Circuit assembly welding spot quality on-line detection method and system

Abstract

The invention relates to the technical field of detection, in particular to a circuit assembly welding spot quality online detection method and system. According to the method, by obtaining the real-time temperature data of each welding point in the welding process, the temperature change of the welding points can be monitored in real time in the welding process so as to adjust the preset welding parameters, and the temperature gradient distribution data of each welding point at different time nodes can be accurately extracted through the dynamic temperature change curve; the welding process can be automatically optimized according to the temperature change of each welding spot through real-time data feedback and analysis, optimal parameter configuration can be carried out according to different welding spots and different working conditions through adjustment, and the welding process can be optimized by analyzing multi-dimensional data such as thermal stress, external dynamic stress and deformation comprehensive indexes of each welding spot. By means of the method, the quality of the welding points can be evaluated more accurately, then automatic welding parameter adjustment is achieved by combining real-time data collection and deformation analysis, the stability and consistency of the quality of the welding points are improved, and the risk of unqualified welding points is reduced.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to an online detection method and system for the quality of solder joints of circuit components. Background Art

[0002] In the welding process of copper busbars, process control of solder joints is very important. Improper welding may affect the electrical conductivity of the copper busbar itself, and then affect the stability of the entire power system. Therefore, the quality inspection of circuit component solder joints is a crucial step in the electronic manufacturing process. For example, welding temperature that is too high or too low will cause changes in the physical properties of the copper busbar, which may lead to a decrease in conductivity and even thermal damage to the copper busbar. Therefore, for copper busbars, ensuring the quality of solder joints is crucial to ensure its carrying capacity and stable operation. Quality inspection helps prevent electrical connection problems caused by poor welding, thereby improving the reliability of the connection between the circuit board and the copper busbar.

[0003] At present, the main method for detecting the quality of circuit component solder joints is to detect the quality of circuit component solder joints through automatic optical inspection, wherein automatic optical inspection is to scan the solder joints through a camera and a high-resolution image acquisition system, and to analyze and detect whether the quality of the solder joints is qualified through software. However, factors affecting the quality of solder joints include temperature changes during the welding process affecting the fluidity of the solder, thereby causing defects in the shape and surface features of the solder joints, and shaking during the cooling process of the solder joints, which cause quality abnormalities. Automatic optical inspection can only perform static analysis on the quality of the solder joints after welding is completed. Therefore, it is impossible to adjust the welding process of the circuit component solder joints according to the exact reasons affecting the quality of the solder joints. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for online detection of solder joint quality of circuit components, aiming to solve the technical problems in the prior art.

[0005] The present invention provides a method for online detection of solder joint quality of circuit components, comprising: Acquire the continuous real-time temperature of each welding point of the circuit component at multiple consecutive moments during the welding process under preset welding parameters, and construct a dynamic temperature change curve diagram according to the multiple continuous real-time temperatures; Extracting temperature gradient distribution data of each welding point at multiple time nodes according to the dynamic temperature change curve diagram, and determining the thermal stress area according to each temperature gradient distribution data; Obtain the displacement deformation and stress deformation at each welding point in each thermal stress area by means of a high-speed sensor, and obtain the corresponding external dynamic deformation according to each displacement deformation and stress deformation; Obtaining a corresponding external dynamic stress according to each of the external dynamic deformations, and obtaining a total stress according to each of the external dynamic stresses and the thermal stress; Obtaining a deformation comprehensive index according to each of the total stresses, and determining a relationship between the deformation comprehensive index and a preset threshold range; If the deformation comprehensive index is greater than the upper limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are reduced in real time according to the deformation comprehensive index; If the deformation comprehensive index is less than the lower limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are increased in real time according to the deformation comprehensive index; If the deformation comprehensive index is within the preset threshold range, the radius of the corresponding welding point after cooling is obtained, and the corresponding moment of inertia is obtained according to each welding point radius; Obtaining a corresponding solder joint deformation according to each of the moments of inertia and the solder joint radius, and determining whether the solder joint deformation is less than a preset deformation; If the deformation of the welding point is not less than the preset deformation, the welding point is judged to be unqualified; If the deformation of the welding point is smaller than the preset deformation, the welding point is judged to be of qualified quality.

[0006] Preferably, the step of constructing a dynamic temperature change curve diagram according to the plurality of continuous real-time temperatures comprises: Acquire parameter characteristics of each welding point, wherein the parameter characteristics include density, specific heat capacity and thermal conductivity; Obtaining the initial temperature and heat source power of each welding point, and obtaining the heat source temperature change rate according to the heat source power, density and specific heat capacity; Obtaining a heat source diffusivity according to the thermal conductivity, density and specific heat capacity; According to the initial temperature, the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature, and the second-order partial derivative of the Z-axis temperature of the corresponding welding point in the X-axis direction, the Y-axis direction, and the Z-axis direction are obtained; Obtaining the temperature spatial change rate according to the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature, and the second-order partial derivative of the Z-axis temperature; Acquire a time step according to the plurality of continuous real-time temperatures, and acquire a real-time temperature of a welding point in a corresponding next continuous real-time temperature according to the time step, the temperature spatial change rate, the heat source diffusion rate, the heat source temperature change rate and the initial temperature; With time as the X-axis and temperature as the Y-axis, a time-temperature coordinate axis is established, and the initial temperature is plotted as the starting point on the time-temperature coordinate axis; The real-time temperature of the welding point corresponding to each time step is plotted as a connection point on the time-temperature coordinate axis, and the starting point and multiple connection points are sequentially connected through curves to obtain a dynamic temperature change curve diagram.

[0007] Preferably, the step of acquiring the corresponding thermal stress according to each of the temperature gradient distribution data and determining the thermal stress area according to the thermal stress comprises: Acquire the vertical temperature change rate and the horizontal temperature change rate according to each of the temperature gradient distribution data; Obtaining the thermal expansion coefficient and elastic modulus of each welding point, and obtaining the corresponding vertical strain force according to each thermal expansion coefficient and vertical temperature change rate; Obtaining a corresponding horizontal strain force according to each of the thermal expansion coefficients and the temperature change rate in the horizontal direction, and obtaining a corresponding Poisson's ratio according to each of the horizontal strain force and the vertical strain force; Obtaining thermal stress at a corresponding welding point according to each of the Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data; Determining whether the thermal stress is greater than a preset stress; If the thermal stress is greater than the preset stress, the welding point corresponding to the thermal stress is determined as a thermal stress area; If the thermal stress is not greater than the preset stress, the welding point corresponding to the thermal stress is determined as a non-thermal stress area.

[0008] Preferably, the step of obtaining the displacement deformation and stress deformation at each welding point in each thermal stress area by a high-speed sensor, and obtaining the corresponding external dynamic deformation according to each displacement deformation and stress deformation comprises: Obtaining the initial abscissa, initial ordinate and initial vertical coordinate of each welding point in each thermal stress zone by means of a high-speed sensor; The real-time horizontal coordinate, real-time vertical coordinate and real-time vertical coordinate of each welding point in each thermal stress area at each preset time point are obtained by high-speed sensors; Obtain the displacement deformation of the corresponding welding point according to each of the real-time horizontal coordinate, the real-time vertical coordinate, the real-time vertical coordinate, the initial horizontal coordinate, the initial vertical coordinate and the initial vertical coordinate; Obtain the thermal expansion coefficient, temperature gradient distribution data and initial length of each welding point in each thermal stress area; Obtaining the stress deformation of the corresponding welding point according to each of the thermal expansion coefficients, the temperature gradient distribution data and the initial length; The corresponding external dynamic deformation is obtained according to each of the stress deformation and displacement deformation.

