A MEMS mirror package structure based on magnetic damping effect and a laser steering device

Abstract

The application provides a MEMS scanner package structure based on magnetic damping effect and a laser steering device, comprising: a magnetic shell, an installation cavity for installing a MEMS scanner mirror assembly and a MEMS scanner actuator assembly arranged in the magnetic shell; the magnetic shell comprises an upper magnet for enclosing a shell, a lower magnetic conductor, an upper magnetic conductor arranged at a joint of the upper magnet and the lower magnetic conductor and extending into the installation cavity to separate the MEMS scanner mirror assembly and the MEMS scanner actuator assembly, and a lower magnet arranged at the bottom of the installation cavity and below the MEMS scanner actuator assembly; the upper magnet, the upper magnetic conductor, the lower magnet and the lower magnetic conductor form a stable magnetic field in the installation cavity. The application fills the MEMS scanner with the magnetic shell to generate a stable endogenous magnetic field, suppresses impact vibration and improves the mechanical reliability of the MEMS scanner device.

Description

Technical Field

[0001] This application belongs to the field of optical galvanometer technology, and particularly relates to a MEMS galvanometer packaging structure and laser steering device based on magnetic damping effect. Background Technology

[0002] MEMS galvanometers are miniature optical devices based on microelectromechanical systems. They achieve high-precision beam control through electromagnetic or electrostatic actuation and have been widely used in fields such as lidar, industrial manufacturing, and automotive displays.

[0003] MEMS galvanometers are precision electronic devices manufactured using semiconductor processes based on single-crystal silicon. Single-crystal silicon itself is a brittle material, prone to fracture. To improve the mechanical reliability (e.g., shock, vibration) of silicon-based MEMS galvanometers, various packaging structures have been designed in the industry. Traditional methods to increase mechanical reliability mainly involve filling with flexible materials, such as soft adhesives or adding flexible damping pads. This type of improvement method relies on flexible connection structures to reduce the impact strength of the device. While it can improve the reliability of MEMS galvanometer devices, it also introduces new problems, such as insufficient connection strength and lateral displacement under high impact.

[0004] Therefore, there is an urgent need for a more reliable packaging structure for MEMS galvanometers. Utility Model Content

[0005] This application discloses a MEMS galvanometer packaging structure and a laser steering device based on the magnetic damping effect. The magnetic shell forms an endogenous stable magnetic field, which suppresses impact vibration and improves the structural stability of the MEMS galvanometer under repeated impacts in different directions, as well as the mechanical reliability of the MEMS galvanometer device.

[0006] Other objectives and advantages of this application can be further understood from the technical features disclosed herein.

[0007] To achieve one or more of the above objectives or other objectives, this application provides a MEMS galvanometer packaging structure based on magnetic damping effect, comprising: a magnetic housing; a mounting cavity disposed within the magnetic housing for mounting a MEMS galvanometer mirror assembly and a MEMS galvanometer actuator assembly; the magnetic housing includes an upper magnet and a lower magnetic conductor for enclosing and forming the housing; an upper magnetic conductor disposed at the connection between the upper magnet and the lower magnetic conductor, extending into the mounting cavity to separate the MEMS galvanometer mirror assembly and the MEMS galvanometer actuator assembly; and a lower magnet disposed at the bottom of the mounting cavity and located below the MEMS galvanometer actuator assembly; the upper magnet, the upper magnetic conductor, the lower magnet, and the lower magnetic conductor form a stable magnetic field within the mounting cavity.

[0008] This MEMS galvanometer packaging structure based on magnetic damping effect converts mechanical motion energy into heat dissipation through the interaction between the moving parts in the MEMS galvanometer and the magnetic field. Relying on eddy current damping and hysteresis damping, the structure works in synergy with the upper magnet, the upper magnetic conductor, the lower magnet, and the lower magnetic conductor in the packaging structure to generate a magnetic damping effect, enabling the packaging structure to suppress impact vibration.

