JP4149891B2 - Capacitor, circuit board with built-in capacitor, and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electrolytic capacitor that can be built in a substrate, a circuit board with a built-in capacitor, and a functional module with a built-in capacitor.

  In recent years, with the miniaturization and increase in density of electric / electronic devices, instead of the conventional method of forming an electric circuit by mounting individual components on a substrate, a circuit board including a plurality of components for each functional block is provided. A technique is often used in which a module is formed as one package and a predetermined electric circuit is formed by combining necessary modules. This module is generally formed by mounting components necessary for a daughter board on one or both sides. However, if the method of mounting components on the substrate surface is adopted, it is impossible to make the module area smaller than the area of the components to be mounted (that is, the total footprint of the components). Therefore, even when this method is used, there is a limit to increasing the density. In addition, in order to arrange components on a plane, the connection distance between components must be long depending on the configuration, and as a result, there is a problem of increased loss and increased inductance components for high frequencies. is there.

  In order to eliminate or alleviate such a problem, there has been proposed a module in which components are not only two-dimensionally mounted on the substrate surface but also placed in the substrate and the components are arranged three-dimensionally ( For example, see Patent Document 1). Specifically, Patent Document 1 discloses an electrically insulating substrate made of a mixture containing 70 wt% to 95 wt% of an inorganic filler and a thermosetting resin, and a plurality of the insulating insulating substrates formed on at least the main surface of the electrically insulating substrate. The plurality of wiring patterns are electrically connected to at least one active component and / or passive component disposed inside the electrically insulating substrate and electrically connected to the wiring pattern. Thus, there is shown a circuit component built-in module including an inner via formed in the electrically insulating substrate. According to such a module, it is possible to increase the density by three-dimensional connection, and it is possible to reduce loss and inductance component by shortening the wiring.

  One of main components constituting such a functional module is a capacitor. In recent years, with the digitalization and high-speed operation of electronic devices, it has been strongly demanded that the capacitors used therefor have a large capacitance and a low impedance in a high-frequency region.

  Conventionally, as the capacitor, an electrolytic capacitor using a valve metal such as aluminum or tantalum, or a multilayer ceramic capacitor using Ag / Pd or Ni as an electrode and barium titanate or the like as a dielectric is generally used. I came. In addition to these, solid electrolytic capacitors having a cathode made of a conductive polymer are also used. A solid electrolytic capacitor is preferably used to satisfy the above requirements because the capacity per unit volume of the component is large and the thickness of the component is small and the profile can be reduced.

  An example of the structure of the solid electrolytic capacitor will be described below. The solid electrolytic capacitor is provided on the anode valve metal body, the dielectric oxide film provided on the surface of the anode valve metal body, the solid electrolyte layer provided on the dielectric oxide film, and the solid electrolyte layer. And a capacitor element having a cathode current collector. The valve metal body for anode is, for example, an aluminum metal foil for anode. This electrode foil is usually roughened, and a dielectric oxide film is formed on the treated surface. As the solid electrolyte layer, a conductive polymer layer made of polypyrrole, polythiophene, polyaniline or the like is formed. Further, a carbon layer and an Ag paste layer are sequentially formed on the conductive polymer layer to constitute a cathode current collector. Usually, an anode terminal and a cathode terminal made of a lead frame are joined to the capacitor element, and the whole is sealed with a mold resin to form a capacitor as a component (see, for example, Patent Document 2).

  In order to reduce the equivalent series resistance (hereinafter abbreviated as ESR) of such a solid electrolytic capacitor and further reduce the equivalent series inductance (hereinafter abbreviated as ESL) due to the external connection terminal portion of the capacitor, Attempts have been made. For the purpose of reducing ESR, development of materials for conductive polymer layers and cathode materials such as carbon layers and Ag paste layers have been actively conducted. On the other hand, the anode connection is performed by welding or the like to the lead frame material, and the anode connection has a lower connection resistance than the cathode connection. For this reason, improving the anode connection to lower the ESR has not been actively performed.

JP-A-11-220262 (FIG. 4). JP 2002-198264 A (paragraphs [0003] to [0004], FIG. 11).

  When the capacitor is built in the substrate, the smaller the capacitor size, the more effectively the geometric effect such as miniaturization and high density of the module, and the electrical effect such as short wiring and low impedance. However, the capacitor package having the above-described structure tends to increase in size because a mold resin and a lead frame are arranged around the capacitor element. Therefore, when the capacitor package having such a structure is used, the above-described effect cannot be sufficiently exhibited. Therefore, it has been attempted to directly connect a capacitor element to a substrate and connect it three-dimensionally without using a mold resin and a lead frame.

  When a capacitor element is mounted on a wiring layer having a predetermined wiring pattern using solder, the valve metal that becomes the anode of the capacitor does not get wet with the solder. Therefore, the solder used when mounting ordinary chip components Connection is not applicable. In recent years, the use of lead tends to be restricted from the viewpoint of environmental protection, and Sn-Pb eutectic solder which has been conventionally used is becoming unusable. As an alternative solder material, a lead-free solder material has been developed, but generally the melting point of a lead-free solder material is higher than that of eutectic solder. As the melting point of the solder material increases, the capacitor element is more damaged by heat during mounting, and as a result, the characteristics of the capacitor deteriorate. In order to avoid such an inconvenience, a method of connecting a capacitor to a wiring pattern using a conductive adhesive not containing lead is also used.

  However, even if the capacitor anode and the wiring pattern are connected with a conductive adhesive, the anode connection resistance increases due to the presence of a dielectric film on the surface of the valve metal that serves as the anode, resulting in low ESR. There was a problem that could not be realized. Further, since the surface of the valve metal is roughened, when contacted with the conductive adhesive, the conductive adhesive is sucked into the pore portion (that is, the concave portion) of the anode generated by the roughening. As a result, there is a problem that the connection resistance is increased, and the bonding strength between the anode and the conductive adhesive is lowered, resulting in a reduction in connection reliability.

  The present invention has been made to solve these problems, and can be connected to a wiring layer with a low resistance, and is suitable for embedding in a circuit board. I will provide a. In addition, the present invention provides a circuit board with a built-in capacitor that is small, high-density, low-profile, capable of high-frequency response and high-current drive with low ESL, a manufacturing method thereof, and a module with a built-in capacitor having an electrical function in a single package provide.

  In order to solve the above-described problems, the present invention provides an anode valve metal body having a capacitance forming portion and an electrode lead portion, a dielectric oxide film provided on the surface of the anode valve metal body, and the dielectric oxide An electrolytic capacitor comprising a solid electrolyte layer provided on a film and a cathode current collector provided on the solid electrolyte layer, wherein at least one penetrating through an electrode lead portion of the anode valve metal body An electrolytic capacitor in which a hole is formed and a core portion of the valve metal body is exposed to the outside is provided.

  The electrolytic capacitor of the present invention is characterized in that at least one through hole is formed in the electrode lead-out portion of the anode valve metal body, and the core portion of the valve metal body is exposed to the outside. Here, the “core portion” of the valve metal body refers to a metal portion of the valve metal body. In the electrolytic capacitor of the present invention, the core portion is exposed to the outside on at least a part of the inner surface of the through hole. The portion where the core portion is exposed to the outside is the surface of a metal that has not been oxidized or the surface of a thin oxide film that is generated by natural oxidation. Therefore, the interface resistance of the connection part between the part where the core part is exposed to the outside and the conductor (for example, conductive adhesive) is compared with the interface resistance of the connection part between the dielectric oxide film and the conductor. Very small. Therefore, in the present invention, the portion where the core portion is exposed to the outside (this portion is also simply referred to as “core portion exposed portion”) is caused to function as the anode connection portion. Therefore, according to the present invention, an electrolytic capacitor having a low connection resistance value at the anode, low ESR, and high reliability can be obtained.

  In the electrolytic capacitor of the present invention, preferably, the through hole is filled with a conductive resin composition containing a metal powder and a thermosetting resin, and is connected to the core of the valve metal body. The connection between the conductive resin composition and the core portion of the valve metal body is realized by curing the thermosetting resin. In the electrolytic capacitor having this configuration, the exposed portion of the core of the valve metal body is covered with the conductive resin composition and electrically connected thereto. Therefore, in this electrolytic capacitor, the exposed portion of the core part of the valve metal body functions as a connection part via the conductive resin composition. Moreover, the presence of the conductive resin composition makes it possible to easily and reliably electrically connect the core portion of the valve metal body and another member (for example, the wiring layer of the circuit board). This is because it is not necessary for the conductive adhesive to enter the through hole and make contact with the inner surface for connection. Therefore, the electrolytic capacitor having this configuration has a lower ESR and a higher reliability.

  In the electrolytic capacitor in which the through hole is filled with the conductive resin composition, the diameter of the through hole is preferably 0.5 to 2 times the thickness of the anode valve metal body. If the diameter of the through hole is within this range, it is easy to fill the through hole with the conductive resin, and it is easy to hold the conductive resin composition in the through hole. When the diameter of the through hole is large, the filled conductive resin composition may fall off.

Alternatively, in the electrolytic capacitor of the present invention, preferably, a single conductive particle or conductive fiber is disposed, and the conductive particle or conductive fiber is at least part of the core portion of the valve metal body in the through hole. They are in contact with each other. The contact portion between the conductive particle and the exposed portion of the core is electrically connected. Therefore, in the electrolytic capacitor having this configuration, the exposed portion of the core portion of the valve metal body functions as a connecting portion via the conductive particles or conductive fibers present in the through holes. The electrolytic capacitor having this configuration is also easy to connect with a conductive adhesive because conductive particles or conductive fibers exist in the through holes. Therefore, this electrolytic capacitor also has lower ESR and improved reliability.
It is preferable that the end portions of the conductive particles or conductive fibers located in the through holes slightly protrude from the surface on the side connected to the other member (for example, the wiring board) of the electrode lead portion. Thereby, connection to a wiring layer etc. becomes easier.

  An electrolytic capacitor in which conductive particles or conductive fibers are arranged in the through holes is formed by penetration of the conductive particles or conductive fibers, that is, through the conductive particles or conductive fibers. It is preferred that According to this structure, the electrical connection between electroconductive particle or electroconductive fiber and the core part of the valve metal body for anodes becomes more reliable. Thereby, higher reliability can be achieved.

  In the electrolytic capacitor of the present invention having the above through hole, preferably, at least one conductive particle is in contact with the core portion of the anode valve metal body at the electrode lead-out portion of the anode valve metal body. Here, the conductive particles are in contact with the core of the anode valve metal body means that a part of the conductive particles penetrates the dielectric oxide film provided on the surface of the anode valve metal body. This means that the core has been reached. The core part in contact with the conductive particles can be electrically connected to another member (for example, a wiring board) through the conductive particles. That is, this conductive particle functions as a connecting portion of the anode, like the exposed portion of the core. Therefore, according to this configuration, the area of the connecting portion of the anode is further increased, so that the connection resistance is further reduced and an electrolytic capacitor with lower loss can be obtained.

  The electrolytic capacitor for bringing the conductive particles into contact with the core portion of the anode valve metal body is preferably one in which at least a part of the conductive particles is coated with a thermosetting resin. That is, the conductive particles are preferably fixed to the anode valve metal body with a thermosetting resin. According to this configuration, the connection strength between the conductive particles and the anode valve metal body can be improved. Thereby, an electrolytic capacitor with high connection stability and high reliability can be obtained.

  Alternatively, the electrolytic capacitor of the present invention having the above through-hole is preferably one in which a conductive resin composition containing a metal powder and a thermosetting resin is applied to the surface of the electrode lead portion of the anode valve metal body. is there. This configuration also increases the connection area contributing to the connection with other members (for example, the wiring board) in the anode. As a result, the connection resistance is further reduced, and the connection reliability can be further increased.

  The present invention also provides a circuit board with a built-in capacitor in which the electrolytic capacitor of the present invention is located in an electrical insulating layer and connected to the wiring layer by a conductive adhesive. The phrase “electrolytic capacitor is located in the electrical insulating layer” means that the electrolytic capacitor is partially or entirely embedded in the electrical insulating layer. This circuit board with a built-in capacitor includes an electrolytic capacitor with a small size that does not have a mold resin, a lead frame, or the like. Further, the electrolytic capacitor and the wiring layer are electrically connected via a conductive adhesive at the exposed portion of the core of the valve metal body in the anode and on the surface of the current collector for the cathode in the cathode. As described above, according to the electrolytic capacitor of the present invention, in particular, the anode and the wiring layer can be connected with low resistance. Therefore, the circuit board with a built-in capacitor according to the present invention is 1) low profile, 2) downsizing and high density can be realized, 3) low ESR and low ESL, high frequency response and large current drive are possible. It has the characteristic of being.

In the circuit board with a built-in capacitor according to the present invention, preferably, wiring layers are located on both surfaces of the electrical insulating layer, that is, both surfaces, and the wiring layers are electrically connected via an inner via formed in the electrical insulating layer. Is connected to. According to this configuration, the two wiring layers can be arbitrarily connected at a desired position via the inner via, and a short wiring can be realized. Therefore, such a configuration contributes to downsizing, high density and low profile of the circuit board with a built-in capacitor, and further reduces the loss and inductance component of the circuit board with a built-in capacitor.
In this specification, the term “surface” for a layer or a sheet-like material means a surface perpendicular to the thickness direction unless otherwise specified.

  In the circuit board with a built-in capacitor according to the present invention, preferably, the electrical insulating layer in which the capacitor is positioned includes an inorganic filler and a thermosetting resin. By appropriately selecting the inorganic filler constituting the electrically insulating substrate, the linear expansion coefficient, thermal conductivity, and dielectric constant of the electrically insulating layer can be controlled. As a result, a circuit board with a built-in capacitor having high reliability and excellent heat dissipation and high-speed response can be obtained. Moreover, the linear expansion coefficient, glass transition point, and elastic modulus of the electrical insulating layer can be controlled by appropriately selecting the thermosetting resin constituting the electrical insulating layer. As a result, a circuit board with a built-in capacitor having high reliability can be obtained.

