Circuit board exposure machine calibration methods, devices, electronic equipment and storage media

Abstract

This application discloses a calibration method, apparatus, electronic device, and storage medium for a circuit board exposure machine, relating to the field of circuit board manufacturing. According to a first aspect of this application, a calibration method for a circuit board exposure machine is proposed, applied to a circuit board exposure machine including a camera, a platform, and a digital micromirror. The method includes: moving the camera based on a standard target point on a test board to calibrate the camera; moving the platform based on the standard target point to calibrate the platform; acquiring a first exposure result from the digital micromirror and calibrating the digital micromirror based on the first exposure result; acquiring a second exposure result from the digital micromirror and calibrating the circuit board exposure machine based on the second exposure result. The circuit board exposure machine calibration method according to the first aspect of this application allows for step-by-step inspection of each key component of the circuit board exposure machine, enabling rapid identification of problematic components and reducing repair time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit board manufacturing, in particular to a circuit board exposure machine calibration method and device, electronic equipment and storage medium. BACKGROUND

[0002] LDI (Laser Direct Imaging), also known as laser direct imaging technology, is a technology that uses laser direct imaging principle to project a circuit image directly on a circuit board with a photoresist to realize pattern transfer. A direct imaging exposure machine using this technology can directly write an image on a substrate without using a film tool, saving the cost of a film.

[0003] In order to ensure the accuracy of image writing, calibration is required in the actual application process of the direct imaging exposure machine (hereinafter referred to as the exposure machine). The existing calibration method generally completes calibration through the following steps: (1) prepare a photosensitive film marked with standard coordinate points. (2) use the exposure machine to expose the photosensitive film to obtain new coordinate points. (3) compare the deviation distance of the new coordinate points and the standard coordinate points. (4) write the distance into the compensation algorithm to complete the calibration. The defect of this calibration method is that the whole software calibration is used, that is, the whole error of the exposure machine is compensated and calibrated by software. When the deviation is too large to be calibrated by software alone, each component of the exposure machine needs to be calibrated respectively. The existing calibration method cannot locate the error in which component of the exposure machine. SUMMARY

[0004] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of protection of the claims.

[0005] Based on the above problems, the present application provides a circuit board exposure machine calibration method, device, electronic equipment and storage medium, which can quickly locate which component has a problem and reduce the repair time.

[0006] According to a first aspect of the present application, a circuit board exposure machine calibration method is provided, applied to a circuit board exposure machine, the circuit board exposure machine comprising a camera, a platform and a digital micromirror, the method comprising: moving the camera based on a standard target point of a test board, calibrating the camera; moving the platform based on the standard target point, calibrating the platform; obtaining a first exposure result of the digital micromirror, and calibrating the digital micromirror according to the first exposure result; obtaining a second exposure result of the digital micromirror, and calibrating the circuit board exposure machine according to the second exposure result. According to the circuit board exposure machine calibration method of the first aspect of the present application, each key part of the circuit board exposure machine can be checked step by step, so that the component which has a problem can be quickly located, and the repair time is reduced.

[0007] In some embodiments, the test board is placed on the platform, the standard target based on the test board moves the camera, calibrates the camera, including: using the camera to capture the position of the standard target, obtaining a capture position; obtaining a target capture error according to the actual position of the standard target and the capture position; calibrating the camera based on the target capture error.

[0008] In some embodiments, the test board is placed on the platform, the standard target based on the test board moves the platform, calibrates the platform, including: moving the platform according to a predetermined movement distance; obtaining an actual movement distance using the camera; obtaining a movement error according to the actual movement distance and the predetermined movement distance; calibrating the platform based on the movement error.

[0009] In some embodiments, the digital micro-mirror includes N micro-mirror groups, one of the micro-mirror groups is composed of M micro-mirror units, N and M are integers greater than 1; the first exposure result of the digital micro-mirror is obtained, and the digital micro-mirror is calibrated according to the first exposure result, including: using the circuit board exposure machine to expose on the photosensitive film to obtain the first exposure result; the first exposure result includes N first check patterns, the first check pattern is the exposure result of the micro-mirror group, the first check pattern includes M check sub-patterns, and the check sub-pattern is the exposure result of the micro-mirror unit; calibrating the micro-mirror unit of each micro-mirror group according to the check sub-pattern, thereby calibrating the digital micro-mirror; and / or, calibrating the digital micro-mirror according to the first check pattern.

[0010] In some embodiments, calibrating the micro-mirror unit of each micro-mirror group according to the check sub-pattern includes: selecting any check sub-pattern in the first check pattern of the micro-mirror group as a reference sub-pattern; obtaining a first deviation of the reference sub-pattern from each check sub-pattern in the first check pattern; and calibrating each micro-mirror unit in the micro-mirror group according to the first deviation.

[0011] In some embodiments, calibrating the digital micro-mirror according to the first exposure result includes: selecting any first check pattern in the first exposure result as a reference check pattern; obtaining a second deviation of the reference check pattern from each first check pattern in the first exposure result; and calibrating the micro-mirror group according to the second deviation, thereby calibrating the digital micro-mirror.

