JPS625630A - Aluminum electrolytic capacitor - 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 Field of the Invention The present invention relates to aluminum electrolytic capacitors, and more particularly to chip-type aluminum electrolytic capacitors.

2. Description of the Related Art A conventional leadless electronic component, such as a chip-type aluminum electrolytic capacitor, is constructed as shown in FIGS. 2a and 2b. That is, an anode foil made by roughening aluminum foil and forming a dielectric film by anodizing and a cathode foil made by roughening aluminum foil are wound through a separator and impregnated with a driving electrolyte. Constructing a capacitor element 1, housing the capacitor element 1 in a bottomed cylindrical metal case 2, and sealing the open end with an elastic sealing material 3 such as rubber to constitute an aluminum electrolytic capacitor, Then, the lead wire 4 drawn out from the aluminum electrolytic capacitor is electrically and mechanically connected to the comb-shaped terminal 5 by a method such as welding, and then a molded resin sheath 6 is applied to the entire body except for the comb-shaped terminal 5, and the finished product is completed. It was considered a good item.

Problems to be Solved by the Invention - Such chip-type aluminum electrolytic capacitors are coated with a molded resin exterior 6 as described above in order to provide solderability tm=ts when mounted on a printed circuit board. Generally, mold resin exterior is 100℃~150℃
Under such harsh conditions, the driving electrolyte of the electrolytic capacitor evaporates, causing a decrease in capacitance and an increase in tanδ. This resulted in deterioration of characteristics such as.

The present invention solves these problems, and improves the soldering heat resistance of chip-type aluminum electrolytic capacitors, and does not cause characteristic deterioration such as a decrease in capacitance or an increase in tanδ even when a molded exterior is applied. The purpose is to provide chip-type aluminum electrolytic capacitors.

Means for Solving the Problems In order to solve the above problems, the present invention houses a capacitor element in a cylindrical metal case with a bottom, and seals the open end using an elastic sealing material such as rubber. The main body of the aluminum electrolytic capacitor is constructed by sheathing with a two-layered tube having heat resistance on the outside and heat shrinkable on the inside, and the lead wire drawn out from the aluminum electrolytic capacitor main body. The comb-shaped terminals are electrically and mechanically connected by methods such as welding, and the entire body except the comb-shaped terminals is coated with molded resin to complete the product.

Function The present invention has the above-mentioned configuration, in other words, it is covered with a heat-resistant tube on the outside, so that the influence of heat when the molded covering is applied does not propagate inside the aluminum electrolytic capacitor. Can suppress transpiration,
There is no characteristic deterioration such as a decrease in capacitance or an increase in tan δ.

Furthermore, since the tube according to the present invention has a two-layer structure with a heat-shrinkable inner part, when making the sleeve exterior, the inner heat-shrinkable part shrinks due to slight heating, resulting in a heat-shrinkable part. Since the part with the rim will also be stretched and shrunk, a sleeve can be easily applied.

Embodiment An embodiment of the present invention will be described with reference to the drawings. In addition, in the drawings, the same numbers are given to the same parts as in the prior art.

In FIG. 1, a capacitor element 1 is made by winding an anode foil, a cathode foil, and a separator and impregnating it with a driving electrolyte. The capacitor element 1 is housed in a metal case 2, and the open end is covered with a sealing material 3.
A two-layered tube 7 according to the present invention is attached to form an aluminum electrolytic capacitor body, and a lead wire 4 drawn out from the aluminum electrolytic capacitor body is connected to a comb-shaped terminal 6. A molded resin exterior 6 is applied to the entire product except for the comb-shaped terminals, and the finished product is prepared.

Next, a comparison between the product of the present invention and the conventional product is shown.

Prepare 60 aluminum electrolytic capacitors with a rating of 16 Vi OμF, divide them into two, make 25 of them as products of the present invention, cover them with a two-layered tube consisting of polyimide on the outside and vinyl chloride on the inside, and then mold them. I did the exterior. The remaining 25 pieces were molded without tube packaging as conventional products.

We investigated the changes in the characteristics of these inventive products and conventional products before and after the mold exterior (pass/fail judgment was performed using a tan δ value of 12%).
Shown in the table.

As is clear from the table, in the products of the present invention, out of 25 defective products had an increase in tan δ value before and after molding. On the other hand, with conventional products, the tan is reduced by applying a molded exterior.
There were 3 defective products out of 25 with a δ value exceeding 12%.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, according to the present invention, a chip-type aluminum electrolytic capacitor is obtained which has no increase in tan δ value before and after the mold exterior and does not suffer from characteristic deterioration, and its industrial value is great. be.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing essential parts of an aluminum electrolytic capacitor according to the present invention, and FIGS. 2a and 2b are a sectional view and a side view of a conventional chip-type aluminum electrolytic capacitor. 1... Capacitor element, 2... Case, 3... Sealing material, 4... Lead wire, 5
... Comb-shaped terminal, 6 ... Molded resin exterior, 7 ... Tube. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
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Claims (2)

[Claims] (1) Anode foil and cathode foil are wound through a separator and impregnated with driving electrolyte to form a capacitor element, and this capacitor element is housed in a cylindrical metal case with a bottom, and the open end is covered with rubber. The main body of the aluminum electrolytic capacitor is constructed by sealing the cap with an elastic sealing material such as, An aluminum electrolytic capacitor in which the lead wire drawn out from the capacitor body is connected to a comb-shaped terminal, and the entire body except the comb-shaped terminal is covered with molded resin. (2) The aluminum electrolytic capacitor according to claim 1, which uses a two-layer tube with an outer layer made of polyimide or polyferene sulfide and an inner layer made of vinyl chloride.