Flexible circuit board visual inspection device and flexible circuit board visual inspection method

Abstract

The application provides a flexible circuit board visual detection device, which comprises an illumination system, a detection platform, an image acquisition system, an image processing system, a control system and a flexible circuit board visual detection method using the system. The device can detect surface scratches and corrosion defects on both sides of the flexible circuit board, improves the comprehensiveness of detection, and thus improves the production quality of the flexible circuit board.

Description

Technical Field

[0001] This invention relates to the field of flexible circuit board inspection technology, and in particular to a flexible circuit board visual inspection device and a flexible circuit board visual inspection method using the system. Background Technology

[0002] With the continuous progress and development of society, various technologies are constantly improving. Flexible circuit boards are favored for their excellent characteristics such as light weight, thinness, convenient installation, and free bending and folding. By embedding circuit designs on flexible thin plastic sheets, a large number of precision components can be stacked in narrow and limited spaces, thereby forming flexible circuits.

[0003] Currently, quality inspection of flexible circuit boards mainly relies on manual visual inspection, which is costly and inefficient. With the rapid development of the electronics industry, circuit board designs are becoming increasingly precise and high-density, and traditional manual inspection methods can no longer meet production demands.

[0004] During the production of flexible circuit boards, improper operation often leads to scratches or corrosion on the surface of the flexible circuit boards due to liquid splashes. However, current machine vision automatic inspection of flexible circuit boards can mostly only detect solder joints and circuit defects, and cannot detect surface scratches and corrosion, which affects the production quality of flexible circuit boards. Therefore, there is an urgent need for a machine vision-based efficient calibration and inspection method for flexible circuit boards to solve the existing problems. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a flexible circuit board visual inspection device and a flexible circuit board visual inspection method using the system.

[0006] To achieve the above objectives, the present invention provides a visual inspection device for flexible circuit boards, comprising:

[0007] Lighting system, including drive mechanism and light source;

[0008] The testing platform includes a platform, and multiple clamping devices, multiple flipping devices and a carrier platform set on the platform. The carrier platform is fixed on the testing platform. The multiple flipping devices are symmetrically and evenly distributed on both sides of the carrier platform. Each flipping device is rotatably connected to a clamping device for clamping and fixing a flexible circuit board.

[0009] The image acquisition system includes a camera, which captures images of the flexible circuit board and then transmits the captured image information to the image processing system.

[0010] An image processing system, including an image processor, receives and processes data received from an image acquisition system;

[0011] The control system, including a terminal display screen, a storage module, and an alarm module, is used to control the visual inspection device.

[0012] The preferred embodiment of the above technical solution is: lifting devices are symmetrically arranged on both sides of the platform, and the tilting device is slidably arranged on one side opposite to the two lifting devices.

[0013] The preferred embodiment of the above technical solution is that there are two holding devices and two flipping devices.

[0014] The preferred embodiment of the above technical solution is: the alarm module is an alarm light and / or a voice unit.

[0015] The preferred embodiment of the above technical solution is: the light source is a ring light source.

[0016] The preferred embodiment of the above technical solution is: the image acquisition system is equipped with an area array image sensor.

[0017] The preferred embodiment of the above technical solution is: it also includes a robotic arm for picking up and placing flexible circuit boards.

[0018] The present invention also provides a visual inspection method for flexible circuit boards, which uses the flexible circuit board visual inspection device described above to inspect the flexible circuit board, and the steps are as follows:

[0019] S1: The robotic arm picks up the flexible circuit board and places it on the carrier platform, then illuminates the flexible circuit board using the lighting system.

[0020] S2: After the lifting platform is lowered, the clamping device clamps the flexible circuit board. After the image acquisition system acquires the original image of one side / front, the flexible circuit board is flipped and the original image of the other side / back is acquired. Then the two original images are converted into image information and transmitted to the image processing system.

[0021] S3: The image processing system processes the original image input into the image processing system to detect whether there are defects;

[0022] S4: When a defect is detected, the image processing system sends a signal to the control system and displays the defect on the terminal display screen, while storing the defect in the storage module; at the same time, the alarm module will issue an alarm through the voice unit and the alarm light will provide a light warning.

