Confocal Scanning Acoustic Microscopy, generally known as CSAM is a non-destructive (NDT) analysis equipment for detecting and imaging microscopic structures or defects inside a specimen. It is widely used in semiconductors and electronic components by use of the reflection and transmission properties of ultrasonic waves. This technology has an outstanding benefit is its ability to find hidden defects within an assembly that can occur during manufacturing or reliability testing. Defects such as fine cracks, voids, porosity and delaminations can be identified and analysed effectively using CSAM than many other NDT methods such as X-Ray or IR Imaging. Because it is highly sensitive to the elastic properties of the materials it travels through.
Having said that, C-SAM and X-ray techniques complement each other as most labs have both equipment for they reveal different features. Where X-ray relies on differential attenuation of the X-ray energy, CSAM relies on material change and is more sensitive in detecting air-pocket type defects such as cracks, voids and delaminations.