PCB warpage detection method and apparatus

Abstract

The application is suitable for the field of PCB detection technology, and particularly relates to a PCB warping detection method and device. The PCB warping detection method comprises the following steps: obtaining a first type of image of a PCB; obtaining first feature information according to the first type of image; obtaining a second type of image of the PCB; wherein the motion state of the PCB in the second type of image is different from that in the first type of image; the exposure time length of the second type of image is greater than that of the first type of image; obtaining second feature information according to the second type of image; and determining the warping condition of the PCB according to the first feature information and the second feature information. The method detects the PCB in static and dynamic states respectively, and verifies the detection results to determine the warping condition of the PCB, thereby effectively improving the accuracy of detecting the warping condition of the PCB and reducing misjudgment and missed detection.

Description

Technical Field

[0001] This application belongs to the field of PCB testing technology, and in particular relates to PCB warpage testing methods and equipment. Background Technology

[0002] A PCB, or Printed Circuit Board, is the carrier for electrical connections between electronic components. The flatness of the PCB is a prerequisite for maintaining good connections between electronic components.

[0003] In existing technologies, the flatness of PCB boards is usually tested using contact methods. However, for small PCB boards, contact testing methods can easily damage the PCB board. Existing non-contact testing methods are not accurate enough and cannot accurately determine whether the PCB board is warped. Summary of the Invention

[0004] This application provides a PCB warpage detection method and device, which can solve the technical problem of not being able to accurately determine whether warpage has occurred on small-sized PCBs.

[0005] In a first aspect, embodiments of this application provide a PCB warpage detection method, applied to a PCB warpage detection device; the PCB warpage detection method includes: Acquire a first type of image of the PCB board; wherein the PCB board in the first type of image is in a static state; Based on the first type of image, first feature information is obtained; wherein, the first feature information is used to indicate the presence of warping on the PCB board; A second type of image of the PCB board is acquired; wherein the PCB board in the second type of image is in motion; the exposure time for acquiring the second type of image is greater than the exposure time for acquiring the first type of image; Based on the second type of image, second feature information is obtained; wherein, the second feature information is used to indicate the presence of warping on the PCB board; The warping of the PCB board is determined based on the first feature information and the second feature information.

[0006] The technical solutions described in this application embodiment have at least the following technical effects: This method performs tests on the PCB board under both static and dynamic conditions, cross-referencing the results to determine the warping status of the PCB board. This effectively improves the accuracy of PCB board warping detection, reduces false positives and missed detections, and employs non-contact testing to avoid damaging the PCB board during testing. It can adapt to PCB boards of different sizes and materials, giving the PCB warping detection equipment good adaptability and effectively improving testing efficiency.

[0007] In one possible implementation of the first aspect, acquiring the first type of image of the PCB board includes: Turn on the first light source; Issue the first acquisition command to obtain the first image; Control the first light source to turn off, and control the second light source to turn on; Issue the first acquisition command to acquire the second image; The first image and the second image are identified as the first type of image.

[0008] In one possible implementation of the first aspect, obtaining the first feature information based on the first type of image includes: Extract the first shadow information from the first image; wherein the first shadow information is used to indicate the area and position of the shadow of the PCB board in the first image; Extract the second shadow information from the second image; wherein the second shadow information is used to indicate the area and position of the shadow of the PCB board within the second image; The first feature information is obtained based on the first shadow information and the second shadow information.

[0009] In one possible implementation of the first aspect, acquiring the second type of image of the PCB board includes: Perform a first vibration operation; wherein the first vibration operation is used to vibrate the PCB board; Issue a second acquisition command to obtain a third image; Perform a second vibration operation; wherein the second vibration operation is used to vibrate the PCB board; the vibration direction of the second vibration operation is different from that of the first vibration operation; Issue a second acquisition command to obtain a fourth image; The third image and the fourth image are identified as images of the second type.

[0010] In one possible implementation of the first aspect, obtaining the second feature information based on the second type of image includes: Obtain the motion state information of the PCB board in the second type of image; Based on the motion state information of the PCB board in the second type of image, the second type of image is analyzed to obtain the second feature information.

[0011] In one possible implementation of the first aspect, obtaining the motion state information of the PCB board in the second type of image includes: Obtain the first vibration information of the first vibration operation; Obtain the second vibration information of the second vibration operation; The first vibration information and the second vibration information are determined as the motion state information of the PCB board in the second type of image.

