JPS6031219A - 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 chip-shaped solid-state "decomposition 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 group, and a solid electrolyte layer and a cathode part are formed on the film. A conductive 'fL layer is formed to construct a capacitor element 2,
After welding the L recorder rod lead 1 and the anode terminal 3 made of a metal frame, and soldering the cathode terminal 4 made of the same metal frame to the cathode conductive layer of the capacitor element 2, the resin exterior is formed by transfer molding. The anode terminal 3 and cathode terminal 4t were separated from the metal frame and completed by bending. 5 is an exterior resin.

However, in the chip-shaped solid electrolytic capacitor as described above, since the anode lead 1 and the anode terminal 3 are welded, disconnection due to poor welding and contact instability occur. Anode terminal after molding 3. When bending along the surface of the external resin, good dimensional accuracy is achieved due to the springiness of the pupil pancreas.
9' could not be obtained, and mechanical stress during the bending process caused cracks in the exterior resin 5, resulting in 1 yield and II (
j #T4 There were problems such as worsening f-grades.

In addition, 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 part of the anode terminal plate, as seen in %-82 (No. 144). It is a non-exterior type,
It was difficult to form a sharp corner of the capacitor, and when the capacitor was mounted on a printed circuit board using an automatic insertion machine, the product could not be securely clamped, causing some to fall off, resulting in low production efficiency.

Also the anode lead? : There is a model that has an external electrode part without welding, but it has the same problem.

The present invention solves the above-mentioned problem 'f' and provides a chip-shaped solid electrolytic capacitor with high heat resistance and productivity.

The present invention will be explained below using examples shown in FIGS. 2 to 10.

First, as shown in FIG. 2, the lead-out leads 1 of a plurality of prismatic anode bodies 6 made of a valve metal such as tantalum or aluminum made of 10,000 ml of lead-out leads 1 are welded to the power supply bar 7.
A dielectric oxide film 8 is formed on the surface of the anode N body 6, and a semiconductor solid electrolyte layer 9 such as manganese dioxide and a cathode conductive layer 1 such as carbon and silver base are formed on the surface of the anode N body 6.
O is formed as follows.

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 such as silver base is coated and hardened on the anode side end, and 10% of the conductive layer 12 is coated on the anode side end.
A capacitor element is constructed by forming an electroless plating layer 13 of metal, copper or the like on the leads 1 having no dielectric oxide film.

Next, as shown in FIG. 3, an anode terminal 15 and a cathode terminal are formed into an L-shape or a U-shape by pressing, bending, etc., and have a notch 14 into which the lead-out lead 1 is inserted. 16 and at least one of the capacitor element 2, the anode terminal 15 and the cathode terminal 16 are fitted to both ends of the capacitor element 2 and fixed at a predetermined position, and the terminals are fixed. After positioning,
The ream solder marked E is heated to weld the anode terminal 15 and the electroless plating layer 13, and the cathode terminal 16 and the electroless plating layer 13 as shown in FIG. 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 higher is used. Note that instead of using the cream solder described above, the capacitor element 2 is immersed in molten solder in advance to adhere solder to the electroless plating M13 of the capacitor element 2, and while the solder is heated and melted, the above terminals are attached. 15 and 16 may be fitted and positioned to predetermined dimensions.

Figures 5 to 7 show the anode terminal 15 and cathode terminal 1G.
in another embodiment, each of which is continuously formed into a frame shape,
It can be bath-bonded in the same manner as described above, and after welding, it is cut 1'J1# as shown in FIG. 4 by cutting at the location indicated by the arrow.

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

The chip-shaped electrolytic capacitor of the present invention is manufactured as described above.

Therefore, it does not have a bath contact structure, which simplifies the process and allows for easy miniaturization. Also, there is no disconnection or unstable contact due to poor welding. Since the pre-formed terminals are welded with solder after being coated with resin, there are no accidents such as cracks caused by mechanical stress being applied to the lead-out part of the terminal during processing, and a product with extremely high reliability can be obtained. When clamping a product using an automatic 5W machine, a part of the corner of the product is sharply formed into an L-shape or a U-shape, and the flatness of the end surface is ensured, so it does not fall off. It can be clamped and centered stably without any problems, and the accuracy of positioning and placement on printed circuit boards and the mounting rate can be significantly improved. When soldering a product to a printed circuit board, no solder is used in the exterior resin, resulting in 4J'i loss and increased leakage current.
There are effects such as no wire h1 damage and greatly improved heat resistance.

8 and 9 show an anode terminal 15 and a cathode terminal 16.
In the embodiment where the reinforcing resin 18 is applied partially or entirely to the joint between the terminal and the exterior resin 11, it is not possible to use a solder with a lower melting point. In addition to greatly reducing heat stress during each layer.

Soldering using a solder dip method or the like can further improve the heat resistance.

The table shows the chip electrolytic capacitors of the present invention and conventional molded resin-sheathed capacitors with a rating of 25 V and 1 μF, respectively, for 5 seconds, 10 seconds in a molten solder bath at temperatures of 240'C, 260'C, and 280'C. It shows the results of investigating defects when immersed for 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 the defects were solder blow-out, cracks, and Itli wire damage in the conventional product, and terminal displacement and terminal dislocation in the product of the present invention.

Figure 10 shows the results of measuring the capacitance, loss, impedance, and leakage current characteristics of the product by immersing it in molten solder at a temperature of 250"C for 3 seconds three times. In the figure (
2) is a conventional product in which the anode terminal and cathode conductive layer are soldered and covered with molded resin; (A' is another product in which the anode terminal and cathode conductive layer are bonded with conductive adhesive and covered with molded resin); (B) is a conventional product.As mentioned 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 is suitable for industrial use. It is of great practical value.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional chip electrolytic capacitor;
Figure 4 is a schematic diagram of an example of a chip electrolytic capacitor in the manufacturing process of the present invention, Figure 3, Figure 5~
FIG. 7 is a process explanatory diagram of chip-shaped electrolytic capacitors having different terminal shapes in the manufacturing process of the present invention, FIG. 8 and FIG. FIG. 10 is a heat resistance test characteristic diagram of a chip-shaped electrolytic capacitor comparing a conventional product and a product of the present invention. 1: Anode lead 6: Anode body 8: Dielectric oxide film 9: Solid electrolyte layer 10: Cathode conductive layer 11: Exterior resin layer 13: Electroless plating layer 15: Anode terminal 16: Cathode terminal 17: Solder layer 18: Reinforcing resin patent applicant Nichicon Spulog Co., Ltd. Figure 1 Figure 2 Figure 4 Figure 7, J %\) Figure 10 (A') (B)

Claims (2)

[Claims] (1) Having an anode lead, forming a VC dielectric oxide film on the anode body surface made of a valve gold film, and forming a solid electrolytic n-layer and a cathode conductive layer on the skin; The end of the cathode extraction electrode is covered with exterior resin, and a conductive layer and an electroless plating layer are sequentially formed on the end, and then connected to the anode terminal and cathode terminal via a solder layer thereon. A chip-shaped solid electrolytic capacitor characterized by: (2) At the joint between the above anode terminal and cathode terminal and the exterior position 1 resin? A chip-shaped [211-body electrolytic capacitor] according to claim 1, characterized in that the chip-shaped [211-body electrolytic capacitor] is coated with a 111-strong resin.