In practical applications, the microscopes are often used to determine whether two materials are successfully bonded, and whether there are delaminations, voids, or other anomalies at the bond layer. The data in the acoustic images often gives significant clues about process control issues.
An acoustic microscope has an ultrasonic transducer that both pulses ultrasound into the target and picks up the return echoes from the interior of the target. Because ultrasound doesn't travel well through air, the transducer is coupled to the sample by water or another fluid. The transducer normally scans one line across the target, moves ahead one space and scans back across the target. At each x-y coordinate, the transducer emits a pulse of ultrasound and receives return echoes from the various depths in the sample.