Projection type linear scanning calibration method, system and equipment for digital micromirror device

Abstract

The invention discloses a projection type linear scanning calibration method, system and equipment of a digital micromirror device, the calibration method is used for manufacturing a printed circuit board, the calibration method comprises the following steps: obtaining size data of a DMD and size data of a target product, and lenses in the DMD are sequentially arranged along the transverse direction; determining a required lens; obtaining the coordinate of the first required lens and the coordinate of the last required lens through the camera; calculating an initial linear relation between the first required lens and the last required lens; according to the initial linear relation, the position offset of the first lens and the position offset of the last lens are calculated, and the position offset range of the needed lenses is determined according to the position offset. According to the invention, by adopting a linear calibration mode, only the required head and tail lenses are calibrated, so that the calibration workload is small, and the time is short; and meanwhile, the method has small influence on the production efficiency of the PCB, and the calibration is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of lens calibration methods, and in particular to a projection linear scanning calibration method, system and equipment for a digital micromirror device. Background Art

[0002] In today's PCB (printed circuit board) lithography field, digital micromirror device (DMD)-based lithography technology is widely used.

[0003] DMD position relationship calibration is to project the DMD onto the camera or onto a photosensitive film, and then the camera captures the image to confirm the position relationship. The DMD used usually has this problem: the lens is used for a long time, causing the internal temperature of the lens to rise, and the resulting temperature drift causes the projection axis to shift, and there is a large fluctuation in the position between the lenses.

[0004] In conventional DMD lens offset calibration, rectangular calibration is often used (i.e. rectangular expansion and contraction: measuring the coordinates of four target positions to form a rectangle). This calibration method requires a long period of production suspension, which has a significant impact on production efficiency. The calibration accuracy is low, and each lens needs to be inspected and calibrated during the calibration process, which takes a long time.

[0005] Therefore, there is an urgent need to develop a projection linear scanning calibration method and system for a digital micromirror device. Summary of the invention

[0006] In view of the above problems, the present invention provides a projection linear scanning calibration method, system and device for a digital micromirror device.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0008] In a first aspect, the present invention provides a projection linear scanning calibration method of a digital micromirror device for use in printed circuit board manufacturing, comprising:

[0009] Acquire dimension data of a DMD and dimension data of a target product, wherein the lenses in the DMD are sequentially arranged in a horizontal direction;

[0010] Determine the required lens;

[0011] Obtain the coordinates of the first lens and the last lens through the camera;

[0012] Calculate the initial linear relationship between the required first shot and the required last shot;

[0013] According to the initial linear relationship, the position offset of the first lens and the position offset of the last lens are calculated, and the position offset range of the required lenses is determined accordingly.

[0014] In a preferred embodiment, the position offset of the first lens and the position offset of the last lens are calculated according to the initial linear relationship, and the position offset range of the required lens is determined accordingly:

[0015] After the required lens is used for a certain period of time, a second linear relationship of the first required lens is calculated according to the slope of the initial linear relationship and the coordinates of the first required lens after the certain period of time, and a second linear relationship of the last required lens is calculated according to the slope of the initial linear relationship and the coordinates of the last required lens after the certain period of time, and a difference between the intercepts of the initial linear relationship and the second linear relationship of the first required lens is used as a position offset of the first required lens, and a difference between the intercepts of the initial linear relationship and the second linear relationship of the last required lens is used as a position offset of the last required lens; and a position offset range of the required lens between the first required lens and the last required lens is determined according to the position offset of the first required lens and the position offset of the last required lens.

[0016] In a preferred embodiment, the intercept is a lateral intercept.

[0017] In a preferred embodiment, the intercept is a longitudinal intercept.

[0018] In a preferred embodiment, the step of obtaining the coordinates of the first lens and the last lens through a camera specifically includes: obtaining the coordinates of the first lens and the last lens through a camera during exposure.

[0019] In a preferred embodiment, the calibration method further includes:

[0020] Get a training dataset;

[0021] An offset calculation model is trained, wherein the input of the offset calculation model is the number of required lenses and the positions of the required lenses, and the output is a position offset or a position offset range.

[0022] In a preferred embodiment, the training data set includes information on the number of required shots, initial coordinate information of the first required shot, initial coordinate information of the last shot, shot usage time information, coordinate information of the first required shot corresponding to the shot usage time, coordinate information of the last required shot corresponding to the shot usage time, and an offset compensation value corresponding to the shot usage time.

