Circuit board defect detection system and method used in circuit board production process

Abstract

The invention relates to the technical field of image data processing, and particularly discloses a circuit board defect detection system and method used in a circuit board production process, and the system is provided with a defect component statistics module, an automatic image acquisition module and a defect feedback module. Comparing with a preset index to obtain a comparison result, counting defective components and related detection lines according to the comparison result, then automatically acquiring circuit board images, extracting image data of the defective components and the detection lines, improving image detection efficiency, and judging production quality defects of the defective components and the detection lines by combining the data. According to the method, the corresponding production quality indexes are obtained, and production quality feedback is performed on the components or the circuits according to the indexes, so that the circuit board defect detection is completed, the problems of the defective components and the circuits on the circuit board can be accurately identified, each detail is ensured not to be omitted, and the production quality of the circuit board is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of image data processing, and in particular to a circuit board defect detection system and method used in a circuit board production process. Background Art

[0002] With the rapid development of electronic technology, circuit boards, as the core component of electronic equipment, have a direct impact on the performance and reliability of the equipment. In the electronics manufacturing industry, the production volume of circuit boards is huge, and the quality requirements are getting higher and higher. Traditional defect detection methods, such as manual visual inspection, are inefficient and accuracy is greatly affected by human factors. It can no longer meet the needs of modern industrial production. Therefore, the development of an efficient and accurate circuit board defect detection method has become an urgent need for the electronics manufacturing industry.

[0003] For example, the invention patent with the announcement number CN113689420B announces a circuit board solder joint defect detection method, device and detection equipment, including: based on a 3D linear array scanning camera, obtaining the original depth image of the circuit board to be detected; determining the fitting plane of the circuit board to be detected based on the original depth image; using the fitting plane as the reference plane, converting the original depth image into a detection depth image of the circuit board to be detected; determining the solder joint height values ​​of each area of ​​interest within the solder joint area of ​​the circuit board to be detected based on the detection depth image; determining the area of ​​interest whose solder joint height value is not within the solder joint height threshold range corresponding to the area of ​​interest as the solder joint defect area of ​​the circuit board to be detected.

[0004] For example, the invention patent with the announcement number CN115330757B announces a circuit board solder joint defect detection method and system, which obtains a circuit board area image; in the RGB color space of the circuit board area image, sets the number of starting centers of the mean shift and the size of the mean shift window; obtains the drift amount of each mean shift window based on the difference in the number of points between the mean shift window and the overlap area; obtains the cluster center in the RGB color space based on the drift amount, expands the cluster center with a set expansion step, calculates the possibility that the points expanded each time belong to the cluster corresponding to the cluster center based on the total number of points corresponding to two adjacent expansions, and determines the solder joint area; calculates the abnormality degree of the corresponding solder joint area based on the area of ​​the solder joint area, confirms the defective solder joint based on the abnormality degree, and uses the influence of multiple window overlap areas on the window drift to improve the window drift amount, thereby accurately segmenting the solder joint area and facilitating the defect identification of the solder joint.

[0005] In combination with the above technical solutions, it is found that there is a technical solution for circuit board defect detection, whose detection process is relatively complicated and the required data is difficult to obtain. In the process of circuit board defect detection, the accuracy of the data is prone to large deviations, resulting in large deviations in circuit board defect detection, which ultimately affects the use of the circuit board. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a circuit board defect detection system and method for use in a circuit board production process, which can effectively solve the problems involved in the above-mentioned background technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: In a first aspect, the present invention provides a circuit board defect detection system for use in a circuit board production process, including: a defective component statistics module, which is used to detect the signal transmission of each component of the circuit board to be detected, determine the signal transmission evaluation index of each component of the circuit board to be detected, and compare it with the predefined signal transmission evaluation preset index to obtain a signal transmission comparison result, and count each defective component based on the signal transmission comparison result, and obtain a number of lines corresponding to each defective component through a line connection method, which are recorded as each detection line; an automatic image acquisition module, which is used to automatically acquire an image of the circuit board to obtain an image of the circuit board, and extract image data of each defective component and image data of each detection line from it; a defect feedback module, which is used to determine the production quality defects of each defective component and each detection line, and synthesize the image data of each defective component and the image data of each detection line to obtain the production quality index of each defective component and the production quality index of each detection line, so as to feedback the production quality defects of the components or the detection lines, and finally complete the circuit board defect detection in the circuit board production process.

[0008] As a further solution, the signal transmission evaluation index of each component of the circuit board to be detected is determined, and the specific determination process is: by detecting the signal transmission of each component of the circuit board to be detected, the signal transmission detection data of each component of the circuit board to be detected is obtained, specifically including the voltage signal value, current signal value, signal frequency value of each component of the circuit board to be detected at each signal detection time point and the maximum signal rise time of each component of the circuit board to be detected within the signal detection period; the voltage signal value of each component of the circuit board to be detected at each signal detection time point is multiplied by the current signal value of each component of the circuit board to be detected at each signal detection time point to obtain the signal power of each component of the circuit board to be detected at each signal detection time point; the signal frequency value of each component of the circuit board to be detected at each signal detection time point is averaged. Processing is performed to obtain the mean signal frequency of each component of the circuit board to be detected within the signal detection period; the maximum environmental interference signal strength value and the maximum environmental humidity of the detection area to which the circuit board to be detected belong within the signal detection period are obtained; the signal rise limit time and the environmental adaptation humidity are extracted from the circuit board detection information library; according to the signal power of each component of the circuit board to be detected at each signal detection time point, the mean signal frequency of each component of the circuit board to be detected within the signal detection period, the maximum signal rise time of each component of the circuit board to be detected within the signal detection period, the maximum environmental interference signal strength value of the detection area to which the circuit board to be detected belongs within the signal detection period, and the maximum environmental humidity of the detection area to which the circuit board to be detected belongs within the signal detection period, a comprehensive analysis is performed to obtain the signal transmission evaluation index of each component of the circuit board to be detected.

