Optical device for precisely measuring and adjusting gradient of multiple working surfaces and calculation method

Abstract

The invention relates to an optical device for precisely measuring and adjusting the gradient of multiple working surfaces and a calculation method. The optical device comprises an optical sensor system, a moving system and a data processing unit which are matched with one another, the optical sensor system comprises a lifting device and an optical sensor which is fixed on the moving end of the lifting device, is in signal connection with the data processing unit and is used for acquiring image data; the moving system comprises an X-axis moving platform and a Y-axis moving platform fixed on the moving end of the X-axis moving platform; according to the invention, the measurement precision is improved to a motor motion precision range, independent measurement of the absolute inclination of a working surface and an optical system is realized, the limitation of a traditional measurement mode is overcome so as to be suitable for a complex space environment and diversified adjustment requirements, and the operation process is simplified so as to improve the working efficiency; and the reliability and the consistency of the system are improved. The optical device and the calculation method for precisely measuring and adjusting the inclination of the multiple working surfaces are provided.

Description

Technical Field

[0001] The present invention relates to the field of optical measurement technology, and in particular to an optical device and a calculation method for precise measurement and adjustment of the inclination of multiple working surfaces. Background Art

[0002] With the rapid development of the semiconductor industry, wafer inspection technology plays an increasingly important role in improving production efficiency and ensuring product quality. Wafer inspection is an indispensable part of the semiconductor manufacturing process. It accurately detects surface defects, pattern alignment, etc. of wafers to ensure that the quality of wafers meets manufacturing requirements.

[0003] However, existing wafer inspection equipment has some problems with the replacement of support points. First, when the size of the wafer does not match the size of the support point, the support point must be replaced with a matching size. However, the process is cumbersome, time-consuming and labor-intensive, because the support point at the original position must be manually removed first, and then the support point with the matching size must be installed at the original position, and the technician must re-level it, so the replacement efficiency is low. Secondly, since the replacement process is more cumbersome, the equipment requires a long period of downtime maintenance, which not only affects the continuous operation of the production line, but also directly leads to a decrease in production efficiency. In addition, in order to adapt to wafers of various sizes, it is necessary to equip support points of various sizes, which will increase production costs and cause waste of resources, which urgently needs to be resolved. Summary of the Invention

[0004] In view of the current status of the above-mentioned prior art, the technical problem to be solved by the present invention is to provide an optical device and calculation method for precise measurement and adjustment of the inclination of multiple working surfaces, which improves the measurement accuracy to the range of motor motion accuracy and realizes independent measurement of the absolute inclination of the working surface and the optical system, while overcoming the limitations of traditional measurement methods to be suitable for complex spatial environments and diverse adjustment requirements, and also simplifies the operation process to improve work efficiency, and improves system reliability and consistency.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: an optical device for precise measurement and adjustment of the inclination of multiple working surfaces, characterized in that it includes an optical sensor system, a mobile system and a data processing unit that cooperate with each other, the optical sensor system includes a lifting device and an optical sensor fixed on the mobile end of the lifting device and connected to the data processing unit by signal for acquiring image data, the mobile system includes an X-axis mobile platform and a Y-axis mobile platform fixed on the mobile end of the X-axis mobile platform; the optical sensor is a camera; the camera is an area array camera or a line scan camera.

[0006] A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces, characterized by comprising the following steps:

[0007] S1. Initial settings:

[0008] Set the optical sensor system at the initial height, prepare the mobile system and fix the sample on the moving end of the Y-axis mobile platform, and set the plane where the sample is located as the working surface;

[0009] S2. Data collection:

[0010] Acquire comprehensive image data using an optical sensor system at predetermined heights and positions;

[0011] S3. Data processing:

[0012] Dividing the image data into sub-regions for calculating the optimal height of each sub-region;

[0013] S4, precision adjustment:

[0014] S41, adjustment process:

[0015] Based on the calculated inclination data, accurately adjust the position of the working surface and the optical sensor system, such as by adjusting the support structure, fine-tuning screws or other precise adjustment mechanisms;

[0016] S42, loop iteration:

[0017] Repeat steps S2-S3 until the working surface and the optical sensor system reach the required accuracy requirements.

[0018] Preferably, step S2 includes:

[0019] S21. Initial data collection:

[0020] S211: If a mobile system is used, the optical sensor system is called to obtain image information of the current field of view of the working surface at the initial height;

[0021] S212: If the mobile system is not used, the area array camera is set at the defocused position h1 to capture image information of the work surface to be adjusted as the information of the first column of field of view 1;

[0022] S22, position change collection:

[0023] Control the X-axis mobile platform to move the work surface horizontally, and call the optical sensor to obtain image information of the work surface;

[0024] S23, height change collection:

[0025] Adjust the Y-axis moving platform to change the distance between the optical sensor system and the work surface, repeat the above process, and obtain image data of the work surface at different heights.

[0026] Preferably, step S3 includes:

[0027] S31. Sub-area division:

[0028] S311: If the camera is an area array camera, the acquired image data is divided into sub-regions with multiple rows and columns, each sub-region corresponding to a small area on the working surface, to facilitate detailed analysis;

[0029] S312: If the camera is a line scan camera, divide each column of image data into multiple regions according to the required accuracy, with one region in each column as a basic unit, and each region is divided into multiple column sub-regions;

[0030] S313: If the mobile system is not used and the camera is an area array camera, the image data within a single field of view is divided into multiple sub-areas according to the required accuracy;

[0031] S32, optimal height calculation: for each sub-region, calculate its optimal height using an algorithm based on image quality assessment;

[0032] S33, inclination calculation: Analyze the optimal height data and calculate the absolute inclination of the working surface and the optical sensor system;

[0033] S34, data analysis: by analyzing the calculation results of multiple sub-areas, the absolute inclinations of the working surface and the optical sensor system relative to the reference surface are obtained respectively;