  The inner via is preferably made of a mixture of conductive powder and thermosetting resin. The conductive powder is a powder made of a conductive material (specifically, metal). The thermosetting resin forms an inner via in a cured state. Such an inner via has high reliability, and therefore increases connection reliability of the entire circuit board.

The capacitor built-in circuit board of the present invention, when electrolytic capacitors are built in which the conductive resin composition is filled in the electrode lead-out portion of the anode valve metal element for the metal powder contained in the resin composition It is preferable that the conductive filler contained in the conductive adhesive is of the same type. As a result, the resistance value of the connection portion between the electrode lead portion serving as the anode of the capacitor and the wiring layer is lowered, and the reliability is improved. Similarly, even when the conductive resin composition is applied to the electrode lead portion of the anode valve metal body of the electrolytic capacitor, the metal powder contained in the conductive resin composition is electrically conductive contained in the conductive adhesive. It is preferable that it consists of the same kind of material as a conductive filler. Similarly, when the conductive particles or conductive fibers are located in the through holes, the conductive particles or conductive fibers are preferably made of the same type of material as the conductive filler contained in the conductive adhesive. Similarly, when at least one conductive particle is in contact with the core portion of the valve metal body in the electrode lead portion of the anode valve metal body, the conductive particle is also included in the conductive adhesive contained in the conductive adhesive. It is preferable to consist of the same kind of material as the filler. That is, it is preferable that the conductive component located in the electrode lead portion of the electrolytic capacitor and the conductive filler contained in the conductive adhesive are unified materials.

  In addition, when the circuit board with a built-in capacitor according to the present invention has the above-described inner via, the inner via is preferably arranged so as to coincide with a through hole formed in the electrolytic capacitor. That is, the inner via and the through hole are preferably positioned on a straight line. According to this configuration, since the connection length between the electrolytic capacitor and the wiring layer can be shortened, the ESR and ESL of the circuit board can be further reduced.

In the configuration through holes of the inner via and the electrolytic capacitor matches, the conductive resin composition is filled in the through hole electrolytic capacitor is built in the capacitor built-in circuit board is formed on the electrode lead portions of the anode valve metal element for When it is a thing, it is preferable that the electroconductive powder contained in an inner via | veer and the metal powder contained in an electroconductive resin composition consist of the same kind of material. Thereby, the connection resistance between the electrode lead portion serving as the anode of the electrolytic capacitor and the inner via is reduced, and the connection reliability is improved. Similarly, when the conductive resin composition is applied to the electrode lead portion of the anode valve metal body of the electrolytic capacitor, the metal powder contained in the conductive resin composition is the conductive powder contained in the inner via. Are preferably made of the same type of material. Similarly, when conductive particles or conductive fibers are located in the through holes, the conductive particles or conductive fibers are preferably made of the same type of material as the conductive powder contained in the inner via. Similarly, when at least one conductive particle is in contact with the core portion of the valve metal body in the electrode lead-out portion of the anode valve metal body, the conductive particle is a conductive powder contained in the inner via. It is preferable to consist of the same kind of material. That is, it is preferable that the conductive component located in the electrode lead portion of the electrolytic capacitor and the conductive powder contained in the inner via are made of unified materials.

  The circuit board with a built-in capacitor according to the present invention further includes a semiconductor chip, and the semiconductor chip is electrically connected to the electrolytic capacitor located in the electrical insulating layer, and the wiring layer is formed in the electrical insulating layer. It may be connected to the external electrode through the inner via. This circuit board with a built-in capacitor exhibits a predetermined function as one module together with the semiconductor element and other components provided as necessary. Here, the “module” refers to a component that can be added, deleted, and replaced as one unit (unit), such as a memory module and a plug-in module. The semiconductor chip is, for example, a switching element or a microprocessor.

  Alternatively, the circuit board with a built-in capacitor according to the present invention is also provided with at least one component selected from a semiconductor chip such as a switching element or a microprocessor, another capacitor, and an inductor as an electrically insulating layer or the like on which the electrolytic capacitor is located. It may be located within the electrical insulating layer and electrically connected to the wiring layer. Such a circuit board with a built-in capacitor also exhibits a predetermined function as one module.

  According to these configurations, it is possible to obtain a circuit board with a built-in capacitor that functions as a small, low-profile, high-density functional module having an electric circuit function as a single package. Further, according to the configuration in which the elements constituting the electric circuit are built in the substrate, a smaller and lower-profile circuit module can be obtained. Furthermore, according to these configurations, since the wiring length of the entire circuit can be shortened, it is possible to form a circuit module with low loss and a small stray capacitance and inductance. Further, since passive components can be arranged in the vicinity of the semiconductor chip, noise resistance is improved. Therefore, according to the present invention, there is obtained a circuit board with a built-in capacitor that functions as an excellent functional module that realizes 1) downsizing, 2) high density, 3) low profile, and 4) excellent high-speed response. be able to.

When the semiconductor chip is a switching element and the inductor is electrically connected to the semiconductor chip and the capacitor, the circuit board with a built-in capacitor including these functions as a switching power supply module. That is, the capacitor-embedded circuit board having such a configuration is a switching power supply module in which a switching element, a capacitor, and an inductor are electrically connected,
The capacitor is the electrolytic capacitor of the present invention, the capacitor is located in the electrical insulating layer, and is connected to the wiring layer by a conductive adhesive,
The wiring layer can be specified as a switching power supply module connected to an external electrode through an inner via formed in the electrical insulating layer. The switching power supply module is preferably a DC / DC converter module, for example. In the switching power supply module, when a large-capacity and low-profile electrolytic capacitor is used, the power density can be improved while reducing the ripple voltage. Further, by incorporating the electrolytic capacitor of the present invention in the electrical insulating layer, the power density can be further improved.

When the semiconductor element is a microprocessor, the circuit board with a built-in capacitor provided with the semiconductor element functions as a microprocessor module. That is, the capacitor-embedded circuit board having such a configuration is a microprocessor module in which at least one microprocessor and a capacitor are electrically connected,
The capacitor is the electrolytic capacitor of the present invention, the capacitor is located in the electrical insulating layer, and is connected to the wiring layer by a conductive adhesive,
The wiring layer can be specified as a microprocessor module connected to an external electrode via an inner via formed in the electrical insulating layer. Alternatively, a circuit board with a built-in capacitor having a microprocessor is a microprocessor module including the circuit board with a built-in capacitor according to the present invention and at least one microprocessor, and the microprocessor is a wiring layer of the circuit board with a built-in capacitor. It can be specified as a microprocessor module that is electrically connected to.

In this microprocessor module, the microprocessor is generally mounted on the surface of the circuit board of the present invention. The microprocessor is preferably arranged so that the electrolytic capacitor of the present invention is located directly below the microprocessor. According to this arrangement, the area occupied by the module can be reduced. Further, according to such an arrangement, the distance between the microprocessor and the capacitor can be shortened, so that a microprocessor module with excellent high-speed response can be obtained.

  In the above, “metal powder” or “conductive particles” as the conductive component contained in the conductive resin composition, “conductive filler” as the conductive component contained in the conductive adhesive, and contained in the inner via The term “conductive powder” is used as the conductive component. They are not clearly different from each other, and are common in that they have a function of ensuring the conductivity of the composition or mixture in which they are contained. Also, it should be noted that these are all materials made of a conductive material, and their specific shapes and materials may coincide as described later.

The present invention also provides a method for producing the electrolytic capacitor of the present invention. Specifically, the electrolytic capacitor of the present invention is:
(A) oxidizing the surface of the anode valve metal body having the capacity forming part and the electrode lead part to form a dielectric oxide film; and (b) providing a solid electrolyte layer on the dielectric oxide film, Obtaining an electrolytic capacitor structure by a method including providing a cathode current collector on a solid electrolyte layer; and (c) a through hole in the electrode lead-out portion of the anode valve metal body of the obtained electrolytic capacitor structure. Is formed by a manufacturing method including exposing the core of the valve metal body. In this specification, the term “electrolytic capacitor structure” refers to a solid electrolytic capacitor before the through hole is formed, and is used to distinguish it from the electrolytic capacitor according to the present invention. The electrolytic capacitor structure can be called an electrolytic capacitor in that it functions as a capacitor itself.

Alternatively, the electrolytic capacitor of the present invention is
(A) oxidizing the surface of the anode valve metal body having the capacitance forming portion and the electrode lead portion to form a dielectric oxide film;
(C) forming a through hole in the electrode lead portion of the anode valve metal body to expose the core portion of the valve metal body; and (b) providing a solid electrolyte layer on the dielectric oxide film; The cathode current collector is provided on the solid electrolyte layer in this order (that is, (a), (c), (b) in this order).

  Any of the above methods is characterized in that a through hole is formed in the electrode lead portion of the anode valve metal body of the electrolytic capacitor to expose the core portion of the valve metal body. The two manufacturing methods described above differ in the timing of forming the through hole. The former is a method in which a through hole is formed after providing a solid electrolyte layer and a cathode current collector, and the latter is a method in which a through hole is formed before providing them. According to the method of forming the through hole after providing the solid electrolyte layer or the like, there is an advantage that the core portion is not oxidized even if heat treatment is performed when polymerizing the electrolyte. On the other hand, according to the method of forming the through hole before providing the solid electrolyte layer or the like, there is an advantage that it is easy to handle the workpiece when forming the through hole.

  (A) and (b) included in the above manufacturing method are operations generally included in the method of manufacturing a solid electrolytic capacitor. In the present specification including the following explanation, in order to clarify the characteristics of each manufacturing method of the present invention and to avoid redundant description, “a valve metal for an anode having a capacitance forming portion and an electrode lead portion” will be described. “Oxidizing the surface of the body to form a dielectric oxide film” is simply referred to as the operation of (a). “A solid electrolyte layer is provided on the dielectric oxide film, and a cathode collector is formed on the solid electrolyte layer. “Providing the electric body” may be simply referred to as the operation (b).

Moreover, the method for producing an electrolytic capacitor of the present invention includes preparing a conductive resin composition containing a metal powder and an uncured thermosetting resin,
Filling the through hole formed in the electrode lead portion of the valve metal body for the anode with the conductive resin composition, and further connecting the conductive resin composition to the core portion of the metal body by heat treatment. It's okay. According to such a manufacturing method, an electrolytic capacitor having a configuration in which the through hole is filled with the conductive resin composition and connected to the core portion of the valve metal body is obtained.

  This manufacturing method preferably further includes pressurizing the electrode lead portion of the anode valve metal body after filling the through hole with the conductive resin composition. By adding the pressurizing step, the connection between the core of the anode valve metal body and the conductive resin composition becomes stronger. According to the electrolytic capacitor manufactured in this way, when the electrode lead-out portion is connected to another member (specifically, a wiring board), the connection resistance is further reduced, and the connection reliability is further improved. To do.

The present invention also provides an electrolytic capacitor manufacturing method,
Obtaining an electrolytic capacitor structure by a method including the operations of (a) and (b), and at least one particle diameter larger than the thickness of the anode valve metal body of the obtained electrolytic capacitor structure Provided is a production method including penetrating the conductive particles into the electrode lead-out portion by placing the conductive particles in the electrode lead-out portion of the anode valve metal body and pressurizing the conductive particles.

The present invention also provides an electrolytic capacitor manufacturing method,
An electrolytic capacitor is obtained by a method including the operation of (a) and the operation of (b), and at least one conductive fiber longer than the thickness of the anode valve metal body is used as an electrode of the anode valve metal body. A manufacturing method including penetrating a drawer is provided.

  In the two manufacturing methods described above, through holes are formed in the electrode lead portion by passing the conductive particles or conductive fibers through the electrode lead portion of the valve metal body, and the conductive particles or conductive fibers are placed in the through holes. It is located in. According to this manufacturing method, an electrolytic capacitor having a configuration in which the conductive particles or conductive fibers and the core portion of the valve metal body are in close contact with each other can be easily obtained.

The present invention also provides an electrolytic capacitor manufacturing method,
Obtaining an electrolytic capacitor structure by a method including the operations of (a) and (b), and stacking a plurality of the obtained electrolytic capacitor structures in the thickness direction;
Passing at least one conductive fiber longer than the thickness of the stacked electrolytic capacitor structures through the electrode lead-out portion of the anode valve metal body of each electrolytic capacitor structure; and cutting the conductive fibers A manufacturing method is provided that includes separating electrolytic capacitors into pieces.

  According to this manufacturing method, one or a plurality of conductive fibers can be penetrated at once to the electrode lead portions of the valve metal bodies of the plurality of electrolytic capacitor elements. Therefore, an electrolytic capacitor having a configuration in which the conductive fiber penetrates the electrode lead portion of the valve metal body can be manufactured with high productivity.

  In any of the above-described electrolytic capacitor manufacturing methods of the present invention, at least one conductive particle is placed on the electrode lead-out portion of the anode valve metal body and pressed to thereby apply the conductive particle to the anode valve metal. It may further include contacting the core of the body. In this operation, the pressurization is carried out in such a way that a part of each conductive particle penetrates the dielectric oxide film of the electrode lead portion and reaches the core of the valve metal body, and a part is above the surface of the dielectric oxide film. (I.e., projecting). That is, the pressurization is performed such that a part of each conductive particle is embedded in the electrode lead-out portion. By further including such an operation, it is possible to obtain an electrolytic capacitor having a configuration in which the conductive particles are in contact with the core portion of the valve metal body at the electrode lead portion of the anode valve metal body in which the through hole is formed. it can.

