MEMS micromirror, optical apparatus, and terminal device

Abstract

A MEMS micromirror, an optical apparatus, and a terminal device. The MEMS micromirror comprises a galvanometer (31) and a structure layer. The structure layer carries the galvanometer (31). The structure layer comprises a motion structure. The motion structure controls the galvanometer (31) to move to process light. At least part of the motion structure is made of a material having a Mohs hardness of 9 or greater.

Description

A MEMS micromirror, optical device and terminal equipment

[0001] This application claims priority to Chinese Patent Application No. 202411759972.9, filed on November 29, 2024, entitled “A MEMS Micromirror, Optical Device and Terminal Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of galvanometer technology, and more particularly to a MEMS micromirror, optical device and terminal equipment. Background Technology

[0003] The vibration frequency of the galvanometer affects the imaging resolution. In related technologies, a lower galvanometer vibration frequency results in a lower scanning speed or lower imaging resolution. Summary of the Invention

[0004] This application provides a MEMS micromirror, optical device, and terminal equipment that can improve imaging resolution.

[0005] In a first aspect, this application provides a MEMS micromirror, the MEMS micromirror including a galvanometer and a structural layer, the structural layer supporting the galvanometer, the structural layer including a motion structure, the motion structure controlling the movement of the galvanometer to process light, and at least a portion of the material in the motion structure having a Mohs hardness greater than or equal to 9.

[0006] Optionally, the motion structure includes:

[0007] A first moving part, the first moving part being adapted to carry the galvanometer; and

[0008] A first cantilever, the first end of which is connected to the first moving part, the movement of the first cantilever to control the movement of the first moving part, and the Mohs hardness of the first cantilever being greater than or equal to 9.

[0009] Optionally, the material of the first cantilever includes one of alumina, silicon carbide, and tungsten carbide.

[0010] Optionally, the motion structure includes:

[0011] A second moving part, connected to the second end of the first cantilever, is provided with a magnetic component; and

[0012] The second cantilever has a first end connected to the second moving part, and the movement of the second cantilever controls the movement of the second moving part.

[0013] Optionally, the length of the second cantilever is longer than the length of the first cantilever.

[0014] Optionally, the material of the second cantilever is the same as that of the first cantilever.

[0015] Optionally, the surface roughness of the first cantilever is less than or equal to 50 nm, and / or the surface roughness of the second cantilever is less than or equal to 50 nm.

[0016] Optionally, the structural layer includes a base; the moving structure is disposed on the base.

[0017] Optionally, the magnetic component includes a drive circuit, and a conductive circuit is provided on the second cantilever, the conductive circuit being electrically connected to the drive circuit.

[0018] Optionally, along the thickness direction of the structural layer, the projection of the second moving part is a ring structure, the projection of the first moving part is located inside the ring structure, the second end of the first cantilever is connected to the inner periphery of the second moving part, and the first end of the second cantilever is connected to the outer periphery of the second moving part; the drive circuit is arranged around the periphery of the second moving part.

[0019] Optionally, the MEMS micromirror further includes:

[0020] A support layer is connected to the surface of the structural layer opposite to the galvanometer. The support layer is used to support and reinforce the structural layer and to prevent interference with the movement of the galvanometer.

[0021] Optionally, the support layer material is the same as the structural layer material, or the support layer material is different from the structural layer material, and the support layer is bonded to the structural layer.

[0022] Optionally, the material of the support layer includes one of silicon, alumina, and glass.

[0023] Optionally, the resistivity of the drive circuit is less than or equal to 2.5 × 10⁻⁸ Ω·m.

[0024] Optionally, the resistivity of the conductive line is less than or equal to 2.5 × 10⁻⁸ Ω·m, and / or the fatigue strength of the conductive line is greater than or equal to 120 MPa.

[0025] Optionally, the material of the conductive circuit includes one of Au, Ag, and AuNi.

[0026] Optionally, the MEMS micromirror further includes a second cantilever and a first sensor, wherein the first sensor is disposed on the first cantilever and / or the second cantilever.

[0027] Secondly, this application provides an optical device, the optical device comprising:

[0028] MEMS micromirrors as described above; and

[0029] The light source is fixed relative to the MEMS micromirror, with the light-emitting surface of the light source facing the galvanometer.

[0030] Thirdly, this application provides a terminal device, which includes the optical device provided in the second aspect of this application.

[0031] The MEMS micromirror described in this application includes a galvanometer and a structural layer. The galvanometer is mounted on the structural layer and can move under the control of a moving structure within the structural layer to process light. At least a portion of the material in the moving structure has a Mohs hardness greater than or equal to 9, which significantly increases the natural frequency of the moving structure during movement, thereby increasing the movement frequency of the galvanometer. This improves both the scanning speed and the imaging resolution of the MEMS micromirror.

