Measurement method and device of MEMS (Micro Electro Mechanical System) galvanometer
By performing contour scanning when the bias voltage of the MEMS galvanometer is 0 and the first voltage value, position information is obtained and deflection angle is calculated, the problems of high complexity and low accuracy of measurement angle in the prior art are solved, and high-precision and low-cost angle measurement are achieved.
Patent Information
- Application Number
- CN202311061731.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-22
- Publication Date
- 2025-02-25
AI Technical Summary
The prior art relies on high-precision motors and self-collimator to increase operational complexity and cost when measuring the angular accuracy of MEMS galvanometers. In short distances, the accuracy of the photoelectric position detector is reduced, resulting in an increase in measurement error.
By performing a contour scanning when the bias voltage of the MEMS galvanometer is 0 and the first voltage value, the first and second position information are obtained, the first deflection angle is determined based on these information, and the angle accuracy of the MEMS galvanometer is calculated by comparing the first deflection angle with the expected deflection angle.
It realizes high-precision measurement of the angle accuracy of the MEMS galvanometer in a simple test environment, reduces operational complexity and cost, and improves measurement accuracy, with angle accuracy up to 1e-5 degrees.
Smart Images
Figure CN119509339A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the semiconductor field, and in particular to a method and device for measuring a MEMS galvanometer. Background Art
[0002] A micro-electro-mechanical system (MEMS) galvanometer is a miniature optical device made using semiconductor technology. The reflector in the MEMS galvanometer can be deflected at an angle under the action of a control signal. In this way, the MEMS galvanometer can achieve beam scanning. Such characteristics make the MEMS galvanometer have a wide range of application scenarios, such as laser radar, optical communication, spectral analysis, etc.
[0003] In order to make the MEMS galvanometer meet the accuracy requirements, the angle accuracy of the MEMS galvanometer needs to be measured.
[0004] In some scenarios, the angular accuracy of the MEMS galvanometer can be determined by a high-precision motor. In this case, the MEMS galvanometer can be fixed on a high-precision turntable by a tooling, and the MEMS galvanometer is coaxially arranged with the high-precision turntable. During the measurement process, first, the MEMS galvanometer is aligned with the center of the autocollimator. Then, the MEMS galvanometer is rotated by an angle in the first direction relative to the calibration substrate; thereafter, driven by a high-precision motor, the high-precision turntable is rotated to drive the MEMS galvanometer to rotate the same angle in the direction opposite to the first direction. After the rotation is completed, the deviation angle between the MEMS galvanometer and the autocollimator can be obtained, and the angular accuracy of the MEMS can be determined based on the deviation angle. However, such a solution requires the use of high-precision motors and autocollimators, which increases the complexity of the operation, increases the cost, and reduces the efficiency.
[0005] In some scenarios, the determination of the angular accuracy of the MEMS galvanometer can also be achieved by a photoelectric position sensitive detector (PSD) and the like. In this case, the deflection angle of the MEMS galvanometer is associated with the light spot displacement on the optical sensor of the PSD. Through this association, the light spot displacement on the PSD can be determined based on the first deflection angle of the MEMS galvanometer. The second deflection angle can be determined based on the light spot displacement and the distance between the MEMS galvanometer and the mirror surface of the PSD. The difference between the first deflection angle and the second deflection angle can be determined as the angle accuracy. However, such a scheme depends on the performance of the PSD, especially the constraints of the photosensing area and pixel resolution of the optical sensor of the PSD. When the distance between the MEMS galvanometer and the optical sensor of the PSD is small, the area of the light spot may be larger than the area of a single pixel. This will result in a decrease in the accuracy of the angle calculation and an increase in the measurement error.
[0006] Therefore, how to overcome the above-mentioned problem in measuring the angle accuracy of the MEMS galvanometer is an issue that needs to be solved urgently. Summary of the invention
[0007] The present application provides a method and device for measuring a MEMS galvanometer to improve measurement accuracy while reducing operation complexity and cost.
[0008] In a first aspect, the present application provides a method for measuring a MEMS galvanometer. The method includes: when the bias voltage of the MEMS galvanometer is 0, performing a profile scan on the first surface of the MEMS galvanometer to obtain first position information of the MEMS galvanometer; when the bias voltage of the MEMS galvanometer is a first voltage value, performing a profile scan on the first surface of the MEMS galvanometer to obtain second position information of the MEMS galvanometer, wherein the first voltage value is not 0; based on the first position information and the second position information, determining a first deflection angle of the MEMS galvanometer; according to the first deflection angle and the second deflection angle, determining the angular accuracy of the MEMS galvanometer, wherein the second deflection angle is the expected deflection angle of the MEMS galvanometer when the bias voltage is the first voltage value.
