A method and system for measuring wire bond offset of an integrated circuit leadframe

Abstract

The present application belongs to the technical field of image detection, and particularly relates to a bonding wire offset measurement method and system for an integrated circuit lead frame. First, a displacement field with temperature prior constraints is constructed based on the position deviation of the positioning mark points in the bonding area image and process state data, local thermal deformation of the lead frame is solved, and local thermal deformation analysis results are obtained. Then, the local thermal deformation analysis results are used to perform thermal deformation compensation on the theoretical design coordinates of the bonding points. Based on the compensated coordinates and the spatial distribution characteristic data of the bonding wires, the bonding wire offset distance and offset direction angle of each bonding point are calculated. The bonding wire offset distance of each bonding point is used to calculate a comprehensive bonding quality index, and comprehensive bonding quality evaluation is completed, thereby providing a quantitative basis for subsequent early warning and process parameter adjustment, and forming a complete chain from thermal deformation analysis, offset measurement to quality evaluation.

Description

Technical Field

[0001] This invention belongs to the field of image detection technology, specifically relating to a method and system for measuring the offset of bonding wires in an integrated circuit lead frame. Background Technology

[0002] Wire bonding is a core process in semiconductor packaging. The alignment accuracy of the bonding wires in the lead frame directly determines the electrical performance and packaging reliability of the integrated circuit. Bonding wire misalignment is a key issue that can cause poor device contact, short circuits, and even packaging failure, and is an important factor affecting chip packaging yield.

[0003] Bonding is a high-temperature process, and the lead frame is prone to localized micro-thermal deformation due to factors such as bonding temperature, process duration, and the thermal expansion characteristics of the frame material. This causes the actual bonding reference to deviate from the theoretical design reference. Traditional machine vision inspection technology does not consider the impact of thermal deformation and lacks a thermal error compensation mechanism, resulting in systematic errors in the calculation of offset. Furthermore, traditional inspection simply calculates the offset distance without considering spatial characteristics such as the curvature and orientation angle of the bond line, lacking quantitative evaluation of the offset direction angle. The quality assessment dimension is singular, and existing solutions can only achieve passive defect detection. They have not established a closed-loop mechanism for quality grading assessment and linkage control of equipment parameters, making it impossible to adaptively adjust bonding process parameters and correct bonding offset defects at the source. This restricts the improvement of packaging process accuracy and product yield.

[0004] To address the aforementioned issues, this application presents a method and system for measuring the bonding wire offset of an integrated circuit lead frame. Summary of the Invention

[0005] To address the shortcomings of the prior art mentioned in the background section, this application proposes a method and system for measuring the bonding wire offset of integrated circuit lead frames. By separating the thermal deformation error of the lead frame from the bonding process deviation online, the method balances measurement accuracy and computational efficiency, and effectively evaluates the bonding quality, thereby solving the problems in the background section.

[0006] In a first aspect, to achieve the above objective, this application provides a method for measuring the bonding wire offset of an integrated circuit lead frame, which includes the following specific steps: Step S1: Obtain images of the bonding area of ​​the lead frame and bonding process status data through the image acquisition module; Step S2: Perform edge detection and centerline fitting on the bonding region image to extract the spatial distribution feature data of the bonding lines; Step S3: Based on the positional deviation of the positioning markers in the bonding region image and the process status data, construct a displacement field with temperature prior constraints, solve the local thermal deformation of the lead frame, and obtain the local thermal deformation analysis results. Step S4: Use the results of local thermal deformation analysis to perform thermal deformation compensation on the theoretical design coordinates of the bonding points. Based on the compensated coordinates and the spatial distribution characteristics of the bonding lines, calculate the bonding line offset distance and offset direction angle of each bonding point. Step S5: Calculate the comprehensive bond quality index based on the bond line offset distance of each bond point to complete the comprehensive bond quality assessment; Step S6: Issue an early warning based on the comprehensive bonding quality assessment results and output bonding parameter adjustment instructions to the wire bonding equipment control system.