[0032] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0033] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0034] Figure 1 is a schematic diagram of the first-view structure of a MEMS micromirror in some embodiments of this application;

[0035] Figure 2 is a schematic diagram of the structure of an optical device in some embodiments of this application;

[0036] Figure 3 is a schematic diagram of the second-view structure of the MEMS micromirror in some embodiments of this application;

[0037] Figure 4 is a schematic diagram of the third-view structure of the MEMS micromirror in some embodiments of this application;

[0038] Figure 5 is a schematic diagram of the drive circuit installed on the mounting structure in some embodiments of this application;

[0039] Figure 6 is a schematic diagram of the sensor mounted on the mounting structure in some embodiments of this application.

[0040] Reference numerals: 01-Light source; 1-Base; 11-Second center hole; 2-Second torsion member; 21-Second moving part; 22-Second cantilever; 3-First torsion member; 31-Galvanometer; 32-First moving part; 33-First cantilever; 4-First circuit; 41-First pad; 5-First sensor; 6-Second circuit; 61-Second pad; 7-Second sensor; 8-Third circuit; 81-Third pad; 9-Support layer; 10-Drive circuit; x-First direction; y-Second direction; z-Galvanometer orientation; d-Light ray; f-Target area. Detailed Implementation

[0041] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0043] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or at least two of the features. In the description of this application, unless otherwise stated, "at least two" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0044] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "left", "right", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] In the description of this application, the specific measurement steps for "Mohs hardness" are as follows:

[0047] 1) A pyramidal diamond needle was used as the reference because it has the highest hardness (10);

[0048] 2) The diamond needle is rubbed against the surface of the mineral being tested in sequence, i.e., scratching is performed;

[0049] 3) After each scratch, the depth of the scratch is used to determine the hardness level of the tested mineral. The Mohs hardness scale divides hardness into 10 levels, from 1 (softest, talc) to 10 (hardest, diamond);

[0050] 4) Based on the scratch pattern, assign the hardness of the tested mineral to the corresponding grade. For example, if a mineral can scratch calcite (hardness 3) but cannot scratch fluorite (hardness 4), then the Mohs hardness of that mineral is between 3 and 4.

[0051] This application provides a terminal device. Exemplarily, the terminal device may be a vehicle, a drone, a space satellite, etc. For ease of understanding, the terminal device of this application will be described in detail below in conjunction with a vehicle, but this does not mean that the terminal device in this application is limited to vehicles. In this application embodiment, the vehicle can be of various types; exemplary, it may be a sedan, an off-road vehicle, or a sport utility vehicle (SUV), etc.

[0052] Referring to Figures 1 and 2, the vehicle in this embodiment includes an optical device, which comprises a light source 01 and a MEMS (Micro-Electro-Mechanical System) micromirror. The light-emitting surface of the light source 01 can face the galvanometer 31 of the MEMS micromirror to emit light d to the MEMS micromirror. The galvanometer 31 of the MEMS micromirror can vibrate relative to the light source 01 to change the propagation path of the light d, enabling the light d to scan the target structure or form an image within the target area f. The optical device in this embodiment can be of various types, such as a head-up display (HUD), lidar, intelligent headlight system, transparent A-pillar, vehicle holographic imaging system, etc. For example, in some embodiments of this application, the optical device is a lidar, the light source 01 is used to emit a laser to the MEMS micromirror, and the MEMS micromirror is used to change the propagation path of the laser so that the laser scans the target structure to collect information about the target structure; in some embodiments of this application, the optical device is a head-up display system, the light source 01 is used to emit a projection light d to the MEMS micromirror, the projection light d can be a red, green and blue laser, and the parameters of different colors of laser, such as brightness, can be controlled individually, the MEMS micromirror is used to change the propagation path of the projection light d so that the projection light d forms an image on the windshield.

[0053] Please refer to Figures 1 and 2. Of course, in some embodiments of this application, the optical device provided in this application embodiment can also be used in other fields such as laser welding. The light source 01 is used to emit laser to the MEMS micromirror, and the MEMS micromirror is used to change the propagation path of the laser so that the laser scans the welding area to perform welding.

[0054] Referring to Figures 1 and 2, the MEMS micromirror in this embodiment includes a galvanometer 31 and a structural layer. In this embodiment, the structural layer specifically includes a base 1 and a motion structure. The base 1 and the motion structure can be an integrated structure processed by etching or other methods, or they can be a combined structure fixed together by bonding or other methods. The base 1 provides a mounting foundation for the motion structure and ensures that the motion structure can move relative to the base 1. The galvanometer 31 is specifically a lens capable of reflecting light. For a galvanometer 31 capable of reflecting light, it typically has a reflective surface. The reflective surface can generally be a coating or plating structure capable of reflecting light. The galvanometer 31 is mounted on the motion structure of the structural layer and can move under the control of the motion structure to process light. At least a portion of the material in the motion structure has a Mohs hardness greater than or equal to 9, which greatly increases the natural frequency of the motion structure during movement, thereby increasing the motion frequency of the galvanometer.