[0009] In some possible embodiments, the operation of determining a first deflection angle of a MEMS galvanometer based on first position information and second position information may include: determining a maximum movement distance of an edge of the MEMS galvanometer based on the first position information and the second position information; and determining the first deflection angle based on the maximum movement distance and the radius value of the MEMS galvanometer.
[0010] In some possible implementations, the maximum moving distance, the radius value, and the first deflection angle may satisfy a trigonometric function relationship.
[0011] In some possible implementations, there may be a linear relationship between the bias voltage of the MEMS galvanometer and the second deflection angle of the MEMS galvanometer.
[0012] In some possible implementations, the operation of determining the angular accuracy of the MEMS galvanometer according to the first deflection angle and the second deflection angle may include: determining the difference between the first deflection angle and the second deflection angle as the angular accuracy.
[0013] In some possible implementations, the contour scanning may be achieved by a three-dimensional profiler.
[0014] In some possible implementations, the bias voltage may include at least one of the following: an X-axis bias voltage for the MEMS galvanometer; or a Y-axis bias voltage for the MEMS galvanometer.
[0015] In a second aspect, the present application provides a device for measuring a MEMS galvanometer. The device includes: a three-dimensional profiler, a driver, and a computing device. The driver is used to: set the bias voltage of the MEMS galvanometer. The three-dimensional profiler is used to: when the bias voltage is 0, perform a contour scan on the MEMS galvanometer to obtain the first position information of the MEMS galvanometer; when the bias voltage is a first voltage value, perform a contour scan on the MEMS galvanometer to obtain the second position information of the MEMS galvanometer. The computing device is used to: determine a first deflection angle based on the first position information and the second position information; determine the angular accuracy of the MEMS galvanometer according to the first deflection angle and the second deflection angle, wherein the second deflection angle is the expected deflection angle of the MEMS galvanometer when the bias voltage is the first voltage value.
[0016] In some possible implementations, the three-dimensional profiler may include a profilometer and a confocal microscope.
[0017] In some possible implementations, the above-mentioned device may further include: a stage for carrying the MEMS galvanometer.
[0018] The technical solution provided by this application may have the following beneficial effects:
[0019] In the present application, the first position information is obtained when the bias voltage of the MEMS galvanometer is 0, and the second position information is obtained when the bias voltage of the MEMS galvanometer is a first voltage value. Based on the first position information, the second position information and the size of the MEMS galvanometer, the first deflection angle of the MEMS galvanometer can be determined using a functional relationship. By comparing the first deflection angle with the expected deflection angle, the angular accuracy of the MEMS galvanometer can be obtained. In this way, the angular accuracy can be obtained through a simple test environment, reducing the complexity and cost of the measurement. In addition, thanks to the high-precision characteristics of the three-dimensional profilometer, the angle measured using the three-dimensional profilometer also has a high accuracy, which improves the accuracy of the measured angular accuracy.
[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic diagram of a measurement system of a MEMS galvanometer in an embodiment of the present application.
[0022] Figure 2 It is a schematic diagram of a measurement scenario of a MEMS galvanometer in an embodiment of the present application.
[0023] Figure 3 This is a top view of the MEMS galvanometer in the embodiment of the present application.
[0024] Figure 4 This is a flow chart of a method for measuring a MEMS galvanometer in an embodiment of the present application.
[0025] Figure 5 It is a three-dimensional distribution diagram of the depth value of the MEMS galvanometer in the embodiment of the present application.
[0026] Figure 6 It is a two-dimensional distribution diagram of the depth value of the MEMS galvanometer in the embodiment of the present application.
[0027] Figure 7 Schematic diagram of the trigonometric function relationship used in the measurement method in the embodiment of the present application.
[0028] Figure 8 This is a curve diagram of the angle accuracy obtained by the measurement method in the embodiment of the present application.
[0029] Fig. 9 Schematic diagram of the structure of the computing device in the embodiment of the present application. DETAILED DESCRIPTION
[0030] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.
[0031] In order to illustrate the technical solution described in this application, a specific embodiment is provided below for illustration.
[0032] First, a measurement system for realizing the measurement of a MEMS galvanometer in an embodiment of the present application is described. Figure 1 Schematic diagram of the measurement system of the MEMS galvanometer in the embodiment of the present application. Figure 1 As shown, the measuring system 1 includes a three-dimensional profiler 11, a driver 12, a computing device 13, and a stage 14. The three-dimensional profiler 11 is used to perform contour scanning on the MEMS galvanometer. The driver 12 is used to set the bias voltage of the MEMS galvanometer. The computing device 13 is used to process and calculate the data obtained by the contour scanning of the three-dimensional profiler 11. The stage 14 is used to carry the MEMS galvanometer.
