JP2018098248A - Manufacturing method of multilayer ceramic electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a multilayer ceramic electronic component having an excellent cutting side surface.SOLUTION: A manufacturing method of a multilayer ceramic electronic component, comprises steps of: manufacturing a mother block including a plurality of laminated ceramic green sheets and an inner electrode pattern arranged along a plurality of boundary surfaces between the ceramic green sheets; acquiring a plurality of green chips that includes a lamination structure constructed by having a plurality of ceramic layers in a raw state and a plurality of inner electrodes 26 by cutting the mother block along first and second direction cutting-plane lines orthogonal each other, and in which each inner electrode 26 exposes to a cutting side surface 20 appeared by the cutting along the first direction cutting-plate line; eliminating a metal component of the cutting side surface 20; acquiring a raw component main body by forming a raw ceramic protection layer in the cutting side surface 20 obtained by eliminating the metal component; and burning the raw component main body.SELECTED DRAWING: Figure 9

Description

The present invention relates to a method for manufacturing a multilayer ceramic electronic component.

An example of the multilayer ceramic electronic component is a multilayer ceramic capacitor. In order to manufacture a multilayer ceramic capacitor, for example, a ceramic green sheet on which internal electrodes are formed is laminated, and the raw component body obtained is fired, and then external electrodes are formed on opposite end surfaces of the sintered component body. Form. As a result, a multilayer ceramic capacitor is obtained in which the internal electrodes drawn out on both end faces are electrically connected to the external electrodes.

In recent years, with the miniaturization and high functionality of electronic components, multilayer ceramic capacitors are required to be small and have high capacity. In order to reduce the size and increase the capacity of the multilayer ceramic capacitor, it is effective to increase the effective area of the internal electrodes occupying the ceramic green sheet, that is, the area of the internal electrodes facing each other.

For example, Patent Document 1 includes a step of producing a mother block including a plurality of laminated ceramic green sheets and internal electrode patterns respectively disposed along a plurality of interfaces between the ceramic green sheets; By cutting the mother block along a cutting line in the first direction and a cutting line in the second direction orthogonal to each other, the mother block has a laminated structure composed of a plurality of ceramic layers and a plurality of internal electrodes in a raw state. And a step of obtaining a plurality of green chips in which the internal electrode is exposed on a cut side surface that appears by cutting along the cutting line in the first direction, and applying a ceramic paste to the cut side surface, Forming a ceramic protective layer, and obtaining a raw component body, and firing the raw component body. Mick method of manufacturing an electronic component is disclosed.

Japanese Patent No. 5678905

In the method described in Patent Document 1, the area of the internal electrodes facing each other is increased by cutting the mother block so that the internal electrodes are exposed on the side surfaces. However, a method such as dicing is used for cutting the mother block, and the internal electrodes hang down due to the stress at the time of cutting. Therefore, the shorter the distance between the internal electrodes, the more the internal electrodes are in contact across the layers. (Hereinafter, also referred to as a short-circuit portion) is likely to occur on the cut side surface. Furthermore, the cut side surface is likely to be rough due to stress during cutting. If a chip component is manufactured in such a state, the short-circuit defect rate at the stage after degreasing increases. From the above, it has been difficult to obtain a good cut side face in the method for producing a high-capacity multilayer ceramic capacitor.

The above problem is not limited to the case of manufacturing a multilayer ceramic capacitor, but is a problem common to the case of manufacturing a multilayer ceramic electronic component other than the multilayer ceramic capacitor.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for producing a multilayer ceramic electronic component having a good cut side surface.

In the first aspect, the method for manufacturing a multilayer ceramic electronic component of the present invention includes a plurality of laminated ceramic green sheets, and internal electrode patterns respectively disposed along a plurality of interfaces between the ceramic green sheets. A step of fabricating a mother block, and cutting the mother block along a cutting line in a first direction and a cutting line in a second direction orthogonal to each other, thereby providing a plurality of ceramic layers in a raw state and a plurality of interiors And a step of obtaining a plurality of green chips, wherein the internal electrodes are exposed on a cut side surface that appears by cutting along the cutting line in the first direction, and a metal on the cut side surface. A raw component body by forming a raw ceramic protective layer on the side of the cut after removing the metal component and the metal component And obtaining, characterized in that it comprises a step of firing the raw component body.