Alternatively, any of the above electrolytic capacitor manufacturing methods
A conductive resin composition containing at least one conductive particle and an uncured thermosetting resin is placed on the electrode lead-out portion of the anode valve metal body and pressed to thereby apply the conductive particle to the anode. It may further include bringing the conductive resin composition into contact with the electrode lead-out portion of the anode valve metal body by contacting the core portion of the valve metal body for heat treatment and heat treatment. Here, the pressurization is performed so that a part of the conductive particles is embedded in the electrode lead-out portion in the same manner as described above. By further including these operations, the conductive particles come into contact with the core part of the valve metal body at the electrode lead part of the anode valve metal body in which the through-holes are formed, and to the electrode lead part by the thermosetting resin. An electrolytic capacitor having a fixed configuration can be obtained.

Alternatively, in any of the methods for producing an electrolytic capacitor of the present invention, a conductive resin composition containing a metal powder and a thermosetting resin is applied to an electrode lead portion of the anode valve metal body, and heat treatment is performed. The conductive resin composition may be further adhered to the electrode lead portion of the anode valve metal body. By these operations, an electrolytic capacitor having a structure in which a conductive resin composition layer containing metal powder and a thermosetting resin is formed on the surface of the electrode lead portion of the anode valve metal body in which the through hole is formed is obtained. be able to.

  When forming the layer of the conductive resin composition on the electrode lead portion of the anode valve metal body, the electrode lead portion may be pressurized after the conductive resin composition is applied. In that case, the conductive resin composition can be more firmly bonded to the surface of the electrode lead portion. Pressurization and heat treatment may be performed simultaneously.

  In addition, a conductive resin composition layer is formed in advance on the surface of the flat plate by coating, and the electrode lead portion of the anode valve metal body is sandwiched between the flat plate, and the conductive resin composition is drawn out of the electrode metal electrode for the anode. It is also possible to transfer to the part. In that case, the conductive resin composition is applied by transfer. Preferably, the electrode lead portion is pressurized during transfer. This is for further strengthening the adhesion of the resin composition. In addition, when the particle size of the metal powder contained in the resin composition is larger than the thickness of the dielectric oxide film, a capacitor having a configuration in which the metal powder (= particles) is in contact with the core is obtained when the applied pressure is large. It is done.

The present invention also provides a method for manufacturing a circuit board with a built-in capacitor.
Preparing a circuit board on which a wiring layer having a predetermined wiring pattern is formed on the surface of the electrical insulating layer;
Providing a conductive adhesive comprising a conductive filler and an uncured thermosetting resin;
Preparing a sheet-like material comprising a thermosetting resin composition containing an uncured thermosetting resin and an inorganic filler as an electrically insulating substrate;
Applying the conductive adhesive to a predetermined position on the surface of the wiring layer of the circuit board;
After the electrolytic capacitor of the present invention is placed on the applied adhesive, the conductive adhesive is cured by heat treatment, and the electrolytic capacitor is placed on the circuit board (more precisely, wiring of the circuit board) And by laminating the electrically insulating base material on the circuit board on which the electrolytic capacitor is fixed, and then applying heat and pressure, the electrolytic capacitor is located inside, that is, built in. A manufacturing method is provided that includes forming an electrically insulating layer. In this manufacturing method, an electrolytic capacitor is attached to the surface of a circuit board, and a sheet-like electrically insulating base material is stacked thereon, and then heated and pressed to provide an electrically insulating layer on the surface of the circuit board. And it is a method of obtaining the circuit board with a built-in capacitor in the form in which the electric insulating layer covers the electrolytic capacitor (that is, the electrolytic capacitor is embedded in the electric insulating layer).

  In the above method for producing a circuit board with a built-in capacitor, the electrical insulating layer constituting the circuit board is preferably made of a thermosetting resin composition constituting the electrically insulating base material. When the electrically insulating substrate and the electrically insulating layer of the circuit board are made of the same material, internal stress generated when the electrically insulating substrate is laminated and integrated can be reduced. Thereby, a circuit board with a built-in capacitor with high connection reliability can be obtained.

The present invention also provides a method for manufacturing a circuit board with a built-in capacitor.
Providing a conductive adhesive comprising a conductive filler and an uncured thermosetting resin;
Preparing a sheet-like material comprising a thermosetting resin composition containing an uncured thermosetting resin and an inorganic filler as an electrically insulating substrate;
Applying the conductive adhesive to a predetermined position on the surface of the metal foil;
After placing the electrolytic capacitor of the present invention on the applied conductive adhesive, the conductive adhesive is cured by heat treatment, and the electrolytic capacitor is fixed to a metal foil.
After laminating the electrically insulating base material on the metal foil to which the electrolytic capacitor is fixed, the electrolytic capacitor forms an electrically insulating layer located inside the electrolytic capacitor by heating and pressing, and the metal foil is patterned. Provided is a manufacturing method that includes forming a wiring layer having a predetermined wiring pattern by performing annealing. The metal foil is preferably a copper foil.

  In this manufacturing method, the electrolytic capacitor is fixed to the surface of a metal foil serving as a wiring layer, and an electrically insulating substrate is laminated thereon. That is, in this manufacturing method, the electrolytic capacitor is built in the electrical insulating layer and the production of the circuit board having the wiring layer and the electrical insulating layer is simultaneously performed. Therefore, according to this manufacturing method, since it is not necessary to prepare a circuit board in advance, a smaller and lower-capacitor built-in circuit board can be manufactured. Further, according to this manufacturing method, since the electrolytic capacitor can be arranged at a position close to the external electrode of the circuit board, a circuit board with a built-in capacitor with improved high frequency response can be obtained.

The present invention also provides a method for manufacturing a circuit board with a built-in capacitor.
Forming a wiring layer having a predetermined wiring pattern on one side of the release carrier;
Providing a conductive adhesive comprising a conductive filler and an uncured thermosetting resin;
Preparing a sheet-like material comprising a thermosetting resin composition containing an uncured thermosetting resin and an inorganic filler as an electrically insulating substrate;
Applying a conductive adhesive to a predetermined position on the surface of the wiring layer;
After placing the electrolytic capacitor of the present invention on the applied conductive adhesive, the conductive adhesive is cured by heat treatment to fix the electrolytic capacitor,
The electrical insulating substrate is laminated on the release carrier to which the electrolytic capacitor is fixed, and then heated and pressed to form an electrical insulating layer in which the electrolytic capacitor is located, and the release A manufacturing method including peeling a carrier to expose a wiring layer on a surface is provided. This manufacturing method also does not require a circuit board for fixing the electrolytic capacitor, so that it is possible to manufacture a circuit board with a built-in capacitor that is smaller and has a lower profile and improved high-frequency response.

  In any of the above methods for producing a circuit board with a built-in capacitor, it is preferable to apply a conductive adhesive by printing. According to the printing, the conductive adhesive can be applied only at a necessary position with high accuracy.

  In any of the above-described methods for manufacturing a circuit board with a built-in capacitor, one or a plurality of through holes are formed at predetermined positions as an electrically insulating base material, and conductive powder and a thermosetting resin are placed in the through holes. It is preferable to prepare what is filled with via paste. The via paste is subjected to heat treatment at an appropriate time (specifically, when the electrically insulating base material is laminated and the electrically insulating layer is formed), and the thermosetting resin is cured, so that the inner paste is cured. Form a via. Therefore, according to the manufacturing method including this operation, when the wiring layers are located on both surfaces of the electrically insulating base material, it is possible to obtain a circuit board with a built-in capacitor in which the two wiring layers are connected as desired. it can.

  When forming a through hole in the electrically insulating base material and filling this with a via paste, the via paste filled in the through hole is in contact with the electrode lead portion of the anode valve metal body of the electrolytic capacitor, It is preferable that the electrolytic capacitor is positioned in the electrically insulating substrate. Thereby, the wiring layer located on the surface of the electrically insulating substrate and the electrolytic capacitor can be electrically connected via the inner via, so that the wiring distance is shorter and the connection resistance is lower. A built-in circuit board can be manufactured.

  As described above, the electrolytic capacitor of the present invention is an element that does not have a mold resin and a lead frame. By forming a through hole in the electrode lead portion of the anode valve metal body, the electrolytic capacitor of the valve metal body is formed. The core is exposed. The exposed surface of the core portion functions as a connection portion that can be connected to other members (particularly a wiring board) with low resistance. The electrolytic capacitor of the present invention provided with such a connection portion is suitable for connection to a wiring layer of a wiring board using a conductive adhesive. In addition, since the electrolytic capacitor of the present invention is in the form of an element, the use of the electrolytic capacitor provides a circuit board with a built-in capacitor that has a low profile, low connection resistance, and high reliability.

  Furthermore, the electrolytic capacitor of the present invention is built in a circuit board together with other components to provide a small and high-density component built-in module. The component built-in module according to the present invention exhibits many functions despite its small installation area. Further, in the module, the wiring length can be shortened, and the semiconductor chip and the capacitor can be arranged close to each other, whereby the stray capacitance and the stray inductance can be reduced. Therefore, according to the present invention, a component built-in module having a predetermined circuit function, low loss, and excellent high-speed response can be obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, specific forms of the electrolytic capacitor, the circuit board with built-in capacitor, and the component built-in module according to the present invention will be described together with the manufacturing method thereof with reference to the drawings.

  The basic configuration of the present invention includes an anode valve metal body having a capacity forming portion and an electrode lead portion, a dielectric oxide film provided on the surface of the anode valve metal body, and provided on the dielectric oxide film. A solid electrolytic capacitor structure comprising a solid electrolyte layer and a cathode current collector provided on the solid electrolyte layer. This can be said to correspond to a conventional electrolytic capacitor. The electrolytic capacitor of the present invention is configured by forming a through hole in the electrode lead portion of the anode valve metal body of the solid electrolytic capacitor structure and exposing the core portion of the valve metal body to the outside.

  FIG. 1 shows a cross-sectional view of a solid electrolytic capacitor as a basic configuration of the present invention. In FIG. 1, 10 is an anode valve metal body, 10A is a capacity forming portion, and 10B is an electrode leading portion. 11 is a dielectric oxide film, 12 is a solid electrolyte layer, and 13 is a cathode current collector. Reference numeral 14 denotes an insulator for ensuring insulation between the anode part and the cathode part.

  As the anode valve metal body 10, for example, a foil body or a sintered body made of a material selected from aluminum, tantalum and niobium can be used. Preferably, aluminum is used. This is because aluminum is inexpensive and excellent in productivity. The anode valve metal body 10 is generally roughened by electrolytic etching. This is to increase the surface area.

  As the solid electrolyte layer 12, for example, a conductive polymer such as polypyrrole, polythiophene, or polyaniline can be used. The solid electrolyte layer 12 preferably further includes a dopant in order to increase the conductivity of the conductive polymer and reduce the resistance value. As the dopant, for example, aryl sulfonate ions such as alkyl naphthalene sulfonate and para-toluene sulfonate, or aryl phosphate ions can be used.

  As the cathode current collector 13, an Ag paste layer having a carbon layer as an adhesive layer, a foil of Cu, Ni, or Al, or a metal foil of these layers on the side in contact with the solid electrolyte layer 12 is carbon. The foil body in which the layer was formed can be used.

  The insulator 14 is preferably provided in order to ensure the insulation between the anode and the cathode and prevent the occurrence of a short circuit. As the insulator 14, for example, polyimide, polyamide, polyphenylene ether (PPE), polyphenylene sulfide (PPS), or polyphenylene oxide (PPO) can be used.

  In the solid electrolytic capacitor shown in FIG. 1, only one anode electrode lead portion 10B is provided. The solid electrolytic capacitor as the basic configuration of the present invention may have a three-terminal structure with two electrode lead portions of the anode, or a four-terminal structure with two electrode lead portions for both the cathode and the anode. It's okay. Each embodiment described below can also be applied to these capacitors.

(Embodiment 1)
One embodiment of the electrolytic capacitor of the present invention is shown in FIGS. FIG. 2B is a plan view of the electrolytic capacitor shown in FIG. 2A and 2B, 10C indicates the core of the anode valve metal body 10, and 15 is a through hole. Of the exposed surface of the through hole 15, the portion excluding the portion of the dielectric oxide film 11 corresponds to the core portion exposed portion 10D. In FIG. 2, the same members or elements as those described in FIG. 1 are denoted by the same reference numerals, and description of those members or elements is omitted here.

  A method for manufacturing this type of electrolytic capacitor will be described with reference to the drawings. First, a metal foil serving as an anode valve metal body is prepared. Here, a case where an aluminum foil is used will be described as an example.

  First, an alternating current is applied to the aluminum foil, and electrolytic etching is performed in an electrolytic solution mainly composed of hydrochloric acid. As a result, the surface of the aluminum foil is roughened to obtain the anode valve metal body 10 having fine irregularities on the surface as shown in FIG. Next, the anode valve metal body 10 is anodized in a neutral electrolyte, and a dielectric oxide film 11 having a desired withstand voltage is formed on the surface thereof. The dielectric oxide film 11 is generally formed to have a thickness of 1 to 20 nm. However, the thickness of the dielectric oxide film 11 is not limited to this range, and is selected according to the desired performance of the electrolytic capacitor. Next, portions other than the capacity forming portion 10A of the anode valve metal body 10 are masked, and a conductive polymer such as polypyrrole, polythiophene, or polyaniline is chemically polymerized using a solution containing a dopant and each monomer. Alternatively, it is formed by a combination of chemical polymerization and electrolytic polymerization. This conductive polymer layer becomes the solid electrolyte layer 12.

