A method and device for automatic optical inspection and correction of solder mask pattern on circuit board

Abstract

The present invention relates to a method and device for automatic optical inspection and correction of a solder mask pattern of a circuit board. The method uses a structured light with the same shape as the inspected area and complementary color to the inspected material as a light source, uses the pattern contour line obtained by photography as a boundary, generates a processing path, uses laser photoetching to remove the solder mask material that contaminates the welding area, and uses a printing and coating method to fill the missing solder mask. The implementation of the present invention can automatically correct the defects in the solder mask manufacturing process of the circuit board and improve the yield rate. The present invention uses a structured light with a shape and color matching the inspected pattern as a light source, and the inspection process is easy and the result is accurate; directly uses CAM data, laser removal, and printing to fill the gap, without chemical processes, with a high degree of automation, high precision, and environmental friendliness. The present invention is suitable for inspecting and correcting solder mask patterns in the manufacture of bare circuit boards and before circuit board assembly, and is suitable for directly removing solder mask materials and making solder mask patterns; it is also suitable for inspecting and correcting patterns in other processing processes.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit manufacturing, and relates to a technique for inspecting and correcting solder resist patterns, in particular to a method and a device for automatically optically inspecting and correcting solder resist patterns on circuit boards. Background Art

[0002] In electronic products, the circuit board acts as a skeleton, providing a physical channel for electrical connection between components and is a structural carrier for fixing and installing components. The electrical connection channel is realized by conductive patterns and metallized holes. The quality of component installation and fixation is closely related to the performance of solder mask patterns and welding areas. The main production process of circuit boards also revolves around the solderability of conductive patterns, metallized holes, solder mask patterns and welding areas.

[0003] Among them, the processing of solder mask pattern and solderability treatment is carried out after the conductive pattern and hole metallization are completed. This means that even if the conductive pattern and metallized hole are qualified, if there are defects in the solder mask pattern and solderability treatment, the circuit board will be scrapped, resulting in large losses. Furthermore, once the defects in the solder mask pattern and welding area enter the assembly stage, in addition to causing obvious component installation problems, such as short circuits between solder joints, it may also cause hidden problems, such as cold soldering, affecting the reliability of electronic products. Therefore, for the production of electronic products, it is of great significance to check whether the solder mask pattern and welding area are qualified, as well as to correct the defects in the solder mask pattern and welding area.

[0004] Solder resist masks and protects the surface of printed conductors, as well as the blank areas of the board. When soldering components to circuit boards, solder resist acts as an isolation agent, which can prevent short circuits between conductors or pads caused by the free flow of molten solder to a certain extent. In addition, solder resist is insulating, heat-resistant, and chemical-resistant, and is a permanent protective layer on the surface of printed boards. It acts as a mechanical isolation agent, which can prevent the conductors from being scratched or scratched during storage and use of printed boards. It also has three protection functions: moisture-proof, salt spray-proof, mildew-proof, and weather-resistant.

[0005] On the surface of the circuit board, the solder resist is a protective covering layer for the circuit board, which is selectively coated on the surface of the finished printed circuit board. Except for the pads and the inner wall of the metallized holes, all other positions on the board surface are coated with solder resist, and the area covered with solder resist forms a solder resist pattern. In the existing circuit board production, the production of solder resist pattern is completed by the graphic transfer process, which is an indirect manufacturing technology. Commonly used methods include screen printing method and photochemical imaging method. The process routes of both methods require the base plate to be light-drawn first, and then the graphic transfer is performed.

[0006] Taking the photochemical imaging method as an example, the brief process is: substrate and ink preparation → coating the first side of the whole board → pre-drying → coating the second side of the whole board → pre-drying → exposure → development → post-curing. First, the whole board is coated with liquid photosensitive solder resist. After pre-drying, the circuit board is exposed with the base plate as a light-blocking masking film. Then, the unexposed solder resist on the masked area is removed by development and washing to form the initial solder resist pattern. Finally, the formed solder resist pattern is thoroughly cured to end the solder resist pattern production process. The photochemical imaging method uses photosensitive solder resist. In order to prevent the base plate and the solder resist from sticking together, the solder resist must be pre-cured before exposure. After development, the solder resist can be thoroughly cured. The whole process is cumbersome and the operation window is small. Pre-curing, also known as pre-drying, is one of the key points of the process. Pre-curing is not complete curing. If the time is slightly shorter and the strength is slightly weaker, if the solder resist is locally in liquid state, it will stick to the plate and make the base plate scrapped; if the time is slightly longer and the strength is slightly higher, if the solder resist has been partially cured, it cannot be removed or is not removed cleanly during development, resulting in defects such as residual solder resist in the welding area.