According to the first aspect of the present invention, since the sagging of the internal electrode generated at the time of cutting can be removed by removing the metal component on the cut side surface of the green chip where the internal electrode is exposed, the occurrence of a short-circuit portion is generated. Can be prevented. As a result, a good cut side surface can be obtained.

In the first aspect of the method for manufacturing a multilayer ceramic electronic component according to the present invention, the plurality of green chips arranged in the row and column directions are spaced apart from each other before the step of removing the metal component. The method further comprises the step of rolling the plurality of green chips to align the cut side surfaces of each of the plurality of green chips into an open surface, wherein the metal component of the cut side surface that is the open surface is provided. It is preferable to remove. In this case, removal of the metal component on the cut side surface and formation of the ceramic protective layer can be performed efficiently.

In the second aspect, the method for producing a multilayer ceramic electronic component of the present invention includes a plurality of laminated ceramic green sheets, and internal electrode patterns respectively disposed along a plurality of interfaces between the ceramic green sheets. And a step of producing a mother block and a laminated structure composed of a plurality of ceramic layers and a plurality of internal electrodes in a raw state by cutting the mother block along a cutting line in a first direction. And a step of obtaining a plurality of rod-shaped green block bodies in which the internal electrode is exposed on a cut side surface that appears by cutting along the cutting line in the first direction, a step of removing a metal component on the cut side surface, Forming the raw ceramic protective layer on the cut side surface after removing the metal component; and the rod having the raw ceramic protective layer formed thereon Cutting the green block body along a cutting line in a second direction orthogonal to the first direction to obtain a plurality of raw component bodies, and firing the raw component bodies. It is characterized by providing.

In the second aspect of the present invention, since the sagging of the internal electrode generated during cutting can be removed by removing the metal component on the cut side surface of the rod-shaped green block body from which the internal electrode is exposed, a short circuit is caused. Generation | occurrence | production of a location can be prevented. As a result, a good cut side surface can be obtained.

In the second aspect of the method for manufacturing a multilayer ceramic electronic component according to the present invention, the interval between the plurality of rod-shaped green block bodies arranged in a predetermined direction is increased before the step of removing the metal component. In the state, the method further comprises a step of rolling the plurality of rod-shaped green block bodies to align the cut side surfaces of each of the plurality of rod-shaped green block bodies so as to form an open surface. It is preferable to remove the metal component on the cut side surface. In this case, removal of the metal component on the cut side surface and formation of the ceramic protective layer can be performed efficiently.

Hereinafter, when the first aspect and the second aspect of the present invention are not particularly distinguished, they are simply referred to as “a method for producing a multilayer ceramic electronic component of the present invention”.

In the method for manufacturing a multilayer ceramic electronic component of the present invention, it is preferable that an etching process is performed in the step of removing the metal component. The internal electrode sagging can be removed by dissolving the metal component.

The etching treatment is preferably performed by immersing the green chip or the rod-shaped green block body in an acid or alkali solution that dissolves the metal component.

In the method for manufacturing a multilayer ceramic electronic component of the present invention, it is preferable that laser treatment is performed in the step of removing the metal component. The sagging of the internal electrode can be removed by burning off the metal component with a laser.

The laser light wavelength in the laser treatment is preferably 350 nm or more. When the laser beam wavelength is 350 nm or more, the metal component can be selectively removed from the cut side surface.

Laser irradiation energy in the laser treatment, 100 mJ / cm ² or more, preferably 10000 mJ / cm ² or less.

In the method for manufacturing a multilayer ceramic electronic component of the present invention, the raw ceramic protective layer is formed by attaching a green sheet for a ceramic protective layer or by applying a ceramic protective layer paste, The green sheet for ceramic or the paste for ceramic protective layer preferably contains substantially no Mg. To date, by forming a raw ceramic protective layer using a ceramic protective layer green sheet or ceramic protective layer paste containing Mg, a different phase is formed at the end of the internal electrode to reduce the short-circuit defect rate. The method of making it known is known. On the other hand, in the method for manufacturing a multilayer ceramic electronic component of the present invention, even if Mg is not substantially contained in the ceramic protective layer green sheet or the ceramic protective layer paste, the short-circuit defect rate can be reduced. .

In the method for manufacturing a multilayer ceramic electronic component of the present invention, the raw ceramic protective layer is preferably formed by applying a ceramic protective layer paste. Compared to the method of applying the ceramic protective layer green sheet, the method of applying the ceramic protective layer paste causes less damage to the green chip or rod-shaped green block body when forming the raw ceramic protective layer. . Therefore, the short-circuit defect rate can be further reduced.

