Piezoelectric sensor, its manufacturing method, and tactile feedback device

Abstract

The present disclosure provides a piezoelectric sensor, a method for manufacturing the same, and a tactile feedback device, the piezoelectric sensor including a base substrate, a first electrode layer, a piezoelectric thin film layer, an insulating layer, and a second electrode layer spaced apart from the base substrate in this order, the insulating layer contacting at least a portion of the piezoelectric thin film layer prevents shorting of the piezoelectric sensor and improves product yield.

Description

[Technical Field]

[0001] The present disclosure relates to the field of sensors, and more particularly to piezoelectric sensors, methods for making the same, and tactile feedback devices. [Background technology]

[0002] Haptics is a key technology in current scientific development. Specifically, haptic feedback allows devices to interact with the human body through the sense of touch. Haptic feedback can be divided into two types: vibration feedback and haptic reproduction technology. Summary of the Invention

[0003] The present disclosure provides a piezoelectric sensor, a manufacturing method thereof and a tactile feedback device, and the specific technical solutions are as follows:

[0004] An embodiment of the present disclosure provides a piezoelectric sensor, the piezoelectric sensor comprising: The piezoelectric element includes a base substrate, a first electrode layer, a piezoelectric thin film layer, an insulating layer, and a second electrode layer spaced apart from the base substrate in this order, where the insulating layer contacts at least a portion of the piezoelectric thin film layer.

[0005] Optionally, embodiments of the present disclosure may include at least one hollow structure on a side of the piezoelectric thin film layer away from the base substrate, The insulating layer is filled in each of the hollow structures.

[0006] Optionally, in embodiments of the present disclosure, the orthogonal projection of the insulating layer on the base substrate is entirely within the area of ​​the orthogonal projection of the piezoelectric thin film layer on the base substrate.

[0007] The orthogonal projection of the insulating layer on the base substrate and the orthogonal projection of the piezoelectric thin film layer on the base substrate overlap each other.

[0008] Optionally, in embodiments of the present disclosure, the insulating layer comprises at least one of polyimide, silica, and alumina.

[0009] Optionally, in an embodiment of the present disclosure, the thickness relationship between the insulating layer and the piezoelectric thin film layer satisfies the following relationship: d PI ≦0.1*d PZT d PI represents the thickness of the insulating layer, and d PZT represents the thickness of the piezoelectric thin film layer.

[0010] Optionally, in an embodiment of the present disclosure, the thickness range of the insulating layer is [50 nm, 200 nm].

[0011] Optionally, in the embodiment of the present disclosure, the thickness range of the piezoelectric thin film layer is (0.2 μm).

[0012] Optionally, in an embodiment of the present disclosure, the capacitance relationship between the piezoelectric thin film layer and the insulating layer satisfies the following relationship: C PI ≧100C PZT C PI is the above Insulation layer represents the capacitance of PZT is the above Piezoelectric thin film layer represents the capacitance of

[0013] Optionally, in an embodiment of the present disclosure, the electrical resistance relationship between the piezoelectric thin film layer and the insulating layer satisfies the following relationship: R PI ≧1000R PZT R PI is the above Insulation layer represents electrical resistance, R PZT is the above Piezoelectric thin film layer Represents electrical resistance.

[0014] Optionally, in embodiments of the present disclosure, a lyophilic material layer is disposed on the side of the piezoelectric thin film layer away from the base substrate.

[0015] Optionally, in embodiments of the present disclosure, the piezoelectric thin film layer comprises at least one of aluminum nitride, zinc oxide, lead zirconate titanate, barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, and gallium lanthanum silicate.

[0016] Optionally, in the embodiment of the present disclosure, a plurality of first electrodes are provided on a side of the first electrode layer closer to the piezoelectric thin film layer. columnar It has a structure.

[0017] Optionally, in the embodiment of the present disclosure, a plurality of second electrodes are provided on the side of the second electrode layer closer to the piezoelectric thin film layer. columnar It has a structure.

[0018] Optionally, in the embodiment of the present disclosure, a plurality of third electrodes are provided on the side of the first electrode layer closer to the piezoelectric thin film layer. columnar a plurality of fourth electrode layers on a side of the second electrode layer that is closer to the piezoelectric thin film layer; columnar a third structure on the base substrate; columnar orthogonal projection of the structure and the base substrate columnar The orthogonal projections of the structures do not overlap with each other.

[0019] Correspondingly, an embodiment of the present disclosure provides a haptic feedback device, the haptic feedback device including a haptic feedback circuit and a piezoelectric sensor according to any one of the above claims; the haptic feedback circuit is located on a side of the second electrode layer away from the first electrode layer, or on a side of the first electrode layer away from the second electrode layer; The haptic feedback circuit is used to generate voltage pulses based on received commands to cause vibrations in a structure.

[0020] Accordingly, an embodiment of the present disclosure provides a method for fabricating a piezoelectric sensor, the method comprising: forming a first electrode layer on a base substrate; forming a piezoelectric thin film layer on a side of the first electrode layer away from the base substrate; forming an insulating layer in contact with at least a portion of the piezoelectric thin film layer on a side of the piezoelectric thin film layer away from the first electrode layer; and forming a second electrode layer on the insulating layer on a side remote from the piezoelectric thin film layer.

