Automatic optical failure detection on large ultrasonic arrays

The search for improved resolution in super-resolution ultrasound (SRUS) imaging leads to larger ultrasound arrays and smaller elements. A current large row-column addressed (RCA) array spans
$\approx 21\times 21\ \text{mm}^{2}$
with
$190 +190$
elements separated by a kerf of
$3\ \mu\mathrm{m}$
. Increasing array dimensions and decreasing feature sizes not only makes fabrication more complex, but makes quality control more challenging. In this work, we present a method for acquiring a series of high resolution microscope images of an array, combining them to a large gigapixel mosaic, making dynamic and robust optical artefact correction, before performing automatic detection of optically visible defects on such large arrays. These in combination are meant as a tool for a first line of elimination of non-ideal arrays.