[0023] In a second aspect, the present invention provides a projection linear scanning calibration system for a digital micromirror device, comprising:

[0024] An acquisition module, used for acquiring the size data of the DMD and the size data of the target product, wherein the lenses in the DMD are arranged in sequence along the horizontal direction;

[0025] A determination module, used for determining a required lens;

[0026] A coordinate detection module, used for obtaining the coordinates of the first lens and the last lens through a camera;

[0027] The calculation module is used to calculate the initial linear relationship between the first lens required and the last lens required; and to calculate the position offset of the first lens required and the position offset of the last lens required according to the initial linear relationship, and determine the position offset range of the required lens accordingly.

[0028] In a third aspect, the present invention provides an electronic device comprising: a memory; one or more processors; one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing any one of the projection linear scanning calibration methods for the digital micromirror device described in the first aspect of the present invention.

[0029] In a fourth aspect, the present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium includes instructions, and when the instructions are run on a computer, the computer executes the projection linear scanning calibration method for the digital micromirror device described in the first aspect of the present invention.

[0030] The projection linear scanning calibration method, system, equipment and storage medium of the digital micromirror device of the present invention adopt a linear calibration method, and only two lenses, the first lens and the last lens, need to be calibrated, and there is no need to calibrate each required lens, so that the calibration workload is reduced and the time is saved. This method can realize the knowledge of temperature drift while meeting production needs; at the same time, it has little impact on the production efficiency of PCB boards, and the calibration is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 Flow chart of projection linear scanning calibration method for digital micromirror device Figure 1 .

[0033] Figure 2Flow chart of projection linear scanning calibration method for digital micromirror device Figure 2 .

[0034] Figure 3 The framework diagram of the projection linear scanning calibration system for digital micromirror devices.

[0035] Figure 4 A schematic diagram of the structure of an electronic device. DETAILED DESCRIPTION

[0036] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0038] It should be noted that the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0039] See also Figure 1 , a projection linear scanning calibration method of a digital micromirror device for PCB manufacturing, the method comprising:

[0040] Acquire dimension data of a DMD and dimension data of a target product, wherein the lenses in the DMD are sequentially arranged in a horizontal direction;

[0041] Determine the required lens;

[0042] Obtain the coordinates of the first lens and the last lens through the camera;

[0043] Calculate the initial linear relationship between the required first shot and the required last shot;

[0044] According to the initial linear relationship, the position offset of the first lens and the position offset of the last lens are calculated, and the position offset range of the required lenses is determined accordingly.

[0045] It should be understood that the above method does not represent or imply that all steps must be executed in this order. For example, obtaining the coordinates of the first lens and the last lens through the camera is not only performed before calculating the initial linear relationship between the first lens and the last lens, but also needs to be performed once before each step of calculating the position offset of the first lens and the position offset of the last lens. A person of ordinary skill in the art can transform or change the execution order of the above steps based on the present invention. Some embodiments of the above method are described below.

[0046] See also Figure 2 , the projection linear scanning calibration method specifically includes:

[0047] S1. Obtain the dimension data of DMD; obtain the dimension data of the target product;

[0048] It can be understood that the target product is a product that needs to be obtained based on DMD lithography, which can be understood as a pattern that needs lithography.

[0049] The size data of the DMD includes the size data of all lenses in the DMD, and the size includes width and height.

[0050] Furthermore, the size data of the DMD also includes the position data of all lenses in the DMD.

[0051] All lenses of DMD are arranged in sequence along the horizontal direction, that is, the X direction. The lens size corresponding to the X direction is called the lens width, and the lens size corresponding to the Y direction is called the lens length. The Y direction is the longitudinal direction and is perpendicular to the X direction.

[0052] S2. Determine the required number of lenses based on the data obtained in S1, and determine the required lenses based on the required number of lenses.

[0053] After calculating and cutting according to the size of the pattern to be photoetched and the size data of the DMD, the target product is printed, that is, the required number of lenses is determined and all required lenses are determined according to the size data of the DMD and the size data of the target product.

[0054] Usually, the required lens is part or all of all of the lenses in the DMD that are set sequentially. Generally, the lens that ranks first in the DMD is the first lens required.

[0055] Here, the number of lenses to be used is determined based on the width of each lens and the width of the target product. As an example and not a limitation, for example, a digital micromirror device DMD has 12 lenses, each lens has a width of 104 mm, and if the width of the target product is 540 mm, then the sixth DMD lens is determined to be the last lens to be used. The lenses required are the first lens to the sixth lens.

[0056] S3, perform calibration, project the target by scanning, and obtain the center coordinates (x1, y1) of the first lens and the center coordinates (x1, y1) of the last lens through the camera. last ,y last ), and calculate the k value and b value in the linear equation y=kx+b to obtain the initial linear relationship. x is the independent variable of the equation, y is the dependent variable of the equation, k is the slope, that is, the linear coefficient value, and b is the slope distance, that is, the basic value.

[0057] Here, S3 is equivalent to determining the initial coordinates.

