JPH09237737A - Method for manufacturing laminated ceramic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminated ceramic capacitor in which variations of volume are reduced and cracks and delamination does not generate by a method wherein printing slippage of conductive paste is prevented and a paint film of a specific thickness is obtained. SOLUTION: This manufacturing method comprises: a step of printing a desired pattern 7 using conductive paste on a ceramic green sheet 2; a step of stacking the plurality of ceramic green sheets 2 on which the pattern 7 is printed; and a step of burning a laminated molding. In this embodiment, in the pattern printing step, this pattern 7 is transferred from a printed board 3 formed with the desired pattern 7 with the conductive paste to a transferer 1, and the transferer 1 is pressed to the ceramic green sheet 2 at pressure 0.05 to 5kg/cm<2> so that the pattern 7 is transferred to the ceramic green sheet 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated ceramic capacitor in which a desired pattern is printed on a ceramic green sheet, a plurality of the ceramic green sheets are laminated and fired.

[0002]

2. Description of the Related Art Conventionally, electronic parts such as monolithic ceramic capacitors are coated with a conductive paste on a ceramic green sheet by a screen printing method or the like to form a desired pattern, and a plurality of the ceramic green sheets are laminated. It was produced by a so-called sheet laminating method in which it is then sintered.

Further, the ceramic green sheet is
Generally, alumina (Al ₂ O ₃ ) or mullite (3) is used depending on the electrical and thermal characteristics required as a substrate material.
Al ₂ O ₃ · 2SiO ₂ ), aluminum nitride (Al
N) or various ceramic raw material powders such as barium titanate (BaTiO ₃ ), a binder composed of an organic additive and a solvent is added to prepare a ceramic slurry, and the ceramic slurry is formed into a band-shaped carrier film by a doctor blade method. It is produced by continuously applying the coating on top and then drying.

In recent years, demands for light weight and miniaturization of various electronic parts have become stricter, and in order to satisfy the demands, the sheet thickness per layer is made thinner, the number of layers is further increased, and laminated ceramics are also used. For capacitors,
In order to realize smaller size and larger capacity, use of a dielectric material having a high dielectric constant and further reduction of the sheet thickness have been performed.

[0005]

However, in the above-described conventional manufacturing method, since the screen printing method is used when printing the conductive paste, there are various problems as described below.

That is, for example, when a conductive paste is printed on a rectangular area on a ceramic green sheet, in the conventional screen printing method, the printing size and the printing position of the conductive paste vary by about ± 15 μm. It was
As a result, when a multilayer capacitor was constructed, the obtained capacitance tended to vary among the obtained products. Moreover, the variations in the print size and print position are not constant, and tend to increase as the screen mesh deteriorates.

Further, in the screen printing method, generally, a conductive squeegee is printed while scraping the conductive paste on the mesh screen while applying a constant pressure with a rubber squeegee. Tend to be thin, while those with a small printing area tend to be thickly printed. Furthermore, when the coating film thickness is reduced, the metal powders in the print pattern are non-uniformly aggregated to form a bead, or the print pattern is faint, and the continuity of the electrode cannot be maintained. As a result, the capacity is reduced, cracks and delamination occur between the ceramic layer and the conductor layer.

As described above, the conventional screen printing method has a very serious problem in that it is impossible to prevent a considerable amount of print deviation and, moreover, the print deviation increases with time due to deterioration of the screen mesh. Therefore, in the case of electronic components that are becoming smaller and have larger capacities, variations in characteristics such as the obtained capacitance cannot be ignored due to the print misalignment as described above. In addition, there is a problem in that there is a variation in capacitance due to variations in coating film thickness and the fading of the conductor layer, a reduction in capacitance, and cracks and delamination occur.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to prevent printing deviation of a conductive paste and obtain a coating film having a constant thickness so that there is little variation in capacity and cracking. Another object of the present invention is to provide a method for manufacturing a monolithic ceramic capacitor that does not cause delamination.

[0010]

A method of manufacturing a laminated ceramic capacitor according to the present invention comprises a step of printing a desired pattern on a ceramic green sheet by using a conductive paste, and a ceramic green sheet on which the pattern is printed. In a method of manufacturing a laminated ceramic capacitor, which comprises a step of laminating a plurality of layers and a step of firing the laminated molded body, the pattern printing step comprises forming the pattern from a printing plate on which a desired pattern is formed by the conductive paste. Transfer to a transfer member, and press the transfer member at a pressure of 0.05 to 5 kg /
In this method, the pattern is transferred to the ceramic green sheet by pressing the ceramic green sheet with cm ² .