[0055] Referring to Figures 1 and 2, in some embodiments of this application, the motion structure specifically includes a first motion part 32 and a first cantilever 33. The first motion part 32 is structurally adapted to the galvanometer 31 for supporting and mounting the galvanometer 31. The first end of the first cantilever 33 is fixedly connected to the first motion part 32. When the first cantilever 33 twists, the first motion part 32 rotates with the twist of the first cantilever 33, controlling the galvanometer 31 to move accordingly. Based on this, the Mohs hardness of the first cantilever 33 can be made greater than or equal to 9 to increase the natural frequency of the motion structure. For ease of reference, in the embodiments of this application, the galvanometer 31, the first motion part 32, and the first cantilever 33 are collectively referred to as the first torsion member 3.

[0056] Referring to Figures 1 and 2, in some embodiments of this application, the material of the first cantilever 33 in the first torsion member 3 includes one of the following: alumina, silicon carbide, and tungsten carbide. With this structural form, the first cantilever 33 has high hardness, low mass, and high strength, which can better meet the requirements for high-frequency resonance. Moreover, the above-mentioned materials also have high thermal conductivity and chemical stability, making them less prone to thermal damage, which is beneficial to improving the reliability of the first cantilever 33. For example, silicon carbide has a Mohs hardness of 9.25 and a thermal conductivity of 3.3–4.9 W·cm⁻¹·K⁻¹, making silicon carbide the material of the first cantilever 33 is beneficial to improving the temperature resistance, chemical stability, and imaging resolution of the MEMS micromirror device.

[0057] Referring to Figures 1 and 2, in some embodiments of this application, the motion structure further includes a second motion part 21 and a second cantilever 22. The second motion part 21 is connected to the second end of the first cantilever 33, and the first end of the second cantilever 22 is connected to the second motion part 21. When the second motion part 21 rotates, the second cantilever 22 undergoes adaptive torsion. A magnetic element is provided on the second motion part 21 to drive its movement. For ease of reference, in this embodiment, the second motion part 21 and the second cantilever 22 are collectively referred to as the second torsion member 2. Preferably, the length of the second cantilever 22 is longer than the length of the first cantilever 33, and the material of the second cantilever 22 is the same as that of the first cantilever 33.

[0058] Referring to Figures 1 and 2, in some embodiments of this application, the surface roughness of the second cantilever 22 of the second torsion member 2 along the first direction x is less than or equal to 50 nanometers. This is beneficial for improving the fatigue strength of the second torsion member 2. In some embodiments of this application, the surface roughness of the first cantilever 33 of the first torsion member 3 along the second direction y is less than or equal to 50 nanometers. This is beneficial for improving the fatigue strength of the first torsion member 3.

[0059] Referring to Figures 1 and 2, in some embodiments of this application, the structural layer further includes a base 1. The base 1 is specifically an annular structure. Along the first direction x, both ends of the second torsion member 2 are fixedly connected to the base 1, and the middle portion includes a second moving part 21. In other words, both ends of the second moving part 21 along the x direction are connected to the base 1 via second cantilever 22, and the extension direction of the second cantilever 22 extends along the x direction. Along the second direction y, both ends of the first torsion member 3 are fixedly connected to the second moving part 21, and the middle portion includes a mirror surface 31; in other words, both ends of the first moving part 32 along the y direction are connected to the second moving part 21 via first cantilever 33, and the extension direction of the first cantilever 33 extends along the y direction. The second direction y intersects the first direction x. A magnetic element is fixed to the second moving part 21 to drive the second moving part 21 to reciprocate relative to the base 1, and the axis of rotation is parallel to the first direction x, thereby driving the first moving part 32 to reciprocate relative to the second moving part 21, and the axis of rotation is parallel to the second direction y. In this way, the magnetic component is fixed to the second moving part 21, causing the second moving part 21 to twist relative to the base 1. During the twisting process of the second moving part 21 relative to the base 1, it can cause the first moving part 32 to resonate, causing the first moving part 32 to twist as well. The Mohs hardness of the first cantilever 33 of the first torsion member 3 is greater than or equal to 9, which results in a larger natural frequency of the first moving part 32. Consequently, the reciprocating torsion frequency of the first moving part 32 caused by resonance is also larger. A larger reciprocating torsion frequency of the first moving part 32 can improve the imaging resolution. Moreover, it is understood that when the optical device in the embodiment of this application is a lidar, a larger reciprocating torsion frequency of the first moving part 32 can also improve the scanning speed of the laser, thereby improving the accuracy of the lidar's information acquisition.

[0060] In addition, the second motion unit 21 is driven by a magnetic component to perform a torsional motion relative to the base 1. The driving force generated by the magnetic component is relatively large, which can drive the second motion unit 21 to perform a large-amplitude motion relative to the base 1. Even when the first cantilever 33 has a high Mohs hardness, the second motion unit 21 can also drive the first motion unit 32 to vibrate a large amplitude, thus meeting the requirements for scanning and imaging.

[0061] Referring to Figures 1 and 2, it should be explained that in the embodiments of this application, during the reciprocating torsion of the second torsion member 2 relative to the base 1 and during the reciprocating torsion of the first torsion member 3 relative to the second moving part 21, the relative position of the galvanometer 31 and the light source 01 changes, which changes the optical path of the light d emitted by the light source 01 onto the galvanometer 31, thereby enabling the light d to image or scan the target structure.