[0023] The preferred embodiment of the above technical solution is as follows: The internal processing flow of the image processing system includes the following steps:

[0024] Step 1: Preprocessing. Image processing techniques are used to preprocess the original front and back images acquired by the image acquisition system.

[0025] Step 2: Mathematical morphology processing, which involves applying nonlinear filtering to the preprocessed front and back original images;

[0026] Step 3: Masking. Using a mask created by an image processing algorithm that is suitable for flexible circuit boards, the non-flexible circuit board areas in the original front and back images are masked to reveal the edge line features of the flexible circuit board. Then, the original front and back images are segmented to extract the front and back images.

[0027] Step 4: Image comparison and detection processing. The front and back images of the masked image are copied, and then binarized and input into the hue-saturation color space unit respectively.

[0028] As described above, the flexible circuit board visual inspection device and the flexible circuit board visual inspection method using the system of the present invention can detect surface scratches and corrosion defects on both sides of the flexible circuit board, thereby improving the comprehensiveness of the inspection and thus improving the production quality of the flexible circuit board. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the testing platform.

[0030] Figure 2 This is a flowchart of the internal processing flow of an image processing system.

[0031] Component designation explanation

[0032] 1 platform

[0033] 2 Vehicle Platform

[0034] 3. Clamping device

[0035] 4. Tilting device

[0036] 5. Lifting device Detailed Implementation

[0037] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0038] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0039] like Figure 1 As shown, the present invention provides a visual inspection device for flexible circuit boards, including: a photo system, an inspection platform, an image acquisition system, and an image processing system.

[0040] The lighting system includes a drive mechanism and a light source. The drive mechanism can adjust the incident position of the light source so that the light source illuminates the flexible circuit board at a 45-degree angle, which improves the clarity of the image and is more conducive to image acquisition by the image acquisition system 2.

[0041] Furthermore, in this invention, a ring-shaped LED light source is preferably used, which has a larger illumination area and makes the field of view clearer.

[0042] The testing platform includes a platform 1, and multiple clamping devices 3, multiple flipping devices 4, and a carrier table 2 disposed on the platform 1. The carrier table 2 is fixed to the testing platform and is used to place the flexible circuit board to be tested. The multiple flipping devices 4 are symmetrically and evenly distributed on both sides of the carrier table 2, and each flipping device 4 is rotatably connected to a clamping device 3 for clamping and fixing the flexible circuit board during the testing process. When the clamping device 3 clamps the flexible circuit board, the flipping device 4 can flip it, thereby realizing the testing of both sides of the flexible circuit board. In this invention, it is preferable to have two clamping devices 3 and two flipping devices 4.

[0043] In this invention, lifting devices 5 are preferably symmetrically arranged on both sides of the carrier platform, and a flipping device is slidably arranged on one side of the two lifting devices 5 facing each other. The flipping device can reciprocate in the sliding track, thereby driving the clamping device to move, so as to adjust the detection position of the flexible circuit board.

[0044] The image acquisition system includes a camera, which takes pictures of the flexible circuit board and then transmits the captured image information to the image processing system.

[0045] Furthermore, the image acquisition system is also connected to a robotic arm to pick up flexible circuit boards and place them onto the carrier platform 2.

[0046] An image processing system includes an image processor that receives and processes data received from an image acquisition system.

[0047] The control system includes a terminal display screen, a storage module, and an alarm module, used to control the visual inspection device. The terminal display screen can show defects in the flexible circuit board, making it easy for users to understand the location of the defects. The alarm module is preferably connected to a voice unit and / or an alarm light. The voice unit and the alarm light can respectively emit prompt sounds and provide light warnings, enabling operators to promptly detect defective products and clearly understand the location of the defects, thereby improving the detection rate and significantly improving product quality.

[0048] The present invention also provides a visual inspection method for flexible circuit boards, which uses the flexible circuit board visual inspection device described above to inspect the flexible circuit board, and the steps are as follows:

[0049] S1: The robotic arm picks up the flexible circuit board and places it on the carrier platform 2, and illuminates the flexible circuit board using the lighting system.

[0050] S2: After the lifting platform is lowered, the clamping device 3 clamps the flexible circuit board. After acquiring the original image of one side / front through the image acquisition system, the flexible circuit board is flipped and the original image of the other side / back is acquired. Then the two original images are converted into image information and transmitted to the image processing system.

