Multi-layer piezoelectric ceramic component and piezoelectric device

A multi-layer piezoelectric ceramic component includes: a piezoelectric ceramic body having a cuboid shape having upper and lower surfaces facing in a thickness direction, first and second end surfaces facing in a length direction, and a pair of side surfaces facing in a width direction; first internal electrodes formed in the piezoelectric ceramic body and drawn to the first end surface; second internal electrodes formed in the piezoelectric ceramic body and drawn to the second end surface; a first terminal electrode formed on the first end surface; and a second terminal electrode formed on the second end surface, the first and second internal electrodes each having a width equal to a distance between the pair of side surfaces, at least one of the pair of side surfaces including a groove extending in non-parallel with the length direction.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Priority Patent Application JP 2018-013962 filed Jan. 30, 2018, the entire contents of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to a multi-layer piezoelectric ceramic component usable as a piezoelectric actuator and to a piezoelectric device.

A piezoelectric actuator is an actuator that includes a piezoelectric element including a piezoelectric material and an electrode, and uses deformation that is caused in the piezoelectric material by an inverse piezoelectric effect when a voltage is applied to the electrode. The piezoelectric actuator includes a bimorph piezoelectric actuator that includes two piezoelectric actuators.

A general bimorph piezoelectric actuator has a structure in which the piezoelectric actuators are attached to both surfaces of a metal plate, and one of the piezoelectric actuators is expanded and the other one of the piezoelectric actuators is contracted, to enable the whole of the actuator to be largely deformed. Further, in the bimorph piezoelectric actuator, a piezoelectric actuator having an element bimorph structure in which two piezoelectric actuators are integrated is developed (for example, WO 2013/051328).

SUMMARY

From the viewpoint of insulation properties and moisture resistance, an insulating film may be provided to a surface of the element as described above in a later step. In this case, how to improve adhesion properties of the insulating film, in order to maintain insulation properties and moisture resistance, is important.

In view of the circumstances as described above, it is desirable to provide a multi-layer piezoelectric ceramic component and a piezoelectric device, in which adhesion properties of an insulating film formed on a surface of an element are improved.

According to an embodiment of the present disclosure, there is provided a multi-layer piezoelectric ceramic component including a piezoelectric ceramic body, first internal electrodes, second internal electrodes, a first terminal electrode, and a second terminal electrode.

The piezoelectric ceramic body has a cuboid shape having an upper surface and a lower surface facing each other in a thickness direction, a first end surface and a second end surface facing each other in a length direction, and a pair of side surfaces facing each other in a width direction.

The first internal electrodes are formed in the piezoelectric ceramic body, and are drawn to the first end surface.

The second internal electrodes are formed in the piezoelectric ceramic body, and are drawn to the second end surface, the second internal electrodes being laminated alternately with the first internal electrodes at predetermined distances from the respective first internal electrodes in the thickness direction.

The first terminal electrode is formed on the first end surface, and is electrically connected to the first internal electrodes.

The second terminal electrode is formed on the second end surface, and is electrically connected to the second internal electrodes.

The first internal electrodes and the second internal electrodes each have a width equal to a distance between the pair of side surfaces, and at least one of the pair of side surfaces includes a groove extending in non-parallel with the length direction.

With such a configuration, when a voltage is applied between the first internal electrodes and the second internal electrodes, the piezoelectric ceramic body can be deformed. Further, since at least one of the pair of side surfaces includes a groove extending in non-parallel with the length direction, if an insulating film is formed on the side surface, adhesion properties of the insulating film are improved by an anchoring effect. Moreover, the first internal electrodes and the second internal electrodes each have a width equal to the width of the piezoelectric ceramic body, and restraint by the piezoelectric ceramic body (side margins) covering the side surfaces of those internal electrodes disappears, which makes it possible to prevent reduction in displacement performance.

The multi-layer piezoelectric ceramic component may further include third internal electrodes and a third terminal electrode.

