JPH02277215A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To form an electrolytic capacitor of a stable characteristic even at a high temperature and to realize its high reliability by a method wherein a capacitor element is housed in a metal case and an opening part is sealed by using an elastic sealing body such as a rubber of the like. CONSTITUTION:An anode foil 6 which has been formed by roughening the surface of a high-purity aluminum foil electrochemically and on which a dielectric film has been formed by an anodic oxidation operation and a cathode foil 7 whose surface has been roughened are wound via a separator 8; their terminal end part is fixed by using an adhesive tape 9; this wound body is impregnated with an electrolyte for drive use. This capacitor element 1 is housed in a metal case 2 and fixed by using a sealing rubber 3. As the adhesive tape 9 for winding fixation use, an adhesive tape composed of a base material of polyphenylene sulfide is used. Thereby, even when an electrolytic capacitor is soldered at an assembly operation of an electronic circuit, the adhesive tape is not dissolved; this capacitor has a stable characteristic even at a high temperature; high reliability of the electrolytic capacitor can be realized.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electrolytic capacitor.

2. Description of the Related Art In recent years, as electronic devices have become lighter, thinner, shorter, and smaller, electronic circuits mounted on electronic devices have been packaged in higher density. Conventional electrolytic capacitors are made by winding an anode foil with a roughened surface and a dielectric film formed by anodizing, and an anode foil with a roughened surface through a separator such as paper, and then the terminal end of the anode foil. It is fixed with adhesive tape such as polypropylene or polyethylene terephthalate and impregnated with a driving electrolyte to form a capacitor element, which is then housed in a metal case and sealed using an elastic sealant such as rubber. It constituted an electrolytic capacitor.

Problems to be Solved by the Invention However, in the electrolytic capacitor shown in the conventional example, soldering is performed when assembling and configuring an electronic circuit. The capacitor element melts due to lack of heat resistance, causing the winding of the capacitor element to loosen, resulting in a decrease in capacitance, and in the case of bipolar electrolytic capacitors, the outermost electrode foil comes into contact with the case, resulting in a short circuit. .

The present invention is intended to solve these conventional drawbacks, and aims to provide an electrolytic capacitor with stable characteristics even under high temperatures and to improve the reliability of the electrolytic capacitor.

Means for Solving the Problems In order to achieve this object, the present invention is constructed by housing a capacitor element in a metal case and sealing the capacitor element with an elastic sealing body such as rubber. An adhesive tape made of a polyphenylene sulfide base material is used to secure the device.

Function: In the electrolytic capacitor constructed as described above, an adhesive tape made of polyphenylene sulfide base material is used as the adhesive tape for winding, which is one of the materials of the capacitor element, so that the electrolytic capacitor has stable characteristics even under high temperatures. The aim is to improve the reliability of electrolytic capacitors.

Example An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a capacitor element, which includes an anode foil 6 made of a high-purity aluminum foil electrochemically roughened and then anodized to form a dielectric film, and a roughened cathode foil. 7 are wound together with a separator 8 in between, the terminal end of which is fixed with an adhesive tape 9, and the carried material is impregnated with a driving electrolyte. This capacitor element l is housed in a metal case 2 and fixed with a sealing rubber 3, and has an anode foil 6 and a cathode foil 7 of the capacitor element l.
An anode lead wire 4 and a cathode lead 5 are connected to and drawn out to the outside.

In the electrolytic capacitor according to the embodiment of the present invention, the winding adhesive tape 9 constituting the capacitor element 1 is an adhesive tape made of a base material of polyphenylene sulfide.

To give a detailed explanation of the adhesive tape for fixing the capacitor element of the electrolytic capacitor mentioned above, adhesive tape is usually made by laminating an adhesive material onto a plastic film as a base material (Table 1). As shown in , the heat resistance of the base plastic film is very low for conventional polypropylene and polyethylene terephthalate, but polyphenylene sulfide is extremely strong. For this reason, when adhesive tape made of polyphenylene sulfide film is used for electrolytic capacitors, the adhesive tape will not melt during soldering when assembling electronic circuits, and the electrolytic capacitor will have stable characteristics even under high temperatures. This makes it possible to improve the reliability of electrolytic capacitors.

As described above, the electrolytic capacitor of the present invention uses an adhesive tape made of a polyphenylene sulfide base material as the adhesive tape for winding, which is one material of the capacitor element, and the electrolytic capacitor has stable characteristics even under high temperatures. , it is possible to improve the reliability of electrolytic capacitors.

(Example 1) As shown in FIG. 1, an electrolytic capacitor having an outer diameter of φ4×5 mm and having a rating of 16V10 μF was prepared using polyphenylene sulfide as an adhesive tape for wrapping an internal capacitor element.

(Example 2) As shown in FIG. 1, a bipolar electrolytic capacitor with a rating of 10v10 μF and an external size of φ4×5 mm was prepared using polyphenylene sulfide as an adhesive tape for wrapping an internal capacitor element.

(Conventional Example 1) As shown in FIG. 1, an electrolytic capacitor having an outer diameter of φ4×5 mm and having a rating of 16 V and 10 μF was made using polypropylene as an adhesive tape for wrapping an internal capacitor element.

(Conventional Example 2) As shown in FIG. 1, a bipolar electrolytic capacitor with a rating of 10v10 μF and an external size of φ4×5 mm was made using polypropylene as an adhesive tape for wrapping an internal capacitor element.

FIGS. 1 and 2 show the results of examining the rate of capacitance change and change in leakage current before and after soldering for these embodiments and conventional capacitors.

As is clear from Fig. 2 a, b, and Fig. 3, Examples 1 and 2
, soldering is performed when assembling and configuring electronic circuits, and the soldering process does not melt the adhesive tape used to wrap the capacitor element due to the heat of the process, and prevents the capacitor element from loosening. In particular, in the case of the bipolar electrolytic capacitor of Example 2, the outermost electrode foil came into contact with the aluminum case, and no short circuit occurred.

As can be seen from the results above, according to the present invention, the soldering performed when assembling and configuring electronic circuits is
Soldering prevents the adhesive tape used to wrap the capacitor element from melting due to the heat of the time (it prevents the capacitor element from loosening, and the capacitance decreases. Especially for bipolar electrolytic capacitors, the outermost electrode Since the foil and the case do not come into contact and cause a short circuit, it is possible to provide an electrolytic capacitor with high characteristics and high reliability at a low cost, and its practical effects are great.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing an electrolytic capacitor according to an embodiment of the present invention, and Fig. 2 a and b show the electrolytic capacitance of the electrolytic capacitor according to the embodiment of the present invention and the conventional electrolytic capacitor. FIG. 3 is a characteristic diagram showing leakage current before and after soldering of a bipolar electrolytic capacitor according to the present invention and a conventional bipolar electrolytic capacitor. 1...Capacitor element, 2...Metal case, 3...Sealing rubber, 4...Anode lead wire, 5...Cathode lead Line, 6...
Anode foil, 7...Cathode foil, 8...Separator, 9...Adhesive tape. Name of agent Patent attorney Shigetaka Awano and 1 other person Figure 1 Figure 2 Quick estimate Fuhanda t1 second half - ft + 7 front # - town 7 night

Claims (1)

[Claims] An electrolytic capacitor comprising a capacitor element housed in a metal case and sealed using a sealing body, and characterized in that an adhesive tape made of a polyphenylene sulfide base material is used to secure the capacitor element. .