Smt production line spi-printer closed loop control method, device and equipment

Abstract

The application discloses a kind of SPI-printing machine closed-loop control method, device and equipment in SMT production line.The method comprises: obtaining incoming circuit board's solder paste printing simulation coordinate data and the actual coordinate data of solder paste printing after completion printing, the solder paste printing simulation coordinate data is determined based on the pad actual coordinate data of the incoming circuit board and the pad reference coordinate data in preset Gerber data;According to the solder paste printing simulation coordinate data and the actual coordinate data of solder paste printing, solder paste alignment is carried out, and printing machine inherent deviation compensation data is obtained;The printing machine inherent deviation compensation data is transmitted to printing machine, to make the printing machine adjust steel mesh alignment according to the printing machine inherent deviation compensation data.The technical scheme provided by the application improves the reliability of SPI-printing machine closed-loop control, thereby greatly improves the printing precision and quality stability, and further improves the overall yield and production efficiency of SMT production line.

Description

Technical Field

[0001] This invention relates to the field of surface mount technology, and in particular to a closed-loop control method, apparatus and equipment for an SPI printer in an SMT production line. Background Technology

[0002] Currently, the closed-loop control of the printing process in SMT production lines generally adopts a single-point closed-loop mode of SPI solder paste inspection - printer parameter adjustment. This means that after SPI completes printing, the solder paste quality of the PCB / FPCB is inspected, and the solder paste quality data is directly fed back to the printer for adjustment to complete the closed-loop compensation. This mode assumes that the incoming PCB / FPCB materials are in an ideal, deviation-free state. However, in actual production, incoming materials often have individual differences such as pad misalignment, sub-board deformation, board expansion and contraction, and positioning hole misalignment. The solder paste printing deviation actually detected by SPI essentially includes both incoming material deviation and inherent printer deviation (such as squeegee wear, stencil alignment deviation, mismatched pressure / speed parameters, and abnormal demolding). Existing technology ignores the impact of incoming material differences on printing quality and directly feeds back all overall deviations to the printer adjustment parameters. This may lead to blind compensation situations such as "adjusting squeegee pressure when the incoming material pads are misaligned," causing the closed-loop compensation to deviate from the actual error source, resulting in low compensation accuracy, or even exacerbating the deviation after compensation. Meanwhile, since the differences in incoming materials are irregular and random, while the inherent deviations of the printing press are relatively stable, using irregular incoming material deviation data to correct the printing press parameters may lead to frequent fluctuations in the compensation parameters, resulting in extremely unstable printing quality. Summary of the Invention

[0003] This invention provides a method, apparatus, and equipment for closed-loop control of an SPI printer in an SMT production line, to eliminate the influence of incoming material differences, improve the reliability of SPI printer closed-loop control, and thereby improve printing accuracy and quality stability.

[0004] In a first aspect, embodiments of the present invention provide a closed-loop control method for an SPI-printer in an SMT production line, the method comprising: The simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after printing are obtained. The simulated coordinate data of solder paste printing is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. Solder paste alignment is performed based on the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine. The inherent deviation compensation data of the printing press is transmitted to the printing press so that the printing press can adjust the stencil alignment according to the inherent deviation compensation data of the printing press.

[0005] Optionally, the step of aligning the solder paste according to the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine includes: Calculate the centroid of the solder paste in the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing, respectively; Based on the centroid of the solder paste, the centered coordinates of each solder paste in the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing are calculated respectively, and the covariance term between the two types of centered coordinates is calculated. The first target rotation angle is calculated based on the covariance term, and the first target translation amount is calculated based on the first target rotation angle and the solder paste centroid. The printer inherent deviation compensation data includes the first target rotation angle and the first target translation amount.

[0006] Optionally, obtaining the simulated coordinate data of solder paste printing on the incoming circuit board includes: Calculate the centroid of the pad in the actual coordinate data of the pad and the reference coordinate data of the pad, respectively; Based on the centroid of the pad, calculate the centered coordinates of each pad in the actual coordinate data of the pad and the reference coordinate data of the pad, and calculate the covariance term between the two types of centered coordinates. The second target rotation angle is calculated based on the covariance term, and the second target translation amount is calculated based on the second target rotation angle and the pad centroid. The solder pad reference coordinate data are adjusted based on the second target rotation angle and the second target translation amount to obtain the solder paste printing simulation coordinate data.