In the method for producing a multilayer ceramic electronic component of the present invention, the thickness of the ceramic green sheet for producing the mother block is preferably 1 μm or less. In the manufacturing method of the multilayer ceramic electronic component of the present invention, since the sagging of the internal electrode is removed, even when the ceramic green sheet is thin, that is, when the distance between the internal electrodes is short, occurrence of a short-circuited portion is prevented. can do.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the laminated ceramic electronic component which has a favorable cut | disconnected side surface can be provided.

FIG. 1 is a perspective view schematically showing an example of a multilayer ceramic capacitor obtained by the method for manufacturing a multilayer ceramic electronic component of the present invention. FIG. 2 is a perspective view schematically showing an example of a component main body constituting the multilayer ceramic capacitor shown in FIG. FIG. 3 is a perspective view schematically showing an example of a green chip prepared for producing the component main body shown in FIG. FIG. 4 is a plan view schematically showing an example of a ceramic green sheet on which an internal electrode pattern prepared for producing the green chip shown in FIG. 3 is formed. FIG. 5A is a perspective view for explaining a process of laminating the ceramic green sheets shown in FIG. 4, and FIGS. 5B and 5C are laminating the ceramic green sheets shown in FIG. It is a top view for demonstrating the process to do. FIG. 6 is a perspective view for explaining a process of cutting the mother block. FIG. 7 is a perspective view illustrating a state in which a plurality of green chips arranged in the row and column directions are spaced apart from each other. FIGS. 8A and 8B are perspective views for explaining a process of rolling the green chip. FIG. 9A and FIG. 9B are diagrams for explaining the process of removing the metal component on the cut side surface. FIG. 10 is a diagram for explaining a process of forming a raw ceramic protective layer.

Hereinafter, the manufacturing method of the multilayer ceramic electronic component of the present invention will be described.
However, the present invention is not limited to the following configurations, and can be applied with appropriate modifications without departing from the scope of the present invention. Note that the present invention also includes a combination of two or more desirable configurations of the present invention described below.

As an embodiment of the method for manufacturing a multilayer ceramic electronic component of the present invention, a method for manufacturing a multilayer ceramic capacitor will be described as an example. In addition, the manufacturing method of this invention is applicable also to multilayer ceramic electronic components other than a multilayer ceramic capacitor.

First, a multilayer ceramic capacitor obtained by the method for producing a multilayer ceramic electronic component of the present invention will be described.
FIG. 1 is a perspective view schematically showing an example of a multilayer ceramic capacitor obtained by the method for manufacturing a multilayer ceramic electronic component of the present invention. FIG. 2 is a perspective view schematically showing an example of a component main body constituting the multilayer ceramic capacitor shown in FIG.

A multilayer ceramic capacitor 11 shown in FIG. 1 includes a component body 12. As shown in FIG. 2, the component main body 12 has a rectangular parallelepiped shape or a substantially rectangular parallelepiped shape, and is opposed to a pair of main surfaces 13 and 14 facing each other, a pair of side surfaces 15 and 16 facing each other, and the like. And a pair of end faces 17 and 18.

FIG. 3 is a perspective view schematically showing an example of a green chip prepared for producing the component main body shown in FIG.
As will be described later, the component main body 12 shown in FIG. 2 has raw ceramic protective layers 22 and 23 on a pair of side surfaces 20 and 21 facing each other of the green chip 19 shown in FIG. It can be obtained by firing those formed respectively. In the following description, a part derived from the green chip 19 in the fired component main body 12 will be referred to as a laminated portion 24.

As shown in FIGS. 2 and 3, the laminated portion 24 in the component main body 12 includes a plurality of ceramic layers 25 extending in the direction of the main surfaces 13 and 14 and stacked in a direction perpendicular to the main surfaces 13 and 14, and ceramics. It has a laminated structure composed of a plurality of pairs of internal electrodes 26 and 27 formed along the interface between the layers 25. The component body 12 has a pair of ceramic protective layers 22 and 23 disposed on the cut side surfaces 20 and 21 of the laminate 24 to provide the side surfaces 15 and 16 respectively. The ceramic protective layers 22 and 23 preferably have the same thickness.

In FIGS. 1 and 2, for convenience of explanation, the boundary between the laminated portion 24 and each of the ceramic protective layers 22 and 23 is clearly shown, but such a boundary does not appear clearly. May be.

