JPH0119249B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated solid electrolytic capacitor in which valve metal foils such as aluminum foil and tantalum foil are laminated, and a method for manufacturing the same.

In conventional solid electrolytic capacitors, for example, a lead wire terminal serving as an anode terminal is connected to an Al rod with a roughened surface, and then chemical conversion is performed to form a chemical conversion film, which is then immersed in a manganese nitrate solution and fired to form a manganese dioxide layer. was being generated. The element with the manganese dioxide layer formed thereon is immersed in carbon black or carbon graphite suspension and dried to form a carbon layer. A conductive paste is applied onto the carbon layer, and a cathode lead wire terminal is further applied to the conductive paste. Connect. A capacitor is formed by housing the element with the anode and cathode lead wire terminals connected in this way in a case and sealing it or covering it with an insulating resin. There is also a solid capacitor in which a foil or plate is used instead of the Al rod of the element as a capacitor using the same method as described above. However, solid electrolytic capacitors made in the above manner have difficulty in mass production because they are manufactured by cutting into individual elements, and when round or square rods are used for the elements, they cannot function as electrodes. Since this is mainly a roughened surface area, there is a problem that the core cannot be used effectively. Furthermore, when foils or plates are used as elements, the workability of laminating them is poor, and since the electrode foils are handled one by one, the coating, manganese dioxide layer, carbon layer, etc. formed on the electrode foils are easily destroyed, resulting in lower yields. Unfortunately, the breakage also caused defects in characteristics, resulting in a short lifespan.

Under these circumstances, in recent years, there has been a particular demand for smaller size, thinner profile, and lower price, but these demands cannot be met, and for example, when installing electrolytic capacitors in hybrid integrated circuits, electrolytic capacitors have to be used. Methods such as attaching an external capacitor or using an expensive tantalum capacitor were used.

The present invention has been made in view of the above points, and includes Al,
This invention relates to a laminated solid electrolytic capacitor formed by punching a valve metal foil or metal plate made of Ta, Nb, Ti, etc. into a comb shape to form an electrode foil, and laminating the same, and a method for manufacturing the same, and will be described below using examples. 1st
0.1 as shown in the side sectional view in Figure 2 and the plan view in Figure 2.
A mm-thick Al electrode foil 1 is etched by known means to roughen the surface, then chemically treated to form an oxide film 2, and the electrode foil is punched into a comb shape as shown in Figure 2. A comb-shaped electrode foil is provided with a base 3 and a plurality of teeth 4. Alternatively, after roughening the surface, it may be punched into a comb shape and subjected to a chemical conversion treatment to form an oxide film 2 to form a comb-shaped electrode foil. The base 3 of this comb-shaped electrode foil
Silicone, slightly extending from the root of tooth 4,
A heat-resistant insulation coating such as polyamide or fluorine-based resin is applied to form an insulation coating 5, which is immersed in a manganese nitrate solution, then pulled up and baked at 250°C for 7 hours to form a manganese dioxide layer 6. However, reconversion is performed to repair the oxide film 2 destroyed by firing. The desired manganese dioxide layer 6 is obtained by repeating this immersion in a manganese nitrate solution, firing, and reconversion several times. The required number of comb-shaped electrode foils with manganese dioxide layers 6 formed in this way are laminated so that the insulating coatings 5 overlap, and each of the insulating coatings 5 is heated and bonded, as shown in FIG. The Al electrode foils 1 are laminated with gaps between the foils to form a laminated electrode. Alternatively, the comb-shaped electrode foil may be bonded by newly applying an adhesive onto the insulating coating film 5. This adhesion of the insulating coating 5 prevents the carbon suspension from penetrating into the anode side due to capillary action during immersion into the carbon suspension in the subsequent step. The laminated Al electrode foil 1 is immersed in carbon black or carbon graphite suspension to deposit carbon between the gaps and on the surface of the Al electrode foil 1 of the laminated electrode, and then pulled up and dried and baked, as shown in Fig. 4. A carbon layer 7 is formed. The comb-shaped Al electrode foil 1 laminated as described above has the structure shown in FIG. Then, a conductive paint is applied onto the anode terminal portion 8 and the carbon layer 7, and dried and baked to form the cathode terminal portion 9. This state is shown in FIG. 5, and by cutting along the line B-B' to the width of the tooth 4, a multilayer solid electrolytic capacitor 10 as shown in FIG. 6 can be obtained.