  Next, on both surfaces of the anode valve metal body 10, the insulator 14 is disposed at the boundary between the capacitance forming portion 10A where the solid electrolyte layer 12 is formed and the electrode lead portion 10B. The insulator 14 is formed by adhering a tape made of a film of an appropriate insulating material (for example, a polyimide film). Subsequently, a carbon paste is applied to the surface of the solid electrolyte layer 12 and then cured, and further an Ag paste is applied thereon and then heated and cured. These carbon layer and Ag paste layer act as the current collector 13 for cathode. The carbon paste and the Ag paste are applied by dipping, for example. Alternatively, the cathode current collector 13 may be formed by laminating metal foils such as Cu, Ni, or Al as described above. In that case, the metal foil can be bonded to the solid electrolyte layer 12 using carbon paste.

  Next, defect repair of the dielectric oxide film 11 and insulation treatment of the solid electrolyte layer 12 are performed. Specifically, the treatment is performed by applying a predetermined voltage in an atmosphere of high temperature and high humidity (for example, 85 ° C. and 80% RH) and then drying. When this process is completed, an electrolytic capacitor structure having the structure shown in FIG. 1 is obtained.

Next, a through hole 15 is formed in the electrode lead-out portion 10B of the anode valve metal body 10, and the unoxidized core portion 10C of the anode valve metal body 10 is exposed to the outside. Thereby, the electrolytic capacitor of the present invention having the core exposed portion 10D as shown in FIG. The through hole 15 can be formed by, for example, an NC punching machine. Alternatively, the through hole 15 can be formed by a method using a punching die or a YAG laser. The diameter of the through hole 15 is, for example, 30 to 300 μm. However, the dimension of the through hole 15 is not limited to this. Moreover, it is preferable to form a plurality of through holes 15. FIG. 2B exemplarily shows an electrolytic capacitor in which three through holes 15 are formed. As the number of through holes 15 increases, the connection resistance when connecting to the wiring layer decreases, so that a low-loss circuit board with built-in capacitor and component built-in module can be obtained, and connection reliability is improved. However, the greater the number of through holes 15, the lower the strength of the electrode lead portion 10B. Therefore, it is necessary to select the number of the through holes 15 within a range in which the electrolytic capacitor is not damaged by the force applied when manufacturing the circuit board with a built-in capacitor. Generally, the number of through holes 15 is preferably 1 to 8 per 1 mm ² .

  In the manufacturing method described above, the through hole 15 is formed in the electrode lead portion 10B of the anode valve metal body 10 after the electrolytic capacitor as shown in FIG. 1 is formed. In another method, after forming the dielectric oxide film 11, the through hole 15 is formed in the electrode lead portion 10B of the anode valve metal body 10, and then the solid electrolyte layer 12 and the cathode current collector 13 are formed. Also good. According to this method, since the through hole can be formed before the solid electrolytic capacitor structure as a basic structure is completed, the workpiece can be handled without worrying about damage to the solid electrolyte layer or the like when forming the through hole. Can do.

(Embodiment 2)
Another embodiment of the electrolytic capacitor of the present invention is shown in FIG. In FIG. 3, reference numeral 16 denotes a conductive resin composition containing metal powder and a thermosetting resin, which is filled in the through hole 15 and electrically connected to the core portion 10 </ b> C of the anode valve metal body 10. In FIG. 3, the same members or elements as those described with reference to FIGS. 1 and 2 are denoted by the same reference numerals, and description of those members or elements is omitted here.

  A method for manufacturing this type of electrolytic capacitor will be described with reference to the drawings. First, an electrolytic capacitor having a through hole as shown in FIG. 2 is manufactured by a method similar to the method described in the first embodiment.

  A conductive resin composition is prepared by mixing metal powder and a thermosetting resin. The metal powder is preferably made of a metal excellent in conductivity and stability. For example, a metal or alloy powder containing Ag, Cu, Au, Ni, Co or Pd as a main component can be used, and an Ag or Cu powder or an alloy powder containing Ag or Cu is preferably used. The metal powder preferably has a diameter of 0.1 to 100 μm. The thermosetting resin is mixed with the metal powder in an uncured state. As the thermosetting resin, for example, an epoxy resin, a phenol resin, or a polyimide resin can be used. These resins are preferably used because of their high reliability. The uncured thermosetting resin is preferably mixed at a ratio of 30 to 150 parts by volume when the metal powder is 100 parts by volume. Furthermore, the conductive resin composition may contain a curing agent, a curing catalyst, a surfactant and / or a coupling agent.

  Next, the through hole 15 is filled with a conductive resin composition. As a filling method, for example, a method by screen printing and a method using a dispenser can be adopted. Then, heat treatment is performed to cure the thermosetting resin in the conductive resin composition 16, thereby connecting the conductive resin composition 16 to the core portion 10 </ b> C of the anode valve metal body 10 through the through hole 15. As a result, the electrolytic capacitor of the present invention as shown in FIG. 3 is obtained.

  The heat treatment temperature and time are not particularly limited as long as the capacitor characteristics are not deteriorated due to the thermal decomposition of the solid electrolyte layer 12. The heat treatment temperature is usually 80 to 180 ° C., and the heat treatment time is usually 5 to 30 minutes. After this heat treatment is completed, it is preferable to perform defect repair of dielectric oxide film 11 and insulation treatment of solid electrolyte layer 12 in the same manner as in the first embodiment.

  In the present embodiment, the diameter of the through hole 15 is preferably 0.5 to 2 times the thickness of the anode valve metal body 10. The reason is as described above. The anode valve metal body 10 is preferably formed of a metal foil having a thickness of about 40 to 150 μm from the viewpoint of reducing the height of the circuit board with a built-in capacitor. Therefore, when using a foil having such a thickness, the diameter of the through hole is selected from the range of 20 to 300 μm depending on the thickness of the metal foil.

  Further, the cross-sectional shape of the through hole 15 is not limited to a circle, and may be any shape such as a square, a rectangle, or an ellipsoid. When the through hole 15 is not circular, the preferable dimension of the through hole is defined by the minimum value and the maximum value of the cross section difference. Specifically, the minimum value of the cross-sectional difference of the through hole is larger than 0.5 times the thickness of the anode valve metal body, and the maximum value is smaller than twice the thickness of the anode valve metal body. preferable. Also in this embodiment, a plurality of through holes 15 may be formed, and each through hole may be filled with a conductive resin composition.

  In this embodiment, it is preferable to pressurize the electrode lead portion 10B of the anode valve metal body 10 after filling the through hole 15 with the conductive resin composition 16. This is because the metal powder contained in the conductive resin composition 16 filled in the through hole 15 is firmly connected to the core portion 10C of the through hole 15 by this pressurizing step, and the connection resistance value is lowered. The method of pressurization is not particularly limited. For example, press pressurization using a flat plate or pressurization with compressed air may be performed. Pressurization may be performed simultaneously with the heat treatment.

  In the electrolytic capacitor of this embodiment, since the conductive resin composition is in contact with the core portion of the anode valve metal body, it can function as a connecting portion of the anode. Therefore, the electrolytic capacitor of this form can be easily connected to the wiring board without inserting, for example, a conductive adhesive into the through hole.

(Embodiment 3)
Another embodiment of the electrolytic capacitor of the present invention is shown in FIG. In FIG. 4, reference numeral 17 denotes conductive particles. The conductive particles 17 are located in the through holes 15 and are in contact with and electrically connected to the core portion 10 </ b> C of the anode valve metal body 10. In FIG. 4, the same members or elements as those described with reference to FIGS. 1 to 3 are denoted by the same reference numerals, and description of these members or elements is omitted here.

  A method for manufacturing this type of electrolytic capacitor will be described with reference to the drawings. First, a solid electrolytic capacitor structure having a basic configuration as shown in FIG. 1 is manufactured by a method similar to the method described in the first embodiment.

  Conductive particles 17 having a particle diameter larger than the thickness of the anode valve metal body 10 are prepared. Next, the conductive particles 17 are placed on the electrode lead-out portion 10B of the anode valve metal body 10 and pressurized, thereby penetrating the conductive particles 17 through the anode valve metal body 10 and forming the through holes 15. At the same time, the conductive particles 17 are brought into contact with the core portion of the anode valve metal body 10. As a result, an electrolytic capacitor as shown in FIG. 4 is obtained.

  As the conductive particles 17, particles having high conductivity and a hardness that can penetrate the anode valve metal body 10 without being damaged when pressed are used. Specifically, for example, particles made of a metal or alloy containing as a main component one kind of metal selected from the group consisting of Ag, Cu, Ni, Pd, Pt, and Au are used. The conductive particles 17 have a particle size larger than the thickness of the anode valve metal body 10, preferably 1.0 to 1.2 times the thickness of the anode valve metal body 10, more preferably 1.05. It has a particle size of ~ 1.2 times. When the conductive particles having such a particle diameter are penetrated, the upper and lower ends of the particles protrude from the surface of the capacitor after the penetration, which is advantageous for connection to another member (for example, a wiring board). The method of pressurization is not particularly limited. For example, the conductive particles 17 can be penetrated by pressing.

  In the electrolytic capacitor of this form, since the conductive particles are in contact with the core part of the anode valve metal body, it can function as a connecting part of the anode. Therefore, the electrolytic capacitor of this embodiment can be easily connected to the wiring board as in the second embodiment.

  According to the method described above, the through hole can be formed by a simple method. In another method, as described in the first embodiment, a through hole is formed in advance, and conductive particles having a particle size slightly larger than the diameter of the through hole are press-fitted into the through hole. The same electrolytic capacitor as the above-described form can be obtained.

  As a modification of the present embodiment, there is a configuration in which the conductive particles 17 penetrate the anode valve metal body 10 at a plurality of locations. According to such an electrolytic capacitor, the connection resistance can be further reduced when connecting to the wiring board.

(Embodiment 4)
Another embodiment of the electrolytic capacitor of the present invention is shown in FIG. In FIG. 5, 18 is a conductive fiber. The conductive fiber 18 is located in the through hole 15 and is in contact with and electrically connected to the core portion 10C of the anode valve metal body 10. In FIG. 5, the same members or elements as those described with reference to FIGS. 1 to 4 are denoted by the same reference numerals, and description of these members or elements is omitted here.

  A method for manufacturing this type of electrolytic capacitor will be described with reference to the drawings. First, a solid electrolytic capacitor structure having a basic configuration as shown in FIG. 1 is manufactured by a method similar to the method described in the first embodiment.

  A conductive fiber 18 having a length longer than the thickness of the anode valve metal body 10 is prepared. Next, the conductive fiber 18 is passed through the electrode lead-out portion 10B of the anode valve metal body 10 to form the through hole 15, and at the same time, the conductive fiber 18 is brought into contact with the core portion of the anode valve metal body 10. . As a result, an electrolytic capacitor as shown in FIG. 5 is obtained.

  The conductive fiber 18 has a high conductivity and is formed of a metal material that can be processed into a fiber shape or a fine wire shape. Specifically, a metal or an alloy mainly composed of one kind of metal selected from the group consisting of Ag, Cu, Ni, Pd, Pt, Au, and Al is processed into a fibrous or fine wire shape. Can be used as the fiber 18. The conductive fiber 18 has a length larger than the thickness of the anode valve metal body 10, and preferably has a length 1.0 to 1.2 times the thickness of the anode valve metal body 10, More preferably, it has a length of 1.05 to 1.2 times. When the conductive fiber having such a length is penetrated, the upper and lower ends of the fiber protrude from the surface of the capacitor after the penetration, which is advantageous for connection to another member (for example, a wiring board). The diameter of the conductive fiber 18 is preferably 20 to 200 μm. The method for penetrating the conductive fiber 18 is not particularly limited. For example, the conductive fiber 18 can be penetrated by pressing, pressing with a wire bonder, or ultrasonic pressing.

  In the capacitor of this form, since the conductive fiber is in contact with the core portion of the anode valve metal body, it can function as a connecting portion of the anode. Therefore, the electrolytic capacitor of this embodiment can be easily connected to the wiring board as in the second embodiment.

  According to the method described above, the through hole can be formed by a simple method. In another method, as described in the first embodiment, a through hole is formed in advance, the through hole has a diameter slightly larger than the diameter of the through hole, and the length thereof is a valve metal for an anode. By press-fitting conductive fibers larger than the thickness of the body, the same electrolytic capacitor as that shown in the figure can be obtained.

  As a modification of the present embodiment, there is a configuration in which the conductive fibers 18 penetrate the anode valve metal body 10 at a plurality of locations. According to such an electrolytic capacitor, the connection resistance can be further reduced when connecting to the wiring board.

(Embodiment 5)
Another method for obtaining the electrolytic capacitor of the fourth embodiment will be described as a fifth embodiment. 6A to 6C schematically show the respective steps of the method in cross-sectional views. In FIG. 6, the same members or elements as those described with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and description of these members or elements is omitted here.

  First, a solid electrolytic capacitor structure having a basic configuration as shown in FIG. 1 is manufactured by a method similar to the method described in the first embodiment. Next, in the thickness direction, in other words, in the thickness direction, the obtained solid electrolytic capacitor is such that the surfaces (that is, the surfaces perpendicular to the thickness direction of the foil constituting the anode valve metal body) face each other. A plurality of them are overlapped (FIG. 6A). Accordingly, the electrode lead portions 10B of the anode valve metal body 10 of each electrolytic capacitor are aligned (that is, aligned) in the thickness direction.

  As in the case of manufacturing the electrolytic capacitor of the fourth embodiment, the conductive fiber 18 is prepared. In this embodiment, the conductive fiber 18 needs to be longer than the total thickness d of the laminated solid electrolytic capacitor structure. If the length of the conductive fiber 18 is shorter than d, the conductive fiber 18 may not be able to be reliably penetrated into the electrode lead portion 10B of the anode valve metal body 10 of each electrolytic capacitor structure.

