Bonding quality detection method and system

Abstract

The invention provides a bonding quality detection method and system, and the method comprises the steps: determining a defect detection parameter of each detection point according to a first ultrasonic signal corresponding to each detection point of a to-be-detected bonding piece; and according to the second ultrasonic signal corresponding to the at least part of the detection section of the detected bonding piece, determining a bonding strength predicted value of the at least part of the detection section. According to the embodiment of the invention, comprehensive evaluation of the bonding quality can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bonding detection, in particular to a bonding quality detection method and system. BACKGROUND

[0002] In the field of automobile manufacturing, structural adhesive is widely used for bonding between two metal components as a common connecting means.

[0003] The detection method of bonding quality is usually a destructive detection method, in which each detected bonding metal component needs to be physically disassembled, the relevant mechanical parameters are recorded during the disassembly process, and the bonding quality is evaluated according to the recorded mechanical parameters.

[0004] In order not to destroy each detected bonding metal component, the related art usually adopts a non-destructive ultrasonic detection method. However, the existing non-destructive detection method is not comprehensive in evaluating the bonding quality. SUMMARY

[0005] Therefore, the present application aims to provide a bonding quality detection method and system, which aims to at least solve the technical problem that the non-destructive detection method of the prior art is not comprehensive in evaluating the bonding quality.

[0006] According to a first aspect of the present application, a bonding quality detection method is provided, comprising: According to the first ultrasonic signal corresponding to each detection point of the measured bonding component, the defect detection parameter of each detection point is determined; wherein the first ultrasonic signal is obtained by processing the signal output by the first receiving member in the first ultrasonic assembly, and the first transmitting member and the first receiving member in the first ultrasonic assembly are arranged opposite to each other along the thickness direction of the measured bonding component; According to the second ultrasonic signal corresponding to at least part of the detection segment of the measured bonding component, the bonding strength prediction value of at least part of the detection segment is determined; wherein the second ultrasonic signal is obtained by processing the signal output by the second receiving member in the second ultrasonic assembly, and the second transmitting member and the second receiving member in the second ultrasonic assembly are located on the same side of the thickness direction of the measured bonding component.

[0007] In the embodiments of the present application, the defect detection parameters of each detection point can be determined according to the first ultrasonic signal, so as to determine whether the measured adhesive joint is good or has an adhesive defect, and determine the position of the adhesive defect when the adhesive defect exists. The adhesive strength prediction value of at least part of the detection section can be determined according to the second ultrasonic signal, so as to realize comprehensive evaluation of the adhesive quality. In addition, the adhesive quality detection system detects the adhesive quality of the measured adhesive joint based on the air-coupled ultrasonic detection method. The air-coupled ultrasonic detection method has the characteristics of no need of coupling agent, non-contact, and no damage to the measured adhesive joint, can avoid the reuse of the measured adhesive joint due to damage, and can improve the detection efficiency and reduce the comprehensive cost. At the same time, the air-coupled ultrasonic detection method can also avoid the secondary pollution and damage risk caused by the contact detection.

[0008] Optionally, after determining the defect detection parameters of each detection point according to the first ultrasonic signal corresponding to each detection point of the measured adhesive joint, the method further comprises: judging whether there is an abnormal detection point according to the defect detection parameters of each detection point; determining the adhesive strength prediction value of at least part of the detection section according to the second ultrasonic signal corresponding to at least part of the detection section of the measured adhesive joint, comprising: if the abnormal detection point exists, determining a target detection section corresponding to the abnormal detection point; determining the adhesive strength prediction value of the target detection section according to the second ultrasonic signal corresponding to the target detection section.

[0009] Optionally, determining the adhesive strength prediction value of at least part of the detection section according to the second ultrasonic signal corresponding to at least part of the detection section of the measured adhesive joint, comprising: determining the attenuation coefficient and the dispersion phase offset according to the second ultrasonic signal corresponding to at least part of the detection section of the measured adhesive joint; calling a reference wave velocity, a center frequency, a propagation distance, and a material geometric parameter of the measured adhesive joint; determining the equivalent stiffness of at least part of the detection section according to the reference wave velocity, the center frequency, the propagation distance, the dispersion phase offset, the attenuation coefficient, and the material geometric parameter of the measured adhesive joint; determining the adhesive strength prediction value of at least part of the detection section according to the equivalent stiffness of at least part of the detection section; The measured adhesive joint comprises a first workpiece, an adhesive, and a second workpiece. When the second ultrasonic assembly is located on one side of the measured adhesive joint, the distance between the first workpiece and the second ultrasonic assembly is less than the distance between the second workpiece and the second ultrasonic assembly. The material geometric parameters of the measured adhesive joint include a density of the first workpiece, a thickness of the first workpiece, a thickness of the adhesive, an adhesive area, and a shear modulus of the adhesive.

[0010] Optionally, the determining the equivalent stiffness of the at least partial detection section according to the reference wave velocity, the center frequency, the propagation distance, the dispersion phase offset, the attenuation coefficient, and the material geometric parameters of the measured adhesive joint comprises: correcting the reference wave velocity according to the dispersion phase offset, the center frequency, and the propagation distance to obtain a corrected wave velocity; determining a corrected shear modulus according to the shear modulus of the adhesive, the attenuation coefficient, and the thickness of the adhesive; determining a normal stiffness according to the density of the first workpiece, the corrected wave velocity, the adhesive area, and the thickness of the first workpiece; determining a shear stiffness according to the corrected shear modulus, the adhesive area, and the thickness of the adhesive; determining the equivalent stiffness of the at least partial detection section according to the normal stiffness and the shear stiffness.

[0011] Optionally, the calculation formula of the equivalent stiffness is: K_eq = ; K n = ρc²A / h; K t = G a A / t; c=c0× [1 - (Δφ(f0)·c0) / (2πf0d)]; G a = G a0 × exp[-α(f0)·t]; wherein K_eq is the equivalent stiffness, K n is the normal stiffness, K t is the shear stiffness, ρ is the density of the first workpiece, c is the corrected wave velocity, A is the adhesive area, h is the thickness of the first workpiece, G a is the corrected shear modulus, t is the thickness of the adhesive, c0 is the reference wave velocity, Δφ(f0) is the dispersion phase offset at the center frequency f0, f0 is the center frequency, d is the propagation distance, G a0 is the shear modulus of the adhesive, and α(f0) is the attenuation coefficient at the center frequency f0.

[0012] Optionally, when the equivalent stiffness is less than or equal to a critical stiffness, the calculation formula of the adhesive strength prediction value is: σ_strength = σ_max × [1-exp(-K_eq / K_ref)]; wherein σ_strength is the bonding strength prediction value, σ_max is the theoretical maximum bonding strength under the breaking experiment, K_eq is the equivalent stiffness, and K_ref is the reference stiffness under the breaking experiment.

