JPH0316272Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to solid electrolytic capacitors, and particularly relates to a display mechanism for displaying the manufacturing month, etc. of a chip-type solid electrolytic capacitor using a plate-shaped external lead member.

[Prior art]

In general, this type of solid electrolytic capacitor is made by press-molding metal powder having a valve action into a prismatic shape and sintering it, as disclosed in, for example, Japanese Utility Model Application Publication No. 58-193626. A metal wire having the above-mentioned structure is planted as an anode lead, a plate-shaped first external lead member is welded to the anode lead, and an oxide layer is formed on the circumferential surface of the capacitor element.
A plate-shaped second external lead member is connected to the electrode lead layer formed via the semiconductor layer and the graphite layer using a conductive adhesive, and the entire circumferential surface of the capacitor element is molded and covered with a resin material. , and the lead-out ends of the first and second external lead members are bent and arranged along the lower surface of the resin material.

By the way, in this solid electrolytic capacitor,
The product type, characteristics, manufacturing month, etc. are displayed in the center of the upper surface of the resin material.
The first display symbol that displays manufacturing history, etc.
A second band-shaped display symbol for indicating polarity is stamped on the top end of the external lead member side of the solid electrolytic capacitor. Moreover, the polarity of the first and second external lead members can be easily identified by the second display symbol.

However, in recent years, with the trend towards smaller, lighter, thinner and smaller solid electrolytic capacitors, there has been a strong demand for smaller size without exception.For example, 2.54 x 4.57 x 2.54 mm
Smaller versions have been put into practical use.

When solid electrolytic capacitors are miniaturized in this way, it is difficult to stamp all the display symbols on the upper surface of the resin material. On the other hand, if the first display symbol is made extremely small, it is possible to stamp it, but it not only becomes difficult to recognize it, but also makes it difficult to stamp it clearly.

[Problem that the invention attempts to solve]

Therefore, in the past, only the most necessary items such as characteristics were stamped, and information such as manufacturing month and manufacturing history were not stamped, so if a defective accident occurred, it would be difficult to determine which solid electrolytic capacitor was used. It has a manufacturing history such as
Furthermore, it is not possible to determine when the product was manufactured, making it difficult to determine the exact cause of the defect.

Therefore, an object of the present invention is to provide a solid electrolytic capacitor with a simple structure that allows a symbol indicating the month of manufacture etc. to be reliably formed even if the exterior form is made smaller.

[Means to solve the problem]

Therefore, in order to achieve the above-mentioned purpose, the present proposal:
An electrode lead layer is formed on the circumferential surface of a capacitor element made of a metal powder having a valve action, and a metal wire having a valve action is led out from the metal powder as an anode lead, and a first electrode layer is formed on the anode lead of the capacitor element. A second external lead member is welded to the electrode lead layer using a conductive adhesive, and the entire circumferential surface of the capacitor element is covered with a resin material. A symbol indicating the month of manufacture, etc. is engraved so that a concave portion is formed in the inner end portion of the second external lead member to which the adhesive is applied.

[Effect]

According to this invention, the symbol indicating the month of manufacture etc. is engraved on the inner end of the second external lead member, so it can be clearly displayed despite the miniaturization of the exterior form, and it also prevents defective accidents. Sometimes, it is possible to accurately determine the cause based on the manufacturing month and manufacturing history.

Moreover, since this display symbol is engraved so that a recess is formed on the surface facing the electrode extraction layer, the conductive adhesive can enter the recess and increase the adhesive strength to the second external lead member. .

〔Example〕

Next, an example of application of the present invention to a chip-type solid electrolytic capacitor will be described with reference to FIGS. 1 and 2.

In the figure, 1 is a capacitor element made by pressure-forming metal powder having a valve action, such as tantalum or aluminum, into a prismatic shape and sintering it, and a metal wire having a valve action is placed at the center of the element as an anode. The leads 2 are planted prior to pressure molding of the metal powder. Note that this anode lead 2 can also be led out by welding to the circumferential surface of the capacitor element 1. An electrode lead layer 3 is formed on the circumferential surface of the capacitor element 1 via an oxide layer, a semiconductor layer, and a graphite layer. On the other hand, for example, a plate-shaped first external lead member 4 is welded to the anode lead 2 of the capacitor element 1.
For example, a plate-shaped second external lead member 5 is connected to the electrode lead layer 3 using a conductive adhesive 6. Note that as the conductive adhesive 6, a silver paste containing silver powder, a binder, and a solvent is suitable. In particular, a symbol 7 indicating the month of manufacture is engraved on the inner end portion 5a of the second external lead member 5 so that a recess is formed on the surface to which the conductive adhesive 6 is applied. The entire circumferential surface of the capacitor element 1 is molded and covered with a resin material 8.
The first and second external lead members 4,
5 is bent along the side and bottom surfaces of the resin material 8.

[Effect of idea]

As described above, according to the present invention, the symbols indicating the month of manufacture, etc. are dispersed and engraved on the inner end portion of the second external lead member, so that the display can be displayed without being influenced by the miniaturization of the exterior form. Symbols can be displayed clearly. Therefore, when a trouble occurs, the cause can be accurately investigated.

Moreover, since this display symbol is engraved so that a recess is formed on the surface to which the conductive adhesive is bonded, the conductive adhesive enters the recess of the engraved mark, increasing the adhesive strength to the second external lead member. can be increased.

[Brief explanation of the drawing]

Figure 1 is a side sectional view showing one embodiment of the present invention, Figure 2
The figure is a perspective view of the inner end portion of the second external lead member. In the figure, 1 is a capacitor element, 2 is an anode lead, 3 is an electrode lead layer, 4 and 5 are first and second external lead members, 5a is an inner end portion, 6 is a conductive adhesive, and 7 is a display symbol , 8 are resin materials.

Claims (1)

[Claims for Utility Model Registration] (1) Forming an electrode lead layer on the circumferential surface of a capacitor element made of metal powder that has a valve action and from which a metal wire that has a valve action is led out as an anode lead. Then, a first external lead member is welded to the anode lead of this capacitor element, a second external lead member is connected to the electrode lead layer using a conductive adhesive, and the entire circumferential surface of the capacitor element is covered with resin. The second external lead member is coated with a conductive adhesive, and a symbol indicating the month of manufacture is engraved so that a recess is formed in the inner end portion of the second external lead member to which the conductive adhesive is applied. solid electrolytic capacitor. (2) The solid electrolytic capacitor according to claim 1, wherein the conductive adhesive is a silver paste containing silver powder and a binder.