Welding defect signal extraction technology based on OMP algorithm

Flip-chip technology has been rapidly developed and widely used in the field of microelectronic packaging, and defect detection has also received increasing attention. In the experiment, ultrasonic testing was used to detect defects on flip chip. Aiming at the problem that the interference noise of the ultrasonic detection defect signal seriously affects the location of the defects and the signal extraction, we use the algorithm based on orthogonal matching pursuit (OMP) to extract the defect signal and adopt the Gabor atom library which is optimally matched with the ultrasonic signal to achieve matching the ultrasonic echo signals adaptively and greatly reducing the complexity of the sparse decomposition algorithm. The simulated and actual ultrasonic defect signals were tested separately and compared with the matching pursuit algorithm. The result shows that OMP can extract defect signals more effectively in the noise background.