[0034] Preferably, the step S32 includes:

[0035] S321, optimization method based on gradient value:

[0036] For each sub-region, obtain image data at different heights, calculate the gradient value of each image, and select the height with the highest gradient value as the optimal height of the sub-region;

[0037] The core idea of ​​this method is that the image is clearest at the optimal height, where the gradient value is the largest;

[0038] h best =argmax(grad(I h ));

[0039] Among them, I h Represents the image acquired at height h, grad(I h ) is the gradient value of the image;

[0040] If the camera is an area array camera, the method based on normal distribution fitting is as follows:

[0041] The image quality at different heights is fitted by a normal distribution model. The gradient values ​​and gg of the images at different heights conform to the normal distribution. Statistical methods such as maximum likelihood estimation (MLE) are used to fit these data, and the mean position of the distribution is selected as the optimal height of the sub-region.

[0042] P(h)~N(μ,σ 2 );

[0043] Where P(h) represents the image quality at height h, which obeys the normal distribution N(μ, σ 2 ), where μ is the optimal height and σ is the standard deviation of the distribution; by fitting the data, h that maximizes P(h) is selected as the optimal height.

[0044] Preferably, the step S33 includes:

[0045] S331. Calculation of absolute inclination of working surface:

[0046] Compare the optimal heights of sub-areas at the same relative position under each optical field of view in the same column, eliminate the influence of the optical sensor system, and calculate the absolute inclination of the working surface;

[0047] S332, calculation of absolute tilt of optical sensor system:

[0048] Compare the optimal height changes of sub-areas at different positions within the same optical field of view and on the same column to obtain the relative tilt of the optical sensor system and the working surface. Using the known absolute tilt of the working surface, remove the influence of the working surface from the relative tilt to ultimately calculate the absolute tilt of the optical sensor system.

[0049] Divide the plane into x-direction and y-direction, and approximate a small area as a point. Take the x-direction section as an example, and the y-direction is the same;

[0050] Assume that the initial distance between the camera surface and the reference surface is h c0 , the distance between the working surface and the reference surface is h w0 , at this time the reference distance h between the working surface and the camera surface wc0 =h c0 -h w0 , the focal distance is set to h f , camera width d c , camera surface inclination θ1, working surface inclination θ2;

[0051] Take any point on the working surface, set it as point 1, and the horizontal distance between point 1 and the reference point is d w1 , then the vertical distance h from point 1 to the reference plane is w1=h w0 +d w1 *sinθ2, point 1 corresponds to the point in the camera and the position offset distance inside the camera is d c1 , then the distance h from the corresponding camera point to the reference plane c1 =h c0 +d c1 *sinθ1;

[0052] Therefore, the distance between point 1 and the corresponding point of the camera is:

[0053] h wc1 =h c1 -h w1 =h wc0 +d w1 *sinθ2-(d c1 *sinθ1), (Formula 1)

[0054] Based on the above knowledge, the optimal height distribution obtained in step S3 is divided into three columns abc, each column has three viewing areas, and each viewing area contains three rows and three columns, a total of 9 small areas.

[0055] Preferably, the step S332 includes:

[0056] S3321. Calculation of the inclination of the working surface in the X direction:

[0057] S3322, Calculation of camera surface X-direction tilt:

[0058] Points in the same column along the x direction within the same field of view, such as H a11 , H a12 , H a13 ,;

[0059] According to formula 1, we have:

[0060]

[0061] Similarly:

[0062] H a11 -H a13 =(d a11-w1 -d a13-w1 )*sinθ2+(d a13-c1 -d a11-c1 )

[0063] *sinθ1;

[0064] but:

[0065] θ1=sin -1 H a11 -H a12 -(d a11-w1-d a12-w1 )*sinθ2 / (d a12-c1 -d a11-c1 );θ1=sin -1 H a11 -H a13 -(d a11-w1 -d a13-w1 )*sinθ2 / (d a13-c1 -d a11-c1 );

[0066] Due to measurement errors, we average the angles obtained at different points, and we have:

[0067]

[0068] Since the above calculation is valid for different positions of points in the same x direction within the same field of view, multiple groups of points are added to the calculation;

[0069] The distance d corresponding to points in different regions is xxx-w1 Recorded in steps S1-S2, the corresponding optimal height H x x It has been obtained in step S3, so the inclination θ1 of the optical surface in the X direction can be obtained;

[0070] By traversing all the visual field areas, calculating their optical surface X-direction inclination θ1 and averaging them, we can obtain a more accurate optical surface X-direction inclination θ1;

[0071] S3323. Calculation of the X-direction inclination θ2 of the partial and overall working surfaces:

[0072] Since the obtained θ2 values ​​come from a small number of points, different results can be obtained according to different averaging methods;

[0073] If θ1 obtained from different fields of view for the same row is compared, the obtained value is the change in the X-direction tilt of the field of view corresponding to the row;

[0074] If the θ1 obtained for all points in the same row are averaged, the average inclination of the working surface in the X direction of the row is obtained;

[0075] If the average X-direction inclinations of the working surfaces of different rows are averaged, the overall X-direction inclination of the working surface can be obtained;

[0076] S3324. Calculation of the inclination between the working surface and the optical surface in the Y direction.

