Different-layer positioning compensation method for substrate position error compensation in printing process

Abstract

The invention discloses a different-layer positioning compensation method for substrate position error compensation in the printing process. The different-layer positioning compensation method comprises the following steps that firstly, equipment is prepared; 2, printing for the first time and setting a reference; step 3, substrate treatment and secondary placement; 4, identifying and selecting feature points; step 5, deviation calculation; step 6, performing pattern compensation; 7, secondary printing is carried out; according to the invention, non-contact and high-precision different-layer pattern alignment compensation is realized, and the precision can reach a micron level. Dependence on precision of a mechanical platform is reduced, and equipment cost is saved. The algorithm is simple and efficient and is suitable for being integrated in an existing visual system and printing software. Continuous printing of multi-layer, multi-angle and high-density patterns is supported, and the manufacturing yield is improved. And the method is high in universality and can be suitable for other fields needing positioning.

Description

Technical Field

[0001] The present invention relates to the field of precision printing or micro-nano manufacturing technology, and in particular to a heterogeneous layer positioning compensation method for compensating for substrate position errors during a printing process. Background Art

[0002] During precision printing or graphic transfer processes, the same substrate often undergoes multiple print runs. For example, after the first pass of graphic printing, the substrate must be removed for heat treatment, coating, etching, and other processing before being returned to the equipment for the next layer. However, when the substrate is re-placed, it is difficult to perfectly align its position, and nozzles and tooling may need to be replaced, resulting in positional and angular deviations between printed patterns.

[0003] Currently, the commonly used compensation method is to adjust the substrate angle by a mechanical rotating platform, but this has obvious defects: the positioning scale and positioning fixture are subject to human placement errors and are no longer applicable in the field of flexible printing (where positioning accuracy requires micron-level or even several microns); visual positioning marks determine the position of the object by calibrating the mark points, and compensation is achieved by rotating the substrate or placement head, which makes it difficult to achieve micron-level accuracy, and the mechanical movement is limited by the rotation angle.

[0004] In summary, the existing methods have insufficient compensation capabilities in high-precision scenarios, and a non-mechanical, high-precision and low-cost compensation method is urgently needed. Summary of the Invention

[0005] The purpose of the present invention is to provide a different-layer positioning compensation method for compensating for substrate position errors during printing, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for compensating for substrate position errors during printing, comprising the following steps:

[0007] Step 1: Equipment preparation: Use a printing device with an integrated visual recognition system that can image the substrate surface and obtain the pixel coordinates or physical coordinates of the pattern on the substrate;

[0008] Step 2: First Print and Reference Setting: Print the first layer of graphics on the substrate, specify the upper left corner of the printed graphics or the intersection of the extended lines as the alignment reference point, and record the initial graphics design coordinates;

[0009] Step 3: Substrate processing and secondary placement: After taking out the substrate for process processing, place it back into the device substrate;

[0010] Step 4: Feature point identification and selection: The visual recognition system images the substrate surface, identifies the last printed pattern, selects a straight line segment in the pattern, selects two points on the straight line segment, and obtains their pixel coordinates or physical coordinates;

[0011] Step 5: Deviation calculation: Calculate the rotation angle and displacement deviation between the current image and the original image based on the coordinates of the two points;

[0012] Step 6: Graphics compensation: The software performs overall rotation and translation transformation on the printing path or graphics based on the calculated rotation angle and displacement deviation to obtain the calibrated graphics or printing path;

[0013] Step 7: Second printing: Start the printing device and perform a second printing based on the calibrated graphics or printing path to achieve precise alignment with the first printed graphics.

[0014] Preferably, in step four, the straight line segment is preferentially selected as a horizontal line segment, and the selection method includes manual selection and automatic selection. Manual selection is performed by manually clicking in the visual system to obtain the coordinates of two points, and automatic selection is performed by identifying the line segment through a machine vision algorithm and automatically selecting two points.

[0015] Preferably, the step four is specifically as follows: select a horizontal line segment in the graphic, select two points on the line segment manually or automatically, obtain their pixel coordinates or physical coordinates, recorded as (X1, Y1) and (X2, Y2); when manually selecting points, a person clicks on two points in the visual system on the host computer with a mouse to obtain the coordinates; when automatically selecting points, the host computer searches for the horizontal line from top to bottom according to the drawn graphic, and the three axes of the machine run to the corresponding approximate area, and identifies the line segment within the field of view based on the features and grayscale, and automatically selects two points and records the coordinates.

[0016] Preferably, the step 5 is specifically as follows: calculating the rotation angle a and displacement deviation between the current image and the original image according to the coordinates of the two selected points; the rotation angle a satisfies The displacement deviation is determined by the coordinate change of the reference point. Assuming that the initial reference point coordinates are (X0, Y0) and the current reference point coordinates are (X′, Y′), the translation amount ΔX = X′-X0, ΔY = Y′-Y0.