[0012] In one possible implementation of the first aspect, the step of analyzing the second type of image based on the motion state information of the PCB board in the second type of image to obtain the second feature information includes: Based on the first vibration information, the third image is analyzed to obtain the first abnormality information; Based on the second vibration information, the fourth image is analyzed to obtain the second anomaly information; The second feature information is obtained based on the first anomaly information and the second anomaly information.

[0013] In one possible implementation of the first aspect, the step of analyzing the third image based on the first vibration information to obtain the first abnormality information includes: Extract multiple first line information from the third image; Based on the first vibration information, multiple pieces of the first line information are filtered, and the mismatched first line information is identified as the first abnormal information. The step of analyzing the fourth image based on the second vibration information to obtain the second abnormal information includes: Extract multiple second line information from the fourth image; Based on the second vibration information, multiple pieces of the second line information are filtered, and the mismatched second line information is identified as the second abnormal information.

[0014] In one possible implementation of the first aspect, determining the warpage of the PCB board based on the first feature information and the second feature information includes: The first feature information and the second feature information are matched to obtain matching degree data; Based on the matching degree data, the warpage of the PCB board is determined.

[0015] Secondly, embodiments of this application provide a PCB warpage detection system, including: A first acquisition unit is configured to acquire a first type of image of a PCB board; wherein the PCB board in the first type of image is in a static state; A first analysis unit is configured to obtain first feature information based on the first type of image; wherein the first feature information is used to indicate the presence of warping on the PCB board; The second acquisition unit is used to acquire a second type of image of the PCB board; wherein the PCB board in the second type of image is in motion; and the acquisition exposure time of the second type of image is greater than the acquisition exposure time of the first type of image. The second analysis unit is used to obtain second feature information based on the second type of image; wherein the second feature information is used to indicate the presence of warping on the PCB board; A determining unit is configured to determine the warping condition of the PCB board based on the first feature information and the second feature information.

[0016] Thirdly, embodiments of this application provide a PCB warpage detection device, including: The testing platform has a testing surface; An image acquisition device is disposed on the detection platform; the image acquisition device is used to acquire images of the PCB board on the detection plane. A vibration generator is disposed on the detection plane; the vibration generator is used to cause the PCB board on the detection plane to vibrate. A control device is disposed on the detection platform; the control device is electrically connected to the image acquisition device and the vibration generator respectively.

[0017] Fourthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes a PCB warpage detection device to execute the PCB warpage detection method described in any one of the first aspects.

[0018] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of a PCB warpage detection method provided in an embodiment of this application; Figure 2 This is a schematic diagram of the implementation process of step S100 in a PCB warpage detection method provided in an embodiment of this application; Figure 3This is a schematic diagram of the implementation process of step S200 in a PCB warpage detection method provided in an embodiment of this application; Figure 4 This is a schematic diagram of the implementation process of step S300 in a PCB warpage detection method provided in an embodiment of this application; Figure 5 This is a schematic diagram of the implementation process of step S400 in a PCB warpage detection method provided in an embodiment of this application; Figure 6 This is a schematic diagram of the implementation process of step S410 in a PCB warpage detection method provided in an embodiment of this application; Figure 7 This is a schematic diagram of the implementation process of step S420 in a PCB warpage detection method provided in an embodiment of this application; Figure 8 This is a schematic diagram of the implementation process of step S4201 in the PCB warpage detection method provided in an embodiment of this application; Figure 9 This is a schematic diagram of the implementation process of step S4202 in the PCB warpage detection method provided in an embodiment of this application; Figure 10 This is a schematic diagram of the implementation process of step S500 in the PCB warpage detection method provided in an embodiment of this application; Figure 11 This is a schematic diagram of the PCB warpage detection device provided in the embodiments of this application; Figure 12 This is a schematic diagram of the PCB warpage detection system provided in the embodiments of this application; Figure 13 This is a schematic diagram of the control device of the PCB warpage detection equipment provided in the embodiments of this application.

[0021] The following are the labeling elements in the figure: 100. PCB warpage detection equipment; 10. Detection platform; 20. Image acquisition device; 30. Vibration generator; 40. Control device. Detailed Implementation

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0023] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0024] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0025] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0026] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0028] In existing technologies, the flatness of PCB boards is usually tested using contact methods. However, for small PCB boards, contact testing methods can easily damage the PCB board. Existing non-contact testing methods are not accurate enough and cannot accurately determine whether the PCB board is warped.

