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 sensor technology, and in particular to piezoelectric sensors, methods for making same, and tactile feedback devices. [Background technology]

[0002] Haptics is a key aspect of current technological development. Specifically, haptic feedback allows the terminal to interact with the human body through the sense of touch. Haptic feedback can be divided into two categories: 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, and 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, in embodiments of the present disclosure, the piezoelectric thin film layer may include at least one hollow structure on a side thereof away from the base substrate, Each of the hollow structures is filled with the insulating layer.

[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] An orthogonal projection of the insulating layer on the base substrate and an 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 includes at least one of polyimide, silica, and alumina.

[0009] Optionally, in embodiments 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 represents the capacitance of the piezoelectric thin film layer, and C PZT represents the capacitance of the insulating layer.

[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 represents the electrical resistance of the piezoelectric thin film layer, and R PZT represents the electrical resistance of the insulating layer.

[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 lanthanum gallium silicate.

[0016] Optionally, in the embodiment of the present disclosure, the first electrode layer has a plurality of first pole-like structures on a side closer to the piezoelectric thin film layer.

[0017] Optionally, in embodiments of the present disclosure, the second electrode layer has a plurality of second pole-like structures on a side closer to the piezoelectric thin film layer.

[0018] Optionally, in an embodiment of the present disclosure, the first electrode layer has a plurality of third pole-shaped structures on a side closer to the piezoelectric thin film layer, and the second electrode layer has a plurality of fourth pole-shaped structures on a side closer to the piezoelectric thin film layer, and the orthogonal projections of any of the third pole-shaped structures on the base substrate and any of the fourth pole-shaped structures on the base substrate 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 a structure to vibrate.

[0020] Correspondingly, 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 away from the piezoelectric thin film layer.

[0021] Optionally, in embodiments of the present disclosure, forming an insulating layer on a side of the piezoelectric thin film layer away from the first electrode layer and in contact with at least a portion of the piezoelectric thin film layer may include: applying a polyimide material to the side of the piezoelectric thin film layer away from the first electrode layer by 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 description of the drawings]

[0022] [Figure 1] 1 is a schematic planar structural diagram showing a case in which a crack exists in a piezoelectric layer of a thin-film vibration chip in a related art; [Diagram 2] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Diagram 5] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 8] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 9] FIG. 2 is a structural schematic diagram of a piezoelectric sensor according to an embodiment of the present disclosure. [Figure 10] FIG. 2 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 diagram 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 PREFERRED EMBODIMENTS

[0023] In order to make the technical solutions and advantages of the embodiments of the present disclosure clearer, 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, and not all of the embodiments. In addition, the features of the embodiments and embodiments of the present disclosure can be combined with each other as long as they are not contradictory. All other embodiments obtained based on the described embodiments of the present disclosure without requiring the creative labor of 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 common 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 articles appearing before the words cover the elements or articles listed after the words and their equivalents, and do not exclude other elements or articles.

[0025] Thin film piezoelectric materials have the characteristics of high dielectric constant and transparency, which is very suitable for the structure of a screen-integrated vibrator. If the surface charge distribution is unevenly accumulated or the voltage is too high, the vibrator will experience a breakdown phenomenon. For example, the upper and lower electrodes maintain an open circuit, but the piezoelectric thin film layer structure is destroyed. For example, the upper and lower electrodes will be short-circuited due to destruction, causing the entire vibrator to fail. The main cause of the short circuit is that during the process, particles, particles or thin film stress causes cracks in the piezoelectric thin film layer. In this crack state, if electrodes are directly deposited on the piezoelectric thin film layer, it will cause a high risk of short circuit. Thus, how to avoid short circuits in piezoelectric sensors has become a technical problem that needs to be solved urgently.

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

[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 shorting of 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, in which 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 arranged in sequence spaced apart from the base substrate 1, and the insulating layer 4 contacts at least a portion of the piezoelectric thin film layer 3.

[0029] In a specific implementation process, 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, and is not limited thereto. Those skilled in the art can set up the base substrate 1 according to the actual application needs.

[0030] In a specific implementation process, 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), chromium (Cr), and those skilled in the art can set the first electrode layer 2 according to the actual application needs, and there is no limitation here. Accordingly, the fifth electrode layer 5 can also be made of the same material as the first electrode layer 2, and will not be described in detail here.