[0009] Preferably, the step of obtaining the corresponding external dynamic stress according to each external dynamic deformation, and obtaining the corresponding total stress according to each external dynamic stress and thermal stress comprises: Performing first-order time derivative processing on each of the external dynamic deformations to obtain a deformation change rate; Performing second-order time derivative processing on each of the deformation change rates to obtain deformation acceleration; Obtaining the elastic modulus and density of the corresponding welding point according to each of the external dynamic deformations, and obtaining the corresponding deformation stress according to each of the density and deformation acceleration; Obtaining a corresponding inertial force according to each of the external dynamic deformation amounts and the elastic modulus, and obtaining a corresponding external dynamic stress according to each of the inertial force and the deformation stress; The thermal stress of each welding point is obtained, and the corresponding total stress is obtained according to each thermal stress and the external dynamic stress.

[0010] Preferably, the step of obtaining a corresponding deformation comprehensive index according to each of the total stresses comprises: Obtaining a modulus characteristic of each welding point, wherein the modulus characteristic includes an elastic modulus and a viscosity coefficient; Obtaining corresponding elastic strain force according to each of the elastic moduli and the total stress; Obtaining the yield strength of each welding point, and determining whether the total stress is greater than the yield strength; If the total stress is greater than the yield strength, the plastic modulus of the corresponding welding point is obtained, and the corresponding plastic strain increment rate is obtained according to each of the plastic modulus, elastic strain force and total stress; Obtaining corresponding plastic strain force according to each of the plastic strain increment rates, total stress, elastic strain force and elastic modulus; The corresponding viscous strain force is obtained according to each of the viscosity coefficients and the total stress, and the deformation comprehensive index is obtained according to each of the viscous strain force, the elastic strain force and the plastic strain force.

[0011] The present application also provides a circuit component solder joint quality online detection system, comprising: A construction module is used to obtain the continuous real-time temperature of each welding point of the circuit component during the welding process under preset welding parameters at multiple consecutive moments, and to construct a dynamic temperature change curve diagram according to the multiple continuous real-time temperatures; A determination module, used to extract temperature gradient distribution data of each welding point at multiple time nodes according to the dynamic temperature change curve diagram, and determine the thermal stress area according to each temperature gradient distribution data; A first acquisition module is used to acquire the displacement deformation and stress deformation at each welding point in each thermal stress area through a high-speed sensor, and acquire the corresponding external dynamic deformation according to each displacement deformation and stress deformation; A second acquisition module, used for acquiring the corresponding external dynamic stress according to each of the external dynamic deformations, and acquiring the total stress according to each of the external dynamic stresses and the thermal stress; A first judgment module, used for obtaining a deformation comprehensive index according to each of the total stresses, and judging a relationship between the deformation comprehensive index and a preset threshold interval; If the deformation comprehensive index is greater than the upper limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are reduced in real time according to the deformation comprehensive index; If the deformation comprehensive index is less than the lower limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are increased in real time according to the deformation comprehensive index; If the deformation comprehensive index is within the preset threshold range, the radius of the corresponding welding point after cooling is obtained, and the corresponding moment of inertia is obtained according to each welding point radius; A second judgment module is used to obtain a corresponding solder joint deformation according to each of the moments of inertia and the solder joint radius, and to judge whether the solder joint deformation is less than a preset deformation; If the deformation of the welding point is not less than the preset deformation, the welding point is judged to be unqualified; If the deformation of the welding point is smaller than the preset deformation, the welding point is judged to be of qualified quality.

[0012] Preferably, the determining module comprises: A first acquisition unit, used for acquiring a vertical temperature change rate and a horizontal temperature change rate according to each of the temperature gradient distribution data; A second acquisition unit is used to acquire the thermal expansion coefficient and elastic modulus of each welding point, and acquire the corresponding vertical strain force according to each thermal expansion coefficient and vertical temperature change rate; a third acquisition unit, configured to acquire a corresponding horizontal strain force according to each of the thermal expansion coefficients and the temperature change rate in the horizontal direction, and to acquire a corresponding Poisson's ratio according to each of the horizontal strain force and the vertical strain force; A fourth acquisition unit, used for acquiring the thermal stress at the corresponding welding point according to each of the Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data; A determination unit, used to determine whether the thermal stress is greater than a preset stress; If the thermal stress is greater than the preset stress, the welding point corresponding to the thermal stress is determined as a thermal stress area; If the thermal stress is not greater than the preset stress, the welding point corresponding to the thermal stress is determined as a non-thermal stress area.

[0013] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned circuit component solder joint quality online detection method when executing the computer program.

[0014] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for online detection of solder joint quality of circuit components are implemented.

[0015] The beneficial effects of the present invention are as follows: by acquiring the real-time temperature data of each welding point during the welding process, the present invention can monitor the temperature changes of the welding points in real time during the welding process, and then adjust the preset welding parameters, so as to avoid welding point defects caused by inappropriate temperature. The dynamic temperature change curve can help to accurately extract the temperature gradient distribution data of each welding point at different time nodes. By analyzing the temperature gradient, the thermal stress area that may exist in the welding process can be identified. By real-time monitoring of the temperature changes, it can be ensured that the fluidity of the solder is in the most suitable range, so as to avoid defects such as irregular welding point shape and incomplete welding. Through real-time data feedback and analysis, the system can automatically optimize the welding process according to the temperature changes of each welding point. This adaptive adjustment can optimize the parameters for different welding points and different working conditions. Configuration, thereby improving the overall welding quality. By obtaining the displacement deformation and stress deformation of each welding point in the thermal stress area through high-precision sensors, real-time monitoring of the welding process can be achieved, and welding parameters can be dynamically adjusted according to real-time data, thereby avoiding the situation where problems cannot be corrected when they are discovered later. By analyzing multi-dimensional data such as thermal stress, external dynamic stress and deformation comprehensive index of each welding point, the quality of the welding point can be evaluated more accurately. Through a comprehensive analysis of the deformation, thermal stress and deformation after cooling during the welding process, these influencing factors can be comprehensively considered, and then automatic welding parameter adjustment can be achieved by combining real-time data acquisition and deformation analysis, avoiding welding defects caused by external factors such as temperature and pressure, improving the stability and consistency of the quality of the welding points, and reducing the risk of unqualified welding points. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of a method flow according to an embodiment of the present invention.

[0017] Figure 2 FIG. 1 is a schematic diagram of a device structure according to an embodiment of the present invention.

[0018] Figure 3 A schematic diagram of the internal structure of a computer device according to an embodiment of the present application.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0021] like Figure 1-Figure 3 As shown, the present application provides a method for online detection of solder joint quality of circuit components, comprising: S1. Obtaining continuous real-time temperatures of the circuit component at each welding point during the welding process under preset welding parameters at multiple consecutive moments, and constructing a dynamic temperature change curve diagram according to the multiple continuous real-time temperatures, wherein the preset welding parameters include welding time and welding current; S2. extracting temperature gradient distribution data of each welding point at multiple time nodes according to the dynamic temperature change curve diagram, and determining the thermal stress area according to each temperature gradient distribution data; S3, obtaining the displacement deformation and stress deformation at each welding point in each thermal stress area through a high-speed sensor, and obtaining the corresponding external dynamic deformation according to each displacement deformation and stress deformation; S4. Obtaining a corresponding external dynamic stress according to each of the external dynamic deformations, and obtaining a total stress according to each of the external dynamic stresses and the thermal stress; S5. Obtaining a deformation comprehensive index according to each of the total stresses, and determining a relationship between the deformation comprehensive index and a preset threshold range; If the deformation comprehensive index is less than the lower limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified; If the deformation comprehensive index is within the preset threshold range, the radius of the corresponding welding point after cooling is obtained, and the corresponding moment of inertia is obtained according to each welding point radius; S6. Obtaining a corresponding solder joint deformation according to each of the moments of inertia and the solder joint radius, and determining whether the solder joint deformation is less than a preset deformation; If the deformation of the welding point is not less than the preset deformation, the welding point is judged to be unqualified; If the deformation of the welding point is smaller than the preset deformation, the welding point is judged to be of qualified quality.

