Linear micro motor stator structure, preparation method thereof and micro motor

Abstract

The invention belongs to the technical field of linear ultrasonic motors, and particularly relates to a linear micro motor stator structure, a preparation method thereof and a micro motor. According to the technical scheme, the linear micro motor stator structure comprises an elastic substrate, and at least one side of the elastic substrate is connected with a piezoelectric film; the friction head protrudes out of the surface and is connected with the piezoelectric film or the elastic substrate; and the thickness of the piezoelectric film is less than 10 microns. According to the linear micro motor stator structure, the preparation method thereof and the micro motor, a standing wave linear motor is designed and prepared based on a piezoelectric film, low-voltage and high-torque output is achieved, meanwhile, a rotary micro motor structure is provided based on the arc-shaped micro motor stator structure, and thin compact terminal application is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of linear ultrasonic motors, and in particular relates to a linear micromotor stator structure and a preparation method thereof, as well as a micromotor. Background Art

[0002] As a category of ultrasonic motors, linear ultrasonic motors utilize the inverse piezoelectric effect of piezoelectric elements and the ultrasonic vibration of elastic bodies. Through the friction between the stator and the mover, the micro-vibration of the elastic body is converted into the macroscopic linear motion of the mover, which directly pushes the load. It has the following characteristics: 1) It directly generates linear motion and traction, without motion errors caused by auxiliary mechanisms such as connecting rods, lead screws and balls; 2) The structure is relatively simple and the design is flexible; according to the form of fluctuation, it can be divided into standing wave type and traveling wave type; existing piezoelectric linear ultrasonic motors are all based on bulk piezoelectric ceramics, and are mainly prepared by patch type, bolt compression type and piezoelectric stacking type.

[0003] The patent with publication number CN219554840U utilizes a multi-layer piezoelectric ceramic drive, which is manufactured by stacking and sintering 20 to 60 layers of ceramics with a thickness of 15 to 17 microns, and the preparation process is complex.

[0004] Patent publication number CN119765984A primarily utilizes multilayer piezoelectric ceramics, with piezoelectric layers arranged on two orthogonal sides of an elastomer. Simultaneously driving the two orthogonal piezoelectric layers excites different orthogonal vibration modes, causing the friction head to produce elliptical motion, driving the mover. Using multilayer bulk ceramics prevents thinning the resonator (stator), and the multilayer process is complex.

[0005] Existing linear ultrasonic motors are basically based on bulk PZT ceramics for excitation. The driving voltage is high, and miniaturization, especially thinning, is difficult to achieve. They are difficult to adapt to very small and compact environments, such as the zoom and aperture adjustment of mobile phone cameras. In addition, since bulk ceramics are prepared by cast iron sintering, the ceramics themselves are difficult to sinter in large pieces. For example, it is very difficult to sinter piezoelectric ceramics with a thickness of less than 0.1mm and an area greater than 100mm (four inches). They can only be prepared in small pieces, and the production efficiency is low. Summary of the Invention

[0006] In order to solve the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a linear micromotor stator structure and its preparation method and a micromotor, which is designed based on piezoelectric film and prepares a standing wave linear motor to achieve low voltage and high torque output to meet the needs of thin and compact terminal applications.

[0007] The technical solution adopted in the present invention is:

[0008] The linear micromotor stator structure includes an elastic base with a piezoelectric film connected to at least one side of the elastic base; and a friction head protruding from the surface, the friction head being connected to the piezoelectric film or the elastic base; the thickness of the piezoelectric film is less than 10 μm.

[0009] The present invention utilizes the inverse piezoelectric effect of a piezoelectric film to excite an elastic body to generate standing waves and bending vibration modes. When the vibration resonates near the bending vibration mode frequency, the contacts are stimulated to perform elliptical motion, thereby driving the actuator to perform linear motion. The friction head can be connected to the piezoelectric film or directly to the elastic body. To enhance driving capability, piezoelectric film can also be plated on both the front and back surfaces of the elastic substrate.

[0010] The present invention designs and prepares a standing wave linear micromotor stator structure based on a piezoelectric film. The thickness of the piezoelectric film is less than 10 μm, making the thinnest linear micromotor stator structure less than 0.5 mm, achieving low voltage and high torque output, and meeting the needs of thin and compact terminal applications.

[0011] As a preferred embodiment of the present invention, the thickness of the elastic base is less than 0.2 mm, the length of the elastic base is less than 4 mm, the width of the elastic base is 0.8 mm, and the diameter of the friction head is 0.3 mm.

