JP4507310B2 - Method for peeling multilayer ceramic element and inspection method for multilayer ceramic element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a peeling method for peeling a multilayer ceramic element having a structure in which ceramic layers and metal internal electrode layers are alternately laminated with a specific layer, and a method for inspecting the multilayer ceramic element.
[0002]
[Prior art]
In recent years, a multilayer ceramic element having a structure in which ceramic layers and metal internal electrode layers are alternately stacked, such as multilayer ceramic capacitors and multilayer piezoelectric components, has a structure in which external electrodes are provided so as to be electrically connected to the metal internal electrode layers. Multilayer ceramic electronic components are widely used. In this multilayer ceramic electronic component, downsizing and thinning are being promoted. In particular, in order to meet the market demand for multilayer ceramic capacitors, actual thinning and multilayering are progressing. is there.
[0003]
As the above-mentioned miniaturization and thinning proceed, it becomes easy to cause a failure or malfunction inside the multilayer ceramic element. In this case, depending on the situation, several hundred layers of ceramic layers are laminated. In addition, it is necessary to perform analysis and measurement on specific layers of the metal internal electrode layer to confirm the characteristics.
[0004]
In addition, when developing a multilayer ceramic electronic component having a new function or a multilayer ceramic electronic component having higher characteristics than conventional products, it is necessary to test each ceramic layer, each metal internal electrode layer, or a specific layer. It may be necessary to perform analysis and confirm the characteristics.
[0005]
[Problems to be solved by the invention]
By the way, conventionally, for example, when detecting a defective portion (for example, a low-resistance portion) inside the multilayer ceramic capacitor, the end surface and the side surface of the multilayer ceramic element are polished, and the internal electrode is exposed to the end surface and the side surface. A defective part was detected by a method such as measuring the electric resistance between layers.
[0006]
However, as the size and capacity of multilayer ceramic capacitors has increased, the thickness of the ceramic layer and metal internal electrode layer has decreased, and the analysis from the side or end surface measured the characteristics of the interface that caused the failure. , It is difficult to narrow down or identify defective parts.
[0007]
In addition, in the method of polishing the end face and side surface of the multilayer ceramic element, even if the failure location (failed layer) in the stacking direction can be specified, the bonding surface between the ceramic layer and the metal internal electrode layer at the failure occurrence portion can be identified. Since it cannot be exposed, the actual situation is that the cause of the failure cannot be sufficiently elucidated through accurate analysis and analysis.
[0008]
In addition, there is a method of polishing (planar polishing) the multilayer ceramic element from the upper surface side or the lower surface side. However, in the case of a multilayer ceramic element having a thin film and multiple layers, a specific layer (interface) is exposed smoothly. Thus, it is extremely difficult to polish in the plane direction, and there is a problem that when the surface is polished up to a predetermined layer, the polished and removed layer cannot be analyzed.
[0009]
The present invention solves the above problems, and even when the thickness of the ceramic layer and the metal internal electrode layer is thin, the multilayer ceramic element can be reliably peeled off at a desired interface. It is an object of the present invention to provide a method for inspecting a multilayer ceramic element that can be efficiently inspected by applying the method and the peeling method.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the inventors have conducted various studies, and in a multilayer ceramic element having a structure in which ceramic layers and metal internal electrode layers are alternately stacked, the bonding interface between the metal internal electrode layer and the ceramic layer is used. However, it is confirmed that the multilayer ceramic element can be peeled off at a desired interface by reducing the metal oxide to a metal by an experiment, focusing on the fact that the metal oxide is bonded via a metal oxide. The present invention was completed through experiments and examinations.
[0011]
The method for peeling the multilayer ceramic element of the present invention (Claim 1) is as follows:
A method for peeling a multilayer ceramic element, wherein a multilayer ceramic element having a structure in which ceramic layers and metal internal electrode layers are alternately stacked is peeled at an interface between a specific ceramic layer and a specific metal internal electrode layer,
At least a part of the multilayer ceramic element is immersed in an electrolytic solution capable of reducing a metal oxide (metal oxide) constituting the metal internal electrode layer to a metal,
A specific metal internal electrode layer in contact with a specific ceramic layer to be peeled is used as a cathode electrode, a cathode terminal is connected to the cathode, and a voltage is applied from the cathode terminal to the metal internal electrode layer. The multilayer ceramic element is peeled off at the interface between the specific ceramic layer and the specific metal internal electrode layer by reducing the metal oxide present at the interface between the electrode layer and the specific ceramic layer to a metal. It is said.
