Piezoelectric element, piezoelectric vibrator, manufacturing method thereof, and electronic device

Abstract

The present invention provides a piezoelectric element, a piezoelectric vibrator, a manufacturing method thereof, and an electronic device, and relates to the field of piezoelectric technology. The present invention provides a first electrode and a second electrode located on the first electrode in the piezoelectric element, the second electrode has an opening exposing the first electrode, and a piezoelectric structure is provided in the piezoelectric element, the piezoelectric structure includes a first piezoelectric portion and a second piezoelectric portion provided around the first piezoelectric portion, the first piezoelectric portion is provided in the opening and in contact with the first electrode, the second piezoelectric portion is provided on a side of the second electrode away from the first electrode, and the second piezoelectric portion has orientation. By adding the second electrode to the first electrode, and growing the first piezoelectric portion on the first electrode, and growing the second piezoelectric portion on the second electrode, the second piezoelectric portion surrounding the first piezoelectric portion has orientation, thereby improving the film strength at the edge of the piezoelectric structure, avoiding defects at the edge of the piezoelectric structure, and thus avoiding damage at the defective position due to vibration.

Description

Technical Field

[0001] The present invention relates to the field of piezoelectric technology, and in particular to a piezoelectric element, a piezoelectric vibrator, a manufacturing method thereof, and an electronic device. Background Art

[0002] With the rapid advancement of electronic technology, people have higher and higher requirements for the user experience of electronic devices. Most of the current electronic devices can only provide visual and auditory experiences, but cannot bring tactile experiences to users. Therefore, tactile reproduction technology came into being.

[0003] The existing tactile reproduction technology is to set a piezoelectric element in an electronic device and provide tactile feedback through the vibration of the piezoelectric element. However, in the existing piezoelectric element, the film layer corresponding to the piezoelectric structure grown on the first electrode is not oriented, resulting in a low film strength of the film layer corresponding to the piezoelectric structure. Therefore, in the process of patterning the film layer corresponding to the piezoelectric structure to obtain the piezoelectric structure, defects are likely to appear at the edge of the piezoelectric structure, which in turn causes the piezoelectric element to be easily damaged due to vibration at the defective position when in use, causing the piezoelectric element to fail. Summary of the invention

[0004] The present invention provides a piezoelectric element, a piezoelectric vibrator, a method for manufacturing the same, and an electronic device to solve the problem that the film layer corresponding to the piezoelectric structure in the existing piezoelectric element has no orientation, defects are easily generated at the edge of the piezoelectric structure during manufacturing, and the defective position is easily damaged due to vibration.

[0005] In order to solve the above problems, the present invention discloses a piezoelectric element, comprising: a first electrode and a second electrode disposed on the first electrode, wherein the second electrode has an opening exposing the first electrode;

[0006] The piezoelectric element also includes a piezoelectric structure, which includes a first piezoelectric portion and a second piezoelectric portion arranged around the first piezoelectric portion, the first piezoelectric portion is arranged in the opening and in contact with the first electrode, and the second piezoelectric portion is arranged on a side of the second electrode away from the first electrode; wherein the second piezoelectric portion has orientation.

[0007] Optionally, along a direction from the second piezoelectric portion to the first piezoelectric portion, a width of the first piezoelectric portion is 10 to 20 times a width of the second piezoelectric portion.

[0008] Optionally, the material of the first electrode is indium tin oxide, and the material of the second electrode is platinum.

[0009] Optionally, in a direction perpendicular to the plane where the first electrode is located, the thickness of the first electrode is 100 nm to 500 nm, and the thickness of the second electrode is less than 100 nm.

[0010] Optionally, in a direction perpendicular to a plane where the first electrode is located, a thickness of the first piezoelectric portion is greater than a thickness of the second electrode.

[0011] Optionally, in a direction perpendicular to the plane where the first electrode is located, the sum of the thickness of the second electrode and the thickness of the second piezoelectric portion is equal to the thickness of the first piezoelectric portion.

[0012] Optionally, materials of the first piezoelectric portion and the second piezoelectric portion are both piezoelectric ceramics.

[0013] Optionally, the piezoelectric element further includes a third electrode disposed on a side of the piezoelectric structure away from the first electrode.

[0014] In order to solve the above problem, the present invention further discloses a piezoelectric vibrator, comprising: a substrate and a plurality of the above piezoelectric elements arranged on the substrate.

[0015] Optionally, the piezoelectric vibrator further includes an insulating layer covering the substrate and each of the piezoelectric elements, the insulating layer having a first via hole and a second via hole corresponding to each of the piezoelectric elements;

[0016] The piezoelectric vibrator also includes a routing layer arranged on a side of the insulating layer away from the piezoelectric element, the routing layer includes a first signal line and a second signal line corresponding to each of the piezoelectric elements, each of the first signal lines is connected to the first electrode in the corresponding piezoelectric element through the first via hole, and each of the second signal lines is connected to the third electrode in the corresponding piezoelectric element through the second via hole.

