Piezoelectric element, piezoelectric vibrator, and electronic device

Abstract

The piezoelectric element, the piezoelectric vibrator and the electronic device provided by the embodiments of the present application can avoid the problem of piezoelectric element failure by setting a defect repairing layer with a dielectric constant greater than that of the piezoelectric material layer between the piezoelectric material layer and the second electrode, so that when the piezoelectric material layer has a defect site due to manufacturing process or other reasons, the defect repairing layer can fill the defect site, i.e. the defect repairing layer can perform surface repair on the piezoelectric material layer, avoid the phenomenon of breakdown caused by the arc effect of the sharp discharge due to the existence of the defect site, and thus avoid the problem of piezoelectric element failure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piezoelectricity, in particular to a piezoelectric element, a piezoelectric vibrator and an electronic device. BACKGROUND

[0002] With the rapid progress of electronic technology, people's requirements for the use experience of electronic devices are getting higher and higher. Most of the current electronic devices can only provide visual and auditory experience, and cannot bring users tactile experience. Therefore, tactile reproduction technology has emerged as the times require.

[0003] The existing tactile reproduction technology is to set a piezoelectric element in an electronic device, and to provide tactile feedback through the vibration of the piezoelectric element. However, in the existing piezoelectric element, when the surface charge distribution is uneven and accumulates or the voltage is too high, a breakdown phenomenon will occur. The breakdown of the piezoelectric element will cause the piezoelectric element or even the entire vibration device to fail. SUMMARY

[0004] The piezoelectric element, the piezoelectric vibrator and the electronic device provided by the embodiments of the present application solve the problem that the piezoelectric element or even the entire vibration device fails due to the breakdown of the piezoelectric element.

[0005] The piezoelectric element provided by the embodiments of the present application comprises a first electrode, a piezoelectric material layer arranged on one side of the first electrode, a defect repair layer arranged on the side of the piezoelectric material layer away from the first electrode, and a second electrode arranged on the side of the defect repair layer away from the first electrode. The dielectric constant of the defect repair layer is greater than the dielectric constant of the piezoelectric material layer.

[0006] In a possible implementation manner, the material of the defect repair layer in the piezoelectric element provided by the embodiments of the present application comprises at least one of PbZrO3, BaTiO3 and ZrTiO3.

[0007] In a possible implementation manner, the thickness of the defect repair layer in the piezoelectric element provided by the embodiments of the present application is greater than 0.1 times the thickness of the piezoelectric material layer.

[0008] In a possible implementation manner, the second electrode in the piezoelectric element provided by the embodiments of the present application comprises a plurality of second sub-electrodes arranged in an array. Each adjacent two second sub-electrodes are electrically connected through an independent connecting structure, and the connecting structure is located on the side of the second electrode away from the first electrode. The material of the first electrode and the material of the second electrode are both transparent conductive materials, and the material of the connecting structure is metal.

[0009] The material of the first electrode and the material of the second electrode are both transparent conductive materials, and the material of the connecting structure is metal.

[0010] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, the connecting structure comprises a first connecting part and a second connecting part which are arranged in a stack and electrically connected, the first connecting part is in contact with the second sub-electrode; wherein the material of the first connecting part comprises Ti or Cr, and the material of the second connecting part comprises Al or Au.

[0011] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, the first connecting part comprises a first sub-connecting part and a second sub-connecting part which are arranged independently, the first sub-connecting part is in contact with one of the second sub-electrodes of the two adjacent second sub-electrodes, and the second sub-connecting part is in contact with the other of the two adjacent second sub-electrodes.

[0012] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, the thickness of the first connecting part is less than 10 nm, and the thickness of the second connecting part is less than 500 nm.

[0013] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, further comprising an insulating layer between the second electrode and the connecting structure, and the connecting structure is electrically connected with the second sub-electrode through a via hole penetrating through the insulating layer.

[0014] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, the thickness of the insulating layer is greater than 2 times the thickness of the second sub-electrode.

[0015] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, the material of the insulating layer is photoresist or SiO2.

[0016] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, the thickness of the piezoelectric material layer is 500 nm to 2000 nm.

[0017] In a possible implementation, in the piezoelectric element provided by the embodiment of the present application, the piezoelectric material layer comprises at least one of lead zirconate titanate, aluminum nitride, zinc oxide, barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, and lanthanum gallium silicate.

[0018] Correspondingly, the embodiment of the present application further provides a piezoelectric vibrator comprising a substrate and a plurality of piezoelectric elements as described above provided on the substrate.

