Flatness Characterization
Surface topography evaluation is achieved by projecting a linear grating onto a specimen surface and analyzing the interference fringes produced by the shadow. Utilizing shadow moiré allows manufacturers to generate a three-dimensional height map of the specimen with high spatial resolution. This approach is widely adopted for characterizing the dynamic warpage of semiconductor packages during thermal transitions.
Precision Calibration
Measuring out-of-plane deformation requires calibrating the optical path and grating position to a known reference standard. System resolution in shadow moiré configurations is dictated by the grid spacing and the observation angle of the digital sensor. External thermal fluctuations can cause drift in the optical alignment, which must be corrected using stable fixture materials.
Software algorithms convert the recorded phase shifts into absolute height measurements across the entire surface.
Fixture Configuration
Proper mounting of the specimen prevents gravity-induced sag from distorting the calculated flatness profile. Secure clamping ensures that only thermally-induced stresses are measured during the analysis.
Solder Joint Integrity
Electronic assemblies are subject to extreme temperature cycles during reflow, which can cause substrate bending. High-density component testing relies on shadow moiré profiles to ensure that package warpage stays within the tolerances set by industrial boards. Measuring this distortion before mass assembly helps engineers redesign the substrate layers and minimize joint failure rates.
This metrology tool ensures that components remain coplanar throughout the manufacturing process.