[0012] In some embodiments, the second exposure result includes a second verification pattern and a third verification pattern, the second verification pattern includes a first compensation sub-pattern of each of the micro-mirror units, and the third verification pattern includes a second compensation sub-pattern of each of the micro-mirror units; the obtaining the second exposure result of the digital micro-mirror, and calibrating the circuit board exposure machine according to the second exposure result, includes: obtaining a first center position of each of the first compensation sub-patterns in the second verification pattern; obtaining a second center position of each of the second compensation sub-patterns in the second verification pattern; calculating a alignment distance between the first center position and the second center position; and calibrating the circuit board exposure machine according to the alignment distance.

[0013] In some embodiments, the first compensation sub-pattern is a dot, and the second compensation sub-pattern is a ring, and an inner diameter of the ring is greater than a radius of the dot.

[0014] In some embodiments, the inner diameter of the ring is twice the radius of the dot, and an outer diameter of the ring is three times the radius of the dot.

[0015] According to a second aspect of the present application, a circuit board exposure machine calibration device is further provided, which is applied to a circuit board exposure machine including a camera, a platform and a digital micro-mirror, and includes: a camera calibration module configured to calibrate the camera based on a standard target point of a test board; a platform calibration module configured to calibrate the platform based on the standard target point; a digital micro-mirror calibration module configured to obtain a first exposure result of the digital micro-mirror, and calibrate the digital micro-mirror according to the first exposure result; and a calibration verification module configured to obtain a second exposure result of the digital micro-mirror, and calibrate the circuit board exposure machine according to the second exposure result.

[0016] According to a third aspect of the present application, an electronic device is further provided, which includes a memory, a processor, a communication bus, a communication interface, and a computer program stored in the memory and executable on the processor, the communication bus is configured to realize connection communication between the processor and the memory; the processor realizes the circuit board exposure machine calibration method according to any one of the above descriptions when executing the computer program.

[0017] According to a fourth aspect of the present application, a storage medium is further provided, which is a readable storage medium, and the readable storage medium stores a computer program, the computer program is configured to make a computer execute the circuit board exposure machine calibration method according to any one of the above descriptions.

[0018] It can be understood that the beneficial effects of the second aspect and the fourth aspect compared with the related art are the same as the beneficial effects of the first aspect compared with the related art, which can be seen from the related description in the first aspect and will not be repeated here.

[0019] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the application. The objects and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a flowchart of an image transfer method.

[0021] Figure 2 is a schematic diagram of an electronic device according to an embodiment of the present application.

[0022] Figure 3 is a flowchart of a circuit board exposure machine calibration method according to an embodiment of the present application.

[0023] Figure 4 is a schematic diagram of camera calibration according to an embodiment of the present application.

[0024] Figure 5 is a schematic diagram of platform calibration according to an embodiment of the present application.

[0025] Figure 6 is a schematic diagram of a first exposure result according to an embodiment of the present application.

[0026] Figure 7 is a schematic diagram of a first exposure result according to another embodiment of the present application.

[0027] Figure 8 is a schematic diagram of digital micromirror calibration according to an embodiment of the present application.

[0028] Figure 9 is a schematic diagram of digital micromirror calibration according to another embodiment of the present application.

[0029] Figure 10 is a partial schematic diagram of a second exposure result according to an embodiment of the present application.

[0030] Figure 11 is a schematic diagram of a second verification pattern of a second exposure result according to an embodiment of the present application.

[0031] Figure 12 is a schematic diagram of a third verification pattern of a second exposure result according to an embodiment of the present application.

[0032] Figure 13 is a structural diagram of a verification device of a circuit board exposure machine according to an embodiment of the present application. Detailed Implementation

[0033] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that the embodiments of this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the embodiments of this application with unnecessary detail.

[0034] It should be noted that although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0035] LDI, short for Laser Direct Imaging, is a type of direct-write exposure technology. When applied to PCB exposure, this technology saves time compared to traditional mask (film) exposure, reducing the time required for multiple processes such as board making and process verification, thus significantly improving production efficiency. Furthermore, since it eliminates the need for masks (film), it can optimize alignment errors caused by thermal expansion and avoid defects resulting from mask flaws, thereby improving PCB manufacturing precision and yield.

[0036] Some existing circuit board exposure machines using direct-write exposure technology employ projection imaging lenses based on DMD (Digital Micro-mirror Device). These lenses have a more compact optical structure and allow for easier improvement in exposure efficiency by adding exposure heads. They feature high resolution, high contrast, high brightness, and fast response.

[0037] A digital micromirror is an optical micro-electrical-mechanical system (MEMS) with electronic input and optical output, and it is also a type of spatial light modulator. It consists of many small reflective surfaces, each of which is called a micromirror unit. Each micromirror unit is an independent entity and can be flipped at different angles (positive or negative), so the light reflected through the micromirror unit can present different angles.