[0007] Optionally, obtaining the actual coordinate data of the solder paste printing after completion includes: Obtain an image of the entire circuit board after printing is completed; Identify solder paste outlines in the whole board image and determine the outline center of each solder paste outline; The actual coordinate data for solder paste printing is determined based on the center of the outline.

[0008] Optionally, before determining the actual coordinate data for solder paste printing based on the contour center, the method further includes: The actual coordinate data of the single panel PcsMark in the incoming circuit board are obtained by measuring equipment. Identify the actual PcsMark position data of individual panels in the overall panel image; Coordinate system alignment is performed based on the actual coordinate data of the single-panel PcsMark and the actual position data of the single-panel PcsMark. Determining the actual coordinate data for solder paste printing based on the contour center includes: Based on the actual position data of the single panel PcsMark, the actual coordinate data of the solder paste printing corresponding to the center of each contour are determined.

[0009] Optionally, the method further includes: Obtain actual quality data of solder paste printing after the printing is completed; The actual quality data of the solder paste printing is transmitted to the printing machine so that the printing machine can adjust its process parameters based on the actual quality data of the solder paste printing.

[0010] Secondly, embodiments of the present invention also provide a closed-loop control device for an SPI-printer in an SMT production line, the device comprising: The coordinate data acquisition module is used to acquire the simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after printing is completed. The simulated coordinate data of solder paste printing is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. The compensation data determination module is used to perform solder paste alignment based on the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine. The compensation data feedback module is used to transmit the inherent deviation compensation data of the printing press to the printing press, so that the printing press can adjust the stencil alignment according to the inherent deviation compensation data of the printing press.

[0011] Thirdly, embodiments of the present invention also provide a solder paste testing device, the device comprising: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the SPI-printer closed-loop control method in the SMT production line provided in any embodiment of the present invention.

[0012] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the SPI-printer closed-loop control method in an SMT production line provided in any embodiment of the present invention.

[0013] Fifthly, embodiments of the present invention also provide a computer program product, which includes a computer program that, when executed by a processor, implements the SPI-printer closed-loop control method in an SMT production line provided in any embodiment of the present invention.

[0014] This invention provides a closed-loop control method for an SPI-printer in an SMT production line. First, it acquires simulated coordinate data of solder paste printing on the incoming circuit board and actual coordinate data of the solder paste after printing. The simulated coordinate data is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in preset Gerber data. Then, solder paste alignment is performed based on the simulated and actual coordinate data to obtain inherent deviation compensation data for the printer. This inherent deviation compensation data is then transmitted to the printer so that it can adjust the stencil alignment according to the inherent deviation compensation data. The SPI-printer closed-loop control method provided by this invention first determines the simulated coordinate data of solder paste printing based on the actual and reference coordinate data of the pads, and then calculates the deviation compensation data with the actual coordinate data. This eliminates incoming material deviation and only performs closed-loop compensation for inherent deviations of the printer, improving the reliability of the SPI-printer closed-loop control, thereby significantly improving printing accuracy and quality stability, and ultimately improving the overall yield and production efficiency of the SMT production line. Attached Figure Description

[0015] Figure 1 This is a flowchart of the SPI-printer closed-loop control method in an SMT production line provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the SPI-printer closed-loop control device in an SMT production line provided in Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the solder paste testing device provided in Embodiment 3 of the present invention. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0017] Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the steps as sequential processes, many of these steps can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the steps can be rearranged. The process can be terminated when its operation is complete, but may also have additional steps not included in the figures. The process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0018] Example 1 Figure 1This is a flowchart of the SPI-printer closed-loop control method in an SMT production line provided in Embodiment 1 of the present invention. This embodiment is applicable to situations requiring printing process control in various SMT production lines, especially suitable for scenarios with high-precision printing requirements such as FPC flexible boards, multi-panel boards, and MiniLED packaging boards. This method can be executed by the SPI-printer closed-loop control device in the SMT production line provided in this embodiment of the invention. This device can be implemented in hardware and / or software, and is generally integrated into solder paste inspection (SPI) equipment. Figure 1 As shown, the method specifically includes the following steps: S11. Obtain the simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after printing is completed. The simulated coordinate data of solder paste printing is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data.

