JP2728099B2 - Solid electrolytic capacitor and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a solid electrolytic capacitor using an organic conductive polymer for a cathode and a method for manufacturing the same.

[Conventional technology]

Conventionally, due to the demand for downsizing electronic circuits, especially hybrid integration, miniaturization and chipping of electrolytic capacitors are expected, but fixed electrolytic capacitors using organic conductive polymers are the electrolytic capacitors that fulfill these expectations. There is practical use.

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. Since an organic conductive polymer is used for the cathode body, a cathode terminal for the cathode body is taken out. 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.

Further, in a solid electrolytic capacitor, it is required to improve heat resistance against solder reflow, moisture resistance against deterioration due to moisture in the air, and the like, and to improve productivity to reduce production cost.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a solid electrolytic capacitor in which the structure for taking out the anode terminal and the cathode terminal is simplified and the moisture resistance is improved.

In addition, the present invention provides a method for manufacturing a solid electrolytic capacitor that improves productivity and realizes production of a solid electrolytic capacitor with high reliability by simplifying and facilitating a structure for extracting an anode terminal and a cathode terminal. This is the purpose of 2.

[Means for solving the problem]

In order to achieve a first object, a solid electrolytic capacitor according to the present invention includes an insulating layer selectively formed on a surface of an anode body having a dielectric layer formed thereon, and the dielectric layer exposed from the insulating layer. A solid electrolyte layer provided on the layer, a cathode conductor layer provided on the upper surface of the solid electrolyte layer, a conductive member connected to the cathode conductor layer, and an end side of the conductive member and An insulating coating that selectively exposes a part of the anode body to cover an outer surface of the capacitor element, and is electrically connected to the anode body selectively exposed from the insulating coating and installed on the insulating coating. And a cathode terminal electrically connected to the conductive member selectively exposed from the insulating coating and disposed on the insulating coating.

Further, the method for manufacturing a solid electrolytic capacitor of the present invention,
In order to achieve the second object, a surface portion of the anode body on which a dielectric layer is formed is selectively exposed, an insulating layer is provided on a surface portion of the anode body, and the dielectric layer exposed from the insulating layer is provided. A solid electrolyte layer is formed on the surface of the layer, a conductive member is connected to the upper surface of the solid electrolyte layer via a cathode conductor layer, and an insulating coating is formed on the outer surface of the capacitor element except for a part of the conductive member. Forming a part of the anode body together with the insulating coating to expose a part of the anode body from the insulating coating; and forming an anode terminal electrically connected to the exposed anode body on the insulating coating. And a cathode terminal connected to an end of the conductive member is formed on the insulating coating.

[Action]

In the solid electrolytic capacitor of the present invention, the insulating layer formed on the surface of the anode body by selectively exposing the surface of the anode body on which the dielectric layer is formed, and the insulating layer formed on the dielectric layer are provided. A capacitor element is formed by the solid electrolyte layer and a conductive member connected on a cathode conductor layer provided on the upper surface of the solid electrolyte layer, and the surface of the capacitor element is coated with an insulating material. That is, the end side of the conductive member and a part of the anode body are selectively exposed to form an insulating coating covering the outer surface of the capacitor element, and the insulating coating is provided as an exterior member. Then, an anode terminal electrically connected to the anode body selectively exposed from the insulating coating and installed on the insulating coating is formed,
A cathode terminal is formed electrically connected to the conductive member selectively exposed from the insulating coating and disposed on the insulating coating. With such a configuration, the simplification of the lead-out structure of the anode terminal and the cathode terminal and the insulation resistance, the anode terminal and the cathode terminal ensure the moisture resistance of the solid electrolytic capacitor.

In the method for manufacturing a solid electrolytic capacitor according to the present invention, after the formation of the capacitor element, an insulating coating covering an outer surface of the capacitor element except for an end side of the conductive member is formed, and then the insulating coating is formed. Cutting a part of the anode body to expose a part of the anode body from the insulating coating, forming an anode terminal electrically connected to the exposed anode body on the insulating coating, A cathode terminal connected to the end of the conductive member is formed on the insulating coating. Therefore, according to this manufacturing method, the anode terminal and the cathode terminal can be easily taken out, and the productivity can be improved.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 shows an embodiment of a method for manufacturing a solid electrolytic capacitor of the present invention, and FIG. 2 shows a solid electrolytic capacitor manufactured by the method.

As shown in FIG. 1A, a substrate 2 is provided as an anode body, and this substrate 2 is formed of a highly pure aluminum plate or aluminum alloy plate having a thickness of about 1 mm. Then, after the surface of the substrate 2 is subjected to surface enlargement processing by etching, the dielectric layer 4 is formed by anodic oxidation.

Next, on the surface of the substrate 2, resist layers 6 and 8, which selectively form an insulating layer, are formed by screen printing using a screen in which a transmission window is selectively formed. According to such a printing technique, the resist layers 6 and 8 can be formed at desired positions with high precision selectivity. In this case, although the resist layers 6 and 8 are formed as the insulating layers, the insulating layers may be formed by using other insulating materials such as coating. By such selective formation of the resist layers 6 and 8, an exposed portion of the dielectric layer 4 is selectively formed at the center of the substrate 2, and a solid electrolyte layer 10 is formed on the upper surface of the dielectric layer 4. Is done. The solid electrolyte layer 10 is composed of an organic semiconductor layer such as a polypyrrole polymer film formed by a process such as chemical polymerization or electrolytic polymerization.