Also, a step of printing a desired pattern on the ceramic green sheet using a conductive paste,
Lamination comprising a step of forming a ceramic green sheet on the pattern, a step of producing a laminated compact by repeating the pattern printing step and the ceramic green sheet forming step, and a step of firing the laminated compact In the method for manufacturing a ceramic capacitor, in the pattern printing step, the pattern is transferred to a transfer body from a printing plate on which a desired pattern is formed by the conductive paste, and the transfer body is pressed at a pressure of 0.05 to 5 kg / cm. ^{In step 2} , the ceramic green sheet is pressed to transfer the pattern to the ceramic green sheet.

[0012]

In the method for manufacturing a monolithic ceramic capacitor of the present invention, a desired pattern is formed by the conductive paste, and the pattern is transferred to the green sheet from the printing plate that does not change its shape with time using a transfer body. Since it does so, it does not deform or deteriorate like a screen mesh. Therefore, the accuracy of the pattern shape and the accuracy of the printing position can be effectively improved, and the variation in the capacitance can be reduced when the multilayer capacitor is configured.

When a roller is used as the transfer member, a constant pressure of 0.05 to 5 kg / cm ² always acts on the conductive paste, regardless of the size of the printed area of the internal electrodes. The coating film thickness is constant, and cracks due to thickness variation and delamination between the ceramic layer and the conductor layer can be eliminated.

Further, according to the present invention, it is always 0.05 to 5k.
Since a constant pressure of g / cm ² acts on the conductive paste, the density of the electrode film after coating is high and a dense sintered body can be obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for manufacturing a multilayer ceramic capacitor of the present invention, a pattern is transferred from a printing plate on which a desired pattern is formed to a transfer body, and the transfer body is subjected to a pressure of 0.05 to 5 kg / cm. ^{In step 2} , the pattern is transferred to the ceramic green sheet by pressing it against the ceramic green sheet.

In the present invention, so-called offset printing is used because a solid surface is more easily obtained than in gravure printing, and a dense and continuous film can be formed.

Further, the pressure of the transfer member is 0.05 to 5 kg / c.
When the pressure was smaller than 0.05 kg / cm ² , the ceramic green sheet was pressed against the ceramic green sheet at a pressure of less than 0.05 kg / cm ² because a pinhole was generated in the printed pattern and the capacity was lost. V. This is because the value becomes large. On the other hand, if it is larger than 5 kg / cm ² , the ceramic green sheet will be broken or the coating film will be crushed by the pressure, and a printed pattern of a predetermined size cannot be obtained. The pressing force of the transfer member against the green sheet is 0.5 in terms of improvement of electrostatic capacity and dimensional accuracy of the printed pattern.
˜2 kg / cm ² is desirable.

Further, when the pattern is transferred from the printing plate to the transfer body, the pressing force of the transfer body onto the printing plate is 0.1 because the pattern is efficiently transferred to the transfer body.
-10 kg / cm ² is desirable, especially 0.5-5 k
g / cm ² is desirable.

In the present invention, as the raw material powder for the conductive paste, any conductive material such as gold, platinum, silver, palladium, iron, cobalt, nickel, copper or alloys thereof can be applied. The particle size of the raw material powder for the conductive paste can be preferably several μm to submicron. Further, in order to improve the dispersibility of the raw material powder for the conductive paste, it is desirable to use the raw material powder whose surface is modified to a high molecular weight organic substance by using a coupling agent such as a silane coupling agent.

A desired amount of the same raw material powder as that of the ceramic green sheet may be added as a co-material to the raw material powder for the conductive paste in order to improve the adhesion with the ceramic green sheet.

It is desirable that the powder used is sufficiently dispersed in order to prevent the occurrence of a short circuit between the electrodes due to agglomeration of particles and poor dispersion. Therefore, various resins, dispersants and the like are used in various combinations as organic additives.

Examples of the resin include cellulose resins, rosin resins, polyvinyl resins, butyral resins,
There are polyester-based resins, acrylic-based resins, epoxy-based resins, polyamide-based resins, polyurethane-based resins, alkyd-based resins, maleic acid-based resins, polyamide-based resins, petroleum-based resins, and the like, and these resins may be used alone or in combination. As a resin that suppresses particle aggregation and improves dispersion, a cellulose resin is desirable because of its compatibility with other resins and solvents.

As the dispersant, any surfactant generally used for preparing a paste can be used.
Polymeric surfactants are desirable for reasons of paste stabilization.

The solvent is not particularly limited as long as it is compatible with the organic additive to be used, and examples thereof include alcohols such as ethanol, carbitol, toluene, acetic acid ester, xylene, hydrocarbons, Esters, ether alcohols, ketones, etc. can be used.

Further, when preparing a homogeneous solution of a desired amount of organic additive and solvent, a surfactant, if necessary, as an auxiliary agent,
A plasticizer, an antistatic agent, an antifoaming agent, an antioxidant, a lubricant, a curing agent, etc. can be used as appropriate.