The third internal electrodes may be formed in the piezoelectric ceramic body, and are drawn to a position of the first end surface, the position being different from a position to which the first internal electrodes are drawn, the third internal electrodes being laminated alternately with the second internal electrodes at predetermined distances from the respective second internal electrodes in the thickness direction.

The third terminal electrode may be electrically connected to the third internal electrodes at a position of the first end surface, the position being different from the position to which the first internal electrodes are drawn.

The third internal electrodes may each have a width equal to a distance between the pair of side surfaces.

In the multi-layer piezoelectric ceramic component, the pair of side surfaces may be covered with an insulating film made of an insulator different from the piezoelectric ceramic body.

In the multi-layer piezoelectric ceramic component, the piezoelectric ceramic body may have a relationship in which a length is larger than a width and the width is larger than a thickness.

According to another embodiment of the present disclosure, there is provided a piezoelectric device including a vibration member and a multi-layer piezoelectric ceramic component mounted to the vibration member.

The multi-layer piezoelectric ceramic component includes a piezoelectric ceramic body, first internal electrodes, second internal electrodes, a first terminal electrode, and a second terminal electrode.

The piezoelectric ceramic body has a cuboid shape having an upper surface and a lower surface facing each other in a thickness direction, a first end surface and a second end surface facing each other in a length direction, and a pair of side surfaces facing each other in a width direction.

The first internal electrodes are formed in the piezoelectric ceramic body, and are drawn to the first end surface.

The second internal electrodes are formed in the piezoelectric ceramic body and are drawn to the second end surface, the second internal electrodes being laminated alternately with the first internal electrodes at predetermined distances from the respective first internal electrodes in the thickness direction.

The first terminal electrode is formed on the first end surface, and is electrically connected to the first internal electrodes.

The second terminal electrode is formed on the second end surface, and is electrically connected to the second internal electrodes.

The first internal electrodes and the second internal electrodes each have a width equal to a distance between the pair of side surfaces, and at least one of the pair of side surfaces includes a groove extending in non-parallel with the length direction.

With such a configuration, a piezoelectric device including the multi-layer piezoelectric ceramic component described above is provided.

As described above, according to the present disclosure, it is possible to provide a multi-layer piezoelectric ceramic component and a piezoelectric device, in which adhesion properties of an insulating film formed on a surface of an element are improved.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each figure, an X-Y-Z coordinate system is used in some cases.

Configuration of Multi-layer Piezoelectric Ceramic Component

FIGS. 1 and 2are each a perspective view of a multi-layer piezoelectric ceramic component100according to an embodiment.FIG. 2is a view of the opposite side fromFIG. 1.

As shown inFIGS. 1 and 2, the multi-layer piezoelectric ceramic component100includes a piezoelectric ceramic body101, first internal electrodes102, second internal electrodes103, third internal electrodes104, a first surface electrode105, a second surface electrode106, a first end surface terminal electrode107, a second end surface terminal electrode108, a third end surface terminal electrode109, a first surface terminal electrode110, and a second surface terminal electrode111.

The piezoelectric ceramic body101is made of a piezoelectric ceramic material. The piezoelectric ceramic body101includes a plurality of piezoelectric ceramic layers arranged in a Z-axis direction. The plurality of piezoelectric ceramic layers are provided in the Z-axis direction between the first internal electrodes102and the second internal electrodes103and also between the third internal electrodes104and the second internal electrodes103. In this embodiment, the plurality of piezoelectric ceramic layers are also referred to as the piezoelectric ceramic body101.

As shown inFIGS. 1 and 2, the piezoelectric ceramic body101has a cuboid shape. Assuming that the X-axis direction is a length direction, the Y-axis direction is a width direction, and the Z-axis direction is a thickness direction, the piezoelectric ceramic body101has such a shape that the length is larger than the width and the width is larger than the thickness (length>width>thickness).