[0012]
At least a part of the multilayer ceramic element is immersed in an electrolytic solution capable of reducing the metal oxide (metal oxide) constituting the metal internal electrode layer to a metal, and is in contact with a specific ceramic layer to be peeled off The metal internal electrode layer is used as a cathode electrode, a cathode terminal is connected to the metal internal electrode layer, and a voltage is applied from the cathode terminal to the metal internal electrode layer (cathode electrode). It is possible to reduce the metal oxide present at the interface to a metal, and to cause peeling at the interface between the metal internal electrode layer and the specific ceramic layer.
[0013]
That is, in the method for peeling a multilayer ceramic element of the present invention, a voltage is applied to a metal internal electrode layer in contact with a specific ceramic layer to be peeled, and the metal oxide bonded to the ceramic layer is subjected to an electrochemical reduction reaction. By reducing to metal, the bonding interface is peeled off.
[0014]
In the present invention, since the metal oxide is reduced to a metal by an electrochemical reduction reaction, the pH of the electrolytic solution is important. Then, it is necessary to select an electrolytic solution capable of realizing a desirable pH from the relationship between the type of metal used for the internal electrode, the pH of the electrolytic solution, and the electromotive force of the metal. In addition, normally, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, etc. which adjusted pH to the predetermined range are illustrated as a preferable electrolyte solution.
[0015]
Moreover, as a cathode voltage applied to a metal internal electrode layer, the voltage (usually about 1.7-3.0V voltage) more than the electromotive force of the metal is normally applied. By applying a voltage of 1.7 to 3.0 V, the metal oxide existing at the interface between the metal internal electrode layer and the ceramic layer is efficiently reduced, and the multilayer ceramic element is peeled off at the desired interface. It becomes possible to do.
[0016]
Moreover, the peeling method of the multilayer ceramic element of Claim 2 is as follows.
While immersing at least part of the anode electrode and the multilayer ceramic element in the electrolytic solution,
A specific metal internal electrode layer in contact with a specific ceramic layer to be peeled off is used as a cathode electrode, and a cathode terminal is connected to this,
By applying current to the anode electrode immersed in the electrolytic solution and the metal internal electrode layer (cathode electrode), the metal oxide present at the interface between the specific metal internal electrode layer and the specific ceramic layer is converted to metal. It is characterized by being reduced to
[0017]
In the electrolytic solution, immersing at least a part of the anode electrode and the multilayer ceramic element, using the metal internal electrode layer in contact with the specific ceramic layer as a cathode electrode, and connecting the cathode terminal to this, the anode electrode and the metal interior When the electrode layer (cathode electrode) is energized, the metal internal electrode layer (cathode electrode) is reduced to the metal oxide existing at the interface with the ceramic layer to be peeled off to the metal internal electrode layer. It is possible to reliably peel the multilayer ceramic element at the interface between the ceramic layer and the specific ceramic layer.
[0018]
According to a third aspect of the present invention, there is provided a method for peeling a multilayer ceramic element, wherein a part of the multilayer ceramic element is immersed in the electrolytic solution and a specific ceramic layer to be peeled is contacted in a region not immersed in the electrolytic solution. Connect the cathode terminal to the metal internal electrode layer,
The specific ceramic of the specific metal internal electrode layer is energized through the anode electrode immersed in the electrolytic solution and the cathode terminal connected to the metal internal electrode layer that is not partially immersed in the electrolytic solution. It is characterized in that the metal oxide present at the interface with the layer is reduced to metal.
[0019]
A part of the multilayer ceramic element is immersed in an electrolytic solution, and in a region not immersed in the electrolytic solution, a cathode terminal is connected to a specific metal internal electrode layer in contact with a specific ceramic layer to be peeled, and an anode electrode, The ceramic to be peeled off even when the cathode terminal connected to the metal internal electrode layer, which is not partly immersed in the electrolyte, is energized, and the ceramic layer is thin (for example, 5 μm or less) Only in the metal internal electrode layer in contact with the layer, the metal oxide existing at the interface with the ceramic layer can be reduced to metal, and the multilayer ceramic element can be reliably peeled off at the predetermined interface. become.