[0022] As described in the above steps S1-S6, the current circuit component solder joint quality detection method mainly detects the quality of the circuit component solder joints through automatic optical inspection, wherein the automatic optical inspection scans the solder joints through a camera and a high-resolution image acquisition system, and uses software to analyze and detect whether the quality of the solder joints is qualified. However, factors affecting the quality of the solder joints include temperature changes during the welding process affecting the fluidity of the solder, which in turn causes defects in the shape and surface features of the solder joints (this is because during the welding process, the temperature of the welding area rises sharply, and the solder begins to change from solid to liquid. If the fluidity of the solder is enhanced, if the temperature control is unstable at this time, it may cause the solder to flow excessively or splash, resulting in an uneven solder joint surface or excessive solder overflow causing a short The quality abnormalities caused by factors such as poor solder fluidity, which may lead to insufficient wettability of the welding area, forming voids or incomplete contact, resulting in weak solder joints) and shaking during the cooling process of the solder joint (for example, if shaking occurs during the cooling process, the solder may solidify prematurely in some areas while other parts are not solidified, resulting in unstable contact or weak solder joints). Automatic optical inspection can only perform static analysis on the quality of the solder joint after the welding is completed. Therefore, it is impossible to adjust the welding process of the circuit component solder joint according to the accurate reasons affecting the quality of the solder joint. The present invention obtains the real-time temperature of each soldering point of the circuit component at multiple consecutive moments during the welding process under preset welding parameters, and constructs a dynamic temperature change curve diagram according to the multiple consecutive real-time temperatures. , the temperature gradient distribution data of each welding point at multiple time nodes are extracted through the dynamic temperature change curve diagram, and the thermal stress area is determined according to each temperature gradient distribution data, wherein the temperature gradient distribution data of each welding point at multiple time nodes extracted according to the dynamic temperature change curve diagram is calculated by the difference method or the numerical differential method, and the real-time temperature at multiple consecutive moments of the welding point can be obtained by infrared thermal imaging technology or temperature sensors. By obtaining the real-time temperature data of each welding point during the welding process, the temperature change of the welding point can be monitored in real time during the welding process. If an abnormal temperature change of a certain welding point is detected during the welding process (for example, the temperature is too high or too low), the preset welding parameters can be adjusted immediately ( The temperature gradient distribution data of each welding point at different time nodes can be accurately extracted through the dynamic temperature change curve. The temperature gradient is one of the key factors affecting the quality of the solder joint, because it determines the fluidity and cooling rate of the solder, thereby affecting the shape, strength and stability of the solder joint. By analyzing the temperature gradient, the thermal stress areas that may exist in the welding process can be identified. These areas are usually the root cause of solder joint quality problems. By discovering these problem areas in advance, dynamic adjustments can be made during the welding process to reduce the negative impact of thermal stress on the solder joint.Since temperature changes will directly affect the fluidity of solder, and thus affect the shape and surface characteristics of solder joints, real-time monitoring of temperature changes can ensure that the fluidity of solder is in the most suitable range, thereby avoiding defects such as irregular solder joint shape and incomplete welding. Through real-time data feedback and analysis, the system can automatically optimize the welding process according to the temperature changes of each solder joint. This adaptive adjustment can configure the optimal parameters for different solder joints and different working conditions, thereby improving the overall welding quality. The displacement deformation and stress deformation at each soldering point in each thermal stress area are obtained by high-speed sensors, and the corresponding external dynamic deformation is obtained according to each displacement deformation and stress deformation, and the corresponding external dynamic stress is obtained according to each external dynamic deformation, and the total stress is obtained according to each external dynamic stress and thermal stress, and the deformation comprehensive index is obtained according to each total stress, and the deformation comprehensive index is obtained according to each total stress, and the judgment is made. The relationship between the comprehensive deformation index and the preset threshold interval is determined. If the comprehensive deformation index is greater than the upper limit of the preset threshold interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are reduced in real time according to the comprehensive deformation index. If the comprehensive deformation index is less than the lower limit of the preset threshold interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are increased in real time according to the comprehensive deformation index. If the comprehensive deformation index is within the preset threshold interval, the radius of the welding point after cooling of the corresponding welding point is obtained, and the corresponding moment of inertia is obtained according to the radius of each welding point, and the corresponding welding point deformation is obtained according to each moment of inertia and the welding point radius, and it is determined whether the welding point deformation is less than the preset deformation. If the welding point deformation is not less than the preset deformation, the quality of the welding point is determined to be unqualified. If the welding point deformation is less than the preset deformation, the quality of the welding point is determined to be qualified. Since traditional automatic optical inspection can only perform static detection after welding is completed, it is impossible to monitor the quality changes during the welding process in real time. By obtaining the displacement deformation and stress deformation of each welding point in the thermal stress area through high-precision sensors, real-time monitoring of the welding process can be achieved. This makes it possible to instantly judge the quality of the welding point during the welding process and dynamically adjust the welding parameters according to the real-time data, thereby avoiding the situation where problems cannot be corrected when they are discovered later. By analyzing the multi-dimensional data such as thermal stress, external dynamic stress and deformation comprehensive index of each welding point, the quality of the welding point can be evaluated more accurately. By calculating the stress and deformation comprehensive index, the quality status of the welding point can be analyzed from the perspectives of internal stress and deformation, and then the potential defects in welding can be more accurately predicted and discovered. The adjustment of welding parameters can be automatically triggered by the relationship between the deformation comprehensive index and the preset threshold, which makes the entire welding process more automated and reduces the errors and lags of manual judgment and adjustment. The system can automatically optimize welding parameters according to real-time data, improve the consistency and reliability of welding quality, and dynamically adjust welding parameters to identify potential quality problems in advance during the welding process and adjust process parameters in real time to avoid the generation of unqualified welding points. This preventive measure can effectively reduce the incidence of welding quality problems.Improve the qualified rate of products. During the welding process, factors such as temperature change, thermal stress, and cooling speed will affect the quality of the solder joints, and these factors may be complex and dynamically changing. Through multi-dimensional analysis (including thermal stress, deformation, stress distribution, etc.), the comprehensive impact of various factors can be fully evaluated, thereby improving the adaptability to welding quality under complex working conditions. In addition to being affected by temperature and solder fluidity, factors such as shaking during the cooling process and changes in the external environment may also cause quality abnormalities. The present invention can comprehensively consider these influencing factors through a comprehensive analysis of deformation, thermal stress, and deformation after cooling during the welding process, and then realize automatic welding parameter adjustment by combining real-time data acquisition and deformation analysis, avoiding welding defects caused by external factors such as temperature and pressure, improving the stability and consistency of solder joint quality, and reducing the risk of unqualified solder joints.

