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EP-4206635-B1 - PIEZOELECTRIC SENSOR AND HAPTIC FEEDBACK DEVICE

EP4206635B1EP 4206635 B1EP4206635 B1EP 4206635B1EP-4206635-B1

Inventors

  • CHEN, YUJU

Dates

Publication Date
20260506
Application Date
20210528

Claims (11)

  1. A piezoelectric sensor, comprising: a base substrate (1), a first electrode layer (2), arranged on the base substrate (1); a piezoelectric thin film layer (3), arranged on a side of the first electrode layer (2) facing away from the base substrate (1); an insulating layer (4), arranged on a side of the piezoelectric thin film layer (3) facing away from the base substrate (1); and a second electrode layer (5), arranged on a side of the insulating layer (4) facing away from the base substrate (1); wherein the insulating layer (4) is in contact with at least part of the piezoelectric thin film layer (3); wherein a capacitance of the piezoelectric thin film layer (3) and a capacitance of the insulating layer (4) satisfy a following relationship: C PI ≥ 100 C PZT ; wherein C PI represents the capacitance of the insulating layer (4) and C PZT represents the capacitance of the piezoelectric thin film layer (3); characterized in that a side of the first electrode layer (2) facing the piezoelectric thin film layer (3) is provided with a plurality of first columnar structures (10); or a side of the second electrode layer (5) facing the piezoelectric thin film layer (3) is provided with a plurality of second columnar structures (20).
  2. The piezoelectric sensor according to claim 1, wherein the piezoelectric thin film layer (3) comprises at least one hollow structure (f), and each of the at least one hollow structure (f) is filled with the insulating layer (4).
  3. The piezoelectric sensor according to any one of claims 1 to 2, wherein an orthographic projection of the piezoelectric thin film layer (3) on the base substrate (1) covers an orthographic projection of the insulating layer (4) on the base substrate (1).
  4. The piezoelectric sensor according to any one of claims 1 to 2, wherein an orthographic projection of the insulating layer (4) on the base substrate (1) and an orthographic projection of the piezoelectric thin film layer (3) on the base substrate (1) overlap each other.
  5. The piezoelectric sensor according to any one of claims 1 to 4, wherein a material of the insulating layer (4) comprises at least one of polyimide, silica, or alumina; a material of the piezoelectric thin film layer (3) comprises at least one of aluminum nitride, zinc oxide, lead zirconate titanate, barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, or lanthanum gallium silicate.
  6. The piezoelectric sensor according to any one of claims 1 to 5, wherein a thickness of the insulating layer (4) and a thickness of the piezoelectric thin film layer (3) satisfy a following relationship: d PI ≤ 0.1 * d PZT ; wherein d PI represents the thickness of the insulating layer (4) and d PZT represents the thickness of the piezoelectric thin film layer (3).
  7. The piezoelectric sensor according to any one of claims 1 to 6, wherein a thickness of the insulating layer (4) is greater than or equal to 50 nm; and the thickness of the insulating layer (4) is less than or equal to 200 nm; a thickness of the piezoelectric thin film layer (3) is greater than 0; and the thickness of the piezoelectric thin film layer (3) is less than or equal to 2µm.
  8. The piezoelectric sensor according to any one of claims 1 to 7, wherein a resistance of the piezoelectric thin film layer (3) and a resistance of the insulating layer (4) satisfy a following relationship: R PI ≥ 1000 R PZT ; wherein R PI represents the resistance of the piezoelectric thin film layer (3) and R PZT represents the resistance of the insulating layer (4).
  9. The piezoelectric sensor according to any one of claims 1 to 8, wherein a side of the piezoelectric thin film layer (3) facing away from the base substrate (1) is provided with a lyophilic material layer.
  10. The piezoelectric sensor according to any one of claims 1 to 9, wherein a side of the first electrode layer (2) facing the piezoelectric thin film layer (3) is provided with a plurality of third columnar structures (30); a side of the second electrode layer (5) facing the piezoelectric thin film layer (3) is provided with a plurality of fourth columnar structures (40); and an orthographic projection of each of the third columnar structures (30) on the base substrate (1) does not overlap with an orthographic projection of each of the fourth columnar structures (40) on the base substrate (1).
  11. A haptic feedback device, comprising a haptic feedback circuit (100) and the piezoelectric sensor (200) according to any one of claims 1 to 10; wherein: the haptic feedback circuit (100) is arranged on a side of the second electrode layer (5) facing away from the first electrode layer (2); or the haptic feedback circuit (100) is arranged on a side of the first electrode layer (2) facing away from the second electrode layer (5); wherein the haptic feedback circuit (100) is configured to generate a voltage pulse in accordance with a received instruction to cause a structural body to vibrate.