The printing plate used in the production method of the present invention has a flat plate shape, a cylindrical shape, or a cylindrical shape, preferably a lithographic plate, or a flat plate-shaped intaglio or a cylindrical intaglio.

However, if there is no misregistration of printing, for example, in the case of a flat plate, a relief plate, in which a printing pattern is printed, and in the case of a cylindrical plate, the plate plate is wound around a cylindrical roller. May be. Further, it has a doctor blade for scraping off the conductive paste depending on the type of plate. The blade is made of metal, stainless steel, rubber, resin, or the like. The shape, depth, number of lines, etc. of the intaglio plate are appropriately selected depending on the printing pattern and the film thickness after printing. Further, the material of the printing plate may be made of a material other than metal. For example, it may be made of ceramics or glass, or may be made of synthetic resin as long as it is a rigid material that does not easily change its shape over time, but the printing plate is made of ceramics because of its long life. Is desirable.

The transfer member used in the manufacturing method of the present invention is preferably made of an elastic material at least on the surface thereof, because the printing plate is hard, and particularly preferably made of silicone rubber. However, it is not particularly limited as long as it has excellent transferability. The hardness of the surface of the transfer body is 30 because the transfer efficiency is high.
It is desirable that the angle is -80 degrees. The shape does not have to be a roller, and may be a curved elastic body used for pad printing or the like, or a flat elastic body as long as it does not cause printing deviation.

Further, the surface roughness Ra of the transfer body is preferably 0.1 μm or less from the viewpoint of reducing the surface roughness of the pattern surface and the surface roughness of the surface of the green sheet laminated on the pattern. Particularly, the surface roughness Ra of the transfer body is 1/4 of the thickness of the internal electrode after the capacitor is manufactured.
It is desirable that:

As the ceramic green sheet used in the present invention, those produced by the pulling method, the doctor blade method, the reverse roll coater method, the gravure coater method, the screen printing, the gravure printing or the like are used.
The thickness is 0.5 to 5 because of its small size and large capacity.
Desirably, it is 0 μm. The thinner the better, the better in terms of capacity. In particular, in a capacitor formed by forming a pattern on the surface of a thin ceramic green sheet, stacking a green sheet on this pattern, and repeating the above-mentioned pattern and green sheet stacking steps alternately,
Since the dielectric layer can be made thin, it is desirable from the viewpoint of improving the capacitance.

The thickness of the internal electrodes is preferably 3 μm or less, more preferably 1 μm or less from the viewpoint of miniaturization and high reliability.

FIG. 1 shows an offset printing machine using a flat printing plate used in the present invention. In FIG. 1, reference numeral 1 is a transfer member composed of a roller.
A ceramic green sheet 2 and a printing plate 3 are arranged on both sides of the. The printing plate 3 is an intaglio, and the recess 4 of the printing plate 3 is filled with a conductive paste. Further, the transfer body 1 is provided with a blade 5 that moves with the movement thereof and fills the concave portion 4 with the conductive paste, and the blade 5 has a paste reservoir. Reference numeral 6 is a support plate for the green sheet 2.

Then, a method of printing a pattern made of a conductive paste on a ceramic green sheet is shown in FIG.
To (d). First, as shown in FIG. 2B, the transfer body 1 is rotated while being pressed against the printing plate 3 at a pressure of 0.1 to 10 kg / cm ² , as shown in FIG.
The pattern 7 is copied around the transfer body 1 and is shown in FIG.
As shown in (c), the transfer body 1 is rotated while being pressed against the green sheet 2 at a pressure of 0.05 to 5 kg / cm ² , and the pattern 7 is formed on the upper surface of the green sheet 2 as shown in FIG. Can be transcribed.

A method of printing a pattern on a ceramic green sheet when a cylindrical printing plate is used in the present invention will be described with reference to FIG.

In this offset printing machine, a transfer body 13 made of a roller is arranged in the vicinity of a cylindrical printing plate 11 made of an intaglio so that the transfer body 13 can come into contact with the cylindrical printing plate 11. A green sheet 15 is arranged in the vicinity of 13. Further, the cylindrical printing plate 11 is provided with a blade 5 for filling the concave portion with the conductive paste,
This blade 5 has a paste reservoir.

In such an offset printing machine, the transfer member 13 is applied to the cylindrical printing plate 11 at a pressure of 0.1 to 10 kg / cm.
² is contacted and rotated to transfer the pattern 7 onto the transfer body 13,
The transfer body 13 is moved to the green sheet 15, and the transfer body 1 is transferred.
3 is pressed against the green sheet at a pressure of 0.05 to 5 kg / cm ² , and the pattern 7 is transferred to the green sheet 15.