[0033] Figure 2 Schematic diagram of the measurement scene of the MEMS galvanometer in the embodiment of the present application. Figure 2As shown, the MEMS galvanometer 2 is placed on the stage 14 through the MEMS fixture 3. In one embodiment, the stage 14 can be placed horizontally, that is, the upper surface of the stage 14 can be a horizontal surface. The MEMS fixture 3 can be set on the stage 14. With the help of the MEMS fixture 3, the MEMS galvanometer 2 can be placed horizontally on the stage 14. It can be understood that the stage 14 is not necessary in the measurement system 1, and the embodiment of the present application does not specifically limit this.
[0034] The three-dimensional profiler 11 may be located above the stage 14. The detection portion 111 of the three-dimensional profiler 11 may face the MEMS galvanometer 2 on the stage 14. In one embodiment, the detection portion of the three-dimensional profiler 11 may be displaced in the first direction and / or the second direction relative to the stage 14. For example, Figure 2 In the embodiment, the first direction may be a horizontal direction, and the second direction may be a vertical direction. In this way, the first direction may be parallel to the plane where the upper surface of the stage 14 is located, and the second direction may be perpendicular to the plane where the upper surface of the stage 14 is located. By displacing in the first direction, the detection unit 111 of the three-dimensional profiler 11 can measure the depth of each position point on the upper surface of the MEMS galvanometer 2 to achieve the profile scanning of the MEMS galvanometer 2. It can be understood that the depth of each position point on the upper surface of the MEMS galvanometer 2 is the distance between the position point and the detection unit 111 located directly above the position point. By displacing in the second direction, the distance between the detection unit 111 of the three-dimensional profiler 11 and the stage 14 can be changed. In one embodiment, the displacement of the three-dimensional profiler 11 relative to the stage 14 can be achieved by a displacement mechanism (not shown) of the three-dimensional profiler 11. In one embodiment, the displacement of the three-dimensional profiler 11 relative to the stage 14 can be achieved by a displacement mechanism (not shown) of the stage 14. Of course, the displacement of the three-dimensional profiler 11 relative to the stage 14 can be achieved by the displacement mechanism of the three-dimensional profiler 11 and the displacement mechanism of the stage 14 .
[0035] In one embodiment, the three-dimensional profiler 11 may include a profilometer, a confocal microscope, etc. In one example, the profilometer may include an optical three-dimensional surface profiler, a white light interferometer, etc. It should be noted that although the imaging principles of the profilometer and the confocal microscope may be different, both can realize the profile scanning of the MEMS galvanometer 2. Of course, the three-dimensional profiler 11 may also include other devices that can be used to realize profile scanning, and the embodiment of the present application does not specifically limit this.
[0036] The driver 12 can be electrically connected or electrically coupled to the MEMS galvanometer 2 placed on the stage 14 to achieve the setting of the bias voltage of the MEMS galvanometer 2. In one embodiment, the driver 12 can be an independent driver. In one embodiment, the driver 12 can be located inside or on the surface of the MEMS tooling 3 and / or the stage 14.
[0037] Figure 3 FIG. 1 is a top view of the MEMS galvanometer in the embodiment of the present application. Figure 3 As shown, the MEMS galvanometer 2 may include a galvanometer 21, a magnet 22 and a coil 23. The galvanometer 21 may be a circular or other shaped lens. The magnet 22 may be disposed below the galvanometer 21. The coil 23 may be disposed around the galvanometer 21. Driven by the bias voltage set by the driver 12 for the MEMS galvanometer 2, a current may flow in the coil 23. In the magnetic field of the magnet 22, the current in the coil 23 causes the coil 23 to be acted upon by the Lorentz force according to Fleming's right hand rule. Under the action of the Lorentz force, the coil 23 together with the galvanometer 21 may be deflected.
[0038] In one embodiment, continue to refer to Figure 3 , the galvanometer 21 can be deflected in two directions, the X-axis and the Y-axis. These two directions can be orthogonal. Through the deflection in the X-axis and Y-axis directions, the galvanometer 21 can achieve deflection at any angle. In one embodiment, the bias voltage of the MEMS galvanometer 21 may include an X-axis bias voltage and a Y-axis bias voltage. The X-axis bias voltage may correspond to the deflection of the galvanometer 21 in the X-axis direction (i.e., rotation around the Y-axis). The Y-axis bias voltage may correspond to the deflection of the galvanometer 21 in the Y-axis direction (i.e., rotation around the X-axis). Correspondingly, the driver 12 may provide at least one of the X-axis bias voltage and the Y-axis bias voltage for the galvanometer 21.