[0038] Figure 1is a flow chart of image transfer of a circuit board exposure machine of the embodiment of the present application. The digital micro-mirror of the circuit board exposure machine usually contains thousands of small mirrors (micro-mirror units), and the opening and closing of each mirror is driven by software to divide the image into exposed and non-exposed areas. The material to be exposed is placed on the platform and moves with the movement of the platform. Referring to Figure 1 , the exposure image transfer process of the circuit board exposure machine can be briefly described as follows: first, the exposure material is placed on the platform, and the position on the material to be exposed for image transfer is determined by the camera (i.e. S10 camera target acquisition, determine the image transfer area). Then, according to the above-mentioned target acquisition data, S20 is executed in the software to construct a virtual plane according to the image transfer area to determine how to control the digital micro-mirror to complete the image transfer. Finally, S30 is executed according to the virtual plane to make the platform move, and at the same time, the digital micro-mirror is used to expose the exposure material. Specifically, while the platform is moving, the light emitted by the digital micro-mirror is projected onto a specific position on the material to be exposed to expose the position (i.e. S40 digital micro-mirror exposure), thereby realizing image transfer.

[0039] In this process, the actual image obtained by image transfer and the theoretical image may have errors due to the precision of three key hardware, i.e. the camera, the platform and the digital micro-mirror. For example: the camera may have an upper limit of precision, so that the accuracy of target acquisition is not enough and the exposure range is wrong. The micro-mirror units in the digital micro-mirror may be curved due to temperature changes or the components adjusting the inclination of the micro-mirror units may be offset. The stepping and movement of the platform may also be deviated due to temperature or voltage changes.

[0040] In the circuit board exposure machine using direct writing exposure technology, the following calibration method is known: first, a photosensitive film marked with standard coordinate points is prepared, and the photosensitive film is covered on a glass plate with small deformation. Then, the exposure machine is used to expose the photosensitive film to obtain new coordinate points. Finally, the deviation distance between the new coordinate points and the standard coordinate points is compared, and the distance is written into the compensation algorithm to complete the calibration. On the one hand, since the standard coordinate points on the photosensitive film are pre-calibrated and designed and cannot be changed, the calibration program can only be designed according to the standard coordinate points on the photosensitive film. When the array of the digital micro-mirror is large, if the photosensitive film is small, multiple calibrations may be required. On the other hand, this method belongs to overall software calibration, i.e. software compensation calibration of the overall error of the exposure machine. When the deviation is too large to be calibrated by software alone, each component of the exposure machine needs to be calibrated separately. The existing calibration method cannot locate the error in which component of the exposure machine.

[0041] Therefore, the present application provides a circuit board exposure machine calibration method, which is applied to the circuit board exposure machine, for example, a typical circuit board exposure machine includes a master control unit for controlling the circuit board exposure machine, a digital micromirror for exposure, a camera for target determination position, a platform for moving and containing the material to be exposed. Some circuit board exposure machines may also include a special exposure darkroom for improving exposure effect, a human-computer interaction assembly for facilitating staff operation, a detection module integrated with functions such as temperature monitoring and voltage detection to ensure normal operation of the circuit board exposure machine, and various safety devices for facilitating job safety.

[0042] The circuit board exposure machine calibration method of the present application can be executed by the master control unit of the circuit board exposure machine or an external computing device connected to the circuit board exposure machine. These devices are, for example, Figure 2 The electronic device shown in FIG. 1, Figure 2 is a schematic diagram of the electronic device of the present application embodiment, referring to Figure 2 The electronic device 10 provided by the present application embodiment includes a memory 101, a processor 102, a communication bus 103, and a communication interface 104. The communication bus 103 is used to realize the communication connection between the memory 101 and the processor 102; the communication interface 104 is used for communication with the outside; and the processor 102 is used to execute one or more computer programs stored in the memory 101 to realize at least one step of any one of the circuit board exposure machine calibration methods in the present application embodiment.

[0043] The circuit board exposure machine calibration method of the present application will be described below.

[0044] Figure 3 is a flowchart of the circuit board exposure machine calibration method of the present application embodiment.

[0045] Referring to Figure 3 The circuit board exposure machine calibration method of the present application embodiment is applied to a circuit board exposure machine, which includes a camera, a platform, and a digital micromirror. The method includes:

[0046] S100: moving the camera based on the standard target point of the test board, and calibrating the camera;

[0047] S200: moving the platform based on the standard target point, and calibrating the platform;

[0048] S300: obtaining a first exposure result of the digital micromirror, and calibrating the digital micromirror according to the first exposure result;

[0049] S400: Obtain a second exposure result of the digital micro-mirror, and calibrate the circuit board exposure machine according to the second exposure result.

[0050] According to the circuit board exposure machine calibration method, each key part of the circuit board exposure machine can be checked step by step, so that the problem part can be quickly located, and the maintenance time is reduced.

