JP7158151B2 - Laminated piezoelectric ceramic parts and piezoelectric devices - Google Patents

Description

The present invention relates to a laminated piezoelectric ceramic component and a piezoelectric device that can be used as a piezoelectric actuator.

A piezoelectric actuator is composed of a piezoelectric element having a piezoelectric material and an electrode, and is an actuator that utilizes deformation that occurs in the piezoelectric material due to the inverse piezoelectric effect when a voltage is applied to the electrode. A piezoelectric element is constructed by laminating a plurality of layers of internal electrodes inside a piezoelectric body. A part of the internal electrode is drawn out to the surface of the piezoelectric body and electrically connected to a terminal electrode provided on the surface of the piezoelectric body (for example, Patent Documents 1 to 3).

Republished No. 2015-114849 Republished No. 2014-69138 JP 2016-46472 A

In the structure described above, electrical connection between the internal electrodes and the terminal electrodes must be ensured. This is because if there is a connection failure between the internal electrode and the terminal electrode, a portion that does not function as a piezoelectric element (capacitance dropout) is generated and the displacement performance is lowered.

Conventionally, a capacitance meter or the like is used to check whether the internal electrodes are connected to the terminal electrodes. However, with this method, it is necessary to establish continuity between the internal electrodes, which takes time for measurement. In addition, if only one of the plurality of internal electrodes is not connected to the terminal electrode, there is a possibility that the connection failure cannot be detected. There is

SUMMARY OF THE INVENTION In view of the circumstances as described above, an object of the present invention is to provide a laminated piezoelectric ceramic component and a piezoelectric device capable of detecting connection failures quickly and accurately.

To achieve the above object, a laminated piezoelectric ceramic component according to one aspect of the present invention includes a piezoelectric ceramic body, a first internal electrode, a second internal electrode, a first terminal electrode, and a second terminal. and an electrode.
The piezoelectric ceramic body has a rectangular parallelepiped shape satisfying length>width>thickness, and has upper and lower surfaces facing each other in the thickness direction, first and second end faces facing each other in the length direction, and a pair of side surfaces facing each other.
The first internal electrode is formed inside the piezoelectric ceramic body and led out to the first end surface.
The second internal electrode is formed inside the piezoelectric ceramic body, led out to the second end surface, and alternately laminated with the first internal electrode at a predetermined distance in the thickness direction. .
The first terminal electrode is formed on the first end face and electrically connected to the first internal electrode.
The second terminal electrode is formed on the second end surface and electrically connected to the second internal electrode.
At the first end surface, a portion of the first internal electrode is covered with the first terminal electrode, and a portion of the first internal electrode closer to the side surface than the first terminal electrode is exposed. there is

According to this configuration, a portion of the first internal electrode that is not covered with the first terminal electrode (hereinafter referred to as an exposed portion) is exposed on the first end face. Therefore, by determining whether or not there is an exposed portion by image processing in an image of the first end surface, it is possible to detect poor connection between the first internal electrode and the first terminal electrode. Faster and more accurate detection is possible compared to the case of target detection.

The width of the first internal electrode and the second internal electrode and the distance between the pair of side surfaces may be the same.

When the first internal electrode and the second internal electrode are embedded inside the piezoelectric ceramic body and are not exposed on the side surface, the piezoelectric ceramic body (side margin) covering the side surface of these internal electrodes restrains the internal electrode. Deformation of the laminated piezoelectric ceramic component is suppressed, but according to the above configuration, restraint due to side margins does not occur, and deterioration of displacement performance can be prevented.

The laminated piezoelectric ceramic component is
a third internal electrode formed inside the piezoelectric ceramic body, led out to the first end surface, and alternately laminated with the second internal electrode at a predetermined distance in the thickness direction;
A third electrode formed on the first end face, electrically connected to the third internal electrode, electrically insulated from the first terminal electrode, and electrically connected to the third internal electrode. 3 terminal electrodes, and
In the first end face, a portion of the third internal electrode is covered with the third terminal electrode, and a portion of the third internal electrode closer to the side surface than the third terminal electrode is exposed. may

According to this configuration, it is possible to further detect poor connection between the third internal electrode and the third terminal electrode by performing image processing on the image of the first end surface.