[0039] The computing device 13 may be connected to the three-dimensional profiler 11. In one embodiment, the connection between the computing device 13 and the three-dimensional profiler 11 may be a communication connection, an electrical connection, etc. In one embodiment, the computing device 13 may obtain the data of the contour scan from the three-dimensional profiler 11 through the above connection, and obtain the angle accuracy of the MEMS galvanometer 2 based on the data. In one embodiment, the computing device 13 may be implemented by a general-purpose processor. For example, the computing device 13 may be a computing device such as a personal computer, a tablet computer, a mobile phone, a server, or the like. For example, the computing device 13 may include a program or code running on a computing device for implementing a computing function.
[0040] In one embodiment, the measurement system 1 may further include a controller 15. The controller 15 may be connected to at least one of the three-dimensional profiler 11, the driver 12, the computing device 13, and the stage 14. The connection may be a communication connection, an electrical connection, etc. In one embodiment, the controller 15 may be used to control the three-dimensional profiler 11 to perform at least one of the following operations: displacement, contour scanning, and sending the contour scanning data to the computing device 13. In one embodiment, the controller 15 may be used to control the driver 12 to set the bias voltage of the MEMS galvanometer 2. In one embodiment, the controller 15 may be used to instruct the computing device 13 to perform at least one of the following operations: receiving data from the three-dimensional profiler 11, data processing and / or calculation; sending the bias voltage set by the driver 12 to the computing device 13. In one embodiment, the controller 15 may be used to control the stage 14 to displace.
[0041] In one embodiment, the controller 15 may be independent of the computing device 13 and the controller 15. In one example, the controller 15 may be an independent control circuit. For example, the controller 15 may include a programmable logic device (PLD), a programmable logic controller (PLC), a field programmable gate array (FPGA), or other programmable devices. For example, the controller 15 may include a dedicated electronic circuit. In one embodiment, the controller 15 and the computing device 13 may be integrated. For example, the controller 15 and the computing device 13 may be set on the same computing device. For example, the controller 15 may be implemented by a program or code running on the computing device for implementing a computing function, or by another program or code running on the computing device for implementing a control function.
[0042] In the following, based on the above-mentioned measurement system, the measurement method of the MEMS galvanometer according to the embodiment of the present application is described. Figure 4 FIG. 1 is a flow chart of a method for measuring a MEMS galvanometer in an embodiment of the present application. Figure 4 As shown, the measurement method of the MEMS galvanometer 2 according to the embodiment of the present application includes steps S410 to S440.
[0043] It is understandable that before step S410 to step S440, the MEMS galvanometer 2 needs to be placed on the stage 14. During the execution of step S410 and step S420, the MEMS galvanometer 2 on the stage 14 is stationary relative to the stage 14 (except for the deflection of the galvanometer 21).
[0044] In step S410 , when the bias voltage of the MEMS galvanometer mirror 2 is 0, a contour scan is performed on a first surface of the MEMS galvanometer mirror 2 to obtain first position information of the MEMS galvanometer mirror 2 .
[0045] When the MEMS galvanometer 2 is placed on the stage 14 , the upper surface of the MEMS galvanometer 2 (ie, the surface facing away from the stage 14 and toward the three-dimensional profiler 11 ) is the first surface of the MEMS galvanometer 2 .
[0046] Specifically, under the action of the driver 12, the bias voltage of the MEMS galvanometer 2 is set to 0. For example, the driver 12 may not apply a bias voltage, or may apply a bias voltage having a value of 0. It is understandable that, because the bias voltage may include an X-axis bias voltage and a Y-axis bias voltage, the X-axis bias voltage and the Y-axis bias voltage are both set to 0 at this time.
[0047] When the bias voltage is 0, the three-dimensional profiler 11 can perform a profile scan on the first surface of the MEMS galvanometer 2. For example, the three-dimensional profiler 11 can scan the first surface of the MEMS galvanometer 2 by white light interference to obtain the first position information of the MEMS galvanometer 2.
[0048] The first position information includes a distance value along the vertical direction (i.e., a direction perpendicular to the first surface) between at least one position point on the first surface of the MEMS galvanometer 2 and the detection part 111 of the three-dimensional profilometer 11. It can be understood that, in the case where the height of the detection part 111 of the three-dimensional profilometer 11 is used as a reference, the distance value can also be understood as the depth value of the corresponding position point.
