JPH0536568A - Manufacture of laminated ceramic electronic component - Google Patents

Abstract

PURPOSE:To stably laminate a dielectric green sheet on a base sheet without damaging the dielectric green sheet 10 to 20mm thick in its lamination operation and without causing the defect of the sheet due to the printing operation of a conductive paste by a method wherein the dielectric green sheet is laminated to form a composite sheet in which the sheet is united to the base sheet. CONSTITUTION:A composite sheet 10 in which a dielectric green sheet 12 has been formed on a plastic base sheet 11 is thermocompression-bonded to a carrier plate 13 by using the green sheet 12 as a bonding face. Then, the base sheet 11 is stripped, a ceramic layer 12a is formed on the carrier plate 13, a conductive paste is printed on the ceramic layer 12a and dried, and an internal electrode layer 18 is formed. Then, the composite sheet 10 is overlapped with and thermocompression-bonded to the ceramic layer 12a on which the internal electrode layer 18 has been formed while the green sheet 12 is used as the bonding face, and the base sheet 11 is stripped. Said process is repeated the prescribed number of times, and a laminated body 19 which is composed of the ceramic layer 12a and the internal electrode layer 18 is obtained.

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 electronic component such as a laminated ceramic capacitor, a laminated varistor, a laminated piezoelectric element, a laminated chip inductor and the like. More specifically, the present invention relates to a method for manufacturing a laminated ceramic electronic component using a dielectric green sheet having a thickness of 10 to 20 μm.

[0002]

2. Description of the Related Art Among laminated ceramic electronic components of this type, for example, a laminated ceramic capacitor is composed of a ceramic element body in which ceramic layers and electrode layers are alternately laminated and fired. Here, the internal electrode layers are alternately taken out to one outer surface and the other outer surface of the ceramic body, and the terminal electrodes for external connection are formed on the taken-out portions. The lamination method of this monolithic ceramic capacitor includes a dry lamination method and a wet lamination method. In the dry lamination method, first, a dielectric powder is kneaded with an organic binder, a plasticizer and a solvent to prepare a dielectric slurry, and this slurry is formed into a dielectric green sheet by a doctor blade method, a calendar roll method or the like. Next, this green sheet is cut into a predetermined size, and a conductive paste containing a noble metal such as Pd or Ag / Pd as a main component is printed on the green sheet by a screen printing method or the like to form an internal electrode layer. Next, a plurality of green sheets having the internal electrode layers are laminated and integrated by thermocompression bonding to form a laminated body. In the wet lamination method, the dielectric slurry and the conductive paste are alternately printed and applied on a predetermined plate, and this is repeated a plurality of times to form a laminated body. The laminated body thus formed is cut into a desired shape, and 1200-1
After firing at 400 ° C., a terminal electrode for external connection is provided to form a monolithic ceramic capacitor.

In order to make this monolithic ceramic capacitor smaller and have a larger capacity, it is necessary to use ceramic powder having a high dielectric constant or to make the dielectric green sheet thinner. However, in the dry laminating method, if the thickness of the green sheet is reduced to 20 μm or less, the mechanical strength of the green sheet itself is lowered, and the positional deviation easily occurs at the time of laminating. There was a problem that cracks and wrinkles were likely to occur on the sheet. There is also a method of increasing the amount of organic binder in the dielectric slurry in order to increase the mechanical strength, but the sheet density becomes smaller, and as a result, the dielectric density after sintering decreases and the reliability of the capacitor deteriorates. There was a flaw. Further, the above-mentioned wet lamination method has a problem in that the number of times of printing is increased and thus the manufacturing cost is increased. Further, both of the lamination methods have a problem in that the solvent contained in the printed conductive paste reacts with the green sheet to cause sheet defects such as pinholes and distortion due to swelling in the green sheet.

