Alignment method of LDI exposure machine and LDI exposure machine

Abstract

The invention discloses an alignment method of an LDI exposure machine and the LDI exposure machine, the LDI exposure machine comprises a motion platform used for pulling a substrate to move and a plurality of alignment cameras, the motion platform is located below the plurality of alignment cameras, and the alignment method comprises the following steps: controlling the motion platform to move and obtaining the real-time moving distance of the motion platform; obtaining a shooting spacing distance of the alignment camera; when the real-time moving distance reaches the shooting interval distance, triggering an image acquisition signal once, wherein the image acquisition signal is used for indicating the plurality of alignment cameras to synchronously acquire the image information of the positioning points; determining segmented image information of each positioning point according to the image information of all the positioning points; and performing alignment according to the segmented image information of each positioning point. By adopting the alignment method, the alignment speed of the LDI exposure machine can be improved to the greatest extent when the number of the positioning point partitions on the substrate is large, and the problem of camera redundancy is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of LDI exposure, and in particular to an alignment method of an LDI exposure machine and an LDI exposure machine. Background Art

[0002] In the related art, the existing LDI (laser direct imaging) exposure machine searches for the position of each positioning point in turn through the line spacing, controls the mutual vector movement of the camera and the motion platform, so that the camera stops shooting the positioning point image after reaching above each positioning point, and then performs alignment through the positioning point image of each positioning point. However, this method can only align the positioning points one by one during the alignment process, so there is a problem of slow alignment speed when there are many positioning point partitions on the substrate, thereby reducing the production capacity of the exposure machine. In addition, when multiple cameras are set to collect positioning point images for alignment, only one camera can collect images at the same time, which causes the problem of camera redundancy. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to propose a method for aligning an LDI exposure machine, which can maximize the alignment speed of the LDI exposure machine when there are many positioning point partitions on the substrate and avoid the problem of camera redundancy.

[0004] A second objective of the present invention is to provide an LDI exposure machine.

[0005] In order to solve the above problems, an embodiment of the first aspect of the present invention provides an alignment method for an LDI exposure machine, wherein the LDI exposure machine includes a motion platform for pulling a substrate to move and a plurality of alignment cameras, wherein the motion platform is located below the plurality of alignment cameras, and the alignment method includes: controlling the movement of the motion platform and obtaining a real-time moving distance of the motion platform; obtaining a shooting interval distance of the alignment camera; triggering an image acquisition signal every time the real-time moving distance reaches the shooting interval distance, wherein the image acquisition signal is used to instruct a plurality of alignment cameras to synchronously acquire positioning point image information; determining segmented image information of each positioning point based on the image information of all positioning points; and performing alignment based on the segmented image information of each positioning point.

[0006] According to the alignment method of the LDI exposure machine of the embodiment of the present invention, the motion platform is loaded with the substrate and moved along the length direction of the substrate. After the motion platform moves to the shooting interval distance each time, it triggers multiple alignment cameras to shoot to obtain all the positioning point image information at one time, and then the segmented image information of each positioning point is screened and obtained, and then the segmented image information of each positioning point is used for positioning, without obtaining each positioning point image one by one and positioning, and at the same time, the motion platform is controlled to move along the length direction of the substrate to reduce the number of multi-zone alignment movements to one, so that when there are many positioning point zones on the substrate, the positioning speed can be maximized, and the positioning speed of the LDI exposure machine is improved. In addition, multiple alignment cameras can synchronously shoot images at the same time, thereby avoiding the problem of camera redundancy.

[0007] In some embodiments, controlling the motion platform to move includes: controlling the motion platform to move at a constant speed.

[0008] In some embodiments, obtaining the shooting interval distance of the aiming camera includes: determining the shooting interval distance of the aiming camera according to the pixel size and lens magnification of the aiming camera.

[0009] In some embodiments, the segmented image information of each positioning point is determined based on the image information of all the positioning points, including: performing image stitching based on the image information of all the positioning points to obtain stitched image information; obtaining a GDS coordinate mapping relationship about the positioning points, and obtaining a conversion relationship between a substrate position unit and an image pixel unit; and determining the segmented image information of each positioning point in the stitched image information based on the GDS coordinate mapping relationship and the conversion relationship.

[0010] In some embodiments, obtaining a GDS coordinate mapping relationship about a positioning point includes: obtaining GDS coordinate information of a reference positioning point and GDS coordinate information of a non-reference positioning point; determining the GDS coordinate mapping relationship based on the GDS coordinate information of the reference positioning point and the GDS coordinate information of the non-reference positioning point; determining segmented image information of each positioning point in the stitched image information based on the GDS coordinate mapping relationship and the conversion relationship, including: determining a target positioning point in the stitched image information corresponding to the reference positioning point; determining the segmented image information of each positioning point based on the target positioning point, the GDS coordinate mapping relationship and the conversion relationship.

