Defect online detection method and system in PCB production process and computer equipment

Abstract

The invention relates to the technical field of PCB detection, and discloses an online defect detection method and system in the PCB production process and computer equipment, the detection accuracy can be improved by combining production parameters, image information and a design circuit diagram, potential defects can be found in the early stage, the PCB is divided into a plurality of areas, and the detection efficiency is improved. According to the PCB, each area can be independently welded and detected, the complexity of the whole PCB is reduced, the PCB is divided into a plurality of areas which are detected one by one, a specific defect area can be effectively positioned, through the regionalized detection and maintenance process, the unqualified area can be locally processed, the production efficiency is improved, and the production cost is reduced. By adopting the strategy based on multi-round detection, feedback and regional repair, through accurate positioning, local repair, detection efficiency improvement and automatic processing, the rejection rate of unqualified products is greatly reduced, the maintenance success rate is improved, and the problems of difficulty in PCB defect detection and resource waste in the prior art can be effectively solved.

Description

Technical Field

[0001] The present application relates to the technical field of PCB detection, and in particular to an online defect detection method, system and computer equipment in a PCB production process. Background Art

[0002] With the development of electronic product technology, the trend of surface mounting and miniaturization of components is becoming more and more obvious, and the density of products is also increasing. In the production process of PCB, the first step is to make a PCB bare board, which is provided with welding holes for welding components on the PCB bare board. After all components are welded, the PCB is obtained, and then the PCB is tested for defects. Although this detection method can detect defective products, due to the increasing precision of PCB, even if defective products are detected, it is difficult to repair them and they can only be scrapped, which causes a huge waste of resources. Summary of the invention

[0003] The present application provides an online defect detection method in a PCB production process, aiming to solve the technical problems in the prior art.

[0004] The present application provides a method for online defect detection in a PCB production process, comprising:

[0005] Obtain production parameter information and board image information of the target PCB board when production is completed;

[0006] Generate a first test result according to the production parameter information and the light board image, wherein the first test result includes qualified and unqualified;

[0007] Obtain location information of multiple electronic components on unqualified PCB bare boards and design circuit diagrams;

[0008] According to the design circuit diagram and the position information of the electronic components, the PCB light board is divided according to the preset conditions to obtain multiple divided areas;

[0009] Selecting a divided area from multiple divided areas as a target area according to a preset rule, and obtaining any electronic components corresponding to the target area;

[0010] Solder and install any electronic components according to the electronic component position information in the corresponding target area to obtain a regional PCB, and perform a functional test on the regional PCB to obtain a second test result;

[0011] Determine whether the second detection result meets the preset requirements;

[0012] If satisfied, return to the step of selecting one divided area from the multiple divided areas as the target area according to the preset rule, until all divided areas are traversed to obtain the PCB;

[0013] If not, the defect cause is generated according to the second detection result, and the regional PCB corresponding to the second detection result is transferred to the maintenance station.

[0014] Preferably, the step of generating the first detection result according to the production parameter information and the light board image comprises:

[0015] Obtain PCB layer number information, board material information and mechanical strength information based on production parameter information;

[0016] Obtaining comprehensive mechanical stress according to the mechanical strength information, PCB layer number information and plate information;

[0017] Determining whether the comprehensive mechanical stress meets the first production standard index;

[0018] If the comprehensive mechanical stress meets the first production standard index, obtaining PCB bare board size information, PCB solder hole information and silk screen information according to the bare board image information;

[0019] Obtaining hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information;

[0020] Determining whether the hole position deviation meets the second production standard index;

[0021] If the light board image information meets the second production standard index, the first detection result of the PCB light board is determined to be qualified;

[0022] If the production parameter information does not meet the first production standard index, the first detection result of the PCB bare board is determined to be unqualified.

[0023] Preferably, the step of obtaining the comprehensive mechanical stress according to the mechanical strength information, the PCB layer number information and the plate material information comprises:

[0024] Obtaining bending strength, peel strength and water absorption rate according to the mechanical strength information;

[0025] Obtaining mechanical performance indicators according to the bending strength, peel strength and water absorption rate;

[0026] Acquire shear stress according to the mechanical performance index, and acquire bending stress according to the PCB layer number information;

[0027] The plate thickness, heat flow, heat transfer area, thermal conductivity and thermal expansion coefficient are obtained according to the plate information, and the temperature difference is calculated according to the plate thickness, heat flow, heat transfer area and thermal conductivity, wherein the calculation formula is:

[0028]

[0029] Where W(C) represents the temperature difference, R(L) represents the heat flow, B(H) represents the plate thickness, C(M) represents the heat transfer area, and R(D) represents the thermal conductivity;

[0030] Obtaining thermal stress according to the temperature difference, thermal expansion coefficient and bending modulus;

[0031] The comprehensive mechanical stress is calculated based on the thermal stress, bending stress and shear stress, wherein the calculation formula is:

[0032]

[0033] Among them, Z(YL) represents the comprehensive mechanical stress, W(YL) represents the bending stress, J(YL) represents the shear stress, and R(YL) represents the thermal stress.

[0034] Preferably, the step of obtaining shear stress according to the mechanical performance index and obtaining bending stress according to the PCB layer number information comprises:

[0035] Obtaining bending modulus and shear characteristics according to the mechanical performance index, and obtaining bending moment according to the bending modulus;

[0036] Acquire shear strength and shear area according to the shear characteristics, and acquire shear cross-sectional area according to the shear area;

[0037] Obtaining shear force according to the shear strength and the shear cross-sectional area, and obtaining shear stress according to the shear force and the shear area;

[0038] Acquire the wiring density and the number of PCB layers according to the PCB layer number information, and acquire the distance of the wiring from the neutral axis, the wiring width, and the wiring thickness according to the wiring density;

[0039] Acquire the wiring cross-sectional area according to the wiring width and the wiring thickness, and acquire the section moment of inertia according to the wiring cross-sectional area and the distance of the wiring from the neutral axis;

[0040] The bending stress is calculated according to the number of PCB layers, the moment of inertia of the cross section, the distance of the wiring from the neutral axis and the bending moment, wherein the calculation formula is:

[0041]

[0042] Where W(YL) represents bending stress, W(J)i represents the i-th bending moment, B(J) i represents the distance of the i-th wiring from the neutral axis, J(G) i It represents the i-th section moment of inertia, i represents the sequence number of the section moment of inertia, and N represents the number of PCB layers.

