JP2896161B2 - Solid electrolytic capacitors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor using an organic conductive polymer or the like on a cathode side.

[Prior art]

Conventionally, due to the demand for miniaturization of electronic circuits, especially for hybrid integration, downsizing and chipping of electrolytic capacitors are expected.Fixed electrolytic capacitors using organic conductive polymers are expected as electrolytic capacitors that fulfill this expectation. is there. In this type of solid electrolytic capacitor, for example, an aluminum plate is used as an anode body to perform a surface enlargement process by etching on a surface thereof, a dielectric layer is formed on the surface by electrolytic treatment, and an upper surface of the dielectric layer is formed. It is known that a cathode body is formed by growing an organic semiconductor layer.

[Problems to be solved by the invention]

By the way, such a solid electrolytic capacitor is similar in principle to a conventional solid electrolytic capacitor,
In order to realize a highly reliable element based on electrical characteristics such as low impedance, there are various problems in taking out electrodes and the like. In particular, a cathode body is formed on a dielectric layer selectively formed on a substrate forming an anode body, and since an organic conductive polymer is used for the cathode body, extraction of a cathode terminal with respect to the cathode body However, even if an organic conductive polymer that can be expected to have low impedance is used, there are inconveniences such as an increase in connection resistance in terminal connection and a decrease in connection reliability. Also, even if the capacitor element itself is miniaturized,
The terminal structure is complicated, the volume occupied by the terminal with respect to the solid electrolytic capacitor is large, and the volume efficiency in forming the capacitance is reduced. Therefore, an object of the present invention is to provide a solid electrolytic capacitor which realizes simplification of taking out an anode terminal and a cathode terminal.

[Means for Solving the Problems]

A solid electrolytic capacitor according to the present invention, wherein a dielectric layer and a solid electrolyte layer are selectively formed on a surface portion of an anode body, and a chip-shaped capacitor element having an exposed portion of the anode body formed therein; and An outer container having an anode terminal corresponding to the exposed portion of the anode body and a cathode terminal corresponding to the solid electrolyte layer, wherein the exposed terminal of the anode body has the anode terminal of the outer container, and the solid electrolyte The cathode terminal of the outer container is connected to the layer with a conductive adhesive to combine the outer container and the capacitor element, and the capacitor element is accommodated in the outer container.

[Action]

In the solid electrolytic capacitor of the present invention, the capacitor element and the outer container having the necessary anode and cathode terminals are formed independently, and the exposed portion of the anode body of the capacitor element is connected to the anode terminal of the outer container. In addition, by connecting the solid electrolyte layer of the capacitor element to the cathode terminal of the outer container, the capacitor element and the outer container are combined, and the capacitor element is accommodated in the outer container. Therefore, in the solid electrolytic capacitor of the present invention, the outer container to accommodate the capacitor element, the anode terminal and the cathode terminal can be formed simultaneously, and the terminal structure is simplified,
A highly accurate solid electrolytic capacitor with improved moisture resistance is realized.

