JPS6031220A - Method of producing chip-shaped 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 The present invention relates to a method for manufacturing a chip-shaped solid electrolytic capacitor.

A conventional chip-shaped electrolytic capacitor has an anode lead 1 as shown in Fig. 1, an oxide film is formed on the surface of the anode body made of a valve metal, and a solid electrolyte layer and a conductive cathode part are formed on the film. A layer was formed to constitute a capacitor element 2, the anode lead 1 and an anode terminal 3 made of a metal frame were welded, and a cathode terminal 4 made of the same metal frame as the cathode conductive layer of the capacitor element 2 was welded by solder. Thereafter, the anode terminal 3 and the cathode terminal 4 were separated from the metal frame and bent to produce a resin exterior by transfer molding. 5 is an exterior resin.

However, in the method for manufacturing a chip-shaped solid electrolytic capacitor as described above, since the anode lead 1 and the anode terminal 3 are welded, disconnection and unstable contact may occur due to poor welding. When bending the anode terminal 3 and cathode terminal 4 along the surface of the exterior hat after molding, good dimensional accuracy cannot be obtained due to the springiness of the terminals, and mechanical stress during the bending process This causes problems such as cracks in the exterior resin 5 and deterioration of yield and reliability.

Therefore, as seen in Japanese Utility Model Application Publication No. 52-82044, a solid electrolytic capacitor has been proposed in which an anode lead wire of a capacitor element and an anode terminal plate having a slit are connected at the slit portion of the anode terminal plate. However, it is a non-exterior type, and it is difficult to form a part of the capacitor sharply at the corners, so when installing it on a printed circuit board using an automatic insertion machine, the product may not be clamped properly and may fall off. The production efficiency was low.

There is also a device in which the external electrode portion is constructed without bath contacting the anode lead, but there is a similar problem.

The present invention solves the above-mentioned problems and provides a method for manufacturing a chip-shaped solid electrolytic capacitor that has poor heat resistance and productivity.

Hereinafter, the present invention will be explained with reference to the embodiments shown in Factor 2 to FIG.

First, as shown in FIG. 2, the lead-out leads 1 of a plurality of prismatic positive bodies 6 made of valve metal such as tantalum or aluminum having lead-out leads 1 are welded to the power supply bar 7. A dielectric oxide film 8 is formed on the surface, and a semiconductor solid electrolyte layer 9 such as manganese dioxide and a cathode conductive layer 10 such as carbon and silver base are sequentially formed on the film.

Next, an epoxy resin is applied to cover the anode body 6, leaving the ends of the anode and cathode extraction electrodes selectively, to form an exterior resin layer 11. Next, a conductive layer 12 made of silver beneto or the like is coated and cured on the anode side end, and the conductive layer 10.
Electroless plating layer 13f of nickel, copper, etc. is formed on lead 12 and lead-out lead 1 having no dielectric oxide film to constitute a capacitor element.

Next, as shown in FIG. 3, the lead-out lead 1t has a notch 14 for insertion, and is pressed, bent, etc.
After applying cream solder to a predetermined joint of at least one of the anode terminal 15 and cathode terminal 16 formed in a letter or U-shape and the capacitor element 2, the anode terminal 15 is attached to both ends of the capacitor element 2. and cathode terminal 1
6 are fitted and fixed in a predetermined position to position the terminals, the cream solder is heated to form the anode terminal 15 and the electroless plating layer 13, and the cathode terminal 16 and the electroless plating layer 13.
and solder bath as shown in Figure 4. Reference numeral 17 denotes the solder layer welded with this solder, and a high melting point solder having a melting point of 220'C or more is used. Note that instead of using the cream solder described above, a layer of solder is applied on the electroless plating layer 13 of the capacitor element 2 by immersing the capacitor element 2 in a solder bath, and then the solder is heated and melted. However, the terminals 15 and 16 may be fitted and positioned to predetermined dimensions.

Figures 5 to 7 show the anode terminal 15υ and cathode terminal 16.
in another embodiment, each of which is continuously formed into a frame shape,
Welding can be performed in the same manner as described above, and after welding, the parts shown by the arrows are cut and separated as shown in FIG.

Next, after an aging and inspection process, the lead-out lead 1 is cut off from the base of the anode terminal 15 to complete the process.

Chip shape produced by the manufacturing method of the present invention! The electrolytic capacitor does not have a welded structure, which simplifies the process and allows for easy miniaturization. In addition, unstable @ wire and contact due to poor welding will not occur. Since the pre-formed terminals are welded with solder after being coated with resin, there are no accidents such as mechanical stress being applied to the lead-out portion of the terminals during processing, resulting in cracks, and an extremely reliable product can be obtained. Unless the product is clamped using an automatic mounting machine, a part of the corner of the product is formed into a sharp L-shape or U-shape, and the flatness of the end face is ensured, so it is stable and does not fall off. It can be clamped and centered, and the accuracy of the mounting position on the printed circuit board and the mounting rate can be significantly improved. When soldering the printed circuit board Km product, since no solder is used in the exterior resin, there is no loss, no increase in leakage current, no disconnection accidents, and heat resistance is greatly improved.