[0029] To address the aforementioned problems, this application provides a PCB warpage detection method and apparatus. This method, applied to a PCB warpage detection apparatus, involves acquiring a first type of image of the PCB board; obtaining first feature information based on the first type of image; acquiring a second type of image of the PCB board; wherein the motion state of the PCB board in the second type of image differs from that in the first type of image; the exposure time for acquiring the second type of image is longer than that for acquiring the first type of image; obtaining second feature information based on the second type of image; and determining the warpage of the PCB board based on the first and second feature information. This method, by performing detection on the PCB board in both static and dynamic states and cross-referencing the static and dynamic detection results, effectively improves the accuracy of PCB warpage detection, reduces false positives and missed detections, and employs non-contact detection to avoid damage to the PCB board during inspection. It is adaptable to PCB boards of different sizes and materials, giving the PCB warpage detection apparatus good adaptability and effectively improving detection efficiency.

[0030] The PCB warpage detection method provided in this application embodiment can be applied to the PCB warpage detection device 100. In this case, the PCB warpage detection device 100 is the execution subject of the PCB warpage detection method provided in this application embodiment. This application embodiment does not impose any restrictions on the specific type of PCB warpage detection.

[0031] For example, please see Figure 11 The PCB warpage detection equipment 100 may include a detection platform 10, an image acquisition device 20, a vibration generator 30, and a control device 40. The detection platform 10 has a detection plane; the image acquisition device 20 is disposed above the detection platform 10; the vibration generator 30 is disposed on the detection plane; and the control device 40 is disposed on the detection platform 10, and the control device 40 is electrically connected to the image acquisition device 20 and the vibration generator 30 respectively.

[0032] It is understood that the inspection platform 10 is a component used to provide a flat surface for placing the PCB board, such as a metal workbench or a flat conveyor belt, but not limited to these. The image acquisition device 20 is a device used to acquire images of the PCB board surface. The image acquisition device 20 may include multiple light sources and at least one image acquisition device. The angles formed by the light rays from the multiple light sources and the surface of the PCB board are different, and the multiple light sources can be independently controlled to be switched on and off separately. The image acquisition device is positioned directly above the PCB board, and the incident light angle of the image acquisition device is perpendicular to the upper surface of the PCB board. The image acquisition device may be a CCD camera or a high-speed camera, but not limited to these. The vibration generator 30 is a component used to vibrate the PCB board to change the motion state of the PCB board. The vibration generator 30 may be an electromagnetic vibration generator 30 or a rotating eccentric block vibration generator 30, but not limited to these. The control device 40 may be a tablet computer, a laptop computer, a desktop computer, a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, a computer, a laptop computer, a handheld communication device, a handheld computing device, etc.

[0033] This setup, with an image acquisition device 20 including multiple light sources on the inspection platform 10, allows for easy detection of PCB warpage in a static state by using different incident angles from the multiple light sources. A vibration generator 30 is also installed on the inspection platform 10. The PCB under inspection is placed on the vibration generator 30, which alters the PCB's motion state, amplifying the warpage anomaly in a dynamic manner. By verifying the static and dynamic inspection results, the warpage condition of the PCB is determined, effectively improving the accuracy of PCB warpage detection, reducing false positives and missed detections. Furthermore, the non-contact inspection method avoids damage to the PCB during inspection and can adapt to PCBs of different sizes and materials, giving the PCB warpage detection equipment 100 good adaptability and effectively improving inspection efficiency.

[0034] To better understand the PCB warpage detection method provided in this application, the specific implementation process of the PCB warpage detection method provided in this application will be described below by way of example.

[0035] Figure 1 This illustration shows a schematic flowchart of a PCB warpage detection method provided in an embodiment of this application. The PCB warpage detection method includes: S100, acquire the first type of image of the PCB board; wherein, the PCB board in the first type of image is in a static state.

[0036] It can be understood that the first type of image is an image of the PCB board when the PCB board is in a static state. The first type of image may include multiple images, and the light source in each image may be changed, such as the incident angle of the light source, the color of the light source, the frequency of the light source, etc., but is not limited to these.

[0037] As an optional embodiment of this application, please refer to Figure 2 S100, acquire the first type of image of the PCB board, including: S110 controls the first light source to turn on.

[0038] It can be understood that the incident angle of the first light source on the upper surface of the PCB board is the first preset angle.

[0039] S120 issues the first acquisition command to acquire the first image.

[0040] It can be understood that the first acquisition command is used to control the image acquisition device to acquire an image of the PCB board surface with a short exposure time. The shutter speed of the image acquisition device can be 1 / 60 second or 1 / 250 second, but is not limited to these. The first image is the image of the upper surface of the PCB board when it is in a static state, with the incident angle of the light source at a first preset angle.