As shown in FIGS. 2 and 3, the internal electrode 26 and the internal electrode 27 oppose each other with the ceramic layer 25 interposed therebetween. When the internal electrode 26 and the internal electrode 27 face each other, electrical characteristics are developed. That is, a capacitance is formed in the multilayer ceramic capacitor 11 shown in FIG.

The internal electrode 26 has an exposed end exposed at the end surface 17 of the component main body 12, and the internal electrode 27 has an exposed end exposed at the end surface 18 of the component main body 12. On the other hand, since the ceramic protective layers 22 and 23 described above are disposed, the internal electrodes 26 and 27 are not exposed to the side surfaces 15 and 16 of the component body 12.

As shown in FIG. 1, the multilayer ceramic capacitor 11 is further formed on at least one pair of end surfaces 17 and 18 of the component body 12 so as to be electrically connected to the exposed ends of the internal electrodes 26 and 27, respectively. External electrodes 28 and 29 are formed, respectively.

The external electrodes 28 and 29 are respectively formed on at least one pair of end surfaces 17 and 18 of the component body 12, and in FIG. 1, the external electrodes 28 and 29 wrap around the main surfaces 13 and 14 and parts of the side surfaces 15 and 16. Has a part.

For example, Ni, Cu, Ag, Pd, an Ag—Pd alloy, Au, or the like can be used as the conductive material constituting the internal electrode.

As the ceramic material constituting the ceramic layer and the ceramic protective layer, for example, a dielectric ceramic mainly composed of BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , CaZrO _3, or the like can be used.

The ceramic material constituting the ceramic protective layer is preferably at least the same as the main component of the ceramic material constituting the ceramic layer. In this case, it is particularly preferred that ceramic materials having the same composition are used for both the ceramic layer and the ceramic protective layer.

As described above, the manufacturing method of the present invention can be applied to multilayer ceramic electronic components other than multilayer ceramic capacitors. For example, when the multilayer ceramic electronic component is a piezoelectric component, a piezoelectric ceramic such as a PZT ceramic is used, and when the thermistor is a semiconductor ceramic such as a spinel ceramic.

The external electrode is preferably composed of a base layer and a plating layer formed on the base layer. For example, Cu, Ni, Ag, Pd, an Ag—Pd alloy, Au, or the like can be used as the conductive material constituting the base layer. The underlayer may be formed by applying a co-fire method in which a conductive paste is applied onto an unfired component body and simultaneously fired with the component body, and the conductive paste is applied onto the fired component body. It may be formed by applying a post-fire method. Alternatively, the underlayer may be formed by direct plating, or may be formed by curing a conductive resin including a thermosetting resin.

The plating layer formed on the base layer preferably has a two-layer structure of Ni plating and Sn plating thereon.

Next, a method for manufacturing the multilayer ceramic capacitor 11 shown in FIG. 1 will be described as an example of the method for manufacturing the multilayer ceramic electronic component of the present invention.

First, a ceramic green sheet to be a ceramic layer is prepared. For example, the ceramic green sheet is formed on a carrier film using a die coater, a gravure coater, a micro gravure coater, or the like.

The thickness of the ceramic green sheet is usually 3 μm or less, preferably 1 μm or less, and more preferably 0.6 μm or less.

Next, a conductive paste is printed on the ceramic green sheet with a predetermined pattern.

FIG. 4 is a plan view schematically showing an example of a ceramic green sheet on which an internal electrode pattern prepared for producing the green chip shown in FIG. 3 is formed.
As shown in FIG. 4, an internal electrode pattern 32 to be each of the internal electrodes 26 and 27 is formed by printing a conductive paste with a predetermined pattern on the ceramic green sheet 31 to be the ceramic layer 25. Is done. Specifically, a plurality of strip-like internal electrode patterns 32 are formed on the ceramic green sheet 31.

The thickness of the internal electrode pattern is not particularly limited, but is preferably 1.5 μm or less.

Thereafter, a stacking process is performed in which a predetermined number of ceramic green sheets on which internal electrode patterns are formed are stacked while being shifted, and a predetermined number of ceramic green sheets on which no internal electrode patterns are formed are stacked on the top and bottom.

