Gold thread segmentation detection method and system in chip AOI detection, electronic equipment and computer readable medium

Abstract

The invention discloses a gold thread segmentation detection method and system in chip AOI detection, electronic equipment and a computer readable medium, and the method comprises the following steps: obtaining a chip image; performing welding spot positioning on the chip image to obtain a first welding spot coordinate and a second welding spot coordinate of a gold wire; calculating the length L and the inclination angle of the gold thread according to the coordinates of the first welding spot and the second welding spot; the gold wire is divided into a plurality of sections, each section corresponds to a detection area, the detection area is formed by connecting indented end points, and the indented end points are obtained through calculation according to coordinates of a first welding spot and a second welding spot, a preset indentation proportion, the length and the angle; for each section of gold thread, performing threshold segmentation by using the gray threshold corresponding to the section, and extracting the region of the section of gold thread; and judging whether the gold thread areas are communicated or not and whether the whole gold thread is communicated or not so as to determine whether the gold thread has defects or not. According to the invention, the gold thread detection algorithm complexity and cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor defect detection technology, and in particular to a method and system for gold wire segmentation detection in chip AOI inspection, electronic equipment, and computer-readable medium. Background Technology

[0002] As integrated circuit manufacturing processes continue to advance and packaging technologies develop towards higher density and performance, wire bonding (WB), as a core process for chip electrical interconnection, directly determines the reliability of the package and the performance of the final electronic device. In the WB process, micron-sized metal wires (usually gold wires) connect chip pads to external pins in specific spatial arcs, forming a precise path for electrical signal transmission. Therefore, the shape and position of the gold wires themselves, as well as the integrity of the bonding points, are crucial for evaluating WB quality and preventing potential failures.

[0003] Automated optical inspection (AOI) systems rely on high-precision two-dimensional image acquisition and analysis of gold wire. However, because gold wire is a cylindrical structure with spatial curvature, under illumination from a single fixed light source, different sections exhibit varying surface normal directions, resulting in significant differences in the light intensity reflected to the camera. This physical characteristic causes the same gold wire to display severe grayscale unevenness in the two-dimensional image; for example, some sections are bright, while others are dark or even lack sufficient contrast with the background.

[0004] Existing detection schemes based on traditional image processing algorithms typically aim to detect individual gold lines as a whole in a single operation. The core idea is to design or adopt robust and complex line-finding algorithms (such as dynamic programming and adaptive edge tracking) that can adapt to grayscale gradations in order to extract complete and continuous gold line contours directly from the background.

[0005] However, this "holistic detection" strategy faces significant bottlenecks in practical applications: 1. High algorithm complexity and significant time consumption: Complex line-finding algorithms require iterative calculations or global optimization to address interruptions and interference caused by uneven grayscale, resulting in enormous computational overhead. In high-density chip packaged images, processing time increases exponentially, hindering the production efficiency of real-time detection.

[0006] 2. Parameter sensitivity and difficulty in guaranteeing stability: The performance of this type of algorithm is highly dependent on the preset initial point, energy function parameters, or regularization constraints. Faced with different products, different lighting conditions, or slight changes in the shape of the gold wire, the algorithm may fail (such as wire divergence or premature termination), resulting in unstable detection results and requiring frequent manual intervention and parameter readjustment.

[0007] 3. High difficulty in engineering implementation and maintenance: Complex algorithm models are not easy to develop and debug, which increases the development and maintenance costs of the software and reduces the operability for users. Summary of the Invention

[0008] According to a first aspect of the present invention, a method for gold wire segmentation detection in chip AOI inspection is provided, comprising the following steps: Acquire chip image; Solder joints are located in the chip image to obtain the coordinates of one solder joint of the gold wire. and the coordinates of the two welding points ; Calculate the length L and tilt angle of the gold wire based on the coordinates of solder joint 1 and solder joint 2. ; The gold wire is divided into multiple segments, each corresponding to a detection area. The detection area is formed by connecting the indented endpoints. The indented endpoints are determined based on the coordinates of the first and second solder joints, a preset indentation ratio, and length. and angle Calculated; For each segment of gold line, use the corresponding grayscale threshold to perform threshold segmentation and extract the gold line region of that segment; Determine whether each segment of the gold thread is connected, and whether the entire gold thread is connected, in order to determine whether there are any defects in the gold thread.

