Calibration, set-up and performance evaluation in an IC inspection system

Abstract

Many papers on automatic inspection systems ignore the issues of calibration, setup and performance evaluation, assuming (apparently) that they merely involve `straightforward engineering.' In reality developing effective and robust procedures and algorithms to implement these features can be a demanding process. In fact, unbeknownst to the developers or users, the performance of many inspection systems could be significantly improved through better setup and calibration routines. In this tutorial paper we discuss both theoretical and practical issues. We start by reviewing the statistical framework underlying performance evaluation. Next we examine possible sources of inspection performance degradation. Last we describe calibration, setup and performance evaluation procedures and associated image analysis algorithms for an automated IC inspection system. While these procedures are specific to a particular system, we attempt to generalize them wherever possible.