[0058] It can be understood that the calculated b value is different according to the setting of the coordinate origin. For example, if the initial center position of the first lens is the coordinate origin, the b value is 0.

[0059] S4. After the required lens is used for a certain period of time, the center coordinates (x1', y1') of the first required lens and the center coordinates (x' last ,y' last ), according to the k value obtained in S3, a new linear relationship is calculated. Specifically, the second linear relationship of the first lens required is calculated, and the second linear relationship of the last lens required is calculated. The slope of the second linear relationship is equal to the slope of the initial linear relationship.

[0060] Usually, the execution of S4 needs to be timed with S3. The length of the time interval is not limited and can be set according to actual needs.

[0061] S5. Calculate the displacement offset, and use the difference between the intercept of the initial linear relationship and the second linear relationship of the first lens as the position offset of the first lens, that is, the position compensation of the first lens is known, and use the difference between the intercept of the initial linear relationship and the second linear relationship of the last lens as the position offset of the last lens, that is, the position compensation of the last lens is known.

[0062] S6. Determine a position offset range of a required lens between the required first lens and the required last lens according to the position offset of the required first lens and the position offset of the required last lens.

[0063] Specifically, the position offset range is between the position offset of the required first lens and the position offset of the required last lens, greater than the position offset of the required first lens and less than the position offset of the required last lens, or greater than the position offset of the required last lens and less than the position offset of the required first lens.

[0064] The method further includes S7, adjusting all required lenses according to the position offset / position compensation amount.

[0065] S4 to S6 are repeatedly executed to continuously obtain and record the offset compensation value.

[0066] It is understandable that the camera cannot obtain the coordinates of the lens in absolute real time. It is necessary to pause the lithography and project it onto the camera before the coordinates can be measured.

[0067] Here, during exposure, the coordinates of the first lens and the last lens are obtained through the camera. That is, there is no need to stop the production of the PCB, and the lens coordinates are obtained by pausing for a few seconds or tens of seconds (usually within 30 seconds) at the beginning of exposure.

[0068] As a preferred embodiment, the intercept used to calculate the position offset is a lateral intercept, and the lens is adjusted lateraly according to the position offset.

[0069] In other embodiments, the intercept used to calculate the position offset is a longitudinal intercept, and the lens is adjusted longitudinally according to the position offset.

[0070] It can be understood that in some embodiments, the intercept may be a transverse intercept and a longitudinal intercept, the transverse intercept is used to obtain the transverse position offset, and the transverse position offset is obtained according to the longitudinal intercept.

[0071] The projection linear scanning calibration method of the digital micromirror device also includes the step of training an offset compensation value calculation model.

[0072] According to the above steps S1 to S6, a training data set is constructed, and the training data set includes information on the number of required shots, initial coordinate information of the first required shot, initial coordinate information of the last shot, shot usage time information, coordinate information of the first required shot corresponding to the shot usage time, coordinate information of the last required shot corresponding to the shot usage time, and an offset compensation value corresponding to the shot usage time.

[0073] The offset calculation model is trained according to the training data set, wherein the input of the offset calculation model is the required number of lenses, the initial coordinate information of the first lens required, and the initial coordinate information of the last lens; the output of the offset model is the position offset or the position offset range.

[0074] See also Figure 3 The present invention provides a projection linear scanning calibration system 100 for a digital micromirror device, the system comprising:

[0075] An acquisition module 10 is used to acquire the size data of the DMD and the size data of the target product, wherein the lenses in the DMD are arranged in sequence along the horizontal direction;

[0076] A determination module 20, used to determine the required lens;

[0077] A coordinate detection module 30, used to obtain the coordinates of the first lens and the last lens through a camera;

[0078] The calculation module 40 is used to calculate the initial linear relationship between the first lens required and the last lens required; and to calculate the position offset of the first lens required and the position offset of the last lens required according to the initial linear relationship, and determine the position offset range of the required lens accordingly.

[0079] When the system is implemented, the calibration method in any of the above embodiments may be referred to to implement the calibration embodiment, and the specific implementation steps will not be repeated.

[0080] See also Figure 4 According to the method of the present invention, an electronic device can be implemented, and the electronic device includes: a memory; one or more processors; one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing the projection linear scanning calibration method of the digital micromirror device according to any of the above embodiments.

[0081] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0082] The memory may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage. In addition, the memory may include any combination of computer-readable storage media, such as semiconductor memory chips, magnetic disks, and optical disks.

[0083] The memory stores executable codes, and when the executable codes are processed by the processor, the processor can execute part or all of the methods described above.

[0084] The technicians in the field to which the present invention belongs can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0085] The present invention also provides a computer-readable storage medium, which includes instructions. When the instructions are executed on a computer, the computer executes each step of the projection linear scanning calibration method for a digital micromirror device described in any of the above embodiments.