[0011] In some embodiments, the alignment method also includes: determining an initial recognition position of each positioning point in the corresponding segmented image information; determining a mapping relationship function between the positioning point image information collected by each adjacent two alignment cameras among multiple alignment cameras; determining a final recognition position of each positioning point in the corresponding segmented image information based on the mapping relationship function and the initial recognition position; and determining a substrate position recognition result of each positioning point based on the final recognition position of each positioning point.

[0012] In some embodiments, determining a mapping relationship function between the image information of the positioning points captured by each adjacent two alignment cameras among a plurality of alignment cameras includes: determining the image coordinate information of each positioning point in the image information of the positioning points captured by each alignment camera; and determining the mapping relationship function between the image information of the positioning points captured by each adjacent two alignment cameras based on the image coordinate information of each positioning point.

[0013] In some embodiments, the substrate position recognition result of each positioning point is determined according to the final recognition position of each positioning point, including: determining the mapping relationship between the image coordinate information about the positioning point and the substrate coordinate information; performing position conversion on the final recognition position of each positioning point according to the mapping relationship to determine the substrate position recognition result of each positioning point.

[0014] A second aspect of the present invention provides an LDI exposure machine, comprising: a plurality of alignment cameras, each alignment camera being used to collect positioning point image information in response to an image acquisition signal; a motion platform, the motion platform being located below the plurality of alignment cameras, the motion platform being used to pull a substrate to move; and a controller, the controller being connected to the motion platform and the plurality of alignment cameras, and being used to execute the alignment method of the LDI exposure machine described in any one of the above embodiments.

[0015] According to the LDI exposure machine of the embodiment of the present invention, by executing the alignment method of the LDI exposure machine of the above embodiment, the alignment speed of the LDI exposure machine can be maximized when there are many positioning point partitions on the substrate, avoiding the problem of camera redundancy.

[0016] In some embodiments, the LDI exposure machine also includes: a PSO board, which is connected to the controller and each alignment camera, and is used to split the image acquisition signal sent by the controller into multiple image acquisition sub-signals, and send each image acquisition sub-signal to each alignment camera; a light source, which is located below the multiple alignment cameras, and is connected to the PSO board, and is used to perform strobing according to the image acquisition signal.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a schematic diagram of an LDI exposure machine according to an embodiment of the present invention; Figure 2 is a flow chart of an alignment method of an LDI exposure machine according to an embodiment of the present invention; Figure 3 is a schematic diagram of an LDI exposure machine according to an embodiment of the present invention; Figure 4 is a flow chart of an alignment method of an LDI exposure machine according to another embodiment of the present invention; Figure 5 A flow chart of an alignment method of an LDI exposure machine according to another embodiment of the present invention.

[0019] Reference numerals: LDI exposure machine 10; Host computer 1; controller 2; axis driver 3; PSO board 4; light source 5; memory module 6; alignment camera 7; motion platform 8. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0021] In order to solve the above problems, a first embodiment of the present invention provides an alignment method for an LDI exposure machine. The alignment method can maximize the alignment speed of the LDI exposure machine when there are many positioning point partitions on the substrate, thereby avoiding the problem of camera redundancy.

[0022] In an embodiment, Figure 1As shown, the LDI exposure machine 10 includes a motion platform 8 for pulling the substrate to move and a plurality of alignment cameras 7, and the motion platform is located below the plurality of alignment cameras. Among them, the alignment camera supports the motion flying function, and the alignment camera can be a high-line frequency line scan camera, and the high-line frequency line scan camera is 16380*1, combined with a 0.5-fold line scan lens, to build a single imaging system, and the shooting range of the plurality of alignment cameras can cover the entire substrate to form a full-board coverage scan, which can maximize the field of view of the imaging system, and the coverage area can reach 114mm*7mm (width*height), and the size of the image taken by the alignment camera is 6384*2048. Specifically, there are a plurality of positioning points prepared on the substrate through the GDS (Geodetic Coordinate, ground coordinate system) design drawings about the positioning points, and the plurality of positioning points on the substrate are randomly distributed. Based on this, the substrate is placed on the motion platform, and the motion platform pulls the substrate to move, and at the same time, the plurality of alignment cameras collect the images of the plurality of positioning points.

[0023] Reference below Figure 2 The alignment method of the LDI exposure machine according to the embodiment of the present invention is described as follows: Figure 2 As shown, the method includes steps S1 to S5.

[0024] Step S1, controlling the motion platform to move and obtaining the real-time moving distance of the motion platform.

