JP4458470B2 - Multilayer solid electrolytic capacitor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multilayer solid electrolytic capacitor using a polymer electrolyte and a method for manufacturing the same.

  Conventionally, there is a multilayer solid electrolytic capacitor using a polymer electrolyte as shown in FIG. 3 (hereinafter referred to as “prior art”). The multilayer solid electrolytic capacitor 110 according to the prior art shown in FIG. 3 is called a three-terminal transmission line element type. In this multilayer solid electrolytic capacitor 110 according to the prior art, the conductive polymer film 2 is a solid electrolyte, an anodic oxide film is formed on the surface of the valve action metal to form the valve action metal anode body 1, and the insulating resin 6 is provided. Formed on the resist forming portion 1b in the boundary region, completely separated into the anode portion 1c and the cathode portion 1a, and then formed the conductive polymer film 2 so as to cover the cathode portion 1a, and further, a graphite layer around it 3. A silver paste layer (cathode layer) 4 is sequentially formed to form unit elements. Three unit elements are stacked, the anode part is connected by the conductive paste 9b, the cathode part 1a is connected by the silver paste layer 4 and laminated, and the anode part 1c and the anode terminal metal plate 10 are joined by the conductive paste 9b. The anode terminal. Further, the upper side and the periphery of the silver paste layer 4 as the cathode layer are covered with the heat-adhesive resin-impregnated tape 5a, and the upper side is covered with the reinforcing plate 7, while the lower side of the silver paste layer 4 on the bottom side is The hole 5c is covered with a heat-adhesive resin-impregnated tape 5b, and the hole 5c is filled with a conductive paste 9a, and then covered with a metal plate 8 for cathode terminals to form cathode terminals, thereby forming a multilayer capacitor. .

  In each of the unit elements to be laminated as described above, a method of laminating and connecting a graphite layer and a silver paste layer on a conductive polymer film in order is generally used. For example, the lamination disclosed in Patent Document 1 is generally used. Such a stacked connection is also made in the solid electrolytic capacitor.

JP-A-6-168854

  However, in the multilayer capacitor as disclosed in the prior art, each element has a graphite interface and a silver paste interface as shown in FIG. There is a problem that (ESR) becomes high.

  Further, as shown in FIG. 3, each element has a graphite layer and a silver paste layer, and there is a problem that the product height becomes high corresponding to the thickness of the graphite layer and the silver paste layer.

  Furthermore, it is necessary to apply graphite and silver paste to each element, and there is a problem that it is difficult to reduce material costs and man-hours.

  Therefore, a technical problem of the present invention is to provide a multilayer solid electrolytic capacitor having a small ESR, a low profile and a low cost, and a method for manufacturing the same.

According to a first aspect of the present invention, there is provided a method for producing a multilayer solid electrolytic capacitor comprising: an anode body having an anodized film formed on a surface region of an enlarged plate-like or foil-like valve action metal; In the method for producing a multilayer solid electrolytic capacitor comprising a capacitor element having a solid electrolyte layer, a surface on which an anodic oxide film of the anode body is formed before forming the solid electrolyte layer of the conductive polymer A step of forming a cathode structure, forming an anode part on another surface area, blocking each other by an insulating material, and joining only the anode part by a conductive paste or welding to form a laminated structure of the anode body; And a step of joining each cathode part by forming a conductive polymer by polymerization on the cathode part of the laminated structure.

According to a second aspect of the present invention, in the method for manufacturing a multilayer solid electrolytic capacitor according to the first aspect of the present invention, the two-terminal structure having one anode terminal and one cathode terminal, or two anode terminals and one cathode terminal are provided. The anode part and the cathode part are formed so as to have a three-terminal structure.

According to a third aspect of the present invention, there is provided the method for manufacturing a multilayer solid electrolytic capacitor according to the first or second aspect , wherein the conductive polymer layer on one of the stacked ends of the stacked capacitor elements is a graphite layer and / or silver. It connects with the metal plate for cathodes through a paste layer, It is characterized by the above-mentioned.

According to a fourth invention, in the method for producing a multilayer solid electrolytic capacitor according to any one of the first to third inventions, the monomer of the conductive polymer is selected from aniline, pyrrole, thiophene, or a derivative thereof. It is characterized by doing.

