JPH0231781Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention incorporates a cylindrical electrolytic capacitor into the space of an exterior case that has a cylindrical space inside, and fills the opening of the exterior case with resin. This invention relates to a chip-type electrolytic capacitor.

[Conventional technology and its problems]

First, as shown in FIG. 3, the cylindrical electrolytic capacitor 2 is assembled into a cylindrical space 11 previously formed inside the exterior case 1, and the lead wires 21a and 21b led out from the electrolytic capacitor 2 are connected to the cylindrical space 11. As a bent chip electrolytic capacitor 3, it was introduced in the Showa era.
1959 Utility Model Publication No. 3557 ``Chip type electrolytic capacitor''. The electrolytic capacitor 2 is constructed by incorporating a capacitor element in which an anode foil and a cathode foil (not shown) are wound through a separator made of electrolytic paper into a cylindrical case 23 together with a sealing body 22 made of a rubber material or the like. The abutting portion of the sealing body 22 is drawn 23a, and the open end of the case 23 is curled 23b, which are of the kind generally available on the market. However, in the chip type electrolytic capacitor 3 having this structure, the sealing body 22 may not be able to withstand the heat stress during solder dipping or reflowing of the chip type electrolytic capacitor 3, and the sealing body 22 may pop out from the case 23, or the characteristics as an electrolytic capacitor may deteriorate. There is a drawback that this occurs.

In order to eliminate such defects, there is a chip type electrolytic capacitor 3A in which the opening 12 of the exterior case 1 after the electrolytic capacitor 2 is assembled is filled with resin 4 and then hardened, as shown in FIG. However, even such a chip type electrolytic capacitor 3A is still unable to withstand the above-mentioned thermal stress, and the filled resin 4 often peels off inside the case 1 or jumps out from inside the outer case 1. ing.

[Purpose of the invention and improvements]

However, in order to eliminate the above-mentioned drawbacks, the present invention provides a chip-type electrolytic capacitor in which the exterior case is filled with resin so that even the drawing part of the electrolytic capacitor is integrated. be.

〔Example〕

Hereinafter, an embodiment of a chip type electrolytic capacitor 3B according to the present invention will be described based on FIGS. 1 and 2.

The exterior case 1 is made of a thermosetting resin such as phenol resin, epoxy resin, diallyl phthalate resin, or silicone resin, or thermoplastic resin such as polyphenylene sulfide resin, or ceramic material, and is heat resistant. , its external shape is a square prism. Moreover, the exterior case 1 has a cylindrical space 11 with one side as an opening 12 inside. The opening 12 connected to the cylindrical space 11 is configured to have a width wider than the diameter of the space 11, and although it is formed as a rectangular shape here, it may have a cylindrical shape with a large diameter.

The cylindrical space 11 of such an exterior case 1
Inside, an electrolytic capacitor 2 having substantially the same diameter is assembled with its sealing body side facing the opening 12. At this time, the drawn portion 23a of the electrolytic capacitor 2 is located in the opening 12. After the electrolytic capacitor 2 is installed, the opening 12 is filled with liquid resin 4 and cured by ultraviolet curing, heat curing, or room temperature curing means. Note that the flat lead wires 21a and 21b from the electrolytic capacitor 2 through the resin 4 are bent and placed in grooves 13a and 13b formed on the bottom surface of the exterior case 1.

[Effect of idea]

According to such a chip type electrolytic capacitor 3B, the swelling of the sealing body 22 caused by the increase in the internal pressure of the electrolytic capacitor 2 caused by the heat stress such as at least 240° C. or higher during solder dipping or reflowing can be prevented from forming on the sealing body side. Since the resin 4 on the outside and the resin 4 on the drawing part side can be held and suppressed, defective products caused by the filled resin 4 peeling off inside the case 1 or coming out from inside the outer case 1, which conventionally occur, can be suppressed. It is possible to prevent the occurrence of Therefore, it is possible to provide a chip type electrolytic capacitor 3B with excellent heat resistance.

Incidentally, the conventional chip type electrolytic capacitor 3
After preparing 100 chip type electrolytic capacitors A and 3B according to the present invention and immersing them in a solder bath at a bath temperature of 260°C for 5 seconds, the occurrence of defective products due to peeling or popping out of the filled resin has been avoided in the conventional example. While there were 32 pieces, in the present invention there were 0 pieces.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a chip-type electrolytic capacitor according to the present invention, FIG. 2 is a partial cross-sectional view taken along line A-A in FIG. 1, FIG. 3 is a partial cross-sectional view showing the first conventional example, and FIG. The figure is a partial side sectional view showing a second conventional example. In the figure, 1...exterior case, 2...electrolytic capacitor, 3, 3A, 3B...chip type electrolytic capacitor, 4...resin.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A chip-type electrolytic capacitor in which a cylindrical electrolytic capacitor is assembled in a cylindrical space pre-formed inside an outer case, and the opening of the outer case is filled with resin, A chip-type electrolytic capacitor in which the drawing part of the electrolytic capacitor is also filled with resin. (2) A chip-type electrolytic capacitor as claimed in claim (1) of the utility model registration, characterized in that the opening of the outer case has a width wider than the diameter of the space.