[0013] Optionally, the bonding quality detection method further comprises: generating a scan imaging map according to the defect detection parameters of each of the detection points, and outputting the scan imaging map.

[0014] Optionally, generating a scan imaging map according to the defect detection parameters of each of the detection points, and outputting the scan imaging map, comprises: generating a scan imaging map according to the defect detection parameters of each of the detection points; associating the scan imaging map with the bonding strength prediction values of at least part of the detection sections; wherein the measured bonding member has n detection sections, each of the detection sections covers v detection points, the scan imaging map has n pixel sections, each of the pixel sections covers v pixel points, the plurality of pixel points and the plurality of detection points correspond one-to-one, and the bonding strength prediction value of one detection section is associated with a corresponding pixel section; outputting the scan imaging map.

[0015] Optionally, the defect detection parameters comprise a power spectrum peak value and / or a maximum amplitude value. determining the defect detection parameters of each of the detection points according to the first ultrasonic signals corresponding to each of the detection points of the measured bonding member, comprises: determining the power spectrum peak value and / or the maximum amplitude value of each of the detection points according to the first ultrasonic signals corresponding to each of the detection points of the measured bonding member; generating a scan imaging map according to the defect detection parameters of each of the detection points, and outputting the scan imaging map, comprises: generating a first scan imaging map according to the power spectrum peak values of each of the detection points, and / or generating a second scan imaging map according to the maximum amplitude values of each of the detection points, and outputting the first scan imaging map and / or the second scan imaging map.

[0016] According to a second aspect of the present application, a bonding quality detection system is also provided, comprising a first ultrasonic assembly and a second ultrasonic assembly, the first ultrasonic assembly comprising a first transmitter and a first receiver arranged oppositely along the thickness direction of a measured bonding member, and the second ultrasonic assembly comprising a second transmitter and a second receiver located on the same side of the thickness direction of the measured bonding member. The bonding quality detection system further comprises a processing device configured to perform the bonding quality detection method as described above.

[0017] The above description is merely a summary of the technical solutions of the present application. In order to enable one of ordinary skill in the art to better understand the technical means of the present application and implement the same according to the contents of the specification, and in order to enable the above and other purposes, features and advantages of the present application to be more apparent, the following detailed description of the specific embodiments of the present application is provided. BRIEF DESCRIPTION OF DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not to be considered as limiting of the present application. Moreover, in the drawings, like reference numerals refer to similar components throughout the several views. In the drawings: Figure 1 is a step flow chart of a bonding quality detection method provided by an embodiment of the present application; Figure 2 is a schematic diagram of detection by a first ultrasonic assembly in a bonding quality detection method provided by an embodiment of the present application Figure 1 ; Figure 3 is a schematic diagram of detection by a first ultrasonic assembly in a bonding quality detection method provided by an embodiment of the present application Figure 2 ; Figure 4 is a schematic diagram of detection by a second ultrasonic assembly in a bonding quality detection method provided by an embodiment of the present application Figure 1 ; Figure 2 is a schematic diagram of detection by a second ultrasonic assembly in a bonding quality detection method provided by an embodiment of the present application Figure 6 ; Figure 7 is a schematic diagram of signals output by a second receiving member when there is no bonding defect and when there is a bonding defect in a bonding quality detection method provided by an embodiment of the present application; Figure 8 is a schematic diagram of a corresponding relationship between bonding stiffness and bonding strength prediction values in a bonding quality detection method provided by an embodiment of the present application; Figure 9 is a schematic diagram of signals output by a first receiving member when there is no bonding defect and when there is a bonding defect in a bonding quality detection method provided by an embodiment of the present application; Figure 10 is a schematic diagram of peak value changes of power spectra when there is no bonding defect and when there is a bonding defect in a bonding quality detection method provided by an embodiment of the present application; Figure 11 is a schematic diagram of a scanning imaging diagram provided by an embodiment of the present application; Figure 1 is a step flow chart of another bonding quality detection method provided by an embodiment of the present application.

[0019] Reference signs: 1 - first ultrasonic assembly, 11 - first transmitter, 12 - first receiver, 2 - second ultrasonic assembly, 21 - second transmitter, 22 - second receiver, 3 - scanning robot, 4 - bonded workpiece, 41 - first workpiece, 42 - bonding glue, 43 - second workpiece; R1 - detection point, R2 - detection section. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the various embodiments of the present application will be described in detail below with reference to the drawings. However, those of ordinary skill in the art can understand that, in the various embodiments of the present application, many technical details are presented in order to make the readers better understand the present application. However, the technical solutions claimed by the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the following embodiments is for the convenience of description and should not constitute any limitation on the specific implementation of the present application. The various embodiments can be combined and referenced to each other without contradiction.

[0021] In related technologies, the detection method of bonding quality is usually a destructive detection method. In this method, each detected bonded metal assembly needs to be physically disassembled, the relevant mechanical parameters are recorded during the disassembly process, and the bonding quality is evaluated according to the recorded mechanical parameters. The destructive detection method is limited by the detection principle and application scene, and has the disadvantages of non-reusable samples, strong sampling detection limitations, low detection efficiency, high comprehensive cost, poor adaptability to disassembly detection of complex structures, etc.

[0022] In order not to destroy each detected bonded metal assembly, in related technologies, a non-destructive ultrasonic detection method is usually used. However, the existing non-destructive detection method is not comprehensive in evaluating the bonding quality.

[0023] In addition, for the non-destructive detection method of phased array ultrasonic testing (PAUT, Phased Array Ultrasonic Testing), a coupling agent needs to be applied on the surface of the ultrasonic probe and the detected test piece to match the acoustic impedance difference between the probe and the detected test piece, which increases the risk of scratching or scratching the surface of the test piece during the rapid movement of the ultrasonic probe during detection, and the use of the coupling agent also introduces secondary pollution, which increases the complexity of the detection work. In addition, there are difficulties in coupling ultrasonic waves for quality detection and evaluation of the bonding interface of the curved structure.

[0024] To solve the above problems, the embodiments of the present application provide a bonding quality detection method and system, which will be described in detail below.

[0025] Referring to Figures 2 to 5 , a flow chart of steps of a bonding quality detection method provided by an embodiment of the application is shown, which is executed by a processing device in a bonding quality detection system.

[0026] Referring to Figure 3 , the bonding quality detection system comprises a first ultrasonic assembly 1 and a second ultrasonic assembly 2. The first ultrasonic assembly 1 comprises a first transmitting member 11 and a first receiving member 12 arranged oppositely along the thickness direction of a measured bonding piece 4. The second ultrasonic assembly 2 comprises a second transmitting member 21 and a second receiving member 22 located on the same side of the thickness direction of the measured bonding piece 4.

