Wafer chip pre-scanning positioning method and system

Abstract

The invention discloses a wafer chip pre-scanning positioning method and a wafer chip pre-scanning positioning system, which are used for realizing positioning operation of a camera center and a wafer center, then determining a starting point for realizing chip scanning on a wafer, and determining a subsequent scanning path, a step pitch of scanning movement and a direction of scanning movement, and relates to the technical field of semiconductor manufacturing. According to the wafer chip pre-scanning positioning method and system, the image data is acquired, the acquired image data is arranged in sequence to form the image data set, the chip features in the image data are determined according to the gray value, and the feature parts in the image data are subjected to duplicate removal operation in combination with coordinate setting; according to the method and the device, each chip is subjected to re-positioning combination to form complete MAP data, so that corresponding chip features can be effectively determined, repeated feature removal operation is more efficiently judged and realized, rapid formation of the complete MAP data is guaranteed, and scanning and positioning operation of the wafer chips is better carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and particularly to a pre-scanning and positioning method and system for wafer chips. Background Art

[0002] In the process of semiconductor manufacturing, the alignment of wafer chips is a crucial step. Wafer chips need to be aligned multiple times during the processing to ensure the accuracy of each process step. However, traditional wafer chip alignment methods often have problems such as low alignment accuracy and long processing time, seriously affecting the efficiency and quality of semiconductor manufacturing.

[0003] Refer to the patent with the title: A method for scanning a wafer disk (Patent Publication No.: CN115312431A, Patent Publication Date: November 8, 2022). By scanning M chips in the row where the reference chip is located and N chips in the column where the reference chip is located, the first scanning length and the second scanning length are obtained. According to the first scanning length and the second scanning length, the actual pitch of the chips can be obtained, and thus the mechanical coordinates of the feature points of each chip can be obtained based on the mechanical coordinates of the feature points of the reference chip and the actual pitch. Therefore, it is not necessary to scan and position each chip on the wafer disk, which can reduce the chip scanning time to improve the chip positioning efficiency. In addition, since the chips directly obtain the actual pitch of the chips according to the first scanning length and the second scanning length, without the need to input through a wafer tester, the actual pitch of the chips can be directly obtained and the mechanical coordinates of each chip can be obtained by applying the actual pitch, thereby improving the accuracy of chip positioning, preventing misalignment between the probe and the test point, and improving the accuracy of chip testing.

[0004] Based on the description of the above document, the existing wafer chips have uncertainties and may have irregular phenomena of disorderly placement, so that high-efficiency positioning operations cannot be achieved during the scanning and positioning process. At the same time, during camera acquisition, the large-range image acquisition is not clear enough, while the high-precision image acquisition involves a small field of view, which easily causes the problem of repeated features in the image data and is not convenient for forming complete image data. For this reason, the present invention provides a pre-scanning and positioning method and system for wafer chips. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a pre-scanning and positioning method and system for wafer chips, which solves the problems that the existing wafer chips have uncertainties and may have irregular phenomena of disorderly placement, so that high-efficiency positioning operations cannot be achieved during the scanning and positioning process. At the same time, during camera acquisition, the large-range image acquisition is not clear enough, while the high-precision image acquisition involves a small field of view, which easily causes the problem of repeated features in the image data and is not convenient for forming complete image data.

[0006] To achieve the above object, the present invention is realized by the following technical solutions: A pre-scanning and positioning method for a wafer chip, specifically including the following steps: Step 1: Realize the positioning operation of the camera center and the wafer center, then determine the starting point for scanning the chips on the wafer, and at the same time determine the subsequent scanning path, the step distance of scanning movement, and the direction of scanning movement; Step 2: Based on the operation in Step 1, use the camera to perform scanning and complete the image acquisition operation, arrange the acquired image data in sequence to form an image data set, determine the chip features in the image data according to the gray value, and combine the coordinate setting to perform the duplicate removal operation on the feature part in the image data, and re-position and combine each chip to form a complete MAP data; Step 3: Perform the chip mounting operation according to the complete MAP data and the positions of the corresponding chips, and display the data through a visualization interface.

