JPS5940764Y2 - solid electrolytic capacitor - Google Patents

Description

[Detailed description of the invention] The present invention relates to a face bonding type chip type solid electrolytic capacitor, and more specifically, it provides a rectangular solid electrolytic capacitor that is easy to manufacture and can be automatically fed and automatically aligned using a parts feeder. It is.

Conventionally, as a face bonding type chip type solid electrolytic capacitor, one having the structure shown in FIG. 1 has been generally used.

That is, a dielectric material is formed by anodizing on the surface of a sintered body, which is constructed by molding and sintering metal powder of a valve metal such as tantalum, and has a protruding lead-in wire 1 such as a tantalum wire drawn out from the center of one end face. By forming an oxide film, then forming a manganese dioxide layer on the dielectric oxide film by thermal decomposition of a manganese nitrate solution, and sequentially laminating a carbon layer, a silver paint layer, and a solder layer on the manganese dioxide layer. A metal plate 3, which constitutes a capacitor element 2 and serves as an anode terminal which can be soldered, is connected to the protruding lead-in wire 1 of the capacitor element 2 by welding so as to be located on the same plane as the surface of the solder layer 2a of the capacitor element 2. It consists of:

In the case of the structure shown in Figure 1, the strength of the anode terminal is weak, and leakage current increases when exposed to external stress. As shown in Figure 2, capacitor element 2 and metal plate 3
There is also a structure in which resin 4 is placed between the two.

However, although the conventional solid electrolytic capacitors shown in FIGS. 1 and 2 have the advantage of being simple in structure and can be manufactured at low cost, as mentioned above, The one shown in the figure is very weak against external stress and has the disadvantage of unstable characteristics. Although it is possible to make the anode terminal part strong to some extent by reinforcing the anode terminal part, there is a drawback that the resin 4 sags and the product dimensions vary widely.

On the other hand, in recent years, automatic supply and automatic alignment of electronic components have progressed.
Chip-shaped ceramic capacitors and the like that can meet these demands have been developed.

However, solid electrolytic capacitors, which play an important role as capacitive elements in electronic circuits, have been developed that are capable of automatic supply and automatic alignment, and are favorable in terms of price, size, etc. Even if it is possible to create a rectangular shape that can be automatically supplied and automatically aligned, the current situation is that the price is high and the shape is large, so solid electrolytic capacitors have been developed to meet these demands. I'm looking forward to the development of something that can be done.

The present invention was devised in response to such demands, and will be described below with reference to FIG. 3 and FIG. 4, which show embodiments of the present invention.

Figures 3a and 3b show a solid electrolytic capacitor according to an embodiment of the present invention. In the figure, 10 is a capacitor element, and this capacitor element 10 is formed by molding and sintering metal powder of a valve metal such as tantalum. A protruding lead-in wire 11 such as a tantalum wire is connected to the surface of the prismatic sintered body constructed by this method, and a dielectric oxide film, such as manganese dioxide, is applied to the surface of the sintered body by a conventional method. solid electrolyte layer,
It is constructed by sequentially laminating a cathode layer made of carbon and a cathode conductive layer made of silver paint.

Therefore, the protruding lead-in wire 11 protrudes from the end of the end face of the Fi capacitor element 10.

Reference numeral 12 denotes a prismatic anode terminal connected and fixed to the tip of the protruding lead-in wire 11 of the capacitor element 10 by welding. The anode terminal 12 is made of a metal member having a thickness approximately equal to the thickness of the capacitor element 10 and which can be soldered.

13//i A cathode terminal constructed by forming a solder layer, a silver paint layer, etc. on the end of the capacitor element 10 opposite to the side from which the protruding lead-in wire 11 is drawn out, and this cathode terminal 1
3 and the anode terminal 12 are located on the same plane.

14 is an insulating resin layer such as epoxy resin, and this insulating resin layer 14 is formed between the portion of the capacitor element 10 other than the cathode terminal 13 and between the capacitor element 10 and the anode terminal 12. The surface of the insulating resin layer 140 is also located on the same plane as the anode terminal 12 and the cathode terminal 13.

Here, in the sintered body used in the present invention, the protruding lead-in wire 11 is arranged on the surface of the sintered body and the button is pressed.
cannot be buried and molded at the same time.