[0019] S12. Based on the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing, perform solder paste alignment to obtain the inherent deviation compensation data of the printing machine.

[0020] S13. The inherent deviation compensation data of the printing press is transmitted to the printing press so that the printing press adjusts the stencil alignment according to the inherent deviation compensation data of the printing press.

[0021] Specifically, a high-precision metrology machine with an absolute error ≤ ±10μm and a repeatability ≤ 1μm can be used to accurately capture and scan the incoming circuit boards (such as PCBs / FPCBs) fed by the board loading machine. This allows for the acquisition of full-dimensional geometric data of the incoming circuit boards, which can be bound to a unique identifier (such as an identification code) for subsequent calculations and problem traceability. The acquired geometric data includes at least the actual coordinates of the pads on the circuit board, i.e., the actual coordinates of all pads on the entire board. It can also include the actual coordinates of reference points, specifically the actual coordinates of the large board Mark and / or the actual coordinates of the single panel PcsMark. The metrology machine may include a vision positioning module, which can capture images of the incoming circuit boards using a camera and then calculate the required geometric data using relevant algorithms.

[0022] The simulated coordinate data for solder paste printing can be determined directly by the aforementioned measurement and measurement machine based on the actual coordinate data of the collected pads and the pad reference coordinate data in the preset Gerber data of the corresponding incoming circuit board, and then transmitted to the SPI for backup, or uploaded to a unified data center and retrieved by the SPI according to the circuit board identification when needed. Alternatively, the aforementioned measurement and measurement machine can transmit the actual coordinate data of the collected pads to the SPI, or the SPI can retrieve it according to the circuit board identification when needed, and then determine it based on the actual coordinate data of the pads and the pad reference coordinate data in the preset Gerber data of the corresponding incoming circuit board. The simulated coordinate data for solder paste printing serves as the benchmark for subsequent deviation compensation data calculation. It does not directly use the preset Gerber data, but rather considers the actual situation of the incoming materials and redetermines it based on the actual coordinate data of the pads, thereby eliminating a certain amount of incoming material deviation.

[0023] In an optional implementation, obtaining the simulated coordinate data of solder paste printing on the incoming circuit board includes: calculating the centroid of the pads in the actual coordinate data of the pads and the reference coordinate data of the pads, respectively; calculating the centered coordinates of each pad in the actual coordinate data of the pads and the reference coordinate data of the pads based on the centroids of the pads, and calculating the covariance term between the two types of centered coordinates; calculating a second target rotation angle based on the covariance term, and calculating a second target translation amount based on the second target rotation angle and the centroid of the pads; adjusting the reference coordinate data of the pads based on the second target rotation angle and the second target translation amount to obtain the simulated coordinate data of solder paste printing.

[0024] Specifically, due to potential issues such as board expansion and contraction, localized deformation and distortion in the incoming circuit board, the global error between the actual coordinate data and the reference coordinate data of all pads may be significant under the traditional large-board Mark positioning mode. In other words, the deviation between the actual coordinate data of each pad and the corresponding pad in the reference coordinate data may be severe. Therefore, after completing the large-board Mark alignment, a whole-board pad alignment mode can be adopted to determine the second target translation amount and the second target rotation angle. These are used to perform overall translation and rotation of the reference coordinate data of the pads, reducing the global error of all pads. The adjusted data can then be used as the simulated coordinate data for solder paste printing. Preferably, the second target translation amount and the second target rotation angle can be calculated with the goal of minimizing the global error of all pads. The optimal alignment algorithm is then used to optimize the alignment results of all pads on the entire board, and the optimal alignment value for the entire board is selected to complete the coordinate calibration.