[0049] In one embodiment, when the bias voltage is 0, the galvanometer 21 in the MEMS galvanometer 2 may be flush or parallel to the first surface of the MEMS galvanometer 2. At this time, the multiple distance values corresponding to the various position points of the galvanometer 21 of the MEMS galvanometer 2 in the first position information may be equal or substantially equal. In one example, when the bias voltage is 0, the galvanometer 21 in the MEMS galvanometer 2 may also have a certain angle relative to the first surface of the MEMS galvanometer 2. At this time, the multiple distance values corresponding to the various position points of the galvanometer 21 of the MEMS galvanometer 2 in the first position information may be unequal.
[0050] In one embodiment, after the three-dimensional profilometer 11 obtains the first position information, the first position information may be sent to the computing device 13 .
[0051] In step S420 , when the bias voltage of the MEMS galvanometer mirror 2 is a first voltage value, a contour scan is performed on a first surface of the MEMS galvanometer mirror 2 to obtain second position information of the MEMS galvanometer mirror 2 .
[0052] Here, the first voltage value is a voltage value not equal to zero.
[0053] In one embodiment, the number of the first voltage values may be one or more. For example, the first voltage value may be a single value. For another example, the first voltage value may include multiple values. In the latter case, the first voltage value may also be referred to as a first voltage value set (or a first voltage value sequence). It is understood that the number of the first voltage values may be selected as needed, for example, 1, 6, 10, 20, and the embodiment of the present application does not specifically limit this.
[0054] In one embodiment, the first voltage value is within a first value range. The first value range may be, for example, 0 to the maximum bias voltage of the MEMS galvanometer 2. For example, the maximum bias voltage of the MEMS galvanometer 2 may be 180V (volts), and the first voltage value may be between 0 and 180V, that is, greater than 0 and less than or equal to 180V.
[0055] In one embodiment, when there are multiple first voltage values, the multiple first voltage values are all included in the first value range. In one embodiment, the multiple first voltage values can be randomly distributed, equally spaced, uniformly distributed, or distributed in other ways.
[0056] In one embodiment, when a plurality of first voltage values are equally spaced or uniformly distributed, the difference between two adjacent first voltage values can be referred to as a step length. The step length can be an integer multiple of the minimum interval of the bias voltage. The minimum interval of the bias voltage can be determined by the maximum bias voltage of the MEMS galvanometer 2 and the numerical range of the digital-to-analog converter (DAC) of the driver 12. In one example, the maximum bias voltage can be 180V, the numerical range of the DAC can be 0 to 4095, and the minimum interval is 180 / 4095 volts (approximately 0.04V). In this way, the step length can be 0.04V, 0.08V, 0.2V, 20V, 60V, 100V, etc.
[0057] In one embodiment, step S420 can be performed for the X-axis, and the first voltage value can include an X-axis bias voltage. In one embodiment, step S420 can be performed for the Y-axis, and the first voltage value can include a Y-axis bias voltage. Of course, it can be understood that step S420 can also be performed for a combination of the X-axis and the Y-axis. In one embodiment, in order to obtain the X-axis deflection angle of the galvanometer 21 of the MEMS galvanometer 2, the first voltage value can include an X-axis bias voltage, and the Y-axis bias voltage is 0. For example, through the driver 12, the X-axis bias voltage can be set to: -100V, -60V, -20V, 20V, 60V, 100V. In one embodiment, in order to obtain the Y-axis deflection angle of the galvanometer 21 of the MEMS galvanometer 2, the first voltage value can include a Y-axis bias voltage, and the X-axis bias voltage is 0. For example, through the driver 12, the Y-axis bias voltage can be set to: -100V, -60V, -20V, 20V, 60V, 100V.
[0058] When the bias voltage is the first voltage value, the three-dimensional profiler 11 can perform a profile scan on the first surface of the MEMS galvanometer 2. For example, the three-dimensional profiler 11 can scan the first surface of the MEMS galvanometer 2 by white light interference, thereby obtaining the second position information of the MEMS galvanometer 2.
[0059] The second position information includes a distance value between at least one position point on the first surface of the MEMS galvanometer 2 and the detection portion 111 of the three-dimensional profiler 11 in the vertical direction (ie, a direction perpendicular to the first surface).
[0060] In one embodiment, after the three-dimensional profilometer 11 obtains the second position information, the second position information may be sent to the computing device 13 .
[0061] In step S430 , a first deflection angle of the MEMS galvanometer 2 is determined based on the first position information and the second position information.
[0062] Here, step S430 may be implemented by the computing device 13. Specifically, the computing device 13 may receive the first position information and the second position information from the three-dimensional profiler 11, and determine the first deflection angle of the galvanometer 21 of the MEMS galvanometer 2 according to the first position information and the second position information.
