JP2959028B2 - Chip type solid electrolytic capacitor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a chip-type solid electrolytic capacitor, and more particularly, to a structure of a cathode layer.

[Prior Art] Conventionally, this type of chip-type solid electrolytic capacitor has a
As shown in the figure, an oxide film layer, an electrolyte layer, a first carbon layer, and a first carbon layer formed sequentially on the surface of an anode body 1 made of a valve metal from which an anode lead wire 2 is led out by a known technique. An outer resin layer 4 deposited on the peripheral surface of the element and a first part formed on a part of the tip of the mounting surface so that the plating layer 3 and the first plating layer 3 on the surface opposite to the anode lead wire lead-out surface are exposed. A second carbon layer 9, a solder layer 11 deposited on the surface opposite to the lead wire lead-out surface and on the second carbon layer 9 via a second plating layer 10, and connected to the tip of the anode lead wire 2. The external anode terminal 7 is provided.

[Problems to be solved by the invention]

The above-described conventional chip-type solid electrolytic capacitor has the following features. (1) As shown in FIG.
Since the three layers of the second carbon layer 9, the second plating layer 10, and the solder layer 11 are formed, the thickness is increased, and the height is increased accordingly.

(2) Similarly, since the mounting surface has the second carbon layer 9 formed on the exterior resin layer 4, the adhesion is poor, and the fixing strength is liable to decrease.

(3) Further, since the solder layer 11 is formed with a swelling, there is a possibility that the solder layer 11 will come into contact with other components in the vicinity after mounting.

There is a disadvantage that.

An object of the present invention is to eliminate the conventional disadvantages, reduce the height dimension, improve the connection reliability and improve the fixing strength, and furthermore, make the facing surface of the lead wire lead-out surface flat,
An object of the present invention is to provide a chip-type solid electrolytic capacitor that can reduce the possibility of contact with other components adjacent after mounting.

[Means for solving the problem]

In the chip type solid electrolytic capacitor of the present invention, an oxide film layer, an electrolyte layer, a first carbon layer, and a first plating layer are sequentially formed on the surface of an anode body made of a metal having a valve action from which an anode lead wire is led. The exposed element, the exterior resin layer laid out such that the first plating layer at the leading end of the mounting surface and the opposing surface of the lead wire leading surface are exposed, and the facing surface of the mounting surface and the lead wire leading surface are exposed. An external cathode terminal is formed directly on the first plating layer via a solder layer or a conductive adhesive, and further includes an external anode terminal connected to the anode lead.

〔Example〕

Next, the present invention will be described with reference to the drawings. First
The figure is a longitudinal sectional view of one embodiment of the present invention. An oxide film layer, an electrolyte layer, a carbon layer, and a first plating layer 3 are sequentially formed on the surface of the anode body 1 obtained by pressing and sintering the tantalum powder. Next, an epoxy resin is adhered by electrostatic adhesion except for the part opposite to the anode lead wire lead-out surface and the tip of the mounting surface, and is cured by heating to form the exterior resin layer 4.
Furthermore, a solder paste is applied on the exposed first plating layer 3 on the front end of the mounting surface and the surface facing the lead wire lead-out surface, and further, the external cathode terminal 6 is deposited and connected through a reflow furnace. Then, a cathode layer is formed. Finally, a U-shaped external anode terminal 7 was connected to the tip of the anode lead wire 2 by welding to form a chip-type solid electrolytic capacitor.

FIG. 2 is a longitudinal sectional view of another embodiment of the present invention. The process up to the formation of the exterior resin layer 4 is the same as that of the first embodiment,
Applying a silver paste on the exposed first plating layer,
The external cathode terminal 6 was connected to form a cathode layer. Further, a U-shaped external anode terminal 7 was connected to the anode lead wire 2 by a welding method to form a chip solid electrolytic capacitor.

〔The invention's effect〕

As described above, the present invention has the following effects. An exterior resin layer is deposited on the peripheral surface of the element so as to expose the first plating layer at a part opposite to the anode lead wire lead-out surface and at the tip of the mounting surface, and the first mounting surface is exposed. Since the cathode layer is formed on the plating layer without intervening the exterior resin layer, the number of overlapping layers is reduced, and the height dimension is 100 to 150.
Micron smaller. Further, the reliability of the connection is improved, and the fixing strength is improved.

Furthermore, the opposite surface of the lead wire lead-out surface is formed in a plane,
Since there is no swelling in the case of a solder layer, the possibility of contact with other components adjacent after mounting is reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a solid electrolytic capacitor according to one embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a solid electrolytic capacitor according to another embodiment of the present invention, and FIG. It is a longitudinal cross-sectional view of an example. DESCRIPTION OF SYMBOLS 1 ... Anode body, 2 ... Anode lead wire, 3 ... Oxide film layer-1st plating layer, 4 ... Exterior resin layer, 9 ... 2nd carbon layer, 10 ... 2nd plating layer , 15, 11 ... solder layer, 7 ... external anode terminal, 8 ... conductive adhesive (silver paste), 6 ... external cathode terminal, 12 ... mounting surface.

Claims (1)

(57) [Claims] 1. An anode body made of a valve metal, from which an anode lead wire is led, an oxide film layer, an electrolyte layer, a carbon layer, and a plating layer sequentially formed on the surface of the anode body; An exterior resin layer formed so that a part of the plating layer on the opposing surface and the peripheral surface of the element is exposed, and a solder layer or an external connected via a conductive adhesive on the exposed plating layer. A chip-type solid electrolytic capacitor including a cathode terminal and an external anode terminal connected to the anode lead.