JPH04299512A - Chip type bipolar solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To enhance the reliability upon the title capacitor by a method wherein the connected surfaces of a pair of capacitor elements are overlapped with each other not only on one surface but also on multiple surfaces to increase the connecting strength so that the open or loose contact mode between the pair of capacitor elements due to the physical stress such as the pressure, the stress strain thereof in the insulating resin sealing compound implanting work during the molding step may be reduced. CONSTITUTION:A pair of valve working metallic capacitor element main bodies 1a, 1b respectively in concave and convex shapes are connected to each other using a conductive bonding agent or solder, etc., while the same kind of metallic anode lead wires 2a, 2b erected from the mutual capacitor element main bodies 1a, 1b are welded into an outer terminal 3 to be molded using an insulating resin sealing compound 5.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip-type bipolar solid electrolytic capacitor, and more particularly to the shape of each of the stacked capacitor elements of a chip-type bipolar solid electrolytic capacitor formed by stacking and connecting a pair of capacitor elements.

0002

2. Description of the Related Art Conventionally, a chip type bipolar solid electrolytic capacitor has an anode as shown in FIG. 3 are welded, and at the same time the cathode is welded to the cathode conductor layer of the pair of capacitor elements 1 and the conductive adhesive 4.
Alternatively, they may be overlaid and connected to each other via solder or the like, and the entire structure may be molded with an insulating resin sealant 5.

As another conventional technique, as shown in FIG. 7, the cathode conductor layer of a pair of capacitor elements is connected to the opposing surfaces of a pair of capacitor elements 1 via a conductive adhesive 4 or solder. There are also devices that are connected and further molded as a whole with an insulating resin sealant 5.

0004

[Problems to be Solved by the Invention] However, in the above-mentioned conventional connection structure of a pair of capacitor elements, the capacitor is damaged due to physical stress such as pressure and stress strain caused when insulating resin sealant is injected during molding. This has the disadvantage that the connection between the elements is broken, resulting in an open or loose contact mode, which significantly reduces the reliability of the capacitor.

[0005] The purpose of the present invention is to prevent capacitor elements from being connected to each other due to physical stress such as pressure and stress strain caused when injecting an insulating resin sealant during molding, resulting in an open or loose contact mode. It is an object of the present invention to provide a chip type bipolar solid electrolytic capacitor that can improve reliability as a capacitor without causing a decrease in reliability as a capacitor.

[0006]

[Means for Solving the Problems] The chip-type bipolar solid electrolytic capacitor of the present invention has a pair of valve-acting metal capacitor element bodies each having a concave and convex shape, and is coated with a conductive adhesive or a convex shape. are overlappingly connected via solder, etc., and the anode lead wires of the same type of metal planted from each other's capacitor elements are connected to the anode terminal, and then molded with an insulating resin sealant. It is composed of the following characteristics.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a perspective view of a capacitor element before assembly, a superimposed element, and a plan view of a part of the manufacturing process for explaining an embodiment of the present invention. Further, FIG. 2 is a schematic cross-sectional view of an element used in one embodiment.

First, a method for manufacturing a capacitor element will be explained. After press-forming metal powder with valve action such as tantalum, niobium, aluminum, etc. while planting an anode lead wire 20 that can be anodized, the vacuum degree is about 10-5 To
The sintered body 10 is sintered at a temperature approximately 3/4 of the melting temperature of the above-mentioned valve metal in a high vacuum furnace of RR or an inert gas furnace such as argon or nitrogen. A dielectric film 11 is formed by this method, and an anode body element is obtained.

Next, this anode body element is impregnated with a manganese nitrate solution and thermally decomposed at a temperature of around 200° C. to form an electrolyte of a manganese dioxide layer 12 on the surface of the dielectric film 11, and then the cathode portion is led out. For this purpose, a graphite layer 13, a silver paste layer or a solder layer, ie, a so-called cathode conductor layer 14, are sequentially formed to obtain a capacitor element as shown in FIG.

