JPS6025021B2 - 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.
At least a capacitor element 3 is built into an aluminum case 2, the capacitor element 3 is sealed with a rubber sealing body 4, and the aluminum case 2 itself is configured as a first electrode, for example, a cathode,
A first metal terminal plate 5 is fixed here, and a rubber sealing body 4 is also attached.
A second metal terminal plate 7 is fixed to the second electrode, for example, an anode, of the lead wire 6 via the cable, and the rubber sealing body 4 and the second metal terminal plate 7 are further fixed with an insulating resin 8. Was.

As shown in Table 2 below, when such conventional chip-type electrolytic capacitors are immersed in solder at a temperature of 260 [OC], the rubber seal expands, causing damage to the electrolytic capacitor. Capacity [F], Loss [%] Leakage current [MuA]
The change in temperature was so great compared to before the solder immersion that it became unusable.

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 and 3.

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. A first metal cap terminal plate 5 is fixed to a first lead wire 9 provided in the aluminum case 2, and a second electrode of a second lead wire 6 is connected via a rubber seal 4. For example, a second metal cap terminal plate 7 is fixed to the anode, and the entire aluminum case 2 and rubber seal 4 between the first and second metal terminal plates 5 and 7 are covered with an insulating resin 8. do.

As shown in FIG. 3, in a chip-type electrolytic capacitor 1 which is another embodiment of the present invention, first and second lead wires 9 and 6 are drawn out from a rubber seal 4, and the first lead line 9
is folded back to the opposite side and fixed to the first metal cap terminal plate 5, and the other parts are the same as the chip type electrolytic capacitor 1 shown in FIG.

In the chip type electrolytic capacitor 1 according to the present invention, the first
The shape of the second metal cap terminal plates 5 and 7 may be a round cylinder or a rectangular cylinder as shown in the figure, or may be of other shapes.

Furthermore, in order to automate the polarity determination of chip-type electrolytic capacitors, it is preferable that the first metal cap terminal plate 5 is made of a non-magnetic material such as yellow steel, and the second metal cap terminal plate 7 is made of a magnetic material such as iron. . The insulating resin 8 is a thermosetting resin such as epoxy resin or phenol resin, or an ultraviolet curable resin such as modified epoxy resin or phenol resin. Examples of resin coating and molding methods include spin coating and mold molding. Next, Tables 1 and 2 show the electrolytic capacitor rating 50[V]-1
Regarding [rF], a comparison is shown before and after the test in which the product according to the present invention and the product according to the conventional example were immersed in a sand gap of 1 in solder at a temperature of 260 [° C.]. Table 1 is according to the present invention,
Table 2 is based on subordinate examples. Table 1...Invention K
As can be seen from Table 1 and Table 2, the product according to the present invention has a higher capacity [F] even after solder immersion than the conventional example. It is possible to provide a stable chip-type electrolytic capacitor with little change in loss [%] and leakage current [A].

In addition, it can withstand long-term use at an ambient temperature of 85 [°C] and 200 field hours.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a conventional example, FIG. 2 is a partial sectional view showing one embodiment of the present invention, and FIG. 3 is a partial sectional view showing another embodiment of the present invention. In the figure, 1 is a chip type electrolytic capacitor, 2 is an aluminum case, 3 is a capacitor element, 4 is a rubber seal, 5 and 7 are terminal plates, 6 and 9 are lead wires, and 8 is resin. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. At least a capacitor element is assembled in an aluminum case, sealed with a rubber sealing body, a first metal cap terminal is fixed to a first lead wire, and a second metal cap terminal is fixed to a second lead wire.
A chip type electrolytic capacitor consisting of a metal cap terminal fixed to the aluminum case and an insulating resin coated on the entire aluminum case. 2. The chip-type electrolytic capacitor according to claim 1, wherein the resin is a thermosetting resin. 3. The chip-type electrolytic capacitor according to claim 1, wherein the resin is an ultraviolet curing resin. 4. The chip-type electrolytic capacitor according to claim 1, wherein the first metal cap terminal plate is a non-magnetic material, and the second metal cap terminal plate is a magnetic material.