JPS59194420A - Chip type 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 aims to stabilize the characteristics and improve the reliability of a wound capacitor element of a chip-shaped electrolytic capacitor by using a lead having a hollow cylindrical tab portion.

BACKGROUND ART In recent years, as electronic devices have become smaller, the electronic components mounted on them have become lighter, thinner, shorter, and smaller. The same is true in the field of aluminum electrolytic capacitors, but compared to other electronic components, the capacitor element has a liquid electrolyte inside it, so in order to make it into a chip, the sealing part (74 structure) is not only complicated but also complicated. However, the size and shape are large, and as a result, a small electrolytic capacitor with a lead-out lead is shared with other chip components, resulting in a complicated mounting method and many other industrial drawbacks.

FIG. 1 is a cross-sectional view of a chip-shaped electrolytic capacitor manufactured by a conventional method, in which an anode lead 2 and a cathode lead 3 led out from a wound capacitor element 1 are connected to an elastic sealing member 4.
After inserting it into the metal case 5 and sealing it by winding or other methods, pull out the cathode lead 3 to the opposite side of the sealing part to create a 7 ohm, and then insert the anode lead 2 and the cathode lead 3 into the metal case 5. The lead-out lead 3 is connected to a lead frame 6 or the like serving as an external terminal, and is covered with a heat-resistant resin 7.

Chips manufactured by this method? ! T-solution capacitors are nothing but resin-clad small cylindrical electrolytic capacitors, which are currently being used in large quantities, and are too large in size and shape compared to other chip-shaped electronic components to be called chip components. Because the product was packaged with resin, its cross section was square, as shown in Figure 2 (a).

Therefore, it had the disadvantage of causing instability in its position after being mounted on a printed circuit board, so as shown in (Main), the electrolytic capacitor after sealing was press-formed into a flat shape with a rectangular cross section. However, since the connection parts (tabs) 2a and 3a of the conventional lead lead with the electrode foil are flat as shown in Fig. Even if the tab is flat and circular as shown in FIG. This has the serious disadvantage of causing a decrease in electrical characteristics such as an increase in leakage current.

The present invention eliminates the above-mentioned drawbacks and provides a chip-shaped electrolytic capacitor that is small and highly reliable.

The present invention will be explained below with reference to the embodiments shown in FIGS. 4 and 5.

Figure 4 (a) shows a hollow cylindrical tab 8 made of aluminum.
The hollow cylindrical tab 8a and the electrode foil 91.10 are connected to each other by the extraction lead 8 having a diameter of 41.1. Next vc the bipolar foils 9, 10 and separator 11 such as paper
The capacitor element 12 is formed by impregnating the capacitor element 12 with an electrolytic solution, and storing the capacitor element 12 in a metal case 13.
An elastic 20R body is inserted into the opening of the case 13 and sealed. Then, as shown in FIG. 4(C), they are placed in upper and lower press jigs 14 and 15 and pressed from the outside to form a flat shape, and then coated with a heat-resistant resin 16 such as epoxy to form a resin exterior. Then, a chip-shaped electrolytic capacitor is completed.

According to the present invention, the electrode foil 9 of the extraction lead 8. Since the part connected to the capacitor element 10 has a hollow cylindrical shape, the capacitor element 12
During press molding, the tab 8a portion not only becomes easier to flatten compared to conventional products, but also has greater adaptability to changes in the shape of the wound element 12. f
Since no space is created between f19.10 and the separator 11, -δ also does not increase, and the impedance characteristics can be significantly improved.

Also, since there is no edge part of the tab 8a, during press molding,
The anodic oxide film is not destroyed, so leakage current does not increase, and an extremely reliable capacitor can be obtained.

Figure 5 shows a 16V rated battery manufactured based on the above-mentioned example.
The relationship between the frequency change and impedance of the tR solution cocidenser is shown comparing the 10 μF inventive product ■ with the conventional product @ of the same rating, and it shows that the impedance value of the inventive product ■ is significantly reduced compared to the conventional product [phase]. It has been demonstrated that good results can be obtained.

In the above embodiment, the capacitor element 12 was housed in the metal case 13 and then pressure-bonded, and then covered with the resin 16. However, it is also possible to use a resin case instead of the metal case, After direct pressure welding,
Similar effects can be obtained by selecting appropriate combinations of the exterior structure, such as resin exterior, depending on the shape of the element and the constituent materials.

As described above, the present invention makes it possible to manufacture a chip-shaped electrolytic capacitor that is small and has excellent electrical characteristics, and is of great industrial and practical value.

[Brief explanation of the drawing]

Figure 1 is an axial cross-sectional view of a conventional chip-shaped electrolytic capacitor, Figures 2 (a) and (b) are A-A' cross-sectional views of the conventional chip-shaped electrolytic capacitor, and Figure 3 is FIG. 4, which is a perspective view of the lead of a conventional chip-shaped electrolytic capacitor, is an embodiment of the chip-shaped electrolytic capacitor of the present invention.
(b) is a perspective view of the drawer lead connected to electrode foil, (c) is an explanatory diagram of the process of forming the capacitor element into a flat shape, and (b) is the main part of the chip electrolytic capacitor. FIG. 5 is an impedance-frequency characteristic diagram of a chip-shaped electrolytic capacitor comparing a conventional product and a product of the present invention.

Claims (2)

[Claims] (1) A drawer lead having a hollow cylindrical tab is connected to an electrode foil, the electrode foils are placed facing each other, and wound through a separator to form a capacitor element, and then the element is pressed from the outside and flattened. A chip-shaped electrolytic capacitor characterized by being formed into a shape. (2) A patent claim characterized in that the capacitor element in which the electrode foils are wound so as to face each other is housed in a cylindrical metal case, which is then sealed and then press-fitted to form a flat shape, which is then packaged with resin. The chip-shaped electrolytic capacitor according to item 1.