[0027] The measured bonding piece 4 is a three-layer structure, which comprises a first workpiece 41, a bonding glue 42 and a second workpiece 43. The materials of the first workpiece 41 and the second workpiece 43 are preferably metal, for example, the material of the first workpiece 41 is steel, aluminum, etc., and the material of the second workpiece 43 is steel, aluminum, etc. After the first workpiece 41 is bonded to the second workpiece 43 by the bonding glue 42, bonding defects may exist at the bonding position, such as air bubbles, air holes, debonding, weak bonding, etc. The bonding defects of air bubbles and air holes can refer to the air bubble defects and air hole defects in the bonding glue 42 in Figure 5 and Figure 2 . The bonding quality detection system is specifically used to detect the following defect detection parameters to determine whether the measured bonding piece 4 is well bonded or has bonding defects, and to determine the position of the bonding defects when there are bonding defects, and further determine the bonding strength prediction value to achieve a comprehensive evaluation of the bonding quality.

[0028] The first transmitting member 11 and the second transmitting member 21 are both ultrasonic transmitting probes, and the first receiving member 12 and the second receiving member 22 are both ultrasonic receiving probes. The second transmitting member 21 and the second receiving member 22 are arranged obliquely relative to the measured bonding piece 4. The ultrasonic transmitting probe is used to convert the same impedance and high-power electrical signals output by the ultrasonic excitation module into ultrasonic signals through a piezoelectric crystal by using the inverse piezoelectric effect. The ultrasonic receiving probe converts the ultrasonic signals into analog signals and outputs them by using the piezoelectric effect.

[0029] During the detection process, the first transmitting member 11 in the first ultrasonic assembly 1 is located on one side of the measured bonding piece 4, and the first receiving member 12 in the first ultrasonic assembly 1 is located on the other side of the measured bonding piece 4. For example, referring to Figure 3 and Figure 4 , during the detection process, the first transmitting member 11 in the first ultrasonic assembly 1 is located above the measured bonding piece 4, and the first receiving member 12 in the first ultrasonic assembly 1 is located below the measured bonding piece 4. During the detection process, the first transmitting member 11 in the first ultrasonic assembly 1 can also be located below the measured bonding piece 4, and the first receiving member 12 in the first ultrasonic assembly 1 is located above the measured bonding piece 4.

[0030] During the detection, the second transmitting member 21 and the second receiving member 22 in the second ultrasonic assembly 2 are located on one side of the measured adhesive 4. For example, referring to Figure 5 and Figure 1 , during the detection, the second transmitting member 21 and the second receiving member 22 in the second ultrasonic assembly 2 are both located above the measured adhesive 4. The second transmitting member 21 and the second receiving member 22 in the second ultrasonic assembly 2 can also be located below the measured adhesive 4. During the detection, the first ultrasonic assembly 1 and the second ultrasonic assembly 2 are non-contact with the measured adhesive 4.

[0031] Specifically, the adhesive quality detection system detects the adhesive quality of the measured adhesive 4 based on an air-coupled ultrasonic detection method. The air-coupled ultrasonic detection method has the characteristics of no need for a coupling agent, non-contact, and no damage to the measured adhesive 4. The principle of the air-coupled ultrasonic detection is that air is used as an ultrasonic propagation medium, an ultrasonic probe is used to emit ultrasonic waves to the measured adhesive 4, the reflection and transmission characteristics of ultrasonic waves at different medium interfaces are used to receive and analyze the echo signals, and the adhesive quality is comprehensively evaluated. In addition, in this method, the arrangement form of the ultrasonic probe is flexible, and different types of ultrasonic waves, such as longitudinal waves, Lamb waves, and surface waves, can be excited by changing the inclination angle of the ultrasonic probe and the surface of the measured adhesive 4.

[0032] Referring to Figure 2 , the adhesive quality detection method comprises: S101, determining defect detection parameters of each detection point according to the first ultrasonic signals corresponding to each detection point of the measured adhesive.

[0033] The measured adhesive 4 has m detection points R1 arranged in an array, and the measured adhesive 4 also has n detection segments R2, m is greater than n, preferably each detection segment R2 covers v detection points R1, m = n x v, and v is greater than 2. In other embodiments, the number of detection points R1 covered by each detection segment R2 can be different. The shape of the detection point R1 can be square, and the detection segment R2 is a straight line segment. The detection point R1 is detected by the first ultrasonic assembly 1, and the detection segment R2 is detected by the second ultrasonic assembly 2. In order to improve the detection accuracy and resolution, the ultrasonic beam is converged to the position of the detection point R1, and the ultrasonic assembly uses a point focusing probe with a center frequency f0 of 500 kHz-2 MHz and a focal length of 20-30 mm. When detected by the second ultrasonic assembly 2, the second transmitting member 21 and the second receiving member 22 correspond to the two end points of the detection segment R2, respectively.

[0034] The bonding quality detection system further comprises a scanning robot 3, the first ultrasonic assembly 1 is installed on the scanning robot 3 during detection by the first ultrasonic assembly 1, and the scanning robot 3 drives the first ultrasonic assembly 1 to move along a set scanning path, so as to detect each detection point R1.

[0035] The bonding quality detection system further comprises an analog-digital conversion module. The first ultrasonic signal is a digital signal. Referring to Figure 3 and Figure 4 When the first ultrasonic assembly 1 detects one of the detection points R1, the first transmitting member 11 emits ultrasonic waves, the ultrasonic waves pass through air, the measured bonding member 4 and air in sequence and are received by the first receiving member 12, the first receiving member 12 outputs a first analog signal after receiving the ultrasonic waves, the first analog signal is first subjected to optimization processing, and then is converted into a first digital signal by the analog-digital conversion module, and the first digital signal is processed to obtain the first ultrasonic signal.

[0036] The first digital signal can be obtained by coarse noise reduction processing, and the coarse noise reduction processing can include digital band-pass filtering, wavelet transform and the like. For detection of one detection point R1, the first transmitting member 11 can emit ultrasonic waves once or multiple times, and when the ultrasonic waves are emitted multiple times, multiple first digital signals will be obtained. The multiple first digital signals are subjected to point-to-point averaging processing to integrate into a comprehensive digital signal, and then the comprehensive digital signal is processed to obtain the first ultrasonic signal.

[0037] After detection of the current detection point R1 is completed, the scanning robot 3 drives the first ultrasonic assembly 1 to move to the next detection point R1 for continuous detection. At the next detection point R1, the first receiving member 12 outputs an analog signal after receiving ultrasonic waves, and the analog signal is processed to obtain a first ultrasonic signal. That is, the first ultrasonic signal corresponds to the detection point R1.