[0007] Although the cost of applying solder resist by screen printing is low, its accuracy is limited and it is even more difficult to meet the requirements of electronic product refinement. In fact, no matter which technology is used, it is difficult to make a finer graphic structure clearly and cleanly due to the limitations of graphic resolution and position accuracy. The defects of solder resist patterns have become a process problem and are difficult to completely eliminate. On the one hand, solder resist appears in areas where solder resist should not be applied, that is, solder resist pads, which pollute the welding area, resulting in poor welding and cold welding; on the other hand, there is no solder resist coating in areas where solder resist should be applied, such as between two pads, that is, the solder resist is blank, which cannot prevent the flow of solder between solder joints during welding, resulting in solder bridging and short circuit.

[0008] At present, solder mask pattern inspection still remains in manual inspection or using ordinary circuit board appearance inspection equipment. Manual inspection is slow and the work quality is unstable; ordinary appearance inspection equipment is affected by the environment and the color of the solder mask, the identification accuracy fluctuates greatly, and the effect is not ideal. For defective circuit boards, the current common practice is to remove the solder mask and re-manufacture the solder mask pattern. It is not easy to remove the solder mask that has been completely cured. Most of them use a high-concentration alkaline solution, soak for a long time at a high temperature, and the operating environment is relatively harsh, which will also affect the intrinsic quality of the circuit board. Re-manufacturing the solder mask pattern, because the manufacturing technology itself has not changed, there is no complete success. After repeated processing, if the defects cannot be eradicated, the finished product can only be scrapped, which is an important reason for the high cost and waste of resources in circuit board production. Summary of the invention

[0009] In view of the shortcomings of the prior art, the present invention provides a method and device for automatic optical inspection and correction of solder resist patterns on circuit boards, which are used for automatic optical inspection and correction of solder resist patterns on circuit boards, and are also used for directly removing solder resist to make solder resist patterns. The present invention uses structured light with the same shape as the inspected area and complementary color to the inspected material as the light source, uses the pattern contour obtained by photography as the boundary, generates a processing path, uses laser photoetching to remove solder resist materials that contaminate the welding area, and uses a printing and coating method to fill in the missing solder resist.

[0010] In the present invention, the inspection and correction of the solder mask pattern are divided into two stages: one stage is used to inspect and correct the solder mask contamination in the welding area. When solder mask appears on the inspected area, it is necessary to remove it by laser photoetching; the other stage is used to inspect and correct the solder mask missing in the solder mask area. When the base material is exposed on the inspected area, it is necessary to spray solder mask to cover it.

[0011] In the stage of inspecting and correcting solder mask contamination in the welding area, use structured light that is complementary to the shape and color of the solder mask pattern as the light source, take pictures with a camera, first check whether there is solder mask contamination on the welding area, that is, whether there is solder mask pad, and the distribution of solder mask that should not exist on the pad; then, for the defects of solder mask pad, use the pattern contour line obtained by photography as the boundary, generate the processing path, and use laser photoetching to remove the solder mask material that should not exist; finally, still use structured light source illumination, take pictures with a camera, obtain the surface information of the welding area, and judge whether the defects are corrected. The specific steps are as follows:

[0012] Step (1) uses the CAM data of the circuit board solder mask pattern to generate a pattern that is complementary to the shape of the solder mask pattern. Different CAM systems and different manufacturing technologies have different ways of expressing patterns and data formats. The pattern required in this step is the soldering area or soldering pad pattern that is not masked by the solder mask. Because in some cases, the area where the solder paste is applied is smaller than the area where the solder paste can flow, the pattern in this step is not necessarily the same as the SMT solder paste template opening pattern.

[0013] Step (2), using the obtained pattern to generate structured light data. The structured light in the present invention refers to a light beam whose cross section completely matches the shape and size of the pattern, or a light spot projected on a target pattern, whose shape and size are exactly equal to the target pattern. The structured light data is generated by a CAM system, or by a CAM system and a control system respectively, and includes configuration data and control data, which are used to configure and control the photographic light source and the structured light generator of the laser processing system. The configuration data defines the shape and color of the light projected by the structured light generator, so that its shape is the same as that of the inspected area, and its color is complementary to that of the inspected surface. The control data generates drive instructions to the structured light generator, camera, laser light source, and motion control system according to the definition of the configuration data, and executes processing actions such as projection and photographing.

