Detection of delamination in IC packages using the phase of microwaves

To detect the delamination in IC packages, a microwave nondestructive testing method that utilizes an open-ended coaxial line sensor has been developed. The coaxial line sensor acts both as a source and receiver of microwave signal that is transmitted into and reflected from the package. The phase of the effective reflection coefficient measured at the aperture of the coaxial line sensor is varied with the thickness of the delamination layer. The phase difference in the case of package with and without delamination was calculated for evaluation of the delamination effectively. The high sensitivity of the present technique makes it very useful to detect delaminations in IC packages. Also, the method has the potential for inspection of other dielectric materials.