[0041] S130 controls the first light source to turn off and the second light source to turn on.

[0042] It can be understood that the incident angle of the second light source on the upper surface of the PCB board is a second preset angle, which is not equal to the first preset angle. The brightness of the second light source can be equal to the brightness of the first light source.

[0043] S140 issues the first acquisition command to acquire the second image.

[0044] It can be understood that the second image is the image of the upper surface of the PCB board when the light source is incident at a second preset angle, and the PCB board is in a static state.

[0045] S150, the first image and the second image are identified as images of the first class.

[0046] It can be understood that the first image and the second image are surface images of the PCB board when it is static, with light sources shining on the PCB board surface at different incident angles, and the image acquisition device acquiring the images at the same angle.

[0047] With this setup, surface images of the PCB board are acquired when the first light source and the second light source are turned on, resulting in a first image and a second image. The first image and the second image are images of the PCB board under static conditions from two different light sources. By acquiring images from two different light sources, it is possible to avoid missed detections caused by the lack of obvious warping features under a single light source, thereby enhancing the richness of feature information and improving the reliability, comprehensiveness, and effectiveness of the detection results.

[0048] S200, based on the first type of image, obtain first feature information; wherein, the first feature information is used to indicate the presence of warping on the PCB board.

[0049] It is understood that the first feature information is the basis for determining the presence of warping on the PCB board in the first type of image. For example, it could be the area, position, and shape of a shadow on the PCB board in the image, the area, position, and shape of a bright spot, the length of the diagonal of the PCB board, or the area of ​​the upper surface of the PCB board, but it is not limited to these. The first feature information can be obtained by measuring the first type of image using image processing software such as Photoshop or CAD, but it is not limited to these methods. The first feature information of a flat PCB board is used as the standard feature information. When the PCB board warps, the first feature information obtained in the first type of image differs from the standard feature information of a flat PCB board, thus indicating the presence of warping on the PCB board.

[0050] As an optional embodiment of this application, please refer to Figure 3 S200, Based on the first type of image, obtain the first feature information, including: S210, Extract the first shadow information from the first image.

[0051] It is understood that the first shadow information includes the area and location of the shadow within the first image. This can be obtained by inputting the first image into image processing software, converting it into a grayscale image, and then using the image processing software to statistically analyze the grayscale values ​​to determine the area where the shadow is located and its grayscale range. Alternatively, edge detection algorithms (such as Canny edge detection, Sobel edge detection, etc.) can be used to detect edge information in the first image, and then the shadow area can be located by combining the edge information to determine the boundary and range of the shadow, thereby obtaining the first shadow information. However, this method is not limited to these methods.

[0052] S220, Extract the second shadow information from the second image.

[0053] It is understood that the second shadow information includes the area and position of the shadow within the second image, and can be obtained in the same way as the first shadow information.

[0054] S230, based on the first shadow information and the second shadow information, the first feature information is obtained.

[0055] It can be understood that the position information of the shadow in the first image in the first shadow information is compared with the position information of the shadow in the second image in the second shadow information, and the overlapping part is marked. The position information of the overlapping part is the position information of various parts on the PCB board that are not on the same plane as the upper surface of the PCB board, and the position information of the overlapping part is the first feature information.

[0056] With this setup, the first shadow information and the second shadow information are extracted from the first image and the second image acquired when the PCB board is in a static state, respectively. The overlapping part of the first shadow information and the second shadow information is marked to obtain the first feature information. This can accurately and completely detect the warping position on the PCB board when the PCB board is in a static state, thus improving the detection sensitivity of warping on the PCB board.

[0057] S300, acquire a second type of image of the PCB board; wherein the PCB board in the second type of image is in motion; the acquisition exposure time of the second type of image is greater than the acquisition exposure time of the first type of image.

[0058] It is understandable that the second type of image is an image of the PCB board captured with a long exposure time while the PCB board is in motion. The exposure time of the second type of image is greater than 1 second.

[0059] As an optional embodiment of this application, please refer to Figure 4 S300, acquires the second type of image of the PCB board, including: S310, perform the first vibration operation; wherein, the first vibration operation is used to vibrate the PCB board.

[0060] It is understandable that the first vibration operation is to control the vibration generator 30 to vibrate along the length of the PCB board, thereby causing the PCB board to move back and forth along its own length. If there is warping on the PCB board, the balance of the PCB board will be disrupted and it will shake on the detection platform 10. The movement trajectory of the warped part will be different from the length direction of the PCB board.

