Ensuring reliability and repeatability in LIGA mold insert fabrication

As of today, four products with LIGA parts are commercially available: microParts' spectrometer, mechanical drives by micromotion and Faulhaber and an optical fiber connector by Spinner. This indicates that LIGA technology is advancing from a pace-making technology to a key technology for microsystems fabrication. This success was made possible in part by a consistent focus on making the technology reliable. In general, the key technical issues for yield enhancement can be categorized as follows: finding and qualifying external suppliers; modifying processes to reduce handling; finding ways to monitor each machine involved; establishing quality specifications between the process steps; and last but not least improving the understanding of each process step. We give examples for all of these issues.