[0020]
When the thickness of the ceramic layer is 5 μm or less, in the region immersed in the electrolyte solution of the multilayer ceramic element, when the cathode terminal is connected to the metal internal electrode layer and energized, even at the interface close to the interface to be peeled off Partial peeling occurs, but as described above, if the cathode terminal is connected to the metal internal electrode layer and energized in an area that is not immersed in the electrolytic solution, the peeling should occur only at the interface where peeling is desired. Can do.
[0021]
The multilayer ceramic element peeling method according to a fourth aspect is characterized in that the multilayer ceramic element is a multilayer ceramic capacitor element.
As for the multilayer ceramic capacitor, the thickness of the ceramic layer is reduced and the capacity is increased, and there is an increased chance of internal failure. However, the present invention is applied to the peeling of the multilayer ceramic capacitor element as in claim 4. By doing so, it can contribute to the analysis of the failure occurrence of the multilayer ceramic capacitor element which is thinned and multilayered, and the analysis for improving the characteristics, which is particularly meaningful.
[0022]
Moreover, the inspection method of the multilayer ceramic element of the present invention (Claim 5) is as follows.
After peeling the multilayer ceramic element at the interface between the specific ceramic layer and the specific metal internal electrode layer by the multilayer ceramic element peeling method according to any one of claims 1 to 4,
At least one characteristic selected from the group consisting of chemical composition, electrical characteristics, physical characteristics, presence / absence of structural defects, thickness, and appearance characteristics of at least one of the ceramic layer and the metal internal electrode layer exposed on the peeling surface is examined. It is characterized by that.
[0023]
The method for peeling a multilayer ceramic element according to any one of claims 1 to 4, wherein the multilayer ceramic element is peeled off at the interface between the specific ceramic layer and the specific metal internal electrode layer, thereby polishing. Compared to exposing a specific layer, it is possible to expose the desired interface without damaging the peeled surface (exposed surface), making it possible to more reliably investigate the properties of the peeled surface, This can contribute to improving the characteristics of the multilayer ceramic element.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be shown, and the features thereof will be described in more detail.
[0025]
[Embodiment 1]
FIG. 1 is a diagram showing an embodiment of a method for peeling a multilayer ceramic element of the present invention.
In the first embodiment, as shown in FIG. 2, a multilayer ceramic capacitor element (multilayer ceramic element) having a structure in which barium titanate ceramic layers 2 and metal internal electrode layers 1 made of Ni are alternately stacked. The multilayer ceramic capacitor 5 in which the external electrodes 4a and 4b are disposed on both ends of the multilayer ceramic capacitor 5 will be described as an example, and the multilayer ceramic element 3 is peeled off at a predetermined interface.
[0026]
In the first embodiment, as shown in FIG. 1, the lower part of the multilayer ceramic element (multilayer ceramic capacitor element) 3 held in the sample holder 15 is immersed in the electrolytic solution 12 placed in the electrolytic cell 11 and specified to be peeled off. A specific metal internal electrode layer 1a in contact with the ceramic layer 2a is used as a cathode electrode, and a cathode terminal (probe) 13 is brought into contact with (connected to) the cathode electrode 14 and a cathode electrode (metal) By energizing the internal electrode layer 1a), the metal oxide existing at the interface between the metal internal electrode layer 1a and the ceramic layer 2a was reduced to a metal, whereby the multilayer ceramic element 3 was peeled off at a predetermined interface. . In addition, conditions, such as the laminated ceramic element used as the sample, the electrolysis apparatus used for peeling, and the electrolytic solution, are as follows.