[0017] In order to solve the above problems, the present invention also discloses a method for manufacturing a piezoelectric vibrator, comprising:

[0018] forming a plurality of first electrodes on a substrate;

[0019] forming a second electrode on each of the first electrodes; each of the second electrodes having an opening exposing the first electrode;

[0020] forming a piezoelectric structure on each of the first electrodes and the corresponding second electrode;

[0021] The piezoelectric structure includes a first piezoelectric portion and a second piezoelectric portion arranged around the first piezoelectric portion, the first piezoelectric portion is arranged in the opening and in contact with the first electrode, and the second piezoelectric portion is arranged on a side of the second electrode away from the first electrode; the second piezoelectric portion has orientation.

[0022] Optionally, after the step of forming a piezoelectric structure on each of the first electrodes and the corresponding second electrode, the method further includes:

[0023] forming a third electrode on a side of each of the piezoelectric structures away from the first electrode to obtain a plurality of piezoelectric elements;

[0024] forming an insulating layer covering the substrate and each of the piezoelectric elements; the insulating layer having a first via hole and a second via hole corresponding to each of the piezoelectric elements;

[0025] A routing layer is formed on a side of the insulating layer away from the piezoelectric element; the routing layer includes a first signal line and a second signal line corresponding to each of the piezoelectric elements, each of the first signal lines is connected to the first electrode in the corresponding piezoelectric element through the first via hole, and each of the second signal lines is connected to the third electrode in the corresponding piezoelectric element through the second via hole.

[0026] In order to solve the above problem, the present invention also discloses an electronic device, comprising the above piezoelectric vibrator.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] A first electrode and a second electrode located on the first electrode are provided in a piezoelectric element, the second electrode has an opening exposing the first electrode, and a piezoelectric structure is provided in the piezoelectric element, the piezoelectric structure includes a first piezoelectric portion and a second piezoelectric portion provided around the first piezoelectric portion, the first piezoelectric portion is provided in the opening and in contact with the first electrode, the second piezoelectric portion is provided on a side of the second electrode away from the first electrode, and the second piezoelectric portion has orientation. By adding a second electrode to the first electrode, and growing the first piezoelectric portion on the first electrode, and growing the second piezoelectric portion on the second electrode, the second piezoelectric portion surrounding the first piezoelectric portion has orientation, and the film strength of the oriented second piezoelectric portion is higher, thereby improving the film strength of the edge of the piezoelectric structure, avoiding defects at the edge of the piezoelectric structure, and thus avoiding damage to the defective position due to vibration during the use of the piezoelectric element, thereby improving the reliability of the piezoelectric element. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a piezoelectric element of the related art is shown;

[0030] Figure 2 A schematic structural diagram of a piezoelectric element according to an embodiment of the present invention is shown;

[0031] Figure 3 shows an XRD pattern of the first piezoelectric portion in an embodiment of the present invention;

[0032] Figure 4 shows an XRD pattern of the second piezoelectric portion in an embodiment of the present invention;

[0033] Figure 5 A schematic diagram showing the structure of another piezoelectric element according to an embodiment of the present invention is shown;

[0034] Figure 6 A schematic plan view of a piezoelectric vibrator according to an embodiment of the present invention is shown;

[0035] Figure 7 A schematic structural diagram of a piezoelectric vibrator according to an embodiment of the present invention is shown;

[0036] Figure 8 A flow chart of a method for manufacturing a piezoelectric vibrator according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] In related technologies, such as Figure 1 As shown, the piezoelectric element includes a first electrode 111 and a piezoelectric structure 112 disposed on the first electrode 111, and the piezoelectric structure 112 has no orientation. The specific manufacturing process is: after forming the first electrode 111, a piezoelectric film (i.e., a film layer corresponding to the piezoelectric structure 112) is formed on the first electrode 111, the piezoelectric film is annealed, and after annealing, the piezoelectric film is patterned to form the desired piezoelectric structure 112.

[0039] However, since the material of the first electrode 111 is ITO (Indium Tin Oxides), the piezoelectric film formed on the first electrode 111 has no orientation, resulting in a low film strength of the piezoelectric film. Therefore, in the process of patterning the piezoelectric film to obtain the piezoelectric structure 112, defects may appear at the edge of the formed piezoelectric structure 112. In the process of using the piezoelectric element to vibrate to achieve tactile feedback, the defective position is easily damaged due to vibration, causing the piezoelectric element to fail.

[0040] Therefore, in the embodiment of the present invention, a second electrode is added to the first electrode, and a first piezoelectric portion is grown on the first electrode, and a second piezoelectric portion is grown on the second electrode, so that the second piezoelectric portion surrounding the first piezoelectric portion has an orientation. The film strength of the oriented second piezoelectric portion is higher, thereby improving the film strength at the edge of the piezoelectric structure and avoiding defects at the edge of the piezoelectric structure. Therefore, in the process of using the piezoelectric element, damage due to vibration at the defective position is avoided, thereby improving the reliability of the piezoelectric element.