In the above embodiment, the carbon layer 7 is formed by immersion in a carbon suspension, and then a conductive paint is applied to form the anode terminal part 8 and the cathode terminal part 9, and the multilayer solid electrolytic capacitor 10 is obtained by cutting. As described above, after forming the carbon layer 7, as shown in FIG. 7, an insulating material such as resin is injected and molded onto the carbon layer 7, leaving the tips of the teeth 4, to form the fixing band 11. After forming the carbon layer 7 left on the tip of the tooth 4, a conductive paint is applied to form the cathode terminal part 19, and the same conductive paint is applied to the end face of the base part 3 to form the anode terminal part 18. It can also be cut into a multilayer solid electrolytic capacitor. In either case, if all or part of the anode and cathode terminals are covered with resin and hermetically sealed, this multilayer solid electrolytic capacitor can be set on the conductor of a printed circuit board and solder reflowed. It can be directly connected to the board, and costs can be reduced without the need for external electrolytic capacitors or the use of expensive tantalum capacitors, which are conventional. In the above embodiment, a comb-shaped electrode foil having the shape of the Al electrode foil 1 as shown in FIG. 2 was used, but as shown in FIG. 8, an Al electrode foil 21 having teeth 24 on both sides was used. You may. In the above embodiment, Al was used as the electrode foil, but valve metals such as Ta, Nb, and Ti may also be used. The adhesion of the insulating coating 5 in the case of lamination is provided to prevent short circuits due to penetration of carbon black or carbon graphite suspension into the base 3 side, that is, the anode terminal side. Furthermore, in place of the manganese dioxide layer, an organic semiconductor such as N-normalpropylquinoline-TCNQ salt or N-isopropylquinoline-
TCNQ salt, methylquinoline-TCNQ salt, ethylquinoline-TCNQ salt, TTF-TCNQ salt, etc. may be used.

Since the present invention is constructed as described above, the shape of the Al electrode foil should be the same as shown in FIG. This makes it possible to use the material effectively, and it is also possible to produce a large number of capacitors easily and at the same time, making it possible to provide multilayer solid electrolytic capacitors at low cost. Since destruction of the carbon layer is eliminated, a multilayer solid electrolytic capacitor with excellent leakage current and tanδ characteristics can be obtained.

[Brief explanation of drawings]

The drawings all show examples of the present invention, and FIG. 1 is a side sectional view of an Al electrode foil, FIG. 2 is a plan view of the Al electrode foil, and FIG. 3 is a side view showing a state in which the Al electrode foils are laminated. , Fig. 4 is a side sectional view showing a state in which a carbon layer is formed on the laminated Al electrode foil, Fig. 5 is a plan view showing a state in which an anode and cathode terminal portion are formed in the laminated Al electrode foil, and Fig. 6 7 is a perspective view of a multilayer solid electrolytic capacitor, FIG. 7 is a partial cross-sectional perspective view showing a state in which anode and cathode terminals are formed according to another embodiment, and FIG. 8 is a perspective view of another embodiment of a comb-shaped electrode foil. FIG. DESCRIPTION OF SYMBOLS 1... Al electrode foil, 2... Oxide film, 3... Base, 4... Teeth, 5... Insulating coating film, 6... Manganese dioxide layer, 7... Carbon layer, 8... Anode terminal part, 9... Cathode terminal portion, 10... Multilayer solid electrolytic capacitor, 11... Fixing band.

Claims (1)

[Scope of Claims] 1 A plurality of electrode foils with oxide films formed thereon, an insulating coating film applied to both sides of the electrode foils, and laminated with gaps between the electrode foils due to adhesion between the insulating coating films. A multilayer solid electrolytic capacitor comprising an electrode, an anode terminal section provided at one end of the multilayer electrode separated by the insulating coating film, a semiconductor layer at the other end, and a cathode terminal section provided on a carbon layer. 2. The multilayer solid electrolytic capacitor according to claim 1, characterized in that a fixing band is provided on the carbon layer. 3. The multilayer solid electrolytic capacitor according to claim 1 or 2, wherein a part or all of the anode terminal portion and the cathode terminal portion are externally packaged. 4. The multilayer solid electrolytic capacitor according to any one of claims 1 to 3, wherein the electrode foil is made of Al, Ta, Nb, or Ti. 5 The semiconductor layer is manganese dioxide, lead dioxide, N-
Normal propylquinoline-TCNQ salt, N-
Isopropylquinoline-TCNQ salt, methylquinoline-TCNQ salt, ethylquinoline-TCNQ salt,
The multilayer solid electrolytic capacitor according to any one of claims 1 to 4, characterized in that the multilayer solid electrolytic capacitor is composed of one or more types of TTF-TCNQ salts. 6. A step of forming an insulating coating film on both sides of the bases and the roots of the teeth of a plurality of comb-shaped electrode foils, a step of forming a semiconductor layer on the teeth of the comb-shaped electrode foils, and a step of overlapping the comb-shaped electrode foils to form the insulating coating film. a step of adhering the bonded comb-shaped electrode foils to each other to form a laminated electrode; a step of immersing the bonded comb-shaped electrode foil in carbon black or carbon graphite suspension to form a carbon layer; manufacturing a multilayer solid electrolytic capacitor comprising the steps of: applying a conductive paint to the other end of the tooth to form a cathode terminal and an anode terminal; and cutting along the width of the tooth to obtain individual elements. Method. 7. The method for manufacturing a multilayer solid electrolytic capacitor according to claim 6, which comprises inserting a step of forming a fixing band while leaving the tips of the teeth of the electrode foil after forming the carbon layer. 8. Claim 6, characterized by comprising a step of covering and encasing part or all of the anode terminal and cathode terminal of each element with an insulator.
8. The method for manufacturing a multilayer solid electrolytic capacitor according to item 7.