Description: Optomec’s proposed innovation is a direct-write additive manufacturing process, creating 25um electrical interconnects that can accommodate 3D steps and are terminated in a wire bond pad. These printed interconnects will minimize packaging space by replacing traditional wire bonds with conformal fan-out electrodes. This additive manufacturing proposal “is a science enabling technology for the next strategic class of astrophysics missions,” as stated in scope description of solicitation S12.06. Improving the packaging for large format multishutter arrays is a goal relevant to several NASA missions, including the Large UV/Optical/IR Surveyor (LUVOIR) and the Habitable Exoplanet Observatory (HabEx) missions. Optomec’s innovation uses metal nanoparticle dispersions or “inks” to create pad and trace patterns, and these patterns are functionalized by sintering the metal nanoparticles at low temperatures or with a laser to make electrically conductive conformal interconnects. The Aerosol Jet® technology creates a high velocity stream of tightly collimated droplets, which means that liquid inks can easily be jetted in precise patterns. Tilting the jetting head relative to the flat substrate gives direct vision of both horizontal surfaces and vertical sidewalls, enabling interconnect printing over steps up to 1.5mm high and beyond. The tight collimation of the Aerosol Jet stream also means that Optomec can create very fine features, 25um size and smaller. The Phase II effort will focus on prototyping Microshutter Array (MSA) interconnects packages and testing these packages for reliability in harsh conditions. The project will further optimize the printable materials and sintering processes to facilitate robust thermo-mechanical and electrical interconnections.

Benefits: The printed interconnect innovation is directly relevant to several NASA programs. It will reduce space requirements and improve packaging reliability for next-generation microshutter arrays, such as those needed for the Large UV/Optical/IR Surveyor(LUVOIR), the Habitable Exoplanet Observatory (HabEx), and the Cosmic Evolution Through UV Spectroscopy (CETUS) missions. It has the potential to reduce the size and weight of electronic assemblies used in a wide range of other projects.

Conformal 3D printed interconnects have a wide variety of potential commercial applications. Two immediate markets for this innovation are in RF packaging, where it can improve RF transmission efficiency at very high frequencies used by defense and aerospace agencies, and in reducing size and increasing packing density in micro-LED applications.