Electromagnetic drive scanning mirror vacuum packaging structure

Abstract

The application provides an electromagnetic driving scanning mirror vacuum packaging structure, which comprises a tube shell, a waiting scanning chip placement block and a cover plate are arranged in the tube shell, first and second magnets corresponding to each other are arranged on the cover plate and the shell, pins for forming electrical connection with the waiting scanning chip are arranged on the tube shell, and a light window assembly is connected to the opening end of the tube shell. The application has the advantages of integrated vacuum packaging, good air tightness, reduced product power consumption through the design of the integrated vacuum packaging structure, simple structure, convenient assembly and suitability for batch packaging and processing.

Description

Technical Field

[0001] This invention relates to the fields of micro-nano manufacturing and laser display technology, and in particular to the vacuum packaging shell structure of an electromagnetically driven scanning mirror. Background Technology

[0002] MEMS micromirrors can achieve one-dimensional or two-dimensional scanning of light beams by twisting, and are currently widely used in 3D scanning, laser display, lidar and other fields. Low cost, low power consumption, high precision, large rotation angle and high reliability are the main characteristics of MEMS micromirrors.

[0003] In solid-state lidar based on MEMS (Micro-Electro-Mechanical System) micromirror technology, two common methods are employed for detecting targets at long distances: coaxial and non-coaxial optical paths. In coaxial scanning, both the emitted and received light passes through the MEMS micromirror, requiring the micromirror to have a large mirror surface. However, large-mirror micromirrors have significant inertia, necessitating greater driving force to achieve a wider scanning angle. Currently, the effective diameter of commercially available large-aperture galvanometers does not exceed 8 mm.

[0004] In a vacuum, the damping during galvanometer movement is minimal, significantly improving energy efficiency and reducing power consumption. Therefore, vacuum packaging is crucial for ensuring long-distance ranging of large-size galvanometers. In existing electromagnetic drive technologies for MEMS scanning micromirrors, one or more sets of closed coils are integrated onto the movable chip of the MEMS micromirror. However, how to dissipate heat during vacuum packaging remains a significant challenge. While some similar structures exist, they primarily utilize non-hermetic packaging, resulting in high power consumption and short measurement distances. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art by providing a vacuum packaging structure for an electromagnetically driven scanning mirror. This structure not only solves the problem of vacuum packaging of the device but also the problem of heat conduction. Furthermore, it adopts an integrated optimized design of the casing to solve assembly difficulties, reduce assembly complexity, and improve the assembly yield, making it suitable for mass production.

[0006] This application provides the following technical solution: A vacuum packaging structure for an electromagnetically driven scanning mirror is characterized by the following: it comprises a tube housing consisting of a base plate and a frame; a column is provided on the base plate; two diagonally distributed blocks extend from the inner wall of the frame, each block having a set of screw holes and a chip positioning groove; an opening is provided on the frame wall, through which a set of pins electrically connected to the chip to be scanned are inserted; a pair of first magnets are adsorbed on the base plate, the pair of first magnets being distributed along another diagonal line within the frame; a cover plate is connected to the two blocks, the cover plate having clearance holes corresponding to the chip to be scanned, and a second magnet corresponding to the first magnets on the cover plate, the opposing faces of the first and second magnets having the same pole; and an inclined optical window assembly is connected to the open end of the frame, so that the tube housing forms a vacuum-sealed cavity.

[0007] Based on the above technical solutions, the following further technical solutions are also possible: The first magnet has an adhesive layer that corresponds to the chip waiting to be scanned.

[0008] The upper opening of the frame is provided with a beveled edge that corresponds to and cooperates with the light window assembly.

[0009] The column is electroplated with metal, such as gold, titanium, or other precious metals.

[0010] The frame is made of non-magnetic metal material, and the frame is welded to the base plate with high-temperature solder.

[0011] The bottom surface of the cover plate is provided with a groove for the bonding wire.