[0051] Specifically, in S100, the camera is moved based on the standard target points of the test board, and the camera is calibrated. The test board is placed on the platform of the circuit board exposure machine. The test board can be a glass plate marked with standard points, but the same effect can also be obtained by using a conventional photosensitive film marked with standard target points on the glass plate. Reference Figure 4 , Figure 4 is a schematic diagram of camera calibration of the present application. The test board 201 is marked with a plurality of standard target points 204. The standard target points 204 can be a template marked and calibrated by the manufacturer in advance, or obtained by exposure during the last use. It is easy to understand that Figure 3 For clarity, only a part of the test board is selected as an example, and the size of the standard target points and the distance between the standard target points are exaggerated. The actual ratio can be different from that shown in the drawings.

[0052] Firstly, S101 is performed, the positions of the standard target points 204 are collected by using the camera 203, and the collected positions are obtained. Specifically, the camera 203 is moved while the platform 202 is not moved, and the actual coordinates of the standard target points 204 are measured by the camera. The coordinates can be obtained by image recognition, for example, the shape of the standard target points 204 is recognized from the picture taken by the camera, so that the relative coordinates of the standard target points 204 with the coordinate origin are obtained by image recognition, and the collected positions of the standard target points 204 are obtained.

[0053] Then, S102 is performed to obtain the target acquisition error according to the actual positions of the standard target points 204 and the collected positions. The target acquisition error is obtained by comparing the collected positions of the standard target points with the actual positions of the standard target points. The target acquisition error is compared with the first threshold value. If it is greater than the first threshold value, it is judged that further calibration is needed. In some embodiments, the first threshold value is set to 2 μm, but it is easy to understand that the value of the first threshold value should depend on the processing technology and the circuit board exposure machine and the camera itself. Different cameras and different processes should take different threshold values.

[0054] As Figure 4As shown, since there can be multiple standard targets 204 on the test plate 201 in some embodiments, the grab target errors of the multiple standard targets 204 can also be measured, and the standard deviation or average of the grab target errors can be obtained. When the standard deviation or average of the grab target errors is greater than a preset first threshold, it is determined that further calibration is needed, or when the grab target error with the largest value is greater than a second threshold, it is determined that further calibration is needed. The second threshold is greater than the first threshold.

[0055] If it is considered that the camera needs to be calibrated, S103 needs to be performed to calibrate the camera based on the grab target error. The calibration of the camera 203 can be calibrated by software, for example, updating the coordinate configuration table of the camera 203 according to the collection position, compensating the camera 203 to solve the error, or adjusting the position of the camera, it is easy to understand that the specific calibration method is not limited in any way.

[0056] It should be noted that although in the above embodiment, it is mentioned that the test plate 201 can be composed of a non-deformable glass plate and a photosensitive film with standard targets 204 marked on the glass plate, it is obvious that using a glass plate with standard targets 204 can save costs, and therefore is a better embodiment.

[0057] Based on the above embodiments, the calibration of the camera can be completed. Compared with known technologies, the cost of the photosensitive film is saved.

[0058] In S200: calibrating the platform based on the standard target movement platform, the following steps can be included:

[0059] S201: moving the platform according to a predetermined movement distance, so that the test plate moves with the platform;

[0060] S202: obtaining a movement error according to an actual movement distance and the predetermined movement distance;

[0061] S203: calibrating the platform based on the movement error.

[0062] Specifically, in S201: moving the platform according to a predetermined movement distance, so that the test plate moves with the platform, the test plate can use the same test plate as in S100, that is, after S100 is completed, the test plate can not be removed and calibration can continue. It is easy to understand that a new glass test plate can also be selected, and if the camera has been calibrated before or the camera error is small, S100 can be directly performed without S100.

[0063] Figure 5 is a schematic diagram of the platform 302 movement error calibration method of the embodiment of the application. Referring to Figure 5The camera 303 is used to record the position of any one standard target 304 on the test board 301. The platform 302 is moved by a preset distance under the drive of the power device built in the platform 302 or the external pushing device. The camera 303 is used again to obtain the position of the standard target 304 after the movement, so as to obtain the actual movement distance of the standard target 304.

[0064] Then, S202 is performed to obtain the movement error according to the actual movement distance and the predetermined movement distance. In some embodiments, as shown in FIG. 5, the movement can be performed in the same direction for multiple times, and the first actual movement distance L1, the second actual movement distance L2, the third actual movement distance L3, and the Nth (N is greater than 3) actual movement distance Ln of the standard target 304 are obtained by the camera 303, wherein the Nth actual movement distance Ln is greater than the third actual movement distance L3, the third actual movement distance L3 is greater than the second actual movement distance L2, and the second actual movement distance L2 is greater than the first actual movement distance L1. The actual movement distances and the expected movement distances are compared respectively, and one or more statistically significant values such as standard deviation and average value are calculated, and the movement error is obtained according to the values.

[0065] It is easy to understand that after the movement error of the platform 302 in one direction is obtained, the direction can be changed, and the above process can be repeated to obtain the movement error of the platform 302 in another direction.

[0066] After the movement error is obtained, S200 is performed to calibrate the platform based on the movement error. The calibration can be performed by updating the platform coordinate configuration table, in some embodiments, for example, the platform is moved by steps, and the calibration can be completed by adjusting the frequency or the like, or the calibration can be compensated according to the movement error. It is easy to understand that the calibration mode is not limited.