[0062] Please refer to Figures 1 and 2. It should be explained that in this embodiment, the magnetic component drives the second moving part 21 to move under the action of an external magnetic field, causing the second moving part 21 to reciprocate and twist relative to the base 1. During the reciprocating and twisting process of the second moving part 21 relative to the base 1, it drives the first moving part 32 to resonate, thereby causing the first moving part 32 to twist relative to the second moving part 21.

[0063] Referring to Figures 1 and 2, in some embodiments of this application, the light source 01 is fixed relative to the base 1. This makes the setting of the light source 01 more convenient.

[0064] Referring to Figures 1 and 2, in some embodiments of this application, the material of the galvanometer 31 includes at least one of silver and aluminum. Silver and aluminum have high reflectivity to light d, which is beneficial for improving imaging quality and scanning accuracy.

[0065] Referring to Figures 1 and 2, in some embodiments of this application, both the first direction x and the second direction y are parallel to the galvanometer 31. This allows the second moving part 21 and the first moving part 32 to drive the galvanometer 31 to rotate relative to the base 1 at a larger angle, which is beneficial for increasing the imaging area and the scanning area.

[0066] Referring to Figures 1 and 2, in some embodiments of this application, the second direction y is perpendicular to the first direction x. This is beneficial for increasing the scanning or projection area of ​​the light ray d.

[0067] Referring to Figures 1 and 2, in some embodiments of this application, along the second direction y, the torsional axis of the second moving part 21 relative to the base 1 is located at the middle of the galvanometer 31. This reduces the space occupied by the galvanometer 31 during the movement of the second moving part 21 relative to the base 1, thus improving the structural compactness. In some embodiments of this application, along the first direction x, the torsional axis of the first moving part 32 relative to the second moving part 21 is located at the middle of the galvanometer 31. This also reduces the space occupied by the galvanometer 31 during the movement of the first moving part 32 relative to the second moving part 21, further improving the structural compactness.

[0068] Referring to Figures 1 and 2, in some embodiments of this application, the second torsion member 2 includes two second cantilever arms 22 and a second moving part 21. The two second cantilever arms 22 extend in the same direction, and their arrangement direction is the same as their extension direction. The ends of the two second cantilever arms 22 that are far apart from each other are fixedly connected to the base 1, and their ends that are close to each other are fixedly connected to both ends of the second moving part 21, that is, the first end of the second cantilever arm 22 is connected to the outer periphery of the second moving part 21. Here, the two ends of the second moving part 21 refer to the two ends of the second moving part 21 in the extension direction of the second cantilever arm 22. The second moving part 21 has a ring structure, that is, the projection of the second moving part 21 along the thickness direction of the structural layer is a ring structure. The through direction of the first central hole formed by the ring structure is perpendicular to the extension direction of the second cantilever arm 22. It can be understood that the extension direction of the second cantilever arm 22 is the extension direction of the torsion axis of the second moving part 21 relative to the base 1. The first torsion member 3 is disposed within the first central hole. The first torsion member 3 includes two first cantilever arms 33, a first moving part 32, and a galvanometer 31. The two first cantilever arms 33 extend in the same direction, and their arrangement direction is the same as their extension direction. The ends of the two first cantilever arms 33 that are far apart from each other are fixedly connected to the second moving part 21, while their ends that are close together are fixedly connected to both ends of the first moving part 32. That is, the projection of the first moving part 32 is located inside the annular structure. The second end of the first cantilever arm 33 is connected to the inner circumference of the second moving part 21. Specifically, the first cantilever arm 33 is a beam-shaped structure fixedly connected between the inner circumference of the second moving part 21 and the outer circumference of the first moving part 32, and is suspended within the first central hole. The two ends of the first moving part 32 refer to the two ends of the first moving part 32 in the extension direction of the first cantilever arm 33. The galvanometer 31 is disposed on the first moving part 32. It can be understood that the extension direction of the first cantilever arm 33 is the extension direction of the torsion axis of the first moving part 32 relative to the base 1. This helps to improve the stability of the first torsion member 3 within the second moving part 21, which has a ring-shaped structure. The two ends of the second moving part 21 are connected to the base 1 through two second cantilever arms 22, making the installation of the second torsion member 2 and the first torsion member 3 on the base 1 more stable.

[0069] Referring to Figures 1 and 2, in some embodiments of this application, at least one of the second cantilever 22 and the first cantilever 33 may have a rectangular cross-section. This facilitates manufacturing. In some embodiments of this application, at least one of the second cantilever 22 and the first cantilever 33 may have a circular cross-section, which helps reduce stress concentration and improves stress distribution.

[0070] Referring to Figures 1 and 2, in some embodiments of this application, the base 1 has an annular structure, and the second torsion member 2 is disposed within the second central hole 11 enclosed by the base 1. The through direction of the second central hole 11 is perpendicular to the extension direction of the second torsion member 2. The second cantilever 22 is specifically a beam-shaped structure fixedly connected between the inner circumferential surface of the base 1 and the outer circumferential surface of the second moving part 21, and is suspended within the second central hole 11. This structure is relatively simple and helps to improve the stability of the second torsion member 2 installed on the base 1. In some embodiments of this application, the through direction of the second central hole 11 enclosed by the base 1 is the same as that of the first central hole enclosed by the second moving part 21.