For the surfaces of the piezoelectric ceramic body101, surfaces facing in the width direction (Y-axis direction) are assumed as a first side surface101aand a second side surface101b, and surfaces facing in the length direction (X-axis direction) are assumed as a first end surface101cand a second end surface101d. Further, surfaces facing in the thickness direction (Z-axis direction) are assumed as an upper surface101eand a lower surface101f.

FIG. 3is a plan view of the first side surface101a.FIG. 4is a plan view of the second side surface101b.

FIG. 5is a plan view of the first end surface101c.FIG. 6is a plan view of the second end surface101d.

FIG. 7is a plan view of the upper surface101e.FIG. 8is a plan view of the lower surface101f.

As shown inFIGS. 3 and 4, the piezoelectric ceramic body101includes a first region101gon the upper surface101eside and a second region101hon the lower surface101fside, which are divided in the Z-axis direction. The thickness of the first region101gand the thickness of the second region101hsuitably have a ratio of 1:1.

The first internal electrodes102are formed in the first region101gand face the second internal electrodes103and the first surface electrode105via the piezoelectric ceramic body101(seeFIGS. 3 and 4).FIG. 9is a cross-sectional view of the multi-layer piezoelectric ceramic component100, which shows the first internal electrode102, and is also a cross-sectional view taken along the line A-A ofFIGS. 3 and 4. As shown inFIG. 9, the first internal electrode102is drawn to the first end surface101c, partially exposed at the first end surface101c, and electrically connected to the first end surface terminal electrode107.

Further, the first internal electrode102has the same width as the width (Y-axis direction) of the piezoelectric ceramic body101and is exposed at the first side surface101aand the second side surface101b(seeFIGS. 3 and 4). The number of first internal electrodes102is not particularly limited, and the first internal electrodes102may be a single layer or a plurality of layers.

The third internal electrodes104are formed in the second region101hand face the second internal electrodes103and the second surface electrode106via the piezoelectric ceramic body101(seeFIGS. 3 and 4).FIG. 10is a cross-sectional view of the multi-layer piezoelectric ceramic component100, which shows the third internal electrode104, and is also a cross-sectional view taken along the line B-B ofFIGS. 3 and 4. As shown inFIG. 10, the third internal electrode104is drawn to the first end surface101c, partially exposed at the first end surface101c, and electrically connected to the third end surface terminal electrode109.

Further, the third internal electrode104has the same width as the width (Y-axis direction) of the piezoelectric ceramic body101and is exposed at the first side surface101aand the second side surface101b(seeFIGS. 3 and 4). The number of third internal electrodes104is not particularly limited, and the third internal electrodes104may be a single layer or a plurality of layers.

The second internal electrodes103are formed in the first region101gand the second region101h.

The second internal electrodes103are laminated alternately with the first internal electrodes102in the first region101gat predetermined distances from the respective first internal electrodes102in the thickness direction (Z-axis direction) and face the respective first internal electrodes102via the piezoelectric ceramic body101(seeFIGS. 3 and 4).

Further, the second internal electrodes103are laminated alternately with the third internal electrodes104in the second region101hat predetermined distances from the respective third internal electrodes104in the thickness direction (Z-axis direction) and face the respective third internal electrodes104via the piezoelectric ceramic body101(seeFIGS. 3 and 4).

FIG. 11is a cross-sectional view of the multi-layer piezoelectric ceramic component100, which shows the second internal electrode103, and is also a cross-sectional view taken along the line C-C of FIGS.3and4. As shown inFIG. 11, the second internal electrode103is drawn to the second end surface101d, exposed at the second end surface101d, and electrically connected to the second end surface terminal electrode108.

Further, the second internal electrode103has the same width as the width (Y-axis direction) of the piezoelectric ceramic body101and is exposed at the first side surface101aand the second side surface101b(seeFIGS. 3 and 4). The number of second internal electrodes103may be set to correspond to the number of first internal electrodes102and the number of third internal electrode104.