As another example of using a cylindrical printing plate, FIG.
There is an offset printing machine as shown in. In this offset printing machine, in the vicinity of the cylindrical printing plate 11 made of intaglio,
A transfer body 13 composed of a roller is arranged so as to be able to contact the columnar printing plate 11, and a long ceramic green sheet 15 is arranged in the vicinity of the transfer body 13. The green sheet 15 is wound in a roll shape and supported by rollers 19. Further, a blade 5 similar to that shown in FIG. 3 is arranged.

In such an offset printing machine, the transfer body 13 is brought into contact with the cylindrical printing plate 11 and rotated, whereby the pattern is transferred from the cylindrical printing plate 11 to the transfer body 13, and the green sheet is transferred from the transfer body 13. Transfer to 15. In this case, as shown in FIGS. 1 and 3, the green sheet is not cut into a predetermined length and has a long shape.
Printing can be continuously performed by the transfer body 13.

The cylindrical printing plate 11 shown in FIGS. 3 and 4 has through holes formed in a pattern as shown in FIG. 5, and the squeegee 2 is formed on the inner surface of the cylindrical printing plate 11.
1 may be arranged and the conductive paste may be transferred to the transfer body 13 through the through hole by the squeegee 21.

Further, the flat printing plate 3 in FIG. 1 and the cylindrical printing plate 11 in FIGS. 3 and 4 have been described with respect to an example of being formed from an intaglio plate, but may be a relief plate, a flat plate printing plate or a cylindrical plate. You may use the thing which screen-printed on the surface of the printing plate and which electroconductive paste was transferred.

Further, in the above-mentioned example, the example in which the transfer member composed of a roller is used has been described, but a plate-shaped transfer member 23 as shown in FIG. 6 may be used.

As the material to be printed used in the manufacturing method of the present invention, as shown in FIGS. 1, 2 and 3, a ceramic green sheet processed into a predetermined size is used, or as shown in FIG. A ceramic green sheet wound into a roll as shown may be used. Further, a green sheet printed on a carrier film in a predetermined size by a doctor blade method, screen printing, gravure printing or the like may be used.

Further, the ceramic green sheet in the present invention includes a thin sheet formed by screen printing, gravure printing or the like. When such a thin ceramic green sheet is used, a pattern is printed on the surface of the ceramic green sheet using the electrode paste according to the method of the present invention, and the surface of the pattern is subjected to the above-mentioned screen printing, gravure printing, etc. A thin ceramic green sheet is formed by printing, and the steps from pattern printing to formation of the ceramic green sheet are repeated to form a laminated molded body, which is then fired to form a chip-type laminated ceramic capacitor. It

[0044]

【Example】

Example 1 Two types of belt-shaped ceramic green sheets having a thickness of 7.5 μm and 15 μm were produced by forming a ceramic slurry by a doctor blade method on a belt-shaped carrier film made of synthetic resin and drying it. The green sheet is based on Nb ₂ O for 100 parts by weight of BaTiO _3.
5 1.8 parts by weight, MgO 0.3 parts by weight, La ₂ O ₃ 0.
2 parts by weight, SiO ₂ 0.1 parts by weight, Al ₂ O ₃ 0.1 parts by weight, ZnO 0.01 parts by weight are added and mixed, and 5.4% by weight of butyral resin as a binder is added thereto.

Next, the green sheet was peeled from the carrier film and punched out into a size of 200 × 200 mm,
A pattern is printed on one main surface of the obtained green sheet using an electrically conductive paste by an offset printing apparatus as shown in FIG.

First, the green sheet 2 is fixed on the support plate 6 of the printing apparatus by vacuuming.

The transfer layer 1 made of a roller has a surface layer made of silicone rubber and has a hardness of 50 degrees and a surface roughness of 0.01 μm.
It is. Further, the transfer body is parallel to the rotation axis of the transfer body 1 with respect to the green sheet 2 and the printing plate 3, and the green sheet 2
And the printing plate 3 are reciprocated between the green sheet 2 and the printing plate 3 with a predetermined pressure.

The printing plate 3 is a flat plate intaglio plate. A plurality of recesses 4 are formed at a predetermined interval on the flat plate intaglio, and the recesses 4 are formed so as to have a planar shape that matches the printed shape of the conductive paste. It is provided in.

Before the transfer body 1 passes over the printing plate 3, a conductive paste containing 45% by weight of palladium (Pd) and 55% by weight of a vehicle is supplied to the concave portion 4 by the blade 5, and the ceramic green is formed by offset printing. Printed on sheet 2. That is, as shown in FIG. 2B, the transfer body 1 is pressed against the printing plate 3 at a pressure of 1 kg / cm ² , and the pattern on the printing plate 3 is transferred to the transfer body 1.
As shown in (c), the pressing force of the transfer body 1 on the green sheet was changed, and the pattern 7 on the transfer body 1 was retransferred onto the green sheet 2 as the printing medium at a printing speed of 20 m / min.

