Study on Sub-Millimeter Defect Detection Method Based On High-Frequency Ultrasound

During the electronic packaging process, material inhomogeneity and stress concentration can lead to the generation of sub-millimeter defects, which have a significant impact on product reliability. Traditional non-destructive testing (NDT) techniques, such as X-ray imaging, are difficult to achieve efficient and high-precision defect characterization. To overcome these limitations, a 50 MHz high-frequency ultrasonic microscopic imaging system is designed and built based on C-scan mode, and the performance of this platform through experiments is verified. The experimental results show that under the current conditions, the minimum defect size that this system can resolve is 200 μm, and it can achieve the visualization of sub-millimeter defects. The platform has a sampling frequency of 500 MHz and a maximum scanning speed of 1000 mm/s. This indicates the potential of the platform in high-resolution quality inspection in the field of microelectronic packaging.