[0014] Step (3), take a photo using a structured light with a color complementary to the solder resist pattern as a light source. In order to highlight the target pattern, a color light with the same shape and size as the area not masked by the solder resist and a color complementary to the solder resist is used as a light source, and the surface information of the area is obtained by photography. Illuminating with a light source with the same shape and size as the inspected area can limit the information obtained to an effective and limited range, eliminate interference from irrelevant information, and the results are clear at a glance; using a color light with a color complementary to the solder resist color as a light source makes it easy to distinguish whether the details in the information obtained come from excess solder resist, because under complementary light, the image produced by the defective area has little contrast and is not prominent, while the contrast between the excess solder resist and the color of other materials will be magnified, the presence of solder resist will appear darker, and the defects of solder resist contaminated pads will be more prominent. Image processing only needs to focus on information that reaches a certain degree of black.

[0015] Step (4) is to obtain the contour line of the pattern as the boundary of the pattern to be removed by laser photo-etching, and generate a processing path. The CAM system generates a processing path based on the processing method of the laser processing system, that is, the shape and size of the area to be processed by the laser for photo-etching. In a general laser processing system, the cross-section of the laser beam is a circle, and a point-by-point and line-by-line processing method is used to remove materials. A single laser projection can remove materials on a circular area with a diameter of about tens of microns. A structured laser processing system can generate a laser spot with the same shape and size as the selected area to be processed, which acts on the material in a sheet. It is a patterned processing method. A single laser projection can remove materials on a pattern area with a diagonal of about several millimeters.

[0016] Step (5) uses structured laser photolithography to remove the solder resist material forming the above pattern from the welding area. Most solder resists are high molecular polymers. Compared with the base metal of the welding area, the optical power threshold value of laser removal is significantly lower. It is easier to select a processing system to remove the solder resist without damaging the base metal of the welding area. For example, infrared band processing equipment with CO2 laser or fiber laser as light source can be selected, and ultraviolet band light source laser processing equipment can also be selected, but laser processing equipment with the same band as the solder resist color should not be selected. For another example, optical fiber continuous laser processing equipment can be selected, and laser processing equipment with various pulse widths can also be selected. The important parameter of laser processing is the laser power per unit area. In the present invention, only the solder resist material on the welding area needs to be removed. Therefore, during the processing, the focused laser light power density used should be kept greater than the minimum power density required to remove the organic material of the solder resist, preferably greater than 1.2 times the minimum light power density required to remove the solder resist and lower than or close to the minimum light power density required to remove the metal layer covered thereunder.

[0017] Step (6), take a photo again using structured light with a color complementary to the solder mask pattern as the light source, and compare the data obtained by the photo with the standard data to check the removal effect.

[0018] Step (7), loop processing or report results.

[0019] In the stage of checking and correcting the missing solder mask in the solder mask area, use structured light with the same shape as the solder mask pattern and complementary color to the base material as the light source, take pictures with a camera, first check the missing solder mask in the solder mask area and its distribution, that is, confirm the location where the solder mask should exist, whether there are pinholes, gaps, and missing blocks; then, for the defects on the solder mask area, use the pattern contour line obtained by photography as the boundary, generate the processing path, and print the solder mask material to fill it; finally, still use the structured light source for illumination, take pictures with a camera, obtain the surface information of the solder mask area, and judge whether the defects have been corrected. The specific steps are as follows:

[0020] Step (1) uses the CAM data of the circuit board solder mask pattern to generate structured light data with the same shape as the solder mask pattern. The structured light in this step refers to a light beam whose cross section completely matches the shape and size of the solder mask pattern, or a light spot projected on the target pattern, whose shape and size are exactly equal to the expected solder mask pattern. The structured light data is generated by the CAM system, or by the CAM system and the control system respectively, and includes configuration data and control data, which are used to configure and control the photographic light source and the structured light generator of the laser processing system. The configuration data defines the shape and color of the light projected by the structured light generator, so that its shape is the same as the inspected area and its color is complementary to the color of the inspected surface. The control data sends drive instructions to the structured light generator, camera, laser light source, and motion control system according to the definition of the configuration data to perform processing actions such as projection and photographing.

[0021] Step (2), take a photo with the structured light that should be masked by solder resist as the light source. In order to highlight the solder resist pattern area, which should have been coated with solder resist but is missing the defect of solder resist, use a color light with the same shape and size as the solder resist pattern and complementary color to the base material as the light source, and take a photo to obtain the surface information of the area. Illuminating with a light source with the same shape and size as the inspected area can limit the information obtained to an effective and limited range, eliminate the interference of irrelevant information, and the result is clear at a glance; using a color light with complementary color to the base material that should have been masked by solder resist but may be exposed due to solder resist coating problems as the light source, it is easy to distinguish the details in the information obtained, whether it comes from the lack of solder resist, because under complementary light, the image contrast produced by the defective area is not large and not prominent, and the contrast between the base material that should not be exposed in the defective area and other color materials will be magnified, and the existence of exposed points will appear darker. Image processing only needs to focus on information that reaches a certain degree of black.