[0063] In one embodiment, the computing device 13 may perform data processing on the first location information and / or the second location information. In the following, the data processing performed by the computing device 13 on the second location information is taken as an example for description. It can be understood that the data processing performed by the computing device 13 on the second location information may be the same.
[0064] In one embodiment, the computing device 13 may perform data filtering on the second position information. Specifically, the computing device 13 may remove noise data in the second position information.
[0065] In one embodiment, the computing device 13 may generate a distribution map based on the second location information. Figure 5 It is a three-dimensional distribution diagram of the depth value of the MEMS galvanometer in the embodiment of the present application. Figure 6 2 is a two-dimensional distribution diagram of the depth value of the MEMS galvanometer in the embodiment of the present application. Figure 5 and 6 As shown, the horizontal axis represents the pixel coordinates when the three-dimensional profiler 11 performs contour scanning, and the vertical axis represents the depth value obtained by performing contour scanning on the first surface of the MEMS galvanometer 2. It can be seen from the figure that under the action of the first voltage value, the galvanometer 21 of the MEMS galvanometer 2 is angularly deflected relative to the first surface. The deflected angle is the first deflection angle, which can be represented by α. It can be understood that the computing device 13 can also generate a distribution table or other data forms based on the second position information.
[0066] In one embodiment, the calculation device 13 may calculate the first position information and the second position information to obtain the first deflection angle.
[0067] Specifically, the calculation device 13 may perform calculation based on the processed or original first position information and the second position information.
[0068] In one embodiment, step S430 may include a first step and a second step.
[0069] In the first step, based on the first position information and the second position information, the maximum moving distance of the edge of the MEMS galvanometer 2 is determined.
[0070] Specifically, by performing data fitting on the first position information, the depth value of each position point of the galvanometer 21 when the bias voltage is 0 can be determined; and by performing data fitting on the second position information, the depth value of each position point of the galvanometer 21 when the bias voltage is the first voltage value can be determined, and then the maximum moving distance can be determined.
[0071] In one embodiment, the maximum moving distance may be the maximum value of the distance between the edge of the galvanometer 21 when the bias voltage is the first voltage value and the edge of the projection thereof perpendicularly projected onto the plane where the galvanometer 21 is located when the bias voltage is 0. In one embodiment, when the galvanometer 21 is flush with the first surface when the bias voltage is 0, the maximum moving distance may be the maximum distance that the edge of the galvanometer 21 moves in the vertical direction. For example, Figure 6As shown, the maximum moving distance can be represented by d. It can be understood that, when the bias voltage only includes the X-axis bias voltage, the maximum moving distance can be the distance that the edge of the galvanometer 21 is located on the X-axis and moves in the vertical direction. Similarly, when the bias voltage only includes the Y-axis bias voltage, the maximum moving distance can be the distance that the edge of the galvanometer 21 is located on the Y-axis and moves in the vertical direction.
[0072] In the second step, a first deflection angle is determined according to the maximum moving distance and the radius value of the MEMS galvanometer 2 .
[0073] It is understandable that the galvanometer mirror 21 of the MEMS galvanometer mirror 2 is usually a plane mirror. Therefore, the radius value, the maximum moving distance, and the first deflection angle of the galvanometer mirror 21 may satisfy a trigonometric function relationship. Figure 7 Schematic diagram of the trigonometric function relationship used in the measurement method in the embodiment of the present application. Figure 7 As shown, the radius value r of the galvanometer 21, the maximum moving distance d, and the first deflection angle α can satisfy a right-angle trigonometric function relationship. Specifically, the radius value r of the galvanometer 21 is the length of the hypotenuse of the triangle, and the maximum moving distance d is the side of the triangle opposite to the first deflection angle α. In this way, the radius value r of the galvanometer 21, the maximum moving distance d, and the first deflection angle α satisfy: sinα=d / r. By transformation, it can be obtained that α=arcsin(d / r). In addition, for the first voltage value, the first deflection angle α can be expressed as: α(U).
[0074] In step S440 , the angle accuracy of the MEMS galvanometer 2 is determined according to the first deflection angle and the second deflection angle.
[0075] Here, the second deflection angle is the expected deflection angle of the MEMS galvanometer 2 when the bias voltage is the first voltage value. In one embodiment, according to the working principle of the MEMS galvanometer 2, the expected deflection angle of the galvanometer 21 in the MEMS galvanometer 2 satisfies a functional relationship with the bias voltage. Then, according to the functional relationship, the second deflection angle θ of the galvanometer 21 at the first voltage value U can be expressed as: θ(U). In one example, the functional relationship can be a linear relationship. At this time, the second deflection angle θ(U)=kU, where k is a proportional coefficient.