[0007] Preferably, the positioning operation of the camera center and the wafer center in Step 1 is as follows: Place the wafer on the carrier table, and complete the limiting operation of the wafer through the clamping device; Mark the center of the wafer, then roughly move the camera to make the marked wafer center located in the field of view of the camera, and take the center of the cross cursor of the moving camera as the starting point, and establish the coordinate axes X 1 and Y 1 with the direction of the cross cursor adjacent to the marked wafer center. Then determine the coordinates of the marked wafer center as (x 1 , y 1 ); According to the coordinates (x 1 , y 1 ), perform the moving operation of the camera, move x 1 distance in the horizontal direction of the X 1 axis, and move y 1 distance in the horizontal direction of the Y 1 axis, so that the center of the cross cursor of the moving camera coincides with the marked wafer center to complete the positioning operation.

[0008] Preferably, the operation of determining the scanning starting point in Step 1 is as follows: Realize the image acquisition of the entire wafer, make a first ray from the wafer center in the horizontal extension direction of the X 1 axis, and a first intersection point is generated at the boundary of the wafer where the first ray intersects. Make a second ray from the wafer center in the horizontal extension direction of the Y 1 axis, and a second intersection point is generated at the boundary of the wafer where the second ray intersects; Set the tangent of the wafer boundary at the first intersection point and intersect with the X 1The axes remain parallel. Set the tangent line of the wafer boundary at the second intersection point and parallel to the Y 1 axis. The extensions of the two tangent lines intersect, and the current intersection point is the starting point of the scan; Then, at the intersection of the reverse extensions of the first ray and the second ray with the wafer boundary, the end point of the scan is obtained in the same way as the determination of the starting point of the scan.

[0009] Preferably, the operations of determining the subsequent scan path, scan moving step size, and scan moving direction in step one are as follows: Determine the scan path: The camera moves from the starting point of the scan in the direction parallel to the coordinate axis X 1 until it reaches the vertical position flush with the end point of the scan. Then the camera resets to the starting point of the scan and moves in the direction parallel to the coordinate axis Y 1 . After moving a single vertical step size, the camera synchronously moves in the direction parallel to the coordinate axis X 1 and repeats the operation until the end point of the scan; Determine the scan moving step size: Set the number of acquired images on the path in the horizontal direction parallel to the X 1 axis to be M, and the actual distance from the starting point of the scan to the end point of the scan to be L 1 . Then the distance on the path in the horizontal direction is: , and the corresponding horizontal step size is L 2 / M. The distance of the horizontal step size is positive and less than the field of view length of the camera for acquiring images; Set the number of acquired images on the path in the horizontal direction to be N, and the distance on the path in the horizontal direction parallel to the Y 1 axis is also equal to L 2 . Then the corresponding vertical step size is L 2 / N. The distance of the vertical step size is positive and less than the field of view width of the camera for acquiring images; Determine the scan moving direction: The camera moves according to the set path and completes the one-time acquisition operation of the images.

[0010] Preferably, the operation of determining the chip features in the image data according to the gray value in step two is as follows: After extracting the image data set, perform graying operations on all of them in sequence. Set pixel points equidistantly on the grayed image, and the setting of the pixel points is determined in the horizontal and vertical directions of the scan respectively; Determine the boundary points of the chip features according to the change of the gray values of the pixel points, and sequentially perform the closed-loop connection operation of the boundary points to form complete chip features.

[0011] Preferably, the operation of determining the boundary points of the chip features is: Take two pixel points with changing gray values in the horizontal direction, and set multiple analysis points at equal distances and horizontally between the two pixel points; Extract the gray values of multiple analysis points and judge the change of gray values. When it is on the left side of the chip feature, the previous analysis point when the gray value has changed is the current horizontal boundary point. When it is on the right side of the chip feature, the next analysis point when the gray value has changed is the current horizontal boundary point; Extract two pixel points with changing gray values in the vertical direction, and obtain the vertical boundary points according to the principle of obtaining the horizontal boundary points. Starting from the horizontal boundary point on the left side, form a boundary closed loop in the order of up, right, down, and left to obtain the complete chip feature.