[0031] In a specific implementation process, the piezoelectric thin film layer 3 is 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 ensuring the vibration characteristics of the piezoelectric sensor, specifically, the material for fabricating the piezoelectric thin film layer 3 can be selected according to the actual use needs of those skilled in the art, and is not limited thereto. Here, when the piezoelectric thin film layer 3 is fabricated using PZT, PZT has a high piezoelectric coefficient, so that the piezoelectric characteristics of the corresponding piezoelectric sensor can be guaranteed, and the corresponding piezoelectric sensor can be applied to a tactile feedback device, and PZT has a high light transmittance, so that 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 part of the piezoelectric thin film layer 3, and the insulating layer 4 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, and in Fig. 2, the insulating layer 4 completely covers the side of the piezoelectric thin film layer 3 away from the base substrate 1 and can further contact a part 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 process, the entire piezoelectric thin film layer 3 may be provided on the side of the first electrode layer 2 away from the base substrate 1, thereby improving the manufacturing efficiency of the piezoelectric sensor. In addition, the piezoelectric thin film layer 3 may be patterned as necessary, for example, the piezoelectric thin film layer 3 may be disposed in an area of ​​the first electrode layer 2 away from the base substrate 1, thereby realizing flexible design of the piezoelectric sensor. In a specific implementation process, the insulating layer 4 contacts at least a part of the piezoelectric thin film layer 3, so that 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 insulating layer 4 prevents a short circuit caused by contact between the second electrode layer 5 and the first electrode layer 2, thereby avoiding the risk of a short circuit in the piezoelectric sensor and improving the product yield.

[0034] In the 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 the insulating layer 4 is filled in each of the hollow structures f. Here, the at least one hollow structure f may be one or more. In FIG. 3, the at least one hollow structure f is shown as one, and of course, other numbers may be used, and are not limited here. The hollow structure f may be a crack present in the piezoelectric thin film layer 3. When there are multiple hollow structures f, the size of each of the hollow structures f does not have to be equal, and the distribution thereof may be randomly distributed based on the actual process conditions. As shown in FIG. 4, the insulating layer 4 completely fills each of the hollow structures f, and the thickness of the insulating layer 4 filled in each of the hollow structures 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 structure f are both perpendicular to the plane on which the base substrate 1 is located, and "equal" here does not mean completely equal, but is approximately equal, or nearly equal. In this way, the hollow structures f in the piezoelectric thin film layer 3 are effectively filled through the insulating layer 4, and the risk of short-circuiting the piezoelectric sensor is avoided, and since the insulating layer 4 completely fills each of the hollow structures f, when the other parts of the insulating layer 4 other than the parts filled in each of 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, which ensures the stability of the structure for manufacturing the subsequent piezoelectric sensor and improves 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. In this way, 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 the 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 process, if the hollow structure f exists in the piezoelectric thin film layer 3, the location of the hollow structure f always has strong capillary force and porosity, and when a wet process is adopted, the insulating layer 4 can flow into the hollow structure f through gravity leveling. For example, when a wet process is adopted to apply PI to the side of the piezoelectric thin film layer 3 away from the base substrate 1, PI has excellent leveling properties on the surface of the piezoelectric thin film layer 3, so that 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. Since PI has excellent high-temperature curing (cyclization) properties, PI is wet-applied to the side of the piezoelectric thin film layer 3 away from the base substrate 1, and then the PI is cured at a high temperature within a range of 200°C to 300°C to form the insulating layer 4. This ensures that the insulating layer 4 has stable insulating properties and improves the performance of the piezoelectric sensor.

[0038] In a specific implementation process, a wet process can further be 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 avoiding the risk of short-circuiting 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 more to form the insulating layer 4, which ensures that the insulating layer has stable insulating properties and improves the usage 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 avoid the risk of short circuiting the piezoelectric sensor and improve the performance of the piezoelectric sensor. Of course, the piezoelectric thin film layer 3 can be provided in other ways, 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 a 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 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, without being 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 usage performance 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 implementation, 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, for example, the thickness of the insulating layer 4 is 60 nm, for example, the thickness of the insulating layer 4 is 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 circuit 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, for example, the thickness of the piezoelectric thin film layer 3 is 1 μm, 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 of 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 represents the capacitance of the piezoelectric thin film layer 3, and C PZT represents the capacitance of the insulating layer 4.