[0027]
(1) Outline of multilayer ceramic element (sample) to be peeled (1) Sample 1
Ni internal electrode layer thickness: 1 μm
Ceramic layer thickness: 3μm
Number of layers: 350 layers Element size: Length 3.2 mm x width 1.6 mm x thickness 1.6 mm
(2) Sample 2
Ni internal electrode layer thickness: 1 μm
Ceramic layer thickness: 7μm
Number of layers: 109 layers Element size: Length 3.2 mm x width 1.6 mm x thickness 1.6 mm
[0028]
(2) Electrolytic device In the first embodiment, as shown in FIG. 1, as an electrolytic device, an electrolytic tank 11 into which an electrolytic solution 12 is placed, a specific ceramic layer 2 a to be peeled off of a multilayer ceramic element (sample) 3, and Cathode terminal that can be brought into contact only with a specific metal internal electrode layer (cathode electrode) 1a in contact (in the first embodiment, the tip is sharply sharpened so as to be able to contact only with a specific metal internal electrode layer 1a. A probe (made of tungsten, tip diameter: 1 μm) 13, an anode electrode 14 immersed in an electrolytic solution, a sample holder 15 for holding the multilayer ceramic element (sample) 3, and a DC power source 16. The provided electrolyzer was used.
[0029]
The cathode terminal (probe) 13 was brought into contact with a specific metal internal electrode layer 1a using a micromanipulator (not shown).
Further, a platinum plate was used as the anode electrode 14.
The electrolytic solution 12 was put in the electrolytic cell 11 in such an amount that a part of the exposed metal internal electrode layer 1 of the multilayer ceramic element (sample) 3 was immersed.
[0030]
(3) Removal of external electrode and exposure of metal internal electrode Both ends and both sides (total 4 sides) of the multilayer ceramic capacitor shown in FIG. 2 are polished, and external electrodes 4a and 4b on both sides and both sides are removed. As shown in FIG. 3, the metal internal electrode layer 1 was exposed from both end faces and both side faces of the multilayer ceramic element 3. Depending on the polishing conditions of both end surfaces and both side surfaces of the multilayer ceramic element 3, some of the external electrodes 4a and 4b may remain on both the upper and lower surfaces of the multilayer ceramic element 3, but this may adversely affect the peeling. Absent.
[0031]
(4) Fixing of Sample to Sample Holder As shown in FIG. 1, the multilayer ceramic element (sample) 3 with the metal internal electrode layer 1 exposed from both end surfaces and both side surfaces is fixed to the sample holder 15. At this time, it attaches to the sample holder 15 so that the grind | polished side surface and end surface may contact electrolyte solution.
[0032]
(5) Selection of Electrolytic Solution In the first embodiment, considering that the metal internal electrode layer 1 is a Ni electrode, a 1N (1N) potassium hydroxide aqueous solution with pH = 14 was used as the electrolytic solution. Note that the pH of the electrolytic solution is important, and the pH at which the metal oxide is reduced to a metal is realized from the relationship between the pH of the electrolytic solution and the electromotive force of the metal according to the type of the metal. It is possible to use various solutions capable of Therefore, for example, an aqueous sodium hydroxide solution can be used.
In the case of a Ni electrode, even when pure water having a pH of 7 and a dilute aqueous potassium hydroxide solution having a pH of 10 are used as an electrolytic solution, the Ni oxide in the Ni electrode is reduced to metal Ni, and the multilayer ceramic element 3 is obtained. It has been confirmed that peeling can be performed at a desired interface.
[0033]
(6) Applied voltage In the first embodiment, the Ni internal electrode layer 1a in contact with the cathode terminal 13 was used as a cathode electrode, and a voltage of 1.7 to 2.0 V was applied thereto. Note that if the applied voltage is too high, peeling occurs even at the interface close to the interface to be peeled, which is not preferable.
Note that the multilayer ceramic element 3 could not be peeled at a low voltage of 1.0 V or less.
[0034]
(7) A voltage is applied to the Ni internal electrode layer (cathode electrode) 1a in contact with the peeled cathode terminal (probe) 13 at the bonding interface, and the cathode terminal (probe) 13 is contacted after 50 to 60 minutes have elapsed. Cracks occurred at the interface between the Ni internal electrode layer (cathode electrode) 1a, and the multilayer ceramic element 3 peeled off at the interface between the specific ceramic layer 2a and the Ni internal electrode layer 1a as shown in FIG.
