JPS5838601Y2 - Cotai Denkai Capacitor - Google Patents

Description

[Detailed description of the invention] The present invention relates to a solid electrolytic capacitor, and in particular, to prevent peeling of the lower part of the cathode layer that is likely to occur during the soldering process of an external lead wire to the cathode layer formed on the circumferential surface of a capacitor element. The purpose is to

Conventional capacitors of this type are tantalum and niobium.

A capacitor element is formed by pressure-molding a metal powder such as aluminum that has a valve action into a cylinder shape and sintering this compact, and then a semiconductor layer such as manganese dioxide and a cathode layer are formed on the surface of the capacitor element. At the same time as a solder layer is formed on the circumferential surface, an external lead wire is connected to the circumferential surface, and the outer circumferential surface is covered with a resin material such as an epoxy resin.

By the way, the cathode layer is formed by dipping and depositing a silver paste made of vinyl resin and silver on the graphite layer at least on the side and bottom surfaces of the capacitor element. The silver paste layer deposited in this way has excellent adhesion to the capacitor element.

However, since the adhesiveness of the silver paste layer on the bottom part is weak, the silver paste layer on the bottom part peels off along with the solder layer during the soldering process, resulting in the product's characteristics being damaged due to heat. be.

This project was proposed in view of these points, and involves forming a cathode layer on at least the side and bottom parts of a capacitor element, which is made by press-molding metal powder with valve action into a cylindrical shape and sintering it. , in which an external lead wire is led out from this cathode layer, a conductive member containing an epoxy resin and silver is dip-coated on the cathode layer at the lower side and bottom portions of the capacitor element, and the conductive member and It is characterized in that a solder layer is formed by dip deposition on the cathode layer exposed from the conductive member.

An embodiment of the present invention will be described with reference to the drawings. 1 is a content element made by press-molding metal powder having a valve action such as tantalum, aluminum, niobium, etc. into a cylindrical shape and sintering it; 2 is a content element; 3 is a semiconductor layer such as manganese dioxide formed on the oxide film on the circumferential surface of the capacitor element; 4 is a semiconductor layer formed on the semiconductor layer 3; The formed graphite layer 5 is a silver paste layer made of silver and a resin material such as vinyl resin, which is formed on the graphite layer 4 at least on the side and bottom parts of the capacitor element 1, and together with the graphite layer 4. Forms the cathode layer.

Reference numeral 6 denotes a conductive member which is dip-coated on the cathode layer below the side and bottom portions of the capacitor element 1, and is mainly composed of an epoxy resin and silver.

Reference numeral 7 denotes a first external lead wire bent into, for example, an L shape, and its bent portion 7a crosses the anode lead 2 and is welded.

A second external lead wire 8 is brought into contact with the outer peripheral surface of the silver paste layer 5, and is electrically and mechanically connected simultaneously with the formation of the solder layer 9 in the soldering process.

Reference numeral 10 denotes an exterior insulating material that covers the entire circumferential surface of the capacitor element 1, and a dipping method, a fluid dipping method, or the like is used for the exterior.

Since the present invention is constructed as described above, even if the adhesion of the cathode layer at the bottom of the capacitor element is low, the conductive member is integrally attached to the side wall and bottom of the capacitor element. In addition, peeling of the cathode layer during the soldering process is significantly reduced, and therefore the tan caused by the increase in resistance of the capacitor caused by peeling of the cathode layer is reduced.
Deterioration of δ can be improved.

If the vinyl resin in the conductive member is replaced with another resin material, the effect of preventing peeling of the cathode layer, which has a high adhesive strength, will be halved.

[Brief explanation of drawings]

The figure is a sectional view showing an embodiment of the present invention. 1...Contensor element, 4, 5...
... Cathode layer, 7, 8... External lead wire, 9...
...Solder layer, 6... Conductive member.

Claims (1)

[Scope of utility model registration request] A capacitor element formed by press-molding and sintering a metal powder having a valve action into a cylindrical shape has a cathode layer formed on at least the side and bottom parts, and an external lead wire is led out from this cathode layer, A conductive member containing an epoxy resin and silver is dip-coated on the cathode layer below the side faces and the bottom of the capacitor element, and a solder layer is dip-coated on the conductive member and the cathode layer exposed from the conductive member. A solid electrolytic capacitor characterized by being formed by bonding.