[0022] Step (3), the outline of the pattern is obtained as the boundary of the processed area, and the printing path and the light curing path are generated. The CAM system generates the processing path according to the parameters of the equipment used in step (4) and step (5) below. The processing path generation in this step should be carried out in accordance with the principle of "better big than small", that is, it is tolerated to appropriately expand the printing and curing range to ensure the overall repair effect, and the curing range must be larger than the printing range to avoid the phenomenon that the printed solder resist is not cured and contaminates the circuit board. According to claim 3 of the present invention, it is preferred to repair the missing solder resist in the solder resist area first, and then repair the solder resist contamination in the welding area. The requirements for the solder resist printing system are not high. The important thing is to ensure that the solder resist is applied to all the parts where the solder resist is missing, and it does not matter whether the printing system has excess solder resist applied to the parts where the solder resist should not be applied, because even if there is excess solder resist applied, it can be discovered and repaired during the stage of repairing the solder resist contamination in the welding area.

[0023] Step (4), spray printing the solder resist material. Preferably, a spray printing device that sprays and cures at the same time is used to reduce the number of processing steps.

[0024] Step (5), using structured light as a light source to cure the printed solder resist material. Of course, the optical power density of the laser beam used to remove the solder resist can be reduced so that it does not reach the threshold value for removing the solder resist, such as using a defocused laser beam to cure the solder resist in this step.

[0025] Step (6), take a photo again using structured light with a color complementary to that of the base material as the light source, and compare the data obtained by taking the photo with the standard data to check the printing effect.

[0026] Step (7), loop processing or report results.

[0027] The equipment of the present invention is composed of a data processing system, an equipment operating system, a workpiece and processing head motion control system, an illumination and light curing system, a laser photoetching removal system, a printing and coating system, a workpiece fixing and automatic and manual loading and unloading system, and a positive pressure and negative pressure cleaning system. Among them, the cross-section of the light used for illumination, light curing, and laser photoetching is a structured light with controlled shape and color, and the light spot projected on the target pattern has a shape and size that is exactly equal to the solder mask pattern and welding area pattern. The structured light required by the equipment is generated by a DMD device, and the DMD distributes and transmits the received light. Before the light enters the DMD for processing, it undergoes shaping, light homogenization, and color matching.

[0028] In addition to having the functions of general laser processing and automatic optical inspection equipment, the software of the present invention, i.e., the data processing and equipment operating system of the equipment, also generates data required by the structured light generator DMD, including configuration data and control data, which are used to configure and control the photographic light source and the structured light generator of the laser processing system. The configuration data defines the shape and color of the light projected by the structured light generator, so that its shape is the same as the inspected area and its color is complementary to the color of the inspected surface. The control data generates driving instructions to the structured light generator, camera, laser light source, and motion control system according to the definition of the configuration data, and executes processing actions such as projection and photographing.

[0029] According to the method of the present invention, the equipment is divided into several functional units, including an automatic optical inspection unit, a laser solder resist photoetching removal processing unit, and a solder resist printing unit. Among them, different light sources and DMD devices are selected for automatic optical inspection and laser processing respectively to generate structured light with different physical properties. The present invention preferably adopts the design of each unit as an independent functional module that can be spliced ​​into a set, and the workpiece enters each functional module in turn, is inspected, and is corrected. The present invention also supports the use of multifunctional integrated design, that is, the automatic optical inspection function is integrated with the laser processing function or the printing function. The equipment of the present invention uses opaque materials to manufacture the machine cover to isolate the interference of ambient light on the photo taking and improve the inspection accuracy. Similarly, in order to ensure the consistency of the printing effect, the present invention is designed with a constant temperature system so that the material storage, transportation and distribution of the printing and coating system are not affected by changes in ambient temperature. For the application of the present invention to direct laser removal of solder resist, DMD devices can be omitted, and laser photoetching removal can be completed with an ordinary laser beam, and the transmission and distribution control of light can be realized with a general scanning device.

[0030] The advantages and effects of the present invention are:

[0031] 1. The present invention provides a technical solution for systematically checking and correcting manufacturing defects of solder mask patterns and solderability processing, with a high degree of automation.

[0032] 2. The present invention uses structured light illumination that matches the inspected area and material to increase the contrast of defect display and provide accurate inspection results.

[0033] 3. The present invention uses laser photoetching to remove solder resist contaminants in the welding area and uses solder resist printing technology to fill in the missing solder resist. The process is environmentally friendly and the result is precise.

