Exposure method and exposure apparatus

Abstract

The application discloses an exposure method and an exposure device, and belongs to the field of printed circuit board production. The exposure method of the application processes the sub-picture data and the alignment process in parallel, effectively shortening the exposure time. The application can cache the processed picture data in the host computer or the exposure system. Meanwhile, the suction cup of the exposure device of the application has the freedom of four directions of X-axis, Y-axis, Z-axis and rotating shaft, can correct the deviation of the PCB plate through rotation and translation, thereby replacing the rotation and translation processing of the pattern according to the alignment result of the substrate mark point in the sub-picture system. The process reduces the time consumption of the pattern processing in the sub-picture system, further improves the equipment capacity, avoids the step-shaped deviation problem caused by the small-angle inclined line of the horizontal line after the pattern processing, ensures the analytical precision of the exposure pattern, and improves the exposure quality.

Description

Technical Field

[0001] This invention relates to an exposure method and exposure equipment, belonging to the field of printed circuit board manufacturing. Background Technology

[0002] A digital exposure machine refers to a computer that processes the exposed pattern in real time and converts it into machine-readable graphic data. The host computer controls the beam modulator to realize the real-time display of the pattern. Then, the optical imaging system focuses the graphic beam onto the surface of the substrate coated with photosensitive material to complete the direct imaging and exposure of the pattern.

[0003] The biggest advantage of digital exposure machines compared to traditional exposure machines is that they digitize the exposure pattern and can directly calculate the actual deformation based on the marking points on the substrate, thereby modifying the exposure pattern in real time and achieving higher pattern accuracy.

[0004] The higher the precision of the exposure pattern, the larger the amount of image data that the digital exposure machine needs to process. For example, an exposure pattern of 500x500mm with a resolution of 3µm requires approximately 3.2GB of data; when the resolution increases to 1.5µm, the data size becomes approximately 23.3GB. Doubling the resolution results in a more than sevenfold increase in data volume, significantly increasing the workload of image data processing and transmission time. This increased processing and transmission time negatively impacts equipment production efficiency and reduces the capacity of the digital exposure machine.

[0005] Furthermore, the placement of PCB boards is done manually or by automated equipment, and deviations in the board placement position result in different coordinate values ​​for the marker points obtained each time, requiring each board to undergo reprocessing of its graphic data. As resolution increases, the data volume increases significantly, leading to longer data processing and transmission times, which reduces the exposure machine's capacity.

[0006] The current exposure process of a digital exposure machine is as follows: Start -- Part number preparation -- Alignment -- Exposure parameter sending -- Image data processing -- Exposure execution -- Exposure end. Each step is sequential, but when processing complex graphics or increasing graphic resolution, the graphic data processing and data transmission times increase, affecting the exposure machine's production efficiency and reducing equipment capacity. Furthermore, during graphic processing, issues such as small-angle diagonal lines can occur, reducing exposure quality. Summary of the Invention

[0007] To address the problems of low throughput and poor exposure quality in existing exposure machines, this invention provides an exposure method and exposure equipment, the technical solution of which is as follows:

[0008] The first objective of this invention is to provide an exposure device, comprising: a base, a precision motion system, an alignment system, an exposure system, and a data processing system;

[0009] The precision motion system includes an exposure platform with a rotating component located below it, which is mounted on an XYZ three-axis moving component. The XYZ three-axis moving component includes a Y-axis moving track, an X-axis moving platform, and a Z-axis moving platform. The Y-axis moving track is fixedly mounted on the base, and the X-axis moving platform is mounted on the Y-axis moving track. The Z-axis moving platform is mounted on a sliding track on the upper surface of the X-axis moving platform. The exposure platform achieves rotational motion and translational motion in the XYZ directions through the rotating component and the XYZ three-axis moving component.

[0010] The alignment system and the exposure system are mounted on the exposure platform via a platform support structure, and the platform support structure is fixedly mounted on the base.

[0011] The data processing system is used to digitize the image to be exposed and send the image data to the exposure system.

[0012] Optionally, the rotating component is a DD motor.