[0035]
According to the method of the first embodiment described above, a specific Ni internal electrode in contact with a specific ceramic layer 2a to be peeled off by immersing the multilayer ceramic element 3 in an electrolytic solution 12 capable of reducing Ni oxide to a metal. Since the layer 1a is used as a cathode electrode, a cathode terminal (probe) 13 is brought into contact only with the Ni internal electrode layer 1a, and a voltage is applied from the cathode terminal 13, so that a specific Ni internal electrode layer 1a Only the metal oxide present at the interface with the ceramic layer 2a can be reduced to metal, and the multilayer ceramic element 3 can be reliably peeled off at a predetermined position.
That is, by applying a voltage only to a specific Ni internal electrode layer 1a, an electrochemical reaction occurs only in the Ni internal electrode layer 1a, and Ni oxides bonded to the ceramics on the surface of the ceramic layer 2a are reduced. As a result, the bond (bonding) strength between the Ni internal electrode layer 1a and the ceramic layer 2a decreases, and peeling occurs at the interface between the two. At this time, if the applied voltage is high, the time required until peeling occurs is shortened. However, when the thickness of the ceramic layer is thin (for example, the thickness of the ceramic layer is the same as that of Sample 1 of Embodiment 1). In the case of 5 μm or less), the voltage leaks to the adjacent Ni internal electrode layer, and peeling occurs to the adjacent interface.
[0036]
In addition, after peeling the multilayer ceramic element 3 at the interface between the specific ceramic layer 2a and the specific metal internal electrode layer 1a as described above, the ceramic layer 2a and the metal internal electrode exposed on the release surface are separated. It is possible to directly check the necessary characteristics such as the chemical composition, electrical characteristics, physical characteristics, presence / absence of structural defects, thickness, appearance properties, etc. of the layer 1a. Can be collected reliably.
[0037]
[Embodiment 2]
In the second embodiment, although not particularly illustrated, a laminated piezoelectric element (laminated layer) having a structure in which ceramic layers made of lead zirconate titanate-based piezoelectric ceramics and Ag-Pd-based metal internal electrode layers are alternately stacked. A case where a piezoelectric element (multilayer ceramic element) is peeled off at a predetermined interface will be described by taking a multilayer piezoelectric part in which an external electrode is disposed on a ceramic element) as an example.
[0038]
(1) Outline of multilayer ceramic element (sample) to be peeled Ag-Pd internal electrode layer thickness: 1 μm
Ceramic layer thickness: 180 μm
Element size: 30mm length x 20mm width x 5mm thickness
[0039]
Note that the electrolytic device (2) of the first embodiment, the method (3) for removing the external electrode and exposing the metal internal electrode, and the method (4) for fixing the sample to the sample holder are the same as those in the second embodiment. Since it is the same, in order to avoid duplication, description of the corresponding part of Embodiment 1 is used, and description thereof is omitted here.
[0040]
(5) Selection of Electrolytic Solution Also in this Embodiment 2, a 1N (1N) potassium hydroxide aqueous solution with pH = 14 was used as the electrolytic solution. In Embodiment 2, the metal internal electrode layer was a noble metal electrode (Ag—Pd electrode), but could be reliably peeled off with a 1N (1N) potassium hydroxide aqueous solution with pH = 14. In addition, even when a dilute aqueous potassium hydroxide solution with a pH of 10 was used, it was confirmed that the metal oxide of the metal internal electrode layer was reduced to metal and the multilayer ceramic element (piezoelectric element) could be peeled off at the desired interface. ing.
However, when pure water having pH 7 was used, the multilayer ceramic element (piezoelectric element) could not be peeled off.
[0041]
(6) Applied voltage In this Embodiment 2, since noble metal (Ag—Pd) is used as an electrode, 2.0 to 3 is applied to the Ag—Pd internal electrode layer (cathode electrode) in contact with the cathode terminal. A voltage of .0V was applied.
[0042]
(7) A voltage is applied to the specific Ag-Pd internal electrode layer (cathode electrode) in contact with the peeled cathode terminal (probe) at the bonding interface, and after 50 to 60 minutes have elapsed, the cathode terminal (probe) is The interface of the contacted Ag—Pd internal electrode layer (cathode electrode) was cracked, and the multilayer ceramic element (piezoelectric element) could be peeled off at the interface between the specific ceramic layer and the Ag—Pd internal electrode layer.
