JPS5940520A - Chip type electrolytic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a chip-shaped electrolytic capacitor.

In recent years, advances in semiconductor technology such as IC and LSI have led to the miniaturization and thinning of electronic stand-piece sets, as well as the rapid spread of automatic insertion and mounting technology for electronic components.

Various chip types have been devised in the field of capacitors, some of which are already in practical use.

However, since electrolytic capacitors use an electrolyte, it is difficult to make them into chips, and their structure is complicated. For this reason, conventionally, as shown in FIG. 1, an element 1 is wound with a separator between a pair of aluminum electrodes 2C1 to which a lead-out lead 2 is connected in advance, and the element 1 is impregnated with an electrolytic solution and then housed in an inner case 3 and sealed. rear,
It is well known that a metal electrode 4 for an external terminal is connected to a lead-out lead 2 and molded with a resin 5 for the exterior.

Since the conventional chip-shaped electrolytic capacitor manufactured as described above has a connecting part between the drawer lead 2 and the external terminal metal electrode 4, there are restrictions on the finished dimensions of the product due to the manufacturing process. As shown in Fig. 1, the lead 2 penetrates the side wall surface of the interior wood case 3, so even if we have taken measures to maintain the internal airtightness, we have not yet been able to obtain a perfect product. However, even though the electrical characteristics were improved, there were many drawbacks such as not creating an ocular field.

The present invention eliminates the above-mentioned drawbacks and provides a chip-shaped electrolytic capacitor that is small and has high heat resistance.

The present invention will be explained below with reference to the embodiments shown in FIGS. 2 and 3.

Fig. 2 is a perspective view of a chip-shaped 1fi capacitor during the manufacturing process, and Fig. 3 is a cross-sectional view of a chip-shaped electrolytic capacitor. The capacitor element 1 formed by winding is inserted into a heat-shrinkable resin tube 6 with excellent heat resistance such as Teflon, and after inserting an elastic body 7 such as rubber into the pull-out leads 2 at both ends, the tube is heated and shrunk. The element 1 and the elastic body 7, such as rubber, are tightened and fixed. Thereafter, a liquid resin 8 such as epoxy or urethane is applied to the openings at both ends and hardened. Note that instead of the elastic body 7, a sealing body made of thermosetting resin, heat=if plastic resin, or the like may be used.

The product thus manufactured is further molded with exterior resin 5. Next, as shown in FIG. 3, a conductive layer 9 is formed by applying silver paste or the like to the drawer reel 2 at both ends and its end face and hardening.

Then, an electroless plating process made of a metal capable of soldering, such as nickel or copper, is applied to form the -1- printed conductor layer 9.
After forming an electroless plating layer 10 on the lead-out lead 2, a solder plating layer 11 is formed to complete the process.

According to the method for forming the external electrode described above, the base material can be treated regardless of whether it is a non-ferrous metal or a resin.

Therefore, the extraction lead 2 can be pulled out with the aluminum connected to the electrode foil, and not only does it not have a connecting part such as welding of the extraction lead like conventional products, but also has the shrinkage force of the heat-shrinkable resin tube 6. Since the entire wound capacitor element 1 is tightened, the distance between the wound anode foil and cathode foil electrodes is narrowed, making it possible to improve the electrical characteristics.

Further, the lead-out portion of the lead-out lead 2 is formed by an elastic body 7 or a seal 11 body 7.
A highly reliable chip-shaped electrolytic capacitor/condenser was obtained since the liquid tree + Iir 8 ensured double airtightness.

Next, a chip-shaped electrolytic capacitor with a rating of 25V and 3.3μF was manufactured based on the above-mentioned example, and after immersing it in molten solder at a temperature of 260℃ for 10 seconds, it was
Leave it in an atmosphere of 5'C and observe its change over time /fill
The table shows the results compared with conventional products.

As is clear from the table, it was confirmed that the products of the present invention exhibit extremely stable characteristics compared to conventional products even in life tests under high-temperature loads.

As described above, the chip-shaped electrolytic capacitor of the present invention has two advantages: the capacitor element is tightened by the contraction force of the heat-shrinkable resin tube, and airtightness is maintained by the elastic body of the sealing part or the sealing body and the resin layer. Tomo tc.

It becomes possible to integrate the lead lead and the solder plating layer forming the external terminal, and it becomes possible to manufacture a capacitor with excellent characteristics, which is of great industrial and practical value.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional chip electrolytic capacitor;
The figure is a perspective view of a chip-shaped electrolytic capacitor during the manufacturing process of the present invention, and FIG. 3 is a sectional view of an embodiment of the chip-shaped electrolytic capacitor of the present invention. 1: Capacitor element 2: Output lead 5, 8: Resin
6: Heat-shrinkable resin tube 9: Conductive layer 10: Electroless plating layer 11: Solder plating layer Patent applicant Nippon Capacitor Industry Co., Ltd.

Claims (1)

[Claims] A condenser element is formed by making an anode foil and a cathode foil face each other with a separator interposed therebetween, and the element is impregnated with an electrolytic solution, and the four lead-out leads extending from the element in two opposite directions are made of an amenophobic material such as rubber or the like. A resin tube is inserted through a sealant such as resin, and the heat-shrinkable resin tube is heated and shrunk, and a resin layer is formed to surround this, and a conductive layer is formed on the protruding parts of the drawer leads at both ends of the southern resin layer. A chip-shaped electrolytic capacitor characterized in that an electrode is formed by sequentially forming an electroless plating layer and a solder plating layer, and the electrode is connected to the above-mentioned lead.