[0009] The magnetic housing is arranged symmetrically.

[0010] The magnetic poles of the upper magnet and the portion connected to the upper magnetic conductor are different from those of the lower magnet near the MEMS galvanometer actuator assembly.

[0011] The upper magnet is an irregularly shaped magnet, and the irregularly shaped magnetic pole portion of the upper magnet forms a receiving groove with the upper magnetic conductor. The MEMS galvanometer mirror assembly extends at least partially into the receiving groove.

[0012] The upper magnet is positioned above the MEMS galvanometer mirror assembly and has an optical aperture, with the axis of the optical aperture aligned with the axis of the magnetic housing.

[0013] The cross-section of the aperture is an inverted trapezoid.

[0014] Both the MEMS galvanometer mirror assembly and the MEMS galvanometer actuator assembly have a metal layer.

[0015] A PCB circuit structure is installed below the upper magnet, and the PCB circuit structure is connected to the MEMS galvanometer actuator assembly via a metal wire.

[0016] The upper magnet and the lower magnet are permanent magnets; the lower magnetic conductor and the upper magnetic conductor are soft magnets.

[0017] This application also provides a laser steering device, including a MEMS galvanometer packaging structure based on the magnetic damping effect as described in any of the preceding claims.

[0018] The above-mentioned MEMS galvanometer packaging structure and laser steering device based on magnetic damping effect have at least the following beneficial effects: (1) By filling the MEMS galvanometer with a magnetic shell, a stable endogenous magnetic field is generated, which suppresses impact vibration. (2) The relative motion between the magnetic field and the conductor generates damping force, which suppresses device displacement by consuming vibration / impact capacity. (3) Compared with the traditional metal shell by adding a physical flexible structure, the initial stress structure is not changed, avoiding the defects of insufficient strength and easy lateral displacement of traditional flexible connection, so that the MEMS galvanometer has the characteristic of maintaining structural stability under repeated impacts in different directions, which significantly enhances the mechanical reliability of the MEMS galvanometer device. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the MEMS galvanometer packaging structure based on the magnetic damping effect of this application.

[0021] Figure 2 This is a schematic diagram of the intrinsic magnetic field of the MEMS galvanometer packaging structure based on the magnetic damping effect in this application.

[0022] The meanings of the markings in the diagram are as follows: 1. Magnetic housing; 11. Upper magnet; 12. Lower magnetic conductor; 13. Upper magnetic conductor; 14. Lower magnet; 15. Optical aperture; 2. Mounting cavity; a. MEMS galvanometer mirror assembly; b. MEMS galvanometer actuator assembly; c. PCB circuit structure; d. Metal wire. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the drawings. The embodiments of this application shown in the drawings and described with reference to the drawings are merely exemplary, and this application is not limited to these embodiments.

[0024] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the structures and / or processing steps closely related to the scheme according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0025] like Figure 1As shown, a MEMS galvanometer packaging structure based on magnetic damping effect includes: a magnetic housing 1; a mounting cavity 2 disposed within the magnetic housing 1 for mounting a MEMS galvanometer mirror assembly a and a MEMS galvanometer actuator assembly b; the magnetic housing 1 includes an upper magnet 11 and a lower magnetic conductor 12 for enclosing and forming the housing; an upper magnetic conductor 13 disposed at the connection between the upper magnet 11 and the lower magnetic conductor 12 and extending into the mounting cavity 2 to separate the MEMS galvanometer mirror assembly a and the MEMS galvanometer actuator assembly b; and a lower magnet 14 disposed at the bottom of the mounting cavity 2 and located below the MEMS galvanometer actuator assembly b; the upper magnet 11, the upper magnetic conductor 13, the lower magnet 14, and the lower magnetic conductor 12 form a stable magnetic field within the mounting cavity 2. Thus, through the interaction between the moving parts in the MEMS galvanometer (the MEMS galvanometer mirror assembly a and the MEMS galvanometer actuator assembly b) and the magnetic field, mechanical motion energy is converted into heat energy dissipation. Relying on eddy current damping and hysteresis damping, and in synergy with the upper magnet 11, the upper magnetic conductor 13, the lower magnet 14 and the lower magnetic conductor 12 in the packaging structure, a magnetic damping effect is generated, enabling the packaging structure to suppress impact vibration.