[0009] As a further solution, the defective components are counted based on the signal transmission comparison result. The specific statistical process is: if the signal transmission comparison result shows the second signal transmission comparison result, the component of the circuit board to be tested corresponding to the signal transmission evaluation index is recorded as a defective component, and in this way, a number of components of the circuit board to be tested whose signal transmission evaluation index is less than or equal to the preset signal transmission evaluation index are counted and recorded as defective components.

[0010] As a further solution, the production quality index of each defective component is specifically analyzed as follows: by performing production quality defect judgment on each defective component and each detection circuit, the production quality defect judgment data of each defective component and the production quality defect judgment data of each detection circuit are obtained; wherein the production quality defect judgment data of each defective component specifically includes the average operating voltage, the average operating current and the maximum temperature of each defective component within the production quality assessment cycle; the average operating voltage of each defective component within the production quality assessment cycle is ratioed with the average operating current of each defective component within the production quality assessment cycle to obtain the average operating resistance of each defective component within the production quality assessment cycle; the operating resistance reference value, the adjacent adaptation spacing and the temperature reference value are extracted from the circuit board detection information library; the production quality index of each defective component is obtained based on the average operating resistance of each defective component within the production quality assessment cycle, the maximum temperature of each defective component within the production quality assessment cycle, the offset length of each defective component and the minimum adjacent component spacing of each defective component.

[0011] As a further solution, the production quality index of each detection line is specifically determined as follows:

[0012]

[0013] In the formula, XL h is the production quality index of the hth detection line, h is the number of each detection line, h=1,2,3,...,H, H is the total number of detection lines, DL h is the number of short-circuit position points of the hth detection circuit, HL h is the percentage of leaking solder joints in the hth detection circuit, L h is the maximum spacing between adjacent lines of the hth detection line, L ′ is the reference distance between adjacent lines, P h is the minimum response frequency of the hth detection line in the production quality assessment cycle, P ′ is the minimum response frequency standard value, b2 is the production quality weight corresponding to the single short circuit location point predefined in the circuit board detection information library, b3 is the production quality weight corresponding to the leaking solder ratio predefined in the circuit board detection information library, and e is a natural constant.

[0014] As a further solution, the production quality defect feedback of components or detection lines is performed, and the specific feedback process is: the production quality index of each defective component is verified with the predefined component production quality adaptation index. If the production quality index of a defective component is less than the component production quality adaptation index, component production quality defect feedback is performed on the defective component; the production quality index of each detection line is verified with the predefined line production quality adaptation index. If the production quality index of a detection line is less than the line production quality adaptation index, line production quality defect feedback is performed on the detection line.

[0015] The second aspect of the present invention provides a circuit board defect detection method for a circuit board production process, comprising: defective component statistics: detecting the signal transmission of each component of the circuit board to be detected, determining the signal transmission evaluation index of each component of the circuit board to be detected, and comparing it with a predefined signal transmission evaluation preset index to obtain a signal transmission comparison result, counting each defective component based on the signal transmission comparison result, and obtaining a number of circuits corresponding to each defective component through a line connection method, which are recorded as each detection circuit; automatic image acquisition: automatic image acquisition of the circuit board to obtain an image of the circuit board, from which image data of each defective component and image data of each detection circuit are extracted; defect feedback: production quality defect determination is performed on each defective component and each detection circuit, and the image data of each defective component and the image data of each detection circuit are combined to obtain the production quality index of each defective component and the production quality index of each detection circuit, so as to perform production quality defect feedback on the components or detection circuits, and finally complete the circuit board defect detection in the circuit board production process.

[0016] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0017] (1) The present invention provides a circuit board defect detection system and method for use in the circuit board production process. First, the signal transmission of each component is evaluated and compared with the preset index to obtain a comparison result. Based on this, the defective components and their related detection circuits are counted. Then, the circuit board image is automatically collected, and the image data of the defective components and the detection circuits are extracted to improve the image detection efficiency. Based on these data, the production quality defects of each defective component and the detection circuit are determined, and the corresponding production quality index is obtained. Based on these indexes, the production quality feedback is provided to the components or circuits, thereby completing the circuit board defect detection. The defective components and circuit problems on the circuit board can be accurately identified to ensure that every detail is not missed and the circuit board production quality is ensured.

[0018] (2) The present invention detects the signal transmission of each component of the circuit board to be tested and determines the signal transmission evaluation index of each component of the circuit board to be tested. By detecting the signal transmission of each component, it is possible to accurately identify which components may have defects, thereby providing data support for subsequent production quality determination and screening out defective components. This not only improves the efficiency of circuit board defect detection, but also helps to reduce misjudgments and missed judgments, and improves the accuracy of defect location.

[0019] (3) The present invention accurately locates components or detection circuits with quality problems through the production quality index of each defective component and the production quality index of each detection circuit, thereby avoiding blind inspection of the entire circuit board, providing feedback on production quality defects of components or detection circuits, and improving the quality of circuit board products. By identifying components and circuit traces in the circuit board, the circuit board to be inspected and the pad background can be separated, thereby improving the efficiency of circuit board defect analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0021] Figure 1 It is a schematic diagram of system module connection of the present invention.

[0022] Figure 2 The figure is a schematic flow chart of the method steps of the present invention. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Reference Figure 1 As shown, the first aspect of the present invention provides a circuit board defect detection system for use in a circuit board production process, comprising: a defective component statistics module, an automatic image acquisition module and a defect feedback module.

