Chip clamp automatic adjusting method and system

Abstract

The invention relates to the technical field of chip mounting, in particular to an automatic adjusting method and system for a chip clamp, and the method comprises the following steps: monitoring and automatically calibrating the pressure applied by the clamp in real time to ensure that the pressure meets the chip mounting standard, analyzing a to-be-mounted chip by using a camera, optimizing the shape recognition, and adjusting the track of the clamp to correct the offset. And analyzing the correlation between the pressure and the mounting quality according to the data after mounting, and establishing an optimized control closed loop. According to the invention, through real-time monitoring and automatic adjustment of pressure parameters, the dependence on manual adjustment is reduced, the automation level of the production process is improved, through detailed pressure adjustment, each chip is ensured to be accurately processed in the mounting process, the product quality is improved, the rejection rate is reduced, and the production efficiency is improved. The application of the image analysis technology allows the chip to be accurately evaluated before mounting, and the distance between the clamps is automatically adjusted, so that the mounting precision is improved, and the requirements of various chip shapes and sizes are met.

Description

Technical Field

[0001] The present invention relates to the technical field of chip soldering technology, in particular to an automatic adjustment method and system for a chip fixture. Background Art

[0002] The chip soldering technology field involves the process of installing electronic components (such as integrated circuit chips, resistors, capacitors, etc.) onto a printed circuit board (PCB). It is a core link in modern electronic manufacturing. The key lies in achieving high-precision and high-efficiency automated production. A chip mounter is the main equipment in this technical field, which can quickly and accurately place electronic components at designated positions. This process involves multiple steps, including rapid picking up of components, precise placement, and soldering and fixing. With the development of electronic devices towards high integration and miniaturization, the chip soldering technology has been continuously progressing, and the requirements for precision and reliability are also getting higher and higher.

[0003] Among them, the automatic adjustment method for a chip fixture is how to automatically adjust the fixture (i.e., a mechanical device for fixing and transporting chips) in a chip soldering production line to adapt to chips of different sizes and shapes, ensuring that the chips are accurately soldered onto the circuit board. Its main uses are to improve production efficiency and quality control, reduce manual intervention, and at the same time enhance the flexibility and adaptability of the soldering process. By automatically adjusting the position and pressure of the fixture, it can be ensured that each component is installed in the correct position with the correct posture.

[0004] The existing technology often faces problems such as long pressure adjustment response time and insufficient precision during the chip soldering process. Especially when dealing with small or complex-shaped chips, the inherent pressure settings cannot meet the requirements of precise soldering. The pressure error caused by the lack of a real-time feedback mechanism is likely to cause slight deviations in the soldering position, which is unacceptable in high-precision electronic manufacturing and is likely to lead to an increase in the defective rate of products. In addition, the existing technology has poor adaptability to new chip designs and cannot be effectively adjusted to the optimal soldering state, affecting the overall production efficiency and product reliability. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art that during the chip soldering process, there are often problems such as long pressure adjustment response time and insufficient precision. Especially when dealing with small or complex-shaped chips, the inherent pressure settings cannot meet the requirements of precise soldering. The pressure error caused by the lack of a real-time feedback mechanism is likely to cause slight deviations in the soldering position, which is unacceptable in high-precision electronic manufacturing and is likely to lead to an increase in the defective rate of products. In addition, the existing technology has poor adaptability to new chip designs and cannot be effectively adjusted to the optimal soldering state, affecting the overall production efficiency and product reliability, the embodiments of the present invention provide an automatic adjustment method and system for a chip fixture. The technical solutions are as follows: On the one hand, an automatic adjustment method for a chip fixture is provided, including the following steps: S1: Based on the chip mounting process, the initial pressure applied by the fixture on the standard test piece is monitored in real time, the pressure readings are captured, compared with the standard pressure range, the pressure parameters are automatically calibrated, and the pressure calibration index is obtained; S2: According to the pressure calibration index, the deviation between the current pressure setting and the target pressure is evaluated, the adjustment range of the fixture pressure is calculated, and the pressure setting is updated in real time to obtain the pressure adjustment record; S3: Based on the pressure adjustment record, the image of the chip to be mounted is captured before the fixture is loaded, the gray-scale distribution and edge contour of the image are analyzed, the shape coincidence degree of the mounting point is calculated, the recognition boundary interference caused by pressure change is judged, the contour spacing is automatically corrected, and the shape recognition optimization result is generated; S4: According to the shape recognition optimization result, the starting and ending coordinates of the fixture movement trajectory are obtained, the reflection delay and intensity of the ultrasonic signal are synchronized, the offset section on the fixture trajectory is identified, the deviation is corrected, and the trajectory offset calibration data is obtained; S5: The trajectory offset calibration data is called, the residual pressure after mounting is collected, the symmetry of the solder joints and the proportion of the pad contact area are measured synchronously, the correlation between pressure change and mounting quality is identified, and the control closed-loop optimization result is established.

[0006] On the other hand, the pressure calibration index includes the initial deviation amount, the adjustment threshold, and the standard pressure matching result. The pressure adjustment record includes the adjusted pressure value, the pressure matching degree, and the update frequency. The shape recognition optimization result includes the edge clarity, the contour matching accuracy, and the interference correction level. The trajectory offset calibration data includes the identified offset points, the adjusted coordinate accuracy, and the path optimization details. The control closed-loop optimization result includes the correlation between pressure and quality, the solder joint symmetry analysis result, and the contact area ratio adjustment result.

