Micro Systems Technologies (MST), MicroElectroMechanical Systems (MEMS) and Additive Manufacturing (AM) have been playing important roles in different industrial sectors such as semiconductor, precision engineering, aerospace, oil & gas and etc. Besides continuing effort for MEMS-based measurement techniques, related effort in MEMS measurement is also applicable to non-MEMS-based manufacturing such as AM. This paper introduces a micro-scale surface metrology at the National Metrology Centre based on a large scanning range laser confocal microscope for measuring surface structures. A laser confocal probe projecting a single laser spot onto the testing surface is fixed above the sample rather than a laser spot scanning over the testing surface for an area measurement in conventional laser confocal microscopy. There are two unique features in this configuration: 1) its optical axis can be always perpendicular to the test surface and no need to compensate/correct the warpage effect because of the laser deflection for scanning purpose and 2) a large scanning area can be flexibly introduced by a separate 2-dimensional moving stage. Corresponding measurement working principle and system instrumentation & configuration are described. These measured features and structures include dimensional and surface functional parameters as in material removal/wear, cutting tool edge, laser marking, micro-channel in microfluidic device, lens array mold, surface flatness/deformation of super-low reflection (less than 2%) surface, low reflection rock surface and relatively rough AM surfaces. It successfully demonstrated the laser confocal microscope is applicable to surface features’ measurement on both smooth and rough surfaces in order to provide proper quality control feedback to related manufacturing.
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This research is supported by the National Metrology Centre, A*STAR. Grant number is not applicable
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