[0025] The first aspect of the present invention provides a circuit board defect detection system for use in a circuit board production process, and also includes: a circuit board detection information library, which is used to store signal rise limit time, environmental adaptation humidity, operating resistance reference value, adjacent adaptation spacing, temperature reference value and preset values ​​of various factors, etc.

[0026] The defective component statistics module is connected to the automatic image acquisition module, the automatic image acquisition module is connected to the defect feedback module, and the defective component statistics module and the defect feedback module are both connected to the circuit board detection information library.

[0027] The defective component statistics module is used to detect the signal transmission of each component of the circuit board to be detected, determine the signal transmission evaluation index of each component of the circuit board to be detected, and compare it with the predefined signal transmission evaluation preset index to obtain the signal transmission comparison result, and count the defective components based on the signal transmission comparison result, and obtain a number of lines corresponding to each defective component through line connection, which are recorded as each detection line.

[0028] The above-mentioned circuit connection method is specifically welding connection, which is one of the most commonly used connection methods in circuit board manufacturing. It achieves the fixation and electrical connection of components and circuit boards by welding the pins of components to the pads or solder points on the circuit board. Welding connection has the advantages of firm connection, good conductivity, and not easy to loosen. It is suitable for components that need permanent connection.

[0029] Specifically, the signal transmission evaluation index of each component of the circuit board to be tested is determined by the following specific determination process:

[0030] By detecting the signal transmission of each component of the circuit board to be detected, the signal transmission detection data of each component of the circuit board to be detected is obtained, specifically including the voltage signal value, current signal value, signal frequency value of each component of the circuit board to be detected at each signal detection time point and the maximum signal rise time of each component of the circuit board to be detected within the signal detection period.

[0031] The above-mentioned signal detection time points specifically refer to a number of signal detection time points that divide the signal detection cycle into time points, wherein the signal detection cycle is a period of time used to evaluate the signal transmission quality of each component of the circuit board. The signal detection cycle is determined by the circuit board inspection personnel based on a comprehensive analysis of factors such as the status of the circuit board, specific needs, and the inspection environment.

[0032] The above voltage signal value and current signal value can be measured by a multimeter, the signal frequency value can be measured by an oscilloscope, and the rise time can be detected by a timer.

[0033] The voltage signal value of each component of the circuit board to be detected at each signal detection time point is multiplied by the current signal value of each component of the circuit board to be detected at each signal detection time point to obtain the signal power of each component of the circuit board to be detected at each signal detection time point.

[0034] The signal frequency values ​​of each component of the circuit board to be detected at each signal detection time point are averaged to obtain the signal frequency average of each component of the circuit board to be detected within the signal detection period.

[0035] Obtain the maximum interference signal strength value and the maximum humidity of the environment in the detection area of ​​the circuit board to be detected within the signal detection period.

[0036] The above-mentioned environmental interference signal strength value can be measured by a spectrum analyzer, and the environmental humidity can be measured by a hygrometer.

[0037] The signal rise time limit and the environmental adaptation humidity are extracted from the circuit board detection information library.

[0038] According to the signal power of each component of the circuit board to be detected at each signal detection time point, the average signal frequency of each component of the circuit board to be detected in the signal detection period, the maximum signal rise time of each component of the circuit board to be detected in the signal detection period, the maximum environmental interference signal strength value of the detection area of ​​the circuit board to be detected in the signal detection period, and the maximum environmental humidity of the detection area of ​​the circuit board to be detected in the signal detection period, the signal transmission evaluation index of each component of the circuit board to be detected is obtained. The specific method is as follows:

[0039]

[0040] In the formula, XH y is the signal transmission evaluation index of the yth component of the circuit board to be tested. In this embodiment, it is used to measure the signal transmission quality of each component in the circuit board to be tested. When the signal transmission quality of each component in the circuit board to be tested is at a high level, it indicates that the circuit board to be tested is in good condition. If there is a component with low signal transmission quality, it indicates that the circuit board to be tested may have defects.

[0041] y is the number of each component, y=1,2,3,...,Y, and Y is the total number of components.

[0042] XG yt It is the signal power of the yth component of the circuit board to be detected at the tth signal detection time point, which refers to the signal energy carried or transmitted by the components in the circuit board to be detected at a certain signal detection time point.

[0043] t is the number of each signal detection time point, t=1, 2, 3, ..., T, and T is the total number of signal detection time points.

[0044] XP yIt is the average signal frequency of the yth component of the circuit board to be tested within the signal detection period. It refers to the frequency range in which the components in the circuit board to be tested can respond or operate normally during the signal detection period. This range is usually expressed in Hertz (Hz).

[0045] SS y It is the maximum signal rise time of the yth component of the circuit board to be detected within the signal detection cycle, which refers to the maximum time required within a reasonable range for the output voltage or current of the component in the circuit board to be detected to rise from 10% of a certain initial value, i.e. a low level, to 90% of a certain initial value, i.e. a high level, within the signal detection cycle.

[0046] SS ′ Defining the duration of a signal rise refers to the maximum duration specified when discussing the duration of a signal rise.

[0047] GX is the maximum environmental interference signal strength value of the detection area to which the circuit board to be detected belongs within the signal detection period. It refers to the maximum external interference signal strength encountered during the detection of the circuit board in the detection area. This interference signal may come from various sources, including but not limited to electromagnetic interference (EMI), radio noise, power supply fluctuations, radiation from other electronic equipment, etc.

[0048] SD is the maximum environmental humidity of the detection area of ​​the circuit board to be detected within the signal detection cycle, which refers to the maximum environmental humidity that enables the circuit board to maintain normal working status during the detection of the circuit board in the detection area.