[0023] In one embodiment, the step S1 of constructing a dynamic temperature change curve graph according to the plurality of continuous real-time temperatures comprises: S11, obtaining parameter characteristics of each welding point, wherein the parameter characteristics include density, specific heat capacity and thermal conductivity; S12, obtaining the initial temperature and heat source power of each welding point, and calculating the heat source temperature change rate according to the heat source power, density and specific heat capacity, wherein the calculation formula is: ; Wherein, R(WB) represents the rate of change of heat source temperature, R(GL) represents the heat source power, C(MD) represents the density, and C(BR) represents the specific heat capacity; S13, calculating the heat source diffusivity according to the thermal conductivity, density and specific heat capacity, wherein the calculation formula is: ; Wherein, R(KS) represents the heat source diffusivity, R(DL) represents the thermal conductivity, C(MD) represents the density, and C(BR) represents the specific heat capacity; S14, obtaining the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature, and the second-order partial derivative of the Z-axis temperature of the corresponding welding point in the X-axis direction, the Y-axis direction, and the Z-axis direction according to the initial temperature; S15, obtaining the temperature spatial change rate according to the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature, and the second-order partial derivative of the Z-axis temperature; S16, obtaining a time step according to the plurality of continuous real-time temperatures, and calculating the real-time temperature of the welding point in the next continuous real-time temperature according to the time step, the temperature spatial change rate, the heat source diffusion rate, the heat source temperature change rate and the initial temperature, wherein the calculation formula is: ; Where S(WD) represents the real-time temperature of the welding point in the next continuous real-time temperature, C(WD) represents the initial temperature, S(BC) represents the time step, W(KB) represents the temperature spatial change rate, R(WB) represents the heat source temperature change rate, and R(KS) represents the heat source diffusion rate; S17, establishing a time-temperature coordinate axis with time as the X-axis and temperature as the Y-axis, and plotting the initial temperature as the starting point on the time-temperature coordinate axis; S18, plotting the real-time temperature of the welding point corresponding to each time step as a connection point on the time-temperature coordinate axis, and connecting the starting point and multiple connection points in sequence through curves to obtain a dynamic temperature change curve diagram.

[0024] As described in the above steps S11-S18, the calculation formulas for the above-mentioned heat source temperature change rate, the calculation formula for the heat source temperature change rate, and the calculation formula for the real-time temperature are all normalized in advance to eliminate the dimensional differences between different variables. The purpose is to ensure that all variables are at the same order of magnitude, so that the calculation is more stable and effective. The heat source temperature change rate is the ratio between the heat source power and the product of the material density and specific heat capacity. This ratio represents the contribution of the heat source power to the temperature change per unit volume, and is the temperature change rate caused by the heat source in the material. The temperature spatial change rate refers to the Laplace operator of the temperature of the welding point in the grid unit at each time step, that is, the second-order spatial derivative of the temperature, which describes The spatial variation of the temperature field is described, indicating how heat diffuses in space, wherein the real-time temperature of the welding point in each next continuous real-time temperature is obtained by the temperature of the welding point in the previous continuous real-time temperature through the above calculation formula. The present invention obtains the density, specific heat capacity and thermal conductivity of the parameter characteristics of each welding point, obtains the initial temperature and heat source power of each welding point through the first continuous real-time temperature, calculates the heat source temperature change rate according to the heat source power, density and specific heat capacity, calculates the heat source diffusion rate according to the thermal conductivity, density and specific heat capacity, obtains the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature and the second-order partial derivative of the Z-axis temperature of the corresponding welding point in the X-axis direction, the Y-axis direction and the Z-axis direction according to the initial temperature, and obtains the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature and the second-order partial derivative of the Z-axis temperature of the corresponding welding point in the X-axis direction, the Y-axis direction and the Z-axis direction according to the initial temperature. The temperature spatial change rate is obtained by summing the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature and the second-order partial derivative of the Z-axis temperature. The time step is obtained through multiple continuous real-time temperatures. The present invention uses continuous real-time temperatures to track the temperature changes of the welding points during the welding process in real time. By real-time calculation of information such as temperature, heat source power, thermal conductivity, etc. at each moment, the temperature distribution and change rate during the welding process can be obtained, so that the welding parameter anomalies during the welding process can be monitored and responded to in time. By obtaining characteristic parameters such as density, specific heat capacity and thermal conductivity of each welding point, the thermodynamic properties of the welding point can be deeply analyzed. These physical parameters can provide more comprehensive thermal behavior information of the welding point, which is helpful to accurately predict the welding quality and find possible defects. The calculation of the heat source temperature change rate based on the heat source power, density and specific heat capacity, as well as the calculation of the heat source diffusivity based on thermal conductivity, density and specific heat capacity, is helpful for analyzing the heat transfer characteristics in the welding process. Through these calculations, we can better understand the thermal behavior of the welding point, and timely discover potential problems such as uneven heat source or overheating, thereby effectively avoiding welding quality problems. The spatial change rate of the welding point temperature can be calculated based on the second-order partial derivatives of the temperature on the X-axis, Y-axis and Z-axis, thereby revealing the gradient change of the temperature field and helping to analyze whether there is uneven temperature or abnormal area at the welding point, thereby guiding the optimization of the welding process. By calculating dynamic characteristics such as the temperature change rate and diffusivity, some minor welding defects or uneven phenomena can be discovered earlier.The limitation of traditional automatic optical inspection that can only perform static inspection on external defects of cooled solder joints is avoided. Through dynamic analysis, defects can be prevented in advance and the stability of welding quality can be improved. By combining high-precision thermal imaging images and meticulous thermodynamic calculations, more accurate solder joint quality inspection results are provided. The real-time temperature of the solder joint corresponding to the next continuous real-time temperature is calculated according to the time step, temperature spatial change rate, heat source diffusion rate, heat source temperature change rate and initial temperature. The time-temperature coordinate axis is established with time as the X-axis and temperature as the Y-axis, and the initial temperature is used as the starting point to draw it on the time-temperature coordinate axis. The real-time temperature of the solder joint corresponding to each time step is drawn as a connection point on the time-temperature coordinate axis, and the starting point and multiple connection points are connected in sequence through curves to obtain a dynamic temperature change curve. Since the traditional automatic optical inspection method can only perform static inspection on the cooled solder joint after welding is completed, it cannot directly capture the dynamic changes (such as temperature, stress, etc.) that occur during the welding process. By calculating the real-time temperature based on dynamic factors such as the time step, the spatial temperature change rate, and the heat source diffusion rate, and drawing a dynamic temperature change curve, the temperature changes in the welding process can be monitored in real time and the dynamic characteristics of welding can be captured. Such dynamic monitoring can help detect abnormalities in the welding process, such as overheating or uneven temperature, and respond in time. Through the generated time-temperature curve, the temperature changes of the welding point at different time steps can be clearly observed, which can not only help detect external defects of the weld, but also further evaluate the uniformity of temperature distribution during welding and the stability of welding quality. For example, too fast a temperature change rate may cause welding defects, while uneven temperature distribution may affect the quality of welding. This method can comprehensively evaluate the welding quality, not just the external morphology. By calculating the real-time temperature changes and drawing the dynamic temperature change curve, possible temperature abnormal areas in the welding process can be identified in advance. These abnormal areas may indicate potential problems in the welding process, such as local overheating, heat accumulation or uneven cooling. These problems usually need to be detected by temperature changes, and the automatic optical inspection law may not be able to capture these dynamic changes. Real-time temperature data allows problems to be discovered during the welding process, rather than waiting until the welding is completed to analyze them. By monitoring the dynamic changes in temperature, the welding process can be more finely controlled. Based on the real-time data feedback of temperature, the welding operation can be adjusted during the process to avoid welding defects caused by rapid or uneven temperature changes. Compared with traditional welding quality detection, the monitoring of dynamic temperature changes helps to adjust the preset welding parameters in real time and improve the stability and reliability of welding. The dynamic temperature change curve provides rich data and can evaluate the welding quality more objectively. Through the numerical calculation of temperature changes, the evaluation of welding quality no longer relies on manual visual inspection, but uses precise numerical data to obtain the quality evaluation results of the solder joint.The data-driven evaluation method is more objective and reliable, avoiding the deviations and errors that may be caused by manual inspection. Through real-time dynamic temperature monitoring and time-temperature curve drawing, it can effectively improve the accuracy of welding point quality inspection. Dynamic monitoring not only avoids the information lag caused by static inspection, but also makes the inspection results more comprehensive. It can accurately predict potential welding defects through temperature change curves, thereby improving the quality and production efficiency of the welding process.