20 layers of the green sheets coated with the conductive paste were laminated so that the drawn out sides of the conductive paste layers were alternately staggered to form a laminated molded body.

Then, the obtained laminated compact is heated to a temperature of 400 ° C. in the atmosphere to burn the binder, and then fired in the atmosphere at 1300 ° C. for 2 hours to obtain a ceramic sintered body. It was After firing, an indium-gallium paste was applied to each end surface of the obtained ceramic sintered body to form an external electrode electrically connected to the internal electrode, and a laminated ceramic capacitor in which the internal electrode was made of Pd was produced.

The external dimensions of the thus obtained monolithic ceramic capacitor are 1.6 mm in width and 3.2 mm in length, and the thickness of the dielectric layer interposed between the internal electrodes is 5 μm, 1 mm.
It was 0 μm. The total number of dielectric layers is 20,
The area of the counter electrode per layer was 2.1 mm ² .

The transfer rate of the pattern from the transfer body to the green sheet is (weight per unit volume of the coating film printed on the green sheet) / (weight per unit volume of the coating film before transferring to the green sheet). Calculated by
Electron microscope observation of the fracture surface of the sample, measuring and observing the thickness of the internal electrode and the presence of pinholes in the internal electrode,
The breakage of the green sheet during transfer was visually observed. Furthermore, the capacitance was measured by an LCR meter under the conditions of 1 kHz, 1 Vrms, and temperature of 25 ° C. Also,
The coefficient of variation of capacity (hereinafter referred to as CV value) was calculated. This coefficient of variation C.I. V. The value was calculated by dividing the standard deviation of the capacitance by the thickness of the dielectric layer.

The results are shown in Tables 1 and 2. Table 1 shows the case where the thickness of the dielectric layer is 5 μm, and Table 2 shows the case where the thickness of the dielectric layer is 10 μm.

[0055]

[Table 1]

[0056]

[Table 2]

As is clear from Tables 1 and 2, the laminated ceramic capacitors manufactured by the method of the present invention have a variation in capacitance C.I. V. The value is small within 3%, and the capacity does not drop sharply. Further, the sample was hardened with resin, polished, and observed under a metallurgical microscope at a magnification of 300 times to check for the presence of cracks and delamination. As a result, the multilayer ceramic capacitor manufactured by the method of the present invention had cracks and delamination. I confirmed not to do it.

On the other hand, when the pressing force is smaller than 0.05 kg / cm ² , pinholes are formed on the pattern surface, and the coefficient of variation C. V. It can be seen that the value is 3% or more. Also, it is understood that when the pressing force exceeds 5 kg / cm ² , the green sheet is torn. Furthermore, in this case, as shown in No. 9 of Table 1, the electrode film is crushed, becomes larger than the designed area, and is short-circuited.

Surface roughness Ra of transfer body (0.01 μm)
Was ¼ or less of the internal electrode thickness (0.9 to 1.6 μm).

Example 2 The present inventors set the pressing force of the transfer member to the green sheet to 1
kg / cm ² , the printing speed is kept constant at 20 m / min,
The other conditions and the manufacturing method were the same as in Example 1, and an experiment was conducted in which the printing plate was replaced and the coating thickness of the conductive paste was changed.

Fracture surface electron microscope observation was performed on 100 samples using the same printing plate to determine the average thickness of the internal electrodes. In addition, the electrostatic capacity was measured in the same manner as above, and the coefficient of variation C. V. The value was determined, and the obtained multilayer capacitors were each hardened with resin for 100 samples and polished, and the presence of cracks and delamination was inspected by observing with a metal microscope at a magnification of 300 times.

As a comparative example, an electrode layer thickness, capacitance, C.I. V. The value was determined, and the presence or absence of cracks and delamination was confirmed. In this case, the outer dimensions, the thickness of the dielectric ceramic layer, the total number of dielectric ceramic layers, and the area of the counter electrode per layer are the same as those when the conductive paste is printed by the offset printing. When printing the conductive paste, the screen mesh was changed to change the coating thickness. These multilayer capacitors also have electrode layer thickness, capacitance, C.I.
V. The value was determined, and the presence or absence of cracks and delamination was confirmed.

The results are shown in Tables 3 and 4. Table 3 shows the case where the thickness of the dielectric layer is 5 μm, and Table 4 shows the case where the thickness of the dielectric layer is 10 μm.

[0064]

[Table 3]

[0065]

[Table 4]

As is clear from Tables 3 and 4, the monolithic ceramic capacitors manufactured by the method of the present invention have a small variation in capacitance within 3%, a rapid reduction in capacitance, and cracks and decapsulation. It turns out that the occurrence of fatal defects such as lamination can be prevented.