[0051] S3: The image processing system processes the original image input into the image processing system to detect whether there are defects;

[0052] S4: When a defect is detected, the image processing system sends a signal to the control system and displays the defect on the terminal display screen, while storing the defect in the storage module; at the same time, the alarm module will issue an alarm through the voice unit and the alarm light will provide a light warning.

[0053] Furthermore, such as Figure 2 As shown, the internal processing flow of the image processing system includes the following steps:

[0054] Step 1: Preprocessing. Image processing techniques are used to preprocess the original front and back images acquired by the image acquisition system to improve the quality of the original images.

[0055] Step 2: Mathematical morphology processing. Nonlinear filtering is applied to the preprocessed front and back original images to suppress noise in the acquired original images caused by factors such as machine vibration or differences in the sensitivity of electrical coupling components, thereby further improving the clarity of the original images.

[0056] Step 3: Masking. Using a processing area mask created by an image processing algorithm, suitable for flexible circuit boards, the non-flexible circuit board areas in the original front and back images are masked to reveal the edge line features of the flexible circuit board. Then, the original front and back images are segmented and the front and back images are extracted.

[0057] Step 4: Image comparison and detection processing. Copy the front and back images after masking, and then perform binarization and input hue-saturation color space units respectively.

[0058] Furthermore, in step four, the front and back black and white flexible circuit board images after binarization are matched for defect detection. A global image matching comparison algorithm is used to match the front and back black and white flexible circuit board images with the front and back black and white example images point by point. After discovering suspected solder joints and circuit defects, the region is grown based on these points for local individual matching.

[0059] The input image comparison unit, which processes the front and back color flexible circuit board images by the input hue saturation color space unit, extracts color and texture defects from the front and back flexible circuit board images by comparing them with example front and back color images, thereby detecting surface scratches and corrosion defects in the front and back color flexible circuit board images.

[0060] Specifically, in the image comparison and detection process of the image processing system, after copying the images of the front and back flexible circuit boards, binarization processing and input hue-saturation color space units are performed respectively, so that the flexible circuit board image detection process is divided into two directions. The binarization processing can detect solder joints and circuit defects in the flexible circuit board image; the flexible circuit board image input to the hue-saturation color space unit is adjusted, and its hue, brightness and color saturation will be clearer.

[0061] By comparing the front and back color sample images through the image comparison unit, color and texture defects of the front and back color flexible circuit board images can be extracted, and surface scratches and corrosion defects of the front and back color flexible circuit board images can be detected, which improves the comprehensiveness of flexible circuit board inspection and increases the production quality of flexible circuit boards.

[0062] During image acquisition, factors such as uneven lighting, machine vibration, and differences in the sensitivity of CCD sensors (industrial cameras) can cause the acquired raw images to contain varying degrees of noise, resulting in blurred edges in the processed images. Mathematical morphology processing, a nonlinear filtering method, uses structural elements of a certain shape to measure and extract the corresponding shapes in the raw image, thereby preserving the original details, suppressing noise, and improving the clarity of the raw image. At the same time, masking can occlude non-flexible circuit board areas in the raw image, revealing the edge line features of the flexible circuit board. After segmenting the raw image, the front and back flexible circuit board images can be extracted, facilitating image comparison and detection, and increasing the practicality of flexible circuit board image detection.

[0063] The flexible circuit board visual inspection device and the flexible circuit board visual inspection method using the system disclosed in this invention can detect surface scratches and corrosion defects on both sides of the flexible circuit board, improving the comprehensiveness of the inspection and thus improving the production quality of the flexible circuit board.