[0021] Optionally, in embodiments of the present disclosure, forming an insulating layer in contact with at least a portion of the piezoelectric thin film layer on a side of the piezoelectric thin film layer away from the first electrode layer may include: applying a polyimide material to the side of the piezoelectric thin film layer away from the first electrode layer using a wet process; and curing the polyimide material at a high temperature to form an insulating layer in contact with at least a portion of the piezoelectric thin film layer on a side of the piezoelectric thin film layer away from the first electrode layer. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic planar structural diagram showing a crack in a piezoelectric layer of a thin-film vibration chip in the related art; [Figure 2] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 3] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 4] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 5] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 6] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 7] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 8] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 9] 1 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 10]FIG. 1 is a structural schematic diagram of a haptic feedback device according to an embodiment of the present disclosure. [Figure 11] 1 is a method flow chart of a method for fabricating a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 12] 12 is a flowchart of one method of step S103 in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] In order to clarify the technical solutions and advantages of the embodiments of the present disclosure, the following will clearly and completely describe the technical solutions of the embodiments of the present disclosure with reference to the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all of the embodiments. In addition, the features of the embodiments of the present disclosure can be combined with each other unless they are inconsistent. All other embodiments obtained based on the described embodiments of the present disclosure without requiring creative work by those skilled in the art are within the scope of protection of the present disclosure.

[0024] Unless otherwise defined, technical or scientific terms used in this disclosure should have the ordinary meaning as understood by a person of ordinary skill in the field to which this disclosure belongs. As used in this application, words such as "comprises" or "comprises" or similar words mean that the elements or items appearing before the words cover the elements or items listed after the words and their equivalents, and do not exclude other elements or items.

[0025] Thin-film piezoelectric materials have high dielectric constants and transparency, making them ideal for screen-integrated resonator structures. However, if the surface charge distribution is unevenly distributed or the voltage is too high, the resonator may be destroyed. For example, the upper and lower electrodes may maintain an open circuit, but the piezoelectric thin-film layer structure may be destroyed. Alternatively, the upper and lower electrodes may be destroyed, causing a short circuit and the entire resonator to fail. The short circuit occurs mainly during the manufacturing process, when cracks occur in the piezoelectric thin-film layer due to particles, particles, or thin-film stress. When these cracks occur, directly depositing electrodes on the piezoelectric thin-film layer poses a high risk of short circuiting. Therefore, how to prevent short circuits in piezoelectric sensors is an urgent technical issue that needs to be resolved.

[0026] In the related art, Figure 1 is a schematic plan view of a thin film vibrating chip with cracks in the piezoelectric layer. During the manufacturing process, cracks will occur in the piezoelectric layer due to particles, particles, or thin film stress. If electrodes are directly deposited on the piezoelectric layer, the cracks will cause short circuits in the thin film vibrating chip, thereby reducing the yield of the product.

[0027] In view of this, embodiments of the present disclosure provide a piezoelectric sensor, a manufacturing method thereof, and a tactile feedback device to avoid short circuits in the piezoelectric sensor and improve product yield.

[0028] As shown in FIG. 2, FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure, and the piezoelectric sensor includes a base substrate 1, a first electrode layer 2, a piezoelectric thin film layer 3, an insulating layer 4, and a second electrode layer 5, which are sequentially spaced apart from the base substrate 1, and wherein the insulating layer 4 contacts at least a portion of the piezoelectric thin film layer 3.

[0029] In a specific implementation, the base substrate 1 may be a substrate made of glass, a substrate made of silicon or silica (SiO2), a substrate made of sapphire, or a substrate made of a metal wafer; this is not limited thereto, and those skilled in the art can install the base substrate 1 according to the actual application needs.

[0030] In a specific implementation, the first electrode layer 2 may be made of indium tin oxide (ITO), indium zinc oxide (IZO), titanium gold (Ti-Au) alloy, titanium aluminum titanium (Ti-Al-Ti) alloy, titanium molybdenum (TiMo) alloy, or titanium (Ti), gold (Au), silver (Ag), molybdenum (Mo), copper (Cu), tungsten (W), or chromium (Cr). Those skilled in the art can configure the first electrode layer 2 according to actual application needs, and this is not limited thereto. Accordingly, the fifth electrode layer 5 may also be made of the same material as the first electrode layer 2, and this will not be described in detail here.

[0031] In a specific implementation, the piezoelectric thin film layer 3 may be made of aluminum nitride (AlN), ZnO (zinc oxide), lead zirconate titanate (Pb(Zr,Ti)O3, PZT), barium titanate (BaTiO3), lead titanate (PbTiO3), potassium niobate (KNbO3), lithium niobate (LiNbO3), lithium tantalate (LiTaO3), langasite (La3Ga5SiO 14), thus ensuring the transparency of the piezoelectric sensor while also ensuring the vibration characteristics of the piezoelectric sensor. Specifically, those skilled in the art can select materials for fabricating the piezoelectric thin film layer 3 according to their actual application needs, and the selection is not limited thereto. When PZT is used to fabricate the piezoelectric thin film layer 3, PZT has a high piezoelectric coefficient, which ensures the piezoelectric characteristics of the corresponding piezoelectric sensor, allowing the corresponding piezoelectric sensor to be applied to a tactile feedback device. Furthermore, PZT has high translucency, so when it is integrated into a display device, it does not affect the display quality of the display device.

