JPH06333774A - Method for forming electrode of stacked porcelain capacitor and manufacture of stacked porcelain capacitor using the method - Google Patents

Abstract

PURPOSE:To enhance the positional accuracy of an internal electrode, to increase the degree of integration, and to reduce the cost of a stacked porcelain capacitor to be used as a circuit element of various kinds of electronic equipments in manufacturing thereof. CONSTITUTION:A thin-film electrode 4 formed on one face of a supporter pallet 3 which is made by forming a peel-off layer 2 on one face of a rigid body 1 is placed face to face with a front face 8a of a dielectric layer 8 and then are bonded to the front face 8a by heating the electrode by a thermal press 10 from a face 9 of the supporter pallet 3 to form an internal electrode layer 11. After that, a dielectric layer 6 of a dielectric green sheet is placed face to face with the dielectric layer 8 on which the internal electrode layer 11 is formed and then only the dielectric layer 6 is stacked by thermal transfer on the dielectric layer 8 by means of the thermal press 10. This job is repeated until the internal electrode layers 11 are stacked in the specified number of laminations and a stacked body constituted of the stacked internal electrode layers 11 and the dielectric layer 6 is obtained. Nextly the stacked body is cut into chips and burned and then an external electrode is formed. By this method, a good accuracy is achieved for the internal electrode layer 11. And, the supporter pallet 3 can be reused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming an internal electrode of a laminated ceramic capacitor and a method of manufacturing a laminated ceramic capacitor using the method.

[0002]

2. Description of the Related Art In recent years, with the development of ultra-small, thin and lightweight electronic devices such as radios, microcassette recorders, electronic tuners, video cameras, etc., there has been a strong demand for miniaturization and large capacity of laminated porcelain capacitors used as circuit elements. It started to come. In order to reduce the size and increase the capacity of the laminated ceramic capacitor, it is essential to make the dielectric layer thinner. In the conventional laminated porcelain capacitor, an electrode layer is formed directly on a dielectric green sheet by a screen printing method so as to have a desired shape. Since this method is wet, the solvent of the electrode paste redissolves the binder component of the dielectric green sheet, and the dielectric green sheet swells locally,
It transforms. Further, as the dielectric layer becomes thinner, pinholes are more likely to occur, and when the electrode paste is pressed into contact with the squeegee in screen printing, the electrode paste penetrates into this pinhole, causing a short circuit defect.

On the other hand, when electrodes are formed by a screen printing method or the like as the number of layers is increased, the electrode thickness becomes considerably large. The portion where the electrode is formed is thicker than the portion where the electrode is not formed. Therefore, in the case of thermocompression bonding with a flat plate such as a press, the laminating pressure becomes higher in the portion where the electrodes are formed than in the portion where the electrodes are not formed, so that the laminating pressure becomes non-uniform and internal structural defects occur.

As a countermeasure for these problems, a thermal transfer method in which the electrode thickness is remarkably thinner than that in the screen printing method and the electrode is formed by a dry method, and an invention for improving the accuracy of the internal electrode has been made (for example, JP-A-64). -42809 publication,
See Japanese Patent Laid-Open No. 3-108709).

A method of forming electrodes of a conventional laminated ceramic capacitor will be described below. As shown in FIG. 6, after preparing an electrode material supply zone 23 in which a thin film electrode layer 22 having a desired shape is formed on a support film 21, a thin film is formed on the dielectric layer 24 by thermal transfer using a heat press 25 or the like. Internal electrode 2
6 is formed.

[0006]

However, in the above-described conventional method, the surface of the support film 21 which is the support of the electrode material supply zone 23 on which the thin film electrode layer 22 is formed is directly heated for thermal transfer, and the thin film electrode is then transferred. Layer 22 to dielectric layer 24
After being formed on the support film 21, there is a problem that the support film 21 shrinks and wrinkles and cannot be reused, resulting in high cost, and the support film 21 is deformed, so that the positional accuracy of the internal electrodes 26 deteriorates. Had.

The present invention solves the above-mentioned problems of the prior art, and is a method for forming an electrode of a laminated ceramic capacitor which has good internal electrode position accuracy and can reduce cost, and a laminated ceramic capacitor using the method. It is intended to provide a manufacturing method.