[0049] SD ′ Adapting humidity to the environment refers to the corresponding environmental humidity when the circuit board components are in the best working condition, that is, the standard value corresponding to the predefined environmental humidity.

[0050] a1 is the signal transmission influencing parameter corresponding to the signal power mean value predefined in the circuit board detection information library, a2 is the signal transmission influencing parameter corresponding to the signal frequency mean value predefined in the circuit board detection information library, and a3 is the signal transmission influencing parameter corresponding to the maximum environmental interference signal strength value predefined in the circuit board detection information library.

[0051] As mentioned above, the signal transmission influencing parameters corresponding to the signal power mean, the signal transmission influencing parameters corresponding to the signal frequency mean, and the signal transmission influencing parameters corresponding to the maximum environmental interference signal strength value are all directly obtained from the circuit board detection information library, and represent the numerical values ​​of the degree of influence on the signal transmission evaluation indicators of each component of the circuit board to be detected during the signal transmission evaluation of each component of the circuit board to be detected; in this embodiment, the signal transmission influencing parameters corresponding to the signal power mean, the signal transmission influencing parameters corresponding to the signal frequency mean, and the signal transmission influencing parameters corresponding to the maximum environmental interference signal strength value have a value range of (0, 1), for example, the signal power mean and the signal transmission influencing parameters corresponding to the signal power mean preset in the circuit board detection information library form a mapping set, and the real-time signal power mean is brought into the mapping set to obtain the signal transmission influencing parameters corresponding to the signal power mean, wherein the mapping relationship can be a one-to-one correspondence or a many-to-one relationship.

[0052] In this embodiment, when the signal frequency of each component on the circuit board increases, the speed of change of the electronic signal will increase, so more energy will be consumed, that is, the signal power may increase. On the contrary, if the signal frequency decreases, the power may decrease; as the signal frequency increases, the rise time of the signal usually decreases. This is because as the signal frequency increases, the signal changes faster, thereby shortening the signal rise time; if the rise time of the signal is too short and is less than the normal range, its anti-interference ability is usually weaker, causing the components of the circuit board to be more susceptible to external interference signals during normal operation; in addition, when the components of the circuit board are operating normally, excessive humidity in the environment may cause the circuit board to absorb moisture, thereby causing corrosive effects on the circuit board, which may cause unstable operation of the digital circuit. When the ambient humidity is too low, the air becomes dry, which may cause changes in the internal material properties, also affecting the performance of the circuit board.

[0053] Furthermore, the signal transmission comparison result is specifically a first signal transmission comparison result or a second signal transmission comparison result.

[0054] The first signal transmission comparison result is specifically that the signal transmission evaluation index of a component of the circuit board to be detected is greater than the signal transmission evaluation preset index predefined in the circuit board detection information library.

[0055] The second signal transmission comparison result is specifically that the signal transmission evaluation index of a component of the circuit board to be detected is less than or equal to a preset signal transmission evaluation index.

[0056] Specifically, the statistics of defective components are counted based on the signal transmission comparison result, and the specific statistical process is:

[0057] If the signal transmission comparison result shows the second signal transmission comparison result, the component of the circuit board to be tested corresponding to the signal transmission evaluation index is recorded as a defective component, and a number of components of the circuit board to be tested whose signal transmission evaluation index is less than or equal to the preset signal transmission evaluation index are counted and recorded as defective components.

[0058] If the signal transmission comparison result shows the first signal transmission comparison result, there is no need to perform defect detection on a component of the circuit board to be tested. When the signal transmission evaluation indicators of all components of the circuit board to be tested are greater than the preset signal transmission evaluation indicators, it means that the performance of the circuit board to be tested in signal transmission has reached the usable standard, and there are no defects in each component and each detection circuit.

[0059] The automatic image acquisition module is used to automatically acquire images of the circuit board to obtain an image of the circuit board, from which image data of each defective component and image data of each detection circuit are extracted.

[0060] The above-mentioned automatic image acquisition of circuit boards is specifically carried out during the production process of circuit boards. The production line is equipped with image acquisition equipment, such as high-definition CCD cameras, which are one of the core components of the automatic optical inspection (AOI) system. It is responsible for real-time and high-precision image acquisition of circuit boards and components thereon during the production process of circuit boards. These image data will be used for subsequent image processing and defect detection.

[0061] Furthermore, the image data of each defective component specifically includes an offset length of each defective component and a minimum distance between adjacent components of each defective component.

[0062] The above-mentioned offset length and the minimum distance between adjacent components can be detected by a laser rangefinder.

[0063] The image data of each detection circuit is specifically the number of welding points of each detection circuit.

[0064] The number of the above welding points can be obtained by automatic detection and counting by an automatic optical detector.

[0065] The defect feedback module is used to determine the production quality defects of each defective component and each detection circuit, and to obtain the production quality index of each defective component and the production quality index of each detection circuit by integrating the image data of each defective component and the image data of each detection circuit, so as to provide production quality defect feedback to the components or detection circuits, and finally complete the circuit board defect detection in the circuit board production process.

[0066] Specifically, the production quality index of each defective component is analyzed in the following process:

[0067] By performing production quality defect determination on each defective component and each detection line, production quality defect determination data of each defective component and production quality defect determination data of each detection line are obtained.

[0068] The production quality defect determination data of each defective component specifically includes the average operating voltage, average operating current and maximum temperature of each defective component during the production quality assessment cycle.

[0069] The above-mentioned production quality assessment cycle is a period of time used to conduct production quality assessment on defective components and circuits of a circuit board. The production quality assessment cycle is determined by circuit board inspectors based on a comprehensive analysis of factors such as the status of defective components and circuits, actual assessment requirements, and assessment environment.