[0009] Furthermore, solder joints are located on the chip image to obtain the coordinates of one solder joint of the gold wire. and the coordinates of the two welding points Specifically: Threshold segmentation is performed on the chip image to extract areas with gray values ​​within a preset range as potential solder joint areas; Perform an opening operation on the potential solder joint area to remove noise; For a given solder joint region, calculate the center of the inscribed circle as the coordinates of the solder joint. For the region with two weld points, the centroid is used as the coordinate of the two weld points. .

[0010] Furthermore, the length L and tilt angle of the gold wire The calculation formula is: ; .

[0011] Furthermore, the indented endpoints are calculated using the following formula: For the indentation in the direction of a solder joint, let the indentation ratio be... Then the coordinates of the indented solder joint for: ; For the indentation in the direction of the two weld points, let the indentation ratio be... Then the coordinates of the indented solder joint for: .

[0012] Furthermore, determining whether each gold wire segment is connected involves: for each gold wire segment, determining whether the extracted gold wire segment contains both of its corresponding indentation endpoints. If so, the segment is connected; otherwise, the segment is broken or offset.

[0013] Furthermore, determining whether the entire gold line is continuous involves: Merge the various gold line regions to obtain the connected region of the entire gold line; Determine the coordinates of the solder joint before indentation. and the coordinates of the two welding points If all lines are within a connected area, then the gold lines are normal; otherwise, there may be breaks or deviations.

[0014] Furthermore, the grayscale threshold corresponding to each gold line segment is set independently based on the actual grayscale distribution of that gold line segment in the image.

[0015] According to a second aspect of the present invention, a gold wire segmentation detection system for chip AOI inspection is provided, comprising the following steps: The image acquisition module is used to acquire chip images; The solder joint positioning module is used to locate solder joints in the chip image and obtain the coordinates of a solder joint for the gold wire. and the coordinates of the two welding points ; The parameter calculation module is used to calculate the length L and tilt angle of the gold wire based on the coordinates of the first and second solder joints. ; The segmented calculation module divides the gold wire into multiple segments, each corresponding to a detection area. Each detection area is formed by connecting the indented endpoints. The indented endpoints are determined based on the coordinates of the first and second solder joints, a preset indentation ratio, and length. and angle Calculated; The segmentation and extraction module is used to perform threshold segmentation on each segment of gold line using the corresponding grayscale threshold, and extract the gold line region of that segment. The defect detection module is used to determine whether each segment of the gold wire is connected, and whether the entire gold wire is connected, in order to determine whether there is a defect in the gold wire.

[0016] According to a third aspect of the present invention, an electronic device is provided, comprising: a memory, a processor, and a computer program, wherein the computer program is stored in the memory, and the processor executes the computer program to perform a gold wire segmentation detection method in chip AOI detection according to the first aspect.

[0017] According to a fourth aspect of the present invention, a computer-readable medium having processor-executable non-volatile program code is provided, the program code causing the processor to perform a method for gold wire segmentation detection in chip AOI inspection according to the first aspect.

[0018] A method for segmented detection of gold wires in chip AOI inspection according to an embodiment of the present invention has the following beneficial effects: 1. The first and second weld points are located directly using threshold segmentation, which is simple to extract. The extraction of the first weld point avoids the complexity of adjusting multiple parameters using calipers, and the extraction of the second weld point avoids the use of template matching algorithms, thereby improving the extraction speed of weld points and reducing the algorithm time. 2. To address the issue of uneven grayscale along the same gold line, a segmented detection technique is proposed. The gold line is detected in segments according to a custom-defined indentation ratio, thus avoiding false detections caused by uneven grayscale. 3. Reduce the complexity of the gold line detection algorithm. Traditional algorithms rely more on line-finding algorithms to extract gold lines, which have many and complex parameters and are not easy to debug. This method directly uses threshold segmentation to extract gold lines, with fewer parameters, lower algorithm complexity, and easier debugging, thus reducing the cost of algorithm development and maintenance.

