JPS6140019A - Solid electrolytic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to solid electrolytic capacitors, particularly those having low leakage current.
This invention relates to a solid electrolytic capacitor with excellent high frequency pulse characteristics.

Conventional technology Recent advances in semiconductor ICs have enabled high-speed MO in electronic computers, etc.
As RAMs have come into widespread use, pulse signals with fast response speeds, that is, extremely fast rise speeds, are being used, and various noise limiters are being used to remove the noise generated in high-speed pulse circuits. − capacitor is used. These capacitors generally include ceramic capacitors and solid electrolytic capacitors made of tantalum, aluminum, etc., and the latter is widely used because it can have a relatively large capacity, be small, and be manufactured at low cost5. However, since the sintered body for the anode is formed by molding and sintering powdered metal, the equivalent series resistance of the capacitor is large (the impedance at high frequencies is large). As shown in the figure, the lead wire is embedded in a powder metal molded body and molded.
A through hole is provided in the axial direction of the molded body and sintered, and a lead wire is embedded in the powder metal molded body and the thickness of the lead wire is embedded in the peripheral surface of the molded body as in Japanese Utility Model Application Publication No. 50-104948. Attempts have been made to form concave portions that substantially reduce the size of

Problems to be Solved by the Invention When using a powdered metal with a small particle size and a high CV (product of capacitance and formation voltage), the conventional method of forming through holes in the phase direction as described above There was a drawback that press molding was difficult.

Furthermore, the density at the pressurized end portion of the molded body becomes high, and penetration of the solid electrolyte layer becomes insufficient, so there is a limit to the reduction in equivalent series resistance.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention involves molding and sintering a powdered metal for forming an oxide film to form a sintered body, and forming an oxide film layer and a solid electrolyte layer on the surface of the sintered body. In a solid electrolytic capacitor in which cathode layers are sequentially formed, the above metal for forming a powder oxide film is formed into a plate shape having holes or irregularities, calcined, a drawer tab is welded to this, and further sintered. This is a solid electrolytic capacitor characterized in that a sintered body for an anode is formed by

Function Since the powdered oxide film forming metal is formed into a plate shape with holes or a plate shape with unevenness, press molding is easy even when using a small diameter powdered metal, and the solid electrolyte inside the molded body is easily formed. A porous sintered body with good layer permeability is obtained, and response characteristics to high-speed pulses are improved due to the effect of reducing equivalent series resistance and impillance.

EXAMPLES Hereinafter, the present invention will be explained with reference to examples shown in FIGS. 1 to 9.

FIG. 1(A) is a perspective view of a sintered body for an anode, and FIG. 1(II) is a side sectional view thereof, in which powdered tantalum metal for forming an oxide film is molded to form a powder compact having a large number of holes 1. , degree of vacuum 5
After calcining for 15 minutes at xlO-6 Torr and temperature 1700°C, a pull-out tab 2 made of Tankle wire was welded to this, and further the vacuum was 5xlO-6 Torr and temperature 170°C.
The porous sintered body 3 is formed by sintering at 0° C. for 15 minutes. Next, the drawer tab 2 is welded to a conductive metal plate for chemical conversion, the sintered body 3 is immersed in a chemical liquid to form an oxide film on the surface of the sintered body, and the sintered body is immersed in a manganese nitrate solution and baked several times to form a solid. After forming an electrolyte layer, using graphite or silver paste, etc., the tab 2 is separated from the conductive metal plate for chemical conversion, the anode agent lead terminal is welded, and the cathode conductive layer and the cathode layer lead terminal are connected with solder. Completed with resin exterior.

Figure 2 shows that a solid electrolytic capacitor with two terminals in the same direction with a rating of 35V and 11μF was fabricated based on the above-mentioned embodiment, and the rise time T'r ''l'n's was connected to it through a series resistance of 50Ω and a parallel resistance of 50Ω. The capacitor terminal voltage was measured by applying a rectangular wave pulse voltage of Shown below.

The table and Figure 3 are comparison diagrams of the impedance and equivalent series resistance (ESR) frequency characteristics of the same product.
is the impedance of the product of the present invention, curve C is the impedance of the conventional product, curve C is the equivalent series resistance of the product of the present invention, and curve d is the equivalent series resistance of the conventional product.

As is clear from FIGS. 3 and 4, it was demonstrated that the product of the present invention can significantly improve the pulse response characteristics and frequency characteristics.

In addition, FIGS. 4 to 9 show other embodiments, where 4 is a hole and 5 is a hole.
．． 6.7.8 is a recess. Reference numeral 10 indicates a drawer i-b 2 welded to the flat side of the plate. Both of them could be manufactured in the same manner as in the above-mentioned embodiments, and their electrical properties were similar to those of the products of the present invention shown in FIGS. 2 and 3.

In the above-described embodiments, the terminal lead-out method can be used for a flat chip type, a three-terminal lead type, a four-terminal lead type, etc., as appropriate.

Effects of the Invention As described above, the solid electrolytic capacitor of the present invention provides a solid electrolytic capacitor with low loss and high high-speed pulse response speed, and furthermore, it is possible to easily mold high-v powder metal with small particle size. This is extremely advantageous in terms of improving quality and productivity.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the porous sintered body of the solid electrolytic capacitor of the present invention, in which (A) is a perspective view, (D) is a side sectional view, and FIG.
Figure 3 is a pulse response characteristic diagram of a solid electrolytic capacitor comparing a conventional product and the product of the present invention. Figure 3 is a frequency characteristic diagram of impedance and equivalent series resistance of a solid electrolytic capacitor comparing a conventional product and the present invention. Figure 4 8 are perspective views of different porous sintered bodies of solid electrolytic capacitors of the present invention, and FIG. 9 is side views of other embodiments of porous sintered bodies of solid electrolytic capacitors of the present invention. . 1.4: Hole 2: Drawer tab 3.9.10.11.12.13.14: Sintered body 5
．． 6.7.8: Recess

Claims (1)

[Claims] In a solid electrolytic capacitor formed by molding and sintering a metal for forming a powdery oxide film to form a sintered body, and sequentially forming an oxide film layer, a solid electrolyte layer, and a cathode conductive layer on the surface of the sintered body, the above-mentioned powdery oxide A solid electrolytic capacitor characterized in that a metal for forming a film is formed into a plate shape having holes or irregularities, calcined, a pull-out tab is welded to the plate, and a porous sintered body is formed by further sintering. .