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Updated: Jan 22, 2026

Full-field Strain Measurements for Microstructurally Small Fatigue Crack Propagation Using Digital Image Correlation Method
Published on: January 16, 2019
Full-field microsurface profilometry using image correlation without vertical scanning
Abstract:
A full-field microprofilometry involving innovative image correlation was developed for profile measurement without vertical scanning. High-speed optical inspection has become critical for confirming precise dimensions in semiconductor fabrication such as microbumping in 3D stacked ICs and precision manufacturing. A digital micromirror device (DMD) is designed to serve as a point-light-source array in a quasiconfocal optical configuration and perform lateral scanning to minimize signal crosstalk between neighboring testing points. More importantly, multiple diffractive images are detected and measured with a prebuilt depth-correlated database to extract the height information of a tested surface. A 100-nm repeatability can be realized in the absence of a detector pinhole and without vertical scanning, thus achieving high-speed submicrometer-scale surface profilometry.
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