[0008]

In order to achieve this object, an electrode forming method of a laminated ceramic capacitor of the present invention and a manufacturing method of a laminated ceramic capacitor using the method are a support made of a rigid plate having a peeling layer. A thin film electrode formed in a predetermined shape on the pallet is pressure-bonded while heating the support pallet, and is thermally transferred to the surface of the dielectric layer to form the internal electrode layer. The thin film electrodes on the above-mentioned support pallet are superposed on the surface of the dielectric layers that are made by stacking multiple dielectric layers so that they can be transferred to an object, and then heat compression is applied from the side where the thin film electrodes are not formed. After forming the internal electrode layer on the surface of the dielectric layer by thermal transfer, heat transfer lamination is performed again on the surface of the dielectric layer on which only the dielectric layer on the dielectric green sheet is electrode-formed. The operation of forming the internal electrode layer by thermal transfer of the thin film electrode on the carrier pallet onto the dielectric layer is repeated, and the internal electrode layer and the dielectric layer are repeatedly laminated up to a predetermined number of layers, and then the dielectric green sheet. A laminated molded body obtained by stacking a plurality of upper dielectric layers,
Alternatively, after forming a thin film electrode on the support pallet on the surface of the dielectric layer on the support film that enables transfer to the object by thermocompression in advance, heat pressing from the support film surface side A thin film electrode and a dielectric layer were simultaneously transferred by thermal transfer to a dielectric layer on which another electrode was formed, and the dielectric layer on the supporting film was repeatedly laminated until a predetermined number of laminated layers were obtained. This is a method in which a laminated molded body is cut into chips and fired, and then external electrodes are formed to obtain a laminated ceramic capacitor.

[0009]

In this method, since the support pallet on which the thin film electrode for the internal electrode is formed is made of a rigid plate, deformation due to heating does not occur and the positional accuracy of the internal electrode is improved, so that the support pallet can be reused. Is possible.

[0010]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a rigid plate 1 made of a polyimide resin, which is a heat-resistant resin having a thickness of 1 mm, has a release layer 2 formed of a melamine-based material on one side thereof. The thin film electrode 4 made of nickel and having a thickness of 0.1 μm is formed by the method so as to have a predetermined internal electrode shape. Further, as shown in FIG. 2, a dielectric layer 6 having a thickness of 15 μm is formed on one side of the polyester support film 5 by a doctor blade method which enables thermal transfer by containing an appropriate amount of a binder component having a low softening point and a plasticizer. Then, the dielectric green sheet 7 is obtained.

As shown in FIG. 3A, the surface 8 of the dielectric layer 8 in which 20 dielectric green sheets 7 are laminated by thermal transfer.
a and the thin film electrode 4 on the support pallet 3 face each other,
As shown in FIG. 3 (b), the hot press 10 is applied to the surface 9 side of the support pallet 3 on which the thin film electrodes 4 are not formed.
While heating at 30 ° C., pressure is applied in the direction of the white arrow. Then, as shown in FIG. 3C, when the support pallet 3 is cooled and then the support pallet 3 is peeled off, the thin film electrode 4 on the support pallet 3 is thermally transferred to the dielectric layer 8 and the internal electrode 11 is removed. It is formed. Then, as shown in FIG.
The dielectric layer 6 of the dielectric green sheet 7 is opposed to the dielectric layer 8 on which the internal electrodes 11 are formed, and the heat press 10 is performed.
Thus, only the dielectric layer 6 is laminated by thermal transfer, and a thin film electrode formed on another support pallet is formed on the dielectric layer 6 by thermal transfer. Further, the dielectric layer of the dielectric green sheet is laminated thereon by thermal transfer in the same manner as described above. By repeating this operation, a laminated molded body having 150 layers was produced. After cutting this into chips, each chip-shaped molded body was subjected to 1300 ° C. in a reducing atmosphere,
External electrodes were formed on the sintered body that had been fired under the firing conditions of holding for 2 hours by a usual method to produce a laminated ceramic capacitor.