[0070] The above operating voltage value and operating current value can be measured by a multimeter, and the tolerable temperature value can be measured by a temperature sensor.

[0071] The average operating voltage of each defective component during the production quality assessment cycle is ratioed with the average operating current of each defective component during the production quality assessment cycle to obtain the average operating resistance of each defective component during the production quality assessment cycle.

[0072] The operating resistance reference value, adjacent adaptation spacing and temperature reference value are extracted from the circuit board detection information library.

[0073] The production quality index of each defective component is obtained by comprehensive analysis based on the average operating resistance of each defective component during the production quality assessment cycle, the maximum temperature of each defective component during the production quality assessment cycle, the offset length of each defective component, and the minimum adjacent component spacing of each defective component. The specific method is as follows:

[0074]

[0075] In the formula, ZL q is the production quality index of the qth defective component. In this embodiment, it is used to measure whether the production quality of the component determined to be potentially defective is defective. When the production quality index of the defective component is large, it means that the component determined to be defective may not have a defect problem itself, and the production quality of the component has met the use standard.

[0076] q is the serial number of each defective component, q=1, 2, 3, ..., Q, and Q is the total number of defective components.

[0077] R qIt is the average operating resistance of the qth defective component during the production quality assessment cycle, which refers to the resistance characteristics or resistance value exhibited by the defective component during the production quality assessment cycle. Resistance is an important parameter in electronic components. It indicates the magnitude of the resistance of the conductor to the current, usually measured in ohms (Ω).

[0078] R ′ The reference value of the operating resistance refers to the adaptation value of the predefined operating resistance.

[0079] W q is the maximum temperature of the qth defective component during the production quality assessment cycle, and refers to the maximum component temperature corresponding to when the defective component can maintain normal operation during the production quality assessment cycle.

[0080] W ′ The temperature reference value refers to the predefined adaptation value of the circuit board component temperature.

[0081] CC q is the offset length of the qth defective component, which refers to the deviation length between the defective component and the expected position due to operational errors and other reasons during the mounting process.

[0082] J q The minimum distance between adjacent components of the qth defective component refers to the minimum distance between the defective component and its adjacent components.

[0083] J ′ The adjacent adaptation spacing refers to the reference value of the predefined adjacent spacing.

[0084] b1 is the production quality weight corresponding to the offset length predefined in the circuit board inspection information library.

[0085] In a specific embodiment, the production quality weight corresponding to the offset length can be directly obtained from the circuit board detection information library during use, and the corresponding relationship can be a pre-set mapping relationship. For example, the offset length and the production quality weight corresponding to the offset length preset in the circuit board detection information library form a mapping set, and the real-time offset length is brought into the mapping set to obtain the production quality weight corresponding to the offset length. The mapping relationship can be a one-to-one correspondence or a many-to-one relationship. In this embodiment, its value range is (0, 1).

[0086] In this embodiment, the operating resistance of each defective component of the circuit board will generate heat during operation. If the operating resistance value is too large and deviates from the operating resistance reference value, it may cause the component to overheat, thereby affecting its temperature value to also deviate from the temperature reference value; when the operating resistance is too large, it will also affect the change of its offset length. If the value of the operating resistance deviates from the reference value, it may cause insufficient electrical clearance with other components, thereby causing repulsion of the component and increasing the offset length; if the offset of the component is too large, it may also cause insufficient distance from the heat source of other components, thereby increasing the risk of overheating and affecting the temperature value of the circuit board components; similarly, if the spacing between adjacent spacings between components is too small and deviates from the reference value, it may limit the heat dissipation space of the component, thereby increasing the possibility of its temperature value deviating from the reference value. In summary, if the production quality index of a defective component is too low, it means that its performance cannot meet the expected standard, the component does have a defect problem, and is more likely to malfunction or fail during use, resulting in a decrease in the performance of the entire circuit board, so that the circuit board where the component is located cannot be used.

[0087] Furthermore, the production quality index of each detection line is specifically analyzed as follows:

[0088] The number of short-circuit position points of each detection circuit is obtained, wherein the position points are arranged at the connection points between each defective component and each detection circuit, and are used to detect whether there is a short circuit between each defective component and each detection circuit.

[0089] The number of the short-circuit positions can be determined by detecting the current change at each position. The current change at the position where a short circuit occurs will be much greater.

[0090] The number of welding points of each detection circuit is processed by difference with the preset number of welding points of each detection circuit predefined in the circuit board detection information library to obtain the number of welding leaks of each detection circuit, and then the ratio is processed with the preset number of welding points to obtain the welding leak ratio of each detection circuit.

[0091] The production quality defect determination data of each detection line specifically includes the maximum spacing between adjacent lines of each detection line and the minimum response frequency of each detection line within a production quality assessment cycle.

[0092] The adjacent spacing between the above lines can be obtained by laser ranging, and the response frequency can be measured by an oscilloscope.

[0093] According to the minimum adjacent spacing of each defective component, the circuit adjacent spacing reference value corresponding to each component adjacent minimum spacing interval predefined in the circuit board detection information library is matched. The specific matching process is: obtaining a mapping set between the component adjacent minimum spacing and the circuit adjacent spacing reference value from the circuit board detection information library, determining the interval corresponding to the component adjacent minimum spacing, and assigning the circuit adjacent spacing reference value corresponding to the interval to the detection circuit, so as to obtain the circuit adjacent reference spacing through matching.

[0094] According to the average operating resistance of each defective component within the production quality assessment cycle, it is matched with the minimum response frequency standard value corresponding to each operating resistance interval predefined in the circuit board detection information library. The specific matching process is: obtain the mapping set between the operating resistance average and the minimum response frequency standard value from the circuit board detection information library, determine the interval corresponding to the operating resistance average, and assign the minimum response frequency standard value corresponding to the interval to the detection line, so as to obtain the minimum response frequency standard value through matching.