[0043] Preferably, the step of dividing the PCB light board according to preset conditions according to the design circuit diagram and the electronic component position information to obtain a plurality of divided areas comprises:

[0044] Acquire multiple circuit modules according to the designed circuit diagram;

[0045] Marking the position of the electronic components corresponding to each circuit module in the PCB optical board to obtain multiple marking areas;

[0046] Obtaining the function type of the electronic components in each marked area, and determining whether the function type belongs to the power control type;

[0047] If the function type belongs to the power control type, the marked area is marked as a power control module area, and the load current of each power control module area is obtained;

[0048] Setting a preset current interval and comparing it with the load current;

[0049] If the load current is less than the lower limit of the preset current interval, the corresponding power control module area is divided into a low current division area;

[0050] If the load current is within the preset current interval, the corresponding power control module area is divided into a stable current division area;

[0051] If the load current is greater than the upper limit of the preset current interval, the corresponding power control module area is divided into a high current division area;

[0052] If the function type does not belong to the power control type, the marked area is marked as a signal execution module area, and the length, inductance and capacitance of the transmission line of each signal execution module area are obtained;

[0053] Acquire a signal transmission speed according to the inductance and capacitance, and acquire a signal propagation delay according to the signal transmission speed and length;

[0054] Setting a preset propagation delay interval and comparing it with the signal propagation delay;

[0055] If the signal propagation delay is less than the lower limit of the preset propagation delay interval, the corresponding signal execution module area is divided into a low-frequency signal division area;

[0056] If the signal propagation delay is within the preset propagation delay interval, the corresponding signal execution module area is divided into intermediate frequency signal division areas;

[0057] If the signal propagation delay is greater than an upper limit value of a preset propagation delay interval, the corresponding signal execution module area is divided into a high-frequency signal division area.

[0058] Preferably, the step of performing functional testing on the regional PCB to obtain a second test result comprises:

[0059] Acquiring electrical performance characteristics of the regional PCB, wherein the electrical performance characteristics include load impedance, characteristic impedance, transmission line effect, and conductivity;

[0060] Obtaining a reflection coefficient according to the load impedance and the characteristic impedance, and obtaining a reflection loss according to the reflection coefficient and the transmission line effect;

[0061] obtaining electrical conductivity according to the electrical conductivity;

[0062] Obtaining resistance according to the characteristic impedance, and obtaining current carrying capacity according to the resistance and conductivity;

[0063] A second detection result is obtained according to the reflection loss and the current carrying capacity.

[0064] The present application also provides an online defect detection system in a PCB production process, comprising:

[0065] The first acquisition module is used to acquire production parameter information and image information of the target PCB light board when the production is completed;

[0066] A generating module, used for generating a first detection result according to the production parameter information and the light board image, wherein the first detection result includes qualified and unqualified;

[0067] The second acquisition module is used to obtain the position information of multiple electronic components and the design circuit diagram on the unqualified PCB bare board;

[0068] A division module is used to divide the PCB light board according to preset conditions according to the design circuit diagram and the position information of the electronic components to obtain multiple division areas;

[0069] A selection module, used to select a divided area from multiple divided areas as a target area according to a preset rule, and obtain any electronic components corresponding to the target area;

[0070] A detection module is used to weld and install any electronic components according to the position information of the electronic components in the corresponding target area to obtain a regional PCB, and perform a functional test on the regional PCB to obtain a second test result;

[0071] A judging module, used to judge whether the second detection result meets the preset requirements;

[0072] If satisfied, return to the step of selecting one divided area from the multiple divided areas as the target area according to the preset rule, until all divided areas are traversed to obtain the PCB;

[0073] If not, the defect cause is generated according to the second detection result, and the regional PCB corresponding to the second detection result is transferred to the maintenance station.

[0074] Preferably, the generating module comprises:

[0075] A first acquisition unit is used to acquire PCB layer number information, plate material information and mechanical strength information according to production parameter information;

[0076] A second acquisition unit is used to acquire comprehensive mechanical stress according to the mechanical strength information, PCB layer number information and plate information;

[0077] A first judging unit, used to judge whether the comprehensive mechanical stress meets a first production standard index;

[0078] If the comprehensive mechanical stress meets the first production standard index, obtaining PCB bare board size information, PCB solder hole information and silk screen information according to the bare board image information;

[0079] A third acquisition unit is used to acquire the hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information;

[0080] A second judging unit, used to judge whether the hole position deviation meets a second production standard index;

[0081] If the light board image information meets the second production standard index, the first detection result of the PCB light board is determined to be qualified;

[0082] If the production parameter information does not meet the first production standard index, the first detection result of the PCB bare board is determined to be unqualified.

[0083] The present application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0084] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0085] The beneficial effects of the present application are as follows: the present invention can improve the accuracy of detection by combining production parameters, image information and design circuit diagrams, so that potential defects can be discovered at an early stage. For detected unqualified PCBs, through detailed regional division and accurate defect positioning, it is possible to identify which parts need to be repaired. By dividing the PCB into multiple regions, each region can be welded and tested separately, reducing the complexity of the entire PCB. Through regional division, it is easier to locate the specific target area when a problem occurs, thereby achieving accurate troubleshooting and repair. Through functional testing, the performance of the regional PCB can be effectively verified in a local range. By dividing the PCB into multiple regions and testing them one by one, the specific defective area can be effectively located. Through this regionalized detection and repair process, unqualified areas can be locally processed to improve production efficiency. By adopting this strategy based on multiple rounds of detection, feedback and regional repair, the scrap rate of unqualified products is greatly reduced, and the repair success rate is improved through accurate positioning, local repair, improved detection efficiency and automated processing. It can effectively solve the problems of difficult PCB defect detection, complex repair, and waste of resources in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 The figure is a schematic diagram of a method flow of an embodiment of the present application.

[0087] Figure 2 Schematic diagram of the device structure of an embodiment of the present application.

[0088] Figure 3 A schematic diagram of the internal structure of a computer device according to an embodiment of the present application.

[0089] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0090] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0091] like Figure 1-Figure 3 As shown, the present application provides a method for online defect detection in a PCB production process, comprising:

[0092] S1, obtaining production parameter information and image information of the target PCB board when production is completed;

[0093] S2. Generate a first test result according to the production parameter information and the light board image, wherein the first test result includes qualified and unqualified;

[0094] S3, obtaining location information of multiple electronic components on the unqualified PCB bare board and a design circuit diagram;

[0095] S4, dividing the PCB light board according to preset conditions according to the design circuit diagram and the position information of the electronic components to obtain multiple divided areas;

[0096] S5. Select one divided area from the multiple divided areas as a target area according to a preset rule, and obtain any electronic components corresponding to the target area;

[0097] S6, welding and installing any electronic components according to the electronic component position information in the corresponding target area to obtain a regional PCB, and performing a functional test on the regional PCB to obtain a second test result;

[0098] S7, determining whether the second detection result meets the preset requirements;

[0099] If satisfied, return to the step of selecting one divided area from the multiple divided areas as the target area according to the preset rule, until all divided areas are traversed to obtain the PCB;

[0100] If not, the defect cause is generated according to the second detection result, and the regional PCB corresponding to the second detection result is transferred to the maintenance station.

