JP2004228319A - Method of manufacturing laminated ceramic electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a laminated ceramic electronic component having such a structure that hardly causes a lamination deviation in a laminate which is obtained by stacking a plurality of ceramic green sheets. <P>SOLUTION: The method of manufacturing the laminated ceramic electronic component includes a process wherein, in order to obtain the laminate by stacking a plurality of ceramic green sheets on a stacking surface 6a of a stacking stage 6, a liquid 7 which is burned down when burning is applied on the stacking surface 6a of the stacking stage 6 in advance. Thereafter, the first ceramic green sheet 2A is stacked and then the rest of the ceramic green sheets are stacked sequentially. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor, and more particularly, to a method for manufacturing a multilayer ceramic electronic component in which a plurality of ceramic green sheets are stacked to obtain a multilayer body. About the method.
[0002]
[Prior art]
Conventionally, when manufacturing a multilayer ceramic electronic component, a plurality of ceramic green sheets are stacked to obtain a mother laminate. An example of a method of laminating a plurality of ceramic green sheets is described in Patent Document 1 below. In the method described in Patent Document 1, when manufacturing a multilayer ceramic capacitor, internal electrodes are printed on long ceramic green sheets. Thereafter, a ceramic green sheet having a predetermined size is punched from the long ceramic green sheet on which the internal electrodes are printed, and the ceramic green sheets are stacked in a stacking stage. In this way, a plurality of ceramic green sheets are sequentially laminated, and then a plurality of ceramic green sheets are pressed in the thickness direction to obtain a mother ceramic laminate.
[0003]
[Patent Document 1]
JP-A-8-97074
[Problems to be solved by the invention]
As described above, when manufacturing a conventional multilayer ceramic electronic component, a plurality of ceramic green sheets 102 to 104 are stacked on a stacking stage 101 as shown in FIG. In this case, the plurality of ceramic green sheets adhere to each other because the ceramic green sheets include an organic binder and a solvent. However, since the lamination stage 101 is made of a metal such as stainless steel, the ceramic green sheet is difficult to adhere to the lamination stage 101. Therefore, when the laminate 105 shrinks due to drying or the like, the end of the laminate 105 may float from the upper surface 101a of the laminate stage 101, as shown in FIG.
[0005]
In the laminated body portion in which such floating occurs, particularly, in the corner portion, there is a problem that the laminated ceramic green sheets are wrinkled or the laminated body is partially shrunk, thereby causing a lamination shift. there were. When a laminate of individual multilayer ceramic electronic component units is cut from a mother ceramic laminate in which lamination misalignment has occurred, the internal electrodes will not be arranged at correct positions in the laminate of individual multilayer ceramic electronic component units. . For example, as shown in FIG. 6, in the stacked body 111, although the plurality of internal electrodes 112 must be located at the center in the width direction, the inner electrodes 112 are shifted from the side surface 111a to the side surface 111b due to stacking shift. Had to be done. In extreme cases, the internal electrode 112 was even exposed on the side surface 111b.
[0006]
An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a method for manufacturing a multilayer ceramic electronic component including a step in which lamination misalignment is less likely to occur when stacking a plurality of ceramic green sheets.
[0007]
[Means for Solving the Problems]
The present invention provides a step of sequentially laminating a plurality of ceramic green sheets on a lamination surface of a lamination stage, and taking out an unfired ceramic laminate obtained by laminating a plurality of ceramic green sheets from the lamination stage. Baking, and a step of forming an external electrode on the outer surface of the sintered body obtained by baking, wherein the plurality of ceramic green sheets are laminated on a lamination stage. In this case, a ceramic green sheet is brought into close contact with the lamination surface of the lamination stage by surface tension, and a liquid that burns off during firing is applied, and then a plurality of ceramic green sheets are laminated.
[0008]
In the present invention, a plurality of ceramic green sheets are laminated after a liquid that is burned off during firing is applied to the upper surface of the lamination stage. The liquid forms a liquid film on the stacking stage, and thus acts to adhere the lower surface of the ceramic green sheet to be stacked first by the surface tension to the upper surface of the stacking stage by the surface tension. Therefore, when a plurality of ceramic green sheets are stacked on the stacking stage, floating at the end of the stack is unlikely to occur.
[0009]
In the present invention, the liquid that is burned off during the firing is not particularly limited, but is preferably an inert liquid that does not adversely affect the ceramic laminate, and a solvent that does not dissolve and swell the ceramic green sheet is, for example, Octanol, diisobutyl ketone, or dihydroterpineol acetate may be used.
[0010]
In the present invention, the step of laminating a plurality of ceramic green sheets is not particularly limited, but after applying the liquid on the lamination stage, the ceramic green sheets are laminated on at least one ceramic green sheet on the lamination stage. Is done. In this case, it is preferable that the lamination is performed by pressing at least one ceramic green sheet on the lamination surface or the previously laminated ceramic green sheet on the lamination stage, whereby the ceramic green sheets are sufficiently bonded to each other. A closely adhered laminate can be easily obtained.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be clarified by describing a manufacturing method according to an embodiment of the present invention with reference to the drawings.