[0012] As a preferred solution of the present invention, the elastic base is a rectangular parallelepiped or arc-shaped structure.

[0013] As a preferred embodiment of the present invention, the piezoelectric film is sequentially provided with several electrode zones. Four adjacent electrode zones are sequentially applied with AC drive signals of 0°, 180°, 180°, and 0° (B1 mode), or 0°, 180°, 0°, and 180° (B2 mode). The drive frequency of both the B1 and B2 modes is greater than 20 kHz, achieving ultrasonic silent drive.

[0014] As a preferred embodiment of the present invention, when piezoelectric films are connected to both sides of the elastic substrate, the driving phases of the four adjacent electrode partitions on the upper side are opposite to the driving phases of the four adjacent electrode partitions on the lower side. For the B1 mode, in the upper electrode partition, the first electrode partition, the second electrode partition, the third electrode partition, and the fourth electrode partition are applied with AC driving signals of 0°, 180°, 180°, and 0°, respectively; in the lower electrode partition, the first electrode partition, the second electrode partition, the third electrode partition, and the fourth electrode partition are applied with AC driving signals of 180°, 0°, 0°, and 180°, respectively. For the B2 mode, in the upper electrode partition, the first electrode partition, the second electrode partition, the third electrode partition, and the fourth electrode partition are applied with AC driving signals of 0°, 180°, 0°, and 180°, respectively; in the lower electrode partition, the first electrode partition, the second electrode partition, the third electrode partition, and the fourth electrode partition are applied with AC driving signals of 180°, 0°, 180°, and 0°, respectively.

[0015] As a preferred embodiment of the present invention, the material of the elastic substrate is one of single crystal silicon, stainless steel, copper alloy, and iron-nickel alloy.

[0016] As a preferred embodiment of the present invention, the material of the friction head is one of alumina gemstone, zirconium oxide, tin ball, copper core ball and copper column.

[0017] As a preferred embodiment of the present invention, an upper electrode is provided on the side of the piezoelectric film away from the elastic substrate, and a lower electrode is provided on the side of the piezoelectric film close to the elastic substrate; the elastic substrate includes top silicon, buried oxide layer and bottom silicon arranged in sequence, and the top silicon is in contact with the lower electrode.

[0018] As a preferred embodiment of the present invention, an upper electrode is provided on the side of the piezoelectric film away from the elastic substrate, and a lower electrode is provided on the side of the piezoelectric film close to the elastic substrate; a substrate structure is bonded to the side of the elastic substrate away from the piezoelectric film.

[0019] A method for preparing a linear micromotor stator structure comprises the following steps:

[0020] S1: Connecting the piezoelectric film to the elastic substrate to form a piezoelectric film-SOI structure;

[0021] S2: patterning the top electrode by photolithography;

[0022] S3: etching or corroding the piezoelectric film;

[0023] S4: etching the lower electrode;

[0024] S5: etching the top silicon of the elastic substrate;

[0025] S6: etching the bottom silicon of the elastic substrate to complete the release;

[0026] S7: Weld or bond the friction head to the upper electrode.

[0027] A method for preparing a linear micromotor stator structure comprises the following steps:

[0028] S1: Connecting the piezoelectric film to the elastic substrate to form a piezoelectric film-SOI structure;

[0029] S2: patterning the top electrode by photolithography;

[0030] S3: etching or corroding the piezoelectric film;

[0031] S4: etching the lower electrode;

[0032] S5: etching the top silicon of the elastic substrate;

[0033] S6: Carve steps on the bottom silicon of the elastic substrate so that an area in the middle of the bottom silicon is higher than the edge;

[0034] S7: Etch the step portion of the bottom silicon to complete the release of the device and form a friction head.

[0035] At this time, the friction head is formed by etching the bottom silicon of the elastic substrate.

[0036] A method for preparing a linear micromotor stator structure comprises the following steps:

[0037] S1: The elastic substrate is a metal substrate, and the lower electrode is grown on the metal substrate;

[0038] S2: growing piezoelectric thin films by magnetron sputtering or sol-gel method;

[0039] S3: growing the top electrode by photolithography;

[0040] S4: After cutting and forming, the metal substrate is bonded to the substrate structure;

[0041] S5: Bond or weld the friction head to the upper electrode.