As a method for solving these problems, the following two manufacturing methods have been proposed. The first manufacturing method is to first form an electrode layer on the front surface of a plastic base sheet, and then contact a back surface of this base sheet with a structure having projections and depressions matching the pitch of the electrode layer, and then from the top of this electrode layer to the base. A method in which a dielectric slurry is applied to a sheet to obtain a composite sheet in which a green sheet in a portion without an electrode layer is thickened, and then the composite sheet is thermocompression-bonded a plurality of times to a carrier plate with the ceramic layer of the green sheet as an adhesive surface ( JP-A-3-960206). In the second manufacturing method, an electrode layer is formed by printing on the ceramic layer of a composite sheet in which a ceramic layer of a green sheet is formed on a plastic base sheet, then cut with a cutting head and sucked and held by the head. And transferring it into the pressure-bonding mold a plurality of times to obtain a laminate (Japanese Patent Laid-Open No. Hei 2-16271).
0). The first method is to increase the thickness of the green sheet in the portion where the electrode layer is not formed on the base sheet, so that when the ceramic layer of the green sheet is dried, the surface of the ceramic layer becomes flat, whereby the electrode The feature is that even if the green sheet for embedding becomes thin, it can be stacked stably. In the second method, since the composite sheet is held by the cutting head from the cutting to the stacking, the green sheet has a feature that it can be stacked with high accuracy even if it has a thickness of 20 μm or less.

[0005]

However, both of the above two methods are methods in which the electrode layers are formed by printing and then laminated, so that the electrode layers are printed on the plastic base sheet and the ceramic layer on the base sheet, respectively. When
There is a problem that a mechanism for sucking and holding the base sheet and an accurate control mechanism for setting the position of the electrode layer are required. Further, there is a problem that a reading mechanism or a positioning mechanism with high accuracy is required for aligning the green sheets during stacking.

An object of the present invention is to stably maintain a dielectric green sheet having a thickness of 10 to 20 μm at the time of lamination and without causing a sheet defect due to printing of a conductive paste for forming an electrode layer. It is an object of the present invention to provide a method for manufacturing a laminated ceramic electronic component that can be laminated. Another object of the present invention is to achieve a high performance, including a small-sized and large-capacity laminated ceramic capacitor, by laminating dielectric green sheets with high precision with relatively few steps without requiring an expensive positioning mechanism. Another object of the present invention is to provide a method for manufacturing the monolithic ceramic electronic component.

[0007]

In order to achieve the above-mentioned object, the manufacturing method of the present invention, as shown in FIGS.
(a) a step of forming a dielectric green sheet 12 on a plastic base sheet 11 to obtain a composite sheet 10,
(b) thermocompression-bonding the composite sheet 10 to the carrier plate 13 with the green sheet 12 as an adhesive surface,
(c) a step of peeling the base sheet 11 from the composite sheet 10 thermocompression-bonded to the carrier plate 13 to form a ceramic layer 12a on the carrier plate 13,
(d) A step of printing and drying a conductive paste on the ceramic layer 12a on the carrier plate 13 to form the internal electrode layer 18, and (e) the composite sheet 10 being the green sheet 12 thereof.
Is bonded to the ceramic layer 12a on which the internal electrode layer 18 is formed, and thermocompression bonded to the base sheet 11
And a step of (f) repeating the steps (d) and (e) a predetermined number of times to obtain a laminate 19 composed of the ceramic layer 12a and the internal electrode layer 18. The laminated body 19 is preferably hydrostatically treated together with the carrier plate 13 to integrate the ceramic layer 12 a and the internal electrode layer 18.