[0076] Specifically, after obtaining the first front rotation angle and the second deflection angle, the calculation device 13 can obtain the angle accuracy of the MEMS galvanometer 2 through calculation.
[0077] In one embodiment, the angular accuracy may be the difference between the first deflection angle and the second deflection angle. In this case, step S440 may include: determining the difference between the first deflection angle and the second deflection angle as the angular accuracy. In some cases, the angular accuracy Dev(U) calculated by the computing device 13 at the first voltage value U may be: Dev(U)=θ(U)-α(U). The angular accuracy Dev(U) obtained at this time may not only characterize the magnitude of the angular deviation, but also characterize the direction of the angular deviation. In some cases, the angular accuracy Dev(U) calculated by the computing device 13 at the first voltage value U may be: Dev(U)=|α(U)-θ(U)|. At this time, the absolute value of the difference between the first deflection angle and the second deflection angle is determined as the angular accuracy, and the determined angular accuracy Dev(U) is not a negative number. It can be understood that the angular accuracy obtained based on the difference between the first deflection angle and the second deflection angle reflects the absolute angular deviation, and therefore can be referred to as the absolute angular accuracy.
[0078] Figure 8 This is a curve diagram of the angle accuracy obtained by the measurement method in the embodiment of the present application. Figure 8 In the figure, the horizontal axis represents the bias voltage and the vertical axis represents the absolute angle accuracy. Figure 8 As shown in FIG. 1 , a fitting curve of absolute angle accuracy is obtained for different bias voltages. From the curve, it can be seen that for -100V, -50V, 0V, 50V, 100V, etc., the angle accuracy varies, but does not exceed 0.01 degrees.
[0079] In one embodiment, the angle accuracy may be the ratio of the first deflection angle to the second deflection angle. In this case, step S440 may include: determining the ratio between the first deflection angle and the second deflection angle as the angle accuracy. Specifically, the calculation device 13 may calculate that the angle accuracy Dev(U) under the first voltage value U satisfies: Dev(U)=α(U) / θ(U). It can be understood that the angle accuracy obtained based on the difference between the first deflection angle and the second deflection angle reflects the relative angle deviation and can therefore be referred to as relative angle accuracy.
[0080] Through the above steps S410 to S440 , the embodiment of the present application can determine the angle accuracy of the MEMS galvanometer 2 .
[0081] In the present application, the first position information is obtained when the bias voltage of the MEMS galvanometer is 0, and the second position information is obtained when the bias voltage of the MEMS galvanometer is a first voltage value. Based on the first position information, the second position information and the size of the MEMS galvanometer, the first deflection angle of the MEMS galvanometer can be determined using a functional relationship. By comparing the first deflection angle with the expected deflection angle, the angular accuracy of the MEMS galvanometer can be obtained. In this way, the angular accuracy can be obtained through a simple test environment, reducing the complexity and cost of the measurement.
[0082] In addition, the profile scanning accuracy of 3D profilers such as profilometers and confocal microscopes is high, which can reach the nanometer level. Using such a 3D profiler, the angle accuracy can reach 1e -5 The high-precision characteristics of the sensor significantly improve the accuracy of the measured angle accuracy.
[0083] Based on the same inventive concept, an embodiment of the present application further provides a computing device, which may be an electronic device or a chip or system on chip in an electronic device, or a functional module in an electronic device. Fig. 9 Schematic diagram of the structure of the computing device in the embodiment of the present application. Fig. 9 As shown, the computing device 13 may include an acquisition module 901, a first determination module 902, and a second determination module 903. The acquisition module 901 is configured to acquire first position information and second position information, wherein the first position information is obtained by performing a contour scan on the first surface of the MEMS galvanometer when the bias voltage of the MEMS galvanometer is 0, and the second position information is obtained by performing a contour scan on the first surface of the MEMS galvanometer when the bias voltage of the MEMS galvanometer is a first voltage value, and the first voltage value is not 0. The first determination module 902 is configured to determine a first deflection angle of the MEMS galvanometer based on the first position information and the second position information. The second determination module 903 is configured to determine the angular accuracy of the MEMS galvanometer according to the first deflection angle and the second deflection angle, wherein the second deflection angle is the expected deflection angle of the MEMS galvanometer when the bias voltage is the first voltage value.
[0084] It should be noted that the specific implementation process of the acquisition module 901, the first determination module 902, and the second determination module 903 can be referred to Figures 1 to 8 The detailed description of the embodiment is omitted for brevity. In addition, the acquisition module 901, the first determination module 902, and the second determination module 903 mentioned in the embodiment of the present application may be one or more processors.