[0071] Referring to Figures 2, 3, and 4, in some embodiments of this application, the MEMS micromirror further includes a support layer 9. The support layer 9 has a ring structure, and its extension path matches that of the base 1. Along the through direction of the second central hole 11, the support layer 9 and the galvanometer 31 are located on opposite sides of the base 1, with the support layer 9 and the sides of the base 1 close to each other. In this way, the support layer 9 can strengthen the base 1, which is beneficial to improving the strength of the base 1. In some embodiments of this application, the end face of the support layer 9 away from the galvanometer 31 is used to fix it to an external device. In this way, along the through direction of the second central hole 11, the support layer 9 supports the second torsion member 2 and the first torsion member 3 from the external device, so that the second torsion member 2 and the first torsion member 3 have a distance from the external device, making it less likely for the galvanometer 31 to interfere with the external device during the torsion of the second torsion member 2 and the first torsion member 3.

[0072] Please refer to Figures 2, 3 and 4. In some embodiments of this application, the support layer 9 may be made of the same material as the base 1, or it may be made of a different material than the base 1. The support layer 9 is chemically bonded to the base 1. For example, the material of the support layer 9 may include one of silicon, alumina and glass.

[0073] Referring to Figures 1 and 2, in some embodiments of this application, the second torsion member 2 is integrally formed with the first cantilever 33 and the first moving part 32 of the first torsion member 3. This structural form makes the processing and manufacturing of the second torsion member 2 and the first cantilever 33 and the first moving part 32 of the first torsion member 3 more convenient.

[0074] Referring to Figures 1 and 2, in some embodiments of this application, the second torsion member 2 is made of the same material as the first cantilever 33 and the first moving part 32 of the first torsion member 3. This makes the processing and manufacturing of the second torsion member 2 and the first torsion member 3 more convenient.

[0075] Referring to Figures 2 and 5, in some embodiments of this application, the magnetic component is a drive circuit 10. The drive circuit 10 is arranged around the periphery of the aforementioned second moving part 21, that is, along the thickness direction of the structural layer, the drive circuit 10 also has a ring structure, and the ring structure is arranged around the first central hole on the aforementioned second moving part 21.

[0076] MEMS micromirrors also include conductive circuitry. Specifically, the conductive circuitry includes a first circuit 4, which is integrated onto the base 1. The first end of the first circuit 4 is connected to the drive circuit 10, and the fatigue strength of the material of the first circuit 4 is greater than or equal to 120 MPa. The drive circuit 10 and the first circuit 4 form a circuit layer. With this structure, the first circuit 4, integrated onto the base 1, allows for convenient and stable connection to an external device via its second end. The first end of the first circuit 4 is fixedly connected to the drive circuit, which is fixed to the second moving part 21, specifically to the middle of the second torsion member 2. In other words, the first end of the first circuit 4 is fixedly connected to the middle of the second torsion member 2. During operation, the second torsion member 2 torsional relative to the base 1. During this torsion process, the first circuit 4 undergoes repeated deformation, requiring high fatigue strength. By ensuring that the fatigue strength of the material of the first circuit 4 is greater than or equal to 120 MPa, the fatigue strength of the first circuit 4 is high, effectively meeting the fatigue strength requirements and resulting in high reliability.

[0077] Referring to Figures 2 and 5, in this embodiment, the first line 4 is used to electrically connect the drive line 10 to an external device. For example, it can be used to electrically connect the drive line 10 to a power supply or controller. The power supply provides power to the drive line 10, causing it to generate a magnetic field. The controller can be used to control the current frequency within the drive line 10, thereby controlling the frequency of the magnetic field generated by the drive line 10, and consequently controlling the vibration frequency of the galvanometer 31. Table 1 shows the simulation results of a MEMS micromirror based on silicon carbide material under a test environment of 200mA and 1.4T. These results include the resonant frequency (or harmonic frequency) of the first cantilever 33 (i.e., the fast axis) and the maximum stress experienced when twisted by 12.5 degrees; and the resonant frequency, deflection angle, and maximum stress experienced when twisted by 6.5 degrees of the second cantilever 22 (i.e., the slow axis).

[0078] Table 1 Simulation results of MEMS micromirrors based on silicon carbide materials.

[0079] As shown in Table 1, in the three simulation results of the MEMS micromirror based on silicon carbide, the resonant frequencies of the galvanometer 31 reached 63.187 kHz, 54.715 kHz, and 50.337 kHz, respectively. In other words, the MEMS micromirror based on silicon carbide can guarantee that the resonant frequency of the galvanometer 31 is at least greater than 50 kHz. This is beneficial to improving the resolution of the MEMS micromirror; specifically, the resolution of the MEMS micromirror is expected to reach 1080P. Currently, the resonant frequencies of existing silicon-based MEMS micromirrors are basically around 27 kHz, and their resolution is only 720P.