[0043]
In the second embodiment, the sample is the multilayer piezoelectric component as described above, and the types of the electrode material and the ceramic material are different from those in the multilayer ceramic capacitor of the first embodiment. It was possible to surely peel off at the desired interface.
[0044]
In addition, after the multilayer ceramic element (piezoelectric element) is peeled off at the interface between the specific ceramic layer and the specific metal internal electrode layer as described above, the ceramic layer and the metal internal electrode exposed on the peeled surface. It is possible to directly check the required properties such as the chemical composition, electrical properties, physical properties, presence or absence of structural defects, thickness, appearance properties, etc., and to ensure the cause of failure and data for property improvement Can get to.
[0045]
In the above embodiment, the multilayer ceramic capacitor and the multilayer piezoelectric component have been described as examples. However, the present invention is widely applied to the case where a multilayer ceramic element constituting another multilayer ceramic electronic component is peeled off at a desired interface. It is possible.
[0046]
The invention of the present application is not limited to the above embodiment in other respects as well. The ceramic material constituting the ceramic layer, the type of metal constituting the metal internal electrode layer, the type of electrolytic solution, and the electrolysis apparatus used for electrolysis Various applications and modifications can be made within the scope of the gist of the invention with respect to the specific configuration and electrolysis conditions.
[0047]
【The invention's effect】
As described above, the multilayer ceramic element according to the present invention (Claim 1) is a method for peeling off an electrolytic solution capable of reducing a metal oxide (metal oxide) constituting a metal internal electrode layer to a metal. A specific metal internal electrode layer that is in contact with a specific ceramic layer to be separated is immersed in at least a part of the multilayer ceramic element as a cathode electrode, and a cathode terminal is connected to the cathode, and the metal internal electrode layer (cathode) is connected to the cathode terminal. Since the voltage is applied to the electrode), the metal internal electrode layer of the metal internal electrode layer is reduced to the metal, and the metal internal electrode layer and the specific ceramic layer are reduced to the metal. It is possible to cause the multilayer ceramic element to peel off at the interface with.
[0048]
Further, as in the method for peeling a multilayer ceramic element according to claim 2, an anode electrode and at least a part of the multilayer ceramic element are immersed in an electrolytic solution, and a metal internal electrode layer in contact with a specific ceramic layer is used as a cathode electrode. When the anode terminal and the metal internal electrode layer (cathode electrode) are energized with the cathode terminal connected thereto, the metal internal electrode layer (cathode electrode) is present at the interface with the ceramic layer to be peeled off. By reducing the metal oxide to metal, the multilayer ceramic element can be reliably peeled off at the interface between the metal internal electrode layer and the specific ceramic layer.
[0049]
Further, as in the method for peeling a multilayer ceramic element according to claim 3, a part of the multilayer ceramic element is immersed in an electrolytic solution, and in a region not immersed in the electrolytic solution, a specific ceramic layer to be peeled is contacted. When the cathode terminal is connected to the metal internal electrode layer and the anode electrode and the cathode terminal connected to the metal internal electrode layer not partially immersed in the electrolyte are energized, the thickness of the ceramic layer is Even when it is thin (for example, 5 μm or less), it becomes possible to reduce the metal oxide existing at the interface with the ceramic layer only to the metal only for the metal internal electrode layer in contact with the ceramic layer to be peeled, The multilayer ceramic element can be reliably peeled off at a predetermined interface, and the present invention can be further effectively realized.
[0050]
In addition, regarding the multilayer ceramic capacitor, the ceramic layer is particularly thinned and the capacity is increased, and the chance of occurrence of an internal failure is also increasing. By applying the above, it is possible to contribute to the analysis of the occurrence of failure of the multilayered ceramic capacitor element that is thinned and multilayered, and the analysis for improving the characteristics, which is particularly meaningful.
