JPH0247847B2 - CHITSUPUGATADENKAIKONDENSA - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a chip type electrolytic capacitor with high heat resistance and high productivity. Recently, research into chipping electronic components has been actively conducted in order to make electronic devices smaller and thinner, and to save labor in assembly, and various structures for electrolytic capacitors have been studied and developed. As shown in FIG. 1, a conventional chip-type electrolytic capacitor has a capacitor element 2 housed in a metal case 1, sealed with an elastic sealing body 3, and connected directly to the metal case 1 itself or via a cathode lead wire 4. A metal terminal plate 5 for the cathode was fixed to the metal terminal plate 5 for the cathode, and a metal terminal plate 7 for the anode was fixed to the lead wire 6 for the anode via the elastic sealing body 3, and the entire metal case 1 was coated with an insulating resin 8. . Further, as shown in FIG. 2, the above-mentioned cathode lead wire 4 and anode lead wire 6 are welded to a metal frame 9 instead of the metal terminal plates 5 and 7, and the entire metal case 1 is covered with an insulating exterior resin. 8 was covered. Such conventional chip electrolytic capacitors are
Since the lead wires 4, 6 and the metal terminal plates 5, 7 or the metal frame 9 are welded and coated with resin 8, they can be immersed in molten solder at a temperature of 260°C or heat cycled at high and low temperatures. When testing, it was found that there were welding defects, and the exterior resin 8
There was a drawback that wire breakage occurred due to the expansion and contraction of the wire. In addition, it takes time to replace these defective products mounted on the printed circuit board, and there is a problem in that other parts are thermally damaged when re-immersed in molten solder. In order to eliminate the above-mentioned drawbacks, the present invention provides a chip-shaped electrolytic capacitor that is heat-resistant and can be produced efficiently without using a metal terminal plate or a metal frame. The present invention will be explained below with reference to embodiments shown in FIGS. 3 to 6. FIG. 3 is a cross-sectional view of a main part in the manufacturing process of a chip-shaped electrolytic capacitor, in which a capacitor element 12 is housed in a metal case 11 and sealed with an elastic sealing member 13. At this time, the anode lead wire 14 led out from the capacitor element 12 is made of an aluminum wire and a solderable metal wire such as copper or brass welded to the tip thereof, and the other end of the aluminum wire is formed flat. Connected to the anode electrode foil. Further, the cathode tab 15 connected to the cathode electrode foil is connected to the metal case 11, and the solderable cathode lead wire 16 is welded to the bottom of the metal case 11. Next, it is molded on the metal case 11 by a transfer molding method or the like.
The outer surface of the elastic sealing member 13 near the base of the lead wire 14 is exposed by fitting and covering the cylindrical shape, and the other outer surface is covered with an insulating exterior resin 17.
After the lead wires 14 and 16 are inserted between the upper mold 18 and the lower mold 19, the lead wires 14 and 16 are pressed against each other, and the lead wires are formed into a flat shape from the root to the tip of the drawer to a predetermined length. After cutting and molding as shown in FIG. 4, the external terminals 14a, 16a are bent into an L shape along the surface of the exterior resin 17 as shown in FIG.
Configure and complete. FIG. 6 shows another embodiment in which the anode lead wire 14 and the cathode lead wire 20 are inserted through the elastic sealing body 13 and both are pulled out from the same direction. , 20a are L at the same time
It is completed by folding it into a letter shape. Further, the coating with the resin 17 may be performed after the lead wire is flattened. Since the chip-type electrolytic capacitor of the present invention is constructed as described above, there is no welding work for external terminals, and there is no connection point such as welding in the exterior resin, so it cannot be immersed in molten solder or exposed to high temperatures. Even if a heat cycle test is performed at a low temperature, there is no risk of wire breakage, and a product with extremely high heat resistance and reliability can be obtained. In addition, since the elastic sealing body near the base of the lead wire is exposed and the other outer surfaces are covered with exterior resin, it will not explode even if the internal pressure rises in the event of a capacitor malfunction, and gas will be released from the exposed part to ensure safety. A capacitor with high performance can be obtained. The table shows the solder heat resistance test in which the conventional product and the inventive product were immersed at a temperature of 260℃ for 10 seconds, and a temperature of 85℃ and -40℃.
A heat cycle test was conducted in which a heat cycle of 30 minutes at each temperature was repeated 50 times, and the failure rate (number of failures/number of tests) was compared. All conventional products had welded parts peeling off.

[Table] As mentioned above, the chip-shaped electrolytic capacitor of the present invention has extremely high heat resistance and is extremely advantageous in terms of productivity, and is of great industrial and practical value.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views of conventional chip-type electrolytic capacitors, Figures 3 to 5 are examples of the present invention, and Figure 3 is a cross-section of important parts in the manufacturing process of chip-type electrolytic capacitors. Figure 4 is a perspective view of the manufacturing process of the same chip-type electrolytic capacitor, Figure 5 is
Figure A is a sectional view of a chip-type electrolytic capacitor, Figure 6B is a side view of the same, Figure 6A is a cross-sectional view of another embodiment of the chip-type electrolytic capacitor of the present invention in the manufacturing process, and Figure 6B is a chip-type of the same. FIG. 2 is a completed perspective view of an electrolytic capacitor. 1, 11: Metal case, 2, 12: Capacitor element, 3, 13: Elastic sealing body, 4, 6, 14, 1
6: Lead wire, 8, 17: Exterior resin, 14a, 1
6a: External terminal.

Claims (1)

[Claims] 1. In a chip-type electrolytic capacitor in which the lead wire led out from the capacitor element is inserted through an elastic sealing body, housed in a metal case, and the opening of the case is tightened, the entire case is covered with an exterior resin. The outer surface of the elastic sealing body near the base of the wire is exposed and the other outer surface is covered with exterior resin, and the lead wire protruding from the elastic sealing body is pressed into flat shape from the vicinity of the base to the tip. A chip-type electrolytic capacitor characterized by having an external terminal formed by bending it into an L-shape along the surface.