[0101] As described in the above steps S1-S2, with the development of electronic product technology, the trend of surface mounting and miniaturization of components is becoming more and more obvious, and the density of products is also increasing. In the production process of PCB, the first step is to make a PCB bare board, which is provided with welding holes, and the welding holes are used to weld components on the PCB bare board. When all components are welded, the PCB is obtained, and then the PCB is tested for defects. Although this detection method can detect defective products, due to the increasing precision of PCB, even if defective products are detected, the difficulty of repair is relatively large, and they can only be scrapped, which causes a huge waste of resources. The present invention obtains production parameter information and board image information of a target PCB board when production is completed, and generates a first detection result according to the production parameter information and the board image. The first detection result includes qualified and unqualified. This method can identify potential problems earlier, and can effectively judge whether the quality meets expectations in the early stage after the PCB production is completed, avoiding the waste of resources when defects can only be discovered in the later stage by the traditional method. By obtaining the position information of multiple electronic components and the design circuit diagram on the unqualified PCB board, and dividing the PCB board according to preset conditions according to the design circuit diagram and the position information of the electronic components to obtain multiple divided areas, this can help accurately locate the fault area and identify which parts of the components have potential problems. Compared with the traditional method based on overall detection, this method based on regional division can find problems more carefully, avoiding false alarms or missed alarms caused by overall misjudgment. As the complexity of the PCB increases, simply through surface observation or traditional detection methods (such as relying only on the detection of welding holes and connection points) may not be able to accurately identify all defects. By combining production parameters, image information and design circuit diagrams, The accuracy of detection can be improved, so that potential defects can be discovered in the early stage, avoiding the high cost and difficulty of later maintenance. For unqualified PCBs detected, detailed area division and accurate defect positioning can be used to identify which parts need to be repaired. Accurate detection avoids a large amount of resource waste caused by the scrapping of the entire board in traditional methods. By selecting a divided area as the target area from multiple divided areas according to preset rules, and obtaining any electronic components corresponding to the target area, any electronic components are welded and installed according to the electronic component position information in the corresponding target area to obtain a regional PCB, and then the regional PCB is functionally tested to obtain a second test result. By dividing the PCB into multiple areas, each area can be welded and tested separately, reducing the complexity of the entire PCB. Through regional division, it is easier to locate the specific target area when a problem occurs, thereby achieving accurate troubleshooting and repair. The traditional PCB overall detection method may require repeated detection of the entire board, while this regionalized method greatly improves the efficiency of problem location by concentrating on detecting specific areas.Since the electronic components of each area are soldered and installed according to the location information in the area, maintenance personnel can quickly identify and repair defects in specific areas without having to deal with the entire circuit board. This local repair method avoids the high cost and difficulty of replacing the entire PCB, while reducing the potential risks caused by improper maintenance. Through functional testing, the performance of the regional PCB can be effectively verified in a local range, so that even if a problem occurs in a certain area, it can be discovered and handled in time through functional testing, while traditional overall testing may have the risk of missing the problem area, resulting in missed detection or incomplete detection. By judging whether the second test result meets the preset requirements If the requirement is met, the system returns to the step of selecting a divided area from the multiple divided areas as the target area according to the preset rule, until all the divided areas are traversed to obtain the PCB. If it is not met, the defect cause is generated according to the second detection result, and the PCB in the area corresponding to the second detection result is transmitted to the maintenance station. By dividing the PCB into multiple areas and detecting them one by one, the specific defective area can be effectively located. If an area fails to meet the detection requirements, the system will generate a defect cause and transmit the problem area to the maintenance station for repair. Compared with the traditional overall detection, this method can find problems more carefully and avoid the waste of scrapping due to overall failure. The current traditional inspection method often has to choose to scrap the entire PCB when defects are found, especially on complex and precise PCBs, which will lead to a large waste of resources. However, through this regional inspection and repair process, the unqualified area can be locally processed, and only the problematic part instead of the entire PCB can be repaired, thereby greatly reducing resource waste and improving production efficiency. Through multiple rounds of judgment and feedback mechanisms, each inspection can be more accurately focused on a specific area until all areas are tested to meet the preset requirements. Compared with testing all areas at one time, this process of gradual optimization and refined repair not only improves the accuracy of repair, but also avoids the problem of one-time treatment. Failed repairs or more resource waste caused by improper management. By automatically generating the cause of the defect based on the second test result and transmitting it to the maintenance station, maintenance personnel can quickly understand the specific defect type and location, and achieve more efficient processing. Targeted maintenance can significantly improve the repair efficiency, avoid blind repairs or wrong repairs, and reduce maintenance time and costs. Therefore, this strategy based on multi-round detection, feedback and regional repairs can greatly reduce the scrap rate of unqualified products and improve the repair success rate through precise positioning, local repairs, improved detection efficiency and automated processing. It can effectively solve the problems of difficult PCB defect detection, complex maintenance, and resource waste in the existing technology.

[0102] In one embodiment, the step S2 of generating the first detection result according to the production parameter information and the light board image includes:

[0103] S21, obtaining PCB layer number information, board material information and mechanical strength information according to production parameter information;

[0104] S22, obtaining comprehensive mechanical stress according to the mechanical strength information, PCB layer number information and plate information;

[0105] S23, judging whether the comprehensive mechanical stress meets the first production standard index;

[0106] If the comprehensive mechanical stress meets the first production standard index, obtaining PCB bare board size information, PCB solder hole information and silk screen information according to the bare board image information;

[0107] S24, obtaining hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information;

[0108] S25, judging whether the hole position deviation meets the second production standard index;

[0109] If the light board image information meets the second production standard index, the first detection result of the PCB light board is determined to be qualified;

[0110] If the production parameter information does not meet the first production standard index, the first detection result of the PCB bare board is determined to be unqualified.

