A material clamping detection method, a synchronous control system and a wire bonding machine for the wire bonding machine

Abstract

The application provides a material clamping detection method for a wire bonding machine. The method adopts a non-contact displacement detection method based on optical texture detection to realize real-time acquisition and displacement matching operation of reflected light information on the surface of a material sheet, thereby realizing high-precision real-time detection of the movement state of the material sheet. The actual moving distance of the material sheet and the moving distance of a material pulling motor are compared and analyzed synchronously through synchronous control, thereby realizing material clamping detection. In addition, the application also discloses a wire bonding machine and a synchronous control system of the wire bonding machine. The wire bonding machine comprises a light source generator, a first optical lens, a second optical lens, a matrix pixel image sensor, a digital processor and a synchronous control system. The light source generator generates detection light which is irradiated to the surface of the material sheet through the first optical lens. The reflected light is imaged to the image sensor through the second optical lens to form pixel light intensity distribution data. The digital processor performs displacement matching and beat synchronous operation on the data, thereby realizing material clamping detection and protection.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging equipment, and more particularly to a method for detecting material clips, a synchronous control system, and a wire bonding machine. Background Technology

[0002] In the field of semiconductor packaging equipment, wire bonding machines are crucial for connecting crystals and pins within a chip. Their feeding mechanism needs to stably and controllably drive the wafer along a predetermined trajectory from the feeding guide to the output tray. This process typically involves guide splicing, transfer, tray positioning matching, and other complex mechanical transmission structures. During operation, wafers are prone to jamming, misalignment, or stalling. If jamming occurs and the equipment cannot detect and implement protective measures in time, it can not only lead to abnormal wafer transport but also cause equipment downtime, chip damage, or even the scrapping of the entire wafer. Therefore, wafer jam detection has always been a key technology in wire bonding machine control systems.

[0003] Currently, common methods for detecting material jamming in wire bonding machines in the industry mainly include detection methods based on changes in drive current and detection methods based on contact displacement. Among these, the current-change-based method typically determines whether material jamming has occurred by detecting an abnormal increase in the load current of the material pulling motor. However, this method is highly dependent on the drive structure and is generally used in wire bonding machines that employ linear servo drive systems for the material pulling mechanism. For wire bonding machines that use rotary servos and screw drives or stepper motors to drive the material pulling mechanism, factors such as motor characteristics, torque amplification, mechanical backlash, inertia, and transmission errors limit its applicability, making it difficult to detect jamming effectively or to balance detection sensitivity and false alarm rate.

[0004] Some existing wire bonding machines employ contact-based detection structures, such as using an encoder with a rubber pressure roller to detect the movement of the wafer and determine if jamming has occurred. While this approach can adapt to different types of drive mechanisms, the direct contact between the detection component and the wafer introduces unnecessary mechanical seams, increases pulling resistance and friction, and consequently increases the risk of wafer jamming. Furthermore, since the semiconductor wafers used in wire bonding machines typically have openings such as positioning holes, momentary stalling or free-spinning can easily occur when the contact roller passes through these areas, causing the detection system to misinterpret it as jamming. To avoid false alarms, the system often needs to add filtering or delay processing, which reduces the real-time performance of jam detection and fails to meet the high-speed, high-precision anomaly protection requirements of high-value chip packaging processes.

[0005] Therefore, how to develop a jam detection method that can be adapted to various drive structures and has high sensitivity, high real-time performance and high reliability without increasing the risk of material jamming in wire bonding machines has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this application is to propose a material jam detection method, a synchronous control system, and a wire bonding machine for wire bonding machines, so as to realize a material jam detection method, a synchronous control system, and a wire bonding machine that can adapt to various drive structures and have high sensitivity, high real-time performance, and high reliability.

[0007] Firstly, a method for detecting material jamming in a wire bonding machine is provided, employing the following technical solution: The detection light is irradiated onto the surface of the moving material after passing through the first optical lens, and the reflected light intensity information representing the surface texture of the material is obtained. The reflected light intensity information is projected onto the matrix pixel image sensor using a second optical lens to obtain pixel light intensity distribution data. The pixel light intensity distribution data is read according to the preset reading rhythm, and displacement matching calculation is performed on the pixel light intensity distribution data of two adjacent reading rhythms to obtain the displacement distance information of the material in the X-axis and Y-axis directions of the current reading rhythm. According to the control cycle of the wire bonding machine synchronous control system, the displacement distance information of the material in the X-axis and Y-axis directions read in a single control cycle is filtered and accumulated to obtain the actual movement distance of the material in the corresponding control cycle. Obtain the moving distance of the material pulling motor within the corresponding control cycle, and compare the actual moving distance of the material with the moving distance of the material pulling motor to obtain the moving distance comparison result; The wire bonding machine is checked for jamming based on the distance comparison results. If jamming occurs, a jam protection operation is performed and a jam alarm signal is sent simultaneously.

[0008] Secondly, a synchronous control system for a wire bonding machine is provided, which performs the aforementioned method for detecting jamming in a wire bonding machine.

[0009] Thirdly, a wire bonding machine is provided, comprising a light source generator, a first optical lens, a second optical lens, a matrix pixel image sensor, a material stage, a digital processor, and the synchronous control system described in the second aspect. The material stage includes a feeding motor, a feeding guide rail, and a sheet clamp. The feeding motor controls the movement of the feeding guide rail. The sheet to be processed is placed on the feeding guide rail and fixed by the sheet clamp. The first and second optical lenses are positioned above the material stage. The light source generator is positioned above the first optical lens, and the matrix pixel image sensor is positioned above the second optical lens. The digital processor executes a portion of the jam detection method described in the first aspect. Light emitted from the light source generator passes through the first optical lens and illuminates the sheet to be processed. Light reflected from the sheet to be processed passes through the second optical lens and illuminates the matrix pixel image sensor. The first optical lens is a focusing lens for focusing the light emitted from the light source generator onto the surface of the sheet to be processed, and the second optical lens is an imaging lens for imaging the reflected light from the surface of the sheet to be processed and projecting it onto the matrix pixel image sensor.

[0010] The beneficial effects of the embodiments of this application are: This application provides a method for detecting material jamming in a wire bonding machine, a synchronous control system, and the wire bonding machine itself. By employing a non-contact displacement detection method based on optical texture detection, it performs real-time acquisition and displacement matching calculations of reflected light information from the surface of the material sheet, achieving high-precision real-time detection of the material sheet's motion state. Compared to existing solutions that detect jamming through changes in motor current, this invention does not rely on linear servo motors or specific drive structures, and can be adapted to various material pulling drive methods such as rotary servo motors and stepper motors, thus improving the system's applicability. Furthermore, compared to solutions using contact detection structures such as rubber pressure roller encoders, this invention avoids mechanical contact with the material sheet, preventing additional pulling resistance or introducing new jamming risks, and avoiding interference from openings such as material sheet positioning holes and punching holes. By synchronously comparing and analyzing the actual movement distance of the material sheet with the theoretical movement distance of the pulling motor, it can also promptly identify states such as pulling deceleration, deviation, and lateral abnormalities, thereby achieving high-sensitivity, high-real-time, and high-reliability jamming detection and abnormality protection during the wire bonding machine's material pulling process, improving equipment operational stability and packaging operation reliability. Attached Figure Description