[0038] The transmittance of the ultrasonic waves is different due to the difference in bonding quality when the ultrasonic waves penetrate the measured bonding member 4. For a well-bonded area, the transmittance of the ultrasonic waves is high, and for an area with bonding defects, the transmittance of the ultrasonic waves is significantly reduced. Therefore, the defect detection parameter of the detection point R1 can be determined according to the first ultrasonic signal. The defect detection parameter is a parameter for judging whether each detection point R1 has a bonding defect, and the defect detection parameter can include a power spectrum peak value, a maximum amplitude and the like. If all the detection points R1 do not have bonding defects, it indicates that the measured bonding member 4 is well bonded. If some of the detection points R1 have bonding defects, it indicates that the measured bonding member 4 has bonding defects.

[0039] S102, determining a bonding strength prediction value of at least part of the detection section corresponding to the second ultrasonic signal of the measured bonding member.

[0040] When the second ultrasonic assembly 2 is in use, the second ultrasonic assembly 2 is installed on the scanning robot 3, and the scanning robot 3 drives the second ultrasonic assembly 2 to move along a set scanning path, so as to detect at least part of the detection section R2. The second ultrasonic signal is a digital signal. When the second ultrasonic assembly 2 is in use, the ultrasonic wave emitted by the second emitting member 21 is a surface wave or a Lamb wave.

[0041] With reference to Figure 5 and Figure 6 When the second ultrasonic assembly 2 detects one of the detection sections R2, the second emitting member 21 emits an ultrasonic wave, which passes through air, the first workpiece 41 in the measured adhesive member 4, and air in sequence and is received by the second receiving member 22. The second receiving member 22 outputs a second analog signal after receiving the ultrasonic wave. The second analog signal is first subjected to optimization processing, and then converted into a second digital signal by an analog-to-digital conversion module. The second digital signal is processed to obtain a second ultrasonic signal.

[0042] The second digital signal can be obtained by coarse noise reduction processing, which can include digital band-pass filtering, wavelet transform, etc. For the detection of one detection section R2, the second emitting member 21 can emit an ultrasonic wave once or multiple times. When the ultrasonic wave is emitted multiple times, multiple second digital signals will be obtained. The multiple second digital signals are subjected to point-to-point averaging processing to integrate into a comprehensive digital signal. Then, the comprehensive digital signal is processed to obtain a second ultrasonic signal.

[0043] After the detection of the current detection section R2 is completed, the scanning robot 3 drives the second ultrasonic assembly 2 to move to the next detection section R2 for continuous detection. At the next detection section R2, the second receiving member 22 outputs a second analog signal after receiving an ultrasonic wave. The second analog signal is processed to obtain a second ultrasonic signal. That is, the second ultrasonic signal corresponds to the detection section R2. The adhesive strength prediction value is the adhesive strength of the detection section R2 predicted according to the second ultrasonic signal and other parameters. The other parameters can include a reference wave speed, a center frequency f0, a propagation distance, material geometric parameters of the measured adhesive member 4, etc.

[0044] In the embodiments of the present application, the defect detection parameters of each detection point R1 can be determined according to the first ultrasonic signal, so as to determine whether the measured bonding member 4 is well bonded or has bonding defects, and to determine the position of the bonding defects when the bonding defects exist. The bonding strength prediction value of at least part of the detection section R2 can be determined according to the second ultrasonic signal, so as to realize comprehensive evaluation of the bonding quality. In addition, the bonding quality detection system detects the bonding quality of the measured bonding member 4 based on the air-coupled ultrasonic detection method. The air-coupled ultrasonic detection method has the characteristics of no need of coupling agent, non-contact, and no damage to the measured bonding member 4, can avoid the reuse of the measured bonding member 4 due to damage, and can improve the detection efficiency and reduce the comprehensive cost. At the same time, the air-coupled ultrasonic detection method can also avoid the secondary pollution and other damage risks caused by the contact detection.

[0045] In some embodiments, after determining the defect detection parameters of each detection point according to the first ultrasonic signal corresponding to each detection point of the measured bonding member, the method further comprises: determining whether there is an abnormal detection point according to the defect detection parameters of each detection point. Determining the bonding strength prediction value of at least part of the detection section of the measured bonding member according to the second ultrasonic signal corresponding to the at least part of the detection section of the measured bonding member comprises: if there is an abnormal detection point, determining a target detection section corresponding to the abnormal detection point; and determining the bonding strength prediction value of the target detection section according to the second ultrasonic signal corresponding to the target detection section.

[0046] In some embodiments, determining whether there is an abnormal detection point according to the defect detection parameters of each detection point comprises: determining whether the defect detection parameters of each detection point R1 are in an abnormal value range; the detection point R1 whose defect detection parameters are in the abnormal value range is an abnormal detection point, and the detection point R1 whose defect detection parameters are not in the abnormal value range is a normal detection point.

[0047] Under the same detection condition, the normal range of the defect detection parameters of a plurality of well-bonded regions and the abnormal range of the defect detection parameters of different bonding defect regions are calibrated in advance. The abnormal value range can be obtained by combining the abnormal ranges of the defect detection parameters of different bonding defect regions. If the defect detection parameters of the detection point R1 are in the abnormal value range, it indicates that the detection point R1 is an abnormal detection point, and there is a bonding defect at the detection point R1.

[0048] The measured adhesive 4 has m detection points R1 arranged in an array, and the measured adhesive 4 also has n detection sections R2, m is greater than n, preferably each detection section R2 covers v detection points R1, m = n x v, v is greater than 2, and therefore v detection points R1 correspond to one detection section R2. When determining the target detection section corresponding to the abnormal detection point, if several abnormal detection points correspond to the same target detection section, then the adhesive strength prediction value is calculated only once for the target detection section.

[0049] In this embodiment, for the case where there is an abnormal detection point, only the adhesive strength prediction value of the corresponding target detection section needs to be calculated, and since other detection points do not have adhesive defects, the adhesive strength prediction value does not need to be calculated, which can greatly reduce the calculation amount and improve the test efficiency.

[0050] In some embodiments, if there is no abnormal detection point, the detection point with the defect detection parameter in the normal low value range is taken as the specified detection point, and the specified detection section corresponding to the specified detection point is determined, and then the adhesive strength prediction value of the specified detection section is determined according to the second ultrasonic signal corresponding to the specified detection section.

[0051] Based on the same detection condition, the normal ranges of the defect detection parameters of multiple well-bonded areas are calibrated in advance, the multiple normal ranges are combined to obtain a normal numerical range, and the normal numerical range can be divided into multiple sections, and the section with the smallest numerical value is taken as the normal low value range. For example, the normal numerical range is divided into four sections, and the section with the smallest numerical value is taken as the normal low value range. In this embodiment, for the case where there is no abnormal detection point, i.e., the case where the overall bonding is good, only the adhesive strength prediction value of the specified detection section corresponding to the specified detection point needs to be calculated, which can greatly reduce the calculation amount.