[0034] 4. The present invention uses structured laser to remove solder resist, which can replace the existing photochemical method or screen printing method and is used to manufacture solder resist patterns with fewer steps, high precision and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1This is a structural diagram of an automatic optical inspection and correction device for circuit board solder resist contamination according to Embodiment 1 of the present invention;

[0036] In the figure: 1. Automatic loading system; 2. Granite platform; 3. A workbench; 4. Structured light projection assembly; 5. Camera; 6. X1 mobile system; 7. Equipment operation and control system; 8. Granite beam; 9. Y1 mobile system; 10. Automatic unloading system; 11. B workbench; 12. Structured laser head; 13. X2 mobile system; 14. Y2 mobile system.

[0037] Figure 2 Structured light generated for structured light projection components that is complementary to the shape and color of the solder mask pattern.

[0038] Figure 3 Schematic diagram of a camera taking pictures of structured light projection.

[0039] In the figure: 4-1. Light source; 4-2. Color wheel; 4-3. DMD; 4-4. Reflector; 4-5. Projection lens; 4-6. Structured light; 4-7. Solder mask area; 4-8. Structured light projection; 5. Camera.

[0040] Figure 4 Schematic diagram of the area of ​​the circuit board contaminated by solder resist.

[0041] In the figure: 4-7-1. Solder pad; 4-7. Solder mask area; 4-7-2. Solder mask contamination

[0042] Figure 5 This is an image of solder resist contamination obtained by taking a photo.

[0043] Figure 6 This is a process flow chart of automatic optical inspection and removal of solder mask contamination on a circuit board according to Embodiment 1 of the present invention.

[0044] Figure 7 This is a structural diagram of an automatic optical detection and correction device for solder resist leakage on a circuit board according to Embodiment 2 of the present invention.

[0045] In the figure: 1. Automatic loading system; 2. Granite platform; 3. A workbench; 4. Structured light projection component; 5. Camera; 6. X1 mobile system; 7. Equipment operation and control system; 8. Granite beam; 9. Y1 mobile system; 10. Automatic unloading system; 11. B workbench; 13. X2 mobile system; 14. Y2 mobile system; 15. Curing structured light; 16. Print head.

[0046] Figure 8 The structured light generated for the structured light projection component has the same shape as the solder resist pattern and is complementary in color to the base material masked by the solder resist.

[0047] Fig. 9 A schematic diagram of solder mask leakage on a circuit board;

[0048] In the figure: 4-7-1. Solder pad; 4-7. Solder mask area; 4-7-3. Solder mask leakage.

[0049] Fig.10 Photograph taken of an area of ​​a circuit board with solder resist voids.

[0050] Fig.11 This is a process flow chart of automatic optical inspection and removal of solder mask leaks in circuit boards according to Example 2. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with the following embodiments. The following embodiments are illustrative, not restrictive, and the protection scope of the present invention cannot be limited by the following embodiments.

[0052] Example 1

[0053] An automatic optical inspection and correction device for solder resist contamination of circuit boards, such as Figure 1 As shown, it includes: automatic loading system 1, granite platform 2, A workbench 3, structured light projection assembly 4, camera 5, X1 mobile system 6, equipment operation and control system 7, granite beam 8, Y1 mobile system 9, automatic unloading system 10, B workbench 11, structured laser head 12, X2 mobile system 13 and Y2 mobile system 14. Y1 mobile system 9 and Y2 mobile system 14 are fixedly installed in parallel and at intervals on the granite platform 2, A workbench 3 is slidably installed on the Y1 mobile system 9, and B workbench 11 is slidably installed on the Y2 mobile system 14. One end of the Y1 mobile system 9 is connected to the automatic loading system 1, and the other end is connected to the automatic unloading system 10. The Y2 mobile system 14 is the same as the Y1 mobile system 9, and one end is also connected to the automatic loading system 1, and the other end is connected to the automatic unloading system 10, but the loading and unloading directions are opposite to those of the Y1 mobile system 9. A granite beam 8 is installed above the Y1 moving system 9 and the Y2 moving system 14, and the granite beam 8 is vertically arranged with the Y1 moving system 9 and the Y2 moving system 14. An X1 moving system 6 is slidably installed on one side of the granite beam 8, and an X2 moving system 13 is installed on the other side opposite thereto. A structured light projection assembly 4 and a camera 5 are slidably installed on the X1 moving system 6, and a structured laser head 12 is slidably installed on the X2 moving system 13.