The width of the third internal electrode and the distance between the pair of side surfaces may be the same.

The pair of side surfaces may be covered with an insulating film made of an insulating material different from the piezoelectric ceramic body.

The insulator may be an insulating resin material.

To achieve the above object, a piezoelectric device according to one aspect of the present invention includes a laminated piezoelectric ceramic component and a vibrating member.
The laminated piezoelectric ceramic component is mounted on the vibrating member and includes a piezoelectric ceramic body, a first internal electrode, a second internal electrode, a first terminal electrode, and a second terminal electrode.
The piezoelectric ceramic body has a rectangular parallelepiped shape satisfying length>width>thickness, and has upper and lower surfaces facing each other in the thickness direction, first and second end faces facing each other in the length direction, and a pair of side surfaces facing each other.
The first internal electrode is formed inside the piezoelectric ceramic body and led out to the first end surface.
The second internal electrode is formed inside the piezoelectric ceramic body, led out to the second end surface, and alternately laminated with the first internal electrode at a predetermined distance in the thickness direction. .
The first terminal electrode is formed on the first end face and electrically connected to the first internal electrode.
The second terminal electrode is formed on the second end surface and electrically connected to the second internal electrode.

As described above, according to the present invention, it is possible to provide a laminated piezoelectric ceramic component and a piezoelectric device capable of detecting connection failures quickly and accurately.

1 is a perspective view of a laminated piezoelectric ceramic component according to an embodiment of the present invention; FIG. It is a perspective view of the laminated piezoelectric ceramic component. It is a top view of the 1st side of the laminated piezoelectric ceramic component. It is a top view of the 2nd side of the laminated piezoelectric ceramic component. It is a top view of the 1st end surface of the laminated piezoelectric ceramic component. It is a top view of the 2nd end surface of the laminated piezoelectric ceramic component. It is a top view of the upper surface of the laminated piezoelectric ceramic component. It is a top view of the lower surface of the laminated piezoelectric ceramic component. FIG. 4 is a cross-sectional view showing first internal electrodes of the laminated piezoelectric ceramic component; FIG. 4 is a cross-sectional view showing a second internal electrode of the laminated piezoelectric ceramic component; FIG. 4 is a cross-sectional view showing a third internal electrode of the laminated piezoelectric ceramic component; It is an enlarged view of the first end face of the laminated piezoelectric ceramic component. It is an enlarged view of the first end face of the laminated piezoelectric ceramic component. It is a waveform of the drive voltage of the same laminated piezoelectric ceramic component. FIG. 3 is a perspective view of a laminated piezoelectric ceramic component according to a comparative example; 1 is a perspective view of a laminated piezoelectric ceramic component according to an embodiment of the present invention; FIG. It is a top view of the 1st end surface of the laminated piezoelectric ceramic component. It is a perspective view of the laminated piezoelectric ceramic component. FIG. 4 is a schematic diagram of a sheet member used for manufacturing the laminated piezoelectric ceramic component. 1 is a schematic diagram of a piezoelectric device according to an embodiment of the invention; FIG. FIG. 10 is a perspective view of a laminated piezoelectric ceramic component according to a modified example of the present invention;

A laminated piezoelectric ceramic component according to an embodiment of the present invention will be described. In each figure below, the three mutually orthogonal directions are the X direction, the Y direction, and the Z direction.

[Structure of storage electric ceramic component]
1 and 2 are perspective views of a laminated piezoelectric ceramic component 100 according to this embodiment, and FIG. 2 is a view seen from the opposite side of FIG.

As shown in FIGS. 1 and 2, the laminated piezoelectric ceramic component 100 includes a piezoelectric ceramic body 101, a first internal electrode 102, a second internal electrode 103, a third internal electrode 104, a first surface electrode 105 and a second surface electrode. 106 , a first surface terminal electrode 107 , a second surface terminal electrode 108 , a third surface terminal electrode 109 , a first surface terminal electrode 110 and a second surface terminal electrode 111 .

The piezoelectric ceramic body 101 is made of a piezoelectric ceramic material. The piezoelectric ceramic body 101 can be made of, for example, lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), lead zirconate titanate (PbZrO ₃ —PbTiO ₃ ), or the like.