[0012] Preferably, the step of removing duplicates from the feature part in the image data by combining coordinate settings in step two is as follows: Starting from the image data at the scanning starting point, select the adjacent image for analysis operation; Taking the lower left corner point of each image as the origin, establish the X 2 axis along the horizontal boundary of the image, and establish the Y 2 axis along the vertical boundary of the image. Mark the midpoint of the lower boundary of all chip features in the image data to form a reference point, and mark it as J hg , where h represents the chip feature corresponding to the column number, and g represents the chip feature corresponding to the row number; For the duplicate removal operation of adjacent images in the horizontal direction, record the spacing values of the reference points of adjacent chip features in the corresponding column direction, and then compare the last column item result of the left adjacent image with the first to last column item results of the right adjacent image in turn. Determine whether duplicate removal operation is required according to the comparison result; For the duplicate removal operation of adjacent images in the vertical direction, record the spacing values of the reference points of adjacent chip features in the corresponding row direction, and then compare the last row item result of the upper adjacent image with the first to last row item results of the lower adjacent image in turn. Determine whether duplicate removal operation is required according to the comparison result; After removing duplicates, the remaining chip features are repositioned and combined based on the first image feature.

[0013] Preferably, the result comparison operation principles for adjacent images in the horizontal direction or vertical direction are the same. The horizontal direction analysis point comparison operation is as follows: If the distance between each adjacent reference point between the last column item reference point J h1 and the reference point J hg in the left image and the distance between the first column item reference point J h1 and the reference point J hgIf the distance between each corresponding adjacent reference point is the same, then the first column item in the current right image is a repeated feature; Conversely, the distance between the last column item reference points in the left image is compared with the distance between the corresponding subsequent column item reference points in the right image in sequence. If no abnormal comparison result occurs during the comparison process, there is no repeated feature in the current adjacent images. If an abnormal comparison result occurs during the comparison process, there is a problem result in the corresponding column item in the current right image; At this time, it is necessary to compare the distance between the reference points of the previous column item of the column item with the problem result and the penultimate column item of the left image. If the corresponding result values are the same, all the column items including the column item with the problem result and its previous items in the right image are repeated features. Otherwise, they are normal features.

[0014] Preferably, the operation of repositioning and combining each chip to form a complete MAP data in step two is as follows: After determining the repeated features based on the determined results, the repeated features in the latter image of the current adjacent image data are removed, and the chip features that are not removed are retained; Based on the first image feature, and in accordance with the comparison direction and results, the retained chip features are filled into the first image feature in sequence for expansion. The image is expanded and features are supplemented through the horizontal distance between the chip features in the adjacent column item direction, and the image is expanded and features are supplemented through the column item distance between the chip features in the adjacent horizontal direction. Finally, a complete MAP data is formed.

[0015] The present invention also discloses a pre-scanning positioning system for wafer chips, including: Parameter setting module: used to set the starting point of the camera, and perform setting operations on the subsequent scanning path, scanning step distance, and scanning direction, and perform a one-time continuous scanning; Image acquisition module, which acquires image data through the camera based on the set scanning path; Image analysis module, which performs the operation of removing repeated features in adjacent images through the position analysis of corresponding chip features; Image positioning and recombination module, which forms a complete MAP data by repositioning and combining the retained image data; Visualization interface, used to display the positioned MAP data.

[0016] The present invention provides a pre-scanning positioning method and system for wafer chips. Compared with the prior art, it has the following beneficial effects: 1. The pre-scanning and positioning method and system for wafer chips collect images, arrange the collected image data in sequence to form an image data set, determine the chip features in the image data based on the gray values, and perform duplicate removal operations on the feature parts in the image data by combining coordinate settings. Then, reposition and combine each chip to form a complete MAP data, so as to effectively determine the corresponding chip features, more efficiently judge and implement the removal of duplicate features, ensure the rapid formation of complete MAP data, and better perform the scanning and positioning operations of wafer chips.

[0017] 2. The pre-scanning and positioning method and system for wafer chips perform the positioning operation of the camera center and the wafer center, then determine the starting point for scanning the chips on the wafer, and at the same time determine the subsequent scanning path, the step distance of scanning movement, and the direction of scanning movement. After determining the path in this way, the scanning process can be carried out in an orderly manner, and setting the starting point can completely achieve the image acquisition of all features without missing data problems. At the same time, the scanning acquisition is completed at one time, improving the efficiency of data acquisition.