[0032] The insulating layer 4 located between the piezoelectric thin film layer 3 and the second electrode layer 5 contacts at least a portion of the piezoelectric thin film layer 3, and can contact the entire piezoelectric thin film layer 3; for example, the insulating layer 4 completely covers the side of the piezoelectric thin film layer 3 away from the base substrate 1; in Figure 2, the insulating layer 4 completely covers the side of the piezoelectric thin film layer 3 away from the base substrate 1 and can also contact a portion of the piezoelectric thin film layer 3; for example, the insulating layer 4 fills only cracks in the piezoelectric thin film layer 3. Also, for example, the insulating layer 4 is provided only in a partial region of the piezoelectric thin film layer 3 away from the base substrate 1.

[0033] In a specific implementation, the entire piezoelectric thin film layer 3 may be disposed on the side of the first electrode layer 2 away from the base substrate 1, thereby improving the manufacturing efficiency of the piezoelectric sensor. Furthermore, the piezoelectric thin film layer 3 may be patterned as needed, for example, by disposing the piezoelectric thin film layer 3 on the region of the first electrode layer 2 away from the base substrate 1, thereby realizing flexible design of the piezoelectric sensor. In a specific implementation, the insulating layer 4 contacts at least a portion of the piezoelectric thin film layer 3. Therefore, even if a crack exists in the piezoelectric thin film layer 3, the insulating layer 4 can effectively fill the crack. Thus, after the second electrode layer 5 is deposited, the presence of the insulating layer 4 prevents a short circuit due to contact between the second electrode layer 5 and the first electrode layer 2. This thereby reduces the risk of a short circuit in the piezoelectric sensor and improves product yield.

[0034] In an embodiment of the present disclosure, FIG. 3 is a structural schematic diagram of one of the piezoelectric sensors, which includes at least one hollow structure f on the side of the piezoelectric thin film layer 3 away from the base substrate 1, and each hollow structure f is filled with the insulating layer 4. Here, the at least one hollow structure f may be one or more. While FIG. 3 shows the case where the at least one hollow structure f is one, other numbers are possible and are not limited thereto. The hollow structure f may be a crack present in the piezoelectric thin film layer 3. When there are multiple hollow structures f, the sizes of the hollow structures f do not need to be equal, and their distribution may be random based on actual process conditions. As shown in FIG. 4, the insulating layer 4 completely fills each hollow structure f, and the thickness of the insulating layer 4 filled in each hollow structure f is equal to the depth of the corresponding hollow structure f. Here, the thickness direction of the insulating layer 4 and the depth direction of the hollow structures f are both perpendicular to the plane on which the base substrate 1 is located, and "equal" here does not mean completely equal, but rather approximately equal. In this way, the hollow structures f in the piezoelectric thin film layer 3 are effectively filled via the insulating layer 4, avoiding the risk of short-circuiting the piezoelectric sensor. Furthermore, because the insulating layer 4 completely fills each hollow structure f, when the other parts of the insulating layer 4 other than those filled in the hollow structures f completely cover the side of the piezoelectric thin film layer 3 away from the base substrate 1, the side of the piezoelectric thin film layer 3 away from the base substrate 1 is realized to be flush with each other, ensuring the stability of the structure used to manufacture the piezoelectric sensor and improving the performance of the piezoelectric sensor.

[0035] In an embodiment of the present disclosure, as shown in FIGS. 4 and 5, the orthographic projection of the insulating layer 4 on the base substrate 1 is completely within the region range of the orthographic projection of the piezoelectric thin film layer 3 on the base substrate 1. In a specific implementation process, the insulating layer 4 may be provided only in a region where cracks are likely to occur in the piezoelectric thin film layer 3. For example, it may be provided only in the region where the hollow structure f exists. The insulating layer 4 may be filled only in the hollow structure f, or may be partially filled in the hollow structure f. For example, the overall thickness of the piezoelectric thin film layer 3 along the direction perpendicular to the plane where the base substrate 1 is located is b, the depth of the hollow structure f is c, and the thickness of the insulating layer 4 along the direction perpendicular to the plane where the base substrate 1 is located is d, and c ≤ b and d ≤ c. Here, as shown in FIG. 5, when the insulating layer 4 completely fills the hollow structure f, b = c = d. As shown in FIG. 6, when the insulating layer 4 partially fills the hollow structure f, b = c and d < c. Thus, the hollow structure f on the piezoelectric thin film layer 3 is filled through the insulating layer 4 to avoid the short-circuit risk of the piezoelectric sensor.

[0036] In an embodiment of the present disclosure, as shown in FIG. 3, the orthographic projection of the insulating layer 4 on the base substrate 1 and the orthographic projection of the piezoelectric thin film layer 3 on the base substrate 1 overlap each other. In a specific implementation process, the insulating layer 4 can completely cover the side of the piezoelectric thin film layer 3 away from the base substrate 1. Even if there are originally cracks in the piezoelectric thin film layer 3, the hollow structure f can be effectively filled through the insulating layer 4, avoiding the short-circuit risk of the piezoelectric sensor and improving the product yield.

