Development of a High-Resolution Touch Trigger Probe Based on an Optical Lever for Measuring Micro Components

Abstract

The characterization of a high-precision component with its dimensions has become a key problem in ensuring the performance of system parts. A touch trigger probe plays an important role in experimentally measuring these properties. In this study, a new high-resolution touch trigger probe based on a modified optical lever method is proposed. Only one optical sensor is adopted. The sensing principle of the developed probe in 3D is investigated through the probe’s sensitivity models. An optimizing design of the elastic suspension is demonstrated. Experiments on probe performance are conducted by measuring a step height and a gauge block. Experimental results indicate that the probe achieves a resolution of up to 1 nm in 3D and a measurement standard deviation of 18.3 nm. The probe has a permissible range of ± <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20~\mu \text{m}$ </tex-math></inline-formula> in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${x}/{y}$ </tex-math></inline-formula> -axis and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20~\mu \text{m}$ </tex-math></inline-formula> in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${z}$ </tex-math></inline-formula> -axis. The drift of the probe is 5.2 nm within 30 min. The comprehensive uncertainty of the probing system is 18.45 nm. The developed probe can be used in micro/nano coordinate measuring machines.