Scanning acoustic microscope

A scanning acoustic microscope (SAM) is a device which uses focused sound to investigate, measure, or image an object (a process called scanning acoustic tomography). 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 SAM useful in detecting voids, cracks, and delaminations within microelectronic packages.

The joint IPC/JEDEC standard J-STD-035 specifies acoustic microscopy procedures for detecting delaminations, cracks and voids in nonhermetic plastic-encapsulated components; it was first published in 1999 and revised as J-STD-035A in 2022. As devices have become smaller, multilayered and more densely mounted, and as wafer bonding has spread, inspection has extended from packaged parts to bonded 300 mm wafers, and fully automated in-line systems that load, inspect, judge and sort parts are used in volume production alongside laboratory instruments. In the semiconductor industry the same class of instrument is also called a scanning acoustic tomograph (SAT), a term used by Hitachi for its FineSAT series, while the name C-SAM originated with Sonoscan (now Nordson SONOSCAN).