Scalable Micron-Sized Flexible Interconnects Enabled by Dielectric-Metal 3D Printing Technology for the Packaging of Large and Segmented Nuclear Physics Detectors

As many next-generation nuclear physics detectors continue to grow and become more segmented, the associated challenges of manufacturing and packaging such large detectors has geared the DOE Office of Nuclear Physics (NP) to seek packaging technologies for next- generation nuclear physics detectors that address modularity, re-workability, reliability, and minimal electrical parasitics. Conventional electronic packaging technologies cannot be used with these large and segmented detectors. To address these conventional electronic packaging limitations and fulfill the aforementioned next-generation detector goals, DUJUD will develop micro-electromechanical system (MEMS) type additively manufactured 3D flexible micro-interconnects (MEMS-3FIs) using its proprietary additive manufacturing technology. The proposed MEMS-3FI interconnects are 3D printed compliant interconnects, hence no permanent connections are formed which enables re-workability of these large NP detectors. This re-workability feature in turn facilitates the modularity of the large NP detector system as any segment of the detectors may be replaced or upgraded independent of the degree of segmentation; this re-workability also maintains the reliability of the system as a whole. Furthermore, as the MEMS-3FI interconnects are additively manufactured, the design space associated with these interconnects are much larger than their conventional counterparts and hence 3D geometrical optimization methodologies may be readily employed to minimize electrical parasitics. DUJUD seeks to develop these MEMS-3FI interconnects for next-generation NP detectors. The Phase I effort will prove the suitability of the mechanical and electrical characteristics of the MEMS- 3FI interconnects for NP detectors; this effort will also demonstrate a proof of concept for the modularity and re-workability of the 3D printed package concept of which the MEMS-3FI interconnects are a part. Specifically, “package” testbeds will be designed and manufactured to attain four-point resistance and mechanical compliance measurements of the MEMS-3FI interconnects. A large “package” testbed will also be designed and manufactured to demonstrate the modularity of the system via housing multiple testbed die. A pitch scaling and temperature dependence analysis will also be performed. In addition to the needs of the nuclear physics community, the proposed MEMS-3FI will also benefit taxpayers as segmented NP systems with a re-workability capability enable system upgrades which are historically less costly than constructing a brand-new system from the ground up. Additionally, re- workability lowers the cost of troubleshooting and repair. In the smartphone camera market, the MEMS-3FI interconnects could replace through-silicon-vias (TSVs) in charge-coupled device (CCD) chips, resulting in better image quality for smartphone camera users.