As shown in FIGS. 1 and 2, the piezoelectric ceramic body 101 has a rectangular parallelepiped shape. Assuming that the X direction is the length, the Y direction is the width, and the Z direction is the thickness, the piezoelectric ceramic body 101 has a shape of length>width>thickness.

Regarding the surface of the piezoelectric ceramic body 101, the surfaces facing in the width direction (Y direction) are defined as a first side surface 101a and a second side surface 101b, and the surfaces facing in the length direction (X direction) are defined as a first end surface 101c and a second end surface. 101d. Moreover, the surfaces facing each other in the thickness direction (Z direction) are defined as an upper surface 101e and a lower surface 101f.

3 is a plan view showing the first side surface 101a, and FIG. 4 is a plan view showing the second side surface 101b. FIG. 5 is a plan view showing the first end face 101c, and FIG. 6 is a plan view showing the second end face 101d. FIG. 7 is a plan view showing the upper surface 101e, and FIG. 8 is a plan view showing the lower surface 101f.

As shown in FIGS. 3 and 4, the piezoelectric ceramic body 101 has a first region 101g on the upper surface 101e side and a second region 101h on the lower surface 101f side. The thickness of the first region 101g and the thickness of the second region 101h are preferably 1:1.

The first internal electrode 102 is formed inside the first region 101g and faces the second internal electrode 103 and the first surface electrode 105 via the piezoelectric ceramic body 101 (see FIGS. 3 and 4). FIG. 9 is a cross-sectional view of the laminated piezoelectric ceramic component 100 showing the first internal electrodes 102, taken along line AA in FIGS. 3 and 4. FIG. As shown in FIG. 9, the first internal electrode 102 is drawn out to the first end surface 101c, partially exposed on the first end surface 101c, and electrically connected to the first end surface terminal electrode 107. As shown in FIG.

The first internal electrode 102 has the same width (Y direction) as the piezoelectric ceramic body 101, and is exposed on the first side surface 101a and the second side surface 101b (see FIGS. 3 and 4). The number of layers of the first internal electrode 102 is not particularly limited, and may be one layer or multiple layers.

The second internal electrode 103 is formed inside the first region 101g and the second region 101h. Inside the first region 101g, the second internal electrodes 103 are alternately laminated with the first internal electrodes 102 with a predetermined distance in the thickness direction (Z direction) from the first internal electrodes 102, and the piezoelectric ceramic body 101 is It faces the first internal electrode 102 via the first internal electrode 102 (see FIGS. 3 and 4).

In addition, the second internal electrodes 103 are alternately laminated with the third internal electrodes 104 at a predetermined distance in the thickness direction (Z direction) from the third internal electrodes 104 inside the second region 101h, forming a piezoelectric ceramic body. It faces the third internal electrode 104 via 101 (see FIGS. 3 and 4).

10 is a cross-sectional view of the laminated piezoelectric ceramic component 100 showing the second internal electrodes 103, taken along line BB in FIGS. 3 and 4. FIG. As shown in FIG. 10, the second internal electrode 103 is drawn out to the second end surface 101d and electrically connected to the second end surface terminal electrode 108. As shown in FIG.

The second internal electrode 103 has the same width (Y direction) as the piezoelectric ceramic body 101, and is exposed on the first side surface 101a and the second side surface 101b (see FIGS. 3 and 4). The number of layers of the second internal electrodes 103 can be set according to the number of layers of the first internal electrodes 102 and the third internal electrodes 104 .

The third internal electrode 104 is formed inside the second region 101h and faces the second internal electrode 103 and the second surface electrode 106 via the piezoelectric ceramic body 101 (see FIGS. 3 and 4). FIG. 11 is a cross-sectional view of the laminated piezoelectric ceramic component 100 showing the third internal electrodes 104, taken along line CC of FIGS. 3 and 4. FIG. As shown in FIG. 11, the third internal electrode 104 is pulled out from the first end face 101c and partially exposed on the first end face 101c, and electrically connected to the third end face terminal electrode 109. As shown in FIG.