[0019] Correspondingly, the embodiment of the present application further provides an electronic device comprising the piezoelectric vibrator as described above provided by the embodiment of the present application.

[0020] The beneficial effects of the embodiment of the present application are as follows:

[0021] The piezoelectric element, piezoelectric vibrator and electronic device provided by the embodiment of the present application set a defect repairing layer with a dielectric constant greater than that of the piezoelectric material layer between the piezoelectric material layer and the second electrode, so that when the piezoelectric material layer has a defect site due to manufacturing process or other reasons, the defect repairing layer can fill the defect site, that is, the defect repairing layer can perform surface repair on the piezoelectric material layer, avoiding the phenomenon of breakdown caused by the arc effect of the sharp discharge due to the existence of the defect site, thereby avoiding the problem of failure of the piezoelectric element. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A structural schematic diagram of a piezoelectric element provided in the related art is shown in FIG. 1.

[0023] Figure 2 A structural schematic diagram of a piezoelectric element provided by the embodiment of the present application is shown in FIG. 2.

[0024] Figure 3 A structural schematic diagram of another piezoelectric element provided by the embodiment of the present application is shown in FIG. 3.

[0025] Figure 4 A structural schematic diagram of a piezoelectric element provided by the embodiment of the present application is shown in FIG. 4. Figure 3 A planar schematic diagram of part of the film layer is shown in FIG. 5.

[0026] Figure 5 A repair schematic diagram when the piezoelectric element is broken down is shown in FIG. 6.

[0027] Figure 6 A structural schematic diagram of another piezoelectric element provided by the embodiment of the present application is shown in FIG. 7.

[0028] Figure 7 A structural schematic diagram of a piezoelectric vibrator provided by the embodiment of the present application is shown in FIG. 8. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. And in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0030] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "comprising" or "including," and similar terms used in this invention, mean that the element or object preceding the term encompasses the element or object listed following the term and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "inner," "outer," "upper," and "lower" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] It should be noted that the dimensions and shapes of the figures in the accompanying drawings do not reflect actual proportions and are intended only to illustrate the content of the invention. Furthermore, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0032] In related technologies, such as Figure 1 As shown, the piezoelectric element includes: a first electrode 1, a piezoelectric material layer 2 (e.g., PZT) disposed on the first electrode 1, and a second electrode 3 disposed on the piezoelectric material layer 2. During operation, utilizing the inverse piezoelectric effect, the first electrode 1 is grounded, and a high-frequency AC voltage signal (V2) is applied to the second electrode 3. AC This allows for the application of a high-frequency AC voltage signal to the piezoelectric material layer 2, thereby generating high-frequency vibration. However, when uneven charge distribution accumulates on the surface of the piezoelectric element or the voltage is too high, breakdown can occur. Piezoelectric element breakdown can lead to two outcomes: one is that the first electrode 1 and the second electrode 3 remain open, but the PZT layer structure is damaged; the other is that the first electrode 1 and the second electrode 3 become short-circuited due to breakdown, resulting in the failure of the piezoelectric element or even the entire vibrating device. However, the reasons for piezoelectric element breakdown can be divided into two categories. One is the wiring thermal effect, that is, when the heat generated by the piezoelectric element during operation is much greater than the heat dissipated, the piezoelectric element is prone to breakdown and wiring burnout. The other is when the instantaneous temperature of the piezoelectric element reaches the PZT phase separation temperature, PZT volume change and arc effect (Arc) will occur simultaneously. Arc is the potential that generates Arc when there is a pressure difference between the first electrode 1 and the second electrode 3. This potential is related to the distance and electrothermal density between the first electrode 1 and the second electrode 3. When there is a defect site 4 in the PZT film, due to the shortened distance, and if the defect site 4 has a pointed shape, an arc effect of tip discharge will be formed, resulting in breakdown.

[0033] In view of this, to avoid the problem of piezoelectric element failure due to breakdown, embodiments of the present invention provide a piezoelectric element, such as...Figure 2 As shown in the figure, it comprises: a first electrode 1, a piezoelectric material layer 2 arranged on one side of the first electrode 1, a defect repairing layer 5 arranged on the side of the piezoelectric material layer 2 away from the first electrode 1, and a second electrode 3 arranged on the side of the defect repairing layer 5 away from the first electrode 1; wherein the dielectric constant of the defect repairing layer 5 is greater than the dielectric constant of the piezoelectric material layer 2.