[0037] In an embodiment of the present disclosure, the insulating layer 4 includes at least one of polyimide (PI), silica (SiO2), and alumina (Al2O3). In a specific implementation, if the hollow structure (f) exists in the piezoelectric thin film layer 3, the hollow structure (f) always has strong capillary force and porosity. Therefore, when a wet process is used, the insulating layer 4 can flow into the hollow structure (f) through gravity leveling. For example, when a wet process is used to apply PI to the side of the piezoelectric thin film layer 3 away from the base substrate 1, the PI has excellent leveling properties on the surface of the piezoelectric thin film layer 3, so the PI can quickly level the hollow structure (f). This ensures the flatness of the surface of the piezoelectric thin film layer 3 away from the base substrate 1 while avoiding the risk of short-circuiting the piezoelectric sensor. PI has excellent high-temperature curing (cyclization) properties, so by wet-coating PI on the side of the piezoelectric thin film layer 3 away from the base substrate 1 and then curing the PI at a high temperature between 200°C and 300°C to form the insulating layer 4, it is ensured that the insulating layer 4 has stable insulating properties and improves the usability of the piezoelectric sensor.

[0038] In a specific implementation, a wet process can be further adopted to coat SiO2 on the side of the piezoelectric thin film layer 3 away from the base substrate 1, thereby leveling the hollow structure f and ensuring the surface flatness of the side of the piezoelectric thin film layer 3 away from the base substrate 1, while at the same time avoiding the risk of short-circuiting of the piezoelectric sensor. After wet coating SiO2 on the side of the piezoelectric thin film layer 3 away from the base substrate 1, the SiO2 is cured at a high temperature of 300°C or higher to form the insulating layer 4, which ensures that the insulating layer has stable insulating properties and improves the performance of the piezoelectric sensor.

[0039] In a specific implementation, a dry deposition process can be used to coat Al2O3 on the side of the piezoelectric thin film layer 3 away from the base substrate 1, and the insulating properties of Al2O3 can be used to prevent short circuits in the piezoelectric sensor and improve its performance. Of course, other methods can be used to install the piezoelectric thin film layer 3, which will not be described in detail here.

[0040] In the embodiment of the present disclosure, the thickness relationship between the insulating layer 4 and the piezoelectric thin film layer 3 satisfies the following relationship: d PI ≦0.1*d PZT d PI represents the thickness of the insulating layer 4, and d PZT represents the thickness of the piezoelectric thin film layer 3.

[0041] In the specific implementation process, the inventor's actual research has found that when the thickness of the piezoelectric thin film layer 3 is constant, the thickness of the insulating layer 4 applied to the side of the piezoelectric thin film layer 3 away from the base substrate 1 is set to within 10% of the thickness of the piezoelectric thin film layer 3. For example, when the thickness of the piezoelectric thin film layer 3 is 2 μm, the thickness of the insulating layer 4 may be 200 nm, or even 100 nm, or even 50 nm, but is not limited thereto. In this way, the insulating properties of the insulating layer 4 are ensured, while at the same time, the risk of short-circuiting of the piezoelectric sensor is avoided and the vibration characteristics of the piezoelectric sensor when driven by high-frequency AC are ensured, thereby improving the usability of the piezoelectric sensor.

[0042] In the embodiment of the present disclosure, the thickness range of the insulating layer 4 is [50 nm, 200 nm].

[0043] In a specific embodiment, the thickness of the insulating layer 4 is 50 nm to 200 nm. For example, the thickness of the insulating layer 4 is 100 nm, or 60 nm, or 50 nm. When the thickness of the insulating layer 4 is within the above range, the insulating layer 4 has excellent insulating properties, thereby effectively avoiding the risk of short-circuiting of the piezoelectric sensor. In the embodiment of the present disclosure, the thickness range of the piezoelectric thin film layer 3 is (0.2 μm).

[0044] In a specific implementation, the thickness of the piezoelectric thin film layer 3 is 0 to 2 μm. For example, the thickness of the piezoelectric thin film layer 3 is 0.5 μm, or for example, the thickness of the piezoelectric thin film layer 3 is 1 μm, or for example, the thickness of the piezoelectric thin film layer 3 is 2 μm. In practical applications, the thickness of the piezoelectric thin film layer 3 can be set as close to zero as possible, which ensures good vibration characteristics of the piezoelectric thin film layer 3 while simultaneously achieving a thin design for the piezoelectric sensor.

[0045] In the embodiment of the present disclosure, the capacitance relationship between the piezoelectric thin film layer 3 and the insulating layer 4 satisfies the following relationship: C PI ≧100C PZT C PI is the above Insulating layer 4 represents capacitance, C PZT is the above Piezoelectric thin film layer 3 Represents capacitance.

[0046] In a specific implementation, when the material used for the piezoelectric thin film layer 3 is constant, for example, a film layer made of PbTiO3, the thickness of the piezoelectric thin film layer 3 is constant, and the facing area between the first electrode layer 2 and the second electrode layer 5 is constant, the capacitance of the piezoelectric thin film layer 3 can be calculated based on the capacitance calculation formula:

number

number

number

[0047] In the embodiment of the present disclosure, the electrical resistance relationship between the piezoelectric thin film layer 3 and the insulating layer 4 satisfies the following relational expression: R PI ≧1000R PZT R PI is the above Insulating layer 4 represents electrical resistance, R PZT is the above Piezoelectric thin film layer 3 Represents electrical resistance.