[0012]
In the present embodiment, a multilayer ceramic capacitor is manufactured as a multilayer ceramic electronic component. In this embodiment, the manufacturing apparatus shown in FIG. 2 is used. As shown in FIG. 2, a long mother ceramic green sheet 2 is fed from a supply reel 1. The printing paste is printed on the upper surface of the long mother ceramic green sheet 2 by the printing machine 3 to print a plurality of internal electrode patterns. Then, after drying in the drying furnace 4, a rectangular ceramic green sheet is punched out by the cutting and laminating device 5. The cutting and laminating device 5 is configured to hold the punched rectangular ceramic green sheet on the lower surface by suction.
[0013]
The cutting and laminating device 5 is moved above the laminating stage 6 while the rectangular mother ceramic green sheet punched as described above is held on the lower surface of the cutting and laminating device 5. The mother ceramic green sheets are stacked on the stacking surface 6a.
[0014]
In the present embodiment, the lamination stage 6 has an annular side wall 6b and an opening above. In this case, the lamination surface 6a is a bottom portion surrounded by the annular side wall b. This lamination stage 6 is to be a press die in a later step. Of course, a stacking stage having an annular side wall with an upper surface serving as a stacking surface may be used.
[0015]
In the present embodiment, prior to lamination in the lamination stage 6, a liquid 7 is applied in advance on the lamination surface 6a of the lamination stage 6, as shown in FIG. As the liquid 7, an appropriate liquid that does not affect ceramics in a firing configuration described later is used. As such a liquid, octanol, diisobutyl ketone, dihydroterpineol acetate, or the like is preferably used because of its slow drying property, and more preferably, dihydroterpineol acetate is used.
[0016]
In the present embodiment, the first ceramic green sheet 2A is laminated after the liquid 7 is applied to the lamination surface 6a of the lamination stage 6. That is, the first ceramic green sheet 2A is held on the lower surface of the cutting and laminating apparatus 5 and moves to the laminating section, and the laminating stage 6 is raised, and as shown in FIG. The ceramic green sheet 2A is placed on the lamination surface 6a of No. 6.
[0017]
At this time, as shown in FIG. 1C, the end of the ceramic green sheet 2A is brought into close contact with the lamination surface 6a of the lamination stage 6 due to the surface tension of the liquid 7.
Thereafter, by driving the cutting / stacking device 5 again, the second and subsequent ceramic green sheets are sequentially stacked on the ceramic green sheet 2A.
[0018]
In the present embodiment, the ceramic green sheets held on the lower surface of the cutting and laminating apparatus 5 are laminated while being pressed against the laminating surface 6a of the laminating stage 6 or the upper surface of the previously laminated ceramic green sheets. Therefore, the adhesion between the ceramic green sheets is enhanced.
[0019]
After a predetermined number of ceramic green sheets are laminated as described above, the resulting laminate is pressed in the thickness direction to obtain a mother laminate. Although not clear in FIG. 1, when manufacturing a multilayer ceramic capacitor, after stacking plain ceramic green sheets on which internal electrodes are not printed, an appropriate number of ceramic green sheets on which internal electrode patterns are printed is formed. An appropriate number of plain ceramic green sheets on which the internal electrode patterns are not printed are laminated.
[0020]
The laminate obtained as described above is shown in a schematic front sectional view in FIG. In the mother laminate 11, a plurality of internal electrodes 12 are arranged so as to overlap with each other via a ceramic layer.
[0021]
The mother ceramic laminate 11 is cut in the thickness direction to obtain a laminate of individual multilayer ceramic capacitors. FIG. 3B shows the laminate obtained in this manner. In the multilayer body 13, the internal electrodes 14a to 14d overlap with the ceramic layers interposed therebetween.
[0022]
Thereafter, the laminated body 13 is fired to obtain the ceramic sintered body 15 shown in FIG. By forming the external electrodes 16 and 17 on the end surfaces 15a and 15b of the ceramic sintered body 15, a multilayer ceramic capacitor 18 is obtained.
[0023]
As described above, in the above-described embodiment, when the first ceramic green sheet 2A is laminated, the liquid 7 is previously applied to the lamination surface 6a of the lamination stage 6, and therefore, the ceramic green sheet 2A is formed by the surface tension of the liquid 7. Is adhered to the lamination surface 6A of the lamination stage 6. Accordingly, the end of the mother ceramic laminate obtained by laminating a plurality of ceramic green sheets hardly floats from the lamination surface 6a. Therefore, it is possible to effectively suppress the occurrence of stacking misalignment which has been a problem in the related art. Therefore, it is unlikely to cause stacking misalignment or bias in the position of the internal electrode in the finally obtained multilayer body of individual multilayer ceramic capacitors and in the sintered body obtained by firing the multilayer body.
[0024]
Next, specific experimental examples will be described.