[0025] Specifically, the least squares rigid registration method can be used to solve for the second target rotation angle and the second target translation amount, so that after rotating and translating the pad reference coordinate data based on the second target rotation angle and the second target translation amount, the global alignment error between the pad and the actual pad coordinate data reaches a unique global minimum. Let the actual pad coordinate data include the actual pad coordinates Pi=(Xi,Yi), i=1,2,…,N, and the pad reference coordinate data include the pad reference coordinates Si=(xi,yi), i=1,2,…,N, then the pad centroid coordinates in the actual pad coordinate data are: ; The centroid coordinates of the pads in the pad reference coordinate data are: ; Furthermore, the centered coordinates of each pad in the actual coordinate data and the reference coordinate data of the pads can be calculated as follows: ; Constructing the covariance term includes: ; Therefore, the rotation angle of the second objective can be calculated based on the above covariance term as follows: ; The translation of the second target is calculated as follows: ; The aligned coordinates obtained after rotating and translating the pad reference coordinate data are: ; After obtaining the second target translation amount and the second target rotation angle, the pad reference coordinate data can be translated and rotated as a whole to generate the solder paste printing simulation coordinate data of the whole board. This data is used to simulate the solder paste printing action and operation logic of the printer in actual production. While conforming to the actual working conditions of the printer, this data makes up for the accuracy defects of traditional large board Mark positioning and can accurately reflect the overall solder paste landing status of the incoming material in the actual printing process.

[0026] The aforementioned measurement machine can be pre-positioned between the board loading machine and the printing machine at the beginning of the SMT production line. After the printing machine completes the printing of the incoming circuit board, it flows to the SPI. The SPI can use a camera to capture the image of the entire board after printing, thereby determining the actual coordinate data of the solder paste printing.

[0027] In an optional implementation, obtaining the actual coordinate data of the solder paste printing after completion includes: acquiring a complete image of the incoming circuit board after printing; identifying the solder paste outlines in the complete image and determining the outline center of each solder paste outline; and determining the actual coordinate data of the solder paste printing based on the outline center. Specifically, existing arbitrary image recognition algorithms and outline center positioning algorithms can be used to obtain the outline center, thereby determining the corresponding actual coordinate data of the solder paste printing for each outline center based on the reference point position in the complete image.

[0028] Further optionally, before determining the actual coordinate data of solder paste printing based on the contour center, the method further includes: acquiring the actual coordinate data of individual panel PcsMarks in the incoming circuit board using a measuring device; identifying the actual position data of individual panel PcsMarks in the whole board image; aligning the coordinate system based on the actual coordinate data of individual panel PcsMarks and the actual position data of individual panel PcsMarks; the step of determining the actual coordinate data of solder paste printing based on the contour center includes: using the actual position data of individual panel PcsMarks as a reference, determining the corresponding actual coordinate data of solder paste printing for each contour center.

[0029] Specifically, SPI can retrieve the actual coordinate data of the reference points collected by the metrology machine. Specifically, it can use the actual coordinate data of the single-panel PcsMark and simultaneously identify the actual position data of the single-panel PcsMark in the overall board image after printing. This allows for precise coordinate system calibration using the PcsMark as the detection reference, ensuring consistency between the SPI detection coordinates and the metrology machine's measurement coordinates, reducing global errors and resulting in more accurate actual coordinate data for solder paste printing. After coordinate system alignment, the PcsMark can be used as a reference to determine the center of each contour, i.e., the precise X / Y coordinates of each point of actual solder paste in the metrology machine's coordinate system. By using the PcsMark alignment mode, targeted adaptation can be made for differences in incoming materials of individual sub-boards, making the offset detection of each sub-board in multi-panel boards more accurate and improving the printing yield of multi-panel boards. Specifically, two PcsMarks can be selected, with one as the origin, and aligned according to the direction of the line connecting the two points.

[0030] Furthermore, based on the obtained simulated and actual coordinate data of solder paste printing, solder paste alignment calculations can be performed. By calculating the deviation between the actual and simulated coordinate data, inherent deviation compensation data for the printing press can be obtained, which characterizes the printing press's own error. This inherent deviation compensation data can then be transmitted to the printing press, allowing it to correct the overall coordinate alignment of the stencil based on the inherent deviation compensation data, while material deviation is not included in the closed-loop compensation.

[0031] In an optional implementation, the step of aligning the solder paste according to the simulated coordinate data and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine includes: calculating the centroid of the solder paste in the simulated coordinate data and the actual coordinate data of solder paste printing respectively; calculating the centered coordinates of each solder paste in the simulated coordinate data and the actual coordinate data of solder paste printing based on the centroid of the solder paste, and calculating the covariance term between the two types of centered coordinates; calculating a first target rotation angle based on the covariance term, and calculating a first target translation amount based on the first target rotation angle and the centroid of the solder paste, wherein the inherent deviation compensation data of the printing machine includes the first target rotation angle and the first target translation amount.

