JPS58115809A - Molded chip solid electrolytic condenser - Google Patents

Abstract

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

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a molded chip solid electrolytic capacitor with improved manufacturing yield and reliability.

(b) Background of the technology Solid electrolytic capacitors are manufactured by sintering valve metals (pulp metals) such as tantalum (Ta) and aluminum into sintered elements. The surface area of the capacitor is expanded and used as a capacitor element, and the surface of the capacitor element is transformed into an oxide film of the required thickness by electrolytic oxidation treatment.

Additionally, K1111m salt such as manganese nitrate (Mm(NO)
s) By repeating impregnation with water and thermal decomposition, an oxidizing conductor layer such as MmO! A layer is formed on the oxide and film of the anode element, and a conductive layer such as a graphite layer and a silver (A) layer are formed on this layer.
#) This is a capacitor that has a logical structure with 11111 layers.

The characteristic of solid electrolytic capacitors is that they can be made small and have a large capacity, and resin-molded solid electrolytic capacitors have been put into practical use.

However, as electronic circuits become more integrated circuits, the passive elements used in these circuits are also required to be smaller, and the conventional molded chip solid electrolytic capacitors have been further downsized, with a length of 3 x width of 2 x height of 1.
．． It became necessary to develop an ultra-small molded solid electrolytic capacitor weighing about 3 grams.

The present invention makes it possible to obtain such small capacitors with good yield and high reliability.

(C1 Prior Art and Problems No. iml is a side view of a capacitor element made by the conventional method before molding, and Fig. 2 is a front view of this, showing that the element is made of a large number of capacitors welded to a bar. No 1
1i structure is shown. This type of capacitor is usually manufactured in units of one per unit. That is, T
In the case of a capacitor element, T1 powder is pressed into a cylindrical shape, into which a Ta wire is inserted, and then sintered at a temperature of around 1000° C. to form a pellet, which is used as a capacitor element. In the case of an M-:1 capacitor, the M-wire component with lead wires is electrolytically etched with MfM immersed in a hydrochloric acid-based casing to obtain a highly concentrated material, which is used as a capacitor element.

Next, the tips of the lead wires are explosively connected to the bar with the capacitor elements aligned at a certain interval and height, forming a unit consisting of several dozen capacitor elements. Molded chip solid electrolytic capacitors are manufactured by using 10 pieces as one piece.

3 Here, we will describe an example in which a Tafi structure is used as a capacitor element. The Ta capacitor element 1 for a molded solid electrolytic capacitor is manufactured with the tip of the anode lead wire 2 in explosive contact with the bar 3, as shown in Figure 82, and the outside of the capacitor element 1 is electrically conductive to the graphite cathode. A sex paint has been applied.

The conventional manufacturing method is to attach the par 3 to the cathode terminal 5 of the lead frame 4, and then attach the anode lead 4I2 of the capacitor element 1 all at once at the position indicated by the dashed line 6. Then, the anode lead II2 is connected to the anode terminal 7.
It was made in a way that caused an explosion. Here, the lead frame 4 was punched out of the same metal plate as the cathode terminal 5 to which the cathode of the capacitor element l is soldered and the anode terminal 7 to which the anode lead II2 is explosively welded.

After the mold is completed, the terminals 5.7 of the lead frame 4 are cut using force and force at the position 8.9 indicated by the two-dot chain line in Figures 1 and 2 to obtain a capacitor. In this conventional case, since the connection between the cathode terminal 5 of the lead frame 4 and the capacitor element 1 is made by solder, the adhesive force is weak, so that the lead lI before molding is applied.
Due to the tension and 7 w y when cutting the parts 2 and 7, the soldering part tends to deviate, causing so-called element detachment, which is exacerbated by the heat stress during the next resin molding process and causes detachment. Otherwise, incomplete contact occurred, resulting in radiation or loss between the terminals of the capacitor.

Further, when using a lead frame 4 as shown in the second picture, which is made by punching from a single metal plate, the workability is poor, and improvements are needed in view of these points.

4. OBJECTS OF THE INVENTION The present invention is to provide a molded chip solid electrolytic capacitor that is easy to manufacture and has a high production yield.