On the other hand, in the conventional screen-printed monolithic ceramic capacitor, when the thickness of the dielectric layer is 10 μm or 5 μm, when the electrode layer thickness is 1.2 μm or less, the capacitance is drastically reduced. Seen. In addition, C.I. V. All values were above 3%. Next, when the thickness of the dielectric layer was 10 μm, delamination occurred when the electrode layer thickness was 1.2 μm or less, and cracks occurred when the electrode layer thickness became thick. Even if the thickness of the dielectric layer is 5 μm, the thickness of the dielectric layer is 10 μm.
The same tendency as in the case of m was observed.

From the above, it can be seen that in screen printing, as the thickness of the electrode layer becomes thinner, the decrease in capacity becomes more prominent and the occurrence rate of delamination becomes higher. It is also found that cracks are likely to occur when the electrode layer thickness is large. On the other hand, in the offset printing of the present invention, there is almost no variation in capacitance regardless of the thickness of the electrode layer. In addition, neither crack nor delamination was observed.

Example 3 First, 97.5 mol% of BaTiO ₃ and CaZrO
_{3 to} 2.0 mol% and 0.5 mol% of MnO to 100 mol parts of the main component, 0.5 mol parts of Y ₂ O ₃ was added and mixed, and 5.4 parts of butyral resin as a binder was added thereto. Two types of ceramic green sheets of 7.5 μm and 15 μm formed by adding the weight% are formed in the same manner as above, and a conductive paste containing 45% by weight of nickel (Ni) and 55% by weight of a vehicle is formed on the surface thereof. Printing speed 2
Printing was carried out in the same manner as in Example 1 while keeping the pressure constant at 0 m / min and changing the pressing force of the transfer body against the green sheet, and 20 layers of this green sheet were laminated to obtain a laminated molded body. The obtained laminated molded body was heated to 80 in a nitrogen atmosphere.
After heating to a temperature of 0 ° C. to burn the binder, it was fired at 1250 ° C. for 2 hours in a reducing atmosphere, and further heat-treated at 900 ° C. in a nitrogen atmosphere to obtain a ceramic sintered body. After firing, an indium-gallium paste was applied to each end surface of the obtained ceramic sintered body to form an external electrode electrically connected to the internal electrode.
Was produced.

The external dimensions of the thus obtained monolithic ceramic capacitor are 1.6 mm in width and 3.2 mm in length, and the thickness of the dielectric layer interposed between the internal electrodes is 5 μm, which is 1 μm.
It was 0 μm. The total number of dielectric layers is 20,
The area of the counter electrode per layer was 2.1 mm ² .

In the same manner as in Example 1, the transfer rate of the pattern from the transfer body to the green sheet, the average thickness of the internal electrodes and the presence or absence of pinholes in the internal electrodes were measured and observed, and the breakage of the green sheet was observed. Furthermore, the capacitance, the coefficient of variation C. V. The value was determined.

The results are shown in Tables 5 and 6. Table 5 shows the case where the thickness of the dielectric layer is 5 μm, and Table 6 shows the case where the thickness of the dielectric layer is 10 μm.

[0073]

[Table 5]

[0074]

[Table 6]

As is clear from Tables 5 and 6, it can be seen that the laminated ceramic capacitors manufactured by the method of the present invention have a small variation in capacitance within 3%, and the capacitance does not drop sharply. In addition, the sample is hardened with resin and polished, and is observed with a metallurgical microscope at a magnification of 300 times.
As a result of inspecting for the presence of cracks and delamination,
It was confirmed that the multilayer ceramic capacitor manufactured by the method of the present invention was free from cracks and delamination.

Further, the surface roughness Ra (0.01
μm) is 1 / th of the internal electrode thickness (0.9 to 1.6 μm)
It was 4 or less.

Example 4 The inventors of the present invention set the pressing force of the transfer member to the green sheet to 1
kg / cm ² , the printing speed is kept constant at 20 m / min,
The other conditions and the manufacturing method were the same as in Example 3, and an experiment was conducted in which the printing plate was replaced and the coating thickness of the conductive paste was changed.

Fracture surface electron microscope observation was carried out on 100 samples using the same printing plate to determine the average thickness of the internal electrodes. Capacitance, coefficient of variation of capacity, presence of cracks and delamination were measured in the same manner as in the above-mentioned examples.

As a comparative example, a multilayer capacitor obtained by screen-printing a conductive paste was similarly subjected to electrode layer thickness, capacitance, C.I. V. The value was determined, and the presence or absence of cracks and delamination was confirmed. In this case, the outer dimensions, the thickness of the dielectric ceramic layer, the total number of dielectric ceramic layers, and the area of the counter electrode per layer are the same as those when the conductive paste is printed by the offset printing. When printing the conductive paste, the screen mesh was changed to change the coating thickness. These multilayer capacitors also have electrode layer thickness, capacitance, C.I.
V. The value was determined, and the presence or absence of cracks and delamination was confirmed.