[0080] Referring to Figures 2 and 5, in some embodiments of this application, the drive circuit 10 includes a coil. The resistivity of the coil material is less than or equal to 2.5 × 10⁻⁸ Ω·m. This helps reduce the heat generated by the coil, making the MEMS micromirror less susceptible to overheating damage and improving its reliability. In some embodiments of this application, the coil material may include at least one of copper and silver.

[0081] Referring to Figures 2 and 5, in some embodiments of this application, the resistivity of the material of the first circuit 4 is less than or equal to 2.5 × 10⁻⁸ Ω·m. This helps to reduce the heat generated by the first circuit, and the first circuit, the second torsion member 2, and the first torsion member 3 are less likely to be damaged by overheating, which helps to improve the reliability of the MEMS micromirror.

[0082] Referring to Figures 2 and 5, in some embodiments of this application, the material of the first circuit 4 includes one of the following: silver (Ag), gold (Au), and a gold-nickel alloy (AuNi) such as gold-plated nickel. This results in higher fatigue strength for the first circuit 4, better meeting its fatigue strength requirements. Furthermore, the lower resistance of the first circuit 4 helps reduce the heat generated by the first circuit, making the first circuit, second torsion member 2, and first torsion member 3 less prone to overheating damage, thus improving the reliability of the MEMS micromirror.

[0083] Referring to Figures 2 and 5, in some embodiments of this application, a first pad 41 is further included. The second end of the first line 4 is connected to the first pad 41, and the first pad 41 is fixedly connected to the base 1. External devices can be connected to the first line 4 by soldering to the first pad 41. In this way, the connection between the external device and the first line 4 is more convenient and reliable.

[0084] Referring to Figures 2 and 5, in some embodiments of this application, the first line 4 includes a first extension segment. The extension path of the first extension segment matches the extension path of the second cantilever 22. The first extension segment is fixedly connected to the second cantilever 22. One end of the first extension segment is located at the second moving part 21, and the other end is located at the base 1. In this way, by mounting the first extension segment on the second cantilever 22, the installation of the first line 4 is more stable and has higher reliability.

[0085] Referring to Figures 2 and 5, in some embodiments of this application, there are two first lines 4. The two first lines 4 are respectively connected to the positive and negative terminals of the power supply, and the first extensions of the two first lines 4 can be respectively mounted on the two second cantilever arms 22. In this way, the two first lines 4 are less likely to interfere with each other, and the processing and manufacturing are more convenient.

[0086] Referring to Figures 2, 5, and 6, in some embodiments of this application, the MEMS micromirror further includes a first sensor 5 and a second circuit 6. The first sensor 5 is fixed to at least one of the second torsion member 2 and the first torsion member 3. The second circuit 6 is integrated on the base 1, and the first end of the second circuit 6 is connected to the first sensor 5. The fatigue strength of the material of the second circuit 6 is greater than or equal to 120 MPa. This structural form allows the second circuit 6 to be conveniently and securely connected to an external device through its second end. The first end of the second circuit 6 is fixedly connected to the first sensor 5, and the first sensor 5 is fixed to at least one of the second torsion member 2 and the first torsion member 3. That is, during the operation of the MEMS micromirror, the second circuit 6 undergoes repeated deformation, requiring high fatigue strength. By ensuring that the fatigue strength of the material of the second circuit 6 is greater than or equal to 120 MPa, the high fatigue strength of the second circuit 6 can better meet the fatigue strength requirements of the second circuit 6, resulting in high reliability of the second circuit 6.

[0087] Referring to Figures 2, 5, and 6, in this embodiment of the application, the second line 6 is used to electrically connect the first sensor 5 to an external device. For example, it can be used to electrically connect the first sensor 5 to a power supply or a receiver, etc. The power supply is used to power the first sensor 5, and the receiver can be used to receive the output information of the first sensor 5.

[0088] Referring to Figures 2, 5, and 6, in some embodiments of this application, the first sensor 5 includes a first force sensor, which is disposed at the end of the first torsion member 3 in the second direction y, for detecting the torque of the end of the first torsion member 3 in the second direction y relative to the second moving part 21. Thus, by using the output information of the first force sensor, the attitude of the first torsion member 3 relative to the second moving part 21 can be confirmed, and the movement of the second torsion member relative to the second moving part 21 can be controlled by the attitude of the first torsion member 3 relative to the second moving part 21, forming a closed-loop control, which is relatively convenient.

[0089] Referring to Figures 2, 5, and 6, in some embodiments of this application, the first force sensor can be a piezoresistive strip or a piezoelectric film, etc. This makes processing and manufacturing more convenient.

[0090] Referring to Figures 2, 5, and 6, in some embodiments of this application, the first sensor 5 includes a first temperature sensor disposed at the end of the first torsion member 3 in the second direction y, for detecting the temperature of the end of the first torsion member 3 in the second direction y. Thus, by using the output information of the first temperature sensor, the temperature of the end of the first torsion member 3 in the second direction y can be confirmed, and the movement of the first torsion member 3 relative to the second moving part 21 can be controlled by controlling the temperature of the end of the first torsion member 3 in the second direction y, which helps to reduce the occurrence of thermal damage. For example, if the detected temperature is too high, the torsion frequency of the first torsion member 3 relative to the second moving part 21 can be reduced to lower the temperature and reduce the occurrence of thermal damage; if the detected temperature is slightly lower, the torsion frequency of the first torsion member 3 relative to the second moving part 21 can be appropriately increased to improve the imaging resolution.