[0007] On the other hand, the specific steps for obtaining the pressure calibration index are as follows: S101: Based on the chip mounting process, the initial pressure applied by the fixture on the standard test piece is monitored in real time through a pressure sensor, data collection and recording are performed, the real-time pressure readings are captured, and the captured pressure data is sorted to establish a pressure monitoring record; S102: The pressure monitoring record is called, the continuous pressure readings are analyzed, whether the pressure is within the standard range is checked, the abnormal pressure points outside the standard range are identified, and the abnormal points are statistically counted to obtain the abnormal pressure statistics; S103: Based on the abnormal pressure statistics, if there is a deviation, the pressure parameters are automatically calibrated to match the mounting standard, and the pressure calibration index is obtained.

[0008] On the other hand, the specific steps for obtaining the pressure adjustment record are as follows: S201: Evaluate the deviation between the current fixture pressure setting and the target pressure according to the pressure calibration index, collect real-time pressure readings, compare them with the target pressure standard, determine the direction and magnitude of pressure adjustment, and obtain the pressure deviation determination result; S202: Based on the pressure deviation determination result, calculate the adjustment magnitude of the fixture pressure, automatically adjust the fixture pressure to match the specifications of the current chip batch, and update the pressure setting in real time to obtain the pressure adjustment record.

[0009] On the other hand, the steps for obtaining the shape recognition optimization result are specifically as follows: S301: Based on the pressure adjustment record, capture the image of the chip to be mounted before fixture loading through a camera, extract the gray-scale distribution of the chip area in the image, identify the position and shape of the edge contour, analyze the gray-scale gradient distribution of the image, and determine the gray-scale change at each point to obtain the edge gray-scale feature; S302: Use the edge gray-scale feature to extract the boundary coordinates of the actual mounting points in the image, compare them with the difference from the standard shape contour, analyze the distance difference between the mounting points in the image and the standard contour and the change in the boundary closing curvature, and calculate the shape coincidence degree; S303: Based on the shape coincidence degree, compare it with the historical misjudgment data of mounting, judge the recognition boundary interference caused by pressure changes, and automatically correct the contour spacing to generate the shape recognition optimization result.

[0010] On the other hand, the steps for obtaining the trajectory offset calibration data are specifically as follows: S401: According to the shape recognition optimization result, obtain the start and end coordinates of the fixture movement trajectory, synchronously measure the reflection delay and intensity of the ultrasonic signal, determine the propagation characteristics of the signal on the trajectory, and obtain the acoustic wave propagation feature; S402: Use the acoustic wave propagation feature, combined with the fixture movement trajectory coordinates, identify the offset section on the trajectory, determine the offset area and degree by analyzing the changes in the reflection delay and intensity of the signal, and adjust the fixture path to correct the identified deviation to obtain the trajectory offset calibration data.

[0011] On the other hand, by analyzing the changes in the reflection delay and intensity of the signal, use the formula: ; Calculate the signal offset , identify the offset section on the trajectory, where represents the intensity of the th reflected signal, represents the intensity of the th reflected signal, represents the propagation speed of the acoustic wave in the medium, Represents the total number of signal measurements.

[0012] On the other hand, the steps for obtaining the optimized result of the control closed-loop are specifically as follows: S501: Call the trajectory offset calibration data, collect the residual pressure after chip mounting, continuously measure at points within the mounting area through a pressure sensor, analyze the fluctuation trend and uniformity of the pressure distribution, and obtain the pressure distribution index; S502: Based on the pressure distribution index, analyze the geometric symmetry of the solder joints, calculate the proportion of the pad contact area, conduct a correlation analysis with the solder joint symmetry data, evaluate the relationship between the contact area and the solder joint symmetry, and generate the contact surface symmetry index; S503: Based on the contact surface symmetry index, integrate the fixture movement and chip mounting cycle data, analyze the influence of the fixture movement on the residual pressure and the quality of the solder joints, evaluate the optimization effect of the fixture movement, and establish the optimized result of the control closed-loop.

[0013] On the other hand, for collecting the residual pressure after chip mounting, continuously measure at points within the mounting area through a pressure sensor, and use the formula: ; Calculate the standard deviation of the pressure , and analyze the fluctuation trend and uniformity of the pressure distribution to obtain the pressure distribution index, where represents the residual pressure at the th measurement point, represents the average value of the residual pressures at all measurement points, represents the total number of measurement points.

[0014] On the other hand, a chip fixture automatic adjustment system is provided. This system is applied to the chip fixture automatic adjustment method and includes: The pressure monitoring module, based on the chip mounting process, continuously monitors the initial pressure applied by the fixture on the standard test piece through a pressure sensor, continuously analyzes the pressure readings, compares with the pressure standard range, and if there is a deviation, automatically calibrates the pressure parameters to obtain the pressure calibration index; The pressure adjustment module, according to the pressure calibration index, evaluates the deviation between the current pressure setting and the target pressure, calculates the adjustment range of the fixture pressure, matches it with the specifications of the current chip batch, and updates the pressure setting in real time to obtain the pressure adjustment record; The image processing module, based on the pressure adjustment record, captures the image of the chip to be mounted before fixture loading, analyzes the gray-scale distribution and edge contour of the image, calculates the shape coincidence degree of the mounting points, compares with the historical misjudgment data of chip mounting, judges the recognition boundary interference caused by pressure changes, and automatically corrects the contour spacing to generate the optimized result of shape recognition; Based on the shape recognition optimization result, the trajectory optimization module obtains the starting and ending coordinates of the fixture movement trajectory, synchronizes the reflection delay and intensity of the ultrasonic signal, identifies the offset section on the fixture trajectory, adjusts the fixture path to correct the deviation, and obtains the trajectory offset calibration data; The quality control module calls the trajectory offset calibration data, collects the residual pressure after the placement is completed, synchronously measures the solder joint symmetry and the proportion of the pad contact area, identifies the correlation between the pressure change and the placement quality, and integrates the fixture movement and placement cycle data to establish the control closed-loop optimization result.