[0025] Specifically, Figure 3 As shown, the LDI exposure machine includes an axis driver 3 and a controller 2. The axis driver 3 is used to drive the motion platform to move. Based on this, the upper computer sends a positioning point alignment instruction to the controller 2. After the controller 2 receives the alignment instruction, the controller 2 controls the axis driver 3 to drive the motion platform from the starting position of the motion platform along a direction perpendicular to the alignment camera to the end position of the motion platform, and the motion platform will feedback the real-time moving distance of the motion platform to the controller 2 in real time during the movement.

[0026] Step S2, obtaining the shooting interval distance of the camera.

[0027] The shooting interval distance can be understood as the distance between two adjacent images shot by the aiming camera, and the shooting interval distance is determined by the shooting range of the aiming camera.

[0028] Step S3, triggering an image acquisition signal every time the real-time moving distance reaches the shooting interval distance, the image acquisition signal is used to instruct multiple aiming cameras to synchronously acquire the positioning point image information.

[0029] Specifically, the shooting field of view of the alignment camera on the substrate is fixed. In order to capture the image information of all areas on the substrate, in this application, multiple alignment cameras are fixed above the motion platform and the motion platform is controlled to move, so that multiple alignment cameras can capture images of different substrate width areas within the same length range of the substrate. That is to say, all positioning points on the substrate are divided into multiple shooting substrate areas in the length direction of the substrate by the shooting interval distance. When the real-time moving distance of the motion platform reaches the shooting interval distance, the motion platform loads the substrate and moves to the unshot substrate area, then an image acquisition signal is triggered once, so that multiple alignment cameras synchronously capture the image information of each corresponding substrate area in the shooting substrate area until the image information of all areas on the substrate is captured. Therefore, compared with the prior art in which the alignment camera and the motion platform perform relative vector movements multiple times, in this application, multiple alignment cameras are combined to cover the substrate width area, and the motion platform is controlled to perform a single movement along the length direction of the substrate to reduce the number of multi-partition alignment movements to once, thereby maximizing the positioning point image capture speed.

[0030] Step S4, determining the segmented image information of each positioning point according to the image information of all positioning points.

[0031] Specifically, since the images taken by the aiming camera contain positioning point images and non-positioning point images, it is necessary to filter out the positioning point images from all the captured images. That is to say, the host computer will receive all the positioning point image information about all the captured images, filter out the image information of each positioning point from all the positioning point image information, and then segment the image of each positioning point from all the captured images through the image segmentation algorithm, thereby obtaining the segmented image information of each positioning point.

[0032] Step S5: performing alignment according to the segmented image information of each positioning point.

[0033] Specifically, in the prior art, it is impossible to determine each positioning point image after obtaining all images, so each positioning point image can only be obtained one by one and then positioned. For this reason, the image recognition algorithm is used in the present application to identify and process the segmented image information of each positioning point to determine the position information of each positioning point in the segmented image, and then the position information of each positioning point in the segmented image is converted into the position information of each positioning point in the substrate, so as to realize the rapid alignment of the LDI exposure machine. Therefore, compared with the existing LDI exposure machine that aligns each positioning point one by one through the mutual vector movement of the control machine and the motion platform, in the present application, after all the positioning point image information is obtained at one time, the segmented image information of each positioning point can be screened and then positioned through the segmented image information of each positioning point, instead of obtaining each positioning point image one by one and then positioning, and at the same time, by controlling the motion platform to move along the length direction of the substrate, the number of multi-partition alignment movements is reduced to one, so that the alignment speed of the LDI exposure machine can be maximized. In addition, multiple alignment cameras can synchronously capture images at the same time, thereby avoiding the problem of camera redundancy.

[0034] According to the alignment method of the LDI exposure machine of the embodiment of the present invention, the motion platform is loaded with the substrate and moved along the length direction of the substrate. After the motion platform moves to the shooting interval distance each time, it triggers multiple alignment cameras to shoot to obtain all the positioning point image information at one time, and then the segmented image information of each positioning point is screened and obtained, and then the segmented image information of each positioning point is used for positioning, without obtaining each positioning point image one by one and positioning, and at the same time, the motion platform is controlled to move along the length direction of the substrate to reduce the number of multi-zone alignment movements to one, so that when there are many positioning point zones on the substrate, the positioning speed can be maximized, and the positioning speed of the LDI exposure machine is improved. In addition, multiple alignment cameras can synchronously shoot images at the same time, thereby avoiding the problem of camera redundancy.

[0035] In some embodiments, controlling the motion platform to move includes: controlling the motion platform to move at a constant speed.