[0011] To more clearly illustrate the solutions in this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1This is a flowchart illustrating the wire jam detection method for wire bonding machines provided in this application; Figure 2 This is a structural schematic diagram of the wire bonding machine provided in this application. Detailed Implementation

[0013] To make the technical problem to be solved, the technical solution and the beneficial effects of this application clearer, the following is in conjunction with the appendix. Figures 1 to 2 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

[0014] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0015] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0016] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0017] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0018] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0019] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0020] This application aims to provide a non-contact method, apparatus, and wire bonding machine for detecting material jamming. This method and apparatus are adaptable to various wire bonding machine feed motors, while avoiding increased jamming risk due to the jamming detection device. Furthermore, it can be adapted to sheet positioning holes to improve detection performance. This jamming detection method is applied in a wire bonding machine, which can be divided into three layers from bottom to top: a sensor and a digital processor (FPGA, etc.) for reading sensor data, a synchronous control system, and a controller (computer, etc.).

[0021] The digital processor is integrated into the data reading end of the matrix pixel image sensor. It is used to acquire image texture data output by the matrix pixel image sensor in real time, perform cross-correlation calculation on the texture data blocks acquired in two adjacent acquisition cycles, calculate the actual displacement of the material to be processed in adjacent acquisition cycles, and transmit the calculated actual displacement to the synchronous control system. The synchronous control system compares the actual displacement with the theoretical displacement of the material pulling motor, and determines whether a jamming abnormality has occurred based on the comparison result.

[0022] The synchronous control system of the wire bonding machine is a functional unit used to execute the aforementioned material jam detection method. Its core operating logic is as follows: according to the preset material pulling step length, the material pulling motor is controlled to drive the material pulling guide to complete a single material pulling action. At the same time, during the material pulling process, the matrix pixel image sensor is controlled to collect the texture image of the surface of the material to be processed in real time. The texture image information of adjacent frames is sent to the digital processor to complete the feature matching calculation to obtain the actual movement displacement data of the material to be processed. Then, the actual movement displacement data is compared with the theoretical movement displacement data corresponding to the current step of the material pulling motor. When the difference exceeds the preset allowable threshold, it can be determined that a material jam abnormality has occurred in the current material pulling process, and the shutdown protection command of the wire bonding machine is immediately triggered.

[0023] Figure 1 This is a schematic flowchart of a wire bonding machine jam detection method according to an embodiment of this application. (Reference) Figure 1 The wire bonding machine jam detection method provided in the embodiments of this application includes steps S1 to S6: S1, the detection light is irradiated onto the surface of the moving material after passing through the first optical lens, and the reflected light intensity information representing the surface texture of the material is obtained; Specifically, the detection light can be generated by a light-emitting diode, a laser emitter, or other light source capable of providing stable illumination. After being emitted, the detection light first undergoes optical path shaping through a first optical lens. The first optical lens is used to focus, collimate, or control the diffusion of the detection light, enabling it to be projected onto the surface of the material to be inspected at a predetermined illumination angle and spot size, thereby improving the stability of texture acquisition. Considering the actual movement of the material in the wire bonding machine, the detection area is typically selected near the front or rear guide rails of the feeding mechanism, but other possibilities are not excluded.

[0024] Due to material processing techniques, metal etching, rolling, or stamping processes, the surface of a material sheet naturally possesses microscopic textures, rough structures, or differences in reflectivity. When detection light shines on the surface of the material sheet, different areas will form different distributions of reflected light intensity due to differences in surface height, reflection angle, and material texture, thus forming reflected light information that can characterize the current position of the material sheet. This reflected light information is not a complete image in the traditional sense, but rather a set of optical information used to describe the spatial variation characteristics of the surface texture of the material sheet. Furthermore, since the material sheet often has perforated patterns such as positioning holes, these patterns are read as a small portion of the reflected light in the reflected information and can be used as part of the material sheet's feature information for further identification. In this respect, it is superior to contact methods using rubber pressure rollers.

[0025] During the movement of the sheet, the reflected light information collected at different times will shift accordingly with the change of the sheet's position. Therefore, the system can deduce the sheet's displacement information by utilizing the texture change relationship between different time points. Since the surface texture features of the sheet are directly acquired optically, no additional contact mechanical structure is required. Therefore, the detection area will not create additional resistance to the sheet's movement, nor will it introduce new risks of jamming. This allows it to be adapted to different types of feeding mechanisms and drive structures.

[0026] S2, using the second optical lens to project the reflected light information onto the matrix pixel image sensor to obtain pixel light intensity distribution data; Specifically, light reflected from the surface of the sheet is focused and imaged onto the photosensitive area of ​​the matrix pixel image sensor after passing through the second optical lens. The second optical lens establishes an optical mapping relationship between the surface texture of the sheet and the pixel array of the image sensor, enabling local texture changes on the sheet surface to be accurately converted into light intensity changes on the image sensor. The second optical lens can be a fixed-focus lens, a miniature imaging lens, or an optical lens structure with a certain depth of field to adapt to the limited installation space inside the wire bonding machine and the working conditions of small fluctuations in sheet height.

[0027] Matrix pixel-type image sensors can employ CMOS image sensors, CCD image sensors, or other pixel array optical sensors with high-speed sampling capabilities. Each pixel unit in the image sensor corresponds to the reflected light intensity at different locations on the material surface, converting the corresponding light intensity into a digital electrical signal output, thereby forming two-dimensional pixel light intensity distribution data. Due to the spatial continuity of the material surface texture, adjacent pixels can form a grayscale distribution relationship with texture characteristics.

[0028] To meet the real-time detection requirements of high-speed material feeding scenarios in wire bonding machines, the matrix pixel image sensor is preferably configured to continuously output image data at a high sampling frequency, enabling the system to acquire continuous texture change information of the material within a short time interval. Since the system only needs to utilize local texture changes for displacement detection, the image resolution can be adjusted according to the detection accuracy requirements, thereby reducing the amount of data processing and improving the efficiency of displacement calculation.

[0029] S3, read pixel light intensity distribution data according to the preset reading rhythm, and perform displacement matching calculation on the pixel light intensity distribution data of two adjacent reading rhythms to obtain the displacement distance information of the material in the X-axis direction and Y-axis direction of the current reading rhythm; Further, the steps of reading pixel light intensity distribution data according to a preset reading rhythm and performing displacement matching calculations on the pixel light intensity distribution data of two adjacent reading rhythms to obtain the displacement distance information of the material in the X-axis and Y-axis directions at the current reading rhythm specifically include: Read the first pixel light intensity distribution data collected by the matrix pixel image sensor under the current reading cycle, and establish the first light intensity data matrix; Read the second pixel light intensity distribution data collected by the matrix pixel image sensor in the previous reading cycle, and establish the second light intensity data matrix; Enumerate different combinations of X-axis and Y-axis displacement within a preset range, perform pixel-by-pixel difference calculation between the first light intensity data matrix and the second light intensity data matrix after corresponding displacement offset, and perform weighted summation on the difference results; The X-axis displacement and Y-axis displacement corresponding to the minimum value of the weighted summation are selected as the actual displacement distance information of the material at the current reading cycle.