[0026] The principle of the MEMS galvanometer packaging structure is as follows: the upper magnet 11, the upper magnetic conductor 13, the lower magnet 14, and the lower magnetic conductor 12 form a stable and distributed high-intensity magnetic field within the mounting cavity 2, and the magnetic field lines are as follows: Figure 2 As shown by the blue dashed line, when an impact is applied to the MEMS mirror, the MEMS mirror actuator assembly b will undergo displacement, and the deformation of the MEMS mirror actuator assembly b will cause the MEMS mirror surface assembly a to oscillate. The oscillation of the MEMS mirror surface assembly a and the displacement of the MEMS mirror actuator assembly b will cut the magnetic field lines in the magnetic field, generating an induced current in the metal layer of the MEMS mirror (such as the gold layer of the MEMS mirror surface assembly a, the aluminum layer of the MEMS mirror actuator assembly b, etc.). The induced current will then generate an induced magnetic field, which is opposite in direction to the aforementioned high-intensity magnetic field. The induced magnetic field can resist the movement that cuts the magnetic field lines and suppress the movement generated when the MEMS mirror is impacted, thereby enabling the MEMS mirror to maintain structural stability under repeated impacts in different directions and improving the mechanical reliability of the MEMS mirror device.

[0027] The magnetic housing 1 is symmetrically arranged, meaning that the upper magnet 11, the lower magnetic conductor 12, the upper magnetic conductor 13, the lower magnet 14, the MEMS galvanometer mirror assembly a, and the MEMS galvanometer actuator assembly b are all symmetrically arranged. This symmetrical arrangement of the magnetic housing 1 further enhances the stability of the intrinsic magnetic field, eliminates magnetic field gradients, and provides a stable operating environment for the MEMS galvanometer device. Simultaneously, when the MEMS galvanometer mirror assembly a and the MEMS galvanometer actuator assembly b are subjected to external excitation, the symmetrical magnetic field ensures that the driving force is evenly distributed in all directions, eliminating mechanical crosstalk, suppressing torsional deformation, and improving overload resistance under high-frequency impact vibration.

[0028] The upper magnet 11 and the lower magnet 14 are permanent magnets, while the lower magnetic conductor 12 and the upper magnetic conductor 13 are soft magnets. The upper magnet 11 is at least partially located above the MEMS galvanometer mirror assembly a and is symmetrically arranged. The upper magnetic conductors 13 are symmetrically arranged below the upper magnet 11. The lower magnet 14 is located directly below the MEMS galvanometer actuator assembly b, and the lower magnetic conductor 12 is located below the lower magnet 14. The lower magnetic conductor 12 is a concave magnetic conductor, and the upper magnetic conductor 13 is a ring-shaped magnetic conductor, resulting in a simple structure that is easy to manufacture. The lower magnetic conductor 12, the upper magnetic conductor 13, and the upper magnet 11 surround each other to form a magnetic housing 11, thereby creating a stable and symmetrical magnetic field on both sides of the MEMS galvanometer mirror assembly a and the MEMS galvanometer actuator assembly b inside the magnetic housing 1, and improving the impact resistance of the packaging structure.