[0052] In some embodiments, if there is no abnormal detection point, the adhesive strength prediction value of each detection section is determined according to the second ultrasonic signal corresponding to each detection section of the measured adhesive. In this embodiment, the adhesive strength prediction values of all detection sections on the measured adhesive 4 can be determined, and the evaluation of the bonding quality is more comprehensive.

[0053] In some embodiments, the adhesive strength prediction value of at least part of the detection sections of the measured adhesive is determined according to the second ultrasonic signal corresponding to the at least part of the detection sections, including: determining the attenuation coefficient and the dispersion phase offset according to the second ultrasonic signal corresponding to the at least part of the detection sections of the measured adhesive; calling the reference wave velocity, the center frequency, the propagation distance, and the material and geometric parameters of the measured adhesive; determining the equivalent stiffness of the at least part of the detection sections according to the reference wave velocity, the center frequency, the propagation distance, the dispersion phase offset, the attenuation coefficient, and the material and geometric parameters of the measured adhesive; The bonding strength prediction value of the at least partial detection section is determined according to the equivalent stiffness of the at least partial detection section.

[0054] When the second ultrasonic assembly 2 is located on one side of the measured bonding member 4, for example, when the second ultrasonic assembly 2 is located above the measured bonding member 4, the distance between the first workpiece 41 and the second ultrasonic assembly 2 is smaller than the distance between the second workpiece 43 and the second ultrasonic assembly 2, that is, the first workpiece 41 is closer to the second ultrasonic assembly 2. The material geometric parameters of the measured bonding member 4 include the density of the first workpiece 41, the thickness of the first workpiece 41, the thickness of the bonding glue 42, the bonding area, and the shear modulus of the bonding glue 42.

[0055] The reference wave velocity, the center frequency, the propagation distance, and the material geometric parameters of the measured bonding member 4 are parameters determined and stored in advance and can be directly called when used. The second ultrasonic signal is subjected to frequency domain analysis to obtain an amplitude spectrum and a phase spectrum, and the attenuation coefficient and the dispersion phase offset can be determined based on the amplitude spectrum and the phase spectrum. The attenuation coefficient can be specifically the attenuation coefficient a(f0) at the center frequency f0. The dispersion phase offset refers to the difference between the phase spectrum obtained according to the actual received signal and the theoretical phase spectrum at the same frequency point, and the dispersion phase offset can be specifically the dispersion phase offset Δφ(f0) at the center frequency f0.

[0056] The equivalent stiffness of the at least partial detection section is determined according to the reference wave velocity, the center frequency, the propagation distance, the dispersion phase offset, the attenuation coefficient, and the material geometric parameters of the measured bonding member, which can include: correcting the reference wave velocity according to the dispersion phase offset, the center frequency, and the propagation distance to obtain a corrected wave velocity; determining a corrected shear modulus according to the shear modulus of the bonding glue, the attenuation coefficient, and the thickness of the bonding glue; determining a normal stiffness according to the density of the first workpiece, the corrected wave velocity, the bonding area, and the thickness of the first workpiece; determining a shear stiffness according to the corrected shear modulus, the bonding area, and the thickness of the bonding glue, and determining the equivalent stiffness of the at least partial detection section according to the normal stiffness and the shear stiffness. In this embodiment, the equivalent stiffness is determined based on multiple parameters and a correction manner, and then the bonding strength prediction value is determined, and the accuracy of the determined bonding strength prediction value is higher.

[0057] Correspondingly, the bonding strength prediction value of the target detection section is determined according to the second ultrasonic signal corresponding to the target detection section of the measured bonding member, which includes: determining the attenuation coefficient and the dispersion phase offset according to the second ultrasonic signal corresponding to the target detection section of the measured bonding member; calling the reference wave velocity, the center frequency, the propagation distance, and the material geometric parameters of the measured bonding member; determining the equivalent stiffness of the target detection section according to the reference wave velocity, the center frequency, the propagation distance, the dispersion phase offset, the attenuation coefficient, and the material geometric parameters of the measured bonding member; and determining the bonding strength prediction value of the at least partial detection section according to the equivalent stiffness of the target detection section.

[0058] Specifically, the calculation formula of the equivalent stiffness is: K_eq = (Equation 1) K n = ρc²A / h (Equation 2) K t = G a A / t (Equation 3) c=c0× [1 - (Δφ(f0)·c0) / (2πf0d)] (Equation 4) G a = G a0 × exp[-α(f0)·t] (Equation 5) wherein K_eq is the equivalent stiffness, K n is the normal stiffness, K t is the shear stiffness, ρ is the density of the first workpiece 41, c is the corrected wave speed, A is the bonding area, h is the thickness of the first workpiece 41, G a is the corrected shear modulus, t is the thickness of the bonding glue 42, c0 is the reference wave speed, Δφ(f0) is the dispersion phase shift at the center frequency f0, f0 is the center frequency, d is the propagation distance, G a0 is the shear modulus of the bonding glue 42, and α(f0) is the attenuation coefficient at the center frequency f0.

[0059] The calculation formula of the normal stiffness K n and the shear stiffness can be established based on the adhesive rheological model. exp is the exponential function. The units of K_eq, K n , and G a may be N / m, the unit of α(f0) may be Np / m, the unit of A may be m², the unit of ρ may be kg / m³, and the unit of h may be m.

[0060] α(f0) (Equation 6) d is the propagation distance, specifically the horizontal propagation distance of the Lamb wave based on the detection of the second ultrasonic assembly 2. The propagation distance can be set by the scanning parameters, and the motion of the ultrasonic assembly is controlled according to the scanning parameters when the scanning robot 3 is running. The scanning parameters can include the moving step, the dwell time of a single detection point R1 or a detection section R2, the propagation distance based on the detection of the second ultrasonic assembly 2, etc. is the amplitude spectrum of the second ultrasonic signal at the center frequency f0, is the amplitude spectrum of the reference signal at the center frequency f0. The reference signal is specifically the amplitude spectrum of the received signal at the center frequency f0 measured in a well-bonded area under the same detection conditions. is a predetermined and stored parameter.

[0061] Δφ(f0) = φ_exp(f0) - φ_theory(f0) (Equation 7) φ_exp(f0) is the phase spectrum of the second ultrasonic signal at the center frequency f0. The second ultrasonic signal is subjected to Fourier transform to obtain the phase spectrum φ_exp(f0) of the second ultrasonic signal at the center frequency f0. φ_theory(f0) is the theoretical phase spectrum at the center frequency f0, which is calculated based on ideal material parameters (thickness, density, elastic constant, etc.) and Lamb wave theory. φ_theory(f0) is a predetermined and stored parameter. The reference wave velocity c0 is the value of the theoretical phase velocity c_theory(f0) at the center frequency f0. Referring to Figure 7 Compared with the case without bonding defects, the time domain signal will show nonlinearly changing dispersion when there are bonding defects.