[0012] The cover plate is made of non-magnetic material and has undergone anodizing treatment.

[0013] The light window assembly includes a metal cover frame made of non-magnetic material, with a glass light window connected to the metal cover frame. The glass window is coated with a coating material selected according to the wavelength of light transmission. The surface of the metal cover is electroplated with an anti-oxidation precious metal layer such as gold or titanium.

[0014] A first magnet positioning strip extends from the frame wall below the opening, corresponding to and engaging with one of the first magnets.

[0015] Advantages of the invention: This invention provides an integrated vacuum packaging system with excellent gas tightness. By designing an integrated vacuum packaging structure, product power consumption can be reduced. The structure is simple, easy to assemble, and suitable for mass production packaging. Attached Figure Description

[0016] Figure 1 This is a three-dimensional schematic diagram of the present invention without the light window component installed; Figure 2This is a top view of the pipe shell; Figure 3 This is a three-dimensional schematic diagram of the cover plate; Figure 4 This is a bottom view of the cover plate; Figure 5 The structure of this invention is shown in the schematic diagram; Figure 6 This is a schematic diagram showing the distribution of the first and second magnets and the chip; Figure 7 This is a schematic diagram of the light window assembly. Detailed Implementation

[0017] like Figure 1-7 As shown, an electromagnetically driven scanning mirror vacuum packaging structure includes a weakly magnetic base plate 1, on which an elliptical cylindrical column 1a is attached. Gold is electroplated onto the column 1a.

[0018] A frame 2 is welded onto the base plate 1 using high-temperature solder. The frame 2 is a square tubular structure made of non-magnetic metal material, with a beveled edge 1b at its upper end. Two blocks 2a extend inward from the inner wall of the frame 2, and the two blocks 2a are diagonally distributed. There is a certain distance between the blocks 2a and the elliptical cylindrical column 1a.

[0019] Two blocks 2a have diagonally distributed chip positioning slots 2c, and a set of screw holes 2b are provided on the upper surface of block 2a outside the chip positioning slots 2c. A certain height difference is left between the bottom of the chip positioning slot 2c and the upper surface of the elliptical cylindrical body 1a.

[0020] On one side of the frame 2 of one of the blocks 2a, there is a horizontally distributed elongated opening 2d. A set of pins 3 that are electrically connected to the chip 6 waiting to be scanned are connected within the opening 2d. A first magnet positioning strip 10 extends outward from the inner side of the frame 2 below the opening 2d.

[0021] Two L-shaped first magnets 4 are arranged, with the pair of first magnets 4 distributed along another diagonal line inside the frame 2. One of the first magnets 4 contacts the first magnet positioning strip 10 to position it. An adhesive layer 7 corresponding to the chip 6 waiting to be scanned is provided on the upper surface of each first magnet 4.

[0022] The waiting-to-scan chip 6 is electrically connected to the pin 3 via bonding wires. Then, the waiting-to-scan chip 6 is placed on the chip positioning slot 2c. At this time, the other two diagonal parts of the waiting-to-scan chip 6 are bonded to the adhesive layer 7. Ensure that the mirror structure of the waiting-to-scan chip 6 is facing upwards. At this time, the waiting-to-scan chip 6 is installed in place, and the lower surface of the waiting-to-scan chip 6 does not contact the elliptical cylindrical body 1a.

[0023] A cover plate 5 is provided, and second screw holes 5b corresponding to screw holes 2b are provided on the cover plate 5. Screws are inserted into the screw holes 2b and second screw holes 5b to connect and fix the cover plate 5 to the block 2a. The cover plate 5 is provided with clearance holes 5a corresponding to the chip 6 waiting to be scanned, so as to expose the mirror structure 6a on the upper surface of the scanning chip 6.

[0024] A second magnet 9, corresponding to the first magnet 4, is embedded under the cover plate 5. The first magnet 4 and the second magnet 9 are distributed on the upper and lower sides of the scanning chip 6, and the opposite faces of the first magnet 4 and the second magnet 9 have the same pole. The magnetic poles at the top of the two first magnets 4 are different.