[0030] Specifically, the preset reading cycle can be the reading frequency of the matrix pixel image sensor. After the digital processor reads and receives continuous image data output by the matrix pixel image sensor according to this reading cycle, it can establish a pixel matrix correspondence between the image data at the current reading cycle and the image data at the previous reading cycle. Since the surface texture of the sheet will shift in position in the continuous images during the movement, the system can use the texture change relationship between images at different time points to deduce the sheet's movement distance. The digital processor can adopt FPGA, DSP, CPU, or other processor architectures with high-speed computing capabilities.

[0031] Then, using a cross-correlation matching algorithm, the pixel intensity distribution matrices obtained from two adjacent acquisitions are matched for displacement offset. The offset with the highest correlation and smallest difference is found, which is the actual displacement of the sheet between two adjacent reading cycles. The entire calculation process is completed by a digital processor integrated into the sensor, and the calculation result is directly output to the synchronous control system. No complex data processing is required from the host computer, which can meet the real-time detection requirements of the wire bonding machine's feeding process. At the same time, by simultaneously calculating the displacement in both the X and Y axes, not only the actual moving distance in the feeding direction can be obtained, but also the lateral offset of the sheet can be obtained, thereby assisting in the identification of abnormal states such as sheet deviation.

[0032] During the displacement matching process, the digital processor preferably enumerates different combinations of X-axis and Y-axis displacements within a preset search range, and calculates the pixel-by-pixel difference between the current image and the historical image after the corresponding offset. For each displacement combination, the system calculates the grayscale difference between corresponding pixels and performs a weighted summation of all pixel differences to form the matching error value for the corresponding displacement combination. The weighting method can be adjusted according to the image center region, texture intensity, or edge features.

[0033] When the error value corresponding to a certain combination of X-axis and Y-axis displacements is the smallest, it indicates that the current image and historical images have the highest similarity under that displacement condition. Therefore, the system outputs the corresponding displacement combination as the actual moving distance information of the material at the current moment. Among them, the X-axis direction corresponds to the normal material pulling direction, and the Y-axis direction corresponds to the lateral offset direction of the material, thus enabling simultaneous detection of states such as material pulling deceleration, deviation, and abnormal offset.

[0034] Furthermore, the steps of enumerating different combinations of X-axis and Y-axis displacements within a preset range, calculating the pixel-by-pixel difference between the first and second light intensity data matrices after corresponding displacement offsets, and performing a weighted summation operation on the difference results specifically include: Set the X-axis displacement search range and the Y-axis displacement search range, and generate multiple combinations of displacements to be matched according to a preset step size; For each combination of displacements to be matched, the first light intensity data matrix is ​​subjected to corresponding X-axis and Y-axis coordinate offset processing to obtain the corresponding offset light intensity data matrix. The offset light intensity data matrix and the second light intensity data matrix are compared pixel by pixel in the overlapping area to calculate the light intensity difference between corresponding pixels and obtain the difference matrix. Based on the position distribution of each pixel in the matrix, the light intensity change characteristics, or the signal-to-noise ratio information, the pixel difference in the difference matrix is ​​assigned a corresponding weight, and the weighted pixel differences are accumulated to obtain the matching evaluation value corresponding to the current combination of displacement to be matched. Record the matching evaluation value corresponding to each displacement combination to be matched, and establish the correspondence between the displacement combination and the matching evaluation value, so as to select the displacement combination with the smallest matching evaluation value as the actual displacement distance information of the current reading cycle of the material.

[0035] The matching evaluation value measures the similarity between two texture images under different displacement combinations. The smaller the value, the higher the texture overlap between the two images, and the closer the corresponding displacement combination is to the actual displacement produced by the material. This texture feature-based displacement matching method does not require additional markings on the material; it directly utilizes the surface texture features of the material itself to complete the calculation, simplifying the detection process and not causing any additional impact on the processing of the material. For special structures such as positioning holes on the material, they will present obvious low-intensity areas in the pixel light intensity distribution data. This feature can actually be used as an auxiliary matching feature point to further improve the calculation accuracy of displacement matching without interfering with the matching results.

[0036] Specifically, during displacement matching calculations, the X-axis and Y-axis displacement search ranges are first preset based on the maximum possible movement distance of the wire bonding machine's feeding mechanism between two adjacent reading cycles. For example, the search ranges can be determined based on the feeding speed, reading frequency, and mechanism motion accuracy, ensuring that the actual displacement of the material falls within the preset search intervals. Subsequently, the search ranges are discretized according to a preset step size, forming multiple combinations of displacements to be matched, thus providing candidate displacement parameters for subsequent matching calculations.

[0037] For each displacement combination to be matched, the first light intensity data matrix corresponding to the current reading cycle is subjected to coordinate offset processing, so that it generates a corresponding spatial displacement relative to the second light intensity data matrix corresponding to the previous reading cycle. After the offset is completed, the two sets of light intensity data are compared pixel by pixel in the overlapping area, and the light intensity difference between corresponding pixels is calculated. Since the surface texture of the material remains stable in a short period of time, when the displacement combination is close to the actual displacement of the material, the texture features in the two sets of light intensity data can achieve a high degree of overlap, and the corresponding light intensity difference is relatively small; conversely, when the displacement combination deviates from the actual displacement, the two sets of texture images are misaligned, and the light intensity difference will increase significantly.

[0038] To improve the stability and anti-interference ability of the matching results, after obtaining the difference matrix, the differences can be further weighted according to the importance of each pixel. Specifically, the weights can be determined based on parameters such as the texture richness of the region where the pixel is located, the amplitude of local gray-level changes, the strength of edge features, the signal-to-noise ratio level, or the reliability of historical matching. Regions with obvious texture features and high recognizability are given larger weights, while regions with high texture repetition or those easily affected by noise are given smaller weights, thus making the matching evaluation results more accurately reflect the true correspondence between the two sets of images.

[0039] Subsequently, the weighted differences of each pixel are summed to obtain the matching evaluation value corresponding to the current displacement combination to be matched, and the matching evaluation values ​​corresponding to all displacement combinations to be matched are recorded. By comparing the matching evaluation values, the X-axis displacement and Y-axis displacement combination corresponding to the smallest matching evaluation value is selected as the actual displacement distance information of the material under the current reading cycle. Since the two sets of texture images corresponding to this displacement combination have the highest overlap, it can more accurately reflect the real movement of the material between adjacent reading cycles.

[0040] Furthermore, since the natural texture, processing marks, embossed structures, and positioning hole edges on the material surface can all form stable light intensity variation information in the pixel light intensity distribution data, this solution can achieve displacement measurement without additional detection marks on the material surface. In particular, structures such as positioning holes, cuts, and edge notches typically create light intensity features with significant contrast to the surrounding area, providing strong feature constraints during the matching process, which is beneficial for improving displacement recognition accuracy and matching stability. Even if the material experiences slight vibration, swaying, or light intensity fluctuations, the matching calculation, based on a comprehensive evaluation of a large number of pixels throughout the entire area, can still maintain good measurement accuracy and reliability.