[0062] In some embodiments, when the equivalent stiffness is less than or equal to the critical stiffness, the calculation formula of the bonding strength prediction value is: σ_strength = σ_max × [1-exp(-K_eq / K_ref)] (Equation 8) Wherein, σ_strength is the bonding strength prediction value, σ_max is the theoretical maximum bonding strength under the destruction experiment, K_eq is the equivalent stiffness, and K_ref is the reference stiffness under the destruction experiment. The units of σ_strength and σ_max are MPa, and σ_max can be obtained by statistical analysis of a plurality of ideal bonding samples through a standard bonding destruction experiment. K_ref refers to the equivalent stiffness value corresponding to σ_max, which can be obtained by ultrasonic detection of ideal bonding samples. The relationship between the bonding strength prediction value and the equivalent stiffness can be referred to Figure 11 When the equivalent stiffness is greater than the critical stiffness, the bonding strength prediction value can be taken as the value corresponding to the critical stiffness. The critical stiffness can be K_ref.

[0063] In this embodiment, the relationship between the equivalent stiffness and the bonding strength prediction value is determined based on the theoretical maximum bonding strength measured under the destruction experiment and the reference stiffness, and the accuracy of the determined bonding strength prediction value is high.

[0064] In some embodiments, referring to Figure 10 The bonding quality detection method further includes: S103, generating a scanning imaging map according to the defect detection parameters of each detection point, and outputting the scanning imaging map.

[0065] The scan imaging diagram is a C-scan imaging diagram, the horizontal and vertical coordinates of the scan imaging diagram are consistent with the coordinates of the detection points R1 when the measured bonding member 4 is detected, and the scan imaging diagram can be imaged 1:1. The scan imaging diagram has m pixel points, and the m pixel points correspond to the m detection points R1 one by one. When the scan imaging diagram is generated, different ranges of defect detection parameters can be corresponded to different colors, and the different ranges at least include the normal value range and the abnormal value range, or the normal value range and the abnormal value range can be divided into multiple small range. The range of the defect detection parameter of the detection point R1 is different, and the color of the corresponding pixel point of the scan imaging diagram is different. Referring to Figure 8 , based on the color difference, whether there is a bonding defect and the position of the bonding defect can be observed on the scan imaging diagram.

[0066] When the scan imaging diagram is generated, a deep learning model such as convolutional auto-encoding, U-net (U-shaped network) network can be used to optimize the edge information and position information around the imaging diagram more finely, and clear defect imaging can be realized.

[0067] In some embodiments, the scan imaging diagram is generated according to the defect detection parameters of each detection point, and the scan imaging diagram is output, including: generating a scan imaging diagram according to the defect detection parameters of each detection point; associating the scan imaging diagram with the bonding strength prediction value of at least part of the detection section; outputting the scan imaging diagram.

[0068] Wherein, the measured bonding member 4 has n detection sections R2, each detection section R2 covers v detection points R1, the scan imaging diagram has n pixel sections, each pixel section covers v pixel points, and the plurality of pixel points correspond to the plurality of detection points R1 one by one. The bonding strength prediction value of one detection section R2 is associated with the corresponding one pixel section. Specifically, the scan imaging diagram has m pixel points, and the m pixel points correspond to the m detection points R1 one by one. After associating the scan imaging diagram with the bonding strength prediction value of at least part of the detection section R2, the interactive display function can be realized on the output scan imaging diagram, for example, when the mouse hovers over any position on the image, the corresponding bonding strength prediction value can be displayed through the data tag. In this embodiment, the scan imaging diagram is associated with the bonding strength prediction value of at least part of the detection section R2, so that the bonding strength prediction value of the corresponding position can be intuitively observed on the scan imaging diagram.

[0069] In some embodiments, the defect detection parameters include power spectrum peak value and / or maximum amplitude; According to the first ultrasonic signals corresponding to the detection points of the measured adhesive joint, the defect detection parameters of the detection points are determined, including: determining the power spectrum peak value and / or the maximum amplitude of each detection point according to the first ultrasonic signals corresponding to the detection points of the measured adhesive joint; According to the defect detection parameters of each detection point, a scanning imaging map is generated and output, including: generating a first scanning imaging map according to the power spectrum peak value of each detection point, and / or generating a second scanning imaging map according to the maximum amplitude of each detection point, and outputting the first scanning imaging map and / or the second scanning imaging map.

[0070] The maximum amplitude refers to the maximum value of each amplitude of the first ultrasonic signal on the time axis. For reference Figure 9 Compared with no adhesive defects, the maximum amplitude will be greatly reduced when there are adhesive defects. The defect detection parameter is preferably only the power spectrum peak value, at which time the above normal value range and abnormal value range correspond to the range of the power spectrum peak value, and the output is the first scanning imaging map.

[0071] The calculation formula of the power spectrum is: (Formula 9) Wherein, k refers to the signal segmentation number, refers to the power spectrum of the first k segment signal at the frequency , and the unit is mV², refers to the frequency domain complex value obtained by performing fast Fourier transform on the first k segment ultrasonic signal, L refers to the signal segmentation length, which is usually selected as a power of 2, which is convenient for fast Fourier calculation and ensures the stability of frequency resolution. The power spectrum peak value refers to the maximum value reached by the power spectrum within a preset frequency band near the center frequency. For reference Figures 2 to 5 Compared with no adhesive defects, the power spectrum peak value will be greatly reduced when there are adhesive defects, and the frequency corresponding to the power spectrum peak value is different, that is, there is a certain frequency shift.

[0072] In another embodiment provided in the present application, a bonding quality detection system is also provided, referring to Figure 2 , the bonding quality detection system comprises a first ultrasonic assembly 1 and a second ultrasonic assembly 2, the first ultrasonic assembly 1 comprises a first transmitting member 11 and a first receiving member 12 arranged oppositely along the thickness direction of the measured adhesive joint 4, and the second ultrasonic assembly 2 comprises a second transmitting member 21 and a second receiving member 22 located on the same side of the thickness direction of the measured adhesive joint 4; the bonding quality detection system further comprises a processing device, which is used to execute the bonding quality detection method as above.