[0077] Preferably, the step S3321 includes:

[0078] S33211: If a mobile system is used and the camera is an area array camera, based on the above basic knowledge, for points with the same relative position in different fields of view, such as H a11 , H b11 , H c11 , it is obvious that the position offset distance of the points in the camera is the same, set as d c , then according to formula 1:

[0079] H a11 -H b11 =h wc0 +d a11-w1 *sinθ2-(d c *sinθ1)-(h wc0

[0080] +d b11-w1 *sinθ2-(d c *sinθ1))

[0081] =(d a11-w1 -d b11-w1 )*sinθ2;

[0082] Similarly:

[0083] H a11 -H c11 =(d a11-w1 -d c11-w1 )*sinθ2;

[0084] Then we have:

[0085] θ2=sin -1 H a11 -H b11 / (d a11-w1 -d b11-w1 );

[0086] θ2=sin -1 H a11 -H c11 / (d a11-w1 -d c11-w1 );

[0087] Due to measurement errors, we average the angles obtained at different points, and we have:

[0088]

[0089] Since the above calculation is valid for points in different regions with the same relative position, multiple groups of points are added to the calculation;

[0090] The distance d corresponding to different areas xxx-w1Recorded in steps S1-S2, the corresponding optimal height H xxx It has been found, so the inclination of the working surface in the X direction θ2 can be calculated;

[0091] S33212: If the camera is a line scan camera, calculate the inclination of the working surface in the X direction:

[0092] Since only the columns divided along the X direction are needed to calculate the inclination θ2 in the X direction and the inclination θ1 in the X direction of the camera surface, the inclination θ2 in the X direction and the inclination θ1 in the X direction of the camera surface can be calculated;

[0093] S33213: If the system is not used and the camera is an area array camera, the relative inclination θ between the working surface and the optical surface in the X direction is calculated as follows:

[0094] Assume that the relative inclination between the working surface and the optical surface is θ, set one end of the working surface as the reference starting point, and the reference distance between the working surface and the optical surface is h. wc0 , the horizontal distance between any point 1 on the working surface and the reference starting point is d1, and the distance H1 between the working surface of point 1 and the optical surface is:

[0095] H1=h wc0 +d1*sinθ;

[0096] The difference between different points in the same column is:

[0097] H a11 -H a12 =(d a11 -d a12 )*sinθ;

[0098] H a11 -H a13 =(d a11 -d a13 )*sinθ;

[0099] but:

[0100] θ=sin -1 H a11 -H a12 / (d a11 -d a12 );

[0101] θ=sin -1 H a11 -H a13 / (d a11 -d a13 );

[0102] Due to measurement errors, the angles obtained at different points are averaged, and we have:

[0103]

[0104] Since the above calculations are valid for different points in the same column, multiple groups of points are added to the calculations;

[0105] The distance d corresponding to different areas x is the optical parameter of the system, which is directly obtained from the structural parameters of the system. The corresponding optimal height H xxx It has been found, so the relative inclination θ between the working surface and the optical surface in the X direction can be calculated;

[0106] Preferably, the step S3324 includes:

[0107] S33241: If a mobile system is used and the camera is an area scan or line scan camera, since the direction selection is not specific, the Y-direction data in the above formula can be replaced with the corresponding Y-direction data to obtain the Y-direction inclination between the working surface and the optical surface.

[0108] S33242: If a mobile system is not used and the camera is an area array camera, since the direction selection is not specific, the relative inclination θ between the working surface and the optical surface in the Y direction can be obtained by replacing the X direction data in the formula with the corresponding Y direction data.

[0109] Compared with the prior art, the advantages of the present invention are:

[0110] 1. The present invention realizes micron-level high-precision absolute tilt measurement:

[0111] Technical means: By relying on the high-precision motion control of the vertical motor for measurement accuracy and combining it with precise height measurement data in multiple areas, the inclination of the working surface and the optical surface can be accurately measured respectively.

[0112] Different from existing technologies: Traditional methods mainly rely on the resolution of spirit levels or optical sensors, which are difficult to break through accuracy limitations; this invention uses high-precision motors and algorithms to improve measurement accuracy to the range of motor motion accuracy, easily achieving absolute inclination measurement with micron-level or even higher accuracy.

[0113] 2. The present invention can measure the absolute inclination of the working surface and the optical system relative to the reference surface respectively:

[0114] Technical means: Using a multi-row and multi-column data analysis method, by comparing the changes in the optimal height of different sub-areas, the influence of the optical system and the working surface is separated, and the absolute inclination of the two is independently calculated.

[0115] Different from the existing technology: traditional optical methods can usually only measure relative parallelism and cannot obtain absolute inclination; the present invention uses an innovative algorithm to achieve independent measurement of the absolute inclination of the working surface and the optical system, providing more comprehensive inclination information.

[0116] 3. The present invention expands the scope of application and can adapt to complex working environments:

[0117] Technical means: Due to the use of non-contact optical measurement methods and the absence of the need to place measurement tools directly on the surface to be adjusted, the system can work in various spatial environments.

[0118] Different from the existing technology: traditional tools such as levelers are difficult to use when space is limited, the ground is uneven, or the equipment layout is complex; the present invention overcomes these limitations and is suitable for complex spatial environments and diverse adjustment needs.

[0119] 4. The present invention simplifies the operation process and reduces equipment costs:

[0120] Technical means: No need to rely on traditional levels or special adjustment tools, measurement and adjustment can be completed only through optical sensors and motion control systems.

[0121] Unlike existing technologies, which require specialized adjustment tools and manual operation, increasing equipment costs and operational complexity, this invention reduces reliance on manual labor and specialized equipment, simplifies operational procedures, and improves work efficiency.

[0122] 5. The present invention improves the adjustment flexibility and realizes precise adjustment in all directions:

[0123] Technical means: By accurately calculating the inclination data of the optical surface and the working surface, the angle between the working surface and the optical surface can be accurately adjusted as needed to achieve precise adjustment in all directions.

[0124] Different from the existing technology: the traditional method has a single function and can usually only perform horizontal adjustment; the present invention can adapt to the needs of precise adjustment in multiple directions and angles, and is particularly suitable for situations where the optical system itself cannot be leveled.

[0125] 6. The present invention enhances system reliability and ensures consistency in measurement and regulation:

[0126] Technical means: Through precise motor control and innovative calculation algorithms, the accuracy of measurement data and the stability of the adjustment process are ensured.