[0025] In one embodiment, the step S2 of acquiring the corresponding thermal stress according to each temperature gradient distribution data and determining the thermal stress area according to the thermal stress comprises: S21, acquiring a vertical temperature change rate and a horizontal temperature change rate according to each of the temperature gradient distribution data; S22, obtaining the thermal expansion coefficient and elastic modulus of each welding point, and obtaining the corresponding vertical strain force according to each thermal expansion coefficient and vertical temperature change rate; S23, obtaining a corresponding horizontal strain force according to each of the thermal expansion coefficients and the temperature change rate in the horizontal direction, and obtaining a corresponding Poisson's ratio according to each of the horizontal strain force and the vertical strain force; S24, calculating the thermal stress at the corresponding welding point according to each of the Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data, wherein the calculation formula is: ; Wherein, R(YL) represents thermal stress, R(PZ) represents thermal expansion coefficient, W(TF) represents temperature gradient distribution data, T(XM) represents elastic modulus, and B(SB) represents Poisson's ratio; S25, determining whether the thermal stress is greater than a preset stress; If the thermal stress is greater than the preset stress, the welding point corresponding to the thermal stress is determined as a thermal stress area; If the thermal stress is not greater than the preset stress, the welding point corresponding to the thermal stress is determined as a non-thermal stress area.

[0026] As described in the above steps S21-S25, the above calculation formula for calculating the thermal stress at the corresponding welding point according to the Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data needs to normalize the parameters in advance to eliminate the dimensional differences between different variables, the purpose of which is to ensure that all variables are at the same order of magnitude, so as to make the calculation more stable and effective. The present invention obtains the vertical temperature change rate and the horizontal temperature change rate through each temperature gradient distribution data, obtains the thermal expansion coefficient and elastic modulus of each welding point, and obtains the corresponding vertical strain force according to each thermal expansion coefficient and the vertical temperature change rate, and obtains the vertical strain force according to each temperature gradient distribution data. The corresponding horizontal strain force is obtained from the thermal expansion coefficient and the horizontal temperature change rate, and the corresponding Poisson's ratio is obtained according to each horizontal strain force and vertical strain force. The thermal stress at the corresponding welding point is calculated according to each Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data. It is judged whether the thermal stress is greater than the preset stress. If the thermal stress is greater than the preset stress, the welding point corresponding to the thermal stress is determined as a thermal stress area. If the thermal stress is not greater than the preset stress, the welding point corresponding to the thermal stress is determined as a non-thermal stress area. Since the automatic optical inspection method can only detect static defects after welding is completed, it cannot directly capture the dynamic changes occurring during the welding process.The method of calculating thermal stress through temperature gradient data can monitor in real time the stress changes that may occur during the welding process, especially the strain caused by thermal expansion and temperature gradient. This can identify the stress concentration areas generated during the welding process in advance, and avoid potential defects in the welds due to uneven stress during the welding process. By calculating the thermal stress of each welding point and comparing it with the preset stress value, it can accurately identify which welding points may deform or break due to excessive thermal stress. This method based on stress analysis can supplement traditional appearance inspection, reduce the possibility of missed inspections and misjudgments, and ensure that the welding quality is under monitoring throughout the entire welding process. The method of inferring thermal stress through physical parameters such as thermal expansion coefficient and elastic modulus avoids the interference of the external environment on the test results, and can more objectively and accurately evaluate the quality of the welding points. Real-time calculation of thermal stress and timely judgment of whether it exceeds the safety range can effectively prevent cracks in solder joints or other structural damage caused by excessive thermal stress. This can provide a scientific basis for defect prediction in the welding process, help improve the control level of welding quality, avoid the need for later repairs, and thus improve production efficiency and product reliability. By combining multiple physical quantities such as temperature gradient distribution, thermal expansion coefficient, elastic modulus, Poisson's ratio, etc., it can comprehensively reflect the behavior of solder joints under thermal stress, rather than relying solely on a single parameter. This method provides a more multidimensional and comprehensive quality assessment, and can better handle the various factors that may arise in complex welding processes, thereby supplementing traditional automatic optical inspection and providing a more comprehensive means of welding quality detection, which can greatly improve quality assurance in the welding process and ensure product reliability and safety.

[0027] In one embodiment, the step S3 of obtaining the displacement deformation and stress deformation at each welding point in each thermal stress area by a high-speed sensor, and obtaining the corresponding external dynamic deformation according to each displacement deformation and stress deformation, comprises: S31, obtaining an initial horizontal coordinate, an initial vertical coordinate, and an initial vertical coordinate of each welding point in each thermal stress region by a high-speed sensor; S32, obtaining the real-time horizontal coordinate, real-time vertical coordinate and real-time vertical coordinate of each welding point in each thermal stress area at each preset time point through a high-speed sensor; S33, according to each of the real-time horizontal coordinate, real-time vertical coordinate, real-time vertical coordinate, initial horizontal coordinate, initial vertical coordinate and initial vertical coordinate, the displacement deformation of the corresponding welding point is obtained, and the calculation formula is: ; Wherein, W(BX) represents the displacement deformation, S(HB) represents the real-time horizontal coordinate, C(HB) represents the initial horizontal coordinate, S(ZB) represents the real-time vertical coordinate, C(ZB) represents the initial vertical coordinate, S(CB) represents the real-time vertical coordinate, and C(CB) represents the initial vertical coordinate; S34, obtaining the thermal expansion coefficient, temperature gradient distribution data and initial length of each welding point in each thermal stress area; S35, obtaining the stress deformation of the corresponding welding point according to each of the thermal expansion coefficients, the temperature gradient distribution data and the initial length, wherein the calculation formula is: ; Wherein, Y(BX) represents stress deformation, R(PZ) represents thermal expansion coefficient, C(CD) represents initial length, and W(TF) represents temperature gradient distribution data; S36. Obtain a corresponding external dynamic deformation according to each of the stress deformation and displacement deformation.

[0028] As in the above steps S31- S36, wherein the calculation formula for obtaining the stress deformation of the corresponding welding point according to the thermal expansion coefficient, the temperature gradient distribution data and the initial length needs to normalize the parameters in advance to eliminate the dimensional differences between different variables, the purpose of which is to ensure that all variables are at the same order of magnitude, so that the calculation is more stable and effective. The present invention obtains the initial horizontal coordinate, initial vertical coordinate and initial vertical coordinate of each welding point in each thermal stress area and the real-time horizontal coordinate, real-time vertical coordinate and real-time vertical coordinate of each welding point in each thermal stress area at each preset time point through a high-speed sensor, obtains the displacement deformation of the corresponding welding point according to each real-time horizontal coordinate, real-time vertical coordinate, real-time vertical coordinate, initial horizontal coordinate, initial vertical coordinate and initial vertical coordinate, calculates the stress deformation of the corresponding welding point through the thermal expansion coefficient, temperature gradient distribution data and initial length of each welding point in each thermal stress area, obtains the corresponding external dynamic deformation according to each stress deformation and displacement deformation, uses a high-speed sensor to obtain the coordinate data of each welding point in real time, can dynamically monitor the physical changes such as thermal stress, displacement deformation in the welding process, by continuously tracking the real-time position of each welding point, can find potential defects or abnormalities in the welding process, and make adjustments or corrections in time, and uses the real-time coordinates and initial length to calculate the stress deformation of the corresponding welding point. The initial coordinate data can accurately calculate the displacement and deformation of the welding point, and combined with the thermal expansion coefficient, temperature gradient distribution data and initial length, the stress and deformation of the welding point can be further calculated. This method takes into account the influencing factors of temperature and stress, and can more accurately reflect the welding quality than relying solely on visual inspection, especially for those welding points where no obvious defects can be seen on the surface. By detecting the real-time thermal stress and displacement changes during the welding process, these problems can be warned in advance, thereby avoiding quality problems caused by dynamic changes in the welding process. For example, possible thermal cracks, incomplete welding, material deformation and other problems can be discovered and repaired early through this method. The real-time data obtained by this method can more accurately reflect the stress state, thermal effect and deformation trend during the welding process, and can more accurately control the welding quality, which helps to reduce quality fluctuations caused by unstable factors and improve the stability and consistency of the overall welding. The automatic acquisition and processing of real-time data by high-speed sensors and data analysis systems can greatly reduce manual intervention, reduce errors through data analysis, and improve the accuracy and reliability of detection. This not only improves the controllability of welding quality, but also optimizes the stability and consistency of the entire welding process, thereby reducing the defect rate and improving production efficiency and product reliability.