  According to the present invention, the laminated structure of the anode body is manufactured in advance, and the cathode portion is connected to each other by a conductive polymer formed by polymerization. A graphite layer, a silver paste layer, and the like required for the layer are not necessary, and the interface of the cathode layer can be reduced. As a result, it is possible to provide a multilayer solid electrolytic capacitor having a low ESR, a low profile, and a low cost, and a method for manufacturing the same. Further, even when the cathode part of each element is connected using a graphite layer or a silver paste layer after the laminated structure of the anode body is manufactured, it is useful to reduce the man-hours by carrying out collectively after the lamination.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a multilayer capacitor according to Embodiment 1 of the present invention. The multilayer solid electrolytic capacitor 100 is a rectangular flat solid electrolytic capacitor, and FIG. 1 shows a cross section perpendicular to the rectangular surface and parallel to the longitudinal direction. In addition, although there is a part where hatching is omitted in order to avoid complexity, each part shows a cross-sectional shape. This multilayer capacitor is called a three-terminal transmission line element type, similar to that shown in FIG.

  In the multilayer solid electrolytic capacitor 100 according to Embodiment 1 of the present invention, the conductive polymer film 2 is a solid electrolyte, and the surface of a valve-acting metal having a plate-like or foil-like valve action is etched by an infinite number of voids. The surface of the valve-acting metal having a surface area increased by 200 times or the like is formed by forming a hole, and an anodic oxide film is formed on the surface of the expanded valve-acting metal to become the cathode portion 1a. And Here, tantalum, aluminum, niobium, or the like can be used as the valve metal. Next, the cathode portion 1a and the anode portion 1c on the surface of the anodized film layer are completely cut off by the insulating resin 6 formed on the resist forming portion 1b, and only the anode portion 1c is electrically conductive paste 9b or welded. A laminated structure of the anode body is manufactured by electrical bonding.

  After that, the conductive polymer film 2 is formed so as to cover the cathode part 1a, and the conductive polymer film 2 is connected between the cathode parts 1a of the stacked unit elements. A graphite layer 3 and a silver paste layer (cathode layer) 4 are sequentially formed on the outer periphery. In other words, the graphite layer 3 and the silver paste layer (cathode layer) 4 are formed on the portions where the conductive polymer film 2 is exposed on the two side surfaces, the top surface and the bottom surface. As a result, the laminated element shown in a perspective view in FIG. 2 is obtained. Next, the anode portion 1c on the bottom surface side and the anode terminal metal plate 10 are joined with a conductive paste 9b to form an anode terminal, and the upper side and the periphery of the silver paste layer 4 as a cathode layer are covered with a heat-adhesive resin impregnated tape 5a. Further, the outside is covered with a reinforcing plate 7, and on the other hand, the bottom side of the silver paste layer 4 is covered with a heat-adhesive resin-impregnated tape 5 b provided with a hole 5 c, and the conductive paste is placed in the hole 5 c. After filling with 9a, the cathode terminal is formed by covering with the cathode terminal metal plate 8 to form a multilayer capacitor.

  By the way, in the embodiment of the present invention, a polymer film whose monomer is aniline, pyrrole, thiophene, or a derivative thereof can be used for the conductive polymer film 2, which is for element reinforcement. As the metal reinforcing plate 7 and the metal plate 8 for the cathode terminal, a plate material such as copper, a copper-based alloy, or a nickel alloy can be used. However, the plate is not limited to these as long as it is a plate material made of an electronic component terminal material. It is not something. Moreover, as the heat-adhesive resin-impregnated tape, an acrylic base material impregnated with an epoxy resin is used, but there is no particular limitation as long as the resin base material is impregnated with an adhesive. Instead of forming the graphite layer 3 and the silver paste layer 4 on the outer peripheral portion of the laminated structure on which the conductive polymer film 2 is formed and connecting to the metal plate 8 for the cathode terminal, the graphite layer 3 Alternatively, connection to the cathode terminal metal plate 8 may be performed using only one of the silver paste layers 4.

