Bonding silver wire quality detection method and system

Abstract

The invention discloses a bonding silver wire quality detection method and system, and relates to the technical field of bonding quality detection.The bonding silver wire quality detection method comprises the steps that a thermal infrared imager is adopted to scan a bonding area, and temperature field distribution data in the bonding process is obtained; scanning the bonding area by adopting a magnetic conductivity measuring probe to obtain magnetic conductivity distribution data of the bonding area; performing 10 * 10 grid division on the bonding area, and performing feature extraction on the temperature field distribution data and the magnetic conductivity distribution data based on divided grids to obtain thermal feature parameters and magnetic feature parameters; and calculating a bonding silver wire quality score according to the thermal characteristic parameters and the magnetic characteristic parameters, and judging the bonding quality of the silver wire according to a score result to obtain a bonding quality evaluation result. According to the method, the limitation of traditional single parameter detection is broken through, the accuracy and reliability of bonding quality evaluation are remarkably improved, and a systematic technical support is provided for improvement of the bonding process level.

Description

Technical Field

[0001] The present invention relates to the technical field of bonding quality detection, in particular to a method and system for detecting the quality of bonded silver wires. Background Art

[0002] Bonded silver wire is a key process for realizing electrical interconnection between chips and lead frames in microelectronic packaging. Traditional bonding quality detection mainly relies on destructive tensile tests and shear tests. This detection method not only causes sample loss, but also can only perform sampling detection, and cannot guarantee the quality of each bonding point in mass production. With the development of non-destructive testing technology, methods such as infrared thermography and magnetic permeability detection have gradually been applied to bonding quality assessment. However, existing non-destructive testing methods generally have problems such as single detection parameters, insufficient feature extraction, and fuzzy evaluation criteria. For example, it is difficult to identify microscopic defects at the bonding interface only relying on the temperature field distribution, and simply using magnetic permeability detection cannot accurately reflect the energy input characteristics during the bonding process, which limits the reliability and accuracy of the detection results.

[0003] Currently, the following problems mainly exist in the technology for detecting the quality of bonded silver wires: First, the acquisition of detection data lacks systematicness. Temperature field measurement is easily affected by the environment, and the spatial resolution of magnetic permeability detection is insufficient; Second, the method for extracting characteristic parameters is too simple, and the spatial characteristic information of the temperature field and magnetic permeability distribution is not effectively utilized; Third, the quality evaluation criteria are not perfect, lacking a comprehensive analysis method for multi-source detection data, and it is difficult to achieve accurate quantitative evaluation. These problems seriously restrict the efficiency and reliability of bonding quality detection.

[0004] In view of the above problems, the present invention proposes a method and system for detecting the quality of bonded silver wires, mainly solving technical problems such as inaccurate data acquisition, insufficient feature extraction, and imperfect evaluation criteria in the quality detection of bonded silver wires, and belongs to the technical field of microelectronic packaging quality detection. Summary of the Invention

[0005] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title. However, such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above existing problems, the present invention is proposed.

[0007] Therefore, the present invention provides a method and system for detecting the quality of bonded silver wires, which can solve the problems mentioned in the background art.

[0008] To solve the above technical problems, the present invention provides the following technical solutions:

[0009] In a first aspect, the present invention provides a method for detecting the quality of bonded silver wires, which includes scanning a bonding area with an infrared thermal imager to obtain temperature field distribution data during the bonding process;

[0010] scanning the bonding area with a magnetic permeability measurement probe to obtain magnetic permeability distribution data of the bonding area;

[0011] dividing the bonding area into a 10×10 grid, and respectively extracting features from the temperature field distribution data and the magnetic permeability distribution data based on the divided grid to obtain thermal feature parameters and magnetic feature parameters;

[0012] calculating a quality score for the bonded silver wires according to the thermal feature parameters and the magnetic feature parameters, and judging the quality of the silver wire bonding according to the scoring result to obtain a bonding quality evaluation result.

[0013] As a preferred solution of the method for detecting the quality of the bonded silver wires of the present invention, wherein: the obtaining of the temperature field distribution data during the bonding process includes,

[0014] fixing the bonded silver wires on a test platform, and the test platform uses a temperature control system to maintain a constant temperature environment;

[0015] installing the infrared thermal imager on a fixed bracket above the test platform, and the fixed bracket adopts an anti-vibration structure;

[0016] setting the working parameters of the infrared thermal imager, the working parameters include sampling frequency, spatial resolution and temperature resolution, and the setting of the working parameters is completed through the control software of the infrared thermal imager;

[0017] arranging 4 temperature calibration reference points around the bonded silver wires, and the temperature calibration reference points adopt standard blackbody radiation sources;

[0018] establishing a temperature calibration curve according to the temperature calibration reference points, and the calculation formula of the temperature calibration curve is as follows:

[0019] T = f(X) = a θ X 2 + b θ X + c θ (θ = 1, 2, 3);

[0020] wherein, T is the actual temperature value, f(X) is the temperature calibration function, X is the measurement value of the infrared thermal imager, a θ is the quadratic term coefficient of the θ-th temperature interval, b θis the first-order coefficient of the θ-th temperature range, cθ is the constant term of the θ-th temperature range, θ is the temperature range identifier, and its value range is 1, 2, 3; when X < 30, θ = 1; when 30 ≤ X < 40, θ = 2; when X ≥ 40, θ = 3;

[0021] Each coefficient is solved by the least squares method, and the calculation formula is as follows:

[0022]

[0023] Among them, is the actual temperature value of the j-th calibration point, is the measured value of the j-th calibration point, n 1 is the total number of calibration points;

[0024] The bonded silver wire is scanned by the infrared thermal imager to collect the original temperature data of the bonding area;

[0025] The original temperature data is substituted into the temperature calibration curve to obtain the temperature field distribution data.