[0073] The measured adhesive 4 is a three-layer structure, and the measured adhesive 4 includes a first workpiece 41, an adhesive 42, and a second workpiece 43. The materials of the first workpiece 41 and the second workpiece 43 are preferably metal, for example, the material of the first workpiece 41 is steel, aluminum, etc., and the material of the second workpiece 43 is steel, aluminum, etc. After the first workpiece 41 is bonded to the second workpiece 43 by the adhesive 42, bonding defects such as air bubbles, pores, debonding, and weak bonding may exist at the bonding site. The bonding quality detection system is specifically used to detect defect detection parameters to determine whether the measured adhesive 4 is well bonded or has bonding defects, and to determine the location of the bonding defects when the bonding defects exist, and further determine the bonding strength prediction value, so as to realize comprehensive evaluation of the bonding quality.

[0074] During the detection process, the first emitting member 11 in the first ultrasonic assembly 1 is located on one side of the measured adhesive 4, and the first receiving member 12 in the first ultrasonic assembly 1 is located on the other side of the measured adhesive 4. For example, referring to Figure 3 and Figure 4 During the detection process, the first emitting member 11 in the first ultrasonic assembly 1 is located above the measured adhesive 4, and the first receiving member 12 in the first ultrasonic assembly 1 is located below the measured adhesive 4. During the detection process, the first emitting member 11 in the first ultrasonic assembly 1 can also be located below the measured adhesive 4, and the first receiving member 12 in the first ultrasonic assembly 1 is located above the measured adhesive 4.

[0075] During the detection process, the second emitting member 21 and the second receiving member 22 in the second ultrasonic assembly 2 are located on one side of the measured adhesive 4. For example, referring to Figure 5 and ​ During the detection process, the second emitting member 21 and the second receiving member 22 in the second ultrasonic assembly 2 are both located above the measured adhesive 4. The second emitting member 21 and the second receiving member 22 in the second ultrasonic assembly 2 can also be located below the measured adhesive 4. During the detection process, the first ultrasonic assembly 1 and the second ultrasonic assembly 2 are non-contact with the measured adhesive 4.

[0076] Specifically, the bonding quality detection system detects the bonding quality of the measured adhesive 4 based on an air-coupled ultrasonic detection method. The air-coupled ultrasonic detection method has the advantages of no need for coupling agent, non-contact, and no damage to the measured adhesive 4. The principle of air-coupled ultrasonic detection is that air is used as the ultrasonic transmission medium, ultrasonic waves are emitted to the measured adhesive 4 by an ultrasonic probe, the reflection and transmission characteristics of ultrasonic waves at different medium interfaces are used to receive and analyze the echo signals, and the bonding quality is comprehensively evaluated. In addition, in this method, the arrangement form of the ultrasonic probe is flexible, and different types of ultrasonic waves such as longitudinal waves, Lamb waves, and surface waves can be excited by changing the inclination angle of the ultrasonic probe and the surface of the measured adhesive 4.

[0077] The bonding quality detection system further comprises an ultrasonic excitation module, which comprises a signal generation unit, a power amplification unit, an impedance matching unit and the like. The signal generation unit is used to generate an electrical signal with a specific frequency, pulse width and repetition frequency as a source signal for exciting the piezoelectric element of the ultrasonic transmitting probe. The power amplification unit is used to power amplify the electrical signal. The impedance matching unit is used to match the source signal with the input impedance of the ultrasonic transmitting probe. The ultrasonic transmitting probe is used to convert the electrical signal with the same impedance and high power output by the ultrasonic excitation module into an ultrasonic signal through a piezoelectric crystal by means of the inverse piezoelectric effect. The ultrasonic receiving probe converts the ultrasonic signal into an analog signal by means of the piezoelectric effect and outputs the analog signal.

[0078] The first receiving member 12 and the second receiving member 22 both output analog signals. The bonding quality detection system further comprises a signal conditioning and optimization module, which comprises a preamplifier unit, a gated amplifier unit, an ultrasonic signal band-pass filter unit and a weak signal transmission line. The main function of the signal conditioning and optimization module is to optimize and condition the analog signals output by the first receiving member 12 and the second receiving member 22, so as to facilitate subsequent data acquisition and analysis and improve the signal-to-noise ratio of the signals. Since the original electrical signal output by the ultrasonic receiving probe is usually weak, contains noise and is easily affected by electromagnetic interference after the ultrasonic wave is strongly attenuated by air coupling, the weak signal transmission line is used to strengthen the shielding of the surrounding strong electromagnetic interference, and then the preamplifier and the gated amplifier are connected to enhance the available signal, and then the ultrasonic signal band-pass filter unit is used to remove the noise signal interference of the environment. The bonding quality detection system further comprises an analog-to-digital conversion module, which is used to convert the optimized analog signal into a digital signal.

[0079] The processing device can comprise a processing module and a main control module, or can only comprise one large integrated module. The processing device is electrically connected to the analog-to-digital conversion module to receive the converted digital signal and perform software processing on the digital signal. After processing, a first ultrasonic signal or a second ultrasonic signal is obtained. Then, the defect detection parameters are determined according to the first ultrasonic signal, and the bonding strength prediction value is determined according to the second ultrasonic signal.

[0080] The main control module can comprise an industrial-grade processor, a peripheral interface unit, a power management unit, a software logic unit and the like. The main control module can be used to coordinate the collaborative work of various sub-modules, realize the automation and intelligentization of the detection process, and can realize functions such as system initialization and parameter configuration, automatic control of the detection process, real-time monitoring of the state of each module, data interaction and integration, and human-computer interaction response. The main control module physically connects each sub-module through hardware and logically controls each sub-module through software, which not only ensures the efficiency and accuracy of the detection process, but also reduces the risk of failure through real-time monitoring. The bonding quality detection system further comprises a scanning robot 3, when the first ultrasonic assembly 1 is detected, the first ultrasonic assembly 1 is installed on the scanning robot 3, the scanning robot 3 drives the first ultrasonic assembly 1 to move along the set scanning path, so as to detect each detection point R1. When the second ultrasonic assembly 2 is detected, the second ultrasonic assembly 2 is installed on the scanning robot 3, the scanning robot 3 drives the second ultrasonic assembly 2 to move along the set scanning path, so as to detect at least part of the detection section R2.

[0081] The scanning robot 3 can include a robot movement unit, a path control unit, a mechanical arm, etc., the mechanical arm is used to be connected with the first ultrasonic assembly 1 or the second ultrasonic assembly 2, the mechanical arm uses various posture sensors to ensure high-precision operation, the path control unit is responsible for connecting the main control module and the robot movement unit module, and is responsible for instruction analysis, generating a scanning path and control movement logic, so as to ensure that the scanning robot 3 can complete the coverage of the whole detection area according to the preset logic. Through the setting of the scanning robot 3, manual scanning can be replaced, and the consistency of repetitive work can be ensured.

[0082] It should be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0083] Each of the embodiments in the present specification is described in a related manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment mainly explains the difference from other embodiments. Especially, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the related parts can be referred to the part of the method embodiment.

