Batch fabrication of micro-optical sensing and imaging devices

As demonstrated in microelectronics, the batch fabrication based on the processing of wafers can lead to a significant reduction in prize as well as in size. This concept was adapted to the fabrication of imaging optics extensively used in mobile phone cameras relying on small pixels and low resolutions such as VGA. We report on batch fabricated customer specific opto-electronical modules used in machine sensing and automotive applications relying on large pixel sizes and non-conventional sensor characteristics. We specially focus on the lens mold mastering for the subsequent UV-replication since comparatively large sag heights of 250 mu m are required. Two technological approaches were applied, first, based on reflow of photoresist and, second, using diamond turning for the generation of a single lens mold and a subsequent step&repeat-process for array mastering on 8 '' wafers. Aspects of the optical design and simulation, the batch fabrication based on 8 '' wafers and characterization results are provided by the example of an f/1.1 opto-electronic sensor and an objective for a global shutter imager using 550x550 pixels with 3.6 mu m pitch.