Fig.5 (a) is a perspective view for demonstrating the process of laminating | stacking the ceramic green sheet shown in FIG.
As shown in FIG. 5A, a predetermined number of ceramic green sheets 31 on which the internal electrode patterns 32 are formed are stacked while being shifted by a predetermined interval along the width direction, that is, half the width direction dimension of the internal electrode patterns 32. . Further, a predetermined number of ceramic green sheets on which no internal electrode pattern is printed are stacked above and below.

FIGS. 5B and 5C are plan views for explaining a process of laminating the ceramic green sheets shown in FIG. FIGS. 5B and 5C are enlarged views of the first and second ceramic green sheets, respectively.
5B and 5C, a cutting line 33 in the width direction (vertical direction in FIGS. 5B and 5C) perpendicular to the direction in which the strip-shaped internal electrode pattern 32 extends, and Each part of the cutting line 34 in the longitudinal direction perpendicular to this (the left-right direction in FIGS. 5B and 5C) is shown. The strip-shaped internal electrode pattern 32 has a shape in which two internal electrodes 26 and 27 are connected to each other at respective lead portions and are continuous in the longitudinal direction. 5B and 5C, the cutting lines 33 and 34 are shown in common.

As a result of the lamination step, a mother block including a plurality of laminated ceramic green sheets and internal electrode patterns respectively arranged along a plurality of interfaces between the ceramic green sheets is obtained. The obtained mother block is pressed in the stacking direction by means such as isostatic pressing.

A plurality of green chips is obtained by cutting the pressed mother block along a cutting line in a first direction and a cutting line in a second direction orthogonal to each other. For this cutting, for example, methods such as dicing, pressing, and laser cutting are applied.

FIG. 6 is a perspective view for explaining a process of cutting the mother block.
In FIG. 6, the mother block 35 is cut along a cutting line 33 in a first direction and a cutting line 34 in a second direction orthogonal to each other to obtain a plurality of green chips 19 arranged in the row and column directions. In FIG. 6, the uppermost internal electrode pattern 32 located inside the mother block 35 is indicated by a broken line. In FIG. 6, six green chips 19 are taken out from one mother block 35, but in reality, a larger number of green chips 19 are taken out.

As shown in FIG. 3, each green chip 19 has a laminated structure including a plurality of ceramic layers 25 in a raw state and a plurality of internal electrodes 26 and 27. The cut side surfaces 20 and 21 of the green chip 19 are surfaces that appear by cutting along the cutting line 33 in the first direction, and the cutting end surfaces 36 and 37 are surfaces that appear by cutting the cutting line 34 in the second direction. All of the internal electrodes 26 and 27 are exposed on the cut side surfaces 20 and 21. Further, only the internal electrode 26 is exposed on one cut end face 36, and only the internal electrode 27 is exposed on the other cut end face 37.

In addition, as shown in FIG. 6, the mother block 35 may be cut in a state of being attached on the expandable adhesive sheet 38 so that the plurality of green chips 19 are arranged in the row and column directions. preferable. In this case, the adhesive sheet 38 can be expanded by an expanding device (not shown).

FIG. 7 is a perspective view illustrating a state in which a plurality of green chips arranged in the row and column directions are spaced apart from each other.
By extending the adhesive sheet 38 shown in FIG. 6, as shown in FIG. 7, the plurality of green chips 19 arranged in the row and column directions are in a state in which the interval between them is increased.

Subsequently, it is preferable that a rolling step is performed in which a plurality of green chips are rolled to align the cut side surfaces of the plurality of green chips to open surfaces.

FIGS. 8A and 8B are perspective views for explaining a process of rolling the green chip.
By rotating the green chip 19 shown in FIG. 8A by 90 degrees, as shown in FIG. 8B, the cut side surface 20 can be made an open surface facing upward.

A step of removing the metal component on the cut side surface is performed. In this step, the ceramic component on the cut side surface may be removed, but preferably only the metal component is removed. When performing the above-mentioned rolling process, it is preferable that the process of removing the metal component of the cut side surface which faced upward by the rolling process is performed.

The step of removing the metal component on the cut side surface may be performed at any stage after the mother block is cut and before the raw ceramic protective layer is formed. Therefore, for example, the metal component on the cut side surface before the rolling step may be removed, or the metal component on the cut side surface obtained by cutting may be removed without performing the rolling step.