[0019] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0020] Figure 1 This is a flowchart of a gold wire segmentation detection method in chip AOI inspection according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram illustrating the calculation of the endpoint after indentation along a solder joint direction in a gold wire segmentation detection method for chip AOI inspection according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram illustrating the division of a gold wire into two segments in a gold wire segmentation detection method for chip AOI inspection according to an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram illustrating the single-segment detection of gold wires in a gold wire segmentation detection method according to an embodiment of the present invention.

[0024] Figure 5This is a structural diagram of a gold wire segmentation detection system for chip AOI inspection according to an embodiment of the present invention.

[0025] Figure 6 This is a structural diagram of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0026] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, further illustrating the present invention.

[0027] First, combine Figures 1-4 This invention describes a method for segmented detection of gold wires in chip AOI inspection, which is widely used in chip AOI inspection.

[0028] like Figures 1-4 As shown in the figure, a method for gold wire segmentation detection in chip AOI inspection according to an embodiment of the present invention includes the following steps: like Figure 1 As shown, in S1, the chip image is acquired.

[0029] like Figure 1 As shown, in S2, solder joints are located on the chip image to obtain the coordinates of one solder joint of the gold wire. and the coordinates of the two welding points Specifically: Threshold segmentation is performed on the chip image to extract regions with grayscale values ​​within a preset range as potential solder joint areas; threshold segmentation can be achieved using... The formula is performed, where It is an image exist The grayscale value of the coordinates. It is the lower limit of the grayscale of the solder joint. It is the upper limit of grayscale for solder joints.

[0030] Perform an opening operation on the potential solder joint area to remove noise; the opening operation can be performed using... The formula is used, where... The image is to be processed. The structure element representing the opening operation.

[0031] For a given solder joint region, calculate the center of the inscribed circle as the coordinates of the solder joint. For the region with two weld points, the centroid is used as the coordinate of the two weld points. .

[0032] like Figure 1 As shown, in S3, the length L and tilt angle of the gold wire are calculated based on the coordinates of solder joint one and solder joint two. The length L and tilt angle of the gold wire. The calculation formula is: ; .

[0033] like Figures 1-3 As shown, in S4, the gold wire is divided into multiple segments, each corresponding to a detection area. The detection area is formed by connecting the indented endpoints. The indented endpoints are determined based on the coordinates of the first and second solder joints, the preset indentation ratio, and the length. and angle The calculated result is as follows: The indented endpoints are calculated using the following formula: For the indentation in the direction of a solder joint, let the indentation ratio be... Then the coordinates of the indented solder joint for: ; For the indentation in the direction of the two weld points, let the indentation ratio be... Then the coordinates of the indented solder joint for: ; in Let be the coordinates of a solder joint. Here are the coordinates of the two weld points. The length of the gold wire. The angle of inclination of the gold wire is defined. The gold wire is divided into multiple segments using the above method. The endpoints of each segment are then connected after indentation to generate the indented gold wire region.

[0034] like Figure 1 , 4 As shown, in S5, for each gold line segment, the corresponding grayscale threshold is used for threshold segmentation to extract the gold line region. The grayscale threshold corresponding to each gold line segment is set independently according to the actual grayscale distribution of that gold line segment in the image, in order to overcome the problem of large grayscale differences in different parts of the same gold line.

[0035] like Figure 1 , 4 As shown, in S6, it is determined whether each segment of the gold wire is connected, and whether the entire gold wire is connected, to determine if there are any defects in the gold wire. Specifically, determining whether each segment of the gold wire is connected involves: for each segment, determining whether the extracted segment's region simultaneously contains both corresponding indentation endpoints; if so, the segment is connected; otherwise, the segment is broken or offset. Determining whether the entire gold wire is connected involves: merging the segments of the gold wire to obtain the connected region of the entire gold wire; and determining the coordinates of the solder joint before indentation. and the coordinates of the two welding points If all lines are within a connected area, then the gold lines are normal; otherwise, there may be breaks or deviations.

