JPH08130160A - Manufacture of multilayer ceramic electronic component - Google Patents

Abstract

PURPOSE: To manufacture a multilayer ceramic electronic component which facilitates the relief of an internal stress produced in a baking process and which does not have a structural defect such as a delamination. CONSTITUTION: A plurality of layers of iner electrodes 2 and a plurality of ceramic layers 1 are alternately provided so as to have the inner electrodes 2 face each other with the ceramic layers 1 therebetween to constitute a multilayer part 3. On both the upper and lower sides of the multilayer part 3, outer layers 4a and 4b in which inner electrodes 2 are not provided and whose thickness ratio is within a range of 1:2-1:3 are formed to constitute a multilayer ceramic unit 5. The multilayer ceramic unit 5 is baked and a minute warpage in a required direction is created in the baked unit 5a to relieve an internal stress which is caused by the partial difference in contraction factors when the multilayer ceramic unit 5 is baked.

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 an electronic component, and more particularly to a method for manufacturing a laminated ceramic electronic component such as a laminated ceramic capacitor and a laminated ceramic filter.

[0002]

2. Description of the Related Art For example, in a monolithic ceramic capacitor, which is one of typical monolithic ceramic electronic components, as shown in FIG. So as to face each other, a laminated portion 3 in which a plurality of layers of the internal electrodes 2 and the ceramic layers 1 are alternately arranged, and internal electrodes disposed on the upper and lower surfaces of the laminated portion 3 are arranged. The external electrodes 6a and 6b, which are electrically connected to the internal electrodes 2 that are drawn out to the end faces of the different sides alternately, are arranged at both ends of the ceramic laminated body 5 that is provided with the outer layer portions 4a and 4b made of non-ceramic layers. The outer layer portions 4a and 4b on the upper and lower surfaces are usually designed to have the same thickness.

By the way, when manufacturing the above-mentioned conventional monolithic ceramic capacitor, when the ceramic laminate 5 is fired, a difference occurs in the shrinkage rate between the outer layer portions 4a and 4b and the laminate portion 3. This is because the internal electrode 2 is formed by applying a conductive paste on the surface of the ceramic layer (ceramic green sheet) 1 that constitutes the laminated portion 3, so that the shrinkage that occurs during firing is affected by the internal electrode 2. This is because the contraction rate in the plane is larger than that of the outer layer portions 4a and 4b in which the internal electrodes are not arranged, and the ceramic layer 1 and the outer layer portions 4a and 4b forming the laminated portion 3 are formed of the same material. It also occurs when it is done.

Thus, during firing, the outer layer portions 4a, 4b
If there is a difference in shrinkage ratio between the laminated portion 3 and the laminated portion 3, a structural defect such as delamination occurs in the laminated portion 3 and desired characteristics cannot be obtained.

The present invention solves the above-mentioned problems and manufactures a monolithic ceramic electronic component capable of alleviating the generation of internal stress in the firing process and preventing the occurrence of structural defects such as delamination. The purpose is to provide a method.

[0006]

In order to achieve the above object, a method of manufacturing a monolithic ceramic electronic component according to the present invention is a method of manufacturing a monolithic ceramic electronic component in which internal electrodes are provided in a ceramic. , A thickness ratio of 1: 2 to 1: 3 is provided on the upper and lower surfaces of the laminated portion in which a plurality of layers of the internal electrodes and the ceramic layers are alternately arranged so that the internal electrodes face each other via the ceramic layers. A ceramic laminated body is formed by arranging an outer layer portion formed of a ceramic layer in which the internal electrodes are not arranged, the ceramic laminated body is fired, and the sintered body is formed in a predetermined direction. It is characterized by causing a minute warp.

[0007]

The thickness ratio of each of the internal electrodes and the ceramic layers of the plurality of layers is 1: 2 on the upper and lower surfaces of the laminated portion.
When the ceramic laminate formed by disposing the outer layer portion in the range of to 1: 3 is fired, a slight warp in a predetermined direction occurs in the sintered body.

Then, due to this minute warp, for example,
When an internal electrode is formed by applying a conductive paste on the surface of a ceramic layer (ceramic green sheet) that constitutes the laminated part, the contraction rate of the laminated part is It becomes possible to alleviate the internal stress caused by the fact that the contraction rate of the outer layer portion where the electrodes are not provided is larger than that of the outer layer portion, and prevent the occurrence of structural defects such as delamination.

The thickness ratio of the outer layer portions on the upper and lower sides is 1:
In the case of 2 to 1: 3, regarding which side of the outer layer portion on the upper surface side or the lower surface side to increase the thickness, the configuration of the laminated portion (for example, the application mode of the internal electrode to the ceramic layer and the position of both of them) is determined. Relationships, etc.).

[0010]

EXAMPLES Examples of the present invention will be shown below to explain the features thereof in more detail. In this embodiment, a case of manufacturing a monolithic ceramic capacitor will be described as an example.

In this embodiment, as shown in FIG. 1, a plurality of dielectric sheets (ceramic layers) 1 printed with a conductive paste (internal electrode) 2 are stacked to form a laminated portion 3, and the upper and lower surfaces thereof are further formed. After stacking dummy sheets (outer layer portions) 4a and 4b made of the same material as the ceramic layer 1 on which no internal electrode is provided, the ceramic laminate 5 is formed by pressure bonding.

