Characterization of laser-welded structures in glass using acoustic microscopy

Glass substrates are playing an increasingly important role in the production of microchips. This paper will demonstrate the potential of scanning acoustic microscopy (SAM) used for the characterization of laser-welded structures in thin glass slides. Structures within the volume of a glass sample can be imaged quickly and with high accuracy using this method. In particular, it should be noted that not only the depth information, but also the height profile of the structures can be obtained from ultrasonic cross-sectional images. Measurements only take a few minutes. While certain structures can be visualized in 3D using ultrasonic Time-of-Flight (ToF) measurements, current research is focusing on the 3D representation of more general structures based on the Synthetic Aperture Focusing Technique (SAFT).