[0061] S320 issues a second acquisition command to obtain a third image.

[0062] It is understood that the second acquisition command is used to control the image acquisition device to acquire a surface image of the PCB board with a long exposure time. The shutter speed of the image acquisition device can be 1 second or 2 seconds, but is not limited to this. The third image is the image obtained by the image acquisition device 20 with long exposure under the action of the first vibration operation. Under long exposure, the reciprocating movement trajectory of the PCB board along its own length direction is displayed as a linear trailing shadow in the image. If there is warping on the PCB board, the movement trajectory of the warped part is displayed as an arc-shaped trailing shadow or a straight trailing shadow that is different from its own length direction in the image.

[0063] S330, execute the second vibration operation; wherein, the second vibration operation is used to vibrate the PCB board; the vibration direction of the second vibration operation is different from that of the first vibration operation.

[0064] It can be understood that the second vibration operation is to control the vibration generator 30 to vibrate along the width direction of the PCB board, thereby causing the PCB board to move back and forth along its own width direction.

[0065] S340 issues a second acquisition command to acquire a fourth image.

[0066] It can be understood that the fourth image is an image obtained by the image acquisition device 20 using long exposure under the action of the second vibration operation on the PCB board. If there is warping on the PCB board, the movement trajectory of the warped part will be displayed in the image as an arc-shaped trailing shadow or a straight trailing shadow that is different from its own width direction.

[0067] S350, the third and fourth images are identified as images of the second class.

[0068] This setup, by vibrating the PCB board in two different directions and acquiring third and fourth images under each vibration operation using long exposure, allows for the acquisition of PCB board warpage data from multiple dimensions. This increases the amount of material available for assessing PCB board warpage, provides a basis for dynamic feature comparison in subsequent analysis, and helps to more accurately determine the warpage.

[0069] S400, based on the second type of image, obtain second feature information; wherein, the second feature information is used to indicate the presence of warping on the PCB board.

[0070] It is understood that the second feature information is the basis information used in the second type of image to determine whether there is warping on the PCB board. For example, it may include the presence of trailing lines in the second type of image that are different from the vibration direction, as well as the line direction and line position, but is not limited to this.

[0071] As an optional embodiment of this application, please refer to Figure 5S400, based on the second type of image, obtain the second feature information, including: S410, acquire motion state information of the PCB board in the second type of image.

[0072] It is understandable that motion state information is used to indicate the vibration direction of the PCB board.

[0073] In one possible implementation, please refer to Figure 6 S410, acquire motion state information of the PCB board in the second type of image, including: S4101, Obtain the first vibration information of the first vibration operation.

[0074] It is understood that the first vibration information includes the vibration direction and amplitude of the first vibration operation. The first vibration information can be fixed data preset within the PCB warpage detection device 100, or it can be input by the operator for modification, but is not limited to this.

[0075] S4102, Obtain the second vibration information of the second vibration operation.

[0076] It can be understood that the second vibration information includes the vibration direction and amplitude of the second vibration operation. The method for obtaining the second vibration information is the same as the method for obtaining the first vibration information.

[0077] S4103, the first vibration information and the second vibration information are determined as the motion state information of the PCB board in the second type of image.

[0078] With this setup, the motion state information of the PCB board in the second type of image is obtained based on the first vibration information and the second vibration information. The vibration information of the PCB warping detection device 100 is converted into the motion state information of the PCB board, which is beneficial for intuitive observation and detection of the PCB board, realizing accurate motion state analysis, and facilitating correlation analysis with image information.

[0079] S420: Based on the motion state information of the PCB board in the second type of image, analyze the second type of image to obtain the second feature information.

[0080] It is understandable that, based on the motion state information of the PCB board in the second type of image, the moving distance and displacement trajectory of the warped PCB board can be calculated. For example, an initial image of the PCB board is generated, and each pixel in the initial image is used as its midpoint, with the vibration direction in the vibration information as its direction, and the vibration amplitude as its length to generate a straight line, thereby simulating the generation of a standard second type image of a warped PCB board. The standard second type image is then compared with the third and fourth images respectively to obtain the second feature information.

[0081] In one possible implementation, please refer to Figure 7S420, Based on the motion state information of the PCB board in the second type of image, analyze the second type of image to obtain the second feature information, including: S4201, based on the first vibration information, analyze the third image to obtain the first abnormal information.