[0008]

When the composite sheet 10 is thermocompression-bonded to the carrier plate 13 with the green sheet 12 as an adhesive surface, and the ceramic layer 12 formed on the carrier plate 13
Similarly, when the composite sheet 10 is subjected to thermocompression bonding to a, the electrode layer 18 is not yet formed on the composite sheet 10, so that a highly accurate reading mechanism or positioning mechanism is not required for the alignment of the sheets at the time of stacking. Becomes Further, since the positioning of the internal electrode layers 18 which are alternately arranged to connect to the terminal electrodes is performed when printing is performed on the ceramic layer 12a on the carrier plate 13, the printing base is paralleled by a predetermined distance. Only a reciprocating motion is required and a simple mechanism can be performed with high accuracy. Furthermore, after the surface of the ceramic layer 12a is flattened by thermocompression bonding, the electrode layers 18 are printed, so that the laminated body 19 is parallel to each other, and the thickness of the electrode layers 18 can be reduced even in multilayer printing up to about 100 layers. The increased amount is forcibly embedded in the ceramic layer 12a. When the green sheets 12 are stacked in multiple layers of more than 100 layers, the ratio of the thickness of the electrode layer 18 in the laminated body 19 is smaller than that of the ceramic layer 12a, which causes a density difference. Ceramic layer 1 after water pressure treatment
2a and the internal electrode layer 18 are integrated to make the stacking density uniform.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. Example 1 As shown in FIG. 1, a composite sheet 10 having a dielectric green sheet 12 formed on the upper surface of a polyester base sheet 11 was prepared. This composite sheet 10
75 μm thick polyester base sheet 11 coated with a silicone release agent, and a barium titanate-based dielectric slurry having JIS-R characteristics according to the doctor blade method and then dried And a dielectric green sheet 12 having a thickness of 20 μm. This dielectric slurry has a polyvinyl butyral of 7.0% by weight, a plasticizer of 4.0% by weight, and a dielectric powder mainly composed of barium titanate as 100% by weight.
0.2% by weight of pine tree, 0.1% by weight of release agent, 8 toluene
It was prepared by mixing 48% by weight of a mixed solvent of 0 / ethanol 20 in a polypot for 48 hours. Next, the composite sheet 10 was placed on a carrier plate 13 made of aluminum whose surface was anodized with the green sheet 12 facing downward, and thermocompression-bonded by the heat press machines 14 and 15. The thermocompression bonding was carried out at a pressure of 45 Kg / cm ² for 15 seconds while maintaining the temperature of 60 ° C. by the heaters 14a and 15a.

As shown in FIG. 2, the carrier plate 13
After cooling to room temperature, only the base sheet 11 was peeled off from the composite sheet 10 to form the ceramic layer 12a on the carrier plate 13. The following composite sheet 10 was superposed on the ceramic layer 12a with the green sheet 12 facing downward, and thermocompression-bonded by the hot press machines 14 and 15 in the same manner, and only the base sheet 11 was peeled from the composite sheet 10. As shown in FIG. 3, this lamination, thermocompression bonding, and peeling are repeated six times in total to obtain a laminated body 16 having a thickness of 120 μm (20 μm × 6 times) consisting of six ceramic layers 12 a on the carrier plate 13. It was This carrier plate 13
Is transferred to a printing base 17 and a conductive paste containing Pd as a main component is screen-printed on the surface of the laminate 16 at 80 ° C.
And dried for 4 minutes to form the internal electrode layer 18. The following composite sheet 10 is superposed on the surface of the laminated body 16 on which the electrode layer 18 is formed, with the green sheet 12 facing downward, and thermocompression-bonded by the heat press machines 14 and 15 in the same manner. Peeled off.

Formation of the electrode layer 18 and the green sheet 1
The lamination of No. 2 was repeated 100 times, and 5 layers of only the green sheet 12 were further laminated thereon to obtain a laminated body 19 shown in FIG. This laminated body 19 is used as a carrier plate 13
Was treated with hydrostatic pressure. The hydrostatic pressure treatment is performed by encapsulating the laminate 19 in a nylon bag (not shown) and vacuum-packing the product, and then placing the product in a hydrostatic machine (not shown) at 300 kg / 65 ° C. in water.
This was done by applying a pressure of cm ² . The hydrostatically treated laminate 19 shown in FIG. 5 was peeled from the carrier plate 13, and this laminate 19 was cut into a 3216 type multilayer ceramic capacitor element body. The element body was subjected to binder removal processing, then held at 1300 ° C. for 2 hours, and fired at atmospheric pressure to obtain a chip type multilayer ceramic capacitor element body.
An internal analysis was performed on each of the 20 chip-type monolithic ceramic capacitor elements, and none of them had defects such as delamination and cracks.