The third internal electrode 104 has the same width (Y direction) as the piezoelectric ceramic body 101 and is exposed on the first side surface 101a and the second side surface 101b (see FIGS. 3 and 4). The number of layers of the third internal electrode 104 is not particularly limited, and may be one layer or multiple layers.

The first surface electrode 105 is formed on the upper surface 101 e (see FIG. 1) and electrically connected to the second end surface terminal electrode 108 . Also, the first surface electrode 105 is separated from the first surface terminal electrode 110 and the second surface terminal electrode 111 on the upper surface 101e and is electrically insulated therefrom (see FIG. 7).

The second surface electrode 106 is formed on the bottom surface 101f and electrically connected to the second end surface terminal electrode 108 . (See Figure 3).

The first end surface terminal electrode 107 is formed on the first end surface 101 c (see FIG. 1) and electrically connected to the first internal electrode 102 . Also, the first end surface terminal electrode 107 is electrically insulated from the third internal electrode 104 and the third end surface terminal electrode 109 . The first end surface terminal electrode 107 is formed between the upper surface 101e and the lower surface 101f on the first end surface 101c and is electrically connected to the first surface terminal electrode 110. As shown in FIG.

A second end surface terminal electrode 108 is formed on the second end surface 101 d (see FIG. 2) and electrically connected to the second internal electrode 103 . The second end face terminal electrode 108 is formed between the upper surface 101e and the lower surface 101f on the second end face 101d and is electrically connected to the first surface electrode 105 and the second surface electrode .

The third end surface terminal electrode 109 is formed on the first end surface 101 c (see FIG. 1) and electrically connected to the third internal electrode 104 . Also, the third facet terminal electrode 109 is electrically insulated from the first internal electrode 102 and the first facet terminal electrode 107 . The third facet terminal electrode 109 is formed between the top face 101e and the bottom face 101f on the first facet 101c and is electrically connected to the second facet terminal electrode 111 .

The first surface terminal electrode 110 is formed on the upper surface 101e (see FIG. 1). The first surface terminal electrode 110 is electrically connected to the first end surface terminal electrode 107 and electrically isolated from the second surface terminal electrode 111 and the first surface electrode 105 .

The second surface terminal electrode 111 is formed on the upper surface 101e (see FIG. 1). The second surface terminal electrode 111 is electrically connected to the third end surface terminal electrode 109 and electrically insulated from the first surface terminal electrode 110 and the first surface electrode 105 .

First internal electrode 102 , second internal electrode 103 , third internal electrode 104 , first surface electrode 105 , second surface electrode 106 , first facet terminal electrode 107 , second facet terminal electrode 108 , third facet terminal electrode 109 , the first surface terminal electrode 110 and the second surface terminal electrode 111 are made of a conductive material. This conductive material can be, for example, any of Ag, Ag/Pd, Pd, Cu and Ni.

The laminated piezoelectric ceramic component 100 has the configuration as described above. As described above, the first internal electrode 102, the second internal electrode 103, and the third internal electrode 104 are formed inside the piezoelectric ceramic body 101, and the first internal electrode 102 and the second internal electrode 103 are connected through the piezoelectric ceramic body 101. are opposed to each other, and the third internal electrode 104 and the second internal electrode 103 are opposed to each other. The first internal electrode 102, the second internal electrode 103 and the third internal electrode 104 are insulated from each other.

Although the size of the laminated piezoelectric ceramic component 100 is not particularly limited, L/W is preferably about 16 to 50, where L is the length (X direction) and W is the width (Y direction). Also, the thickness (Z direction) is preferably about 0.5 mm to 1.5 mm.

[Regarding the first end face]
As described above, the first internal electrode 102 and the third internal electrode 104 are drawn out from the first end surface 101c and connected to the first end surface terminal electrode 107 and the third end surface terminal electrode 109, respectively.

FIG. 12 is a plan view showing the first internal electrodes 102 and the first end face terminal electrodes 107 on the first end face 101c, and is a partially enlarged view of FIG. As shown in the figure, the first internal electrode 102 has a covered portion 102a and an exposed portion 102b on the first end surface 101c.

Covered portion 102 a is a portion covered by first end face terminal electrode 107 . The exposed portion 102b is a portion that is not covered with the first end surface terminal electrode 107 and is exposed to the first end surface 101c. The exposed portion 102b is located on the second side surface 101b side with respect to the covered portion 102a.