[0082] It is understandable that the first abnormal information is the line information in the third image whose length and direction do not match the amplitude and direction indicated by the first vibration information. Based on the first vibration information, a standard second type image of the non-warped PCB board under the first vibration operation can be generated and compared with the third image. Lines in the third image whose direction or length is different from those in the standard second type image are extracted, and the position, length, and direction of the lines are taken as the first abnormal information.

[0083] For example, please refer to Figure 8 S4201, Based on the first vibration information, analyze the third image to obtain the first abnormal information, including: S42011, extract multiple first line information from the third image.

[0084] It is understood that the first line information includes the length, direction, and position coordinates of the lines in the third image. For example, the third image can be grayscaled or denoised, and edges in the image can be detected using the Canny or Sobel operators. The edge pixels in the edge image can be analyzed and fitted to obtain the parametric equations of the lines in the image, and then the length, direction, and position coordinates of the straight lines or curves in the third image can be calculated. Alternatively, the first line information in the third image can be extracted using a line extraction model. The line extraction model is trained using multiple sets of training data. Each set of training data includes a second type of image and identification information used to identify the length, direction, and position coordinates of the lines in the second type of image, but is not limited to this.

[0085] S42012, based on the first vibration information, multiple first line information are filtered, and the mismatched first line information is identified as the first abnormal information.

[0086] It is understood that the length and direction of the lines in the standard second-type image of a warp-free PCB board can be obtained based on the amplitude and direction of vibration in the first vibration information. The length of the lines in the standard second-type image of a warp-free PCB board is equal to the amplitude in the first vibration information, and the direction of the lines in the standard second-type image of a warp-free PCB board is parallel to the vibration direction in the first vibration information. Using the length and direction of the lines indicated by the first vibration information as reference information, all the first line information in the third image is compared. The first line information with differences in length or direction can be identified as the first abnormal line, and the position of the first abnormal line can be identified as the first abnormal information.

[0087] S4202, based on the second vibration information, analyze the fourth image to obtain the second anomaly information.

[0088] It can be understood that the second abnormal information is the line information in the fourth image whose length and direction do not match the amplitude and direction indicated by the second vibration information. Based on the second vibration information, a standard second type image of the non-warped PCB board under the second vibration operation can be generated and compared with the fourth image. Lines in the fourth image whose direction or length is different from those in the standard second type image are extracted, and the position, length, and direction of the lines are used as the second abnormal information.

[0089] For example, please refer to Figure 9 S4202, Based on the second vibration information, analyze the fourth image to obtain the second anomaly information, including: S42021, Extract multiple second line information from the fourth image.

[0090] It is understandable that the method for extracting the second line information can be the same as the method for extracting the first line information.

[0091] S42022, based on the second vibration information, multiple second line information are filtered, and the mismatched second line information is identified as the second abnormal information.

[0092] It is understandable that the method for filtering the second line information can be the same as the method for extracting the first line information.

[0093] This setup allows for the extraction of multiple first line information from the third image, which is then compared with first vibration information to filter out mismatched first anomalies. Similarly, multiple second line information from the fourth image is extracted and compared with second vibration information to filter out mismatched second anomalies. The first and second vibration operations cause the PCB board to undergo regular reciprocating motion, resulting in straight line trails on flat parts during long-exposure image acquisition, while warped parts form straight lines or arcs in different directions. This facilitates the rapid detection of PCB board warping, reduces the probability of false positives and false negatives, and effectively improves the accuracy and efficiency of the inspection process.

[0094] S4203, based on the first abnormal information and the second abnormal information, obtain the second feature information.

[0095] It is understandable that the position data of each abnormal line in the first abnormal information is compared with the position data of each abnormal line in the second abnormal information, and the position data that overlap are used as the second feature information.

[0096] By analyzing the third and fourth images, we can obtain first and second abnormal information that indicate length and direction different from vibration direction and amplitude. The abnormal information where the median data of the first and second abnormal information overlap is used as the second feature information. This allows us to accurately and completely obtain the warping position that can be detected on the PCB board in dynamic conditions. By analyzing and comparing from multiple dimensions, we can reduce the possibility of missed detections and misjudgments, and effectively improve the detection accuracy of the PCB board.

[0097] S500 determines the warping status of the PCB board based on the first feature information and the second feature information.

[0098] It is understandable that the actual warping of the PCB board can be obtained by comparing the overlapping parts of the warping data collected when the PCB board is in a static state and the warping data collected when the PCB board is in a dynamic state.

[0099] As an optional embodiment of this application, please refer to Figure 10 S500, based on the first feature information and the second feature information, determines the warpage of the PCB board, including: S510, Match the first feature information and the second feature information to obtain matching degree data.