[0018] 3. When there is an abnormal comparison result during the comparison of adjacent images in the pre-scanning and positioning method and system for wafer chips, there is a problem result in the corresponding column item in the current right image. At this time, it is necessary to compare the distance between the reference points of the previous column item of the column item with the problem result and the penultimate column item of the left image. If the corresponding result values are the same, all the column items including the column item with the problem result and its previous items in the right image are duplicate features; otherwise, they are normal features. This can avoid the similarity of features at intervals, achieve compensation evaluation, improve the error tolerance rate while ensuring the accuracy of determining duplicate features, so as to achieve more accurate data retention and positioning combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the operation flow chart of the scanning and positioning method of the present invention; Figure 2 is the principle block diagram of the scanning and positioning system of the present invention; Figure 3 is the schematic diagram of the positioning of the camera center and the wafer center of the present invention; Figure 4 is the schematic diagram of determining the scanning starting point of the present invention; Figure 5 is a partial schematic diagram of the present invention for scanning and collecting images according to the path. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Please refer to Figures 1 - 5 , the present invention provides three technical solutions: Embodiment 1. A method for pre-scanning and positioning a wafer chip, specifically including the following steps: Step 1. Implement the positioning operation of the camera center and the wafer center, and then determine the starting point for scanning the chips on the wafer, and at the same time determine the subsequent scanning path, the step distance of scanning movement, and the direction of scanning movement; Step 2. Based on the operation in Step 1, use the camera to perform scanning and complete the image acquisition operation, arrange the acquired image data in sequence to form an image data set, determine the chip features in the image data according to the gray value, and combine the coordinate setting to perform duplicate removal operation on the feature part in the image data, and re-position and combine each chip to form a complete MAP data; Step 3. Perform the chip mounting operation according to the complete MAP data and the positions of the corresponding chips, and display the data through a visualization interface.

[0022] Among them, through the image acquisition operation, arranging the acquired image data in sequence to form an image data set, determining the chip features in the image data according to the gray value, and combining the coordinate setting to perform duplicate removal operation on the feature part in the image data, and re-positioning and combining each chip to form a complete MAP data, so as to effectively determine the corresponding chip features, and more efficiently judge and implement the removal operation of duplicate features, so as to ensure the rapid formation of complete MAP data and better perform the scanning and positioning operation of the wafer chip.

[0023] In the embodiment of the present invention, the positioning operation of the camera center and the wafer center in Step 1 is as follows: Place the wafer on the carrier table, and complete the limiting operation of the wafer through the clamping device; Mark the center of the wafer, and then roughly move the camera to make the marked wafer center located in the field of view of the camera. Take the center of the cross cursor of the moving camera as the starting point, and establish coordinate axes X 1 and Y 1 , and then determine the coordinates of the marked wafer center as (x 1 , y 1 ); According to the coordinates (x1 , y 1 ), implement the movement operation of the mobile camera, moving horizontally along the X 1 axis by a distance of x 1 , and moving horizontally along the Y 1 axis by a distance of y 1 to make the center of the cross cursor of the mobile camera coincide with the center of the marked wafer to complete the positioning operation.

[0024] In the embodiment of the present invention, the operation of determining the scanning starting point in step one is as follows: Implement image acquisition of the entire wafer, draw a first ray from the center of the wafer in the horizontal extension direction of the X 1 axis, and a first intersection point is generated at the boundary of the wafer where the first ray intersects. Draw a second ray from the center of the wafer in the horizontal extension direction of the Y 1 axis, and a second intersection point is generated at the boundary of the wafer where the second ray intersects; Set the tangent of the wafer boundary at the first intersection point and keep it parallel to the X 1 axis. Set the tangent of the wafer boundary at the second intersection point and keep it parallel to the Y 1 axis. The extensions of the two tangents intersect, and the current intersection point is the scanning starting point; Then, at the intersection of the reverse extensions of the first ray and the second ray with the wafer boundary, the scanning end point is obtained in the same way as the determination method of the scanning starting point.