[0041] Embodiment 1

[0042] Reference Figure 2 , showing a schematic structural diagram of a piezoelectric element according to an embodiment of the present invention.

[0043] An embodiment of the present invention provides a piezoelectric element 21, comprising: a first electrode 211 and a second electrode 212 arranged on the first electrode 211, the second electrode 212 having an opening exposing the first electrode 211; the piezoelectric element 21 also includes a piezoelectric structure, the piezoelectric structure includes a first piezoelectric portion 213 and a second piezoelectric portion 214 arranged around the first piezoelectric portion 213, the first piezoelectric portion 213 is arranged in the opening and in contact with the first electrode 211, and the second piezoelectric portion 214 is arranged on a side of the second electrode 212 away from the first electrode 211; wherein the second piezoelectric portion 214 has orientation.

[0044] In actual products, the first electrode 211 is a planar electrode, and a second electrode 212 is added to the first electrode 211 . The second electrode 212 is actually a ring electrode having an opening exposing the first electrode 211 . The first electrode 211 and the second electrode 212 together constitute the bottom electrode of the piezoelectric element 21 .

[0045] Furthermore, a piezoelectric structure is disposed on the first electrode 211 and the second electrode 212 . The piezoelectric structure includes a first piezoelectric portion 213 and a second piezoelectric portion 214 disposed around the first piezoelectric portion 213 . The first piezoelectric portion 213 and the second piezoelectric portion 214 are an integrally formed structure.

[0046] The first piezoelectric portion 213 is arranged in the opening and in contact with the first electrode 211. Since the first piezoelectric portion 213 is directly grown on the first electrode 211, the first piezoelectric portion 213 has no orientation, that is, the first piezoelectric portion 213 is a non-oriented structure; and the second piezoelectric portion 214 is arranged on the side of the second electrode 212 away from the first electrode 211. Since the second piezoelectric portion 214 is directly grown on the second electrode 212, by reasonably selecting the material of the second electrode 212, the second piezoelectric portion 214 grown on the second electrode 212 can have orientation, that is, the second piezoelectric portion 214 is an oriented structure.

[0047] The oriented structure refers to the fact that under certain external fields, macromolecular chains, chain segments or microcrystals can be preferentially and orderly arranged along the direction of the external field. The film strength of the non-oriented structure is low, while the film strength of the oriented structure is high. Therefore, the film strength of the second piezoelectric part 214 is higher than the film strength of the first piezoelectric part 213.

[0048] Since the second piezoelectric portion 214 is arranged around the first piezoelectric portion 213, and the first piezoelectric portion 213 is not oriented, and the second piezoelectric portion 214 is oriented, therefore, the oriented second piezoelectric portion 214 is arranged at the edge of the non-oriented first piezoelectric portion 213, which can improve the film strength of the edge of the piezoelectric structure 21 and avoid defects at the edge position of the piezoelectric structure 21. Therefore, in the process of using the piezoelectric element 21, the defective position is avoided from being damaged due to vibration, thereby improving the reliability of the piezoelectric element 21.

[0049] It should be noted that the orthographic projection of the first piezoelectric portion 213 on the first electrode 211 and the orthographic projection of the second electrode 212 on the first electrode 211 do not overlap, and the orthographic projection of the second piezoelectric portion 214 on the first electrode 211 is within the orthographic projection of the second electrode 212 on the first electrode 211 .

[0050] In the embodiment of the present invention, the material of the first electrode 211 is indium tin oxide, and the material of the second electrode 212 is platinum.

[0051] The material of the first electrode 211 is the same as that used in the related art, which is indium tin oxide, so that the first piezoelectric structure 213 formed on the indium tin oxide has no orientation; the second electrode 212 is added to the first electrode 211, and the material of the second electrode 212 is platinum (Pt), so that the second piezoelectric structure 214 formed on the metal platinum has orientation.

[0052] In the embodiment of the present invention, the materials of the first piezoelectric portion 213 and the second piezoelectric portion 214 are both piezoelectric ceramics (Piezoelectric Ceramic, PZT). For example, the material of the piezoelectric ceramics can be lead zirconate titanate binary piezoelectric ceramics, the chemical formula of which is Pb(Zr 1-x Ti x )O3, belongs to ABO3 perovskite structure.

[0053] Through experimental detection, X-ray diffraction is performed on the position corresponding to the first piezoelectric part 213, and the following can be obtained: Figure 3 The XRD spectrum shown in FIG. 1 is obtained by performing X-ray diffraction on the position corresponding to the second piezoelectric portion 214. Figure 4 The XRD pattern shown in Figure 3 and Figure 4 In the figure, the horizontal axis is the X-ray diffraction angle 2θ, and the vertical axis is the diffraction intensity.