The length (T1 in the figure) of the exposed portion 102b at the first end surface 101c is preferably 50 μm or more, more preferably 100 μm or more.

FIG. 13 is a plan view showing the third internal electrode 104 and the third end face terminal electrode 109 on the first end face 101c, and is a partially enlarged view of FIG. As shown in the figure, the third internal electrode 104 has a covered portion 104a and an exposed portion 104b on the first end surface 101c.

A covered portion 104 a is a portion covered with the third end face terminal electrode 109 . The exposed portion 104b is a portion that is not covered with the first end surface terminal electrode 109 and is exposed to the first end surface 101c. The exposed portion 104b is located on the first side surface 101a side with respect to the covered portion 104a.

The length (T2 in the drawing) of the exposed portion 104b at the first end surface 101c is preferably 50 μm or longer, more preferably 100 μm or longer.

[Operation of storage electric ceramic parts]
The laminated piezoelectric ceramic component 100 can independently apply a voltage between the first internal electrode 102 and the second internal electrode 103 and between the third internal electrode 104 and the second internal electrode 103 .

When a voltage is applied between the first internal electrode 102 and the second internal electrode 103, a reverse piezoelectric effect occurs in the piezoelectric ceramic body 101 between the first internal electrode 102 and the second internal electrode 103, and a voltage is generated in the first region 101g. Deformation (stretching) occurs in the X direction. Also, when a voltage is applied between the third internal electrode 104 and the second internal electrode 103, a reverse piezoelectric effect occurs in the piezoelectric ceramic body 101 between the third internal electrode 104 and the second internal electrode 103, and the second region Deformation (stretching) occurs in the X direction at 101h.

Thus, in the laminated piezoelectric ceramic component 100, the deformation of the first region 101g and the deformation of the second region 101h can be independently controlled. By deforming the first region 101g and the second region 101h in the X direction, the laminated piezoelectric ceramic component 100 can be deformed (bent) in the Z direction.

FIG. 14 shows an example of voltage waveforms applied to the laminated piezoelectric ceramic component 100. FIG. 14(a) shows the waveform of the voltage (V1) between the first internal electrode 102 and the second internal electrode 103, and FIG. 14(b) shows the waveform of the voltage between the third internal electrode 104 and the second internal electrode 103. FIG. (V2) waveform. Note that V ₀ indicates the potential of the second internal electrode 103 . As shown in the figure, it is possible to expand one of the first region 101g and the second region 101h and contract the other by setting the voltage V1 and the voltage V2 to reverse biases of the same phase.

By setting the thickness of the first region 101g and the thickness of the second region 101h to 1:1, the deformation amounts of the first region 101g and the second region 101h become symmetrical, which is preferable. Also, the waveforms of the voltage V1 and the voltage V2 are not limited to those shown in FIG. 14, and may be sine waves or triangular waves.

[About marginless structure]
The laminated piezoelectric ceramic component 100 has a structure in which the first internal electrode 102, the second internal electrode 103 and the third internal electrode 104 are exposed on the first side surface 101a and the second side surface 101b as described above.

FIG. 15 is a perspective view of a laminated piezoelectric ceramic component 300 according to a comparative example.

As shown in the figure, the laminated piezoelectric ceramic component 300 includes a piezoelectric ceramic body 301 , surface electrodes 302 , first terminal electrodes 303 and second terminal electrodes 304 . The laminated piezoelectric ceramic component 300 also includes internal electrodes (not shown) corresponding to the first internal electrode 102 , the second internal electrode 103 and the third internal electrode 104 .

In the laminated piezoelectric ceramic component 300 , the internal electrodes are embedded inside the piezoelectric ceramic body 301 without being exposed on the side surfaces and end surfaces. As shown in FIG. 15, side margins S made of a piezoelectric material are provided on the side surfaces of the internal electrodes, and end margins E made of a piezoelectric material are provided on the end surfaces of the internal electrodes.

The side margins S and the end margins E act as restraints that suppress the displacement of the laminated piezoelectric ceramic component 300 when the laminated piezoelectric ceramic component 300 is driven, and reduce the displacement performance of the laminated piezoelectric ceramic component 300 .