As described above, according to this embodiment, since the thin film electrode 4 having a thickness of 0.5 μm is used as the internal electrode 11, the step between the portion where the internal electrode 11 is formed and the portion where it is not formed is extremely small. It is possible to produce a highly laminated laminate of 150 layers. Further, since the rigid plate 1 made of heat-resistant resin is used for the support pallet 3 on which the thin film electrodes 4 are printed, it is possible to form electrodes on the dielectric layer 8 without receiving large thermal strain even when heated at 130 ° C. There is no deviation. Therefore, even in the case of a highly-laminated molded body having 150 layers, the cutting yield due to the displacement of the electrodes does not occur at the time of cutting, and the production yield can be improved.

As a comparative example, the above-mentioned conventional method, that is, FIG.
As shown in FIG. 1, an electrode material supply band 23 in which a thin film electrode 22 is formed on a polyester support film 21 having a thickness of 50 μm so as to have a predetermined electrode shape
In the method of forming the internal electrodes 26 on the dielectric layer 24 by thermocompression bonding at 30 ° C., shrinkage and wrinkles due to heat are generated in the polyester support film 21, and the internal electrodes 26 are formed at desired accurate electrode positions. However, when the dielectric layers 24 having the internal electrodes 26 with poor positional accuracy were stacked, the positional displacement of the internal electrodes 26 increased, and a cutting failure of about 60 to 80% occurred when the laminated molded body was cut.

In the conventional method, the polyester support film 21 on which the thin film electrodes 22 are printed shrinks and wrinkles due to heat and cannot be reused. In this embodiment, however, a heat-resistant material having no problem such as heat shrinkage is used. Since it is used, it can be reused and reduced in cost, and its industrial value is extremely high.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 4A, after the thin film electrode 4 of the support pallet 3 described in the first embodiment is opposed to the dielectric layer 6 of the dielectric green sheet 7 described in the first embodiment, As shown in FIG. 4B, the support pallet 3 on which the thin film electrodes 4 are not formed is heated by a heat press 10 at 130 ° C. from the side of the support pallet 3 and pressure-bonded in the direction of the white arrow. Then, as shown in FIG. 4C, after the support pallet 3 is cooled, when the support pallet 3 is peeled off, the thin film electrode 4 on the support pallet 3 is thermally transferred to the dielectric layer 6, and the internal electrode 11 is removed. It is formed.

As shown in FIG. 5 (a), after the green sheet 7 having the internal electrodes 11 formed thereon faces the dielectric layer 8 described in the first embodiment, the surface of the support film 5 is hot pressed. While heating at 130 ° C. using No. 10, pressure is applied in the direction of the white arrow. Then, as shown in FIG. 5B, after the supporting film 5 is cooled, the supporting film 5 is peeled off to simultaneously form the internal electrodes 11 and the dielectric layer 6 of the supporting film 5 on the dielectric layer 8 by thermal transfer. To do. This operation was repeated to produce a laminated molded body having 150 layers. After cutting this into chips, the external electrodes are formed by a normal method on the sintered body obtained by firing the respective chip-shaped formed bodies in a reducing atmosphere at 1300 ° C. for 2 hours to form a laminated ceramic capacitor. It was made.

As described above, according to this embodiment, the same effect as that of the first embodiment can be obtained. In the first and second embodiments, the heat-resistant resin is used as the support pallet 3 on which the thin film electrodes 4 are printed, but a rigid plate made of metal such as stainless steel may be used without any problem. Further, the sputtering method was used as a printing method for the support pallet 3,
The same effect can be obtained by using a thin film forming method such as vacuum deposition. Further, although the hot press 10 was used for the production of the laminated molded body, the same effect can be obtained even if a hot roll is used.