[0048] In a specific implementation, when the material used for the piezoelectric thin film layer 3 is constant, for example, a film layer made of PbTiO3, the thickness of the piezoelectric thin film layer 3 is constant, and the cross-sectional area of ​​the piezoelectric thin film layer 3 parallel to the plane on which the base substrate 1 is located is constant, the capacitance of the piezoelectric thin film layer 3 can be calculated based on the electrical resistance formula:

number

number

[0049] The electrical resistance relationship between the piezoelectric thin film layer 3 and the insulating layer 4 is R PI ≧1000R PZT If the above condition is satisfied, the insulating layer 4 has excellent insulating properties and effectively avoids the risk of short circuiting of the piezoelectric sensor. If the electrical resistance of the piezoelectric thin film layer 3 is constant, the material and corresponding thickness range of the insulating layer 4 can be determined based on the electrical resistance calculation formula, and the insulating layer 4 can be installed based on the actual situation of the piezoelectric thin film layer 3 in actual application, thereby realizing flexible manufacturing of the piezoelectric sensor.

[0050] In the embodiment of the present disclosure, a lyophilic material layer is disposed on the side of the piezoelectric thin film layer 3 away from the base substrate 1. The lyophilic material layer not only ensures that the insulating layer 4 quickly levels on the side of the piezoelectric thin film layer 3 away from the base substrate 1, but also has relatively good high-temperature curing properties, ensuring stable insulating properties of the insulating layer 4 and further improving the performance of the piezoelectric sensor.

[0051] In the embodiments of the present disclosure, the first electrode layer 2 and the second electrode layer 5 can be arranged using the following four implementation methods. In the first implementation method, as shown in FIG. 2 , the first electrode layer 2 and the second electrode layer 5 are both whole-layer plate structures, or at least one of the first electrode layer 2 and the second electrode layer 5 may include a pattern design, and the orthogonal projection of the second electrode layer 5 on the base substrate 1 is completely within the area range of the orthogonal projection of the first electrode layer 2 on the base substrate 1.

[0052] In the embodiment of the present disclosure, in the second type of realization, as shown in FIG. 6, a plurality of first columnar The second electrode layer 5 may have a plate-like structure of the entire layer, or the second electrode layer 5 may include a pattern design, thus avoiding short-circuiting of the piezoelectric sensors through the insulating layer 4, while simultaneously insulating the first electrodes of the plurality of piezoelectric sensors. columnar Through the structure 10, the contact area between the piezoelectric thin film layer 3 and the first electrode layer 2 is increased, the structural stability between the piezoelectric thin film layer 3 and the first electrode layer 2 is ensured, and the performance of the piezoelectric sensor is improved.

[0053] In the specific implementation process, each of the above first columnar The size of the structure 10 is the same, and each of the first columnar The structures 10 may be distributed at uneven intervals or at equal intervals. columnar The distribution of the structure 10 can be set, and is not limited thereto. columnar When the structures 10 are distributed at equal intervals, the uniformity of the transmittance at each position of the piezoelectric sensor is ensured, and the performance of the piezoelectric sensor is ensured.

[0054] In the embodiment of the present disclosure, in the third type of realization, as shown in FIG. 7, the first electrode layer 2 is a plate-like structure of the entire layer, or the first electrode layer 2 may include a pattern design, and the second electrode layer 5 has a plurality of second electrodes on the side close to the piezoelectric thin film layer 3. columnar structure 20, thus avoiding short-circuiting of the piezoelectric sensors through the insulating layer 4 while columnar Through the structure 20, the contact area between the piezoelectric thin film layer 3 and the second electrode layer 5 is increased, the structural stability between the piezoelectric thin film layer 3 and the second electrode layer 5 is ensured, and the performance of the piezoelectric sensor is improved.

[0055] In the specific implementation process, each of the above two columnar The size of the structure 20 is the same, and each of the second columnarThe structures 20 may be distributed at uneven intervals or at equal intervals. columnar The distribution of the structure 20 can be set, and is not limited here. columnar When the structures 20 are distributed at equal intervals, the uniformity of the light transmittance at each position of the piezoelectric sensor is ensured, and the performance of the piezoelectric sensor is ensured.