[0111] As described in the above steps S21-S25, the present invention obtains PCB layer information, plate information and mechanical strength information through production parameter information, and obtains comprehensive mechanical stress based on the mechanical strength information, PCB layer information and plate information. By obtaining parameters such as layer information, plate information and mechanical strength in real time during the production process, the mechanical properties of the PCB can be evaluated at an early stage. Comprehensive mechanical stress analysis helps to identify potential weak links or design defects, and can clarify weak areas of plates and structures, helping maintenance personnel to locate fault locations more accurately, avoiding PCB failures caused by unreasonable structures or excessive stress in the later stage, and judging whether the comprehensive mechanical stress meets the first production standard index. If so, according to the light board image information Obtain PCB bare board size information, PCB solder hole information and silk screen information, and obtain hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information, and then judge whether the hole position deviation meets the second production standard index, if it meets, the first detection result of the PCB bare board is judged as qualified, otherwise, the first detection result of the PCB bare board is judged as unqualified, wherein the method for obtaining hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information is specifically to obtain the PCB bare board size deviation through the PCB bare board size information, obtain the solder hole information deviation through the PCB solder hole information and obtain the silk screen alignment deviation through the silk screen information, and then obtain the sum of the PCB bare board size deviation, the solder hole information deviation and the silk screen alignment deviation, that is, The hole position deviation can be calculated. By comprehensively considering the impact of mechanical stress on PCB during the production stage, potential structural problems can be identified at an early stage, which helps to correct improper operations in the production process in a timely manner, avoid cracks or other defects caused by stress, and reduce the production of defective products in the later stage. By obtaining the image information of the light board, the key information such as the size, solder holes and silk screen of the PCB can be accurately analyzed. With this information, problems such as solder hole deviation and size discrepancy can be detected, so as to find out the deviation that may occur in production early. Through accurate defect detection and evaluation, a more accurate judgment can be made on the qualification of the PCB, so that repair measures can be taken when it can be repaired to avoid unnecessary scrapping. Through the judgment of the first and second production standard indexes, The consistency and standardization of the inspection process can be guaranteed, so that every PCB in the production process can meet high quality requirements. When a PCB is found to be unqualified, if the specific cause of the problem (such as hole position deviation, size error, etc.) can be determined in advance, the problem can be repaired or adjusted more accurately instead of being completely scrapped. This method can effectively improve the repair ability of the production line and avoid excessive scrapping of irreparable PCBs. Through the comprehensive use of light board image analysis, size information and solder hole information, potential defects or deviations can be located very accurately, which can help later maintenance personnel quickly and accurately identify problems when facing complex and high-precision PCBs, reduce maintenance difficulty, and improve maintenance efficiency.

[0112] In one embodiment, the step S22 of acquiring the comprehensive mechanical stress according to the mechanical strength information, the PCB layer number information and the plate material information includes:

[0113] S221, obtaining bending strength, peel strength and water absorption rate according to the mechanical strength information;

[0114] S222, obtaining mechanical performance indicators according to the bending strength, peel strength and water absorption rate;

[0115] S223, obtaining shear stress according to the mechanical performance index, and obtaining bending stress according to the PCB layer number information;

[0116] S224. Obtain the plate thickness, heat flow, heat transfer area, thermal conductivity and thermal expansion coefficient according to the plate information, and calculate the temperature difference according to the plate thickness, heat flow, heat transfer area and thermal conductivity, wherein the calculation formula is:

[0117]

[0118] Where W(C) represents the temperature difference, R(L) represents the heat flow, B(H) represents the plate thickness, C(M) represents the heat transfer area, and R(D) represents the thermal conductivity;

[0119] S225, calculating thermal stress according to the temperature difference, thermal expansion coefficient and bending modulus, wherein the calculation formula is:

[0120] R(YL)=W(C)*R(X)*W(Q);

[0121] Among them, R(YL) represents thermal stress, W(C) represents temperature difference, R(X) represents thermal expansion coefficient, and W(Q) represents bending modulus;

[0122] S226. Calculate the comprehensive mechanical stress according to the thermal stress, bending stress and shear stress, wherein the calculation formula is:

[0123]

[0124] Among them, Z(YL) represents the comprehensive mechanical stress, W(YL) represents the bending stress, J(YL) represents the shear stress, and R(YL) represents the thermal stress.

[0125] As described in the above steps S221-S226, the present invention obtains bending strength, peel strength and water absorption rate through mechanical strength information, and obtains mechanical performance indicators based on bending strength, peel strength and water absorption rate, obtains shear stress through mechanical performance indicators, and obtains bending stress through PCB layer number information, wherein bending strength is the ability of a material to break under bending load, and is usually used to evaluate the bending resistance and structural stability of a PCB, peel strength is an important indicator for evaluating the interlayer bonding strength of a PCB, and mainly measures the degree of bonding firmness between different layers, and water absorption rate refers to the ability of a material to absorb water under certain conditions, and is usually used to evaluate the performance stability of a PCB in a humid environment. Through physical parameters such as mechanical strength and water absorption rate, the structural performance of a PCB can be more accurately predicted and analyzed. This method does not rely on the traditional "scrap if there is a problem" model, but can analyze the performance and defects of a PCB from multiple dimensions. For example, bending strength and peel strength can be used to determine whether a PCB has structural defects during the production process, thereby providing a theoretical basis for maintenance and repair, reducing the situation of complete scrapping, and by predicting potential defects in advance, it is possible to identify which PCBs have defects. The defects can be restored to their normal functions through repair, avoiding unnecessary scrapping, thereby reducing resource consumption in the production process. Analyzing the potential problems of PCB based on mechanical performance indicators helps to accurately locate the defect type and location of PCB, so that the repair can be more targeted and avoid blind repair or wrong repair. This not only improves the maintenance efficiency, but also reduces the difficulty of maintenance, because maintenance personnel can accurately identify whether there is bad welding, mechanical damage or other structural problems based on indicators such as shear stress and bending stress, thereby reducing the maintenance cost caused by unclear fault diagnosis. The plate thickness, heat flow, heat transfer area, thermal conductivity and thermal expansion coefficient are obtained through plate information, and the temperature difference is calculated based on the plate thickness, heat flow, heat transfer area and thermal conductivity. The thermal stress is calculated by the temperature difference, thermal expansion coefficient and bending modulus, and the comprehensive mechanical stress is calculated based on the thermal stress, bending stress and shear stress. Among them, the parameters are normalized in the calculation formulas of the above temperature difference, thermal stress and comprehensive mechanical stress. The existing technology often relies on directly scrapping after the PCB defects are found, resulting in a large amount of electronic components. Waste, especially in the production of high-precision, multi-layer PCBs.However, by accurately calculating mechanical stresses such as thermal stress and bending stress, it is possible to more accurately determine which PCB problems are repairable rather than directly scrapping them, which can greatly reduce unnecessary waste of resources. By combining factors such as heat flow, heat transfer area, thermal conductivity, and thermal expansion coefficient to calculate temperature difference and thermal stress, and then evaluating the quality of the PCB based on the comprehensive mechanical stress, the accuracy and reliability of defect detection can be improved. This can not only avoid missed inspections, but also detect potential problems in a timely manner and reduce the flow of defects into downstream links. When a PCB is judged to be unqualified, traditional methods often only rely on simple size and solder hole deviation detection, while ignoring more complex factors such as thermal stress. By calculating thermal stress, bending stress, and shear stress, PCB defects can be clearly identified. The specific type and source of the defect can help maintenance personnel to carry out repairs more targetedly instead of blindly. Accurate thermal stress and mechanical stress calculations can help the production line identify possible problem areas in advance, avoid defects in the later stages of production, and lead to rework, repair or scrap. By predicting and avoiding these potential problems in the early stages of production, downtime can be reduced, production processes can be optimized, and production efficiency can be improved. Therefore, by combining the thermal and mechanical properties data of the board to calculate the temperature difference, thermal stress, bending stress, etc., and finally obtaining the comprehensive mechanical stress, a more comprehensive and accurate detection method can be provided for the PCB production process. This method can improve the accuracy of defect detection, reduce resource waste, optimize the maintenance process, improve production efficiency, and reduce the environmental burden.