[0017] Preferably, the step six is ​​specifically as follows:

[0018] When generating a print path or graphic, the software uses the upper left corner or extension line as the rotation origin and transforms the print path or graphic as a whole based on the calculated rotation angle a and translation amounts ΔX and ΔY. Specifically, the graphic or print path is rotated in the opposite direction by an angle of -a and the compensation vector is translated (-ΔX, -ΔY) to obtain the calibrated graphic or print path.

[0019] Preferably, the image processing of the visual recognition system includes grayscale processing and edge detection, and is combined with template matching and corner detection algorithms to improve the accuracy of coordinate extraction.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention achieves non-contact, high-precision alignment compensation for inter-layer graphics, achieving micron-level accuracy. This reduces reliance on mechanical platform precision, saving equipment costs. The algorithm is simple and efficient, making it suitable for integration into existing vision systems and printing software. It supports continuous printing of multi-layer, multi-angle, and high-density graphics, improving manufacturing yield. Its high versatility makes it applicable to other applications requiring positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the first printing pattern of the substrate of the present invention;

[0023] Figure 2 This is a schematic diagram of the position change of the substrate after being processed and then placed back into the device;

[0024] Figure 3 Schematic diagram of feature line segment and two-point coordinate extraction of the present invention;

[0025] Figure 4 This is a comparison diagram before and after the graphic compensation of the present invention;

[0026] Figure 5 is a schematic diagram of substrate placement of the present invention;

[0027] Figure 6 It is a design graphic diagram of the present invention;

[0028] Figure 7 This is the first printing diagram of the present invention;

[0029] Figure 8 The present invention is that the substrate is rotated after being placed and taken, and the printed image is not compensated;

[0030] Figure 9 It is the rotating design graphic of the present invention;

[0031] Figure 10 The present invention designates the lower right corner as the printing starting point for the first time to print the image. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] See also Figure 1-10 The present invention provides a method for compensating for substrate position errors during printing, comprising the following steps:

[0034] Step 1: Equipment Preparation: Use a printing device with an integrated visual recognition system that can image the substrate surface and obtain the pixel coordinates or physical coordinates of the graphics on the substrate. The visual recognition system processes the image through grayscale processing and edge detection, and also combines template matching and corner detection algorithms to improve coordinate extraction accuracy.

[0035] Step 2: First Print and Reference Setting: Print the first layer of graphics on the substrate, specify the upper left corner of the printed graphics or the intersection of the extended lines as the alignment reference point, and record the initial graphics design coordinates;

[0036] Step 3: Substrate processing and secondary placement: After taking out the substrate for process processing, place it back into the device substrate;

[0037] Step 4: Feature point identification and selection: The visual recognition system images the substrate surface, identifies the last printed graphic, selects a straight line segment in the graphic, selects two points on the straight line segment, and obtains their pixel coordinates or physical coordinates; the straight line segment gives priority to the horizontal line segment, and the selection methods include manual selection and automatic selection. Manual selection involves manually clicking in the visual system to obtain the coordinates of two points, while automatic selection involves identifying the line segment through a machine vision algorithm and automatically selecting the two points; select a horizontal line segment in the graphic, select two points on the line segment manually or automatically, and obtain their pixel coordinates or physical coordinates, recorded as (X1, Y1) and (X2, Y2); when manually selecting points, a person manually clicks on two points in the visual system on the host computer with a mouse to obtain the coordinates; when automatically selecting points, the host computer searches for horizontal lines from top to bottom according to the drawn graphic, and the three axes of the machine move to the corresponding approximate area. The line segment is identified within the field of view based on the features and grayscale, and two points are automatically selected and their coordinates are recorded;

[0038] Step 5. Deviation calculation: Calculate the rotation angle and displacement deviation between the current figure and the original figure based on the coordinates of the two points; Calculate the rotation angle a and displacement deviation between the current figure and the original figure based on the coordinates of the two selected points; The rotation angle a satisfies The displacement deviation is determined by the coordinate change of the reference point. Assuming the initial reference point coordinates are (X0, Y0) and the current reference point coordinates are (X′, Y′), the translation amount ΔX = X′-X0, ΔY = Y′-Y0;

[0039] Step 6: Graphics Compensation: The software performs a rotation and translation transformation on the print path or graphic based on the calculated rotation angle and displacement deviation to obtain a calibrated graphic or print path. When generating a print path or graphic, the software uses the upper left corner or the extension line as the rotation origin and performs a comprehensive transformation on the print path or graphic based on the calculated rotation angle a and translation amounts ΔX and ΔY. Specifically, the graphic or print path is rotated in the opposite direction by an angle of -a and translated by a compensation vector (-ΔX, -ΔY) to obtain a calibrated graphic or print path.

[0040] Step 7: Second printing: Start the printing device and perform a second printing based on the calibrated graphics or printing path to achieve precise alignment with the first printed graphics.

[0041] Example:

[0042] Taking high-resolution inkjet printing equipment as an example, the specific implementation process is as follows:

[0043] First print and reference record: Print the first layer of graphics on the substrate, record the initial graphic design coordinates, and set the upper left corner of the graphics as the alignment reference point.

[0044] Substrate processing and secondary placement: After the substrate is taken out for heat treatment and other process treatments, it is placed on the equipment baseboard again, and the visual system is started to collect the substrate surface image.