[0042] The method of growing a piezoelectric film on both sides of a metal substrate or bonding two layers of piezoelectric films on one side of a metal substrate back to back to form a piezoelectric film on both sides of a metal substrate is similar to this process and will not be described in detail here.

[0043] The preparation process flow provided by the present invention can prepare piezoelectric films with a thickness of less than 10μm and an area greater than 100mm (four inches), and a motor stator structure can be prepared based on this piezoelectric film. It can also meet the needs of batch preparation and realize low-cost batch production, especially the process of metal substrate, avoiding the use of multiple complex and expensive MEMS photolithography and etching processes.

[0044] The micro motor includes a linear micro motor stator structure, a substrate and a mover. The linear micro motor stator structure is attached to the substrate, and the mover is closely attached to the side of the linear micro motor stator structure where a friction head is arranged.

[0045] As a preferred solution of the present invention, the linear micromotor stator structure is provided with an internal cavity on the side facing the substrate, a magnet is provided in the internal cavity, and the magnet is attached to the substrate; the material of the mover is magnetic material or a part of magnetic material.

[0046] A micromotor comprises a linear micromotor stator structure, a base, and a fixed housing mounted on the base. The linear micromotor stator structure has an arc-shaped elastic base, which is mounted on the base. The fixed housing is provided with a friction layer structure within the fixed housing. An axis structure for limiting the rotational displacement of the friction layer structure is embedded in the inner wall of the fixed housing. The friction layer structure is closely attached to the side of the linear micromotor stator structure where the friction head is provided, and a ring magnet is mounted on the friction layer structure. Based on the arc-shaped micromotor stator structure, the present invention proposes a rotary micromotor structure that can be used in terminal applications such as aperture adjustment and prism anti-shake.

[0047] The beneficial effects of the present invention are:

[0048] 1. The present invention designs and prepares a standing wave linear micromotor stator structure based on a piezoelectric film. The thickness of the piezoelectric film is less than 10 μm, making the linear micromotor stator structure as thin as less than 0.5 mm, achieving low-voltage and high-torque output, meeting the requirements of thin and compact terminal applications.

[0049] 2. The preparation process provided by the present invention can prepare piezoelectric films with a thickness of less than 10μm and an area greater than 100mm (four inches), and a motor stator structure can be prepared based on this piezoelectric film. It can also meet the needs of batch preparation and achieve low-cost batch production, especially the process of metal substrate, avoiding the use of multiple complex and expensive MEMS photolithography and etching processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the stator structure of three types of linear micro motors;

[0051] Figure 2 It is a schematic diagram of the working mode of the linear micromotor stator structure;

[0052] Figure 3 is the stress tensor diagram of the linear micromotor stator structure under the working mode;

[0053] Figure 4 This is a schematic diagram of applying AC drive signal to the linear micromotor structure of a single-sided piezoelectric film;

[0054] Figure 5This is a schematic diagram of applying AC drive signals to a linear micromotor structure with double-sided piezoelectric film;

[0055] Figure 6 This is a process diagram of the first preparation method of the linear micromotor stator structure;

[0056] Figure 7 This is a process diagram of the second preparation method of the linear micromotor stator structure;

[0057] Figure 8 This is a process diagram of the third preparation method of the linear micromotor stator structure;

[0058] Figure 9 It is a structural diagram of a micro motor;

[0059] Figure 10 It is a structural diagram of the arc-shaped linear micromotor stator structure;

[0060] Figure 11 It is a structural schematic diagram of a rotary micromotor based on an arc-shaped linear micromotor stator structure.

[0061] In the figure: 10-piezoelectric film; 20-elastic substrate; 30-friction head; 40-substrate structure; 50-magnet; 60-base plate; 70-mover; 80-fixed shell; 101-upper electrode; 102-lower electrode; 201-top silicon; 202-bottom silicon; 601-base; 602-anchor point; 701-friction layer structure; 702-ring magnet; 101A-first electrode partition; 101B-second electrode partition; 101C-third electrode partition; 101D-fourth electrode partition. DETAILED DESCRIPTION

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0063] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features therein may be combined with each other unless there is a conflict.

[0064] like Figure 1As shown, the linear micromotor stator structure of this embodiment includes an elastic base 20, with a piezoelectric film 10 connected to at least one side of the elastic base 20; and a friction head 30 protruding from the surface, connected to the piezoelectric film 10 or the elastic base 20. The piezoelectric film 10 has a thickness of less than 10 μm and an area greater than 100 mm (4 inches). The piezoelectric film 10 can be made of materials such as PZT, PMN-PT, or PZN-PT.