It should be noted that at least one of the first side surface101a, the second side surface101b, the first end surface101c, or the second end surface101dincludes a groove having an arithmetic average roughness (Ra) of, for example, 0.2 μm or more and 2.0 μm or less. The groove will be described later with reference to other drawings.

The first surface electrode105extends from the second end surface101dside to be formed on the upper surface101e(seeFIG. 1) and is electrically connected to the second end surface terminal electrode108. The first surface electrode105faces one of the first internal electrodes102in the Z-axis direction via the piezoelectric ceramic body101. Further, the first surface electrode105is apart from and electrically insulated from the first surface terminal electrode110and the second surface terminal electrode111on the upper surface101e(seeFIG. 7).

The second surface electrode106extends from the second end surface101dside to be formed on the lower surface101fand is electrically connected to the second end surface terminal electrode108(seeFIG. 2). The second surface electrode106faces one of the third internal electrodes104in the Z-axis direction via the piezoelectric ceramic body101.

The first end surface terminal electrode107is formed on the first end surface101c(seeFIG. 1) and is electrically connected to the first internal electrodes102. Further, the first end surface terminal electrode107is electrically insulated from the third internal electrodes104and the third end surface terminal electrode109. The first end surface terminal electrode107is formed between the upper surface101eand the lower surface101fon the first end surface101cand is electrically connected to the first surface terminal electrode110.

The third end surface terminal electrode109is formed on the first end surface101c(seeFIG. 1) and is electrically connected to the third internal electrodes104. Further, the third end surface terminal electrode109is electrically insulated from the first internal electrodes102and the first end surface terminal electrode107. The third end surface terminal electrode109is formed between the upper surface101eand the lower surface101fon the first end surface101cand is electrically connected to the second surface terminal electrode111.

The second end surface terminal electrode108is formed on the second end surface101d(seeFIG. 2) and is electrically connected to the second internal electrodes103. Further, the second end surface terminal electrode108is formed between the upper surface101eand the lower surface101fon the second end surface101dand is electrically connected to the first surface electrode105and the second surface electrode106.

The first surface terminal electrode110is formed on the upper surface101e(seeFIG. 1). The first surface terminal electrode110is electrically connected to the first end surface terminal electrode107and is electrically insulated from the second surface terminal electrode111and the first surface electrode105.

The second surface terminal electrode111is formed on the upper surface101e(seeFIG. 1). The second surface terminal electrode111is electrically connected to the third end surface terminal electrode109and is electrically insulated from the first surface terminal electrode110and the first surface electrode105.

The first internal electrodes102, the second internal electrodes103, the third internal electrodes104, the first surface electrode105, the second surface electrode106, the first end surface terminal electrode107, the second end surface terminal electrode108, the third end surface terminal electrode109, the first surface terminal electrode110, and the second surface terminal electrode111are each made of an electrically conductive material. The electrically conductive material may be any one of, for example, Ag, Ag/Pd, Pd, Cu, and Ni.

As described above, the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are formed in the piezoelectric ceramic body101, the first internal electrodes102and the second internal electrodes103face each other via the piezoelectric ceramic body101, and the third internal electrodes104and the second internal electrodes103face each other via the piezoelectric ceramic body101. The first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are insulated from one another.

Groove

FIG. 12Ais a schematic view of the first side surface101aincluding grooves120.FIG. 12Bshows a part of a cut surface taken along the line D-D ofFIG. 12A. The grooves120may be not only provided to the first side surface101a, but also provided to at least one of the first side surface101a, the second side surface101b, the first end surface101c, or the second end surface101d.

The first side surface101aaccording to this embodiment is a surface at which the piezoelectric ceramic body101, the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are exposed and to which the grooves120are provided. Each of the grooves120extends in non-parallel with the X-axis direction (length direction). For example, the groove120is configured to be arc-like on the X-Z axis plane. The groove120may continuously extend or may be intermittent. Further, the groove120may be linear. The number of grooves120may be set to be denser or coarser than that of the example shown in the figures.