Furthermore, a molded product having the structure of the present invention is manufactured as follows. First, Figure 1(a), (
As shown in FIG. 1(c), the capacitor element body 1a and the capacitor element body 1b, one of which is concave and one of which is convex, are shown in FIG.
As shown in FIG. 3, they are overlapped and connected via a conductive adhesive 4 or solder. At the same time, as shown in FIG. 1(d), the anode lead wires 2a, 2b and the external terminal 3 are electrically welded to each other by known means. Incidentally, a plurality of the above-mentioned external terminals 3 are manufactured by integrating them into one plate, and after welding the anode lead wires 2a and 2b to each other at the same time, unnecessary parts are removed. Furthermore, the entire structure is molded using an insulating resin sealant 5.

FIG. 3 is a perspective view of a capacitor element before assembly, a stacked element, and a plan view of a part of the manufacturing process for explaining another embodiment of the present invention. In this embodiment, as shown in FIGS. 3(a) and 3(b), a capacitor element body 1c and a capacitor element body 1d, one of which has two concave portions and the other of which has two convex portions, are constructed. As shown in (c), they are overlapped and connected via a conductive adhesive 4 or solder. At the same time, as shown in FIG. 3(d), the anode lead wires 2c, 2d and the external terminal 3 are electrically connected to each other by known means. Thereafter, molding is carried out using the same means as in the embodiment described above.

Next, we will compare the 90° peel connection strength ratios of capacitors according to the first embodiment of the present invention shown in FIG. 1, the second embodiment shown in FIG. 3, and the conventional example with the structure shown in FIGS. 6 and 7. The results are shown in Figure 8. FIG. 8 shows that all of the embodiments of the present invention are improved over the conventional example.

In this embodiment, a concave capacitor element is used.
Although a convex shape or a similar shape is used, it goes without saying that the present invention is not limited to the case where the capacitor element bodies 1e and 1f have continuous concavities and convexities as shown in FIG.

The circuit diagram of this embodiment can be shown as shown in FIG.

[0015]

Effects of the Invention As explained above, in the present invention, the connection surfaces of a pair of capacitor elements are overlapped not on one surface but on many surfaces, so that the connection area can be larger than that of the conventional example. The connection strength between elements increases in proportion to the contact area. This is explained in 9 above.
This is also clear from the 0° peel connection strength ratio.

Since this connection strength increases, the open or loose contact mode between capacitor elements due to physical stress such as the pressure and stress strain caused when injecting the insulating resin seal during molding is reduced, and the capacitor The reliability of the system can be improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a capacitor element before stacking and a capacitor element after stacking, and a plan view of a part of the manufacturing process, for explaining an embodiment of the present invention.

FIG. 2 is a sectional view of a capacitor element used in one embodiment of the present invention.

FIG. 3 is a perspective view of a capacitor element before stacking and a capacitor element after stacking, and a plan view of a part of the manufacturing process, for explaining another embodiment of the present invention.

FIG. 4 is a perspective view of a capacitor element after stacking according to a third embodiment of the present invention.

FIG. 5 is a circuit diagram of a chip type bipolar structure electrolytic capacitor according to an embodiment of the present invention.

FIG. 6 is a perspective view of an example of a conventional chip-type bipolar solid electrolytic capacitor and a plan view of a part of the manufacturing process.

FIG. 7 is a perspective view of another example of a conventional chip-type bipolar solid electrolytic capacitor and a plan view of a part of the manufacturing process.

[Fig. 8] Example 1 of the present invention, Example 2, conventional example (Fig. 6), and 9 after connecting capacitor elements of the conventional example (Fig. 7).
FIG. 3 is a relational diagram showing a 0° peel connection strength ratio.

[Explanation of symbols]

1, 1a, 1b, 1c, 1d, 1e, 1f Capacitor element body 2, 2a, 2b, 2c, 2d Anode lead 3
External terminal 4 Conductive adhesive 5 Insulating resin sealant 10 Sintered body 11 Dielectric film 12 Manganese dioxide layer 13 Graphite layer 14 Cathode conductor layer

Claims (1)

[Claims] Claim 1: A pair of metal capacitor element bodies each having a valve action, each having a concave and convex shape, connected by conductive adhesive or solder, etc., and having the same type of capacitor element bodies planted from each other's capacitor element bodies. A chip-type bipolar solid electrolytic capacitor characterized in that a metal anode lead wire is welded to an external terminal and then molded with an insulating resin sealant.