[0054] like Figure 3 As shown in FIG. 1 , after performing X-ray diffraction on the position corresponding to the first piezoelectric portion 213, two diffraction peaks can be found, which are the diffraction peaks of 101PZT and 111PZT, 101PZT refers to the diffraction peak of the first piezoelectric portion 213 along the crystal plane (101), and 111PZT refers to the diffraction peak of the first piezoelectric portion 213 along the crystal plane (111). Figure 3 The XRD spectrum at the corresponding position of the first piezoelectric portion 213 shown in the figure is compared with the PZT standard XRD spectrum, and it is found that Figure 3 The peak values ​​of the diffraction peaks in the XRD spectrum shown are substantially equal to the peak values ​​of the diffraction peaks in the PZT standard XRD spectrum, and therefore, it can be determined that the first piezoelectric portion 213 has no orientation.

[0055] like Figure 4 As shown, after performing X-ray diffraction at the position corresponding to the second piezoelectric portion 214, three diffraction peaks can be found, which are the diffraction peaks of 001PZT, 111Pt and 002PZT, 001PZT refers to the diffraction peak of the second piezoelectric portion 214 along the crystal plane (001), 111Pt refers to the diffraction peak of the second electrode 212 along the crystal plane (111), 002PZT refers to the diffraction peak of the second piezoelectric portion 214 along the crystal plane (002), Figure 4 The XRD spectrum at the corresponding position of the second piezoelectric portion 214 shown in the figure is compared with the PZT standard XRD spectrum, and it is found that Figure 4 In the XRD spectrum shown, the peak value of the diffraction peak of 001PZT is greater than the peak value of the corresponding diffraction peak in the standard XRD spectrum of PZT, so it can be determined that the second piezoelectric portion 214 is preferentially oriented along the (001) crystal plane.

[0056] It should be noted that, when the second piezoelectric portion 214 is subjected to X-ray diffraction, the X-rays will irradiate the second electrode 212 below the second piezoelectric portion 214. Figure 4 There will be a diffraction peak of the second electrode 212 along the crystal plane (111).

[0057] Further, along the direction from the second piezoelectric portion 214 to the first piezoelectric portion 213 , the width d2 of the first piezoelectric portion 213 is 10 to 20 times the width d1 of the second piezoelectric portion 214 .

[0058] In the related art, the piezoelectric structure is directly formed on the first electrode, and the material of the first electrode is indium tin oxide. In the actual manufacturing process, after the piezoelectric film is formed on the first electrode, the piezoelectric film needs to be subjected to high temperature annealing in an air environment. When the piezoelectric film is subjected to high temperature annealing, the entire structure is placed in a high temperature environment. At this time, the first electrode is also subjected to high temperature annealing, so that the resistance of the first electrode using indium tin oxide increases, resulting in uneven charge distribution of the first electrode, and charge accumulation occurs at the first electrode, causing the piezoelectric structure to be broken down and burned. In the embodiment of the present invention, the second electrode 212 is added to the first electrode 211, and the material of the first electrode 211 is indium tin oxide, and the material of the second electrode 212 is platinum. Since the conductivity of platinum is greater than the conductivity of indium tin oxide, the resistance of the entire bottom electrode (including the first electrode 211 and the second electrode 212) can be reduced by adding the second electrode 212, and the charge distribution area is increased, and the accumulation of charge due to uneven distribution is reduced, thereby avoiding the breakdown of the piezoelectric structure and improving the reliability of the piezoelectric element 21.

[0059] Furthermore, since the width d1 of the second piezoelectric portion 214 is substantially equal to the width of the second electrode 212, setting the width d2 of the first piezoelectric portion 213 to 10 to 20 times the width d1 of the second piezoelectric portion 214 can effectively control the width of the second electrode 212, thereby effectively reducing the resistance of the bottom electrode through the second electrode 212, and more effectively preventing the piezoelectric structure from being punctured.

[0060] In the embodiment of the present invention, the thickness of the first electrode 211 is 100 nm to 500 nm, and the thickness of the second electrode 212 is less than 100 nm in a direction perpendicular to the plane where the first electrode 211 is located. For example, the thickness of the first electrode 211 can be 200 nm, 300 nm, 400 nm, etc., and the thickness of the second electrode 212 can be 30 nm, 50 nm, 80 nm, etc.

[0061] By properly setting the thickness of the first electrode 211 and the second electrode 212 , the thickness of the piezoelectric element 21 can be reduced while the piezoelectric element 21 can work normally.

[0062] In the embodiment of the present invention, along a direction perpendicular to the plane where the first electrode 211 is located, the thickness of the first piezoelectric portion 213 is greater than the thickness of the second electrode 212 .

[0063] Since it is necessary to subsequently set a third electrode on the side of the piezoelectric structure away from the first electrode 211, that is, to set the top electrode of the piezoelectric element 21 on the side of the piezoelectric structure away from the first electrode 211, it is necessary to set the thickness of the first piezoelectric part 213 to be greater than the thickness of the second electrode 212 to avoid direct contact between the third electrode and the second electrode 212, which would cause the piezoelectric element 21 to fail to work normally.