The grooves120are formed, for example, when the first side surface101ais cut with a disc-like dicing blade. For example, when diamond abrasive grains or the like included in the dicing blade scratch the first side surface101a, the grooves120are formed. The grooves120are so-called dicing traces. Surface roughness of the first side surface101aon which the grooves120are formed is controlled by adjusting a grain size of the diamond abrasive grains.

In such a manner, in this embodiment, at least one of the first side surface101a, the second side surface101b, the first end surface101c, or the second end surface101dincludes the grooves120.

FIG. 12Cshows an example in which an insulating film112is formed on the first side surface101a.

From the viewpoint of insulation properties and moisture resistance between the electrodes, the insulating film112may be provided to the first side surface101aat which the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are exposed.

In such a case, since the first side surface101aincludes the grooves120, adhesion properties between the insulating film112and the first side surface101aare largely improved by an anchoring effect. Further, in a case where the dicing traces are used as the grooves120, the step of polishing the first side surface101a, the second side surface101b, the first end surface101c, and the second end surface101dcan be omitted, and increase in cost of the multi-layer piezoelectric ceramic component100can be suppressed.

The size of the multi-layer piezoelectric ceramic component100is not particularly limited, but assuming that the length (X-axis direction) is L and the width (Y-axis direction) is W, it is suitable that L/W is approximately 16 to 50. Further, it is suitable that the thickness (Z-axis direction) is approximately 0.5 mm to 1.5 mm.

Operation of Multi-layer Piezoelectric Ceramic Component

In the multi-layer piezoelectric ceramic component100, a voltage can be independently applied between the first internal electrodes102and the second internal electrodes103and between the third internal electrodes104and the second internal electrodes103.

When a voltage is applied between the first internal electrodes102and the second internal electrodes103, an inverse piezoelectric effect occurs in the piezoelectric ceramic body101between the first internal electrodes102and the second internal electrodes103and causes deformation (expansion and contraction) in the X-axis direction in the first region101g. Further, when a voltage is applied between the third internal electrodes104and the second internal electrodes103, an inverse piezoelectric effect occurs in the piezoelectric ceramic body101between the third internal electrodes104and the second internal electrodes103and causes deformation (expansion and contraction) in the X-axis direction in the second region101h.

In such a manner, in the multi-layer piezoelectric ceramic component100, the deformation in the first region101gand the deformation in the second region101hcan be independently controlled. The first region101gand the second region101hare separately deformed in the X-axis direction, and thus the multi-layer piezoelectric ceramic component100can be deformed (bent) in the Z-axis direction.

FIGS. 13A and 13Bshow examples of voltage waveforms applied to the multi-layer piezoelectric ceramic component100.FIG. 13Ashows a waveform of a voltage (V1) applied between the first internal electrodes102and the second internal electrodes103.FIG. 13Bshows a waveform of a voltage (V2) applied between the third internal electrodes104and the second internal electrodes103. It should be noted that V0represents a potential of the second internal electrodes103. As shown inFIGS. 13A and 13B, when the voltage V1and the voltage V2are set as reverse bias voltages in the same phase, one of the first region101gand the second region101hcan be expanded, and the other one of the first region101gand the second region101hcan be contracted.

In particular, even if such an operation continues over a long period of time, since the insulating film112tightly adheres to the first side surface101a, the second side surface101b, the first end surface101c, and the second end surface101d, the insulating film112is less likely to be peeled off from those side surfaces and end surfaces in the multi-layer piezoelectric ceramic component100.

It should be noted that when the thickness of the first region101gand the thickness of the second region101hhave a ratio of 1:1, the first region101gand the second region101hare symmetrical with each other in terms of the amount of deformation, which is suitable. Further, the waveforms of the voltage V1and the voltage V2are not limited to those shown inFIGS. 13A and 13Band may be each a sine wave or a triangle wave.