[0095] The production quality index of each detection line is obtained through comprehensive analysis based on the number of short-circuit position points of each detection line, the proportion of leaky welds of each detection line, the maximum spacing between adjacent lines of each detection line, and the minimum response frequency of each detection line within the production quality assessment cycle.

[0096] Specifically, the production quality index of each detection line is determined by:

[0097]

[0098] In the formula, XL h is the production quality index of the hth detection circuit. In this embodiment, it is used to measure whether the production quality of the circuit connected to the defective component is defective. When the production quality index of the detection circuit is small, it means that the circuit connected to the defective component may have defects and the production quality of the detection circuit does not meet the use standard.

[0099] h is the number of each detection line, h=1,2,3,...,H, and H is the total number of detection lines.

[0100] DL h The number of short-circuit position points of the hth detection circuit refers to the number of specific locations in the circuit board circuit where short-circuit faults are determined and counted through detection. Short circuit refers to the phenomenon that current does not pass through components, but flows directly from the positive electrode through the wire back to the negative electrode, which will cause the components in the circuit to fail to work normally and may even damage the power supply.

[0101] HL hThe ratio of solder leaks of the hth detection circuit refers to the ratio of solder leaks to all soldering points determined by detection during the soldering process of the circuit board. A solder leak refers to the phenomenon that soldering is preset but not performed due to operational errors or other reasons.

[0102] L h The maximum spacing between adjacent lines of the h-th detection line refers to the maximum value of the spacing between the detection line and its adjacent lines.

[0103] L ′ The reference distance between adjacent lines refers to the preset reference value of the distance between the detection line and its adjacent lines.

[0104] P h is the minimum response frequency of the hth detection line within the production quality assessment cycle, which refers to the minimum value of the signal frequency that the detection line can respond to or detect within the production quality assessment cycle.

[0105] P ′ It is the minimum response frequency standard value, which refers to the reference value corresponding to the preset minimum response frequency value.

[0106] b2 is the production quality weight corresponding to a single short circuit location point predefined in the circuit board detection information library, b3 is the production quality weight corresponding to the proportion of leaking solder joints predefined in the circuit board detection information library, and e is a natural constant.

[0107] The production quality weight corresponding to a single short-circuit position point and the production quality weight corresponding to the leaky solder ratio are both directly obtained from the circuit board detection information library, indicating the numerical value of the degree of influence on the production quality index of each detection line during the production quality assessment of each detection line; a single short-circuit position point and the production quality weight corresponding to the single short-circuit position point preset in the circuit board detection information library form a mapping set, and the real-time single short-circuit position point is brought into the mapping set to obtain the production quality weight corresponding to the single short-circuit position point, wherein the mapping relationship can be a one-to-one correspondence or a many-to-one relationship; the leaky solder ratio and the production quality weight corresponding to the leaky solder ratio preset in the circuit board detection information library form a mapping set, and the real-time leaky solder ratio is brought into the mapping set to obtain the production quality weight corresponding to the leaky solder ratio, wherein the mapping relationship can be a one-to-one correspondence or a many-to-one relationship. In this embodiment, the value range of the production quality weight corresponding to the single short-circuit position point and the production quality weight corresponding to the leaky solder ratio are both (0, 1).

[0108] In this embodiment, an increase in the number of short-circuit position points may mean that there are problems with welding quality, such as improper welding process, improper selection of welding materials or welding equipment failure. These problems may also lead to an increase in the proportion of leaky welds. Therefore, the number of short-circuit position points can indirectly reflect the proportion of leaky welds. The size of the adjacent spacing between lines is closely related to the probability of short-circuit failures. When the adjacent spacing between lines deviates from the reference spacing, the risk of short-circuit failures will increase, thereby increasing the number of short-circuit position points and reducing the production quality index of the detection line. When the minimum response frequency is too high or too low, it may have a negative impact on the production quality of the detection line. When the minimum response frequency is too high, the transmission of the signal on the circuit board line may be affected by attenuation and loss, resulting in a decrease in signal quality. When the minimum response frequency is too low, it may cause the high-frequency signal components to fail to be fully responded to, and the signal transmission in the line is distorted.

[0109] Furthermore, the production quality defect feedback of the components or the detection circuits is performed, and the specific feedback process is as follows:

[0110] The production quality index of each defective component is verified with the component production quality adaptation index predefined in the circuit board detection information library. If the production quality index of a defective component is less than the component production quality adaptation index, the component production quality defect feedback is given to the defective component.

[0111] The above-mentioned feedback on component production quality defects of the defective components can be specifically that when the production quality inspection component on the production line identifies that there are production quality problems with components on a circuit board, the production quality inspection component will automatically mark the defective circuit board, and present the defective components of the marked circuit board on the electronic display screen, and generate a defect report, wherein the report will record in detail the specific location of the defective component, the severity of the defect, the defect image, etc., so that the circuit board inspection personnel can quickly and accurately understand the problem and formulate effective solutions accordingly.

[0112] The above-mentioned production quality inspection components refer to equipment specifically used for quality inspection of products in the production line. They can monitor the production quality of products in real time, detect potential quality problems in a timely manner, and provide accurate feedback to circuit board inspectors.

[0113] The production quality index of each detection line is checked against the line production quality adaptation index predefined in the circuit board detection information library. If the production quality index of a certain detection line is less than the line production quality adaptation index, feedback on the line production quality defects is given to the detection line.