  Next, as shown in FIG. 6B, the conductive fibers 18 are passed through the electrode lead portions 10B of the anode valve metal body 10 of the plurality of electrolytic capacitor structures. The penetration can be performed by employing the method described in the fourth embodiment. Then, the capacitors are separated into individual pieces by cutting the conductive fibers 18 located between the electrode lead portions 10B of the anode valve metal body 10 of each electrolytic capacitor structure. As a result, the electrolytic capacitor shown in FIG. 6C is obtained.

  Also in this embodiment, the conductive fibers may be penetrated at a plurality of locations in each electrolytic capacitor structure. Also in this embodiment, a through hole is formed in advance in the electrode lead portion 10B of the anode valve metal body 10 of each electrolytic capacitor structure, and the conductive hole has a diameter slightly larger than the diameter of the through hole. May be penetrated. In this case, the through hole may be formed at a time after the electrolytic capacitor structure is laminated as shown in FIG. Or after laminating | stacking the electrolytic capacitor which formed the through-hole so that a through-hole may correspond, you may make a fiber penetrate.

  In another method, an electrolytic capacitor having a form as shown in FIG. 6B may be produced without cutting the conductive fiber, and this may be used as a component for a circuit board. The electrolytic capacitor of this form can increase its capacity according to the number of laminated electrolytic capacitors. Therefore, when this manufacturing method is applied, an electrolytic capacitor having a desired capacity can be easily obtained by appropriately selecting the number of solid electrolytic capacitor structures as a basic configuration.

(Embodiment 6)
Another embodiment of the electrolytic capacitor of the present invention is shown in FIG. In FIG. 7, 19 is a conductive particle. FIG. 7 shows the electrolytic capacitor of the form shown in FIG. 3 in which the conductive particles 19 are in contact with the core of the anode valve metal body at the electrode lead-out part 10B of the anode valve metal body 10. In FIG. 7, the same members or elements as those described with reference to FIGS. 1 to 6 are denoted by the same reference numerals, and description of these members or elements is omitted here.

  A method for manufacturing this type of electrolytic capacitor will be described with reference to the drawings. First, an electrolytic capacitor having a structure as shown in FIG. 3 is manufactured by a method similar to the method described in the second embodiment.

  Conductive particles 19 are prepared, placed on the electrode lead-out portion 10B of the anode valve metal body 10, and pressurized. As a result, the conductive particles 19 pass through the dielectric oxide film 11 formed on the surface of the anode valve metal body 10 and come into contact with the core portion 10 </ b> C of the anode valve metal body 10. When a plurality of conductive particles are used, it is not always necessary that all the conductive particles come into contact with the core portion 10C of the anode valve metal body 10. Even if the particles are not in contact with the core portion 10C, if they are in contact with the particles in contact with the core portion 10C, the electrical connection between the particles not in contact with the core portion and the core portion is as follows. It will be secured indirectly. Further, the conductive particles 19 are also roughened by etching or the like and pass through a region having unevenness (that is, a roughened layer), and are part of the core part and subjected to roughening treatment such as etching. It is preferable to contact an unaffected part. The roughened layer is a region in the thickness direction including irregularities formed by roughening. The boundary between the roughened layer and the region not affected by the roughening treatment corresponds to the surface when the unevenness is eliminated on the sliced surface when sliced by a surface perpendicular to the thickness direction. Usually, the thickness of the roughened layer (that is, the distance in the thickness direction between the apex of the highest convex part and the bottom of the deepest concave part) is 20 to 100 μm.

As the conductive particles 19, for example, those described in connection with the third embodiment can be used. However, unlike the third embodiment, in this embodiment, the conductive particles 19 penetrate only the dielectric oxide film 11 and do not penetrate the entire thickness of the anode valve metal body 10. Therefore, the conductive particles 19 is greater than the thickness of the dielectric oxide film 11 preferably has a particle size smaller than the thickness of the positive electrode valve metal body 10. For example, when a plurality of conductive particles 19 are used, it is preferable that at least one conductive particle 19 has a particle size of 30 to 70 μm. The conductive particles having such a particle diameter penetrate through the dielectric oxide film, further penetrate the roughening layer, and are affected by the roughening treatment in the core portion 10C of the anode valve metal body 10. Direct contact with the parts that are not. When at least one of the plurality of conductive particles has the above particle size, the other conductive particles may be less than 30 μm and may be in the range of 0.1 to 30 μm. However, it should be noted that the specific range of the preferable particle diameter varies depending on the thickness of the anode valve metal body and the thickness of the dielectric oxide film.

  The conductive particles 19 are preferably arranged so as to cover the entire surfaces of both electrode lead portions 10B as shown in the figure. Or you may arrange | position the electroconductive particle 19 so that the whole one surface of the electrode extraction part 10B may be covered. Alternatively, the conductive particles 19 may be disposed so as to cover only part of one or both surfaces of the electrode lead portion 10B.

  In a modification of this embodiment, at least a part of the conductive particles is covered with a thermosetting resin. In such a method of manufacturing an electrolytic capacitor, the conductive particles are applied to the electrode lead portion in the form of a conductive resin composition mixed with an uncured thermosetting resin. Specifically, the application is performed by printing, dipping, or a method using a dispenser. Then, after the conductive particles are brought into contact with the core portion of the anode valve metal body by pressurization, the thermosetting resin is cured by heat treatment, and the conductive resin composition is adhered to the electrode lead portion. In the electrolytic capacitor of this form, since the thermosetting resin fixes the conductive particles more firmly, the possibility of the conductive particles falling off becomes smaller, and therefore the core of the conductive particles and the anode valve metal body is reduced. Connection reliability with the part increases. A thermosetting resin is not specifically limited, For example, an epoxy resin, a phenol resin, a polyimide resin, or an isocyanate resin can be used. The uncured thermosetting resin is preferably mixed at a ratio of 25 to 100 parts by volume when the conductive particles are 100 parts by volume.

  In another method, a conductive resin composition containing conductive particles and an uncured thermosetting resin is applied to an appropriate position on a flat plate, and the electrode lead portion of the anode valve metal body is sandwiched between the two flat plates. Thus, the conductive resin composition may be transferred to the electrode lead portion. In that case, the conductive resin composition is applied to the electrode lead portion by transfer. In this case, the conductive particles can be brought into contact with the core of the anode valve metal body by pressurizing the flat plate simultaneously with the transfer. Furthermore, the thermosetting resin can be simultaneously cured by performing heating simultaneously with pressurization. Therefore, transfer using a flat plate is a preferable method in that the conductive resin composition can be arranged (that is, coated) and the conductive particles can be fixed at a time.

  The electrolytic capacitor shown in FIG. 7 has a through hole 15 filled with a conductive resin composition. The present embodiment is not limited to the illustrated form, and may be applied to the form shown in any of FIGS. In any form, the conductive particles are first brought into contact with the core of the anode valve metal body, and then a through hole is formed. If necessary, a conductive resin is formed in the through hole. The composition may be filled or conductive particles or conductive fibers may be located.

(Embodiment 7)
As Embodiment 7, the conductive resin composition containing a metal powder and a thermosetting resin in the electrode lead-out portion of the anode valve metal body of the electrolytic capacitor according to Embodiments 1 to 5 of the present invention described above. The coated electrolytic capacitor will be described together with its manufacturing method.
As the conductive resin composition used for coating, it is preferable to prepare the same conductive resin composition as described in connection with the second embodiment. Therefore, the detailed description is abbreviate | omitted.

  The conductive resin composition is applied to the surface of the electrode lead portion of the anode valve metal body by an appropriate method. As a coating method, for example, a screen printing method, a dipping method, or a method using a dispenser can be employed. Thereafter, the conductive resin composition is subjected to heat treatment to cure the uncured thermosetting resin and adhere to the surface of the electrode lead-out portion of the anode valve metal body. The heat treatment temperature and time are not particularly limited, and the conditions exemplified in connection with Embodiment 2 can be used. When manufacturing an electrolytic capacitor of this form, it is preferable to repair the defect of the dielectric oxide film and insulate the solid electrolyte layer in the same manner as in the first embodiment after applying the conductive resin composition. .

  Moreover, it is preferable to pressurize the electrode lead part of the anode valve metal body after applying the conductive resin composition to the electrode lead part surface of the anode valve metal body. This is because the adhesive strength and electrical connectivity between the conductive resin composition and the electrode lead portion are improved.

  In another method, the conductive resin composition is applied to a desired position on a flat plate, and the electrode lead-out portion of the anode valve metal body is sandwiched between the two flat plates, whereby the conductive resin composition is removed from the anode valve metal body. It is also possible to transfer it to the electrode lead-out portion and apply it. In this case, the flat plate may be pressurized simultaneously with the transfer. Furthermore, the conductive resin composition can be simultaneously adhered to the electrode lead-out portion by simultaneously performing heating and simultaneous heating. As described above, the transfer using a flat plate has an advantage that coating, pressurization, and heat treatment can be performed with a small number of steps.

(Embodiment 8)
As an eighth embodiment, a method for manufacturing a circuit board with a built-in capacitor using the electrolytic capacitor of the present invention will be described. 8A to 8D schematically show the respective steps of the method in cross-sectional views.

  First, the outline of the manufacturing procedure of the circuit board with a built-in capacitor according to the present invention will be described with reference to the drawings. First, in the preparation stage, 1) a circuit board 22 on which a wiring layer 21 having a predetermined wiring pattern is formed, and 2) a conductive adhesive 23 containing a conductive filler and an uncured thermosetting resin. 3) A sheet-like material made of a thermosetting resin composition containing an uncured thermosetting resin and an inorganic filler is prepared as the electrically insulating substrate 25. If necessary, the electrical insulating base material 25 is formed with a through hole 27 at a desired position, and a via paste 26 containing conductive powder and uncured thermosetting resin is filled therein. Keep it.

  A conductive adhesive 23 is applied to a predetermined position on the surface of the wiring layer 21 of the prepared circuit board 22. Then, the electrolytic capacitor 24 of the present invention (corresponding to that shown in FIG. 3) is disposed on the conductive adhesive 23, and the conductive adhesive 23 is cured by heat treatment. As a result, as shown in FIG. 8A, the electrolytic capacitor 24 is fixed and electrically connected to the wiring layer 21.

  Next, the electrically insulating base material 25 and the copper foil 28 are laminated on the circuit board 22 to which the electrolytic capacitor 24 is attached as shown in FIG. As a result, as shown in FIG. 8C, the electrically insulating base material 25 is adhered to the surface of the circuit board 22 to form the electrically insulating layer 29, and the electrolytic capacitor 24 is positioned in the electrically insulating layer 29 ( That is, it is built-in). Further, the via paste 26 is cured by this heating and pressurization to form the inner via 30. Then, the copper foil 28 is patterned and processed into a predetermined wiring pattern to form a wiring layer 21a, thereby completing a circuit board with a built-in capacitor as shown in FIG.

  The circuit board 22 is not particularly limited, and for example, a printed wiring board such as a glass epoxy board, a paper phenol board, and an aramid epoxy board, and a ceramic board such as an alumina board and a glass-alumina board can be used. The material constituting the wiring layer 21 is appropriately selected depending on the type of circuit board. For example, a copper foil can be used for a printed wiring board, and a sintered body of metal powder made of Cu, Ag, Pd, Mo, W, or the like can be used for a ceramic substrate. The number of wiring layers 21 included in the circuit board 22 is not particularly limited. In addition to the multilayer board as illustrated, a double-sided board having wiring layers only on both surfaces (that is, the number of wiring layers is 2) is provided. Can be used.

  The circuit board 22 preferably has an insulating layer made of the same material as an electrically insulating base material 25 described later. When the material for the insulating layer is selected in this way, the insulating layer becomes the same material in the finally obtained circuit board with built-in capacitor, thereby eliminating or reducing the generation of internal stress that occurs when different types of materials are stacked. be able to. Thereby, the connection reliability of the circuit board with a built-in capacitor can be improved.

  The conductive filler constituting the conductive adhesive 23 is not particularly limited as long as the specific resistance value and the contact resistance value are low and stable particles. Specifically, a metal or alloy powder containing Ag, Cu, Au, Ni, Pd or Pt as a main component can be used as the conductive filler. In particular, a powder of Ag or Cu or a powder made of an alloy containing Ag or Cu is preferably used. As an uncured thermosetting resin constituting the conductive adhesive 23, for example, an epoxy resin, a phenol resin, a polyamide resin, or a polyamideimide resin can be used. These resins are preferably used in terms of high reliability. The thermosetting resin is preferably mixed at a ratio of 30 to 150 parts by volume when the conductive filler is 100 parts by volume. Furthermore, the conductive adhesive 23 may contain one or more additives selected from a curing agent, a curing catalyst, a surfactant, a coupling agent, and a lubricant.

  The conductive adhesive 23 is obtained by mixing a conductive filler and an uncured thermosetting resin. As a mixing method, a mixing method using three rolls, a mixing method using a planetary mixer, or the like is employed. Alternatively, a commercially available conductive adhesive 23 may be used.

  As a method for applying the conductive adhesive 23 to a predetermined position on the surface of the wiring layer 21 of the circuit board 22, a printing method or a dispenser method can be used. In consideration of productivity, a method using metal mask printing is preferably used. The heat treatment after placing the electrolytic capacitor 24 on the electric adhesive 23 is performed at a temperature at which the thermosetting resin in the conductive adhesive can be cured. Preferably, the heat treatment is performed at a temperature in the range of 80 to 180 ° C. for 5 to 30 minutes. If the temperature becomes too high, the solid electrolyte layer in the electrolytic capacitor may be thermally decomposed, which may adversely affect the characteristics of the electrolytic capacitor.