FIG. 9A and FIG. 9B are diagrams for explaining the process of removing the metal component on the cut side surface. FIG. 9A and FIG. 9B are enlarged views of the vicinity of the cut side surface shown from the end surface direction of the green chip.
As shown in FIG. 9A, a dripping 26A of the internal electrode 26 exists on the cut side surface 20 due to stress at the time of cutting. By removing the metal component of the cut side surface 20, the sagging 26A of the internal electrode 26 can be removed as shown in FIG. 9B.

Methods for removing metal components include, for example, etching treatment (chemical etching, electrolytic etching, etc.), laser treatment, electron beam treatment (CP method, FIB method, etc.), blast treatment (sand blast treatment, etc.), discharge treatment, ultrasonic wave Processing and the like. These processes may be combined. From the viewpoint of preventing the occurrence of a short-circuit portion, etching treatment or laser treatment is preferable.

The etching treatment is preferably performed by immersing the green chip in an acid or alkali solution that dissolves the metal component. For example, when the conductive material of the internal electrode is Ni, a cyan or no cyan etchant can be used. The etching process may be chemical etching or electrolytic etching.

The temperature of the etching process is not particularly limited, and is, for example, 50 ° C. or higher and 100 ° C. or lower.

The time for the etching process is not particularly limited, and is, for example, not less than 10 seconds and not more than 30 seconds.

The laser treatment is preferably performed by irradiating a laser on the cut side surface facing upward.

The laser light wavelength in the laser treatment is preferably 350 nm or more. Moreover, it is preferable that a laser beam wavelength is 1200 nm or less, and it is more preferable that it is 1000 nm or less.

The laser irradiation energy in the laser treatment is preferably 100 mJ / cm ² or more, and more preferably 500 mJ / cm ² or more. Further, the laser irradiation energy is preferably 10000 mJ / cm ² or less, more preferably 5000 mJ / cm ² or less.

The beam waveform in the laser processing is preferably a top hat.

The pulse width in laser processing is preferably in the range of microseconds to picoseconds.

After removing the metal component on the cut side, a raw ceramic protective layer is formed on the cut side. The raw ceramic protective layer is formed by, for example, attaching a ceramic protective layer green sheet or applying a ceramic protective layer paste.

FIG. 10 is a diagram for explaining a process of forming a raw ceramic protective layer.
As shown in FIG. 10, a green ceramic protective layer 22 is formed by applying a ceramic protective layer green sheet to the cut side surface 20 after removing the metal component, or by applying a ceramic protective layer paste. can do.

The ceramic protective layer green sheet or the ceramic protective layer paste preferably contains the same ceramic raw material as the main component of the ceramic green sheet for producing the mother block.

Moreover, it is preferable that Mg is not substantially contained in the ceramic protective layer green sheet or the ceramic protective layer paste.

After forming the raw ceramic protective layer, a drying step is performed as necessary. In the drying process, the green chip 19 on which the raw ceramic protective layer 22 is formed is placed in an oven set at 120 ° C. for 5 minutes, for example.

Next, it is preferable that a rolling process similar to the process described with reference to FIG. 8 is performed. That is, it is preferable that a rolling process is performed in which a plurality of green chips are rolled to align the cut side surfaces of the plurality of green chips to be open surfaces. In this case, by rotating the green chip by 180 degrees, the cut surface on the opposite side can be made an open surface facing upward.

Similarly to the above, the metal component on the cut side surface may be removed and the raw ceramic protective layer formed on the opposite cut side surface. The method and conditions for removing the metal component may be the same or different. Moreover, after forming a raw ceramic protective layer, a drying process is performed as needed. Thus, a raw component body is obtained.

The obtained raw component body is fired. The firing temperature is, for example, in the range of 900 ° C. or higher and 1300 ° C. or lower, although it depends on the ceramic material or metal material contained in the raw component body.

External electrodes 28 and 29 are formed by applying a conductive paste to both end surfaces 17 and 18 of the component body after firing, baking, and then plating as necessary. The application of the conductive paste may be performed on the raw component body, or the conductive paste may be baked at the same time as the raw component body is fired.

In this way, the multilayer ceramic capacitor 11 shown in FIG. 1 is manufactured.

In the embodiment described above, the mother block is cut into a cutting line in the first direction and a cutting line in the second direction to obtain a plurality of green chips, and then the metal component on the cut side surface is removed, and the raw ceramic protective layer is formed. Although formed, it can be changed as follows.