In contrast, the laminated piezoelectric ceramic component 100 does not have side margins and end margins. Therefore, it is possible to cause a large displacement without being affected by the restraining action of these margins, and it is possible to prevent deterioration of the displacement performance.

Furthermore, in the laminated piezoelectric ceramic component 100, the first internal electrodes 102 and the third internal electrodes 104 extend from the first end surface 101c to the first side surface 101a or the second side surface 101b (see FIG. 1). As a result, the influence of stress can be reduced, and an increase in the amount of displacement and an improvement in element strength are realized.

[About detection of poor connection]
In the laminated piezoelectric ceramic component 100, it is possible to detect poor connection using the image of the first end surface 101c. FIG. 16 is a perspective view of part of the laminated piezoelectric ceramic component 100. FIG. As shown in the figure, it is assumed that the first internal electrode 102 includes a first internal electrode 102' that does not reach the first end surface 101c.

FIG. 17 is a schematic diagram showing the first end surface 101c in this case. As shown in the figure, the exposed portion 102b of the first internal electrode 102' does not appear on the first end surface 101c. This makes it possible to detect that the first internal electrode 102 ′ is not electrically connected to the first end face terminal electrode 107 .

Specifically, in the inspection process of the laminated piezoelectric ceramic component 100, the image of the first end surface 101c is imaged, and the image of the exposed portion 102b can be detected by performing image processing on this image. It is possible to detect poor connection quickly and accurately by image processing.

The continuity between the third internal electrode 104 and the third end face terminal electrode 109 can also be detected in the same manner. It should be noted that the exposed portion 102b and the exposed portion 104b of the first end face 101c need to have a constant size when detected by image processing, and the length T1 (see FIG. 12) and the length T2 (see FIG. 13) are 50 μm. 100 μm or more is more preferable.

[Insulating film]
The laminated piezoelectric ceramic component 100 may have an insulating film. FIG. 18 is a perspective view showing a laminated piezoelectric ceramic component 100 having an insulating film 112. FIG.

As shown in the figure, the insulating film 112 covers the outer periphery of the laminated piezoelectric ceramic component 100 . The insulating film 112 is provided with an opening 112a that exposes a part of the first surface terminal electrode 110, the second surface terminal electrode 111, and the first surface electrode 105. Through the opening 112a, the first surface terminal electrode 110, Electrical connections are made to the second surface terminal electrode 111 and the first surface electrode 105 .

The range covered by the insulating film 112 is not limited to that shown in FIG. 18, and covers at least the first side surface 101a and the second side surface 101b where the first internal electrode 102, the second internal electrode 103 and the third internal electrode 104 are exposed. Anything is fine.

The material of the insulating film 112 is not particularly limited as long as it is an insulating material, but an insulating resin such as SiN or acrylic resin is suitable, for example. The insulating film 112 is made of a material different from that of the piezoelectric ceramic body 101, and a soft material can be used.

[About manufacturing method]
A method of manufacturing the laminated piezoelectric ceramic component 100 will be described.

The laminated piezoelectric ceramic component 100 can be manufactured by laminating sheet members. FIG. 19 is a schematic diagram showing a sheet member. 19(a) shows the first surface electrode 105, the first surface terminal electrode 110, the second surface terminal electrode 111 and the sheet member 210 composed of the piezoelectric ceramic body 201, and FIG. 19(b) shows the first internal electrode 102. and a sheet member 220 made of the piezoelectric ceramic body 201 .

19(c) shows a sheet member 230 composed of the second internal electrode 103 and the piezoelectric ceramic body 201, and FIG. 19(d) shows a sheet member 240 composed of the third internal electrode 104 and the piezoelectric ceramic body 201. FIG. FIG. 19(e) shows a sheet member 250 composed of the second surface electrode 106 and the piezoelectric ceramic body 201. FIG.

First, a sheet member made of only a piezoelectric ceramic body (hereinafter referred to as a piezoelectric sheet member) is laminated on the sheet member 250, and the sheet member 240, the piezoelectric sheet member, and the sheet member 230 are laminated in this order thereon. Further, the sheet members 240 and the sheet members 230 are alternately laminated with the piezoelectric sheet member interposed therebetween.