[0032] Specifically, similar to the process of determining the simulated coordinate data for solder paste printing described above, the least squares rigid registration method can be used to obtain the inherent deviation compensation data of the printing press. This ensures that after adjusting the actual coordinate data for solder paste printing based on the inherent deviation compensation data, the global alignment error between the actual and simulated coordinate data reaches a unique global minimum. The specific calculation process can refer to the calculation process of the simulated coordinate data for solder paste printing described above, replacing the actual coordinate data of the pads with the simulated coordinate data and the reference coordinate data of the pads with the actual coordinate data of the solder paste printing. The first target rotation angle and the first target translation are then calculated accordingly, thereby determining the inherent deviation compensation data of the printing press. Furthermore, based on the inherent deviation compensation data, a closed-loop offset rotation compensation command for the printing press can be generated and sent to the printing press. The printing press can prioritize adjusting the X-axis and Y-axis coordinates and rotation angle of the stencil alignment according to the inherent deviation compensation data to complete the printing offset and rotational precision compensation for the next batch of incoming circuit boards.

[0033] Based on the above technical solution, optionally, the method further includes: acquiring actual quality data of solder paste printing after printing is completed; transmitting the actual quality data of solder paste printing to the printing machine, so that the printing machine adjusts the process parameters according to the actual quality data of solder paste printing.

[0034] Specifically, while collecting the actual coordinate data of solder paste printing, the system can simultaneously collect actual solder paste printing quality data such as volume, area, bridging, and solder shortage / excess. This collected data can then be transmitted to the printing press, allowing it to autonomously generate adjustment commands for process parameters such as squeegee pressure, angle, and stencil cleaning based on this data. This multi-dimensional data feedback via SPI allows for more precise adjustments to printing press parameters to better align with actual production needs, improving the accuracy of data application and the autonomy of equipment operation, ultimately enhancing printing quality.

[0035] Furthermore, a closed-loop iteration can be performed according to the above process. SPI detection is performed on each printed incoming circuit board to collect actual coordinate data and actual quality data of solder paste printing. At the same time, the corresponding simulated coordinate data of solder paste printing is obtained. Then, the actual quality data of solder paste printing and the calculated inherent deviation compensation data of the printing machine are continuously fed back to the printing machine in a closed loop to adjust the relevant parameters, forming a dynamic closed-loop iterative control of the entire process.

[0036] Based on the above technical solutions, the printer can also be pre-calibrated to address incoming material deviations. This can be achieved using the aforementioned measuring machine. The entire board's pads are aligned and matched based on the actual and reference coordinate data of the pads, similar to the process of determining the simulated coordinate data for solder paste printing. An optimal alignment algorithm is used to calculate the offset rotation parameter used to eliminate incoming material deviations. This ensures that after adjusting the reference coordinate data based on this offset rotation parameter, the global alignment error between the reference coordinate data and the actual coordinate data reaches a unique global minimum. This offset rotation parameter is then transmitted to the printer. After aligning the stencil with the large board mark of the incoming circuit board, the printer obtains basic alignment data. This data is then superimposed with the offset rotation parameter to obtain the actual deviation compensation data used to eliminate incoming material differences. Based on this actual deviation compensation data, the printing alignment mechanism is automatically adjusted to achieve precise pre-calibration compensation for incoming material differences, ensuring high-precision alignment between the stencil openings and the incoming pads. Combined with the aforementioned closed-loop control process, parameters can be continuously optimized, further ensuring the stability of printing quality.

[0037] Based on the above technical solutions, all printing closed-loop related data, such as the original geometric data collected by the measuring machine, the offset rotation parameters generated by the measuring machine and transmitted to the printing machine, the solder paste printing simulation coordinate data, the actual solder paste printing coordinate data, the actual solder paste printing quality data, the printing machine's inherent deviation compensation data, and the closed-loop iteration results, can be associated and bound to the unique identifier of the corresponding incoming circuit board for storage. This allows for rapid traceability of the entire printing process based on the unique identifier, providing comprehensive data support for quality problem investigation and process optimization.