[0064] Furthermore, in a direction perpendicular to the plane where the first electrode 211 is located, the sum of the thickness of the second electrode 212 and the thickness of the second piezoelectric portion 214 is equal to the thickness of the first piezoelectric portion 213 .

[0065] That is to say, the surface of the first piezoelectric portion 213 away from the first electrode 211 and the surface of the second piezoelectric portion 214 away from the first electrode 211 are located in the same plane. When the third electrode is subsequently manufactured, the surface of the third electrode away from the first electrode 211 can also be located in the same plane to ensure the flatness of the piezoelectric element 21.

[0066] like Figure 5 As shown, the piezoelectric element 21 further includes a third electrode 215 disposed on a side of the piezoelectric structure away from the first electrode 211. The third electrode 215 is actually a top electrode of the piezoelectric element 21, and the third electrode 215 covers the first piezoelectric portion 213 and the second piezoelectric portion 214.

[0067] The structure of the third electrode 215 can be the same as that of the first electrode 211, both are planar electrodes, and the material of the third electrode 215 can also be indium tin oxide. In addition, the shapes of the first electrode 211 and the third electrode 215 are both rectangular, and the shape of the second electrode 212 is a rectangular ring.

[0068] It should be noted that the embodiment of the present invention adds a second electrode 212 at the edge of the first electrode 211, and uses indium tin oxide as the material of the first electrode 211 and the third electrode 215, and uses platinum as the material of the second electrode 212. While reducing the bottom electrode resistance and improving the film strength at the edge of the piezoelectric structure, the transmittance of the piezoelectric element 21 can be guaranteed, so that light can normally pass through the piezoelectric element 21. Therefore, the piezoelectric element 21 of the embodiment of the present invention can be used in electronic devices that require piezoelectric elements with high transmittance.

[0069] In an embodiment of the present invention, a second electrode is added to the first electrode, and a first piezoelectric portion is grown on the first electrode, and a second piezoelectric portion is grown on the second electrode, so that the second piezoelectric portion surrounding the first piezoelectric portion has an orientation, and the film strength of the oriented second piezoelectric portion is higher, thereby improving the film strength at the edge of the piezoelectric structure and avoiding defects at the edge of the piezoelectric structure. Therefore, in the process of using the piezoelectric element, damage due to vibration at the defective position is avoided, thereby improving the reliability of the piezoelectric element.

[0070] Embodiment 2

[0071] Reference Figure 6 A schematic plan view of a piezoelectric vibrator according to an embodiment of the present invention is shown. Figure 7 FIG. 1 is a schematic diagram showing the structure of a piezoelectric vibrator according to an embodiment of the present invention. Figure 7 for Figure 6 Cross-sectional view along section AA'.

[0072] The embodiment of the present invention provides a piezoelectric vibrator, including a substrate 22 and a plurality of the above-mentioned piezoelectric elements 21 disposed on the substrate 22 .

[0073] Among them, the substrate 22 can be a flexible substrate or a rigid substrate. For example, the material of the flexible substrate can be PI (Polyimide), PET (Polyethylene Terephthalate) or PDMS (Polydimethylsiloxane), and the rigid substrate can actually be a glass substrate.

[0074] A plurality of piezoelectric elements 21 are disposed on the substrate 22 . Specifically, the substrate 22 is disposed on a side of the first electrode 211 away from the piezoelectric structure, that is, the substrate 22 is directly in contact with the first electrode 211 in the piezoelectric element 21 .

[0075] Furthermore, the piezoelectric vibrator further includes an insulating layer 23 covering the substrate 22 and each piezoelectric element 21, the insulating layer 23 having a first via hole and a second via hole corresponding to each piezoelectric element 21; the piezoelectric vibrator further includes a wiring layer arranged on a side of the insulating layer 23 away from the piezoelectric element 21, the wiring layer including a first signal line corresponding to each piezoelectric element 21 (not shown in FIG. Figure 7 ), each first signal line is connected to the first electrode 211 in the corresponding piezoelectric element 21 through a first via hole, and each second signal line 241 is connected to the third electrode 215 in the corresponding piezoelectric element 21 through a second via hole.

[0076] Among them, the material of the insulating layer 23 is at least one of silicon nitride and silicon oxide, and the insulating layer 23 has multiple first vias and multiple second vias passing through, each piezoelectric element 21 corresponds to a first via and a second via, and the first via can expose the first electrode 211 in the piezoelectric element 21, and the second via can expose the third electrode 215 in the piezoelectric element 21.