[0091] Referring to Figures 2, 5, and 6, in some embodiments of this application, the resistivity of the material of the second circuit 6 is less than or equal to 2.5 × 10⁻⁸ Ω·m. This helps to reduce the heat generated by the second circuit, and the second circuit, the second torsion member 2, and the first torsion member 3 are less prone to overheating damage, which is beneficial to improving the reliability of the MEMS micromirror.

[0092] Referring to Figures 2, 5, and 6, in some embodiments of this application, the material of the second circuit 6 includes at least one of the following: silver (Ag), gold (Au), and a gold-nickel alloy (AuNi) such as gold-plated nickel. This results in higher fatigue strength for the second circuit 6, better meeting its fatigue strength requirements. Furthermore, the lower resistance helps reduce the heat generated by the second circuit, making the second circuit, the second torsion member 2, and the first torsion member 3 less prone to overheating damage, thus improving the reliability of the MEMS micromirror.

[0093] Referring to Figures 2, 5, and 6, in some embodiments of this application, a second pad 61 is further included. The second end of the second line 6 is fixedly connected to the second pad 61, and the second pad 61 is fixedly connected to the base 1. External devices can be connected to the second line 6 by soldering to the second pad 61. In this way, the connection between the external device and the second line 6 is more convenient and reliable.

[0094] Referring to Figures 2, 5, and 6, in some embodiments of this application, the second line 6 includes a second extension segment. The extension path of the second extension segment matches the extension path of the second cantilever 22. The second extension segment is fixedly connected to the second cantilever 22, with one end located at the second moving part 21 and the other end located at the base 1. Thus, by mounting the second extension segment on the second cantilever 22, the installation of the second line 6 is more stable and reliable.

[0095] Referring to Figures 2, 5, and 6, in some embodiments of this application, both the first extension segment and the second extension segment are fixed to the second cantilever 22. The first and second extension segments are arranged along the through direction of the first central hole, and an insulating layer is provided between the first and second extension segments. The material of the insulating layer may include at least one of silicon dioxide and silicon nitride. In this way, both the first and second extension segments can be supported by the second cantilever 22 and are mutually insulated, making it less likely for them to interfere with each other, and the installation of the first and second extension segments is relatively stable. In the embodiments of this application, the orientation z of the galvanometer 31 can point from the first extension segment to the second extension segment, or it can point from the second extension segment to the first extension segment; this application does not limit this.

[0096] Referring to Figures 2, 5, and 6, in some embodiments of this application, the first central hole is oriented in a specific direction, with the first line 4 and the drive line 10 located on one side of the insulating layer, and the second line 6 and the first sensor 5 located on the other side of the insulating layer. This design minimizes the mutual interference between the first line 4 and the second line 6 and facilitates their arrangement.

[0097] Referring to Figures 2, 5, and 6, in some embodiments of this application, the MEMS micromirror further includes a second sensor 7 and a third circuit 8. The third circuit 8 is integrated on the base 1, and its first end is connected to the second sensor 7. The second sensor includes a second force sensor, which is disposed at the end of the second torsion member 2 in the first direction x, for detecting the torque of the end of the second torsion member 2 in the first direction x relative to the base 1. In this way, the attitude of the second torsion member 2 relative to the base 1 can be confirmed by the output information of the second force sensor, and the movement of the first torsion member relative to the base 1 can be controlled by the attitude of the second torsion member 2 relative to the base 1, thus forming a closed-loop control, which is relatively convenient.

[0098] Referring to Figures 2, 5, and 6, in some embodiments of this application, the third line 8 has a third pad 81, which is fixedly connected to the second end of the third line 8 and to the base 1. External devices can be connected to the third line 8 by soldering to the third pad 81. In this way, the connection between the external device and the third line 8 is more convenient and reliable.

[0099] Referring to Figures 2, 5, and 6, in this embodiment of the application, the third line 8 is used to electrically connect the second sensor 7 to an external device. For example, it can be used to electrically connect the second sensor 7 to a power supply or a receiver, etc. The power supply is used to power the second sensor 7, and the receiver can be used to receive the output information of the second sensor 7.

[0100] Referring to Figures 2, 5, and 6, in some embodiments of this application, the first central hole is oriented in a specific direction, with the first line 4 and the drive line 10 located on one side of the insulating layer, and the second sensor 7 and the third line 8 located on the other side of the insulating layer. This design minimizes the mutual interference between the first line 4 and the third line 8 and facilitates their arrangement.

[0101] Referring to Figures 2, 5, and 6, in some embodiments of this application, the second force sensor can be a piezoresistive strip or a piezoelectric film, etc. This makes processing and manufacturing more convenient.

