JPH07169641A - Formation of electrode of multilayer porcelain capacitor and manufacture of stacked porcelain capacitor - Google Patents

Abstract

PURPOSE:To provide a method for forming an electrode of a multilayer porcelain capacitor by which the electrode can be formed in a very accurate shape and the capacitor can be manufactured at low cost. CONSTITUTION:This method includes a process wherein a peel-off layer 11 is formed on a projecting face of a supporting pallet 9 which forms a desired electrode shape and then a thin-film internal electrode layer 12 is formed on the surface of the peel-off layer 10 and a process wherein the internal electrode layer 12 is thermal-transferred to a dielectric layer 15 for lamination by heating the supporting pallet 9.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In recent years, with the development of ultra-compact, thin and lightweight electronic devices such as radios, microcassette recorders, electronic tuners, video cameras, etc., multilayer porcelain capacitors used as circuit elements have also become smaller and have larger capacities. Has come to be strongly demanded. In order to reduce the size and increase the capacity of the multilayer ceramic capacitor, it is essential to make the dielectric layer thinner.

In a conventional laminated ceramic capacitor, an electrode layer having a desired shape is directly formed on a dielectric green sheet by a screen printing method using an electrode paste. However, since this screen printing method is a wet method, the solvent of the electrode paste redissolves the binder component of the dielectric green sheet, and the dielectric green sheet locally swells or deforms. Further, as the dielectric layer becomes thinner, pinholes are more likely to occur, and when the electrode paste was pressed into contact with the squeegee during screen printing, the electrode paste entered this pinhole, causing a short circuit defect.

Further, in this screen printing method, the thickness of the electrode becomes considerably thick at about 1.5 to 2.5 μm after printing and drying. Therefore, when the stacking is advanced, the pressure at the time of stacking becomes non-uniform in the part where the electrode layer is present and the part where the electrode layer is not present, which causes a structural defect of the sintered body. As measures against these,
As shown in FIG. 5, an electrode material supply band 3 in which an internal electrode layer 2 having a desired shape made of a thin film is formed on a support film 1 is prepared, and the electrode material supply band 3 is hot pressed 5 on a dielectric layer 4. A method has been proposed in which the internal electrode layer 2 is formed on the dielectric layer 4 by thermal transfer using.

Further, as shown in FIG. 6, an electrode material supply band 7 in which an internal electrode layer 6 made of a thin film is formed on a support film 1
A method has also been proposed in which a desired thin film electrode is formed on the dielectric layer 4 by thermal transfer in which a heat press 8 having a concavo-convex shape so as to obtain a desired shape is pressed and thermocompression bonded. JP-A-64-42809).

[0006]

However, in these conventional examples, the support film 1 for the electrode material supply zones 3 and 7 is used.
Since the film is directly heated, after the heat transfer is performed and the electrode layer is formed on the dielectric layer 4, shrinkage, wrinkles, and the like occur in the support film 1, so that the support film 1 cannot be reused, which causes a cost problem. There is. Further, since the support film 1 is deformed, there is a problem in the positional accuracy of the electrodes.

Further, in the conventional example shown in FIG. 5, since the thin film electrode layer 2 on the support film 1 has a desired shape, the thin film electrode layer 2 is formed and then the electrode layer 2 is etched to have a desired shape. Need to be processed. Therefore, the process becomes complicated and there is a cost problem. On the other hand, in the method of pressing with the hot press 8 having a predetermined shape, foil breakage at the time of thermal transfer is deteriorated, and there is a problem in the electrode shape accuracy.

Therefore, an object of the present invention is to provide an electrode forming method for a laminated ceramic capacitor and a manufacturing method for a laminated ceramic capacitor which are excellent in the precision of the electrode shape and can be manufactured at low cost.

[0009]

According to a first aspect of the present invention, there is provided an electrode forming method for a laminated ceramic capacitor, wherein a peeling layer is formed on a convex surface of a supporting pallet having a desired electrode shape, and a thin internal electrode layer is formed on the surface of the peeling layer. And a step of heating the support pallet to thermally transfer the internal electrode layer to the dielectric layer for lamination.

According to a second aspect of the present invention, there is provided an electrode forming method for a laminated ceramic capacitor, wherein the supporting pallet for forming the internal electrodes is made of a rigid plate. A method of manufacturing a laminated ceramic capacitor according to claim 3, wherein a peeling layer is formed on a convex surface of the supporting pallet having a desired electrode shape, and an internal electrode layer made of a thin film is formed on the surface of the peeling layer.
A step of heating the support pallet to thermally transfer the internal electrode layers to the dielectric layer for lamination; a step of sequentially laminating a plurality of dielectric layers having the internal electrode layers by thermal transfer to form a laminated molded body; The step of cutting the molded body into chips, firing and forming external electrodes.

