JPH05299287A - Laminated porcelain capacitor green sheet and manufacture of the capacitor using the green sheet - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a laminated porcelain capacitor where a dielectric layer is thin and which is stable in quality and enhanced in degree of lamination and productivity, where the laminated porcelain capacitor is used as a circuit element in various kinds of electronic equipments. CONSTITUTION:A dielectric layer 2 which can be transferred onto a transfer subject 7 by thermocompression is formed on a support 1, and an engraved part 3, which has the same shape as with a prescribed capacitor electrode layer 4 and a depth of d smaller than the thickness of the electrode layer 4, is provided to the surface of the dielectric layer 2, and the electrode layer 4 is formed through the engraved part 3, where a level difference between a part where an electrode is formed and another part where no electrode is formed is lessened, so that laminating pressure can be set uniform when the electrode layers 4 are formed, and the transfer subject 7 is hardly delaminated even if it is burned, subsequently a laminated porcelain capacitor of this design can be enhanced in production yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated porcelain capacitor green sheet which does not cause lamination defects in the production of laminated porcelain capacitors used in radios, microcassette recorders, electronic tuners, video cameras and the like, and a laminated sheet using the same. The present invention relates to a method for manufacturing a porcelain capacitor.

[0002]

2. Description of the Related Art A method for manufacturing a laminated porcelain capacitor is one in which a slurry having a dielectric powder, a binder, a plasticizer and an organic solvent is used and a doctor blade method or the like is used to form a ceramic film having a thickness of ten and several μm on a support such as an organic film. Prepare a dielectric green sheet, peel off the one with electrodes printed on it from the support, stack a plurality of sheets, make a laminated molded body by pressure bonding, and then cut into chips with predetermined dimensions and bake After that, an external electrode is generally provided to produce the electrode.

Recently, the demand for smaller size and larger capacity of laminated ceramic capacitors has been further strengthened, and for that purpose, it is indispensable to make the dielectric layers thin and highly laminated, that is, increase the number of laminated layers. However, as the dielectric layer becomes thinner, it becomes almost impossible from the viewpoint of handling to peel and laminate the dielectric layers formed on the support one by one from the support. Therefore, a method in which a dielectric layer is formed on a support, an electrode layer is formed on the surface of the dielectric layer, the dielectric layer and the electrode layer are transferred by pressure bonding from the support side, and then the support is peeled off and laminated. Is proposed. (For example:
7577). When laminated by this method, the dielectric layer and the electrode layer are integrally pressure-bonded to the support, and therefore the dielectric layer and the electrode layer are easily covered with the support even if the dielectric layer is so thin that it cannot be handled. Can be laminated to a copy.

A conventional green sheet for a laminated ceramic capacitor will be described below. As shown in FIG. 4, a doctor blade was slurried on a support 1 made of a polyester film and containing a dielectric powder containing barium titanate as a main component, a phthalate ester-based plasticizer and a binder containing a bratil resin as a main component. 15μ thickness formed by the method
As shown in FIG. 5, after printing a commercially available palladium paste on the surface of the dielectric layer 2 having a thickness of m by a screen printing method to form an electrode layer 4 having a thickness of 3 μm, as shown in FIG.
The surface 6 side of the support 1 on which the dielectric layer 2 is not formed is heat-pressed by using a heat press 5 to perform the dielectric layer 2 and the electrode layer 4
Is transferred to the object 7 placed on the table 8, and the step of peeling the support 1 is repeated a predetermined number of times to obtain a laminated molded body in which a predetermined number of dielectric layers 2 and electrode layers 4 are laminated.

As described above, when a green sheet having the electrode layer 4 formed on the surface of the dielectric layer 2 formed on the support 1 is laminated by heating and transferring the dielectric layer 2 and the electrode layer 4, a high lamination is achieved. In the portion where the electrode is formed and the portion where the electrode is not formed, the thickness of the portion where the electrode is formed becomes thicker than the portion where the electrode is not formed by the thickness of the electrode. Therefore, when hot-pressing with a flat plate such as a heat press 5,
Since the laminating pressure is higher in the portion where the electrodes are formed than in the portion where the electrodes are not formed, the laminating pressure becomes non-uniform. For this reason, a stacking failure due to a transfer failure occurs, and the manufacturing yield of the highly stacked molded body deteriorates. Further, even if a molded product that is likely to suffer from such a stacking failure is fired to produce a sintered product, delamination occurs, the quality deteriorates, and the productivity deteriorates.