[0126] In one embodiment, the step S223 of acquiring shear stress according to the mechanical performance index and acquiring bending stress according to the PCB layer number information includes:

[0127] S2231, obtaining a bending modulus and a shear characteristic according to the mechanical performance index, and obtaining a bending moment according to the bending modulus;

[0128] S2232, obtaining a shear strength and a shear area according to the shear characteristics, and obtaining a shear cross-sectional area according to the shear area;

[0129] S2233, obtaining a shear force according to the product of the shear strength and the shear cross-sectional area, and obtaining a shear stress according to a quotient obtained by dividing the shear force and the shear area;

[0130] S2234, obtaining a wiring density and a number of PCB layers according to the PCB layer number information, and obtaining a distance of the wiring from the neutral axis, a wiring width, and a wiring thickness according to the wiring density;

[0131] S2235, obtaining a wiring cross-sectional area according to the wiring width and the wiring thickness, and obtaining a section moment of inertia according to the wiring cross-sectional area and the distance of the wiring from the neutral axis;

[0132] S2236. Calculate the bending stress according to the number of PCB layers, the moment of inertia of the cross section, the distance of the wiring from the neutral axis, and the bending moment, wherein the calculation formula is:

[0133]

[0134] Where W(YL) represents bending stress, W(J) i represents the i-th bending moment, B(J) i represents the distance of the i-th wiring from the neutral axis, J(G) i It represents the i-th section moment of inertia, i represents the sequence number of the section moment of inertia, and N represents the number of PCB layers.

[0135] As described in the above steps S2231-S2236, the present invention obtains the bending modulus and shear characteristics through mechanical performance indicators, and obtains the bending moment according to the bending modulus, obtains the shear strength and shear area through the shear characteristics, and obtains the shear cross-sectional area according to the shear area, obtains the shear force through the product of the shear strength and the shear cross-sectional area, and obtains the shear stress according to the quotient after dividing the shear force and the shear area, wherein the bending modulus refers to the stiffness of the material, which determines the degree of deformation of the material when subjected to force, the shear strength refers to the material's ability to resist damage under shear load, the bending moment is an important parameter of the bending effect caused by external loads (such as force or moment), and the shear area refers to the area where the shear force acts. In structural analysis, the shear area usually refers to The effective shear area on the cross section of the structural object, through the bending modulus, shear strength and other mechanical performance indicators to analyze the PCB, can more accurately evaluate the structure and material state of the PCB from the physical properties. Through mechanical performance testing, small defects in the PCB can be found at an early stage, even when the electrical performance is not completely failed, possible structural weaknesses or cracks, which helps to locate the specific location of the problem (such as welding points, contact points, substrate cracks, etc.), rather than just surface defects. By analyzing the mechanical properties of each PCB, not only can the accuracy of defect detection be improved, but also unqualified components or circuit boards can be screened out earlier in the production process, avoiding more subsequent processing or more serious failures, ensuring improved production efficiency, and through The wiring density and the number of PCB layers are obtained through the PCB layer information, and the distance of the wiring from the neutral axis, the wiring width and the wiring thickness are obtained according to the wiring density. The wiring cross-sectional area is obtained through the wiring width and the wiring thickness, and the section moment of inertia is obtained according to the wiring cross-sectional area and the distance of the wiring from the neutral axis. The bending stress is calculated according to the number of PCB layers, the section moment of inertia, the distance of the wiring from the neutral axis and the bending moment. Among them, the wiring density usually refers to the density of circuit traces in the PCB (such as the trace length or density per unit area), which affects the thermal distribution and mechanical stress of the PCB. The distance from the neutral axis refers to the vertical distance from each point on the cross section to the neutral axis during the bending process. The neutral axis is the area where no tensile or compressive deformation occurs during the bending process. The section moment of inertia is related to A quantity related to the shape and geometric properties of the structural cross-section. It reflects the resistance of the cross-section to bending. The parameters in the above bending stress calculation formula are normalized. Through detailed calculation of parameters such as wiring density, wiring width, and wiring thickness, the stress and deformation of the PCB in actual use can be predicted more accurately, especially when subjected to external force or heat load. This helps to discover potential structural defects in the design stage and avoid over-reliance on later quality inspections. By optimizing the design of the PCB structure, electrical performance problems (such as signal interference, short circuit or open circuit) and mechanical performance problems (such as deformation or cracks of the PCB board caused by stress) caused by unreasonable wiring can be reduced, which can significantly improve the reliability of the PCB and reduce the failure rate.By calculating the mechanical properties and stress of wiring, the wiring and PCB layer number can be optimized, thereby reducing unnecessary material waste and manufacturing costs. By calculating bending stress and section inertia moment, etc., more durable, bending-resistant and fatigue-resistant PCBs can be designed, which helps improve the reliability of PCBs in long-term use, especially when affected by factors such as vibration, thermal expansion or external pressure. Accurate wiring density and thickness calculation can help designers optimize heat distribution and avoid electrical failures or mechanical damage caused by local overheating, which can improve the long-term stability of PCBs in high-load, high-temperature environments.

[0136] In one embodiment, the step S4 of dividing the PCB light board according to preset conditions according to the design circuit diagram and the electronic component position information to obtain a plurality of divided areas includes:

[0137] S41, obtaining multiple circuit modules according to the designed circuit diagram;

[0138] S42, marking the position of the electronic components corresponding to each circuit module in the PCB optical board to obtain a plurality of marking areas;

[0139] S43, obtaining the function type of the electronic components in each marked area, and determining whether the function type belongs to the power control type;

[0140] S44, if the function type belongs to the power control type, then mark the marked area as a power control module area, and obtain the load current of each power control module area;

[0141] S45, setting a preset current interval, and comparing it with the load current;

[0142] If the load current is less than the lower limit of the preset current interval, the corresponding power control module area is divided into a low current division area;

[0143] If the load current is within the preset current interval, the corresponding power control module area is divided into a stable current division area;

[0144] If the load current is greater than the upper limit of the preset current interval, the corresponding power control module area is divided into a high current division area;

[0145] S46. If the function type does not belong to the power control type, the marked area is marked as a signal execution module area, and the length, inductance and capacitance of the transmission line of each signal execution module area are obtained;

[0146] S47, obtaining a signal transmission speed according to the inductance and the capacitance, and obtaining a signal propagation delay according to the signal transmission speed and the length;

[0147] S48, setting a preset propagation delay interval, and comparing it with the signal propagation delay;

[0148] If the signal propagation delay is less than the lower limit of the preset propagation delay interval, the corresponding signal execution module area is divided into a low-frequency signal division area;

[0149] If the signal propagation delay is within the preset propagation delay interval, the corresponding signal execution module area is divided into intermediate frequency signal division areas;

[0150] If the signal propagation delay is greater than an upper limit value of a preset propagation delay interval, the corresponding signal execution module area is divided into a high-frequency signal division area.