[0025] In the embodiment of the present invention, the operations of determining the subsequent scanning path, scanning moving step size, and scanning moving direction in step one are as follows: Determine the scanning path: The camera moves from the scanning starting point in the direction parallel to the coordinate axis X 1 until it reaches the vertical position level with the scanning end point, and then the camera resets to the scanning starting point and moves in the direction parallel to the coordinate axis Y 1 . After moving a single vertical step size, the camera synchronously moves in the direction parallel to the coordinate axis X 1 and repeats the operation until the scanning end point; Determine the scanning moving step size: Set the number of acquired images on the horizontal path parallel to the X 1 axis as M, and the actual distance from the scanning starting point to the scanning end point is L 1 , then the distance on the horizontal path is: , and the corresponding horizontal step size is L 2 / M. The distance of the horizontal step size is positive and less than the field of view length of the camera for image acquisition; Set the number of acquired images on the horizontal path as N, and the distance on the horizontal path parallel to the Y 1 axis is also equal to L 2, the corresponding vertical step distance is L 2 / N, and the distance of the vertical step distance is a positive value and less than the field of view width of the image collected by the camera; Determine the scanning movement direction: The camera moves according to the setting of the path and completes the one-time image acquisition operation.

[0026] Among them, by implementing the positioning operation of the camera center and the wafer center, then determining the starting point for scanning the chips on the wafer, and at the same time determining the subsequent scanning path, the step distance of the scanning movement, and the direction of the scanning movement, so as to ensure the orderly progress of the scanning process after determining the path, and setting the starting point can completely realize the image acquisition of all features, without the problem of missing data, and at the same time complete the scanning acquisition at one time, improving the efficiency of data acquisition.

[0027] In the embodiment of the present invention, the operation of determining the chip features in the image data according to the gray value in step two is as follows: After extracting the image data set, perform graying operations in sequence. Set pixel points at equal intervals on the grayed image, and the setting of the pixel points is determined in the horizontal and vertical directions of the scan respectively; Determine the boundary points of the chip features according to the change of the gray value of the pixel points, and sequentially perform the closed-loop connection operation of the boundary points to form a complete chip feature.

[0028] In the embodiment of the present invention, the operation of determining the boundary points of the chip features is as follows: Take two pixel points where the gray value changes in the horizontal direction, and set multiple analysis points at equal intervals and horizontally between the two pixel points; And extract the gray values of multiple analysis points, and judge the change of the gray value. When located on the left side of the chip feature, the previous analysis point when the gray value has changed is the current horizontal boundary point. When located on the right side of the chip feature, the next analysis point when the gray value has changed is the current horizontal boundary point; And extract two pixel points where the gray value changes in the vertical direction, and obtain the vertical boundary points according to the same principle as the horizontal boundary points, and form a boundary closed loop in the order of first up, then right, then down, and finally left starting from the horizontal boundary point on the left to obtain a complete chip feature.

[0029] In the embodiment of the present invention, the steps of removing duplicates from the feature part in the image data by combining coordinate settings in step two are as follows: Starting from the image data at the scanning starting point, select the adjacent image for analysis operation; Taking the lower left corner point of each image as the origin, establish the X 2 axis along the horizontal boundary of the image, and establish the Y 2An axis is used to mark the midpoint of the lower boundary of all chip features in the image data to form a reference point, which is marked as J. hg , where h represents the chip feature corresponding to the nth column and g represents the chip feature corresponding to the nth row. For the duplicate removal operation of adjacent images in the horizontal direction, the distance values between the reference points of adjacent chip features in the corresponding column direction are recorded. Then, the results of the last column item of the left image and the results of the first to last column items of the right image in the adjacent images are compared in sequence. Whether the duplicate removal operation is required is confirmed according to the comparison results. For the duplicate removal operation of adjacent images in the vertical direction, the distance values between the reference points of adjacent chip features in the corresponding row direction are recorded. Then, the results of the last row item of the upper image and the results of the first to last row items of the lower image in the adjacent images are compared in sequence. Whether the duplicate removal operation is required is confirmed according to the comparison results. After the duplicate removal is completed, the remaining chip features are repositioned and combined based on the first image feature.