[0006]

As described above, in the conventional structure, even if it can be applied to a low-lamination product without any problem, a lamination defect will occur as the number of layers increases, so that a laminate having a high degree of lamination can be produced. In addition, there is a problem that the manufacturing yield of the product is significantly deteriorated, and when manufacturing a laminated ceramic capacitor by firing a laminated molded body in which these lamination defects are feared, delamination easily occurs due to the lamination defect and the quality deteriorates. It had a problem that productivity deteriorates.

The present invention solves the above-mentioned problems of the prior art. A green sheet for a laminated ceramic capacitor in which a dielectric layer is thin and a lamination failure does not occur even with a high number of laminations, and a quality using the green sheet is stable and produced. An object of the present invention is to provide a method for manufacturing a laminated ceramic capacitor having high properties.

[0008]

In order to achieve this object, a green sheet for a laminated ceramic capacitor of the present invention and a method for manufacturing a laminated ceramic capacitor using the same are provided with a predetermined electrode formed on the surface of a dielectric layer. It has the same shape as the layer and the engraved part whose depth is less than the thickness of the electrode layer.After forming the electrode layer in the engraved part, from the surface side of the support opposite to the dielectric layer. In this method, the electrode layer and the dielectric layer are transferred to the object by heating and pressure bonding, and then the support is peeled off and laminated.

[0009]

In this structure and method, the step between the part where the electrode is formed and the part where the electrode is not formed becomes small, the pressure during pressing becomes uniform, and delamination during baking is prevented. Become.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 showing an embodiment of the present invention, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 1 and 2, the present embodiment is characterized in that a predetermined capacitor electrode layer is formed on the surface of the dielectric layer 2 formed on the support 1 in the above-described conventional structure. This is because the engraved portion 3 having the same shape as that of the above and having a depth d less than the thickness of the electrode layer is added. When the electrode layer 4 having the same thickness as that of the conventional method is printed on the engraved portion 3 as shown in FIG. 3, the step difference between the portion where the electrode is formed and the portion where the electrode is not formed is equal to the depth d of the engraved portion 3. Compared to the conventional example,
The step difference between the portion where the electrode is formed and the portion where the electrode is not formed becomes small. Therefore, the pressure uniformity at the time of thermocompression bonding with the hot press described in the conventional example with reference to FIG. 6 is improved,
The manufacturing yield of the high-lamination molded product is improved. Further, even if a sintered body is produced, delamination can be significantly suppressed, the quality is stable, and the productivity can be improved.

When the depth d of the engraved portion 3 is set to be equal to or larger than the thickness of the electrode layer 4 and the electrodes are printed on the engraved portion 3 and then the electrodes are laminated, when the layers are transferred by hot pressing, the electrode layer 4 and the dielectric material are not transferred. A void is formed between the layers 2, and the portion where the electrode is formed is less likely to receive the laminating pressure than the portion where the electrode is not formed, resulting in non-uniformity of the laminating pressure, which is a cause of laminating failure.

The transfer rate of the green sheet for laminated ceramic capacitors according to the present embodiment, the transfer rate of the green sheet for laminated ceramic capacitors of the conventional example, and the lamination of the comparative example in which the depth d of the engraved portion 3 is made equal to or larger than the thickness of the electrode layer 4. The transfer rate of the green sheet for a porcelain capacitor is shown in comparison with (Table 1).

[0015]

[Table 1]

In all of the examples, conventional examples and comparative examples, the dielectric layer 2 was formed to a thickness of 15 μm by the doctor blade method, the depth d of the engraved portion 3 of the example was 2.7 μm, and the engraved portion 3 of the comparative example was formed. The depth d is 3.5 μm. The electrode layer 4 was printed so that the thickness of each of the three examples was 3 μm.

Using each of the green sheets produced as described above, the heat press 6 was operated at 100 ° C. for 7 hours as described with reference to FIG.
The transferability of the laminated moldings of each layer number of 10 to 150 layers under the pressure of 0 kg / cm ² is shown in the transfer rate (Table 1) for each layer number.

The transfer rate of 100% means that the dielectric layer 2 and the electrode layer 4 are completely transferred to the object 7 and the transfer rate is 5%.
0% means 50% transferred to the object 7 and 50% transferred to the support 1.
It shows the state of being left untransferred.