[0100] It can be understood that the matching degree data refers to the percentage of the PCB board surface area where the first feature information and the second feature information simultaneously indicate warping. The position data in the first feature information is matched with the position data in the second feature information to obtain the overlapping position data where the position data in the first feature information and the position data in the second feature information are the same. For example, the PCB board can be divided into multiple regions, the number of regions with overlapping position data can be counted, and the result can be divided by the total number of regions to obtain the percentage of the PCB board surface area where warping exists, i.e., the matching degree data. Alternatively, the points where multiple overlapping position data are located can be connected by straight lines, the area enclosed by the multiple overlapping position data can be calculated, and the result can be divided by the total area of ​​the PCB board surface to obtain the percentage of the PCB board surface area where warping exists, i.e., the matching degree data. However, it is not limited to these methods.

[0101] S520 determines the warpage of the PCB board based on the matching degree data.

[0102] It is understandable that a threshold data can be preset, or the tester can input a threshold data, and the matching degree data can be compared with the threshold data. If the matching degree data is greater than or equal to the threshold data, it can be determined that the PCB board has warping; if the matching degree data is less than the threshold data, it can be determined that the PCB board does not have warping.

[0103] This setup allows for the collection of first and second feature information, serving as indicators of warpage on the PCB board, in both static and dynamic states. The first and second feature information are matched to determine overlap, yielding matching degree data. This matching degree data is then compared with a threshold value to ascertain the degree of warpage on the PCB board. By analyzing and matching static and dynamic PCB boards, warpage evidence verified from both static and dynamic perspectives is obtained. This multi-dimensional detection effectively improves the accuracy of PCB board warpage detection, reduces interference from single factors, enhances the stability of the detection process, eliminates the need for manual intervention, reduces labor costs, and improves detection efficiency and consistency, thus increasing overall detection efficiency.

[0104] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0105] Corresponding to the PCB warpage detection method described in the above embodiments, this application also provides a PCB warpage detection system, wherein each unit of the system can implement each step of the PCB warpage detection method. Figure 12 The diagram shows a structural block diagram of the PCB warpage detection system provided in the embodiments of this application. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0106] Reference Figure 12 The system includes: The first acquisition unit is used to acquire a first type of image of the PCB board. The first analysis unit is used to obtain first feature information based on the first type of image; wherein the first feature information is used to indicate the presence of warping on the PCB board; The second acquisition unit is used to acquire a second type of image of the PCB board; wherein the motion state of the PCB board in the second type of image is different from the motion state of the PCB board in the first type of image; and the acquisition exposure time of the second type of image is greater than that of the first type of image. The second analysis unit is used to obtain second feature information based on the second type of image; wherein the second feature information is used to indicate the presence of warping on the PCB board; The determining unit is used to determine the warpage of the PCB board based on the first feature information and the second feature information.

[0107] It should be noted that the information interaction and execution process between the above-mentioned units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0108] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units is merely an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the system can be divided into different functional units to complete all or part of the functions described above. The functional units in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0109] This application also provides a PCB warpage detection device 100, please refer to... Figure 11 The device includes a control unit 40. Figure 13 This is a schematic diagram of the structure of a control device 40 provided in an embodiment of this application. Figure 13 As shown, the control device 40 of this embodiment includes: at least one processor 41 ( Figure 13 Only one is shown in the image), at least one memory 42 ( Figure 13 (Only one is shown in the diagram) and a computer program 43 stored in the at least one memory 42 and executable on the at least one processor 41, wherein when the processor 41 executes the computer program 43, it causes the control device 40 to perform the steps in any of the above-described PCB warpage detection method embodiments, or causes the control device 40 to perform the functions of each unit in the above-described system embodiments.

[0110] For example, the computer program 43 may be divided into one or more units, which are stored in the memory 42 and executed by the processor 41 to complete this application. The one or more units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 62 in the electronic device 6.

[0111] The control device 40 can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The control device 40 may include, but is not limited to, a processor 41 and a memory 42. Those skilled in the art will understand that... Figure 13 This is merely an example of the control device 40 and does not constitute a limitation on the control device 40. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, buses, etc.

[0112] The processor 41 can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0113] In some embodiments, the memory 42 may be an internal storage unit of the control device 40, such as a hard disk or memory of the control device 40. In other embodiments, the memory 42 may be an external storage device of the control device 40, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the control device 40. Furthermore, the memory 42 may include both internal storage units and external storage devices of the control device 40. The memory 42 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory 42 can also be used to temporarily store data that has been output or will be output.