[0007] In a preferred embodiment based on the above scheme, step S2 specifically includes: Step S21: Read the bonding region image; Step S22: Perform edge detection on the bonding region image and extract the bonding line edge contour data; Step S23: Based on the edge contour data, fit the trajectory of the bond line centerline using the least squares method; Step S24: Calculate the orientation angle and radius of curvature of each segment of the bond line based on the centerline trajectory to obtain the actual spatial orientation data; Step S25: Integrate actual spatial orientation data to generate bond line spatial distribution characteristic data.

[0008] In a preferred embodiment based on the above scheme, step S3 specifically includes: Step S31: Obtain the bonding region image and process status data, wherein the process status data includes bonding temperature, bonding time, and thermal expansion coefficient of the lead frame material; Step S32: Calculate the thermal load distribution during the bonding process based on the process status data; Step S33: Compare the actual image position of the positioning marker in the bonding region image with the preset design position to obtain the positioning marker position deviation vector; Step S34: Using the position deviation vector as the control point and the temperature field as the smoothing constraint, construct the global displacement field using thin plate spline interpolation, solve for the displacement vector at each position of the lead frame, and generate the local thermal deformation analysis results.

[0009] In a preferred embodiment based on the above scheme, step S34 specifically includes: Step S341: Obtain thermal load distribution and positioning mark point position deviation data; Step S342: Using the position deviation vector of the positioning marker point as the interpolation control point, and using the temperature field data as the smoothing constraint for thin plate spline interpolation, construct the global displacement field function; Step S343: Solve the global displacement field function to obtain the displacement vector corresponding to each pixel coordinate; Step S344: Integrate displacement vectors to generate local thermal deformation analysis results.

[0010] In a preferred embodiment based on the above scheme, step S4 specifically includes: Step S41: Obtain spatial distribution characteristic data of bond lines and local thermal deformation analysis results; Step S42: Based on the results of local thermal deformation analysis, obtain the thermal deformation displacement vector corresponding to the theoretical design position of each bonding point, perform displacement compensation, and obtain the compensated reference position. Step S43: Based on the spatial distribution characteristic data, locate the actual connection position of the bonding line at each bonding point; Step S44: Calculate the difference between the actual connection position and the compensated reference position to obtain the bond line offset distance and bond line offset direction angle for each bond point. The calculation formulas for the bond line offset distance and bond line offset direction angle are as follows: in, The offset distance of the bonding line at the j-th bonding point; In the formula, Let be the bonding line offset direction angle at the j-th bonding point, and atan2 be the arctangent function in the four quadrants. Let x be the x-coordinate of the actual connection position of the bonding line at the j-th bonding point. Let be the ordinate of the actual connection position of the bond line at the j-th bond point. Here is the x-coordinate of the compensated reference position of the j-th bonding point. The ordinate is the ordinate of the compensated reference position of the j-th bonding point.

[0011] In a preferred embodiment based on the above scheme, step S5 specifically includes: Step S51: Obtain the bond line offset distance for all bond points; Step S52: Calculate the overall bond quality index. The formula for calculating the overall bond quality index is: Where FS is the overall bond quality index, and N is the total number of bond sites. The preset offset threshold; Step S53: Divide the bonding quality level according to the interval of the comprehensive bonding quality index, obtain the comprehensive bonding quality assessment result, and output the comprehensive bonding quality assessment result for simultaneous presentation of the current bonding quality level during early warning.

[0012] In a preferred embodiment based on the above scheme, step S6 specifically includes: Step S61: Obtain the bond quality level from the comprehensive bond quality assessment results; Step S62: Execute graded early warning according to the bonding quality level. When the comprehensive bonding quality index corresponding to the bonding quality level is lower than the first threshold, a first-level early warning is triggered, and the bonding head displacement compensation parameters and bonding temperature adjustment parameters are output to the wire bonding equipment control system. When the bonding quality grade is lower than the second threshold but not lower than the first threshold, a level 2 early warning is triggered, and bonding head displacement compensation parameters are output to the wire bonding equipment control system. When the bonding quality grade is not lower than the second threshold, no warning is triggered, and the current process parameters are maintained.