Therefore, in the present invention, first, valve metal powder such as tantalum powder is molded using a press, vacuum sintered using a general method to obtain a prismatic sintered body, and then tantalum is applied to the surface of the sintered body. The protruding lead-in wire 11, such as a wire, is welded by a butt welding method or the like so that it is located almost on the same plane as the surface of the sintered body, or a recess into which the protruding lead-in wire 11 fits is provided in advance in the sintered body, and the button is pressed. Then, the protruding lead-in wire 11 is fitted into the recessed portion, and overlap welding is performed to connect and fix it to the surface of the sintered body, thereby obtaining a sintered body having the protruding lead-in wire 11.

In addition, the anode terminal 12 is made of a metal such as iron or steel that can be soldered and welded to a valve metal wire such as a tantalum wire, and when the metal member is welded to the protruding lead-in wire 11, the outer peripheral surface is A rectangular or round shape with a thickness that is approximately flush with the capacitor element 10 is used.

Furthermore, in order to reduce the overall length, it is necessary to weld the anode terminal 12 as close to the capacitor element 10 as possible, but in this case, before welding the anode terminal 12 to the protruding lead-in wire 11, Resin is applied to the end surface of the element 10 from which the protruding lead-in wire 11 is drawn out, and the resin reinforces the protruding lead-in wire 11 to reduce the stress applied during welding, and also to reduce the stress applied during welding.
What is necessary is to insulate it from 2.

Note that when welding the anode terminal 12 to the protruding lead-in wire 11,
Grooves may be provided in the anode terminal 12 to facilitate alignment of the anode terminal 12 and facilitate welding.

4a and 4b show a solid electrolytic capacitor according to another embodiment of the present invention, in which the insulating resin layer 1
4 is formed so as to be covered by the connecting portion 1 of the anode terminal 12 with the protruding lead-in wire 11. In addition to the effect of the above embodiment, it has the advantage that the anode and cathode can be easily distinguished. ing.

As is clear from the above description, the solid electrolytic capacitor according to the present invention can provide the following effects.

(1) Since the protruding lead-in wire is connected to the surface of the sintered body, and the anode terminal, which has approximately the same thickness as the capacitor element, is connected to the protruding lead-in wire, it is possible to form a well-shaped rectangular shape. This enables automatic alignment and automatic transfer using a parts feeder, which facilitates attachment to circuit boards and increases product value.

(2) The size is the same as the conventional one in which a metal plate is simply welded to a protruding lead-in wire, and the shape is not particularly large.

(3) Compared to the conventional manufacturing process, the cost is not so high because the process of providing the insulating resin layer is increased.

(4) Because the cathode terminal, insulating resin layer, and anode terminal are on almost the same plane, sometimes when installing the anode and cathode to the circuit board, first, the insulating resin layer is bonded to the circuit board with adhesive, and then the anode and cathode are attached. Connections can be made and installation is extremely easy.

As described above, the solid electrolytic capacitor according to the present invention can fully meet the current demands for a face bonding type capacitor.

[Brief explanation of the drawing]

Figures 1 and 2 are perspective views showing a conventional solid electrolytic capacitor, Figures 3a and 3b are a perspective view and a sectional view, respectively, showing a solid electrolytic capacitor according to an embodiment of the present invention, and Figure 4. FIGS. 1A and 1B are a perspective view and a cross-sectional view, respectively, of solid electrolytic capacitors according to other embodiments of the present invention. 10...Capacitor element, 11...Protruding lead-in wire, 12...Anode terminal, 13...
- Cathode terminal, 14... Insulating resin layer.

Claims (1)

[Scope of utility model registration request] A protruding lead-in wire is connected to the surface of a prismatic sintered body formed by molding and sintering metal powder of a valve metal, and a dielectric oxide film, a solid electrolyte layer, and a cathode layer are provided on the surface of the sintered body. A capacitor element is constructed by sequentially laminating cathode conductive layers, and a conductive layer is provided at the end of the capacitor element opposite to the side from which the protruding lead-in wire is drawn out to serve as a cathode terminal.
Connect and fix the anode terminal to the tip of the protruding lead-in wire so that it is located on the same plane as the cathode terminal, and whose thickness is approximately equal to the thickness of the capacitor element. A solid electrolytic capacitor comprising a portion covered with an insulating resin and an insulating resin filled between the end face of the capacitor element and the anode terminal.