[0034] The piezoelectric element provided by the embodiment of the present application has the defect repairing layer 5 with a dielectric constant greater than that of the piezoelectric material layer 2 arranged between the piezoelectric material layer 2 and the second electrode 3. When the piezoelectric material layer 2 has a defect site 4 due to manufacturing process or other reasons, the defect repairing layer 5 can fill the defect site 4, i.e. the defect repairing layer 5 can repair the surface of the piezoelectric material layer 2, thereby avoiding the breakdown phenomenon caused by the arc effect of the sharp discharge due to the existence of the defect site 4, and thus the problem of failure of the piezoelectric element can be avoided.

[0035] In the piezoelectric element provided by the embodiment of the present application, as shown in the figure, Figure 2 The material of the defect repairing layer 5 can include but is not limited to at least one of PbZrO3, BaTiO3 and ZrTiO3.

[0036] It should be noted that the above-mentioned several materials of the defect repairing layer 5 are inorganic materials, and of course can also be organic materials, as long as the dielectric constant is greater than that of the piezoelectric material layer 2.

[0037] In the piezoelectric element provided by the embodiment of the present application, as shown in the figure, Figure 2 The thickness of the defect repairing layer 5 is greater than 0.1 times the thickness of the piezoelectric material layer 2, so that the setting of the defect repairing layer 5 can ensure the storage capacity of the charge and also can well fill and repair the piezoelectric material layer 2.

[0038] In the piezoelectric element provided by the embodiment of the present application, the thickness of the piezoelectric material layer can be 500nm-2000nm. For example, when the thickness of the piezoelectric material layer can be 500nm, the thickness of the defect repairing layer 5 should be greater than 50nm; when the thickness of the piezoelectric material layer can be 600nm, the thickness of the defect repairing layer 5 should be greater than 60nm; when the thickness of the piezoelectric material layer can be 1000nm, the thickness of the defect repairing layer 5 should be greater than 100nm; and so on.

[0039] In the piezoelectric element provided by the embodiment of the present application, as shown in Figure 3 and Figure 4 , Figure 4 as Figure 3 a plan view of the second electrode 3, of course, Figure 3 only a part of the structure of the piezoelectric element is shown, the second electrode 3 includes a plurality of second sub-electrodes 31 arranged in an array, each two adjacent second sub-electrodes 31 are electrically connected by an independent connecting structure 6, and the connecting structure 6 is located on the side of the second electrode 3 away from the first electrode 1; wherein,

[0040] The material of the first electrode 1 and the material of the second electrode 3 can both be transparent conductive material, for example, can be indium tin oxide (ITO), and can also be indium zinc oxide (IZO) and the like; the material of the connecting structure 6 can be metal, for example, Ti / Al and the like. In this way, when breakdown occurs at a certain position on the surface of the piezoelectric element, as shown in Figure 5 , for example, short-circuit breakdown occurs at the second sub-electrode 31 at the position of the second column and the third row, local heating occurs at this position, and since the bulk energy density of metal is much smaller than that of transparent conductive material such as ITO, the heat production of the connecting structure 6 will be much higher than that of the first electrode / piezoelectric material layer / second electrode, and the connecting structure 6 around the second sub-electrode 31 that has breakdown will be preferentially fused, so that the second sub-electrode 31 at the position of breakdown is open-circuited and isolated from the remaining second sub-electrodes 31, thereby achieving that the remaining second sub-electrodes 31 are not broken down and burned out, and thus the problem of failure of the entire piezoelectric element can be avoided.

[0041] In the piezoelectric element provided by the embodiment of the present application, the thickness of the first electrode can be 250nm-500nm, and the thickness of the second electrode can be 250nm-500nm.

[0042] In the piezoelectric element provided by the embodiment of the present application, as shown in Figure 6 , the connecting structure 6 includes a first connecting part 61 and a second connecting part 62 which are arranged in a stack and electrically connected, the first connecting part 61 is in contact with the second sub-electrode 31 and electrically connected thereto; wherein, the material of the first connecting part 61 can include Ti or Cr, and the material of the second connecting part 62 can include Al or Au. In this way, the first connecting part 61 acts as an adhesion layer to enhance the adhesion between the second connecting part 62 and the second sub-electrode 31; the second connecting part 62 acts as a main conductive layer, and a high-frequency alternating voltage signal can be loaded to the second electrode through the second connecting part 62, and the first electrode 1 is grounded.