[0046] In a specific implementation, when the material used for the piezoelectric thin film layer 3 is constant, for example, the film layer is 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 is calculated based on the capacitance 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 represents the electrical resistance of the piezoelectric thin film layer 3, and R PZT represents the electrical resistance of the insulating layer 4.

[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 requirement is satisfied, the insulating layer 4 has excellent insulating properties and effectively avoids the risk of short circuit 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 according to the electrical resistance calculation formula, and the insulating layer 4 can be set according to the actual situation of the piezoelectric thin film layer 3 in practical 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. Here, the lyophilic material layer not only ensures that the insulating layer 4 is quickly leveled 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, ensures stable insulating properties of the insulating layer 4, and further improves the use performance of the piezoelectric sensor.

[0051] In the embodiment of the present disclosure, the first electrode layer 2 and the second electrode layer 5 can be provided by adopting 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 a whole-layer plate structure, 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, the first electrode layer 2 has a plurality of first pole-shaped structures 10 on the side close to the piezoelectric thin film layer 3, and the second electrode layer 5 is a plate-shaped structure of the entire layer, or the second electrode layer 5 may include a pattern design, thus avoiding short-circuiting of the piezoelectric sensor through the insulating layer 4, and at the same time, increasing the contact area between the piezoelectric thin film layer 3 and the first electrode layer 2 through the plurality of first pole-shaped structures 10, ensuring the structural stability between the piezoelectric thin film layer 3 and the first electrode layer 2, and improving the usage performance of the piezoelectric sensor.

[0053] In a specific implementation, the size of each of the first pole-shaped structures 10 is the same, and each of the first pole-shaped structures 10 may be distributed at unequal intervals or may be uniformly distributed at equal intervals, and the distribution state of the first pole-shaped structures 10 can be set according to the actual application demand, and is not limited here. Here, when each of the first pole-shaped structures 10 is distributed at equal intervals, it can ensure the uniformity of the transmittance at each position of the piezoelectric sensor, and ensure the use performance of the piezoelectric sensor.

[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 has a plurality of second pole-like structures 20 on the side of the second electrode layer 5 close to the piezoelectric thin film layer 3, thus avoiding short-circuiting of the piezoelectric sensor through the insulating layer 4, and at the same time, increasing the contact area between the piezoelectric thin film layer 3 and the second electrode layer 5 through the plurality of second pole-like structures 20, ensuring the structural stability between the piezoelectric thin film layer 3 and the second electrode layer 5, and improving the usage performance of the piezoelectric sensor.

[0055] In a specific implementation, the size of each of the second pole-shaped structures 20 is the same, and each of the second pole-shaped structures 20 may be distributed at unequal intervals or may be distributed at equal intervals, specifically, the distribution state of the second pole-shaped structures 20 can be set according to the actual application demand, and is not limited here. Here, when each of the second pole-shaped structures 20 is distributed at equal intervals, it can ensure the uniformity of the light transmittance at each position of the piezoelectric sensor, and ensure the use performance of the piezoelectric sensor.

[0056] In the embodiment of the present disclosure, in the fourth type of realization, as shown in FIG. 8, the first electrode layer 2 has a plurality of third pole-like structures 30 on the side close to the piezoelectric thin film layer 3, and the second electrode layer 5 has a plurality of fourth pole-like structures 40 on the side close to the piezoelectric thin film layer 3, and the orthogonal projection of any of the third pole-like structures 30 on the base substrate 1 and the orthogonal projection of any of the fourth pole-like structures 40 on the base substrate 1 do not overlap with each other. Through the plurality of third pole-like structures 30, the contact area between the piezoelectric thin film layer 3 and the first electrode layer 2 is increased, and through the plurality of fourth pole-like structures 40, the contact area between the piezoelectric thin film layer 3 and the second electrode layer 5 is increased, thereby ensuring the structural stability of the piezoelectric thin film layer 3 between the first electrode layer 2 and the second electrode layer 5, respectively, and improving the performance of the piezoelectric sensor. In addition, the orthogonal projection of any of the third pole-like structures 30 on the base substrate 1 and the orthogonal projection of any of the fourth pole-like structures 40 on the base substrate 1 do not overlap with each other. For example, the orthogonal projection of any one of the fourth pole-shaped structures 40 on the base substrate 1 falls completely within the range of the orthogonal projection of the spacing area between two adjacent third pole-shaped structures 30 on the base substrate 1, thereby achieving structural stability while at the same time ensuring the uniformity of the thickness of the piezoelectric thin film layer 3, avoiding a situation in which the piezoelectric thin film layer 3 is prone to destruction at thin positions due to uneven thickness thereof, and further ensuring the usability of the piezoelectric sensor.