  The electrically insulating substrate 25 can be manufactured according to the following procedure. First, a predetermined amount of thermosetting resin (uncured) and an inorganic filler are weighed and mixed. The mixing method at this time is not particularly limited, and for example, a method using a planetary mixer, a method using a ball mill using ceramic balls, or a method using a planetary stirrer can be employed. Then, the obtained thermosetting resin composition is processed into a sheet shape. The processing method is not particularly limited, and may be appropriately selected according to the state of the thermosetting resin composition. Specifically, a doctor blade method, an extrusion method, a method using a curtain coater, or a method using a roll coater can be used. In particular, the doctor blade method or the extrusion method is preferably used because it is simple.

The thermosetting resin contained in the electrical insulating substrate 25 is, for example, an epoxy resin, a phenol resin, an isocyanate resin, or a polyamideimide resin. These resins are preferably used because of their high reliability. As the inorganic filler, for example, a filler made of Al ₂ O ₃ , SiO ₂ , SiC, AlN, BN, MgO or Si ₃ N ₄ is preferably used. In particular, since a filler made of Al ₂ O ₃ or SiO ₂ can be easily mixed with a thermosetting resin, an electrically insulating substrate produced using the filler can have a filler at a high concentration. Further, when a filler made of Al ₂ O ₃ , SiC or AlN is used, the thermal conductivity of the electrically insulating substrate 25 is improved, and the heat insulating property of the electrically insulating layer 29 is increased in the circuit board with a built-in capacitor. Two or more fillers made of different materials may be mixed and used. The inorganic filler is preferably used in a granular form having a diameter of 0.1 to 100 μm. In the material constituting the electrically insulating substrate, generally, when the inorganic filler is 100 parts by volume, the thermosetting resin is mixed in a proportion of 20 to 200 parts by volume, but the present invention is not limited to this. Absent.

  The electrically insulating substrate 25 may further include one or more additives selected from a curing agent, a curing catalyst, a coupling agent, a surfactant, and a colorant. Moreover, according to the method processed into a sheet form, when mixing an inorganic filler and a thermosetting resin, a solvent may be added and the viscosity of a mixture may be adjusted. As a solvent used for viscosity adjustment, for example, methyl ethyl ketone (MEK), isopropanol, or toluene can be used. When these solvents are added, after the thermosetting resin composition is processed into a sheet, it is necessary to perform a drying treatment to remove the solvent component. The drying is not limited to a specific method as long as the drying is performed at a temperature lower than the curing start temperature of the thermosetting resin.

  When forming the through hole 27 in the electrically insulating base material 25, the through hole may be formed using, for example, an NC punching machine, or may be formed by a carbon dioxide laser. Alternatively, the through hole may be formed by a punching method using a mold.

  The via paste 26 is prepared by kneading a conductive powder and an uncured thermosetting resin. As a kneading method, a method similar to the kneading method used when producing the conductive adhesive 23 can be used. As the conductive powder, for example, a metal or alloy powder mainly composed of Ag, Cu, Au, Ni, Pd or Pt can be used. In particular, a powder of Ag or Cu or a powder made of an alloy containing Ag or Cu is preferably used. As the thermosetting resin, for example, an epoxy resin, a phenol resin, an isocyanate resin, a polyamide resin, or a polyamideimide resin can be used. These resins are preferably used because of their high reliability. The thermosetting resin is preferably mixed at a ratio of 30 to 150 parts by volume when the conductive powder is 100 parts by volume. Further, a curing agent, a curing catalyst, a lubricant, a coupling agent, a surfactant, a high boiling point solvent, and / or a reactive diluent may be added to the via paste 26.

  The method of filling the via paste 26 into the through hole 27 is not particularly limited. For example, a screen printing method can be applied.

  The temperature at the time of heating and pressing in the step shown in FIG. 8B is appropriately determined within a range in which the thermosetting resin in the electrically insulating substrate 25 can be cured and the solid electrolyte of the electrolytic capacitor 24 is not adversely affected. The The temperature is preferably 120 to 200 ° C. The heating and pressurization also results in a layer in which the electrolytic capacitor 24 is positioned (that is, embedded) in the electrically insulating substrate 25 and the electrically insulating substrate 25 is in close contact with the circuit board 22, and the wiring layer 21 and the copper foil The pressure is appropriately selected so as to be electrically connected to the inner via 30 by the inner via 30. The pressure is preferably selected in the range of 0.1 to 3 MPa.

  The copper foil 28 forms the wiring layer 21a in the finally obtained circuit board with a built-in capacitor. The thickness of the copper foil 28 is selected so that the wiring layer 21a has a desired thickness, and is generally 9 to 35 μm. The method for patterning the copper foil 28 is not particularly limited. For example, a chemical etching method using an aqueous solution of iron chloride or copper chloride is used. The copper foil 28 may be another metal foil, such as a nickel foil or an aluminum foil, as necessary.

  In FIG. 8, the electrically insulating substrate 25 is a single sheet. In another form, the electrically insulating substrate may be a laminate of a plurality of the same kind of sheet-like materials. The electrically insulating substrate 25 can be adjusted to a desired thickness depending on the number of sheet-like materials to be laminated. In addition, the electrical insulating base material may be laminated and subjected to a heat and pressure treatment after unnecessary portions are removed (for example, cut or extracted) as necessary. In that case, the positional accuracy of the inner via is increased, which is preferable.

  In each step shown in FIG. 8, the electrolytic capacitor 24 shown in FIG. 3 is used. The built-in electrolytic capacitor is not limited to this, and any type of capacitor described above may be used.

In particular, when an electrolytic capacitor as shown in FIG. 3 is used, the metal powder contained in the conductive resin composition 16 filled in the through hole 15 of the electrode lead portion of the valve metal for the anode, and the conductive adhesive 23 The inside conductive filler is preferably made of the same kind of metal or alloy. In that case, the contact resistance between the conductive resin composition 16 and the conductive adhesive 23 can be kept low, and the reliability during connection is improved. Further, when the electrolytic capacitor is one in which the conductive resin composition is applied to the surface of the electrode lead portion of the anode valve metal body as in the seventh embodiment, the metal powder in the conductive resin composition It is preferable that the conductive filler in the conductive adhesive 23 is the same type of metal or alloy. In any case, preferred metal powders and conductive fillers are made of Cu, Ag, or alloys containing Cu or Ag.

  In FIG. 8B, the electrically insulating base material 25 and the copper foil 28 were laminated on the upper surface of the electrolytic capacitor 24 and heated and pressurized. In a modification of this embodiment, a circuit board may be used instead of the copper foil 28. In this case, the patterning step described with reference to FIG. According to the configuration in which the circuit boards are overlapped, a circuit pattern for rewiring can be formed not only on the electric insulating layer containing the electrolytic capacitor but also on the upper and lower sides thereof. Therefore, such a configuration is preferably employed because the degree of freedom in designing the circuit board with a built-in capacitor is further increased and the wiring capacity is increased. As a circuit board laminated on the electrolytic capacitor, a circuit board similar to the circuit board 22 shown in FIG. 8 can be used. This circuit board also preferably has an insulating layer made of the same material as the electrically insulating base material 25. The circuit boards positioned above and below the electrolytic capacitor are preferably of the same type. This is because warpage and internal stress generated when a circuit board with a built-in capacitor is manufactured can be relaxed.

(Embodiment 9)
As a ninth embodiment, another method of manufacturing a circuit board with a built-in capacitor using the electrolytic capacitor of the present invention will be described. 9A to 9D schematically show the respective steps of the method in cross-sectional views. In FIG. 9, the same members or elements as those described with reference to FIG. 8 are denoted by the same reference numerals, and description of those members or elements is omitted here.

  The conductive adhesive 23 and the electrically insulating base material 25 prepared in the preparation stage are as described in connection with the eighth embodiment. Also in this form, a through hole 27 is formed in the electrically insulating base material 25, and the via paste 26 is filled in the through hole 27.

  In this embodiment, the conductive adhesive 23 is applied to a desired position on the surface of the copper foil 28. Then, the electrolytic capacitor 24 of the present invention (corresponding to that shown in FIG. 1) is disposed on the conductive adhesive 23, the conductive adhesive 23 is inserted into the through hole 15, and then heat-treated to conduct the conductivity. The adhesive 23 is cured. As a result, the electrolytic capacitor 24 is fixed and electrically connected to the copper foil 28 as shown in FIG.

  Next, the electrically insulating base material 25 and another copper foil 28a are laminated on the copper foil 28 to which the electrolytic capacitor is attached as shown in FIG. As a result, as shown in FIG. 9C, an electrical insulating layer 29 bonded to the surface of the copper foil 28 is formed, and the electrolytic capacitor 24 is positioned in the electrical insulating layer 29 (that is, incorporated). Further, the via paste 26 is cured by this heating and pressurization to form the inner via 30. Then, two copper foils 28 and 28a are patterned and processed into a predetermined wiring pattern to form wiring layers 21 and 21a, thereby completing a circuit board with a built-in capacitor as shown in FIG.

  According to this embodiment, there is no circuit board (corresponding to the circuit board 22 in FIG. 8) for supporting the electrolytic capacitor 24. Therefore, the thickness of the capacitor built-in circuit board itself finally obtained can be made close to the thickness of the electrolytic capacitor 24 itself, and a low-profile capacitor built-in circuit board can be obtained. Moreover, in the circuit board with a built-in capacitor obtained by this embodiment, since the distance between the electrolytic capacitor 24 and the outer wiring layer 21 is short, the resistance and the ESL are lower, and therefore, excellent high-speed response is realized. It becomes possible.

  In FIG. 9, the electrolytic capacitor 24 of the first embodiment described with reference to FIG. 2 is used. As shown in FIG. 9A, the electrolytic capacitor 24 and the copper foil 28 are brought into contact with the core of the anode valve metal body when the conductive adhesive 23 enters the through hole 15 of the electrolytic capacitor 24. Are electrically connected. The electrolytic capacitor 24 is not limited to this type, and any type of capacitor described above may be used.

  In this embodiment, as shown in FIG. 9B, the electrically insulating base material 25 is disposed so that the via paste 26 is in contact with the electrode lead portion of the anode valve metal body of the electrolytic capacitor 24. As a result, the inner via 30 is positioned immediately above the through hole 15 of the electrolytic capacitor 24 as shown in FIG. With this configuration, the inner via 30 can be in direct contact with the conductive adhesive 23 through the electrode lead-out portion of the electrolytic capacitor 24 and the through hole 15. Can be further improved. In such a configuration, the conductive powder contained in the inner via 30 and the conductive filler contained in the conductive adhesive 23 are preferably made of the same type of metal or alloy.

  When the electrolytic capacitor has a form as shown in FIG. 3 to FIG. 7, the conductive component (that is, the metal powder contained in the conductive resin composition, or the conductive particle or conductive material) is located in the through hole. The conductive powder contained in the inner via, and the conductive filler contained in the conductive adhesive are preferably made of the same type of metal or alloy. That is, it is preferable that the conductive components are unified into the same type in the connection portion between the electrolytic capacitor and another member or element. Thereby, the resistance of the circuit board with a built-in capacitor is further reduced.

  A method for producing the conductive adhesive 23, a method for applying the conductive adhesive 23, a method for producing the electrically insulating substrate 25, a method for forming the through hole 27, a method for producing the via paste 26, and the via paste 26 Since the method of filling the through hole 27 and the method of patterning the copper foils 28 and 28a and the like are as described in connection with the eighth embodiment, detailed description thereof is omitted here. The heating and pressurization of the laminate of copper foil 28a / electrical insulating base material 25 / copper foil 28 is performed by the lamination of copper foil 28 / electrical insulating base material 25 / circuit board 22 described in connection with the eighth embodiment. The method of heating and pressurizing the body may be applied and implemented.

(Embodiment 10)
As Embodiment 10, another method for manufacturing a circuit board with a built-in capacitor using the electrolytic capacitor of the present invention will be described. 10A to 10D schematically show the respective steps of the method in cross-sectional views. In FIG. 10, 31 indicates a release carrier. 10, the same members or elements as those described with reference to FIGS. 8 and 9 are denoted by the same reference numerals, and description of those members or elements will be omitted here.

  First, an outline of a manufacturing procedure of the circuit board with a built-in capacitor according to the present invention will be described with reference to the drawings. First, a copper foil is laminated on the surface of the release carrier 31A, and the copper foil is etched to form a wiring layer 21A having a predetermined wiring pattern. Also, a conductive adhesive 23 is prepared in the same manner as in the eighth embodiment. Next, the conductive adhesive 23 is applied to a predetermined position on the surface of the wiring layer 21A formed on the release carrier 31A. On top of that, the electrolytic capacitor 24 of the present invention (corresponding to that shown in FIG. 7) is disposed and heat-treated to cure the conductive adhesive 23. As a result, as shown in FIG. 10A, the electrolytic capacitor 24 is fixed and electrically connected to the wiring layer 21A.

Next, the electrically insulating substrate 25 and another release carrier 31B on which the wiring layer 21B is formed are overlaid on the release carrier 31A to which the electrolytic capacitor is attached as shown in FIG. , Heat and pressurize. As shown in the figure, the release carrier 31B is disposed so that the wiring layer 21B is in contact with the electrically insulating substrate 25. As a result, as shown in FIG. 10C, the electrically insulating substrate 25 is adhered to the surfaces of the wiring layers 21A and 21B formed on the release carriers 31A and B to form the electrically insulating layer 29. The electrolytic capacitor 24 is positioned in the electrical insulating layer 29 (that is, incorporated). Further, the via paste 26 is cured by this heating and pressurization to form the inner via 30. Thereafter, the release carriers 31A and 31B are peeled off to expose the wiring layers 21A and 21B, thereby completing the circuit board with a built-in capacitor as shown in FIG.

  As the release carriers 31 </ b> A and 31 </ b> B, a sheet-like material that can form a wiring layer on the surface thereof and that is not damaged when subjected to heat and pressure treatment is used. For example, metal foils such as copper foil and aluminum foil, and resin films such as polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polyimide and polyethylene can be used as the release carriers 31A and 31B.