[0013] Secondly, this application provides a bonding wire offset measurement system for integrated circuit leadframes, including an image acquisition module for acquiring images of the bonding area of ​​the leadframe and bonding process status data. The spatial distribution analysis module is connected to the image acquisition module and is used to perform edge detection and centerline fitting on the bonding region image to extract the spatial distribution feature data of the bonding lines. The thermal deformation analysis module is connected to the image acquisition module and is used to construct a displacement field with temperature prior constraints based on the positional deviation of the positioning markers in the bonding region image and the process state data, solve the local thermal deformation of the lead frame, and obtain the local thermal deformation analysis results. The offset measurement module is connected to the spatial distribution analysis module and the thermal deformation analysis module respectively. It is used to perform thermal deformation compensation on the theoretical design coordinates of the bonding points using the results of local thermal deformation analysis. Based on the compensated coordinates and the spatial distribution characteristic data of the bonding lines, the offset distance and offset direction angle of each bonding point are calculated. The quality assessment module is connected to the offset measurement module and is used to calculate the comprehensive bond quality index based on the bond line offset distance of each bond point, thereby completing the comprehensive bond quality assessment. The early warning adjustment module is connected to the quality assessment module and is used to issue early warnings based on the comprehensive bonding quality assessment results and output bonding parameter adjustment commands to the wire bonding equipment control system. The main control scheduling module is connected to the image acquisition module, spatial distribution analysis module, thermal deformation analysis module, offset measurement module, quality assessment module, and early warning adjustment module, respectively, to coordinate the working sequence and data interaction of each module.

[0014] Thirdly, this application provides an electronic device, including: a processor and a memory, wherein the memory stores a computer program that can be called by the processor; The processor executes the aforementioned method for measuring the bond wire offset of an integrated circuit lead frame by calling a computer program stored in the memory.

[0015] Fourthly, this application provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described method for measuring the bond wire offset of an integrated circuit lead frame.

[0016] Compared with the prior art, the beneficial effects of the present invention are: First, this application constructs a displacement field with temperature prior constraints by combining bonding process state data and positioning mark point position deviation through a thermal deformation analysis module. It solves the local thermal deformation of the lead frame and completes thermal deformation compensation for the theoretical design coordinates of the bonding points. Compared with the shortcomings of traditional detection methods that ignore the microscopic thermal deformation of the frame caused by high bonding temperature and have systematic detection errors, this solution can accurately eliminate the reference offset interference caused by temperature, process time and material thermal expansion, which can significantly improve the accuracy of the bonding point position reference and improve the detection accuracy of bonding line offset measurement from the root.

[0017] Secondly, this application uses a spatial distribution analysis module to perform edge detection and centerline fitting on the bonding region image, extracting spatial distribution feature data such as the bonding line orientation angle and radius of curvature, and quantifies the offset state by combining the offset distance and offset direction angle as dual parameters. This breaks through the limitations of traditional technologies that only measure the offset distance and have a one-sided detection dimension, and can achieve a comprehensive and accurate characterization of the spatial morphology and offset state of the bonding line, making the bonding line offset measurement results more consistent with the actual process state.

[0018] Third, this application constructs a comprehensive bonding quality index based on the offset distance of all bonding points through a quality assessment module, and divides the quality level according to the index range, realizing a standardized and quantitative overall bonding quality assessment. It abandons the problems of traditional fixed threshold judgment and one-sided assessment results, and can accurately and comprehensively reflect the bonding process quality of the entire lead frame, providing reliable data support for subsequent process control.

[0019] Fourth, this application implements differentiated early warning through an early warning adjustment module combined with graded bonding quality levels, and outputs corresponding bonding parameter adjustment instructions to the wire bonding equipment control system. In conjunction with the main control scheduling module, it realizes the coordinated interaction of timing and data of each module, and constructs a fully closed-loop control system from image acquisition, offset measurement, quality assessment to adaptive adjustment of process parameters. This solves the problem that traditional technologies can only passively detect and cannot actively correct process defects. It can effectively improve the bonding offset problem and stably improve the precision and mass production yield of integrated circuit packaging processes. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall process of a method for measuring the bonding wire offset of an integrated circuit lead frame according to the present invention. Figure 2 This is a flowchart illustrating step S3 in the method for measuring the bonding wire offset of an integrated circuit lead frame according to the present invention. Figure 3 This is a schematic diagram of the bonding wire offset measurement system for an integrated circuit lead frame according to the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: To address the technical problems raised in the background art, this application provides a preferred embodiment: such as Figure 1 - Figure 3 As shown, a method for measuring the bonding wire offset of an integrated circuit lead frame includes the following specific steps: Step S1: Obtain images of the bonding area of ​​the lead frame and bonding process status data through the image acquisition module; Step S2: Perform edge detection and centerline fitting on the bonding region image to extract the spatial distribution feature data of the bonding lines; Step S3: Based on the positional deviation of the positioning markers in the bonding region image and the process status data, construct a displacement field with temperature prior constraints, solve the local thermal deformation of the lead frame, and obtain the local thermal deformation analysis results. Step S4: Use the results of local thermal deformation analysis to perform thermal deformation compensation on the theoretical design coordinates of the bonding points. Based on the compensated coordinates and the spatial distribution characteristics of the bonding lines, calculate the bonding line offset distance and offset direction angle of each bonding point. Step S5: Calculate the comprehensive bond quality index based on the bond line offset distance of each bond point to complete the comprehensive bond quality assessment; Step S6: Issue an early warning based on the comprehensive bonding quality assessment results and output bonding parameter adjustment instructions to the wire bonding equipment control system.

