Time Domain Imaging (TDI)™
Utilizes an echo (amplitude & polarity) arrival ‘time’ as a reference, such as standard A-Scan, B-Scan and C-Mode type images.


PBGA 3D Acoustic Microscope Image - Application Note 202

Acoustic solid left, optical image of PGBA middle, diagram right

Sample & Method

Zip-Slice software was first used to scan this plastic-packaged Ball Grid Array (PBGA), creating several acoustic slices at increasing depths into the package. The purpose of the slices is to collect all acoustic data concerning internal features from all depths of the package. 3V software then assembles the slices into a single Acoustic Solid, shown here. Since the Acoustic Solid contains all of the data about internal features, it is later sectioned to reveal desired features. The Acoustic Solid above has not been sectioned yet. The spectrum-like feature at the left edge of the Acoustic Solid is the acoustic color map.


This Acoustic Solid shows only the external features of the PBGA. No defects are visible acoustically in this image because no internal defect reaches the surface of the Acoustic Solid, which can be fully rotated in 3 dimensions. Sectioning (show in Application Notes 206 and 210) displays the internal features.