[0020]

As is apparent from the above description, according to the present invention, a thin film electrode formed in a predetermined shape is pressure-bonded on a support pallet made of a rigid plate having a release layer while heating the support pallet. A method of forming an internal electrode layer by thermal transfer onto the surface of a dielectric layer, and a method of forming a plurality of dielectric layers on a supporting film that can be transferred to an object by thermocompression beforehand on the surface of the dielectric layer described above. After stacking the thin-film electrodes on the support pallet and heating and pressure bonding from the surface side where the thin-film electrodes are not formed to form the internal electrode layer on the surface of the dielectric layer by thermal transfer, from above it on the dielectric green sheet Only the dielectric layer of the above is laminated by thermal transfer on the surface of the dielectric layer on which the electrodes have been formed, and then the thin film electrode on the support pallet is again thermally transferred on the dielectric layer to form the internal electrode layer. The internal electrode layers and the dielectric layers are repeatedly laminated up to a predetermined number of laminated layers, and thereafter, a laminated molded body obtained by stacking a plurality of dielectric layers on the dielectric green sheet, or by thermocompression bonding in advance. After forming a thin film electrode on the support pallet on the surface of the dielectric layer on the support film that enables transfer to the object, heat and pressure bonding from the surface side of the support film The formed dielectric layer is repeatedly transferred to the dielectric layer on which another electrode is formed by thermal transfer of the thin film electrode and the dielectric layer until the predetermined number of layers is obtained, and the laminated molded body is obtained in a chip shape. By the method of forming an external electrode after cutting and firing into a laminated ceramic capacitor, the method for forming an electrode of a laminated ceramic capacitor is excellent in that the positional accuracy of the internal electrodes is good and the cost can be reduced. The method in which the production method of the multilayer ceramic capacitor can be realized using.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a support pallet in a method for forming electrodes of a laminated ceramic capacitor according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a dielectric green sheet in the method for manufacturing the same laminated ceramic capacitor.

3 (a), (b), (c), and (d) are cross-sectional views of essential parts showing the steps of producing a laminated body in the method for producing a laminated ceramic capacitor according to the first embodiment of the present invention.

4 (a), (b) and (c) show the steps of producing an internal electrode layer on a dielectric layer of a dielectric green sheet in the method for producing a laminated ceramic capacitor according to the second embodiment of the present invention. Sectional view

5 (a) and 5 (b) are cross-sectional views of a main part showing a step of producing a laminated compact in the method for producing a laminated ceramic capacitor, respectively.

FIG. 6 is a sectional view of an essential part showing a method for forming electrodes of a conventional laminated ceramic capacitor.

[Explanation of symbols]

 1 Rigid Plate 2 Release Layer 3 Support Palette 4 Thin Film Electrode 5 Support Film 6 Dielectric Layer 10 Heat Press (Heating Means) 11 Internal Electrode Layer

Claims (3)

[Claims] 1. A thin film electrode formed in a predetermined shape on a support pallet made of a rigid plate having a peeling layer is pressure-bonded while heating the support pallet by a heating means to thermally transfer to the surface of a dielectric layer. An electrode forming method for a laminated ceramic capacitor, which comprises forming an internal electrode layer by using the following method. 2. A support made of a rigid plate having a peeling layer on the surface of a dielectric layer formed by stacking a plurality of dielectric layers on a support film capable of being transferred to an object by thermocompression bonding. A thin film electrode formed in a predetermined shape is superposed on a body pallet, an internal electrode layer is formed on the surface of the dielectric layer by thermal transfer, and then the support is formed by thermal transfer on the surface of the dielectric layer on which the internal electrode layer is formed. After laminating one layer of the dielectric on the film, repeat the operation of stacking the thin film electrodes formed in the predetermined shape on the support pallet again and thermally transferring to form the internal electrode layer, and repeating the operation to obtain the predetermined number of layers. After repeatedly stacking the internal electrode layer and the dielectric layer until the above, a laminated molded body formed by stacking a plurality of dielectric layers on the supporting film is cut into chips and fired to form external electrodes. Method of manufacturing a multilayer ceramic capacitor and symptoms. 3. An internal electrode layer formed by the method according to claim 1 on the surface of one layer of a dielectric material on a supporting film which can be transferred to an object by thermocompression bonding. After stacking a plurality of one-layered dielectrics on the surface of the dielectric layer and repeatedly thermally transferring the internal electrode layer and the dielectric layer on the support film at the same time until a predetermined number of layers are laminated, A method for manufacturing a laminated porcelain capacitor, characterized in that a laminated molded body formed by stacking a plurality of one-layered dielectrics on the support film is cut into chips and fired to form external electrodes.