[0041] S4. According to the control cycle of the wire bonding machine synchronous control system, the displacement distance information of the material in the X-axis and Y-axis directions read in a single control cycle is filtered and accumulated to obtain the actual movement distance of the material in the corresponding control cycle. Furthermore, according to the control cycle of the wire bonding machine's synchronous control system, the steps of filtering and accumulating the displacement distance information of the sheet in the X-axis and Y-axis directions read within a single control cycle to obtain the actual movement distance of the sheet within the corresponding control cycle specifically include: According to the control cycle of the wire bonding machine's synchronous control system, data operations are performed on the actual displacement distance of all reading cycles within each control cycle, and the control cycle is greater than the reading cycle. In each control cycle, the displacement data of each reading cycle in the X-axis direction is filtered and accumulated to serve as the actual displacement distance of the material in the X-axis direction within the control cycle. Within each control cycle, the displacement data of each reading cycle in the Y-axis direction is filtered and accumulated to serve as the actual displacement distance of the material in the Y-axis direction within the control cycle; Specifically, wire bonding machine synchronous control systems typically employ a fixed-frequency real-time synchronous control mechanism, where each motion axis and feedback information is updated synchronously according to a unified control cycle. The control cycle frequency for the wire bonding machine can be set between 1kHz and 100kHz, depending on the equipment control requirements. Since the frequency of displacement information output by the image sensor is usually higher than the synchronous control cycle, multiple sets of displacement detection results may be generated within a single control cycle, requiring the system to process these displacement results uniformly.

[0042] The control cycle of the wire bonding machine's synchronous control system is longer than the reading cycle of the matrix pixel image sensor, meaning the reading cycle frequency is higher than the control cycle frequency. Therefore, multiple sets of displacement increment data in the X and Y axes are obtained within a single control cycle. The system first performs outlier filtering on the multiple sets of displacement increments within a single control cycle, eliminating abrupt shifts caused by light fluctuations and noise interference. Then, it accumulates and calculates the remaining valid displacement increments in the X and Y axes respectively, finally obtaining the actual total distance the material has moved in both directions at the end of the current control cycle. This result is then transmitted to the synchronous control logic unit for material jam detection.

[0043] Within a single control cycle, multiple sensors read the data. The digital processor filters and accumulates the X-axis and Y-axis displacement data from these sensors. The X-axis displacement represents the actual movement of the material sheet in the pulling direction, while the Y-axis displacement represents the cumulative offset of the material sheet perpendicular to the pulling direction. By filtering and accumulating the displacement results from each reading cycle across multiple sampling periods, the actual material sheet movement distance corresponding to the control system cycle can be obtained.

[0044] After filtering and accumulation, the digital processor outputs the cumulative X-axis and Y-axis displacement values ​​within a single control cycle as the actual movement result of the material under that control cycle to the synchronous control system. Since all motion axes are updated synchronously based on a unified control cycle, the system can compare the actual movement distance with the corresponding material pulling motor motion information to ensure the consistency of the timing of material jam detection.

[0045] S5, obtain the moving distance of the pulling motor within the corresponding control cycle, and compare the actual moving distance of the material with the moving distance of the pulling motor to obtain the moving distance comparison result; Further, the steps of obtaining the moving distance of the pulling motor within the corresponding control cycle and comparing the actual moving distance of the material with the moving distance of the pulling motor to obtain the moving distance comparison result specifically include: The theoretical moving distance of the pulling motor output by the synchronous control system of the wire bonding machine within a single control cycle, or the actual moving distance obtained by measuring the actual movement of the pulling motor, is used as the moving distance of the pulling motor, and the moving distance of the pulling motor is used as a reference benchmark value. The actual distance the material sheet moves is compared with the distance the feeding motor moves to obtain the distance comparison result.

[0046] Specifically, the wire bonding machine synchronous control system outputs corresponding motion control commands to the feeding motor in each control cycle. The motion control commands include the theoretical moving distance that the feeding motor should complete in that control cycle, i.e., the feeding motor moving distance. In addition, for wire bonding machine feeding systems equipped with sensors such as encoders, the system can also directly use such sensors to measure the displacement information of the feeding system and use the measured displacement data as the feeding motor moving distance. Finally, the feeding motor moving distance is used as the reference benchmark for feeding motion.

[0047] Further, the step of comparing the actual moving distance of the sheet with the moving distance of the feeding motor to obtain the moving distance comparison result specifically includes: The ratio of the actual displacement distance of the material sheet in the X-axis direction within the control cycle to the moving distance of the pulling motor is calculated to obtain the displacement following ratio. The wire bonding machine synchronous control system compares the displacement following ratio with a configurable first threshold. When the displacement following ratio is lower than the first threshold, it is considered that a jamming situation has been detected. And / or calculate the difference between the actual displacement distance of the material sheet in the X-axis direction within the control cycle and the moving distance of the pulling motor to obtain the displacement difference; The wire bonding machine's synchronous control system compares the displacement difference with a configurable second threshold. When the displacement difference is greater than the second threshold, it is considered that a jam has been detected. And / or compare the actual displacement distance of the material in the Y-axis direction within the control cycle with a configurable third threshold through the wire bonding machine synchronous control system. When the actual displacement distance of the material in the Y-axis direction within the control cycle is greater than the third threshold, it is considered that a jamming situation has been detected.

[0048] After obtaining the actual moving distance of the sheet and the moving distance of the feeding motor, the wire bonding machine synchronous control system determines whether there is a jam in the wire bonding machine using the following three judgment conditions: First, jamming detection is based on the displacement following ratio. During normal material pulling, the pulling motor drives the material sheet to move synchronously. The actual moving distance of the material sheet should maintain a stable correspondence with the moving distance of the pulling motor; therefore, their ratio is usually close to 1. When the material sheet is jammed, clamped, or partially obstructed, although the pulling motor continues to run according to the control command, the actual moving distance of the material sheet will be significantly reduced, resulting in a decrease in the displacement following ratio. When the displacement following ratio is lower than a preset first threshold, it indicates that the material sheet has failed to effectively follow the movement of the pulling motor, and the system can determine that there is a risk of jamming. This judgment method uses relative proportions for analysis, which can adapt to different working conditions with different pulling speeds and distances, and has good versatility.

[0049] Second, jam detection is based on displacement difference. Under certain operating conditions, even if the displacement following ratio is still within the allowable range, a certain degree of slippage or accumulated error may have already occurred between the material sheet and the pulling motor. Therefore, this solution further calculates the absolute difference between the actual displacement distance of the material sheet and the moving distance of the pulling motor, and compares it with a second threshold. When the displacement difference exceeds the second threshold, it indicates a significant deviation between the actual and theoretical movement of the material sheet, suggesting an abnormality in the pulling process. Compared to the displacement following ratio method, the displacement difference method focuses more on the magnitude of the actual error. The combination of these two methods improves the accuracy and reliability of jam detection.