[0011]

According to the method of forming electrodes of the laminated ceramic capacitor of claim 1, since the thin film electrode layer is formed on the support pallet which is formed in advance into a desired shape by stamping or the like, a portion not involved in the formation of the electrode is formed. Since the electrode material is deposited in the recesses, not only the etching process as in the conventional method is not required, but also the steps such as cleaning are omitted even after the electrode formation process until the recessed electrodes are deposited and the distinction between the irregularities disappears. Since a thin film can be continuously formed and electrodes can be successively formed, productivity can be improved and cost can be reduced. Furthermore, since the edge portion of the convex surface can be sharpened, the foil can be cut off much better than the conventional electrode formation by pressing, and the accuracy of the shape of the electrode is excellent.

According to the electrode forming method of the laminated ceramic capacitor of claim 2, in claim 1, since the supporting pallet forming the internal electrodes is made of a rigid plate, there is no deformation due to heat in addition to the function of claim 1. Therefore, the position accuracy of the electrode is improved,
Defects at the time of cutting can be significantly reduced, the production yield can be improved, and the supporting pallet can be reused, so that the cost can be reduced.

According to the method of manufacturing a laminated ceramic capacitor of the third aspect, the laminated ceramic capacitor is manufactured by using the electrode forming method of the laminated ceramic capacitor of the first aspect, whereby high reliability and low cost of the laminated ceramic capacitor are obtained. Can be achieved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a laminated ceramic capacitor using an electrode forming method for a laminated ceramic capacitor according to an embodiment of the present invention will be described with reference to FIGS. That is, first, as shown in FIG. 1, a thickness of 1 m made of a polyimide resin which is a heat-resistant resin engraved in advance to have a desired electrode shape.
A melamine-based release layer 10 is formed on the convex surface of the support pallet 9 of a rigid plate of m, and a thin film internal electrode layer 12 made of nickel and having a thickness of 0.5 μm is formed on the surface of the release layer 10 of the support pallet 9 by a sputtering method. To do.

Next, as shown in FIG. 2, after fixing the support pallet 11 on which the internal electrode layers 12 are formed by the process of FIG. 1 to the hot press 13, it is formed on the support film 14 made of polyester film in advance. And a dielectric layer 15 containing barium titanate as a main component is used as the internal electrode layer 12.
The support pallet 9 is pressed against the support pallet 9 side with the heat press 13 while heating at 130 ° C. and cooled.

Next, as shown in FIG. 3, the internal electrode layer 12
Is thermally transferred to the dielectric layer 15 and then the support pallet 11
The internal electrode layer 1 which was on the support pallet 11 after peeling off
2 is formed on the dielectric layer 15. After transferring the internal electrode layer 12 from one support pallet 11 to the dielectric layer 15, it is replaced with the support pallet 11 on which the internal electrode layer 12 is separately prepared, and the heat press 13 is performed in the same manner as described above. The desired number of dielectric layers 15 are fixed by thermal transfer.
Dielectric green sheet 1 having internal electrode layer 12 formed thereon
6 is formed.

The dielectric layer 15 formed on the support film 14 is designed in advance so that a binder component having a low softening point and a plasticizer are contained in appropriate amounts to enable thermal transfer. After that, as shown in FIG. 4, the supporting film side 1 of the dielectric green sheet 16 on which the internal electrode layers 12 are formed.
4, the dielectric green sheets 16 on which the internal electrode layers 12 are formed are laminated by thermal transfer by repeating thermal compression bonding at 100 ° C. by a heat press 17 and peeling the support film 14 after cooling. Molded body 18
To make. After this is cut into chips and fired, external electrodes are formed according to a usual method to produce a laminated ceramic capacitor.

In the electrode forming method of this embodiment, since a rigid plate made of a heat-resistant resin is used for the supporting pallet 9 for forming the thin internal electrode layer 12, the dielectric layer does not suffer a large thermal strain even when heated at 130 ° C. Since the internal electrode layer 12 can be formed on the electrode 15, the internal electrode layer 12 is not displaced. Therefore, the dielectric green sheet 1 having electrodes formed according to the present invention
When 6 was laminated, there was no large displacement of the electrode position, so even if the laminated molded body 18 was cut, no cutting failure due to the displacement of the electrode occurred.