[0038] The technical solution provided by this invention first acquires the simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after completion. The simulated coordinate data is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. Then, solder paste alignment is performed based on the simulated and actual coordinate data to obtain printer inherent deviation compensation data. This printer inherent deviation compensation data is then transmitted to the printer so that the printer can adjust the stencil alignment according to the printer inherent deviation compensation data. By first determining the simulated coordinate data of solder paste printing based on the actual and reference coordinate data of the pads as a reference, and then calculating the deviation compensation data with the actual coordinate data of the solder paste printing, incoming material deviation is eliminated, and closed-loop compensation is performed only for the printer inherent deviation. This improves the reliability of the SPI-printer closed-loop control, thereby significantly improving printing accuracy and quality stability, and ultimately improving the overall yield and production efficiency of the SMT production line.

[0039] Example 2 Figure 2 This is a schematic diagram of the SPI-printer closed-loop control device in an SMT production line provided in Embodiment 2 of the present invention. This device can be implemented in hardware and / or software, and is generally integrated into solder paste inspection equipment to execute the SPI-printer closed-loop control method in an SMT production line provided in Embodiment 1 of the present invention. Figure 2 As shown, the device includes: The coordinate data acquisition module 21 is used to acquire the simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after printing is completed. The simulated coordinate data of solder paste printing is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. The compensation data determination module 22 is used to perform solder paste alignment based on the solder paste printing simulation coordinate data and the solder paste printing actual coordinate data to obtain the inherent deviation compensation data of the printing machine. The compensation data feedback module 23 is used to transmit the inherent deviation compensation data of the printing press to the printing press, so that the printing press can adjust the alignment of the stencil according to the inherent deviation compensation data of the printing press.

[0040] The technical solution provided by this invention first acquires the simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after completion. The simulated coordinate data is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. Then, solder paste alignment is performed based on the simulated and actual coordinate data to obtain printer inherent deviation compensation data. This printer inherent deviation compensation data is then transmitted to the printer so that the printer can adjust the stencil alignment according to the printer inherent deviation compensation data. By first determining the simulated coordinate data of solder paste printing based on the actual and reference coordinate data of the pads as a reference, and then calculating the deviation compensation data with the actual coordinate data of the solder paste printing, incoming material deviation is eliminated, and closed-loop compensation is performed only for the printer inherent deviation. This improves the reliability of the SPI-printer closed-loop control, thereby significantly improving printing accuracy and quality stability, and ultimately improving the overall yield and production efficiency of the SMT production line.

[0041] Based on the above technical solution, optionally, the compensation data determination module 22 is specifically used for: Calculate the centroid of the solder paste in the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing, respectively; Based on the centroid of the solder paste, the centered coordinates of each solder paste in the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing are calculated respectively, and the covariance term between the two types of centered coordinates is calculated. The first target rotation angle is calculated based on the covariance term, and the first target translation amount is calculated based on the first target rotation angle and the solder paste centroid. The printer inherent deviation compensation data includes the first target rotation angle and the first target translation amount.

[0042] Based on the above technical solution, optionally, the coordinate data acquisition module 21 is specifically used for: Calculate the centroid of the pad in the actual coordinate data of the pad and the reference coordinate data of the pad, respectively; Based on the centroid of the pad, calculate the centered coordinates of each pad in the actual coordinate data of the pad and the reference coordinate data of the pad, and calculate the covariance term between the two types of centered coordinates. The second target rotation angle is calculated based on the covariance term, and the second target translation amount is calculated based on the second target rotation angle and the pad centroid. The solder pad reference coordinate data are adjusted based on the second target rotation angle and the second target translation amount to obtain the solder paste printing simulation coordinate data.

[0043] Based on the above technical solution, optionally, the coordinate data acquisition module 21 is specifically used for: Obtain an image of the entire circuit board after printing is completed; Identify solder paste outlines in the whole board image and determine the outline center of each solder paste outline; The actual coordinate data for solder paste printing is determined based on the center of the outline.