[0050] Third, jamming is determined based on the Y-axis offset. Under normal circumstances, the material sheet mainly moves along the pulling direction (X-axis), and the Y-axis displacement should remain within a small range. When the material sheet is skewed, warped, has edge snagging, is jammed on the guide rail, or experiences uneven local force, it may exhibit significant lateral offset during movement, resulting in an abnormally large increase in Y-axis displacement. Therefore, the system monitors the actual displacement distance of the material sheet in the Y-axis direction within the control cycle and compares it with a third threshold. When the Y-axis displacement distance exceeds the third threshold, it can be determined that there is an abnormal offset in the material sheet, considered a jamming situation or a precursor to jamming. By introducing a Y-axis monitoring mechanism, not only can complete jamming faults be detected, but also abnormal states such as pulling offset and deviation can be identified in advance, facilitating early implementation of protective measures.

[0051] Furthermore, the above three judgment conditions can be used individually or in combination. A jam alarm can be triggered when any one of the judgment conditions meets a preset abnormal condition. Preferably, a logic strategy of "displacement following ratio abnormality, displacement difference abnormality, and Y-axis displacement abnormality meeting any one of these three conditions is used to determine jamming" can be adopted to improve fault detection sensitivity; or a logic strategy of "two or more conditions being met simultaneously to determine jamming" can be adopted to reduce the probability of false alarms. The wire bonding machine synchronous control system can parameterize the first, second, and third thresholds according to different sheet types, feeding speeds, and process requirements, thereby achieving the best detection effect under different production scenarios.

[0052] S6. Determine whether the wire bonding machine is jammed based on the comparison result of the moving distance. If the wire bonding machine is jammed, execute the jam protection operation and send a jam alarm signal at the same time.

[0053] Specifically, the synchronous control system of the wire bonding machine can preset the displacement following threshold (and difference threshold) in the X-axis direction to determine whether the sheet material is moving normally with the feeding motor. When the ratio between the actual movement distance in the X-axis direction within the control cycle and the theoretical movement distance of the feeding motor is lower than the displacement following threshold (first threshold) or the difference exceeds the difference threshold (second threshold), it indicates that the feeding motor has output the feeding action, but the sheet material has failed to complete the corresponding displacement synchronously, thus indicating that there is abnormal resistance, partial jamming, or complete jamming in the feeding path.

[0054] Since the Y-axis direction is not the normal feeding direction of the sheet, the wire bonding machine's synchronous control system does not need to calculate the proportional relationship between the Y-axis direction and the theoretical motion. Instead, it directly determines whether the cumulative displacement in the Y-axis direction exceeds the allowable range. When the sheet experiences guide rail interference, edge lifting, local offset, or uneven force, the sheet will exhibit abnormal lateral movement, at which point the cumulative displacement in the Y-axis direction will increase significantly. The wire bonding machine's synchronous control system can identify this abnormal state based on a preset displacement range.

[0055] Furthermore, the jam protection operation includes at least the following steps: enabling the pull motor, reversing the pull motor, releasing the sheet clamps, determining whether the wire bonding machine has jammed based on the movement distance comparison result, and if the wire bonding machine jams, executing the jam protection operation and simultaneously sending a jam alarm signal. Specifically, this includes: The synchronous control system of the wire bonding machine determines whether the wire bonding machine is jammed based on the comparison results of the moving distance. When the wire bonding machine's synchronous control system determines that the wire bonding machine is jammed, it generates control information, which includes the material pulling motor control signal and the material clamping claw control signal. The synchronous control system of the wire bonding machine controls the feeding motor and / or the material clamping jaws based on control information; The wire bonding machine's synchronous control system generates a jamming alarm signal and sends it to the operation terminal.

[0056] When a jam is detected, the wire bonding machine's synchronous control system will take protective measures, including but not limited to disabling the pull motor, reversing the pull motor, and releasing the sheet clamps, to prevent the pull motor from continuously exerting force that could tear, crush, or damage the sheet, or damage the pull mechanism. Simultaneously, a jam alarm signal will be sent to the operating terminal to notify the operator to promptly address the jam and restore normal production. This protection mechanism can terminate abnormal pull immediately after a jam occurs, minimizing the damage to equipment and products and reducing production losses.

[0057] In a specific embodiment of this application, the wire bonding machine is used to bond metal wires to chip pins. During the production process, a lead frame strip needs to be continuously fed into the wire bonding area via a feeding mechanism. This wire bonding machine uses a rotary servo motor in conjunction with a lead screw structure to drive the strip forward. There is a potential risk of material jamming at the splicing position of the feeding guide rail and at the seam between the guide rail and the output tray. Traditional equipment usually relies solely on motor current or encoder feedback for anomaly detection. However, in actual operation, due to large mechanical transmission errors and load fluctuations, it is difficult to accurately distinguish between normal fluctuations and actual material jamming.

[0058] First, a non-contact optical detection assembly is installed at the observation window along the sheet conveying path. This assembly includes a light source generator, a first optical lens, a second optical lens, and a matrix pixel image sensor. The detection light emitted by the light source is shaped by the first lens and then illuminates the surface of the high-speed moving sheet. Due to the stamping texture and microstructure reflection differences on the sheet surface, the reflected light forms a textured light field with spatial characteristics. This light field is imaged by the second lens and projected onto the CMOS matrix pixel sensor. The sensor continuously outputs pixel intensity matrix data at a high frequency (e.g., around 10 kHz).

[0059] For example, in a certain production process, the sheet advances 0.5mm every 1ms at a set cycle. The system acquires a texture image at time t0 and another image at time t1. The FPGA performs displacement matching calculations on the two images, enumerating possible displacement combinations in the X and Y directions within a preset search range. It obtains the point of minimum matching error through pixel-by-pixel difference and weighted summation, thereby calculating the actual distance the sheet moves during that time period. Under normal circumstances, this value should be close to 0.5mm (X direction) and close to 0 in the Y direction.

[0060] Subsequently, the system integrates multiple high-frequency sampling results within a 1kHz control cycle to obtain the actual movement distance of the sheet within that cycle. For example, if 10 image data are acquired within one control cycle, 10 micro-displacement results at the 0.05mm level are obtained respectively. After summing, a displacement of 0.48mm in the X direction is obtained, while the cumulative offset in the Y direction is 0.01mm. This result is uploaded to the wire bonding machine's synchronous control system for comparison and analysis with the theoretical movement distance of 0.5mm output by the feeding motor within the same cycle.

[0061] Under normal conditions, the ratio of the two is approximately 0.96, and the system operates stably. However, during one production run, a partial jam occurred when the sheet passed through the guide rail seam. The pulling motor still moved 0.5mm as instructed, but the optical system detected that the sheet actually moved only 0.12mm, with an abnormal offset of 0.06mm in the Y direction. The FPGA detected a significant decrease in the X-axis displacement following ratio and that the Y-axis offset exceeded the set allowable range for two consecutive cycles, thus determining that the system had entered a jamming state.

[0062] Once the detection is successful, the controller immediately triggers the protection logic: it releases the gripper and, according to the process settings, enables the material pulling motor or performs a reverse ejection action, while simultaneously sending an alarm signal to the host computer. Because this detection process is based on optical texture matching and multi-frame high-frequency sampling, combined with synchronous comparison of the control cycle, it can complete the identification in the early stages of a jam (before it causes the wafer to tear or the chip to be damaged).