On the other hand, after forming a 0.5 μm-thick thin film layer of nickel on a polyester support film 1 having a thickness of 50 μm by a conventional method as shown in FIG. 5, etching treatment is performed to obtain a desired shape. When the thin internal electrode layer 2 is formed and then the electrode is formed on the dielectric layer 4 by thermocompression bonding at 130 ° C. by hot pressing, the supporting film 1
However, the internal electrode layer 2 could not be formed at a desired accurate electrode position due to heat shrinkage and wrinkles. Even when the dielectric layers 4 formed with the internal electrode layers 2 having such poor positional accuracy were laminated, the positional deviation of the electrodes was large, and about 80% of cutting defects were generated when the laminated body was cut. Further, in the conventional method, the support film 1 on which the internal electrode layers 2 are printed shrinks due to heat and wrinkles occur so that it cannot be reused. However, in this embodiment, a heat-resistant material having no problem such as heat shrinkage should be used. As a result, it was possible to reuse it, and cost reduction was achieved.

Although the thin-film internal electrode layer 12 is formed by the sputtering method in the above-described embodiment, the electrode may be formed by another thin-film forming method such as the vapor deposition method in the present invention. Further, although the hot press 17 was used in the production of the laminated molded body 18, it goes without saying that the same effect can be obtained even if a hot roll is used.

[0021]

According to the method for forming an electrode of a laminated ceramic capacitor of the first aspect, since the thin film electrode layer is formed on the support pallet which is formed in advance into a desired shape by stamping or the like, it does not participate in the formation of the electrode. Since the electrode material is deposited in the recesses in the parts, not only the etching process as in the conventional method is not required, but also a process such as cleaning is performed after the electrode formation process until the electrodes in the recesses are deposited and the distinction between the unevenness disappears. Since the thin film can be continuously formed and the electrodes can be successively formed without being omitted, the productivity can be improved and the cost can be reduced. Furthermore, because the edge of the convex surface can be sharpened,
Compared with the conventional electrode formation by pressing, foil breakage is much better, and there is an effect that the precision of the electrode shape is excellent.

According to the electrode forming method of the laminated ceramic capacitor of the second aspect, in the first aspect, since the supporting pallet forming the internal electrodes is made of a rigid plate, there is no deformation due to heat in addition to the effect of the first aspect. Therefore, the position accuracy of the electrode is improved,
Defects at the time of cutting can be significantly reduced, the production yield can be improved, and the supporting pallet can be reused, so that the cost can be reduced.

According to the method of manufacturing a laminated ceramic capacitor of claim 3, by manufacturing the laminated ceramic capacitor by using the electrode forming method of the laminated ceramic capacitor of claim 1, high reliability and low cost of the laminated ceramic capacitor are obtained. Can be achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a thin internal electrode layer is formed on a support pallet in an electrode forming process of a laminated ceramic capacitor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a step of transferring an internal electrode layer to a dielectric layer.

FIG. 3 is a cross-sectional view showing a state after transferring an internal electrode layer to a dielectric layer.

FIG. 4 is a cross-sectional view showing a state in which a laminated molded body is formed.

FIG. 5 is a cross-sectional view illustrating an electrode forming method of a conventional laminated ceramic capacitor.

FIG. 6 is a sectional view illustrating an electrode forming method of another conventional laminated ceramic capacitor.

[Explanation of symbols]

 9 Support pallet 10 Release layer 12 Internal electrode layer 15 Dielectric layer

Claims (3)

[Claims] 1. A step of forming a release layer on a convex surface of a support pallet having a desired electrode shape and an internal electrode layer formed of a thin film on the surface of the release layer; and heating the support pallet to form the internal electrode layer. A method of forming an electrode of a laminated ceramic capacitor, the method comprising: 2. The method for forming an electrode of a laminated ceramic capacitor according to claim 1, wherein the support pallet forming the internal electrode is made of a rigid plate. 3. A step of forming a release layer on a convex surface of a support pallet having a desired electrode shape and an internal electrode layer formed of a thin film on the surface of the release layer; and heating the support pallet to form the internal electrode. A step of thermally transferring the layers to a dielectric layer for lamination, a step of sequentially laminating a plurality of the dielectric layers having the internal electrode layers formed thereon by thermal transfer to form a laminated compact, and the laminated compact having a chip shape. A method of manufacturing a laminated ceramic capacitor, including the steps of cutting into pieces, firing, and forming external electrodes.