[0127] Different from the existing technology: the traditional method is limited by manual operation and tool accuracy, and the measurement and adjustment results are easily affected by subjective factors; the present invention improves the reliability and consistency of the system through automated control and calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0128] Figure 1 It is a structural principle diagram of the present invention;

[0129] Figure 2 This is the multi-region optimal height distribution map of the present invention;

[0130] Figure 3 This is the optimal height distribution diagram of the line scan multiple regions of the present invention;

[0131] Figure 4 This is the optimal height distribution diagram for a single area of ​​the surface array of the present invention;

[0132] Figure 5 A schematic diagram of the distance between each surface of the system of the present invention;

[0133] Figure 6 Schematic diagram of the working surface pattern of the present invention. DETAILED DESCRIPTION

[0134] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0135] In order to keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and known components are omitted.

[0136] like Figure 1 As shown, an optical device for precise measurement and adjustment of the inclination of multiple working surfaces includes an optical sensor system, a mobile system, and a data processing unit that cooperate with each other. The optical sensor system includes a lifting device and an optical sensor fixed to the mobile end of the lifting device and connected to the data processing unit for signal acquisition of image data. The mobile system includes an X-axis mobile platform and a Y-axis mobile platform fixed to the mobile end of the X-axis mobile platform.

[0137] The optical sensor is a camera;

[0138] The camera is an area scan camera or a line scan camera;

[0139] A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces:

[0140] S1. Initial settings:

[0141] Set the optical sensor system to the initial height, prepare the mobile system and fix the sample on the moving end of the Y-axis mobile platform, and set the plane where the sample is located as the working surface. Figure 6 ;

[0142] S2. Data collection:

[0143] Acquire comprehensive image data using an optical sensor system at predetermined heights and positions;

[0144] S21. Initial data collection:

[0145] S211: If a mobile system is used, the optical sensor system is called to obtain image information of the current field of view of the working surface at the initial height;

[0146] S212: If the mobile system is not used, the area array camera is set at the defocused position h1 to capture image information of the work surface to be adjusted as the information of the first column of field of view 1;

[0147] S22, position change collection:

[0148] Control the X-axis mobile platform to move the work surface horizontally, and call the optical sensor to obtain image information of the work surface;

[0149] S23, height change collection:

[0150] Adjust the Y-axis mobile platform to change the distance between the optical sensor system and the work surface, repeat the above process, and obtain image data of the work surface at different heights;

[0151] S3. Data processing:

[0152] Dividing the image data into sub-regions for calculating the optimal height of each sub-region;

[0153] S31. Sub-area division:

[0154] S311: If the camera is an area array camera, the acquired image data is divided into sub-regions with multiple rows and columns, each sub-region corresponding to a small area on the working surface, to facilitate detailed analysis;

[0155] S312: If the camera is a line scan camera, the image data of each column is divided into multiple regions according to the required accuracy, with one region in each column as the basic unit, and each region is divided into multiple column sub-regions; Figure 3 As shown, the image in each region is divided into 3 columns of sub-regions;

[0156] S313: If the mobile system is not used and the camera is an area array camera, the area array camera can only be moved up and down by means of a lifting device, and thus can only adjust the inclination of the working surface relative to the horizontal plane; the image data within a single field of view is divided into multiple sub-areas according to the required accuracy, such as Figure 4 As shown, the image in each field of view is divided into sub-areas of 3 rows and 3 columns;

[0157] S32, optimal height calculation: For each sub-region, use an algorithm based on image quality assessment (such as gradient value optimization algorithm, normal distribution fitting method, etc.) to calculate its optimal height, see Figure 2 ;

[0158] The optimization method based on gradient value is as follows:

[0159] For each sub-region, image data at different heights are obtained, the gradient value of each image is calculated, and the height with the highest gradient value is selected as the optimal height of the sub-region.

[0160] The core idea of ​​this method is that the image is clearest at the optimal height and the gradient value is the largest at this point.

[0161] h best =argmax(grad(I h ));

[0162] Among them, I h Represents the image acquired at height h, grad(I h ) is the gradient value of the image.

[0163] If the camera is an area array camera, the method based on normal distribution fitting is as follows:

[0164] The image quality at different heights is fitted by the normal distribution model. The gradient values ​​and gg of the images at different heights conform to the normal distribution. Statistical methods such as maximum likelihood estimation (MLE) are used to fit these data, and the mean position of the distribution is selected as the optimal height of the sub-region.

[0165] P(h)~N(μ,σ 2 );

[0166] Where P(h) represents the image quality at height h, which obeys the normal distribution N(μ, σ 2 ), where μ is the optimal height and σ is the standard deviation of the distribution; by fitting the data, h that maximizes P(h) is selected as the optimal height.

[0167] S33, inclination calculation: Analyze the optimal height data and calculate the absolute inclination of the working surface and the optical sensor system;

[0168] S331. Calculation of absolute inclination of working surface:

[0169] Compare the optimal heights of sub-areas at the same relative position under each optical field of view in the same column, eliminate the influence of the optical sensor system, and calculate the absolute inclination of the working surface;

[0170] S332, calculation of absolute tilt of optical sensor system:

[0171] Compare the optimal height changes of sub-areas at different positions within the same optical field of view and on the same column to obtain the relative tilt of the optical sensor system and the working surface. Using the known absolute tilt of the working surface, remove the influence of the working surface from the relative tilt to ultimately calculate the absolute tilt of the optical sensor system.

[0172] For a camera, optimal clarity can only be achieved when the distance of an area reaches the optimal focusing distance. Therefore, the optimal height of each area calculated above is closely related to the distance of that area from the camera. In other words, the optimal clarity of different areas occurs at different heights, and these heights actually correspond to the optimal focusing distance of that area from the camera.