[0114] The above-mentioned feedback on the production quality defects of the inspection circuit can be specifically that when the production quality inspection component on the production line identifies that a circuit connected to a circuit board has a production quality problem, the production quality inspection component will automatically mark the circuit, and present the connection circuit of the marked circuit board on the electronic display screen, and generate a defect report, wherein the report will record in detail the specific location of the inspected circuit, the severity of the defect, the defect image, etc., so that the circuit board inspection personnel can quickly and accurately understand the problem and formulate effective solutions accordingly.

[0115] It needs to be explained that if the production quality index of defective components is less than the component production quality adaptation index, and the production quality index of each detection line is greater than or equal to the line production quality adaptation index, it means that the defective components determined do have production quality problems, resulting in defects in the circuit board, while the detected lines do not have production quality problems; similarly, if the production quality index of each defective component is greater than or equal to the component production quality adaptation index, and the production quality index of the detection line is less than the line production quality adaptation index, it means that the detected lines have production quality problems, resulting in defects in the circuit board, while the defective components determined do not have production quality problems; in addition, if the production quality index of each defective component is greater than or equal to the component production quality adaptation index and the production quality index of each detection line is greater than or equal to the line production quality adaptation index, it means that the detected defective components and lines do not have production quality problems. At this time, if the signal transmission evaluation index of a component of the circuit board to be detected is less than or equal to the preset signal transmission evaluation index, it can be considered whether the detection environment of the circuit board has a negative impact on the signal transmission quality of the circuit board.

[0116] The above considerations are about the detection environment of the circuit board. In a specific embodiment, there may be interference from electromagnetic fields in the detection environment of the circuit board, such as interference from other ground wires, power supplies, etc., which may cause distortion, attenuation or interruption in the signal transmission process; there may be interference from physical obstacles, such as walls, metal objects, etc. in the detection environment, which block or absorb signals, resulting in a decrease in signal transmission quality; there may be interference from external noise, such as external electrical equipment, which may reduce the quality and accuracy of the signal.

[0117] Taking electromagnetic field interference as an example, if there is electromagnetic field interference in the detection environment of the circuit board, a filter can be used to connect the filter to the power input end of the circuit board to reduce the electromagnetic interference from the power grid.

[0118] Reference Figure 2 As shown, the second aspect of the present invention provides a circuit board defect detection method for a circuit board production process, comprising:

[0119] Statistics of defective components: Detect the signal transmission of each component of the circuit board to be tested, determine the signal transmission evaluation index of each component of the circuit board to be tested, and compare it with the predefined signal transmission evaluation preset index to obtain the signal transmission comparison result. Based on the signal transmission comparison result, count the defective components, and obtain several lines corresponding to each defective component through line connection, which are recorded as each detection line.

[0120] Automatic image acquisition: Automatically acquire images of the circuit board to obtain an image of the circuit board, from which image data of each defective component and image data of each detection circuit are extracted.

[0121] Defect feedback: Determine the production quality defects of each defective component and each detection circuit, and combine the image data of each defective component and the image data of each detection circuit to obtain the production quality index of each defective component and the production quality index of each detection circuit. In this way, feedback on production quality defects is provided to components or detection circuits, and finally the circuit board defect detection in the circuit board production process is completed.

[0122] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A circuit board defect detection system used in a circuit board production process, characterized in that: include: The defective component statistics module is used to detect the signal transmission of each component of the circuit board to be detected, determine the signal transmission evaluation index of each component of the circuit board to be detected, and compare it with the predefined signal transmission evaluation preset index to obtain the signal transmission comparison result, and count the defective components based on the signal transmission comparison result, and obtain a number of lines corresponding to each defective component through line connection, which are recorded as each detection line; An automatic image acquisition module is used to automatically acquire images of the circuit board to obtain an image of the circuit board, from which image data of each defective component and image data of each detection circuit are extracted; The defect feedback module is used to determine the production quality defects of each defective component and each detection circuit, and to obtain the production quality index of each defective component and the production quality index of each detection circuit by integrating the image data of each defective component and the image data of each detection circuit, so as to provide production quality defect feedback to the components or detection circuits, and finally complete the circuit board defect detection in the circuit board production process.

2. A circuit board defect detection system for use in a circuit board production process according to claim 1, characterized in that: The specific determination process of determining the signal transmission evaluation index of each component of the circuit board to be detected is as follows: By detecting the signal transmission of each component of the circuit board to be detected, the signal transmission detection data of each component of the circuit board to be detected is obtained, specifically including the voltage signal value, current signal value, signal frequency value of each component of the circuit board to be detected at each signal detection time point and the maximum signal rise time of each component of the circuit board to be detected within the signal detection period; The voltage signal value of each component of the circuit board to be detected at each signal detection time point is multiplied by the current signal value of each component of the circuit board to be detected at each signal detection time point to obtain the signal power of each component of the circuit board to be detected at each signal detection time point; Performing mean processing on the signal frequency values ​​of each component of the circuit board to be detected at each signal detection time point to obtain the signal frequency mean value of each component of the circuit board to be detected within the signal detection period; Obtain the maximum interference signal strength value and the maximum humidity of the environment in the detection area of ​​the circuit board to be detected within the signal detection period; Extract the signal rise time and the environmental adaptation humidity from the circuit board detection information library; Based on the signal power of each component of the circuit board to be detected at each signal detection time point, the average signal frequency of each component of the circuit board to be detected within the signal detection period, the maximum signal rise time of each component of the circuit board to be detected within the signal detection period, the maximum environmental interference signal strength value of the detection area to which the circuit board to be detected belongs within the signal detection period, and the maximum environmental humidity of the detection area to which the circuit board to be detected belongs within the signal detection period, the signal transmission evaluation index of each component of the circuit board to be detected is obtained.