  According to the procedure described above, the laminated capacitor elements do not require the graphite layer, the silver paste layer, and the like that are necessary between the elements of the cathode layer. For this reason, the graphite, silver paste interface of each element, and the contact interface between each element can be reduced, and the ESR can be reduced. Further, the product height can be reduced by an amount corresponding to the thickness of the graphite layer and the silver paste layer. Furthermore, since the graphite and silver paste need only be applied to the outer periphery of the laminated structure, material costs can be reduced. This makes it possible to manufacture a multilayer capacitor with a low ESR, a low profile, and a low cost.

  Next, a second embodiment of the present invention will be described with reference to FIG. On the valve action metal anode body 1, an anode portion 1c only on the left side, a resist formation portion 1b only on the left side, and a cathode portion 1a are formed. In this way, a multilayer metal electrolytic capacitor having a two-terminal structure is manufactured in the same manner as in the first embodiment except that the valve-acting metal anode body 1 having the anode terminal connected to only one side is used. As a result, the obtained effect is the same as that of the first embodiment. By the way, depending on the number of lead-out terminals from the cathode portion, a four-terminal structure or the like is also possible, and can be selected according to the frequency band to be used.

  By the way, in the above embodiment, before forming the conductive polymer film on the anodized film, the anode part of each element is connected to produce a laminated structure. After forming the conductive polymer film on the film, connect the anode parts of each element to make a laminated structure, and then use graphite paste to connect the conductive polymer films adjacent in the stacking direction. May be connected.

  Furthermore, after sequentially forming a conductive polymer film and a graphite layer on the anodized film of the laminated anode body, the anode part of each element is connected to produce a laminated structure, and then a silver paste is applied. It may be used to connect between conductive polymer films adjacent in the stacking direction.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and design changes within a range not departing from the gist of the present invention are also included in the present invention. That is, it goes without saying that various modifications and corrections that can be made by those skilled in the art are included.

  The surface-mount thin multilayer solid electrolytic capacitor according to the present invention can be applied to a multilayer solid electrolytic capacitor of a type that is surface-mounted on a substrate such as a printed wiring board of an electronic component or an electrical component.

1 is a sectional view of a multilayer solid capacitor according to a first embodiment of the present invention. The perspective view which shows the laminated element in an intermediate process. Sectional drawing of the multilayer type solid electrolytic capacitor by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve action metal anode body 1a Cathode part 1b Resist formation part 1c Anode part 2 Conductive polymer film 3 Graphite layer 4 Silver paste layer (cathode layer)
5a, 5b Thermal adhesive resin impregnated tape 5c Hole 6 Insulating resin 7 Reinforcement plate 8 Metal plate for cathode terminal
9a, 9b Conductive paste 10 Metal plate for anode terminal 100, 110 Multilayer solid electrolytic capacitor

Claims (4)

  Multi-layered type in which a capacitor element having an anode body in which an anodized film is formed on a surface region of a plate-like or foil-like valve action metal having an enlarged surface and a solid electrolyte layer of a conductive polymer is laminated. In the method of manufacturing a solid electrolytic capacitor, before forming the solid electrolyte layer of the conductive polymer, the surface region on which the anodized film of the anode body is formed is set as a cathode portion, and the anode portion is provided in another surface region. A step of forming a laminated structure of the anode body by cutting off each other with an insulating material and joining only the anode part with a conductive paste or welding, and polymerizing a conductive polymer on the cathode part of the laminated structure And a step of joining the respective cathode portions by forming the multilayer solid electrolytic capacitor. The anode part and the cathode part are formed so as to have a two-terminal structure having one anode terminal and one cathode terminal, or a three-terminal structure having two anode terminals and one cathode terminal. The method for producing a multilayer solid electrolytic capacitor according to claim 1 . Claim that the layer of conductive polymer at one stack end of the stacked capacitor element, characterized in that connected through the graphite layer and / or silver paste layer on the metal plate for a cathode 1 or claim 2 The manufacturing method of the lamination type solid electrolytic capacitor of description. The method for producing a multilayer solid electrolytic capacitor according to any one of claims 1 to 3 , wherein the monomer of the conductive polymer is selected from aniline, pyrrole, thiophene, or a derivative thereof. .

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