[0057] In a specific implementation, the size of each of the third pole-shaped structures 30 is the same size, the size of each of the fourth pole-shaped structures 40 is the same size, the third pole-shaped structures 30 may be distributed at uneven intervals or at equal intervals, and the fourth pole-shaped structures 40 may be distributed at uneven intervals or at equal intervals, specifically, the distribution of the third pole-shaped structures 30 and the fourth pole-shaped structures 40 can be set according to the actual application needs, and is not limited here. Here, when the third pole-shaped structures 30 are distributed at equal intervals and the fourth pole-shaped structures 40 are distributed at equal intervals, the uniformity of the light transmittance at each position of the piezoelectric sensor is ensured, and the use 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 be provided 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 need to be completely same, and may be approximately same.

[0060] In the embodiment of the present disclosure, FIG. 9 is a structural schematic diagram of the piezoelectric sensor, in which 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 running 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 ) is loaded, a high frequency AC voltage signal is applied to the piezoelectric thin film layer 3 and the insulating layer 4, which generates high frequency vibration, and a laser is used to measure the vibration displacement, thereby ensuring the performance of the piezoelectric sensor. Here, the protective layer can be SiO2, silicon nitride (Si3N4), etc., and is not limited thereto. Of course, in addition to the above-mentioned various film layers, the piezoelectric sensor can also be provided with other film layers according to the actual application, and the specific examples can refer to the 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 show a tendency of 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 completely within the area range 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 completely within the area range 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 completely within the area range of the orthogonal projection of the first electrode layer 2 on the base substrate 1. In this way, there is a step between each film layer, which ensures high-speed leveling in the wet process of each film layer, while ensuring the structural stability of the piezoelectric sensor, thereby improving the use performance of the piezoelectric sensor. In addition, the piezoelectric sensor can be applied in fields such as medical, automotive electronics, and motion tracking systems. In particular, it is applied in the field of wearable devices, medical monitoring and treatment using external or internal implantation, or artificial intelligence electronic skin, etc. Specifically, the piezoelectric sensor can be applied to devices that can generate vibration and mechanical characteristics, such as brake pads, keyboards, mobile terminals, game handles, and in-vehicle devices.

[0062] Based on the same disclosed concept, as shown in FIG. 10, an embodiment of the present disclosure further provides a haptic feedback device, which includes a haptic 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 a voltage pulse based on a received command to generate vibrations in a structure.

[0064] In a specific implementation process, in FIG. 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, and the touch panel can determine the position of the human touch, thereby generating a corresponding vibration waveform, amplitude and frequency, thereby realizing human-computer interaction. For example, the tactile feedback device can be multiplexed with a piezoelectric body, and the piezoelectric sensor can determine the position of the human touch, thereby generating a corresponding vibration waveform, amplitude and frequency, thereby realizing human-computer interaction. Of course, the tactile feedback device can be applied in fields such as medical care, automotive electronics, motion tracking system, etc. according to actual needs, which will not be described in detail here.

