 10 parts by mass of acrylic resin and 90 parts by mass of silver powder, and a capacitor element in which a conductor layer is formed and a cathode part is provided. Produced. Then, remove the long metal plate from the metal frame, and tin-plated a separately prepared surface with a 100 μm thick copper alloy lead frame (32 pairs of 3.4 mm wide tip portions exist, and both tip portions have the same plane. (There is a gap of 1.0 mm when projected onto the upper surface of each of the above-mentioned capacitor elements.) On the upper surface of a pair of tip portions, the cathode portion surface (4.5 mm × 3.3 mm surface) and a part of the lead wire obtained by partially cutting and removing are mounted. The former was solidification of the same silver paste as the cathode part, and the latter was electrically and mechanically connected by spot welding. Next, transfer molding with epoxy resin leaving a part of the lead frame, and resin exterior, further cutting a predetermined portion outside the resin of the lead frame and bending along the exterior portion, size 7.3 × 4.3 × 1.8 640 chip capacitors of mm were produced. Further, aging was performed at 85 ° C. and 4 V for 5 hours, and the resultant was left at 185 ° C. for 30 minutes to obtain a final capacitor having a rated rating of 2.5 V.

Comparative Examples 1 and 2:
Example 1 is the same as Example 1 except that 7V constant voltage energization (Comparative Example 1) and 5V constant voltage energization (Comparative Example 2, re-forming voltage is 5V) instead of energization with constant current in Example 1 Thus, a capacitor was produced.

Example 2:
In Example 1, the conductor is a CV 80,000 μF · V / g niobium sintered body (the dimensions are the same as in Example 1. The mass is 54 mg), the formation voltage is 20 V, the dielectric layer is niobium pentoxide, constant current. A capacitor was fabricated in the same manner as in Example 1 except that the value was 18 mA (the last two times was 34 mA), the number of times was 30, the re-forming voltage was 14 V, and the rating was 4 V.

Comparative Examples 3 and 4:
Example 2 is the same as Example 2 except that constant voltage energization of 14V (Comparative Example 3) and constant voltage energization of 12V (Comparative Example 4, re-forming voltage is 12V) instead of energization with constant current in Example 2. Thus, a capacitor was produced.

The average capacity, ESR, and LC of the capacitor thus prepared were measured by the following methods. Regarding the measurement results and capacity, Table 1 shows the values obtained by dividing the standard deviation by the average capacity.
Capacitor capacity: The capacity was measured at room temperature and 120 Hz using an LCR measuring instrument manufactured by Hewlett-Packard Company.
ESR value: The equivalent series resistance of the capacitor was measured at 100 kHz.
LC value: At room temperature, a predetermined rated voltage (2.5 V value for Example 1 and Comparative Examples 1 and 2, and 4 V value for Example 2 and Comparative Examples 3 and 4) was applied between terminals of a capacitor for 30 seconds. Measured after continuing.

  By comparing Example 1 with Comparative Examples 1 and 2, and Example 2 with Comparative Examples 3 and 4, a semiconductor layer was formed by applying a predetermined DC constant current to a plurality of the conductors at once by using the conductor as an anode. It is understood that a capacitor group having a relatively narrow capacitance distribution, for example, (standard deviation of capacitance / average capacitance) of 10% or less can be obtained.

Claims (14)

  In a method of manufacturing a capacitor using a conductor having a dielectric layer formed on the surface as one electrode and a semiconductor layer formed by an energization method as the other electrode, the conductor is used as an anode, and a plurality of the conductors are batched. And forming a semiconductor layer by applying a predetermined constant DC current.   A metal frame having a plurality of metal substrates on which a plurality of conductor anodes having a dielectric layer formed on the surface are aligned and connected is prepared, and the semiconductor formation portion of the conductor is added to the semiconductor layer forming solution. 2. A semiconductor layer is formed on a dielectric layer of a conductor by applying a constant DC current from a power supply terminal provided on the metallic frame to a cathode plate provided in the semiconductor layer forming container by dipping A method for producing a capacitor as described in 1. above.   The method for producing a capacitor according to claim 1 or 2, wherein the conductor is selected from a metal, an inorganic semiconductor, an organic semiconductor, a mixture of at least one of these, and a laminate in which a conductor is laminated on a surface layer thereof.   The method for producing a capacitor according to claim 1, wherein the semiconductor layer which is the other electrode formed by the energization method is at least one selected from an organic semiconductor layer and an inorganic semiconductor layer. An organic semiconductor composed of a benzopyrroline tetramer and chloranil, an organic semiconductor mainly composed of tetrathiotetracene, an organic semiconductor mainly composed of tetracyanoquinodimethane, the following general formula (1) or (2)

(In Formula (1) and (2), R < ¹ > -R < ⁴ > represents a hydrogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group each independently, X is oxygen, sulfur, Or a nitrogen atom, R ⁵ is present only when X is a nitrogen atom and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ¹ and R ² and R ³ and R ⁴ are bonded to each other. (It may be annular.)
The method for producing a capacitor according to claim 4, wherein the capacitor is at least one selected from organic semiconductors mainly composed of a conductive polymer obtained by doping a polymer containing a repeating unit represented by formula 1 with a dopant. The conductive polymer containing the repeating unit represented by the general formula (1) is represented by the following general formula (3).

(Wherein R ⁶ and R ⁷ are each independently a hydrogen atom, a linear or branched saturated or unsaturated alkyl group having 1 to 6 carbon atoms, or the alkyl group is bonded to each other at an arbitrary position. And a substituent that forms a cyclic structure of at least one 5- to 7-membered saturated hydrocarbon containing two oxygen atoms, and a vinylene bond that may be substituted on the cyclic structure. And those having a phenylene structure which may be substituted.
The method for producing a capacitor according to claim 5, wherein the capacitor is a conductive polymer including a structural unit represented by   The method for producing a capacitor according to claim 6, wherein the conductive polymer is selected from polyaniline, polyoxyphenylene, polyphenylene sulfide, polythiophene, polyfuran, polypyrrole, polymethylpyrrole, and substituted derivatives and copolymers thereof.   The method for producing a capacitor according to claim 7, wherein the conductive polymer is poly (3,4-ethylenedioxythiophene).   The method for producing a capacitor according to claim 4, wherein the inorganic semiconductor is at least one compound selected from molybdenum dioxide, tungsten dioxide, lead dioxide, and manganese dioxide. The method for producing a capacitor according to claim 1, wherein the electrical conductivity of the semiconductor is in the range of 10 ⁻² to 10 ³ S / cm.   A capacitor manufactured by the method according to claim 1.   A capacitor group manufactured by the method according to claim 1, wherein a value obtained by dividing the standard deviation of the capacitance by the average value of the capacitance is 10% or less.   An electronic circuit using the capacitor according to claim 11.   An electronic device using the capacitor according to claim 11.