As is clear from this (Table 1), the laminated ceramic capacitor green sheet according to the present embodiment has 15
Even in a high-lamination product having 0 layers, since the step between the portion where the electrode is formed and the portion where the electrode is not formed is small, the lamination pressure is evenly applied and the lamination is good. The transferability is good, but if the number of stacked layers is further increased, the transferability gradually deteriorates. On the other hand, in the comparative example in which the depth d of the engraved portion 3 is equal to or larger than the thickness of the electrode 4, the transferability is poor even in the case of low stacking.

After cutting each of the laminated compacts shown in Table 1 into chips, the section of the sintered compact which was fired under the firing condition of holding at 1320 ° C. for 2 hours according to a usual method was observed by an electron microscope, and the The incidence of lamination was measured. The results are shown in (Table 2).

[0021]

[Table 2]

As is clear from this (Table 2), in the sintered bodies of the conventional example and the comparative example, the delamination rate increased as the number of layers increased, but the green for laminated ceramic capacitors of this example It can be seen that the sintered body using the sheet has extremely good productivity without the occurrence of delamination.

As described above, according to this embodiment, the support 1 is provided with the dielectric layer 2 which is composed of the dielectric powder, the binder, the plasticizer, and the like, and which is preformed so as to enable the heat transfer. A green sheet for a laminated ceramic capacitor having an engraved portion 3 having the same shape as that of the electrode layer 4 of a predetermined capacitor and having a depth d less than the thickness of the electrode layer 4 is prepared on the surface of the dielectric layer 2. After forming the electrode layer 4 on the engraved portion 3 of the dielectric layer 2, the electrode layer 4 and the dielectric layer 2 are subjected to thermocompression bonding from the surface side of the support 1 on the side opposite to the dielectric layer 2. When the support 1 is peeled off and laminated after thermal transfer to No. 7, the support 1, the dielectric layer 2 and the electrode layer 4 can be integrated and laminated by thermal transfer even if the dielectric layer 2 is thin. Became easier and could not be done in the conventional example Laminate even dielectric layer 2 a thin Te because becomes possible. Further, since the electrode layer 4 is formed on the engraved portion 3 provided on the surface of the dielectric layer 2, the step difference between the portion where the electrode is formed and the portion where the electrode is not formed can be made smaller than that of the conventional example, so that the lamination pressure is uniform. It is possible to improve the property and to produce a highly laminated molded body with stable quality. Delamination does not occur even if this laminated molded body having excellent lamination uniformity is fired to produce a sintered body, the productivity can be remarkably improved, and its industrial value is extremely high.

[0024]

As is apparent from the above description of the embodiments, the present invention engraves the same shape as a predetermined electrode layer formed on the surface of the dielectric layer and having a depth less than the thickness of the electrode layer. After the electrode layer is formed on the engraved portion, the electrode layer and the dielectric layer are transferred to the object by thermocompression bonding from the surface side of the support opposite to the dielectric layer. After that, by peeling the support and stacking it, the dielectric layer is thin, and an excellent green sheet for laminated ceramic capacitors that does not cause stacking failure even with a high number of stacked layers, and the quality using it is stable and highly productive. It is possible to realize an excellent method for manufacturing a laminated ceramic capacitor.

[Brief description of drawings]

FIG. 1 is a schematic oblique view showing the concept of a green sheet for a laminated ceramic capacitor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a schematic cross-sectional view of an electrode layer formed on a green sheet for a laminated ceramic capacitor according to an embodiment of the present invention.

FIG. 4 is a schematic sectional view of a conventional green sheet for a laminated ceramic capacitor.

FIG. 5 is a schematic cross-sectional view of an electrode layer formed on a green sheet for the same laminated ceramic capacitor.

FIG. 6 is a schematic front sectional view showing the concept of a lamination process of a laminated ceramic capacitor.

[Explanation of symbols]

 1 Support 2 Dielectric Layer 3 Engraving

Claims (2)

[Claims] 1. A support and a dielectric layer formed on the support so as to be transferred to an object by thermocompression beforehand, and a predetermined dielectric layer formed on the surface of the dielectric layer. A green sheet for a laminated porcelain capacitor having an engraved portion having the same shape as the shape of the electrode layer of the capacitor and having a depth less than the thickness of the electrode layer. 2. After forming an electrode layer on the engraved portion of the dielectric layer of the green sheet for laminated ceramic capacitors according to claim 1, heating from the surface opposite to the support on which the dielectric layer is formed. A method for manufacturing a laminated porcelain capacitor, which comprises pressure-bonding to thermally transfer the electrode layer and the dielectric layer onto an object, and then peeling off the support to laminate the support.