[0065] Figure 1 (a) shows that the elastic substrate 20 is connected to the piezoelectric film 10 on one side, and the friction head 30 is connected to the piezoelectric film 10 . Figure 1 (b) The piezoelectric film 10 is connected to one side of the elastic base 20 , and the friction head 30 is connected to the side of the elastic base 20 where the piezoelectric film 10 is not provided. Figure 1 (c) shows that both sides of the elastic substrate 20 are connected to the piezoelectric film 10 , and the friction head 30 is connected to the piezoelectric film 10 on one side.

[0066] The present invention utilizes the inverse piezoelectric effect of the piezoelectric film 10 to excite the elastic body to generate standing waves, bending vibration modes B1 and B2. When resonating near the bending vibration mode frequency, the contacts are stimulated to perform elliptical motion, thereby driving the mover 70 to perform linear motion. The friction head 30 can be connected to the piezoelectric film 10 or directly to the elastic body. To enhance driving capability, the piezoelectric film 10 can also be plated on both the front and back surfaces of the elastic substrate 20.

[0067] The present invention designs and prepares a standing wave linear micromotor stator structure based on a piezoelectric film 10. The thickness of the piezoelectric film 10 is less than 10 μm, making the linear micromotor stator structure as thin as less than 0.5 mm, achieving low voltage and high torque output, and meeting the requirements of thin and compact terminal applications.

[0068] The thickness of the elastic base 20 is less than 0.2 mm, the length of the elastic base 20 is less than 4 mm, the width of the elastic base 20 is 0.8 mm, and the diameter of the friction head 30 is 0.3 mm. This example is merely to illustrate the selection of dimensions based on the piezoelectric film 10 and the stator. In actual designs, the elastic base 20 and friction head 30 can be further adjusted based on the application.

[0069] The elastic substrate 20 can be made of materials such as single crystal silicon, stainless steel, copper alloy, and iron-nickel alloy.

[0070] like Figure 4As shown, the electrode partitions are designed based on the directional distribution of stress under modal vibration. For the B1 mode, the adjacent first electrode partition 101A, second electrode partition 101B, third electrode partition 101C, and fourth electrode partition 101D are applied with AC drive signals of 0°, 180°, 180°, and 0°, respectively. For the B2 mode, the adjacent first electrode partition 101A, second electrode partition 101B, third electrode partition 101C, and fourth electrode partition 101D are applied with AC drive signals of 0°, 180°, 0°, and 180°, respectively. The driving frequency of both the B1 and B2 modes is greater than 20 kHz, achieving ultrasonic silent drive. Figure 2 (a) shows the deformation of the linear micromotor stator structure in B1 mode. Figure 2 (b) shows the deformation of the linear micromotor stator structure in the B2 mode. Figure 3 The stress tensor of the linear micromotor stator structure under B1 mode and B2 mode is shown.

[0071] like Figure 5 As shown, when piezoelectric films 10 are connected to both sides of the elastic substrate 20, the drive phases of the four adjacent electrode sections on the upper side are opposite to the drive phases of the four adjacent electrode sections on the lower side. For the B1 mode, AC drive signals of 0°, 180°, 180°, and 0° are applied to the first electrode section 101A, the second electrode section 101B, the third electrode section 101C, and the fourth electrode section 101D on the upper side, respectively. AC drive signals of 180°, 0°, 0°, and 180° are applied to the first electrode section 101A, the second electrode section 101B, the third electrode section 101C, and the fourth electrode section 101D on the lower side, respectively. For the B2 mode, in the upper electrode partition, the first electrode partition 101A, the second electrode partition 101B, the third electrode partition 101C and the fourth electrode partition 101D apply AC drive signals of 0°, 180°, 0°, and 180°, respectively; in the lower electrode partition, the first electrode partition 101A, the second electrode partition 101B, the third electrode partition 101C and the fourth electrode partition 101D apply AC drive signals of 180°, 0°, 180°, and 0°, respectively.

[0072] In one structural form of a linear micromotor stator, an upper electrode 101 is provided on the side of the piezoelectric film 10 away from the elastic substrate 20, and a lower electrode 102 is provided on the side of the piezoelectric film 10 closer to the elastic substrate 20. The elastic substrate 20 includes a top silicon layer 201, a buried oxide layer, and a bottom silicon layer 202, with the top silicon layer 201 in contact with the bottom electrode 102. A friction head 30 is attached to the piezoelectric film 10 (structural form 1) or formed by etching the bottom silicon layer 202 of the elastic substrate 20 (structural form 2).