[0173] If you are using a mobile system, Figure 5 As shown, the plane is divided into the x-direction and the y-direction, and a small area is approximated as a point. Take the x-direction section as an example, and the y-direction is the same;

[0174] Assume that the initial distance between the camera surface and the reference surface is h c0 , the distance between the working surface and the reference surface is h w0 , at this time the reference distance h between the working surface and the camera surface wc0 =h c0 -h w0 , the focal distance is set to h f , camera width d c , camera surface inclination θ1, work surface inclination θ2, (subscripts c, w, f are the first letters of camera, work and focal respectively);

[0175] Take any point on the working surface, set it as point 1, and the horizontal distance between point 1 and the reference point is d w1 , then the vertical distance h from point 1 to the reference plane is w1 =h w0 +d w1 *sinθ2, point 1 corresponds to the point in the camera and the position offset distance inside the camera is d c1 , then the distance h from the corresponding camera point to the reference plane c1 =h c0 +d c1 *sinθ1;

[0176] Therefore, the distance between point 1 and the corresponding point of the camera is:

[0177] h wc1 =h c1 -h w1 =h wc0 +d w1 *sinθ2-(d c1 *sinθ1), (Formula 1)

[0178] According to the above knowledge, if Figure 2 As shown, the obtained optimal height distribution is divided into three columns abc, each column has three visual fields, and each visual field contains three rows and three columns, a total of 9 small areas;

[0179] S3321. Calculation of the inclination of the working surface in the X direction:

[0180] S33211: If a mobile system is used and the camera is an area array camera, based on the above basic knowledge, for points with the same relative position in different fields of view, such as H a11 , H b11 , H c11 , it is obvious that the position offset distance of the points in the camera is the same, set as d c , then according to formula 1:

[0181] H a11 -H b11 =h wc0 +d a11-w1 *sinθ2-(d c *sinθ1)-(h wco

[0182] +d b11-w1 *sinθ2-(d c *sinθ1))

[0183] =(d a11-w1 -d b11-w1 )*sinθ2

[0184] Similarly:

[0185] H a11 -H c11 =(d a11-w1 -d c11-w1 )*sinθ2;

[0186] Then we have:

[0187] θ2=sin -1 H a11 -H b11 / (d a11-w1 -d b11-w1 )

[0188] θ2=sin -1 H a11 -H c11 / (d a11-w1 -d c11-w1 )

[0189] Due to measurement errors, we average the angles obtained at different points, and we have:

[0190]

[0191] Since the above calculation is valid for points in different regions with the same relative position, we can add multiple groups of points into the calculation, such as (H a12 , H b12 , H c12 )、(H a13 , H b13 , H c13 )wait.

[0192] The distance d corresponding to different areas in formula 2 xxx-w1 Recorded in steps S1-S2, the corresponding optimal height H xxx It has been found, so the inclination θ2 of the working surface in the X direction can be found.

[0193] S33212: If the camera is a line scan camera, calculate the inclination of the working surface in the X direction:

[0194] Since only the columns divided along the X direction are needed to calculate the inclination θ2 in the X direction and the inclination θ1 in the X direction of the camera surface, we use Figure 5 The corresponding data in the X direction can be used to calculate the inclination θ2 and the camera surface X direction inclination θ1.

[0195] S33213: If the system is not used and the camera is an area array camera, the relative inclination θ between the working surface and the optical surface in the X direction is calculated as follows:

[0196] Assume that the relative inclination between the working surface and the optical surface is θ, set one end of the working surface as the reference starting point, and the reference distance between the working surface and the optical surface is h. wc0 , the horizontal distance between any point 1 on the working surface and the reference starting point is d1, and the distance H1 between the working surface of point 1 and the optical surface is:

[0197] H1=h wc0 +d1*sinθ

[0198] Then Figure 4 For example, the difference between different points in the same column is:

[0199] H a11 -H a12 =(d a11 -d a12)*sinθ

[0200] H a11 -H a13 =(d a11 -d a13 )*sinθ then:

[0201] θ=sin -1 H a11 -H a12 / (d a11 -d a12 )

[0202] θ=sin -1 H a11 -H a13 / (d a11 -d a13 )

[0203] Due to measurement errors, we average the angles obtained at different points, and we have

[0204]

[0205] Since the above calculation is valid for different points in the same column, we can add multiple groups of points into the calculation, such as (H a21 ,H a22 ,H a23 )、(H a31 ,H a32 ,H a33 )wait.

[0206] The distance d corresponding to different areas in formula 4 x is the optical parameter of the system, which can be directly obtained from the structural parameters of the system. The corresponding optimal height H xxx Since θ is obtained, the relative inclination θ between the working surface and the optical surface in the X direction can be obtained.

[0207] S3322, Calculation of camera surface X-direction tilt:

[0208] Points in the same column along the x direction within the same field of view, such as H a11 , H a12 , H a13 ,

[0209] According to formula 1, we have:

[0210] H a11 -H a12 =h wc0 +d a11-w1 *sinθ2-(d a11-c1 *sinθ1)

[0211] (h wc0+d a12-w1 *sinθ2-(d a12-c1 *sinθ1))

[0212] =(d a11-w1 -d a12-w1 )*sinθ2+(d a12-c1 -d a11-c1 )*sinθ1

[0213] Similarly:

[0214] H a11 -H a13 =(d a11-w1 -d a13-w1 )*sinθ2+(d a13-c1 -d A11-c1 )

[0215] *sinθ1

[0216] but:

[0217] θ1=sin -1 H a11 -H a12 -(d a11-w1 -d a12-w1 )*sinθ2 / (d a12-c1 -d a11-c1)

[0218] θ1=sin -1 H a11 -H a13 -(d a11-w1 -d a13-w1 )*sinθ2 / (d a13-c1 -d a11-c1 )

[0219] Due to measurement errors, we average the angles obtained at different points, and we have:

[0220]

[0221] Since the above calculation is valid for different positions in the same x direction within the same field of view, we can add multiple groups of points into the calculation, such as (H a21 , H a22 , H a23 )、(H a31 , H a32 , H a33 )wait.