[0015] The beneficial effects brought by the technical solution provided by the embodiments of the present invention at least include: Through real-time monitoring and automatic adjustment of pressure parameters, the dependence on manual adjustment is reduced, and the automation level of the production process is improved. Through meticulous pressure adjustment, it is ensured that each chip is precisely processed during the placement process, improving product quality and reducing the scrap rate. The application of image analysis technology allows for precise evaluation of the chip before placement and automatic adjustment of the fixture spacing, which not only improves the placement accuracy but also meets the requirements of various chip shapes and sizes. The synchronous analysis of ultrasonic signals and trajectory offset calibration enables more precise fixture adjustment by providing real-time position feedback and dynamic offset identification, ensuring the efficiency and reliability of the entire placement process. The closed-loop optimization feedback further strengthens the self-correction ability of the fixture control system, achieving continuous improvement in production quality. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 is the main step flow chart of the present invention; Figure 2 is the step flow chart of S1 of the present invention; Figure 3 is the step flow chart of S2 of the present invention; Figure 4 is the step flow chart of S3 of the present invention; Figure 5 is the step flow chart of S4 of the present invention; Figure 6 is the step flow chart of S5 of the present invention; Figure 7 is the system block diagram of the present invention. Detailed Embodiments

[0018] The technical solutions in the present invention will be described below with reference to the accompanying drawings.

[0019] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as an "example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of the word "example" is intended to present concepts in a specific manner. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one of the two can be selected.

[0020] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference is not emphasized, the meanings they express are the same. "of", "corresponding", and "corresponding" can sometimes be used interchangeably. It should be noted that when the difference is not emphasized, the meanings they express are the same.

[0021] In the embodiments of the present invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meanings they express are the same.

[0022] To make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] The embodiments of the present invention provide an automatic adjustment method for a chip fixture, as Figure 1 shown, including the following steps: S1: Based on the chip mounting process, the initial pressure applied by the fixture on the standard test piece is continuously monitored through a pressure sensor, the pressure reading is captured, and the pressure reading is continuously analyzed. According to the analysis result, the pressure reading is compared with the pressure standard range. If there is a deviation, the pressure parameter is automatically calibrated and matched with the mounting standard to obtain a pressure calibration index; S2: According to the pressure calibration index, the deviation between the current pressure setting and the target pressure is evaluated, the adjustment range of the fixture pressure is calculated, the fixture pressure is automatically adjusted, matched with the specifications of the current chip batch, and the pressure setting is updated in real time to obtain a pressure adjustment record; S3: Based on the pressure adjustment record, before the fixture is loaded, the image of the chip to be mounted is captured by a camera, the gray distribution and edge contour of the image are analyzed, the shape coincidence degree of the mounting point is calculated, the coincidence degree is compared with the historical misjudgment data of mounting, the recognition boundary interference caused by the pressure change is judged, and the contour spacing is automatically corrected to generate an optimized result of shape recognition; S4: Based on the optimized shape recognition results, obtain the starting and ending coordinates of the fixture movement trajectory, synchronize the reflection delay and intensity of the ultrasonic signal, identify the offset sections on the fixture trajectory, and adjust the fixture path according to the recognition results to correct the deviation, obtaining the trajectory offset calibration data; S5: Invoke the trajectory offset calibration data, collect the residual pressure after chip mounting is completed, synchronously measure the solder joint symmetry and the pad contact area ratio, analyze the collected information, identify the correlation between pressure changes and mounting quality, and integrate the fixture movement and mounting cycle data to establish the control loop optimization results.

[0024] The pressure calibration indicators include the initial deviation amount, adjustment threshold, and standard pressure matching result. The pressure adjustment record includes the adjusted pressure value, pressure matching degree, and update frequency. The optimized shape recognition results include edge sharpness, contour matching accuracy, and interference correction level. The trajectory offset calibration data includes the identified offset points, adjusted coordinate accuracy, and path optimization details. The control loop optimization results include the correlation between pressure and quality, the solder joint symmetry analysis result, and the contact area ratio adjustment result.

[0025] As Figure 2 shown, the steps for obtaining the pressure calibration indicators are specifically as follows: S101: Based on the chip mounting process, use a pressure sensor to continuously monitor the initial pressure applied by the fixture to the standard test piece, perform data acquisition and recording, capture the real-time pressure readings, and organize the captured pressure data to establish a pressure monitoring record; Before applying the initial pressure, the fixture needs to accurately position the standard test piece to the fixed area of the mounting platform, and then gradually apply force to the center area of the test piece through the fixture mechanical structure. At the same time, the set pressure sensor responds to the change of the applied force in real time. The pressure values captured by the sensor are read periodically, and the sampling frequency is set to once every 0.1 seconds. During the 5-second continuous mounting process, 50 groups of pressure readings can be obtained. Each group of data is accompanied by a time stamp and a sensor number. All pressure readings are continuously cached during the mounting process, and the data is organized in chronological order and archived in tabular form. Each row records a group of sampling data. After the mounting is completed, all pressure values are extracted and averaged to obtain the average initial pressure value for this mounting. Whether there are problems such as short-term uneven pressure application, fixture fatigue, or installation offset is judged through the average value. For example, in actual tests, the first 10 groups of pressure readings are all stable near the reference value, but the middle section fluctuates beyond the tolerance. After recording the complete fluctuation trajectory, the final average initial pressure value can still be accurately output, and each sampling data is archived to generate a complete pressure monitoring record.

