JPS6027176B2 - 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 penetration and long-term high-temperature use. 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 assembled in an aluminum case 2, sealed with a rubber sealing body 4, and the aluminum case 2 itself is configured as a first electrode, for example, a cathode,
The first metal terminal plate 5 is fixed here, and the rubber sealing body 4 is
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 seal 4 and the second metal terminal plate 7 are further fixed to an insulating resin 8. Was. As shown in Table 2 below, such conventional chip-type electrolytic capacitors are immersed in solder solution at a temperature of 260 [OC].
When solid sand or bond is soaked, the rubber sealing body expands and the electrolytic capacitor's capacity [mountain F] and loss [D. F] The change in leakage current [AA] was so large compared to before bonding that it was 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 to 4. In FIG. 2, a chip type electrolytic capacitor 11 according to the present invention has at least a capacitor element 13 built into a cylindrical aluminum case 12, which is sealed with a rubber opening 14, and the aluminum case 12 itself is used as a first electrode. , for example, is configured as a cathode, the lead wire 15 is fixed thereto, and the lead wire 15 is bent into a U-shape toward the rubber sealing body 4.
Also, the second lead wire 16 is connected to the second lead wire 16 via the rubber seal 14
If the electrode, for example the anode, is already bent or the wire 15
Bend it in a U-shape in the direction of the first lead wire 15 so that it is located on the same plane as the first lead wire 15, and insulate the entire first lead wire 15 so that the outer surface of the second lead wire 16 is exposed. The rectangular parallelepiped shape is coated with polyurethane resin 17. A chip type electrolytic capacitor 11 which is another embodiment of the present invention shown in FIG. and second lead wire 1
5 and 16 were pulled out, parallel to each other and bent into a U-shape, and the whole was covered with insulating resin 17 in a rectangular parallelepiped shape so that the outer surfaces of the first and second lead wires 15 and 16 were exposed. It is something. In the chip type electrolytic capacitor 11 according to the present invention, the insulating resin 17 may be a thermosetting resin such as an epoxy resin, a phenol resin, a modified epoxy resin or a phenol resin, or a modified epoxy resin or a phenol resin. Ultraviolet curable resins and thermoplastic resins with high heat resistance such as polybutylene terephthalate or polyphenylene sulfide are preferred, and molding methods include molding. Next, the lead wires 15 and 16 are preferably tin-plated or solder-plated copper wires or steel-core steel-clad wires.
By marking the exposed portions of 6 with lengths and shorts, it will be easier to distinguish between them. In addition, the cord wires 15 and 16 shown in FIGS.
is a round bar shape, but as shown in Figure 4, it may be made into a flat plate shape with a wide width from the middle to the tip, and in this case, it may be bent at the round bar position or at the flat plate position. be. The outer surfaces of the lead wires 15 and 16 may protrude beyond the outer surface of the resin 17 as shown in FIGS. 2 and 3, or may be flush with the outer surface of the resin 17. 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 electrolytic capacitor rating 35 [V]
-3.3 [〃F] The comparison between the test according to the present invention and the conventional example after immersing them in solder liquid 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. Table 1: Based on the present invention Table 2: Based on the conventional example 1
As can be seen from the table and Table 2, the product according to the present invention has a higher capacity than the conventional example even after solder dipping.
French F], loss ■. F], it is possible to provide a stable chip-type electrolytic capacitor with little change in leakage current [A]. Also, the ambient temperature is 85

It can withstand long-term use of [00] and 200 cycles.

[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 embodiment of the present invention. FIG. 3 is a diagram showing another example of the lead wire according to the embodiment. In the figure, 11 is a chip type electrolytic capacitor, 12 is an aluminum case, 13 is a capacitor element, and 14 is a rubber seal □
Body, 15 and 16 are lead wires, 17 is resin. Figure 1 Figure 2 Figure 4 Figure 3

Claims (1)

[Scope of Claims] 1. At least a capacitor element is assembled in an aluminum case, the capacitor element is sealed with a rubber sealing body, the first and second lead wires themselves are bent, and the outer surfaces of the first and second lead wires are bent. A chip-type electrolytic capacitor whose entire surface is covered with resin. 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 resin is a thermoplastic resin with high heat resistance. 5. The chip-type electrolytic capacitor according to claim 1, wherein the lead wire is a tin-plated or solder-plated copper wire. 6. The chip-type electrolytic capacitor according to claim 1, wherein the lead wire is a tin-plated or solder-plated steel-core copper-clad wire. 7. The chip-type electrolytic capacitor according to claim 1, in which the lead wire is lengthened and shortened.