[0073] In another structural form of the linear micromotor stator, an upper electrode 101 is provided on the side of the piezoelectric film 10 away from the elastic substrate 20, and a lower electrode 102 is provided on the side of the piezoelectric film 10 close to the elastic substrate 20; a substrate structure 40 is bonded to the side of the elastic substrate 20 away from the piezoelectric film 10, and a friction head 30 is connected to the piezoelectric film 10 (as structural form three).

[0074] like Figure 6 As shown, the preparation method of the linear micromotor stator structure based on the first structural form includes the following steps:

[0075] S1: If Figure 6 As shown in (a), the piezoelectric film 10 is connected to the elastic substrate 20 to form a piezoelectric film-SOI structure;

[0076] S2: If Figure 6 As shown in (b), the upper electrode 101 is patterned by photolithography;

[0077] S3: If Figure 6 As shown in (c), the piezoelectric film 10 is then etched or corroded;

[0078] S4: As Figure 6 As shown in (c), the lower electrode 102 is etched;

[0079] S5: If Figure 6 As shown in (d), the top silicon 201 of the elastic substrate 20 is etched;

[0080] S6: As Figure 6 As shown in (e), the bottom silicon 202 of the elastic substrate 20 is etched to complete the release;

[0081] S7: As Figure 6 As shown in (f), the friction head 30 is welded or bonded to the upper electrode 101.

[0082] The friction head 30 can be made of materials or in shapes such as alumina gemstone, zirconium oxide, tin ball, copper core ball, copper column, etc.

[0083] like Figure 7 As shown, the preparation method of the linear micromotor stator structure based on the second structural form includes the following steps:

[0084] S1: If Figure 7 As shown in (a), the piezoelectric film 10 is connected to the elastic substrate 20 to form a piezoelectric film-SOI structure;

[0085] S2: If Figure 7 As shown in (b), the upper electrode 101 is patterned by photolithography;

[0086] S3: If Figure 7As shown in (c), the piezoelectric film 10 is then etched or corroded;

[0087] S4: As Figure 7 As shown in (c), the lower electrode 102 is etched;

[0088] S5: If Figure 7 As shown in (d), the top silicon 201 of the elastic substrate 20 is etched;

[0089] S6: As Figure 7 As shown in (e), a step is carved on the bottom silicon 202 of the elastic substrate 20, so that an area in the middle of the bottom silicon 202 is higher than the edge; the step height can be designed to be 20μm;

[0090] S7: As Figure 7 As shown in (f), the step portion of the bottom silicon 202 is etched to complete the release of the device, and the remaining portion forms the friction head 30.

[0091] At this time, the friction head 30 is formed by etching the bottom silicon 202 of the elastic substrate 20 .

[0092] like Figure 8 As shown, the preparation method of the linear micromotor stator structure based on the third structural form includes the following steps:

[0093] S1: If Figure 8 As shown in (a), the elastic substrate 20 is a metal substrate, and the lower electrode 102 is grown on a four-inch, six-inch or eight-inch metal substrate; the thickness of the metal substrate is tens to hundreds of microns;

[0094] S2: If Figure 8 As shown in (b), the piezoelectric film 10 is grown by magnetron sputtering or sol-gel method; the thickness of the piezoelectric film 10 is on the order of several microns;

[0095] S3: If Figure 8 As shown in (c), the upper electrode 101 is grown by photolithography;

[0096] S4: As Figure 8 As shown in (d), after cutting and shaping, the metal base is bonded to the substrate structure 40;

[0097] S5: If Figure 8 As shown in (e), the friction head 30 is bonded or welded to the upper electrode 101.

[0098] The method of growing the piezoelectric film 10 on both sides of the metal substrate or bonding two layers of piezoelectric films 10 on one side of the metal substrate back to back to form a piezoelectric film 10 on both sides of the metal substrate is similar to this process and will not be repeated here.

[0099] The preparation process flow provided by the present invention can prepare piezoelectric films 10 with a thickness of less than 10μm and an area greater than 100mm (four inches), and can meet the needs of batch preparation and realize low-cost batch production, especially the process of metal substrate, avoiding the use of multiple complex and expensive MEMS photolithography and etching processes.