[0030] In the embodiments of the present invention, the principle of the result comparison operation for adjacent images in the horizontal direction or vertical direction is the same. The horizontal direction analysis point comparison operation is as follows: If the distance between each adjacent reference point from the last column item reference point J h1 to the reference point J hg in the left image is the same as the distance between each corresponding adjacent reference point from the first column item reference point J h1 to the reference point J hg in the right image, then the corresponding first column item in the current right image is a duplicate feature. Conversely, the distance between the reference points of the last column item in the left image is compared with the distance between the corresponding subsequent column item reference points in the right image in sequence. If no abnormal comparison result occurs during the comparison process, there is no duplicate feature in the current adjacent images. If an abnormal comparison result occurs during the comparison process, there is a problem result in the corresponding column item in the current right image. At this time, the distance between the reference points of the previous column item of the column item with the problem result needs to be compared with the second last column item of the left image. If the corresponding result values are the same, all the column items including the column item with the problem result and its previous items in the right image are duplicate features. Otherwise, they are normal features.

[0031] And if there are incomplete chip features in the image data, after determining that there are complete corresponding chip features in the adjacent images for the corresponding incomplete chip features, the incomplete chip features are removed, and after retaining the complete corresponding chip features, the priority of retaining the complete corresponding chip features is higher than the priority of removing duplicate features in the subsequent adjacent images.

[0032] In the embodiment of the present invention, the operation of repositioning and combining each chip to form a complete MAP data in step two is as follows: After determining the repeated features according to the judgment result, the repeated features in the latter image of the current adjacent image data are removed, and the chip features that are not removed are retained; Based on the first image feature, and in accordance with the comparison direction and result, the retained chip features are filled into the first image feature in sequence for expansion. The image is expanded and features are supplemented through the horizontal spacing of the chip features in the adjacent column item direction, and the image is expanded and features are supplemented through the column item spacing of the chip features in the adjacent horizontal direction, finally forming a complete MAP data.

[0033] Among them, if there is an abnormal comparison result during the comparison of adjacent images, there is a problem result in the corresponding column item in the current right image. At this time, it is necessary to compare the reference point spacing between the previous column item of the column item with the problem result and the second last column item of the left image. If the corresponding result values are the same, all the column items of the column item with the problem result and its previous items in the right image are repeated features, otherwise they are normal features. This avoids the similarity of features with intervals, realizes compensation evaluation, improves the error tolerance rate while ensuring the accuracy of determining repeated features, so as to achieve more accurate data retention and positioning combination.

[0034] Embodiment 2: The difference compared with Embodiment 1 is that the present invention also discloses a pre-scanning and positioning system for wafer chips, including: Parameter setting module: used to set the starting point of the camera, and perform setting operations on the subsequent scanning path, scanning moving step distance, and scanning moving direction, and perform a one-time continuous scanning; Image acquisition module, which acquires image data through the camera based on the set scanning path; Image analysis module, which performs the operation of removing repeated features in adjacent images through the position analysis of corresponding chip features; Image positioning and recombination module, which forms a complete MAP data by repositioning and combining the retained image data; Visualization interface, used to display the positioned MAP data.

[0035] Embodiment 3: The difference compared with Embodiment 1 and Embodiment 2 is that data collection and repositioning and combination operations are performed on 100 wafer chip samples through the existing pre-scanning and positioning method for wafer chips and the pre-scanning and positioning method of the present invention. Moreover, accurate results already exist for the 100 wafer chip samples. The results of the above operations are compared with the existing accurate results, and the data during the operation process is recorded. The specific results are shown in Table 1:

[0036] In summary, after the application of the wafer chip pre-scanning and positioning method of the present invention on the device, the accuracy of the final result comparison is higher, and the time taken to complete the scanning and generate the result is shorter. Therefore, the wafer chip pre-scanning and positioning method of the present invention can better complete the actual application operation.