[0114] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0115] This application provides a computer program product that, when run on a PCB warpage detection device 100, enables the PCB warpage detection device 100 to perform the steps described in any of the above method embodiments.

[0116] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to the PCB warpage detection device 100, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0117] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0118] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0119] In the embodiments provided in this application, it should be understood that the disclosed PCB warpage detection device 100, PCB warpage detection system, and PCB warpage detection method can be implemented in other ways. For example, the PCB warpage detection system embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be indirect couplings or communication connections through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0120] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0121] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for detecting PCB warpage, characterized in that, Applied to PCB warpage detection equipment; the PCB warpage detection method includes: Acquire a first type of image of the PCB board; wherein the PCB board in the first type of image is in a static state; Based on the first type of image, first feature information is obtained; wherein, the first feature information is used to indicate the presence of warping on the PCB board; A second type of image of the PCB board is acquired; wherein the PCB board in the second type of image is in motion; the exposure time for acquiring the second type of image is greater than the exposure time for acquiring the first type of image; Based on the second type of image, second feature information is obtained; wherein, the second feature information is used to indicate the presence of warping on the PCB board; Based on the first feature information and the second feature information, the warpage of the PCB board is determined; The acquisition of the second type of image of the PCB board includes: Perform a first vibration operation; wherein the first vibration operation is used to vibrate the PCB board; Issue a second acquisition command to obtain a third image; Perform a second vibration operation; wherein the second vibration operation is used to vibrate the PCB board; the vibration direction of the second vibration operation is different from that of the first vibration operation; Issue a second acquisition command to obtain a fourth image; The third image and the fourth image are identified as images of the second type. The step of obtaining the second feature information based on the second type of image includes: Obtain the motion state information of the PCB board in the second type of image; Based on the motion state information of the PCB board in the second type of image, the second type of image is analyzed to obtain the second feature information; The step of obtaining the motion state information of the PCB board in the second type of image includes: Obtain the first vibration information of the first vibration operation; Obtain the second vibration information of the second vibration operation; The first vibration information and the second vibration information are determined as the motion state information of the PCB board in the second type of image; The step of analyzing the second type of images based on the motion state information of the PCB board in the second type of images to obtain the second feature information includes: Based on the first vibration information, the third image is analyzed to obtain the first abnormality information; Based on the second vibration information, the fourth image is analyzed to obtain the second anomaly information; The second feature information is obtained based on the first anomaly information and the second anomaly information; The step of analyzing the third image based on the first vibration information to obtain the first abnormality information includes: Extract multiple first line information from the third image; Based on the first vibration information, multiple pieces of the first line information are filtered, and the mismatched first line information is identified as the first abnormal information. The step of analyzing the fourth image based on the second vibration information to obtain the second abnormal information includes: Extract multiple second line information from the fourth image; Based on the second vibration information, multiple pieces of the second line information are filtered, and the mismatched second line information is identified as the second abnormal information.

2. The PCB warpage detection method as described in claim 1, characterized in that, The acquisition of the first type of image of the PCB board includes: Turn on the first light source; Issue the first acquisition command to obtain the first image; Control the first light source to turn off, and control the second light source to turn on; Issue the first acquisition command to acquire the second image; The first image and the second image are identified as the first type of image.

3. The PCB warpage detection method as described in claim 2, characterized in that, The step of obtaining the first feature information based on the first type of image includes: Extract the first shadow information from the first image; wherein the first shadow information is used to indicate the area and position of the shadow of the PCB board in the first image; Extract the second shadow information from the second image; wherein the second shadow information is used to indicate the area and position of the shadow of the PCB board within the second image; The first feature information is obtained based on the first shadow information and the second shadow information.

4. The PCB warpage detection method as described in claim 1, characterized in that, Determining the warpage of the PCB board based on the first feature information and the second feature information includes: The first feature information and the second feature information are matched to obtain matching degree data; Based on the matching degree data, the warpage of the PCB board is determined.

5. A PCB warpage detection device, comprising: The testing platform has a testing surface; An image acquisition device, wherein the image acquisition device is mounted on the detection platform; The image acquisition device is used to acquire images of the PCB board on the detection plane; A vibration generator is disposed on the detection platform; the vibration generator is used to vibrate the PCB board on the detection plane. A control device is disposed on the detection platform; the control device is electrically connected to the image acquisition device and the vibration generator control device respectively. The control device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the method as described in any one of claims 1 to 4.

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