[0036] As described above, the gold wire segmentation detection method in chip AOI inspection according to an embodiment of the present invention has the following beneficial effects: 1. The first and second weld points are located directly using threshold segmentation, which is simple to extract. The extraction of the first weld point avoids the complexity of adjusting multiple parameters using calipers, and the extraction of the second weld point avoids the use of template matching algorithms, thereby improving the extraction speed of weld points and reducing the algorithm time. 2. To address the issue of uneven grayscale along the same gold line, a segmented detection technique is proposed. The gold line is detected in segments according to a custom-defined indentation ratio, thus avoiding false detections caused by uneven grayscale. 3. Reduce the complexity of the gold line detection algorithm. Traditional algorithms rely more on line-finding algorithms to extract gold lines, which have many and complex parameters and are not easy to debug. This method directly uses threshold segmentation to extract gold lines, with fewer parameters, lower algorithm complexity, and easier debugging, thus reducing the cost of algorithm development and maintenance.

[0037] The above combined with the appendix Figures 1-4 A method for gold wire segmentation detection in chip AOI inspection according to an embodiment of the present invention is described. Furthermore, the present invention can also be applied to a gold wire segmentation detection system in chip AOI inspection.

[0038] Furthermore, according to a second aspect of the present invention, a gold wire segmentation detection system for chip AOI inspection is provided, comprising the following steps: The image acquisition module 100 is used to acquire chip images; Solder joint positioning module 200 is used to locate solder joints in the chip image and obtain the coordinates of a solder joint for the gold wire. and the coordinates of the two welding points ; The parameter calculation module 300 is used to calculate the length L and tilt angle of the gold wire based on the coordinates of the first and second solder joints. ; The segmentation calculation module 400 is used to divide the gold wire into multiple segments, each corresponding to a detection area. The detection area is formed by connecting the indented endpoints, where the indented endpoints are determined based on the coordinates of the first and second solder joints, a preset indentation ratio, and length. and angle Calculated; The segmentation and extraction module 500 is used to perform threshold segmentation on each segment of gold line using the corresponding grayscale threshold, and extract the gold line region of that segment. The defect detection module 600 is used to determine whether each segment of the gold wire is connected, and whether the entire gold wire is connected, in order to determine whether there is a defect in the gold wire.

[0039] The above combined with the appendix Figure 5A gold wire segmentation detection system for chip AOI inspection according to an embodiment of the present invention is described. Furthermore, the present invention can also be applied to an electronic device.

[0040] like Figure 6 As shown, according to a third aspect of the present invention, an electronic device is provided, comprising: a memory 1, a processor 2, and a computer program 3, wherein the computer program 3 is stored in the memory 1, and the processor 2 executes the computer program 3 to perform a gold wire segmentation detection method in chip AOI detection according to the first aspect.

[0041] The above combined with the appendix Figure 6 An electronic device according to an embodiment of the present invention has been described. Furthermore, the present invention can also be applied to an electronic device.

[0042] According to a fourth aspect of the present invention, a computer-readable medium having processor-executable non-volatile program code is provided, the program code causing the processor to perform a method for gold wire segmentation detection in chip AOI inspection according to the first aspect.

[0043] The readable storage medium can be a computer storage medium or a communication medium. A communication medium includes any medium that facilitates the transfer of a computer program from one location to another. A computer storage medium can be any available medium accessible to a general-purpose or special-purpose computer. For example, a readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the ASIC can reside within a device. Of course, the processor and the readable storage medium can also exist as discrete components in a communication device. The readable storage medium can be a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc. The present invention also provides a program product comprising executable instructions stored in the readable storage medium. At least one processor of the device can read the executable instructions from the readable storage medium, and the at least one processor executes the executable instructions to cause the device to implement the gold wire segmentation detection method in chip AOI inspection provided by the various embodiments described above. In the embodiments of the above-described device, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0044] It should be noted that, in this specification, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for segmented detection of gold wires in chip AOI inspection, characterized in that, It includes the following steps: Acquire chip image; Solder joints are located in the chip image to obtain the coordinates of a solder joint for the gold wire. and the coordinates of the two welding points ; Calculate the length L and tilt angle of the gold wire based on the coordinates of solder joint 1 and solder joint 2. ; The gold wire is divided into multiple segments, each corresponding to a detection area. Each detection area is formed by connecting the recessed endpoints. The recessed endpoints are determined based on the coordinates of the first and second solder joints, a preset recess ratio, and the specified length. and angle Calculated; For each segment of gold line, use the corresponding grayscale threshold to perform threshold segmentation and extract the gold line region of that segment; Determine whether each segment of the gold thread is connected, and whether the entire gold thread is connected, in order to determine whether there are any defects in the gold thread.