Next, as shown in FIG. 1B, the solid electrolyte layer 10
A cathode conductor layer 12 serving as a substantial cathode is provided on the upper surface of the substrate, and a conductive foil 14 is connected to the cathode conductor layer 12 as a cathode-side conductive member. For the cathode conductor layer 12, a conductive material having an adhesive property as well as conductivity such as carbon paste and silver paste is used.For the conductive foil 14, a metal foil having high conductivity such as copper foil or silver foil is used. Used. Therefore, the conductive foil 14 is connected to the cathode conductor layer 12 by the adhesive property of the cathode conductor layer 12, and is electrically connected to the solid electrolyte layer 10 via the cathode conductor layer 12. The conductive foil 14 is set to have a length that covers the upper surface of the resist layer 8 and slightly protrudes from its end. With such a configuration, the capacitor element 16 which is a prototype of the solid electrolytic capacitor is formed.

Next, as shown in FIG.
The insulating coating 18 is formed on the entire surface of the insulating coating 16. The insulating coating 18 is formed of a synthetic resin such as an epoxy resin having an insulating property and an excellent moisture resistance. In this case, in order to form the cathode terminal, the end of the conductive foil 14 is exposed so that a part of the insulating coating 18 does not adhere to the surface.

Next, as shown in FIG. 1D, the conductive foil 14 exposed from the insulating coating 18 is bent along the outer surface of the insulating coating 18, for example, toward the upper surface of the capacitor element 16. And the capacitor element on the opposite side of this conductive foil 14
A part of the end face side of 16 is cut by a cutting means such as a laser cutter. In this embodiment, a corner of the capacitor element 16 is cut off obliquely, and a part of the substrate 2 is exposed from the insulating coating 18. In that case, by making the cut reach the substrate 2, a part of the substrate 2 can be exposed.
When the substrate 2 is cut off obliquely, the cut surface becomes an inclined surface, so that the exposed surface more than the thickness of the substrate 2 can be enlarged.

Next, as shown in FIG. 1 (E), the end of the capacitor element 16 exposing a part of the substrate 2 is connected to an anode by a conductive material such as a solderable metal terminal or conductive paste. A terminal 20 is formed, and at the end on the conductive foil 14 side,
The cathode terminal 22 is formed of a similar conductive material. The anode terminal 20 and the cathode terminal 22 are formed so as to cover the end portion of the capacitor element 16 and the peripheral surface near the end portion, and are set so that both are sufficiently electrically insulated through the insulating coating 18.

If the anode terminal 20 is flattened like the cathode terminal 22 by compensating for the cut slope as in the solid electrolytic capacitor shown in FIG. 2, the solder adhesion during face bonding can be reduced. Can be enhanced.

Also, as shown in FIG. 3, if the anode terminal 20 is formed in such a manner that an inclined surface generated by cutting appears on the outer shape, the polarity can be determined on the inclined surface 24 formed on the anode terminal 20, It can be provided for convenience of implementation.

According to such a manufacturing method, the formation of the anode terminal 20 and the cathode terminal 22 becomes easy, and a highly reliable solid electrolytic capacitor can be easily and efficiently produced, and the productivity can be improved.

Also, in the solid electrolytic capacitor produced by such a manufacturing method, the outer surface of the capacitor element 16 is covered by the insulating coating 18, the anode terminal 20, and the cathode terminal 22, so that the moisture resistance is enhanced, and the stable electrical characteristics are improved. Can be maintained.

In the examples, the case where an organic semiconductor layer was used for the solid electrolyte layer was described. However, the solid electrolytic capacitor and the method of manufacturing the same according to the present invention use not only such an organic semiconductor layer but also other electrolyte layers. It is also applicable when there is.

〔The invention's effect〕

As described above, according to the present invention, the following effects can be obtained.

(A) The structure for taking out the anode terminal and the cathode terminal can be simplified and the moisture resistance can be improved.

(B) The simplification and simplification of the structure for taking out the anode terminal and the cathode terminal can improve the productivity and produce a highly reliable solid electrolytic capacitor.

[Brief description of the drawings]

FIG. 1 is a view showing the steps of one embodiment of a method for manufacturing a solid electrolytic capacitor of the present invention, FIG. 2 is a cross-sectional view showing one embodiment of a solid electrolytic capacitor of the present invention, and FIG. It is sectional drawing which shows the other Example of an electrolytic capacitor. 2 ... substrate (anode) 4 ... dielectric layer 6, 8 ... resist layer (insulating layer) 10 ... solid electrolyte layer 12 ... cathode conductive layer 14 ... conductive foil (conductive member) 16 ... ... Capacitor element 18 ... Insulating coating 20 ... Anode terminal 22 ... Cathode terminal

Claims (2)

(57) [Claims] An insulating layer selectively formed on the surface of the anode body on which the dielectric layer is formed; a solid electrolyte layer disposed on the dielectric layer exposed from the insulating layer; A cathode conductive layer provided on the upper surface of the solid electrolyte layer; a conductive member connected to the cathode conductive layer; and selectively exposing an end portion of the conductive member and a part of the anode body. An insulating coating covering the outer surface of the capacitor element, and an anode terminal electrically connected to the anode body selectively exposed from the insulating coating and installed on the insulating coating; and selectively from the insulating coating. And a cathode terminal electrically connected to the exposed conductive member and disposed on the insulating coating. 2. An anode layer on which a dielectric layer is formed is selectively exposed, an insulating layer is provided on the surface of the anode body, and a surface section of the dielectric layer exposed from the insulating layer is provided. Forming a solid electrolyte layer, a conductive member is connected to the upper surface of the solid electrolyte layer via a cathode conductor layer, and an insulating coating is formed on the outer surface of the capacitor element except for a part of the conductive member, By cutting a part of the anode body together with the insulating coating to expose a part of the anode body from the insulating coating, an anode terminal electrically connected to the exposed anode body is formed on the insulating coating. A method of manufacturing a solid electrolytic capacitor, wherein a cathode terminal connected to an end of the conductive member is formed on the insulating coating.