[0025] A groove 5c for accommodating the bonding wire is provided on the bottom surface of the cover plate 5. The cover plate (5) is made of non-magnetic material and has undergone anodizing treatment.

[0026] An inclined light window assembly 8 is sealed to the open end of the frame 2, forming a vacuum-sealed cavity within the tube housing. The light window assembly 8 includes a metal cover frame 8a made of non-magnetic material, with a glass light window 8b connected to the metal cover frame 8a. The glass window is coated, and the surface of the metal cover is electroplated with an anti-oxidation noble metal layer such as titanium.

[0027] The first and second magnets 4 and 9 are heat-resistant and will not weaken at 250°C. The tilted optical window assembly 8 prevents blind spots on the mirror structure caused by reflection when the laser passes through the glass optical window 8b.

Claims

1. An electromagnetic drive scanning mirror vacuum packaging structure, characterized in that: It includes a tubular shell consisting of a base plate (1) and a frame (2). A column (1a) is provided on the base plate (1). Two diagonally distributed blocks (2a) extend from the inner wall of the frame (2). Each block (2a) has a set of screw holes (2b) and a chip positioning groove (2c). An opening (2d) is provided on the wall of the frame (2), and a set of pins (3) electrically connected to the scanning micromirror chip (6) passes through the opening (2d). A pair of first magnets (4) are attracted to the base plate (1). The first magnet (4) is distributed along another diagonal line inside the frame (2); a cover plate (5) is connected to the two blocks (2a), and the cover plate (5) is provided with clearance holes (5a) corresponding to the scanning micromirror chip (6). A second magnet (9) corresponding to the first magnet (4) is provided on the cover plate (5). The opposite faces of the first magnet (4) and the second magnet (9) are the same pole. An inclined light window assembly (8) is connected to the opening end of the frame (2), so that the tube shell forms a vacuum-sealed cavity.

2. The vacuum packaging structure of the electromagnetic driving scanning mirror according to claim 1, wherein: An adhesive layer (7) is provided on the first magnet (4) to correspond to and cooperate with the scanning micromirror chip (6).

3. The vacuum packaging structure of the electromagnetic driving scanning mirror according to claim 1, wherein: The upper opening end of the frame (2) is provided with a bevel that corresponds to and matches the light window assembly (8).

4. The vacuum packaging structure of the electromagnetic driving scanning mirror according to claim 1, wherein: Metal is electroplated onto the column (1a), and the metal material is gold or titanium.

5. The vacuum packaging structure of the electromagnetic driving scanning mirror according to claim 1, wherein: The frame (2) is made of non-magnetic metal material, and the frame (2) and the base plate (1) are welded together by high-temperature solder.

6. The vacuum packaging structure of the electromagnetic driving scanning mirror according to claim 1, wherein: A groove (5c) for the bonding wire is provided on the bottom surface of the cover plate (5).

7. The vacuum packaging structure of the electromagnetic driving scanning mirror according to claim 1, wherein: The cover plate (5) is made of non-magnetic material and is anodized.

8. The electromagnetic drive scanning mirror vacuum packaging structure according to claim 1, characterized in that: The light window assembly (8) includes a metal cover frame (8a) made of non-magnetic material. A glass light window (8b) is connected to the metal cover frame (8a). The glass window is coated, and the surface of the metal cover is electroplated with an anti-oxidation precious metal layer. The precious metal layer material is gold or titanium.

9. The vacuum packaging structure of the electromagnetic driving scanning mirror according to claim 1, wherein: The first and second magnets (4 and 9) have high temperature resistance and will not weaken at 250°C.

10. The electromagnetic drive scanning mirror vacuum packaging structure according to claim 1, characterized in that: A first magnet positioning strip (10) extends from the wall of the frame (2) below the opening (2d) and corresponds to one of the first magnets (4).

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