[0077] A plurality of first signal lines and a plurality of second signal lines are arranged on the insulating layer 23, and each piezoelectric element 21 corresponds to a first signal line and a second signal line. For each piezoelectric element 21, the corresponding first signal line is connected to the first electrode 211 included therein through a first via hole, and is used to provide a first voltage to the first electrode 211 and the second electrode 212, and the corresponding second signal line is connected to the third electrode 215 included therein through a second via hole, and is used to provide a second voltage to the third electrode 215. The materials of the first signal line and the second signal line are conductive materials, for example, the materials of the first signal line and the second signal line are metals or alloys.

[0078] During actual use, a first voltage signal is input to each first signal line to provide a first voltage to the first electrode 211 and the second electrode 212 in each piezoelectric element 21, and a second voltage signal is input to each second signal line to provide a second voltage to the third electrode 215 in each piezoelectric element 21. The first voltage and the second voltage are not equal, and the piezoelectric structure in the piezoelectric element 21 vibrates under the control of the first voltage and the second voltage, so that the first piezoelectric part 213 and the second piezoelectric part 214 in each piezoelectric element 21 vibrates, thereby achieving tactile reproduction.

[0079] In an embodiment of the present invention, a second electrode is added to the first electrode, and a first piezoelectric portion is grown on the first electrode, and a second piezoelectric portion is grown on the second electrode, so that the second piezoelectric portion surrounding the first piezoelectric portion has an orientation, and the film strength of the oriented second piezoelectric portion is higher, thereby improving the film strength at the edge of the piezoelectric structure and avoiding defects at the edge of the piezoelectric structure. Therefore, in the process of using the piezoelectric element, damage due to vibration at the defective position is avoided, thereby improving the reliability of the piezoelectric element.

[0080] Embodiment 3

[0081] Reference Figure 8 , shows a flow chart of a method for manufacturing a piezoelectric vibrator according to an embodiment of the present invention, which may specifically include the following steps:

[0082] Step 801: forming a plurality of first electrodes on a substrate.

[0083] In the embodiment of the present invention, first, a substrate 22 is provided, and the substrate 22 may be a flexible substrate or a rigid substrate. Then, a plurality of first electrodes 211 are formed on the substrate 22 by a patterning process.

[0084] Specifically, a first electrode film is first deposited on the substrate 22, and the first electrode film is subjected to high-temperature annealing in a nitrogen environment to reduce the resistivity of the first electrode film. Then, a photoresist is coated on the first electrode film, the photoresist is exposed and developed, and then the first electrode film in the photoresist removal area is etched and the residual photoresist is removed, thereby forming a plurality of first electrodes 211 on the substrate 22, wherein the material of the first electrode 211 is indium tin oxide.

[0085] Step 802: forming a second electrode on each of the first electrodes; each of the second electrodes has an opening exposing the first electrode.

[0086] In an embodiment of the present invention, after the first electrode 211 is formed on the substrate 22, the second electrode film is first deposited, a photoresist is coated on the second electrode film, the photoresist is exposed and developed, and then the second electrode film in the photoresist removal area is etched and the residual photoresist is removed, thereby forming a second electrode 212 on each first electrode 211.

[0087] Among them, the material of the second electrode 212 is platinum; the shape of the second electrode 212 is annular, for example, the shape of the second electrode 212 is a rectangular ring, which has an opening exposing the first electrode 211, and the opening is located in the middle position of the first electrode 211, then the second electrode 212 is actually located at the edge position of the first electrode 211.

[0088] Step 803, forming a piezoelectric structure on each of the first electrodes and the corresponding second electrodes; wherein the piezoelectric structure includes a first piezoelectric portion and a second piezoelectric portion arranged around the first piezoelectric portion, the first piezoelectric portion is arranged in the opening and in contact with the first electrode, and the second piezoelectric portion is arranged on a side of the second electrode away from the first electrode; the second piezoelectric portion has orientation.

[0089] In the embodiment of the present invention, after the second electrode 212 is formed on each first electrode 211 , a piezoelectric structure is formed on each first electrode 211 and the corresponding second electrode 212 .

[0090] Specifically, a piezoelectric film is first formed by dry coating or sol-gel method, and then the structure formed with the piezoelectric film is placed in an air environment at 550°C to 650°C for high-temperature annealing to achieve the growth of PZT grains, thereby forming a good solid solution phase. Then, a photoresist is coated on the piezoelectric film, the photoresist is exposed and developed, and then the piezoelectric film in the photoresist removal area is etched, thereby forming a piezoelectric structure on each first electrode 211 and the corresponding second electrode 212.

[0091] The piezoelectric structure includes a first piezoelectric portion 213 and a second piezoelectric portion 214 arranged around the first piezoelectric portion 213. The first piezoelectric portion 213 is arranged in the opening and in contact with the first electrode 211. The second piezoelectric portion 214 is arranged on a side of the second electrode 212 away from the first electrode 211. The second piezoelectric portion 214 has orientation.