[0151] As described in the above steps S41-S48, the present invention obtains multiple circuit modules by designing a circuit diagram, and identifies the position of the electronic components corresponding to each circuit module in the PCB optical board to obtain multiple identification areas, by obtaining the function type of the electronic components in each identification area, and judging whether the function type belongs to the power control type, if it does, the identification area is calibrated as the power control module area, and the load current of each power control module area is obtained, by setting a preset current interval and comparing it with the load current, if it is less than the lower limit of the preset current interval, the corresponding power control module area is divided into a low current division area, if it is within the preset current interval, the corresponding power control module area is divided into a stable current division area, if it is greater than the upper limit of the preset current interval, the corresponding power control module area is divided into a high current division area, by clearly identifying the function of the power control module in the circuit design stage, and further subdividing the areas of different current intervals, it can be used in the production process. The current status of each area can be monitored more accurately during the process, which makes it possible to discover potential current anomalies or circuit faults earlier, rather than waiting until the entire PCB is produced before conducting an overall test. This can reduce the workload of PCB repair, and can also locate the problem area in time, improve the detection efficiency, and judge the operating status of the power control module by the preset current interval, and can repair or rework in time when the current deviates from the preset interval, which can effectively avoid the scrapping of defective products, thereby greatly reducing the waste of resources. For example, the area of ​​the high current interval can be readjusted or corrected without scrapping the entire PCB. The current interval division of the power control module area can help better optimize the power design and management. The division of different current intervals helps to analyze the load capacity of each module and ensure that the power module works within a reasonable load range, thereby improving the stability and reliability of the overall system. By marking and dividing the power control module in detail, more accurate fault isolation can be achieved.For example, if a problem occurs in a power control module, the system can clearly determine whether the module belongs to the low current, stable current or high current range, so as to carry out targeted troubleshooting and repair. This method effectively avoids blind spots and misdiagnosis that may occur in traditional PCB detection. If the function type does not belong to the power control type, the identification area is marked as the signal execution module area, and the length, inductance and capacitance of the transmission line of each signal execution module area are obtained, the signal transmission speed is obtained through the inductance and capacitance, and the signal propagation delay is obtained according to the signal transmission speed and length. By setting a preset propagation delay interval and comparing it with the signal propagation delay, if it is less than the lower limit of the preset propagation delay interval, the corresponding signal execution module area is divided into a low-frequency signal division area. If it is within the preset propagation delay interval, the corresponding signal execution module area is divided into an intermediate-frequency signal division area. If it is greater than the upper limit of the preset propagation delay interval, the corresponding signal execution module area is divided into a high-frequency signal division area. Signal division area, by calculating the length, inductance and capacitance of the transmission line of each signal execution module area, the signal transmission speed and signal propagation delay can be accurately calculated, which can help designers better control the signal transmission characteristics of each part of the circuit, avoid excessive signal propagation delay in the circuit, and thus avoid possible signal distortion or timing errors. According to the signal transmission delay, the system can divide the signal execution module area into low-frequency, medium-frequency and high-frequency signal areas, which helps to reasonably distribute and manage signals of different frequencies, avoid mutual interference between high-frequency signals and low-frequency signals or unnecessary transmission errors, thereby improving the stability and performance of the overall circuit. By optimizing the signal transmission path, faults or defective products caused by signal interference and transmission delays are reduced. Accurate signal management and delay control enable PCB to effectively avoid defects and problems that occur later in the design stage, which not only improves manufacturing efficiency, but also reduces the waste of resources for scrapping and rework, and reduces costs.

[0152] In one embodiment, the step S6 of performing functional testing on the regional PCB to obtain a second test result includes:

[0153] S61, obtaining electrical performance characteristics of the regional PCB, wherein the electrical performance characteristics include load impedance, characteristic impedance, transmission line effect, and conductivity;

[0154] S62, obtaining a reflection coefficient according to the load impedance and the characteristic impedance, and obtaining a reflection loss according to the reflection coefficient and the transmission line effect;

[0155] S63, obtaining conductivity according to the conductivity;

[0156] S64, obtaining resistance according to the characteristic impedance, and obtaining current carrying capacity according to the resistance and conductivity;

[0157] S65. Obtain a second detection result according to the reflection loss and the current carrying capacity.

[0158] As described in the above steps S61-S65, the present invention obtains the load impedance, characteristic impedance, transmission line effect and conductivity of the electrical performance characteristics of the regional PCB, and obtains the reflection coefficient based on the load impedance and characteristic impedance, and then obtains the reflection loss through the reflection coefficient and the transmission line effect, wherein the load impedance refers to the impedance of the component or circuit connected to the output end of the circuit board, the characteristic impedance refers to the impedance of the signal when it propagates on the transmission line, and the transmission line effect refers to the transmission line effect that will appear when the frequency of signal propagation is high or the distance of signal transmission is long in the PCB (these effects include signal delay, reflection, distortion and other phenomena), and the transmission line effect is caused by factors such as the inductance and capacitance between the wires and conductors on the PCB and the ground plane. Reflection loss is the energy loss caused by the signal being reflected back to the source due to impedance mismatch during transmission. The reflection coefficient indicates the matching between the load impedance and the characteristic impedance. In traditional PCB defect detection, it is usually judged by solder holes and appearance inspection. However, as PCBs become more and more complex and sophisticated, defects are often not easy to find through traditional methods, resulting in great difficulty in repair and ultimately having to be scrapped. By analyzing electrical performance characteristics such as load impedance, characteristic impedance, transmission line effect, and conductivity, electrical problems on circuit boards can be accurately diagnosed. In particular, by calculating the reflection coefficient and reflection loss, distortion and reflection problems in signal transmission can be located, which helps to detect potential electrical faults in advance. Through precise electrical Characteristic analysis can detect problems and repair them during the production and testing process without having to directly scrap the entire PCB. For example, through the detected reflection loss, impedance mismatch or transmission line effect, the problem area can be locally repaired instead of scrapping the entire circuit board, thus avoiding a large amount of resource waste and improving the sustainability of the production process. By analyzing the load impedance and characteristic impedance, it can help optimize the layout and connection of the circuit board and avoid problems such as signal reflection and crosstalk. By analyzing the reflection loss and impedance characteristics, the transmission of high-frequency signals can be effectively optimized and signal reflection, crosstalk and other problems can be reduced. This is crucial for modern high-frequency electronic applications such as communications, radar, high-speed data transmission, etc., and can ensure the signal quality and Stability, obtain conductivity through conductivity, obtain resistance through characteristic impedance, and obtain current carrying capacity based on resistance and conductivity, and obtain the second detection result through reflection loss and current carrying capacity, where the current carrying capacity refers to the maximum current that the PCB wire can safely pass through, obtain conductivity through conductivity, and obtain resistance in combination with characteristic impedance, and further calculate the current carrying capacity, which can help designers to accurately evaluate the carrying capacity of each electrical path. For modern precision PCBs, current carrying capacity is an important indicator. If the PCB design fails to meet the current carrying requirements, it may cause overheating or circuit failure. The above method can identify and improve potential current carrying problems in advance, thereby avoiding electrical failures.Traditional PCB inspection methods mainly rely on solder holes, appearance inspections, and limited electrical function tests. In many cases, only surface defects can be found, and the inspection cannot accurately locate electrical performance problems, resulting in the choice of scrapping when precision boards have defects. However, the present invention can detect potential electrical problems at an early stage by analyzing electrical performance characteristics such as conductivity, electrical conductivity, and resistance, such as insufficient current carrying capacity or large reflection loss. Since the current carrying capacity is closely related to the thermal management of the PCB, excessive current will cause local overheating, thereby affecting the stability and reliability of the components. By calculating the current carrying capacity, it can be ensured that the current of each signal path and power path will not exceed Design load to avoid component damage or circuit failure caused by overheating, so as to ensure more accurate thermal management during design and reduce the need for later maintenance and repair due to thermal damage. By comprehensively analyzing reflection loss and current carrying capacity, the signal transmission quality on PCB can be better evaluated and optimized. Low reflection loss and appropriate current carrying capacity complement each other, which helps to improve signal stability and integrity, reduce the occurrence of electrical failures, and improve product reliability. In the PCB production process, accurate electrical performance analysis can also improve detection efficiency, reduce maintenance difficulty, and provide a more convenient solution for later maintenance, ultimately reducing costs and improving production efficiency.