[0023] Furthermore: In an optional embodiment, step S2 specifically includes: Step S21: Read the bonding region image; Step S22: Perform edge detection on the bonding region image and extract the bonding line edge contour data; Step S23: Based on the edge contour data, fit the trajectory of the bond line centerline using the least squares method; Step S24: Calculate the orientation angle and radius of curvature of each segment of the bond line based on the centerline trajectory to obtain the actual spatial orientation data; Step S25: Integrate actual spatial orientation data to generate bond line spatial distribution characteristic data.

[0024] In an optional embodiment, step S3 specifically includes: Step S31: Obtain the bonding region image and process status data, wherein the process status data includes bonding temperature, bonding time, and thermal expansion coefficient of the lead frame material; Step S32: Calculate the thermal load distribution during the bonding process based on the process status data; Step S33: Compare the actual image position of the positioning marker in the bonding region image with the preset design position to obtain the positioning marker position deviation vector; Step S34: Using the position deviation vector as the control point and the temperature field as the smoothing constraint, construct the global displacement field using thin plate spline interpolation, solve for the displacement vector at each position of the lead frame, and generate the local thermal deformation analysis results.

[0025] In an optional embodiment, step S34 specifically includes: Step S341: Obtain thermal load distribution and positioning mark point position deviation data; Step S342: Using the position deviation vector of the positioning marker point as the interpolation control point, and using the temperature field data as the smoothing constraint for thin plate spline interpolation, construct the global displacement field function; Step S343: Solve the global displacement field function to obtain the displacement vector corresponding to each pixel coordinate; Step S344: Integrate displacement vectors to generate local thermal deformation analysis results.

[0026] It should be noted that step S33 specifically involves: First, a local sub-image containing the positioning markers is extracted from the bonding region image and then converted to grayscale. Then, subpixel edge extraction and ellipse fitting are performed on the grayscale subimage, with the center of the ellipse as the actual image position of the positioning marker. Next, obtain the preset design coordinates of the positioning markers; Finally, the difference between the actual image position and the preset design coordinates is calculated to obtain the position deviation vector of each positioning marker point in the image plane.

[0027] In an optional embodiment, step S4 specifically includes: Step S41: Obtain spatial distribution characteristic data of bond lines and local thermal deformation analysis results; Step S42: Based on the results of local thermal deformation analysis, obtain the thermal deformation displacement vector corresponding to the theoretical design position of each bonding point, perform displacement compensation, and obtain the compensated reference position. It should be noted that step S42 specifically involves: Step S421: Obtain the theoretical design coordinates and local thermal deformation analysis results of each bonding point; Step S422: Locate the thermal deformation displacement vector corresponding to the theoretical design coordinates of each bonding point; Step S423: Superimpose the theoretical design coordinates with the displacement vector to obtain the reference position coordinates after thermal deformation compensation; Step S43: Based on the spatial distribution characteristic data, locate the actual connection position of the bonding line at each bonding point; Step S44: Calculate the difference between the actual connection position and the compensated reference position to obtain the bond line offset distance and bond line offset direction angle for each bond point. The calculation formulas for the bond line offset distance and bond line offset direction angle are as follows: in, The offset distance of the bonding line at the j-th bonding point; In the formula, Let be the bonding line offset direction angle at the j-th bonding point, and atan2 be the arctangent function in the four quadrants. Let x be the x-coordinate of the actual connection position of the bonding line at the j-th bonding point. Let be the ordinate of the actual connection position of the bond line at the j-th bond point. Here is the x-coordinate of the compensated reference position of the j-th bonding point. The ordinate is the ordinate of the compensated reference position of the j-th bonding point.