[0013] Optionally, the exposure platform is made of marble.

[0014] Optionally, the exposure platform is also equipped with a suction cup assembly.

[0015] A second objective of this invention is to provide an exposure method, implemented using the aforementioned exposure apparatus, comprising:

[0016] Step 1: Place the PCB board to be exposed on the exposure platform, the alignment system performs alignment, and the host computer saves the alignment result;

[0017] Step 2: The data processing system performs image segmentation data processing on the input image to be exposed based on the alignment result, and sends the image after image segmentation data processing to the exposure system;

[0018] Step 3: The exposure system exposes the PCB board;

[0019] Step 4: Place the PCB board with the same pattern as that exposed in Step 1 on the exposure platform, and the data processing system performs image splitting processing; at the same time, the alignment system performs alignment operation, and the precision motion system rotates and translates the PCB board according to the current alignment result and the alignment result in Step 1, so that the current position and angle of the PCB board are consistent with the position and angle in Step 1.

[0020] Step 5: The exposure system exposes the PCB board;

[0021] Step Six: When you need to expose the same pattern on a PCB board, repeat Steps Four and Five.

[0022] Optionally, step two further includes caching the image data after processing the image data. In step four, image processing is no longer performed, and the exposure system directly performs exposure based on the cached image data.

[0023] Optionally, in step two, the data after the image segmentation process is cached in the host computer.

[0024] Optionally, in step two, the data after image segmentation is cached in the exposure system.

[0025] Optionally, the image data processing in step two includes: rotating, translating, or scaling the image based on the alignment results of the PCB board marker points.

[0026] The beneficial effects of this invention are:

[0027] The exposure method of this invention processes image segmentation data and alignment in parallel, effectively shortening the exposure time compared to the serial processing methods in the prior art. This invention can cache the processed image data in a host computer or exposure system. Furthermore, the precision motion system of this invention possesses four degrees of freedom: X-axis, Y-axis, Z-axis, and rotation axis. Compared to existing motion systems with suction cups, it has additional translation and rotation axes, providing greater freedom. When the same pattern needs to be exposed again, the cached image data can be used directly, and the rotation and translation of the motion system can correct the PCB board placement deviation. This replaces the rotation and translation processing performed on the pattern based on the alignment results of the substrate marking points in the image segmentation system. This process reduces the image processing time in the image segmentation system, further improving equipment productivity. Simultaneously, this invention avoids the step-like deviation problem caused by horizontal lines becoming small-angle diagonal lines after image processing, ensuring the resolution accuracy of the exposed pattern and improving exposure quality. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart of the exposure process for existing technologies.

[0030] Figure 2This is an exposure flowchart provided in Embodiment 2 of the present invention.

[0031] Figure 3 This is an exposure flowchart provided in Embodiment 3 of the present invention.

[0032] Figure 4 This is an exposure flowchart provided in Embodiment 4 of the present invention.

[0033] Figure 5 This is a schematic diagram of the method for determining the coordinates of the rotation center according to the present invention.

[0034] Figure 6 This is a schematic diagram illustrating how the exposure method of the present invention solves the problem of step-like deviation.

[0035] Figure 7 This is an overall structural diagram of the exposure device of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0037] Example 1:

[0038] This embodiment provides an exposure device, such as... Figure 7 As shown, it includes: base 1, precision motion system, alignment system 2, exposure system 3, and data processing system;

[0039] The precision motion system includes an exposure platform 4, which may be made of marble and may have suction cup components on the platform to fix the PCB board.

[0040] A rotating component 5 (which can be driven by a DD motor) is located below the exposure platform and is mounted on the XYZ three-axis moving component. The XYZ three-axis moving component includes a Y-axis moving track 6, an X-axis moving platform 7, and a Z-axis moving platform 8. The Y-axis sliding track 6 is fixedly mounted on the base 1, and the X-axis moving platform 7 is mounted on the Y-axis sliding track 6. The Z-axis moving platform 8 is mounted on the sliding track on the upper surface of the X-axis moving platform 7. The exposure platform 4 achieves rotational movement and translational movement in the XYZ directions through the rotating component 5 and the XYZ three-axis moving component.