[0036] Specifically, when the motion platform moves to the uniform motion trigger starting point, where the uniform motion trigger starting point is located between a straight line along the width direction of the substrate and a parallel line on the substrate within the shooting field of view of the alignment camera, the motion platform is controlled to move uniformly along the length direction of the substrate from the uniform motion trigger starting point to the end point of the substrate, so that multiple alignment cameras synchronously collect image information within the substrate area corresponding to each shooting interval distance.

[0037] In some embodiments, obtaining the shooting interval distance of the aiming camera includes: determining the shooting interval distance of the aiming camera according to the pixel size and lens magnification of the aiming camera.

[0038] Specifically, the shooting interval distance of the alignment camera can be obtained by dividing the pixel size of the alignment camera by the lens magnification, wherein the pixel size and lens magnification of the alignment camera are determined by the model of the alignment camera. For example, if the pixel size of the alignment camera is 7 μm and the lens magnification is 0.5, the shooting interval distance is 3.5 μm. Therefore, in the present application, the shooting interval distance is determined by the pixel size and lens magnification of the alignment camera so that multiple alignment cameras can acquire images in the entire area of ​​the substrate.

[0039] In some embodiments, determining the segmented image information of each positioning point according to the image information of all positioning points includes the following steps.

[0040] Image stitching is performed based on all the positioning point image information to obtain stitched image information. That is, all the positioning point image information is information obtained based on images taken by multiple aiming cameras, and all the positioning point image information is input into the image stitching algorithm to obtain stitched image information, that is, the images taken by multiple aiming cameras are stitched through the image stitching algorithm to obtain an image after all the images are stitched together.

[0041] Obtain the GDS coordinate mapping relationship of the positioning points. Since the GDS coordinate information of each positioning point exists in the GDS drawing about the positioning points, obtain the GDS coordinate information of each positioning point in the GDS drawing to determine the association information between each positioning point through the GDS coordinate information of each positioning point. For example, the association information can be the positional relationship between each positioning point or the distance between each positioning point. For example, the GDS coordinate information of one positioning point is expressed as (X1, Y1), and the GDS coordinate information of another positioning point is expressed as (X2, Y2). Then the positional relationship between each positioning point is (X1-X2, Y1-Y2), and the association information between each positioning point is used as the GDS coordinate mapping relationship of the positioning point in the GDS drawing. And, obtain the conversion relationship between the substrate position unit and the image pixel unit, wherein the substrate position unit is a length unit used to describe the physical size, and the width and height of the image pixel unit are used to define the pixel unit. The conversion relationship between the substrate position unit and the image pixel unit is the correspondence between 1 length unit on the substrate and the pixel in the image, 1 length unit can be 1 μm, and the conversion relationship is 7 μm corresponds to 1 pixel.

[0042] The segmented image information of each positioning point in the spliced ​​image information is determined according to the GDS coordinate mapping relationship and conversion relationship. The positioning points on the substrate are prepared according to the GDS coordinate information of each positioning point in the GDS drawing, so the GDS coordinate mapping relationship of the positioning points is the mapping relationship between the positioning points on the substrate. Based on this, the association information between each positioning point is determined by the GDS coordinate information of each positioning point, that is, the positional relationship between each positioning point or the distance between each positioning point, and the distance between each positioning point is converted from the length unit to the pixel size between each positioning point in the image through the conversion relationship between the substrate position unit and the image pixel unit. Therefore, all the positioning points in the image after all images are spliced ​​can be inferred through the pixel size between each positioning point in the image and the positional relationship between each positioning point in the substrate, so as to obtain the segmented image information of each positioning point. Therefore, in this application, the segmented image of each positioning point is obtained by screening from all images taken by the alignment camera through the GDS coordinate mapping relationship and the conversion relationship, so that it is possible to wait for all images to be acquired and then align through the image of each positioning point, instead of obtaining each positioning point image one by one and positioning, so as to maximize the positioning speed and improve the alignment speed of the LDI exposure machine.

[0043] In some embodiments, obtaining a GDS coordinate mapping relationship about a positioning point includes: obtaining GDS coordinate information of a reference positioning point and GDS coordinate information of a non-reference positioning point; determining a GDS coordinate mapping relationship based on the GDS coordinate information of the reference positioning point and the GDS coordinate information of the non-reference positioning point; determining segmented image information of each positioning point in the stitched image information based on the GDS coordinate mapping relationship and the conversion relationship, including: determining a target positioning point in the stitched image information corresponding to the reference positioning point; determining the segmented image information of each positioning point based on the target positioning point, the GDS coordinate mapping relationship and the conversion relationship.

[0044] Among them, the reference positioning point is a positioning point in the GDS drawing that can be clearly distinguished from other positioning points. The reference positioning point can be located at the corner of the drawing, for example, it can be located at the upper left corner, lower left corner, upper right corner or lower right corner.

