JPS6054770B2 - Chip type electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chip-type electrolytic capacitor having a structure that can withstand solder immersion and long-term high-temperature use conditions.

Currently, in response to trends such as miniaturization of electrical components and automation of mounting on printed wiring boards, chip components with lead wires removed from electrical components are being developed, and this is also progressing in the field of electrolytic capacitors.

Conventionally, as shown in FIG. 1, a chip type electrolytic capacitor 1 incorporates at least a capacitor element 3 in an aluminum case 2, seals it with a rubber sealing body 4, and connects the aluminum case 2 itself to a first electrode, For example, it is configured as a cathode, the first metal terminal plate 51 is fixed thereto, and the second electrode of the lead wire 6 via the rubber sealing body 4, for example, the second terminal plate is connected to the anode.
The metal terminal plate 71 is fixed, and the rubber sealing body 4 and the second
The metal terminal plate 71 was fixed with an insulating resin 8.

As shown in Table 2 below, when such a conventional chip-type electrolytic capacitor is immersed in solder at a temperature of 260 [°C] for one circumference, the rubber seal expands and the capacitance of the electrolytic capacitor [ μF], loss [D.

F] The change in leakage current [μA] was so large compared to before immersion in solder that it could not be used. In view of these problems, the present invention provides an improved chip-type electrolytic capacitor in which a heat-resistant resin layer is further provided on the aluminum case.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 4.

In FIG. 2, a chip type electrolytic capacitor 1 according to the present invention incorporates at least a capacitor element 3 in an aluminum case 2, seals it with a rubber sealing body 4, and uses the aluminum case 2 itself as a first electrode, for example, a cathode. and directly attach the first L-shaped terminal plate 5 to this aluminum case.
and the second part of the lead wire 6 through the rubber sealing body 4.
A second L-shaped terminal plate 7 is fixed to the electrode, for example, the anode,
Further, the aluminum case 2 between the first and second terminal plates 5 and 7 and the rubber sealing body 4 are entirely covered with an insulating resin 8.

As shown in FIG. 3, a chip-type electrolytic capacitor 1 according to another embodiment of the present invention has first and second lead wires 6 and 9 drawn out from a rubber sealing body 4, and a second lead wire 9. is fixed to the aluminum case 2, and the others are the second
It is similar to the chip type electrolytic capacitor 1 shown in the figure.

In the chip type electrolytic capacitor 1 according to the present invention, the first
The side surfaces of the second L-shaped terminal plates 5 and 7 may have a rectangular shape as shown in the figure, or may have other shapes such as a hexagonal shape or a semicircular shape.

Furthermore, in order to automate the polarity determination of the chip electrolytic capacitor 1, the first L-shaped terminal plate 5 may be made of a non-magnetic material such as brass, and the second L-shaped terminal plate 7 may be made of a magnetic material such as iron. preferable. As the insulating resin 8, thermosetting resins such as epoxy resins or phenolic resins, ultraviolet curable resins such as modified epoxy resins or phenolic resins, and thermoplastic resins with high heat resistance such as polybutylene terephthalate or polyphenylene sulfide are used. preferable. The resin coating and molding methods are as follows:
Examples include spin coating and mold molding. Note that aging of the capacitor is preferably carried out by applying a voltage in a heating furnace after the resin is cured.

Next, Table 1 and Table 2 show the electrolytic capacitor rating 35 [V]
-3.8 [μF], the comparison between the test according to the present invention and the conventional example after immersing them in a solder solution at a temperature of 260 [°C] for 10 seconds is shown.

Table 1 is based on the present invention, and Table 2 is based on the conventional example. As can be seen from Tables 1 and 2, the product according to the present invention has a higher capacity [μF] and loss CD even after immersion in solder than the conventional example. F], leakage current [μA
] It is possible to provide a stable chip-type electrolytic capacitor with little change.

It can also withstand long-term use at ambient temperatures of 85 [°C] and 200C@. By the way, in FIGS. 2 and 3, the first L-shaped terminal plate 5 is fixed to the surface of the head of the aluminum case 2 by welding or adhesive means.
As shown in FIG. 4, for example, a semicircular recess 10 may be formed in the first L-shaped terminal plate 5, and this recess 10 may be used to secure the terminal plate to the periphery of the head of the aluminum case 2. . With this configuration, it is possible to reduce the size only by the thickness of the first L-shaped terminal plate 5.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a conventional example, FIG. 2 is a partial sectional view showing an embodiment of the present invention, FIG. 3 is a partial sectional view showing another embodiment of the present invention, and FIG. 4 is a partial sectional view showing an L FIG. 7 is a partial view showing a fixed state of the letter-shaped terminal plate in another shape. In the figure, 1 is a chip type electrolytic capacitor, 2 is an aluminum case, 3 is a capacitor element, 4 is a rubber sealing body, 5 and 7 are L-shaped terminal plates, 51 and 71 are metal terminal plates, 6 and 9 are lead wires. , 8 is resin, and 10 is a recess.

Claims (1)

[Claims] 1. At least a capacitor element is assembled in an aluminum case, the capacitor element is sealed with a rubber sealing body, a first L-shaped terminal plate is fixed to the aluminum case, and the first L-shaped terminal plate is connected to the aluminum case through the rubber sealing body. A chip type electrolytic capacitor in which a second L-shaped terminal plate is fixed to a lead wire, and the aluminum case and the rubber sealing body are entirely covered with an insulating resin. 2. The chip-type electrolytic capacitor according to claim 1, wherein a recess is formed in the first L-shaped terminal plate, and the chip-type electrolytic capacitor is fixed to the periphery of the aluminum case using the recess. 3. The chip type electrolytic capacitor according to claim 1 or 2, wherein the second lead wire is fixed to the aluminum case via the rubber sealing body. 4. The chip type electrolytic capacitor according to claim 1, 2 or 3, wherein the resin is a thermosetting resin. 5. The chip type electrolytic capacitor according to claim 1, 2 or 3, wherein the resin is an ultraviolet curable resin. 6. The chip-type electrolytic capacitor according to claim 1, 2 or 3, wherein the resin is a thermoplastic resin with high heat resistance. 7. The chip-type electrolytic capacitor according to claim 1, 2 or 3, characterized in that one of the L-shaped terminal plates is made of a non-magnetic material, and the other L-shaped terminal plate is made of a magnetic material.