[0043] In the piezoelectric element provided by the embodiment of the present application, as shown in Figure 6As shown, the first connecting part 61 comprises a first sub connecting part 611 and a second sub connecting part 612, the first sub connecting part 611 is in contact with one of the two adjacent second sub electrodes 31, and the second sub connecting part 612 is in contact with the other of the two adjacent second sub electrodes 31. In this way, the first sub connecting part 611 and the second sub connecting part 612 are only arranged at the positions in contact with the second sub electrodes 31, i.e. only Ti or Cr is arranged at the positions in contact with the second sub electrodes 31, and the other positions are all the second connecting part 62 (Al or Au) for conducting electricity, so that the conductivity of the connecting structure 6 can be improved.

[0044] In a specific implementation, in the piezoelectric element provided by the embodiment of the present application, as shown in Figure 6 The thickness of the first connecting part 61 can be less than 10 nm, for example, 5 nm; and the thickness of the second connecting part 62 can be less than 500 nm, for example, 100 nm.

[0045] In a specific implementation, in the piezoelectric element provided by the embodiment of the present application, as shown in Figure 3 and Figure 6 The piezoelectric element further comprises an insulating layer 7 between the second electrode 3 and the connecting structure 6, and the connecting structure 6 is electrically connected with the second sub electrode 31 through a via hole penetrating the insulating layer 7. Specifically, the insulating layer 7 has a protective effect, which can avoid damage or oxidation of the connecting structure 6.

[0046] In a specific implementation, in the piezoelectric element provided by the embodiment of the present application, as shown in Figure 3 and Figure 6 The thickness of the insulating layer 7 can be greater than 2 times the thickness of the second sub electrode 31; and the material of the insulating layer 7 can be photoresist, SiO2 or silicon nitride (Si3N4), which is not limited herein.

[0047] In a specific implementation, the piezoelectric element provided by the embodiment of the present application can further comprise other film layers according to actual application, in addition to the above-mentioned film layers.

[0048] In a specific implementation, the piezoelectric material layer is not limited to lead zirconate titanate (Pb(Zr,Ti)O3, PZT), but can also be aluminum nitride (AlN), zinc oxide (ZnO), barium titanate (BaTiO3), lead titanate (PbTiO3), potassium niobate (KNbO3), lithium niobate (LiNbO3), lithium tantalate (LiTaO3), lanthanum gallium silicate (La3Ga5SiO 14at least one of PZT, AlN, ZnO, LiNbO3, LiTaO3, so as to ensure the vibration characteristics of the piezoelectric element while ensuring the transparency of the piezoelectric element, and the material for manufacturing the piezoelectric material layer can be selected according to the actual use needs of the person skilled in the art, which is not limited here. When PZT is used to manufacture the piezoelectric material layer, the piezoelectric characteristics of the corresponding piezoelectric element are ensured due to the high piezoelectric coefficient of PZT, the corresponding piezoelectric element can be applied to a haptic feedback device, and PZT has high light transmittance, which does not affect the display quality of the display device when it is integrated into the display device.

[0049] In summary, the piezoelectric element provided by the embodiment of the present application can avoid breakdown caused by defect sites in the piezoelectric material layer by setting the defect repair layer, and can avoid the problem of failure of the entire piezoelectric element by setting the second electrode as a plurality of independently set second sub-electrodes, and electrically connecting each second sub-electrode through the connecting structure, so that when breakdown occurs at a local position, the second sub-electrode at the position where breakdown occurs can be disconnected from the remaining second sub-electrodes, and the remaining second sub-electrodes are prevented from being burned out due to breakdown, thereby avoiding the problem of failure of the entire piezoelectric element.

[0050] The piezoelectric element provided by the embodiment of the present application can be applied to the fields of medical treatment, automotive electronics, motion tracking systems, etc. It is especially suitable for wearable device field, medical treatment, monitoring and treatment outside the body or implanted in the human body, or applied to the field of electronic skin of artificial intelligence. Specifically, the piezoelectric element can be applied to brake pads, keyboards, mobile terminals, game controllers, vehicle-mounted devices, etc. that can generate vibration and mechanical characteristics.

[0051] Based on the same inventive concept, the embodiment of the present application also provides a piezoelectric vibrator, as shown in Figure 7 The piezoelectric vibrator includes a substrate 10 and a plurality of piezoelectric elements 20 provided on the substrate 10.

[0052] In the specific implementation process, the substrate can be a flexible substrate or a rigid substrate, for example, the material of the flexible substrate can be PI (Polyimide, polyimide), PET (Polyethylene Terephthalate, polyethylene terephthalate) or PDMS (Polydimethylsiloxane, polydimethylsiloxane) and the like, and the rigid substrate can be a glass substrate, a sapphire substrate and the like.