Further, in this embodiment, the thickness of the outer layer portion 4b on the lower surface side is 1 to 4 times the thickness of the outer layer portion 4a on the upper surface side.
The thickness of the outer layer portion 4a on the upper surface side: the thickness of the outer layer portion 4b on the lower surface side = 1: 1, 2: 3, 1: 2
1: 3 and 1: 4).

Then, the ceramic laminated body 5 thus formed is degreased under predetermined conditions and then main-baked,
A sintered body 5 (5a) as shown in FIG. 2 was obtained. (In addition, by disposing external electrodes 6a and 6b (FIG. 3) which are electrically connected to the internal electrode 2 at both ends of this sintered body (ceramic laminated body) 5a, a laminated ceramic capacitor as shown in FIG. 3 is obtained. It is formed.)

Then, for each of the obtained sintered bodies 5a,
The incidence of delamination and the magnitude of warpage were investigated. Table 1 shows the results.

[0015]

[Table 1]

The "magnitude of warpage" in Table 1 means the distance (distance X in FIG. 2) between the surface 7 on which the sintered body 5a is placed and the lower surface of the sintered body 5a. .

From Table 1, the outer layer portions 4a and 4b on both upper and lower surfaces are shown.
When the thickness ratio of 1 is 1, the delamination occurrence rate is 5
It is 6%, and it can be seen that the delamination occurrence rate is 21% when the thickness ratio is 2: 3.

On the other hand, when the thickness ratio is in the range of 1: 2 to 1: 4, the delamination occurrence rate is 0%.

Therefore, from the standpoint of preventing delamination, the thickness of the outer layer portion 4b on the lower surface side is made equal to the thickness of the outer layer portion 4 on the upper surface side.
It can be seen that it is desirable to make the thickness at least twice the thickness of a.

On the other hand, when the thickness ratio is 1: 4, the size of the warp becomes 74 μm, the stability at the time of mounting is deteriorated, and the warp becomes too large, so that the internal electrodes exposed on both end surfaces are exposed. A part (2) of 2 retreats from the end faces and does not conduct with the external electrodes 6a and 6b (FIG. 3) formed on both end faces (not shown), and desired characteristics may not be obtained, which is preferable. Absent.

Therefore, the outer layer portions 4a, 4 on both the upper and lower sides.
The thickness ratio of b is preferably within the range of 1: 2 to 1: 3.

In the above embodiment, the case where the ceramic layer and the outer layer portion forming the laminated portion are made of the same material has been described, but the present invention can be applied to the case where the ceramic layer and the outer layer portion are not made of the same material. Is possible.

In the above embodiments, the case of manufacturing a monolithic ceramic capacitor has been described as an example, but the present invention is not limited to the method of manufacturing a monolithic ceramic capacitor, and a monolithic ceramic filter, a ceramic multi-layer substrate, or the like. Can be applied to the case of manufacturing various types of monolithic ceramic electronic components.

The present invention is not limited to the above-mentioned embodiments in other points as well, and relates to specific structures of the ceramic laminate, internal electrode patterns, etc., and various applications within the scope of the invention. , Can be modified.

[0025]

As described above, according to the method of manufacturing a laminated ceramic electronic component of the present invention, a plurality of layers of internal electrodes and ceramic layers are alternately arranged so that the internal electrodes face each other with the ceramic layers interposed therebetween. A ceramic laminated body is formed by disposing outer layer portions having a thickness ratio in the range of 1: 2 to 1: 3 on both upper and lower sides of the formed laminated portion, and the ceramic laminated body is fired and sintered. Since a slight warpage in a predetermined direction is generated in the body, it is possible to relieve the internal stress caused by the partial difference in shrinkage rate during firing of the ceramic laminate, and to prevent delamination and the like. It is possible to reliably manufacture a highly reliable multilayer ceramic electronic component without structural defects.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a ceramic laminate formed in an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a sintered body obtained by firing a ceramic laminated body formed in one example of the present invention.

FIG. 3 is a cross-sectional view showing a monolithic ceramic capacitor formed by forming external electrodes on the sintered body of FIG.

FIG. 4 is a sectional view showing a conventional monolithic ceramic capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic layer 2 Internal electrode (conductive paste) 3 Laminated parts 4a, 4b Outer layer part (dummy sheet) 5 Ceramic laminated body 5a Sintered body of ceramic laminated body 6a, 6b External electrode

Claims (1)

[Claims] 1. A method of manufacturing a laminated ceramic electronic component, which comprises arranging internal electrodes in a ceramic, comprising a plurality of internal electrodes and ceramic layers such that the internal electrodes face each other with a ceramic layer interposed therebetween. By arranging the outer layer part consisting of the ceramic layer in which the internal electrodes are not arranged, in the thickness ratio of 1: 2 to 1: 3, on both upper and lower sides of the laminated part in which the A method for producing a laminated ceramic electronic component, comprising forming a ceramic laminated body, firing the ceramic laminated body, and causing a minute warp of the sintered body in a predetermined direction.