NDI of delamination in IC packages using millimeter-waves

To detect delamination in integrated circuit (IC) packages, a millimeter-wave inspection system was developed. An open-ended coaxial line sensor was used as a source and also a receiver of the millimeter-wave signal that was transmitted into and reflected from the packages. The phase of the reflection coefficient was measured for inspection of the delamination. The package was scanned in two perpendicular directions on a plane parallel to the package. A two-dimensional image was created by using the raw data of the millimeter-wave measurement. The millimeter-wave image showed almost the same features as that of scanning acoustic tomography, and the delamination was readily detected without using a coupling medium. Furthermore, a graph obtained by scanning the package in one direction along the center line of the package showed a higher sensitivity for distinguishing the delamination, thereby showing a potential for the on-line detection of delamination in an IC package.