[0041] The alignment system 2 and the exposure system 3 are mounted on the exposure platform 4 via the platform support structure 9, and the platform support structure 9 is fixedly mounted on the base 1.

[0042] The data processing system is located in the host computer and is used to digitize the graphic to be exposed and send the graphic data to the exposure system.

[0043] Example 2: Parallel processing of map sub-data processing and alignment processes

[0044] This embodiment provides an exposure method based on the exposure device provided in Embodiment 1.

[0045] Existing exposure process as follows Figure 1 As shown, the process includes: Start -- Part Number Preparation -- Alignment -- Exposure Parameter Preparation -- Image Sub-data Processing -- Data Transfer -- Exposure Execution -- Exposure End. After image sub-data processing is completed, the data is transmitted from the host computer to the exposure system, and then the exposure process is executed. In the current process, each step is sequential; the next step is only performed after the previous step is completed.

[0046] Image segmentation data processing is an essential step in the exposure process. It involves converting images in formats such as GDS into image formats that the exposure system can recognize and process. The exposure system includes multiple DMD components. A complete image can be converted into multiple segments for stitching. Each DMD component processes its corresponding segment and finally synthesizes it into a complete image. In addition, this process will rotate, translate, or scale the image based on the alignment results of the substrate markers.

[0047] The exposure process in this embodiment includes:

[0048] Step 1: Place the PCB board to be exposed on the exposure platform, align it using the alignment system, and save the alignment result on the host computer;

[0049] Step 2: The data processing system performs image segmentation data processing on the input image to be exposed based on the alignment results, and sends the processed image to the exposure system.

[0050] Step 3: The exposure system exposes the PCB board;

[0051] Step 4: Place the PCB board with the same pattern as that exposed in Step 1 on the exposure platform. The data processing system performs image splitting. At the same time, the alignment system performs alignment operation. The precision motion system rotates and translates the PCB board according to the current alignment result and the alignment result in Step 1, so that the current position and angle of the PCB board are consistent with the position and angle in Step 1.

[0052] Step 5: The exposure system exposes the PCB board;

[0053] Step Six: When you need to expose the same pattern on a PCB board, repeat Steps Four and Five.

[0054] In this embodiment of the exposure method, when it is necessary to expose PCB boards with the same pattern, starting from the second board, the pattern data processing flow and the alignment flow can be carried out in parallel. As long as the alignment data is saved when exposing the first board, the precision motion system drives the PCB board on the exposure platform to translate and rotate when exposing each subsequent board, so that the position and angle of the PCB board are consistent with the position and angle of the first PCB board. In this way, the subsequent pattern data processing does not need to be based on the alignment result, so the pattern data processing and alignment flow can be performed simultaneously.

[0055] like Figure 2 As shown, image data processing is performed simultaneously during alignment. After image data processing is complete, data is transmitted, and then exposure is performed. By changing the image data processing flow from serial to parallel, the exposure flow path is shortened. The time for the two processes to run in parallel depends on the longer process. For example, if alignment takes 1200ms and image data processing takes 1500ms, the existing exposure flow would take a total of 2700ms for alignment and data processing. However, with this method, parallel alignment and data processing takes only 1500ms, saving 1200ms and increasing the exposure equipment's capacity.

[0056] On the other hand, the parallel processing of image sub-data and alignment processes only shortens the exposure process path. In existing exposure schemes, for each PCB board, image sub-data processing also rotates, translates, or expands the graphic based on the alignment results of the substrate markers to ensure the accuracy of the exposed graphic position. This embodiment improves this process by using a precision motion system to give the PCB board more freedom in rotation and translation. The movement of the PCB board can be used to match the alignment position and angle saved during the exposure of the first board. Therefore, starting from the exposure of the second PCB board, the image sub-data processing process no longer rotates, translates, or expands the graphic, greatly reducing the amount of computation and further improving production capacity.

[0057] Example 3: The processed graphic data is cached in the host computer.