[0026] S102: Invoke the pressure monitoring record, analyze the continuous pressure readings, check whether the pressure is within the standard range, identify the abnormal pressure points outside the standard range, and count the abnormal points to obtain the abnormal pressure statistics; Read all consecutive pressure readings group by group, compare them with the standard range to make a judgment. Preset a set of upper and lower limit values of pressure that meet the mounting requirements. Compare each group of readings with the upper and lower limits one by one to determine whether they exceed the limits. If a certain group of data exceeds the limits, it is marked as an abnormal point. For example, in a certain mounting, if multiple readings exceed the upper limit or are lower than the lower limit, the data is extracted as a set of abnormal readings, and the time position, the readings themselves, and the sensor numbers to which they belong are recorded. Subsequently, count the number of abnormal points, and at the same time, count the deviation range between the readings of the points and the standard values. Then average all the deviation values to calculate an average index that reflects the overall deviation degree, and further count the frequency of the abnormal values and their distribution in the entire mounting cycle. For example, if multiple abnormal points appear concentratedly within the first 2 seconds during a certain mounting process, identify this time period as a high-risk operation section. In this way, a complete abnormal pressure statistical result is obtained.

[0027] S103: Based on the abnormal pressure statistics, if there is a deviation, automatically calibrate the pressure parameters to match the mounting standard to obtain a pressure calibration index.

[0028] First, determine whether the current average deviation exceeds the preset allowable range. If it exceeds, automatically enter the calibration process, read the currently used pressure setting value, and determine the correction direction according to the overall deviation direction of the abnormal points. If most of the abnormal points are on the high side, it is judged that the current pressure application is too strong and the pressure setting value needs to be reduced. On the contrary, if it is on the low side, adjust to increase the set pressure. Subsequently, based on the maximum current deviation, calculate a correction increment and directly apply this value to the original set pressure to update it to a new target pressure value. At the same time, to improve the mounting control accuracy, moderately narrow the originally set fluctuation tolerance range to enhance the control response ability. For example, when the originally set allowable fluctuation is wide and causes frequent errors, the fluctuation tolerance value can be lowered to restrict the fluctuation range of the next mounting. The updated new parameter values will be directly written into the control for the pressure scheduling of the next mounting cycle to achieve automatic parameter update and form a new pressure calibration index.

[0029] As Figure 3 shown, the specific steps for obtaining the pressure adjustment record are as follows: S201: According to the pressure calibration index, evaluate the deviation between the current pressure setting of the fixture and the target pressure, collect real-time pressure readings, compare them with the target pressure standard, determine the direction and amplitude of the pressure adjustment, and obtain a pressure deviation judgment result; Call the pressure target value and the set tolerance range obtained in the previous stage, extract the current pressure setting value of the fixture before chip mounting, and record the current initial set pressure value, which usually comes from the setting item in the control interface of the mounting equipment. At the same time, read the actual applied pressure value fed back by the pressure sensor in real time, record the pressure value and its time point. For example, if the current pressure applied by the fixture is 4.6N, the target pressure is 4.3N, and the allowable deviation is set to ±0.2N, immediately perform a difference operation on the read real-time value and the target value to determine whether it exceeds the tolerance boundary. In the current example, the difference is 0.3N, which exceeds the allowable range, and it is determined to be in a high state. Subsequently, define this deviation direction as "downward adjustment", and the deviation amplitude is 0.3N. Then, determine whether the pressure deviation continues. If the pressure remains outside the range for three consecutive sampling periods, it is confirmed as a continuous deviation rather than a transient fluctuation. Use this trend as a basis to further weight and judge the deviation stability. For example, if the three consecutive pressure readings are 4.6N, 4.62N, and 4.61N, and the fluctuation amplitude is between ±0.02N, it indicates that the deviation direction and amplitude are stable, and it is determined as an effective deviation that needs to be adjusted. Through the above multiple consecutive samplings and numerical comparisons with the static target value, the direction is judged based on the size relationship between the current pressure value and the target value, and the amplitude is obtained through the direct difference calculation result. At the same time, refer to the standard value in the historical mounting data for secondary confirmation, generate a deviation evaluation between the current setting and the target setting of the fixture once, and the output is the deviation direction "downward adjustment" and the deviation amplitude "0.3N", completing the pressure deviation determination result.

[0030] S202: Based on the pressure deviation determination result, calculate the adjustment amplitude of the fixture pressure, automatically adjust the fixture pressure to match the specifications of the current chip batch, and update the pressure setting in real time to obtain the pressure adjustment record; Read the current deviation direction and deviation amplitude, then extract the control parameters currently used by the fixture, perform a direct correction operation on the current set pressure value and the deviation amplitude, and determine whether the correction falls within the applicable range of the pick-and-place pressure required for the current batch of chips. To this end, it is necessary to retrieve the specification parameter items in the chip batch database. For example, the chip number of the current batch is XH20250415A, and the corresponding pressure requirement is between 4.2N and 4.5N. If the target pressure of the fixture after correction is still within this range, perform parameter update. When performing the correction operation, adopt a step-by-step approximation strategy, that is, reduce the target pressure by a set offset from the current value according to the deviation amplitude. For example, the current fixture pressure is 4.6N, the deviation direction is "downward", and the correction amplitude is 0.3N. After correction, the pressure value is updated to 4.3N. Then compare this value with the chip batch standard range. If the result is within the valid range, confirm the match. Subsequently, record information such as the time of this adjustment operation, the pressure before adjustment, the pressure after adjustment, the adjustment amplitude, and the chip batch number, form a structured adjustment record, and save it to the device log. The updated fixture pressure setting is immediately fed back to the pick-and-place execution control system for subsequent operations, completing the pressure update operation for the current pick-and-place process and obtaining the pressure adjustment record.