[0100] like Figure 9 As shown, the micromotor includes a linear micromotor stator structure, a substrate 60, and a mover 70. The linear micromotor stator structure is attached to the substrate 60, and the mover 70 is closely attached to the side of the linear micromotor stator structure where the friction head 30 is located. The linear micromotor stator structure can be either rectangular or curved.

[0101] In order to ensure that the stator and the mover 70 are reliably attached to each other, an internal cavity is provided on the side of the linear micromotor stator structure facing the substrate 60. A magnet 50 is provided in the internal cavity, and the magnet 50 is attached to the substrate 60. The material of the mover 70 is a magnetic material or a portion of a magnetic material. The stator and the mover 70 are tightly attached together by the magnetic attraction between the magnet 50 and the mover 70, and the magnetic attraction provides a preload force. The magnet 50 is magnetized in the thickness direction. Similarly, the magnet 50 can be placed on the mover 70, and magnetic material can be attached to the inside of the stator to generate magnetic attraction. The principle is the same. The magnet 50 is placed in the internal cavity of the linear micromotor stator structure without increasing the thickness after integration.

[0102] like Figure 10 and Figure 11 As shown, the rotary micromotor structure includes an arc-shaped linear micromotor stator structure, a base 601, and a fixed housing 80 mounted on the base 601. The linear micromotor stator structure is mounted on the base 601, and the base 601 is provided with two anchor points 602 for securing the linear micromotor stator structure at both ends. A friction layer structure 701 is housed within the fixed housing. An axis structure 81 is embedded in the inner wall of the fixed housing 80 to limit the rotational displacement of the friction layer structure 701. The friction layer structure 701 is in close contact with the side of the linear micromotor stator structure where the friction head 30 is located. A ring magnet 702, magnetized in the thickness direction, is mounted on the friction layer structure 701. The ring magnet 702 consists of two semicircular rings. A magnetoresistive sensor 90 is also mounted on the base 601 to detect changes in the magnetic field caused by rotation.

[0103] The elastic base 20 of the linear micromotor stator structure can be a magnetic material, such as magnetic stainless steel, iron-nickel alloy, etc., which forms a magnetic attraction with the annular magnet 702. The magnetic attraction provides the preload necessary for friction drive. The annular magnet 702 is attached to the friction layer structure 701 to form a rotor. When the stator resonates and drives the rotor, the rotor is subjected to a tangential driving force. At the same time, under the limitation of the shaft structure 81, the rotor rotates. As the rotor rotates, the magnetic field changes, and the rotor's rotation angle information can be collected through the magnetoresistive sensor 90. The rotary micromotor structure based on the arc-shaped micromotor stator structure can be used for terminal applications such as aperture adjustment and prism anti-shake.

[0104] This invention utilizes SOI MEMS technology, fabricating the structure through a MEMS etching process. The friction head 30 is then welded or bonded to the device. Alternatively, the friction head 30 can be fabricated integrally by etching the bottom silicon 202 of the elastic substrate 20. The present invention utilizes a zoned electrode design to switch the power supply frequency and phase, enabling the excitation of different standing wave modes and achieving the purpose of switching the stator's motion direction. The present invention utilizes magnetic attraction to apply preload.

[0105] The present invention is not limited to the above-mentioned optional implementation modes. Anyone can derive other forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, any technical solution that falls within the scope defined by the claims of the present invention falls within the scope of protection of the present invention.

Claims

1. A linear micromotor stator structure, characterized by: The invention comprises an elastic substrate (20), at least one side of which is connected to a piezoelectric film (10); and a friction head (30) protruding from the surface, the friction head (30) being connected to the piezoelectric film (10) or the elastic substrate (20); the thickness of the piezoelectric film (10) is less than 10 μm.

2. The linear micromotor stator structure according to claim 1, wherein: The thickness of the elastic base (20) is less than 0.2 mm, and the length of the elastic base (20) is less than 4 mm.

3. The linear micromotor stator structure according to claim 1, wherein: The elastic base (20) is a rectangular parallelepiped or arc-shaped structure.

4. The linear micromotor stator structure according to claim 1, wherein: The piezoelectric film (10) is sequentially provided with a plurality of electrode partitions, and four adjacent electrode partitions sequentially apply AC driving signals of 0°, 180°, 180°, and 0°, or sequentially apply AC driving signals of 0°, 180°, 0°, and 180°.