[0045] Specifically, obtain GDS coordinate information of the reference positioning point and the GDS coordinate information of the non-reference positioning point, determine the association information between the reference positioning point and the non-reference positioning point according to the GDS coordinate information of the reference positioning point and the non-reference positioning point, and use the association information between the reference positioning point and the non-reference positioning point as a GDS coordinate mapping relationship. For example, calculate the positional relationship and distance between the reference positioning point and the non-reference positioning point according to the GDS coordinate information of the reference positioning point and the non-reference positioning point, and use the positional relationship and distance between the reference positioning point and the non-reference positioning point as a GDS coordinate mapping relationship to determine the target positioning point corresponding to the reference positioning point in the stitched image. For example, the reference positioning point can be located in the upper left corner of the drawing, and the target positioning point is in the upper left corner of the stitched image. Then, according to the positional relationship and distance between the reference positioning point and each non-reference positioning point, as well as through the substrate position The conversion relationship between the unit and the image pixel unit converts the distance between the reference positioning point and each non-reference positioning point from the length unit into the pixel size between the reference positioning point and each non-reference positioning point in the image. Therefore, all the positioning points in the image after all images are stitched together can be inferred through the pixel size between the reference positioning point and each non-reference positioning point in the image and the positional relationship between the reference positioning point and each non-reference positioning point in the substrate, so as to obtain the segmented image information of each positioning point. Therefore, in this application, the segmented image of each positioning point is obtained by screening from all images taken by the alignment camera through the GDS coordinate mapping relationship and the conversion relationship, so that it is possible to wait until all images are acquired and then align through the image of each positioning point, instead of obtaining each positioning point image one by one and then positioning, thereby maximizing the positioning speed and improving the positioning speed of the LDI exposure machine.

[0046] In some embodiments, an initial recognition position of each positioning point in the corresponding segmented image information is determined; a mapping relationship function between the positioning point image information collected by each adjacent two alignment cameras among a plurality of alignment cameras is determined; a final recognition position of each positioning point in the corresponding segmented image information is determined based on the mapping relationship function and the initial recognition position; and a substrate position recognition result of each positioning point is determined based on the final recognition position of each positioning point.

[0047] Specifically, in order for the positional relationship between the positioning points in the images taken by all alignment cameras to reflect the positional relationship between the positioning points of the substrate, the present application uses a mapping relationship function between the image information of the positioning points collected by each adjacent two alignment cameras among multiple alignment cameras to associate the image position information of the positioning points in the images taken by all alignment cameras. Specifically, the positional relationship between the same positioning points in the positioning point image information collected by each two adjacent alignment cameras among the multiple alignment cameras is used as the conversion relationship between the positioning point image information collected by each two adjacent alignment cameras among the multiple alignment cameras, and then the conversion relationship between the positioning point image information collected by each two adjacent alignment cameras among the multiple alignment cameras is used as the mapping relationship function between the positioning point image information collected by each two adjacent alignment cameras among the multiple alignment cameras, and then the final recognition position of each positioning point in the corresponding segmented image information is calculated by the initial recognition position of each positioning point in the corresponding segmented image information and the mapping relationship function, wherein the final recognition position of all positioning points in the corresponding segmented image information can reflect the positional relationship between all positioning points of the substrate, and the final recognition position of each positioning point in the corresponding segmented image information is converted to the substrate coordinate system according to the final recognition position of each positioning point in the corresponding segmented image information, so that the substrate coordinate information of the converted positioning point is used as the substrate position recognition result of each positioning point, thereby realizing the alignment of the LDI exposure machine.

[0048] In some embodiments, determining a mapping relationship function between the image information of the positioning points captured by each adjacent two alignment cameras among a plurality of alignment cameras includes: determining the image coordinate information of each positioning point in the image information of the positioning points captured by each alignment camera; and determining the mapping relationship function between the image information of the positioning points captured by each adjacent two alignment cameras based on the image coordinate information of each positioning point.