[0031] As Figure 4 shown, the specific steps for obtaining the shape recognition optimization result are as follows: S301: Based on the pressure adjustment record, capture the image of the chip to be pick-and-placed before the fixture is loaded through a camera, extract the gray-scale distribution of the chip area in the image, identify the position and shape of the edge contour, analyze the gray-scale gradient distribution of the image, and determine the gray-scale change at each point to obtain the edge gray-scale feature; Before each placement, the imaging unit is called to perform real-time imaging on the fixture operation area, and a complete image of the chip to be placed in a stationary state is captured. The image resolution is controlled to be above 200 pixels per millimeter to meet the requirements of gray-scale processing accuracy. After the image capture is completed, the gray-scale distribution extraction of the chip area is carried out. The image pixel points are scanned row by row and column by column, and the gray-scale value of each pixel point is counted. The gray-scale value range is set from 0 to 255, where 0 represents pure black and 255 represents pure white. According to the brightness gradient in the image, the initial edge judgment is carried out to identify the contour line structure of the area with significant gray-scale changes, and then the edge contour position and boundary form are extracted. Specifically, it is to judge the change amplitude of the gray-scale value of each pixel point and its adjacent pixel points one by one. If the gray-scale difference of three consecutive pixel points exceeds the preset threshold of 20, then this point is defined as an edge point. Subsequently, starting from this point, the recognition is carried out in the surrounding area and all edge points are connected to form a preliminary contour. After the contour is completed, the gradient value of the gray-scale change of each edge point is calculated. The specific operation is to calculate the difference between the gray-scale values of the current edge point and the pixels in eight adjacent directions respectively, obtain the local gray-scale change direction and amplitude, and record them in the coordinate array. For example, if the gray-scale value on the left side of an edge point is 190 and the gray-scale value of the current point is 100, then the gray-scale gradient in this direction is -90. If the adjacent directions are -85, -92, -88, etc., it means that this point falls on a clear gray-scale section.

[0032] S302: Using the edge gray-scale features, extract the boundary coordinates of the actual placement points in the image, compare them with the differences in the standard shape contour, analyze the distance difference between the placement points in the image and the standard contour and the change in the boundary closed curvature, and calculate the shape coincidence degree; Extract the boundary coordinates from the set of contour points with reference to the image coordinates to form a complete list of boundary coordinates of the actual placement points in the placement image. The boundary coordinates are stored as a two-dimensional array, and each boundary point contains the X-axis and Y-axis positions. Subsequently, the boundary coordinates are compared one by one with the preset standard shape contour. In the comparison operation, the Euclidean distance value from the placement point in the image to the corresponding position of the standard contour is calculated point by point, and each distance deviation is recorded. Further, the mean and maximum values of all distance deviations are calculated to quantify the deviation degree of the edge contour of the placement point relative to the standard contour. For example, the maximum deviation between the image edge contour and the standard circular contour is 0.42 mm, and the average deviation is 0.17 mm. According to the distance deviation data, the overall deformation trend of the boundary is statistically analyzed. Subsequently, the connection path between the boundary coordinate points is called, and the curvature change of the boundary line is calculated at a certain step size. Specifically, the included angle formed by taking three adjacent points in sequence is taken, and the change of the included angle is used as the basis for the closed curvature of the boundary to determine whether there are discontinuities, curvature mutations, or line segment breaks in the entire boundary. For example, if the curvature change of a continuous five-point segment changes gently within plus or minus 15 degrees, it is judged as a continuous region. If a single-point mutation to 45 degrees occurs, it is marked as a contour mutation point. Finally, the number, distribution position, and fluctuation degree of the mutation points in the entire contour curve are statistically analyzed and compared with the closed curvature curve of the standard contour to obtain the evaluation result of the coincidence degree between the current placement image shape contour and the standard shape.

[0033] S303: Based on the shape coincidence degree, compare with the historical placement misjudgment data, judge the recognition boundary interference caused by pressure changes, and automatically correct the contour spacing to generate an optimized shape recognition result; Read the shape coincidence deviation values and their corresponding placement misjudgment labels in the previous records, compare the coincidence deviation of the current image with the misjudged samples in the historical data. If the current deviation value is higher than the historical average misjudgment deviation, or the boundary closed curvature fluctuation is consistent with the misjudgment record, it is determined that there is recognition boundary interference caused by pressure changes in this image. Further, call the pressure adjustment record of the current placement, compare the pressure change time points corresponding to the interference area. If the placement pressure fluctuates violently by more than 0.3 N or the change rate is greater than 0.1 N / s at this time point, then this point is classified as an interference trigger point, and a local coordinate point spacing adjustment operation is performed on the contour area around the interference trigger point. Specifically, the coordinate points are translated according to the interference direction. For example, if the interference trend is horizontal right shift, the X-axis coordinates of the interfered coordinate points are uniformly reduced by 0.15 mm. At the same time, the contour closed path is recalculated and the curvature value is updated. The corrected new contour will be compared with the standard contour again to confirm whether the coincidence degree after adjustment returns to the normal range. The differences before and after correction are formed into a structured record for output to generate an optimized shape recognition result.

[0034] As Figure 5 shown, the steps for obtaining the trajectory offset calibration data are specifically as follows: S401: Based on the optimized shape recognition results, obtain the start and end coordinates of the fixture motion trajectory, synchronously measure the reflection delay and intensity of the ultrasonic signal, determine the propagation characteristics of the signal on the trajectory, and obtain the acoustic wave propagation characteristics; Obtain the start coordinate and end coordinate of the fixture motion trajectory within the mounting cycle. The extraction method is to read the initial motion position information and the final stop position information of the current batch of fixtures from the motion control unit. The coordinates are all marked with three-dimensional absolute positioning. For example, the start coordinate is (10.0 mm, 5.0 mm, 0.0 mm), and the end coordinate is (30.0 mm, 5.0 mm, 0.0 mm), indicating that the fixture moves 20.0 mm along the X-axis. At the same time, synchronously detect the ultrasonic signal. Arrange several ultrasonic transmitting and receiving units evenly along the fixture motion trajectory. When the fixture starts to move, emit an ultrasonic pulse signal and record its return time. Subtract the transmission time from the return time to obtain the reflection delay of the signal at this position. All detection points are set at an interval of 1 mm, and a set of reflection delay and reflection intensity data is generated for each detection point. The reflection intensity value is recorded according to the amplitude of the received signal. For example, when the fixture moves to the 15 mm position, the received reflection signal delay is 0.5 ms, and the corresponding intensity is 80 dB. And so on, construct a reflection delay map and an intensity distribution map within the entire trajectory range. In subsequent processing, fit the reflection characteristics of each detection point to determine whether there are abnormal fluctuations or reflection interference points during the signal propagation process. If the reflection delay of three adjacent points continuously rises and the intensity drops beyond the preset threshold range, it is initially identified as an abnormal signal segment. Combine the current fixture path to correspond to the abnormal segment, confirm the actual coordinate interval where it is located on the trajectory, and construct the propagation characteristics of the acoustic wave in the fixture motion path.