[0222] The distance d corresponding to points in different regions in formula 3 xxx-w1 Record the corresponding optimal height H in step 1-2 x xθ1 has been obtained, and θ2 has also been obtained, so the inclination θ1 of the optical surface in the X direction can be obtained.

[0223] By traversing all the visual field areas, calculating their optical surface X-direction inclination θ1 and averaging them, we can obtain the optical surface X-direction inclination θ1 with higher accuracy.

[0224] S3323. Calculation of the X-direction inclination θ2 of the partial and overall working surfaces:

[0225] Since the obtained θ2 values ​​come from a small number of points, we can obtain different results based on different averaging methods.

[0226] If we compare the θ1 obtained from different fields of view for the same row, we can obtain the change in the X-direction tilt of the field of view corresponding to the row.

[0227] If we average the θ1 obtained from all points in the same row, we get the average inclination in the X direction of the working surface of the row.

[0228] If the average X-direction inclinations of the working surfaces of different rows are averaged, we can obtain the overall X-direction inclination of the working surface.

[0229] S3324. Calculation of the inclination between the working surface and the optical surface in the Y direction:

[0230] S33241: If a mobile system is used and the camera is an area array or line scan camera, since the direction selection is not specific, the Y direction data in the above formula can be replaced with the corresponding Y direction data to obtain the Y direction inclination between the working surface and the optical surface.

[0231] S33242: If a mobile system is not used and the camera is an area array camera, since the direction selection is not specific, the relative inclination θ between the working surface and the optical surface in the Y direction can be obtained by replacing the X direction data in the above formula with the corresponding Y direction data.

[0232] S34. Data Analysis:

[0233] By analyzing the calculation results of multiple sub-areas, the absolute inclinations of the working surface and the optical sensor system relative to the reference surface are obtained respectively;

[0234] S4, precision adjustment:

[0235] S41, adjustment process:

[0236] Based on the calculated inclination data, accurately adjust the position of the working surface and the optical sensor system, such as by adjusting the support structure, fine-tuning screws or other precise adjustment mechanisms;

[0237] If the working surface deviates 10 degrees from the horizontal X direction and needs to be leveled, rotate the working surface -10 degrees in the horizontal X direction to level it. If the deviation from the horizontal X direction is 30 degrees, rotate the working surface 20 degrees in the horizontal X direction. Similar methods can be used for the Y direction of the working surface and the optical surface.

[0238] S42, loop iteration:

[0239] Repeat steps S2-S4 until the working surface and the optical sensor system reach the required accuracy requirements.

[0240] Features of the present invention:

[0241] 1. Innovative data collection and processing methods:

[0242] Specific motion path design: A specific motion path is proposed for the optical sensor and the work surface. By controlling the vertical and horizontal movement of the optical sensor and the work surface, image data of multiple areas of the work surface can be acquired at different heights and positions.

[0243] Multi-area optimal height calculation: Utilizes optical sensors (such as cameras) to obtain image information of multiple work surface locations at different heights. Adopting innovative algorithms, the optimal height of each sub-area is calculated, accurately assessing the height difference between the work surface and the optical system.

[0244] 2. Innovative algorithm for inclination calculation:

[0245] Separate the influence of the optical system and the working surface: Through multi-row and multi-column data analysis methods, compare the data changes at the same relative position under different optical fields in the same column, separate the influence of the optical system, and independently calculate the absolute inclination of the working surface relative to the reference surface.

[0246] Independent calculation of optical system tilt: Within the same optical field of view, data changes at different locations are analyzed to calculate the tilt variation of the optical system and the working surface. By isolating the known working surface tilt, the absolute tilt of the optical system relative to the reference surface is obtained.

[0247] Global tilt assessment: By calculating the results of multiple sub-areas individually or averaging them, the absolute tilt change of each sub-area can be independently assessed, and the global absolute tilt change can be further derived.

[0248] 3. Efficient computing algorithms and data processing:

[0249] Algorithm optimization: The optimization algorithm based on gradient value and normal distribution fitting method are adopted to accurately calculate the optimal height of each sub-area, thereby improving the accuracy and efficiency of the calculation.

[0250] Multi-region data fusion: By fusing the best height data from multiple sub-regions, the robustness and accuracy of the inclination calculation are improved, and the impact of errors in a single region on the overall measurement results is reduced.

[0251] 4. Supporting motion control strategy:

[0252] Combination of motion path and algorithm: A motion path is designed to closely cooperate with the calculation algorithm to ensure the acquisition of necessary data at key positions and heights, thereby improving the effectiveness of data acquisition; High-precision motion control: Utilizing high-precision vertical and horizontal moving mechanisms, micron-level motion accuracy is achieved, providing hardware support for high-precision measurement.

[0253] 5. Omnidirectional precision adjustment capability:

[0254] Independent adjustment of the working surface and optical system: By calculating the absolute inclination of the working surface and the optical system separately, they can be adjusted independently to meet different application requirements.

[0255] Adaptable to complex working environments: Due to the use of innovative algorithms and motion path design, high-precision adjustment can be achieved in complex spatial environments without relying on traditional adjustment tools.

[0256] Application scenarios:

[0257] 1. Laboratory equipment installation and production line commissioning:

[0258] During the installation, debugging and calibration of high-precision instruments, especially when large equipment requires precise alignment, the system of the present invention can provide micron-level working surface adjustment accuracy. Through high-precision inclination measurement and omnidirectional adjustment capabilities, it can effectively reduce installation time and improve the performance stability of the equipment.