[0054] The working process of the equipment is as follows: the automatic feeding system 1 transfers the single-chip circuit board coated with solder resist in the material frame to the A workbench 3 and fixes it; the structured light projection component 4 generates a structured light with a shape and color complementary to the solder resist pattern. Figure 2 , and project it onto the circuit board, and the camera 5 takes a picture of the structured light projection. Figure 3 If solder resist contaminates the circuit soldering area, Figure 4 , then take a photo to obtain the solder resist contamination image as Figure 5 ; The contour line of the pattern is obtained as the boundary of the pattern to be removed by laser photoetching, and a processing path is generated; the A workbench 3 moves to the other side of the granite beam 8, and the solder resist contamination is removed by a structured laser head 12; at the same time, the B workbench 11 is loaded, and the above-mentioned structured light projection, photography, image processing and structured laser processing path generation steps are performed in the same order; after the laser processing of the A workbench 3 is completed, it returns to the structured light projection area, and the structured light projection component 4 and the camera 5 project and photograph the circuit board again. At the same time, after the projection and photography of the B workbench 11 are completed, it moves to the other side of the granite beam 8 and the structured laser head 12 performs the removal of solder resist contamination; if the result of the secondary projection photography of the circuit board on the A workbench is still solder resist contamination, continue to remove it with a structured laser; at the same time, after the laser processing of the B workbench is completed, it returns to the other side of the beam for secondary projection photography; the above-mentioned structured light projection photography and structured laser removal of solder resist contamination steps are alternately and cyclically performed on the A workbench and the B workbench until the data obtained by the photographed image is completely consistent with the standard data, the automatic unloading system 10 performs unloading, and the platform returns and reloads. The above process flow is shown in Figure 6 .

[0055] Example 2

[0056] An automatic optical inspection and correction device for solder mask leakage on circuit boards, such as Figure 7As shown, it includes an automatic loading system 1, a granite platform 2, an A workbench 3, a structured light projection assembly 4, a camera 5, an X1 mobile system 6, an equipment operation and control system 7, a granite beam 8, a Y1 mobile system 9, an automatic unloading system 10, a B workbench 11, a curing structured light 15, a printing head 16, an X2 mobile system 13, and a Y2 mobile system 14. The Y1 mobile system 9 and the Y2 mobile system 14 are fixedly installed in parallel and at intervals on the granite platform 2, the A workbench 3 is slidably installed on the Y1 mobile system 9, and the B workbench 11 is slidably installed on the Y2 mobile system 14. One end of the Y1 mobile system 9 is connected to the automatic loading system 1, and the other end is connected to the automatic unloading system 10. The Y2 mobile system 14 is the same as the Y1 mobile system 9, and one end is also connected to the automatic loading system 1, and the other end is connected to the automatic unloading system 10, but the loading and unloading directions are opposite to those of the Y1 mobile system 9. A granite beam 8 is installed above the Y1 mobile system 9 and the Y2 mobile system 14, and the granite beam 8 is vertically arranged with the Y1 mobile system 9 and the Y2 mobile system 14. The X1 mobile system 6 is slidably installed on one side of the granite beam 8, and the X2 mobile system 13 is installed on the other side opposite to it. The structured light projection assembly 4 and the camera 5 are slidably installed on the X1 mobile system 6, and the curing structured light 15 and the printing head 16 are slidably installed on the X2 mobile system 13.

[0057] The working process of the equipment is as follows: the automatic feeding system 1 transfers the single-chip circuit board coated with solder resist in the material frame to the A workbench 3 and fixes it; the structured light projection component 4 generates a structured light with the same shape as the solder resist pattern and complementary color to the base material masked by the solder resist. Figure 8 , and project it onto the circuit board, and the camera 5 takes a picture of the structured light projection. If there are places where the solder resist is leaking on the circuit board, such as Fig. 9 , and get the solder mask leak image as Fig.10, the image boundary is processed to generate a printing path; the A workbench 3 moves to the other side of the granite beam 8, and the printing head 16 prints the solder resist at the solder resist leaking area; the curing structured light system generates a structured light with the same shape as the solder resist leaking area to cure the printed solder resist; while the A workbench 3 is printing and curing, the B workbench 11 loads the material and also performs the above-mentioned structured light projection, photography, image processing and printing path generation steps; after the solder resist printing and curing of the A workbench 3 are completed, it returns to the structured light projection area, and the structured light projection group Part 4 and camera 5 project and take pictures of the solder mask area of ​​the circuit board again; at the same time, after the B workbench 11 finishes the projection and photography, it moves to the other side of the granite beam 8, and the printing head 16 prints the solder mask at the gaps in the solder mask, and the curing structured light 15 cures the printing group welding; the above-mentioned structured light projection photography and solder mask gap printing and structured light curing process are alternated and cyclically performed between workbench A and workbench B until the data obtained from the photographed image is completely consistent with the standard data, and the automatic unloading system 10 executes the unloading, and the platform returns and reloads. The above-mentioned process flow is as follows: Fig.11 .

[0058] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept, which all belong to the protection scope of the present invention.