[0056] In the embodiment of the present disclosure, in the fourth type of realization method, as shown in FIG. 8, a plurality of third electrodes are provided on the side of the first electrode layer 2 close to the piezoelectric thin film layer 3. columnar structure 30, and a plurality of fourth electrode layers 5 on the side of the second electrode layer 5 that is closer to the piezoelectric thin film layer 3. columnar structure 40, and columnar The orthogonal projection of the structure 30 and the fourth columnar The orthogonal projections of the structures 40 do not overlap each other. columnar The contact area between the piezoelectric thin film layer 3 and the first electrode layer 2 is increased through the structure 30, and the plurality of fourth columnar The structure 40 increases the contact area between the piezoelectric thin film layer 3 and the second electrode layer 5, thereby ensuring the structural stability between the piezoelectric thin film layer 3 and the first electrode layer 2 and the second electrode layer 5, respectively, and improving the performance of the piezoelectric sensor. columnar The orthogonal projection of the structure 30 and the fourth columnar The orthogonal projections of the structures 40 do not overlap each other. columnar The orthogonal projection of the structure 40 is shown as two adjacent third layers on the base substrate 1. columnar It fits completely within the orthogonal projection of the spacing area between the structures 30, ensuring structural stability while also ensuring the uniformity of the thickness of the piezoelectric thin film layer 3, avoiding situations where the piezoelectric thin film layer 3 is prone to breakage at thin positions due to uneven thickness, and further ensuring the usability of the piezoelectric sensor.

[0057] In the specific implementation process, each of the above three columnar The size of the structures 30 is the same, and each of the fourth columnar The size of the structures 40 is the same, and each of the third columnar The structures 30 may be distributed at uneven intervals or may be distributed at equal intervals, and each of the fourth columnar The structures 40 may be distributed at uneven intervals or at equal intervals. columnar Structure 30 and the fourth columnar The distribution of the structure 40 can be set, and is not limited here. columnar The structures 30 are distributed at equal intervals, and each of the fourth columnar When the structures 40 are distributed at equal intervals, the uniformity of the light transmittance at each position of the piezoelectric sensor is ensured, and the performance of the piezoelectric sensor is ensured.

[0058] Of course, in practical applications, in addition to the above four implementation methods, the first electrode layer 2 and the second electrode layer 5 can also be installed using other methods according to actual needs, which will not be described in detail here.

[0059] The thickness of the first electrode layer 2 is 50 nm to 500 nm, and the thickness of the second electrode layer 5 is 50 nm to 500 nm. For example, the thickness of the first electrode layer 2 is 200 nm, and the thickness of the second electrode layer 5 is 150 nm. In a specific implementation process, the thicknesses of the first electrode layer 2 and the second electrode layer 5 can be set according to actual application needs, and are not limited here. In the present disclosure, "same" does not necessarily mean completely same, but may be approximately same.

[0060] In the embodiment of the present disclosure, FIG. 9 is a structural schematic diagram of the piezoelectric sensor, and the piezoelectric sensor may further include, in addition to the above-mentioned film layers, the first electrode layer 2, the piezoelectric thin film layer 3, the insulating layer 4, a protective layer 6 provided around the second electrode layer 5, and a track layer 7 connected by a via hole penetrating the protective layer 6. In a specific implementation process, by utilizing the inverse piezoelectric effect, the first electrode layer 2 is grounded and a high-frequency AC voltage signal (V AC ), a high-frequency AC voltage signal is applied to the piezoelectric thin film layer 3 and the insulating layer 4, generating high-frequency vibrations, and the vibration displacement can be measured using a laser, thereby ensuring the performance of the piezoelectric sensor. The protective layer can be SiO2, silicon nitride (Si3N4), etc., but is not limited thereto. Naturally, in addition to the various film layers described above, other film layers can be installed in the piezoelectric sensor according to actual applications; for specific examples, refer to conventional installations.

[0061] In the embodiment of the present disclosure, the first electrode layer 2, the piezoelectric thin film layer 3, the insulating layer 4, and the second electrode layer 5, which are sequentially stacked along the base substrate 1, each exhibit a decreasing orthogonal projection area on the base substrate 1. That is, the orthogonal projection of the second electrode layer 5 on the base substrate 1 is entirely within the area of ​​the orthogonal projection of the insulating layer 4 on the base substrate 1, the orthogonal projection of the insulating layer 4 on the base substrate 1 is entirely within the area of ​​the orthogonal projection of the piezoelectric thin film layer 3 on the base substrate 1, and the orthogonal projection of the piezoelectric thin film layer 3 on the base substrate 1 is entirely within the area of ​​the orthogonal projection of the first electrode layer 2 on the base substrate 1. Thus, the presence of steps between each film layer ensures fast leveling during the wet processing of each film layer while also ensuring the structural stability of the piezoelectric sensor, thereby improving the performance of the piezoelectric sensor. The piezoelectric sensor can also be applied in fields such as medical, automotive electronics, and motion tracking systems. In particular, it is applicable to the fields of wearable devices, medical monitoring and treatment used outside the body or implanted inside the human body, or artificial intelligence electronic skin, etc. Specifically, the piezoelectric sensor can be applied to devices that can generate vibrations and mechanical properties, such as brake pads, keyboards, mobile terminals, game handles, and vehicle-mounted devices.

[0062] Based on the same disclosed concept, as shown in FIG. 10, an embodiment of the present disclosure further provides a tactile feedback device, which includes a tactile feedback circuit 100 and the above-mentioned piezoelectric sensor 200.

[0063] The tactile feedback circuit 100 is located on the side of the second electrode layer 5 away from the first electrode layer 2, or on the side of the first electrode layer 2 away from the second electrode layer 5, and the tactile feedback circuit 100 is used to generate voltage pulses based on received commands to cause vibrations in a structure.