[0053] In the specific implementation, the piezoelectric vibrator provided by the embodiment of the present application can also be provided with other structures according to the actual application.

[0054] Based on the same inventive concept, the embodiment of the present application also provides an electronic device comprising the piezoelectric element provided by the embodiment of the present application. Since the principle of solving problems of the electronic device is similar to the piezoelectric element, the implementation of the electronic device can be referred to the implementation of the piezoelectric element, and the repeated parts will not be described here.

[0055] In the actual product, the electronic device can be a display device, and the display device comprises a display panel and the piezoelectric vibrator. The piezoelectric vibrator can be arranged on the light-emitting side of the display panel, so that the display device can realize the display function and the haptic reproduction function at the same time.

[0056] Of course, the electronic device of the embodiment of the present application is not limited to the display device, and can also be any product or component with the haptic reproduction function.

[0057] The piezoelectric element, the piezoelectric vibrator and the electronic device provided by the embodiment of the present application can set the defect repairing layer with the dielectric constant greater than the dielectric constant of the piezoelectric material layer between the piezoelectric material layer and the second electrode. When the piezoelectric material layer has a defect site due to the manufacturing process, the defect repairing layer can fill the defect site, that is, the defect repairing layer can repair the surface of the piezoelectric material layer, avoid the phenomenon of breakdown caused by the arc effect of the sharp discharge due to the existence of the defect site, and thus the problem of failure of the piezoelectric element can be avoided.

[0058] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all the preferred embodiments and all the changes and modifications falling within the scope of the present application.

[0059] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A piezoelectric element, characterized in that, include: A first electrode, a piezoelectric material layer disposed on one side of the first electrode, a defect repair layer disposed on the side of the piezoelectric material layer opposite to the first electrode, and a second electrode disposed on the side of the defect repair layer opposite to the first electrode; wherein, the dielectric constant of the defect repair layer is greater than the dielectric constant of the piezoelectric material layer. The second electrode includes a plurality of second sub-electrodes arranged in an array. Each pair of adjacent second sub-electrodes is electrically connected by an independent connection structure, and the connection structure is located on the side of the second electrode away from the first electrode. The first electrode and the second electrode are both made of transparent conductive materials, and the connection structure is made of metal. The connection structure includes a first connection portion and a second connection portion that are stacked and electrically connected, wherein the first connection portion is in contact with and electrically connected to the second sub-electrode; wherein the material of the first connection portion includes Ti or Cr, and the material of the second connection portion includes Al or Au.

2. The piezoelectric element as described in claim 1, characterized in that, The material of the defect repair layer includes at least one of PbZrO3, BaTiO3, and ZrTiO3.

3. The piezoelectric element as described in claim 1, characterized in that, The thickness of the defect repair layer is greater than 0.1 times the thickness of the piezoelectric material layer.

4. The piezoelectric element as described in claim 1, characterized in that, The first connection portion includes an independently disposed first sub-connection portion and a second sub-connection portion. The first sub-connection portion is electrically connected to one of the two adjacent second sub-electrodes, and the second sub-connection portion is electrically connected to the other of the two adjacent second sub-electrodes.

5. The piezoelectric element as claimed in claim 1, characterized in that, The thickness of the first connecting part is less than 10 nm, and the thickness of the second connecting part is less than 500 nm.

6. The piezoelectric element according to any one of claims 1-5, characterized in that, It also includes an insulating layer located between the second electrode and the connection structure, the connection structure being electrically connected to the second sub-electrode through a via penetrating the insulating layer.

7. The piezoelectric element as claimed in claim 6, characterized in that, The thickness of the insulating layer is greater than twice the thickness of the second sub-electrode.

8. The piezoelectric element as described in claim 6, characterized in that, The insulating layer is made of photoresist or SiO2.

9. The piezoelectric element according to any one of claims 1-5, 7 and 8, characterized in that, The thickness of the piezoelectric material layer is 500nm~2000nm.

10. The piezoelectric element according to any one of claims 1-5, 7 and 8, characterized in that, The piezoelectric material layer includes at least one of lead zirconate titanate, aluminum nitride, zinc oxide, barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, and lanthanum gallium silicate.

11. A piezoelectric vibrator, characterized in that, It includes a substrate and a plurality of piezoelectric elements as described in any one of claims 1-10 disposed on the substrate.

12. An electronic device, characterized in that, Including the piezoelectric vibrator as described in claim 11.

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