[0064] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A visual inspection device for flexible circuit boards, characterized in that, include: A robotic arm is used to pick up and place the flexible circuit board; Lighting system, including drive mechanism and light source; The testing platform includes a platform, and multiple clamping devices, multiple flipping devices, and a carrier platform disposed on the platform. The carrier platform is fixed on the platform. The multiple flipping devices are symmetrically and evenly distributed on both sides of the carrier platform. Each flipping device is rotatably connected to a clamping device for clamping and fixing a flexible circuit board. The image acquisition system includes a camera, which captures images of the flexible circuit board and then transmits the captured image information to the image processing system. An image processing system, including an image processor, receives and processes data received from the image acquisition system; The control system includes a terminal display screen, a storage module, and an alarm module, used to control the visual inspection device; The platform is symmetrically provided with lifting devices on both sides, and the tilting device is slidably disposed on the opposite side of the two lifting devices. The flexible circuit board visual inspection device inspects the flexible circuit board, and the steps are as follows: S1: The robotic arm picks up the flexible circuit board and places it on the carrier platform, and illuminates the flexible circuit board using the lighting system; S2: After the lifting device is lowered, the clamping device clamps the flexible circuit board. After the image acquisition system acquires the original image of the front side, the flexible circuit board is flipped over and the original image of the back side is acquired. Then, the two original images are converted into image information and transmitted to the image processing system. S3: The image processing system processes the original image input into the image processing system; S4: When a defect is detected, the image processing system sends a signal to the control system and displays the defect on the terminal display screen, while storing the defect in the storage module; at the same time, the alarm module will issue an alarm through the voice unit and the alarm light will provide a light warning. The internal processing flow of the image processing system includes the following steps: Step 1: Preprocessing. Image processing techniques are used to preprocess the original front and back images acquired by the image acquisition system. Step 2: Mathematical morphology processing, which involves applying nonlinear filtering to the preprocessed front and back original images; Step 3: Masking. Using a mask created by an image processing algorithm that is suitable for the flexible circuit board, the non-flexible circuit board areas in the original front and back images are masked to reveal the edge line features of the flexible circuit board. Then, the original front and back images are segmented to extract the front and back images. Step 4: Image comparison and detection processing. The front and back images after masking are copied, and then binarized and processed using the input hue-saturation color space unit, respectively. In step four, the front and back black and white flexible circuit board images after binarization are matched for defect detection. A global image matching comparison algorithm is used to match the front and back black and white flexible circuit board images with the front and back black and white example images point by point. After finding suspected solder joints and circuit defects, the region is grown based on these points and local individual matching is performed. The input image comparison unit, which processes the front and back color flexible circuit board images by the input hue saturation color space unit, extracts color and texture defects from the front and back flexible circuit board images by comparing them with example front and back color images, thereby detecting surface scratches and corrosion defects in the front and back color flexible circuit board images.

2. The flexible circuit board visual inspection device according to claim 1, characterized in that: There are two clamping devices and two flipping devices.

3. The flexible circuit board visual inspection device according to claim 1, characterized in that: The light source is a ring light source.

4. The flexible circuit board visual inspection device according to claim 1, characterized in that: The image acquisition system is equipped with an area array image sensor.

5. A visual inspection method for flexible circuit boards, characterized in that: The flexible circuit board is inspected using the flexible circuit board visual inspection device as described in any one of claims 1-4, and the steps are as follows: S1: The robotic arm picks up the flexible circuit board and places it on the carrier platform, and illuminates the flexible circuit board using the lighting system; S2: After the lifting device is lowered, the clamping device clamps the flexible circuit board. After the image acquisition system acquires the original image of the front side, the flexible circuit board is flipped over and the original image of the back side is acquired. Then, the two original images are converted into image information and transmitted to the image processing system. S3: The image processing system processes the original image input into the image processing system; S4: When a defect is detected, the image processing system sends a signal to the control system and displays the defect on the terminal display screen, while storing the defect in the storage module; at the same time, the alarm module will issue an alarm through the voice unit and the alarm light will provide a light warning.

6. The visual inspection method for flexible circuit boards according to claim 5, characterized in that: The internal processing flow of the image processing system includes the following steps: Step 1: Preprocessing. Image processing techniques are used to preprocess the original front and back images acquired by the image acquisition system. Step 2: Mathematical morphology processing, which involves applying nonlinear filtering to the preprocessed front and back original images; Step 3: Masking. Using a mask created by an image processing algorithm that is suitable for the flexible circuit board, the non-flexible circuit board areas in the original front and back images are masked to reveal the edge line features of the flexible circuit board. Then, the original front and back images are segmented to extract the front and back images. Step 4: Image comparison and detection processing. The front and back images after masking are copied, and then binarized and processed using the input hue-saturation color space unit, respectively.

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