[0049] Specifically, for each two adjacent alignment cameras, the image coordinate information of each positioning point in the positioning point image information collected by each alignment camera is determined, that is, the positioning point image information collected by each alignment camera in the two adjacent alignment cameras is obtained, and then the image coordinate information of each positioning point in the positioning point image information is identified by an image recognition algorithm, and the image coordinate information of the positioning point in the same positioning point image collected by each alignment camera in the two adjacent alignment cameras is determined, and then the conversion relationship between the image coordinate information of the same positioning point photographed by the two adjacent alignment cameras is calculated, and the conversion relationship can be the image coordinate difference of the same positioning point photographed by the adjacent alignment cameras, so as to calculate the mapping relationship function between the positioning point image information collected by each two adjacent alignment cameras through the conversion relationship between the image coordinate information of the same positioning point photographed by the adjacent alignment cameras, for example, the conversion relationship between the image coordinate information of a certain same positioning point is used as the mapping relationship function between the image coordinate information of the positioning points collected by the adjacent alignment cameras. Among them, the conversion relationship between the image coordinate information of a certain same positioning point can be the most accurate conversion relationship among the conversion relationships between the image coordinate information of all the same positioning points. Alternatively, the final conversion relationship may be calculated through the conversion relationship between the image coordinate information of all the same positioning points, so that the final conversion relationship is used as a mapping relationship function between the image information of the positioning points collected by adjacent alignment cameras.

[0050] Exemplarily, the first alignment camera and the second alignment camera are two adjacent alignment cameras, and a row of positioning points with equal width and spacing on the substrate are selected, and the spacing may be 110 mm. Then, the first alignment camera and the second alignment camera are used to shoot the selected row of positioning points to obtain positioning point images of the positioning points respectively. Then, the image coordinate information of each positioning point in the positioning point image shot by the first alignment camera and the second alignment camera is identified by an image recognition algorithm, and the conversion relationship between the image coordinate information of the same positioning point shot by the first alignment camera and the second alignment camera is calculated. The conversion relationship may be the image coordinate difference of the same positioning point shot by the first alignment camera and the second alignment camera. For example, The image of a positioning point taken by the camera identifies the coordinates of the positioning point as A (X3, Y3), and the image of the positioning point taken by the second alignment camera identifies the coordinates of the positioning point as B (X4, Y4), then the conversion relationship can be (X3-X4, Y3-Y4), so as to determine the mapping relationship function between the image information of the positioning point collected by the first alignment camera and the second alignment camera through the conversion relationship between the image coordinate information of the same positioning point taken by the first alignment camera and the second alignment camera, for example, the conversion relationship between the image coordinate information of a certain same positioning point is used as the mapping relationship function between the image information of the positioning point collected by the first alignment camera and the second alignment camera. Among them, the conversion relationship between the image coordinate information of a certain same positioning point can be the most accurate conversion relationship among the conversion relationships between the image coordinate information of all the same positioning points.

[0051] In addition, it should be noted that if there is another adjacent third alignment camera to the second alignment camera, the third alignment camera and the second alignment camera are aligned in the above manner to obtain a mapping relationship function between the positioning point image information collected by the second alignment camera and the third alignment camera.

[0052] Based on this, the image information of the positioning points collected by all cameras is associated with each other through the mapping relationship function between the positioning point image information collected by two adjacent alignment cameras. In some embodiments, the substrate position recognition result of each positioning point is determined according to the final recognition position of each positioning point, including: determining the mapping relationship between the image coordinate information of the positioning point and the substrate coordinate information; performing position conversion on the final recognition position of each positioning point according to the mapping relationship to determine the substrate position recognition result of each positioning point.

[0053] The substrate coordinate information is the coordinate information of the positioning point in the substrate in the substrate coordinate system.

[0054] Exemplarily, one or more positioning points in the substrate that can be clearly distinguished from other positioning points are selected, and the positioning points can be located at the upper left corner, lower left corner, upper right corner or lower right corner of the substrate. The user manually inputs the coordinate information of the positioning point in the substrate coordinate system, or uses the GDS coordinate information of the positioning point as the substrate coordinate information of the positioning point, and the controller obtains the substrate coordinate information of the positioning point, and then uses the alignment camera to shoot the image coordinate information of the positioning point, and then calculates the association information between the image coordinate information of the positioning point and the substrate coordinate information through the image coordinate information of the positioning point and the substrate coordinate information, so as to use the association information between the image coordinate information of the positioning point and the substrate coordinate information as the mapping relationship between the image coordinate information of the positioning point and the substrate coordinate information, and then converts the final recognition position of each positioning point according to the mapping relationship to determine the substrate position recognition result of each positioning point, for example, the final recognition position of each positioning point minus the mapping relationship to obtain the substrate position recognition result of each positioning point.

[0055] Finally, the controller can also calculate the rotation, translation and expansion / contraction information of each positioning point according to the substrate position recognition result of each positioning point and the GDS coordinate information of each positioning point.

[0056] In some embodiments, reference Figure 3 As shown, the LDI exposure machine 10 also includes: a PSO (position synchronized output) board 4 and a light source 5 Among them, the PSO board 4 is connected to the controller 2 and each alignment camera 7, and is used to split the image acquisition signal sent by the controller 2 into multiple image acquisition sub-signals, and send each image acquisition sub-signal to each alignment camera 7; the light source 5 is located below the multiple alignment cameras 7, and the light source 5 is connected to the PSO board 4, and is used to perform strobing according to the image acquisition signal.