[0026] As a preferred scheme of the method for detecting the quality of the bonded silver wire of the present invention, wherein: the obtaining of the permeability distribution data of the bonding area includes,

[0027] According to the length L of the bonded silver wire, the scanning area size is set to 2L × L, and the scanning area is divided into m × n measurement points;

[0028] Select the scanning step size and establish the relationship between the sampling points and the area size. The relationship formula is as follows:

[0029] m × Δd = 2L;

[0030] n × Δd = L;

[0031] Among them, Δd is the scanning step size, L is the length of the bonded silver wire, m is the number of sampling points in the X direction, and n is the number of sampling points in the Y direction;

[0032] Place the permeability measurement probe at the initial height and perform raster scanning in the X-Y plane at a height h from the surface of the bonding area;

[0033] Measure the permeability value μ at each measurement point (x i , y j ), and establish a permeability distribution matrix, that is: ij M = [μ

[0034] {m×n}; ij ;

[0035] Among them, (x i , yj ) is the coordinate of the (i, j) - th measurement point, μ ij is the permeability value at the position point (x i , y j ), M is the permeability distribution matrix;

[0036] Based on the permeability distribution matrix M, a bicubic spline interpolation algorithm is used to construct a continuous permeability distribution surface, and permeability distribution data is obtained. The calculation formula of the continuous permeability distribution surface is as follows:

[0037]

[0038] Among them, S(x, y) is the permeability distribution surface function, B i (x) and B j (y) are cubic B - spline basis functions, and the calculation formulas are as follows:

[0039]

[0040]

[0041] Among them, x is the spatial coordinate in the X - direction of the scanning area, x i is the coordinate value of the i - th measurement point in the X - direction, y is the spatial coordinate in the Y - direction of the scanning area, y j is the coordinate value of the j - th measurement point in the Y - direction.

[0042] As a preferred scheme of the method for detecting the quality of the bonded silver wire according to the present invention, wherein: the thermal characteristic parameters include the spatial distribution characteristics of the temperature field, the temperature characteristic value of each grid cell, the average temperature in each grid cell, the standard deviation of the temperature in each grid cell, and the extreme value of the temperature in each grid cell;

[0043] The magnetic characteristic parameters include the permeability distribution characteristics, the average permeability of each grid cell, the magnetic permeability anomaly mark, the degree of magnetic permeability anomaly, and the type of magnetic permeability anomaly.

[0044] As a preferred scheme of the method for detecting the quality of the bonded silver wire according to the present invention, wherein: obtaining the thermal characteristic parameters includes,

[0045] Performing regional segmentation on the temperature field distribution data, dividing the entire bonding area into 10×10 uniform grid cells with the bonding point as the center. The size of the grid cell is 1 / 10 of the length of the bonded silver wire. The division range of the grid cell covers the entire effective detection area of the bonded silver wire. The grid cells are numbered in the order from left to right and from top to bottom, and the numbers are used to identify the spatial position information of each grid cell;

[0046] Collect temperature data in grid cells, obtain the temperature sampling point data sequence within each grid cell, calculate the temperature mean and temperature standard deviation of each grid cell based on the temperature sampling point data sequence, and calculate the temperature eigenvalue according to the temperature mean and temperature standard deviation. The calculation formula is as follows:

[0047]

[0048] Where, T is the temperature eigenvalue, T a is the temperature mean, σ is the temperature standard deviation, k is the temperature fluctuation coefficient, T max is the highest temperature value within the grid cell, T min is the lowest temperature value within the grid cell.

[0049] As a preferred solution of the method for detecting the quality of the bonded silver wire according to the present invention, wherein: obtaining the magnetic characteristic parameters includes,

[0050] Based on the obtained continuous magnetic permeability distribution surface S(x, y), extract the magnetic permeability eigenvalue at the center point of the 10×10 grid cell, and substitute the center point (x c , y c ) of each grid cell into the magnetic permeability distribution surface function. The calculation formula is as follows:

[0051] μ Z = S(x c , y c );

[0052] Where, μ Z is the magnetic permeability eigenvalue of the Z-th grid cell, (x c , y c ) is the center point coordinate of the grid cell;

[0053] Compare the magnetic permeability eigenvalue of the grid cell with the preset standard magnetic permeability range. The standard magnetic permeability range is 0.8μ 0 to 1.2μ 0 , where μ 0 is the magnetic permeability reference value of the standard bonded silver wire;

[0054] When the magnetic permeability eigenvalue of the grid cell is less than 0.8μ 0 , mark the grid cell as an area with abnormally low magnetic permeability. When the magnetic permeability eigenvalue of the grid cell is greater than 1.2μ 0 , mark the grid cell as an area with abnormally high magnetic permeability;

[0055] For the magnetic permeability abnormal area, calculate the degree of magnetic permeability abnormality. The calculation formula is as follows:

[0056]

[0057] wherein, δ is the degree of magnetic permeability anomaly;

[0058] Combining the magnetic permeability anomaly type and the degree of magnetic permeability anomaly of the grid cell to form a magnetic permeability anomaly label for the grid cell;

[0059] Combining the temperature characteristic value of the grid cell and the magnetic permeability anomaly label of the grid cell to establish a 10×10 characteristic parameter matrix; in the characteristic parameter matrix, each matrix element contains the temperature characteristic value and the magnetic permeability anomaly label information of the corresponding grid cell, and the temperature characteristic value is stored in floating-point form;

[0060] Storing the characteristic parameter matrix in a characteristic parameter database.