[0044] Based on the above technical solution, optionally, before determining the actual coordinate data of the solder paste printing according to the contour center, the coordinate data acquisition module 21 is further used for: The actual coordinate data of the single panel PcsMark in the incoming circuit board are obtained by measuring equipment. Identify the actual PcsMark position data of individual panels in the overall panel image; Coordinate system alignment is performed based on the actual coordinate data of the single-panel PcsMark and the actual position data of the single-panel PcsMark. Determining the actual coordinate data for solder paste printing based on the contour center includes: Based on the actual position data of the single panel PcsMark, the actual coordinate data of the solder paste printing corresponding to the center of each contour are determined.

[0045] Based on the above technical solution, optionally, the device further includes: The quality data acquisition module is used to acquire the actual quality data of solder paste printing after the printing is completed. The quality data feedback module is used to transmit the actual quality data of the solder paste printing to the printing machine, so that the printing machine can adjust the process parameters according to the actual quality data of the solder paste printing.

[0046] The SPI-printer closed-loop control device in the SMT production line provided in this embodiment of the invention can execute the SPI-printer closed-loop control method in the SMT production line provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0047] It is worth noting that in the embodiment of the SPI-printer closed-loop control device in the above-mentioned SMT production line, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0048] Example 3 Figure 3 This is a schematic diagram of the solder paste testing device provided in Embodiment 3 of the present invention, showing a block diagram of an exemplary solder paste testing device suitable for implementing the embodiments of the present invention. Figure 3The solder paste testing equipment shown is merely an example and should not be construed as limiting the functionality or scope of the embodiments of the present invention. Figure 3 As shown, the solder paste inspection device includes a processor 31, a memory 32, an input device 33, and an output device 34; the number of processors 31 in the solder paste inspection device can be one or more. Figure 3 Taking a processor 31 as an example, the processor 31, memory 32, input device 33, and output device 34 in the solder paste inspection equipment can be connected via a bus or other means. Figure 3 Taking the example of a connection between China and Israel via a bus.

[0049] The memory 32, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the SPI-printer closed-loop control method in the SMT production line of this embodiment (e.g., the coordinate data acquisition module 21, compensation data determination module 22, and compensation data feedback module 23 in the SPI-printer closed-loop control device in the SMT production line). The processor 31 executes various functional applications and data processing of the solder paste inspection equipment by running the software programs, instructions, and modules stored in the memory 32, thereby realizing the aforementioned SPI-printer closed-loop control method in the SMT production line.

[0050] The memory 32 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on the use of the solder paste inspection equipment. Furthermore, the memory 32 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 32 may further include memory remotely located relative to the processor 31, which can be connected to the solder paste inspection equipment via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0051] Input device 33 can be used to acquire simulated coordinate data of solder paste printing on incoming circuit boards and actual coordinate data of solder paste printing after completion, as well as generate key signal inputs related to user settings and function control of the solder paste inspection equipment. Output device 34 can be used to output the generated printer inherent deviation compensation data, etc.

[0052] Example 4 Embodiment 4 of the present invention also provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform a closed-loop control method for an SPI-printer in an SMT production line, the method comprising: The simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after printing are obtained. The simulated coordinate data of solder paste printing is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. Solder paste alignment is performed based on the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine. The inherent deviation compensation data of the printing press is transmitted to the printing press so that the printing press can adjust the stencil alignment according to the inherent deviation compensation data of the printing press.

[0053] Storage media can be any type of memory device or storage device. The term "storage media" is intended to include: mounting media, such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (e.g., hard disks or optical storage); registers or other similar types of memory elements. Storage media may also include other types of memory or combinations thereof. Furthermore, storage media may reside in a computer system in which the program is executed, or may reside in a different second computer system connected to the computer system via a network (such as the Internet). The second computer system can provide program instructions to the computer for execution. The term "storage media" can include two or more storage media that may reside in different locations (e.g., in different computer systems connected via a network). Storage media may store program instructions (e.g., specifically implemented as a computer program) that can be executed by one or more processors.

[0054] Of course, the computer-executable instructions provided in the embodiments of the present invention are not limited to the operation of the method described above, but can also perform related operations in the SPI-printer closed-loop control method in the SMT production line provided in any embodiment of the present invention.