[0057] And, if Figure 3 As shown, the axis driver 3 is used to drive the motion platform 8 to move, and the memory module 6 is used to store image information collected by the alignment camera 7.

[0058] Specifically, the PSO board is used to receive the image acquisition signal sent by the controller, and split the image acquisition signal sent by the controller into multiple image acquisition sub-signals accordingly, and then send the multiple image acquisition sub-signals to each alignment camera, and each alignment camera performs image acquisition after receiving the image acquisition sub-signal.

[0059] Reference below Figure 4 The alignment method of the LDI exposure machine according to an embodiment of the present invention is described, and the specific contents are as follows.

[0060] Step S6: The host computer obtains the GDS coordinate information of all positioning points.

[0061] Step S7: the controller receives an alignment recognition command about the positioning point, and controls the motion platform to accelerate the motion from the starting point of the motion platform.

[0062] Step S8, when the motion platform moves to the uniform motion triggering starting point, the uniform motion begins.

[0063] Step S9: Every time the real-time moving distance of the motion platform reaches the shooting interval distance, an image acquisition signal is triggered, and the image acquisition signal is sent to the controller.

[0064] In step S10, the controller sends an image acquisition signal to the PSO board. After receiving the image acquisition signal, the PSO board performs voltage boosting processing on the image acquisition signal and then transmits it to the light source controller.

[0065] Step S11, after receiving the image acquisition signal, the light source controller synchronizes the image acquisition signal to multiple alignment cameras and light sources, and executes steps S12 and S14.

[0066] Step S12, aiming the camera to capture all pictures of the motion platform during its unidirectional uniform motion, and storing them in the image queue corresponding to the aiming camera, and executing steps S13 and S15.

[0067] Step S13, the motion platform moves to the limit switch, stops and sends a stop signal to the controller, and the controller sends an image acquisition stop signal to the PSO board to control the multiple alignment cameras to stop acquiring images.

[0068] Step S14, controlling the light source to strobe according to the image acquisition signal.

[0069] Step S15, according to the GDS coordinate mapping relationship, the stitched images containing the positioning points are screened out and input into the image recognition algorithm, and the remaining images except the stitched images containing the positioning points are deleted from all the images.

[0070] Step S16, identifying the stitched image containing the positioning point by using an image recognition algorithm, and calculating the rotation, translation and expansion / contraction information between the GDS coordinate information of the positioning point and the substrate coordinate information of the positioning point.

[0071] Step S17, counting the substrate position recognition results of each positioning point to complete the LDI exposure machine alignment.

[0072] Reference below Figure 5 The alignment method of the LDI exposure machine according to an embodiment of the present invention is described, and the specific contents are as follows.

[0073] Step S18, acquiring images of all areas on the substrate captured by the alignment camera.

[0074] Step S19, using image difference to detect two right-angle positions of the substrate in the image.

[0075] Step S20, calculating the segmented image region of each positioning point in the image according to the rigid transformation.

[0076] Step S21, segmenting the segmented image of each positioning point.

[0077] Step S22, performing sub-pixel position extraction on the segmented image of each positioning point to obtain the initial recognition position of each positioning point in the corresponding segmented image information, and correcting the lens distortion of the alignment camera.

[0078] Step S23, determining the final recognition position of each positioning point in the corresponding segmented image information according to the initial recognition position of each positioning point in the corresponding segmented image information and the mapping relationship function, and performing coordinate transformation on the final recognition position to obtain the substrate position recognition result of each positioning point.

[0079] Step S24, obtaining the substrate position recognition result of each positioning point, and determining the repeated area in the image captured by the adjacent alignment cameras to avoid distortion of the image edge.

[0080] Step S25, completing image processing of all areas on the substrate.

[0081] A second aspect of the present invention provides an LDI exposure machine, such as Figure 3 As shown, the LDI exposure machine 10 includes: a plurality of alignment cameras 7, a motion platform 8 and a controller 2, each alignment camera 7 is used to collect positioning point image information in response to an image acquisition signal; the motion platform 8 is located below the plurality of alignment cameras 7, and the motion platform 8 is used to pull the substrate to move; the controller 2 is connected to the motion platform 8 and the plurality of alignment cameras 7, and is used to execute the alignment method of the LDI exposure machine of any of the above embodiments.

[0082] According to the LDI exposure machine 10 of the embodiment of the present invention, by executing the alignment method of the LDI exposure machine of the above embodiment, the alignment speed of the LDI exposure machine can be maximized when there are many positioning point partitions on the substrate, avoiding the problem of camera redundancy.