Claims

1. A method for correcting solder resist contamination in a soldering area of ​​a circuit board, characterized in that: Use structured light that is complementary to the shape and color of the solder mask pattern as the light source, use the pattern contour obtained by photography as the boundary, generate a processing path, and laser photoetch to remove the solder mask material. The steps are as follows: (1) Using the CAM data of the circuit board solder mask pattern, a pattern complementary to the shape of the solder mask pattern is generated; (2) generating structured light data using the obtained pattern; (3) Using structured light with a color complementary to the solder mask pattern as a light source, projecting it onto the circuit board, and taking a picture of the structured light projection with a camera; (4) Using the contour of the pattern obtained by photographing as the boundary of the pattern to be removed by laser photoetching, a processing path is generated; (5) using structured laser photolithography to remove the solder resist material forming the above pattern from the welding area; (6) Use structured light with complementary color to the solder mask pattern as the light source to project it onto the circuit board, take a picture of the structured light projection with a camera, and compare the data obtained by taking the picture with the standard data to check the removal effect; (7) Circulate processing or report results; The equipment for implementing the above method includes a data processing system, an equipment operating system, a workpiece and processing head motion control system, an illumination and light curing system, a laser photo-etching removal system, a printing and coating system, a workpiece fixing and automatic and manual loading and unloading system, and a positive pressure and negative pressure cleaning system. The equipment is characterized in that the cross-section of the light used in the illumination and light curing system and the laser photo-etching removal system is a structured light with controlled shape and color, and a DMD device is used to control the transmission and distribution of light. The light is shaped, homogenized and color processed before entering the DMD device. The equipment uses an opaque material to manufacture the machine cover to isolate the ambient light from interfering with the photography. The light used in the laser photo-etching removal system is a laser beam, and the transmission and distribution control of the light is realized by a scanning device. The material storage, transportation and distribution of the printing and coating system are all controlled by constant temperature; it includes: an automatic feeding system (1), a granite platform (2), an A workbench (3), a structured light projection component (4), a camera (5), an X1 mobile system (6), an equipment operation and control system (7), a granite beam (8), a Y1 mobile system (9), an automatic unloading system (10), a B workbench (11), an X2 mobile system (13) and a Y2 mobile system (14), in which a granite A Y1 moving system (9) and a Y2 moving system (14) are fixedly installed on the rock platform (2) in parallel and at intervals. A workbench (3) is slidably installed on the Y1 moving system (9), and a B workbench (11) is slidably installed on the Y2 moving system (14). One end of the Y1 moving system (9) is connected to the automatic loading system (1), and the other end is connected to the automatic unloading system (10). The Y2 moving system (14) is the same as the Y1 moving system (9), and one end is also connected to the automatic loading system (1) and the other end is connected to the automatic unloading system (10), except that the loading and unloading directions are the same as those of the Y1 moving system (9). On the contrary, a granite beam (8) is installed above the Y1 moving system (9) and the Y2 moving system (14), and the granite beam (8) is vertically arranged with the Y1 moving system (9) and the Y2 moving system (14). The X1 moving system (6) is slidably installed on one side of the granite beam (8), and the X2 moving system (13) is installed on the other side opposite thereto. The structured light projection assembly (4) and the camera (5) are slidably installed on the X1 moving system (6), and the structured laser head (12) or the curing structured light (15) and the printing head (16) are slidably installed on the X2 moving system (13).

