Nondestructive inspection of delamination in IC packages by high-frequency microwaves

Delamination in IC packages was detected by microwaves. An open-ended coaxial line sensor was employed to couple microwave signals with the package and the package was scanned in two perpendicular directions on a plane parallel to the package. A microwave image was created by measuring the phase of the effective reflection coefficient at the aperture of the coaxial line sensor. A high-frequency microwave was used to obtain a higher spatial resolution. The image obtained from the microwave measurement shows almost the same features as that of a scanning acoustic tomograph. The delamination was detected significantly without a coupling medium. This indicates that microwave imaging is a promising technique for the integrity assessment of IC packages.