[0259] 2. Micro-optical equipment adjustment:

[0260] The high-precision absolute tilt measurement method of the present invention is suitable for scenarios with extremely high requirements for optical system adjustment, such as microscopes, lasers, and optical platforms. It can achieve precise positioning and angle adjustment of optical components, thereby improving the imaging quality and performance of the optical system.

[0261] 3. Automation control system integration:

[0262] The present invention can be integrated with an automated control system to achieve unattended precision adjustment through a preset control program, which can improve production efficiency, ensure consistency in product quality, and reduce labor costs in a large-scale production environment.

[0263] 4. Precision manufacturing and testing:

[0264] In the manufacturing and inspection processes of semiconductor manufacturing, precision machining, optical component production, etc., which require precise adjustment of the working surface angle, the present invention can provide high-precision inclination measurement and adjustment, which helps to improve the processing accuracy and quality control level of the product and meet the needs of high-end manufacturing.

[0265] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. 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. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An optical device for precise measurement and adjustment of the inclination of multiple working surfaces, characterized in that: The invention comprises an optical sensor system, a mobile system and a data processing unit that cooperate with each other. The optical sensor system comprises a lifting device and an optical sensor fixed on the mobile end of the lifting device and connected to the data processing unit by signal for acquiring image data. The mobile system comprises an X-axis mobile platform and a Y-axis mobile platform fixed on the mobile end of the X-axis mobile platform. The optical sensor is a camera; the camera is an area array camera or a line scan camera.

2. A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 1, characterized in that: The following steps are involved: S1. Initial settings: Set the optical sensor system at the initial height, prepare the mobile system and fix the sample on the moving end of the Y-axis mobile platform, and set the plane where the sample is located as the working surface; S2. Data collection: Acquire comprehensive image data using an optical sensor system at predetermined heights and positions; S3. Data processing: Dividing the image data into sub-regions for calculating the optimal height of each sub-region; S4, precision adjustment: S41, adjustment process: Based on the calculated inclination data, accurately adjust the position of the working surface and the optical sensor system, such as by adjusting the support structure, fine-tuning screws or other precise adjustment mechanisms; S42, loop iteration: Repeat steps S2-S3 until the working surface and the optical sensor system reach the required accuracy requirements.

3. A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 2, characterized in that: The step S2 comprises: S21. Initial data collection: S211: If a mobile system is used, the optical sensor system is called to obtain image information of the current field of view of the working surface at the initial height; S212: If the mobile system is not used, the area array camera is set at the defocused position h1 to capture image information of the work surface to be adjusted as the information of the first column of field of view 1; S22, position change collection: Control the X-axis mobile platform to move the work surface horizontally, and call the optical sensor to obtain image information of the work surface; S23, height change collection: Adjust the Y-axis moving platform to change the distance between the optical sensor system and the work surface, repeat the above process, and obtain image data of the work surface at different heights.

4. A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 3, characterized in that: The step S3 comprises: S31. Sub-area division: S311: If the camera is an area array camera, the acquired image data is divided into sub-regions with multiple rows and columns, each sub-region corresponding to a small area on the working surface, to facilitate detailed analysis; S312: If the camera is a line scan camera, divide each column of image data into multiple regions according to the required accuracy, with one region in each column as a basic unit, and each region is divided into multiple column sub-regions; S313: If the mobile system is not used and the camera is an area array camera, the image data within a single field of view is divided into multiple sub-areas according to the required accuracy; S32, optimal height calculation: for each sub-region, calculate its optimal height using an algorithm based on image quality assessment; S33, inclination calculation: Analyze the optimal height data and calculate the absolute inclination of the working surface and the optical sensor system; S34, data analysis: by analyzing the calculation results of multiple sub-areas, the absolute inclinations of the working surface and the optical sensor system relative to the reference surface are obtained respectively; 5. A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 4, characterized in that: The step S32 includes: S321. Optimization method based on gradient value: For each sub-region, obtain image data at different heights, calculate the gradient value of each image, and select the height with the highest gradient value as the optimal height of the sub-region; The core idea of ​​this method is that the image is clearest at the optimal height, where the gradient value is the largest; h best =argmax(grad(I h )); Among them, I h Represents the image acquired at height h, grad(I h ) is the gradient value of the image; If the camera is an area array camera, the method based on normal distribution fitting is as follows: The image quality at different heights is fitted by a normal distribution model. The gradient values ​​and gg of the images at different heights conform to the normal distribution. Statistical methods such as maximum likelihood estimation (MLE) are used to fit these data, and the mean position of the distribution is selected as the optimal height of the sub-region. p(h)~N(μ,σ 2 ); Where p(h) represents the image quality at height h, which obeys the normal distribution N(μ, σ 2 ), where μ is the optimal height and σ is the standard deviation of the distribution; by fitting the data, h that maximizes P(h) is selected as the optimal height.

6. A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 4, characterized in that: The step S33 includes: S331. Calculation of absolute inclination of working surface: Compare the optimal heights of sub-areas at the same relative position under each optical field of view in the same column, eliminate the influence of the optical sensor system, and calculate the absolute inclination of the working surface; S332, calculation of absolute tilt of optical sensor system: Compare the optimal height changes of sub-areas at different positions within the same optical field of view and on the same column to obtain the relative tilt of the optical sensor system and the working surface. Using the known absolute tilt of the working surface, remove the influence of the working surface from the relative tilt to ultimately calculate the absolute tilt of the optical sensor system. Divide the plane into x-direction and y-direction, and approximate a small area as a point. Take the x-direction section as an example, and the y-direction is the same; Assume that the initial distance between the camera surface and the reference surface is h c0 , the distance between the working surface and the reference surface is h w0 , at this time the reference distance h between the working surface and the camera surface wc0 =h c0 -h w0 , the focal distance is set to h f , camera width d c , camera surface inclination θ1, working surface inclination θ2; Take any point on the working surface, set it as point 1, and the horizontal distance between point 1 and the reference point is d w1 , then the vertical distance h from point 1 to the reference plane is w1 =h w0 +d w1 *sinθ2, point 1 corresponds to the point in the camera and the position offset distance inside the camera is d c1 , then the distance h from the corresponding camera point to the reference plane c1 =h c0 +d c1 *sinθ1; Therefore, the distance between point 1 and the corresponding point of the camera is: h wc1 =h c1 -h w1 =h wc0 +d w1 *sinθ2-(d c1 *sinθ1),(Formula 1) Based on the above knowledge, the optimal height distribution obtained in step S3 is divided into three columns abc, each column has three viewing areas, and each viewing area contains three rows and three columns, a total of 9 small areas.

