Enabling Scanning Acoustic Microscopy Inspection of Materials Underneath the Chamfer of the Package

This paper describes how scanning acoustic microscopy can be used to inspect materials under the chamfer of electronic device packages. The technique involves the use of copper tape to locate the areas affected by the chamfer during X-ray radiography. The results are then correlated with known critical package and assembly geometries to determine how far parallel lapping should proceed to ensure that the areas of interest will become observable under acoustic microscopy without interfering with the functionality of the device.