JPH0378775B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a chip-type electrolytic capacitor that can withstand solder immersion and long-term high-temperature use, and has a structure suitable for automated mounting. [Prior Art] Currently, due to trends such as miniaturization of electrical components and automation of mounting on printed wiring boards, chip components in which the lead wires of electrical components are removed have been developed, and this is also progressing in the field of electrolytic capacitors. Conventionally, a chip type electrolytic capacitor 1 as shown in FIG.
A first metal terminal plate 5 is fixed to the electrode, for example, a cathode, and a second metal terminal plate 7 is attached to a second electrode, for example, an anode, of the lead wire 6 via the rubber sealing body 4. Furthermore, the rubber sealing body 4 was fixed to the second metal terminal plate 7 with an insulating resin 8. [Problems to be solved by the invention] Such conventional chip-type electrolytic capacitors have the following problems:
As shown in Table 2 below, when immersed in molten solder at a temperature of 260 [°C] for 10 seconds, the rubber seal expands and the electrolytic capacitor's capacity [μF], loss [%], and leakage current [ μA] was so large that it was unusable compared to before immersion in solder. [Means for Solving the Problems] In view of the above 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. [Example] Hereinafter, an example of the present invention will be described based on FIG. In FIG. 1, a chip-type electrolytic capacitor 10 according to the present invention has a cylindrical aluminum case 2.
0, at least a capacitor element 30 is incorporated in the
It is sealed with a rubber sealing body 40, and a first lead wire 50 and a second lead wire 60 are drawn out from the rubber sealing body 40. These first lead wires 50 and second lead wires 60 are connected to the first lead wire 50 in order to wipe away protrusions that may impede mounting automation from their outer surfaces.
The lead wire 50 is fixed to the inner surface of a plate-shaped first metal terminal plate 70 having a flat outer surface, and the second lead wire 60 is positioned on the opposite side to the first lead wire 50. Fold back to the first metal terminal plate 70
The aluminum case 20 is fixed to the inner surface of a plate-shaped second metal terminal plate 80 having the same shape, and is located between the first metal terminal plate 70 and the second metal terminal plate 80 located on both sides. The entire rubber sealing body 40 is removed by leaving the outer surfaces of both terminal plates 70 and 80, and
The protrusion is covered with an insulating resin 90 without exposing it. In the chip-type electrolytic capacitor 10 according to the present invention, the side surfaces of the first and second metal terminal plates 70 and 80 may be round or square as shown, or may have other shapes. Further, in order to automate the polarity determination of the chip electrolytic capacitor 10, it is preferable that the first metal terminal plate 70 is made of a non-magnetic material such as brass, and the second metal terminal plate 80 is made of a magnetic material such as iron. The insulating resin 90 is a thermosetting resin such as an epoxy resin or a phenolic resin, or an ultraviolet curable resin such as a modified epoxy resin or a phenolic resin. Coating and molding methods for the resin 90 include a spin coating method and a mold molding method. Next, Table 1 and Table 2 show the electrolytic capacitor rating 50
Regarding [V]-1 [μF], the one according to the present invention and the one according to the conventional example were placed in molten solder at a temperature of 260 [℃].
A comparison is shown before and after the 10 second immersion test. Table 1 is based on the present invention, and Table 2 is based on the conventional example.

【table】

【table】

[Table] [Effects] As can be seen from Tables 1 and 2, the product according to the present invention has lower capacitance [μF], loss [%], and leakage current even after immersion in solder than the conventional example. We can provide stable chip electrolytic capacitors with little change in [μA]. Also, the ambient temperature 85
[℃], can withstand long-term use of 2000 hours. Furthermore, the first lead wire is fixed to the inner surface of a plate-shaped first metal terminal plate having a flat outer surface, and the second lead wire is located on the opposite side to the first lead wire. By folding it back like this and fixing it to the inner surface of a plate-shaped second metal terminal plate having the same shape as the first metal terminal plate, the protrusions are removed from the outer surface of the second metal terminal plate, making it easy to handle. This allows for smoother implementation automation.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention;
FIG. 2 is a partial sectional view showing a conventional example. In the figure, 10... Chip type electrolytic capacitor, 20
... Aluminum case, 30 ... Capacitor element, 40 ... Rubber sealing body, 50, 60 ... Lead wire, 70, 80 ... Metal terminal plate, 90 ... Resin.

Claims (1)

[Claims] 1 At least a capacitor element is assembled in a cylindrical aluminum case, sealed with a rubber sealing body, a first lead wire and a second lead wire are drawn out from the rubber sealing body, and the first lead wire is connected to a flat outer surface. The second lead wire is fixed to the inner surface of the first metal terminal board having a surface, and the second lead wire is folded back so as to be located on the opposite side to the first lead wire. A second metal terminal plate is fixed to the inner surface of the second metal terminal plate, and the entire aluminum case and rubber sealing body between the first metal terminal plate and the second metal terminal plate located on both sides are attached to the first metal terminal plate. A chip-type electrolytic capacitor characterized in that the outer surfaces of the terminal plate and the second metal terminal plate are left intact and covered with an insulating resin without exposing the protrusions.