Automatic focusing method and system based on ultrasonic microscope point focusing transducer

Abstract

The embodiment of the invention discloses an automatic focusing method and system based on an ultrasonic microscope point focusing transducer. The method comprises the steps of: acquiring an A scanning signal image of the surface of a test piece; setting focusing parameters; correcting the sound velocity in the intermediary liquid according to the temperature of the intermediary liquid, and calculating the automatic focusing position of the upper surface through the focal length, delay and other parameters of the acoustic lens of the point focusing transducer; analyzing the scanning signal A through discrete wavelet decomposition and Wiener deconvolution to obtain layering information of the test piece; selecting a target focusing interlayer reflection signal according to the layering information of the test piece; moving the transducer to find out the coordinate of the approximate position point with the maximum middle layer reflection signal; moving the point focusing transducer back to the previous coordinate point of the maximum position point coordinate; and moving the point focusing transducer to find the accurate position point coordinate of the maximum value of the reflected signal so as to complete automatic focusing. Therefore, the focusing speed and precision of the point focusing transducer of the ultrasonic microscope in the using process are effectively improved.

Description

technical field [0001] The embodiment of the present application relates to the field of acoustic technology and non-destructive testing technology, and specifically relates to an autofocus method and system based on an ultrasonic microscope point focusing transducer. Background technique [0002] Ultrasonic microscopes are non-destructive testing and microscopic imaging equipment widely used in high-tech manufacturing industries such as chip manufacturing, biomedicine, and material science. Ultrasound microscope (such as figure 1 Schematic diagram of the ultrasonic microscope) liquid-immersion point-focused ultrasonic transducers are commonly used (such as figure 2 Focusing schematic diagram of the point-focused ultrasonic transducer), the transducer can converge the sound beam at one point, so that the energy concentration in the convergence area is strengthened, and the width of the sound beam becomes smaller, which can meet the detection requirements of high sensitivit...

AI Technical Summary

Problems solved by technology

[0003] At present, ultrasonic microscopes generally adopt the manual focusing method, which is not only low in precision but also inefficient, especially in the face of highly integrated IC chips, multi-layer thin film materials, etc., manual focusing has greatly reduced the detection efficiency, and it is possible Affect the detection effect

In the process of scanning imaging and non-destructive testing of complex multi-layer structure specimens, especially chips, by using point-focusing transducers, the focusing process of the middle layer requires the operator to have rich working experience and comparative experience. long operating time

This also largely limits the wide application of ultrasound microscopy

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