Research On Laser Ultrasonic And Bonding Defects Detection In Silicon Detector Structure

In this paper,laser ultrasonic in silicon detector structure and research on adhesive defect detection were studied.Firstly,the research background of bonding structure is introduced in theory and experiment.Start from the laser ultrasonic defect detection,based on the excitation mechanism of laser ultrasonic,the physical model of interaction between laser ultrasonic and defects in silicon detector structure was established.The structure of the model has the characteristics of ultra-thin surface.According to the variational principle,the corresponding finite element model is established and the corresponding algorithm is compiled.On this basis,the excitation and propagation of laser ultrasonic in the structure of silicon detector is simulated theoretically.Select the excitation center point and corresponding bottom point,and different location of points on the upper surface as the receiving points,find vertical surface displacement waveform within a certain time.The method of detecting the adhesive defect in this model is explored in theory.Secondly,according to the structural and functional characteristics of Fizeau interferometer,theoretical analysis is carried out.On this basis,the Fizeau fiber interferometer for laser ultrasonic testing is researched and completed its production.Finally,a laser ultrasonic experimental setup was set up to complete the vibration waveform test of the interferometer.Used it to measure the aluminum surface acoustic wave amplitude and the speed of sound.Making use of the Fizeau interferometers under ideal conditions of bonded silicon detector laser excitation of the heart-shaped ultrasonic wave was detected.