[0061] As a preferred scheme of the method for detecting the quality of the bonded silver wire according to the present invention, wherein: calculating the quality score of the bonded silver wire includes,

[0062] Extracting the temperature characteristic value and the magnetic permeability anomaly data from the characteristic parameter matrix. For each grid cell (i,j) in the 10×10 matrix, extracting the temperature characteristic value T ij and the anomaly type and the degree of anomaly δ in the magnetic permeability anomaly label ij ;

[0063] Normalizing the temperature characteristic value and simultaneously performing weighted calculation on the degree of magnetic permeability anomaly;

[0064] Calculating a comprehensive quality score based on the normalized temperature characteristic value and the weighted degree of magnetic permeability anomaly. The calculation formula is as follows:

[0065] Score = 0.7×(100 - T n ×100) + 0.3×(100 - M w ×100);

[0066] wherein, Score is the comprehensive quality score of the bonded silver wire;

[0067] Judging the quality of the silver wire bonding includes,

[0068] Judging the quality level according to the comprehensive quality score, and dividing the comprehensive quality score into three bonding quality levels, including: when the comprehensive quality score is greater than 85 points, it is grade A quality; when it is between 70 and 85 points, it is grade B quality; when it is less than 70 points, it is grade C quality;

[0069] Storing the bonding quality level and the comprehensive quality score in a quality evaluation database, and the quality evaluation result is used for optimizing the bonding process parameters.

[0070] In a second aspect, the present invention provides a quality inspection system for bonding silver wires, which includes: a temperature data acquisition module, a magnetic permeability data acquisition module, a feature extraction module, and a bonding quality inspection module;

[0071] The temperature data acquisition module is used to scan the bonding area with an infrared thermal imager to obtain the temperature field distribution data during the bonding process;

[0072] The magnetic permeability data acquisition module is used to scan the bonding area with a magnetic permeability measurement probe to obtain the magnetic permeability distribution data of the bonding area;

[0073] The feature extraction module is used to divide the bonding area into a 10×10 grid, and respectively extract features from the temperature field distribution data and the magnetic permeability distribution data based on the divided grid to obtain thermal feature parameters and magnetic feature parameters;

[0074] The bonding quality inspection module is used to calculate the quality score of the bonded silver wire according to the thermal feature parameters and the magnetic feature parameters, judge the bonding quality of the silver wire according to the scoring result, and obtain the bonding quality evaluation result.

[0075] In a third aspect, the present invention provides a computer device, including a memory and a processor, where the memory stores a computer program, and: when the processor executes the computer program, the steps of the method for inspecting the quality of bonded silver wires are implemented.

[0076] In a fourth aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored, and: when the computer program is executed by a processor, the steps of the method for inspecting the quality of bonded silver wires are implemented.

[0077] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention realizes high-precision temperature measurement of ±0.1°C by using an infrared thermal imager in combination with a temperature control system and an anti-vibration bracket for temperature field scanning, and establishing a segmented temperature calibration curve using a standard blackbody radiation source; by adaptively dividing the scanning area and using the bicubic spline interpolation algorithm to construct the magnetic permeability distribution surface, the spatial resolution is increased to 50μm, ensuring the accuracy of defect identification; using a 10×10 grid division to establish a unified spatial reference framework, and fusing two types of feature parameters of the temperature field and magnetic permeability to construct a multi-dimensional feature matrix, realizing a comprehensive characterization of the bonding quality; finally, through temperature eigenvalue normalization and differential weighting calculation of the degree of magnetic permeability anomaly, a scientific three-level quality scoring system is established, and process optimization is supported by database storage, thus breaking through the limitations of traditional single-parameter detection, significantly improving the accuracy and reliability of bonding quality evaluation, and providing systematic technical support for the improvement of the bonding process level. Description of the Drawings

[0078] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0079] Figure 1 It is a method flow chart of a method for detecting the quality of bonding silver wires provided by an embodiment of the present invention and a system.

[0080] Figure 2 It is an internal structure diagram of a computer device for a method for detecting the quality of bonding silver wires provided by an embodiment of the present invention and a system. Specific embodiments

[0081] To make the above objects, features, and advantages of the present invention more comprehensible, the following will describe the specific embodiments of the present invention in detail with reference to the accompanying drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0082] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0083] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selectively exclusive embodiment from other embodiments.

[0084] Embodiment 1, referring to Figure 1 - Figure 2 , which is the first embodiment of the present invention. This embodiment provides a method for detecting the quality of bonding silver wires, including:

[0085] The present application can effectively solve the above-mentioned problems. Next, multiple embodiments will be used to elaborate in detail how to implement the method for detecting the quality of bonding silver wires.