【Example】

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. FIG. 1 shows an embodiment of the solid electrolytic capacitor of the present invention. After the capacitor element 2 and the outer container 7 are independently formed as shown in FIGS. 1A and 1B, by combining them as shown in FIG. 1C. The solid electrolytic capacitor 10 is configured. (A) Capacitor element 2 As shown in FIGS. 1A and 1B, the capacitor element 2 is formed of a valve metal plate such as a high-purity aluminum plate or aluminum alloy plate having a thickness of about 1 mm. Anode body
20 is used. After the surface of the anode body 20 is subjected to a surface enlargement process by etching, a dielectric layer 21 is selectively formed by anodic oxidation leaving an exposed portion 22. Then, on the surface of the anode body 20, the exposed portion 22 where the dielectric layer 21 is not formed is covered, and a resist or the like is selectively printed using a screen having a transmission window formed thereon, so that the transmission of the screen is performed. The insulating layer 23 is selectively formed through the window. Note that the insulating layer 23 may be formed by applying another insulating material in addition to the insulating resist. On the surface of the dielectric layer 21 selectively exposed from the opening 24 of the insulating layer 23, a solid electrolyte layer 25 covering the surface is formed. The solid electrolyte layer 25 is composed of an organic semiconductor layer such as a polypyrrole polymer film formed by a process such as chemical polymerization or electrolytic polymerization. The cathode conductor layer 26 is formed on the surface of the solid electrolyte layer 25 by printing or coating a carbon paste, a conductive paste, or the like. The exposed portion 22 formed on the surface of the anode body 20 is formed by uniformly forming the dielectric layer 21 on the surface of the anode body 20 and then exposed.
The portion of the dielectric layer 21 that should be 22 may be selectively removed. (B) Outer Container 7 As shown in FIG. 1 (A), the outer container 7 is formed by integral molding of an insulating synthetic resin or the like, and has a housing part 70 capable of housing the capacitor element 2. A step 73 for absorbing a step on the surface of the capacitor element 2 is formed at the bottom of the outer container 7, and an anode terminal 71 and a cathode terminal 72 made of a metal plate are formed at the same time as the integral molding. I have. The anode terminal 71 corresponds to the exposed portion 22 of the anode body 20 of the capacitor element 2 on the bottom side of the housing 70,
Further, the cathode terminal 72 is provided corresponding to the cathode conductor layer 26, and the anode terminal 71 and the cathode terminal 72 penetrate through the outer wall of the outer container 7 and are disposed from the outer wall to the bottom surface. It is formed as a bondable electrode terminal. (C) Formation of Solid Electrolytic Capacitor 10 As shown in FIG. 1B, a conductive paste or other conductive material having conductive and adhesive properties is provided on the anode terminal 71 and the cathode terminal 72 inside the outer container 7. After applying the adhesives 74 and 75, the exposed portion 22 of the anode body 20 is joined to the anode terminal 71 side, and the cathode conductor layer 26 is joined to the cathode terminal 72 side. By this bonding, the anode terminal 71 side and the exposed portion of the anode body 20 are exposed.
22 are electrically connected, and the cathode terminal 72 side and the cathode conductor layer 26 are electrically connected. As shown in FIG. 2 and the outer container 7 are united to form a solid electrolytic capacitor 10. In this case, the anode body generated in the capacitor element 2
The step between the exposed portion 22 of 20 and the cathode conductor layer 26 is
As it is absorbed by the step 73 formed on the bottom part of
The capacitor element 2 is horizontally fixed inside the accommodating portion 70 of the outer container 7. As described above, the capacitor element 2 formed independently
In addition, since one solid electrolytic capacitor 10 is formed using the outer container 7, the terminal structure can be simplified,
Outer container 7 for housing capacitor element 2 and anode terminal 71
And the cathode terminal 72 are formed at the same time, so that a highly accurate solid electrolytic capacitor having simplified terminal structure and improved moisture resistance can be obtained. Next, FIG. 2 shows another embodiment of a solid electrolytic capacitor using an outer container. The bottom surface of the outer container 9 is formed horizontally, and the electrode terminals 92A and 92B are provided on the bottom portion, pulled out from the outer container 9, and arranged on the bottom surface side. Inside the outer container 9, the capacitor elements 2A and 2B formed on the single anode body 20 used in the second embodiment are placed, and a conductive adhesive is provided.
The capacitor elements 2A and 2B are electrically connected to each other by the reference numeral 75, and the capacitor elements 2A and 2B are fixed inside the outer casing 9, thereby obtaining a bipolar solid electrolytic capacitor 11. Also in this case, if the anode terminal is formed on the anode body 20, the capacitor element 2A, between the anode terminal and each electrode terminal 92A, 92B,
2B can be used individually. Next, as shown in FIG. 3, a synthetic resin or the like is applied to the back surface of the anode body 20 accommodated in the outer container 7 and one piece of the synthetic resin or the like is interposed between the outer container 7 and the anode body 20. If the insulating coating 13 is formed by invading the
Since the 20 side can be covered and the opening of the outer container 7 can be closed, the moisture resistance of the solid electrolytic capacitor 10 can be improved. Next, as shown in FIG. 4, the accommodating portion 90 is formed deep by raising the side wall of the outer package 9 so that the anode body 20 enters the inside of the outer package 9 from the opening surface thereof, and the back surface of the anode body 20 is formed. If the insulating portion 13 is formed by filling a synthetic resin or the like into the space formed on the portion side, the insulating member 13 covers the anode body 20 side,
In addition, since the opening of the outer container 9 can be closed, the moisture resistance of the solid electrolytic capacitor 11 can be further improved.
This can be similarly formed for the solid electrolytic capacitor shown in FIG. In each of the examples, the cathode conductor layer was provided on the solid electrolyte layer, but by connecting the anode terminal on the solid electrolyte layer with the conductive adhesive, the cathode conductor layer was also used as the conductive adhesive. It is also possible to make it.

【The invention's effect】

As described above, according to the present invention, the following effects can be obtained. (A) Since the capacitor element and the terminal plate can be formed separately, the terminal structure can be simplified, productivity can be improved, and errors in both manufacturing processes do not affect each other. A solid electrolytic capacitor with high accuracy can be realized with improved reliability. (B) The outer container in which the capacitor element is to be accommodated, the anode terminal and the cathode terminal can be formed simultaneously, and the capacitor element can be formed separately, so that the terminal structure can be simplified.
Moreover, the moisture resistance of the solid electrolytic capacitor can be enhanced by the outer container.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the solid electrolytic capacitor of the present invention, and FIGS. 2 to 4 are longitudinal sectional views showing another embodiment of the solid electrolytic capacitor of the present invention. 2 Capacitor element 20 Anode body 21 Dielectric layer 22 Exposed portion 25 Solid electrolyte layer 7, 9 Outer container 10, 11 Solid electrolytic capacitor 71 Anode terminal 72 Cathode terminal 74, 75 ... Conductive adhesive

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Atsuko Kaneko 1-167, Higashi-Ome, Ome-shi, Tokyo 1 Inside Nippon Chemi-Con Corporation (56) References JP-U 2-33426 (JP, U) JP-A 59 −112927 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01G 9/05

Claims (1)

(57) [Claims] 1. A chip-shaped capacitor element in which a dielectric layer and a solid electrolyte layer are selectively formed on a surface portion of an anode body and an exposed portion of the anode body is formed; An outer container having an anode terminal corresponding to the exposed portion and a cathode terminal corresponding to the solid electrolyte layer, wherein the exposed portion of the anode body has the anode terminal of the outer container, and the solid electrolyte layer has the anode terminal. A solid electrolytic capacitor, wherein the cathode terminal of the outer container is connected with a conductive adhesive to combine the outer container and the capacitor element, and the capacitor element is accommodated in the outer container.