[0035] S402: Utilize the acoustic wave propagation characteristics, combine with the fixture motion trajectory coordinates, identify the offset section on the trajectory, determine the offset area and degree by analyzing the changes in the reflection delay and intensity of the signal, and adjust the fixture path to correct the identified deviation to obtain the trajectory offset calibration data; By analyzing the changes in the reflection delay and intensity of the signal, use the formula: ; Calculate the signal offset , identify the offset section on the trajectory, where represents the th reflection signal intensity, represents the th reflection signal intensity, represents the propagation speed of the acoustic wave in the medium, represents the total number of signal measurements; Measure the reflection signal intensity at different time points. The values are obtained through actual measurement by the sensor. For example, the reflection signal intensities collected at five consecutive time points are as follows: , the propagation speed of sound waves in the medium is determined according to the physical properties of the medium and environmental conditions. For example, the propagation speed of sound waves in air is approximately , in the formula, represents the total number of signal measurements, which is 5. Calculate the absolute value of the difference in signal intensity between two consecutive measurements: ; ; ; ; Divide each difference by the propagation speed of sound waves and square it: ; ; ; ; Calculate the sum of these squared values: ; Take the square root of this sum value to obtain the signal offset: ; This result shows that based on the analysis of the time delay and intensity change of sound wave reflection, through actual monitoring data, the signal offset on the calculated trajectory is 0.0462, which reflects the possible position deviation on the trajectory and is the measurement result obtained according to the actual environmental conditions and physical properties. Furthermore, it can be used for further trajectory calibration analysis to ensure the accuracy and operation efficiency of the trajectory.

[0036] As Figure 6 shown, the specific steps for obtaining the control closed-loop optimization result are as follows: S501: Call the trajectory offset calibration data, collect the residual pressure after mounting, continuously measure at the points in the mounting area through the pressure sensor, analyze the fluctuation trend and uniformity of the pressure distribution, and obtain the pressure distribution index; Collect the residual pressure after mounting, continuously measure at the points in the mounting area through the pressure sensor, and use the formula: ; Calculate the standard deviation of the pressure , and analyze the fluctuation trend and uniformity of the pressure distribution to obtain the pressure distribution index, where represents the The residual pressure at each measurement point, represents the average value of the residual pressures at all measurement points, represents the total number of measurement points; denotes the residual pressure value at each measurement point, which is actually obtained through continuous monitoring at various points within the mounting area by a pressure sensor, is the average value of the residual pressures at all measurement points, obtained by summing up all and then dividing by the total number of measurement points and calculated.

[0037] For example, during the mounting process of a certain device, the residual pressure data of 5 measurement points are monitored in total, and the specific values are respectively: , then the average pressure is: ; Substitute into the formula to calculate the value of: ; ; This result indicates that the standard deviation of the pressure measurement values around the average value is 1.414, reflecting that the fluctuation of the measurement data is small, the pressure distribution is relatively uniform. Through the analysis of this standard deviation, the pressure uniformity and potential problem points during the mounting process can be understood and evaluated more accurately, so as to optimize and adjust the production process.

[0038] S502: Based on the pressure distribution index, analyze the geometric symmetry of the solder joints, calculate the proportion of the pad contact area, conduct a correlation analysis with the solder joint symmetry data, evaluate the relationship between the contact area and the solder joint symmetry, and generate the contact surface symmetry index; Perform image analysis operations on the solder joint images after mounting, extract the contour range of the solder joints in the top view, calculate the horizontal projection area of each solder joint through pixel recognition, compare the area with the theoretical contact area of the pad, obtain the actual pad contact area ratio, and at the same time calculate the difference in the boundary extension values on both sides of the symmetry axis of the solder joint shape, extract the coordinate points of the edge points in the left and right symmetry axis directions and compare their relative distances. If the distance deviation is greater than 10%, it is marked as an asymmetric solder joint. For example, if the left and right boundary extensions of a solder joint are 1.9 mm and 2.1 mm respectively, the deviation is 0.2 mm, accounting for 10% of the total length of 2 mm, and it is determined to be asymmetric at the boundary. Establish a mapping between the area ratio and the symmetry level of all solder joints one by one, and perform a correlation analysis operation. Divide the area ratio into three ranges: greater than 90%, between 80% - 90%, and less than 80%. Divide the solder joint symmetry level into A (deviation < 5%), B (deviation 5% - 10%), and C (deviation > 10%). Count the occurrence frequencies of the corresponding solder joint symmetry levels under each range of area ratios, and represent their distribution as a percentage. For example, when the area ratio is above 90%, the proportion of solder joints with grade A is 88%, and when it is between 80% - 90%, the proportion of grade A is 61%. Output the overall correspondence between the contact area and the solder joint symmetry, and generate the contact surface symmetry index.