[0086] Figure 1 It shows a method flow chart of a method for detecting the quality of bonding silver wires and a system, including:

[0087] S1: Use an infrared thermal imager to scan the bonding area and obtain the temperature field distribution data during the bonding process;

[0088] Further, obtaining the temperature field distribution data during the bonding process includes,

[0089] Fix the bonding silver wire on the test platform. The test platform uses a temperature control system to maintain a constant temperature environment. The temperature of the test platform is controlled at 25 ± 0.5 °C, and the temperature control accuracy of the temperature control system is 0.1 °C;

[0090] Install the infrared thermal imager on the fixed bracket above the test platform. The fixed bracket uses an anti-vibration structure. The distance between the lens of the infrared thermal imager and the bonding silver wire is adjusted by a precision displacement platform and fixed at 100 mm;

[0091] Set the working parameters of the infrared thermal imager. The working parameters include a sampling frequency of 60 Hz, a spatial resolution of 50 microns, and a temperature resolution of 0.05 °C. The setting of the working parameters is completed through the control software of the infrared thermal imager;

[0092] Arrange 4 temperature calibration reference points around the bonding silver wire. The temperature calibration reference points use standard blackbody radiation sources. The temperatures of the temperature calibration reference points are 20 °C, 30 °C, 40 °C, and 50 °C respectively. The emissivity of the standard blackbody radiation source is 0.98;

[0093] Establish a temperature calibration curve based on the temperature calibration reference points. The calculation formula of the temperature calibration curve is as follows:

[0094] T = f(X) = a θ X 2 +b θ X + c θ (θ = 1, 2, 3);

[0095] Among them, T is the actual temperature value, f(X) is the temperature calibration function, X is the measurement value of the infrared thermal imager, a θ is the quadratic term coefficient of the θ-th temperature interval, b θ is the linear term coefficient of the θ-th temperature interval, c θ is the constant term of the θ-th temperature interval, θ is the temperature interval identifier, and its value range is 1, 2, 3; when X < 30, θ = 1; when 30 ≤ X < 40, θ = 2; when X ≥ 40, θ = 3;

[0096] Each coefficient is solved by the least squares method. The calculation formula is as follows:

[0097]

[0098] Among them, is the actual temperature value of the j-th reference point, is the measured value of the j-th calibration point, n 1 is the total number of calibration points; it should be noted that the iteration termination condition for solving the coefficients by the least squares method is that the sum of the squared residuals is less than 10 -6 ;

[0099] Scan the bonded silver wire with an infrared thermal imager to collect the original temperature data of the bonding area;

[0100] Substitute the original temperature data into the temperature calibration curve to obtain the temperature field distribution data.

[0101] S2: Use a magnetic permeability measurement probe to scan the bonding area to obtain the magnetic permeability distribution data of the bonding area;

[0102] Furthermore, obtaining the magnetic permeability distribution data of the bonding area includes,

[0103] Set the scanning area size to 2L×L according to the length L of the bonded silver wire, and divide the scanning area into m×n measurement points; where L is the length of the bonded silver wire, m is the number of sampling points in the X direction, and n is the number of sampling points in the Y direction;

[0104] Select the scanning step size and establish the relationship between the sampling points and the area size. The relationship formula is as follows:

[0105] m×Δd = 2L;

[0106] n×Δd = L;

[0107] where Δd is the scanning step size;

[0108] Place the magnetic permeability measurement probe at the initial height and perform a raster scan in the X-Y plane at a height h from the surface of the bonding area; it should be noted that the probe scanning height h is set to 100μm, and this height is the optimal detection distance determined by experimental optimization;

[0109] Measure the magnetic permeability value μ i ,y j ) at each measurement point (x ij ), and establish a magnetic permeability distribution matrix, that is:

[0110] M = [μ ij {m×n};

[0111] where (x i ,y j ) is the coordinate of the (i,j)-th measurement point, μ ij is the magnetic permeability value at the position point (x i ,y j ), and M is the magnetic permeability distribution matrix;

[0112] Based on the permeability distribution matrix M, the bicubic spline interpolation algorithm is used to construct a continuous permeability distribution surface, and the permeability distribution data is obtained. The calculation formula of the continuous permeability distribution surface is as follows:

[0113]

[0114] where S(x, y) is the permeability distribution surface function, and B i (x) and B j (y) are cubic B-spline basis functions, and the calculation formulas are as follows:

[0115]

[0116] where x is the spatial coordinate in the X direction of the scanning area, x i is the coordinate value of the i-th measurement point in the X direction, y is the spatial coordinate in the Y direction of the scanning area, and y j is the coordinate value of the j-th measurement point in the Y direction. It should be noted that in the bicubic spline interpolation algorithm of the present invention, the nodes are selected in a uniform distribution manner, and the node spacing is the same as the scanning step size.

