The use of direct write micro-printing for opto-electronic packaging is being accepted as a key enabling technology, specifically printing microlenses for optical interconnects and solders for electrical interconnects. This paper presents these two areas where micro-printing technology benefits opto-electronic packaging. For increasing light coupling efficiency, a microlens array is actively aligned and attached to a VCSEL array and photodiode array in smart pixel technology. A microlens array is also directly integrated with a VCSEL array in a wafer level fabrication. Solder jet is used for either bumping the VCSEL die or for directly connecting the VCSEL die with circuits on a substrate. By using micro-printing, components can have less part-count and smaller package size. The labor required for conventional optical alignment can be greatly reduced. Thus this technical advancement offers also cost effectiveness in manufacturing.
Donald J. Hayes, Ting Chen, David Wallace, "Digital Printing of Optical Components" in Proc. IS&T Digital Fabrication Conf., 2006, pp 183 - 186, https://doi.org/10.2352/ISSN.2169-4451.2006.22.2.art00055_3