(e) Third aspect of the invention The above-mentioned object of the present invention is to provide a molded chip and a plastic in which the anode lead wire of a resin-molded capacitor element is connected to an anode terminal through a bent 7-hole mink part. This can be achieved by providing a solid electrolyte; a capacitor.

(f) Embodiment 113 of the invention shows this embodiment.T, lead of anode element l! The wire diameter of I2 is 0.3M, and it has seven orifices 2' shouldered in an S-shape. This makes it possible to alleviate the tension and strain that occurs when cutting the lead wire.

Further, in order to fully exhibit this relaxation effect, it is necessary that this portion is not fixed by the resin during resin molding. Therefore, the 7-ohm mink s2' is covered with a resilient organic insulating material 10 such as silicone rubber, foamed urethane, or Teflon to protect the 7-ohm mink s2. Furthermore, in the case of the Honsho-Koji example, the low-voltage transformer 7 is amoled using Ebokiku resin at a temperature of 160°C, and the resin exterior is done, but the capacitor element is subjected to considerable mechanical stress due to this resin mold. has a great influence on the reliability of capacitors. Therefore, the capacitor element 1 is covered with an elastic insulating material such as silicone rubber (commercial name: Silicone R'rV), and then resin molding is performed.

Next, the improved tSStt manufacturing method according to the present invention will be explained with reference to FIGS. 4 to 1Ee.

s14■ (4) is a front view showing the state in which the T1 capacitor element manufactured in one bar is quickly attached to the cathode lead frame, @ is this 11th view, and the 5th garden shows the cutting of the anode lead wire. Positive 1m111. C.B.
+ is this side view, and FIG. 6 is a cross-sectional view of the manufactured molded chip solid electrolytic capacitor according to the present invention.

In 4WA, the cathode lead frame 11 has the front s12 of the cathode terminal 5 pressed into a stepped shape, and the capacitor element l of the bar 3 is pressed against this position and soldered. In addition, the anode lead wire 2 of the capacitor element l
A 7-ohm mink s2 of an S-shaped JiliIII is formed in advance on the substrate, and an organic insulating material 10 such as urethane foam is applied at this stage.

He cut the 1st order ζ anode lead II 2 at a predetermined position and removed the bar 3, 115 m1llζ
Insert the anode lead frame 12 shown, and after positioning, align the lead frames 11 and 12 of each other at multiple positions **1
．． Fix it.

In this case, the lead frames are made of solder-plated nickel silver with a thickness of 0.2 cm, and the lead claims are each 3-point welded131. Now, as shown in Figure 5, the anode lead frame 12 has the front part 14 of the anode terminal 7 pressed into a stepped shape, similar to that for the cathode, and the anode lead wire 2 is welded to this position.

Next, the capacitor element 1 is coated with a resilient organic insulating material 10 such as 7-lion resin over the entire surface. Thereafter, this is resin-molded and the terminals 5.7 of the lead frame are cut, thereby completing the molded chip solid electrolytic capacitor according to the present invention.

FIG. 6 shows the cross-sectional structure of such a capacitor, in which the anode lead wire 2 is formed with a 7-ohm s2 protected by an organic insulating material 1O1.

Further, a resin molded body 15 is formed to further enclose the organic insulating material 10' covering the capacitor element 1.

(gl) Effects of the Invention According to the present invention described above, a molded chip solid electrolytic capacitor can be obtained that eliminates defects caused by mechanical stress, such as open connections between terminals and increased loss.

[Brief explanation of the drawing]

Figure 1 is a side view of a solid electrolytic capacitor element with a conventional structure before resin molding, Figure 2 is an explanatory diagram of the manufacturing process to obtain this positive capacitor. FIG. 1 is a sectional view of a molded solid electrolytic capacitor according to the invention. In the figure, l is the capacitor element, 2 is the anode lead wire, 2
' is the forming part, 5 is the cathode terminal, and 7 (the positive terminal). Fig. 1 Fig. 3

Claims (1)

[Claims] An electrolytic capacitor characterized in that an anode terminal of a resin-molded capacitor element is connected to an anode terminal through a bent seven-pointing part.