[0067] After the above calibration is completed, S300 can be performed to obtain a first exposure result of the digital micromirror, and the digital micromirror is calibrated according to the first exposure result. In some embodiments, the digital micromirror of the circuit board exposure machine includes N micromirror groups, and each micromirror group is composed of M micromirror units, and N and M are integers greater than 1. In some embodiments, S300 includes:

[0068] S310: exposing the photosensitive film by using the circuit board exposure machine to obtain a first exposure result;

[0069] S320: the first exposure result includes N first check patterns, the first check pattern is the exposure result of the micromirror group, and the first check pattern includes M check sub-patterns, and the check sub-pattern is the exposure result of the micromirror unit;

[0070] S330: calibrating the micromirror units of each micromirror group according to the check sub-patterns, so as to calibrate the digital micromirror; and / or, calibrating the digital micromirror according to the first check pattern.

[0071] Specifically, in S310, exposure is performed on the photosensitive film using a circuit board exposure machine to obtain a first exposure result. First, a blank photosensitive film is fixed to a substrate, and exposure is performed using the exposure machine to obtain the first exposure result. The first exposure result can be a dot array pattern as shown in the figure. The substrate can be a copper-clad plate with high flatness. By high flatness, it is meant that the substrate is placed flat on a platform, the suction and pressing plate functions of the platform are turned on, and the substrate plate is lightly pressed at multiple positions by hand to see if there is any arching. Figure 6

[0072] Figure 6 is a schematic diagram of a first exposure result according to an embodiment of the present application. Referring to Figure 6 , the circuit board exposure machine prints a plurality of verification sub-patterns 402 on the photosensitive film 401. The number of verification sub-patterns 402 is the same as the number of micro-mirror units in the digital micro-mirror, which is M. It can be understood that each micro-mirror unit respectively exposes to obtain a corresponding verification sub-pattern. It can be easily understood that Figure 6 For clarity, only a part of the photosensitive film is selected as an example, and the size and distance of the verification sub-pattern are exaggerated. The actual ratio can be different from that shown in the figures.

[0073] In addition, as shown in Figure 6 , the verification sub-patterns can be divided into a plurality of first verification patterns to correspond to the micro-mirror groups composed of a plurality of micro-mirror units. It can be easily understood that the number of first verification patterns on the photosensitive film should be the same as the number of micro-mirror groups, which is N.

[0074] In the embodiment of Figure 6 , the micro-mirror group exposes to obtain a vertically arranged dot array pattern as Z1 or Z2, which is respectively exposed by two independent micro-mirror groups and can be regarded as two different first verification patterns. When input, it is required that each first verification pattern is composed of a plurality of verification sub-patterns 402 with the same size and equal distance. However, due to the error of the micro-mirror, each verification sub-pattern 402 may deviate as shown in Z1. At this time, S320 is performed: the first exposure result includes N first verification patterns, the first verification pattern is the exposure result of the micro-mirror group, the first verification pattern includes M verification sub-patterns, and the verification sub-pattern is the first exposure result of the micro-mirror unit.

[0075] Specifically, the following steps can be performed:

[0076] S321: selecting any verification sub-pattern in the first verification pattern of the micro-mirror group as a reference sub-pattern;

[0077] S322: obtaining a first deviation of the reference sub-pattern from each verification sub-pattern in the first verification pattern;

[0078] ​S323: calibrate each micro mirror unit in the micro mirror group according to the first deviation.

[0079] In some embodiments, the positions of all the check sub-patterns 402 can be measured using the camera, and any one of the first check patterns can be selected, and S321 can be performed to set one of the check sub-patterns 402 as the reference sub-pattern. Then S322 can be performed to obtain the first deviation of the reference sub-pattern from each check sub-pattern in the first check pattern, as shown in FIG. 4B. The other check sub-patterns 402 in the first check pattern can be aligned with the reference sub-pattern in the longitudinal direction so that the first deviation value is close to 0, so that the entire Zl is aligned in the longitudinal direction, and the spacing of each check sub-pattern 402 is kept consistent according to the first deviation. Thus, S323 can be completed to calibrate each micro mirror unit in the micro mirror group according to the first deviation. Further, a new first check pattern can be selected and the step can be repeated so that the check sub-patterns in each first check pattern are all calibrated. Figure 7

[0080] In some embodiments, S300 further includes S330: calibrate each micro mirror unit in each micro mirror group according to the check sub-patterns, so as to calibrate the digital micro mirror; and / or, calibrate the digital micro mirror according to the first check pattern. Specifically, S330 can be divided into the following steps:

[0081] S331: select any one of the first check patterns in the first exposure result as a reference check pattern;

[0082] S332: obtain the second deviation of the reference check pattern from each first check pattern in the first exposure result;

[0083] S333: calibrate the micro mirror group according to the second deviation, so as to calibrate the digital micro mirror.