3. A circuit board defect detection system for use in a circuit board production process according to claim 2, characterized in that: The signal transmission comparison result is specifically a first signal transmission comparison result or a second signal transmission comparison result; The first signal transmission comparison result is specifically that the signal transmission evaluation index of a component of the circuit board to be detected is greater than the preset signal transmission evaluation index; The second signal transmission comparison result is specifically that the signal transmission evaluation index of a component of the circuit board to be detected is less than or equal to a preset signal transmission evaluation index.

4. A circuit board defect detection system for use in a circuit board production process according to claim 3, characterized in that: The specific statistical process of counting defective components based on the signal transmission comparison result is as follows: If the signal transmission comparison result shows the second signal transmission comparison result, the component of the circuit board to be tested corresponding to the signal transmission evaluation index is recorded as a defective component, and a number of components of the circuit board to be tested whose signal transmission evaluation index is less than or equal to the preset signal transmission evaluation index are counted and recorded as defective components.

5. The circuit board defect detection system used in the circuit board production process according to claim 1, characterized in that: The image data of each defective component is specifically the offset length of each defective component and the minimum distance between adjacent components of each defective component; The image data of each detection circuit is specifically the number of welding points of each detection circuit.

6. A circuit board defect detection system for use in a circuit board production process according to claim 1, characterized in that: The specific analysis process of the production quality index of each defective component is as follows: By performing production quality defect determination on each defective component and each detection line, production quality defect determination data of each defective component and production quality defect determination data of each detection line are obtained; The production quality defect determination data of each defective component specifically includes the average operating voltage, average operating current and maximum temperature of each defective component during the production quality assessment cycle; The average operating voltage of each defective component in the production quality assessment cycle is compared with the average operating current of each defective component in the production quality assessment cycle to obtain the average operating resistance of each defective component in the production quality assessment cycle; Extracting the operating resistance reference value, the adjacent matching spacing and the temperature reference value from the circuit board detection information library; The production quality index of each defective component is obtained through comprehensive analysis based on the average operating resistance of each defective component during the production quality assessment cycle, the maximum temperature of each defective component during the production quality assessment cycle, the offset length of each defective component and the minimum adjacent component spacing of each defective component.

7. A circuit board defect detection system for use in a circuit board production process according to claim 6, characterized in that: The specific analysis process of the production quality index of each detection line is as follows: Obtain the number of short-circuit position points of each detection circuit; The number of welding points of each detection circuit is processed by difference with the number of preset welding points of each detection circuit predefined in the circuit board detection information library to obtain the number of leaked welding of each detection circuit, and the ratio is processed with the preset number of welding points to obtain the percentage of leaked welding of each detection circuit; The production quality defect determination data of each detection line specifically includes the maximum spacing between adjacent lines of each detection line and the minimum response frequency of each detection line within a production quality assessment cycle; According to the minimum adjacent spacing of each defective component, the circuit adjacent spacing reference value corresponding to the minimum adjacent spacing interval of each component predefined in the circuit board detection information library is matched to obtain the circuit adjacent reference spacing; According to the average operating resistance of each defective component in the production quality assessment cycle, the minimum response frequency standard value corresponding to each operating resistance interval predefined in the circuit board detection information library is matched to obtain the minimum response frequency standard value; The production quality index of each detection line is obtained through comprehensive analysis based on the number of short-circuit position points of each detection line, the proportion of leaky welds of each detection line, the maximum spacing between adjacent lines of each detection line, and the minimum response frequency of each detection line within the production quality assessment cycle.

8. A circuit board defect detection system for use in a circuit board production process according to claim 7, characterized in that: The specific determination process of the production quality index of each detection line is as follows: In the formula, XL h is the production quality index of the hth detection line, h is the number of each detection line, h=1,2,3,...,H, H is the total number of detection lines, DL h is the number of short-circuit position points of the hth detection circuit, HL h is the percentage of leaking solder joints in the hth detection circuit, L h is the maximum spacing between adjacent lines of the hth detection line, L ′ is the reference distance between adjacent lines, P h is the minimum response frequency of the hth detection line in the production quality assessment cycle, P ′ is the standard value of the minimum response frequency, b2 is the production quality weight corresponding to the single short circuit location point predefined in the circuit board detection information library, b3 is the production quality weight corresponding to the leaking solder ratio predefined in the circuit board detection information library, and e is a natural constant.

9. A circuit board defect detection system for use in a circuit board production process according to claim 1, characterized in that: The specific feedback process of the production quality defect feedback of the components or the detection circuit is as follows: Verify the production quality index of each defective component with the predefined component production quality adaptation index. If the production quality index of a defective component is less than the component production quality adaptation index, feedback on the component production quality defect is given to the defective component. The production quality index of each detection line is checked against the predefined line production quality adaptation index. If the production quality index of a certain detection line is less than the line production quality adaptation index, feedback on line production quality defects is given to the detection line.

10. A method for a circuit board defect detection system used in a circuit board production process as claimed in any one of claims 1 to 9, characterized in that: include: Defective component statistics: detect the signal transmission of each component of the circuit board to be tested, determine the signal transmission evaluation index of each component of the circuit board to be tested, and compare it with the predefined signal transmission evaluation preset index to obtain the signal transmission comparison result. Based on the signal transmission comparison result, count the defective components, and obtain a number of lines corresponding to each defective component through line connection, which are recorded as each detection line; Automatic image acquisition: Automatically acquire images of the circuit board to obtain an image of the circuit board, from which the image data of each defective component and the image data of each detection circuit are extracted; Defect feedback: Determine the production quality defects of each defective component and each detection circuit, and combine the image data of each defective component and the image data of each detection circuit to obtain the production quality index of each defective component and the production quality index of each detection circuit. In this way, feedback on production quality defects is provided to components or detection circuits, and finally the circuit board defect detection in the circuit board production process is completed.

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