<Embodiment 2> 32 under the same conditions as in Embodiment 1 except that the thickness of the dielectric green sheet 12 is 10 μm.
A 16-inch chip type monolithic ceramic capacitor element body was prepared. An internal analysis was carried out on each of the 20 chip-type monolithic ceramic capacitor bodies thus obtained, and none of them had defects such as delamination and cracks.

Although the dielectric slurry having barium titanate-based JIS-R characteristics has been described in Example 1, other dielectric slurries such as lead-based may be used. The material of the base sheet 11 is not limited to polyester, and other plastic sheets may be used. Further, although the multilayer ceramic capacitor has been described, the present invention is not limited to this, and can be applied to the production of a multilayer ceramic electronic component such as a multilayer varistor, a multilayer piezoelectric element, and a multilayer chip inductor.

[0014]

As described above, according to the present invention, 1
When a thin dielectric green sheet having a thickness of 0 to 20 μm is laminated, the green sheet is laminated as a composite sheet integrated with the base sheet, so that it is not damaged.
Further, since the printing of the electrode layer is performed on the flattened surface of the ceramic layer, the electrode layer can be stably formed on the ceramic layer without causing a sheet defect due to the printing. In addition, since the composite sheet is thermocompression bonded with the electrode layer not formed, a highly accurate device is not required for the alignment of the sheets during lamination, and the electrode layer can be printed by the predetermined parallel movement of the printing base. Since it is sufficient, the manufacturing cost is low. In particular, the conventional manufacturing method is one in which the composite sheet to be laminated is flattened by using a structure having irregularities adapted to the pitch of the electrode layers, and the ceramic layer surface to be laminated is hot-pressed by the method of the present invention. Since the layers are flattened by using, the layers are parallel to each other when the electrode layers are printed, and even when printing up to about 100 layers, the increase in the thickness of the electrode layers is forcibly embedded in the ceramic layer and absorbed. it can. Furthermore, 1 green sheet
When the number of layers is more than 00, the obtained laminated body is subjected to hydrostatic pressure treatment to integrate the ceramic layers and the internal electrode layers, whereby the lamination density can be made uniform. As a result, it becomes possible to manufacture high-performance laminated ceramic electronic components including small-sized and large-capacity laminated ceramic capacitors by laminating dielectric green sheets with high precision with relatively few steps.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a composite sheet according to an embodiment of the present invention is thermocompression bonded onto a carrier plate.

FIG. 2 is a diagram showing a situation in which a base sheet is peeled from the thermocompression-bonded composite sheet, the next composite sheet is overlaid and thermocompression bonded.

FIG. 3 is a diagram showing a state in which an internal electrode layer is formed by printing on the surface of the laminated body of the ceramic layers, the following composite sheet is superposed on the internal electrode layer, and thermocompression bonding is performed.

FIG. 4 is a cross-sectional view of a laminated body in which the ceramic layers and internal electrode layers are superposed.

FIG. 5 is a cross-sectional view of a hydrostatically processed laminate.

[Explanation of symbols]

 10 Composite Sheet 11 Plastic Base Sheet 12 Dielectric Green Sheet 12a Ceramic Layer 13 Carrier Plate 14,15 Heat Press Machine 16,19 Laminate 17 Printing Base 18 Internal Electrode Layer

[Procedure amendment]

[Submission date] September 2, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

