Focus tracking techniques for inspection system

Abstract

An improved focus tracking system for an inspection system that positions a line ahead of the imaging field of view in the scan direction and dynamically actuates an optical element to reposition the line when the scan direction changes is provided. Current systems fail to provide leading focus information or adjust to allow for a high-speed scan. The focus tracking system may be used in inspection systems for substrates such as panels and wafers, through-glass vias (TGVs), as well as various electronic devices.

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