  As a method of forming the wiring layer 21A on the surface of the release carrier 31A, as described above, an appropriate metal foil is laminated on the surface of the release carrier 31A and integrated by pressing and / or heating, and then etching is performed. There is a method of patterning by, for example. At this time, in order to increase the adhesive strength between the release carrier and the metal foil, an adhesive layer may be formed on the surface of the release carrier, and the metal foil may be laminated on the adhesive layer. The adhesive layer is removed after peeling the release carrier. Alternatively, the adhesive layer may remain on the release carrier side when the release carrier is peeled off and peeled off together with the release carrier. The adhesive layer is made of, for example, a silicone resin. Alternatively, the wiring layer 21A is formed by plating an appropriate metal (for example, copper) on the surface of the release carrier 31A directly or via an adhesive layer, and then patterning by etching or the like. You can do it. The laminate in which the wiring layer 21B is formed on the surface of the release carrier 31B is also formed by the same method.

  According to this embodiment, as in the ninth embodiment, there is no circuit board (corresponding to the circuit board 22 in FIG. 8) for supporting the electrolytic capacitor 24. Therefore, also in the circuit board obtained by this form, shortening of wiring and reduction in height are realized, thereby obtaining the effect of improving the high-speed response of the circuit board. Further, in this embodiment, a wiring layer having a predetermined wiring pattern is formed in advance on the release carrier. Therefore, it is possible to obtain a circuit board with a built-in capacitor that exhibits the above-described effects more easily and with higher productivity. Further, according to this embodiment, since the electrolytic capacitor is not affected by the patterning process, damage to the electrolytic capacitor during the manufacture of the circuit board can be reduced. Furthermore, according to the manufacturing method of this embodiment, since the wiring layer is formed almost flush with the surface of the electrical insulating layer in the obtained circuit board, the adhesive strength between the wiring and the electrical insulating layer is increased. Higher and less likely to lose wiring.

  A laminate in which a wiring layer is formed on the surface of a release carrier can also be called a wiring transfer sheet, and is generally used in the manufacture of wiring boards. In producing the circuit board with a built-in capacitor according to the present invention, a generally used wiring transfer sheet can be used as long as the electrolytic capacitor according to the present invention can be bonded with a conductive adhesive as described above.

  Method for producing conductive adhesive 23, method for applying conductive adhesive 23, method for producing electrically insulating substrate 25, method for forming through hole 27, method for producing via paste 26, and via paste Since the method of filling the through hole 27 with 26 is as described in connection with the eighth embodiment, detailed description thereof is omitted here. Further, the heating and pressurization of the wiring carrier 31B / electrical insulating base material 25 / release carrier 31A laminate shown in FIG. 10 (b) is the copper foil 28 / electrical insulation described in connection with the eighth embodiment. The method of heating and pressurizing the laminate of the conductive base material 25 / circuit board 22 may be applied.

(Embodiment 11)
As Embodiment 11, a component built-in module of the present invention and a method of manufacturing the module will be described. 11A to 11D schematically show cross-sectional views of each step of the method for obtaining the component built-in module of the present invention. In FIG. 11, 41 is a semiconductor chip, 42 is a chip component, and 43 is an inductor. 11, the members or elements described with reference to FIGS. 8 to 10 are denoted by the same reference numerals, and description of those members or elements is omitted here.

  First, according to the method of the eighth embodiment, a circuit board 40 with a built-in capacitor as shown in FIG. Next, as shown in FIG. 11A, the semiconductor chip 41 and the chip component 42 are mounted on the wiring layer 21 a of the circuit board 40. Then, the electrically insulating base 25A and the copper foil 28 are formed on the circuit board 40 with a built-in capacitor on which the semiconductor chip 41 and the chip component 42 are mounted by a method similar to the method described in the eighth embodiment, as shown in FIG. Are laminated and heated and pressurized as shown in FIG. This electrically insulating substrate 25A has a plurality of through holes 27, and each through hole 27A is filled with a via paste 26A.

  As shown in FIG. 11C, the electrically insulating base material 25A is bonded to the circuit board 41 to form an electrically insulating layer 29A by heating and pressing, and the semiconductor chip 41 and the chip component 42 are electrically insulated layer 29A. Located within (ie, built-in). Further, by this heating and pressing, the via paste 26A is cured to form the inner via 30A. The inner via 30A electrically connects the wiring layer 21a and the wiring layer 21b. The wiring layer 21b is a layer formed by patterning the copper foil 28 into a predetermined wiring pattern.

  Further, another semiconductor chip 41A and an inductor 43 are mounted on the wiring layer 21b to complete a component built-in module having a circuit function as shown in FIG.

  The semiconductor chip 41 is preferably mounted by a flip chip method. The flip chip method is advantageous for reducing the height of the module, and the semiconductor chip 41 can be connected with a short wiring, so that the high-speed response of the component built-in module can be further improved. The built-in chip component 42 is not particularly limited. For example, a normal chip resistor, chip capacitor, chip inductor, and the like can be incorporated as the chip component 42. Further, as a method for mounting the chip component, a method using a conductive adhesive may be used as in the case of the capacitor, or a method using a solder alloy may be used.

  According to the component built-in module according to this embodiment, since the semiconductor chip and the chip component can be arranged in the vicinity of the low-profile capacitor connected to the low resistance, the resistance is low and the stray capacitance and the inductance component are small. An electrical circuit can be formed. Therefore, this component built-in module has low loss and excellent high-speed response. In addition, a plurality of components can be mounted at a high density, whereby a component built-in module having a small area and having many functions can be obtained.

  In the illustrated form, a semiconductor chip 41 and a chip component 42 are incorporated. The built-in components are not limited to these, and may include, for example, an inductor and / or one or more other capacitors.

  As a twelfth embodiment, a switching power supply module of the present invention will be described. FIG. 14 schematically shows a circuit of a DC / DC converter module, which is one of the switching power supply modules of the present invention. In FIG. 14, the portion indicated by reference numeral 51 corresponds to a switching element. FIG. 15 is a schematic cross-sectional view of the switching power supply module of the present invention. In FIG. 15, 52 indicates a switching element. In FIG. 15, members or elements described with reference to FIGS. 8 to 11 are denoted by the same reference numerals, and description of those members or elements is omitted here.

  The module shown in FIG. 15 has a switching element 52, a chip component 42, and an inductor 43 mounted on the wiring layer 21a of the circuit board 40 with a built-in capacitor. In the illustrated embodiment, the circuit board 40 with a built-in capacitor is produced, for example, according to the method of the eighth embodiment. The switching element 52 is preferably mounted by a flip chip method. The chip component 42 and the inductor 43 are mounted using a conductive adhesive or a solder alloy.

  In the switching power supply module of this form, the switching element is disposed in the vicinity of a low-profile and large-capacity electrolytic capacitor connected to a low resistance. Therefore, this switching power supply module can handle a large power density and has a low loss. Further, according to the switching power supply module of this embodiment, since the switching element and the capacitor are connected by a short wiring, an electric circuit with a small inductance component can be formed. Therefore, the switching power supply module of this embodiment is a stable module with excellent high-speed response and low ripple voltage.

  In the illustrated form, only the electrolytic capacitor 24 is incorporated. In other forms, other components may be included, such as inductors, switching elements, and / or other one or more capacitors.

  As a thirteenth embodiment, a microprocessor module of the present invention will be described. FIG. 16 schematically shows a cross-sectional view of the microprocessor module of the present invention. In FIG. 16, 53 is a microprocessor, and 54 is a chip capacitor. In FIG. 16, members or elements described with reference to FIGS. 8 to 11 are denoted by the same reference numerals, and description of those members or elements is omitted here.

  In the microprocessor module of this embodiment, the chip capacitor 54 is built in the electrical insulating layer 29A located on the wiring layer 21a of the circuit board 40 with built-in capacitor, and the microprocessor 53 is formed on the electrical insulating layer 29A. It is mounted on the wiring layer 21b. Here, the chip capacitor 54 functions as a decoupling capacitor, and is appropriately selected according to the frequency characteristics. The chip capacitor 54 is preferably a ceramic capacitor.

The microprocessor module of this form is manufactured as follows. First, the circuit board 40 with a built-in capacitor is produced, for example, according to the method of the eighth embodiment. Next, the chip capacitor 54 is mounted on the wiring layer 21a. The chip capacitor 54 may be mounted using a conductive adhesive or a solder alloy. Then, as in the method of the eleventh embodiment, the electrically insulating base material and the copper foil are laminated and heated and pressed to form the electrically insulating layer 29A in which the chip capacitor 54 is built. The electrically insulating substrate has a through hole filled with a via paste, and this via paste is cured by heating and pressurization to form an inner via 30A that connects the wiring layers 21a and 21b. Next, the copper foil is patterned into a predetermined wiring pattern to obtain a wiring layer 21b. Next, the microprocessor 53 is mounted on the wiring layer 21b to obtain a microprocessor module. The microprocessor 53 is preferably mounted by a flip chip method as shown. The flip chip method is advantageous for reducing the height of the module. Alternatively, the microprocessor 53 may be mounted by a wire bonding method.

  As shown in the figure, the microprocessor 53 is preferably arranged so that the electrolytic capacitor 24 is located immediately below. Thereby, the area occupied by the module can be reduced. Further, according to this arrangement, the distance between the microprocessor and the electrolytic capacitor can be shortened, so that a microprocessor module excellent in high-speed response can be obtained.

In the microprocessor module of this embodiment, a microprocessor and a chip capacitor as a decoupling capacitor are arranged in the vicinity of a low-profile electrolytic capacitor connected to a low resistance. Therefore, the microprocessor and the decoupling capacitor can be connected with a low resistance and a small inductance component. Therefore, the microprocessor module of this form is excellent in high-speed response and power supply stability. In addition, according to this embodiment, since a plurality of capacitors can be mounted with high density, a microprocessor module having a small area and high operational stability can be obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.

(Example 1)
An aluminum foil having a thickness of 130 μm was prepared as an anode valve metal body, and the surface thereof was roughened by electrolytic etching. The roughening was performed by applying an alternating current to the aluminum foil in an electrolytic solution having a concentration of 10% hydrochloric acid as a main component and a liquid temperature of 35 ° C. The thickness of the roughened layer was about 40 μm. Then, this aluminum foil was cut into about 3 mm square. The cut out portion corresponds to a capacity forming portion.

  Next, the above-mentioned aluminum foil is put into an aqueous solution of ammonium adipate (liquid temperature 60 ° C.) having a concentration of 5%, and constant voltage formation is performed at a formation voltage of 8 V, and a surface of the valve metal body for anode has a thickness of 7 nm. A dielectric oxide film was formed. Next, the capacity forming part of the anode valve metal body was immersed in a solution containing a polythiophene monomer, an iron-based oxidizing agent, and a dopant, and a solid electrolyte layer was formed by chemical polymerization. Next, anodic oxidation was performed again in an organic solvent-based electrolytic solution to repair the dielectric oxide film.

  Subsequently, a polyimide tape having a width of 0.5 mm was attached as an insulator to the boundary between the capacity forming portion and the electrode lead-out portion of the anode valve metal body to separate the anode portion and the cathode portion. Then, a carbon paste was applied to the solid electrolyte layer and heat treated to form a carbon layer. Further, an Ag paste was applied to the surface of the carbon layer to form an Ag paste layer, and a cathode current collector composed of the carbon layer and the Ag paste layer was formed.

  Next, the electrode lead portion of the anode valve metal body was formed by punching with a punching die to produce a solid electrolytic capacitor structure having an outer shape of 3 × 5 mm and a thickness of about 0.23 mm as shown in FIG.

  Ten through holes having a diameter of 0.15 mm were formed in the electrode lead-out portion of the anode valve metal body of the obtained solid electrolytic capacitor structure using an NC punching machine. Thereby, an electrolytic capacitor as shown in FIG. 2 was obtained.

  In order to evaluate the obtained electrolytic capacitor, ten samples in which the electrolytic capacitor was mounted on a glass epoxy wiring board were prepared, and the ESR of each sample was measured. The conductive adhesive used for mounting the electrolytic capacitor was prepared by kneading 82 wt% silver powder and 18 wt% epoxy resin with three rolls. The wiring layer of the glass epoxy substrate was formed to have a wiring pattern corresponding to the electrode of the electrolytic capacitor. The electrolytic capacitor is mounted by printing a conductive adhesive on the surface of the wiring layer using a metal mask, placing the electrolytic capacitor on the printed conductive adhesive, and then heat-treating at 150 ° C. for 15 minutes. Carried out. For comparison, ten samples were prepared in which the electrolytic capacitor structure before forming the through hole was similarly mounted on a glass epoxy substrate.

  The ESR of these samples was measured using an impedance meter (manufactured by Agilent). FIG. 12 shows ESR at 100 kHz. As shown in FIG. 12, the ESR of the sample including the capacitor of the present invention having a through hole was significantly smaller than that of the comparative sample, and the variation in connection resistance was small. From this, it can be seen that the electrolytic capacitor of the present invention is suitable for mounting on a wiring board using a conductive adhesive.

  Next, a circuit board with a built-in capacitor was produced according to the following procedure, and its ESR was measured. First, a solid content containing 81 wt% of fused silica powder, 19 wt% of an epoxy resin (including a curing agent), and MEK as a solvent were kneaded with a planetary mixer. The mixing ratio (weight ratio) of the solid content and the solvent was 10: 1. This mixture was applied onto a PET carrier film by the doctor blade method to form a film. Then, MEK was evaporated to produce a 400 μm thick thermosetting sheet.

  Next, a through hole having a diameter of 0.2 mm was formed by a punching machine at a predetermined position of the sheet-like material. Further, 87 wt% of copper powder and 13 wt% of epoxy resin (including a curing agent) were kneaded with three rolls to prepare a via paste. This via paste was filled in the through holes formed in the sheet-like material by a printing method to obtain an electrically insulating substrate.