[0029] The magnetic poles of the upper magnet 11 connected to the upper magnetic conductor 13 and the lower magnet 14 near the MEMS galvanometer actuator assembly b are different. The magnetism of the upper magnetic conductor 13 depends on the magnetism near the connection portion of the upper magnet 11, and the magnetism of the lower magnetic conductor 12 depends on the magnetism near the connection portion of the lower magnet 14. The lower magnetic conductor 12 and the upper magnetic conductor 13 have the same magnetism. The upper magnet 11 is an irregularly shaped magnet, and the irregularly shaped magnetic pole portion of the upper magnet 11 forms a receiving groove with the upper magnetic conductor 13. The MEMS galvanometer mirror assembly a extends at least partially into the receiving groove, so that the magnetic field extends to the fine structure of the MEMS galvanometer mirror assembly a and the MEMS galvanometer actuator assembly b, enhancing the local magnetic field strength. The magnetic pole portion of the upper magnet 11 is inclined, so that the magnetic field on one side is asymmetrically distributed, and the effective magnetic flux of the adsorption surface is improved compared with that of a square magnetic pole. For example, as Figure 2As shown, when the inclined magnetic pole of the upper magnet 11 is the N pole, the magnetic pole of the upper magnetic conductor 13 is the S pole, and the lower magnetic conductor 12 is also the S pole. A magnetic field is formed between the irregular magnetic pole of the upper magnet 11 (including the inclined surface and the plane near the MEMS galvanometer mirror assembly a) and the upper magnetic conductor 13, and a magnetic field is formed between the upper magnetic conductor 13 and the lower magnet 14. The magnetic field lines are... Figure 2 The blue dashed line shows that the magnetic field lines almost completely cover the MEMS galvanometer mirror assembly a and the MEMS galvanometer actuator assembly b. This increases the local magnetic field strength, thereby further improving the effectiveness and strength of the packaging structure in suppressing impact vibrations and enhancing the structural stability of the MEMS galvanometer under repeated impacts from different directions.

[0030] The upper magnet 11 is positioned above the MEMS galvanometer mirror assembly a and has an aperture 15, with the axis of the aperture 15 aligned with the axis of the magnetic housing 1. Furthermore, the upper magnets 11 on both sides of the aperture 15 are symmetrical. This ensures that the magnetic field generated by the permanent magnet remains highly uniform within the controlled area, reducing nonlinear distortion during MEMS galvanometer deflection. The aperture 15 has an inverted trapezoidal cross-section, allowing it to be fitted to the positions of the upper magnet 11, the upper magnetic conductor 13, and the MEMS galvanometer mirror assembly a, ensuring the stability of the filling structure of the upper magnet 11 and the upper magnetic conductor 13.

[0031] Both the MEMS galvanometer mirror assembly a and the MEMS galvanometer actuator assembly b have metal layers. The metal layer in the MEMS galvanometer mirror assembly a is a gold layer, and the metal layer in the MEMS galvanometer actuator assembly b is an aluminum layer. When an impact is applied to the MEMS galvanometer, the oscillation of the MEMS galvanometer mirror assembly a and the displacement of the MEMS galvanometer actuator assembly b will cut the magnetic field lines in the magnetic field. An induced current is generated in the metal layer, and the induced current in turn generates an induced magnetic field to resist the movement that cuts the magnetic field lines and suppress the impact vibration.

[0032] A PCB circuit structure c is mounted below the upper magnetic conductor 13. The PCB circuit structure c is connected to the MEMS galvanometer actuator assembly b via a metal wire d. The PCB circuit structure c is used to power the MEMS galvanometer. Simultaneously, the PCB circuit structure c is disposed within the package structure, symmetrically positioned below the upper magnetic conductor 13 and close to the MEMS galvanometer actuator assembly b. This mechanically restricts the displacement movement of the MEMS galvanometer actuator assembly b, further filling the space within the package structure, facilitating the operation of the PCB circuit structure c, and improving the stability of the package structure.

[0033] In summary, the MEMS galvanometer packaging structure based on the magnetic damping effect of this application fills the MEMS galvanometer with a magnetic shell, generating a stable intrinsic magnetic field to suppress impact vibration. Furthermore, it utilizes the relative motion between the magnetic field and the conductor to generate damping force, suppressing device displacement by consuming vibration / impact energy. Simultaneously, it avoids the shortcomings of insufficient strength and easy lateral displacement inherent in traditional flexible connections, enabling the MEMS galvanometer to maintain structural stability under repeated impacts from different directions, significantly enhancing the mechanical reliability of the MEMS galvanometer device. It also avoids the shortcomings of insufficient strength and easy lateral displacement inherent in traditional flexible connections, enabling the MEMS galvanometer to maintain structural stability under repeated impacts from different directions, significantly enhancing the mechanical reliability of the MEMS galvanometer device.