[0063] The key operational chain of this application is: optical texture acquisition, image matching displacement calculation, FPGA parallel acceleration, control cycle integration, comparison with the theoretical displacement of the motor, and three thresholds (X ratio, X-axis sliding value + Y offset) to determine the jamming, thereby realizing unified identification and protection control of multiple types of jamming in wire bonding machines with complex mechanical structures.

[0064] In specific embodiments of this application, the aforementioned optical path, matrix pixel image sensor, and digital processor can be replaced by dedicated chips, such as optical tracking sensors. By acquiring surface texture through optical tracking sensors, material displacement data can be directly output without the need for additional complex image matching calculations. This simplifies the hardware structure, reduces development and manufacturing costs, and ensures sufficient displacement detection accuracy, meeting the cost control requirements of small and medium batch wire bonding equipment.

[0065] Specifically, an optical tracking sensor is essentially an optical motion detection device that integrates a light source, a matrix CMOS sensor, and a digital signal processing unit. Its working principle involves continuously acquiring texture images of the measured surface within extremely short time intervals and calculating the displacement between adjacent images through internal correlation calculations. In this application, the optical tracking sensor can be installed near the feeding channel, with its detection window facing the moving sheet surface. When the sheet passes through the detection area, the optical tracking sensor uses its built-in light-emitting unit to illuminate the sheet surface and collect the natural texture features of the sheet surface, thereby obtaining real-time motion information of the sheet relative to the chip.

[0066] Since the optical tracking sensor integrates an image acquisition module, a displacement calculation module, and a digital processing module, there is no need to separately set up a matrix pixel image sensor, an image buffer unit, and a displacement matching algorithm processor. The optical tracking sensor can directly output displacement increment data in the X and Y axes, such as ΔX and ΔY data. The wire bonding machine's synchronous control system only needs to read the corresponding displacement data according to the preset control cycle and perform accumulation processing to obtain the actual movement distance of the material within the control cycle. Compared with the implementation method using a complete image matching algorithm, this solution eliminates a large amount of image storage, matrix operations, and correlation search calculation processes, thereby reducing the processor's computational load and improving the system's real-time performance.

[0067] Furthermore, during normal material movement, the optical tracking sensor continuously outputs constantly changing displacement data. The control system compares the accumulated actual X-axis displacement distance within each control cycle with the moving distance of the feeding motor. When the feeding motor has completed the feeding action according to the control command, and the X-axis displacement detected by the optical tracking sensor significantly decreases, stops changing, or deviates significantly from the theoretical displacement, it can be determined that the material is jammed, slipping, or experiencing a feeding abnormality. Since the optical tracking sensor outputs directly calculated motion data, the control system can achieve jam detection without performing complex image matching calculations.

[0068] Meanwhile, optical tracking sensors can typically output Y-axis displacement data synchronously. Therefore, changes in Y-axis displacement can be used to detect abnormalities such as material deviation, lateral offset, or local obstruction. When the material is squeezed by the guide mechanism, gets caught on the edge, or undergoes tilting motion, the Y-axis displacement will increase significantly. The control system can combine this with X-axis displacement data to jointly determine the abnormal state, thereby improving the reliability of material jam detection.

[0069] It should be noted that features such as embossing, machining textures, stamping marks, micro-roughness of the metal surface, and the edges of positioning holes on the sheet material can all serve as reference textures for motion tracking by the optical tracking sensor. Especially in lead frames, metal carrier tapes, PCB connector tapes, and sheets with perforated structures, the rich surface features provide a stable image tracking foundation for the optical tracking sensor, thus ensuring displacement detection accuracy. Even under conditions of varying drawing speed or slight vibration, the optical tracking sensor can continuously output stable displacement information, meeting the real-time requirements of wire bonding machine jam detection.

[0070] Furthermore, compared to implementations using independent image sensors and image processors, using optical tracking sensors for jam detection significantly reduces the number of hardware components and the complexity of software development. The control system only needs to complete displacement data reading, distance accumulation, and threshold comparison to determine jamming. Therefore, it is particularly suitable for cost-sensitive wire bonding machines, retrofitted equipment, and small-to-medium batch automated equipment applications, simplifying the system structure and reducing overall costs while ensuring detection functionality.

[0071] This application also provides a synchronous control system for a wire bonding machine, which performs the jam detection method for the wire bonding machine as described above.

[0072] Specifically, the synchronous control system described in this application can be a main controller, motion controller, PLC control system, embedded control system, or industrial computer control platform of the wire bonding machine. It is used to coordinate the collaborative operation between the material pulling mechanism, the wire bonding mechanism, and the jam detection module. The synchronous control system is not only responsible for sending material pulling control commands to the material pulling motor, but also for acquiring real-time information on the material's movement status and determining whether the material pulling process is normal based on the detection results, thereby achieving integrated management of material pulling control and jam monitoring.

[0073] In one embodiment, the synchronous control system includes a motion control module, a displacement detection module, a data processing module, an anomaly detection module, and a protection control module. The motion control module controls the material pulling motor to perform material pulling actions according to a preset rhythm. The displacement detection module receives material displacement data output from an image detection device, an optical displacement detection device, or an optical tracking sensor. The data processing module filters, accumulates, and performs coordinate transformation on the collected displacement data. The anomaly detection module compares the actual material movement distance with the material pulling motor movement distance and generates a jamming judgment result based on preset judgment rules. The protection control module executes shutdown protection and alarm output upon detecting a jam.

[0074] Furthermore, the synchronous control system establishes a unified control cycle as the data synchronization benchmark for each functional module. Within each control cycle, the system records the theoretical travel distance of the pulling motor while continuously receiving the actual displacement data of the material sheet from the displacement detection module. It then statistically processes multiple sampled data points to obtain the actual travel distance of the material sheet within the corresponding control cycle. By using a unified cycle for data synchronization, an accurate time correspondence between the displacement detection results and the pulling action can be ensured, thereby improving the accuracy of jam detection.

[0075] After completing displacement data acquisition, the synchronous control system can analyze the material pulling status according to preset judgment logic. For example, it calculates the following ratio, displacement difference, and lateral offset between the actual moving distance of the material sheet and the moving distance of the pulling motor, and compares them with corresponding thresholds. When any detection index reaches an abnormal condition, the system can determine that the material sheet is stuck, slipping, deviating, or experiencing abnormal material pulling. Compared with traditional detection methods that rely on motor current changes or limit switch feedback, this application can directly monitor the actual movement state of the material sheet itself, thus the detection results are more accurate and reliable.

[0076] When the synchronous control system detects a material jam, it can immediately execute preset protection strategies. These include stopping the material feeding motor, pausing the welding wire connection, shutting down subsequent workstation actuators, locking the automatic operation status, and recording fault information to prevent further compression, stretching, or damage to the material sheet. Simultaneously, the system can send alarm information to the human-machine interface, the host computer control system, or the factory MES system, enabling operators to promptly handle the fault and restore production.