  On the sample prepared previously by mounting the electrolytic capacitor on a glass epoxy substrate, one sheet of the above-mentioned electrically insulating base material and a copper foil having a thickness of 18 μm with one side roughened are laminated, and the temperature is 180 ° C. Then, they were integrated by heating and pressing at a pressure of 1 MPa. The copper foil was stacked so that the roughened surface was in contact with the electrically insulating substrate. After heating and pressurizing, the copper foil was etched using an iron chloride solution to produce 10 circuit boards with built-in capacitors as shown in FIG. Similarly, ten circuit boards with built-in capacitors were prepared using samples prepared for comparison.

  The ESR of these samples was measured using the impedance meter described above. FIG. 13 shows the ESR at 100 kHz. As shown in FIG. 13, the ESR of the circuit board incorporating the capacitor of the present invention was small and the variation was small. On the other hand, the ESR of the circuit board manufactured using the comparative sample increased with the built-in capacitor, and the variation was large.

(Example 2)
A conductive resin composition was prepared by kneading 82 wt% of silver powder having an average particle diameter of 12 μm and 18 wt% of an epoxy resin (including a curing agent) with three rolls. This conductive resin composition was filled into the through holes of the electrolytic capacitor produced in Example 1 by screen printing. After the filling, heat treatment was performed at 150 ° C. for 10 minutes to adhere the conductive resin composition to the exposed surface of the through hole (that is, fix in the through hole) to obtain an electrolytic capacitor as shown in FIG. Also in Example 2, ten electrolytic capacitors were produced.

  When this electrolytic capacitor was mounted on a glass epoxy substrate in the same manner as in Example 1 and the ESR at 100 kHz was measured, the average was 60 mΩ. This is a value significantly lower than the ESR of the comparative sample shown in FIG. Moreover, this is lower than the average value of Example 1 shown in FIG. From this, it can be seen that filling the through hole with the conductive resin composition is more advantageous for low resistance connection.

  Further, ten circuit boards incorporating this electrolytic capacitor were produced in the same manner as in Example 1, and the ESR was measured. As a result, the average was 75 mΩ at 100 kHz. This is a value significantly lower than the ESR of the comparative sample shown in FIG.

(Example 3)
In the same manner as in Example 1, an electrolytic capacitor structure having the structure shown in FIG. 1 was produced. On the electrode lead portion of the anode valve metal body of this electrolytic capacitor structure, a copper powder classified to a particle size of 150 μm or more is placed, sandwiched between flat plates, and a pressure of 3 MPa is applied to apply the copper powder to the anode valve metal body. Penetrated. Thereby, an electrolytic capacitor as shown in FIG. 4 was produced. About 10 to 15 copper powders were passed through one electrolytic capacitor. In this example, ten electrolytic capacitors were produced.

  When this electrolytic capacitor was mounted on a glass epoxy substrate in the same manner as in Example 1 and measured for ESR at 100 kHz, the average was 55 mΩ. This is a value significantly lower than the ESR of the comparative sample shown in FIG. Moreover, this is lower than the average value of Example 1 shown in FIG. From this, it can be seen that the electrolytic capacitor having the conductive particles penetrated is more advantageous for the low resistance connection.

  Further, ten circuit boards incorporating this electrolytic capacitor were produced in the same manner as in Example 1, and when ESR was measured, the average was 65 mΩ at 100 kHz. This is a value significantly lower than the ESR of the comparative sample shown in FIG.

Example 4
In the same manner as in Example 1, an electrolytic capacitor structure having the structure shown in FIG. 1 was produced. An aluminum wire having a wire diameter of 0.1 mm was passed through the electrode lead portion of the anode valve metal body of this electrolytic capacitor structure at six locations. Then, the aluminum wire was cut with a wire cutter, and the aluminum wire was protruded by about 50 μm above and below the electrode lead portion, and an electrolytic capacitor as shown in FIG. 5 was produced. Also in this example, ten capacitors were produced.

  When this electrolytic capacitor was mounted on a glass epoxy substrate in the same manner as in Example 1 and the ESR at 100 kHz was measured, the average was 70 mΩ. This is a value significantly lower than the ESR of the comparative sample shown in FIG.

  Further, ten circuit boards incorporating this electrolytic capacitor were produced in the same manner as in Example 1, and when ESR was measured, the average was 80 mΩ at 100 kHz. This is a value significantly lower than the ESR of the comparative sample shown in FIG.

(Example 5)
The conductive resin composition produced in Example 2 was prepared, and this conductive resin composition was applied to the surface of a flat plate. Using these two flat plates, the electrode lead portion of the anode valve metal body of the electrolytic capacitor prepared in Example 2 was sandwiched, and a pressure of 30 MPa was applied to transfer the conductive resin composition to the electrode lead portion. . Then, heat treatment was performed at 150 ° C. for 30 minutes to produce an electrolytic capacitor as shown in FIG. Also in this example, ten capacitors were produced.

  When this electrolytic capacitor was mounted on a glass epoxy substrate in the same manner as in Example 1 and the ESR at 100 kHz was measured, the average was 50 mΩ. This is a value significantly lower than the ESR of the comparative sample shown in FIG.

  Further, ten circuit boards incorporating this electrolytic capacitor were produced in the same manner as in Example 1, and when ESR was measured, the average was 65 mΩ at 100 kHz. This is a value significantly lower than the ESR of the comparative sample shown in FIG.

  In the electrolytic capacitor of the present invention, the through hole formed in the electrode lead portion of the anode valve metal body provides an electrical connection portion having a low connection resistance. Therefore, this electrolytic capacitor is useful for manufacturing a circuit board with a built-in capacitor that is small in size, has a high density and has a low profile, and has a low ESR and is capable of high-frequency response and large current drive.

It is sectional drawing which shows the conventional electrolytic capacitor equivalent to the basic composition of this invention. (A) And (b) is sectional drawing and a top view which respectively show an example of embodiment of the electrolytic capacitor of this invention. It is sectional drawing which shows another example of embodiment of the electrolytic capacitor of this invention. It is sectional drawing which shows another example of embodiment of the electrolytic capacitor of this invention. It is sectional drawing which shows another example of embodiment of the electrolytic capacitor of this invention. (A)-(c) each shows each process which manufactures the electrolytic capacitor of this invention typically. It is sectional drawing which shows another example of embodiment of the electrolytic capacitor of this invention. (A)-(d) each shows typically each process in one form of the method of manufacturing the circuit board with an electrolytic capacitor of this invention. (A)-(d) each shows typically each process in another form of the method of manufacturing the circuit board with an electrolytic capacitor of this invention. (A)-(d) each shows typically each process in another form of the method of manufacturing the circuit board with an electrolytic capacitor of this invention. (A)-(d) each shows typically each process in the method of manufacturing the component built-in module of this invention. It is a graph which shows ESR in 100kHz of the wiring board with which the electrolytic capacitor obtained in Example 1 was mounted. It is a graph which shows ESR in 100kHz of the circuit board with which the electrolytic capacitor obtained in Example 1 was incorporated. It is a circuit diagram which shows typically the electric circuit of the switching power supply module of this invention. It is sectional drawing which shows an example of embodiment of the switching power supply module of this invention. It is sectional drawing which shows an example of embodiment of the microprocessor module of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Valve metal body for anodes 10A ... Capacitance formation part 10B ... Electrode extraction part 10C ... Core part 10D ... Core part exposure part 11 ... Dielectric oxide film 12 ... Solid Electrolyte layer 13 ... Current collector for cathode 14 ... Insulator 15 ... Through hole 16 ... Conductive resin 17 ... Conductive particles 18 ... Conductive fiber 19 ... Conductive Particles 21, 21a, 21b, 21A, 21B ... Wiring layer 22 ... Circuit board 23 ... Conductive adhesive 24 ... Electrolytic capacitor 25 ... Electrical insulating substrate 26 ... Via paste 27 ... Through hole 28, 28a ... Copper foil 29, 29A ... Electrical insulation layer 30, 30A ... Inner via 31A, 31B ... Release carrier 40 ... Circuit board with built-in capacitor 41, 41A ... Semiconductor chip 42 ... Chip component 43 ... Inductor 51 ... Switching element 52 ... Switching element 53 ... Microprocessor 54 ... Chip co Capacitors

Claims (6)

An anode valve metal body having a capacitance forming portion and an electrode lead portion; a dielectric oxide film provided on a surface of the anode valve metal body; a solid electrolyte layer provided on the dielectric oxide film; An electrolytic capacitor comprising a cathode current collector provided on a solid electrolyte layer, wherein at least one through hole is formed in an electrode lead portion of the anode valve metal body, and the core portion of the valve metal body Prepare an electrolytic capacitor that is exposed to the outside,
Preparing a circuit board on which a wiring layer having a predetermined wiring pattern is formed on the surface of the electrical insulating layer;
Providing a conductive adhesive comprising a conductive filler and an uncured thermosetting resin;
A sheet-like material comprising a thermosetting resin composition containing an uncured thermosetting resin and an inorganic filler , wherein one or a plurality of through holes are formed at a predetermined position, and the conductive powder and uncoated Preparing an electrical insulating substrate filled with a via paste containing a cured thermosetting resin ;
Applying the conductive adhesive to a predetermined position on the surface of the wiring layer of the circuit board;
The electrolytic capacitor is disposed on the applied conductive adhesive, and after the conductive adhesive has entered the through hole, the conductive adhesive is cured by heat treatment, and the electrolytic capacitor And laminating the electrically insulating base material on the circuit board to which the electrolytic capacitor is fixed, and then heating and pressurizing the electrical insulating layer in which the electrolytic capacitor is located. and forming, a including a manufacturing method to form the inner via
The electrolytic capacitor is connected so that an inner via included in the electrical insulating layer is in contact with a conductive adhesive that has entered a through hole formed in the electrode lead portion of the anode valve metal body of the electrolytic capacitor. Located in the electrically insulating layer ;
Manufacturing method of circuit board with built-in capacitor.   The manufacturing method of the circuit base with a built-in capacitor according to claim 1, wherein the electrical insulating layer constituting the circuit board and the electrical insulating base material are made of the same thermosetting resin composition. An anode valve metal body having a capacitance forming portion and an electrode lead portion; a dielectric oxide film provided on a surface of the anode valve metal body; a solid electrolyte layer provided on the dielectric oxide film; An electrolytic capacitor comprising a cathode current collector provided on a solid electrolyte layer, wherein at least one through hole is formed in an electrode lead portion of the anode valve metal body, and the core portion of the valve metal body Prepare an electrolytic capacitor that is exposed to the outside,
Providing a conductive adhesive comprising a conductive filler and an uncured thermosetting resin;
A sheet-like material comprising a thermosetting resin composition containing an uncured thermosetting resin and an inorganic filler , wherein one or a plurality of through holes are formed at a predetermined position, and the conductive powder and uncoated Preparing an electrical insulating substrate filled with a via paste containing a cured thermosetting resin ;
Applying the conductive adhesive to a predetermined position on the surface of the metal foil;
The electrolytic capacitor is disposed on the applied conductive adhesive, and after the conductive adhesive has entered the through hole, the conductive adhesive is cured by heat treatment, and the electrolytic capacitor Fixing to metal foil,
After laminating the electrical insulating base material on the metal foil to which the electrolytic capacitor is fixed, the electrolytic capacitor forms an electrical insulating layer located inside the electrolytic capacitor and forms an inner via. And a manufacturing method including patterning a metal foil to form a wiring layer having a predetermined wiring pattern ,
The electrolytic capacitor is connected so that an inner via included in the electrical insulating layer is in contact with a conductive adhesive that has entered a through hole formed in the electrode lead portion of the anode valve metal body of the electrolytic capacitor. Located in the electrically insulating layer ;
Manufacturing method of circuit board with built-in capacitor.   The method for manufacturing a circuit board with a built-in capacitor according to claim 3, wherein the metal foil is a copper foil. An anode valve metal body having a capacitance forming portion and an electrode lead portion; a dielectric oxide film provided on a surface of the anode valve metal body; a solid electrolyte layer provided on the dielectric oxide film; An electrolytic capacitor comprising a cathode current collector provided on a solid electrolyte layer, wherein at least one through hole is formed in an electrode lead portion of the anode valve metal body, and the core portion of the valve metal body Prepare an electrolytic capacitor that is exposed to the outside,
Forming a wiring layer having a predetermined wiring pattern on one side of the release carrier;
Providing a conductive adhesive comprising a conductive filler and an uncured thermosetting resin;
A sheet-like material comprising a thermosetting resin composition containing an uncured thermosetting resin and an inorganic filler , wherein one or a plurality of through holes are formed at a predetermined position, and the conductive powder and uncoated Preparing an electrical insulating substrate filled with a via paste containing a cured thermosetting resin ;
Applying the conductive adhesive to a predetermined position on the surface of the wiring layer;
The electrolytic capacitor is disposed on the applied conductive adhesive, and after the conductive adhesive has entered the through hole, the conductive adhesive is cured by heat treatment, and the electrolytic capacitor Fixing to the release carrier,
After laminating the electrically insulating substrate on the release carrier to which the electrolytic capacitor is fixed, the electrolytic capacitor forms an electrically insulating layer in which the electrolytic capacitor is located and forms an inner via. And peeling the release carrier to expose the wiring layer on the surface ,
The electrolytic capacitor is connected so that an inner via included in the electrical insulating layer is in contact with a conductive adhesive that has entered a through hole formed in the electrode lead portion of the anode valve metal body of the electrolytic capacitor. Located in the electrically insulating layer ;
Manufacturing method of circuit board with built-in capacitor.   The manufacturing method of the circuit board with a built-in capacitor according to claim 1, wherein the conductive adhesive is applied by printing.

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