[0051]
Moreover, the inspection method of the multilayer ceramic element of the present invention (Claim 5) is a multilayer ceramic element peeling method according to any one of Claims 1 to 4, wherein the multilayer ceramic element is separated from a specific ceramic layer and a specific ceramic layer. After peeling at the interface with the metal internal electrode layer, at least one of the ceramic layer and metal internal electrode layer exposed on the peeled surface, chemical composition, electrical characteristics, physical characteristics, presence or absence of structural defects, thickness, appearance properties, etc. Since the characteristics of are examined, it is possible to expose the desired interface without damaging the peeled surface (exposed surface) compared to the case where a specific layer is exposed by a method such as polishing, The characteristics of the peeled surface can be examined more reliably, which can contribute to improving the characteristics of the multilayer ceramic element.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment (Embodiment 1) of a method for peeling a multilayer ceramic element of the present invention.
FIG. 2 is a cross-sectional view showing a multilayer ceramic capacitor that is an object to be peeled in the first embodiment.
3 is a perspective view showing a multilayer ceramic element (multilayer ceramic capacitor element) in which both end surfaces and both side surfaces of a multilayer ceramic capacitor are polished to expose a metal internal electrode layer in Embodiment 1. FIG.
4 is a perspective view showing a state in which the multilayer ceramic element is peeled off at a predetermined interface in Embodiment 1. FIG.
[Explanation of symbols]
1 Metal Internal Electrode Layer 1a Specific Metal Internal Electrode Layer 2 Ceramic Layer 2a Specific Ceramic Layer 3 Multilayer Ceramic Element (Multilayer Ceramic Capacitor Element)
4a, 4b External electrode 5 Multilayer ceramic capacitor 11 Electrolytic tank 12 Electrolytic solution 13 Terminal for cathode (probe)
14 Anode electrode 15 Sample holder 16 DC power supply

Claims (5)

A method for peeling a multilayer ceramic element, wherein a multilayer ceramic element having a structure in which ceramic layers and metal internal electrode layers are alternately stacked is peeled at an interface between a specific ceramic layer and a specific metal internal electrode layer,
At least a part of the multilayer ceramic element is immersed in an electrolytic solution capable of reducing a metal oxide (metal oxide) constituting the metal internal electrode layer to a metal,
A specific metal internal electrode layer in contact with a specific ceramic layer to be peeled is used as a cathode electrode, a cathode terminal is connected to the cathode, and a voltage is applied from the cathode terminal to the metal internal electrode layer. The multilayer ceramic element is peeled off at the interface between the specific ceramic layer and the specific metal internal electrode layer by reducing the metal oxide present at the interface between the electrode layer and the specific ceramic layer to a metal. A method for peeling a multilayer ceramic element. While immersing at least part of the anode electrode and the multilayer ceramic element in the electrolytic solution,
A specific metal internal electrode layer in contact with a specific ceramic layer to be peeled is used as a cathode electrode, and a cathode terminal is connected to this,
By applying current to the anode electrode immersed in the electrolytic solution and the metal internal electrode layer (cathode electrode), the metal oxide present at the interface between the specific metal internal electrode layer and the specific ceramic layer is converted to metal. 2. The method for peeling a multilayer ceramic element according to claim 1, wherein the multilayer ceramic element is reduced. A part of the multilayer ceramic element is immersed in the electrolytic solution, and in a region not immersed in the electrolytic solution, a cathode terminal is connected to a specific metal internal electrode layer in contact with a specific ceramic layer to be peeled off,
The specific ceramic of the specific metal internal electrode layer is energized through the anode electrode immersed in the electrolytic solution and the cathode terminal connected to the metal internal electrode layer that is not partially immersed in the electrolytic solution. 3. The method for peeling a multilayer ceramic element according to claim 2, wherein the metal oxide present at the interface with the layer is reduced to a metal. The method for peeling a multilayer ceramic element according to claim 1, wherein the multilayer ceramic element is a multilayer ceramic capacitor element. After peeling the multilayer ceramic element at the interface between the specific ceramic layer and the specific metal internal electrode layer by the multilayer ceramic element peeling method according to any one of claims 1 to 4,
At least one characteristic selected from the group consisting of chemical composition, electrical characteristics, physical characteristics, presence / absence of structural defects, thickness, and appearance characteristics of at least one of the ceramic layer and the metal internal electrode layer exposed on the peeling surface is examined. A method for inspecting a multilayer ceramic element.

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