The results are shown in Tables 7 and 8. Table 7 shows the case where the thickness of the dielectric layer is 5 μm, and Table 8 shows the case where the thickness of the dielectric layer is 10 μm.

[0081]

[Table 7]

[0082]

[Table 8]

As is clear from Table 7 and Table 8, the laminated ceramic capacitor manufactured by the manufacturing method of the present invention has a small variation in capacitance within 3%, and the capacitance is not rapidly reduced, and cracks and It can be seen that the occurrence of a fatal defect such as delamination can be prevented.

On the other hand, in the case of the screen-printed monolithic ceramic capacitor, the electrode layer thickness is 1. When the thickness of the dielectric layer is 10 μm and 5 μm.
When the thickness is 2 μm or less, the capacity is reduced. In addition, C.I. V.
All values were above 3%. Next, when the thickness of the dielectric layer was 10 μm, delamination occurred when the thickness of the electrode layer was 1.1 μm or less. However, no cracks occurred. Even when the thickness of the dielectric layer was 5 μm, the same tendency was observed as when the thickness of the dielectric layer was 10 μm.

From the above, it can be seen that in screen printing, as the thickness of the electrode layer becomes thinner, the decrease in capacity becomes more prominent and the occurrence rate of delamination becomes higher. It is also found that cracks are likely to occur when the electrode layer thickness is large. On the other hand, in the offset printing of the present invention, there is almost no variation in capacitance regardless of the thickness of the electrode layer. In addition, neither crack nor delamination was observed.

Example 5 First, 97.5 mol% of BaTiO ₃ and CaZrO
_{3 to} 2.0 mol% and 0.5 mol% of MnO to 100 mol parts of the main component, 0.5 mol parts of Y ₂ O ₃ was added and mixed, and 5.4 parts of butyral resin as a binder was added thereto. The ceramic slurry formed by adding weight% was formed on a belt-shaped carrier film made of synthetic resin by a gravure printing method to form a ceramic green sheet of 5 μm.

On the surface of this ceramic green sheet,
Printing was performed in the same manner as in Example 1 above, with a conductive paste composed of 45% by weight of nickel (Ni) and 55% by weight of a vehicle being kept constant at a printing speed of 20 m / min while changing the pressing force of the transfer member against the green sheet. Then, a pattern was formed. A ceramic green sheet having a thickness of 5 μm was formed on the surface of this pattern by the above-mentioned gravure printing method, and the steps from pattern formation to formation of the ceramic green sheet were repeated to obtain a laminated molded body having 20 layers of green sheets.

The obtained laminated molded article was heated to a temperature of 800 ° C. in a nitrogen atmosphere to burn the binder,
Baking at 1250 ° C for 2 hours in a reducing atmosphere,
Heat treatment was performed at 900 ° C. in a nitrogen atmosphere to obtain a ceramic sintered body.

After firing, an indium-gallium paste was applied to each end surface of the obtained ceramic sintered body to form an external electrode electrically connected to the internal electrode.
A multilayer ceramic capacitor made of i was produced.

The external dimensions of the thus obtained monolithic ceramic capacitor were 1.6 mm in width and 3.2 mm in length, and the thickness of the dielectric layer interposed between the internal electrodes was 3 μm.

The total number of dielectric layers was 20, and the area of the counter electrode per layer was 2.1 mm ² .

In the same manner as in Example 1, the transfer rate of the pattern from the transfer body to the green sheet, the average thickness of the internal electrodes and the presence or absence of pinholes in the internal electrodes were measured and observed, and the breakage of the green sheet was observed. Furthermore, the capacitance, the coefficient of variation C. V. The value was determined.

The results are shown in Table 9.

[0094]

[Table 9]

As is clear from Table 9, the monolithic ceramic capacitor manufactured by the method of the present invention has a small variation in capacitance within 3%, and the capacitance does not drop sharply. Also, the sample is hardened with resin and polished,
As a result of observing the presence or absence of cracks and delamination by observing with a metallurgical microscope at a magnification of 300 times, it was confirmed that the multilayer ceramic capacitor manufactured by the method of the present invention did not have cracks and delamination.

Further, the surface roughness Ra (0.01
μm) is 1 / th of the internal electrode thickness (1.0 to 1.6 μm)
It was 4 or less.

Example 6 The present inventors set the pressing force of the transfer member on the green sheet to 1
kg / cm ² , the printing speed is kept constant at 20 m / min,
The other conditions and the manufacturing method were the same as in Example 5, and an experiment was conducted in which the printing plate was replaced and the coating thickness of the conductive paste was changed.