That is, by cutting the mother block along only the cutting line in the first direction, a plurality of rod-shaped green block bodies are obtained in which the internal electrodes are exposed on the cutting side surfaces that appear by cutting along the cutting line in the first direction. After removing the metal component on the cut side surface and forming a raw ceramic protective layer, it is cut into cutting lines in the second direction to obtain a plurality of raw component bodies, and then the raw component bodies are fired May be. After firing, a multilayer ceramic electronic component can be manufactured by performing the same process as in the above-described embodiment.

Examples in which the method for producing a multilayer ceramic electronic component of the present invention is disclosed more specifically below. In addition, this invention is not limited only to these Examples.

[Production of multilayer ceramic capacitors]
Example 1
A polyvinyl butyral binder, a plasticizer and ethanol as an organic solvent were added to BaTiO ₃ as a ceramic raw material, and these were wet mixed by a ball mill to prepare a ceramic slurry. Next, this ceramic slurry was formed into a sheet by a lip method to obtain a rectangular ceramic green sheet. Next, a conductive paste containing Ni was screen-printed on the ceramic green sheet to form an internal electrode pattern containing Ni as a main component.

A plurality of ceramic green sheets on which internal electrode patterns were formed were stacked while shifting in the width direction, and ceramic green sheets on which no internal electrode patterns were printed were stacked on the top and bottom to obtain a mother block. The obtained mother block was pressed in the laminating direction by an isostatic press.

The pressed mother block was cut into a chip shape to obtain a green chip in which individual internal electrodes were exposed on both end faces and both side faces. After cutting, ultrasonic cleaning with pure water was performed.

An etching process was performed on one cut side surface of the green chip. Enstrip NP-1 solution: Enstrip NP-2 solution: pure water = 1: 1: 3 (volume ratio) was used as an etchant, and was immersed at a temperature of 70 ° C. for 20 seconds.

After the etching treatment, ultrasonic cleaning with pure water was performed, and then moisture was dried. Subsequently, a green ceramic protective layer was adhered to the cut side surface after the etching treatment to form a raw ceramic protective layer. The composition of the ceramic protective layer green sheet is the same as the composition of the ceramic green sheet.

A green ceramic protective layer was formed on the other cut side surface of the green chip in the same manner as described above after etching. As a result, a raw component body was obtained.

The obtained raw component body was degreased in a nitrogen atmosphere and then fired in a hydrogen / nitrogen mixed atmosphere. After firing, an external electrode was formed by applying and baking a conductive paste, and a multilayer ceramic capacitor of Example 1 was produced.

(Example 2)
A green chip was produced by the same method as in Example 1. Laser treatment was performed on one cut side of the green chip. The laser irradiation conditions were as follows: laser beam wavelength: 532 nm, laser irradiation energy: 5700 mJ / cm ² , beam waveform: top hat, pulse width: 20 nanoseconds.

Thereafter, as in Example 1, a raw ceramic protective layer was formed. Also on the other cut side surface of the green chip, a raw ceramic protective layer was formed after laser treatment in the same manner as described above. In addition, the external electrodes were formed by the same method as in Example 1 to produce the multilayer ceramic capacitor of Example 2.

(Comparative Example 1)
Except that the etching process was not performed on the cut side surface of the green chip, the external electrodes were formed in the same manner as in Example 1 to produce a multilayer ceramic capacitor of Comparative Example 1.

[Evaluation]
(Completely shorted point)
Using a scanning electron microscope (SEM), the cut side surface before forming the external electrode was photographed at a magnification of 7000 times. In 14 to 16 internal electrodes, the number of locations where Ni particles completely contact each other across the layers was measured. The results are shown in “Completely short-circuited locations” in Table 1. A case where the number of completely short-circuited portions was 0 was evaluated as ◎ (excellent), and a case where it was 1 or more was evaluated as × (impossible).

(Short rate after degreasing)
The capacitance of 100 multilayer ceramic capacitors was measured with an LCR meter, and the occurrence rate of short-circuit defects was calculated. The results are shown in “Short rate after degreasing” in Table 1. A case where the short-circuit rate after degreasing was less than 80% was evaluated as ◎ (excellent), a case where it was 80% or more and less than 100% was evaluated as ○ (good), and a case where it was 100% was evaluated as × (impossible).

