Wide-Field Reflective Imaging with an Epi-Illumination Multi-Camera Array Microscope

Abstract

We present an epi-illumination multi-camera array microscope (epi-MCAM) designed for wide-field reflective imaging of non-transparent samples. The epi-MCAM contains 24 tightly packed and synchronized epi-illumination microscope units, arranged in a $4 \times 6$ planar array at 18 mm spacing. Each unit contains a unique CMOS image sensor (13 megapixels each), an objective and tube lens pair, and a beamsplitter and epi-illumination light path. An epi-MCAM capture cycle produces a stitched image covering $72 \times 108~\mathrm{mm}^2$ at a micrometer scale resolution down to 2.46 $\mu$m. To image samples exceeding this native field of view, we translate the entire array across the sample surface to enable high-resolution coverage of large objects. We demonstrate the system's ability to image both flat and three-dimensionally structured reflective samples, such as semiconductor wafers and printed circuit boards, which highlight the epi-MCAM's strong potential within industrial inspection applications.