JPS6286814A - Laminated ceramic capacitor - 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 [Industrial Application Field] The present invention relates to a multilayer ceramic capacitor, and particularly to means for displaying product identifying information on the multilayer ceramic capacitor itself.

[Summary of the Invention] The present invention provides a multilayer ceramic capacitor formed by laminating a plurality of ceramic sheets and then firing them together, in which a ceramic sheet having an indication on one side is 8!
The idea is to include information that identifies the product in the multilayer ceramic capacitor itself by including it in a part of the single-layer ceramic sheet.

[Prior Art] For example, in an electronic component such as a capacitor, its capacitance, rating IJIE, and other characteristics are displayed using the surface of the capacitor. However, since chip-type multilayer ceramic capacitors, for example, are extremely small, there is no room to display information other than capacitance, rated voltage, and other minimum characteristics. Even when it is done, it is only barely achieving its initial purpose by substituting symbols, colors, etc.

Furthermore, information such as the manufacturer, loft number, and processing history cannot be displayed on the bottom of a small multilayer ceramic capacitor. Information such as the manufacturer, rod number, and processing history may be displayed on packaging boxes, bags, etc., but the consumer must manage such information to the extent that it can be traced even after the capacitor has been used. The reality is that there is hardly any system in place.

On the other hand, information such as the manufacturer, loft number, and processing history is undeniably important information that will lead to future improvements in the unlikely event that a capacitor malfunctions. In the past, because such information was not made clear, there were relatively many cases in which the cause of a failure was not thoroughly investigated.

[Problems to be Solved by the Invention] Therefore, the present invention provides information such as characteristics such as capacitance and rated voltage, as well as information such as the manufacturer, rod number, and processing history that can be used as clues to investigate the cause when an abnormality occurs. The purpose is to enable display on the multilayer ceramic capacitor itself.

Means for Solving Problem E] In the present invention, by including a ceramic sheet bearing a display in a part of a plurality of ceramic sheets constituting a multilayer ceramic capacitor, the surface of the multilayer ceramic capacitor is The above-mentioned technical problem is solved by making the part also contribute to the display.

[Function] According to the present invention, the amount of information to be displayed can be arbitrarily increased by increasing the number of layers of the ceramic sheet on which the display is applied. Furthermore, if such a display exists inside a stack of ceramic sheets, the displayed information can be read by gradually polishing the surface of the multilayer ceramic capacitor.

[Embodiment] FIG. 1 shows a plurality of ceramic sheets that constitute a WI layer ceramic capacitor according to an embodiment of the present invention, separated from each other.

As shown in FIG. 1, a plurality of ceramic sheets constituting a multilayer ceramic capacitor include a plurality of inner layer sheets 2a to 2d on which internal electrodes 1a to 1d are formed, respectively, and a plurality of outer layer sheets on which no such internal electrodes are formed. sheet 38
~3g. And a plurality of inner layer sheets 2a
~2d in between, outer layer sheets 3a~3d and outer layer sheet 3
They are laminated with a resistance of 0 to 3 Ω and fired to form the interstitial body.

Conventionally, from the point of view of insulating properties, at least two outer layer sheets 38 to 3g are provided on each side of inner layer sheets 2a to 2d in a normal multilayer ceramic capacitor, and in this embodiment, Among the outer layer sheets 3a to 3g that originally existed in this way, outer layer sheet 3b
It should be noted that the display was performed using ~3g. Therefore, it is not necessarily necessary to take the trouble to use an outer layer sheet on which no internal electrodes are formed in order to provide a display, and therefore, it does not hinder the ability to make the multilayer ceramic capacitor thinner.

In FIG. 1, specific indications are illustrated for the outer layer sheets 3b to 3g. These display rMJ, rX10
3J, r256J, rMRTJ, rKYTJ, rJPN
J is information specifying the product, including manufacturing loft number, characteristics, manufacturer, manufacturing location, and the like. As shown in the figure, in addition to using characters to provide such a display, symbols, figures, etc. may also be used.