[0084] Figure 7 FIG. 1 is a schematic diagram of the relative position calibration of a micro mirror group before calibration according to an embodiment of the present application. As shown in FIG. 1, the micro mirror group includes three micro mirror units, and each micro mirror unit includes a plurality of micro mirrors. The three micro mirror units are arranged in a row, and the relative position of each micro mirror unit is deviated from the ideal position. Figure 7 Figure 7 FIG. 2 is a first exposure result showing a state in which the relative position deviation of the micro mirror group is large. As shown in FIG. 2, the first exposure result is obtained by exposing the micro mirror group to light. The first exposure result shows that the relative position of each micro mirror unit in the micro mirror group is deviated from the ideal position.

[0085] Figure 8 FIG. 4B is a schematic diagram of calibrating the digital micro mirror based on the reference sub-pattern according to an embodiment of the present application. As shown in FIG. 4B, the reference sub-pattern is aligned with the other check sub-patterns in the first check pattern in the longitudinal direction so that the first deviation value is close to 0, so that the entire Zl is aligned in the longitudinal direction, and the spacing of each check sub-pattern 402 is kept consistent according to the first deviation. Figure 8 ​​In some embodiments, after the calibration of each micro-mirror unit in the micro-mirror group according to the second deviation, the entire digital micro-mirror is further calibrated. At this time, the longitudinal calibration of the first check pattern in the Z1 area has been completed, and therefore the check sub-patterns 402 in the same row in the transverse direction can be calibrated and aligned in the transverse direction based on the first check pattern in the Z1 area. Similarly, after the alignment is completed, the check sub-patterns 402 in the same row are made to have consistent positions in the transverse direction according to the second deviation.

[0086] Further, in some embodiments, the spacing of each first check pattern can also be calibrated respectively. That is, by adjusting the relative positions of each micro-mirror group, the alignment of each first check pattern is completed based on a first check pattern as a reference check pattern.

[0087] The calibration in the above S300 can be completed by replacing the coordinate configuration table of the digital micro-mirror, and the image after the calibration is as shown in FIG. 4. Figure 9

[0088] In S400, the second exposure result of the digital micro-mirror is obtained, and the line board exposure machine is calibrated according to the second exposure result. In some embodiments, the second exposure result can include a second check pattern and a third check pattern, the second check pattern includes a first compensation sub-pattern of each micro-mirror unit, and the third check pattern includes a second compensation sub-pattern of each micro-mirror unit.

[0089] S410: The first center position of each first compensation sub-pattern in the second check pattern is obtained.

[0090] S420: The second center position of each second compensation sub-pattern in the second check pattern is obtained.

[0091] S430: The alignment distance between the first center position and the second center position is calculated.

[0092] S440: The line board exposure machine is calibrated according to the alignment distance.

[0093] Figure 10 FIG. 4 is a schematic diagram of a check sub-unit according to an embodiment of the present application. Referring to FIG. 4, the check sub-unit includes a first check pattern 401 and a second check pattern 402. Figure 10 ​In some embodiments, one check subunit 50 includes a first compensation sub-pattern 501 and a second compensation sub-pattern 502, the first compensation sub-pattern 501 is a circle, and the second compensation sub-pattern 502 is a circular ring. In this embodiment, the inner diameter of the second compensation sub-pattern 502 is greater than the radius of the first compensation sub-pattern 501. The inner diameter of the circular ring is twice the radius of the circle, and the outer diameter of the circular ring is three times the radius of the circle. This setting is to make the camera better search, locate and measure the first compensation sub-pattern 501 and the second compensation sub-pattern 502. But the specific size relationship can not be limited, which should be determined according to the measurement accuracy of the camera and the corresponding measurement method of the camera.

[0094] Further, the first compensation sub-pattern 501 and the second compensation sub-pattern 502 can also be other patterns, for example, the first compensation sub-pattern 501 can be a regular octagon, and the second compensation sub-pattern 502 can be a circular ring with multiple symmetrical notches. As can be easily understood in combination with the following, the shape and size of the first compensation sub-pattern and the second compensation sub-pattern are set to facilitate the identification and search of the common center, and the first compensation sub-pattern and the second compensation sub-pattern can be any shape and size without departing from this concept.

[0095] In some embodiments, the positions and radii of the first compensation sub-pattern 501 and the second compensation sub-pattern 502 are obtained by MSA (Measurement Systems Analysis), so the radii and sizes of the first compensation sub-pattern 501 and the second compensation sub-pattern 502 should be determined according to the MSA and the measurement accuracy of the camera. In the exposure process, the first compensation sub-pattern 501 and the second compensation sub-pattern 502 are obtained by two exposures respectively, and in order to facilitate the search of the camera, the first compensation sub-pattern 501 can be set to green, and the second compensation sub-pattern 502 can be set to red. Of course, it can also be set to other easily contrasting colors.

[0096] The second exposure result is obtained by two exposures, Figure 11 is a first exposure schematic diagram of the second exposure result of the embodiment of the application, Figure 12 is a second exposure schematic diagram of the second exposure result of the embodiment of the application.