Using a barium titanate-based ceramic composition and polyvinyl butyral as a binder, a plurality of 2 μm-thick ceramic green sheets were laminated to obtain a mother laminate. According to the above embodiment, when laminating, dihydroterpineol acetate was previously applied onto the laminating surface 6a of the laminating stage mainly made of steel. Lamination displacement in the obtained laminate was evaluated. The evaluation of the lamination misalignment is to measure the ratio of the n = about 7,000 lamination misalignments among a large number of individual multilayer ceramic capacitor laminates obtained from the mother ceramic laminate. It was done by doing.
[0025]
For comparison, a laminate was obtained and evaluated in the same manner as in the above example, except that the dihydroterpineol acetate was not applied. As a result, in the above example, the occurrence rate of lamination misalignment was 0.5%, whereas the lamination misalignment was extremely high at 60.0% when dihydroterpineol acetate was not applied. Had occurred.
[0026]
The present invention is not limited to the above-described multilayer ceramic capacitor, and can be applied to various methods for manufacturing multilayer ceramic electronic components such as a multilayer ceramic substrate and a multilayer ceramic inductor.
[0027]
Further, in the above embodiment, octanol, diisobutyl ketone, and dihydroterpineol acetate are described as examples that are difficult to dry, but the present invention is not limited to this, and n-heptane, for example, may be used.
[0028]
【The invention's effect】
According to the method for manufacturing a laminated ceramic electronic component according to the present invention, the ceramic green sheet is brought into close contact with the lamination surface of the lamination stage by surface tension, and a plurality of ceramic green sheets are applied after a liquid that burns off during firing is applied. Are laminated to obtain a laminate. Therefore, since the lower surface of the ceramic green sheet to be laminated first is securely adhered to the lamination surface of the lamination stage by the surface tension of the liquid, the occurrence of floating at the end of the obtained laminated body is effectively suppressed. be able to. Therefore, it is possible to suppress the stacking deviation caused by the occurrence of the floating, to provide a multilayer ceramic electronic component having excellent reliability, and to effectively increase the non-defective rate of the multilayer ceramic electronic component. Become.
[0029]
In the present invention, when octanol, diisobutyl ketone, or dihydroterpineol acetate is used as the above-mentioned liquid, it does not adversely affect ceramics during firing, so that a multilayer ceramic electronic component having desired characteristics can be obtained reliably and at a high yield. be able to.
[0030]
When a plurality of ceramic green sheets are laminated on at least one ceramic green sheet by being pressed on the lamination stage or the previously laminated ceramic green sheet on the lamination stage, adhesion of the ceramic green sheets is performed. Thus, it is possible to provide a multilayer ceramic electronic component with less lamination displacement.
[Brief description of the drawings]
FIGS. 1A, 1B, and 1C illustrate a step of laminating a first ceramic green sheet after applying a liquid to a lamination surface of a lamination stage in one embodiment of the present invention. FIG. 2 is a schematic front cross-sectional view for illustrating an example of the present invention, and a cross-sectional view showing an enlarged portion surrounded by a circle A in FIG.
FIG. 2 is a schematic configuration diagram for explaining a ceramic green sheet lamination system used in an embodiment of the present invention.
FIGS. 3A and 3B are schematic front sectional views showing a mother ceramic laminate and a laminate of individual multilayer ceramic capacitors prepared in an embodiment of the present invention.
FIG. 4 is a front sectional view showing a multilayer ceramic capacitor obtained in one embodiment of the present invention.
FIGS. 5A and 5B are schematic front cross-sectional views illustrating a process of laminating a plurality of ceramic green sheets and a problem in a conventional method for manufacturing a multilayer ceramic electronic component.
FIG. 6 is a cross-sectional view of a ceramic laminate for explaining a deviation in the position of an internal electrode when a lamination shift occurs in a conventional method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Supply reel 2 ... Ceramic green sheet 2A ... Ceramic green sheet 3 ... Printing machine 4 ... Drying furnace 5 ... Cutting / lamination apparatus 6 ... Lamination stage 6a ... Lamination surface 6b ... Annular side wall 7 ... Liquid 11 ... Mother laminated body 12 ... internal electrode 13 ... laminated bodies 14a to 14d ... internal electrode 15 ... sintered bodies 15a and 15b ... end faces 16, 17 ... external electrodes 18 ... multilayer ceramic capacitor

Claims (3)

A step of sequentially laminating a plurality of ceramic green sheets on a lamination surface of the lamination stage,
Removing the unfired ceramic laminate obtained by laminating a plurality of ceramic green sheets from the lamination stage, and firing;
Forming an external electrode on the outer surface of the sintered body obtained by firing, a method for manufacturing a multilayer ceramic electronic component,
In laminating the plurality of ceramic green sheets on the lamination stage, the laminating surface of the lamination stage is applied with a liquid that is burned off during firing while applying the ceramic green sheets in close contact with surface tension. And a method for manufacturing a multilayer ceramic electronic component. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein a liquid selected from octanol, diisobutyl ketone, and dihydroterpineol acetate is used as the liquid that is burned off during the firing. 2. The stacking of the plurality of ceramic green sheets, wherein the ceramic green sheets are pressure-bonded on the stacking surface or the ceramic green sheets stacked first on at least one ceramic green sheet on a stacking stage. 3. Or the manufacturing method of the multilayer ceramic electronic component of 2.

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