Paper 14085-66
Paper 14085-66
Measurement of deep microholes on PCB using a spectral-domain coherent interferometry system
15 April 2026 • 15:10 - 15:30 CEST | Luxembourg/Salon 2 (Niveau/Level 0)
Abstract
We report a practical, noncontact system for measuring deep micro-holes on PCBs (example: 300 µm diameter, 6 mm depth) by combining spectral domain coherent interferometry with a large-travel positioning machine. An energy centroid signal-processing method yields micron-level precision and a depth relative error below 1%. Multithreaded scanning enables coverage of ≥ 50 cm × 50 cm panels, and an image-analysis pipeline referenced to machining standards attains a 97% bad hole detection rate. The platform provides a scalable solution for accurate, factory compatible inspection of challenging through-hole geometries.
Presenter
Hongyu Shen
Huazhong Univ of Science and Technology (China)
My name is Hongyu Shen. I am a doctoral student at the School of Optoelectronics, Huazhong University of Science and Technology, specializing in optical measurement engineering. My current research concentrates on spectral-domain interferometric techniques for deep micro-holes, primarily aimed at the acquisition and calculation of various geometric parameters. I welcome the opportunity to engage with peers in the fields of optics and metrology.