[0159] The present application also provides an online defect detection system in a PCB production process, comprising:

[0160] The first acquisition module 1 is used to acquire production parameter information and board image information of the target PCB board when the production is completed;

[0161] A generating module 2, used to generate a first detection result according to the production parameter information and the light board image, wherein the first detection result includes qualified and unqualified;

[0162] The second acquisition module 3 is used to obtain the position information of multiple electronic components and the design circuit diagram on the unqualified PCB bare board;

[0163] The division module 4 is used to divide the PCB light board according to preset conditions according to the design circuit diagram and the position information of the electronic components to obtain multiple division areas;

[0164] A selection module 5 is used to select a divided area from multiple divided areas as a target area according to a preset rule, and obtain any electronic components corresponding to the target area;

[0165] The detection module 6 is used to weld and install any electronic components according to the electronic component position information in the corresponding target area to obtain a regional PCB, and perform a functional test on the regional PCB to obtain a second test result;

[0166] A judging module 7 is used to judge whether the second detection result meets the preset requirements;

[0167] If satisfied, return to the step of selecting one divided area from the multiple divided areas as the target area according to the preset rule, until all divided areas are traversed to obtain the PCB;

[0168] If not, the defect cause is generated according to the second detection result, and the regional PCB corresponding to the second detection result is transferred to the maintenance station.

[0169] In one embodiment, the generating module 2 includes:

[0170] A first acquisition unit is used to acquire PCB layer number information, plate material information and mechanical strength information according to production parameter information;

[0171] A second acquisition unit is used to acquire comprehensive mechanical stress according to the mechanical strength information, PCB layer number information and plate information;

[0172] A first judging unit, used to judge whether the comprehensive mechanical stress meets a first production standard index;

[0173] If the comprehensive mechanical stress meets the first production standard index, obtaining PCB bare board size information, PCB solder hole information and silk screen information according to the bare board image information;

[0174] A third acquisition unit is used to acquire the hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information;

[0175] A second judging unit, used to judge whether the hole position deviation meets a second production standard index;

[0176] If the light board image information meets the second production standard index, the first detection result of the PCB light board is determined to be qualified;

[0177] If the production parameter information does not meet the first production standard index, the first detection result of the PCB bare board is determined to be unqualified.

[0178] It should be noted that each module and unit in the online defect detection system in the PCB production process corresponds one-to-one to the steps in the online defect detection method in the PCB production process.

[0179] like Figure 3 As shown, the present application also provides a computer device, which may be a server, and its internal structure may be as shown in Figure 3As shown. The computer device includes a processor, a memory, a network interface and a database connected through a system bus. Among them, the processor designed by the computer is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store all data required for the process of the online defect detection method in the PCB production process. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the online defect detection method based on the PCB production process is implemented.

[0180] Those skilled in the art will understand that Figure 3 The structure shown in is merely a block diagram of a portion of the structure related to the present application solution and does not constitute a limitation on the computer device to which the present application solution is applied.

[0181] An embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, any one of the above-mentioned online defect detection methods based on the PCB production process is implemented.

[0182] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided in this application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0183] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0184] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for online defect detection in a PCB production process, characterized in that: include: Obtain production parameter information and board image information of the target PCB board when production is completed; Generate a first test result according to the production parameter information and the light board image, wherein the first test result includes qualified and unqualified; Obtain location information of multiple electronic components on unqualified PCB bare boards and design circuit diagrams; According to the design circuit diagram and the position information of the electronic components, the PCB light board is divided according to the preset conditions to obtain multiple divided areas; Selecting a divided area from multiple divided areas as a target area according to a preset rule, and obtaining any electronic components corresponding to the target area; Solder and install any electronic components according to the electronic component position information in the corresponding target area to obtain a regional PCB, and perform a functional test on the regional PCB to obtain a second test result; Determine whether the second detection result meets the preset requirements; If satisfied, return to the step of selecting one divided area from the multiple divided areas as the target area according to the preset rule, until all divided areas are traversed to obtain the PCB; If not, the defect cause is generated according to the second detection result, and the regional PCB corresponding to the second detection result is transferred to the maintenance station.

2. The method for online defect detection in a PCB production process according to claim 1, characterized in that: The step of generating a first detection result according to the production parameter information and the light board image comprises: Obtain PCB layer number information, board material information and mechanical strength information based on production parameter information; Obtaining comprehensive mechanical stress according to the mechanical strength information, PCB layer number information and plate information; Determining whether the comprehensive mechanical stress meets the first production standard index; If the comprehensive mechanical stress meets the first production standard index, obtaining PCB bare board size information, PCB solder hole information and silk screen information according to the bare board image information; Obtaining hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information; Determining whether the hole position deviation meets the second production standard index; If the light board image information meets the second production standard index, the first detection result of the PCB light board is determined to be qualified; If the production parameter information does not meet the first production standard index, the first detection result of the PCB bare board is determined to be unqualified.