As shown in Table 1, after the mother block was cut and before the raw ceramic protective layer was formed, in Comparative Example 1 where the cutting side surface was not subjected to etching treatment or laser treatment, a complete short circuit occurred. In contrast, in Example 1 where the etching process was performed on the cut side surface and in Example 2 where the laser process was performed, the number of complete short circuits was 0. Furthermore, in Examples 1 and 2, the short-circuit rate after degreasing was significantly lower than that in Comparative Example 1.

11 Multilayer ceramic capacitors (multilayer ceramic electronic components)
12 Parts main body 13 and 14 Main surface 15 and 16 Side surface 17 and 18 End surface 19 Green chip 20, 21 Cutting side surface 22 and 23 Ceramic protective layer 24 Laminate part 25 Ceramic layer 26 and 27 Internal electrode 26A Internal electrode droop 28 and 29 External Electrode 31 Ceramic green sheet 32 Internal electrode pattern 33 Cutting line 34 in the first direction Cutting line 35 in the second direction Mother block 36, 37 Cutting end face 38 Adhesive sheet

Claims (12)

A step of producing a mother block including a plurality of laminated ceramic green sheets and internal electrode patterns respectively disposed along a plurality of interfaces between the ceramic green sheets;
A laminated structure including a plurality of ceramic layers and a plurality of internal electrodes in a raw state by cutting the mother block along a cutting line in a first direction and a cutting line in a second direction orthogonal to each other. And obtaining a plurality of green chips, wherein the internal electrodes are exposed on a cut side surface that appears by cutting along the cutting line in the first direction;
Removing the metal component of the cut side surface;
Forming a raw ceramic protective layer on the cut side surface after removing the metal component to obtain a raw component body;
And a step of firing the raw component body. A method of manufacturing a multilayer ceramic electronic component, comprising: Before the step of removing the metal component, a plurality of the green chips are rolled by rolling a plurality of the green chips in a state where the plurality of green chips arranged in the row and column directions are widened. Further comprising the step of aligning the cut side surfaces of each of the chips to form an open surface;
The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein a metal component on the cut side surface that is the open surface is removed. A step of producing a mother block including a plurality of laminated ceramic green sheets and internal electrode patterns respectively disposed along a plurality of interfaces between the ceramic green sheets;
By cutting the mother block along a cutting line in the first direction, the mother block has a laminated structure including a plurality of ceramic layers and a plurality of internal electrodes in a raw state, and cutting in the first direction A step of obtaining a plurality of rod-shaped green block bodies in which the internal electrode is exposed on a cut side surface that appears by cutting along a line;
Removing the metal component of the cut side surface;
Forming a raw ceramic protective layer on the cut side surface after removing the metal component;
Cutting the rod-shaped green block body on which the raw ceramic protective layer is formed along a cutting line in a second direction perpendicular to the first direction to obtain a plurality of raw component bodies;
And a step of firing the raw component body. A method of manufacturing a multilayer ceramic electronic component, comprising: Before the step of removing the metal component, by rolling the plurality of rod-shaped green block bodies in a state where the intervals between the plurality of rod-shaped green block bodies arranged in a predetermined direction are widened, Further comprising the step of aligning the cut side surfaces of each of the plurality of rod-shaped green block bodies into an open surface;
The method for producing a multilayer ceramic electronic component according to claim 3, wherein a metal component on the cut side surface that is the open surface is removed. The method for producing a multilayer ceramic electronic component according to claim 1, wherein an etching process is performed in the step of removing the metal component. The method for manufacturing a multilayer ceramic electronic component according to claim 5, wherein the etching treatment is performed by immersing the green chip or the rod-shaped green block body in an acid or alkali solution that dissolves the metal component. The method for producing a multilayer ceramic electronic component according to claim 1, wherein laser treatment is performed in the step of removing the metal component. The method of manufacturing a multilayer ceramic electronic component according to claim 7, wherein a laser beam wavelength in the laser treatment is 350 nm or more. The laser irradiation energy in the laser treatment, 100 mJ / cm ² or more, 10000 mJ / cm ² or less the method of production of a multilayer ceramic electronic component according to claim 7 or 8. The raw ceramic protective layer is formed by attaching a ceramic protective layer green sheet or by applying a ceramic protective layer paste,
The method for manufacturing a multilayer ceramic electronic component according to any one of claims 1 to 9, wherein Mg is not substantially contained in the ceramic protective layer green sheet or the ceramic protective layer paste. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the raw ceramic protective layer is formed by applying a ceramic protective layer paste. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein a thickness of the ceramic green sheet for producing the mother block is 1 μm or less.

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