[0092] That is to say, a first piezoelectric portion 213 without orientation is formed on the first electrode 211 in the opening, and a second piezoelectric portion 214 with orientation is formed on the second electrode 212, and the first piezoelectric portion 213 and the second piezoelectric portion 214 are formed simultaneously using the same composition process; and the farther the second piezoelectric portion 214 is from the first piezoelectric portion 213, the better its orientation.

[0093] Optionally, after step 803, the method further includes steps S81, S82 and S83:

[0094] Step S81, forming a third electrode on a side of each of the piezoelectric structures away from the first electrode to obtain a plurality of piezoelectric elements;

[0095] Step S82, forming an insulating layer covering the substrate and each of the piezoelectric elements; the insulating layer has a first via hole and a second via hole corresponding to each of the piezoelectric elements;

[0096] Step S83, forming a routing layer on a side of the insulating layer away from the piezoelectric element; the routing layer includes a first signal line and a second signal line corresponding to each of the piezoelectric elements, each of the first signal lines is connected to the first electrode in the corresponding piezoelectric element through the first via hole, and each of the second signal lines is connected to the third electrode in the corresponding piezoelectric element through the second via hole.

[0097] After forming a piezoelectric structure on each first electrode 211 and the corresponding second electrode 212, a third electrode 215 is formed on a side of each piezoelectric structure away from the first electrode 211 to obtain a plurality of piezoelectric elements 21. Specifically, a third electrode film is first deposited, a photoresist is coated on the third electrode film, the photoresist is exposed and developed, and then the third electrode film at the photoresist removal area is etched and the residual photoresist is removed, thereby achieving the formation of the third electrode 215 on a side of each piezoelectric structure away from the first electrode 211.

[0098] After forming a plurality of piezoelectric elements 21, an insulating layer 23 is formed to cover the substrate 22 and each piezoelectric element 21, and the insulating layer 23 has a first via hole and a second via hole corresponding to each piezoelectric element 21. Specifically, the insulating layer 23 is first deposited, a photoresist is coated on the insulating layer 23, the photoresist is exposed and developed, and then the insulating layer 23 at the photoresist removal area is etched, and the residual photoresist is removed, thereby forming the first via hole and the second via hole penetrating the insulating layer 23.

[0099] After forming an insulating layer 23 covering the substrate 22 and each piezoelectric element 21, a wiring layer is formed on the insulating layer 23 by a patterning process. The wiring layer includes a first signal line (not shown) corresponding to each piezoelectric element 21. Figure 7 ), each first signal line is connected to the first electrode 211 in the corresponding piezoelectric element 21 through a first via hole, and is used to provide a first voltage to the first electrode 211 and the second electrode 212, and each second signal line 241 is connected to the third electrode 215 in the corresponding piezoelectric element 21 through a second via hole, and is used to provide a second voltage to the third electrode 215.

[0100] In addition, after forming a plurality of piezoelectric elements 21 on the substrate 22, the piezoelectric elements 21 need to be polarized to increase the piezoelectric constants of the first piezoelectric portion 213 and the second piezoelectric portion 214 so that the piezoelectric elements 21 have good piezoelectric properties. According to experimental tests, after the piezoelectric elements 21 are polarized, the piezoelectric constants of the first piezoelectric portion 213 and the second piezoelectric portion 214 are both greater than 1000×10 -12 m / V.

[0101] It should be noted that the piezoelectric element 21 can be polarized before the insulating layer 23 and the wiring layer are formed, that is, the piezoelectric element 21 is polarized before step S82; the piezoelectric element 21 can also be polarized after the insulating layer 23 and the wiring layer are formed, that is, the piezoelectric element 21 is polarized after step S83. Regarding the specific steps of the polarization treatment, the embodiment of the present invention does not limit this.

[0102] In an embodiment of the present invention, a second electrode is added to the first electrode, and a first piezoelectric portion is grown on the first electrode, and a second piezoelectric portion is grown on the second electrode, so that the second piezoelectric portion surrounding the first piezoelectric portion has an orientation, and the film strength of the oriented second piezoelectric portion is higher, thereby improving the film strength at the edge of the piezoelectric structure and avoiding defects at the edge of the piezoelectric structure. Therefore, in the process of using the piezoelectric element, damage due to vibration at the defective position is avoided, thereby improving the reliability of the piezoelectric element.

[0103] Embodiment 4

[0104] An embodiment of the present invention further provides an electronic device, comprising the above-mentioned piezoelectric vibrator.

[0105] For the specific description of the piezoelectric vibrator, reference may be made to the description of the second and third embodiments, which will not be described in detail in the embodiment of the present invention.

[0106] In an actual product, the electronic device may be a display device, which includes a display panel and the above-mentioned piezoelectric vibrator. The piezoelectric vibrator may be arranged on the light-emitting side of the display panel, so that the display device can realize both the display function and the tactile reproduction function.

[0107] Of course, the electronic device according to the embodiment of the present invention is not limited to the display device, and may also be any product or component having a tactile reproduction function.