[0028] The advantages of the above embodiments are as follows: using the position deviation vector of the positioning marker as the control point, the temperature field calculated from the process state data is used as the smoothing constraint for thin plate spline interpolation, rather than simply relying on the density of the marker points to ensure the interpolation accuracy. This allows the displacement field to automatically adjust the smoothing intensity in areas with large temperature gradients, which is closer to the actual non-uniform thermal deformation than pure geometric interpolation and more adaptable to the real-time requirements of online detection than finite element simulation. First, the displacement compensation of the theoretical design coordinates of the bonding point is performed using the results of local thermal deformation analysis. Then, the difference between the actual connection position of the bonding wire and the compensated reference position is calculated. This method can separate the systematic error introduced by the thermal deformation of the lead frame itself from the measurement results, so that the offset can directly reflect the bonding process quality. This solves the problem that existing methods cannot separate thermal deformation error from process deviation. In addition, the offset measurement simultaneously outputs the bonding wire offset distance and offset direction angle. The direction angle can distinguish whether the bonding wire is offset to the inside or outside of the adjacent lead wire, which can provide an auxiliary judgment basis for the bonding short circuit risk and break through the limitation of existing methods that only output scalar distance.

[0029] In an optional embodiment, step S5 specifically includes: Step S51: Obtain the bond line offset distance for all bond points; Step S52: Calculate the overall bond quality index. The formula for calculating the overall bond quality index is: Where FS is the overall bond quality index, and N is the total number of bond sites. The preset offset threshold; Step S53: Divide the bonding quality level according to the interval of the comprehensive bonding quality index, obtain the comprehensive bonding quality assessment result, and output the comprehensive bonding quality assessment result for simultaneous presentation of the current bonding quality level during early warning.

[0030] The advantages of the above embodiments are as follows: the overall bonding quality index adopts a linear decreasing model with a cutoff function. When the offset distance of any bonding point exceeds the preset offset threshold, the quality contribution of that point is forced to zero. This can ensure that the impact of the out-of-standard point on the overall quality index is not diluted by other qualified points, and can make the quality assessment highly sensitive to fatal defects.

[0031] In an optional embodiment, step S6 specifically includes: Step S61: Obtain the bond quality level from the comprehensive bond quality assessment results; Step S62: Execute graded early warning according to the bonding quality level. When the comprehensive bonding quality index corresponding to the bonding quality level is lower than the first threshold, a first-level early warning is triggered, and the bonding head displacement compensation parameters and bonding temperature adjustment parameters are output to the wire bonding equipment control system. When the bonding quality grade is lower than the second threshold but not lower than the first threshold, a level 2 early warning is triggered, and bonding head displacement compensation parameters are output to the wire bonding equipment control system. When the bonding quality grade is not lower than the second threshold, no warning is triggered, and the current process parameters are maintained. It should be noted that the first threshold is less than the second threshold.

[0032] The advantages of the above embodiments are as follows: the quality assessment module maps the comprehensive bonding quality index to the bonding quality level and outputs it, and the early warning and adjustment module executes graded early warnings accordingly and outputs bonding parameter adjustment instructions to the wire bonding equipment control system. This can form an online closed loop from measurement and assessment to process parameter feedback and adjustment, which can effectively improve the quality control efficiency of the bonding process.

