Quality inspection of micro solder joints in laser spot welding by laser ultrasonic method

Ding, Lei; Lu, Qiangbing; Liu, Shiyuan; Xu, Rui; Yan, Xuejun; Xu, Xiaodong; Lu, Minghui; Chen, Yanfeng

doi:10.1016/j.ultras.2021.106567

Cited by 11 publications

(3 citation statements)

References 25 publications

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“…If the failure form of the fillet weld connection and the stress distribution of the weld section are more complex, it is assumed that the shear failure occurs along the plane of the angle line of the weld with less strength and the shear stress is evenly distributed along the length of the weld [9][10][11] .…”

Section: Strength and Permissible Stress Of The Weldmentioning

confidence: 99%

Simulation and Analysis of Welding Spot Failure of PCB Based on ABAQUS

Ma,

Tong,

Liu

et al. 2023

J. Phys.: Conf. Ser.

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In the manufacturing process, the welding spot of PCB may lose efficacy because of the strain and stress impact. The reason for the occurrence of high-stress zones is the effect of the load brought by the manufacturing and assembly process. It is a giant challenge for the industry community to solve the problem of welding spots losing efficacy. In this paper, the manufacturing techniques and assembly process will be analyzed first. With the analysis result, the main impact of load would be checked. Then, with the confirmed allowable stress by calculation, the value of input stress, which may cause the welding spot to lose efficacy, would be obtained. Finally, the result of this study would be confirmed by the simulation result generated by the finite element analysis software.

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Section: Strength and Permissible Stress Of The Weldmentioning

confidence: 99%

Simulation and Analysis of Welding Spot Failure of PCB Based on ABAQUS

Ma,

Tong,

Liu

et al. 2023

J. Phys.: Conf. Ser.

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show abstract

“…Firstly, morphological operations (including one opening operation and one closing operation) are used to eliminate small bright (dark) points outside the light spot in the image; Then the maximum between-class variance is used to determine the segmentation threshold of the image, and all the points in the image that are less than the threshold are set to 0, and other points are used as the components of the spot, keeping the original gray value. Finally, the center position of the spot is calculated by the algorithm in this paper, the center of gravity method and Hough transform method [7].…”

Section: Figure1 Experimental System Block Diagrammentioning

confidence: 99%

High-precision detection of laser spot based on Gaussian spot model

Liang,

Wang

2023

5th International Conference on Information Science, Electrical, and Automation Engineering (ISEAE 2023)

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In order to understand the application of laser spot high precision detection, a laser spot high precision detection based on Gaussian spot model was proposed. Laser spot center location is one of the key techniques in optical measurement. Firstly, by analyzing the common positioning algorithms, this paper presents a Gaussian fitting method using the unsaturation point in the spot image and taking the amplitude point of the fitting function as the center of the spot. Secondly, artificial light spot is used to verify the algorithm. The results show that the error of the algorithm is much less than 0.1 pixel, and it is a feasible spot center location algorithm.

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“…Ultrasonic nondestructive techniques are usually used in weld inspection, as they are convenient, safe, and sensitive to potential in-depth flaws [ 10 ]. Recently, ultrasonic time-of-flight diffraction (TOFD), ultrasonic phased array, and ultrasonic guided waves have been employed in weld inspection, and detection efficiency, evaluation accuracy, and applicable conditions have been significantly improved [ 11 , 12 , 13 , 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

Design and Application of Partial Immersion Focused Ultrasonic Transducers for Austenitic Weld Inspection

Zhang

Qin

Luo

et al. 2022

Sensors

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Austenitic stainless steel is a widely used material in the industry, and the welding technique enables stainless steel components to have different shapes for different applications. Any flaws in the weld will degrade the performance of the austenitic component; thus, it is essential to ultrasonically and nondestructively test flaws in welds to ensure service safety. Recently, weld inspection has been performed using contact transducers, but missed detections or false positives for flaws in welds usually occur due to a poor coupling condition in the detection, a low signal-to-noise ratio, and instantaneous noises. In this study, a partial immersion focused (PIF) ultrasonic transducer is designed and used for austenitic weld inspection to address the above issues. The detailed design and manufacture of the PIF transducer are described, and the advantages of the transducer are shown by comparing the results detected using different kinds of transducers. In addition, in order to suppress false positives, a B-image method optimized using a time-dependent threshold is proposed. Experiments are performed to detect flaws in a welded specimen. All the artificial flaws are evaluated using the developed transducer and the proposed method, but minor flaws are mis-detected when planar transducers are used, verifying the method proposed in this paper.

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Quality inspection of micro solder joints in laser spot welding by laser ultrasonic method

Cited by 11 publications

References 25 publications

Simulation and Analysis of Welding Spot Failure of PCB Based on ABAQUS

Simulation and Analysis of Welding Spot Failure of PCB Based on ABAQUS

High-precision detection of laser spot based on Gaussian spot model

Design and Application of Partial Immersion Focused Ultrasonic Transducers for Austenitic Weld Inspection

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