Regarding Structure Without Side Margin

As described above, the multi-layer piezoelectric ceramic component100has a structure in which the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are exposed at the first side surface101aand the second side surface101b.

FIG. 14is a perspective view of a multi-layer piezoelectric ceramic component300according to a comparative example.

As shown inFIG. 14, the multi-layer piezoelectric ceramic component300includes a piezoelectric ceramic body301, a surface electrode302, a first terminal electrode303, and a second terminal electrode304. Further, the multi-layer piezoelectric ceramic component300includes internal electrodes (not shown) corresponding to the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104.

In the multi-layer piezoelectric ceramic component300, the internal electrodes are not exposed at the side surfaces and are embedded in the piezoelectric ceramic body301. As shown inFIG. 14, side margins S made of a piezoelectric material are each provided on the side surface side of the internal electrodes.

The side margins S are not sandwiched by the internal electrodes in the Z-axis direction when the multi-layer piezoelectric ceramic component300is driven. Thus, the side margins S act as restraint portions that suppress the displacement of the multi-layer piezoelectric ceramic component300. This reduces displacement performance of the multi-layer piezoelectric ceramic component300.

To the contrary, in the multi-layer piezoelectric ceramic component100, each width of the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104is equal to a distance between the pair of side surfaces101aand101b. In other words, the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are exposed at the first side surface101aand the second side surface101bin the multi-layer piezoelectric ceramic component100, and the multi-layer piezoelectric ceramic component100does not include side margins. Thus, it is possible to generate large displacement without receiving a restraint effect provided by the side margins and to prevent the displacement performance from being reduced.

Regarding Insulating Film

FIG. 15is a perspective view of the multi-layer piezoelectric ceramic component100including the insulating film112.

The insulating film112described above may cover not only the first side surface101a, the second side surface101b, the first end surface101c, and the second end surface101dbut also the outer periphery of the multi-layer piezoelectric ceramic component100. Here, in the X-axis direction, the length of the insulating film112formed on the upper surface101eis equal to the length of the second surface electrode106.

In other words, the insulating film112includes an opening112afrom which the first surface terminal electrode110, the second surface terminal electrode111, and the first surface electrode105are partially exposed. In the multi-layer piezoelectric ceramic component100, electrical connection (three-terminal connection) to the first surface terminal electrode110, the second surface terminal electrode111, and the first surface electrode105via the single opening112acan be established. This makes a wiring structure compact.

The range covered with the insulating film112is not limited to the range shown inFIG. 15and only needs to cover at least the first side surface101aand the second side surface101bat which the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are exposed.

It should be noted that the insulating film112is made of a material different from the material of the piezoelectric ceramic body101, and a soft material can be used therefor. Thus, a restraint effect provided by the insulating film112can be made significantly small. In other words, in the multi-layer piezoelectric ceramic component100, the displacement performance is prevented from being reduced.

The material of the insulating film112is not particularly limited as long as the material is an insulating material. For example, examples of the material of the insulating film112include an organic resin of polyimide, polypropylene, acrylic, epoxy, or the like, or an inorganic insulating film of Si3N4, SiO2, or the like. In particular, when an organic resin is used as the insulating film112, the surface roughness of the side surfaces and the end surfaces is made larger than that when the inorganic insulating film is used, so that the adhesion of the insulating film112tends to be improved.

Regarding Production Method

A production method for the multi-layer piezoelectric ceramic component100will be described.

The multi-layer piezoelectric ceramic component100can be produced by laminating sheet members.FIGS. 16A to 16Eare schematic views of respective sheet members.FIG. 16Ashows a sheet member210including the first surface electrode105, the first surface terminal electrode110, the second surface terminal electrode111, and a piezoelectric ceramic body201.FIG. 16Bshows a sheet member220including the first internal electrode102and the piezoelectric ceramic body201.