2. The method for segmented detection of gold wires in chip AOI inspection as described in claim 1, characterized in that, Solder joints are located in the chip image to obtain the coordinates of a solder joint for the gold wire. and the coordinates of the two welding points Specifically: Threshold segmentation is performed on the chip image to extract areas with gray values ​​within a preset range as potential solder joint areas; Perform an opening operation on the potential solder joint area to remove noise; For a given solder joint region, calculate the center of the inscribed circle as the coordinates of the solder joint. For the region with two weld points, the centroid is used as the coordinate of the two weld points. .

3. The method for segmented detection of gold wires in chip AOI inspection as described in claim 1, characterized in that, The length L and tilt angle of the gold wire The calculation formula is: ； 。 4. The method for segmented detection of gold wires in chip AOI inspection as described in claim 1, characterized in that, The indented endpoint is calculated using the following formula: For the indentation in the direction of a solder joint, let the indentation ratio be... Then the coordinates of the indented solder joint for: ； For the indentation in the direction of the two weld points, let the indentation ratio be... Then the coordinates of the indented solder joint for: 。 5. The method for segmented detection of gold wires in chip AOI inspection as described in claim 1, characterized in that, The specific steps for determining whether each gold wire segment is connected are as follows: For each gold wire segment, determine whether the extracted gold wire segment contains both of the corresponding indentation endpoints. If so, the segment is connected; otherwise, the segment is broken or offset.

6. The method for segmented detection of gold wires in chip AOI inspection as described in claim 1, characterized in that, The specific steps for determining whether the entire gold thread is connected are as follows: Merge the various gold line regions to obtain the connected region of the entire gold line; Determine the coordinates of the solder joint before indentation. and the coordinates of the two welding points Whether all are located within the connected area, if so, the gold wire is normal; otherwise, there is a break or offset.

7. The method for segmented detection of gold wires in chip AOI inspection as described in claim 1, characterized in that, The grayscale threshold corresponding to each gold line segment is set independently based on the actual grayscale distribution of that gold line segment in the image.

8. A gold wire segmentation detection system for chip AOI inspection, characterized in that, It includes the following steps: The image acquisition module is used to acquire chip images; The solder joint positioning module is used to locate solder joints in the chip image and obtain the coordinates of a solder joint for the gold wire. and the coordinates of the two welding points ; The parameter calculation module is used to calculate the length L and tilt angle of the gold wire based on the coordinates of the first and second solder joints. ; The segmented calculation module is used to divide the gold wire into multiple segments, each corresponding to a detection area. Each detection area is formed by connecting the indented endpoints, where the indented endpoints are determined based on the coordinates of the first and second solder joints, a preset indentation ratio, and the specified length. and angle Calculated; The segmentation and extraction module is used to perform threshold segmentation on each segment of gold line using the corresponding grayscale threshold, and extract the gold line region of that segment. The defect detection module is used to determine whether each segment of the gold wire is connected, and whether the entire gold wire is connected, in order to determine whether there is a defect in the gold wire.

9. An electronic device, characterized in that, include: The device includes a memory, a processor, and a computer program, wherein the computer program is stored in the memory, and the processor executes the computer program to perform a gold wire segmentation detection method in chip AOI inspection according to any one of claims 1 to 7.

10. A computer-readable medium having processor-executable non-volatile program code, characterized in that, The program code causes the processor to run the gold wire segmentation detection method in chip AOI inspection according to any one of claims 1-7.

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