Description

Field The present disclosure relates to the field of sensor technology, in particular to a piezoelectric sensor and a haptic feedback device. Background Haptic feedback (known as Haptics) is the focus of today's technology development, and in particular, haptic feedback enables the terminal to interact with the human body through touch. Haptic feedback, in turn, can be divided into two categories, one is vibration feedback and the other is tactile reproduction technology. An example of prior art may be found in patent document US2016/204333 A1. Summary The present disclosure provides a piezoelectric sensor, a fabrication method therefor, and a haptic feedback device. And, the solution is as follows. An embodiment of the present disclosure provides a piezoelectric sensor, including: a base substrate, a first electrode layer, arranged on the base substrate; a piezoelectric thin film layer, arranged on a side of the first electrode layer facing away from the base substrate; an insulating layer, arranged on a side of the piezoelectric thin film layer facing away from the base substrate; and a second electrode layer, arranged on a side of the insulating layer facing away from the base substrate; where the insulating layer is in contact with at least part of the piezoelectric thin film layer; a capacitance of the piezoelectric thin film layer and a capacitance of the insulating layer satisfy a following relationship: CPI ≥ 100CPZT; where CPI represents the capacitance of the insulating layer and CPZT represents the capacitance of the piezoelectric thin film layer; where a side of the first electrode layer facing the piezoelectric thin film layer is provided with a plurality of first columnar structures; a side of the second electrode layer facing the piezoelectric thin film layer is provided with a plurality of second columnar structures. In some embodiments, the piezoelectric thin film layer includes at least one hollow structure, and each of the at least one hollow structures is filled with the insulating layer. In some embodiments, an orthographic projection of the piezoelectric thin film layer on the base substrate covers an orthographic projection of the insulating layer on the base substrate. In some embodiments, an orthographic projection of the insulating layer on the base substrate and an orthographic projection of the piezoelectric thin film layer on the base substrate overlap each other. In some embodiments, a material of the insulating layer includes at least one of polyimide, silica, or alumina. In some embodiments, a thickness of the insulating layer and a thickness of the piezoelectric thin film layer satisfy a following relationship: dPI≤0.1*dPZT; where dPI represents the thickness of the insulating layer and dPZT represents the thickness of the piezoelectric thin film layer. In some embodiments, a thickness of the insulating layer is greater than or equal to 50 nm; and the thickness of the insulating layer is less than or equal to 200 nm. In some embodiments, a thickness of the piezoelectric thin film layer is greater than 0; and the thickness of the piezoelectric thin film layer is less than or equal to 2µm. In some embodiments, a resistance of the piezoelectric thin film layer and a resistance of the insulating layer satisfy a following relationship: RPI≥1000RPZT; where RPI represents the resistance of the piezoelectric thin film layer and RPZT represents the resistance of the insulating layer. In some embodiments, a side of the piezoelectric thin film layer facing away from the base substrate is provided with a lyophilic material layer. In some embodiments, a material of 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, or lanthanum gallium silicate. In some embodiments, a side of the first electrode layer facing the piezoelectric thin film layer is provided with a plurality of third columnar structures, the side of the second electrode layer facing the piezoelectric thin film layer is provided with a plurality of fourth columnar structures, and an orthographic projection of each of the third columnar structures on the base substrate does not overlap with an orthographic projection of each of the fourth columnar structures on the base substrate. Accordingly, an embodiment of the present disclosure provides a haptic feedback device, including a haptic feedback circuit and a piezoelectric sensor as described in any one of the above; where: the haptic feedback circuit is arranged on a side of the second electrode layer facing away from the first electrode layer; orthe haptic feedback circuit is arranged on a side of the first electrode layer facing away from the second electrode layer;where the haptic feedback circuit is configured to generate a voltage pulse in accordance with a received instruction to cause a structural body to vibrate. Brief Des