Acoustic Scanning Microscope for Investigation of Subsurface Defects

Abstract

The scanning acoustic microscope has a wide range of application. With the development of pulse wave acoustic microscope it became possible to make sub-surface observation without pretreatment such as polishing of the sample. A precise classification of a defects according to type, position and size can be made. And quantitative evaluation of surface acoustic wave velocity of the material can be easily and directly obtained. To close the gap between the conventional immersion technique and the high frequency ultrasonic microscope we developed an scanning ultrasonic device worked in the frequency range of 5–50 MHz which is very simple, reliable, flexible and easy to use, and has resolution better then 0.05 mm.