JPS6055976B2 - Manufacturing method of semiconductor grain boundary insulated multilayer ceramic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor grain-boundary insulated multilayer ceramic capacitor which is small in size, has a large capacity, and is easy to manufacture.

With the recent miniaturization of electrical equipment, there is a strong demand for miniaturization of electronic components.

Multilayer ceramic capacitors have been widely used so far because they are small and can provide large capacitance. If a larger capacity is required, there are limits to miniaturization. It is generally known that semiconductor ceramic capacitors have extremely large capacitance values compared to other capacitors.

However, until now this type of capacitor has only been used as a so-called single capacitor. The present invention has been made in view of the above points, and relates to a method for manufacturing a multilayer capacitor using grain boundary insulated semiconductor porcelain.

First, in the present invention, as shown in Figure 1, porcelain such as barium titanate or strontium titanate, which is generally used for grain boundary insulated capacitors, is processed in the same way as in the production of conventional multilayer capacitors. Form into a sheet 1.

A mixture of a capacitor electrode 2' made of a high-melting point metal such as gold, platinum, or palladium, and a metal oxide 5 for forming a grain boundary insulator such as copper, manganese, or bismuth is kneaded on one plane of the ceramic sheet 1. Apply electrode 2.

This mixture electrode 2 is applied approximately at the center of the porcelain sheet 1 at a predetermined distance from the outer peripheral edge thereof.

Similarly, on one plane of the porcelain sheet 1, the mixture electrode 2
Extracting electrode 3 for leading out to one side end of the porcelain sheet 1
is applied continuously with a portion of the mixture electrode 2. It is preferable that the extraction electrode 3 is formed of the same material at the same time as the mixture electrode 2 is applied. Next, a plurality of ceramic sheets 1 configured in this manner are prepared, stacked so that the extraction electrodes 3 are alternately positioned, and pressed together to form a laminate 4.

The specific means for forming this laminate 4 may be any conventionally known method. Next, this laminate 4 was heated to 1350 to 1
The laminate 4 is fired in a neutral or oxidizing atmosphere at 450'C to form porcelain, and the metal oxide 5 in the mixture electrode 2 is diffused into the grain boundaries of the laminate to form an insulating layer (not shown). ) and then bake the capacitor electrode 2''.

Finally, external connection electrodes 6 are provided on each side end surface (and the vicinity thereof) from which the extraction electrodes 3 are led out of the laminate 4 configured in this way, and conductive connections are made with each capacitance electrode 2''. Then, a semiconductor grain boundary insulated multilayer ceramic capacitor is obtained.

As a means for applying the external connection electrode 6, plating, baking, adhesion, etc. may be used as in the conventional case. The multilayer ceramic capacitor obtained by the manufacturing method of the present invention is constructed in this manner, and has a large capacity in which the dielectric is an insulating layer formed at the grain boundaries of the ceramic.

Therefore, the size can be reduced as much as possible, and the set can be made smaller. Also, according to the present invention. In the above example, there is no need to change the manufacturing process much from the conventional one, and the electrical properties such as dielectric loss, insulation resistance, and temperature change characteristics are almost the same as the conventional one. 4, the metal oxide 5 in the mixture electrode 2 is diffused during firing to form an insulating layer at the grain boundaries, but in order to make the formation of the insulating layer at the grain boundaries more stable, Similar results can be obtained even if the firing is performed in a separate step from step 4.

That is, a laminate 4 formed by stacking and pressing a plurality of porcelain sheets 1 is first fired in a neutral or reducing atmosphere at a temperature of 1,350 to 1,450°C to form the laminate 4 into porcelain. In this case, the metal oxide 5 in the mixture electrode 2 is
It is diffused into the grain boundaries of the laminate 4. Thereafter, the fired laminate 4 is heat-treated in a neutral or oxidizing atmosphere at a temperature of 1,000 to 1,250°C to form the metal oxide diffused into the grain boundaries into a stable insulating layer. The remaining steps and means in this example may be the same as in the previous example, so their explanation will be omitted. Furthermore, the electrical properties of the multilayer ceramic capacitor obtained in this example were almost comparable to those of conventional capacitors. It should be noted that the things that can be easily recognized from the explanation of each of the above examples of the present invention are naturally included in the scope of the present invention, and the present invention is not limited to the above-mentioned examples. I would like to add that there is no such thing.

[Brief explanation of the drawing]

FIG. 1 is a diagram specifically showing the present invention. 1...Porcelain sheet, 2...Mixture electrode, 2''...Capacitance electrode, 3...Extractor electrode, 4...Lamination body, 5...metal oxide, 6...external connection electrode.

Claims (1)

[Claims] 1. A capacitor electrode is formed on one plane of a porcelain sheet using a mixture of a high melting point metal and a metal oxide for forming a grain boundary insulator, leaving a margin at the end, and Continuing with this capacitance electrode, an extraction electrode for leading out this capacitance electrode to one side end of the porcelain sheet is formed, and a plurality of porcelain sheets are connected to each other.
The extraction electrodes are alternately stacked and pressed together to form a laminate, and this laminate is fired in a neutral or oxidizing atmosphere, and this firing turns the laminate into porcelain and crystallizes the laminate. 1. A method for manufacturing a semiconductor grain boundary insulated multilayer ceramic capacitor, comprising simultaneously forming an insulating layer on the grain boundaries, and then providing external connection electrodes on each lead-out end face of the lead-out electrode. 2. A capacitor electrode is formed on one plane of the porcelain sheet using a mixture of a high-melting point metal and a metal oxide for grain boundary insulator, leaving a margin at the end, and a continuous electrode is formed on this capacitor electrode. Then, an extraction electrode for leading out this capacitor electrode to one side end of the porcelain sheet is formed, and a plurality of porcelain sheets are
The extraction electrodes are alternately stacked and pressed together to form a laminate, and this laminate is fired in a neutral or reducing atmosphere, and then heat-treated in a neutral or oxidizing atmosphere to remove grain boundaries. 1. A method for manufacturing a semiconductor grain-boundary insulated multilayer ceramic capacitor, comprising stably forming an insulating layer, and then providing an external connection electrode on the lead-out end face of the lead-out electrode.