[0037] At the same time, the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0038] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0039] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wafer chip pre-scanning positioning method, characterized in that: The specific steps include: Step 1: realize the positioning operation of the camera center and the wafer center, and then determine the starting point for scanning the chip on the wafer, and at the same time determine the subsequent scanning path, the step distance of the scanning movement, and the direction of the scanning movement; Step 2: Based on the operation in step 1, the camera is used to scan and complete the image acquisition operation, and the acquired image data is arranged in order to form an image data set. The chip features in the image data are determined according to the grayscale value, and the feature parts in the image data are deduplicated in combination with the coordinate setting, and each chip is repositioned and combined to form a complete MAP data; Step 3: Implement chip placement operation according to the complete MAP data and the corresponding chip position, and display the data through a visual interface; The chip feature determination operation in step 2 is: after graying the image, pixel points are set equidistantly on the image, and the pixel points are set in the horizontal and vertical directions of the scan, and then the boundary points of the chip features are determined according to the change in the grayscale value of the pixel points, and the closed-loop connection operation of the boundary points is implemented in sequence to form a complete chip feature.

2. A wafer chip pre-scanning positioning method according to claim 1, characterized in that: The positioning operation of the camera center and the wafer center in step 1 is as follows: Place the wafer on the carrier and use the clamping device to limit the position of the wafer; Mark the center of the wafer, and then roughly move the camera to make the marked center of the wafer in the field of view of the camera, and use the center of the cross cursor of the moving camera as the starting point, and establish the coordinate axes X1 and Y1 in the direction of the cross cursor adjacent to the marked center of the wafer, and then determine the coordinates of the marked center of the wafer as (x1, y1); The moving operation of the mobile camera is realized according to the coordinates (x1, y1), moving x1 distance in the horizontal direction of the X1 axis and y1 distance in the horizontal direction of the Y1 axis, so that the center of the cross cursor of the mobile camera coincides with the center of the marked wafer to complete the positioning operation.

3. A wafer chip pre-scanning positioning method according to claim 2, characterized in that: The operation of determining the scanning starting point in step 1 is: To realize image acquisition of the entire wafer, a first ray is made at the center of the wafer and extends horizontally toward the X1 axis, and a first intersection point is generated at the boundary of the wafer by the first ray, and a second ray is made at the center of the wafer and extends horizontally toward the Y1 axis, and a second intersection point is generated at the boundary of the wafer by the second ray; A tangent line of the wafer boundary is set from the first intersection point and is kept parallel to the X1 axis. A tangent line of the wafer boundary is set from the second intersection point and is kept parallel to the Y1 axis. The two tangent lines intersect in their extension directions, and the current intersection point is the scanning starting point. Then, the scanning end point is obtained at the intersection of the reverse extension point of the first ray and the second ray and the wafer boundary in the same manner as the scanning starting point.

4. A wafer chip pre-scanning positioning method according to claim 2, characterized in that: The operation of determining the subsequent scanning path, scanning movement step and scanning movement direction in step 1 is: Determine the scanning path: the camera moves from the scanning starting point in the direction parallel to the coordinate axis X1, and stops at the vertical position flush with the scanning end point, and then the camera resets to the scanning starting point and moves in the direction parallel to the coordinate axis Y1. After moving a single vertical step, the camera realizes synchronization with the movement in the direction parallel to the coordinate axis X1, and reciprocates until the scanning end point; Determine the scanning movement step: Set the number of acquired images in the horizontal direction of the X1 axis to M, and the actual distance from the scanning start point to the scanning end point to L1, then the distance in the horizontal direction is: , and the corresponding lateral step length is L2 / M, the lateral step length is positive and less than the field of view length of the camera to collect images; Assume that the number of captured images on the horizontal path is N, and the distance from the horizontal path of the Y1 axis is also equal to L2, then the corresponding vertical step is L2 / N, and the vertical step is a positive value and is smaller than the field of view width of the camera captured image; Determine the scanning movement direction: The camera moves according to the path setting and completes the one-time image acquisition operation.