3. The method for online defect detection in a PCB production process according to claim 2, characterized in that: The step of obtaining the comprehensive mechanical stress according to the mechanical strength information, the PCB layer number information and the plate material information comprises: Obtaining bending strength, peel strength and water absorption rate according to the mechanical strength information; Obtaining mechanical performance indicators according to the bending strength, peel strength and water absorption rate; Acquire shear stress according to the mechanical performance index, and acquire bending stress according to the PCB layer number information; The plate thickness, heat flow, heat transfer area, thermal conductivity and thermal expansion coefficient are obtained according to the plate information, and the temperature difference is calculated according to the plate thickness, heat flow, heat transfer area and thermal conductivity, wherein the calculation formula is: Where W(C) represents the temperature difference, R(L) represents the heat flow, B(H) represents the plate thickness, C(M) represents the heat transfer area, and R(D) represents the thermal conductivity; Obtaining thermal stress according to the temperature difference, thermal expansion coefficient and bending modulus; The comprehensive mechanical stress is calculated based on the thermal stress, bending stress and shear stress, wherein the calculation formula is: Among them, Z(YL) represents the comprehensive mechanical stress, W(YL) represents the bending stress, J(YL) represents the shear stress, and R(YL) represents the thermal stress.

4. The method for online defect detection in a PCB production process according to claim 3, characterized in that: The step of obtaining shear stress according to the mechanical performance index and obtaining bending stress according to the PCB layer number information includes: Obtaining bending modulus and shear characteristics according to the mechanical performance index, and obtaining bending moment according to the bending modulus; Acquire shear strength and shear area according to the shear characteristics, and acquire shear cross-sectional area according to the shear area; Obtaining shear force according to the shear strength and the shear cross-sectional area, and obtaining shear stress according to the shear force and the shear area; Acquire the wiring density and the number of PCB layers according to the PCB layer number information, and acquire the distance of the wiring from the neutral axis, the wiring width, and the wiring thickness according to the wiring density; Acquire the wiring cross-sectional area according to the wiring width and the wiring thickness, and acquire the section moment of inertia according to the wiring cross-sectional area and the distance of the wiring from the neutral axis; The bending stress is calculated according to the number of PCB layers, the moment of inertia of the cross section, the distance of the wiring from the neutral axis and the bending moment, wherein the calculation formula is: Where W(YL) represents bending stress, W(J) i represents the i-th bending moment, B(J) i represents the distance of the i-th wiring from the neutral axis, J(G) i It represents the i-th section moment of inertia, i represents the sequence number of the section moment of inertia, and N represents the number of PCB layers.

5. The method for online defect detection in a PCB production process according to claim 1, characterized in that: The step of dividing the PCB light board according to preset conditions according to the designed circuit diagram and the electronic component position information to obtain a plurality of divided areas includes: Acquire multiple circuit modules according to the designed circuit diagram; Marking the position of the electronic components corresponding to each circuit module in the PCB optical board to obtain multiple marking areas; Obtaining the function type of the electronic components in each marked area, and determining whether the function type belongs to the power control type; If the function type belongs to the power control type, the marked area is marked as a power control module area, and the load current of each power control module area is obtained; Setting a preset current interval and comparing it with the load current; If the load current is less than the lower limit of the preset current interval, the corresponding power control module area is divided into a low current division area; If the load current is within the preset current interval, the corresponding power control module area is divided into a stable current division area; If the load current is greater than the upper limit of the preset current interval, the corresponding power control module area is divided into a high current division area; If the function type does not belong to the power control type, the marked area is marked as a signal execution module area, and the length, inductance and capacitance of the transmission line of each signal execution module area are obtained; Acquire a signal transmission speed according to the inductance and capacitance, and acquire a signal propagation delay according to the signal transmission speed and length; Setting a preset propagation delay interval and comparing it with the signal propagation delay; If the signal propagation delay is less than the lower limit of the preset propagation delay interval, the corresponding signal execution module area is divided into a low-frequency signal division area; If the signal propagation delay is within the preset propagation delay interval, the corresponding signal execution module area is divided into intermediate frequency signal division areas; If the signal propagation delay is greater than an upper limit value of a preset propagation delay interval, the corresponding signal execution module area is divided into a high-frequency signal division area.

6. The method for online defect detection in a PCB production process according to claim 1, characterized in that: The step of performing functional testing on the regional PCB to obtain a second test result includes: Acquiring electrical performance characteristics of the regional PCB, wherein the electrical performance characteristics include load impedance, characteristic impedance, transmission line effect, and conductivity; Obtaining a reflection coefficient according to the load impedance and the characteristic impedance, and obtaining a reflection loss according to the reflection coefficient and the transmission line effect; obtaining electrical conductivity according to the electrical conductivity; Obtaining resistance according to the characteristic impedance, and obtaining current carrying capacity according to the resistance and conductivity; A second detection result is obtained according to the reflection loss and the current carrying capacity.

7. An online defect detection system in a PCB production process, characterized in that: include: The first acquisition module is used to acquire production parameter information and image information of the target PCB light board when the production is completed; A generating module, used for generating a first detection result according to the production parameter information and the light board image, wherein the first detection result includes qualified and unqualified; The second acquisition module is used to obtain the position information of multiple electronic components and the design circuit diagram on the unqualified PCB bare board; A division module is used to divide the PCB light board according to preset conditions according to the design circuit diagram and the position information of the electronic components to obtain multiple division areas; A selection module, used to select a divided area from multiple divided areas as a target area according to a preset rule, and obtain any electronic components corresponding to the target area; A detection module is used to weld and install any electronic components according to the position information of the electronic components in the corresponding target area to obtain a regional PCB, and perform a functional test on the regional PCB to obtain a second test result; A judging module, used to judge whether the second detection result meets the preset requirements; If satisfied, return to the step of selecting one divided area from the multiple divided areas as the target area according to the preset rule, until all divided areas are traversed to obtain the PCB; If not, the defect cause is generated according to the second detection result, and the regional PCB corresponding to the second detection result is transferred to the maintenance station.

8. The online defect detection system in the PCB production process according to claim 7, characterized in that: The generating module comprises: A first acquisition unit is used to acquire PCB layer number information, plate material information and mechanical strength information according to production parameter information; A second acquisition unit is used to acquire comprehensive mechanical stress according to the mechanical strength information, PCB layer number information and plate information; A first judging unit, used to judge whether the comprehensive mechanical stress meets a first production standard index; If the comprehensive mechanical stress meets the first production standard index, obtaining PCB bare board size information, PCB solder hole information and silk screen information according to the bare board image information; A third acquisition unit is used to acquire the hole position deviation according to the PCB bare board size information, PCB solder hole information and silk screen information; A second judging unit, used to judge whether the hole position deviation meets a second production standard index; If the light board image information meets the second production standard index, the first detection result of the PCB light board is determined to be qualified; If the production parameter information does not meet the first production standard index, the first detection result of the PCB bare board is determined to be unqualified.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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