[0117] S3: Divide the bonding area into a 10×10 grid, and respectively extract the features of the temperature field distribution data and the permeability distribution data based on the divided grid to obtain thermal characteristic parameters and magnetic characteristic parameters;

[0118] Furthermore, the thermal characteristic parameters include the spatial distribution characteristics of the temperature field, the temperature characteristic value of each grid cell, the average temperature within each grid cell, the standard deviation of the temperature within each grid cell, and the extreme temperature within each grid cell;

[0119] The magnetic characteristic parameters include the permeability distribution characteristics, the average permeability of each grid cell, the magnetic permeability anomaly mark, the degree of magnetic permeability anomaly, and the type of magnetic permeability anomaly;

[0120] Furthermore, extracting the thermal characteristic parameters includes

[0121] Perform regional segmentation on the temperature field distribution data. The entire bonding area is divided into 10×10 uniform grid cells with the bonding point as the center. The size of the grid cell is 1 / 10 of the length of the bonding silver wire. The division range of the grid cell covers the entire effective detection area of the bonding silver wire. The grid cells are numbered in the order from left to right and from top to bottom. The numbers are used to identify the spatial position information of each grid cell;

[0122] Collect temperature data in grid cells, obtain the data sequence of temperature sampling points in each grid cell. The data sequence of temperature sampling points contains 500 temperature data points, and the sampling time interval of the temperature data points is 0.1 second. Calculate the temperature mean and temperature standard deviation of each grid cell based on the data sequence of temperature sampling points, and calculate the temperature characteristic value according to the temperature mean and temperature standard deviation. The calculation formula is as follows:

[0123]

[0124] Where, T is the temperature characteristic value, T a is the temperature mean, σ is the temperature standard deviation, k is the temperature fluctuation coefficient, and the value of the temperature fluctuation coefficient is 0.5. T max is the highest temperature value in the grid cell, and T min is the lowest temperature value in the grid cell.

[0125] Furthermore, the extracted magnetic characteristic parameters include

[0126] Based on the obtained continuous magnetic permeability distribution surface S(x, y), extract the magnetic permeability characteristic value at the center point of a 10×10 grid cell. Substitute the center point (x c , y c ) of each grid cell into the magnetic permeability distribution surface function. The calculation formula is as follows:

[0127] μ Z = S(x c , y c );

[0128] Where, μ Z is the magnetic permeability characteristic value of the Z-th grid cell, and (x c , y c ) is the center point coordinate of this grid cell; the magnetic permeability characteristic value reflects the electrical conductivity and bonding strength of the bonded silver wire in this area, and store the magnetic permeability characteristic value in the corresponding magnetic permeability characteristic database;

[0129] Compare the magnetic permeability characteristic value of the grid cell with the preset standard magnetic permeability range. The standard magnetic permeability range is 0.8μ 0 to 1.2μ 0 , where μ 0 is the magnetic permeability reference value of the standard bonded silver wire, and the magnetic permeability reference value is obtained by measuring the magnetic permeability of 100 qualified bonding samples;

[0130] Based on the comparison result, when the magnetic permeability characteristic value of the grid cell is less than 0.8μ 0 , mark this grid cell as an area with abnormally low magnetic permeability. When the magnetic permeability characteristic value of the grid cell is greater than 1.2μ 0When that happens, mark the grid cell as an area with abnormally high magnetic permeability; for the area with abnormal magnetic permeability, calculate the degree of magnetic permeability abnormality, and the calculation formula is as follows:

[0131]

[0132] where δ is the degree of magnetic permeability abnormality;

[0133] Combine the magnetic permeability abnormality type and the degree of magnetic permeability abnormality of the grid cell to form the magnetic permeability abnormality mark of the grid cell; it should be noted that the magnetic permeability abnormality type includes abnormally low magnetic permeability and abnormally high magnetic permeability; the abnormally low magnetic permeability is manifested as the magnetic permeability of the bonding area being significantly lower than the normal value, usually caused by insufficient bonding pressure, low bonding energy or insufficient interface bonding, and this kind of abnormality may cause problems with insufficient bonding strength; the abnormally high magnetic permeability is manifested as the magnetic permeability of the bonding area being significantly higher than the normal value, often caused by defects such as voids, cracks or severe deformation during the bonding process, and this kind of abnormality usually indicates more serious bonding quality problems;

[0134] Combine the temperature characteristic value of the grid cell and the magnetic permeability abnormality mark of the grid cell to establish a 10×10 characteristic parameter matrix; in the characteristic parameter matrix, each matrix element contains the temperature characteristic value and the magnetic permeability abnormality mark information of the corresponding grid cell, and the temperature characteristic value is stored in floating-point form; store the characteristic parameter matrix in the characteristic parameter database, and the characteristic parameter matrix reflects the temperature distribution characteristics and magnetic permeability distribution characteristics of the bonding area, and the characteristic parameter matrix provides a data basis for the subsequent bonding quality evaluation;

[0135] It should be noted that in the characteristic parameter matrix, the magnetic permeability abnormality mark includes the abnormality type identifier and the abnormality degree value; the abnormality type identifier uses L 1 to represent abnormally low magnetic permeability, uses H 1 to represent abnormally high magnetic permeability, and uses N 1 to represent the normal area; the abnormality degree value uses a numerical value between 0 and 1 to represent the severity of the abnormality, and the larger the numerical value, the more severe the abnormality degree, and the abnormality degree of the normal area is recorded as 0.

[0136] S4: Calculate the bonding silver wire quality score according to the thermal characteristic parameters and magnetic characteristic parameters, judge the silver wire bonding quality according to the scoring result, and obtain the bonding quality evaluation result.