5. The wafer chip pre-scanning positioning method according to claim 1, characterized in that: The operation of determining the boundary points of the chip features is: Take two pixel points whose grayscale values ​​change in the horizontal direction, and set multiple analysis points equidistant between the two pixel points horizontally; And the grayscale values ​​of multiple analysis points are extracted to determine the change of the grayscale values. When the grayscale value is changed on the left side of the chip feature, the previous analysis point is the current horizontal boundary point; when the grayscale value is changed on the right side of the chip feature, the next analysis point is the current horizontal boundary point; The two pixel points where the grayscale value changes in the vertical direction are extracted, and the vertical boundary points are derived according to the same principle as the horizontal boundary points. Starting from the horizontal boundary point on the left, a boundary closed loop is formed in the order of first upward, then rightward, then downward, and finally leftward to obtain the complete chip features.

6. The wafer chip pre-scanning positioning method according to claim 1, characterized in that: The steps of performing the deduplication operation on the characteristic parts in the image data in combination with the coordinate setting in step 2 are as follows: Starting from the image data at the start point of scanning, select the image adjacent to it for analysis operation; Taking the lower left corner of each image as the origin, the X2 axis is established along the horizontal boundary of the image, and the Y2 axis is established along the vertical boundary of the image, so as to mark the midpoint of the lower boundary of all chip features in the image data to form a reference point, which is marked as J. hg , h represents the chip feature corresponding to the column, and g represents the chip feature corresponding to the row; The deduplication operation of adjacent images in the horizontal direction is performed by recording the spacing values ​​of the adjacent chip feature reference points in the corresponding column direction, and then comparing the last column result of the image on the left side of the adjacent images with the first to last column results of the image on the right side in sequence, and confirming whether deduplication operation is required based on the comparison results; The deduplication operation of adjacent images in the vertical direction is performed by recording the spacing values ​​of the adjacent chip feature reference points in the corresponding row direction, and then comparing the last row result of the upper image with the first to last row results of the lower image in sequence, and confirming whether deduplication operation is required based on the comparison results; After deduplication, the remaining chip features are repositioned and combined based on the first image feature.

7. A wafer chip pre-scanning positioning method according to claim 6, characterized in that: The result comparison operation principle of adjacent images in the horizontal direction or the vertical direction is the same. The horizontal analysis point comparison operation is: If the last column entry of the left image refers to point J h1 To reference point J hg The distance between each adjacent reference point and the first column reference point J in the right image h1 To reference point J hg If the distance between each corresponding adjacent reference point is the same, then the first column item corresponding to the current right image is a repeated feature; Otherwise, the spacing between the reference points of the last column item in the left image and the spacing between the reference points of the corresponding subsequent column items in the right image are compared in sequence. If no abnormal comparison results are generated during the comparison process, there are no repeated features in the current adjacent images. If abnormal comparison results are generated during the comparison process, there are problematic results in the corresponding column items in the current right image. At this time, it is necessary to compare the reference point spacing between the preceding sequence items of the problematic result column item and the second to last sequence item in the left image. If the corresponding result values ​​are the same, then the problematic result column item and all the preceding sequence items in the right image are repeated features, otherwise they are normal features.

8. The wafer chip pre-scanning positioning method according to claim 1, characterized in that: In step 2, the operation of repositioning and combining each chip to form a complete MAP data is as follows: After determining the repeated features according to the judgment result, the repeated features in the latter image of the current adjacent image data are eliminated, and the chip features that are not eliminated are retained; Based on the first image feature, the retained chip features are filled into the first image feature in turn according to the comparison direction and results for expansion. The image is expanded and the features are supplemented through the lateral spacing of chip features in the adjacent column direction, and the image is expanded and the features are supplemented through the column spacing of chip features in the adjacent lateral direction, finally forming complete MAP data.

9. A wafer chip pre-scanning positioning system, using a wafer chip pre-scanning positioning method as claimed in any one of claims 1 to 8, characterized in that: include: Parameter setting module: used to set the starting point of the camera, and to set the subsequent scanning path, scanning step and scanning direction, so as to perform one-time continuous scanning; An image acquisition module acquires image data through a camera based on a set scanning path; The image analysis module removes repeated features in adjacent images by analyzing the positions of corresponding chip features; Image positioning and reorganization module, which repositions and reassembles the retained image data to form complete MAP data; Visual interface, used to display the MAP data after positioning.

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