2. A method for correcting solder mask leakage in the solder mask area of ​​a circuit board, using structured light with the same shape as the solder mask pattern and complementary color to the base material as the light source, taking the pattern contour obtained by photography as the boundary, generating a processing path, and printing the solder mask material, the steps are as follows: (1) Using the CAM data of the circuit board solder mask pattern, generate structured light data with the same shape as the solder mask pattern; (2) Use structured light that is complementary to the color of the base material that should be masked by the solder resist as the light source, project it onto the circuit board, and take a picture of the structured light projection with a camera; (3) Using the outline of the pattern obtained by photographing as the boundary of the processed area, generating a printing path and a light curing path; (4) Printing solder resist material; (5) Use structured light as the light source to cure the printed solder resist material; (6) Use structured light with complementary color to the base material as the light source again, project it onto the circuit board, take a picture of the structured light projection with a camera, and compare the data obtained by taking the picture with the standard data to check the printing effect; (7) Circulate processing or report results; The equipment for implementing the above method includes a data processing system, an equipment operating system, a workpiece and processing head motion control system, an illumination and light curing system, a laser photo-etching removal system, a printing and coating system, a workpiece fixing and automatic and manual loading and unloading system, and a positive pressure and negative pressure cleaning system. The equipment is characterized in that the cross-section of the light used in the illumination and light curing system and the laser photo-etching removal system is a structured light with controlled shape and color, and a DMD device is used to control the transmission and distribution of light. The light is shaped, homogenized and color processed before entering the DMD device. The equipment uses an opaque material to manufacture the machine cover to isolate the ambient light from interfering with the photography. The light used in the laser photo-etching removal system is a laser beam, and the transmission and distribution control of the light is realized by a scanning device. The material storage, transportation and distribution of the printing and coating system are all controlled by constant temperature; it includes: an automatic feeding system (1), a granite platform (2), an A workbench (3), a structured light projection component (4), a camera (5), an X1 mobile system (6), an equipment operation and control system (7), a granite beam (8), a Y1 mobile system (9), an automatic unloading system (10), a B workbench (11), an X2 mobile system (13) and a Y2 mobile system (14), in which a granite A Y1 moving system (9) and a Y2 moving system (14) are fixedly installed on the rock platform (2) in parallel and at intervals. A workbench (3) is slidably installed on the Y1 moving system (9), and a B workbench (11) is slidably installed on the Y2 moving system (14). One end of the Y1 moving system (9) is connected to the automatic loading system (1), and the other end is connected to the automatic unloading system (10). The Y2 moving system (14) is the same as the Y1 moving system (9), and one end is also connected to the automatic loading system (1) and the other end is connected to the automatic unloading system (10), except that the loading and unloading directions are the same as those of the Y1 moving system (9). On the contrary, a granite beam (8) is installed above the Y1 moving system (9) and the Y2 moving system (14), and the granite beam (8) is vertically arranged with the Y1 moving system (9) and the Y2 moving system (14). The X1 moving system (6) is slidably installed on one side of the granite beam (8), and the X2 moving system (13) is installed on the other side opposite thereto. The structured light projection assembly (4) and the camera (5) are slidably installed on the X1 moving system (6), and the structured laser head (12) or the curing structured light (15) and the printing head (16) are slidably installed on the X2 moving system (13).

3. A method for automatic optical inspection and correction of a circuit board solder mask pattern, characterized in that: First repair the solder mask missing in the solder mask area, and then repair the solder mask contamination in the welding area. The method for repairing the missing solder resist in the solder resist area is: using structured light with the same shape as the solder resist pattern and complementary color to the base material as the light source, taking the pattern contour obtained by photography as the boundary, generating a processing path, and spraying the solder resist material; The method for repairing solder resist contamination in the welding area is: using structured light complementary to the shape and color of the solder resist pattern as a light source, taking the pattern contour obtained by photography as a boundary, generating a processing path, and laser photoetching to remove the solder resist material; The equipment for implementing the above method includes a data processing system, an equipment operating system, a workpiece and processing head motion control system, an illumination and light curing system, a laser photo-etching removal system, a printing and coating system, a workpiece fixing and automatic and manual loading and unloading system, and a positive pressure and negative pressure cleaning system. The equipment is characterized in that the cross-section of the light used in the illumination and light curing system and the laser photo-etching removal system is a structured light with controlled shape and color, and a DMD device is used to control the transmission and distribution of light. The light is shaped, homogenized and color processed before entering the DMD device. The equipment uses an opaque material to manufacture the machine cover to isolate the ambient light from interfering with the photography. The light used in the laser photo-etching removal system is a laser beam, and the transmission and distribution control of the light is realized by a scanning device. The material storage, transportation and distribution of the printing and coating system are all controlled by constant temperature; it includes: an automatic feeding system (1), a granite platform (2), an A workbench (3), a structured light projection component (4), a camera (5), an X1 mobile system (6), an equipment operation and control system (7), a granite beam (8), a Y1 mobile system (9), an automatic unloading system (10), a B workbench (11), an X2 mobile system (13) and a Y2 mobile system (14), in which a granite A Y1 moving system (9) and a Y2 moving system (14) are fixedly installed on the rock platform (2) in parallel and at intervals. A workbench (3) is slidably installed on the Y1 moving system (9), and a B workbench (11) is slidably installed on the Y2 moving system (14). One end of the Y1 moving system (9) is connected to the automatic loading system (1), and the other end is connected to the automatic unloading system (10). The Y2 moving system (14) is the same as the Y1 moving system (9), and one end is also connected to the automatic loading system (1) and the other end is connected to the automatic unloading system (10), except that the loading and unloading directions are the same as those of the Y1 moving system (9). On the contrary, a granite beam (8) is installed above the Y1 moving system (9) and the Y2 moving system (14), and the granite beam (8) is vertically arranged with the Y1 moving system (9) and the Y2 moving system (14). The X1 moving system (6) is slidably installed on one side of the granite beam (8), and the X2 moving system (13) is installed on the other side opposite thereto. The structured light projection assembly (4) and the camera (5) are slidably installed on the X1 moving system (6), and the structured laser head (12) or the curing structured light (15) and the printing head (16) are slidably installed on the X2 moving system (13).

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