7. A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 6, characterized in that: The step S332 includes: S3321. Calculation of the inclination of the working surface in the X direction: S3322, Calculation of camera surface X-direction tilt: Points in the same column along the x direction within the same field of view, such as H a11 , H a12 , H a13 ,; According to formula 1, we have: Similarly: H a11 -H a13 =(d a11-w01 -d a13-w1 )*sinθ2+(d a13-c1 -d a11-c1 ) *sinθ1; but: θ1=sin -1 H a11 -H a12 -(d a11-w1 -d a12-w1 )*sinθ2 / (d a12-c1 -d a11-c1 );θ1=sin -1 H a11 -H a13 -(d a11-w1 -d a13-w1 )*sinθ2 / (d a13-c1 -d a11-c1 ); Due to measurement errors, we average the angles obtained at different points, and we have: Since the above calculation is valid for different positions of points in the same x direction within the same field of view, multiple groups of points are added to the calculation; The distance d corresponding to points in different regions is xxx-w1 Recorded in steps S1-S2, the corresponding optimal height H xx It has been obtained in step S3, so the inclination θ1 of the optical surface in the X direction can be obtained; By traversing all the visual field areas, calculating their optical surface X-direction inclination θ1 and averaging them, we can obtain a more accurate optical surface X-direction inclination θ1; S3323. Calculation of the X-direction inclination θ2 of the partial and overall working surfaces: Since the obtained θ2 values ​​come from a small number of points, different results can be obtained according to different averaging methods; If θ1 obtained from different fields of view for the same row is compared, the obtained value is the change in the X-direction tilt of the field of view corresponding to the row; If the θ1 obtained for all points in the same row are averaged, the average inclination of the working surface in the X direction of the row is obtained; If the average X-direction inclinations of the working surfaces of different rows are averaged, the overall X-direction inclination of the working surface can be obtained; S3324. Calculation of the inclination between the working surface and the optical surface in the Y direction.

8. A calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 7, characterized in that: The step S3321 includes: S33211: If a mobile system is used and the camera is an area array camera, based on the above basic knowledge, for points with the same relative position in different fields of view, such as H a11 , H b11 , H c11 , it is obvious that the position offset distance of the points in the camera is the same, set as d c , then according to formula 1: H a11 -H b11 =h wc0 +d a11-w1 *sinθ2-(d c *sinθ1)-(h wc0 +d b11-w1 *sinθ2-(d c *sinθ1)) =(d a11-w1 -d b11-w1 )*sinθ2; Similarly: H a11 -H c11 =(d a11-w1 -d c11-w1 )*sinθ2; Then we have: θ2=sin -1 H a11 -H b11 / (d a11-w1 -d b11-w1 ); θ2=sin -1 H a11 -H a11 / (d a11-w1 -d c11-w1 ); Due to measurement errors, we average the angles obtained at different points, and we have: Since the above calculation is valid for points in different regions with the same relative position, multiple groups of points are added to the calculation; The distance d corresponding to different areas xxx-w1 Recorded in steps S1-S2, the corresponding optimal height H xxx It has been found, so the inclination of the working surface in the X direction θ2 can be calculated; S33212: If the camera is a line scan camera, calculate the inclination of the working surface in the X direction: Since only the columns divided along the X direction are needed to calculate the inclination θ2 in the X direction and the inclination θ1 in the X direction of the camera surface, the inclination θ2 in the X direction and the inclination θ1 in the X direction of the camera surface can be calculated; S33213: If the system is not used and the camera is an area array camera, the relative inclination θ between the working surface and the optical surface in the X direction is calculated as follows: Assume that the relative inclination between the working surface and the optical surface is θ, set one end of the working surface as the reference starting point, and the reference distance between the working surface and the optical surface is h. wc0 , the horizontal distance between any point 1 on the working surface and the reference starting point is d1, and the distance H1 between the working surface of point 1 and the optical surface is: H1=h wc0 +d1*sinθ; The difference between different points in the same column is: H a11 -H a12 =(d a11 -d a12 )*sinθ; H a11 -H a13 =(d a11 -d a13 )*sinθ; but: θ=sin -1 H a11 -H a12 / (d a11 -d a12 ); θ=sin -1 H a11 -H a13 / (d a11 -d a13 ); Due to measurement errors, the angles obtained at different points are averaged, and we have: Since the above calculations are valid for different points in the same column, multiple groups of points are added to the calculations; The distance d corresponding to different areas x is the optical parameter of the system, which is directly obtained from the structural parameters of the system. The corresponding optimal height H xxx It has been found, so the relative inclination θ between the working surface and the optical surface in the X direction can be calculated; 9. The calculation method for precise measurement and adjustment of the inclination of multiple working surfaces according to claim 7, characterized in that: The step S3324 includes: S33241: If a mobile system is used and the camera is an area scan or line scan camera, since the direction selection is not specific, the Y-direction data in the above formula can be replaced with the corresponding Y-direction data to obtain the Y-direction inclination between the working surface and the optical surface. S33242: If a mobile system is not used and the camera is an area array camera, since the direction selection is not specific, the relative inclination θ between the working surface and the optical surface in the Y direction can be obtained by replacing the X direction data in the formula with the corresponding Y direction data.

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