[0137] Furthermore, calculating the bonding silver wire quality score includes,

[0138] Extract the temperature characteristic value and the magnetic permeability abnormality data from the characteristic parameter matrix. For each grid cell (l, r) in the 10×10 matrix, extract the temperature characteristic value T lrand the anomaly type and anomaly degree δ in the magnetic permeability anomaly markers lr ;

[0139] Normalize the temperature characteristic value, and the calculation formula is as follows:

[0140]

[0141] where T n is the normalized temperature characteristic value, T lr is the extracted temperature characteristic value, T max and T min are the maximum and minimum values of the temperature characteristic values of all grid cells respectively; it should be noted that normalizing the temperature characteristic value can eliminate the differences in the temperature value ranges during different batches of bonding processes, making the scoring criteria for temperature characteristic values unified and comparable. The range of the normalized temperature characteristic value is unified to 0 - 1, which is convenient for subsequent comprehensive calculation with the magnetic permeability anomaly degree. At the same time, the normalization process can also reduce the influence of temperature measurement errors and ambient temperature fluctuations;

[0142] At the same time, perform weighted calculation on the magnetic permeability anomaly degree, and the calculation formula is as follows:

[0143] M w = δ lr × W;

[0144] where M w is the weighted magnetic permeability anomaly degree, W is the magnetic permeability anomaly degree weight coefficient. The weight coefficient for the area with too low magnetic permeability anomaly is 1.2, and the weight coefficient for the area with too high magnetic permeability anomaly is 1.5; it should be noted that the weighted calculation of the magnetic permeability anomaly degree is considered based on the difference in the influence degree of the magnetic permeability anomaly on the bonding quality. Too high magnetic permeability anomaly often indicates serious bonding defects or void defects in the bonding area, so a higher weight coefficient of 1.5 is given. While too low magnetic permeability anomaly may be caused by slight insufficient bonding strength, and its influence is relatively small, so a lower weight coefficient of 1.2 is given. This differential weight setting can more accurately reflect the actual influence of different types of magnetic permeability anomalies on the bonding quality;

[0145] Calculate the comprehensive quality score based on the normalized temperature characteristic value and the weighted magnetic permeability anomaly degree, and the calculation formula is as follows:

[0146] Score = 0.7×(100 - T n × 100) + 0.3×(100 - M w × 100);

[0147] Among them, Score is the comprehensive quality score of the bonded silver wire. It should be noted that when calculating the comprehensive quality score, a weight ratio of 7:3 is adopted because the temperature characteristic value mainly reflects the energy input and heat conduction characteristics during the bonding process, which is directly related to the bonding strength and the formation of the bonding interface and has strong indicativeness. Therefore, a weight of 0.7 is assigned; while the degree of abnormal magnetic permeability is mainly used to assist in judging the existence of bonding defects and is assigned a weight of 0.3 as a supplementary index. This weight ratio has been verified through a large number of experiments to have good evaluation accuracy;

[0148] The quality grade is determined according to the comprehensive quality score. The comprehensive quality score is divided into three bonding quality grades, including: when the quality score is greater than 85 points, it is grade A quality; when it is between 70 and 85 points, it is grade B quality; when it is less than 70 points, it is grade C quality. It should be noted that the grading standard of the quality grade is determined based on the statistical analysis results of a large number of bonding samples. Among them, 85 points as the threshold value of grade A quality ensures the screening standard of high-quality bonding products, and 70 points as the minimum requirement of qualified quality ensures the basic reliability of the products. This grading method not only considers the strictness of product quality control but also takes into account the reasonable yield rate in actual production;

[0149] The bonding quality grade and the comprehensive quality score are stored in the quality evaluation database, and the quality evaluation results are used for optimizing the bonding process parameters. It should be noted that storing the bonding quality grade and the scoring results in the database is not only used for the quality traceability of the current batch of products but also can discover the correlation law between the bonding process parameters and the bonding quality through data analysis, providing data support for process optimization. At the same time, the accumulated historical data can also be used to establish a more accurate quality evaluation model.

[0150] Example 2, referring to Figure 1 - Figure 2 , which is the second embodiment of the present invention. This embodiment also provides a quality detection system for bonded silver wire, including:

[0151] It includes a temperature data acquisition module, a magnetic permeability data acquisition module, a feature extraction module, and a bonding quality detection module;

[0152] The temperature data acquisition module is used to scan the bonding area with an infrared thermal imager to obtain the temperature field distribution data during the bonding process;

[0153] The magnetic permeability data acquisition module is used to scan the bonding area with a magnetic permeability measurement probe to obtain the magnetic permeability distribution data of the bonding area;

[0154] The feature extraction module is used to divide the bonding area into a 10×10 grid and respectively extract features from the temperature field distribution data and the magnetic permeability distribution data based on the divided grid to obtain thermal feature parameters and magnetic feature parameters;

[0155] The bonding quality detection module is used to calculate the bonding silver wire quality score according to the thermal characteristic parameters and magnetic characteristic parameters, judge the silver wire bonding quality according to the scoring result, and obtain the bonding quality evaluation result.

[0156] This embodiment also provides a computer device, which may be a terminal, and its internal structure diagram may be as Figure 2 shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a carrier network, NFC (Near Field Communication) or other technologies. When the computer program is executed by the processor, it implements a method for detecting the quality of bonded silver wires. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a button, a trackball or a touchpad provided on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0157] This embodiment also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented: scanning the bonding area with an infrared thermal imager to obtain temperature field distribution data during the bonding process;

[0158] scanning the bonding area with a magnetic permeability measurement probe to obtain magnetic permeability distribution data of the bonding area;

[0159] Performing a 10×10 grid division on the bonding area, and respectively performing feature extraction on the temperature field distribution data and magnetic permeability distribution data based on the divided grids to obtain thermal characteristic parameters and magnetic characteristic parameters;

[0160] Calculating the bonding silver wire quality score according to the thermal characteristic parameters and magnetic characteristic parameters, and judging the silver wire bonding quality according to the scoring result to obtain the bonding quality evaluation result.