[0039] S503: Based on the contact surface symmetry index, integrate the fixture movement and placement cycle data, analyze the influence of the fixture movement on the residual stress and the quality of the solder joints, evaluate the optimization effect of the fixture movement, and establish the control loop optimization result; Align the fixture movement trajectory data, placement cycle timestamps, pressure distribution indicators, and solder joint symmetry indicators on the time axis, and perform the fixture movement influence analysis process. First, extract the time points of the fixture starting to apply pressure, reaching the maximum pressure, maintaining a stable pressure, and releasing in each placement cycle, and perform an overlap judgment with the time period of the fluctuation points in the pressure distribution of the corresponding area of the solder joint. For example, if the pressure fluctuation in the solder joint area of a certain chip mainly occurs within the last 0.5 seconds of the fixture pressure release stage, record this overlap relationship as a highly correlated event. Subsequently, extract the speed change, path micro-offset, and attitude angle change values of the fixture movement trajectory in this stage, and compare them one by one with the symmetry change data of the solder joints. If there is a situation where the non-symmetric ratio of the solder joints increases by more than 10% when the attitude deflection angle of the fixture movement is within the range of ±2°, record this influence behavior and mark it as a fixture control parameter that needs to be optimized. Integrate all the successfully matched action and solder joint quality relationship data, summarize it into an association matrix between the action parameters and the probability of solder joint imbalance, and then judge the influence trend of different fixture operation modes on the solder joint quality. Extract the action parameters with an influence degree higher than 15% separately, record the triggering frequency of their residual stress fluctuations and the corresponding solder joint symmetry change levels, form a set of analysis results including the causal relationship between the fixture action parameters and the solder joint quality, and use it as the feedback basis for subsequent action control optimization to establish the control loop optimization result.

[0040] As shown Figure 7 in the figure, the chip fixture automatic adjustment system includes: Based on the chip mounting process, the pressure monitoring module uses a pressure sensor to continuously monitor the initial pressure applied by the fixture to the standard test piece in real time, and continuously analyzes the pressure readings. By comparing with the pressure standard range, if there is a deviation, it automatically calibrates the pressure parameters to obtain the pressure calibration index; Based on the pressure calibration index, the pressure adjustment module evaluates the deviation between the current pressure setting and the target pressure, calculates the adjustment range of the fixture pressure, matches it with the specifications of the current chip batch, and updates the pressure setting in real time to obtain the pressure adjustment record; Based on the pressure adjustment record, the image processing module captures an image of the chip to be mounted before the fixture is loaded, analyzes the gray distribution and edge contour of the image, calculates the shape coincidence degree of the mounting point, compares it with the historical misjudgment data of chip mounting, judges the recognition boundary interference caused by pressure changes, and automatically corrects the contour spacing to generate an optimized shape recognition result; Based on the optimized shape recognition result, the trajectory optimization module obtains the start and end coordinates of the fixture movement trajectory, synchronizes the reflection delay and intensity of the ultrasonic signal, identifies the offset section on the fixture trajectory, and adjusts the fixture path to correct the deviation to obtain the trajectory offset calibration data; The quality control module calls the trajectory offset calibration data, collects the residual pressure after chip mounting, synchronously measures the symmetry of the solder joints and the proportion of the pad contact area, identifies the correlation between pressure changes and chip mounting quality, and integrates the fixture movement and chip mounting cycle data to establish a control closed-loop optimization result.

[0041] It should be understood that the term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after, but it may also represent an "and / or" relationship, which can be specifically understood by referring to the context.

[0042] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single item (s) or plural item (s). For example, at least one of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0043] It should be understood that in various embodiments of the present invention, the sequence numbers of the above processes do not indicate the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0044] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0045] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the devices, apparatuses, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0046] In several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0047] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0048] In addition, the functional units in various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0049] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0050] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for automatically adjusting a chip fixture, characterized in that, The method includes: S1: Based on the chip mounting process, continuously monitor the initial pressure applied by the fixture on the standard test piece, capture the pressure readings, compare with the pressure standard range, automatically calibrate the pressure parameters, and obtain the pressure calibration index; S2: According to the pressure calibration index, evaluate the deviation between the current pressure setting and the target pressure, calculate the adjustment range of the fixture pressure, and update the pressure setting in real time to obtain the pressure adjustment record; S3: Based on the pressure adjustment record, capture the image of the chip to be mounted before the fixture is loaded, analyze the gray distribution and edge contour of the image, calculate the shape coincidence degree of the mounting point, judge the recognition boundary interference caused by the pressure change, automatically correct the contour spacing, and generate the shape recognition optimization result; S4: According to the shape recognition optimization result, obtain the start and end coordinates of the fixture movement trajectory, synchronize the reflection delay and intensity of the ultrasonic signal, identify the offset section on the fixture trajectory, correct the deviation, and obtain the trajectory offset calibration data; S5: Call the trajectory offset calibration data, collect the residual pressure after mounting, synchronously measure the solder joint symmetry and the pad contact area ratio, identify the correlation between the pressure change and the mounting quality, and establish the control loop optimization result.

2. The automatic adjustment method of the chip fixture according to claim 1, wherein The pressure calibration index includes the initial deviation amount, adjustment threshold, and standard pressure matching result. The pressure adjustment record includes the adjusted pressure value, pressure matching degree, and update frequency. The shape recognition optimization result includes edge clarity, contour matching accuracy, and interference correction level. The trajectory offset calibration data includes the identified offset points, adjusted coordinate accuracy, and path optimization details. The control loop optimization result includes the correlation between pressure and quality, solder joint symmetry analysis result, and contact area ratio adjustment result.

3. The automatic adjustment method of the chip fixture according to claim 1, wherein The specific steps for obtaining the pressure calibration index are as follows: S101: Based on the chip mounting process, continuously monitor the initial pressure applied by the fixture on the standard test piece through a pressure sensor, perform data collection and recording, capture the real-time pressure readings, and organize the captured pressure data to establish a pressure monitoring record; S102: Call the pressure monitoring record, analyze the continuous pressure readings, check whether the pressure is within the standard range, identify the abnormal pressure points outside the standard range, and count the abnormal points to obtain the abnormal pressure statistics; S103: Based on the abnormal pressure statistics, if there is a deviation, automatically calibrate the pressure parameters to match the mounting standard and obtain the pressure calibration index.