The markings on the outer layer sheets 3b to 3g are, for example, materials equivalent to those of the internal electrodes 1a to 1d, other metals such as iron, nickel, gold, and silver, or carbon, alumina, etc. after firing the ceramic. However, any method may be used as long as the traces are recognizable. Further, the provision of such a display is applied to the internal electrodes 1a to 1d.
Similarly, it can be performed, for example, by a printing process.

A plurality of ceramic sheets 3a to 3d shown in FIG. 1,
2a to 2d and 38 to 30 are laminated and fired in the same manner as in the manufacturing process of a normal multilayer ceramic capacitor, and then external electrodes 4a to 4b are applied as shown in FIG. As a result, a desired multilayer ceramic capacitor 5 can be obtained.

As shown in FIG. 2, the markings on the outer sheets 3b to 3g are present inside the laminate 6 and cannot be observed from the outside as they are. Of course, it is also possible to further display on the outer surface of the multilayer ceramic capacitor 5 thus obtained.

For example, when an abnormality occurs in a multilayer ceramic capacitor as shown in FIG. 2, and you are trying to understand the cause and read the display inside the multilayer body 6, it is necessary to polish the capacitor 5 sequentially starting from the top surface. Bye.

That is, referring to FIG. 3, the V4 layer ceramic capacitor 5 is fixed in a suitable direction, and polished, for example, by lapping, while keeping its upper surface flat. As the ceramic sheet immediately above the surface on which the indicia is applied is polished and thinned, the indicia appears and becomes progressively clearer. With further polishing, the previous indicia will be removed and the next new indicia will appear. Third
In the example shown in the figure, the rMJ display gradually appears, then the rX103J display, the r256J display, and so on, as the polishing progresses, the displays embedded inside the multilayer ceramic capacitor 5 are used one after another. These can be read sequentially.

Note that the ceramic sheet on which the display is applied, which is a feature of the present invention, can be placed at any position of one multilayer ceramic capacitor. Regarding the example shown in FIG. 1, the display may be applied to all of the outer layers 1-3a to 3g, or only to any of them.

[Effects of the Invention] As described above, according to the present invention, since a part of the ceramic sheets to be laminated is used and a display is applied thereto, limited values such as capacitance and rated voltage are displayed. In addition to information about the characteristics obtained, the am ceramic capacitor itself can contain a number of product identifying information, including manufacturer, rod number, processing history, etc. The amount of information can be increased virtually infinitely, if necessary, by increasing the number of ceramic sheets on which the display is applied.

As described above, since a variety of information can be provided to the multilayer ceramic capacitor itself, appropriate measures can be taken based on such information, for example, in the event of a failure.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing ceramic sheets, separated from each other, constituting a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2 is a perspective view of a multilayer ceramic capacitor formed by laminating the ceramic sheets shown in FIG. 1. FIG. 3 is a diagram illustrating the process of sequentially polishing the multilayer ceramic capacitor of FIG. 2 and reading the display existing inside. In the figure, 1a to 1d are internal electrodes, 28 to 2d are inner layer sheets (ceramic sheets), 3a to 3g are outer layer sheets (ceramic sheets), 5 is a multilayer ceramic capacitor, 6 is a laminate, and "M". rX103J, r256J, rMRTJ, rKYTJ,
rJPNJ is a display. Name 32. /! ;″

Claims (4)

[Claims] (1) In a multilayer ceramic capacitor in which a plurality of ceramic sheets are laminated, fired as one body, and internal electrodes are embedded, a ceramic sheet with a marking on one side is placed in one of the laminated ceramic sheets. A multilayer ceramic capacitor characterized by comprising: (2) The plurality of ceramic sheets include a plurality of inner layer sheets on which internal electrodes are formed and a plurality of outer layer sheets on which no internal electrodes are formed, and the outer layer sheets are positioned with the plurality of inner layer sheets sandwiched between them. The multilayer ceramic capacitor according to claim 1, wherein the multilayer ceramic capacitor is laminated and the display is applied to at least one of the outer layer sheets. (3) The multilayer ceramic capacitor according to claim 1 or 2, wherein the display displays information specifying the product, including the manufacturer, rod number, processing history, characteristics, etc. (4) The multilayer ceramic capacitor according to any one of claims 1 to 3, wherein the display is present inside the laminate of ceramic sheets.