[0077] Furthermore, the first, second, and third thresholds in the synchronous control system can all be set as configurable parameters. Operators can adjust these parameters according to the material of the sheet, the width of the strip, the pulling speed, the equipment model, and the production process requirements, so that the system can adapt to the processing needs of different products. For example, the detection sensitivity can be appropriately increased for thin, flexible strips, and the allowable error range can be appropriately expanded for high-speed pulling scenarios, thereby balancing detection accuracy and system stability.

[0078] Therefore, the synchronous control system described in this application can not only perform synchronous control of the wire bonding machine's feeding mechanism, but also acquire the actual movement status of the sheet material in real time and perform jam detection, achieving deep integration of feeding control and fault protection. When an anomaly is detected, protective measures can be taken in time before the fault escalates, improving the reliability of the wire bonding machine, production continuity, and product yield.

[0079] refer to Figure 2 This application also discloses a wire bonding machine 100, including a light source generator a, a first optical lens b, a second optical lens d, a matrix pixel image sensor e, a material stage c, a digital processor (not shown), and a controller (not shown). The controller executes the jam detection method described above. The workpiece M to be processed is placed on the material stage c. The material stage c includes a pulling motor, a pulling guide rail, and workpiece grippers. The pulling motor controls the movement of the pulling guide rail, and the workpiece M to be processed is placed on the pulling guide rail. Light emitted from the light source generator a passes through the first optical lens b and illuminates the workpiece M to be processed. Light reflected from the workpiece M passes through the second optical lens d and illuminates the matrix pixel image sensor e. The first optical lens b is a focusing lens used to focus the light emitted from the light source generator onto the surface of the workpiece to be processed, and the second optical lens d is an imaging lens used to image the reflected light from the surface of the workpiece to be processed and project it onto the matrix pixel image sensor.

[0080] In this embodiment, the wafer to be processed is positioned on a feeding guide along a predetermined path of the wire bonding machine. The feeding guide carries and guides the movement of the wafer. A light source generator is positioned above or slightly above the wafer, and the detection light emitted by it is directed onto the surface of the wafer after passing through a first optical lens. The first optical lens is preferably a condenser lens, which collimates, focuses, or shapes the detection light emitted by the light source to ensure that the detection light stably covers the preset detection area. Since the wafers used in semiconductor packaging are typically made of copper, alloys, or other metals, numerous naturally occurring micro-textures and surface reflection differences are formed during stamping, etching, and surface treatment. Therefore, when the detection light shines on the wafer surface, different areas will produce reflected light of varying intensities. This reflected light carries information about the current surface texture features of the wafer and changes synchronously with the wafer's position.

[0081] Furthermore, the light reflected from the surface of the sheet is projected onto the matrix pixel image sensor after passing through a second optical lens. The second optical lens is preferably an imaging lens, whose function is to optically image the texture features of the sheet surface onto the photosensitive area of ​​the image sensor, enabling minute texture changes on the sheet surface to be converted into corresponding pixel grayscale changes. The matrix pixel image sensor can be a CMOS image sensor, a CCD image sensor, or other high-speed image acquisition devices. It contains multiple photosensitive pixel units arranged in a matrix, each capable of acquiring light intensity information for its corresponding area. When the sheet is stationary, the texture image acquired by the image sensor remains relatively stable; when the sheet moves, the texture features in the image undergo corresponding spatial displacement. The controller is electrically connected to the matrix pixel image sensor and continuously receives the pixel light intensity distribution data output by the image sensor.

[0082] In this embodiment, a digital processor (FPGA, etc.) can calculate the relative displacement of the sheet at adjacent acquisition times by cross-correlation calculations of two adjacent texture images. Then, by accumulating the relative displacements of all cycles, the cumulative actual displacement of the sheet during the entire feeding process can be obtained. Finally, this actual displacement is transmitted to the controller for jamming status judgment. This detection method eliminates the need for additional markers on the sheet or feeding mechanism, directly utilizing the inherent surface texture features of the sheet to achieve displacement detection. It does not cause additional impact on the sheet structure or wire bonding process, while ensuring the accuracy and response speed of displacement detection, meeting the real-time jamming detection requirements in high-speed feeding scenarios.

[0083] During actual operation, the wire bonding machine's synchronous control system drives the material pulling motor according to a preset control cycle. The controller continuously receives displacement detection results from the matrix pixel image sensor and integrates or accumulates the X-axis and Y-axis displacement distances obtained from multiple sampling cycles within each control cycle to obtain the actual movement distance of the material within the corresponding control cycle. Simultaneously, the controller acquires the theoretical movement distance of the material pulling motor output by the synchronous control system and uses it as a reference for the material pulling motion. Subsequently, the controller calculates the correspondence between the actual movement distance of the material and the theoretical movement distance of the material pulling motor, for example, calculating the displacement following ratio (and difference) between the actual and theoretical movement distances in the X-axis direction. When the controller detects that the displacement following ratio (and / or difference) is lower than a preset threshold, it indicates that although the material pulling motor has performed the pulling action, the material has failed to complete the expected displacement, indicating a risk of material jamming during the pulling process. Simultaneously, when the controller detects that the cumulative displacement in the Y-axis direction exceeds the allowable range, it indicates that the material is experiencing abnormal conditions such as deviation, warping, lateral force, or guide rail interference. The controller can output a jamming control signal based on the above judgment result and send an alarm message to the wire bonding machine control system, triggering protective operations such as stopping the material pulling motor, releasing the grippers, reversing the material retraction, or disabling the drive enable. Because this embodiment uses a completely non-contact optical detection structure, the entire detection process does not require detection components such as rubber wheels or pressure rollers that directly contact the material sheet. Therefore, it will not generate additional friction on the material sheet movement, nor will it cause new jamming phenomena due to the detection mechanism itself. Furthermore, this embodiment directly detects the movement of the material sheet surface texture, rather than indirectly detecting changes in motor load. Therefore, it can be adapted to different types of material pulling drive structures such as linear servo motors, rotary servo motors, and stepper motors, and has strong versatility and engineering application value.

[0084] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A method for detecting material jamming in a wire bonding machine, characterized in that, include: The detection light is irradiated onto the surface of the material sheet after passing through the first optical lens, and the reflected light intensity information representing the surface texture of the material sheet is obtained. The reflected light intensity information is projected onto a matrix pixel image sensor using a second optical lens to obtain pixel light intensity distribution data. The pixel light intensity distribution data is read according to a preset reading rhythm, and displacement matching calculation is performed on the pixel light intensity distribution data of two adjacent reading rhythms to obtain the displacement distance information of the material in the X-axis direction and Y-axis direction under the current reading rhythm. According to the control cycle of the wire bonding machine synchronous control system, the displacement distance information of the material in the X-axis and Y-axis directions read in a single control cycle is filtered and accumulated to obtain the actual moving distance of the material in the corresponding control cycle. Obtain the moving distance of the material pulling motor within the corresponding control cycle, and compare the actual moving distance of the material sheet with the moving distance of the material pulling motor to obtain the moving distance comparison result; Based on the comparison results of the moving distance, it is determined whether the wire bonding machine has jammed. If the wire bonding machine jams, a jam protection operation is performed, and a jam alarm signal is sent simultaneously.