[0084] The above only describes the preferred embodiments of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for testing bonding quality, characterized in that, include: Based on the first ultrasonic signal corresponding to each detection point of the bond under test, the defect detection parameters of each detection point are determined; wherein, the first ultrasonic signal is obtained by processing the signal output by the first receiver in the first ultrasonic component, and the first transmitter and the first receiver in the first ultrasonic component are arranged opposite to each other along the thickness direction of the bond under test. Based on a second ultrasonic signal corresponding to at least a portion of the test segment of the bonded component under test, a predicted bond strength value for at least a portion of the test segment is determined; wherein the second ultrasonic signal is obtained by processing a signal output from a second receiver in a second ultrasonic component, and the second transmitter and the second receiver in the second ultrasonic component are located on the same side of the thickness direction of the bonded component under test.

2. The bonding quality testing method according to claim 1, characterized in that, After determining the defect detection parameters for each detection point based on the first ultrasonic signal corresponding to each detection point of the bonded component under test, the method further includes: Determine whether there are any abnormal detection points based on the defect detection parameters of each detection point; Determining the predicted bond strength value of at least a portion of the tested segments based on the second ultrasonic signal corresponding to at least a portion of the tested adhesive segment includes: If the abnormal detection point exists, then the target detection segment corresponding to the abnormal detection point is determined; The predicted bond strength of the target detection segment is determined based on the second ultrasonic signal corresponding to the target detection segment.

3. The bonding quality testing method according to claim 1, characterized in that, Determining the predicted bond strength value of at least a portion of the tested segments based on the second ultrasonic signal corresponding to at least a portion of the tested adhesive segment includes: The attenuation coefficient and dispersive phase shift are determined based on the second ultrasonic signal corresponding to at least a portion of the detection segment of the bond under test; Call the reference wave velocity, center frequency, propagation distance, and material geometry parameters of the bond under test; The equivalent stiffness of at least a portion of the test segment is determined based on the reference wave velocity, the center frequency, the propagation distance, the dispersive phase shift, the attenuation coefficient, and the material geometry parameters of the bond under test. The predicted bond strength of at least a portion of the test segments is determined based on the equivalent stiffness of at least a portion of the test segments. The tested adhesive component includes a first workpiece, an adhesive, and a second workpiece. When the second ultrasonic component is located on one side of the tested adhesive component, the distance between the first workpiece and the second ultrasonic component is less than the distance between the second workpiece and the second ultrasonic component. The material geometry parameters of the tested adhesive include the density of the first workpiece, the thickness of the first workpiece, the thickness of the adhesive, the bonding area, and the shear modulus of the adhesive.

4. The bonding quality testing method according to claim 3, characterized in that, The step of determining the equivalent stiffness of at least a portion of the test segment based on the reference wave velocity, the center frequency, the propagation distance, the dispersive phase shift, the attenuation coefficient, and the material geometric parameters of the bonded component under test includes: The reference wave velocity is corrected based on the dispersive phase shift, the center frequency, and the propagation distance to obtain the corrected wave velocity; The modified shear modulus is determined based on the shear modulus of the adhesive, the attenuation coefficient, and the thickness of the adhesive. The normal stiffness is determined based on the density of the first workpiece, the corrected wave velocity, the bonding area, and the thickness of the first workpiece. The shear stiffness is determined based on the modified shear modulus, the bonding area, and the thickness of the adhesive. The equivalent stiffness of at least a portion of the detection segment is determined based on the normal stiffness and the shear stiffness.

5. The bonding quality testing method according to claim 4, characterized in that, The formula for calculating the equivalent stiffness is: K_eq = ; K n = ρc²A / h; K t = G a A / t; c=c0 × [1 - (Δφ(f0)·c0) / (2πf0d)]; G a = G a0 × exp[-α(f0)·t]; Where K_eq is the equivalent stiffness, K n For normal stiffness, K t Let ρ be the shear stiffness, ρ be the density of the first workpiece, c be the corrected wave velocity, A be the bonding area, h be the thickness of the first workpiece, and G be the shear stiffness. a To correct for the shear modulus, t is the adhesive thickness, c0 is the reference wave velocity, Δφ(f0) is the dispersive phase shift at the center frequency f0, f0 is the center frequency, d is the propagation distance, and G... a0 Let f(f0) be the shear modulus of the adhesive, and α(f0) be the attenuation coefficient at the center frequency f0.

6. The bonding quality testing method according to any one of claims 3 to 5, characterized in that, When the equivalent stiffness is less than or equal to the critical stiffness, the formula for calculating the predicted bond strength is as follows: σ_strength = σ_max × [1-exp(-K_eq / K_ref)]; Where σ_strength is the predicted bond strength, σ_max is the theoretical maximum bond strength under the failure test, K_eq is the equivalent stiffness, and K_ref is the reference stiffness under the failure test.

7. The bonding quality testing method according to claim 1, characterized in that, The bonding quality testing method further includes: A scanning image is generated based on the defect detection parameters of each detection point, and the scanning image is output.

8. The bonding quality testing method according to claim 7, characterized in that, Generate and output scanned images based on the defect detection parameters of each detection point, including: A scanning image is generated based on the defect detection parameters of each detection point; The scanned image is correlated with the predicted bond strength of at least a portion of the detected segment; The tested adhesive has n detection segments, each detection segment covers v detection points, the scanned image has n pixel segments, each pixel segment covers v pixels, and multiple pixels correspond one-to-one with multiple detection points. The predicted adhesive strength value of a detection segment is associated with a corresponding pixel segment. Output the scanned image.

9. The bonding quality testing method according to claim 7, characterized in that, The defect detection parameters include the power spectrum peak value and / or the maximum amplitude value; Based on the first ultrasonic signal corresponding to each detection point of the bonded component under test, the defect detection parameters for each detection point are determined, including: Based on the first ultrasonic signal corresponding to each detection point of the bonded component under test, determine the peak power spectrum and / or maximum amplitude of each detection point; The step of generating and outputting a scanned image based on the defect detection parameters of each detection point includes: A first scan image is generated based on the power spectrum peak value of each of the detection points, and / or a second scan image is generated based on the maximum amplitude of each of the detection points, and the first scan image and / or the second scan image are output.

10. A bonding quality inspection system, characterized in that, It includes a first ultrasonic component and a second ultrasonic component. The first ultrasonic component includes a first transmitter and a first receiver disposed opposite to each other along the thickness direction of the adhesive being tested. The second ultrasonic component includes a second transmitter and a second receiver located on the same side of the thickness direction of the adhesive being tested. The bonding quality inspection system further includes a processing device for performing the bonding quality inspection method as described in any one of claims 1 to 9.

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