[0029] In one embodiment, step S4 of obtaining the corresponding external dynamic stress according to each of the external dynamic deformations, and obtaining the corresponding total stress according to each of the external dynamic stresses and the thermal stress, comprises: S41, performing first-order time derivative processing on each of the external dynamic deformations to obtain a deformation change rate; S42, performing second-order time derivative processing on each deformation change rate to obtain deformation acceleration; S43, obtaining the elastic modulus and density of the corresponding welding point according to each of the external dynamic deformations, and obtaining the corresponding deformation stress according to the product of each density and the acceleration of the deformation; S44, obtaining a corresponding inertial force according to the product of each of the external dynamic deformation amounts and the elastic modulus, and obtaining a corresponding external dynamic stress according to each of the inertial forces and the deformation stress; S45, obtaining the thermal stress of each welding point, and obtaining the corresponding total stress according to each thermal stress and the external dynamic stress.

[0030] As described in the above steps S41-S45, the corresponding inertial force is obtained according to the product of the external dynamic deformation and the elastic modulus to represent the inertial force caused by vibration or fluctuation in the unit volume of the material, that is, the internal force generated by the material due to the change in acceleration, and the corresponding deformation stress is obtained according to the product of the density and the deformation acceleration to represent the stress of the material at a certain point in time (which is related to the elastic modulus and strain of the material). The calculation formulas of the above inertial force and deformation stress need to normalize the parameters in advance to eliminate the dimensional differences between different variables. The purpose is to ensure that all variables are on the same order of magnitude, so as to make the calculation more stable and effective. The present invention obtains each external dynamic deformation by normalizing the parameters of the inertial force and deformation stress in advance. The deformation rate of change is obtained by performing first-order time derivative processing on the quantity, the deformation acceleration is obtained by performing second-order time derivative processing on each deformation rate of change, the elastic modulus and density of the corresponding welding point are obtained through each external dynamic deformation, and the corresponding deformation stress is obtained according to the product of each density and deformation acceleration, the corresponding inertial force is obtained according to the product of each external dynamic deformation and elastic modulus, and the corresponding external dynamic stress is obtained according to each inertial force and deformation stress, and the corresponding total stress is obtained according to each thermal stress and external dynamic stress. Since the traditional automatic optical inspection method can only detect welds in the cooling state after welding is completed, this may ignore important changes in the welding process. The present invention can capture the dynamic changes of deformation, acceleration and stress in real time during the welding process, so as to more accurately reflect the quality problems in the welding process. For example, problems such as overheating, excessive deformation or stress concentration that may occur in the welding process can be discovered in time, so as to take corrective measures earlier. By processing the second-order time derivative of the deformation change rate and acceleration, a more sophisticated dynamic behavior analysis can be obtained. This not only takes into account the geometric changes of the weld point, but also reflects the changes in the physical state during the welding process, such as the influence of thermal stress and external dynamic stress on the weld point. This comprehensive detection method can provide higher accuracy than the optical detection method, especially at the microscopic level of welding quality, deformation, Thermal stress, dynamic stress and other factors have an important influence on the formation of solder joints. Through dynamic stress analysis and calculation of inertial force, it is possible to more comprehensively evaluate whether solder joints may have potential defects such as micro cracks and solder joint loosening. This helps to immediately detect problems during the welding process, reduce defect omissions, and avoid welding defects that cannot be detected by traditional optical inspections. Taking external dynamic factors (such as inertial force, acceleration, thermal stress, etc.) into consideration can not only improve the real-time monitoring capability of solder joint quality, but also provide data support for the optimization of the welding process. According to the deformation stress, inertial force, total stress and other information obtained by detection, the welding process can be adjusted in time, thereby improving the welding quality and stability, which helps to improve the overall welding quality and production efficiency.

[0031] In one embodiment, the step S5 of obtaining the corresponding deformation comprehensive index according to each total stress comprises: S51, obtaining a modulus feature of each welding point, wherein the modulus feature includes an elastic modulus and a viscosity coefficient; S52, obtaining corresponding elastic strain force according to each elastic modulus and total stress; S53, obtaining the yield strength of each welding point, and determining whether the total stress is greater than the yield strength; If the total stress is greater than the yield strength, the plastic modulus of the corresponding welding point is obtained, and the corresponding plastic strain increment rate is obtained according to the ratio between the difference between each total stress and the elastic strain force and the plastic modulus; S54, calculating the corresponding plastic strain force according to each of the plastic strain increment rates, the total stress, the elastic strain force and the elastic modulus, wherein the calculation formula is: ; Where S(YL) represents plastic strain, Z(YL) represents total stress, T(YL) represents elastic strain, T(ML) represents elastic modulus, and S(ZS) represents plastic strain increment rate; S55. Obtain corresponding viscous strain force according to each of the viscosity coefficients and the total stress, and calculate a deformation comprehensive index according to each of the viscous strain force, the elastic strain force, and the plastic strain force, wherein the calculation formula is: ; Among them, X(ZS) represents the comprehensive deformation index, α represents the weight of viscous strain, N(YL) represents the viscous strain, β represents the weight of elastic strain, T(YL) represents elastic strain, γ represents the weight of plastic strain, and S(YL) represents plastic strain.

[0032] As described in the above steps S51-S55, the calculation formula of the plastic strain force and the calculation formula of the comprehensive deformation index need to normalize the parameters in advance to eliminate the dimensional differences between different variables. The purpose is to ensure that all variables are at the same order of magnitude, so that the calculation is more stable and effective. The present invention obtains the elastic modulus and viscosity coefficient of the modulus characteristics of each welding point, obtains the corresponding elastic strain force according to each elastic modulus and the total stress, obtains the yield strength of each welding point, and determines whether the total stress is greater than the yield strength. If the total stress is greater than the yield strength, the plastic modulus of the corresponding welding point is obtained, and the corresponding plastic strain increment rate is obtained according to the difference between each total stress and the elastic strain force and the ratio between the plastic modulus, the corresponding plastic strain increment rate is calculated according to each plastic strain increment rate, the total stress, the elastic strain force and the elastic modulus, the corresponding viscous strain force is obtained according to each viscosity coefficient and the total stress, and the corresponding viscous strain force is obtained according to each The viscous strain force, elastic strain force and plastic strain force calculate the corresponding deformation comprehensive index. By obtaining the elastic modulus, viscosity coefficient, total stress and other information of each welding point, the dynamic behavior of the welding process can be monitored in real time. This makes it possible to capture potential stress overload, yield or plastic deformation at any time during welding. Through the calculation of the elastic modulus, plastic modulus and viscosity coefficient, combined with the relationship between total stress and strain force, a more accurate analysis of the internal stress state of the welding point can be performed. When the total stress exceeds the yield strength, the plastic strain of the welding point can be obtained by calculating the plastic modulus and strain increment rate, which further helps to determine whether potential defects (such as cracks, deformation, etc.) will be caused. This can provide an in-depth understanding of the mechanical behavior in the welding process and provide more material-level information than simple optical inspection. During the welding process, the welding point may enter the plastic deformation stage due to excessive stress, and may even cause fatigue cracks. By calculating the plastic strain increment rate, plastic strain force, etc., it is possible to predict in real time whether the weld point is at risk of plastic deformation and cracking, especially when the stress exceeds the yield strength. This is crucial for improving the predictive and preventive control of welding quality. Traditional optical inspection methods may miss defects that are not visible on the surface, especially for some minor internal defects such as plastic deformation and thermal cracks.By dynamically monitoring parameters such as stress, strain, and plastic force, potential problems that may not appear on the surface can be effectively detected. The dynamic stress and deformation comprehensive index can reveal the impact of different types of stress on the welding point during the welding process, and help to find internal defects that cannot be identified by optical methods. Combining different mechanical parameters such as elastic strain, plastic strain, and viscous strain can more comprehensively analyze the quality of the welding point. Dynamic calculation of the comprehensive index of these parameters can provide a more accurate and multi-dimensional quality assessment than traditional detection methods. For complex welding points (such as multi-layer welding or welding points with special material requirements), this method can significantly improve the accuracy of quality control. Through real-time dynamic analysis, not only can the immediate problems in the welding process be discovered, but also the stress and deformation of the welding point can be compared. The strain state is modeled to predict the future performance of welding quality. Based on the comprehensive analysis of stress and strain force, the welding parameters can be optimized to improve the overall welding quality and reduce the later rework rate and failure rate. By monitoring the plastic modulus, strain rate, etc., excessive plastic deformation can be avoided, thereby reducing the residual stress after welding, preventing cracks or deformation, and ensuring the strength and durability of the welded joint. For high-precision, large-scale welding processes (such as electronic component manufacturing, automotive parts welding, etc.), by combining dynamic analysis of elastic modulus, plastic modulus, viscosity coefficient, etc., real-time feedback can be combined with automated control to provide fine adjustment in each link of the welding process, which not only improves the intelligence and automation of the welding process, but also ensures production efficiency and quality stability.