[0083] In the embodiment, there are five alignment cameras, and their shooting range can cover an area of ​​up to 114mm*7mm (width*height). There is a redundant field of view of 8mm width between every two alignment cameras, so that the shooting range of all alignment cameras can cover a substrate of 538mm width.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0085] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for aligning an LDI exposure machine, characterized in that: The LDI exposure machine includes a motion platform for pulling the substrate to move and a plurality of alignment cameras, the motion platform is located below the plurality of alignment cameras, and the alignment method includes: Controlling the motion platform to move and obtaining the real-time moving distance of the motion platform; Obtaining the shooting interval distance of the aiming camera; An image acquisition signal is triggered every time the real-time moving distance reaches the shooting interval distance, and the image acquisition signal is used to instruct multiple alignment cameras to synchronously acquire positioning point image information; Determine the segmented image information of each positioning point according to the image information of all positioning points; Alignment is performed based on the segmented image information of each positioning point.

2. The alignment method of the LDI exposure machine according to claim 1, characterized in that: Controlling the motion platform to move, including: The motion platform is controlled to move at a constant speed.

3. The alignment method of the LDI exposure machine according to claim 1, characterized in that: Obtaining the shooting interval distance of the aiming camera includes: The shooting interval distance of the aiming camera is determined according to the pixel size and lens magnification of the aiming camera.

4. The alignment method of the LDI exposure machine according to claim 1, characterized in that: Determine the segmented image information of each positioning point based on the image information of all positioning points, including: Perform image stitching according to image information of all positioning points to obtain stitching image information; Obtaining the GDS coordinate mapping relationship of the positioning point, and obtaining the conversion relationship between the substrate position unit and the image pixel unit; The segmented image information of each positioning point in the spliced ​​image information is determined according to the GDS coordinate mapping relationship and the conversion relationship.

5. The alignment method of the LDI exposure machine according to claim 4, characterized in that: Get the GDS coordinate mapping relationship of the positioning point, including: Obtain the GDS coordinate information of the reference positioning point and the GDS coordinate information of the non-reference positioning point; Determine the GDS coordinate mapping relationship according to the GDS coordinate information of the reference positioning point and the GDS coordinate information of the non-reference positioning point; Determining the segmented image information of each positioning point in the spliced ​​image information according to the GDS coordinate mapping relationship and the conversion relationship includes: Determine a target positioning point in the stitched image information corresponding to the reference positioning point; The segmented image information of each positioning point is determined according to the target positioning point, the GDS coordinate mapping relationship and the conversion relationship.

6. The alignment method of the LDI exposure machine according to any one of claims 1 to 5, characterized in that: The alignment method further comprises: Determine the initial recognition position of each positioning point in the corresponding segmented image information; Determine a mapping relationship function between the image information of the positioning points collected by each two adjacent alignment cameras among the multiple alignment cameras; Determine the final recognition position of each positioning point in the corresponding segmented image information according to the mapping relationship function and the initial recognition position; The substrate position recognition result of each positioning point is determined according to the final recognition position of each positioning point.

7. The alignment method of the LDI exposure machine according to claim 6, characterized in that: Determining a mapping relationship function between the image information of the positioning points collected by each two adjacent alignment cameras among the multiple alignment cameras includes: Determine the image coordinate information of each positioning point in the positioning point image information collected by each alignment camera; A mapping relationship function between the image information of each positioning point collected by two adjacent alignment cameras is determined according to the image coordinate information of each positioning point.

8. The alignment method of the LDI exposure machine according to claim 7, characterized in that: The substrate position recognition result of each positioning point is determined according to the final recognition position of each positioning point, including: Determine a mapping relationship between image coordinate information about a positioning point and substrate coordinate information; The final identified position of each positioning point is converted according to the mapping relationship to determine the substrate position identification result of each positioning point.

9. An LDI exposure machine, characterized in that: include: A plurality of alignment cameras, each alignment camera being used to collect image information of a positioning point in response to an image acquisition signal; A motion platform, the motion platform is located below the plurality of alignment cameras, and the motion platform is used to pull the substrate to move; A controller, wherein the controller is connected to the motion platform and the plurality of alignment cameras, and is used to execute the alignment method of the LDI exposure machine according to any one of claims 1 to 8.

10. The LDI exposure machine according to claim 9, characterized in that: Also includes: A PSO board, the PSO board is connected to the controller and each alignment camera, and is used to split the image acquisition signal sent by the controller into multiple image acquisition sub-signals, and send each image acquisition sub-signal to each alignment camera; A light source is located below the multiple alignment cameras, and the light source is connected to the PSO board and is used for strobing according to the image acquisition signal.

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