[0058] This embodiment provides an exposure method based on the exposure device provided in Embodiment 1, which is a further improvement on the exposure method provided in Embodiment 2.

[0059] In Example 2, the equipment capacity was significantly improved by following the parallel alignment and sub-map data processing flow.

[0060] To further reduce the time consumed in the image splitting process, this embodiment caches the exposed image in the host computer, which can further reduce the image processing time in the image splitting system. Especially when processing complex images such as miniled images, the image splitting processing time can range from 1500ms to 20000ms. The method in this embodiment can greatly reduce the image splitting processing time, shorten the exposure time, and increase the capacity of the exposure equipment. The specific implementation method is as follows:

[0061] When exposing the first substrate, the graphic data is processed and cached in the host computer. When exposing the same graphic on the second substrate and subsequent substrates, the host computer directly calls the cached graphic data and transmits the cached graphic data to the exposure system. The exposure process is as follows: Figure 3 As shown, the method in this embodiment does not process the graphic data from the exposure of the second plate, but only transmits the cached data, thus saving the time spent on processing the image data.

[0062] In addition, the method in this embodiment caches the original exposed pattern, that is, the pattern will not be modified by translation, rotation or other processing based on the alignment result of the substrate marker points. After the host computer obtains the alignment result of the substrate marker points, it controls the suction cup and the substrate to perform translation and rotation movements according to the alignment result, thereby correcting the position of the substrate and making it consistent with the position information of the first board, so as to ensure the positional accuracy and pattern accuracy of the exposed pattern.

[0063] Example 4: Image data is processed and then cached in the exposure system.

[0064] In Example 3, when exposing the first plate, the graphic data is cached in the host computer. Starting from the second plate, the image segmentation system does not process the graphic data, but it needs to transmit the graphic data to the exposure system for exposure. Due to the varying sizes of the graphic data, the transmission time ranges from 50ms to 2000ms. To eliminate the transmission time, based on Example 3, the exposed graphics are cached in the exposure system. The specific implementation method is as follows:

[0065] When exposing the first plate, the host computer processes the graphic data and transmits it to the exposure system. The graphic data is then cached in the exposure system. From the second plate onwards, when exposing the same graphic, the exposure system directly uses the cached data without further processing or transmission of the graphic data. The exposure process is as follows: Figure 4 As shown, this eliminates the time spent by the exposure machine in image data processing and transmission. In contrast to Example 3, this method, starting from the second plate, neither processes nor transmits the image data in the image separation system, saving time spent on image data processing and transmission, and further improving the exposure equipment's capacity.

[0066] This invention corrects angular deviations of the PCB board by using the rotation and translation of the suction cup in the motion system, thereby replacing the graphic data processing flow of the image separation system. The degree of correction of the substrate placement angle determines the alignment accuracy of the exposed pattern. In order to accurately correct the substrate placement angle, the rotation center coordinates of the suction cup must first be accurately found.

[0067] There are two main methods for confirming the center of rotation of a suction cup:

[0068] The first method is to find the coordinates of the suction cup rotation center using the geometric method of the suction cup mounting holes. This method can roughly find the range of the rotation center. However, due to the gap between the suction cup mounting holes and the screws, there are installation errors, as well as human errors when drawing the diagonal, resulting in inaccurate coordinates of the suction cup rotation center found by this method, which will introduce errors into the rotation accuracy of the suction cup.

[0069] The second method involves using the alignment system of the exposure equipment to calibrate the markers on the suction cup, capturing the coordinates of the markers before and after rotation, and then calculating the coordinates of the rotation center using a formula. For example... Figure 5 As shown, any point on the suction cup is designated as marker point A. The coordinates of marker point A before the suction cup rotates are determined by the vision camera of the exposure machine as (x1, y1). After rotating by a certain angle α, the coordinates of marker point A are re-determined by the vision camera as (x2, y2). Finally, the coordinates of the rotation center (x0, y0) are calculated using a formula. This method can accurately find the coordinates of the suction cup rotation center, improving the suction cup rotation accuracy, ensuring the correction accuracy of the substrate placement angle, and thus ensuring the alignment accuracy of the exposed pattern.