Subsequently, the sheet members 220 and the sheet members 230 are alternately laminated with the piezoelectric sheet member interposed therebetween, and the piezoelectric sheet member and the sheet member 210 are sequentially laminated thereon. Subsequently, this laminated body is pressure-bonded, and the binder is removed by heating or the like.

Firing is then performed. At this stage, each internal electrode is embedded in the piezoelectric ceramic body 201 to form a side margin. Subsequently, heat treatment is performed to form the first facet terminal electrode 107 and the third facet terminal electrode 109 on the first facet 101c, and form the second facet terminal electrode 108 on the second facet 101d.

Then cut and remove the side margins. As a result, the piezoelectric ceramic body 101 is formed from the piezoelectric ceramic body 201 . Side margin cutting can be performed by dicing or laser irradiation. By cutting the side margins, the first side surface 101a and the second side surface 101b are formed, and the first internal electrode 102, the second internal electrode 103 and the third internal electrode 104 are exposed from the first side surface 101a and the second side surface 101b ( See Figure 1).

Subsequently, the insulating film 112 is formed except for the opening 112a (see FIG. 18). The insulating film 112 can be formed by a method such as mist deposition, sputtering or dipping. After that, electrical continuity is established with the first surface terminal electrode 110 and the second surface terminal electrode 111, and a DC voltage is applied. Thereby, a polarization process is performed and the piezoelectric ceramic body 101 is activated.

The laminated piezoelectric ceramic component 100 can be manufactured as described above. Note that the manufacturing method of the laminated piezoelectric ceramic component 100 is not limited to the one shown here.

[About piezoelectric devices]
The laminated piezoelectric ceramic component 100 can be mounted on a vibrating member to constitute a piezoelectric device. FIG. 20 is a schematic diagram of a piezoelectric device 400 including the laminated piezoelectric ceramic component 100. FIG. As shown in the figure, the piezoelectric device 400 includes a laminated piezoelectric ceramic component 100, a vibrating member 410 and a joint 420. As shown in FIG.

The vibrating member 410 is a display glass panel or a metal plate, and is not particularly limited. The joint portion 420 is made of resin or the like, and joins the laminated piezoelectric ceramic component 100 to the vibrating member 410 .

In the laminated piezoelectric ceramic component 100 , a region of the upper surface 101 e on the side of the first end face 101 c is joined to the joint portion 420 . Wiring (not shown) is connected to the first surface terminal electrode 110 , the second surface terminal electrode 111 and the first surface electrode 105 via the joint portion 420 .

When a voltage is applied to each electrode, the laminated piezoelectric ceramic component 100 is deformed in the Z direction as described above (arrows in the figure). Thereby, it is possible to vibrate the vibrating member 410 . Note that the mounting method of the laminated piezoelectric ceramic component 100 is not limited to the one shown here, and for example, the entire upper surface 101e may be joined to the joining portion 420. FIG.

[Modification]
In the above description, the laminated piezoelectric ceramic component 100 has a piezoelectric element formed between the first internal electrode 102 and the second internal electrode 103, and a piezoelectric element formed between the third internal electrode 104 and the second internal electrode 103. Although the bimorph laminated piezoelectric actuator is described as the above, the present invention is not limited to this. The laminated piezoelectric ceramic component 100 may have only the first internal electrode 102 and the second internal electrode 103 without the third internal electrode 104 .

FIG. 21 is a perspective view showing the laminated piezoelectric ceramic component 100 without the third internal electrodes 104. FIG. As shown in the figure, the first internal electrode 102 is connected to the first end surface terminal electrode 107 at the first end surface 101c. Also in this configuration, it is possible to detect poor connection between the first internal electrode 102 and the first end surface terminal electrode 107 from the presence or absence of the image of the first internal electrode 102 on the first end surface 101c.

