A Differential Measurement System for Surface Topography Based on a Modular Design

Abstract

In this paper, a novel design of a surface topography measurement system is proposed, to address the challenge of accurate measurement in a relatively large area. This system was able to achieve nanometer-scale accuracy in a measurement range of 100 mm × 100 mm. The high accuracy in a relatively large area was achieved by implementing two concepts: (1) A static coordinate system was configured to minimize the Abbe errors. (2) A differential measurement configuration was developed by setting up a confocal sensor and a film interferometry module to separate the motion error. In order to accommodate the differential measurement probes from both sides of the central stage and ensure the system rigidity with balanced supports, separate linear guides were introduced in this system. Therefore, the motion Degree of Freedom (DoF) was analyzed in order to address the challenge of an over-constrained mechanism due to multiple kinematic pairs. An optimal configuration and a quick assembly process were proposed accordingly. The experimental results presented in this paper showed that the proposed modular measurement system was able to achieve 10 nm accuracy in measuring the surface roughness and 100 nm accuracy in measuring the step height in the range of 100 mm × 100 mm. In summary, the novel concept of this study is the build of a high-accuracy system with conventional mechanical components.

Special Issue on Manufacturing Metrology

“…On this topic, 12 papers were collected. A novel design for a surface topography measurement system was proposed in a relatively large area of 100 mm × 100 mm to achieve nanometer-scale accuracy [8]. The motion error of the stage was separated by a differential measurement configuration for a confocal sensor and a film interferometry module.…”

Hyperspectral analysis for the determination of tensor differential and integral characteristics of the micro profile from the topograms of the strokes printed by intaglio

“…The differential and integral characteristics of printed products made by the intaglio printing method are determined by the experimentally determined laser topogram of the print surface. The laser topogram is a two-dimensional array of ordinates of the micro profile of the paper surface 1,2 . As a rule, profilograms of the micro profile are determined in separate transverse lines and the topogram of the measured area is visualized.…”

A New Image Grating Sensor for Linear Displacement Measurement and Its Error Analysis

“…With the rapid development of advanced manufacturing, high-precision displacement sensing techniques over a long range are in high demand. Typical applications include the processing and measurement of large-size wafers [4], positioning and process control of CNC machine tools [5], development of coordinate measuring machines [6], etc. At present, most high-precision, large-range displacement measurement systems are developed by using laser interferometry or traditional grating sensing.…”