2. The method for detecting jamming in a wire bonding machine as described in claim 1, characterized in that, The step of reading the pixel light intensity distribution data according to a preset reading rhythm, and performing displacement matching calculations on the pixel light intensity distribution data of two adjacent reading rhythms to obtain the displacement distance information of the material in the X-axis and Y-axis directions at the current reading rhythm, specifically includes: Read the first pixel light intensity distribution data collected by the matrix pixel image sensor under the current reading cycle, and establish the first light intensity data matrix; Read the second pixel light intensity distribution data collected by the matrix pixel image sensor in the previous reading cycle, and establish the second light intensity data matrix; Enumerate different combinations of X-axis and Y-axis displacement within a preset range, perform pixel-by-pixel difference calculation between the first light intensity data matrix and the second light intensity data matrix after corresponding displacement offset, and perform weighted summation operation on the difference results; The X-axis displacement and Y-axis displacement corresponding to the minimum value of the weighted summation are selected as the actual displacement distance information of the material at the current reading cycle.

3. The method for detecting material jamming in a wire bonding machine as described in claim 2, characterized in that, The steps of enumerating different combinations of X-axis and Y-axis displacements within a preset range, calculating the pixel-by-pixel difference between the first and second light intensity data matrices after corresponding displacement offsets, and performing a weighted summation operation on the difference results specifically include: Set the X-axis displacement search range and the Y-axis displacement search range, and generate multiple combinations of displacements to be matched according to a preset step size; For each combination of displacements to be matched, the first light intensity data matrix is ​​subjected to corresponding X-axis and Y-axis coordinate offset processing to obtain the corresponding offset light intensity data matrix. The offset light intensity data matrix and the second light intensity data matrix are compared pixel by pixel in the overlapping area to calculate the light intensity difference between corresponding pixels and obtain the difference matrix. Based on the position distribution of each pixel in the matrix, the light intensity change characteristics, or the signal-to-noise ratio information, each pixel difference in the difference matrix is ​​assigned a corresponding weight, and the weighted pixel differences are accumulated to obtain the matching evaluation value corresponding to the current combination of displacement to be matched. Record the matching evaluation value corresponding to each displacement combination to be matched, and establish the correspondence between the displacement combination and the matching evaluation value, so as to select the displacement combination with the smallest matching evaluation value as the actual displacement distance information of the current reading cycle of the material.

4. The method for detecting material jamming in a wire bonding machine as described in claim 2, characterized in that, The step of filtering and accumulating the displacement distance information of the sheet in the X-axis and Y-axis directions read within a single control cycle according to the control cycle of the wire bonding machine synchronous control system to obtain the actual movement distance of the sheet within the corresponding control cycle specifically includes: According to the control cycle of the wire bonding machine synchronous control system, data operations are performed on the actual displacement distance of the material sheet for all reading cycles within each control cycle, wherein the control cycle is greater than the reading cycle. In each control cycle, the displacement data of each reading cycle in the X-axis direction is filtered and accumulated to serve as the actual displacement distance of the material in the X-axis direction within the control cycle. Within each control cycle, the displacement data of each reading cycle in the Y-axis direction are filtered and accumulated to serve as the actual displacement distance of the material sheet in the Y-axis direction within the control cycle.

5. The method for detecting material jamming in a wire bonding machine as described in claim 4, characterized in that, The steps of obtaining the moving distance of the material pulling motor within the corresponding control cycle and comparing the actual moving distance of the material sheet with the moving distance of the material pulling motor to obtain the moving distance comparison result specifically include: The theoretical moving distance of the pulling motor output by the synchronous control system of the wire bonding machine in a single control cycle, or the actual moving distance obtained by measuring the actual movement of the pulling motor, is used as the moving distance of the pulling motor, and the moving distance of the pulling motor is used as a reference benchmark value. The actual moving distance of the material sheet is compared with the moving distance of the feeding motor to obtain the moving distance comparison result.

6. The method for detecting material jamming in a wire bonding machine as described in claim 5, characterized in that, The step of comparing the actual moving distance of the material sheet with the moving distance of the feeding motor to obtain the moving distance comparison result specifically includes: Calculate the ratio of the actual displacement distance of the material sheet in the X-axis direction within the control cycle to the moving distance of the pulling motor to obtain the displacement following ratio; The wire bonding machine synchronous control system compares the displacement following ratio with a configurable first threshold. When the displacement following ratio is lower than the first threshold, it is considered that a jamming situation has been detected. And / or calculate the difference between the actual displacement distance of the material sheet in the X-axis direction within the control cycle and the moving distance of the pulling motor to obtain the displacement difference; The wire bonding machine synchronous control system compares the displacement difference with a configurable second threshold. When the displacement difference is greater than the second threshold, it is considered that a jamming situation has been detected. And / or the actual displacement distance of the sheet in the Y-axis direction within the control cycle is compared with a configurable third threshold by the synchronous control system of the wire bonding machine. When the actual displacement distance of the sheet in the Y-axis direction within the control cycle is greater than the third threshold, it is considered that a jamming situation has been detected.

7. The method for detecting material jamming in a wire bonding machine as described in claim 1, characterized in that, The material jam protection operation includes at least the steps of enabling the pull motor, reversing the pull motor, and releasing the material clamps; determining whether the wire bonding machine has jammed based on the comparison result of the moving distance; and if the wire bonding machine has jammed, executing the material jam protection operation and simultaneously sending a material jam alarm signal. Specifically, this includes: The synchronous control system of the wire bonding machine determines whether the wire bonding machine has jammed based on the comparison result of the moving distance; When the synchronous control system of the wire bonding machine determines that the wire bonding machine is jammed, it generates control information, which includes a material pulling motor control signal and a material clamping claw control signal. The wire bonding machine synchronous control system controls the material pulling motor and / or the material clamping jaws based on the control information; The wire bonding machine synchronous control system generates the jamming alarm signal and sends the jamming alarm signal to the operation terminal.

8. A synchronous control system for a wire bonding machine, characterized in that, The synchronous control system performs the jam detection method for a wire bonding machine as described in any one of claims 1-7.

9. A wire bonding machine, characterized in that, The device includes a light source generator, a first optical lens, a second optical lens, a matrix pixel image sensor, a digital processor, a material stage, and a synchronous control system as described in claim 8. The material stage includes a pulling motor, a pulling guide rail, and a sheet clamp. The pulling motor controls the movement of the pulling guide rail. The sheet to be processed is placed on the pulling guide rail and fixed by the sheet clamp. The first and second optical lenses are disposed above the material stage. The light source generator is disposed above the first optical lens. The matrix pixel image sensor is disposed above the second optical lens. The digital processor executes the jam detection method for a wire bonding machine as described in any one of claims 2-4.

10. The wire bonding machine as described in claim 9, characterized in that, The light emitted by the light source generator passes through the first optical lens and illuminates the workpiece to be processed. The light reflected from the workpiece to be processed passes through the second optical lens and illuminates the matrix pixel image sensor. The first optical lens is a focusing lens for focusing the light emitted by the light source generator onto the surface of the workpiece to be processed, and the second optical lens is an imaging lens for imaging the reflected light from the surface of the workpiece to be processed and projecting it onto the matrix pixel image sensor.

Images