[0161] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

[0162] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application can be implemented in various computer languages. For example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0163] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or a plurality of flows and / or blocks

[0164] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in Figure 1 one or more of the flows Figure 1 or a plurality of flows and / or blocks

[0165] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the functions specified in Figure 1 one or more of the flows Figure 1Steps of the functions specified in one or more boxes.

[0166] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0167] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A method for detecting the quality of a bonding silver wire, characterized in that: Including, using an infrared thermal imager to scan the bonding area and obtain temperature field distribution data during the bonding process; Scanning the bonding area with a magnetic permeability measuring probe to obtain magnetic permeability distribution data of the bonding area; Dividing the bonding area into 10×10 grids, and extracting features of the temperature field distribution data and the magnetic permeability distribution data based on the divided grids to obtain thermal feature parameters and magnetic feature parameters; The quality score of the bonding silver wire is calculated according to the thermal characteristic parameters and the magnetic characteristic parameters, and the bonding quality of the silver wire is judged according to the scoring result to obtain a bonding quality evaluation result.

2. The quality inspection method for bonding silver wire according to claim 1, characterized in that: The obtaining of temperature field distribution data during the bonding process includes: The bonding silver wire is fixed on a test platform, and the test platform adopts a temperature control system to maintain a constant temperature environment; Installing the infrared thermal imager on a fixed bracket above the test platform, wherein the fixed bracket adopts an anti-vibration structure; Setting the working parameters of the infrared thermal imager, wherein the working parameters include sampling frequency, spatial resolution and temperature resolution, and the setting of the working parameters is completed through the control software of the infrared thermal imager; Arrange 4 temperature calibration points around the bonding silver wire, and the temperature calibration points adopt a standard black body radiation source; A temperature calibration curve is established according to the temperature calibration points. The temperature calibration curve calculation formula is as follows: T=f(X)=a θ X 2 +b θ X+c θ (θ=1,2,3); Where T is the actual temperature value, f(X) is the temperature calibration function, X is the value measured by the infrared thermal imager, and a θ is the quadratic term coefficient of the θth temperature interval, b θ is the coefficient of the first-order term in the θth temperature interval, c θ is the constant term of the θth temperature interval, θ is the temperature interval identifier, and its value range is 1, 2, 3; when X<30, θ=1; when 30≤X<40, θ=2; when X≥40, θ=3; Each coefficient is solved by the least square method, and the calculation formula is as follows: in, is the actual temperature value of the jth calibration point, is the measured value of the jth calibration point, and n1 is the total number of calibration points; Scanning the bonding silver wire by the infrared thermal imager to collect original temperature data of the bonding area; Substituting the original temperature data into the temperature calibration curve, the temperature field distribution data is obtained.

3. The quality inspection method of the bonding silver wire according to claim 2, characterized in that: The obtaining of the magnetic permeability distribution data of the bonding area includes: According to the length L of the bonding silver wire, the scanning area size is set to 2L×L, and the scanning area is divided into m×n measurement points; Select the scanning step size and establish the relationship between the sampling point and the area size. The relationship formula is as follows: m×Δd=2L; n×Δd=L; Wherein, Δd is the scanning step length, L is the length of the bonding silver wire, m is the number of sampling points in the X direction, and n is the number of sampling points in the Y direction; The magnetic permeability measuring probe is placed at an initial height and at a height h from the surface of the bonding area, and an XY plane raster scan is performed according to the scanning area; Measure each measuring point (x i ,y j ) at the magnetic permeability value μ ij , establish the magnetic permeability distribution matrix, that is: M=pμ ij ]{m×n} Among them, (x i ,y j ) is the first (x i ,y j ) coordinates of the measurement points, μ ij is the position point (x i ,y j ) is the magnetic permeability value at , M is the magnetic permeability distribution matrix; Based on the magnetic permeability distribution matrix M, a bicubic spline interpolation algorithm is used to construct a continuous magnetic permeability distribution surface to obtain magnetic permeability distribution data. The calculation formula of the continuous magnetic permeability distribution surface is as follows: Among them, S(x,y) is the magnetic permeability distribution surface function, B i (x) and B j (y) is the cubic B-spline basis function, and the calculation formula is as follows: Where x is the spatial coordinate of the scanning area in the X direction, x i is the coordinate value of the i-th measurement point in the X direction, y is the spatial coordinate of the scanning area in the Y direction, and y j is the coordinate value of the jth measurement point in the Y direction.

4. The method for detecting the quality of the bonding silver wire according to claim 3, characterized in that: The thermal characteristic parameters include the spatial distribution characteristics of the temperature field, the temperature characteristic value of each grid unit, the temperature mean value in each grid unit, the temperature standard deviation in each grid unit, and the temperature extreme value in each grid unit; The magnetic characteristic parameters include magnetic permeability distribution characteristics, the mean magnetic permeability of each grid unit, magnetic permeability anomaly marks, magnetic permeability anomaly degrees and magnetic permeability anomaly types.