FIG. 16Cshows a sheet member230including the second internal electrode103and the piezoelectric ceramic body201.FIG. 16Dshows a sheet member240including the third internal electrode104and the piezoelectric ceramic body201.FIG. 16Eshows a sheet member250including the second surface electrode106and the piezoelectric ceramic body201.

First, a sheet member including only a piezoelectric ceramic body (hereinafter, referred to as piezoelectric sheet member) is laminated on the sheet member250, and thereon, the sheet member240, a piezoelectric sheet member, and the sheet member230are laminated in this order. Moreover, the sheet members240and the sheet members230are alternately laminated via piezoelectric sheet members.

Subsequently, the sheet members220and the sheet members230are alternately laminated via piezoelectric sheet members, and thereon, a piezoelectric sheet member and the sheet member210are laminated in this order. Subsequently, this laminate is pressure-bonded, and a binder is removed by heating or the like.

Subsequently, sintering is performed. At this stage, each internal electrode is embedded in the piezoelectric ceramic body201, and side margins are formed. Subsequently, by heat treatment, the first end surface terminal electrode107and the third end surface terminal electrode109are formed on the first end surface101c, and the second end surface terminal electrode108is formed on the second end surface101d.

Subsequently, the side margins are cut by dicing and removed. Accordingly, the grooves120are formed in at least one of the first side surface101a, the second side surface101b, the first end surface101c, or the second end surface101d. It should be noted that the surface roughness of each of the first side surface101a, the second side surface101b, the first end surface101c, and the second end surface101dmay be appropriately adjusted to be predetermined roughness by using a polishing technique.

Accordingly, the piezoelectric ceramic body101is formed from the piezoelectric ceramic bodies201. When the side margins are cut, the first side surface101aand the second side surface101bare formed, and the first internal electrodes102, the second internal electrodes103, and the third internal electrodes104are exposed at the first side surface101aand the second side surface101b(seeFIG. 1).

Subsequently, the insulating film112including the opening112ais formed (seeFIG. 15). The insulating film112can be formed by a method such as mist deposition, sputtering, or dipping. Subsequently, the first surface terminal electrode110and the second surface terminal electrode111are electrically connected, and a DC voltage is applied. This causes a polarizing process and activates the piezoelectric ceramic body101.

The multi-layer piezoelectric ceramic component100can be produced as described above. It should be noted that the production method for the multi-layer piezoelectric ceramic component100is not limited to the method described herein.

Regarding Piezoelectric Device

The multi-layer piezoelectric ceramic component100can be mounted to a vibration member to configure a piezoelectric device.FIG. 17is a schematic view of a piezoelectric device400including the multi-layer piezoelectric ceramic component100. As shown inFIG. 17, the piezoelectric device400includes the multi-layer piezoelectric ceramic component100, a vibration member410, and a joint420.

The vibration member410is a metal plate or a glass panel of a display and is not particularly limited. The joint420is made of a resin or the like and joins the multi-layer piezoelectric ceramic component100to the vibration member410.

In the multi-layer piezoelectric ceramic component100, a region of the upper surface101eon the first end surface101cside is joined to the joint420. Wiring (not shown) is electrically connected to the first surface terminal electrode110, the second surface terminal electrode111, and the first surface electrode105.

When a voltage is applied to each electrode, as described above, the multi-layer piezoelectric ceramic component100is deformed in the Z-axis direction (arrow inFIG. 17). This allows the vibration member410to vibrate. It should be noted that the method of mounting the multi-layer piezoelectric ceramic component100is not limited to that described herein. For example, the entire upper surface101emay be joined to the joint420.

Hereinabove, the embodiment of the present disclosure has been described, but the present disclosure is not limited to the embodiment described above and can be variously modified as a matter of course. Each embodiment is not limited to be an independent embodiment, and some embodiments can be combined as long as it is technically possible.