8 and 9 show an anode terminal 15 and a cathode terminal 16.
In this embodiment, the reinforcing resin 18 is partially or entirely applied at the joint between the terminal and the exterior resin 11, which makes it possible to use solder with a lower melting point, and further reduces thermal stress when welding the terminal. , soldering by a solder dip method can further improve the heat resistance.

The table shows the chip electrolytic capacitors of the present invention and a conventional product coated with molded resin, each with a rating of 2'5V and 1μF, for 5 seconds in a molten solder bath at a temperature of 240'C and 260'0.280°C. It shows the results of investigating defects when immersed for 10 seconds, 20 seconds, and 30 seconds.

In the table, sample group symbol A is a conventional molded product, B is a product of an embodiment of the present invention, and C is a product of an embodiment of the present invention coated with reinforcing resin.

Further, the numerical value in the table is the number of defects/number of tests, and the details of defects were solder blow-out, cracks, and disconnection in the conventional product, and terminal displacement and disconnection in the product of the present invention.

FIG. 10 shows the results of measuring the capacitance, loss, impedance, and leakage current characteristics of the product after immersion in molten solder at a temperature of 250° C. for 3 seconds was repeated three times. In the figure (2
) is a conventional product in which the cathode terminal and cathode conductive layer are soldered and covered with molded resin, α') is another conventional product in which the cathode terminal and cathode conductive layer are bonded with conductive adhesive and covered with molded resin. be.

As described above, the chip-shaped solid electrolytic capacitor of the present invention has significantly improved heat resistance and automatic mounting efficiency, which greatly contributes to improved productivity, and has great industrial and practical value. Some 0

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional chip electrolytic capacitor;
4 are cross-sectional views of one embodiment of a chip-shaped electrolytic capacitor in the manufacturing process of the present invention, and FIGS. Explanatory diagram of electrolytic capacitor process, Figures 8 and 9
The figure is a cross-sectional view of a main part of another embodiment of the chip-shaped electrolytic capacitor of the present invention, and FIG. 10 is a heat resistance test characteristic diagram of the chip-shaped electrolytic capacitor comparing the conventional product and the product of the present invention. l; Anode lead 6: Anode body 8: Dielectric oxide film 9: Solid electrolyte layer 10: Cathode part 2 #electrode 11: Exterior resin layer 13: Electroless plating layer 15: Anode terminal 16: Cathode terminal 17 : Solder layer 18: Reinforcing resin Patent applicant Nichicon Nuprag Co., Ltd. Figure 1 Figure 2 Figure 4 Figure 7, 7, 7-...~ Figure 8 Figure 9 Figure 10 Procedural amendment ( (Method) (December 19, 1983 1, Indication of the case 1982 Patent a No. 1399171-2 Title of the invention Method for manufacturing chip solid electrolytic capacitors 3, Person making the amendment Relationship to the case Patent applicant's mail No. 520-12 690-24 Miori, Azumyo-cho, Takashima-gun, Shiga Prefecture, Date of amendment order: November 8, 1982 (Date of dispatch: November 29, 1988) 5. Subject of amendment: ``Simple drawings of the specification'' 6. Contents of the amendment Page 9, line 15 of the specification is amended as follows: ``Figures 3, 5, 6, and 7 are in the manufacturing process of the present invention.''

Claims (1)

[Scope of Claims] 0) Welding the lead-out leads from the anode body made of a valve metal to a power supply bar, forming a dielectric precipitated film, a solid electrolyte layer, a cathode conductive layer, etc. on the surface of the anode body; A process of resin-coating leaving the ends of the anode and cathode lead-out electrode parts, a process of forming an anode conductive layer, a cathode conductive layer, and an electrode layer of an electroless plating layer on the ends, and a process of forming the above-mentioned lead-out leads into anodes. Insert into the notch of the terminal, anode terminal and anode electrode layer, cathode terminal and cathode! A method for manufacturing a chip-shaped solid electrolytic capacitor, characterized in that the chip-shaped solid electrolytic capacitor is manufactured through the steps of solder welding the electrode layer to the electrode layer, and cutting the lead-out lead from the base of the anode terminal. ((2) In the step of soldering the terminal and the electrode layer, the terminal is fitted and positioned to a predetermined dimension while melting the solder in a heating bath.
A method for manufacturing a chip-shaped solid electrolytic capacitor as described in .