[0065] In addition, 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 the 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 a side remote 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 above part, and will not be described in detail here. The specific implementation process of steps S101 to S103 is as follows:

[0072] First, the first electrode layer 2 is formed on the base substrate 1, for example, ITO is sputtered on 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, which contacts at least a part of the piezoelectric thin film layer 3, and then 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 a side of the piezoelectric thin film layer away from the first electrode layer, includes 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 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 a specific implementation process, the specific implementation process from step S201 to step S202 is as follows:

[0077] First, a wet process is adopted to coat a polyimide material on the side of the piezoelectric thin film layer 3 away from the first electrode layer 2, and when 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 in the cracks, thereby ensuring the insulating properties between the piezoelectric thin film layer 3 and the second electrode layer 5. Then, the polyimide material is cured at high temperature to form an insulating layer 4 in contact with at least a part of the piezoelectric thin film layer 3 on the side of the piezoelectric thin film layer 3 away from the first electrode layer 2, and the polyimide material is cured at, for example, 200° C. to ensure that the insulating layer 4 has stable insulating properties, and thus ensure the use performance of the piezoelectric sensor.

[0078] In the specific implementation process, the principle by which the method for manufacturing the above piezoelectric sensor solves the problem is similar to that of the above-mentioned piezoelectric sensor, so the method for manufacturing the piezoelectric sensor can refer to the implementation of the above-mentioned piezoelectric sensor, and overlapping parts will not be described.

[0079] An embodiment of the present disclosure provides a piezoelectric sensor and a manufacturing method thereof, in which 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 spaced apart from the base substrate 1 in sequence, and 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 is effectively filled through the insulating layer 4. Thus, after depositing the second electrode layer 5, the insulating layer 4 is utilized 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] Although the preferred embodiments of the present disclosure have been described, once the basic inventive concept is understood, those skilled in the art can make additional changes and modifications to these embodiments. Therefore, it is intended that the appended claims be interpreted to cover the preferred embodiments, as well as 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 is also intended to include these modifications and variations.

Claims

1. A piezoelectric sensor, comprising 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, wherein the insulating layer contacts at least a part of the piezoelectric thin film layer, wherein at least one hollow structure is included on a side of the piezoelectric thin film layer away from the base substrate, and the insulating layer is filled in each of the hollow structures, and a lyophilic material layer is provided on a side of the piezoelectric thin film layer away from the base substrate piezoelectric sensor.

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

3. The orthographic projection of the insulating layer on the base substrate and the orthographic 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 any one of Claims 1 to 3.

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 any one of Claims 1 to 4.

6. The thickness range of the insulating layer is [50 nm, 200 nm] The piezoelectric sensor according to any one of Claims 1 to 5.

7. The thickness range of the piezoelectric thin film layer is (0, 2 μm] The piezoelectric sensor according to any one of Claims 1 to 6.

8. The capacitance relationship between the piezoelectric thin film layer and the insulating layer satisfies the following relational expression, 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 any one of Claims 1 to 7.

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 any one of Claims 1 to 8.

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. having a plurality of first columnar structures on a side of the first electrode layer close to the piezoelectric thin film layer The piezoelectric sensor according to any one of Claims 1 to 10.

12. having a plurality of second columnar structures on a side of the second electrode layer close to the piezoelectric thin film layer The piezoelectric sensor according to any one of Claims 1 to 10.

13. It has a plurality of third columnar structures on the side of the first electrode layer close to the piezoelectric thin film layer, and has a plurality of fourth columnar structures on the side of the second electrode layer close to the piezoelectric thin film layer. The orthographic projection of any one of the third columnar structures on the base substrate and the orthographic projection of any one of the fourth columnar structures on the base substrate do not overlap with each other. The piezoelectric sensor according to any one of claims 1 to 10.

14. A tactile feedback device, comprising a tactile feedback circuit and the piezoelectric sensor according to any one of claims 1 to 13, wherein the tactile feedback circuit is located on the side of the second electrode layer away from the first electrode layer, or on the side of the first electrode layer away from the second electrode layer, and the tactile feedback circuit is used to generate a voltage pulse based on a received command so as to generate vibration in the structure. Tactile feedback device.

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

16. Forming the insulating layer in contact with at least a part of the piezoelectric thin film layer on the side of the piezoelectric thin film layer away from the first electrode layer includes: adopting a wet process to apply a polyimide material on the side of the piezoelectric thin film layer away from the first electrode layer; thermally curing the polyimide material to form the insulating layer in contact with at least a part of the piezoelectric thin film layer on the side of the piezoelectric thin film layer away from the first electrode layer. The manufacturing method according to claim 15.

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