When the composite sheet 10 is thermocompression-bonded to the carrier plate 13 with the green sheet 12 as an adhesive surface, and the ceramic layer 12 formed on the carrier plate 13
Similarly, when the composite sheet 10 is subjected to thermocompression bonding to a, the electrode layer 18 is not yet formed on the composite sheet 10, so that a highly accurate reading mechanism or positioning mechanism is not required for the alignment of the sheets at the time of stacking. Becomes Further, since the positioning of the internal electrode layers 18 which are alternately arranged to connect to the terminal electrodes is performed when printing is performed on the ceramic layer 12a on the carrier plate 13, the printing base is paralleled by a predetermined distance. Only a reciprocating motion is required and a simple mechanism can be performed with high accuracy. Further, after the surface of the ceramic layer 12a is flattened by thermocompression bonding, the electrode layers 18 are printed, so that the laminates 19 are parallel to each other, and even in multilayer printing, the increase in the thickness of the electrode layers 18 is due to the ceramic layer. 1
It is forcibly buried in 2a. However, the stack 19
Since there is a density difference between the portion where the electrode layer 18 is present and the portion where the electrode layer 18 is not present, the laminated body 19 is finally subjected to hydrostatic pressure treatment to integrate the ceramic layer 12a and the internal electrode layer 18 to obtain a uniform laminated density. Turn into.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

As described above, according to the present invention, 1
When a thin dielectric green sheet having a thickness of 0 to 20 μm is laminated, the green sheet is laminated as a composite sheet integrated with the base sheet, so that it is not damaged.
Further, since the printing of the electrode layer is performed on the flattened surface of the ceramic layer, the electrode layer can be stably formed on the ceramic layer without causing a sheet defect due to the printing. In addition, since the composite sheet is thermocompression bonded with the electrode layer not formed, a highly accurate device is not required for the alignment of the sheets during lamination, and the electrode layer can be printed by the predetermined parallel movement of the printing base. Since it is sufficient, the manufacturing cost is low. In particular, the conventional manufacturing method is one in which the composite sheet to be laminated is flattened by using a structure having irregularities adapted to the pitch of the electrode layers, and the ceramic layer surface to be laminated is hot-pressed by the method of the present invention. Since the flattening is performed by using, the laminate becomes parallel in each layer when the electrode layers are printed, and even in the multilayer printing, the increase in the thickness of the electrode layers can be forcibly embedded in the ceramic layer and absorbed. Furthermore, the obtained laminated body is subjected to hydrostatic pressure treatment to integrate the ceramic layer and the internal electrode layer, whereby the laminated density can be made uniform. As a result, it becomes possible to manufacture high-performance laminated ceramic electronic components including small-sized and large-capacity laminated ceramic capacitors by laminating dielectric green sheets with high precision with relatively few steps.

Claims (3)

[Claims] 1. A step of (a) forming a dielectric green sheet (12) on a plastic base sheet (11) to obtain a composite sheet (10), and (b) converting the composite sheet (10) to the green sheet. (12) thermocompression bonding to the carrier plate (13) as an adhesive surface, and (c) peeling the base sheet (11) from the composite sheet (10) thermocompression bonded to the carrier plate (13) A step of forming a ceramic layer (12a) on the carrier plate, (d) the ceramic layer (12a) on the carrier plate (13)
A step of printing and drying a conductive paste to form an internal electrode layer (18), and (e) forming the internal electrode layer (18) with the green sheet (12) of the composite sheet (10) as an adhesive surface. The base sheet (11), which is placed on the ceramic layer (12a) that has been formed and is thermocompression bonded.
And a step of (f) repeating the steps (d) and (e) a predetermined number of times to obtain a laminate (19) composed of the ceramic layer (12a) and the internal electrode layer (18). Manufacturing method of electronic parts. 2. After the step (f), the laminated body (19) is subjected to hydrostatic pressure treatment together with the carrier plate (13) to obtain a ceramic layer (12).
The method for producing a multilayer ceramic electronic component according to claim 1, wherein a) and the internal electrode layer (18) are integrated. 3. The method for producing a monolithic ceramic electronic component according to claim 2, wherein the hydrostatic pressure treatment is performed after the laminate (19) together with the carrier plate (13) is covered with a plastic bag and vacuum-packed.