4. The automatic adjustment method of the chip fixture according to claim 1, wherein The specific steps for obtaining the pressure adjustment record are as follows: S201: According to the pressure calibration index, evaluate the deviation between the current pressure setting of the fixture and the target pressure, collect the real-time pressure readings, compare with the target pressure standard, and determine the direction and range of pressure adjustment to obtain the pressure deviation determination result; S202: Based on the pressure deviation determination result, calculate the adjustment range of the fixture pressure, automatically adjust the fixture pressure to match the specifications of the current chip batch, and update the pressure setting in real time to obtain the pressure adjustment record.

5. The automatic adjustment method of the chip fixture according to claim 1, wherein The specific steps for obtaining the shape recognition optimization result are as follows: S301: Based on the pressure adjustment record, capture the image of the chip to be mounted before fixture loading through a camera, extract the gray-scale distribution of the chip area in the image, identify the position and shape of the edge contour, analyze the gray-scale gradient distribution of the image, and determine the gray-scale change of each point to obtain the edge gray-scale feature; S302: Utilize the edge gray-scale feature to extract the boundary coordinates of the actual mounting points in the image, compare with the difference of the standard shape contour, analyze the distance difference from the mounting points in the image to the standard contour and the change of the boundary closing curvature, and calculate the shape coincidence degree; S303: Based on the shape coincidence degree, compare with the historical misjudgment data of mounting, judge the recognition boundary interference caused by pressure change, and automatically correct the contour spacing to generate the optimized result of shape recognition.

6. The automatic adjustment method of the chip fixture according to claim 1, wherein The specific steps for obtaining the trajectory offset calibration data are as follows: S401: According to the optimized result of shape recognition, obtain the start and end coordinates of the fixture movement trajectory, synchronously measure the reflection delay and intensity of the ultrasonic signal, determine the propagation characteristics of the signal on the trajectory, and obtain the acoustic wave propagation feature; S402: Utilize the acoustic wave propagation feature, combine with the fixture movement trajectory coordinates, identify the offset section on the trajectory, determine the offset area and degree by analyzing the change of the reflection delay and intensity of the signal, and adjust the fixture path to correct the identified deviation to obtain the trajectory offset calibration data.

7. The automatic adjustment method of the chip fixture according to claim 6, wherein, For analyzing the change of the reflection delay and intensity of the signal, the formula is used: ； Calculate the signal offset , identify the offset section on the trajectory, where represents the th reflected signal intensity, represents the th reflected signal intensity, represents the propagation speed of sound waves in the medium, represents the total number of signal measurements.

8. The automatic adjustment method of the chip fixture according to claim 1, characterized in that, The specific steps for obtaining the optimized result of the control closed-loop are as follows: S501: Call the trajectory offset calibration data, collect the residual pressure after mounting is completed, continuously measure at the points in the mounting area through a pressure sensor, analyze the fluctuation trend and uniformity of the pressure distribution, and obtain the pressure distribution index; S502: Based on the pressure distribution index, analyze the geometric symmetry of the solder joints, calculate the proportion of the pad contact area, conduct a correlation analysis with the solder joint symmetry data, evaluate the relationship between the contact area and the solder joint symmetry, and generate the contact surface symmetry index; S503: Based on the contact surface symmetry index, integrate the fixture movement and mounting cycle data, analyze the influence of the fixture movement on the residual pressure and the quality of the solder joints, evaluate the optimization effect of the fixture movement, and establish the optimized result of the control closed-loop.

9. The method for automatically adjusting a chip fixture according to claim 8, wherein For collecting the residual pressure after mounting is completed, continuously measure at the points in the mounting area through a pressure sensor, the formula is used: ； Calculate the standard deviation of the pressure , and analyze the fluctuation trend and uniformity of the pressure distribution to obtain the pressure distribution index, where represents the residual pressure at the th measurement point, represents the average value of the residual pressures of all measurement points, represents the total number of measurement points.

10. Chip fixture automatic adjustment system, the system is used to implement the chip fixture automatic adjustment method according to any one of claims 1-9, characterized in that, The system includes: The pressure monitoring module, based on the chip mounting process, continuously monitors the initial pressure applied by the fixture on the standard test piece through a pressure sensor, continuously analyzes the pressure reading, compares with the pressure standard range, and if there is a deviation, automatically calibrates the pressure parameter to obtain the pressure calibration index; The pressure adjustment module, according to the pressure calibration index, evaluates the deviation between the current pressure setting and the target pressure, calculates the adjustment range of the fixture pressure, matches with the specifications of the current chip batch, and updates the pressure setting in real time to obtain the pressure adjustment record; Based on the pressure-adjusted record, the image processing module captures the image of the chip to be mounted before fixture loading, analyzes the gray-scale distribution and edge contour of the image, calculates the shape coincidence degree of the mounting point, compares it with the historical misjudgment data of mounting, judges the recognition boundary interference caused by pressure change, and automatically corrects the contour spacing to generate an optimized result of shape recognition; According to the optimized result of shape recognition, the trajectory optimization module obtains the starting and ending coordinates of the fixture movement trajectory, synchronizes the reflection delay and intensity of the ultrasonic signal, identifies the offset section on the fixture trajectory, and adjusts the fixture path to correct the deviation, obtaining trajectory offset calibration data; The quality control module calls the trajectory offset calibration data, collects the residual pressure after mounting, synchronously measures the symmetry of the solder joints and the proportion of the pad contact area, identifies the correlation between pressure change and mounting quality, and integrates the fixture movement and mounting cycle data to establish an optimized result of the control closed-loop.

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