[0064] 10, the tactile feedback circuit 100 is located on the side of the first electrode layer 2 away from the second electrode layer 5. For example, the tactile feedback device can be integrated with a touch panel, which can determine the location of a human touch and generate a corresponding vibration waveform, amplitude, and frequency to realize human-computer interaction. For example, the tactile feedback device can be multiplexed with a piezoelectric element, which can determine the location of a human touch and generate a corresponding vibration waveform, amplitude, and frequency to realize human-computer interaction. Of course, the tactile feedback device can also be applied to fields such as medicine, automotive electronics, and motion tracking systems according to actual needs, which will not be described in detail here.

[0065] Furthermore, since the principle by which the tactile feedback device solves the problem is similar to that of the piezoelectric sensor, the relevant structure of the piezoelectric sensor 200 in the tactile feedback device can refer to the implementation of the piezoelectric sensor 200, and overlapping parts will not be described.

[0066] Based on the same disclosed concept, as shown in FIG. 11, an embodiment of the present disclosure further provides a method for fabricating a piezoelectric sensor, which includes the following steps S101 to S104.

[0067] In S101, a first electrode layer is formed on a base substrate.

[0068] In S102, a piezoelectric thin film layer is formed on the side of the first electrode layer away from the base substrate.

[0069] In S103, an insulating layer is formed on the side of the piezoelectric thin film layer away from the first electrode layer so as to be in contact with at least a portion of the piezoelectric thin film layer.

[0070] In S104, a second electrode layer is formed on the insulating layer on the side away from the piezoelectric thin film layer.

[0071] In the specific implementation process, the specific structure of the piezoelectric sensor in the fabrication method is the same as the description in the previous part, and will not be described in detail here. The specific implementation process of steps S101 to S103 is as follows:

[0072] First, a first electrode layer 2 is formed on the base substrate 1. For example, ITO is sputtered onto the base substrate 1, and then the ITO is patterned by photolithography and etching to form the first electrode layer 2 in a desired pattern. Next, a piezoelectric thin film layer 3 is formed on the side of the first electrode layer 2 away from the base substrate 1. For example, the piezoelectric thin film layer 3 is deposited on the side of the first electrode layer 2 away from the base substrate 1, and then the piezoelectric thin film layer 3 is patterned by photolithography and etching to form the piezoelectric thin film layer 3 in a desired pattern. Next, an insulating layer 4 is applied to the side of the piezoelectric thin film layer 3 away from the first electrode layer 2, contacting at least a portion of the piezoelectric thin film layer 3. Next, the second electrode layer 5 is formed on the side of the insulating layer 4 away from the piezoelectric thin film layer 3. For example, ITO is sputtered on the side of the insulating layer 4 away from the piezoelectric thin film layer 3, and then the ITO is patterned by photolithography and etching to form the second electrode layer 5 in a desired pattern.

[0073] In an embodiment of the present disclosure, as shown in FIG. 12, step S103, i.e., forming an insulating layer in contact with at least a portion of the piezoelectric thin film layer on the side of the piezoelectric thin film layer away from the first electrode layer, includes steps S201 and S202.

[0074] In S201, a wet process is used to coat a polyimide material on the side of the piezoelectric thin film layer away from the first electrode layer.

[0075] In S202, the polyimide material is cured at a high temperature to form an insulating layer in contact with at least a portion of the piezoelectric thin film layer on a side of the piezoelectric thin film layer away from the first electrode layer.

[0076] In the specific implementation process, the specific implementation process from step S201 to step S202 is as follows:

[0077] First, a polyimide material is applied by a wet process to the side of the piezoelectric thin film layer 3 away from the first electrode layer 2. If cracks exist in the piezoelectric thin film layer 3, the polyimide material will flow into the cracks by gravity leveling due to its strong capillary force and porosity, thereby ensuring the insulating properties between the piezoelectric thin film layer 3 and the second electrode layer 5. Next, the polyimide material is cured at high temperature to form an insulating layer 4 that contacts at least a portion of the piezoelectric thin film layer 3 on the side of the piezoelectric thin film layer 3 away from the first electrode layer 2. The polyimide material is cured at, for example, 200°C, ensuring that the insulating layer 4 has stable insulating properties and thereby ensuring the performance of the piezoelectric sensor.

[0078] In the specific implementation process, the principle by which the method for manufacturing the piezoelectric sensor solves the problem is similar to that of the above-mentioned piezoelectric sensor. Therefore, the method for manufacturing the piezoelectric sensor can refer to the implementation of the above-mentioned piezoelectric sensor, and overlapping explanations will be omitted.

[0079] An embodiment of the present disclosure provides a piezoelectric sensor and a manufacturing method thereof, wherein the piezoelectric sensor includes the base substrate 1, and the first electrode layer 2, the piezoelectric thin film layer 3, the insulating layer 4, and the second electrode layer 5, which are sequentially spaced apart from the base substrate 1. The insulating layer 4 contacts at least a portion of the piezoelectric thin film layer 3, so that even if a crack exists in the piezoelectric thin film layer 3, the crack can be effectively filled through the insulating layer 4. Thus, after depositing the second electrode layer 5, the insulating layer 4 is used to avoid the risk of a short circuit due to contact between the second electrode layer 5 and the first electrode layer 2, i.e., the risk of a short circuit in the piezoelectric sensor is avoided, thereby improving product yield.