[0102] Referring to Figures 2, 5, and 6, in some embodiments of this application, the second sensor 7 includes a second temperature sensor disposed at the end of the second torsion member 2 in the first direction x, for detecting the temperature of the end of the second torsion member 2 in the first direction x. Thus, by using the output information of the second temperature sensor, the temperature of the end of the second torsion member 2 in the first direction x can be confirmed, and the movement of the second torsion member 2 relative to the base 1 can be controlled by controlling the temperature of the end of the second torsion member 2 in the first direction x, which helps to reduce the occurrence of thermal damage.

[0103] Referring to Figures 2, 5, and 6, in some embodiments of this application, the resistivity of the material of the second circuit 6 is less than or equal to 2.5 × 10⁻⁸ Ω·m. This helps reduce the heat generated by the second circuit 6, making the MEMS micromirror less prone to overheating damage and improving its reliability. In some embodiments of this application, the material of the second circuit 6 may include at least one of copper and silver.

[0104] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or at least two embodiments or examples.

[0105] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A MEMS micromirror, characterized in that, The MEMS micromirror includes: galvanometer (31), and A structural layer that supports the galvanometer (31), the structural layer including a motion structure that controls the movement of the galvanometer to process light, wherein at least a portion of the material in the motion structure has a Mohs hardness greater than or equal to 9.

2. The MEMS micromirror according to claim 1, characterized in that, The motion structure includes: The first moving part (32) is adapted to carry the galvanometer (31); and A first cantilever (33) has a first end connected to the first moving part (32), and the first cantilever (33) moves to control the movement of the first moving part (32). The first cantilever (33) has a Mohs hardness greater than or equal to 9.

3. The MEMS micromirror according to claim 2, characterized in that, The material of the first cantilever (33) includes one of alumina, silicon carbide and tungsten carbide.

4. The MEMS micromirror according to claim 2 or 3, characterized in that, The motion structure includes: The second moving part (21) is connected to the second end of the first cantilever (33), and the second moving part (21) is provided with a magnetic element; and The second cantilever (22) has its first end connected to the second moving part (21), and the second cantilever (22) moves to control the movement of the second moving part (21).

5. The MEMS micromirror according to claim 4, characterized in that, The length of the second cantilever (22) is longer than the length of the first cantilever (33).

6. The MEMS micromirror according to claim 4, characterized in that, The material of the second cantilever (22) is the same as that of the first cantilever (33).

7. The MEMS micromirror according to claim 4, characterized in that, The surface roughness of the first cantilever (33) is less than or equal to 50 nm, and / or the surface roughness of the second cantilever (22) is less than or equal to 50 nm.

8. The MEMS micromirror according to any one of claims 1 to 7, characterized in that, The structural layer includes a base (1); the moving structure is disposed on the base (1).

9. The MEMS micromirror according to any one of claims 4 to 7, characterized in that, The magnetic component includes a drive circuit (10), and a conductive circuit is provided on the second cantilever (22), the conductive circuit being electrically connected to the drive circuit (10).

10. The MEMS micromirror according to claim 9, characterized in that, Along the thickness direction of the structural layer, the projection of the second moving part (21) is a ring structure, the projection of the first moving part (32) is located inside the ring structure, the second end of the first cantilever (33) is connected to the inner periphery of the second moving part (21), the first end of the second cantilever (22) is connected to the outer periphery of the second moving part (21), and the drive line is arranged along the periphery of the second moving part.

11. The MEMS micromirror according to any one of claims 1 to 7, characterized in that, The MEMS micromirror also includes: A support layer (9) is connected to the surface of the structural layer opposite to the galvanometer (31). The support layer (9) is used to support and strengthen the structural layer and prevent the movement of the galvanometer (31) from being interfered with.

12. The MEMS micromirror according to claim 11, characterized in that, The material of the support layer (9) is the same as that of the structural layer, or the material of the support layer (9) is different from that of the structural layer, and the support layer (9) is bonded to the structural layer.

13. The MEMS micromirror according to claim 11, characterized in that, The material of the support layer (9) includes one of silicon, alumina, and glass.

14. The MEMS micromirror according to claim 9, characterized in that, The resistivity of the drive circuit (10) is less than or equal to 2.5 × 10⁻⁸ Ω·m.

15. The MEMS micromirror according to claim 9, characterized in that, The resistivity of the conductive line is less than or equal to 2.5 × 10⁻⁸ Ω·m, and / or the fatigue strength of the conductive line is greater than or equal to 120 MPa.

16. The MEMS micromirror according to claim 9, characterized in that, The material of the conductive circuit includes one of Au, Ag, and AuNi.

17. The MEMS micromirror according to any one of claims 2-4, characterized in that, The MEMS micromirror also includes a second cantilever (22) and a first sensor (5), wherein the first sensor (5) is disposed on the first cantilever (33) and / or the second cantilever (22).

18. An optical device, characterized in that, include: MEMS micromirrors as described in any one of claims 1-17; and The light source (01) is fixed relative to the MEMS micromirror, and the light-emitting surface of the light source (01) faces the galvanometer (31).

19. A terminal device, characterized in that, Includes the optical device as described in claim 18.

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