[0033] Example 2: Based on the same inventive concept as Embodiment 1, such as Figure 3 As shown, this embodiment provides a bonding wire offset measurement system for integrated circuit lead frames, including an image acquisition module for acquiring images of the bonding area of ​​the lead frame and bonding process status data. The spatial distribution analysis module is connected to the image acquisition module and is used to perform edge detection and centerline fitting on the bonding region image to extract the spatial distribution feature data of the bonding lines. The thermal deformation analysis module is connected to the image acquisition module and is used to construct a displacement field with temperature prior constraints based on the positional deviation of the positioning markers in the bonding region image and the process state data, solve the local thermal deformation of the lead frame, and obtain the local thermal deformation analysis results. The offset measurement module is connected to the spatial distribution analysis module and the thermal deformation analysis module respectively. It is used to perform thermal deformation compensation on the theoretical design coordinates of the bonding points using the results of local thermal deformation analysis. Based on the compensated coordinates and the spatial distribution characteristic data of the bonding lines, the offset distance and offset direction angle of each bonding point are calculated. The quality assessment module is connected to the offset measurement module and is used to calculate the comprehensive bond quality index based on the bond line offset distance of each bond point, thereby completing the comprehensive bond quality assessment. The early warning adjustment module is connected to the quality assessment module and is used to issue early warnings based on the comprehensive bonding quality assessment results and output bonding parameter adjustment commands to the wire bonding equipment control system. The main control scheduling module is connected to the image acquisition module, spatial distribution analysis module, thermal deformation analysis module, offset measurement module, quality assessment module, and early warning adjustment module, respectively, to coordinate the working sequence and data interaction of each module.

[0034] The parameters and steps of each unit module in the above-described integrated circuit lead frame bonding wire offset measurement system of the present invention to achieve the corresponding functions can be referred to the parameters and steps in the embodiments of the integrated circuit lead frame bonding wire offset measurement method described above, and will not be repeated here.

[0035] The specific implementation process of the bonding wire offset measurement method for integrated circuit leadframes provided in this solution is as follows: First, the bonding area image of the leadframe is acquired through the image acquisition module, and process status data during the bonding process is acquired simultaneously. The process status data includes bonding temperature, bonding time, and the thermal expansion coefficient of the leadframe material.

[0036] Then, the spatial distribution analysis module performs edge detection and centerline fitting operations on the bonding region image, extracts the edge contour of the bonding line, fits the centerline trajectory of the bonding line, calculates the orientation angle and radius of curvature of each segment of the bonding line, and integrates them to generate spatial distribution feature data of the bonding line.

[0037] Next, the actual image position of the positioning mark point is identified from the bonding region image by the thermal deformation analysis module and compared with the preset design position to obtain the position deviation vector of the positioning mark point. At the same time, the thermal load distribution during the bonding process is calculated based on the process state data. With the position deviation vector as the control point and the temperature field as the smoothing constraint, the global displacement field is constructed by thin plate spline interpolation. The displacement vector of each position of the lead frame is solved to generate the local thermal deformation analysis results.

[0038] Next, the local thermal deformation analysis results are retrieved through the offset measurement module, and corresponding thermal deformation displacement compensation is applied to the theoretical design coordinates of each bonding point to obtain the compensated reference position. Then, the actual connection position of the bonding line at each bonding point is located according to the spatial distribution characteristic data, and the difference between the actual connection position and the compensated reference position is calculated to obtain the bonding line offset distance and offset direction angle of each bonding point.

[0039] Next, the bond line offset distances of all bond points are summarized through the quality assessment module, the comprehensive bond quality index is calculated, and the bond quality level is divided according to the numerical range of the index to generate the comprehensive bond quality assessment result.

[0040] Finally, the early warning adjustment module executes graded early warnings based on the comprehensive bonding quality assessment results and outputs corresponding bonding parameter adjustment commands to the wire bonding equipment control system. Throughout the process, the main control scheduling module coordinates the timing synchronization and data interaction of the image acquisition module, spatial distribution analysis module, thermal deformation analysis module, offset measurement module, quality assessment module, and early warning adjustment module to achieve measurement closed loop.

[0041] Example 3: Based on the same inventive concept as Embodiment 1, this embodiment provides an electronic device, including: a processor and a memory, wherein the memory stores a computer program that can be called by the processor; The processor executes the above-described method for measuring the bond wire offset of an integrated circuit lead frame by calling a computer program stored in the memory.

[0042] It should be noted that all computer programs for a method of measuring the bond wire offset of an integrated circuit lead frame are implemented in C language.

[0043] Example 4: Based on the same inventive concept as in Embodiment 1, this embodiment proposes a computer-readable storage medium having an erasable and rewritable computer program stored thereon. When a computer program runs on a computer device, it causes the computer device to perform the aforementioned method for measuring the bonding wire offset of an integrated circuit lead frame.