REFERENCE SIGNS LIST 100 Laminated piezoelectric ceramic component 101 Piezoelectric ceramic body 101a First side surface 101b Second side surface 101c First end surface 101d Second end surface 101e Upper surface 101f Lower surface 101g First area 101h Second area 102 Second area 1 internal electrode 103 second internal electrode 104 third internal electrode 105 first surface electrode 106 second surface electrode 107 first end terminal electrode 108 second end terminal electrode 109 third end terminal electrode 110 DESCRIPTION OF SYMBOLS 1st surface terminal electrode 111... 2nd surface terminal electrode 112... Insulating film 400... Piezoelectric device 410... Vibration member 420... Joint part

Claims (6)

It has a rectangular parallelepiped shape with length>width>thickness, and has upper and lower surfaces facing in the thickness direction, first and second end surfaces facing in the length direction, and a pair of side surfaces facing in the width direction. a piezoelectric ceramic body having
a first internal electrode formed inside the piezoelectric ceramic body and led out to the first end surface;
a second internal electrode formed inside the piezoelectric ceramic body, led out to the second end surface, and alternately stacked with the first internal electrode at a predetermined distance in the thickness direction;
a third internal electrode formed inside the piezoelectric ceramic body, led out to the first end surface, and alternately laminated with the second internal electrode at a predetermined distance in the thickness direction;
a first terminal electrode formed on the first end surface and electrically connected to the first internal electrode;
a second terminal electrode formed on the second end face and electrically connected to the second internal electrode;
A third electrode formed on the first end face, electrically connected to the third internal electrode, electrically insulated from the first terminal electrode, and electrically connected to the third internal electrode. 3 terminal electrodes and
At the first end surface, a part of the first internal electrode is covered with the first terminal electrode, and a portion of the first internal electrode closer to the side surface than the first terminal electrode is exposed. the length along the width direction of the first internal electrode exposed at the first end surface is 50 μm or more,
In the first end face, a part of the third internal electrode is covered with the third terminal electrode, and a portion of the third internal electrode closer to the side than the third terminal electrode is exposed. and a length along the width direction of the third internal electrode exposed at the first end face is 50 μm or more. The laminated piezoelectric ceramic component according to claim 1,
A multilayer piezoelectric ceramic component, wherein widths of the first internal electrode and the second internal electrode and a distance between the pair of side surfaces are the same. The laminated piezoelectric ceramic component according to claim 1 ,
A multilayer piezoelectric ceramic component, wherein the width of the third internal electrode and the distance between the pair of side surfaces are the same. The laminated piezoelectric ceramic component according to any one of claims 1 to 3 ,
A laminated piezoelectric ceramic component, wherein the pair of side surfaces are covered with an insulating film made of an insulating material different from the piezoelectric ceramic body. The laminated piezoelectric ceramic component according to claim 4 ,
The laminated piezoelectric ceramic component, wherein the insulator is an insulating resin material. a vibrating member;
a laminated piezoelectric ceramic component mounted on the vibrating member;
The laminated piezoelectric ceramic component is
It has a rectangular parallelepiped shape with length>width>thickness, and has upper and lower surfaces facing in the thickness direction, first and second end surfaces facing in the length direction, and a pair of side surfaces facing in the width direction. a piezoelectric ceramic body having
a first internal electrode formed inside the piezoelectric ceramic body and led out to the first end surface;
a second internal electrode formed inside the piezoelectric ceramic body, led out to the second end surface, and alternately stacked with the first internal electrode at a predetermined distance in the thickness direction;
a third internal electrode formed inside the piezoelectric ceramic body, led out to the first end surface, and alternately laminated with the second internal electrode at a predetermined distance in the thickness direction;
a first terminal electrode formed on the first end surface and electrically connected to the first internal electrode;
a second terminal electrode formed on the second end face and electrically connected to the second internal electrode;
A third electrode formed on the first end face, electrically connected to the third internal electrode, electrically insulated from the first terminal electrode, and electrically connected to the third internal electrode. 3 terminal electrodes and
At the first end surface, a part of the first internal electrode is covered with the first terminal electrode, and a portion of the first internal electrode closer to the side surface than the first terminal electrode is exposed. the length along the width direction of the first internal electrode exposed at the first end surface is 50 μm or more,
In the first end face, a part of the third internal electrode is covered with the third terminal electrode, and a portion of the third internal electrode closer to the side than the third terminal electrode is exposed. and a length along the width direction of the third internal electrode exposed at the first end face is 50 μm or more.

Images