Widefield Microscope Systems for Micro-LED Display Inspection

Miniaturization is driving the development of micro-LEDs, which are increasingly used as subpixels within next-generation micro-LED displays. In the 2026 International Edition of inVISION magazine, Excelitas Group Product Manager Michael Bulk explores how high-precision optics are tackling one of the toughest manufacturing challenges this technology presents: achieving uniform performance across large micro-LED arrays.

With millions of subpixels in a single display, even slight inconsistencies in luminance or color are immediately visible to the human eye, a defect known as the mura effect. The article explains how leading metrology providers address this through "demura" correction, a process that requires highly accurate, high-resolution measurement of every micro-LED's luminance, colorimetry and precise coordinates to calculate and apply the necessary adjustments.

Bulk details how inspection system suppliers performing this work, whether on-wafer through photoluminescence or on-panel through direct subpixel measurement, depend on the Excelitas Optem^® mag.x 125 Widefield Microscope to deliver the resolution, large fields-of-view and edge-to-edge image sharpness required for accurate, high-throughput measurement. The microscope supports large image sensor sizes up to 57 mm and achieves micron resolution across a 5 mm field of view, while its built-in autofocus compensates for variations in wafer flatness to maintain crisp imaging at the fast tact times demanded by industrial manufacturing.

Read the full article, "Widefield Microscope Systems for Micro-LED Display Inspection," in inVISION magazine to learn how Excelitas optics are enabling the precision and speed required for next-generation micro-LED display inspection.