Nondestructive Inspection of Chip Size Package by Millimeter Waves

Chip size package was inspected by millimeter waves. Millimeter wave image was created using the phase and amplitude of the reflection coefficient, measured by a network analyzer. To obtain a high spatial resolution, an open-ended coaxial line sensor was used. Solder bumps and delamination under the silicon chip of the package were observed effectively. It is shown that millimeter wave technique has a good prospect for integrity assessment of chip size package.