[0044] For example, computer-readable storage media can be read-only memory, random access memory, read-only optical disc, magnetic tape, floppy disk, and optical data storage devices.

[0045] The various embodiments in this invention are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device and medium embodiments are relatively simple in description because they are fundamentally similar to the method embodiments; relevant parts can be referred to the descriptions in the method embodiments.

[0046] The systems, media, and methods provided in the embodiments of the present invention are in one-to-one correspondence. Therefore, the systems and media also have similar beneficial technical effects as their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the systems and media will not be repeated here.

[0047] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0048] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart. Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0049] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0050] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0051] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0052] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0053] Computer-readable media include both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0054] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover 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. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. The above are merely embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for measuring the bonding wire offset of an integrated circuit lead frame, characterized in that, Includes the following steps: Step S1: Obtain images of the bonding area of ​​the lead frame and bonding process status data through the image acquisition module; Step S2: Perform edge detection and centerline fitting on the bonding region image to extract the spatial distribution feature data of the bonding lines; Step S3: Based on the positional deviation of the positioning markers in the bonding region image and the process status data, construct a displacement field with temperature prior constraints, solve the local thermal deformation of the lead frame, and obtain the local thermal deformation analysis results. Step S4: Use the results of local thermal deformation analysis to perform thermal deformation compensation on the theoretical design coordinates of the bonding points. Based on the compensated coordinates and the spatial distribution characteristics of the bonding lines, calculate the bonding line offset distance and offset direction angle of each bonding point. Step S5: Calculate the comprehensive bond quality index based on the bond line offset distance of each bond point to complete the comprehensive bond quality assessment; Step S6: Issue an early warning based on the comprehensive bonding quality assessment results and output bonding parameter adjustment instructions to the wire bonding equipment control system.

2. The method for measuring the bonding wire offset of an integrated circuit lead frame according to claim 1, characterized in that: Step S2 specifically includes: Step S21: Read the bonding region image; Step S22: Perform edge detection on the bonding region image and extract the bonding line edge contour data; Step S23: Based on the edge contour data, fit the trajectory of the bond line centerline using the least squares method; Step S24: Calculate the orientation angle and radius of curvature of each segment of the bond line based on the centerline trajectory to obtain the actual spatial orientation data; Step S25: Integrate actual spatial orientation data to generate bond line spatial distribution characteristic data.

3. The method for measuring the bonding wire offset of an integrated circuit lead frame according to claim 1, characterized in that: Step S3 specifically includes: Step S31: Obtain the bonding region image and process status data, wherein the process status data includes bonding temperature, bonding time, and thermal expansion coefficient of the lead frame material; Step S32: Calculate the thermal load distribution during the bonding process based on the process status data; Step S33: Compare the actual image position of the positioning marker in the bonding region image with the preset design position to obtain the positioning marker position deviation vector; Step S34: Using the position deviation vector as the control point and the temperature field as the smoothing constraint, construct the global displacement field using thin plate spline interpolation, solve for the displacement vector at each position of the lead frame, and generate the local thermal deformation analysis results.

4. The method for measuring the bonding wire offset of an integrated circuit lead frame according to claim 3, characterized in that: Step S34 specifically includes: Step S341: Obtain thermal load distribution and positioning mark point position deviation data; Step S342: Using the position deviation vector of the positioning marker point as the interpolation control point, and using the temperature field data as the smoothing constraint for thin plate spline interpolation, construct the global displacement field function; Step S343: Solve the global displacement field function to obtain the displacement vector corresponding to each pixel coordinate; Step S344: Integrate displacement vectors to generate local thermal deformation analysis results.