[0055] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0056] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0057] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a solder paste testing device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0058] Example 5 Embodiment 5 of the present invention also provides a computer program product, which includes a computer program (also referred to as code or instructions). The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it is used to execute the SPI-printer closed-loop control method in the SMT production line provided in any of the above embodiments, and has the corresponding beneficial effects of the execution method.

[0059] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A closed-loop control method for an SPI-printer in an SMT production line, characterized in that, include: The simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after printing are obtained. The simulated coordinate data of solder paste printing is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. Solder paste alignment is performed based on the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine. The inherent deviation compensation data of the printing press is transmitted to the printing press so that the printing press can adjust the stencil alignment according to the inherent deviation compensation data of the printing press.

2. The closed-loop control method for the SPI-printer in an SMT production line according to claim 1, characterized in that, The step of aligning the solder paste according to the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine includes: Calculate the centroid of the solder paste in the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing, respectively; Based on the centroid of the solder paste, the centered coordinates of each solder paste in the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing are calculated respectively, and the covariance term between the two types of centered coordinates is calculated. The first target rotation angle is calculated based on the covariance term, and the first target translation amount is calculated based on the first target rotation angle and the solder paste centroid. The printer inherent deviation compensation data includes the first target rotation angle and the first target translation amount.

3. The closed-loop control method for the SPI-printer in an SMT production line according to claim 1, characterized in that, The acquisition of simulated coordinate data for solder paste printing on the incoming circuit board includes: Calculate the centroid of the pad in both the actual coordinate data and the reference coordinate data of the pad. Based on the centroid of the pad, calculate the centered coordinates of each pad in the actual coordinate data of the pad and the reference coordinate data of the pad, and calculate the covariance term between the two types of centered coordinates. The second target rotation angle is calculated based on the covariance term, and the second target translation amount is calculated based on the second target rotation angle and the pad centroid. The solder pad reference coordinate data are adjusted based on the second target rotation angle and the second target translation amount to obtain the solder paste printing simulation coordinate data.

4. The closed-loop control method for the SPI-printer in an SMT production line according to claim 1, characterized in that, The process of obtaining the actual coordinate data of the solder paste printing after completion includes: Obtain an image of the entire circuit board after printing is completed; Identify solder paste outlines in the whole board image and determine the outline center of each solder paste outline; The actual coordinate data for solder paste printing is determined based on the center of the outline.

5. The closed-loop control method for the SPI-printer in an SMT production line according to claim 4, characterized in that, Before determining the actual coordinate data for solder paste printing based on the contour center, the method further includes: The actual coordinate data of the single panel PcsMark in the incoming circuit board are obtained by measuring equipment. Identify the actual PcsMark position data of individual panels in the overall panel image; Coordinate system alignment is performed based on the actual coordinate data of the single-panel PcsMark and the actual position data of the single-panel PcsMark. Determining the actual coordinate data for solder paste printing based on the contour center includes: Based on the actual position data of the single panel PcsMark, the actual coordinate data of the solder paste printing corresponding to the center of each contour are determined.

6. The closed-loop control method for the SPI-printer in an SMT production line according to claim 1, characterized in that, The method further includes: Obtain actual quality data of solder paste printing after the printing is completed; The actual quality data of the solder paste printing is transmitted to the printing machine so that the printing machine can adjust its process parameters based on the actual quality data of the solder paste printing.

7. A closed-loop control device for an SPI-printer in an SMT production line, characterized in that, include: The coordinate data acquisition module is used to acquire the simulated coordinate data of solder paste printing on the incoming circuit board and the actual coordinate data of solder paste printing after printing is completed. The simulated coordinate data of solder paste printing is determined based on the actual coordinate data of the pads on the incoming circuit board and the pad reference coordinate data in the preset Gerber data. The compensation data determination module is used to perform solder paste alignment based on the simulated coordinate data of solder paste printing and the actual coordinate data of solder paste printing to obtain the inherent deviation compensation data of the printing machine. The compensation data feedback module is used to transmit the inherent deviation compensation data of the printing press to the printing press, so that the printing press can adjust the stencil alignment according to the inherent deviation compensation data of the printing press.

8. A solder paste testing device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the SPI-printer closed-loop control method in the SMT production line as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the SPI-printer closed-loop control method in the SMT production line as described in any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the SPI-printer closed-loop control method in the SMT production line as described in any one of claims 1-6.

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