5. The quality inspection method of bonding silver wire according to claim 4, characterized in that: The thermal characteristic parameters obtained include: Performing regional segmentation on the temperature field distribution data, dividing the entire bonding area into 10×10 uniform grid units with the bonding point as the center, the size of the grid unit is 1 / 10 of the length of the bonding silver wire, the division range of the grid unit covers the entire effective detection area of ​​the bonding silver wire, and the grid units are numbered from left to right and from top to bottom, and the number is used to identify the spatial position information of each of the grid units; The temperature data is collected in the grid unit, and the temperature sampling point data sequence in each grid unit is obtained. The temperature mean and temperature standard deviation of each grid unit are calculated based on the temperature sampling point data sequence. The temperature characteristic value is calculated according to the temperature mean and temperature standard deviation. The calculation formula is as follows: Where T is the temperature characteristic value, T a is the mean temperature, σ is the standard deviation of temperature, k is the temperature fluctuation coefficient, T max is the highest temperature value in the grid cell, T min is the lowest temperature value in the grid cell.

6. The method for detecting the quality of the silver bonding wire according to claim 5, characterized in that: The obtaining of magnetic characteristic parameters comprises: Based on the obtained continuous permeability distribution surface S(x,y), the permeability eigenvalues ​​are extracted at the center point of the 10×10 grid unit, and the center point of each grid unit (x c ,y c ) is substituted into the magnetic permeability distribution surface function, and the calculation formula is as follows: m Z =S(x c ,y c ); Among them, μ Z is the magnetic permeability eigenvalue of the Zth grid unit, (x c ,y c ) is the coordinate of the center point of the grid unit; Comparing the magnetic permeability characteristic value of the grid unit with a preset standard magnetic permeability range, wherein the standard magnetic permeability range is 0.8μ0 to 1.2μ0, where μ0 is the magnetic permeability reference value of the standard bonding silver wire; When the magnetic permeability characteristic value of the grid unit is less than 0.8μ0, the grid unit is marked as an abnormal area with too low magnetic permeability; when the magnetic permeability characteristic value of the grid unit is greater than 1.2μ0, the grid unit is marked as an abnormal area with too high magnetic permeability; For the abnormal magnetic permeability area, the abnormal degree of magnetic permeability is calculated, and the calculation formula is as follows: Among them, δ is the degree of magnetic permeability anomaly; Combining the magnetic permeability anomaly type and the magnetic permeability anomaly degree of the grid unit to form a magnetic permeability anomaly mark of the grid unit; The temperature characteristic value of the grid cell and the magnetic permeability anomaly mark of the grid cell are combined to establish a 10×10 characteristic parameter matrix; in the characteristic parameter matrix, each matrix element contains the temperature characteristic value and magnetic permeability anomaly mark information of the corresponding grid cell, and the temperature characteristic value is stored in the form of a floating point number; The feature parameter matrix is ​​stored in a feature parameter database.

7. The quality inspection method of the bonding silver wire according to claim 6, characterized in that: The calculation of the bonding silver wire quality score includes: Extract temperature eigenvalues ​​and magnetic permeability anomaly data from the characteristic parameter matrix, and for each grid cell in the 10×10 matrix, extract the anomaly type and degree in the temperature eigenvalues ​​and magnetic permeability anomaly marks; The temperature characteristic values ​​are normalized and the degree of magnetic permeability anomaly is weighted. The comprehensive quality score is calculated based on the normalized temperature eigenvalue and the weighted permeability anomaly degree. The calculation formula is as follows: Score=0.7×(100-T n ×100)+0.3×(100-M w ×100); Among them, T n is the normalized temperature characteristic value, M w is the weighted abnormal degree of magnetic permeability, and Score is the comprehensive quality score of the bonding silver wire; The judgment of the silver wire bonding quality includes: Determine the quality grade according to the comprehensive quality score, and divide the comprehensive quality score into three bonding quality grades, including: when the comprehensive quality score is greater than 85 points, it is grade A quality, 70 to 85 points are grade B quality, and less than 70 points are grade C quality; The bonding quality grade and the comprehensive quality score are stored in a quality assessment database, and the quality assessment result is used for optimizing bonding process parameters.

8. A quality inspection system for silver bonding wires, based on the quality inspection method for silver bonding wires according to any one of claims 1 to 7, characterized in that: It includes a temperature data acquisition module, a magnetic permeability data acquisition module, a feature extraction module and a bonding quality detection module; The temperature data acquisition module is used to scan the bonding area using an infrared thermal imager to obtain temperature field distribution data during the bonding process; The magnetic permeability data acquisition module is used to scan the bonding area using a magnetic permeability measurement probe to obtain magnetic permeability distribution data of the bonding area; The feature extraction module is used to divide the bonding area into 10×10 grids, and based on the divided grids, respectively extract features of the temperature field distribution data and the magnetic permeability distribution data to obtain thermal feature parameters and magnetic feature parameters; The bonding quality detection module is used to calculate the bonding silver wire quality score according to the thermal characteristic parameters and the magnetic characteristic parameters, and judge the silver wire bonding quality according to the scoring result to obtain a bonding quality evaluation result.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the quality detection method of the bonding silver wire according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the quality inspection method for bonding silver wires according to any one of claims 1 to 7 are implemented.

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