[0034] Based on the same inventive concept, this application also provides a laser steering device, including any of the MEMS galvanometer packaging structures based on the magnetic damping effect described in the above embodiments. The incident laser is reflected by the MEMS galvanometer mirror component a, amplifying the deflection angle of the incident laser and achieving a wide-range scanning.

[0035] In the description of this application, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for 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. Therefore, they should not be construed as limitations on this application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] Furthermore, it should be noted that in this specification, "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0037] It should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of this application.

Claims

1. A MEMS galvanometer packaging structure based on the magnetic damping effect, characterized in that, include: A magnetic housing (1) is provided inside the magnetic housing (1) and a mounting cavity (2) is used to install the MEMS galvanometer mirror assembly (a) and the MEMS galvanometer actuator assembly (b). The magnetic housing (1) includes an upper magnet (11) for enclosing and forming the housing, a lower magnetic conductor (12), an upper magnetic conductor (13) provided at the connection between the upper magnet (11) and the lower magnetic conductor (12) and extending into the mounting cavity (2) to separate the MEMS galvanometer mirror assembly (a) and the MEMS galvanometer actuator assembly (b), and a lower magnet (14) provided at the bottom of the mounting cavity (2) and located below the MEMS galvanometer actuator assembly (b). The upper magnet (11), the upper magnetic conductor (13), the lower magnet (14) and the lower magnetic conductor (12) form a stable magnetic field in the mounting cavity (2).

2. The MEMS galvanometer packaging structure based on magnetic damping effect according to claim 1, characterized in that, The magnetic housing (1) is arranged symmetrically.

3. The MEMS galvanometer packaging structure based on the magnetic damping effect according to claim 1, characterized in that, The magnetic poles of the upper magnet (11) connected to the upper magnetic conductor (13) and the lower magnet (14) near the MEMS galvanometer actuator assembly (b) are different.

4. The MEMS galvanometer packaging structure based on magnetic damping effect according to claim 3, characterized in that, The upper magnet (11) is an irregularly shaped magnet. The irregularly shaped magnetic pole portion of the upper magnet (11) forms a receiving groove with the upper magnetic conductor (13). The MEMS galvanometer mirror assembly (a) extends at least partially into the receiving groove.

5. The MEMS galvanometer packaging structure based on magnetic damping effect according to claim 1, characterized in that, The upper magnet (11) is located above the MEMS galvanometer mirror assembly (a) and has a light hole (15) provided thereon, and the axis of the light hole (15) is aligned with the axis of the magnetic housing (1).

6. The MEMS galvanometer packaging structure based on magnetic damping effect according to claim 5, characterized in that, The cross-section of the aperture (15) is an inverted trapezoid.

7. The MEMS galvanometer packaging structure based on magnetic damping effect according to claim 1, characterized in that, Both the MEMS galvanometer mirror assembly (a) and the MEMS galvanometer actuator assembly (b) have a metal layer.

8. The MEMS galvanometer packaging structure based on magnetic damping effect according to claim 1, characterized in that, A PCB circuit structure (c) is installed below the upper magnet (13), and the PCB circuit structure (c) is connected to the MEMS galvanometer actuator assembly (b) via a metal wire (d).

9. The MEMS galvanometer packaging structure based on magnetic damping effect according to claim 1, characterized in that, The upper magnet (11) and the lower magnet (14) are permanent magnets; the lower magnetic conductor (12) and the upper magnetic conductor (13) are soft magnets.

10. A laser steering device, characterized in that, Includes a MEMS galvanometer packaging structure based on the magnetic damping effect as described in any one of claims 1-9.

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