[0033] The present application also provides a circuit component solder joint quality online detection system, comprising: A construction module is used to obtain the continuous real-time temperature of each welding point of the circuit component during the welding process under preset welding parameters at multiple consecutive moments, and to construct a dynamic temperature change curve diagram according to the multiple continuous real-time temperatures; A determination module, used to extract temperature gradient distribution data of each welding point at multiple time nodes according to the dynamic temperature change curve diagram, and determine the thermal stress area according to each temperature gradient distribution data; A first acquisition module is used to acquire the displacement deformation and stress deformation at each welding point in each thermal stress area through a high-speed sensor, and acquire the corresponding external dynamic deformation according to each displacement deformation and stress deformation; A second acquisition module, used for acquiring the corresponding external dynamic stress according to each of the external dynamic deformations, and acquiring the total stress according to each of the external dynamic stresses and the thermal stress; A first judgment module, used for obtaining a deformation comprehensive index according to each of the total stresses, and judging a relationship between the deformation comprehensive index and a preset threshold interval; If the deformation comprehensive index is less than the lower limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified; If the deformation comprehensive index is within the preset threshold range, the radius of the corresponding welding point after cooling is obtained, and the corresponding moment of inertia is obtained according to each welding point radius; A second judgment module is used to obtain a corresponding solder joint deformation according to each of the moments of inertia and the solder joint radius, and to judge whether the solder joint deformation is less than a preset deformation; If the deformation of the welding point is not less than the preset deformation, the welding point is judged to be unqualified; If the deformation of the welding point is smaller than the preset deformation, the welding point is judged to be of qualified quality.

[0034] In one embodiment, the determining module includes: A first acquisition unit, used for acquiring a vertical temperature change rate and a horizontal temperature change rate according to each of the temperature gradient distribution data; A second acquisition unit is used to acquire the thermal expansion coefficient and elastic modulus of each welding point, and acquire the corresponding vertical strain force according to each thermal expansion coefficient and vertical temperature change rate; a third acquisition unit, configured to acquire a corresponding horizontal strain force according to each of the thermal expansion coefficients and the temperature change rate in the horizontal direction, and to acquire a corresponding Poisson's ratio according to each of the horizontal strain force and the vertical strain force; A fourth acquisition unit, used for acquiring the thermal stress at the corresponding welding point according to each of the Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data; A determination unit, used to determine whether the thermal stress is greater than a preset stress; If the thermal stress is greater than the preset stress, the welding point corresponding to the thermal stress is determined as a thermal stress area; If the thermal stress is not greater than the preset stress, the welding point corresponding to the thermal stress is determined as a non-thermal stress area.

[0035] It should be noted that each module and unit in the online detection system for the quality of solder joints of circuit components corresponds one-to-one to the steps in the online detection method for the quality of solder joints of circuit components.

[0036] like Figure 3 As shown, the present application also provides a computer device, which may be a server, and its internal structure may be as shown in Figure 3As shown. The computer device includes a processor, a memory, a network interface and a database connected through a system bus. Among them, the processor designed by the computer 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, a computer program and a database. The memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store all data required for the process of the online detection method for the quality of solder joints of circuit components. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the online detection method for the quality of solder joints of circuit components is implemented.

[0037] Those skilled in the art will understand that Figure 3 The structure shown in is merely a block diagram of a portion of the structure related to the present application solution and does not constitute a limitation on the computer device to which the present application solution is applied.

[0038] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, any of the above-mentioned methods for online detection of solder joint quality of circuit components is implemented.

[0039] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided in this application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0040] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0041] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for online detection of solder joint quality of circuit components, characterized in that: include: Acquire the continuous real-time temperature of each welding point of the circuit component at multiple continuous moments during the welding process under preset welding parameters, and construct a dynamic temperature change curve diagram according to the multiple continuous real-time temperatures; Extracting temperature gradient distribution data of each welding point at multiple time nodes according to the dynamic temperature change curve diagram, and determining the thermal stress area according to each temperature gradient distribution data; Obtain the displacement deformation and stress deformation at each welding point in each thermal stress area by means of a high-speed sensor, and obtain the corresponding external dynamic deformation according to each displacement deformation and stress deformation; Obtaining a corresponding external dynamic stress according to each of the external dynamic deformations, and obtaining a total stress according to each of the external dynamic stresses and the thermal stress; Obtaining a deformation comprehensive index according to each of the total stresses, and determining a relationship between the deformation comprehensive index and a preset threshold range; If the deformation comprehensive index is greater than the upper limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are reduced in real time according to the deformation comprehensive index; If the deformation comprehensive index is less than the lower limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are increased in real time according to the deformation comprehensive index; If the deformation comprehensive index is within the preset threshold range, the radius of the corresponding welding point after cooling is obtained, and the corresponding moment of inertia is obtained according to each welding point radius; Obtaining a corresponding solder joint deformation according to each of the moments of inertia and the solder joint radius, and determining whether the solder joint deformation is less than a preset deformation; If the deformation of the welding point is not less than the preset deformation, the welding point is judged to be unqualified; If the deformation of the welding point is smaller than the preset deformation, the welding point is judged to be of qualified quality.

2. The method for online detection of solder joint quality of circuit components according to claim 1, characterized in that: The step of constructing a dynamic temperature change curve diagram according to the plurality of continuous real-time temperatures comprises: Acquire parameter characteristics of each welding point, wherein the parameter characteristics include density, specific heat capacity and thermal conductivity; Obtaining the initial temperature and heat source power of each welding point, and obtaining the heat source temperature change rate according to the heat source power, density and specific heat capacity; Obtaining a heat source diffusivity according to the thermal conductivity, density and specific heat capacity; According to the initial temperature, the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature, and the second-order partial derivative of the Z-axis temperature of the corresponding welding point in the X-axis direction, the Y-axis direction, and the Z-axis direction are obtained; Obtaining the temperature spatial change rate according to the second-order partial derivative of the X-axis temperature, the second-order partial derivative of the Y-axis temperature, and the second-order partial derivative of the Z-axis temperature; Acquire a time step according to the plurality of continuous real-time temperatures, and acquire a real-time temperature of a welding point in a corresponding next continuous real-time temperature according to the time step, the temperature spatial change rate, the heat source diffusion rate, the heat source temperature change rate and the initial temperature; With time as the X-axis and temperature as the Y-axis, a time-temperature coordinate axis is established, and the initial temperature is plotted as the starting point on the time-temperature coordinate axis; The real-time temperature of the welding point corresponding to each time step is plotted as a connection point on the time-temperature coordinate axis, and the starting point and multiple connection points are sequentially connected through curves to obtain a dynamic temperature change curve diagram.

