JPS605577Y2 - Chip type solid electrolytic capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a chip-type solid electrolytic capacitor, and more particularly to an electrode structure of a chip-type solid electrolytic capacitor having an exposed element structure.

Conventionally, chip-type solid electrolytic capacitors with an exposed element structure are
As shown in FIG. 1, the anode body 1 is a porous sintered body made of a metal such as tantalum that has a valve action.
A part of the metal anode lead 2 having a valve action is buried and connected, and a dielectric oxide film 3 is formed on the surface of a part of the anode body 1 and the anode lead 2 by anodic oxidation. A solid electrolyte layer 4 of manganese dioxide or the like is formed by thermal decomposition of manganese nitrate.

After that, a carbon layer 5, a solderable conductor layer 6 such as a conductive silver paint, and a solder layer 7 are sequentially placed on the solid electrolyte layer 4.
After forming the anode terminal electrode 8, the anode terminal electrode 8 is connected to the anode lead-out wire 2 by welding or the like to form a chip type solid electrolytic capacitor.

The chip-type solid electrolytic capacitor with an exposed element structure obtained in this way is used for incorporation into hybrid ICs due to its small size. A conductor layer 6 such as conductive silver paint is formed on the solid electrolyte layer 4 of manganese dioxide etc. formed by thermal decomposition of manganese nitrate etc. and then immersed in a molten solder layer bath. Since the solder layer 7 is formed by methods such as waving, the surface of the solder layer 7 has many irregularities, so when mounting it on a hybrid IC board, etc., it is necessary to handle and mount the capacitor using an automatic feeder or vacuum suction. It was difficult to automate the process.

As an improvement plan for this, as shown in FIG.
A capacitor has been proposed that attempts to solve these drawbacks by attaching a metal plate 9 in parallel on top of the capacitor, but the metal plate 9
It was found that not only did the external dimensions become larger due to the thickness, but also there were drawbacks such as poor manufacturing efficiency, making it unsuitable for mass production.

The purpose of the present invention is to provide a small chip type solid electrolytic capacitor that overcomes these conventional drawbacks, is easy to automatically mount, and is suitable for mass production.

According to the present invention, in a chip type solid electrolytic capacitor element in which a solderable cathode conductor layer is exposed on the outermost layer of the solid electrolytic capacitor element, the cathode conductor layer is exposed so as to have a smooth surface of a desired shape, Moreover, a chip type solid electrolytic capacitor is obtained in which one exposed surface of the cathode conductor layer is made substantially flush with the solderable anode terminal electrode surface.

Hereinafter, a chip type solid electrolytic capacitor according to the present invention will be explained with reference to the drawings.

Figures 3a, b, and c show the manufacturing process of one embodiment of the present invention. First, as shown in Figure 3a, a sintered anode body (corresponding to 1 in Figure 1) is The anode drawer 2, which is embedded and connected and protrudes from the anode body, is connected to a band-shaped fixed metal plate 10 at regular intervals by welding or the like, and in this state, the anode drawer 2 is connected to the anode body (corresponding to 1 in FIG. 1). A dielectric oxide film (corresponding to 3 in Fig. 1), a solid electrolyte layer such as manganese dioxide (corresponding to 4 in Fig. 1), and a carbon layer (corresponding to 5 in Fig. 1) are sequentially formed using known techniques. By forming the capacitor element 11.

Next, as shown in Figure 3, a rectangular parallelepiped casing made of a silicone resin material to which conductive silver paint or conductive adhesive does not adhere, or at least a casing with a desired shape whose opposing surfaces are parallel planes and whose inner walls are smooth. An appropriate amount of conductive silver paint or conductive adhesive was injected into the concave part 12 of the molded product 13 having a concave part 12 consisting of a concave part 12. Then, the capacitor element 11 was fixed to the band-shaped fixing metal plate 10 and the anode drawer 2 was fixed. Insert the fixed metal plate 10 into the molded product 13 until it reaches the stopper 14 position, heat it in that state to cure the conductive silver paint or conductive adhesive, and then remove it from the molded product 13. As shown in FIG. 3C, a chip type solid electrolytic capacitor element is formed having a cathode conductor layer 15 of a desired shape made of conductive silver paint or conductive adhesive as the outermost layer.

Finally, as shown in FIGS. 4a, b, and c, anode terminal electrodes 8a to 8c of various shapes made of solderable metal are placed in the anode drawer 2 so that the anode terminal electrodes are part of the cathode conductor layer. The chip-type solid electrolytic capacitor is completed by connecting the capacitors by welding or the like so that the two surfaces are flush with each other.

Figure 5 is a cross-sectional view of the chip-type solid electrolytic capacitor element according to the present invention, including its internal structure and exterior covered with conductive silver paint or conductive adhesive, and the external shape is constant regardless of the size of the anode body. This shows that the outer surface can be made smooth.

As described above, the chip type solid electrolytic capacitor according to the present invention (a) has a fixed shape and is easy to handle with an automatic feeder.

(b) The surface of the element is smooth, and handling such as vacuum suction is easy.

(c) Since the surface of the element has a flat state, it is easy to temporarily attach it with an adhesive or the like during mounting.

It has the advantages of mass production and automatic supply.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an example of a conventional chip-type solid electrolytic capacitor with an exposed element structure. FIG. 2 is a perspective view of a conventional improved example. 3A to 3C are perspective views showing the manufacturing process of the chip type solid electrolytic capacitor of the present invention. Figures 4a and 4c are perspective views of the chip-type solid electrolytic capacitor of the present invention. Figures 5a and b are the cathode conductor layer coating of the chip-type solid electrolytic capacitor of the present invention when the anode body is large and small. Cross-sectional view showing the state. 1...Anode body, 2...Anode extraction lead, 3...Dielectric oxide film, 4...Solid electrolyte layer, 5...Carphone layer, 6...
・Conductor layer, 7... Solder layer, 8... Anode terminal electrode, 9... Metal plate, 10...
Fixed metal plate, 11...Capacitor element, 12.
...Molded recess, 13...Molded, 1
4... Stopper, 15... Cathode conductor layer (of desired shape).

Claims (1)

[Scope of utility model registration request] In a chip type solid electrolytic capacitor element in which a solderable cathode conductor layer is exposed on the outermost layer of the solid electrolytic capacitor element, the cathode conductor layer is exposed so as to have a smooth surface with a desired shape, and the cathode conductor layer A chip-type solid electrolytic capacitor characterized in that one exposed surface of the capacitor is substantially flush with a solderable anode terminal electrode surface.