5. The method for measuring the bonding wire offset of an integrated circuit lead frame according to claim 4, characterized in that: Step S4 specifically includes: Step S41: Obtain spatial distribution characteristic data of bond lines and local thermal deformation analysis results; Step S42: Based on the results of local thermal deformation analysis, obtain the thermal deformation displacement vector corresponding to the theoretical design position of each bonding point, perform displacement compensation, and obtain the compensated reference position. Step S43: Based on the spatial distribution characteristic data, locate the actual connection position of the bonding line at each bonding point; Step S44: Calculate the difference between the actual connection position and the compensated reference position to obtain the bond line offset distance and bond line offset direction angle for each bond point. The calculation formulas for the bond line offset distance and bond line offset direction angle are as follows: in, The offset distance of the bonding line at the j-th bonding point; In the formula, Let be the bonding line offset direction angle at the j-th bonding point, and atan2 be the arctangent function in the four quadrants. Let x be the x-coordinate of the actual connection position of the bonding line at the j-th bonding point. Let be the ordinate of the actual connection position of the bond line at the j-th bond point. Here is the x-coordinate of the compensated reference position of the j-th bonding point. The ordinate is the ordinate of the compensated reference position of the j-th bonding point.

6. The method for measuring the bonding wire offset of an integrated circuit lead frame according to claim 5, characterized in that: Step S5 specifically includes: Step S51: Obtain the bond line offset distance for all bond points; Step S52: Calculate the overall bond quality index. The formula for calculating the overall bond quality index is: Where FS is the overall bond quality index, and N is the total number of bond sites. The preset offset threshold; Step S53: Divide the bonding quality level according to the interval of the comprehensive bonding quality index, obtain the comprehensive bonding quality assessment result, and output the comprehensive bonding quality assessment result for simultaneous presentation of the current bonding quality level during early warning.

7. The method for measuring the bonding wire offset of an integrated circuit lead frame according to claim 6, characterized in that: Step S6 specifically includes: Step S61: Obtain the bond quality level from the comprehensive bond quality assessment results; Step S62: Execute graded early warning according to the bonding quality level. When the comprehensive bonding quality index corresponding to the bonding quality level is lower than the first threshold, a first-level early warning is triggered, and the bonding head displacement compensation parameters and bonding temperature adjustment parameters are output to the wire bonding equipment control system. When the bonding quality grade is lower than the second threshold but not lower than the first threshold, a level 2 early warning is triggered, and bonding head displacement compensation parameters are output to the wire bonding equipment control system. When the bonding quality grade is not lower than the second threshold, no warning is triggered, and the current process parameters are maintained.

8. A bonding wire offset measurement system for an integrated circuit lead frame, implemented based on the bonding wire offset measurement method for an integrated circuit lead frame as described in any one of claims 1-7, characterized in that, It includes an image acquisition module, used to acquire images of the bonding area of ​​the lead frame and bonding process status data; The spatial distribution analysis module is connected to the image acquisition module and is used to perform edge detection and centerline fitting on the bonding region image to extract the spatial distribution feature data of the bonding lines. The thermal deformation analysis module is connected to the image acquisition module and is used to construct a displacement field with temperature prior constraints based on the positional deviation of the positioning markers in the bonding region image and the process state data, solve the local thermal deformation of the lead frame, and obtain the local thermal deformation analysis results. The offset measurement module is connected to the spatial distribution analysis module and the thermal deformation analysis module respectively. It is used to perform thermal deformation compensation on the theoretical design coordinates of the bonding points using the results of local thermal deformation analysis. Based on the compensated coordinates and the spatial distribution characteristic data of the bonding lines, the offset distance and offset direction angle of each bonding point are calculated. The quality assessment module is connected to the offset measurement module and is used to calculate the comprehensive bond quality index based on the bond line offset distance of each bond point, thereby completing the comprehensive bond quality assessment. The early warning adjustment module is connected to the quality assessment module and is used to issue early warnings based on the comprehensive bonding quality assessment results and output bonding parameter adjustment commands to the wire bonding equipment control system. The main control scheduling module is connected to the image acquisition module, spatial distribution analysis module, thermal deformation analysis module, offset measurement module, quality assessment module, and early warning adjustment module, respectively, to coordinate the working sequence and data interaction of each module.

9. An electronic device, comprising: A processor and a memory, wherein the memory stores a computer program that can be called by the processor, characterized in that: the processor executes a method for measuring the bonding wire offset of an integrated circuit lead frame as described in any one of claims 1-7 by calling the computer program stored in the memory.

10. A computer-readable storage medium, characterized in that: The device stores instructions that, when executed on a computer, cause the computer to perform a method for measuring the bond wire offset of an integrated circuit lead frame as described in any one of claims 1-7.

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