[0070] In the PCB industry, circuit design typically uses horizontal lines, vertical lines, or 45° diagonal lines. By convention, the exposed patterns are basically composed of these three types of lines.

[0071] If the exposure equipment uses a split-image system to process the exposed pattern, and the PCB board is placed at a certain angle, the pattern needs to be rotated. For example, horizontal lines in the pattern... Figure 6 As shown in (a), after rotation, it becomes a small-angle diagonal line. The DMD in the exposure system is composed of micromirrors with a resolution of 10.8 μm. The exposure pattern is obtained by controlling the flipping and projection of micromirrors in different DMD areas. The small-angle diagonal line in the processed pattern will exhibit a step-like deviation in the resulting image obtained through the exposure system, such as... Figure 6 As shown in (b), this problem reduces the resolution of the exposure pattern and affects the exposure quality.

[0072] The exposure equipment and method of this invention correct PCB board placement deviations by using the rotation and translation of a suction cup in the motion system, replacing the graphic processing actions performed by the graphic separation system. Without processing the graphic, the exposure system exposes the original graphic, thus avoiding the step-like deviation problem caused by horizontal lines becoming small-angle diagonal lines after graphic processing. This ensures the resolution accuracy of the exposed graphic and improves the exposure quality.

[0073] Some steps in the embodiments of the present invention can be implemented using software, and the corresponding software program can be stored in a readable storage medium, such as an optical disc or a hard disk.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An exposure method characterized by, The exposure method is realized based on an exposure device; the exposure device comprises a base, a precision motion system, an alignment system, an exposure system and a data processing system; The precision motion system comprises an exposure platform, a rotating assembly is arranged below the exposure platform and is installed on an XYZ three-axis moving assembly through the rotating assembly; the XYZ three-axis moving assembly comprises a Y-axis moving track, an X-axis moving platform and a Z-axis moving platform, the Y-axis moving track is fixedly installed on the base, and the X-axis moving platform is installed on the Y-axis moving track; the Z-axis moving platform is installed on a sliding track on the upper surface of the X-axis moving platform; the exposure platform realizes rotating motion and XYZ three-direction translation motion through the rotating assembly and the XYZ three-axis moving assembly; The alignment system and the exposure system are installed above the exposure platform through a table top support structure, and the table top support structure is fixedly installed on the base; The data processing system is used for digitally processing a to-be-exposed pattern and sending pattern data to the exposure system; The exposure method comprises: Step one: placing a PCB board to be exposed on an exposure platform, an alignment system performing alignment, and an upper computer saving an alignment result; Step two: a data processing system performing split pattern data processing on an input to-be-exposed pattern according to the alignment result, and sending a split pattern data processed pattern to the exposure system; Step three: the exposure system performing exposure on the PCB board; Step four: placing a PCB board needing the same pattern as that in step one on the exposure platform, the data processing system performing split pattern processing, and the alignment system performing alignment operation, the precision motion system rotating and translating the PCB board according to a current alignment result and the alignment result in step one, so that a position and an angle of the current PCB board are consistent with those in step one; Step five: the exposure system performing exposure on the PCB board; Step six: when a PCB board needing the same pattern is needed to be exposed, steps four and five are repeated.

2. The exposure method according to claim 1, wherein The rotating assembly is realized by a DD motor.

3. The exposure method according to claim 1, wherein The material of the exposure platform is marble.

4. The exposure method according to claim 1, wherein The exposure platform is further provided with a suction disc assembly.

5. The exposure method according to any one of claims 1, wherein In step two, the split pattern data processed pattern data is cached, split pattern processing is not performed in step four, and the exposure system directly performs exposure according to the cached pattern data.

6. The exposure method according to claim 5, wherein In step two, the split pattern data processed pattern data is cached in an upper computer.

7. The exposure method according to any one of claims 5, wherein In step two, the split pattern data processed pattern data is cached in the exposure system.

8. The exposure method according to any one of claims 1, wherein In step two, the split pattern data processing comprises rotating, translating or expanding processing on the pattern according to a PCB board mark point alignment result.

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