[0108] In an embodiment of the present invention, a second electrode is added to the first electrode, and a first piezoelectric portion is grown on the first electrode, and a second piezoelectric portion is grown on the second electrode, so that the second piezoelectric portion surrounding the first piezoelectric portion has an orientation, and the film strength of the oriented second piezoelectric portion is higher, thereby improving the film strength at the edge of the piezoelectric structure and avoiding defects at the edge of the piezoelectric structure. Therefore, in the process of using the piezoelectric element, damage due to vibration at the defective position is avoided, thereby improving the reliability of the piezoelectric element.

[0109] For the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0110] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0111] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0112] The piezoelectric element, piezoelectric vibrator, manufacturing method thereof, and electronic device provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A piezoelectric element, characterized in that: include: A first electrode and a second electrode disposed on the first electrode, the second electrode having an opening exposing the first electrode; The piezoelectric element also includes a piezoelectric structure, which includes a first piezoelectric portion and a second piezoelectric portion arranged around the first piezoelectric portion, the first piezoelectric portion is arranged in the opening and in contact with the first electrode, and the second piezoelectric portion is arranged on a side of the second electrode away from the first electrode; wherein the second piezoelectric portion has orientation and the first piezoelectric portion does not have orientation.

2. The piezoelectric element according to claim 1, wherein Along a direction from the second piezoelectric portion to the first piezoelectric portion, a width of the first piezoelectric portion is 10 to 20 times a width of the second piezoelectric portion.

3. The piezoelectric element according to claim 1, wherein The material of the first electrode is indium tin oxide, and the material of the second electrode is platinum.

4. The piezoelectric element according to claim 1, wherein: In a direction perpendicular to the plane where the first electrode is located, the thickness of the first electrode is 100 nm to 500 nm, and the thickness of the second electrode is less than 100 nm.

5. The piezoelectric element according to claim 1, wherein: In a direction perpendicular to a plane where the first electrode is located, a thickness of the first piezoelectric portion is greater than a thickness of the second electrode.

6. The piezoelectric element according to claim 5, characterized in that In a direction perpendicular to a plane where the first electrode is located, a sum of a thickness of the second electrode and a thickness of the second piezoelectric portion is equal to a thickness of the first piezoelectric portion.

7. The piezoelectric element according to claim 1, wherein: The first piezoelectric portion and the second piezoelectric portion are both made of piezoelectric ceramics.

8. The piezoelectric element according to any one of claims 1 to 7, characterized in that: The piezoelectric element further includes a third electrode disposed on a side of the piezoelectric structure away from the first electrode.

9. A piezoelectric vibrator, characterized in that: The invention comprises a substrate and a plurality of piezoelectric elements according to any one of claims 1 to 8 arranged on the substrate.

10. The piezoelectric vibrator according to claim 9, wherein: The piezoelectric vibrator further includes an insulating layer covering the substrate and each of the piezoelectric elements, the insulating layer having a first via hole and a second via hole corresponding to each of the piezoelectric elements; The piezoelectric vibrator also includes a routing layer arranged on a side of the insulating layer away from the piezoelectric element, the routing layer includes a first signal line and a second signal line corresponding to each of the piezoelectric elements, each of the first signal lines is connected to the first electrode in the corresponding piezoelectric element through the first via hole, and each of the second signal lines is connected to the third electrode in the corresponding piezoelectric element through the second via hole.

11. A method for manufacturing a piezoelectric vibrator, characterized in that: include: forming a plurality of first electrodes on a substrate; forming a second electrode on each of the first electrodes; Each of the second electrodes has an opening exposing the first electrode; forming a piezoelectric structure on each of the first electrodes and the corresponding second electrode; Among them, the piezoelectric structure includes a first piezoelectric portion and a second piezoelectric portion arranged around the first piezoelectric portion, the first piezoelectric portion is arranged in the opening and in contact with the first electrode, and the second piezoelectric portion is arranged on a side of the second electrode away from the first electrode; the second piezoelectric portion has orientation and the first piezoelectric portion does not have orientation.

12. The method according to claim 11, characterized in that After the step of forming a piezoelectric structure on each of the first electrodes and the corresponding second electrode, the method further includes: forming a third electrode on a side of each of the piezoelectric structures away from the first electrode to obtain a plurality of piezoelectric elements; forming an insulating layer covering the substrate and each of the piezoelectric elements; the insulating layer having a first via hole and a second via hole corresponding to each of the piezoelectric elements; A routing layer is formed on a side of the insulating layer away from the piezoelectric element; the routing layer includes a first signal line and a second signal line corresponding to each of the piezoelectric elements, each of the first signal lines is connected to the first electrode in the corresponding piezoelectric element through the first via hole, and each of the second signal lines is connected to the third electrode in the corresponding piezoelectric element through the second via hole.

13. An electronic device, characterized in that: Includes the piezoelectric vibrator according to claim 9 or 10.

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