[0085] Based on the same inventive concept, an embodiment of the present application provides an electronic device, including: a memory storing computer executable instructions; a processor connected to the memory, for executing computer executable instructions and capable of executing: obtaining first position information and second position information, wherein the first position information is obtained by performing a contour scan on the first surface of the MEMS galvanometer when the bias voltage of the MEMS galvanometer is 0, and the second position information is obtained by performing a contour scan on the first surface of the MEMS galvanometer when the bias voltage of the MEMS galvanometer is a first voltage value, and the first voltage value is not 0; based on the first position information and the second position information, determining a first deflection angle of the MEMS galvanometer; according to the first deflection angle and the second deflection angle, determining the angular accuracy of the MEMS galvanometer, wherein the second deflection angle is the expected deflection angle of the MEMS galvanometer when the bias voltage is the first voltage value.
[0086] Based on the same inventive concept, the present application provides a computer storage medium, which stores computer executable instructions. After the computer executable instructions are executed by a processor, they can execute: obtaining first position information and second position information, wherein the first position information is obtained by performing a contour scan on the first surface of the MEMS galvanometer when the bias voltage of the MEMS galvanometer is 0, and the second position information is obtained by performing a contour scan on the first surface of the MEMS galvanometer when the bias voltage of the MEMS galvanometer is a first voltage value, and the first voltage value is not 0; based on the first position information and the second position information, determining a first deflection angle of the MEMS galvanometer; according to the first deflection angle and the second deflection angle, determining the angular accuracy of the MEMS galvanometer, wherein the second deflection angle is the expected deflection angle of the MEMS galvanometer when the bias voltage is the first voltage value.
[0087] Those skilled in the art will appreciate that the sequence numbers of the steps in the above embodiments do not imply a sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.
[0088] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.
Claims
1. A method for measuring a micro-electromechanical system (MEMS) galvanometer, characterized in that: include: When the bias voltage of the MEMS galvanometer is 0, a first surface of the MEMS galvanometer is profile scanned to obtain first position information of the MEMS galvanometer; When the bias voltage of the MEMS galvanometer is a first voltage value, performing a profile scan on the first surface of the MEMS galvanometer to obtain second position information of the MEMS galvanometer, wherein the first voltage value is not 0; Determine a first deflection angle of the MEMS galvanometer based on the first position information and the second position information; The angular accuracy of the MEMS galvanometer is determined according to the first deflection angle and the second deflection angle, wherein the second deflection angle is an expected deflection angle of the MEMS galvanometer when the bias voltage is the first voltage value.
2. The method according to claim 1, characterized in that Determining a first deflection angle of the MEMS galvanometer based on the first position information and the second position information includes: Determine a maximum moving distance of an edge of the MEMS galvanometer based on the first position information and the second position information; The first deflection angle is determined according to the maximum moving distance and the radius value of the MEMS galvanometer.
3. The method according to claim 2, characterized in that The maximum moving distance, the radius value and the first deflection angle satisfy a trigonometric function relationship.
4. The method according to claim 1, characterized in that There is a linear relationship between the bias voltage of the MEMS galvanometer and the second deflection angle of the MEMS galvanometer.
5. The method according to claim 1, characterized in that Determining the angle accuracy of the MEMS galvanometer according to the first deflection angle and the second deflection angle includes: A difference between the first deflection angle and the second deflection angle is determined as the angle accuracy.
6. The method according to any one of claims 1 to 5, characterized in that The contour scanning is achieved by a three-dimensional profiler.
7. The method according to any one of claims 1 to 5, characterized in that The bias voltage includes at least one of the following: An X-axis bias voltage for the MEMS galvanometer; Y-axis bias voltage for the MEMS galvanometer.
8. A measuring device for a micro-electromechanical system (MEMS) galvanometer, characterized in that: include: 3D profilometer, actuator, and computing device; Wherein, the driver is used for: Set the bias voltage of the MEMS galvanometer; Wherein, the three-dimensional profiler is used for: When the bias voltage is 0, performing a profile scan on the MEMS galvanometer to obtain first position information of the MEMS galvanometer; When the bias voltage is the first voltage value, performing a profile scan on the MEMS galvanometer to obtain second position information of the MEMS galvanometer; Wherein, the computing device is used for: Determine a first deflection angle based on the first position information and the second position information; The angular accuracy of the MEMS galvanometer is determined according to the first deflection angle and the second deflection angle, wherein the second deflection angle is an expected deflection angle of the MEMS galvanometer when the bias voltage is the first voltage value.
9. The device according to claim 8, characterized in that The three-dimensional profiler includes a profilometer and a confocal microscope.
10. The device according to claim 8 or 9, characterized in that The device also includes: The stage is used for carrying the MEMS galvanometer.