SCANNING ACOUSTIC MICROSCOPE

:''Scanning Acoustic Tomography ('SCAT') redirects here''.
A 'Scanning Acoustic Microscope' ('SAM') is a device which uses focused sound to investigate, measure, or image an object. It is commonly used in failure analysis and non-destructive evaluation. It also has applications in biological and medical research. The semiconductor industry has found the Scanning Acoustic Microscope useful in detecting voids, cracks, and delaminations within microelectronic packages.

Contents

History

Principles of operation

Applications

Resources

History

The first scanning acoustic microscope was developed by Lemons and Quate at Stanford.

Principles of operation

Scanning Acoustic Microscopy works by directing focused sound from a transducer at a small point on a target object. Sound hitting the object is either scattered, absorbed, reflected (scattered at 180°) or transmitted (scattered at 0°). Typically, either the reflected or transmitted sound is gathered and measured. Based on the measurement, a value is assigned to the location investigated. The transducer (or object) is then moved slightly and then insonified again. This process is repeated in a systematic pattern until the entire region of interest has been investigated. Often the values for each point are assembled into an image of the object. The contrast seen in the image is based either on the object's geometry or material composition. The resolution of the image is limited either by the physical scanning resolution or the width of the sound beam (which in turn is determined by the frequency of the sound).

Applications

★ Flaw Detection

★ Medicine and Biology

★ Internal stress investigation

★ Elastic property charaterization

Resources

★ Applied Physics Letters. Early Lemons and Quate SAM paper

★ Sonix. Manufacturer of SAM systems

★ Sonosca. Manufacturer of SAM systems,introduced the worlds first commercially available Acoustic Microscope (SLAM) in 1975