Precision manufacturing process monitoring with acoustic emission

Current demands in high-technology industries such as semiconductor, optics, MEMS, etc. have predicated the need for manufacturing processes that can fabricate increasingly smaller features reliably at very high tolerances. In situ monitoring systems that can be used to characterize, control, and improve the fabrication of these smaller features are therefore needed to meet increasing demands in precision and quality. This paper discusses the unique requirements of monitoring of precision manufacturing processes, and the suitability of acoustic emission (AE) as a monitoring technique at the precision scale. Details are then given on the use of AE sensor technology in the monitoring of precision manufacturing processes; grinding, chemical–mechanical planarization (CMP) and ultraprecision diamond turning in particular.