[0045] Image recognition and feature point selection: The software performs grayscale processing and edge detection on the captured image, automatically extracting the graphic boundary segments and selecting a horizontal line segment. When using the automatic point selection method, the host computer searches for a horizontal line from top to bottom based on the graphic features. The machine's three axes move to the approximate area, identify the line segment based on grayscale and line segment features, and automatically select the end points of the line segment and record their coordinates (X1, Y1) and (X2, Y2).

[0046] Deviation calculation: Combine the initial design coordinates to calculate the rotation angle a. At the same time, the translation amounts ΔX and ΔY of the reference point are calculated.

[0047] Graphics compensation transformation: With the upper left corner as the rotation origin, rotate the graphics or printing path to be printed by an angle of -a in the opposite direction, and translate the compensation vector (-ΔX, -ΔY) to obtain the calibrated graphics and printing path.

[0048] Second Print: Start the second print to align the printed graphics precisely with the first print graphics.

[0049] There are two point selection methods: manual and automatic. The manual method allows people to obtain coordinates by clicking two points in the vision system on the host computer with a mouse. It is suitable for scenarios that require human intervention. The automatic method uses machine vision algorithms to automatically identify line segments and select points, improving efficiency and consistency.

[0050] In the implementation of rotation compensation, the upper left corner or the extension line is used as the rotation origin to ensure the consistency of the rotation reference. The influence of the substrate position error is eliminated by rotating and translating the subsequent printed graphics.

[0051] In addition, image recognition algorithms such as template matching and corner detection can be combined to further improve the accuracy of coordinate extraction, and feature point selection can be fully automated to improve efficiency and consistency.

[0052] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for compensating for substrate position errors during printing, characterized by: The following steps are involved: Step 1: Equipment preparation: Use a printing device with an integrated visual recognition system that can image the substrate surface and obtain the pixel coordinates or physical coordinates of the pattern on the substrate; Step 2: First Print and Reference Setting: Print the first layer of graphics on the substrate, specify the upper left corner of the printed graphics or the intersection of the extended lines as the alignment reference point, and record the initial graphics design coordinates; Step 3: Substrate processing and secondary placement: After taking out the substrate for process processing, place it back into the device substrate; Step 4: Feature point identification and selection: The visual recognition system images the substrate surface, identifies the last printed pattern, selects a straight line segment in the pattern, selects two points on the straight line segment, and obtains their pixel coordinates or physical coordinates; Step 5: Deviation calculation: Calculate the rotation angle and displacement deviation between the current image and the original image based on the coordinates of the two points; Step 6: Graphics compensation: The software performs overall rotation and translation transformation on the printing path or graphics based on the calculated rotation angle and displacement deviation to obtain the calibrated graphics or printing path; Step 7: Second printing: Start the printing device and perform a second printing based on the calibrated graphics or printing path to achieve precise alignment with the first printed graphics.

2. The method for compensating for substrate position errors during printing according to claim 1, characterized in that: In step 4, the straight line segment preferably selects a horizontal line segment, and the selection method includes manual selection and automatic selection. Manual selection is achieved by manually clicking in the visual system to obtain the coordinates of two points, and automatic selection is achieved by identifying the line segment through a machine vision algorithm and automatically selecting two points.

3. The method for compensating for substrate position errors during printing according to claim 2, characterized in that: The step four is specifically as follows: select a horizontal line segment in the figure, select two points on the line segment manually or automatically, obtain their pixel coordinates or physical coordinates, recorded as (X1, Y1) and (X2, Y2); when manually selecting points, a person uses a mouse to click two points in the visual system on the host computer to obtain the coordinates; when automatically selecting points, the host computer searches for the horizontal line from top to bottom according to the drawn figure, and the three axes of the machine run to the corresponding approximate area, identify the line segment within the field of view based on the features and grayscale, and automatically select two points and record the coordinates.

4. The method for compensating for substrate position errors during printing according to claim 1, characterized in that: The step 5 is specifically as follows: calculating the rotation angle a and displacement deviation between the current image and the original image according to the coordinates of the two selected points; the rotation angle a satisfies The displacement deviation is determined by the coordinate change of the reference point. Assuming that the initial reference point coordinates are (X0, Y0) and the current reference point coordinates are (X′, Y′), the translation amount ΔX = X′-X0, ΔY = Y′-Y0.

5. The method for compensating for substrate position errors during printing according to claim 1, characterized in that: The step six is ​​specifically as follows: When generating a print path or graphic, the software uses the upper left corner or extension line as the rotation origin and transforms the print path or graphic as a whole based on the calculated rotation angle a and translation amounts ΔX and ΔY. Specifically, the graphic or print path is rotated in the opposite direction by an angle of -a and the compensation vector is translated (-ΔX, -ΔY) to obtain the calibrated graphic or print path.

6. The method for compensating for substrate position errors during printing according to claim 1, characterized in that: The image processing of the visual recognition system includes grayscale processing and edge detection, and is also combined with template matching and corner detection algorithms to improve the accuracy of coordinate extraction.

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