Fracture surface electron microscope observation was performed on 100 samples using the same printing plate to determine the average thickness of the internal electrodes. Capacitance, coefficient of variation of capacity, presence of cracks and delamination were measured in the same manner as in the above-mentioned examples.

As a comparative example, a conductive paste is screen-printed on a green sheet formed by a gravure printing method, the green sheet is laminated on the pattern, and these steps are repeated to produce a laminated molded body. For the multilayer capacitor obtained by firing under the same conditions as above, the electrode layer thickness, capacitance, C.I. V. The value was determined, and the presence or absence of cracks and delamination was confirmed.

In this case, the outer dimensions, the thickness of the dielectric ceramic layer, the total number of dielectric ceramic layers, and the area of the counter electrode per layer are the same as those when the conductive paste is printed by the offset printing. When printing the conductive paste, the screen mesh was changed to change the coating thickness. These multilayer capacitors also have electrode layer thickness, capacitance, C.I. V. The value was determined, and the presence or absence of cracks and delamination was confirmed.

The results are shown in Table 10.

[0102]

[Table 10]

As is apparent from Table 10, the laminated ceramic capacitor manufactured by the manufacturing method of the present invention is
It can be seen that the variation of the capacity is small within 3%, the capacity is not rapidly reduced, and the occurrence of fatal defects such as cracks and delamination can be prevented.

On the other hand, in the case of the screen-printed monolithic ceramic capacitor, when the thickness of the electrode layer was 0.8 μm or less, the capacitance decreased. In addition, C.I. V. All values were above 3%.

From the above, it can be seen that in screen printing, as the thickness of the electrode layer becomes thinner, the decrease in capacity becomes more prominent and the occurrence rate of delamination becomes higher. It is also found that cracks are likely to occur when the electrode layer thickness is large. On the other hand, in the offset printing of the present invention, there is almost no variation in capacitance regardless of the thickness of the electrode layer. In addition, neither crack nor delamination was observed.

[0106]

According to the method of manufacturing a ceramic electronic component of the present invention, the conductive paste is printed on the ceramic green sheet by offset printing from a printing plate on which a desired printing pattern is formed using a transfer body. As a result, the transfer body and the ceramic green sheet are printed in contact with each other. For example, the pressure of the transfer body composed of a roll is constantly applied to the conductive paste at 0.05 to 5 kg / cm ² , and the printing area of the internal electrodes is increased. It is possible to obtain a coating film having a constant thickness regardless of the size. Further, since the printing plate which is less deteriorated with time is used, not only the conductive paste can be printed on an accurate size and position, but also the printing size and the printing position do not change with time.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an offset printing machine using a flat printing plate.

FIG. 2 is an explanatory diagram showing a process of printing a conductive paste using the offset printing machine of FIG.

FIG. 3 is an explanatory diagram showing an offset printing machine using a cylindrical printing plate.

FIG. 4 is an explanatory diagram showing an offset printing machine that uses a cylindrical printing plate to continuously print a conductive paste on a long green sheet.

FIG. 5 is a perspective view showing a rotary screen used for a cylindrical printing plate of an offset printing machine.

FIG. 6 is a perspective view showing an offset printing machine using a plate-shaped transfer body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transfer body 2 ... Green sheet 3, 11 ... Printing plate 4 ... Recessed portion 5 ... Blade 6 ... Support plate 7 ... Pattern

Claims (2)

[Claims] 1. A step of printing a desired pattern on a ceramic green sheet by using a conductive paste, a step of laminating a plurality of ceramic green sheets having the pattern printed thereon, and a step of firing the laminated compact. In the method for manufacturing a monolithic ceramic capacitor comprising: the pattern printing step, the pattern is transferred from a printing plate on which a desired pattern is formed by the conductive paste to a transfer body, and the transfer body is pressed at a pressure of 0.05 to A method for manufacturing a monolithic ceramic capacitor, comprising pressing the ceramic green sheet at 5 kg / cm ² to transfer the pattern to the ceramic green sheet. 2. A step of printing a desired pattern on the ceramic green sheet using a conductive paste, and a step of forming the ceramic green sheet on the pattern.
A step of producing a laminated molded body by repeating the pattern printing step and the ceramic green sheet forming step,
In the method for manufacturing a laminated ceramic capacitor, which comprises a step of firing the multilayer molded body, the pattern printing step transfers the pattern from a printing plate on which a desired pattern is formed by the conductive paste to a transfer body. A method for manufacturing a monolithic ceramic capacitor, wherein the transfer body is pressed against the ceramic green sheet at a pressure of 0.05 to 5 kg / cm ² to transfer the pattern onto the ceramic green sheet.