[0097] Specifically, without alignment, exposure is performed on a blank photosensitive film to obtain a first exposure result as shown in Figure 11 Then, the camera is used to capture the center positions of each first compensation sub-pattern in the first check pattern obtained by the first exposure, and each micromirror unit is subjected to a second exposure with these center positions as targets, to obtain a second check pattern including a second compensation sub-pattern as shown in Figure 12

[0098] ​The center positions of each first compensation sub-pattern and second compensation sub-pattern in the first and second verification patterns are acquired by using the camera. The alignment distance between the first and second center positions is calculated, for example, the center position distances between the first and second compensation sub-patterns are compared, for example, in an embodiment in which the first compensation sub-pattern is a circle and the second compensation sub-pattern is a ring, the circle center difference value is calculated, and compared with a third threshold value, and whether calibration is needed is determined according to the comparison result. The alignment distance refers to the average difference of the circle centers of the first and second compensation sub-patterns in different directions.

[0099] Therefore, the circuit board exposure machine can be calibrated according to the alignment distance. The calibration method can be completed by adjusting or replacing the coordinate configuration table of the digital micromirror. If the calibration cannot be completed by replacing the coordinate configuration table of the digital micromirror, the above steps are repeated for secondary calibration.

[0100] Figure 13 FIG. 1 is a schematic diagram of a circuit board exposure machine calibration device according to an embodiment of the present application.

[0101] It is easy to understand that the photosensitive film area, the first exposure result, the second exposure result, the number of micromirror groups and micromirror units in the digital micromirror in the above embodiments and the drawings are exemplary and do not have any limitation.

[0102] In the above embodiments, the deviation of each part can be detected respectively, and once the deviation is greater than a predetermined threshold value, the problem position can be quickly located, the time for troubleshooting when calibration is abnormal is shortened, and damaged components can be repaired or replaced in time.

[0103] Moreover, the scheme can cover the pattern position calibration of effective exposure of any area, for example, the user can customize the calibration area, and set the calibration point for the place prone to deviation. The whole plate calibration is not needed every time.

[0104] Reference Figure 10 According to the present application, a circuit board exposure machine calibration device is also provided, which is applied to a circuit board exposure machine including a camera, a platform and a digital micromirror. The device includes: a camera calibration module 601, configured to move the camera based on the standard target point of a test board, and calibrate the camera; a platform calibration module 602, configured to move the platform based on the standard target point, and calibrate the platform; a digital micromirror calibration module 603, configured to acquire a first exposure result of the digital micromirror, and calibrate the digital micromirror according to the first exposure result; and a calibration verification module 604, configured to acquire a second exposure result of the digital micromirror, and calibrate the circuit board exposure machine according to the second exposure result.

[0105] Moreover, those skilled in the art will appreciate that the methods described herein can be embodied only in software, in firmware, in hardware, and / or in a combination of software, firmware, hardware, and / or the like. Certain physical components or all of the components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application- specific integrated circuit. Such software can be distributed on computer readable media, which can comprise any medium for storing or transmitting information such as a computer storage medium (or non-transitory medium) and / or a communication medium (or transitory medium). Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Further, as is known to those skilled in the art, communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as carrier waves or other transport mechanisms, and includes any information delivery media.

[0106] It should also be understood that any reference to an "embodiment" or "embodiments" or "one embodiment" or "some embodiments" etc. in the present application specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrases "in one embodiment" or "in some embodiments" or "in other embodiments" or "in still other embodiments" or the like in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily referring to some, but not all embodiments. The terms "including," "comprising," "having," and variations thereof are meant to cover and encompass both the listed items and any additional items not specifically listed. Unless otherwise noted, the terms "coupled," "connected," "attached," or the like, are meant to encompass a direct connection, an indirect connection, or an indirect connection through one or more intervening parts or components without any physical contact between them. The descriptions in the present application specification are not intended to limit the scope of the application, and the descriptions can be changed in various ways by those skilled in the art without departing from the spirit of the application.

[0107] The embodiments of the application described above are only used to explain the principles of the application and should not be construed as limiting the scope of the application. Those skilled in the art can make various changes and modifications to the embodiments of the application without departing from the spirit of the application.