[0086] The effects of the projection linear scanning calibration method, system and device storage medium of the digital micromirror device of the present invention are as follows: the present invention adopts a linear calibration method, and only needs to calibrate the first lens and the last lens, and does not need to calibrate each required lens. The lens offset between the head and the tail is within the linear expansion and contraction control range, and the calibration workload is small and the time is short. This method can achieve the temperature drift under the condition of meeting production needs. The prior art requires a long pause time, usually 5 minutes, which not only affects the production of PCB boards, but also seriously affects the accuracy of calibration because the temperature drops more during measurement. The projection linear scanning calibration method and system of the present invention do not need to completely stop production, but only need to pause for a few seconds. The pause time is short, the temperature control can be well seen, the calibration is more accurate, and the impact on production efficiency is small.

[0087] The projection linear scanning calibration method of the digital micromirror device of the present invention is a linear expansion and contraction linear scanning calibration method, which can effectively expose each DMD lens in the X direction, and can more effectively control the error, thereby improving the scanning accuracy of the PCB board production lithography equipment.

[0088] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0089] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, electronic devices or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0090] The present invention is described with reference to the flowcharts and / or block diagrams of the methods and systems according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0091] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0093] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0094] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A projection linear scanning calibration method for a digital micromirror device for printed circuit board manufacturing, characterized in that: include: Acquire dimension data of a DMD and dimension data of a target product, wherein the lenses in the DMD are sequentially arranged in a horizontal direction; Determine the required lens; Obtain the coordinates of the first lens and the last lens through the camera; Calculate the initial linear relationship between the required first shot and the required last shot; According to the initial linear relationship, the position offset of the first lens and the position offset of the last lens are calculated, and the position offset range of the required lenses is determined accordingly.

2. The projection linear scanning calibration method of a digital micromirror device according to claim 1, characterized in that: The position offset of the first lens and the position offset of the last lens are calculated according to the initial linear relationship, and the position offset range of the required lens is determined accordingly: After the required lens is used for a certain period of time, a second linear relationship of the first required lens is calculated according to the slope of the initial linear relationship and the coordinates of the first required lens after the certain period of time, and a second linear relationship of the last required lens is calculated according to the slope of the initial linear relationship and the coordinates of the last required lens after the certain period of time, and a difference between the intercepts of the initial linear relationship and the second linear relationship of the first required lens is used as a position offset of the first required lens, and a difference between the intercepts of the initial linear relationship and the second linear relationship of the last required lens is used as a position offset of the last required lens; and a position offset range of the required lens between the first required lens and the last required lens is determined according to the position offset of the first required lens and the position offset of the last required lens.

3. The projection linear scanning calibration method of a digital micromirror device according to claim 1, characterized in that: The intercept is the lateral intercept.

4. The projection linear scanning calibration method of a digital micromirror device according to claim 1, characterized in that: The intercept is the longitudinal intercept.

5. The projection linear scanning calibration method of a digital micromirror device according to claim 1, characterized in that: The obtaining of the coordinates of the first lens and the coordinates of the last lens through the camera specifically includes: obtaining the coordinates of the first lens and the coordinates of the last lens through the camera during exposure.

6. The projection linear scanning calibration method of a digital micromirror device according to claim 1, characterized in that: The calibration method also includes: Get a training dataset; An offset calculation model is trained, wherein the input of the offset calculation model is the number of required lenses and the positions of the required lenses, and the output is a position offset or a position offset range.

7. The projection linear scanning calibration method of a digital micromirror device according to claim 6, characterized in that: The training data set includes information on the number of required shots, initial coordinate information of the first required shot, initial coordinate information of the last shot, shot usage time information, coordinate information of the first required shot corresponding to the shot usage time, coordinate information of the last required shot corresponding to the shot usage time, and an offset compensation value corresponding to the shot usage time.

8. A projection linear scanning calibration system for a digital micromirror device, characterized in that: include: An acquisition module, used for acquiring the dimension data of the DMD and the dimension data of the target product, wherein the lenses in the DMD are arranged in sequence along the horizontal direction; A determination module, used for determining a required lens; A coordinate detection module, used for obtaining the coordinates of the first lens and the last lens through a camera; A calculation module, used for calculating an initial linear relationship between a required first shot and a required last shot; It is used to calculate the position offset of the first lens and the position offset of the last lens according to the initial linear relationship, and determine the position offset range of the required lenses accordingly.

9. An electronic device, characterized in that: include: Memory; one or more processors; One or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any of the projection linear scanning calibration methods for the digital micromirror device according to claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes instructions, and when the instructions are executed on a computer, the computer executes the projection linear scanning calibration method for a digital micromirror device according to any one of claims 1 to 7.

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