3. The method for online detection of solder joint quality of circuit components according to claim 1, characterized in that: The step of determining the thermal stress area according to each of the temperature gradient distribution data comprises: Acquire the vertical temperature change rate and the horizontal temperature change rate according to each of the temperature gradient distribution data; Obtaining the thermal expansion coefficient and elastic modulus of each welding point, and obtaining the corresponding vertical strain force according to each thermal expansion coefficient and vertical temperature change rate; Obtaining a corresponding horizontal strain force according to each of the thermal expansion coefficients and the temperature change rate in the horizontal direction, and obtaining a corresponding Poisson's ratio according to each of the horizontal strain force and the vertical strain force; Obtaining thermal stress at a corresponding welding point according to each of the Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data; Determining whether the thermal stress is greater than a preset stress; If the thermal stress is greater than the preset stress, the welding point corresponding to the thermal stress is determined as a thermal stress area; If the thermal stress is not greater than the preset stress, the welding point corresponding to the thermal stress is determined as a non-thermal stress area.

4. The method for online detection of solder joint quality of circuit components according to claim 1, characterized in that: The step of obtaining the displacement deformation and stress deformation at each welding point in each thermal stress area by a high-speed sensor, and obtaining the corresponding external dynamic deformation according to each displacement deformation and stress deformation, comprises: Obtaining the initial abscissa, initial ordinate and initial vertical coordinate of each welding point in each thermal stress zone by means of a high-speed sensor; The real-time horizontal coordinate, real-time vertical coordinate and real-time vertical coordinate of each welding point in each thermal stress area at each preset time point are obtained by high-speed sensors; Obtain the displacement deformation of the corresponding welding point according to each of the real-time horizontal coordinate, the real-time vertical coordinate, the real-time vertical coordinate, the initial horizontal coordinate, the initial vertical coordinate and the initial vertical coordinate; Obtain the thermal expansion coefficient, temperature gradient distribution data and initial length of each welding point in each thermal stress area; Obtaining the stress deformation of the corresponding welding point according to each of the thermal expansion coefficients, the temperature gradient distribution data and the initial length; The corresponding external dynamic deformation is obtained according to each of the stress deformation and displacement deformation.

5. The method for online detection of solder joint quality of circuit components according to claim 1, characterized in that: The step of obtaining the corresponding external dynamic stress according to each external dynamic deformation, and obtaining the total stress according to each external dynamic stress and thermal stress, comprises: Performing first-order time derivative processing on each of the external dynamic deformations to obtain a deformation change rate; Performing second-order time derivative processing on each of the deformation change rates to obtain deformation acceleration; Obtaining the elastic modulus and density of the corresponding welding point according to each of the external dynamic deformations, and obtaining the corresponding deformation stress according to each of the density and deformation acceleration; Obtaining a corresponding inertial force according to each of the external dynamic deformation amounts and the elastic modulus, and obtaining a corresponding external dynamic stress according to each of the inertial force and the deformation stress; The thermal stress of each welding point is obtained, and the total stress is obtained according to each thermal stress and the external dynamic stress.

6. The method for online detection of solder joint quality of circuit components according to claim 1, characterized in that: The step of obtaining a comprehensive deformation index according to each of the total stresses comprises: Obtaining a modulus characteristic of each welding point, wherein the modulus characteristic includes an elastic modulus and a viscosity coefficient; Obtaining corresponding elastic strain force according to each of the elastic moduli and the total stress; Obtaining the yield strength of each welding point, and determining whether the total stress is greater than the yield strength; If the total stress is greater than the yield strength, the plastic modulus of the corresponding welding point is obtained, and the corresponding plastic strain increment rate is obtained according to each of the plastic modulus, elastic strain force and total stress; Obtaining corresponding plastic strain force according to each of the plastic strain increment rates, total stress, elastic strain force and elastic modulus; The corresponding viscous strain force is obtained according to each of the viscosity coefficients and the total stress, and the deformation comprehensive index is obtained according to each of the viscous strain force, the elastic strain force and the plastic strain force.

7. An online detection system for the quality of solder joints of circuit components, characterized in that: include: A construction module is used to obtain the continuous real-time temperature of each welding point of the circuit component during the welding process under preset welding parameters at multiple consecutive moments, and to construct a dynamic temperature change curve diagram according to the multiple continuous real-time temperatures; A determination module, used to extract temperature gradient distribution data of each welding point at multiple time nodes according to the dynamic temperature change curve diagram, and determine the thermal stress area according to each temperature gradient distribution data; A first acquisition module is used to acquire the displacement deformation and stress deformation at each welding point in each thermal stress area through a high-speed sensor, and acquire the corresponding external dynamic deformation according to each displacement deformation and stress deformation; A second acquisition module, used for acquiring the corresponding external dynamic stress according to each of the external dynamic deformations, and acquiring the total stress according to each of the external dynamic stresses and the thermal stress; A first judgment module, used for obtaining a deformation comprehensive index according to each of the total stresses, and judging a relationship between the deformation comprehensive index and a preset threshold interval; If the deformation comprehensive index is greater than the upper limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are reduced in real time according to the deformation comprehensive index; If the deformation comprehensive index is less than the lower limit of the preset threshold value interval, the quality of the welding point is determined to be unqualified, and the preset welding parameters are increased in real time according to the deformation comprehensive index; If the deformation comprehensive index is within the preset threshold range, the radius of the corresponding welding point after cooling is obtained, and the corresponding moment of inertia is obtained according to each welding point radius; A second judgment module is used to obtain a corresponding solder joint deformation according to each of the moments of inertia and the solder joint radius, and to judge whether the solder joint deformation is less than a preset deformation; If the deformation of the welding point is not less than the preset deformation, the welding point is judged to be unqualified; If the deformation of the welding point is smaller than the preset deformation, the welding point is judged to be of qualified quality.

8. The circuit component solder joint quality online detection system according to claim 7, characterized in that: The determining module comprises: A first acquisition unit, used for acquiring a vertical temperature change rate and a horizontal temperature change rate according to each of the temperature gradient distribution data; A second acquisition unit is used to acquire the thermal expansion coefficient and elastic modulus of each welding point, and acquire the corresponding vertical strain force according to each thermal expansion coefficient and vertical temperature change rate; a third acquisition unit, configured to acquire a corresponding horizontal strain force according to each of the thermal expansion coefficients and the temperature change rate in the horizontal direction, and to acquire a corresponding Poisson's ratio according to each of the horizontal strain force and the vertical strain force; A fourth acquisition unit, used for acquiring the thermal stress at the corresponding welding point according to each of the Poisson's ratio, thermal expansion coefficient, elastic modulus and temperature gradient distribution data; A determination unit, used to determine whether the thermal stress is greater than a preset stress; If the thermal stress is greater than the preset stress, the welding point corresponding to the thermal stress is determined as a thermal stress area; If the thermal stress is not greater than the preset stress, the welding point corresponding to the thermal stress is determined as a non-thermal stress area.

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 method according to any one of claims 1 to 6 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 method according to any one of claims 1 to 6 are implemented.

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