Claims

1. A method for calibrating a circuit board exposure machine, applied to a circuit board exposure machine, the circuit board exposure machine comprising a camera, a platform and a digital micromirror, characterized in that, The method comprises: moving the camera based on a standard target point of a test board, and calibrating the camera; calibrating the platform based on the standard target point, comprising: moving the platform by a predetermined moving distance, and moving the test board along with the platform; obtaining an actual moving distance by using the calibrated camera; obtaining a moving error according to the actual moving distance and the predetermined moving distance; and calibrating the platform based on the moving error; obtaining a first exposure result of the digital micromirror, and calibrating the digital micromirror according to the first exposure result; obtaining a second exposure result of the digital micromirror, and calibrating the circuit board exposure machine according to the second exposure result; wherein the digital micromirror comprises N micromirror groups, and each micromirror group comprises M micromirror units, and N and M are integers greater than 1; the obtaining of the first exposure result of the digital micromirror and the calibration of the digital micromirror according to the first exposure result comprise: exposing on a photosensitive film by using the circuit board exposure machine to obtain a first exposure result; the first exposure result comprises N first check patterns, the first check pattern is an exposure result of the micromirror group, and the first check pattern comprises M check sub-patterns, the check sub-pattern is an exposure result of the micromirror unit; calibrating the micromirror units of each micromirror group according to the check sub-patterns, thereby calibrating the digital micromirror; and / or calibrating the digital micromirror according to the first check pattern; the second exposure result comprises a second check pattern and a third check pattern, the second check pattern comprises a first compensation sub-pattern of each micromirror unit, and the third check pattern comprises a second compensation sub-pattern of each micromirror unit; the obtaining of the second exposure result of the digital micromirror and the calibration of the circuit board exposure machine according to the second exposure result comprise: obtaining a first center position of each first compensation sub-pattern in the second check pattern; obtaining a second center position of each second compensation sub-pattern in the third check pattern; calculating an alignment distance between the first center position and the second center position; calibrating the circuit board exposure machine according to the alignment distance.

2. The method of claim 1, wherein, The test board is placed on the platform, and the moving of the camera based on the standard target point of the test board and the calibration of the camera comprise: acquiring a position of the standard target point by using the camera to obtain an acquired position; obtaining a target acquisition error according to an actual position of the standard target point and the acquired position; calibrating the camera based on the target acquisition error.

3. The method of claim 1, wherein, The calibration of the micromirror units of each micromirror group according to the check sub-patterns comprises: selecting any check sub-pattern in the first check pattern of the micromirror group as a reference sub-pattern; obtaining a first deviation of the reference sub-pattern from each check sub-pattern in the first check pattern; calibrating each micromirror unit in the micromirror group according to the first deviation.

4. The method of claim 1, wherein, The calibration of the digital micromirror according to the first exposure result comprises: Select any first check pattern in the first exposure result as a reference check pattern; Obtain a second deviation of the reference check pattern and each first check pattern in the first exposure result; Calibrate the digital micromirror according to the second deviation.

5. The method of claim 1, wherein, The first compensation sub-pattern is a circle dot, and the second compensation sub-pattern is a circle ring, and the inner diameter of the circle ring is greater than the radius of the circle dot.

6. The method of claim 5, wherein, The inner diameter of the circle ring is twice the radius of the circle dot, and the outer diameter of the circle ring is three times the radius of the circle dot.

7. A circuit board exposure machine calibration device applied to a circuit board exposure machine, the circuit board exposure machine comprising a camera, a platform and a digital micromirror, characterized in that, The device comprises: A camera calibration module for moving the camera based on the standard target points of the test board, and calibrating the camera; A platform calibration module for moving the platform based on the standard target points, and calibrating the platform, comprising: moving the platform by a predetermined moving distance, so that the test board moves with the platform; obtaining an actual moving distance by using the calibrated camera; obtaining a moving error according to the actual moving distance and the predetermined moving distance; and calibrating the platform based on the moving error; A digital micromirror calibration module for obtaining a first exposure result of the digital micromirror, and calibrating the digital micromirror according to the first exposure result; A calibration verification module for obtaining a second exposure result of the digital micromirror, and calibrating the circuit board exposure machine according to the second exposure result; The digital micromirror comprises N micromirror groups, and each micromirror group comprises M micromirror units, and N and M are integers greater than 1; the first exposure result of the digital micromirror is obtained, and the digital micromirror is calibrated according to the first exposure result, comprising: Exposing on a photosensitive film by using the circuit board exposure machine to obtain a first exposure result; the first exposure result comprises N first check patterns, the first check pattern is the exposure result of the micromirror group, the first check pattern comprises M check sub-patterns, and the check sub-pattern is the exposure result of the micromirror unit; Calibrating the micromirror units of each micromirror group according to the check sub-patterns, thereby calibrating the digital micromirror; and / or calibrating the digital micromirror according to the first check pattern; The second exposure result comprises a second check pattern and a third check pattern, the second check pattern comprises a first compensation sub-pattern of each micromirror unit, and the third check pattern comprises a second compensation sub-pattern of each micromirror unit; the second exposure result of the digital micromirror is obtained, and the circuit board exposure machine is calibrated according to the second exposure result, comprising: Obtaining a first center position of each first compensation sub-pattern in the second check pattern; Obtaining a second center position of each second compensation sub-pattern in the third check pattern; Calculating the alignment distance between the first center position and the second center position; Calibrating the circuit board exposure machine according to the alignment distance. 8.An electronic device, comprising a memory, a processor, a communication bus, a communication interface, and a computer program stored in the memory and executable on the processor, characterized in that: The communication bus is used to realize the connection communication between the processor and the memory. The processor realizes the circuit board exposure machine calibration method as claimed in any one of claims 1 to 6 when executing the computer program.

9. A storage medium, the storage medium being a readable storage medium, characterized by The readable storage medium stores a computer program, and the computer program is used to make a computer execute the circuit board exposure machine calibration method as claimed in any one of claims 1 to 6.

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