• 대한기계학회논문집
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• 제12권6호
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• pp.1303-1311
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• 1988

본 연구에서는 적응제어 연삭가공 공정에 사용가능한 인프로세스 표면조도 측 정기술 개발을 목표로 하여 공학을 이용한 비접촉식 조도측정 기술의 개발을 시도하였 으며 포스트 프로세스에도 사용가능 하도록 하였다. 측정기술의 개발은 정반사광과 난반사광의 단순비교 방법 (정반사광에 대한 난반사광의 비율을 이용하는 방법)과 산 란광의 패턴인식(pattern recognition)을 이용하는 방법의 두가지로 진행되었는데, 후 자의 방법에 중점이 두어 졌으며 Beckmann의 산란이론(scattering theory)이 측정시스 템 제작의 관점에서 분석되고 응용되었다.

• Current Optics and Photonics
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• 제7권1호
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• pp.38-46
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• 2023

Optical Fourier-domain reflectometry (OFDR) sensors have been widely used to measure distances with high resolution and speed in a noncontact state. In the electroplating process of a printed circuit board, it is critically important to monitor the copper-plating thickness, as small deviations can lead to defects, such as an open or short circuit. In this paper we employ a phase-based OFDR sensor for in situ relative distance sensing of a sample with nanometer-scale resolution, during electroplating. We also develop an optical-path difference (OPD)-regulated sensing probe that can maintain a preset distance from the sample. This function can markedly facilitate practical measurements in two aspects: Optimal distance setting for high signal-to-noise ratio OFDR sensing, and protection of a fragile probe tip via vertical evasion movement. In a sample with a centimeter-scale structure, a conventional OFDR sensor will probably either bump into the sample or practically out of the detection range of the sensing probe. To address this limitation, a novel OPD-regulated OFDR system is designed by combining the OFDR sensing probe and linear piezo motors with feedback-loop control. By using multiple OFDR sensors, it is possible to effectively monitor copper-plating thickness in situ and uniformize it at various positions.