[0080] While preferred embodiments of the present disclosure have been described, additional changes and modifications to these embodiments may be made by those skilled in the art once the basic inventive concepts are understood. It is therefore intended that the appended claims be interpreted to cover the preferred embodiments and all changes and modifications that are within the scope of the present disclosure.

[0081] Obviously, those skilled in the art can make various modifications and variations to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure also intends to include these modifications and variations.

Claims

1. A piezoelectric sensor, The piezoelectric element includes a base substrate, a first electrode layer, a piezoelectric thin film layer, an insulating layer, and a second electrode layer, which are sequentially spaced apart from the base substrate, the insulating layer contacts at least a portion of the piezoelectric thin film layer; At least one hollow structure is included on the side of the piezoelectric thin film layer away from the base substrate, and the insulating layer is filled in each hollow structure; A lyophilic material layer is provided on the side of the piezoelectric thin film layer away from the base substrate. Piezoelectric sensor.

2. The orthogonal projection of the insulating layer on the base substrate is completely within the range of the orthogonal projection of the piezoelectric thin film layer on the base substrate. The piezoelectric sensor according to claim 1 .

3. The orthogonal projection of the insulating layer on the base substrate and the orthogonal projection of the piezoelectric thin film layer on the base substrate overlap each other. The piezoelectric sensor according to claim 1 .

4. The insulating layer includes at least one of polyimide, silica, and alumina. The piezoelectric sensor according to claim 1 .

5. The thickness relationship between the insulating layer and the piezoelectric thin film layer satisfies the following relational expression: 0<d ＰＩ ≦0.1*d ＰＺＴ d ＰＩ represents the thickness of the insulating layer, and d ＰＺＴ represents the thickness of the piezoelectric thin film layer The piezoelectric sensor according to claim 1 .

6. The thickness range of the insulating layer is [50 nm, 200 nm] The piezoelectric sensor according to claim 1 .

7. The thickness range of the piezoelectric thin film layer is (0.2 μm). The piezoelectric sensor according to claim 1 .

8. The capacitance relationship between the piezoelectric thin film layer and the insulating layer satisfies the following relationship: C ＰＩ ≧100C ＰＺＴ >0 C ＰＩ represents the capacitance of the insulating layer, and C ＰＺＴ represents the capacitance of the piezoelectric thin film layer The piezoelectric sensor according to claim 1 .

9. The electrical resistance relationship between the piezoelectric thin film layer and the insulating layer satisfies the following relational expression: R ＰＩ ≧1000R ＰＺＴ >0 R ＰＩ represents the electrical resistance of the insulating layer, and R ＰＺＴ represents the electrical resistance of the piezoelectric thin film layer The piezoelectric sensor according to claim 1 .

10. The piezoelectric thin film layer includes at least one of aluminum nitride, zinc oxide, lead zirconate titanate, barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, and gallium lanthanum silicate. The piezoelectric sensor according to any one of claims 1 to 9.

11. The first electrode layer has a plurality of first columnar structures on a side closer to the piezoelectric thin film layer. The piezoelectric sensor according to claim 1 .

12. The second electrode layer has a plurality of second columnar structures on a side closer to the piezoelectric thin film layer. The piezoelectric sensor according to claim 1 .

13. The first electrode layer has a plurality of third columnar structures on a side closer to the piezoelectric thin film layer, and the second electrode layer has a plurality of fourth columnar structures on a side closer to the piezoelectric thin film layer, and an orthogonal projection of any of the third columnar structures on the base substrate and an orthogonal projection of any of the fourth columnar structures on the base substrate do not overlap with each other. The piezoelectric sensor according to claim 1 .

14. 1. A haptic feedback device, comprising: a tactile feedback circuit and a piezoelectric sensor according to any one of claims 1 to 13, the haptic feedback circuit is located on a side of the second electrode layer away from the first electrode layer, or on a side of the first electrode layer away from the second electrode layer; The haptic feedback circuit is used to generate voltage pulses based on received commands to cause vibrations in a structure. Tactile feedback device.

15. A method for fabricating a piezoelectric sensor, comprising: forming a first electrode layer on a base substrate; forming a piezoelectric thin film layer on a side of the first electrode layer away from the base substrate; forming an insulating layer in contact with at least a portion of the piezoelectric thin film layer on a side of the piezoelectric thin film layer away from the first electrode layer; forming a second electrode layer on the insulating layer away from the piezoelectric thin film layer; At least one hollow structure is included on the side of the piezoelectric thin film layer away from the base substrate, and the insulating layer is filled in each hollow structure, and a lyophilic material layer is provided on the side of the piezoelectric thin film layer away from the base substrate. How to make a piezoelectric sensor.

16. forming an insulating layer in contact with at least a portion of the piezoelectric thin film layer on a side of the piezoelectric thin film layer away from the first electrode layer; applying a polyimide material to the side of the piezoelectric thin film layer away from the first electrode layer using a wet process; and curing the polyimide material at a high temperature to form the insulating layer in contact with at least a portion of the piezoelectric thin film layer on a side of the piezoelectric thin film layer away from the first electrode layer. The method of claim 15.

Images