5. The linear micromotor stator structure according to claim 4, wherein: When both sides of the elastic substrate (20) are connected to piezoelectric films (10), the driving phase of the four adjacent electrode partitions on the upper side is opposite to the driving phase of the four adjacent electrode partitions on the lower side.

6. The linear micromotor stator structure according to claim 1, wherein: The material of the elastic base (20) is one of single crystal silicon, stainless steel, copper alloy and iron-nickel alloy.

7. The linear micromotor stator structure according to claim 1, wherein: The material of the friction head (30) is one of aluminum oxide gemstone, zirconium oxide, tin ball, copper core ball and copper column.

8. The linear micromotor stator structure according to claim 1, wherein: An upper electrode (101) is provided on the side of the piezoelectric film (10) away from the elastic substrate (20), and a lower electrode (102) is provided on the side of the piezoelectric film (10) close to the elastic substrate (20); the elastic substrate (20) comprises a top silicon (201), a buried oxide layer and a bottom silicon (202) which are arranged in sequence, and the top silicon (201) is in contact with the lower electrode (102).

9. The linear micromotor stator structure according to claim 1, wherein: An upper electrode (101) is provided on the side of the piezoelectric film (10) away from the elastic substrate (20), and a lower electrode (102) is provided on the side of the piezoelectric film (10) close to the elastic substrate (20); and a substrate structure (40) is bonded to the side of the elastic substrate (20) away from the piezoelectric film (10).

10. A method for preparing a linear micromotor stator structure, for preparing the linear micromotor stator structure according to claim 8, characterized in that: The following steps are involved: S1: connecting the piezoelectric film (10) to the elastic substrate (20) to form a piezoelectric film-SOI structure; S2: patterning the upper electrode (101) by photolithography; S3: etching or corroding the piezoelectric film (10); S4: etching the lower electrode (102); S5: etching the top silicon (201) of the elastic substrate (20); S6: etching the bottom silicon (202) of the elastic substrate (20) to complete the release; S7: Welding or bonding the friction head (30) to the upper electrode (101).

11. A method for preparing a linear micromotor stator structure, for preparing the linear micromotor stator structure according to claim 8, characterized in that: The following steps are involved: S1: connecting the piezoelectric film (10) to the elastic substrate (20) to form a piezoelectric film-SOI structure; S2: patterning the upper electrode (101) by photolithography; S3: etching or corroding the piezoelectric film (10); S4: etching the lower electrode (102); S5: etching the top silicon (201) of the elastic substrate (20); S6: Carving steps on the bottom silicon (202) of the elastic substrate (20) so that a region in the middle of the bottom silicon (202) is higher than the edge; S7: etching the step portion of the bottom silicon (202), completing the release of the device, and forming the friction head (30).

12. A method for preparing a linear micromotor stator structure, for preparing the linear micromotor stator structure according to claim 9, characterized in that: The following steps are involved: S1: The elastic substrate (20) is a metal substrate, and a lower electrode (102) is grown on the metal substrate; S2: growing a piezoelectric film (10) by magnetron sputtering or sol-gel method; S3: growing the upper electrode (101) by photolithography; S4: After cutting and forming, the metal substrate is bonded to the substrate structure (40); S5: Bonding or welding the friction head (30) to the upper electrode (101).

13. A micromotor comprising the linear micromotor stator structure according to claim 1, characterized in that: It also includes a substrate (60) and a mover (70), wherein the linear micro-motor stator structure is attached to the substrate (60), and the mover (70) is closely attached to one side of the linear micro-motor stator structure where the friction head (30) is arranged.

14. The micro motor according to claim 13, characterized in that: An internal cavity is provided on the side of the linear micromotor stator structure facing the substrate (60), a magnet (50) is provided in the internal cavity, and the magnet (50) is attached to the substrate (60); the material of the mover (70) is a magnetic material or a part of a magnetic material.

15. A micromotor comprising the linear micromotor stator structure according to claim 3, characterized in that: The invention also includes a base (601) and a fixed housing (80) mounted on the base (601); a linear micro-motor stator structure is mounted on the base (601); a friction layer structure (701) is provided inside the fixed housing (80); an axis structure (81) for limiting the rotational displacement of the friction layer structure (701) is embedded on the inner wall of the fixed housing (80); the friction layer structure (701) is closely attached to a side of the linear micro-motor stator structure where a friction head (30) is provided; and an annular magnet (702) is mounted on the friction layer structure (701).

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